• Journal of Chest Surgery
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• v.50 no.3
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• pp.144-152
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• 2017

Background: The ubiquitin-proteasome system (UPS) is an important pathway of proteolysis in pathologic hypertrophic cardiomyocytes. We hypothesize that MG132, a proteasome inhibitor, might prevent hypertrophic cardiomyopathy (CMP) by blocking the UPS. Nuclear factor kappa-light-chain-enhancer of activated B cells ($NF-{\kappa}B$) and androgen receptor (AR) have been reported to be mediators of CMP and heart failure. This study drew upon pathophysiologic studies and the analysis of $NF-{\kappa}B$ and AR to assess the cardioprotective effects of MG132 in a left ventricular hypertrophy (LVH) rat model. Methods: We constructed a transverse aortic constriction (TAC)-induced LVH rat model with 3 groups: sham (TAC-sham, n=10), control (TAC-cont, n=10), and MG132 administration (TAC-MG132, n=10). MG-132 (0.1 mg/kg) was injected for 4 weeks in the TAC-MG132 group. Pathophysiologic evaluations were performed and the expression of AR and $NF-{\kappa}B$ was measured in the left ventricle. Results: Fibrosis was prevalent in the pathologic examination of the TAC-cont model, and it was reduced in the TAC-MG132 group, although not significantly. Less expression of AR, but not $NF-{\kappa}B$, was found in the TAC-MG132 group than in the TAC-cont group (p<0.05). Conclusion: MG-132 was found to suppress AR in the TAC-CMP model by blocking the UPS, which reduced fibrosis. However, $NF-{\kappa}B$ expression levels were not related to UPS function.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.4A
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• pp.259-270
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• 2005

This paper proposes a mathematical model to analyze call-and packet-level performance of the TD-CDMA/TDD system which could serve a flexible radio resource management against multi-type heterogeneous and asymmetrical traffic conditions. On call-level analysis, the mathematical model based on queueing theory performs multi-dimensional operations using random vectors or matrices to consider multiple types of traffic and also deal with asymmetrical up- and down-direction transmissions separately. Employing the mathematical model, we obtain rail blocking probability for each type of traffic and also the optimum switching-point with the smallest call flocking probability. And on packet-level analysis, employing a non-prioritized queueing scheme between circuit and packet calls, we solve 2-dimensional random vector problem composed of the queue length for packets and the number of circuit calls being served. Finally, packet-level performance is analyzed in terms of the packet loss probability and the buffer size required under mixed-traffic conditions of multiple types of circuit and packet calls.

• Proceedings of the Korea Society for Simulation Conference
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• 1994.10a
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• pp.7-8
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• 1994

최근 들어 원자재, 재공품 또는 완제품을 신속하고 정확하게 공급/배분하기 위해 저장과 인출을 담당하는 Material Handling System을 이용하여 작업자의 개입요소를 줄이며, 제고관리 Computer를 이용하여 입고/출고 명령을 유효적절하게 처리하는 ASRS(Atomated Storage and Retreival System : 자동창고 시스템)가 널리 공급되고 있다. 중앙은행의 현금창고, 병원의 약품창고, 식품/화장품 회사의 배송창고, 군수물자의 군납창고에 이르기까지 물품의 저장 또는 공급의 필용성을 갖는 곳에서는 어디든지 찾아볼 수 있는 ASRS는 가깝게는 관공소나 대형빌딩의 주차장에도 이의 개념이 도입되어 사용됨을 볼 수 있다. 최근의 인금인상, 구인난등의 이유로 ASRS설치는 계속 증가할 추세에 있으나 자동 창고 시스템을 설치하기 위해서는 막대한 초기 투자가 필요하며 시스템의 설계 및 설치후 운영에 대한 연구가 반드시 필요하다. ASRS의 운영 Rule 검증, 수행능력 분석등의 목적을 갖는 연구에는 여러 접근방법이 있을 수 있으나 구성 설비와 운영 Rule의 복잡한 관계로 컴퓨터 시뮬레이션의 거의 유일한 문제해결 방법이다. ASRS의 Modeling에 관한 기존의 연구로는 수리모델 수립. 이산사건 시스템의 관점에서 event-graphy, petri-net을 이용한 modeling이 있으며 ASRS에 대한 전용 Simulator 개발등이 진행되었다. 본 연구의 대상 시스템은 2개의 Rack과 하나의 Stacker Crane 으로 구성된 Aisle과 입출고의 물류를 처리하는 순환 RGVS(Rail Guided Vehicle System), 입/출고장을 구성하는 Conveyor Net등으로 이루어진 제조-물류시스템의 일반적인 ASRS이다. 또 이 ASRS의 입/출고 방식은 전수 입/출고만을 포함하며 Blocking 방지를 위한 Capaicty 예약, 다중설비 선택등의 문제등을 고려하고 있다. 본 연구의 접근방법으로는 ASRS의 개념적인 Reference Model을 수립하고 이 Reference Model에 대한 Formal Model로 DEVS(Discrete Event System Specification)을 이용하여 시스템을 Modeling하였다. 이의 Computer Simulation을 위하여 DEVS형식론 환경에서의 Simulation Language인 DEVSim ++ⓒ를 이용하여 시스템을 구현하였다.

• Korean Journal of Remote Sensing
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• v.31 no.4
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• pp.331-336
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• 2015

In this study, a numerical model developed for sunshine duration based on GIS data was used. This model considers blocking caused by topography and buildings and it is properly applicable to evaluation of sunshine duration environment in urban areas. The model reasonably well predicted the solar altitude and azimuth angels, compared to those provided by Korea Astronomy and Space Science Institute (KASI). The developed model was applied to evaluation of sunshine duration environment around the Seonleung Park located near a building-congested area in Seoul. The model well reproduced shadow caused by buildings and/or topography in the numerical domain at 09:00 on August 1, 2015. In addition, the model was applied to finding a suitable measurement sites for pyrheliometer around the Seonleung Park. The model was also usefully applied to finding a suitable site for pyrheliometer in an urban area.

• Special Issue of the Society of Naval Architects of Korea
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• 2008.09a
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• pp.112-117
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• 2008

The Insulation, which is consist of the glass wool, mineral wool or perforated SUS plate, installed on the wall or under ceiling for the protecting heat and the blocking the noise of engine room area. In our shipyard, designing the structure model of insulation is hard and difficult, Because designed the insulation model is considered of any factors which are hull model properties of panel shape, direction and thickness and service of area. In this paper, We issue the way to utilize shape and direction of the hull model information and specific character of working space in engine room.

• Proceedings of the Korea Society for Simulation Conference
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• 1992.10a
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• pp.8-8
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• 1992

Through a simulation experiment, often an experimenter is concerned with estimating the system parameters of the linear model consisting of m design points from the outputs oft the simulation model. To improve the estimation of the system parameters and reliability of these estimators, appropriate simulation techniques have been developed. For the first order linear model, Schruben and Margolin (1978) exploited the random number assignment rules which uses a combination of common random numbers and antithetic streams in a simulation experiment designed to estimate the system parameters when the design matrix of simulation model admits orthogonal blocking into two blocks. Nozari, Arnold and Pegden (1984) developed a method for appliying the method of control variates to the situation of the linear model having multiple design points. This talk deals with a different way of utilizing controls under the correlation induction strategy of Schruben and Margolin's to improve the simulation efficiency, and presents a procedure for obtaining the estimators of the system parameters analytically. Simulation results on a selected simulation model indicate a promising evidence that a proposed method may yield better results than Schruben and Margolin's method.

• Journal of Internet Computing and Services
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• v.1 no.2
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• pp.11-18
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• 2000

In this paper we present a new extensible model based upon the concept of subtransactions in real-time transaction systems. The nested transaction model originally proposed by J. Moss is extended for real-time uniprocessor transaction systems by adding explicit timing constraints. Based upon the model, an integrated concurrency control and scheduling algorithm is developed, that not only guarantees timing constraints of a set of real-time transactions but also maintains consistency of the database. The algorithm is based on the priority ceiling protocol of Sha et al. We prove that the Real-Time Nested Priority Ceiling Protocol prevents unbounded blocking and deadlock, and maintains the serializability of a set of real-time transactions. We use the upper bound on the duration that a transaction can be blocked to show that it is possible to analyze the schedulability of a transaction set using rate-monotonic priority assignment. This work is viewed as a step toward multiprocessor and distributed real-time nested transaction systems. Also, it is possible to be extended to include the real-time multimedia transactions in the emerging web-based database application areas.

• 한국전산유체공학회:학술대회논문집
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• 2006.05a
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• pp.129-132
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• 2006

A Pacific Ocean circulation model based on the RIAM Ocean Model (RIAMOM) with $1/6^{\circ}C\;and\;1/12^{\circ}C$ horizontal resolution successfully reproduced the peculiar circulation structures of the Pacific Ocean. The volume transports of model agree very well with the results of observations in the northwestern Pacific Ocean. Also our model successfully reproduced the observed structures of the northeastward Ryukyu Current with a subsurface core at $500{\sim}600m$. A Possible mechanism for the subsurface current core of the Ryukyu Current is proposed focusing on the blocking effect of the Ryukyu Island Chain.

• Journal of Advanced Navigation Technology
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• v.15 no.5
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• pp.757-763
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• 2011

This paper presents a channel reservation scheme using Wiener prediction model in order to reduce the rate of forced termination of cognitive users in cognitive radio networks. The proposed method uses Wiener prediction model to predict the number of radio channel required by the reappearance of primary users, and then calculates and reserves the number of channels that cognitive users demand for their spectrum handoff. Through the simulation we investigate cognitive users' forced termination rate and blocking rate with and without channel reservation. In addition we show the bandwidth utilization efficiency for both cases. The results show that the proposed scheme can reduce the forced termination rate of cognitive users at the cost of slightly increasing in blocking rate. Also it is seen that there is little difference in bandwidth utilization efficiency for both cases.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.31 no.6
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• pp.1261-1266
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• 2021

Existing information security risk assessment methods focus on evaluating the vulnerability of information assets. However, when the form of information assets changes and new types of information assets emerge, there is a limitation in that the evaluation standards for them are also added or deleted. Existing methods have insufficient research on the path through which cyber threats are introduced. In particular, there is very little research on blocking the inflow path for web-based information systems with public IPs. Therefore, this paper introduces the main research contents of the BDLA (Blockade and Defense Level Analysis)-based information security risk assessment model. In addition, by applying the BDLA-based information security risk assessment model, the information security risk level was studied by measuring the blockade level and security equipment level of 17 public institutions.