Fuzzy Logic Technique for Image Enhancement

IndexTerms– Fuzzy Logic, Image Processing, Image Enhancement, Image Fuzzification, Image Defuzzification
Whenever an image is changed from one to another form such as, digitizing, scanning, transmitting and storing, some degradation is always occurs at the output stage. Hence, the output image has to go in a process called image enhancement. Image enhancement consists of a collection of techniques that need to improve the overall quality of an image. Fuzzy image processing is the approaches that understand, represent and process the images and their pixels with its values as fuzzy sets. The representation and processing is depending upon the selected fuzzy techniques and the problem to be solved. The idea of fuzzy sets is very simple and natural. For instance, if someone want to define a set of gray levels, one has to define a threshold for gray level from 0 to 100. Here 0 to 100 are element of this fuzzy set; the others do not belong to that set. The basis logic behind fuzzy technique is the basis for human communication. This observation depends upon many of the other statements about fuzzy logic. As fuzzy logic is built on the logics of qualitative description used in everyday language, fuzzy logic is very easy to use. A filtering system needs to be capable of reasoning with values and uncertain information; this suggests the use of fuzzy logic.
II. FUZZY IMAGE PROCESSING — OVERVIEW
Fuzzy image processing techniques is not unique theory. It is a collection of different fuzzy approaches to image processing techniques. The following definition is to be regarded to determine the boundaries of fuzzy digital image processing:
Fuzzy image processing is the approaches that understand, represent and process the digital images and their segments and also features as fuzzy sets. The representation of it and processing is always depending on the selected fuzzy techniques and on the problem which need to be solved [9]. Below a list of general observations is defined about fuzzy logic:

Fuzzy logic is conceptually very easy to understand.

The mathematical concepts behind fuzzy logic reasoning are simple. Fuzzy logic is important approach without the far-reaching complexity.

Everything is indefinite if you look closely enough, but more than that, most things are indefinite. Fuzzy reasoning prepared this understanding into the process rather than just theory.

Fuzzy logic can model the nonlinear functions of mathematically complexity.

One can create a fuzzy logic system to compare any sets of input and output data. This process is very easy by some of the adaptive techniques such as Adaptive Neuro-Fuzzy Inference Systems, which is already available in Fuzzy Logic Toolbox.

Fuzzy logic can be design on the top of experience of experts.

In case of neural networks, it must need training data and generate the outputs. But fuzzy logic will explain you about the experience of people who already understand the whole systems.

Fuzzy logic can be mixed with any conventional control techniques.

Fuzzy systems don’t replace conventional control methods necessarily. Sometimes fuzzy systems increase them and simplify its implementation.

Fuzzy logic is based on natural language communications.

The basis for fuzzy logic is the basis for human communication and this observation explain many of the other statements about fuzzy logic as well. Actually Fuzzy logic is built on the structures of quality description used in everyday languages used for communications. Fuzzy logic is very easy to use.
Natural language, which people used on a daily basis, has been comes by thousands of years of human history to be efficient. Sentences that are written in ordinary language always represent a triumph of efficient communication [3].
Fuzzy image processing has three stages: 1) Image Fuzzification 2) Modification of membership values 3) Image Defuzzification.

Figure 1. Basic Fuzzy Image processing [5]
The fuzzification and defuzzification steps are that in which we do not own fuzzy hardware. So, the coding of image data often called as fuzzification and decoding of the results called as defuzzification are the steps to process images with fuzzy techniques. The main thing of fuzzy image processing is in the intermediate stage that is modification of membership values (See Figure 1). After the image data are transformed from grey-level to the membership plane that is known as fuzzification is appropriate fuzzy techniques which modify the membership values which can be a fuzzy clustering and a fuzzy rule based approach and also it can be a fuzzy integration approach.

The Fuzzy set theory

Fuzzy set theory is the extension of crisp set theory. It works on the concept of partial truth (between 0 & 1). Completely true is 1 and completely false is 0. It was introduced by Prof. Lotfi A. Zadeh in 1965 as a mean to model the vagueness and ambiguity in complex systems [3].

Definition Fuzzy set

A fuzzy set is a pair (A, m) where A is a set and m: A-> [0, 1]. For each, x A m(x) is called the grade of membership of x in (A, m). For a finite set A = {x1,…,xn}, the fuzzy set (A, m) is denoted by {m(x1) / x1,…,m(xn) / xn}. Let x A Then x is called not included in the fuzzy set (A, m) if m(x) = 0, x is called fully included if m(x) = 1, and x is called fuzzy member if 0 m(x) x A |= m(x)>0} is called the support of (A, m) and the set {x A | m(x)=1} is called its kernel.
Fuzzy sets is very easy and natural to understand. If one want to define a set of gray levels one have to determine a threshold, say the gray level from 0 to 100. All gray levels from 0 to 100 are element of this set; the others do not belong to the set (See Figure 2). But the darkness is a matter. A fuzzy set can be model this property in better way. For defining this set, it needs two different thresholds 50 and 150. All the gray levels which are less than 50 are the full member of this set and all the gray levels which are greater than 150 are not the member of this set at all. The gray levels that are between 50 and 150 have a partial membership in the set.

Figure 2. Representation of “dark gray-levels” with a fuzzy and crisp set.

Fuzzy Hyperbolization

An image I of size MxNand L gray levels can be considered as anarray of fuzzy singletons and out of which each are having a value of membership denoted its brightness relative to its brightness levels Iwith I=0 to L-1. For an image I, we can write in the notation of fuzzy sets:

Where g, is the intensity of (m, n)th pixel and µmn its membership value. The membership function characterizes a suitable property of image (e.g. edginess, darkness, textural property) and it can be defined globally for the whole image or locally. The main principles of fuzzy image enhancement is illustrated in Figure.

Figure 3. Fuzzy histogram hyperbolization image enhancements [2]

Image Fuzzification

The image fuzzification transforms the gray level of an image into values of membership function [0…1]. 2 types of transformation functions are used, the triangle membership function, and Gaussian membership functions. A triangular membership functions is shown in Figure 4 and its equation is written as,

Figure 4. Triangular membership functions
The Gaussian membership function is shown in the Figure 5 and is characterized by two parameters {c, σ}. The equation for the Gaussian membership function is written as,

Figure 5. Gaussian membership function

Modification of Membership Function

This process needs to change the values of the membership functions resulted from fuzzification process. In this algorithm, the shape of the membership function is set to triangular to characterize the hedges and value of the fuzzifier β. The fuzzifier β is a linguistic hedge such that β = -0.75 + μ 1.5, so that β has a range of 0.5 – 2. The modification is carried out to the membership values by a hedges operator. The operation is called dilatation if the hedge operator β is equal to 0.5 and it is called concentration if β is equal to 2. If A is a fuzzy set and it’s represented as a set of ordered pairs of element x and its membership value is defined as μ, then Aβ is the modified version of A and is indicated by below equation

The hedge operator operates on the value of membership function as fuzzy linguistic hedges. Carrying hedge operator can be result in reducing image contrast or increasing image contrast, depending on the value of the β. The hedge operators may use to change the overall quality of the contrast of an image.

Image Defuzzification

After the values of fuzzy membership function has been modified, the next step is to generate the new gray level values. This process uses the fuzzy histogram hyperbolization. And this is due to the nonlinearity of human brightness perception. This algorithm modifies the membership values of gray levels by a logarithmic function:

Where, μmn (gmn) is the gray level in the fuzzy membership values, β is hedge operator, and g’mn is the new gray level values.

Fuzzy Inference System (FIS)

Figure 6. Fuzzy Inference Systems
Fuzzy inference is the process of mapping from the input-output using fuzzy logic. Mapping provides a basis from which it is possible to make the decisions. Process of fuzzy inference are mainly, the Membership Functions, the Logical Operations, and If-Then Rules. There are basically 2 types of fuzzy inference systems that is possible to implement in Fuzzy Logic Toolbox. 1) Mamdanitype and 2) Sugeno-type. These 2 types of inference systems vary in the way outputs are determined.
Fuzzy inference systems has been successfully applied in fields such as data classification, decision analysis, automatic control and computer vision. As fuzzy is multidisciplinary, it can be used in fuzzy inference systems such as fuzzy-rule-based systems, fuzzy associative memory, fuzzy expert systems, fuzzy modeling, and fuzzy logic controllers, and simply fuzzy systems.
Mamdani’s fuzzy inference method is the most commonly used fuzzy method. Mamdani’s method was the first control systems designed using fuzzy set theory. It was firstly proposed in 1975 by Ebrahim Mamdani [7] to control a steam engine and boiler combination by synthesizing a set of some linguistic control rules which can be obtained from experienced human operators. Mamdani’s model was based on Lotfi Sade’s 1973 on fuzzy algorithms or complex systems and decision processes [8].
Mamdani-type inference, which defined for Fuzzy Logic Toolbox expects the output membership functions needs to be fuzzy sets. After the aggregation process, there is a fuzzy set for all the output variable that needs defuzzification. In many cases a single spike as an output membership functions are used. This type of output is usually known as a singleton output membership function. It always enhances the efficiency of the defuzzification process as it simplifies the computation required by the more simple Mamdani method, which finds the centroid of a 2D functions. Instead of integrating across the 2D function to find the centroid, one can use the weighted average of some of the data points. Sugeno-type system support this type of model. Sugeno-type systems can be used to design mathematical model of any inference system in which output membership functions are linear or constant.

Fuzzy rule based system

One other approach to infrared image contrast enhancement using fuzzy logic is a Takagi-Sugeno fuzzy rule based system. Takagi-Sugeno rules have consequents which are numeric functions of the input values. This approach is used to enhance the contrast of a gray-scale digital image which proposes the following rules:
IF a pixel is dark, THEN make it darker
IF a pixel is gray, THEN make it mid-gray
IF a pixel is bright, THEN make it brighter
Membership functions in a fuzzy set map all the elements of a set into some real numbers in the range [0, 1]. When the value of membership is higher, the “truth” that the set element belongs to that particular member function is higher as vice versa.
The input membership functions for an image contrast enhancement system is shown in Figure 7. The set of all input image pixel values is mapped to 3 different linguistic terms: Dark, Gray & Bright. The values μi(z) quantify the “degree of membership” of a particular input pixel intensity value to the each of the 3 member functions; denoted by the subscript (i). Thus, μdark(z) assigns value from 0 to 1 and in between to how truly “dark” an input pixel intensity value (z) is. Same way, μgray(z) and μbright(z) characterize how truly Gray or Bright a pixel value z is. The Dark and Bright input membership functions can be implemented by using a sigmoid functions and the Gray input membership function can be implemented by the Gaussian function. The sigmoid function, also known as the logistic function that is continuous and non-linear. This can be defined mathematically as follows:

Where x is input and g(x) is gain. The Gaussian function is defined as below:

Figure 7. Input Membership Functions for the Fuzzy Rule-Based Contrast Enhancement
Three linguistic terms can be defined for the output member functions; and these are referred to as Darker, Mid-gray and Brighter. Because it is common in some of the implementations of Takagi-Sugeno systems, the output fuzzy sets are usually defined as fuzzy singleton that says the output membership functions are single-valued constants. Here the output membership function values can be selected as follows:
Darker = 0 (νd)
Mid-gray = 127 (νg)
Brighter = 255 (νb)
These are shown below:

Figure 8. Output Membership Functions for the Fuzzy Rule-Based Contrast Enhancement
For a Takagi-Sugeno system design, the fuzzy logic rules which determine the outputs of system have been used the following linear combination of input and output membership function value. As the output membership functions are constants, the output νo to any input zo, is given by:

Where, μdark(z), μgray(z) and μbright(z) = the input pixel intensity values and (vd, vg and vb) = the output pixel intensity values. This relationship accomplishes the processes of implication, aggregation and defuzzification together with a numeric computation.
In case of image processing, fuzzy logic is computationally intensive, as it requires the fuzzification, processing of all rules, implication, aggregation and the defuzzification on every pixel in the input digital image. Using a Takagi-Sugeno design which uses singleton output membership functions can reduce computational complexity Figure 9 is the block diagram of the process developed for the fuzzy logic technique implemented for this work.

Figure 9. Flow chart for the implemented fuzzy logic process

Contrast enhancement using an INT-Operator from fuzzy theory

Many researchers have applied the fuzzy set theory to develop new techniques for contrast improvement. A basic fuzzy algorithm for image enhancement, using a global threshold, has been briefly recalled. Let us consider a gray level digital image, represented by the gray level values of the pixels with the range [0;1] and Let l be any gray level of a pixel in this digital image, l [0;1] .
Contrast improvement is a basic point processing operation which mainly used to maximize the dynamic range of the image. A higher contrast in an image can be achieved by darkening the gray level in the lower luminance range and brightening the ones in the upper luminance range. This processing generally implies the use of a non-linear function; Form of such a function could be the one presented in Figure 10. Mathematical expression of such a nonlinear function, Int (l) is as below:

The expression represents operator in the fuzzy set theory, namely the intensification (INT) operator. When it is applied on digital images, it has the effect of contrast enhancement.

Figure 10. Fuzzy intensification
Let us denote the resulting gray levels in the contrast enhanced image by g given by:

Thus, the contrast enhanced image have gray levels of its pixels given by the nonlinear point-wise transformation in Figure 10, applied to the original gray level image.

Implementation on Matlab

The following are the steps which are carried out for the implementation to get the output:

Read the original image.

>> I = imread(‘Input image’)

Convert it into Gray Scale image if it is RGB image.

>> I = rgb2gray(I)

Add the noise to the image.

>> Z = imnoise(I,’gaussian’,0.2);

Calculate size of original image.

>> [row col] = size(Z);

Perform morphological operation on image.

To find Maximum pixel value of image
>> mx = max(max(Z));
To find Minimun pixel value of image
>> mn = min(min(d));
To find Mid point of image
>> mid = (mx+mn)/2;

Apply fuzzy algorithm.

Show the output.

>> figure,imshow(output),title (‘output enhanced image’)

Conclusion

Four different fuzzy approaches has been implemented to enhancement the high voltage images. Compared to the basic approaches, one can notice that fuzzy methods offer a powerful mathematical model for developing new enhancement algorithms. The global fuzzy approaches not gives satisfactory results. But here a locally adaptive procedure for fuzzy enhancement has been proposed. The contrast enhancement of high voltage images is also not satisfactory sometimes. The reason behind that is the physics of EPIDs which produces images with poor dynamics qualities and that is why sometimes there is no information in MVI to be improved. The fuzzy logic algorithms offer many different possibilities to optimize its performance, like parameters of membership functions, due to that it can certainly be expected that fuzzy image enhancement techniques can be applied in many areas of medical imaging in future.
References
[1]Farzam Farbiz, Mohammad Bager Menhaj, Seyed A. Motamedi, and Martin T. Hagan, “A new Fuzzy Logic Filter for image Enhancement” IEEE Transactions on Systems, Man, And Cybernetics-Part B: Cybernetics, Vol. 30, No. 1, February 2000.
[2]Om Parkas Verma, Madasu Hanmandlu, Anil Singh Pariah and Vamp Krishna Madasu “Fuzzy Filter for Noise Reduction in Color Images,” ICGST-GVIP Journal, Vol. 9, No. 5, September 2009, pp.29-43.
[3]Rafael C.Gonzalez and Richard, E. Woods “Digital Image Processing,” New Jersey, Pearson Prentice Hall, Third Edition – 2008.
[4]Aboul Ella Hassanien and Amr Bader, “A comparative study on digital mammography Enhancement algorithms based on Fuzzy Theory,” International Journal of Studies in Informatics and Control, SIC – Volume 12 Number 1, March 2003, pp. 21-31.
[5]Alper Pasha “Morphological image processing with fuzzy logic,” Aerospace and space technology magazines, Vol. 2, No. 3, 2006, pp.27-34.
[6]Tamalika Chaira, Ajoy Kumar Ray, “Fuzzy Image Processing and Applications with MATLAB,” CRC Press, vol. 1, 2010,pp. 47-55.
[7]Mamdani, E.H. and S. Assilian, “An experiment in linguistic synthesis with a fuzzy logic controller,” International Journal of Man-Machine Studies, Elsevier, Vol. 7, No. 1, 1975, pp. 1-13.
[8]Zadeh, L.A., “Outline of a new approach to the analysis of complex systems and decision processes,” IEEE Transactions on Systems, Man, and Cybernetics, Vol. 3, No. 1, Jan. 1973, pp. 28-44.
[9]H. R. Tizhoosh, G. Krell and B. Michaelis, “On Fuzzy Enhancement of Megavoitage Images in Radiation Therapy,” Proceedings of the 6th IEEE International Conference on Fuzzy Systems, July 1997.
[10]Stefan Schulte, Valerie De Witte, and Etienn, E.Kerre, “A Fuzzy Noise Reduction Method for Color Images,” IEEE Transactions on Image Processing, Vol. 16, Issue 5, May 2007, pp. 1425-1436.
[11]C.Castiello, G.Castellano, L.Caponetti and A.M.Fanelli, “Fuzzy Classification of Image Pixels,” IEEE International Symposium on Intelligent Signal Processing, 2003

Gain Enhancement of Multiband Microstrip Radiating Structure

Gain Enhancement of Multiband Microstrip Radiating Structure using Curve Tooth CSRR with Two Different Substrate Material

Muktesh P. Shah1, Shobhit K. Patel2, Mayank A. Ardeshana3, Jigar M. Patel4

Abstract—In this paper Microstrip radiating structure with Complementary Split Ring Resonator (CSRR) using Curve Tooth with two different substrate material for Multiband applications in S band and C band is designed and analyzed. We have introduced Curve Tooth in CSRR to improve Gain in comparison with simple CSRR based design. Also, The same design with two different substrate material like FR4 and Teflon is compared and analyzed. Here, Patch of dimension 44×44mm2 is analyzed. The FR4 based design of Curve Tooth in CSRR has five working bands centered around 1580 MHz, 3180 MHz, 3600 MHz, 4580 MHz, 7190 MHz and Simple CSRR Design has three working bands with center frequency 1560 MHz, 3150 MHz and 3540MHz. The Teflon based design of Curve Tooth in CSRR has five working bands centered around 2250 MHz, 4560 MHz, 5150 MHz, 6540 MHz, 8310 MHz and Simple CSRR Design has four working bands with center frequency 2213 MHz, 4508 MHz, 5050MHz and 6395 MHz. Design results of VSWR, Return loss S11 and Total Gain of all four design is shown and compared in this paper. Also, Design results shows improvement in Gain in Curve Tooth CSRR design. The dimensions of substrate height is 1.57 mm, Patch and Ground height is 0.035 mm which are similar to actual Antenna dimensions. Design results are obtained by a HFSS 13 (High Frequency Structure Simulator) which is mostly used for simulating microwave passive components.
Index Terms— Curve Tooth, CSRR (Complementary Split Ring Resonator), Substrate Materials, Multiband, Microstrip.
I. Introduction
Nowadays, Multiband antenna is a popular choice because same antenna can be used for many applications [12][15][17][18][19]. Microstrip patch antennas are widely used because of their many merits, such as the low volume, light weight, low cost etc. [1-8] However, Patch antennas have a main disadvantage: narrow bandwidth while others are low gain, low power handling capacity etc. [1-8] Still there is a need to design Multiband antenna with improvement in Gain. Metamaterial may solve this need.

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In Recent Scenario, Microstrip patch antennas are widely used in wireless devices and other compact sizes with multiband antenna operation. The irregular shape of the developed planar antenna achieves multi-band (Broadband) performance [11]. In traditional planar antennas, the distances between the edges are fixed and therefore, the antennas dominant mode resonates only at a single frequency [11]. In contrast, the irregular shape of the current antenna facilitates, its broadband character by allowing the structure to have more than one degenerate mode that resonate at more than one frequency, based on the irregularity introduced [11]. In general, multi-sided patches are excellent candidates for broadband operation, since many closely spaced resonant modes can be excited using the different edges of the patches [11]. This property makes them uniquely suited for multi-band operation in wireless applications.
There has been a considerable amount of recent interest in the class of artificial material which is known as Metamaterials that possess simultaneously negative permeability and permittivity, according to a negative index of refraction [1][2]. Such type of metamaterial is known as a double negative material (DNG). To increase the power radiated from electrically small antennas, an application of DNGs has been suggested by Ziolkowski and Kipple [3]. But in this paper a negative permittivity material complementary split ring resonator (CSRR) which is a dual counterpart of split ring resonator (SRR) originally proposed by Pendry have been loaded into the patch. CSRR is composed of two concentric metallic ring slots with slits etched in each ring at its opposite sides. Apart from double negative materials, single negative materials where only one of the material parameters has a negative real value also possess interesting properties and can be used to produce novel devices. In particular the complementary split ring resonator (CSRR) which establishes a negative-permittivity at resonance, is an example of a single negative media (SNG) that can be used to make microwave devices [4]-[6]. Here, we have incorporated curve tooth CSRR to further improve the results of CSRR. The properties of SNG can also be manipulated to increase filter shape factor, improve filter rejection and can also applied to antennas to reduce the spurious effect and increase antenna gain and antenna size reduction [7][9][16][17]. This paper is based on the microstrip radiating structure which integrates a Curve Tooth CSRR design into the ground to provide good return loss and improved gain.
The CSRR is a commonly used resonator etched on the
Metal plane. An effective negative permittivity and negative permeability could be introduced in microstrip devices by loading CSRR [17][18]. In this article, we have etched the CSRR in the ground plane of a microstrip patch underneath the substrate. The CSRR structure model is shown in Figure 1. If the effects of the metal thickness and losses, as well as those of the dielectric substrate are ignored, a perfectly dual behavior is expected for the complementary screen of the SRR. Thus, whereas the SRR can be mainly considered as a resonant magnetic dipole that can be excited by an axial magnetic field, the CSRR (Fig. 1) in essence behaves as an electric dipole (with the same frequency of resonance) that can be excited by an axial electric field. Fig. 1 shows the unit cell structure of SRR model and CSRR model with its equivalent electrical circuit.

Fig. 1 (a) SRR unit cell, (b) Equivalent electric circuit of SRR unit cell, (c) CSRR unit cell, and (d) equivalent electric circuit of CSRR unit cell. [15]
II. Design and Simulation
In this section, we will introduce the design of our antenna. First the conventional patch length and width is designed. After designing the patch, we have taken out five slots from the patch to improve the radiation path. Basic length and width is designed with the use of following equations [5].

Width of the patch can be designed using the equation (1), here f0 is the resonance frequency, εr is relative permittivity of the dielectric substrate and c is speed of light.

Length of the patch can be designed by using the equations (2-5) [5]. Here‘t’ is the thickness of substrate. Using these equations we have derived length and width of conventional patch.
We designed square patch so length and width are same and it is 44 mm, so a square patch is 44×44 mm2 over here which is shown in Figure 2 (a). We have taken out five slots from the patch to increase the Radiation path and to improve the results as shown in figure. The slots taken out have dimension of 8×8 mm2.
A. Design 1
The top view of the Simple CSRR design and Curve tooth with CSRR Design is shown in Figure 2 (a) and 2 (b) respectively. Both the design has outer and inner ring is of 1 mm. Gap between the two rings is 1.5 mm.
Table: 1 Material used for Design1

Design 1

Material

Patch

Copper

Substrate

Teflon with ε = 2.1

Table 1 shows details about the material. Patch is of copper material. Substrate is of Teflon material with ε = 2.1. The base material is also of copper.
Fig. 2 (a) HFSS Model of Simple CSRR Design

Fig.2 (b) HFSS Model of Curve Tooth CSRR Design
For simulation we used HFSS 13 (High Frequency Structure Simulator) of Ansoft, which is very good simulator for simulating microwave passive components specially RF antenna.
Figure 3 (a) and 3 (b) shows the Return Loss (S11) in dB for both the designs. The minimum return loss which we are getting for Simple CSRR design is -31 dB for the band centered around 4.508 GHz and for Curve Tooth CSRR design, it is -37 dB for the band centered around 4.56 GHz.
Figure 4 (a) and 4 (b) shows the VSWR plot for both the designs.

Fig. 3 (a) Return Loss (S11) plot of Simple CSRR Design

Fig. 3 (b) Return Loss (S11) plot of Curve Tooth CSRR Design

Fig. 4 (a) VSWR plot of Simple CSRR Design
Fig. 4 (b) VSWR plot of Curve Tooth CSRR Design
B. Design 2
Here, We have used same design but only substrate material is changed. In this Design we have used FR4 epoxy material for substrate.
Table: 2 Material used for Design1

Design 1

Material

Patch

Copper

Substrate

FR4 epoxy with ε=4.4

Fig. 5 (a) Return Loss (S11) plot of Simple CSRR Design

Fig. 5 (b) Return Loss (S11) plot of Curve Tooth CSRR Design

Fig. 6 (a) VSWR plot of Simple CSRR Design

Fig. 6 (b) VSWR plot of Curve Tooth CSRR Design
Figure 5(a) and 5(b) shows Return loss plot of both CSRR and Curve Tooth CSRR design. Figure 6(a) and 6(b) shows VSWR plot for both the design.
III. Comparative Analysis
A. Design 1
In this design, we used Teflon as a substrate material in which Curve Tooth design has five working bands while Simple CSRR design has four working bands.
Table 3 shows comparison of Return loss and VSWR of the both the design.
Table 3 : Comparison of S11 and VSWR for both design

Band

Design

Frequency
in GHz

Minimum
Return Loss (S11) in dB

VSWR

First

CSRR

2.213

-18.8

1.2601

Curve tooth CSRR

2.25

-17

1.331

Second

CSRR

4.508

-31

1.0549

Curve tooth CSRR

4.56

-37.6

1.0268

Third

CSRR

5.05

-15

1.4183

Curve tooth CSRR

5.15

-14.8

1.4434

Fourth

CSRR

6.395

-27.7

1.0862

Curve tooth CSRR

6.54

-24.7

1.1243

Fifth

CSRR

—–

—–

—–

Curve tooth CSRR

8.31

-12

1.6624

By using curve tooth in CSRR, we have an extra working band and also return loss and VSWR values are very good. We got VSWR of 1.0268 using curve tooth which is nearer to 1.
Figure 7(a) and 7(b) shows Total Gain plot in 3D view for CSRR and Curve tooth CSRR design respectively.

Fig.7 (a) Total Gain plot in 3D view for simple CSRR design

Fig.7 (b) Total Gain plot in 3D view for Curve Tooth CSRR design
Simple CSRR design has Total Gain of 2.6609 dB while Curve Tooth CSRR design has Total Gain of 2.9264dB. So using Curve tooth in CSRR we have improved gain.
B. Design 2
In this design, we used FR4 epoxy as a substrate material in which Curve Tooth design has five working bands while Simple CSRR design has four working bands.
Table 3 shows comparison of Return loss and VSWR of the both the design.
By using curve tooth in CSRR, we have two extra working bands and also return loss and VSWR values are very good. We got VSWR of 1.0931 using curve tooth which is nearer to 1. Figure 8(a) and 8(b) shows Total Gain plot in 3D view for CSRR and Curve tooth CSRR design respectively.
Simple CSRR design has Total Gain of -0.2895 dB while Curve Tooth CSRR design has Total Gain of 3.0368dB. So using Curve tooth in CSRR we have sufficiently increased the gain.

Band

Design

Frequency
in GHz

Minimum
Return Loss (S11) in dB

VSWR

First

CSRR

1.56

-23.6

1.1407

Curve tooth CSRR

1.58

-27

1.0931

Second

CSRR

3.15

-18

1.2780

Curve tooth CSRR

3.18

-19

1.2429

Third

CSRR

3.54

-25

1.1197

Curve tooth CSRR

3.60

-24

1.1318

Fourth

CSRR

—–

—–

—–

Curve tooth CSRR

4.58

-13.9

1.5070

Fifth

CSRR

—–

—–

—–

Curve tooth CSRR

7.19

-17

1.3172

Table 4 : Comparison of S11 and VSWR for both design

Fig.8 (a) Total Gain plot in 3D view for simple CSRR design

Fig.8 (b) Total Gain plot in 3D view for Curve Tooth CSRR design
IV. Conclusion
Here Microstrip patch antenna is designed for multiband applications using five rectangular square slots in the Patch and CSRR in ground. Curve Tooth is also implemented in CSRR to improve the results. Two designs with different substrate material is designed and analyzed. This antenna is compared with simple CSRR design. The result of Design 1 which has Teflon substrate, indicates the five working bands for Curve Tooth CSRR design, 2.25 GHz, 4.56 GHz, 5.15 GHz, 6.54 GHz and 8.31 GHz so the antenna can used for S and C Band Applications while Simple CSRR has four working bands. VSWR is very good for 4.56 GHz frequency which is 1.0268 near to 1. Also, Gain has been improved with Curve Tooth CSRR which is 2.9264 dB compare to Simple CSRR design which has gain of 2.6609 dB. Design 2 which has FR4 substrate, provides five working bands for Curve Tooth CSRR while CSRR design has three working bands. Also, Gain for Curve Tooth CSRR has 3.0368 dB compare to -0.2895 dB for simple CSRR design. So, by using Curve Tooth in CSRR improves results. Also, Dimensions of all Designs are similar to Actual Antenna so when we fabricate the antenna, we will get similar results.
References

V.G. Vesalago, “The Electrodynamics of Substances with Simultaneously Negative Values of Permittivity and Permeability”, Sov. Phys. USPEKHI, pp. 509-514, 1968.
D.R. Smith, W.J. Padilla, D.C. Vier, S.C. Nemat-Nasser, and S. Schultz, “Composite Medium with Simultaneously Negative Permeability and Permittivity”, Phys. Rev. Lett., 84, No. 10, pp. 4184-4187, 2000.
R.W. Ziolkowski and A.D. Kipple, “Application of Double Negative Materials to Increase the Power Radiated by Electrically Small Antennas”, IEEE Transactions on Antennas and Propagation, 51, No. 10, pp. 2626-2640, October 2003.
F. Falcone, T. Lopetegi, J.D. Baena, R. Marques, F. Martin, and M. Sorolla, “Negative- E Stop-Band Microstrip Lines Based on Complementary Split-Ring Resonators”, IEEE Microw. Wireless Compon. Lett, 14, No. 6, pp. 280-282, Jun. 2004.
J. D. Baena, J. Bonache, F. Martin, R. Marques, F. Falcone, et.al., “Equivalent-Circuit Models for Split Ring Resonators Coupled to Planar Transmission Lines, “IEEE Trans. Microw. Theory Tech, 53, No. 4, pp. 1451-1461, Apr. 2005.
J. Garcia-Garcia, , F. Martin, F. Falcone, J. Bonache, J.D. Beano, et.al, “Microwave Filters with Improved Stop Band Based on Sub Wavelength Resonators” IEEE Trans. Microw. Theory Tech, 53, No. 6, pp. 1997-2006, June. 2005.
J.J. Max, Y. Cao and T. Liu, “Design the Size Reduction Patch Antenna Based on Complementary Split Ring Resonator, “ICMMT 2010 proceedings.
Hui Zhang, You-Quan Li, Xi Chen, Yun-Qi Fu, and Nai-Chang Yuan, “ Design of Circular Polarization Microstrip Patch Antenna using Complementary Split Ring Resonator”, 978-1-4244-2609-6, IEEE 2008.
D. Laila, R. Sujith, V. Deepu, C.K., Vasudevan Aanandan and P. Mohanan, “Compact Csrr Based Patch Antenna for Wireless Applications”, 978-1-4244-4819-7, IEEE 2009.
N. Ortiz, F. Falcone, M. Sorolla, “Dual Band Patch Antenna Based on Complementary Split Ring Resonator”, 978-1-4244-2802-1, IEEE 2009.
Zygmond Turski, Aly E. Fathy, David McGee, Gary Ayers, and Sridhar Kanamaluru, “Compact Multi-Band Planar Antenna for Mobile Wireless Terminals,” IEEE, 2001.
M.P.Shah, S. K. Patel, M.A.Ardeshana, J.M. Patel, “Design of Multiband microstrip Radiating Structure for C band Applications,” IJARCCE, Vol.2, Issue.12, Dec 2013, pp. 4560-4563.
S. K. Patel, J. Bhalani, Y.P. Kosta, S.S. Patel, “Design of microstrip meandered patch antenna for mobile communication,” Proceedings of International conference on Advances in Information Technology and Mobile Communication (AIM 2011), Springer, 2011, pp. 184–189.
S.K. Patel and Y.P. Kosta, “E-shape microstrip patch antenna design for GPS application,” Proceeding of Nirma University International conference on Engineering (NUiCONE 2011). IEEE, 2011, p. 1-4.
S.K. Patel and Y.P. Kosta, “Meandered multiband metamaterial square microstrip patch antenna design,” Waves in Random and Complex Media, in press, 2012(DOI: 10.1080/ 17455030.2012.723837).
S.K. Patel and Y.P. Kosta, “Size reduction in Microstrip based radiating structure with artificial substrate,” International Journal of Applied Electromagnetics and Mechanics, in press, 2012.
S.K. Patel and Y P Kosta, “Investigation on radiation improvement of corner truncated triband square microstrip patch antenna with double negative material,” Journal of Electromagnetic Waves and Applications, 2013, Vol. 27, No. 7, 819–833.
S.K. Patel and Y P Kosta, “Triband microstrip–based radiating structure design using Split ring resonator and complementary split ring resonator,” Microwave And Optical Technology Letters / Vol. 55, No. 9, September 2013, Wiley periodicals.
J. M. Patel, S. K. Patel and F. N. Thakkar, “Defected Ground Structure Multiband Microstrip Patch Antenna using Complementary Split Ring Resonator,” IJETEE, Vol. 3, Issue. 2, May 2013.
S.K. Patel and Y.P. Kosta, “Design of Truncated microstrip radiating structure loaded by SRR,” International Journal of Applied Electromagnetics and Mechanics, in press, 2012.
S.K. Patel and Y.P. Kosta, “Dual band parasitic metamaterial square microstrip patch antenna design,” International Journal of Ultra Wideband Communications & Systems 2, no. 4, pp. 225-232 2012.
J. M. Patel, S. K. Patel and F. N. Thakkar, “Comparative analysis of S-shaped Multiband Microstrip patch antenna,” IJAREEIE, Vol. 2, Issue. 7, July 2013.
J. M. Patel, S. K. Patel and F. N. Thakkar, “Design of S-shaped Multiband microstrip patch antenna,” NUiCONE, IEEE, 2012.

 

Ford’s Value Enhancement Plan Analysis

Ford’s Value Enhancement Plan aims to align the interests of various shareholders by offering them different options – the choice of $20 in cash, additional new common shares or a combination of cash and new share. Based on the following analysis, Ford should go ahead with Value Enhancement Plan.
Characteristic of VEP
The Value Enhancement Plan has the feature of stock split and share repurchase. Exchanging existing shares for new shares on a one-for-one basis, shareholders are also offered the option to reinvest $20 to receive additional new Ford common shares. In this sense, share price would decrease while the number of shares outstanding is going to increase. According to Ford’s announcement mentioned in the case, shareholders choosing the share option would receive 0.748 new Ford common shares in lieu of $20 cash. So, the effect is similar to 1.748 for 1 stock split. However, not all the shareholders prefer share option. For those who elect cash option, they would receive $20 as though they sell part of their shares, which reflects the feature of share repurchase.
Advantages of VEP
With the combined feature of stock split and share repurchase, VEP has its strength.
In terms of cash option, since there is no good things to do with the massive cash reserve, returning the excessive cash allows shareholders to make profitable investment by themselves. Unlike cash dividend, returned cash is taxed as capital gains, so it generates tax efficiency for shareholders. In addition, though the price of new Ford shares would decrease, shareholders will not bear any loss, because the reduced price is offset by the cash they receive. But from the company’s point of view, they can reduce dividend payment. Companies tend to keep dividend payout ratio constant, so dividend for each new Ford share will decrease because share price falls. For those who choose to receive $20 in cash, they keep the same amount of shares before VEP is introduced, therefore, the total dividend payment is going to reduce and to some extent, the pressure for increasing dividend level can be relieved a bit. Moreover, the effect of cash option is similar to that of share buyback, the number of new shares outstanding will reduce; thus, earnings per share will increase and it can increase the overall demand for Ford’s share, which will benefit share price in the long run.
If shareholders elect stock option, they can increase voting power and exercise more control over the company. Also, as we discussed in the cash option, share price will increase, so, shareholders will benefit a lot from holding more new Ford shares.
As for the combination of cash and new shares, shareholders can take part of their money out of the stock to make other profitable investment, and they can also maintain their interest in the company. On the one hand, they can enjoy tax efficiency by paying tax of capital gains for cash received, on the other hand, they can enjoy the profit when share price increases and they can have a say in the firm.
VEP is better than cash dividend in terms of tax effect, and compared with share repurchase, it meets shareholders’ need to remain or increase control of the company. Therefore, based on the analysis, Ford should go ahead with VEP.
Possible Choices of Different Shareholders
Ford family member will choose stock option because they want to expand their control in the firm. By supporting VEP, their 40% voting power remains unchanged but their equity in the firm decreases from 5% to 3.6%. If they elect stock option, they hold more common shares, and their voting power is beyond 40%.
Institutional investors, such as TIAA-Cref and the Calpers would choose combination of cash and shares. It’s obvious that VEP favors Ford family members and dilutes institutional investors’ voting power, so it’s hard for them to compete with Ford family members in terms of control even if they reinvest all the $20 cash to buy new Common shares. In this sense, combination of cash and new share is a better choice for them. They can get part of their investment out of Ford stock for good opportunities somewhere else; meanwhile, they can remain interest in Ford.
A regular outsider shareholder doesn’t care about voting power. The purpose of their investment is profit. So, if I was one of them, I would go for cash option, because I would think Ford can’t find profitable projects and there are few growth opportunities. By getting money back, I can make good use of it by myself.
 

Infant Brain Development and Cognitive Enhancement

Introduction

Children nutrition during their first 1000 days is significant to their body development, especially for their brain development. adequate nutrition could be obtained from either breast milk or fortified milk. In further, an improved cognitive function has been observed in both term and preterm infants fed with breast milk when compared with formula. Nevertheless, pregnant women are still susceptible to vitamin B12 deficiency and iodine deficiency in severe areas, and preterm infants are susceptible to docosahexaenoic acid deficiency. Various nutrients requirement might be depended on two parts, postnatal health outcome, and gene expression or molecule mechanisms related to key regions of the cerebral cortex. Traditional maternal diet among poverty areas, or lacking related high-education or ignorance of nutrition needs could influence infant intake of certain nutrients such as zinc and protein. Therefore, within two years old, especially the first year of infant, in order to maintain adequate nutrition, from both breast milk and formula such as fatty acid, vitamin A, B6 and B12, amino acid such as glutamine, iron, iodine, choline and folic acid, dietary supplement might be suggested by their health care professionals1,2. Here, two common questions will be replied in the following part, what kind of DS could/should be taken by pregnant women, what kind of nutrients should be added in fortified formula or breast milk to maintain infant brain development after delivery? Therefore the following 4 dietary supplements would be good implications for pregnant moms and fortified milk manufactures, and future research directions.

Docosahexaenoic acid (DHA)

Docosahexaenoic acid (DHA), a long-chain polyunsaturated fatty acid is one of the membrane composition of brain tissue 3. DHA is beneficial to improve hippocampal function related to cognitive health in children of school age4. Preterm (5 Since preterm infants could not get adequate DHA from maternal utero, Supplementation of DHA might improve brain development among infants6. DHA accumulates in the frontal Robes of the fetal brain during the last trimester of pregnancy. Their deficiency might cause aged cerebral by delayed membranes metabolism.

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DHA might not have apparent benefits on the infant’s brain. A randomized prospective study of DHA given to pregnant women with 400 mg/d from 16 weeks of gestation has shown benefits in infants, including visual acuity at 2 months old and higher receptive and expressive language skills at 18 months old measured by Bayley Scales of Infant Development7. Results from a self-questionnaire among 1516 healthy pregnant women who take DHA during their pregnancy have shown that improved brain development and increased height and head circumference among infants8. Another meta-analysis study among 34 RCT has shown that crystallized intelligence, improved fluid intelligence with supplemented Long-chain polyunsaturated fatty acids (LCPUFA)6. However, a randomized clinical trial among toddlers born preterm infants with 200 mg/d DHA supplementation in their feeding diet has shown that DHA might not improve cognitive development on term infants9. Even a negative effect of DHA taken by pregnant women on childhood neurodevelopment has been reported10.

Iodine

 

Iodine deficiency, combined with a low level of thyroid hormones might cause infant impaired brain development. Besides, severe iodine deficiency may cause cretinism, manifested in impaired speaking ability and etc. Urine Iodine Concentration (UIC)13,14. It has also revealed an adverse outcome point-lower expressive language skills of iodine (
As for the mechanism between iodine and infant neurodevelopment, iodine helps to synthesize thyroid hormones, triiodothyronine T3 and thyroxine T4 in brain development, especially during the first pregnant trimester.

Iodine supplementation during pregnancy might not have a significant advantage to infant cognitive enhancement. A population-based cohort research among 851 Norway mother-infant pairs has shown that mild-to-moderate maternal iodine deficiency (
Due to missing rescue time of vital stage in brain development, none apparent changes in brain development in infants with iodine supplementation among pregnant women has been detected, even if a lower gross motor development in infants has been detected with low iodine supplementation (150 µg to 200 µg) among a small proportion of pregnant women (18%) 13. The same conclusion of a study among 6-18 months old infants has been got in mild-to-moderate iodine deficiency area-Spanish.15 Instead of huge low-income moms in this study, a population with adjusted socioeconomic bias should be selected as future main subjects aimed for accurate relations between iodine intake and outcome. A similar outcome has also been proved in Chinese children of 18 months and 2 years old, with 187.8 μg/L colostrum iodine level measured among 150 women16. However, a recent meta-analysis has shown an association between maternal of mild-to-moderate iodine deficiency and impaired child brain development17.  Besides, hypothyroidism might be induced by iodine deficiency (
Glutamine

 

Since it is during infant stage that the vital process of gut colonization and brain development will occur, and thus relations between the intestinal microbiome and infant brain development have been focused on19. Impaired cognitive development of preterm infants is related to a low level of glutamine20. As for the mechanism between glutamine and brain development, gut-immune-brain axis might be a potential theory. Glutamine has been proved to protect brain health by preventing neonatal infection induced by pathogens, achieved through maintaining gut health21.

Parental or enteral glutamine supplementation might be beneficial to very low birth weight (VLBW) infants on increased morbidity and improved growth outcome. A long-term outcome study has shown that taking enteral glutamine supplementation during Day 3 to day 30 (0.3 g/kg per day) has no apparent beneficial or adverse effects on cognitive improvement for pre-term (22. However, there is still not enough research about the efficacy of glutamine supplementation on infant brain development, this might be caused by several reasons, such as varying doses and injected time, duration time and cognitive measurement. Studies on neurodevelopment follow-up could be conducted to obtain the safety report of glutamine intake.

Bovine Milk Fat Globule Membrane(BFGM)

 

Formula supplemented with Bovine milk fat globule membrane (BFGM) might be beneficial to cognitive improvement. sphingomyelin (SM), one of the brain cell membrane, is composed of BFGM. SM-supplemented breast milk (20% of phospholipids) has been found to improve neurodevelopmental in 24 VLBW infants, showing an increased SMs level and a better score of Visual evoked potentials (VEPs)- increased neurotransmitter without any side effects on preterm infants23.

Besides, a double-blinded randomized study on 160 infants using 6 months supplemented formula might show some benefits of BFGM with infant cognitive enhancement when compared with standard formulas24. Results have revealed a significant change in infant plasma lipidomes, such as an increased level of phosphatidylcholines(PC) and altered content of SMs, indicating the positive effect of BFGM on cognitive development. Although lipid metabolism and further outcome on infant cognitive enhancement are needed to be investigated, SMs has been proved to have none side effects on preterm infants23.

 

The formula contained Sphingomyelin, iron, choline and DHA 11

 

Choline might support infant myelination, there’s a formula patent added with choline (30-300 mg/100g). Besides, folic acid added here has an amount of at least 50 -500 mcg/100g. The effect of this formula (SMs, iron, choline, DHA) on myelination has been observed similar to the effect of the first month breastfed infants. High myelin content has been detected by Magnetic Resonance Imaging (MRI) brain scans for 7 days among infants, and their elevated cognitive abilities including gross motor, visual reception, and language (expressive and receptive and learning abilities have been tested through Mullen Scales of Early Learning.

 

Conclusion

 

Although it might be effective on improved infant visual acuity with maternal intake of DHA, enhanced cognitive development has only been found in older ages-children, the reason might be inefficient infant cognitive tests. For pregnant women, Nordic Naturals ProOmega for 180 Soft gels is my suggested fish oil brand. After delivery, it’s better to add adequate DHA in formula or breast milk. Here are two examples for the term and preterm infants, especially for pre-term ones, the amount of DHA in an infant formula patent is between 30-300mg/100g11. DHA of 9 mg/100 mL has been added in formula supplemented with milk fat globule mMFGM12.

Since outcomes of severe deficient iodine have been solved in most of the area, so people start to concentrate on mild-to-moderate areas. Recommended Dietary Allowance for infants is 110 mcg (0-6 months) and 130mcg (6-12months)6. Recommended doses of iodine added in the formula for infants between 2-5 months old is 70 μg/d18. Since iodized salt is a better source of iodine than a dietary supplement, I would not recommend dietary supplement contained iodine. Besides, in order to improve the efficacy of iodine on the neurodevelopment of infants, certain intake doses and duration of iodine sources are also needed.

I think glutamine supplementation such as L-Glutamine powder from Pure Encapsulations, could be used because it is basically safe. Glutamine could be added L-glutamine
Since SMs (200mg-2g /kg) has been added in infant formula as a patent11. BFGM (4%(wt/wt) of the total protein) has been added in experimental formula 24 (Arla Foods ingredients, Viby, Denmark). Therefore it is possible to add milk polar lipid supplementation in infant diet. 

References

Bar S, Milanaik R, Adesman A. Long- term neurodevelopmental benefits of breastfeeding. Current Opin Pediatr. 2016;28(4):559–566. doi: 10.1097/MOP.0000000000000389.

Belfort MB, Anderson PJ, Nowak VA, et al. Breast milk feeding, brain development, and neurocognitive outcomes: a 7-year longitudinal study in infants born at less than 30 weeks’ gestation. J Pediatr. 2016;177: 133–139.e1 doi: 10.1016/j.jpeds.2016.06.045

Meldrum S1, Simmer K. Docosahexaenoic Acid and Neurodvelopmental Outcomes of Term Infants. Ann Nutr Metab. 2016;69 Suppl 1:22-28.

Baym CL, Khan NA, Monti JM. et al. Dietary lipids are differentially associated with hippocampal-dependent relational memory in prepubescent children. Am J Clin Nutr. 2014 May;99(5):1026-32. doi: 10.3945/ajcn.113.079624.

Blencowe H, Lee AC, Cousens S, et al. Preterm birth-associated neurodevelopmental impairment estimates at regionaland global levels for 2010. Pediatr Res. 2013 Dec;74 Suppl 1:17-34. doi: 10.1038/pr.2013.204.

Kerr-Wilson CO, Mackay DF, Smith GC, et al. Meta-analysis of the association between preterm delivery and intelligence. J Public Health. 2012; 34:209–16. 10.1093

Kelly AM, D.J. K, Sheila M. I. Omega-3 Fatty Acid Deficiency in Infants before Birth Identified Using a Randomized Trial of Maternal DHA Supplementation in Pregnancy. PLoS One. 2014; 9(1): e83764. doi: 10.1371/journal.pone.0083764

Li P, Shang Y, Liu YJ, et al. Effect of docosahexenoic acid supplementation on infant’s growth and body mass index during maternal pregnancy]. Zhonghua Liu Xing Bing Xue Za Zhi. 2018 Apr 10;39(4):449-454. doi: 10.3760/cma.j.issn.0254-6450.2018.04.012.

Keim SA, Boone KM, Klebanoff MA, et al. Effect of Docosahexaenoic Acid Supplementation vs Placebo on Developmental Outcomes of Toddlers Born Preterm A Randomized Clinical Trial. JAMA Pediatr. 2018 Dec 1;172(12):1126-1134. doi: 10.1001/jamapediatrics.2018.3082.

Gould, JF, Treyvaud, K, Yelland, LN, et al. Seven-year follow-up of children born to women in a randomized trial of prenatal DHA supplementation. JAMA. 2017 Mar 21;317(11):1173-1175. doi: 10.1001/jama.2016.21303

US20180352845 NUTRITIONAL COMPOSITIONS AND INFANT FORMULAS TO PROMOTE MYELINATION IN THE BRAIN. https://patentscope.wipo.int/search/en/detail.jsf;jsessionid=A68D9548DCE900B35E8EC24AB5AE94AB.wapp2nA?docId=US234727545&recNum=458&office=&queryString=&prevFilter=&sortOption=Pub Date Desc&maxRec=72849988. Accessed May 1, 2019

Grip T, Dyrlund TS, Ahonen L, et al. Serum, plasma and erythrocyte membrane lipidomes in infants fed formula supplemented with bovine milk fat globule membranes. Pediatr Res. 2018 Nov;84(5):726-732. doi: 10.1038/s41390-018-0130-9.

Markhus MW, Dahl L, Moe V, et al. Maternal Iodine Status is Associated with Offspring Language Skills in Infancy and Toddlerhood. Nutrients. 2018 Sep 9;10(9). pii: E1270. doi: 10.3390/nu10091270.

Dold S, Zimmermann MB, Baumgartner J, et al. A dose-response crossover iodine balance study to determine iodine requirements in early infancy. Am J Clin Nutr. 2016 Sep;104(3):620-8. doi: 10.3945/ajcn.116.134049.

Santiago P, Velasco I, Muela JA, et al. Infant neurocognitive development is independent of the use of iodised salt or iodine supplements given during pregnancy. Br J Nutr. 2013 Sep 14;110(5):831-9. doi: 10.1017/S0007114512005880.

Wu M, Wu D, Wu W, et al. Relationship Between Iodine Concentration in Maternal Colostrum and Neurobehavioral Development of Infants in Shanghai, China. J Child Neurol. 2016 Aug;31(9):1108-13. doi: 10.1177/0883073816639378.

Levie D, Korevaar TIM, Bath SC, et al.  Association of maternal iodine status with child IQ: a meta-analysis of individual-participant data. J Clin Endocrinol Metab. 2019 Mar 28. pii: jc.2018-02559. doi: 10.1210/jc.2018-02559.

Office of Dietary Supplements – Iodine. NIH Office of Dietary Supplements. https://ods.od.nih.gov/factsheets/Iodine-HealthProfessional/#en2. Accessed May 1, 2019

Alexander L. Carlson, Kai Xia, et al. Infant Gut Microbiome Associated with Cognitive Development. Biol Psychiatry. 2018 Jan 15; 83(2): 148–159.

Koob M, Viola A, Le Fur Y, et al. Glutamine plus Glutamate, and Macromolecules Are Decreased in the Central White Matter of Premature Neonates around Term. PLoS One. 2016 Aug 22;11(8):e0160990. doi: 10.1371/journal.pone.0160990

Keunen K, van Elburg RM, van Bel F, et al. impact of nutrition on brain development and its neuroprotective implications following preterm birth. Pediatr Res. 2015 Jan;77(1-2):148-55. doi: 10.1038/pr.2014.171.

de Kieviet JF, Oosterlaan J, van Zwol A, et al. Effects of neonatal enteral glutamine supplementation on cognitive, motor and behavior outcomes in very preterm and/or very low birth weight children at school age. Br J Nutr. 2012 Dec 28;108(12):2215-20. doi: 10.1017/S0007114512000293

Tanaka K, Hosozawa M, Kudo N, et al. The pilot study: Sphingomyelin-fortified milk has a positive association with the neurobehavioural development of very low birth weight infants during infancy, randomized control trial. Brain Dev. 2013 Jan;35(1):45-52. doi: 10.1016/j.braindev.2012.03.004. 

Grip T, Dyrlund TS, Ahonen L, et al. Serum, plasma and erythrocyte membrane lipidomes in infants fed formula supplemented with bovine milk fat globule membranes. Pediatr Res. 2018 Nov;84(5):726-732. doi: 10.1038/s41390-018-0130-9.

 

What Can We Expect from Input Enhancement?

Introduction
Today, it is generally accepted that target grammatical form of L2 (second language) must be noticed to make acquisition happens and that SLA (second language acquisition) instruction must be integrated into language teaching by which the grammatical forms are presented to learners in meaningful context.
IE (Input Enhancement), coined by Sharwood Smith (1991), is a deliberate manipulation to make specific grammatical features of L2 more salient. First of foremost, this technique underscores the fundamental role of input in language teaching. Likewise, the purpose of IE is to draw learners’ attention to target linguistic form in L2 input.
According to Sharwood Smith (1991), learners could be led to noticing target form in two ways: Input Flood (IF) and Textual Enhancement (TE). Through IF, Sharwood Smith (1991) demonstrated the basic idea that the more frequent the exemplars of the target form appear in the input, the more likely the learners will notice the form. In other words, IF manipulates input by saturating L2 linguistic data with target form to draw learners’ attention.
On the other hand, TE is a technique of manipulating the typographical features of a written text to increase the perceptual salience of target grammatical form. The typographical cues such as changing the font style, enlarging the character size, underlining, bolding, capitalizing, and highlighting with colours could be used.
However, the question underpins the concept of IE is: Is it sufficient by exposing L2 manipulated input to learners? This question leads to further investigation as learners might not necessary parse the linguistic structure or make form-meaning connection. Therefore, a more specific question emerges: How effective is IE?
Based on above discussion, this essay will argue that IE plays facilitative role in L2 learning. The purpose of this essay is to depict what aspects of IE could be fruitfully applied to design a language teaching activity. Review on the key empirical studies of IE will be presented in this essay. Throughout, advantages and limitations of IE will be identified within theoretical frameworks which underpin the stance. Then, we will describe how to overcome the shortfalls of IE by integrating IE with other interventions into classroom language teaching. Finally, IE implications and limitation on language teaching will be reiterated as conclusion.
Before discussing the findings and implication of IE, we will first examine several
input and noticing issues in SLA field.
Input and Noticing Issues in SLA Research
Wong (2005) defines of input as “samples of language that learners are exposed to in a communicative context or setting” (Wong, 2005:119). At the same time, VanPatten (2003) describes input as “the language that a learner hears (or reads) that has some kind of communicative intent” (VanPatten, 2003: 25). It is clearly to note that both definitions emphasise the terms of “communicative”. As claimed by VanPatten (2003), learners play communicative role to extract the meaning encoded in the meaning-bearing utterance or sentence. Through these interpretations, we could come to a understanding that L2 learning process engages learners as active participants in a communicative language classroom when they are exposed to L2 input.

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Despite of communicative value of input, it is generally agreed that input is prerequisite for L2 acquisition. However, there is a need to explore whether manipulation is essential to mediate input into intake. Perceivably, the distinction between input and intake has been drawn in SLA literature. For example, Sharwood Smith (1993) defines input as “the potentially processable language data which are made available by chance or by design, to the language learner” whereas intake as “that part of input that has actually been processed …and turned to knowledge of some kind” (pp.167). This interpretation leads to ongoing debate about the role of consciousness and unconsciousness mechanism in learning process. Despite extensive research, it still remains controversial as to what type of cognitive mechanism is necessary for acquisition to occur (Svalberg, 2007: 289).
Firstly, Krashen (1982) draws a distinction between “learning” and “acquisition”. Learning is the result of conscious process whereas acquisition is the product of subconscious process. According to Krashen’s (1982) strong Input Hypothesis, acquisition takes place when learners are exposed to comprehensible input which is a step more advanced than their current proficiency level. This perception not only implies that input is prerequisite for acquisition process, subconscious process also plays superior role compared to conscious process. In such a case, grammar instruction plays no role in L2 acquisition (Krashen, 1982).
Comprehensible Input Hypothesis has thus provokes considerable debate in SLA domain. Among the researchers, Schmidt (1990), contrary to Krashen’s (1982) hypothesis, postulates that conscious awareness is crucial and necessary for L2 acquisition (p.27). According to Schmidt (1995: 20), only input noticed by learners will be mediated into intake. In contrast, disagree with Schmidt’s (1990) strong Noticing Hypothesis, Tomlin & Villa (1994) posit that unconscious detection is the key process whereas conscious awareness only play facilitative role in L2 learning.
Schmidt (1990) outlines six factors influencing noticing when learners process the input, including perceptual saliency of input, frequency of input, instruction, task demands, readiness of learner and processing capacity of learner. During the ongoing debates between the two positions, Sharwood Smith (1993) proposes IE techniques which are linked to Schmidt’s Noticing Hypothesis. IE techniques emphasise on the qualities of input, namely TE (related to input saliency) and IF (related to input frequency). Hereby, we could claim that the rationale for Sharwood Smith’s (1993) IE is driven by Schmidt’s (1990, 1995) Noticing Hypothesis. That is, Noticing Hypothesis is the theoretical basis for IE.
From this point, the debate has indubitably shifted away from general question of “Is noticing necessary?” to more specific questions of “How noticing influence the learning outcome?” and “How intervention facilitate constrained grammar acquisition process?” However, before we claim that IE is efficacy to facilitate L2 acquisition, we need to examine major empirical evidences in SLA research to justify our view on Sharwood Smith’s notion.
Empirical Evidence of IE
As mentioned before, the underpinning theoretical framework for IE is Schmidt’s (1990, 1995) Noticing Hypothesis. Although Noticing Hypothesis remains controversial, linguists’ (e.g. Alanen, 1995; Lee, 2002; Shook, 1994; White, 1998; Wong, 2001) has accumulated evidence over the last decade due to its important role in shedding light on how salient input can contribute to the acquisition of L2 target form.
In this section, we will discuss the advantages and limitations of IE by reviewing empirical SLA studies on IF and TE. Various perspective of effectiveness such as degree of noticing, intake of forms, accurate production of forms and content comprehension will be examined along the discussion.
Input Flood
Empirical Evidence: Input Flood has positive effects
Lee (2002) investigated the effects of input frequency on the incidental acquisition of Spanish future tense morphology. The subjects were 283 university students with different L1 backgrounds. The frequency of target form appeared in the input passages were 6, 10 and 16 exposures. In immediate post-test, he found frequency has positive effects on the comprehension and intake. In both immediate and delayed post-tests, 16F group outperformed 10F and 6F group significantly.
White (1998) investigated the comparison effects of IF and TE on the acquisition of English possessive determiners (PD). 86 French children were divided into 3 treatment groups: textual enhanced input flood (IF-TE group), textual enhanced input flood plus extensive reading and listening (IF-TE+ group) and input flood without enhancement (IF group). In oral picture description task, all subjects experienced improvement. For the frequency of grammatical use, IF-TE+ significantly outperformed the IF-TE and IF group. However, there is no significant difference between IF-TE group and IF group.
Empirical Evidence: Input flood has limited effects
Trahey & White (1993) investigated the effects of IF (positive evidence) on the acquisition of English adverb placement. Subjects were divided into 3 groups: IF group was given flooded positive evidence; IF-EI (A) group received flooded positive evidence and explicit instruction; IF-EI (Q) group received explicit instruction on question formation. They found IF group and IF-EI (A) group performed significantly better than IF-EI (Q) group on using correct word order. However, the results also revealed that IF group and IF-EI (Q) group used incorrect word order more than the IF-EI (A) group.
Williams & Evans (1998) examined the effects of IF (positive evidence) and explicit
instruction on two English target forms: participial adjectives and the passive construction. The university students were divided into 3 groups: IF group received IF with no explicit instruction; IF-EI group received IF and explicit instruction on the forms, rules instruction and corrective feedback; and control group. For the participial adjective, both IF and IF-EI groups showed improvement. However, IF-EI group had significant higher score than IF group. This suggested that explicit instruction had greater effects than IF on this form. For the passive construction, both IF-EI and IF groups made greater improvement than the control group. However, there was no significant difference between IF-EI and IF groups. This suggested that explicit instruction has no greater effect than IF on this target form.
Advantages of Input Flood
Firstly, Sharwood Smith (1993, 2006) claims that the main purpose of IE is to enforce noticing. Studies show that IF increases learners’ attention on target forms without any explicit guidance. This incidental-driven technique provides linguistic materials that are essential for learning problem solution (Doughty & William, 1998: 236). This statement is validated by Lee’s (2002) and White’s (1998) study. The findings supports the basic idea of IF that the more exemplars in a flood the better.
Secondly, IF enhances content comprehension. The major advantage of IF is that it provides a lot of meaning-bearing input (Wong 2005: 42). With the availability of meaning-bearing input, learners are provided opportunities to capture the meaning embedded in words, syntax or morphology. In both immediate and delayed post-test, Lee (2002) found that input frequency has significant positive effects on the comprehension. Thus it could be noticed that through the exemplar-based and implicit learning method, learners could perform form-meaning connection and manage to penetrate the meaning of the message.
Thirdly, IF fosters the intake of the target form. Lee’s (2002) study reported 16F group outperformed 10F and 6F group significantly in post-test. For recall task, 16F and 10F groups performed significantly better than 6F group. Results of oral picture description task in White’s (1998) study also revealed that all subjects experienced improvement in the use of English PD. However, there was no significant difference between IF-TE group and IF group, indicating that IF alone was sufficient to bring improvement whereas TE played no significant role on the correct use of the target form.
Limitation of Input Flood
First of all, studies reported that IF is a volatile technique. Findings from Williams & Evans (1998) study suggested that forms did not behaviour uniformly in IF technique. Different form types can weaken or strengthen the effect of IF through their mutual interaction, as well as the interaction with other variables such as task requirement, individual differences, content complexity, and pragmatic information in the context (Han, Park & Combs, 2008). Thus further investigation on how to eliminate or reduce the effect of the variables when using IF is worthwhile.
Secondly, IF does not provide negative evidence. Trahey & White’s (1993) study revealed the limitation of IF that the flood was not effective in helping learners to be aware of impossible positions or incorrect grammar (Wong, 2005) and explicit instruction such as negative evidence might be necessary.
This situation was also demonstrated in White (1998) study, as subjects’ frequency use of English PD was increased by TE, but both IF and TE did not have help learners to use the grammatical form correctly. That is, no significant difference was found for the accuracy ratio between IF group, IF-TE group and IF-TE plus extensive reading and listening group. However, when measuring the frequency of grammatical use, IF-TE plus extensive reading and listening group significantly outperformed the IF-TE and IF group. These findings suggest that comprehensible input might be more effective than IE in the acquisition of English PD agreement rules. Again, this issue still remains controversial and is worth further investigation as Krashen’s Comprehensible Input Hypothesis is refuted by mostly SLA researchers.
Nevertheless, this phenomenon might be explained by the statement that comprehension precedes production (Lightbown et al, 2002; Krashen, 1982). Wong (2005: 94) cautions that acquisition is slow and complex hence we could not expect learners to use target form correctly immediately after IE treatment.
Thirdly, Input Flood is an implicit technique where no effort is done to direct learners to the embedded forms in the input (Wong, 2005). White’s (1998) study reported that a third of learners were confused about the purpose of the textual enhancement. The textually enhanced input failed to help the learners to figure out the English PD agreement rule.
As seen from empirical evidence, IF is an easy-to-use technique. It could be modified and incorporated easily in the classrooms to emphasize specific target form (Cowan, 2008). However, IF imposes some limitations on language teaching pedagogy which is not as effective as other focus-on-form activities. The discussion of how to apply this technique in language teaching will be demonstrated in next section of this essay.
Textual Enhancement
Like IF, SLA studies on TE also report mixed results. Researchers found that TE has positive effects, has partial effects, and has no effect on L2 acquisition of grammatical features. While Leow (2001) and Leow at al. (2003) have only manipulated the input by TE as an independent variable, the other studies investigated effects of TE in the combination with other intervention.
Empirical Evidence: Textual enhancement has positive effects
Studies conducted by Jourdenais et al. (1995), Shook (1994), Wong (2001) revealed that TE had not only helps learners to notice the target forms in input, but it is also very effective for enhancing learners’ intake new grammatical forms.
Shook (1994) investigated the effects of TE on Spanish present perfect tense and relative pronouns (quen/quein). The subjects were 125 university students. The results revealed that the two experimental groups who received the passages with TE performed significantly better than the control group in all tests. However, there was no significant difference between TE group and TE plus focus on form group, revealing that focus on form information played no role in L2 acquisition.
Jourdenais et al.’s (1995) investigated the effects of TE on the acquisition of Spanish preterite and imperfect past tense forms. Both enhanced and unenhanced versions came with pictures depicting the events of the story. Think-aloud protocols and a picture-based written narration task were used to collect data. Results indicated that TE increased noticing of target L2 form and had a significant positive effect on learners’ output.
Empirical Evidence: Textual enhancement has limited effects
Alanen (1995) examined the effects of TE and explicit information on the acquisition of semi-artificial Finnish locative suffixes and consonant changes. 36 English subjects were divided into 4 groups: unenhanced passages (UE group), unenhanced passages plus explicit information (UE-EI group), enhanced passages (TE group) and enhanced passages plus explicit information (TE-EI group). On the sentence completion test, TE group performed better than UE group. However, Alanen (1995) found that both EI groups performed significantly better than non-EI groups on both target forms. The result, contradict with Shook’s (1994) study, indicated that explicit grammar instruction had greater positive impact than TE.
Results from White’s (1998) study, discussed in the previous section of IF, revealed that TE increased the grammatical use of possessive determiners. However, its impact was not as significant as IF which brought greater improvement. White (1998) concluded that “benefits resulting from the experimental treatment conditions were due to increased exposure through IF of target forms and not to any other kinds of enhancement” (White, 1998: 103). This claim means IF is the only effective tool to enhance L2 acquisition in her study is.
Izumi (2002) investigated the comparative effects of TE and output on the acquisition of English relative clause. Subjects were 61 adults with different L1 backgrounds. Explicit information was given to the subjects to attend to the highlighted form. The results found that output-input task brought measurable gains in target form acquisition. Those who received TE treatment failed to show significant gains in acquisition.
Wong (2001) examined the effects of TE, simplified input and exposure to reading on the acquisition of French gender agreement of past participles. 81 English university learners were respectively exposed to four conditions: enhanced and simplified passages (TE-S group), enhanced and unsimplified passages (TE-US group), unenhanced and simplified passages (UE-S group), and unenhanced and unsimplified passages (UE-US group). It is found that TE and simplification had no significant effects on the intake of the target forms. However, TE had significant positive effects on the content comprehension.
Empirical Evidence: Textual Enhancement has no (or negative) effects
In Leow’s (1997) study the effects of textual length and TE were examined. 84 college learners were divided into 4 groups and were accordingly given an unenhanced long passage, an unenhanced short passage, an enhanced long passage and an enhanced short passage. Results revealed that TE has no effects on either comprehension or intake of the targeted form. Shorter text length improved comprehension but not the intake.
Overstreet (1998) replicated Jourdenais et al.’s (1995) study and found negative effects of TE. He combined two factors, namely TE (bolded, underlined, increased font size, different font types and shadowed) and topic familiarity on the acquisition of Spanish preterite and imperfect past tense forms. 50 university learners were given one story each, either enhanced or unenhanced. Neither factor significantly affected learners’ intake. Moreover, Overstreet (1998) found that TE negatively affected comprehension, mainly due to numerous types of enhancements (Lee & Benati, 2007: 25).
Leow (2001), after a few years of his study in 1997, conducted another study to investigate effect of TE on the acquisition and comprehension of Spanish formal imperative. He did not apply other invention but only TE in this study. The results once again revealed TE has no effects on intake and comprehension.
Leow et al. (2003) examined the effects of TE on the acquisition of Spanish present perfect tense and present subjunctive mood. 72 university learners were divided into two groups. One group was given 2 enhanced passages and another group was given 2 unenhanced passages. Results showed that although subjects noticed the target forms when reading, TE did not enhance the intake of the target forms.
S.Lee (2007), similar to Overstreet’s (1998) study, examined the effects of TE (±TE) and topic familiarity (±F) on English passive construction. 259 Korean subjects were divided to 4 groups: +E/+F group, -E/-F group, -E/+F group and +E/−F group. The results revealed that TE was beneficial for the intake of target form, but interestingly, negatively affected the comprehension.
Advantages and Limitations of TE
Some of above studies demonstrated that TE has significant impact on SLA, either in positive or negative ways.
First of all, TE increases noticing. This technique offers more salient target form in written input that learners may easily miss (Wong, 2005: 49). Jourdenais et al. (1995) stated that “typographical modification can be used as an effective technique for enhancing salience of language features” (Jourdenais et al., 1995: 208). As evidence, both Leow et al. (2003) and Jourdenais et al. (1995) used think aloud protocols and reported that subjects noticed the typographically enhanced target forms when reading.
Second, TE is effective to enhance intake of forms. For example, Alanen (1995)’s study reported that TE group performed better than UE group in sentence completion test. This indicates the positive role of TE on the acquisition of L2 grammar. Jourdenais et al. (1995) also reported that TE had a significant effect on learners’ output.
By contrast, TE failed to demonstrate positive impact on learners’ comprehension and intake in Leow’s (1997, 2001) and Overstreet’s (1998) studies. These studies demonstrated that “implicit noticing” is not as effective as “explicit instruction” and that, “clearly, learners needed more help than the input provided” (White, 1998: 102).
Also, although subjects in both Leow et al.’s (2003) and Jourdenais et al.’s (1995) studies noticed the enhanced target forms, they performed differently in production. Jourdenais et al. (1995) found positive effect of TE on the intake of the target forms whereas Leow et al. (2003) reported that TE did not enhance the intake of the target forms.
In addition, Izumi (2002) found that subjects who received TE treatment failed to show significant gains in acquisition, despite the positive impact on the noticing of the target form. More interestingly, output played significant role in his study.
These findings are contradicted to Ellis (1997) claim that TE is effective to induce learners “to undertake a kind of form function analysis of the structure, as this is exemplified in input that has been specially contrived to illustrate it” (Ellis, 1997: 87). Therefore Polio (2007) states that Sharwood Smith’s focus was “what had been done to the input”, rather than “what happened in learner’s mind” (Polio, 2007, cited in Gass & Selinker, 2008: 388).
However, this notion is inaccurate that Sharwood Smith (1991, 1993) has alerted that we should not rely solely on TE to increase learners’ attention. Noticing triggered artificially by TE might not result in intake. “Although learners may notice the signals, the input may nevertheless be non-salient to their learning mechanism” (Sharwood Smith, 1991: 21). As Ellis (1997) describes the use of TE focuses learners’ attention on specific linguistic features and assists them to encode the meaning embedded in the features, it is suggested here that TE should be integrated with other interventions for better result.
Third, TE enhances comprehension. In Wong (2001)’s study, TE had significant positive effects on the content comprehension, namely it enhanced the recall of the idea units that corresponded to the target forms.
However, evidence from Overstreet’s (1998) and S.Lee’s (2007) studies suggested TE distracted learners’ attention from meaning. The results indicated that TE has negatively affected learners’ comprehension on the content of the passages. In spite of increasing evidence suggesting that TE can promote noticing of certain linguistic features, it remains a matter a debate whether or not it has simultaneously created a trade-off between intake and comprehension (Han, Park & Combs, 2008).
Also, Simard (2009) cautioned that selection and combination of different typographical cues lead to different impacts on the intakes. His study reported that the use of capital letters and a combination of 3 typographical cues promote the intake of the forms. Overstreet’s (1998) use of numerous types of typographical cues might lead to distraction and confusion thus did not enhance the acquisition. Therefore, in order to ensure the quality of instructional material, language teachers should select cues carefully.
Fourth, TE is a volatile and changeable technique. In other words, external variables may affect the effectiveness of TE. For example, with no prior knowledge about the target forms, the technique is not beneficial to learners (e.g. Leow, 1997, 2001; Leow et al. 2003). Alanen’s (1995) study also reported that TE had different effects on different target grammatical forms.
Age and puberty are other factors that might mitigate the effects of TE. In White’s (1998) study, the children who are still developing their L2 may have encountered a cognitive overload problem (Doughty & William, 1998) and therefore constrained the learning process.
Clearly, conflicting results on the impact of IE on acquisition, whether positive, limited or negative, are noticeable from previous studies. Several questions emerged subsequently from the review: are these mixed results attributed to different methodological designs that provide learners different degree of input quality and quantity? Or is it due to different grammatical forms targeted in different studies? If so, does this mean that different target forms are vulnerable variable that correspond to IE techniques in different ways? These insights are meaningful and important for the implication of IE in language pedagogy and will be discussed in following section.
Pedagogical Implications
Nowadays it is common for language teachers to use IE techniques to enhance specific features of L2 in order to draw learners’ attention to target linguistic aspects. Although IE does not provide full and consistent picture to SLA pedagogy, it offers valuable information on how to deliberately draw learners’ attention to target forms.
As shown, uncertainties still exist on the facilitative role of IF and TE in SLA research. The debate on Noticing Hypothesis still remains open while previous studies failed to show conclusive and consistent results on IE effectiveness. However, fortunately, the field has moved from the debate on the necessity of conscious noticing to the mixed results of IE efficacy. That is, the theoretical development has now provided a clearer window to take a glimpse and imply IE techniques more effectively to language pedagogy with underpinning SLA issues.
In contrast with UG, IE is a sub-field of cognitive models which emphasis on how learners process and decode the input. It should be borne in mind that noticing triggered artificially by IE might not result in intake. This implies that one cannot be assured if the enhanced input will become comprehensible and that the effects of IE vary from case to case.
In terms of Input Hypothesis (Krashen, 1982), we argues that input play roles in L2 acquisition with the aids of noticing. As stated by Wong (2005), once target form is noticed, learners need to make form-meaning connection to encode underlies linguistic rules correctly (p.90-91). This notion is in line with VanPatten’s (1996, 2003) input processing theory where “intake” is equalised to “form-meaning connection”. Thus IE and other focus on forms tasks such as processing instruction (VanPatten, 1996, 2003) and consciousness-raising tasks might be combined in language teaching for better results.
Also, it is reckoned that output tasks might be integrated into SLA instruction when applying IE concept. Long (1996) distinguishes two types of input: positive evidence and negative evidence. In coherence with Long’s notion, Sharwood Smith (1993) proposed both positive and negative IE techniques. IE and TE are positive IE whereas negative IE is basically feedback or negative evidence.
When there is a gap between learners’ perception of L2 grammar and evidence in the input, then positive evidence (input) may triggers to change the grammar (Sharwood Smith, 1991: 122-123). On the other hand, when learners are being confronted with their own production (output), negative IE signals that given forms are incorrect, thus warns learners that they have violated the grammatical rules (Sharwood Smith, 1993: 177). This notion implies that IE approach not only adopts Schmidt’s Noticing Hypothesis as major foundation, but has also implies Long’s Interaction Hypothesis as well as Swain’s (1995) Output Hypothesis. Apparently, Sharwood Smith proposal of negative evidence has been generally neglected by SLA researchers. Therefore, it would be beneficial if language teachers reckon that input (positive evidence) and output (negative evidence) are both important to promote acquisition with the aid of noticing.
Particularly, Ellis (1997: 109) asserts that comprehensible input is derived from both input and interactional (output) modifications makes specific linguistic features more salient and facilitates the development of L2. Negotiate for meaning is thus beneficial to promote acquisition. It directs learners’ attention to focus on the form that initially caused understanding problems and also helps learners to modify their interlanguage production whenever the gap is being identified (Long, 1983; Pica, 1992).
Likewise, Wong (2005) suggested that input should not be one-way instruction, namely simply giving input to L2 learners. Learners may be instructed to respond to the input through activities such as quiz, answering questions, story reconstructing, drawing based on oral directions and games. Hereby, “interaction” has been stressed in order to make the IF more meaningful to the learners.
As pointed out by Wong (2005: 46, 60-61), instructors must always keep meaning communication as primary goal of language in attempts of enhancing the input. Attending to both meaning and form is important to make form-meaning connections possible. By this way, respond to the input is a crucial compartment for language learning. This insight is compatible to Ellis’ (1997) claim that input-based interpretation grammar instruction mediates input into intake.
Accordingly, Lee & VanPatten’s (1995: 51) proposal to use learners and classroom setting for language teaching could be combined with IE in a communicative language classroom.
Instructors might integrate grammar teaching into authentic context. For example, input could be presented to learners through If visually and verbally in a natural classroom setting. It will be beneficial if simple scenarios could be constructed.