• Communications of the Korean Institute of Information Scientists and Engineers
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• v.1 no.1
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• pp.42-49
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• 1983

전산기의 신뢰도(reliability)라 함은 사용자가 제출한 입력에 대하여 전산 기가 제공하는 결과의 신빙성의 척도라할 수 있는데, 이것은 주어진 전산기의 부 분품 하나하나가, 그리고 프로그램의 하나하나의 instruction이 설계당시에 목적한 성능을 얼마나 잘 유지하고 있는가를 측정하는 척도라고 볼 수 있습니다. 이 신 뢰도는 전산기의 수명, 필요할 때 전산기가 가동할 확율, 또는 전산기의 성능으로 나타낼 수 있습니다. 제2세대 이전의 전산기들에서는 전자공업과 전산기 기술의 불충분한 발전으로 인하여 비용과 기계의 크기의 한정 때문에 신뢰도 향상을 위 한 대책이 거의 없었습니다. 따라서 현재 볼 수 있는 American Air Line의 SABRE(Semi Automatic Business Research Environment), Bell 전화 연구소의 ESS-I, II, III(Electronic Switching System), IBM의 FMS(Future Manufacturing System)과 같은 real-time 씨스템으로서의 응용분야의 개발은 상 당히 어려운 문제였습니다. 그러나 전자공업의 비약적인 발전에 힘입어 금세대의 범용전산기의 설계가 가능하게 되었고, 오퍼레이팅 씨스템의 발전으로 인하여 multiprogramming, time-sharing, real-time 씨스템 등의 응용분야의 개발이 활발 하게 되었습니다. 이러한 응용분야의 활발한 개발과, 대규모 집적회로 (LSI)의 개 발로 ROM(Read Only Memory)의 가격화, 그리고 microprogram의 보급 등으로 특수 목적의 time sharing operation을 위한 소형 전산기가 발전하게 되었으며 종 래의 범용 전산기 대신에 CDC의 string unit과 pipeline을 이용한 STAR 100과 일리노이 대학의 256processor와 Burrough의 B6500로 구성된 ILLIAC-IV와 같은 초대형 전산기가 등장하게 되었습니다.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.11a
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• pp.31-35
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• 2008

This test cell is developed to provide the fundamentals of operational mechanism and structural configuration, and further to verify thermodynamic calculation with this test data to the institutes or laboratories research and study gas turbine engine for academic purpose. The test cell is installed to monitor and collect real-time data as to temperature, pressure, thrust, fuel flow, and air flow etc. using by NI DAQ(Data acquisition)device and LabVIEW program based on 30lbf-micro turbojet engine.

• Proceedings of the SAREK Conference
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• 2006.06a
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• pp.3-8
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• 2006

The heat pump system is attractive alternatives to conventional heating and cooling systems owing to their higher energy utilization efficiency. The thermal loads of commercial and institutional buildings are generally cooling-dominated. In this study have been developed ice storage type heat pump system for cooling and heating by heat pipe. This system was practiced performance test on evaluation criteria for heat storage systems. Accomplished the actual proof examination and looked into the performance of the system. In this study, measurement and analysis of ice storage type heat pump system for cooling and heating by heat pipe. The heat pump unit COP appears 3.05 for cooling and 4.20 for heating. As a result, the method to energy saving and to using a substitute energy actively that is heat pump cooling & heating system is expected by heat pipe. Thermal storage capacity appears $19.5RTH/m^3$ for cooling.

• Structural Engineering and Mechanics
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• v.71 no.3
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• pp.283-290
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• 2019

In global competition manufacturing companies have to produce modern, new constructions from advanced materials in order to increase competitiveness. The aim of my research was to develop a new composite cellular plate structure, which can be primarily used for structural elements of road, rail, water and air transport vehicles (e.g. vehicle bodies, ship floors). The new structure is novel and innovative, because all materials of the components of the newly developed structure are composites (laminated Carbon Fiber Reinforced Plastic (CFRP) deck plates with pultruded Glass Fiber Reinforced Plastic (GFRP) stiffeners), furthermore combines the characteristics of sandwich and cellular plate structures. The material of the structure is much more advantageous than traditional steel materials, due mainly to its low density, resulting in weight savings, causing lower fuel consumption and less environmental damage. In the study the optimal construction of a given geometry of a structural element of a road truck trailer body was defined by single- and multi-objective optimization (minimal cost and weight). During the single-objective optimization the Flexible Tolerance Optimization method, while during the multi-objective optimization the Particle Swarm Optimization method were used. Seven design constraints were considered: maximum deflection of the structure, buckling of the composite plates, buckling of the stiffeners, stress in the composite plates, stress in the stiffeners, eigenfrequency of the structure, size constraint for design variables. It was confirmed that the developed structure can be used principally as structural elements of transport vehicles and unit load devices (containers) and can be applied also in building construction.

• Journal of the Korean Society of Radiology
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• v.13 no.2
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• pp.159-168
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• 2019

We examined the effect of Siemens ADMIRE (Advanced Modeled Iterative Reconstruction) on image quality by measuring changes in HU, noise, and SNR of background air, fat, muscle, and background signals on a chest CT scan. Experimental results show that as the ADMIRE Strength increases, the noise decreases and the signal increases, consequently the signal-to-noise ratio increases. ADMIRE can reduce noise by 28 ~ 61% compared to FBP, which is a conventional image reconstruction algorithm, and improves SNR by 16 ~ 100%.

• Journal of Hydrogen and New Energy
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• v.30 no.4
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• pp.347-355
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• 2019

As a solution to the growing concern on the global warming, researches are being actively carried out to apply carbon dioxide capture and storage technology to power generation systems. In this study, the integrated gasification combined cycle (IGCC) adopting oxy-combustion carbon capture was modeled and the effect of replacing the conventional air separation unit (ASU) with the ion transport membrane (ITM) on the net system efficiency was analyzed. The ITM-based system was predicted to consume less net auxiliary power owing to an additional nitrogen expander. Even with a regular pressure ratio which is 21, the ITM-based system would provide a higher net efficiency than the optimized ASU-based system which should be designed with a very high pressure ratio around 90. The optimal net efficiency of the ITM-based system is more than 3% higher than that of the ASU-based system. The influence of the operating pressure and temperature of the ITM on system efficiency was predicted to be marginal.

• Archives of Plastic Surgery
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• v.46 no.1
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• pp.75-78
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• 2019

It is difficult to differentiate acute skin failure (ASF) from pressure ulcer (PU). ASF is defined as unavoidable injury resulting from hypoperfusion caused by severe dysfunction of another organ system. We describe a case of ASF mistaken as PU that resulted in a legal dispute. A 74-year-old male patient was admitted to our intensive care unit with sepsis due to bacterial pneumonia. Despite the use of air cushions and regular position changes, skin ulcerations occurred over his occiput, back, buttock, elbow, and ankle. After improvement in his general condition, he was transferred to the department of plastic and reconstructive surgery. Debridement was performed immediately, followed by conservative treatment (including a vacuum-assisted closure device) for 6 weeks. The buttock and occiput wounds were treated surgically. Despite complete healing, his caregivers sued the hospital for failing to prevent PU formation. ASF is a pressure-related injury resulting from hemodynamic instability due to organ system failure. Unlike PU, ASF may occur despite the implementation of all appropriate preventive measures. Furthermore, misdiagnosis of ASF as PU can lead to litigation. Therefore, it is critical for the proper diagnosis to be made quickly, and for physicians to explain that ASF occurs despite proper preventative treatment.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.35 no.2
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• pp.45-52
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• 2019

BEMS(Building Energy Management Systems) have been applied to office buildings and collect relevant building energy data, e.g. temperatures, mass flow rates and energy consumptions of building mechanical systems and indoor spaces. The aforementioned measured data can be beneficially utilized for developing data-driven machine learning models which can be then used as part of MPC(Model Predictive Control) and/or optimal control strategies. In this study, the authors developed ANN(Artificial Neural Network) models of an AHU (Air Handling Unit) and a chiller for a real-life office building using BEMS data. Based on the ANN models, the authors developed optimal control strategies, e.g. daily operation schedule with regard to optimal start and stop of the AHU and the chiller (500 RT). It was found that due to the optimal start and stop of the AHU and the chiller, 4.5% and 16.4% of operation hours of the AHU and the chiller could be saved, compared to an existing operation.

• The Southeast Asian review
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• v.22 no.1
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• pp.207-245
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• 2012

With rapid industrialization and urbanization, numerous cities are faced with urban slum phenomenon combined with housing shortage fueled by population explosion. In Kuala Lumpur, the capital city of Malaysia, the government hereby embarked on supply of public housing to resolve such pending issue. This study aims to understand the periodic changes of public housing as a common basis for basic housing policies with analysis specific features of site plan, block layout, and unit plans. For this purposes, the filed survey during January, 2011 were proceeded. We hereby visited and surveyed a total of 40 apartment complexes for the 1970s~the 2000s (10 complexes respectively on a decade basis). Consequently, Malaysian public apartments prove to offer a very uniform pattern based upon standard plans. Their early plans aren't fairly distincted from those of other countries, but their layouts of plan become differentiated compared with other nations as they actively apply a ventilator called 'air well' in response to tropical climate amid the change of times. This study is expected to broaden our understanding of Malaysia's unique housing culture and lifestyle.

• Journal of ILASS-Korea
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• v.28 no.4
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• pp.191-197
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• 2023

LPG direct injection (LPDi) technology is a method of improving the weaknesses of existing LPG vehicles by directly injection into the combustion chamber. This study was conducted on the comparison of emissions and fuel efficiency performance of the engine and vehicle by applying LPDi technology. The LPDi hybrid engine's maximum output and maximum torque were measured at an equivalent level of less than 1% compared to conventional gasoline fuel. The fuel amount was corrected using the LCU controller, and the THC, CO, and NOx emissions were reduced to 90% in the operating range of the three-way catalyst through air-fuel ratio control. The analysis of THC+NOx and CO emissions in FTP-75 (CVS-75) driving mode satisfied the US LEV III SULEV30 regulation.