• 한국항해항만학회지
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• 제30권8호
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• pp.649-655
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• 2006

연안으로 입사해 들어오는 파랑은 월파형 파랑제어구조물에 의해 증폭, 월파되어 구조물 배후의 유수지에 위치 에너지로 저장될 수 있으며, 수두차의 형태로 저장된 위치에너지는 초저낙차 수차 터빈을 통해 전기에너지로 변환될 수 있다. 본 연구는 이와 같은 월파형 파력발전에 있어서 주어진 입사파 조건에 대해 최대 월파 유량을 획득하는 월파형 파랑제어구조물의 최적 형상을 도출하기 위한 실험적 연구이다. 월파형 파랑제어구조물의 형상 도출을 위한 수조 실험은 삼차원 조파 수조에서 이루어졌으며, 평면 파랑 집중 형상을 가진 삼차원 구조물의 형상은 5가지의 종류로 제작되었다. 파랑제어구조물은 신과 홍(2005)에서 제안한 월파형 파랑제어구조물의 이차원 단면 형상을 토대로 수로폭 및 수렴각을 가진 삼차원 형상으로 확장한 것이다. 본 삼차원 월파실험에서는 20개의 입사파 조건과 각각의 파에 대한 $0^{\circ},\;15^{\circ},\;30^{\circ}$의 상대 입사각을 부여하여 계측된 월파량을 분석하였다.

• 한국운동역학회지
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• 제24권2호
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• pp.139-149
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• 2014

The purpose of this study was to evaluate the effect of angle change of forefoot's adhesive outsole on the electromyographic activity (EMG) of the erector spinae and selected lower limbs muscle during downhill walking over $-20^{\circ}$ ramp. Thirteen male university students (age: $25.4{\pm}3.9$ yrs, height: $176.2{\pm}5.1$ cm, weight: $717.4{\pm}105.0$ N) who have no musculoskeletal disorder were recruited as the subjects. To assess the myoelectric activities of selected muscles, six of surface EMG electrodes with on-site pre-amplification circuitry were attached to erector spinae (ES), rectus femoris (RF), biceps femoris (BF), tibialis anterior (TA), lateral gastrocnemius (LG), and medial gastrocnemius (MG). To obtain maximum EMG levels of the selected muscles for normalization, five maximum effort isometric contraction were performed before the experimental trials. Each subject walked over $0^{\circ}$ and $20^{\circ}$ ramp with three different forefeet's EVA outsole (0, 10, $20^{\circ}$) in random order at a speed of $1.2{\pm}0.1$ m/s. For each trial being analyzed, five critical instants and four phases were identified from the recording. The results of this study showed that the average muscle activities of MG and LG decreased in $20^{\circ}$ shoes compared to $0^{\circ}$ and $10^{\circ}$ ones in the initial double limb stance (IDLS). In initial single limb stance (ISLS) phase, the average muscle activities of ES increased with the angle of forefoot's adhesive outsole, indicating that the increment of shoes' angle induce upper body to flex anteriorly in order to maintain balance of trunk. In terminal double limb stance (TDLS) phase, average muscle activities of TA significantly increased in $20^{\circ}$ outsole compared to $0^{\circ}$ and $10^{\circ}$ ones. There was no external forces acting on the right foot other than the gravity during terminal single limb stance (TSLS) phase, all muscles maintained moderate levels of activity.

• 의료ㆍ복지 건축 : 한국의료복지건축학회 논문집
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• 제17권4호
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• pp.57-68
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• 2011

The purpose of this study is to provide the planning factors of housing for the disabled and elderly based on the inclusive housing design as sustainable neighborhood. The goal of inclusive design is to make buildings and communities more livable for all type of people. Inclusive design should embrace other good design goals and reinforce them, not work against them. To carry out this purpose, we should proceed in the following way: First, we deducted the four design factors (the basic, recommendable, adaptable, and residential factors) by reviewing the characteristics of inclusive housing concepts. Second, we analyzed the related foreign design standards and guidelines such as the ICC/ANSI A117.1 Type C Units (the United States, 2009), Lifetime Standard (the United Kingdom, 2010), and Livable Housing Design Guideline (the Australian, 2010) through four design factors based on inclusive design concepts. Finally, we suggested the housing design factors for the disabled and the elderly in Korea. To conclude, we can make the followings: It is important basic factor that the bedroom and bathroom layout closed to each other. Also, the bedroom has the proper height of light switches, outlets, and windows. The recommendable factors take into consideration stairs and ramp, if existent. The adaptable factors are closely related to domestic housing culture as well as residential factors. Proceeding from this fact, the livability for people with disabilities and older requires accessibility and adaptability that take into account public and efficiency considering the current trend of housing development and urban planning.

• 한국ITS학회 논문지
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• 제17권4호
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• pp.76-85
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• 2018

본 연구는 도시철도 출입구의 계단과 에스컬레이터에 대한 시민이용자의 선호, 계단 높이에 따른 에스컬레이터 설치 요구 정도를 확인하고, 에스컬레이터 편의(amenity)에 대한 지불의사금액(WTP)을 조사하였다. 조사결과 지하철 이용자 89%가 계단보다 에스컬레이터를 선호하고, 2층 높이 이상인 계단에 대해 에스컬레이터가 필요하다고 응답하였다. 특히 연령이 30대 이상인 경우, 성별은 여성일 때 더욱 에스컬레이터를 선호하는 것으로 나타났다. 따라서 통로 폭만을 고려한 설치기준에 이용자의 인적 특성과 시설 특성(계단의 높이)을 고려할 필요가 있다. 지불의사와 관련 개선분야, 경사로높이, 성별, 연령이 상관관계가 높은 것으로 나타났고, 다중로지스틱모형 중 이항로짓모형을 이용하여 WTP를 산출하였다. 서울도시철도를 이용하는 일반 시민은 에스컬레이터 사용가치(신체적 편의)로 34.37원을 지불할 의사가 있는 것으로 분석되었다.

• 한국정밀공학회지
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• 제6권2호
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• pp.40-46
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• 1989

Recently, the researches on cutting the new material have been done for development of aerospace industrial engineering. Especially, titanium ally is well known as heat resisting, antiwear, anticorrosion and difficult-to-machine materials. Many studies on the analysis of shear angle have been done for improving productivity in cutting these materials. In case of titanium alloy, the saw-toothed type of chip which has wave surface of a triangular form, an eccentric from of a continuous type of chip that is produced in the cutting process, was checked. Nakayama supposed that a maximum shear strewss plane and the shear crack in the free surface made an angle of $45^{\circ}$ .deg. , but it's usually much larger than that. In this paper, the author analyzed the shear conditions of the cutting process in the quick-stopping device with the help SEM-photographs, and measured the hypotenuse angle directly in the photographs of the chips. In conclusion, the author tried to find the shear angle in the cutting process with the saw-toothed chip and compared it with the shear angles which can be calculated from the theories established by others. The results obtained are as follows. 1. In case of the saw-toothed chips, the equivalent cutting ratio can be calculated by using the chip thickness to two-thirds of ramp height. 2. The theory of Ernst-Merchant is not applicable to the titanium and its alloys which does not fractured in accordance with the theory of maximum shear stress. 3. When we cut the titanium alloys which produced the saw-toothed chips, the shear angle can be found with the theories of Rowe-Spick, P.K. Wright and the measurement of hypotenuse angle.

• 한국추진공학회지
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• 제25권2호
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• pp.1-11
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• 2021

연소기 내부의 공동은 낮은 속도의 재순환영역과 유동의 진동을 일으켜 연료와 공기의 혼합 효율을 증대시키고, 화염을 유지함으로써 지속적인 연소를 가능하게 한다. 본 연구에서는 공동의 형상 인자에 따른 내부 유동의 특성을 실험과 2차원 전산해석을 통해 관찰하였다. 초음속 연소기 내 유동은 단순히 L/D 이외에도 다양한 공동 형상인자에 따라 크게 영향을 받는 것이 관찰되었다. 동일 L/D에서도 공동의 깊이에 따라 open과 closed 형태가 나타남을 확인하였고, 공동의 후방 경사각, 연소기 높이도 유동 특성이 달라지며, 이는 전압력 손실에 큰 영향을 미치는 것을 확인하였다.

• Tribology and Lubricants
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• 제39권5호
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• pp.203-211
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• 2023

This study experimentally investigates the effects of angular acceleration on the friction and wear performances of a gas foil thrust bearing (GFTB) using a typical GFTB with six pads. The outer radius of the bearing is 31.5 mm, the total bearing area is 2,041 mm² , and the bump foil and incline (ramp) height are both 500 ㎛. The newly developed GFTB test rig for measuring the friction torque and coefficient measures the axial load, drag torque, lift-off speed, and touch-down speed. The experiment is conducted for angular accelerations of 78.5, 314.2, and 328.3 rad/s² at axial loads of 5, 10, and 15 N, respectively. The test shows that the start-up friction coefficient increases with increasing axial load at the same angular acceleration, and the friction coefficient decreases with increasing angular acceleration under the same axial load. As the angular acceleration increases, the lift-off speed at the motor start-up increases, and the touch-down speed at the motor stop decreases. The wear distance of the GFTB for a single on/off cycle increases with increasing axial load at the same angular acceleration and decreases nonlinearly with increasing angular acceleration under the same axial load. The test results suggest that adjusting the rotational angular acceleration helps reduce bearing friction and wear.

• 한국실내디자인학회논문집
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• 제18권3호
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• pp.114-121
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• 2009

The number of the disabled is increasing every year. Growing interest in social welfare, but still the disabled person in places is restricted on the activities are due to obstacles. This study proposes an improvement direction through an research and analysis of installation status of convenient facilities in social welfare halls was planned after that the law of increase of convenience for the disabled person is enforced in 1998. This study analyzed nine social welfare halls of seoul including Yongsan-gu(GW), Guro-gu(GD, HW), Yeongdeungpo-gu(SG), Seodaemun-gu(SD), Dobong-gu(DB), Nowon-gu(NS), Seongbuk-gu(WG) and Dongdaemun-gu(JG). The evaluation criteria for the installation of convenient facilities for the disabled person in each social welfare hall based on the law of increase of convenience for the disabled person, and referred to other data. Also, review the criteria for the installation of convenient facilities, and grasp the present situation through the survey of convenient facilities in social welfare halls, and provides the installation standards of convenient facilities. The result are as followings. There were many problems to be improved in approach of the intermediate space, parking lot, entrance of the inside space and corridor that must be installed for the convenience of the disabled. In the intermediate space, the slope of the ramp, curb, induction handle etc. for a safety must be installed. Parking spaces for the disabled must be located closest to the main entrance, an induction marker or the handle, and the attachment of a directional sign etc. must be improved. In the inside space, it is convenient for the disabled person use to install an automatic door and swing door simultaneously at the main entrance. And, the height of the door handle, an induction block, a braille display panels of the appropriate height in the entrance, a braille display in start and end of the stairs handle, the handle of the side wall, the stairs to prevent slippage etc. must be improved in the corridors. The case of the sanitation which is a recommendation item is equipped formally with disabled toilets are difficult to use. Information and other convenience facilities for the disabled person in all the social welfare halls were not considered.

• 한국운동역학회지
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• 제29권3호
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• pp.157-166
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• 2019

Objective: This study examined the effects of stimulating fingertip temperature on the patterns of force sharing and stability properties during multi-finger force production tasks. Method: 9 adult subjects (male: 3, female: 6, age: $26.11{\pm}4.01yrs$, height: $169.22{\pm}5.97cm$, weight: $61.44{\pm}11.27kg$) participated in this study. The experiment consisted of three blocks: 1) maximal voluntary contraction (MVC) task, 2) single-finger ramp task to quantify enslaving (i.e., unintended force production by non-task fingers), and 3) 12 trials of multi-finger steady-state force production task at 20% MVC. There were three temperature conditions including body-temperature (i.e., control condition), $40^{\circ}C$, and $43^{\circ}C$, and the stimulation was given to the index finger only for all experimental conditions. Results: There were no significant differences in the MVC forces, enslaving, and the accuracy of performance during the steady-state task between the conditions. However, the share of stimulated index finger force increased with the index fingertip temperature, while the share of middle finger force decreased. Also, the coefficient of variation of both index and middle finger forces over repetitive trials increased with the index fingertip temperature. Under the framework of the uncontrolled manifold (UCM) hypothesis used to quantify indices of multi-finger synergies (i.e., stability property) stabilizing total force during the steady-state task, the two variance components within the UCM analysis increased together with the fingertip temperature, while no changes in the synergy indices between the conditions. Conclusion: The current results showed that fingertip temperature stimulation only to index finger does not affect to muscle force production capability of multi-finger, independence of individual fingers, and force production accuracy by the involvement of all four fingers. The effect of fingertip temperature on the sharing pattern and force variation may be due to diffuse reflex effects of the induced afferent activity on alpha-motoneuronal pools. However, the unchanged stability properties may be the reflection of the active error compensation strategies by non-stimulated finger actions.

• 한국가정과교육학회지
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• 제21권3호
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• pp.1-28
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• 2009

본 연구의 목적은 현행 교과서의 노인주거 내용에 대한 교사의 중요도 인식을 조사하여 노인주거 교육내용 구성과 교수학습 과정에 참고할 수 있는 기초 자료를 제공하는 것으로 이를 위해 7차 교육과정 기술 가정 교과서 10종의 주생활단원 노인주거 내용을 5개 내용요소의 67개 항목으로 분석하였으며, 기술 가정 교사 233명을 대상으로 중요도 인식을 조사하였다. '안전성과 안전관리'의 11개 항목 중 욕실과 화장실의 안전에 관한 항목이 가장 비중이 높았으며 욕실 화장실의 안전에 관한 항목(욕실 화장실 바닥 미끄럼 방지 처리, 욕실 화장실 안전 손잡이, '샤워기 욕조 세면대의 위치와 높이조정)에 대한 교사의 중요도 인식도 높았다. '노인실 계획'의 7개 항목에서는 보편적으로 적용할 수 있는 기본적 지침(긴급 통보 장치, 화장실을 가깝게 배치, 턱이 없고 높이가 같은 바닥)에 대한 교사의 중요도 인식이 높았다. '가족축소기 및 주거의존기'의 20개 항목에서는 안전사고 방지를 위한 설비 갖추기와 노후기 주거 상황에 보편적으로 적용 가능한 항목(긴급 통보 장치, 턱이 없고 높이가 같은 바닥, 미끄럽지 않은 바닥)에 대한 중요도 인식이 높았다. '3세대 동거 주택'의 11개 항목에서는 안전에 관한 원칙적 내용이나 세대간의 독립성 확보에 관한 항목(노인을 위한 주거 안전 고려, 독립성을 보장하는 세대간의 공간 배치, 노인 전용의 욕실 화장실 두기)에 대한 중요도 인식이 높았다. '유니버설 디자인의 25개 항목에서는 욕실 화장실의 안전한 사용이나 이동의 편리성을 보장하는 항목(욕실 화장실의 안전 손잡이, 턱이 없고 높이가 같은 바닥, 휠체어가 회전할 수 있는 문이나 통로, 휠체어가 통과할 수 있는 문이나 통로)에 대한 중요도 인식이 높았다. 본 연구의 결과에 따라 노인주거 교육내용 구성과 교수학습에 대해 제언할 점은 첫째, 여러 내용요소에 공통으로 포함되며 교사의 중요도 인식이 높은 4개 항목(긴급 통보 장치, 욕실 화장실 안전 손잡이, 턱이 없고 높이가 같은 바닥, 미끄럽지 않은 바닥)을 보편적인 노인주거 교육내용으로 활용할 수 있으며, 둘째, '안전성과 안전관리'의 중점은 욕실 화장실의 안전이 되어야 하며, 셋째, '노인실 계획'의 중점은 화장실의 근접 배치와 보편적 디자인 지침이 되어야 하며, 넷째, '가족축소기 및 주거의존기'의 중점은 안전사고 방지 설비와 보편적 디자인 지침 및 고령화 대비와 연계되는 내용이 되어야 하며, 다섯째, '3세대 동거 주택'의 중점은 노인 주거 안전과 세대 간의 독립성 확보에 관한 내용이 되어야 하며, 여섯째, '유니버설 디자인'의 중점은 보편적 디자인 지침과 이동의 편리성을 보장하는 것으로 관련법과도 일치하는 내용이 되어야 하는 것이다.