인트라넷 기반의 프로그래밍 교육 시스템 설계 및 구현

이임섭,김한경 國立 昌原大學校 精報通信硏究所 1999 精報通信論文集 Vol.3 No.-

The objective of this study is to present an advanced teaching-learning method that enhance each learner's ability of problem-solving by himself. To support this goal, education system is designed and implemented in the Wold-Wide-Web environments. The system is composed of modules, such as the virtual learning module, asking and answering interface module, manual module, evaluation module, and internet searching module. The WBI(Web Based Instruction) system is implemented with the language of HTML, JAVA Script, Visual Basic Script and ADO(Active Database Object) component is connected to database.

OFDM 기반의 60GHz WLAN을 위한 위상잡음 해석과 위상잡음 억제 알고리즘

김한경,안경승,백흥기,Kim Han-Kyong,Ahn Kyung-Seung,Baik Heung-Ki 한국통신학회 2005 韓國通信學會論文誌 Vol.30 No.12C

본 논문은 4세대 무선 통신방식의 하나인 OFDM 기반의 60GHz 무선 랜에서의 위상잡음의 영향에 관하여 논한다. 60 GHz 주파수 대역은 광대역 전송이 가능할 뿐만 아니라 산소에 의한 전파의 흡수감쇄가 크다는 특성 때문에 주파수 재활용에 대한 실내 무선환경에서의 무선 링크를 밀집시킬 수 있다는 장점이 있다. 그러나 낮은 주파수의 국부 발진기를 체배하거나 높은 주파수의 국부 발진기를 사용하는 경우, 발진기의 비이상적인 특성으로 인해 발생하는 위상잡음은 다중 반송파 시스템에서 공통위상 회전과 부반송파간 간섭의 원인이 된다. 이는 위상 변화에 민감한 OFDM 기반의 무선전송 시스템에 심각한 성능 저하를 발생시키는 원인이 되므로 반드시 해결해야 하는 문제이다. 본 논문에서는 시스템 구현이 용이한 위상잡음 억제 알고리듬을 OFDM 기반의 60 GHz 무선 랜 시스템에 적용하고 이에 따른 성능을 SER 측면에서 분석하였다. 60GHz 대역에서 발생하는 위상잡음 환경에서 위상잡음 억제 알고리듬을 적용한 경우, 그렇지 않은 경우에 비해 16-QAM, 64-QAM에서 각각 6dB, 7.5dB 정도의 SER 성능 향상을 보였다. We investigate the OFDM-based wireless LAN systems operating in the 60 GHz frequency band as part of the fourth-generation (4G) systems. The 60 GHz band is of much interest since this is the band in which a massive amount of spectral space has been allocated worldwide for dense wireless local communications. This paper gives an overview of 60 GHz bandchannel characteristics and an effect on phase noise. The performance of OFDM system is severely degraded by the local oscillator phase noise, which causes both common phase error and inter-carrier interference. In this paper, we apply phase noise suppression (PNS) algorithm that is easy for implementation to OFDM based 60 GHz wireless LAM system and analyze the SER performance. In case of using the PNS algorithm, SER performance is improved about 6dB, 7.5dB, respectively in 16, 64-QAM.

루프 방지를 위한 칼라 스레드 알고리즘의 개선

김한경 한국통신학회 2001 韓國通信學會論文誌 Vol.26 No.12

Ohba에 의해 제안된 칼라 스레드 알고리즘은 루프 경로 설정을 방지하기 위한 새로운 접근 방법으로서 효과적으로 인식되고 있다. 칼라 스레드 알고리즘에서는 스레드의 상태를 null, colored, 7ansparent의 3 종류로 정의함에 따라, 동작의 내부 알고리즘이 복잡한데, 이를 4개 상태로 확대하여 유한상태 기계를 개선하였다. 또 루프 경로를 도출하기 위하여 스레드가 일단 중복이 되면 다시 새로운 칼라를 생성하여 다시 확장하고, 그것이 다시 접수되면 unknown 홉 카운트를 갖는 스레드로 재차 확장하는 방식을 기존의 칼라 스레드를 그대로 사용케 함으로써 네트워크 운행 횟수를 최소한 1회 절약되도록 하였으며 이벤트를 재정의하여 기존의 라우팅 프로토콜과의 결합이 용이하도록 하였다. Colored thread algorithm suggested by Ohba is understood to be effective to prevent from establishing path in loop. 3 kinds of thread state, such as null, colored, transparent, defined in colored thread algorithm which makes difficult and complex to design actions of the thread events, is reconfigured and improved to a 4 states to make the finite state machines simple. The original colored thread algorithm fonds loops by receiving thread of a same color that was generated by the initiator itself and confirms the loops by hop count of unknown thread traversed again along the looped path. This method is modified as to use the same color instead of generating new colored thread for the looped path, leading to save the traversing time. And also redefined the events to make easy coupling with existing protocols.

ATM 전달망 호제어 소프트웨어의 도메인 분석과 객체지향 설계

김한경,구연설 대한전자공학회 1996 전자공학회논문지-A Vol.33 No.4

For the implementation of callcontrol software, it will be shown how to divide problems into dimain and also presents methodologies to specify domains according to the object-orented analysis techniques. Domains is specified by the set of related objects as shown in call control examples. Events and conditons are able to be transformed into system invariant so that is possible to figure out the relationship between domains and those concludes that the software requirements specification can be established for the design and implementation. Relationships existing between domains can be formalized so as to verify software requirements.

큰느타리(새송이)버섯 안정생산기술

김한경 한국버섯학회 2003 버섯 Vol.7 No.2

자낭균 곰보(Morchella esculenta)버섯의 인공재배에 관한 연구

김한경,이강효,정종천,전창성,석순자,장갑열 한국버섯학회 2009 한국버섯학회지 Vol.7 No.1

This study was executed in an attempt to investigate a artificial requisites of fruitbody occurrence. Environmental requirements on habitat for fruitbody occurrence of collected cultures resulted in leading to 13- 16℃ and 75% relative humidity, and requiring silt loam of soil texture which had more nutritional substances than a dry field. Optimal temperature was 25℃, medium PDB, and pH 5.0 in cultural conditions. Mannose required of 5% in ASI 59002, 59003, 59004, but 3% in ASI 59001 was selected as optimum carbon source. The substrates stimulating sclerotium formation were cotton waste, or cotton waste + oak sawdust (mixture ratio of 8:2), which had 20% additive of wheat barn respectively. Sclerotium was formed well in the substrate adjusted chemical properties by applying 2% of calcium sulfate. Sclerotium formation was the most effective in the treatment of peat moss + oak sawdust (mixture ratio of 5:5) + 30% of wheat barn.

팽이버섯 재배기술과 병해방제

김한경 한국버섯학회 1999 버섯 Vol.3 No.1

형상관리

김한경,안유환,노장래,Kim, Han-Gyeong,An, Yu-Hwan,No, Jang-Rae 한국전자통신연구원 1986 전자통신 Vol.8 No.2

TDX의 연구개발, 생산 및 운용중에 적용되는 형상관리 체계 확립은 요구 사항의 제기와 그 적용에 이르기까지의 정보 흐름이 복잡하기 때문에 시스팀 제품관리와 사업관리 관점에서의 많은 문제 해결을 전제로 한다. 본고는 TDX형상관리에 필요한 사항을 제시하고, TDX형상관리를 적합하게 구성하는 방식으로 서술한다.

차량용 공조 시스템의 이해

김한경 대한설비공학회 2000 설비저널 Vol.29 No.10

자동차용 공조 시스템의 이해를 위하여 부 시스템을 중심으로 소개하고자 한다.

모자보건 위험치 접근법에 의한 감별 평점표의 개발에 관한 연구

고응린,박인서,김한경 한양대학교 의과대학 1984 한양의대 학술지 Vol.4 No.2

Recently, the concept and methodology of the risk approach for maternal and child health have been developed by the World Health Organization and its world wide application and research are being strongly recommended. The risk approach which is defined by W. H. O as a managerial tool for the flexible and rational distribution of existing resources, and for developing the appropriate content of maternal and child health care necessitates the development of a technique for the measurement of the individual and community risks in order to be able to classify them into groups by the amount of need for health care. Numerous recent studies have focussed on the identification of relevant risk factors and the definition of normal and adverse outcomes of pregnancy and on how to assign a score to each factor for the quantitative assessment of risk factor as a determinant of pregnancy outcomes. The methodology currently being used to construct a Score Chart may be classified into three broad fields, that is, (1) Arbitrary method (2) Linear discriminant function method and (3) Regression method. The arbitrary method has disadvantages such as lack of theoretical soundness and objectivity. As for the linear discriminant function and regression methods, the need for computer for sophisticated calculation and the requirement of some practically unlikely statistical assumptions are the main disadvantages to be tolerated. Furthermore, most of the scoring system construction were made in and for the hospital setting where modern clinical and computational facilities are available. From an extensive review on the past pros and cons on scoring system so far developed a conclusion could be derived that the system should be individualized for the population it is for and that any such system to be acceptible to primary care level health workers it should be simple in theory, take little time to use, and must be easily constructed even at the level of local community where sophisticated computational tools are not available. The authors suggest a trial of a new approach for constructing risk scores which may be called as a scoring system on the basis of the likelihood method. The likelihood method, in principle, is a statistical tool with is designed to calculate the probability(or likelihood) of having a set of observed values under vaious models and the model for which the probability is the maximum will be chosen as the most appropriate one. In case of applying the likelihood method to risk scoring system the "set of observed values" will be equivalent to the result of clinical check in the prenatal period, and the models will be the spectrum of adverse effect of pregnancy extending from healthfulnss to mortality. A total of 1,500 pregnant women's medical records at the Department of Obstetrics and Gynecology, National Medical Center, Seoul have been surveyed. From the records, a total of 45 antepartum and intrapartum risk factors were checked for each patient as prospective determinants of postpartum outcomes. Of those the follwing 11 factors were identified as having significant power for discriminating the pregnancy outcomes into normal and adverse groups. (1) No. of cesarean-section (2) Experience of abnormal presentation (3) Reasons for visit (4) Chief complaints (5) Systolic blood pressure (6) Heart status (7) General appearance (8) Edema status (9) Uterine cervix status (10) Pelvic status (11) Diagnosis of any other abnormality On the basis of these 11 risk factors, on "M.C.H. risk factor discriminant score chart" was developed as presented in Table 4(Ref. main text). It was learnt that among 34 remaining factors which were assessed from this study as less or none predictive, there are many clinical symptoms or signs such as Rh type, mother's weight, hemoglobin level, e.t.c., which are being widely recognized as important warning signs in clinical practice. This result may be fundamentally attributable to the following two reasons. (1) The criteria set for the classification of pregnancy outcomes into "normal" and "sdverse" groups was on the basis of combined outcomes from both fetal and maternal sides, such that some risk factors which might have been identified as predictive when only one side were taken as criteria were cancelled out by such combination of outcomes. (2) There were some risk factors whose positive rates were very low, say less than 1% so that the pridictive power based on the likelihood method became weaken seriously. The recommendation for the future development of risk score chart based on the likelihood method is to classify the pregnancy outcomes according to the following criteria. (1) Intrapartum outcomes: 1) Adverse outcome group based on fetal variables 2) Adverse outcome group based on maternal variables 3) Normal group (2) Postpatum Outcomes: 1) Adverse outcome group based on fetal variables 2) Adverse outcome group based on maternal variables 3) Normal group