Jai-Eun Kim

Color-Space-Based Visual-MIMO for V2X Communication

In this paper, we analyze the applicability of color-space-based, color-independent visual-MIMO for V2X. We aim to achieve a visual-MIMO scheme that can maintain the original color and brightness while performing seamless communication. We consider two scenarios of GCM based visual-MIMO for V2X. One is a multipath transmission using visual-MIMO networking and the other is multi-node V2X communication. In the scenario of multipath transmission, we analyze the channel capacity numerically and we illustrate the significance of networking information such as distance, reference color (symbol), and multiplexing-diversity mode transitions. In addition, in the V2X scenario of multiple access, we may achieve the simultaneous multiple access communication without node interferences by dividing the communication area using image processing. Finally, through numerical simulation, we show the superior SER performance of the visual-MIMO scheme compared with LED-PD communication and show the numerical result of the GCM based visual-MIMO channel capacity versus distance.

LEA Detection and Tracking Method for Color-Independent Visual-MIMO

Communication performance in the color-independent visual-multiple input multiple output (visual-MIMO) technique is deteriorated by light emitting array (LEA) detection and tracking errors in the received image because the image sensor included in the camera must be used as the receiver in the visual-MIMO system. In this paper, in order to improve detection reliability, we first set up the color-space-based region of interest (ROI) in which an LEA is likely to be placed, and then use the Harris corner detection method. Next, we use Kalman filtering for robust tracking by predicting the most probable location of the LEA when the relative position between the camera and the LEA varies. In the last step of our proposed method, the perspective projection is used to correct the distorted image, which can improve the symbol decision accuracy. Finally, through numerical simulation, we show the possibility of robust detection and tracking of the LEA, which results in a symbol error rate (SER) performance improvement.

Applicability of color-independent visual-MIMO for V2X communication

In this paper, we analyze the applicability of color-space-based color-independent visual-MIMO for V2X. We aim to achieve a visual-MIMO scheme that can maintain the original color and brightness while performing seamless communication. The visual-MIMO system will switch between multiplexing and diversity modes depending on distance. Considering the scenario of a multipath transmission based on our visual-MIMO model, we analyze the channel capacity numerically and we illustrate the significance of networking information such as distance, reference color (symbol), and multiplexing-diversity mode transitions.

Time-Sharing-Based Synchronization and Performance Evaluation of Color-Independent Visual-MIMO Communication

In the field of communication, synchronization is always an important issue. The communication between a light-emitting diode (LED) array (LEA) and a camera is known as visual multiple-input multiple-output (MIMO), for which the data transmitter and receiver must be synchronized for seamless communication. In visual-MIMO, LEDs generally have a faster data rate than the camera. Hence, we propose an effective time-sharing-based synchronization technique with its color-independent characteristics providing the key to overcome this synchronization problem in visual-MIMO communication. We also evaluated the performance of our synchronization technique by varying the distance between the LEA and camera. A graphical analysis is also presented to compare the symbol error rate (SER) at different distances.

Determination of threshold for IR image by using PICA with RBF neural network

This paper is about determining the threshold for a gray scale IR image. At first, Pixel Intensity Clustering Algorithm (PICA) is used to have the center for the Radial Basis Function (RBF) neural network. PICA clusters the image into a defined number. Every group has a centroid which has been used as RBF neural network center. The number of hidden neurons will also be equal to the number of clusters. We give the weight to the output of the hidden neurons on the base of the desired output and the neural network output will be a threshold value for the corresponding gray scale image. The simulation result gives us a clear idea about the desired result.

Synchronization method for color-independent visual-MIMO communication

An effective synchronization method is proposed that maintains color uniformity and ensures that the human eye is unable to detect flickering when using a general purpose commercial camera as a receiver for color-independent visual-MIMO communication.

Interactive Smart Fashion Using User-Oriented Visible Light Communication: The Case of Modular Strapped Cuffs and Zipper Slider Types

Because LEDs offer flexible expressions such as brightness, color control, and various patterns, they are popularly used in multidevice interactions. Moreover, LEDs have excellent physical characteristics. However, existing LED light-based wearable interactions are designed for interest and attention. So, LED can be used in fashion as it can give new look to our style and at the same time also as an interaction device. Therefore, in this paper, we present the design guideline for regulating the technical implementation, design strategies, and directions of interactive LED devices. The technology and design concepts are demonstrated through a case study (analysis) of an existing LED light-based wearable interaction. We also design a scenario-based iterative collaborative design process model. Finally, we develop a smart fashion of modular strapped cuffs and zipper slider types that can be attached and detached according to the user’s preference as the interactive smart fashion using user-oriented visible light communication, ultimately pursuing a visual-MIMO (Multiple-Input Multiple-Output) product through stepwise strategy.

Implementation of color-space-based wearable visual-MIMO system

As the demand for visible light communication (VLC) using the high-speed response characteristics of light-emitting diodes (LEDs) has increased, research on visual-multiple input multiple output (MIMO) processes, which refers to the communication between a LED array and a camera, has been conducted. Notably, LEDs are widely used as the means for interacting with wearable devices. In this paper, we present a wearable visual-MIMO system that combines wearable devices with a color-space-based visual-MIMO system that uses the LEDs of the wearable device as a means of communication. We also present a wearable visual-MIMO prototype and measure the symbol error rate (SER) to evaluate its practicality.

Detection and tracking of overtaking vehicle in Blind Spot area at night time

The BSD (Blind Spot Detection) is one of the key functions of ADAS (Advanced Driver Assistance System). In this paper, we propose an algorithm for detection and tracking a vehicle in blind spot area at nighttime. Since the appearance-based approach that can be used for BSD at daytime is not any more appropriate, a new feature of blobs that is due to the headlights of behind vehicle was adopted. In addition, we calculated the motion vectors of detected blobs and made headlight pairing by use of the projection map. We can successfully generate an alarm signal by tracking the vehicle in blind spot.

Reliable estimation of disparity map in textureless region of roadway

This study proposes a reliable disparity estimation method that plays an important role in stereo vision. Most of conventional disparity estimation algorithms have a critical weakness. They may generate erroneous results in monotonous or textureless areas such as roadways and hallways. To improve the reliability of estimated disparity in such areas, we select a textureless road area as a region of interest (ROI) and generate a synthetic disparity map which can be modelled by a simple gray-scaled gradation pattern according to the depth. Finally, we combine the conventional and synthetic disparity maps to generate a more reliable disparity map. Simulation results show that the disparity map constructed from the proposed algorithm is more reasonable and trustworthy.