A STUDY ON OXIDATION TREATMENT OF URANIUM METAL CHIP UNDER CONTROLLING ATMOSPHERE FOR SAFE STORAGE

Kim, Chang-Kyu,Ji, Chul-Goo,Bae, Sang-Oh,Woo, Yoon-Myeoung,Kim, Jong-Goo,Ha, Yeong-Keong Korean Nuclear Society 2011 Nuclear Engineering and Technology Vol.43 No.4

The U metal chips generated in developing nuclear fuel and a gamma radioisotope shield have been stored under immersion of water in KAERI. When the water of the storing vessels vaporizes or drains due to unexpected leaking, the U metal chips are able to open to air. A new oxidation treatment process was raised for a long time safe storage with concepts of drying under vacuum, evaporating the containing water and organic material with elevating temperature, and oxidizing the uranium metal chips at an appropriate high temperature under conditions of controlling the feeding rate of oxygen gas. In order to optimize the oxidation process the uranium metal chips were completely dried at higher temperature than $300^{\circ}C$ and tested for oxidation at various temperatures, which are $300^{\circ}C$, $400^{\circ}C$, and $500^{\circ}C$. When the oxidation temperature was $400^{\circ}C$, the oxidized sample for 7 hours showed a temperature rise of $60^{\circ}C$ in the self-ignition test. But the oxidized sample for 14 hours revealed a slight temperature rise of $7^{\circ}C$ representing a stable behavior in the self-ignition test. When the temperature was $500^{\circ}C$, the shorter oxidation for 7 hours appeared to be enough because the self-ignition test represented no temperature rise. By using several chemical analyses such as carbon content determination, X-ray deflection (XRD), Infrared spectra (IR) and Thermal gravimetric analysis (TGA) on the oxidation treated samples, the results of self-ignition test of new oxidation treatment process for U metal chip were interpreted and supported.

Audio-signal Transfer System Design and Evaluation based on Power Line Communication

Kim, Kwan-Kyu,Yeom, Keong-Tae,Kim, Yong-Kab The Korean Institute of Electrical and Electronic 2008 Transactions on Electrical and Electronic Material Vol.9 No.3

The paper is to solve the problem of existing audio signal transfer system which has a difficulties of system organization and the increase of additional install cost and unfriendly interior. To solve the existing system, we drew the new audio signal transfer system based on PLC and evaluated it. A transmitter and a receiver were designed using the PLC chip INT5500CS. An audio signal transfer system was configured with a CD player to which audio signals are sent from the transmitter and a speaker connected to the receiver. For performance evaluation of this system, a USBPre external sound card and Smaart Live 5 which is a PC-based sound measuring program were added. As a result of our experiment, the measured signal level is $2{\sim}3$ dB lower than reference signal, latency is 16.69 ms, and the specific character of coherency is bad in high frequency band. Otherwise, this system transmits and receives signals over 90 % in good condition as a result of measuring pink noise, frequency (1 kHz), and phase, magnitude. In view of the result so far achieved, the system designed this study has excellent performance, it resolves defect of existing audio signal transfer system.

Application of Fuzzy Algorithm for Partial Discharge Analysis

Kim, Jin-Su,Yeom, Keong-Tae,Kim, Kwan-Kyu,Kim, Ji-Hyoung 한국정보전자통신기술학회 2008 한국정보전자통신기술학회논문지 Vol.1 No.3

This work involves analyzing partial discharge (PD), which has estimated the detected signal accumulation based on Labview, and analyzing by Fuzzy algorithm. In algorithm, we developed system configuration that detected accumulating PD signal. With practical PD logic implementation of theoretical detected system and hardware implementation, the device for 50kV setup has generated and then has applied with 15k~17kV with 1:1 time probe. Our new class of PD detected algorithm has also compared with PRPDA or Fuzzy algorithm, which has diagnose more conveniently by adding numerical values.

Effect of Chaos and Instability of Brillouin-Active Fiber Based on Optical Communication

Yeom, Keong-Tae(염경태),Kim, Kwan-Kyu(김관규),Kim, Ji-Hyoung(김지형),Kim, Yong-Kab(김용갑) 한국정보전자통신기술학회 2008 한국정보전자통신기술학회논문지 Vol.1 No.1

In this paper the effect of instability and chaos in optical fiber networks based on the Internet is described. Nonlinear optical fiber effect especially Brillouin scattering in networks has emerged as the essential means for the construction of active optical devices used for all-optic in-line switching, channel selection, amplification, oscillation in optical communications and a host of other applications. The inherent optical feedback by the back-scattered Stokes wave in optical networks also leads to instabilities in the form of optical chaos. This paradigm of optical chaos in fiber Internet serves as a test for fundamental study of chaos and its suppression and exploitation in practical application in optical fiber communication. This paper attempts to present a survey and some of our research findings on the nature of Brillouin chaotic effect on Internet based optical communication.

Sound Communication System Design and Characteristic Analysis based on Power Line Communication

Kwan-Kyu Kim,Keong-Tae Yeom,Ji-Hyoung Kim,Yong-K. Kim 대한전자공학회 2008 ICEIC:International Conference on Electronics, Inf Vol.1 No.1

The paper is to solve the problem of existing sound system which has a difficulties of system organization and the increase of additional install cost and unfriendly interior. To solve the existing system, we drew the new sound communication system based on PLC and characteristic analysis it. A transmitter and a receiver were designed using the PLC chip INT5500CS. An sound communication system was configured with a CD player to which sound signals are sent from the transmitter and a speaker connected to the receiver. For characteristic analysis of this system, a USBPre external sound card and Smaart Live 5 which is a PC-based sound measuring program were added. As a rusult of our experiment, the measured signal level is 2~3[㏈] lower than reference signal, latency is 16.69[ms], and the specific character of coherency is bad in high frequency band. Otherwise, this system transmits and receives signals over 90[%] in good condition as a result of measuring pink noise, frequency (1㎑), and phase, magnitude. In view of the result so far achieved ,the system designed this study has excellent perfomance, it resolves defect of existing sound system.

Audio-signal Transfer System Design and Evaluationbased on Power Line Communication

Kwan-Kyu Kim,Keong-Tae Yeom,Yong-Kab Kim 한국전기전자재료학회 2008 Transactions on Electrical and Electronic Material Vol.9 No.3

The paper is to solve the problem of existing audio signal transfer system which has a difficulties of system organization and the increase of additional install cost and unfriendly interior. To solve the existing system, we drew the new audio signal transfer system based on PLC and evaluated it. A transmitter and a receiver were designed using the PLC chip INT5500CS. An audio signal transfer system was configured with a CD player to which audio signals are sent from the transmitter and a speaker connected to the receiver. For performance evaluation of this system, a USBPre external sound card and Smaart Live 5 which is a PC-based sound measuring program were added. As a result of our experiment, the measured signal level is 2~3 dB lower than reference signal, latency is 16.69 ms, and the specific character of coherency is bad in high frequency band. Otherwise, this system transmits and receives signals over 90 % in good condition as a result of measuring pink noise, frequency (1 kHz), and phase, magnitude. In view of the result so far achieved, the system designed this study has excellent performance, it resolves defect of existing audio signal transfer system.

전력선통신 기반 음향 시스템 설계 및 특성 분석

김관규(Kwan-Kyu Kim),염경태(Keong-Tae Yeom),김관웅(Kwan-Woong Kim),김용갑(Yong-Kab Kim) 한국콘텐츠학회 2008 한국콘텐츠학회논문지 Vol.8 No.6

본 논문은 기존의 음향 시스템이 가지고 있는 시스템 구성의 어려움, 추가설치비용 증가, 비 친화적인 인테리어의 문제점을 해결하기 위한 연구이다. 기존 시스템의 문제점을 해결하기 위하여 전력선통신을 기반으로 새로운 음향 시스템을 설계하고 특성을 연구 하였다. PLC 전용칩 INT5500CS을 사용하여 송신기와 수신기를 설계하였으며, 송신부에서 CD PLAYER로 음향 신호를 제공하고 수신부에 스피커를 연결하여 출력하는 음향 시스템을 구성하였다. 구성된 시스템의 특성분석을 위해 USBPre 외장사운드 카드와 PC기반의 음향 측정/분석 프로그램인 Smaart Live 5를 추가 구성하여 실험하였다. 실험 결과, Measurement 신호는 Reference 신호보다 2∼3[㏈]정도의 낮은 신호레벨을 보였으며, Latency는 16.69[㎳]을 확인하였고, Coherency는 고 주파수대역에서 특성이 나빠졌음을 확인 하였다. 반면에, Pink Noise 및 특정 주파수 1[㎑], Phase, Magnitude를 확인한 결과 90[%] 이상으로 정상적인 신호의 송수신이 이루어 졌음을 확인하였다. 이러한 결과, 본 고에서 설계한 시스템의 성능이 우수함을 밝혔고, 이를 통해 기존 오디오 신호 전송 시스템의 문제점을 해결하였다. The paper is to solve the problem of existing sound system, which has difficulties of system organization and the increase of additional install cost and unfriendly interior. To solve the existing system, we drew the new sound system based on PLC and studied it. A transmitter and a receiver were designed using the PLC chip INT5500CS. Sound system was configured with a CD player that sound signals are sent from the transmitter and a speaker connected to the receiver. For analysis of characteristics of this system, a USBPre external sound card and Smaart Live 5 which is a PC-based sound measuring program were added. As a result of our experiment, the measured signal level is 2∼3[㏈] lower than reference signal, latency is 16.69[㎳] and the specific character of coherency is bad in high frequency band. Otherwise, this system transmits and receives signals over 90[%] in good condition as a result of measuring pink noise, frequency(1㎑), and phase, magnitude. In view of the result so far achieved, the system designed our team has excellent performance, it resolves defect of existing audio signal transmition system.

Study of Frequency Response Characteristics in Sound measurment System Used by Optical Sensor

Keong-Tae Yeom,Kwan-Kyu Kim,Hwa-Young Choi,Byeong-Man Kwon,Yong-Kab Kim 대한전자공학회 2008 ICEIC:International Conference on Electronics, Inf Vol.1 No.1

This paper, in order to analyze property of frequency response in Sound measurment system using optical sensor, system was implemented. The capacitance microphone and fiber-optic transmission path type fiberoptic microphone (FOM) have weaknesses in directivity, size, weight, and price. However suggested optical microphone can be constituted by cheap devices, so it has many benefits like small size, light weight, high directivity, etc. Head part of optical microphone which is suggested in this paper is movable back and forth by sound pressure with the attached reflection plate. Operating point is determined by measuring the respond characteristics and choosing the point on which has maximum linearity and sensitivity while changing the distance between optical head and vibrating plate. We measured the output of the O/E transformed signal of the optical microphone while frequency of sound signal is changed using sound measuremnet/analysis program, "Smaart Live" and "USBPre", which are based on PC, and compared the result from an existing capacitance microphone. The measured Optical microphone showed almost similar output characteristics as those of the compared condenser microphone, and its bandwidth performance was about 3㎑ at up to 5 ㏈.

Study of Frequency Response Characteristics in Microphone Used by Optical Sensor

Keong-Tae Yeom,Kwan-Kyu Kim,Yong-Kab Kim 한국전기전자재료학회 2008 Transactions on Electrical and Electronic Material Vol.9 No.3

In this paper, in order to analyze property of frequency response in microphone using optical sensor, acousto-optic sensor system has been implemented. The capacitance microphone and fiber-optic transmission path type fiber-optic microphone (FOM) have weaknesses in directivity, size, weight, and price. However suggested optical microphone can be constituted by cheap devices, so it has many benefits like small size, light weight, high directivity, etc. Head part of optical microphone which is suggested in this paper is movable back and forth by sound pressure with the attached reflection plate. Operating point has also been determined by measuring the response characteristics. The choosing the point, which has maximum linearity and sensitivity has changing the distance between optical head and vibrating plate. We measured the output of the O/E transformed signal of the optical microphone while frequency of sound signal is changed using sound measurement /analysis program, “Smaart Live” and “USBPre”, which are based on PC, and compared the result from an existing capacitance microphone. The measured optical microphone showed almost similar output characteristics as those of the compared condenser microphone, and its bandwidth performance was about 4 kHz at up to 3 dB.

총수담관 결석의 각종 내시경적 제거술의 효과

김남재,김진희,이승민,이상우,성재규,김석현,이병석,이헌영,이경태 대한소화기내시경학회 1999 Clinical Endoscopy Vol.19 No.1

Background/Aims: The objective of this paper is to compare the effectiveness of com-mon bile duct stone extraction by conditions and methods. Methods: Endoscopic sphinc-terotomies with stone extraction were practiced in 71 patients with common bile duct stones by basket extraction, balloon extraction and mechanical lithotripsy. Results: 1) In 71 patients with CBD stone, sex distribution showed predominence in females (56.3%) and most of the cases were over 60 years old. 2) After sphincterotomy, the overall success rate of the stone extraction was 87.3% (with balloon and basket or mechanical lithotrispy). The removal methods of the stone extractions were varied, but the most commonly used method was basket extraction (50.7%). 3) The complications of sphicterotomy were noted in 10 cases and in 8 cases minor bleeding was stopped with a hypertonic saline epinephrine injection. 4) After the stone extraction, counts and levels of leukocyte, aspartate transami-nase, alanine transaminase, alkaline phosphatase and total bilirubin were significantly improved (p <0.05). 5) Removal methods according to stone size did not show a signifi-cant difference, but the mean size of the stones was different. According to the several methods, the mean diameter of stones were different. The stone size was 1.1 cm in the case of spontaneous removal, 1.4 cm in balloon or basket removal, 1.9 cm in mechanical lithotripsy and 2.0 cm in surgical removal. Conclusions: Endoscopic stone extraction was effective and safe method with low rate of complications. However there were some significant difficulties in removing large or impacted stones, therefore EHL, ESWL or operation should be considered.