B-NT 시스템의 성능분석을 위한 시뮬레이터 연구

기장근,노승환 公州大學校工科大學生産技術硏究所 1997 論文集 Vol.5 No.-

This paper presents development of a simulator in which ATM cell transmission delay time between subscribers, average queue length and cell loss of each system can be obtained according to the various structures of B-NT system and change of input traffic. The simulator consists of graphic user interface module, simulation program automatic generator module, B-NT system model library, etc. The results of simulation for the performance analysis of the B-NT system are also presented.

분산형 B-NT 시스템 운용방안에 관한 연구

기장근,노승환 公州大學校工科大學生産技術硏究所 1998 論文集 Vol.6 No.-

This paper presents the application scheme of distributed B-NT system. The distributed B-NT system consists of head node, ring network node, CANS(Centralized Access Node System) and HANS(Home ATM Node System). In this paper ATM cell transfer delay between subscribers, cell loss and cell transfer ratio of head node per each input port according to the various structures of B-NT system and change of input traffic are presented. The results of this paper will be used in constructing the optimized B-NT system.

만성 호중구성 백혈병 1례

기장도,박치영,류보열,김태종,모성환,곽재정,문철호,박근홍,박유환,정춘해 朝鮮大學校 附設 醫學硏究所 1996 The Medical Journal of Chosun University Vol.21 No.1

Chronic neutrophilic leukemia is a very rare myeloproliferative disorder which is characterized by severe sustained mature neutrophilic leukocytosis in peripheral blood (PB), hepatosplenomegaly, elevated leukocyte alkaline phosphatase, serum uric acid. serun viatmin B 12 and the bleeding tendency despite normal platelet count and coagulation time, absence of philadelphia chromosome, and the absence of fever or underlying infection or disease sufficient to mimic a leukemoid reaction. We have experienced a 34-years-old male patient with atypical chronic neutrophilic leukemia. On admission, the leukocyte count was 56,860/uL. severe neutrophic leukocytosis with 76% neutrophils and rare immature forms on PB smear. Many neutrophils had toxic granules, and vacuoloes. Leukocyte alkaline phosphatase score was decreased. The cytogenetic study showed Philadelphia chromosome negative with normal karyotype.

ATM 망에서의 효율적인 연결수락제어 알고리즘 연구

기장근 公州大學校工科大學生産技術硏究所 1993 論文集 Vol.1 No.-

본 논문에서는 사용자가 신고한 트래픽 파라미터와 셀 흐름 측정치를 고려하는 적응적 연결수락제어 방법을 제안하였다. 신고치에 의한 트래픽 예측은 연결 요구나 해제시에 실시간 처리가 가능한 회귀적 계산에 의해 수행되고, 측정치에 의한 트래픽 예측은 연결 개수의 변화가 없을 때 매 측정반영주기 마다 수행된다. 적응적 연결수락제어 방법은 연결 개수와 가장 최근의 연결 수락 또는 해제후의 경과 시간에 따라 측정반영주기 및 측정 반영율을 갱신한다. 제안된 방법에 대해 다양한 트래픽 환경하에서 성능 평가를 수행하여 효율성을 검증 하였다. In this pater, an adaptive connection admission control(CAC) method is proposed. The adaptive CAC uses traffic estimates derived from both traffic parameters specified by user and cell flow measurements. Traffic estimation using user-specified parameters is performed at every moment of connection request or connection release by recursive formula which maker real-time calculation possible. Traffic estimation using cell flow measurements is carried out when the number of connected calls does not change during a measurement reflection period(MRP). The adaptive CAC updated MRP and measurement reflection ratio adaptively according to the number of connections and the elapsed time after last connection or release respectively. Performance analysis for the proposed method is evaluated in several aspects for the cases of both homogeneous and heterogeneous bursty traffic.

무선 LAN용 MAC 프로토콜 설계 및 검증

기장근 公州大學校工科大學生産技術硏究所 1994 論文集 Vol.2 No.-

본 논문에서는 무선 LAN용 MAC 프로토콜의 비동기 통신 부분을 설계하고 이를 구현할수 있는 상태천이도를 제시하였고, 이에 대해 시뮬레이션을 통한 검증을 수행하였다. 프로토콜은 본질적으로 전송전에 충돌을 회피할 수 있는 CSMA/CA 방식을 사용하며, NAV(Network Allocation Vector)라고 하는 가상의 케리어 검출 지시자를 추가 운영함으로써 충돌 확률을 더욱 낮추게 된다. 또한 망 전체에 걸쳐 동기화 된 국부 타이머를 각 스테이션이 운용함으로써 파워 관리 기능이나 주파수 호핑 시스템의 동기화가 용이하게 구현될 수 있다. In this paper, the asynchronous communication portion of the MAC protocol in wireless LAN is proposed in a formal form of state diagram and verified by the simulation. The access method uses a CSMA/CA mechanism. To reduce the probability for access collisions, and to provide fair access to the medium by all stations, a random backoff mechanism is used to randomize the gap between stations accessing the medium. This scheme is further enhanced by the NAV that maintains a "virtual carrier sense". Also, the proposed protocol includes timing synchronization function which can be used for power management, frequency hop synchronization, and other management functions.

휴대전화의 전자파가 생쥐의 뇌에서 p39의 발현에 미치는 영향

정기윤,김경훈,장성근 순천향대학교 기초과학연구소 2004 순천향자연과학연구 논문집 Vol.10 No.2

p39 is a regularory subunit of Cdk5(Cyclin-dependent kinase 5) that regulate cell division. Reletive quantitation of p39 RNA has done by Q-RT PCR method. ICR female mice are exposed at electromagnetic wave making machine simulated as korean standard cellular phone wave frequency and wave length for 9 hours/day for 3 months before sacrificed. Brain regions are removed from sliced brain tissue in 400um thick. Total cellular RNA was extracted from cerebellum, hippocampus, thalamus and hypothalamus for Q-RT PCR process using SYBR green dye. In cerebellum, p39 expression level is decreased at 1/5 of the control. In thalamus and hypothalamus, the level is decreased at half of the control. But in hippocampus the expression level of the p39 is not changed. Differential effect of the cellular phone like electromagnetic wave to verious region of the brain is examined.

선형유도전자펌프내의 자기유체 유동에 관한 수치적 연구

최훈기,유근종,박태봉,은재정,장남영 국립7개대학공동논문집간행위원회 2003 공업기술연구 Vol.3 No.-

Numerical analysis is performed for magnetic and MHD flow fields in Electro-Magnetic(EM) pump. A finite volume method is applied to solve magnetic field governing equations and the Navier-Stokes equations. Vector and scalar potential methods are adopted to obtain the electric and magnetic fields and the resulting Lorentz force in solving Maxwell equations. The magnetic field and velocity distributions are found to be influenced by the magnitude of the Reynolds number and the phase of applied electric current. Computational results indicate that the magnetic flux distribution with changing phase of electric current is characterized by a pair of counter-rotating closed loops. The velocity distribution of the flow field is influenced on the intensity of Lorentz force.

통신 플로토콜의 적합성 검증에 관한 연구

김기영,기장근,김영천 전북대학교 전자산업개발연구소 1990 전자산업연구 Vol.1 No.-

The purpose of this paper is to verify if a protocol implementation conforms to its specification, CCITT No. 7 SCCP. Protocol implementation have to be tested in a manner reflecting most closely a normal operating environment. This implies that the protocol entity must be tested as "black box". Communication protocol can be modeled by a finite state machine with is 1) completely specified, 2) minimal, and 3) strongly connected. This paper is focused on the methods for generating test sequences for communication protocol, considering in particular their effective-ness in detecting possible errors, and their effieciency measured by the length of the test sequence.

자바를 이용한 마이크로 프로세서 시뮬레이터 개발에 관한 연구

김영민,허원,기장근 公州大學校工科大學生産技術硏究所 1998 論文集 Vol.6 No.-

Educational software tends to be momotonous without the interaction between instructors and students. and unidirectional teaching system can't overcome these barriers because the learning process is momotonous without the bidirectional communication. The advanced network system can solve these problems. In this study, a bidirectional microprocessor simulator is developed and a new teaching model is proposed using the simulator. It was named JMPS(JAVA Microprocessor Simulator), which is a software to teach the microprocessor principles and applications. It has two advantages. First, it can teach the principles and applications of microprocessor effectively. Second, it runs on Internet and provides easy communication between a teacher and students.

손가락 끝 점을 이용한 손 형상 인식

김종민,이웅기,장근실,양환석,허진경,박승규 朝鮮大學校 統計硏究所 2007 統計硏究所論文誌 Vol.9 No.1

최근 사용자 친화형 유저 인터페이스 구현을 위해 인간의 손 형상을 실시간으로 인식하는 연구의 중요성이 부각되고 있다. 그러나 인간의 손은 자유도가 크기 때문에 손 형상을 정확히 인식하기란 매우 어렵고 또한 피부색과 유사한 색을 가지는 복잡한 배경에서는 더욱 곤란하다. 본 논문에서는 별도의 센서를 부착하지 않고 카메라를 사용하여 피부색 정보에 의한 손 형상을 분할한 후 손가락 끝 점을 찾는다. 찾은 손가락 끝 점을 이용하여 방향을 탐지하는 알고리즘에 대해 기술한다. 이 방법은 템플리트 매칭을 이용하여 손가락 끝 점을 탐색한 후 찾은 손가락 끝 점과 손목의 중심을 이용하여 전, 후, 좌, 우 방향을 탐지한다. 제안하는 방법을 이용하여 3D 가상현실 공간에서의 네비게이션(Navigation)에 응용하였으며, 실험결과 전진, 후진 및 좌측, 우측의 방향전환도 매우 좋은 결과를 보였다. 또한 본 논문에서 제안하는 방법은 마우스, 키보드, 조이스틱 등의 조작 없이 전, 후, 좌, 우 방향전환을 사용자가 직관적으로 지시함으로써 보다 자연스러운 인간과 컴퓨터의 상호작용을 제공할 수 있을 것이다.