• 한국운동역학회지
• /
• 제16권4호
• /
• pp.73-81
• /
• 2006

The purpose of this study was to investigate the effects of strength training on knee joint torque during walking in an adolescent with trisomy-21 Down syndrome. One adolescent with Down syndrome and one normal child participated in this study. Strength training consisted of eight exercises: squat, hamstring curl, hip adduction, hip abduction, knee extension, toe raise, sit-ups, and hyperextension of the waist. The participant with Down syndrome was participated in strength training for 12 weeks, three times a week, three sets, 10-15 RM; resistance was adjusted according to the principle of progressive overload. To measure the effect of strength training, isokinetic strength variables and knee joint torques were measured before training and after 12 weeks of training. The participant with Down syndrome had some abnormalities in controlling knee motion during walking due to muscle hypotonia, ligament laxity, and weakness of muscles. Post-training isokinetic strength increased compared to pre-training measurements. Knee range of motion were increased after strength training. Strength training did not affect ad/adduction and in/exteranl moments but did have an effect on flexor/extensor moment and timing.

• 전기학회논문지
• /
• 제64권8호
• /
• pp.1161-1167
• /
• 2015

Distribution Management System(DMS) ienhancing distribution automation system-based operation efficiency is an optimized system by various operational applications in a distribution network. DMS employs various applications like topology reconfiguration, volt/var control, and restoration at events such as overload, voltage violation, and a fault in a distribution system. An operation efficiency to employ multi-applications as restoration with short-term load forecasting is higher than a performance by a single application; and the applications are accomplished by an operator’s control. Applications’ combination is determined by various alarm information which means critical issues in order to operate a distribution system. Thus, this paper proposes an application management system which can configure application combination, control applications depending on alarm information and check their performance condition. The proposed application management system can be customized by operator easily and have high operation efficiency and reliability because it is worked by reviewed alarm information from operator.

• 대한전기학회논문지
• /
• 제37권5호
• /
• pp.272-281
• /
• 1988

The problem of optimal transmission system planning is to find the most economical locations and time of transmission line construction under the various constraints such as available rights-of-way, finances, the technical characteristics of power system, and the reliability criterion of power supply, and so on. In this paper the constraint of right-of-way is represented as a finite set of available rights-of-way. And the constructed for a unit period. The electrical constraints are represented in terms of line overload and steady state stability margin. And the reliability criterion is dealt with the suppression of failure cost and with single-contingency analysis. In general, the transmission planning problem requires integer solutions and its objective function is nonlinear. In this paper the objective function is defined as a sum of the present values of construction cost and the minimum operating cost of power system. The latter is represented as a sum of generation cost and failure cost considering the change of yearly load, economic dispatch, and the line contingency. For the calculation of operating cost linear programming is adopted on the base of DC load flow calculation, and for the optimization of main objective function nonlinear Branch-and-Bound algorithm is used. Finally, for improving the efficiency of B & B algorithm a new sensitivity analysis algorithm is proposed.

• ETRI Journal
• /
• 제28권3호
• /
• pp.282-290
• /
• 2006

In vertically overlaid cellular systems, a temporary traffic concentration can occur in a hot-spot area, and this adversely affects overall system capacity. In this paper, we develop an adaptive hot-spot operating scheme (AHOS) to mitigate the negative effects from the nonuniform distribution of user location and the variation in the mixture of QoS requirements in orthogonal frequency division multiple access downlink systems. Here, the base station in a macrocell can control the operation of picocells within the cell, and turns them on or off according to the system overload estimation function. In order to determine whether the set of picocells is turned on or off, we define an AHOS gain index that describes the number of subcarriers saved to the macrocell by turning a specific picocell on. For initiating the picocell OFF procedure, we utilize the changes in traffic concentration and co-channel interference to the neighboring cells. According to computer simulation, the AHOS has been proved to have maximize system throughput while maintaining a very low QoS outage probability under various system scenarios in both a single-cell and multi-cell environments.

• 설비공학논문집
• /
• 제14권9호
• /
• pp.749-755
• /
• 2002

In order to develop a multi-type heat pump system with two indoor units of non-uniform capacities, the optimum refrigerant circuit was developed using capillary tubes. The refrigerant circuit was composed of four main parts, a heating circuit, a cooling circuit, a by-pass circuit and a balance circuit. The system characteristics of multi-type heat pump was investigated through the rating test and the reliability test, using the multi-type psy-chrometric calorimeter. The results of the rating test showed that the capacity of the multi-type heat pump was about 93% of the design value. In particular, the capacity of cooling single mode was about 13% higher than the design value, and the capacity of heating multi mode was about 5% higher than the design value. The reliability of the multi-type heat pump was verified by various reliability tests (overload, extension tube, freeze up, under/over charging, sweat, flood back). The optimal amount of refrigerant charge and compressor capacity were determined from the present work.

• 전기학회논문지
• /
• 제66권7호
• /
• pp.1149-1154
• /
• 2017

In this paper, we propose a sensorless multi-function controller applicable for deep well water pumps using current detection method. The proposed system overcomes various drawbacks of existing sensored system and additional features like Over current protection function due to overload, Under current protection function for idling at low water level and Relay function for starting single phase motors and acts as a level indicator to detect water lever in real time by the current detection method. A prototype of the multi-function controller system is designed and all of its functions are tested in the laboratory. The application of the proposed controller ensures reduction in the power consumption and maintenance cost in the facilities like water and septic tanks, drainage and waste water system, oil and chemical tanks where deep well pumps are used.

• Journal of Information Processing Systems
• /
• 제8권4호
• /
• pp.721-738
• /
• 2012

The Internet has become an increasingly important source for finding the right employees, so more and more companies post their job openings on the Web. The large amount and dynamic nature of career recruiting information causes information overload problems for job seekers. To assist Internet users in searching for the right job, a range of research and commercial systems were developed over the past 10 years. Surprisingly, the majority of existing job search systems support just one, rarely two ways of information access. In contrast, our work focused on exploring a value of comprehensive access to job information in a single system (i.e., a system which supports multiple ways). We designed Proactive, a recommendation system providing comprehensive and personalized information access. To assist the varied needs of users, Proactive has four information retrieval methods - a navigable list of jobs, keyword-based search, implicit preference-based recommendations, and explicit preference-based recommendations. This paper introduces the Proactive and reports the results of a study focusing on the experimental evaluation of these methods. The goal of the study was to assess whether all of the methods are necessary for users to find relevant jobs and to what extent different methods can meet different users' information requirements.

• 한국인터넷방송통신학회논문지
• /
• 제14권6호
• /
• pp.75-84
• /
• 2014

과부하 및 단일장애점(Single Point of Failure), 경로 비최적화, 망 확장성 등의 문제점을 가지고 있는 기존 중앙 집중형 이동성 관리 프로토콜들의 문제점을 해결하기 위해 최근 IETF를 중심으로 분산 이동성 관리 방안이 활발히 연구되고 있다. 본 논문에서는 망기반 부분분산형 이동성 관리 메커니즘 pDMMv6를 제시하고, 시뮬레이션을 통해 다양한 사용자 트래픽 환경에서 기존의 PMIPv6 및 MIPv6 프로토콜과의 성능 비교를 수행하였다. 성능분석 결과로는 UDP 트래픽의 전송율, 단대단 패킷 전송지연시간, 신호 메시지 바인딩 지연시간, 노드별 CPU 점유율 및 다양한 서버-클라이언트 TCP 응용에 따른 응답시간(웹 브라우징, 이메일 송수신, 텔넷 원격접속, FTP 파일전송, 데이터베이스 액세스 등)들을 제시하였다.

• 정보처리학회논문지:컴퓨터 및 통신 시스템
• /
• 제12권1호
• /
• pp.9-16
• /
• 2023

로봇은 군사 분야로까지 활용 범위를 넓히며 다가올 미래전에서 감시경계, 적군 탐지 등 중요한 임무를 맡게 될 것으로 전망된다. 군집 로봇은 다수라는 장점으로 단일 로봇이 수행하기 어렵거나 오랜 시간이 소요된 임무를 보다 효율적으로 수행할 수 있다. 상호 간 인지 및 협업이 필수인 군집 로봇은 방대한 데이터를 주고 받으며, 이로 인해 SW의 검증이 점점 더 어려워지고 있다. 임무 검증의 신뢰성을 높이기 위해 사용하는 Hardware-in-the-loop simulation은 복잡한 군집 로봇의 SW 검증을 가능하게 하나, HILS 장치와 시뮬레이터 간 주고 받는 검증 데이터의 양이 검증 대상 시스템 수에 따라 기하급수적으로 증가하여 통신 과부하가 발생할 수 있다. 본 논문에서는 군집 로봇의 임무 검증에서 발생하는 통신 과부하 문제를 해소하기 위해 디지털 트윈 기반의 통신 최적화 기법을 제안한다. 제안하는 Digital Twin based Multi HILS Framework 하에서 Network DT은 Network Controller 알고리즘을 통해 임무 시나리오에 따라 각 로봇에게 네트워크 자원을 효율적으로 할당할 수 있으며, 군집에 참여하는 개별 로봇들이 요구하는 Sensor Generation Rate를 모두 만족시킬 수 있음을 확인하였다. 또한 데이터 전송에 대한 실험 결과 패킷 손실 비율을 기존 15.7%에서 약 0.2%로 감소시킬 수 있었다.

• 한국인터넷방송통신학회논문지
• /
• 제14권4호
• /
• pp.157-163
• /
• 2014

이용자의 감성은 그 어느 때보다 기업, 정부 그리고 개인 간의 소통에서 중요한 변수로 인식된다. 특히 수많은 연구에서 이용자의 감성을 파악하는 방법으로 음성 톤, 속도, 얼굴 표정, 몸의 이동 방향과 속도, 제스쳐 등이 사용된다. 다중 모달리티는 단일의 모달리티보다 정확도가 높은 반면 멀티 센싱에 따른 인식률 한계와 데이터 처리 부하 그리고 센싱된 값을 추론하는 우수한 알고리즘이 요구된다. 즉 다중 모달리티는 각 모달리티의 개념, 속성이 상이하여 인간의 감성값이라는 표준화된 값으로 전환하는데 오류가 발생할 수 있다. 이 문제를 해결하기 위해 다중 모발리티 중관계망 분석, 문맥 파악, 디지털 필터 등의 기술을 이용하여 이용자에게 우선 순위를 갖는 감성 표현 모달리티를 추출할 필요가 있다. 특정 상황에 우선 순위를 갖는 모달리티와 그 주변을 에워싼 다른 모발리티를 암묵 값으로 처리하면 감성 인식에 있어 컴퓨터 자원의 소비 대비 견고한 시스템을 구성할 수 있다. 본 연구 결과, 암묵 데이터를 활용하여 다중 모발리티 중 가중치를 어떻게 부여할지에 대하여 제안하였다.