• 재활복지공학회논문지
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• 제11권1호
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• pp.29-35
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• 2017

기존의 가정용 요양침대는 매트리스 지지판(mattress support platform) 하부에 설치된 복잡한 기구부로 인해 저상화 실현이 어려웠다. 본 논문에서는 등판과 다리판의 각도를 조절하면서도 저상화가 가능한 요양침대의 구동 메커니즘을 제안한다. 등판과 다리판의 메커니즘은 듀얼 모터(dual motor)를 적용하고, 최적화 기법으로 설계변수를 결정하였다. 승강 메커니즘은 풀리(pulley)구조를 적용하여 제한된 구동기의 가동범위를 최대 두 배까지 높일 수 있도록 설계하였다. 건강한 5명의 피험자($24.4{\pm}0.5$세)가 방바닥에서 240mm의 저상 프로토타입 요양침대와, 600mm의 일반적인 높이의 침대에 올라갈 때의 그 이동 거리를 측정하여 저상화 침대에 대한 유효성을 평가하였다. 그 결과 저상 요양침대를 사용할 때의 이동 거리는 기존 높이의 침대에 비해 평균 38% 작았다. 이것은 저상요양침대가 고령자의 신체적 부담을 줄여주며, 일반침대보다 일상생활 지원에 효과적이라는 것을 보여주었다.

• 한국컴퓨터정보학회논문지
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• 제28권7호
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• pp.1-9
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• 2023

현재, 고속열차 보급이 증가하면서 도심구간의 정차 요구가 증대됨에 따라 도심구간의 고상 플랫폼과 시외구간의 저상 플랫폼 모두 운용이 가능한 열차 개발이 요구되고 있다. 본 논문에서는 저상과 고상 플랫폼에서 사용할 수 있는 플러그인 타입으로 저상과 고상 스텝으로 구성된 열차 측 출입문용 제어기의 설계 및 제작에 관하여 연구하였다. DCU H/W는 32bit MCU를 사용하여 4개의 모터를 제어하고, 33개의 Digital Input과 16개의 Digital Output이 가능하도록 설계하여 구현하였으며, 동작 SW는 EN50128의 소프트웨어 수명 주기에 따라 동작 요구 사항 2개 항목과 제어 요구 사항 12개 항목을 도출하여 설계 구현한 후 각 요구 사항에 대한 시험을 수행하였다. 그 결과 전체 요구 사항 14개 항목 중 목업에서 시험 가능한 13개 항목에 대하여 시험을 수행하였고, 요구 사항을 만족함을 보였다.

• 한국전자통신학회논문지
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• 제18권5호
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• pp.853-858
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• 2023

건설 산업에 다양한 종류의 로봇들이 활용되고 있다. 특히, 일관된 작업의 품질을 보장할 수 있는 미장 자동화에 적용할 수 있는 로봇에 관한 관심이 높다. 이에 본 논문에서는 wheel을 기반으로 미장 자동화를 위한 로봇 플랫폼을 제안한다. 실험을 통해 우리는 설계한 로봇을 이용하여 wheel의 공기압에 따른 표면 압력을 측정하였다. 그 결과, 설계한 로봇은 무른 모르타르 위에서 휠당 균일하고 낮은 압력으로 미장 작업이 가능할 것임을 확인할 수 있었다.

• 제어로봇시스템학회논문지
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• 제12권9호
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• pp.926-934
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• 2006

This paper proposes intelligent control of a virtual walking machine that can generate infinite floor for various surfaces and can provide proprioceptive feedback of walking to a user. This machine allows users to participate in a life-like walking experience in virtual environments with various terrains. The controller of the machine is implemented hierarchically, at low-level for robust actuator control, at mid-level fur platform control to compensate the external forces by foot contact, and at high-level control for generating walking trajectory. The high level controller is suggested to generate continuous walking on an infinite floor for various terrains. For the high level control, each independent platform follows a man foot during the swing phase, while the other platform moves back during single stance phase. During double limb support, two platforms manipulate neutral positions to compensate the offset errors generated by velocity changes. This control can, therefore, satisfy natural walking conditions in any direction. Transition phase between the swing and the stance phases is detected by using simple switch sensor system, while human foot motions are sensed by careful calibration with a magnetic motion tracker attached to the shoe. Experimental results of walking simulations at level ground, slope, and stairs, show that with the proposed machine, a general person can walk naturally on various terrains with safety and without any considerable disturbances. This interface can be applied to various areas such as VR navigations, rehabilitation, and gait analysis.

• International Journal of Naval Architecture and Ocean Engineering
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• 제2권3호
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• pp.155-170
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• 2010

Availability of economic and efficient energy resources is crucial to a nation's development. Because of their low cost and advancement in drilling and exploration technologies, oil and gas based energy systems are the most widely used energy source throughout the world. The inexpensive oil and gas based energy systems are used for everything, i.e., from transportation of goods and people to the harvesting of crops for food. As the energy demand continues to rise, there is strong need for inexpensive energy solutions. An offshore platform is a large structure that is used to house workers and machinery needed to drill wells in the ocean bed, extract oil and/or natural gas, process the produced fluids, and ship or pipe them to shore. Depending on the circumstances, the offshore platform can be fixed (to the ocean floor) or can consist of an artificial island or can float. Semi-submersibles are used for various purposes in offshore and marine engineering, e.g. crane vessels, drilling vessels, tourist vessels, production platforms and accommodation facilities, etc. The challenges of deepwater drilling have further motivated the researchers to design optimum choices for semi-submersibles for a chosen operating depth. In our series of eight papers, we discuss the design and production aspects of all the types of offshore platforms. In the present part I, we present an introduction and critical analysis of semi-submersibles.

• 건축역사연구
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• 제19권6호
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• pp.233-250
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• 2010

Jukseoru as an official pavilion of the government, one of the eight sceneries in Gwndong Area, is located on the cliff over Osipcheon River. This paper interprets form and space of the pavilion with restored old life by analyzing pictures of official party in 18th century in Chosun Dynasty. Every part of the space is occupied by persons by the class and duty: the pricipal guest, nobles, subordinates, gisaengs, court musicians, and guards from the high to the low and from the inside to the outside. Applying the analysis to the Jukseoru pavilion, the noblest lord takes sit on the platform in front of folded screen at main bay under checked ceiling, enclosed by low timber beam. The next northern end bay is a place for subordinates' and servants' waiting for preparation for rice wine. Southern end entrance bay is not a result of later addition but deliberately and originally made for lower place outside the railing of wooden floor: for a waiting woman gisaeng, and subordinates. Outside under the eaves on the platform with bedrock, artificial stone and soil is a place for court musicians, subordinates, and guards. The yard in front of the building is a place for preparing meals by cookers. Every detailed ornamental form is different each other by the place for the occupied class. Existing theory tells that the building, 7 bays gable-and-hipped roof, is a result of structural extention of 2 bays at the 5 bays gabled-roof. However, through the interpretation of old pictures and application to the pavilion, the present Juseoru is not a result of later structural addition, but deliberately designed creation suited to life in hierarchical traditional society.

• Asian Journal of Atmospheric Environment
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• 제6권2호
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• pp.73-82
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• 2012

This study was aimed to thoroughly estimate the characteristics of indoor particulate matter (PM) collected on subway platforms by the cooperative approach of semi-bulk and single particle analyses. The size-resolved PM and its number concentration were measured on the platform in a heavily traveled subway station in Fukuoka, Japan. Particle Induced X-ray Emission (PIXE) and micro-PIXE techniques were applied to the chemical analyses of semi-bulk and single particle, respectively. There was the close resemblance of timely fluctuation between PM number concentration and train service on the third basement floor (B3F) platform compared to the second basement floor (B2F) and its maximum level was marked in rush hour. Higher number counts in large particles ($>1{\mu}m$) and lower number counts in fine particles ($<1{\mu}m$) were shown on the platform compared to an above ground. PM2.5 accounted for 58.2% and 38.2 % of TSP on B3F and on B2F, respectively. The elements that were ranked at high concentration in size-resolved semi-bulk PM were Fe, Si, Ca, S, and Na. The major elements tending to have more elevated levels on B3F than B2F were Fe (4.4 times), Ca (17.3 times), and Si (46.4 times). Although concentrations were very low, Cr ($11.9ng\;m^{-3}$ on B3F, $2.4ng\;m^{-3}$ on B2F), Mn ($3.4ng\;m^{-3}$ on B3F, $0.9ng\;m^{-3}$ on B2F), and Pb ($0.6ng\;m^{-3}$ on B3F, $1.6ng\;m^{-3}$ on B2F) were detected from PM2.5. Individual PM was nearly all enriched in Fe with Si and Ca. Classifying and source profiling of the individual particles by elemental maps and particle morphology were tried and particles were presumably divided into four groups (i.e., train/rail friction, train-rail sparking, ballast/abrasive, and cement).

• Smart Structures and Systems
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• 제6권5_6호
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• pp.595-618
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• 2010

This paper describes the application of a wireless sensor network to a 31 meter-tall medieval tower located in the city of Trento, Italy. The effort is motivated by preservation of the integrity of a set of frescoes decorating the room on the second floor, representing one of most important International Gothic artworks in Europe. The specific application demanded development of customized hardware and software. The wireless module selected as the core platform allows reliable wireless communication at low cost with a long service life. Sensors include accelerometers, deformation gauges, and thermometers. A multi-hop data collection protocol was applied in the software to improve the system's flexibility and scalability. The system has been operating since September 2008, and in recent months the data loss ratio was estimated as less than 0.01%. The data acquired so far are in agreement with the prediction resulting a priori from the 3-dimensional FEM. Based on these data a Bayesian updating procedure is employed to real-time estimate the probability of abnormal condition states. This first period of operation demonstrated the stability and reliability of the system, and its ability to recognize any possible occurrence of abnormal conditions that could jeopardize the integrity of the frescos.

• Nuclear Engineering and Technology
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• 제53권7호
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• pp.2387-2395
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• 2021

Seismic qualifications of electrical equipment, such as cabinet systems, have been emerging as the key area of nuclear power plants in Korea since the 2016 Gyeongju earthquake, including the high-frequency domain. In addition, electrical equipment was sensitive to the high-frequency ground motions during the past earthquake. Therefore, this paper presents the rocking behavior of the electrical cabinet system subjected to Reg. 1.60 and UHS. The high fidelity finite element (FE) model of the cabinet related to the shaking table test data was developed. In particular, the first two global modes of the cabinet from the experimental test were 16 Hz and 24 Hz, respectively. In addition, 30.05 Hz and 37.5 Hz were determined to be the first two local modes in the cabinet. The high fidelity FE model of the cabinet using the ABAQUS platform was extremely reconciled with shaking table tests. As a result, the dynamic properties of the cabinet were sensitive to electrical instruments, such as relays and switchboards, during the shaking table test. In addition, the amplification with respect to the vibration transfer function of the cabinet was observed on the third floor in the cabinet due to localized impact corresponding to the rocking phenomenon of the cabinet under Reg.1.60 and UHS. Overall, the rocking of the cabinet system can be caused by the low-frequency oscillations and higher peak horizontal acceleration.

• 비교문화연구
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• 제42권
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• pp.419-449
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• 2016

이 글에서는 러시아정교회의 이코노스타시스와 한국 감로탱화의 특수성과 서사구조를 비교 고찰하였다. 1장에서는 일반 종교회화와 다른 이콘과 탱화의 도상-지표적 특성을 바탕으로 두 종교예술의 공통점을 살펴보았다. 2장에서는 러시아 종교문화의 이원론적 구조에서의 일원론적 성격, 한국 불교의 밀교적 성격을 토대로 러시아 이콘과 한국 탱화의 현세 이익, 신비적 속성을 보았다. 3장에서는 1-5단의 이코노스타시스와 상,중,하 3단의 감로탱화의 서사구조의 유사성을 바탕으로 이코노스타시스와 감로탱화에 담긴 시공간성과 내세에 대한 세계관을 탐구하였다. 과거, 현재, 미래와 천상, 현세, 지옥이 공존하는 감로탱화의 하단의 특징과 러시아정교회 성당 안에서 이코노스타시스와 마주보고 있는 최후의 심판 벽화를 비교하였다.