• Journal of the Institute of Convergence Signal Processing
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• v.5 no.2
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• pp.165-171
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• 2004

Owing to small sizes and high density to the semiconductor It, it is difficult to discriminate the defects of ICs by human eyes. High precision inspection system with computer vision is essentially established for the manufacturing process due to the variety of defective parts. Especially it is difficult to implement the algorithm for the coplanarity of IC leads. Therefore in this paper, the inspection system which can detect the defects of the SOP types of ICs having 1cm${\times}$0.5cm of the chip size is implemented and evaluated it's performance. In order to optimally detect various items, some principles of geometry are theoretically presented , length measurement, pitch measurement, angle measurement, brightness of image and correcton of position. The interface circuit is designed for implementation of inspection system and connected the HANDLER. In the result, the system could detect two ICs' defects per second and confirmed the resolution of 20$\mu$m per pixel.

• Journal of Satellite, Information and Communications
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• v.6 no.2
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• pp.72-77
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• 2011

Spectrum sensing is a critical functionality of CR network; it allow secondary user to detect spectral holes and to opportunistically use under-utilized frequency bands without causing harmful interference to primary use. Recently, wideband service has been increase for processing abundance of data traffic. So CR network needs a realizable implementation design of spectrum sensing for wideband. To get high resolution performance of wideband sensing must precede algorithm processing for reliability signal detection. By the way, the performance of spectrum sensing can be degraded due to fading and shadowing. In order to overcome this problem, we propose system model of wideband sensing scheme on energy detected collaborative technique. we divide wideband into narrowbands and use narrowbands to detect signal excepting some narrowbands including bad channel through the CSI. And we simulate and analyze in terms of detection probability with various SNR.

• The KIPS Transactions:PartA
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• v.13A no.4 s.101
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• pp.295-304
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• 2006

Java has been established as one of the most widely-used languages owing to its support of object-oriented concepts, safety, and flexibility. Garbage collection in the Java virtual machine is a core component that relieves application programmers of difficulties related to memory management. In this paper, we propose a memory manager and a garbage collector that is implemented on a embedded java virtual machine. The memory manager divide a heap into various-sized cells and manages it as blocks of same-sized cells. So it is possible to allocate and free memory fast. We adopted the 3-color based Mark & Sweep garbage collector as our base algorithm and we propose 4-color based Mark & Sweep garbage collector for supporting multi-threaded program. The proposed garbage collector occurs memory fragmentation but we show through a experiment that the fragmentation ratio is almost fixed according as we create objects continuously.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.13 no.1
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• pp.1-7
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• 2020

Directivity control technology of sound system is a key technology for improving sound quality. Providing a line source rather than a point source in an acoustic system can reduce the effects of attenuation interference at long distances, thereby providing high quality sound. In particular, A line-array speaker system can be used to provide coherent, high-quality sound over long distances. However, high frequencies have shorter wavelengths, so the distance between the speakers of a line array system must be shorter, but there are physical limitations. In this paper, we designed a wave guide and installed it in the speaker's compression driver to solve this problem. We measured and tested various acoustic characteristics to verify the performance of the speaker. As a result, when the line array sound system is constructed using the developed speakers, it is possible to provide a line source in all areas including the treble range, thereby achieving the same effect as a single extended source and providing high quality sound up to far distances.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.2 no.2
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• pp.45-50
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• 2009

This paper presents an active vision system for on-line traffic sign recognition. The system is composed of two cameras, one is equipped with a wide-angle lens and the other with a telephoto lends, and a PC with an image processing board. The system first detects candidates for traffic signs in the wide-angle image using color, intensity, and shape information. For each candidate, the telephoto-camera is directed to its predicted position to capture the candidate in a large size in the image. The recognition algorithm is designed by intensively using built in functions of an off-the-shelf image processing board to realize both easy implementation and fast recognition. The results of on-road experiments show the feasibility of the system.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.2
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• pp.304-309
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• 2004

Recently, the needs for multimedia stream such as digital audio and video in the Internet has increased tremendously. Unlike TCP, the UDP protocol, which has been used to transmit streaming traffic thorough the Internet, does not apply any congestion control mechanism to regulate the data flow thorough the shared network And it leads to congestion collapse of the Internet and results in long-term transmission delay. To avoid any adverse effect on the current Internet functionality, a now protocol of modification or addition of some functionality to perform congestion control and to reduce huge transmission delay in transmitting of multimedia stream are in study. TCP-friendly congestion control mechanism is classified into two : one is window-based congestion control scheme using general window management functionalities, the other is rate-based congestion control scheme using TCP modeling equation. In this paper, we propose an algorithm for improving the transmitting rate on a hybrid TCP-friendly congestion control scheme combined with widow-based and late-based congestion control for multimedia stream. And we also simulate the performance of improved TEAR implementation using NS. With He simulation results, we show that the improved TEAR can provide better fairness and lower rate fluctuations than TCP.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.2
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• pp.509-515
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• 2004

Pulmonary function tests are widely used to diagnose and determine patients' therapy in clinic. And it was also applied in the research of the physiology and dynamics for lung disease. Among the pulmonary function tests, spirometry is the most easy and economic test. Spirometers are medical instruments that measure the instantaneous rate of volume flow of respired Bas. The mechanical spirometer was mostly used in the past. Up to the present, the most popular method of spirometer is the differential pressure technique with which change in the volume of flow are transferred to change in pressure. This kind of instrument suffers from several limitations, pressure drop, difficulty in maintenance and short period of calibration. Therefore, this study has begun to implement ultrasound spirometer, which is free of pressure loss and has wide range, focusing on the flow measurement technique and diagnostic algorithm.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.11
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• pp.2697-2702
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• 2015

In the existing studies providing a method which do exercise according to music speed, the method was used which a user changes playing musics. However, if the method which a user changes directly playing musics is used, flow of exercise can be discontinued during searching musics when anyone want to play a fast music. In this paper, we designed the module which measures the number of steps from a user of wearable smart shoes based on the Arduino, and implemented the module so that the number of steps can be measured correctly by sending data to smart phone based on Android. And it is possible to measure moving distance and pace speed by utilizing a GPS in order to get the more accurate momentum. Also, we can measure more accurate calorie consumption than existing products by measuring the mean value of the calorie consumption for moving distance and the calorie consumption for the number of steps, give motivation of exercise by applying an algorithm of changing music genre according to pace speed, and increase the exercise effect at the same time.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.2
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• pp.317-322
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• 2015

Recently, due to the variety and complexity of marine electronics communication devices, much research has been done to adopt the novel communication protocol. Among them, NMEA2000 protocol, is adopted as standardized protocol to the next generation ship. In this paper, we design and implement the conversion algorithm for sensor protocol based on NMEA2000, and analog data module which convert data format between NMEA2000, CAN, Ethernet, RS232. The present study was designed to implement user-based data monitoring system by supporting various communication protocols through the development and application of key technologies through NMEA2000.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.11
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• pp.2113-2118
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• 2016

Smart Jewelry is applied to the components of the Internet of Things. The process of obtaining the status information to the input of the sensor. And it controls the light color of the LED. Because to express the beauty of twinkling lights that can be felt in the jewelery and aesthetic functions were applied in order to feel the mystery. Smart Jewelry is capable of communication, interaction, wearable. Smart jewelery was equipped with a color, temperature, ambient light sensor. It was designed to allow interaction with a Bluetooth module. Applying an algorithm so that the light jewelry colors can vary depending on the circumstances of the smart jewelry wearer had been implemented by the mobile application. It can be realized in digital technology and the convergence of life. It presents the orientation development of the smart jewelery device on IoT environment.