• 한국산학기술학회논문지
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• 제11권10호
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• pp.3964-3973
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• 2010

본 연구는 박물관에 있어서 계단, 엘리베이터 등의 수직동선 요소에 대한 분석을 하고자 한다. 연구 방법에 있어 가장 기초 단계라는 의미로 각 요소별의 개수를 분석하여 수치적으로 접근하였다. 공간적 범위를 우리나라로 한정하였다. 연구의 결론은 다음과 같다. 첫째, 수직동선 요소를 가장 많이 지닌 사례는 8개이며, 3~4개가 50%를 차지하였다. 연구 초기에 생각했던 것보다 높은 수치의 사례가 있어 다양한 박물관의 실상을 알 수 있었다. 계단의 경우 5개가 제일 높았으며, 일반적으로는 2개의 계단을 가진 것이었다. 엘리베이터의 경우는 1개를 가진 사례가 79%였다. 경사로는 38개 사례 중 9개의 사례에서만 볼 수 있었으며, 1개를 가진 사례가 66%를 차지하였다. 3개 가진 사례도 있었으며, 앞으로의 건축설계의 추세를 보면 더 많은 경사로를 지닌 사례가 나올 것으로 예측된다. 둘째, 코어의 구성에 있어 계단 단독, 엘리베이터 단독, 경사로 단독, 엘리베이터 + 계단, 계단 + 경사로의 구성을 찾을 수 있었으나 엘리베이터 + 경사로, 엘리베이터 + 계단 + 경사로의 조합은 아직 찾을 수 없었다. 계단 + 경사로의 사례는 단 1개이다. 앞으로 계단 + 경사로, 엘리베이터 + 경사로, 엘리베이터 + 계단 + 경사로의 조합을 이용하여 설계한다면 다양한 모습의 박물관이 나타날 수 있을 것으로 예상된다.

• Safety and Health at Work
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• 제11권3호
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• pp.307-313
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• 2020

Background: Many tasks in industrial and health care setting are involved with pushing and pulling tasks up or down on a ramp. An efficient method of moving cart which reduces the risk of low back pain should be concerned. This study aimed to investigate the effects of handling types (HTs) and slope on lumbar spinal load during moving a cart on a ramp. We conducted a 2 × 2 × 4 factorial design with three main factors: 2 HTs, 2 handling directions of moving a cart and 4 degrees of ramp slope. Methods: Thirty healthy male workers performed 14 tasks consist of moving a cart up and down on the ramp of 0°, 10°, 15°, and 20° degrees with pushing and pulling methods. Joint angles from a 3D motion capture system combined with subject height, body weight, and hand forces were used to calculate the spinal load by the 3DSSPP program. Results: Our results showed significant effect of HT, handling directions and slope on compression and shear force of the lumbar spine (p < 0.001). When the ramp gradient increased, the L4/5 compression forces increased in both pushing and pulling (p < 0.001) Shear forces increased in pulling and decreased in pushing in all tasks. At high slopes, pulling generated more compression and shear forces than that of pushing (p < 0.01). Conclusion: Using the appropriate technique of moving a cart on the ramp can reduce the risk of high spinal load, and the pushing is therefore recommended for moving a cart up/down on ramp gradients.

• 대한인간공학회지
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• 제29권4호
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• pp.681-686
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• 2010

Although the height of a ramp is an important design element, it has not been considered in prior studies. Therefore, in this study, the ramp slope and height are considered as independent variables. To analyze the effects of the slope and height, five levels of slope (1:6, 1:8, 1:10, 1:12 and 1:14) and three levels of height (15cm, 30cm and 45cm) are considered. For the dependent variables, the total time, velocity and perceived discomfort were considered as usability measures, pulse rate changes and EMG signals of four related muscles (extensor carpi radialis, triceps brachii, anterior deltoid and posterior deltoid) were considered as physiology measures. As a result, differences among usability and physiological characteristic for the five slopes increased as the height increased. Additionally, slope effects were minor when the height was low (15cm). Almost domestic/international regulations and guidelines related to ramp recommended 1:12 slope for the ramp design, however, there was no significant difference between 1:10 and 1:12 according to result of this study. In addition, slope effects were minor at a low height; thus, a slope of 1:8 can be recommended if the installation space for a gentler ramp is not sufficient.

• 한국도로학회논문집
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• 제10권4호
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• pp.139-150
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• 2008

본 연구는 도로연장측면에서 본선에 비해 상대적으로 연결로에서 발생하는 사고빈도가 높고, 교통사고가 증가하는 추세인 고속도로 연결로의 교통사고 예측모형의 개발에 초점을 두었다. 연결로 유형별(직결, 준직결, 루프)로 통계적으로 유의한 사고인자를 선정하고, 사고율과의 관계가 비선형 임을 분석하여 변수를 변형(Variables Transformation)하여 All possible 방식으로 예측모형을 개발하고, 통계적 진단 및 검증을 거쳐 유의성을 확인하였으며 이에 기존 개발 모형에 비해 예측력이 더욱 우수한 결과를 보였다. 개발된 사고예측모형은 보다 비용면에서 효율적이고, 안전한 트럼펫형 IC 연결로의 설계와 연결로 교통사고 원인분석에 활용될 수 있을 것으로 기대된다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 춘계학술대회논문집
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• pp.467-472
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• 2005

Load/Unload(L/UL) technology includes the benefits, that is, increased areal density, reduced power consumption and improved shock resistance contrary to contact start stop(CSS). It has been widely used in portable hard disk drive and will become the key technology for developing the small form factor hard disk drive. The main objectives of L/UL are no slider disk contact or no media damage. For realizing those, we must consider many design parameters in L/UL systems. In this paper, we focus on the effect of the ramp profile. We can find out the lateral velocities in L/UL process through experiments and simulations for force of voice coil motor and friction force on ramp. And then, we will gain the optimal design of ramp slope to maintain the minimum clearance of suspension dimple and slider with FE model. In special, after finding the point at which air bearing breaks and designing the ramp, we will identify the results for improving unload performance.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2008년도 춘계 학술발표회 초청강연 및 논문집
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• pp.452-461
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• 2008

Previous settlement prediction method based on settlement monitoring such as hyperbolic, monden method were developed under instantaneous loading condition and have restriction to be applied to soft ground under ramp loading condition. In this study, settlement prediction method under ramp loading was developed. New settlement prediction method under ramp loading considers influence factors of consolidation settlement and increase accuracy of settlement prediction using field monitoring data after ramp loading. Large consolidation tests for ideally controlled one dimensional consolidation under ramp loading condition were performed and the settlement behavior was predicted based on the monitoring data. As a result, new prediction method is expected to have great applicability and practicability for the prediction of settlement behavior.

• 한국전기전자재료학회논문지
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• 제21권10호
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• pp.916-922
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• 2008

AC PDP with MgO protective layer coated with the optimum evaporation rate of $5{\AA}/s$ can generate more enhanced efficiency through the vacuum in-line sealing process. However, the optimized process conditions still require the optimum driving scheme on the ramp-up and ramp-down slope of the reset waveform for enhancing the efficiency. In this paper, for the in-situ vacuum sealed PDP with the optimum evaporation rate of MgO protective layer, the address delay time was investigated with various slopes of ramp waveform during a reset ramp-up and ramp-down period. In this study, the minimum statistical delay time was obtained at the ramp-up rate of $6.0 V/{\mu}s$ and the ramp-down rate of $0.7 V/{\mu}s$ of the reset waveform.

• The Journal of Korean Physical Therapy
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• 제24권4호
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• pp.247-252
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• 2012

Purpose: The purpose of this study was to investigate the change of muscle activities during level walking, stairs and ramp climbing in hemiplegic patients. Methods: Eight hemiplegic patients were recruited and agreed to participate in this study. Muscle activity was measured by MP100 system (BIOPAC System Inc., Santa Barbara, CA, USA). Statistical analysis was used as a one-way repeated measure of ANOVA to know the difference according to the gait conditions (level walking, stairs and ramp ascending). Results: In the swing phase, muscle activity of rectus femoris muscle, with the side lower extremities affected, were generally significantly different in the stair and ramp ascending. In addition, biceps femoris muscle with unaffected side lower extremity was generally significantly different in the ramp ascending. In the swing phase, muscle activity of tibialis anterior muscle with unaffected side lower extremities was generally showed a significant difference in the ramp ascending. In the stance phase, climbing stairs and ramps showed an increase in the muscle activities. Further, climbing the stairs increased muscle activities of the gastrocnemius muscle. Conclusion: These findings indicate that compared with the level walking climbing stairs, ramps and muscle activities of lower extremity during each showed different results. It can be seen that in accordance with the terms of gait are different muscles group recruitment.

• 전기학회논문지
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• 제65권12호
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• pp.2046-2052
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• 2016

Ramp metering is one of the most efficient and widely used control methods for an intelligent transportation management system on a freeway. Its objective is to control and upgrade freeway traffic by regulating the number of vehicles entering the freeway entrance ramp, in such a way that not only the alleviation of the congestion but also the smoothing of the traffic flow around the desired density level can be achieved for the maintenance of the maximum mainline throughput. When the cycle of the signal detection is larger than that of the system process, the density tracking problem needs to be considered in the form of the discrete-time system. Therefore, a discrete-time sliding mode control method is proposed for the ramp metering problem in the presence of both input constraint in the on-ramp and exogenous disturbance in the off-ramp considering the random behavior of the driver. Simulations were performed using a validated second-order macroscopic traffic flow model in Matlab environment and the simulation results indicate that proposed control method can achieve better performance than previously well-known ALINEA strategy in the sense that mainstream flow throughput is maximized and congestion is alleviated even in the presence of input constraint and exogenous disturbance.

• 정보저장시스템학회논문집
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• 제3권4호
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• pp.160-166
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• 2007

In this paper, the measured electrical resistance method is proposed to analyze the ramp-tab contact during the load/unload (L/UL) process. Since this method supplies the voltage change due to the resistance change, we can easily and conveniently identify the ramp-tab contact from the acoustic emission (AE) signal. At first, we carefully deposit the conductive material on the surface of the conventional ramp by sputtering method. The ratio frequency (RF) magnetron co-sputtering system is applied to accomplish the deposited double-layers on the ramp surface. One layer is the stainless steel for the conductive layer and the other is the titanium layer for the cohesive function between the ramp surface and the stainless steel layer. In order to guarantee the stiffness and damping properties of the original ramp, the deposited conductive layer is intended to have very thin thickness. After integration the proposed ramp device into the L/UL system and networking the electrical resistance circuit, the L/UL performance is experimentally evaluated by comparing the measured electrical resistance signal and AE signal.