• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2001년도 춘계학술대회논문집
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• pp.1221-1226
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• 2001

A structure gauge assessment is needed to ensure that a railway vehicle can run safely along a length of track without coming unacceptably close to lineside structures or equipment, or to vehicles running on adjacent tracks. This apparently straightforward question is in reality very complicated. The amount of space required for the safe passage of a railway vehicle is significantly greater than its static body profile for a number of reasons as follows: as the vehicle runs along the track, the track input excites the vehicle and it moves on its suspension. On curved track its geometric position leads to curve overthrows. A number of different approaches have been used to answer this question and some are described and specially applied to urban train by computer simulation in this paper. The program used for calculating the kinematic and swept envelope is the VAMPIRE made in U.K.

• 반도체디스플레이기술학회지
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• 제19권3호
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• pp.130-135
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• 2020

This paper describes the results of a study on the unmanned cleaning robot that performs the cleaning of the floating photovoltaic panels. The robot uses two SSC (Sliding Suction Cup) adsorptive devices to move up and down the slope. First, the forces generated when the robot moves up the slope are mechanically analyzed. The robot was designed and manufactured to operate stably by using the presented results. Next, the robot motion was tested on the inclined panel. It has been proven that robots are well designed and built to clean sloped panels.

• 한국농공학회:학술대회논문집
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• 한국농공학회 1999년도 Proceedings of the 1999 Annual Conference The Korean Society of Agricutural Engineers
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• pp.759-764
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• 1999

In intensive agriculture, exceeded chemical fertilizer application would increase the concentration of nitrate nitrogen in groundwater. Consequently, it could bring the eutrophication in lakes and streams. The present study examined runoff loading of nitrogen and phosphorus from the paddy field during non-cropping season. The runoff loading of total-N, ammonia-N, nitrate-N and total-P were 12.96kg/ha, 5.42kg/ha, 1.52kg/ha and 1.41kg/ha. When the runoff loading of nutrients was compared by runoff water and sediments. About 70-80% of total-N by runoff water and the rest 20-30% by runoff sediments were flowed into streams. But 60-70% of total-P by runoff sediments and the rest 30-40% by runoff water were flowed into streams. The phosphorus compounds, which were flowed into streams by runoff sediments and then sedimented, keep exchanging with water at water body in undelivered condition. And it moves gradually into water layer. This process can cause eutrophication continually and repeatedly in water environment. So, a sound program is needed to reduce soil erosion from farmlands.

• Structural Engineering and Mechanics
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• 제55권5호
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• pp.901-911
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• 2015

The goal of this study is to investigate computational convergence of optimal solutions, with respect to optimality criteria (OC) method and methods of moving asymptotes (MMA) as optimization model for non-linear programming of material topology optimization using an acceleration method that makes design variables rapidly move toward almost 0 and 1 values. 99 line topology optimization MATLAB code uses loop vectorization and memory pre-allocation as properly exploiting the strengths of MATLAB and moves portions of code out of the optimization loop so that they are only executed once as restructuring the program. Numerical examples of a simple beam under a lateral load and a given material density limitation provide merits and demerits of the present OC and MMA for 99 line topology optimization code of continuous material topology optimization design.

• Journal of Mechanical Science and Technology
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• 제20권8호
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• pp.1217-1223
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• 2006

Induction heating is a process that is accompanied with magnetic and thermal situation. This paper presents a simulation of a magneto-thermal coupled problem of an induction heating process for moving inductor coil. In the magnetic and thermal analyses, temperature-dependent magnetic and thermal material properties were considered. As the inductor coil moves in the process, solution domains corresponding to inductor changes into those of the air, and the solution domains of air change into those of the inductor. For these reasons, modeling of induction heating process is very difficult with general purpose commercial programs. In this paper, induction heating process for moving coil was simulated with the concept of traveling the position of the heating planes. Finite element program was developed and finite element results were compared with the experimental results.

• 한국해양공학회지
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• 제18권6호
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• pp.101-107
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• 2004

In this paper, the design criteria of future container crane for megaships are investigated. The current loading/unloading capacity of a typical container crane, roughly 30 moves/hr, is too law to meet the requirements of future super containerships, which are expected over 15,000 TEU. After examining the transition of containerships through the years and studying the research trend in developed countries, the specifications of the container crane that can Meet a 15,000 TEU containership are proposed. The structure, trolley and hoist mechanism, outreach, backreach, capacity, speeds, durability, and stability of the future container crane are described.

• 한국농공학회지
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• 제42권2호
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• pp.63-70
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• 2000

The present study was carried out for 7-months (from October 1.1997 to April 30. 1998) at a rice cultivation area blocked from livestock farming, farmstead and industrial complex to investigate the runoff loading of nitrogen and phosphorus in a plot(5,000$m^2$) paddy field areas. The runoff loading of total-N, amminia-N nitrate-N and total-P were 12.96kg/ha, 5.42kg/ha, 1.52kg/ha and 1.41kg/ha , respectively. When the runoff loading of nutrients was compared by dissolved and adsorbed forms, about 66% of total-N by dissolved form and the rest 34% by adsorbed form were flowed into streams. But 56% of total-P by adsorbed form and the rest 44% by dissolved form were flowed into streams. The phosphrous compounds , which were flowed into streams by runoff sediments and then sedimented, keep exchanging with water at water body in undelivered condition. And it moves gradually into water layer. This process can cause eutrophication continually and repeatedly in water environment . So, a sound program is needed to reduce soil erosion from farmlands.

• 한국터널지하공간학회 논문집
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• 제15권4호
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• pp.387-400
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• 2013

본 연구에서는 터널 갱구사면을 대상으로 사면안정성 및 산사태 위험도를 평가하였다. 먼저 사면안정성 해석을 통해 붕괴위험도가 가장 높은 구간을 선정하고 구체적인 붕괴규모를 파악하였다. 해석결과 해발고도 485~495 m인 구간은 강우시 안전율이 0.99로 불안정한 상태로 나타났다. 이 때 붕괴심도는 최대 2.1 m이며 붕괴 길이는 사면의 경사방향으로 18.6 m로 분석되었다. 해당구간에서 사면붕괴 시 파생되는 사태물질의 이동특성을 실시간으로 분석하고 터널 갱구부에 미치는 영향을 파악하고자 산사태 시뮬레이션 해석을 수행하였다. 해석결과 사태물질은 7.74 m/sec의 평균속도를 보이며 주로 계곡부를 따라 산 하부로 이동하는 것으로 분석되었다. 사태물질은 산 하부로 갈수록 점차 확산되며 10초 후에 터널 갱구부 위를 지나고 20.2초 후에 산하부에 도달하는 것으로 분석되었다. 특히 터널 갱구부는 사태물질 이동경로의 중심부에 위치하고 있어 산사태 발생 시 직접적인 피해를 받는 것으로 나타났다.

• 한국지역지리학회지
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• 제13권6호
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• pp.651-673
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• 2007

본 연구에서는 이동 유형을 지역 내 이동과 지역 간 이동으로 구분하여 각각의 원인을 고찰하는 한편 두 가지 유형의 상호 연계성을 이동 후 관찰되는 자가소유에 기초하여 분석하였다. 본 연구에서는 통계청에서 제공하는 1980년부터 2000년까지의 인구주택총조사(Census)를 활용해 우리나라 인구이동의 일반적 특성을 고찰하고 기존의 이동거리에 관한 가설을 검증하는 한편, 이동형태에 따른 자가소유의 결정요인을 분석하였다. 분석 결과 지역 간 이동과 지역 내 이동의 연계를 밝혀주는 Goodman의 세 가지 가설과 Roseman의 조정이동 가설은 우리나라에서 대부분 성립하지만 이러한 경향은 감소하는 추세인 것으로 나타났다. 이동거리에 따른 이주경력 결정요인을 살펴보면 연령이 낮을수록, 차가 거주자일수록, 교육수준이 높을수록, 가구원수가 적을수록 이동성향이 증가했다. 시간이 경과함에 따라 여성의 반복이동 성향이 증가하며 유배우자의 이동성향은 감소하였다. 단거리 이동의 경우여성의 이동성향이 남성에 비해 우세했다. 지역적 특성을 고려하기 위해 통제된 변인 중 보다 앞선 시기에 실업률이 부(-)인 지역으로 향하던 이주가 조사시점과 가까운 시기에는 정(+)인 지역으로 변화한 점과, 교원수 변인이 동일시기 정(+)인 지역에서 부(-)인 지역으로 변화한 점은 주목할 만하다. 이주 후 자가를 소유할 확률은 지역 간 이동에서 여성이 더 높았으며 연령이 증가할수록 확률이 증가하는 것으로 나타났다. 직업유형별로 살펴보면 판매직과 기능적의 경우 이동 후 자가를 소유할 확률이 가장 낮았으며 전문직 종사자는 가장 높은 확률을 보였다. 제주지역으로 이주한 가구가 타지역 이주가구에 비해 자가소유확률이 낮았으며 지가가 높은 지역을 목적지로 택한 가구일수록 자가소유 경향은 낮아졌다. 이동성향이 높은 가구는 자가소유 가능성이 낮은 것으로 나타났다.

• 한국의류산업학회지
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• 제14권6호
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• pp.968-976
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• 2012

This study presents a new method called the SPMP (Semi-automatic profile measuring program) to efficiently measure body shape in elderly women. SPMP can automatically measure the angle of axis (19 items), surface (17 items), lengths (14 items), heights (16 items), widths (13 items), and depth (6 items). In total these 85 items are automatically measured very quickly, accurately, and easily after manually marking an initial 36 points. The utility of SPMP was evaluated using several tests. When SPMP measuring results were compared with manual methods (using a ruler and protractor) in thirteen elderly women using a paired t-test, there was no significant difference found between them. Furthermore, when measurements from SPMP were compared with actual measurement results in selected items from seven elderly women's measurements, smaller mean differences were found than those defined by ISO 20685, with the exception of the abdominal area which moves easily with breathing. Seven independent measurements of a single elderly woman were made by seven students using SPMP, and the values of coefficient of variation were less than 5% for all but 8 items. Finally, this study analyzed the correlation of all 85 item measurements, and found that the angle from the upper chest to the neck towards the front in the axis curved forward as much as the axis angle from the thigh to the waist (r=-0.876, $^{**}p$ < 0.01) bent backwards in elderly women. This detailed analysis helps to understand age-related changes in body posture, and will be useful in future studies.