회전교차로를 활용한 친환경 초기 우수대응기술 개발 및 설계

박형근,맹승진,황주하,아잠 무함마드,Park, Hyeong-Geun,Maeng, Seung-Jin,Hwang, Ju-Ha 한국수자원학회 2017 물과 미래(한국수자원학회지) Vol.50 No.11

휴대용 디지털 방송망에서의 이동성지원을 위한 전력 효율적인 셀 탐색 기법

박형근,Park, Hyung-Kun 한국정보통신학회 2007 한국정보통신학회논문지 Vol.11 No.8

휴대용 디지털 방송 표준으로 추진되고 있는 DVB-H는 유럽 지상파 디지털 방송시스템 표준인 DVB-T 전송망으로 휴대용 수신기에 다양한 멀티미디어데이터를 전송하기 위하여 추가, 보완한 기술규격으로, 휴대형 단말기에서의 방송 수신을 목표로 하고 있다. 이러한 DVB-H시스템은 단말의 이동성과 전력효율성을 중요한 특징으로 하고 있다. 따라서 이동중인 수신기가 다중 주파수 망(MFN)으로 구성된 방송망에서 서로 다른 주파수망으로 이동할 경우 끊김 없는 주파수 핸드오버가 이루어져야 한다. 이때 핸드오버를 위해 인접 주파수들을 검색해야하는데 이 경우 휴대단말에 큰 전력소모를 야기한다. 따라서 보다 전력효율적인 핸드오버를 위한 셀 탐색 기법이 요구된다. 본 논문에서는 보다 빠른 주파수 검색을 통해 전력효율을 증가시킨 Hypothesis 테스팅기반의 핸드오버 방식을 제안하고 그 성능을 비교 분석하였다. DVB-H (Digital Video Broadcasting for Handhold) is a new standard, currently being developed for a portable digital broadcasting, which enhance the multimedia broadcasting service in the Euroapean standard DVB-T (DVB-Terrestrial). Seamless mobility and power saving are essential requirements in the DVB-H system. To support seamless mobility, DVB-H system should provides seamless handover for mobile stations in the MFN (multi frequency network). For seamless handover, the receiver should monitor neighboring cells and it increases the power consumption. And so, power efficient sell searching algorithm for seamless handover is required. In this paper, we propose hypothesis feeling based handover algorithm to enhance the power efficiency by using the fast cell searching, and analyze the performance of handover schemes through the numerical evaluation and simulation.

Rate Control Based Call Admission Control Scheme for CDMA2000 System

박형근,Park, Hyung-Kun The Korean Institute of Communications and Informa 2004 韓國通信學會論文誌 Vol.29 No.9B

In a COMA system, the capacity is variable and mainly depends on multiple access interference. The multiple access interference has a deep relationship with transmitted or received power. The capacity of COMA2000 system is considered to be limited by the forward link capacity. In this paper, we show that the forward link cell load can be represented by the total transmitted power of base station and we propose a forward link call admission control (CAC) strategy for COMA2000 system. The proposed call admission scheme adopts the rate control algorithm for data call. This call admission scheme enables the system to utilize radio resource dynamically by controlling data rate according to the cell load status, and enhance the system throughput and grade of service (GoS). quality of service(QoS) such as blocking and outage probability.

동적 환경 내에서의 자율 에이전트에 의한 다양한 행위의 설계 및 구현

박형근,박종희,Park, Hyung-Keun,Park, Jong-Hee 대한전자공학회 2001 電子工學會論文誌-CI (Computer and Information) Vol.38 No.3

에이전트의 정의와 구현에 관한 연구는 가상현실기술을 이용한 몰입형 교육 시스템 등의 구성에 있어서 매우 중요한 부분을 차지한다. 본 논문에서는 동적인 환경에서 에이전트의 행위의 효율적인 정의와 구현 방법을 제시하되 기존의 연구와 달리 행동의 다양성을 표현에 초점을 맞추고자 한다. 먼저 장이론에 기반하여 공간객체를 정의 한다. 장이론을 도입하여 공간객체를 정의함으로써 공간 객체에 대한 분류적 접근이 아닌 구조적인 접근이 가능해 지고, 공간객체의 동적인 생성 및 소멸과 전체적인 시공간 상황의 변화를 유도할 수 있게 된다, 다음으로 동적인 planning이 가능하도록 에이전트의 행위를 복합행위와 단위행동으로 구분한다, 마지막으로 에이전트와 관련된 객체의 관계에 따라 지식 베이스를 에이전트와 관련 객체들에 분산한다, 이를 통해 에이전트의 지식베이스의 효율적인 관리와 동적인 환경의 구축이 가능하다. 공간객체 내에서의 에이전트의 이동에 관한 상황을 구현함으로써 장이론에 기반한 공간객체의 정의와 행위의 복합행위와 단위행동으로의 구분, 그리고 에이전트와 관련 객체간의 지식 베이스의 분산의 효율성을 검증하였다. The design and implementation of agents is an essential part of the development of immersive types of tutoring systems using virtual reality. This paper proposes several effective mechanisms for the design and implementation of agents. Unlike existing researches we focus on accommodating diversity of agents' behavior in the proposed mechanisms. First, we define the space object based on the field theory. The introduction of the field theory allows us to approach the space objects in a structural manner rather than by their classification. We can also achieve dynamic genesis and extinction of the space objects, and derivation of overall changes in spatio-temporal situations. Second, we classify the behavior of agents into composite behaviors and primitive actions in order to achieve its dynamic planning. Finally, we distribute the knowledge among agents and their associated objects according to their interrelations. By this distribution, we can handle the otherwise prohibitively large amount of knowledge related to agents' behaviors and construct a dynamic environment. By implementing a situation with agent's navigation across a composite space object, we demonstrate the effectiveness of these schemes presented above.

특별 셀 영역을 이용한 OAM 기능의 성능 향상 및 ASIC 설계

박형근,김환용,Park, Hyoung-Keun,Kim, Hwan-Yong 대한전자공학회 1999 電子工學會論文誌, C Vol.c36 No.2

본 논문에서는 ATM을 기반으로 구축된 망에서 다양한 서비서 품질(QoS : quality of service)을 가진 데이터를 셀 손실이나 셀 지연의 관점에서 적절한 처리를 수행함으로써 망 자원을 최대한 활용하고 보다 신뢰성 있는 서비스를 제공하기 위하여 OAM 성능관리 기능의 개선 방안을 제안하였다. 또한, 수시로 변화하는 망의 성능정보를 주기적으로 검출함으로써 융통성과 정밀한 제어가 요구되는 망사이의 연관제어 및 운용, 관리기술을 향상시킬 수 있도록 OAM 셀에 특별 셀 영역을 정의하였다. 제안된 OAM 기능과 셀의 입 . 출력 기능, 메모리나 CPU 같은 주변 소자와의 인터페이스 기능 등을 ASIC으로 설계하였다. 설계된 Chip은 Cadence의 Verilog-XL 시뮬레이터를 이용하여 Back-end 시뮬레이션을 수행한 결과 $2{\mu}s$내에 정확한 제어를 수행하였다. In this paper, the novel scheme of OAM performance management function is proposed to supply the most of network resources and reliable services by processing data having various QoS(quality of service) in the view of cell loss and cell delay of ATM networks Also, the special fields of OAM cell are defined in order to improve correlate control, operation, and management technique between networks which is required to flexibility and precision control as detecting the performance information of the variable networks periodically. The proposed OAM function, the input/output function of cell, and the interface function of the accessory device which is likely to the memory/CPU are designed to ASIC. The designed chip is carried out the back-end simulation using Verilog-XL simulator of Cadence. In result, it is able to performs an accurate control in $2{\mu}s$.

국토해양부 SOC건설사업 관리역량 강화방안 연구

박형근,Park, Hyeong-Geun 한국건설관리학회 2011 건설관리 : 한국건설관리학회 학회지 Vol.12 No.2

급성심근경색증 환자의 진료 질 평가를 위한 병원별 사망률 예측 모형 개발

박형근,안형식,Park, Hyeung-Keun,Ahn, Hyeong-Sik 한국의료질향상학회 2003 한국의료질향상학회지 Vol.10 No.2

Objectives: To develop a model that predicts a death probability of acute myocardial infarction(AMI) patient, and to evaluate a performance of hospital services using the developed model. Methods: Medical records of 861 AMI patients in 7 general hospitals during 1996 and 1997 were reviewed by two trained nurses. Variables studied were risk factors which were measured in terms of severity measures. A risk model was developed by using the logistic regression, and its performance was evaluated using cross-validation and bootstrap techniques. The statistical prediction capability of the model was assessed by using c-statistic, $R^2$ as well as Hosmer-Lemeshow statistic. The model performance was also evaluated using severity-adjusted mortalities of hospitals. Results: Variables included in the model building are age, sex, ejection fraction, systolic BP, congestive heart failure at admission, cardiac arrest, EKG ischemia, arrhythmia, left anterior descending artery occlusion, verbal response within 48 hours after admission, acute neurological change within 48 hours after admission, and 3 interaction terms. The c statistics and $R^2$ were 0.887 and 0.2676. The Hosmer-Lemeshow statistic was 6.3355 (p-value=0.6067). Among 7 hospitals evaluated by the model, two hospitals showed significantly higher mortality rates, while other two hospitals had significantly lower mortality rates, than the average mortality rate of all hospitals. The remaining hospitals did not show any significant difference. Conclusion: The comparison of the qualities of hospital service using risk-adjusted mortality rates indicated significant difference among them. We therefore conclude that risk-adjusted mortality rate of AMI patients can be used as an indicator for evaluating hospital performance in Korea.

급성심근경색증 환자를 대상으로 한 중증도 보정 방법의 평가

박형근,Park, Hyeung-Keun 한국의료질향상학회 2003 한국의료질향상학회지 Vol.10 No.2

Objectives: To evaluate the performance of models to predict AMI patients death using severity adjustment measures in Korea. Methods: Medical records of 861 patients treated by AMI in 7 general hospitals during 1996 and 1997 were reviewed by trained nurses. We measured the severity of patients by APACHE III, MedisGroups, CSI and DS. Using each severity method a predictive mortality for each patient was calculated from a logistic regression model including the severity score. The statistical performance of each severity method model was evaluated by using c-statistics and R2. For each hospital, z scores compared actual and expected mortality rates. Results: The overall in-hospital mortality was 14.5%, ranged from 10.0% to 22.2%. The distributions of severity scores for each method was significantly different by hospitals. The four severity-adjusted models to predict AMI patients death varied in their statistical performance for discrimination power of patients death. Order of Severity-adjusted mortality rates and z scores by four severity measures was different. Conclusion: Severity-adjusted mortality rates of AMI patients might be applied as an indicator for hospital performance evaluation in Korea. Because different severity methods frequently produce different impressions about relative hospital performance, more studies has to be done to use it as quality indicator and more attention should be paid to select appropriate severity measures.

퍼지 확률 기울기 알고리즘을 이용한 등화기 설계

박형근,나유찬,Park, Hyoung-Keun,Ra, Yoo-Chan 한국정보통신학회 2005 한국정보통신학회논문지 Vol.9 No.1

본 논문에서는 스텝 크기(step size)를 자동적으로 조절함으로써 빠른 수렴비와 낮은 초과 MSE를 갖는 TS(Tagaki-Sugeno) 퍼지 모델과 ISI에 강하고 위상변화에 둔감한 CMA(constant modulus algorithm)를 접목시킨 새로운 퍼지 확률 기울기(Fuzzy Stochastic Gradient) 알고리즘을 제시하고 비이상적인 전송채널에 의해서 발생한 왜곡을 보상함으로써 수신 측에서 비트 검출 오류를 감소시키기 위하여 국내 지상파 디지털 TV의 표준으로 되어 있는 VSB 방식에 적용 가능한 등화기(equalizer)를 구현하였다. For high-speed data communication in band-limited channels, main of the bit error are fading and ISI(Inter-Symbol Interference). The common way of dealing with ISI is using equalization in the receiver. In this thesis, channel adaptive equalizer which uses Fuzzy Stochastic Gradient(FSG) and Constant Modulus Algorithm(CMA) is nonlinear equalizer, or Blind equalizer, that works directly on the signals with no training sequences required. This equalizer employs Takagi-Sugeno's fuzzy model that uses the FSG algorithm, to automatically regulate the step size of the descent gradient vector, combining fast convergence rate and low mean square error(MSE), and the CMA which is a special case of Godard's algorithm, to having multiple dispersion constants($R_p$).

2007 한국건축문화대상 준공건축물부분 우수상-목동 현대 하이페리온 II

박형근,Park, Hyeong-Geun 대한건축사협회 2008 建築士 Vol.2008 No.1