• 경영과학
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• 제16권1호
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• pp.39-50
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• 1999

This paper proposes a new call admission control method to enhance the reverse link capacity of a cell with heavy traffic in the CDMA PCS system under the uneven traffic load between cells. Since the capacity of a cell in the CDMA system is restricted by the total interference caused by terminals in the own cell and the adjacent cells, we can enhance the capacity of a cell by reducing the interference from other cells if possible. Our power control method allows that the signal powers received in base stations with heavy traffic be larger than those received in base stations with light traffic in order to make the interference due to other cells in the cells with heavy traffic relatively small. In the previous study, it was assumed that the signal power received by each base station in the CDMA PCS system is same when the call admission control algorithm is implemented. We could show that the reverse link capacity of a cell in the CDMA PCS system can be increased about 20% under our call admission control method.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2006년 제4회 한국유체공학학술대회 논문집
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• pp.275-278
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• 2006

A steam turbine is one of propulsion systems of a LNG carrier, which consists of high pressure (HP) and low pressure (LP) turbines. In order to obtain high power, each one has the form of a multi-stage turbine. Especially, the first stage of a HP turbine is Curtis stage and uses partial admission considering the turbine efficiency. The performance of a HP turbine can be predicted by a mean-line analysis method, because the relatively large value of hub-tip ratio makes the three-dimensional losses small. In this study, a performance analysis method is developed for a multi-stage HP turbine using Chen's loss model developed for the transonic steam turbines. To consider the feature of partial admission, different partial admission models are reviewed, This analysis method can be used in partial load conditions as well as full load condition. The calculation results are also compared with the CFD results about some simple cases to check the accuracy of the program. Performance of two HP turbine models are calculated, and the calculation results are compared with the designed data. The comparison shows the qualitative performance analysis result.

• 한국통신학회논문지
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• 제37B권12호
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• pp.1113-1118
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• 2012

에너지 소비의 효율화를 위한 그린 기술로서 스마트 그리드와 지능형 교통 시스템 등이 주목받고 있다. 이러한 기술의 구현에는 다수의 센서, 액츄에이터 (actuator), 그리고 컨트롤러들이 필요하다. 이러한 구성요소들 간의 machine-to-machine (M2M)통신의 중요성은 높아지고 있다. M2M 통신의 특징은 다수의 machine-type-communication(MTC) 디바이스들이 참여하고, 통신 트래픽 패턴과 QoS 요구조건이 다양하다는 것이다. 이러한 M2M 통신을 효율적으로 지원하기 위한 호 수락 방법들에서는 동일한 시간관련 QoS 조건을 갖는 MTC 디바이스들을 클러스터 단위로 그룹핑하고, QoS 조건 만족여부에 따라 호 수락을 결정하는 방법을 제안하였다. 하지만 이 방법은 데이터 전송주기와 최대 전송지연 시간이 같을 경우에만 적용 가능하다. 본 논문에서는 이러한 제한 없이 사용할 수 있는 방법을 제안한다. 또한 전송 주기와 최대 전송지연 시간이 특별한 관계에 있을 때 최적화할 수 있는 호 수락 제어방법을 제안한다. 제안방법의 QoS 만족 적합성에 대한 증명을 제시하였고, 시뮬레이션을 통해 실제 동작 가능하고, 기존 방법들보다 호 수락 확률에서 우수함을 보였다.

• International Journal of Fluid Machinery and Systems
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• 제2권3호
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• pp.248-253
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• 2009

This paper presents a numerical study for unsteady flows in a high-pressure steam turbine with a partial admission stage. Compressible Navier-Stokes equations are solved by the high-order high-resolution finite-difference method based on the fourth-order compact MUSCL TVD scheme, Roe's approximate Riemann solver, and the LU-SGS scheme. The SST-model is also solved for evaluating the eddy-viscosity. The unsteady two-dimensional flows through whole nozzle-rotor cascade channels considering a partial admission are numerically investigated. 108 nozzle passages with two blockages and 60 rotor passages are simultaneously calculated. The influence of the flange in the nozzle box to the lift of rotors is predicted. Also the efficiency of the partial admission stage changing the number of blockages and the number of nozzles is parametrically predicted.

• ETRI Journal
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• 제26권1호
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• pp.27-37
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• 2004

The architecture in a differentiated services (DiffServ) network is based on a simple model that applies a per-class service in the core node of the network. However, because the network behavior is simple, the network structure and provisioning is complicated. If a service provider wants dynamic provisioning or a better bandwidth guarantee, the differentiated services network must use a signaling protocol with QoS parameters or an admission control method. Unfortunately, these methods increase the complexity. To overcome the problems with complexity, we investigated scalable dynamic provisioning for admission control in DiffServ networks. We propose a new scalable $qDPM^2$ mechanism based on a centralized bandwidth broker and distributed measurement-based admission control and movable boundary bandwidth management to support heterogeneous QoS requirements in DiffServ networks.

• 대한기계학회논문집B
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• 제30권11호
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• pp.1131-1138
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• 2006

Aerodynamic shape design of a partial admission turbine using CFD has been performed. Two step approaches are adopted in this study. Firstly, two-dimensional blade shape is optimized using CFD and genetic algorithm. Initially, the turbine cascade shape is represented by four design parameters. By controlling the design parameters as variables, the non-gradient search is analyzed for obtaining the maximum efficiency. The final two-dimensional blade proved to have a more blade power than the initial blade. Secondly, the three-dimensional CFD analysis including the nozzle, rotor and stator has been conducted. To avoid a heavy computational load due to an unsteady calculation, the frozen rotor method is implemented in steady calculation. The frozen rotor method can detect a variation of the flow-field dependent upon the blade's circumferential position relative to the nozzle. It gives a better idea of wake loss mechanism starting from the lip of the nozzle than the mixing plane concept. Finally, the combination of two and three dimensional design method of the partial admission turbine in this study has proven to be a robust tool in development phase.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 춘계학술대회
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• pp.2100-2104
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• 2004

Amount of Electricity which product generator decide control valve at Turbine. Operating method of Control valve have two mode. First operating method is Partial Arc Admission, and second operating method is Full Arc Admission. Failure of Control Valve have on serious damage electricity lineage. In this Paper, We have investigated resonance that Control Valve spring casing.

• 한국간호교육학회지
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• 제14권1호
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• pp.12-19
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• 2008

Purpose: This study was performed to explore the effects of an admission-education program on knowledge, self-efficacy, self-care and glucose control in type 2 diabetes patients. Method: A single group pre-post test design was used. Twenty-one patients participated in this program during 6 days which consisted of education and practice about exercise, diet, self-care and prevention of complications. Variables at baseline, 3 months, and 6 months were measured. Results: Knowledge level, self-care level and self-efficacy were significantly increased over time after the admission-education program. The $HbA_1C$ level and glucose level in urine were significantly decreased over time after the admission-education program. Conclusion: The admission-education program can increase levels of knowledge, self-care, self-efficacy and decrease glucose levels. Therefore, this admissioneducation program was shown to have a positive effect on the management of diabetes.

• 대한예방한의학회지
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• 제3권1호
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• pp.147-155
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• 1999

In order to investigate the effect of circulating blood and extinguishing blood stasis method on acute ischemic stroke treatment, we compared muscle weakness in two groups. Dansamhwanotang was administered to experimental group and the Sopungtang was administered to comparison group. In prospective and consecutive study, 24 patients(male 14, female 10) were admitted to hospital within 6hours(median $4.21{\pm}2.45)$ after stroke attack. All of them were diagnosed computed tomography as acute cerebral infarction. We divided that patients into two groups. The experimental group was 13, took median $4.17{\pm}1.72hrs$ to admission after stroke attack and the comparison group 11, median $4.31{\pm}2.72hrs$ to admission after stroke attack. There was no statistical difference in time consumed from stroke onset to admission(P>0.05). Muscle weakness was measured on admission and 7 days later on AMA(American Medical Association) method. In the experimental group, muscle weakness on admission was $2.23{\pm}0.51$ and $2.79{\pm}0.72$ in upper and lower extremity, respectively. In comparison group, muscle weakness on admission was $2.17{\pm}0.43$ and $2.67{\pm}0.82$ in upper and lower extremity, respectively. There was no difference in muscle weakness(P〈0.05). In 7 days after, muscle weakness was $2.31{\pm}0.35$ in upper extremity and $3.15{\pm}0.12$ in lower extremity in experimental group, and $2.27{\pm}0.74$ in upper extremity and $3.45{\pm}0.48$, lower extremity in comparison group. There was no meaningful improvement statistically in upper extremity(p<0.05) but significant evolution in lower extremity(p<0.05). The muscle weakness comparison between admission time and 7 days later was as follows. Experimental group had improvement at the degree of $0.24{\pm}0.92$, $0.42{\pm}0.82$ in upper and lower extremity, respectively and comparison group, $0.12{\pm}0.82$, $0.27{\pm}0.97$ in same part(p<0.05). So, Dansamhwanotang administered group had more good muscle weakness improvement than Sopungtang administered group(P>0.05). From the above result, I suppose that circulating blood and extinguishing blood stasis method helps recover hemiparesis caused by acute ischemic cerabral disease, in acute stage at least.

• 한국정보처리학회논문지
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• 제4권8호
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• pp.2070-2079
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• 1997

본 논문에서는 호 수락 제어 문제를 해결하기 위해 퍼지 논리 제어기의 장점과 신경망의 학습 능력을 이용한 ATM 망의 호 수락 제어 시스템을 제안하였다. ATM 망의 새로운 호는 현재 서비스 중인 호의 서비스 품질(QoS : quality of service)이 영향을 받지 않을 경우 망에 접속이 된다. 신경망 호 수락 제어 시스템은 입/출력 패턴의 학습으로 예측성 잇게 호 수락/거절을 하는 시스템이다. 본 논문의 퍼지 신경망 호 수락 제어 시스템에서는 학습 속도 개선을 위해 학습율과 모맨텀 상수에 퍼지 추론을 적용하였다. 이 시스템은 시뮬레이션을 통해 기존의 신경망 방법과 퍼지 신경망 방법에서의 학습 횟수 측정으로 제안 알고리즘의 우수성을 검증하였다. 시뮬레이션 결과 퍼지 학습 규칙에 근거한 퍼지 신경망 CAC(call admission control) 방식이 종래의 신경망 이론에 근거한 CAC 방식보다 학습 속도면에서 약 5배의 속도 향상이 있었다.