• Proceedings of the ESK Conference
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• 1996.10a
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• pp.33-40
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• 1996

본 연구의 목적은 작업생리학적 접근방법(physiological approach)을 이용하여 생리학적 작업 능력(PWC; physiological work capacity)을 추정할 경우 작업형태와 작업방법에 따른 차이점을 비교분석해 보고자 함이다. 작업유형으로는 자전거 에르고미터(cycle ergometer)와 트레드밀 (treadmill)을 사용하였고, 작업방법으로는 각각의 작업유형에 대하여 램프 테스트(ramp test 와 인크리멘탈 테스트(increemntal test)의 차이점을 비교하였다. 또한 외국인들의 생리학적 작업능력(PWC)과 한국인들의 생리학적 작업능력(PWC)을 비교,검토하여 NIOSH(National Institute of Safety and Healty)기준치를 사용하는데 문제점이 없는가를 검토해 보고자 하였다. 작업방법 에 따른 차이점은 자전거 에르고미터의 경우 램프 테스트(ramp test )253.63 ml/min로서 인크리 멘탈 테스트(increemental test) 2859.74ml/min 의 87.70 % 정도로 나타났으며, 트레드 밑의 경우 ramp test 2859.22ml/min로서 incremental test 289.46ml/min의 98.77%정도로 나타났다. 작업유형 에 따른 결과는 자전거 에르고미터의 ramp test 트레드밀의 ramp test 는 ramp test는 트레드밀의 ramp test의 88.72% 정도로 나타났으며, 자전거 에르고미터의 incremental tests는 트레이드밀 작 업의 98.% 정도로 나타났다.

• The Journal of Korean Physical Therapy
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• v.21 no.1
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• pp.35-40
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• 2009

Purpose: The purpose of this study was to investigate change of muscle activities during level walking, stairs and ramp climbing in old adults. Methods: Twelve old adults were recruited and agreed this study. Muscle activity was measured by MP150 system (BIOPAC System Inc., Santa Barbara, USA). Statistical analysis was used one-way ANOVA to know the difference according to gait conditions (level walking, stairs and ramp ascending) Results: In stance phase, muscle activities of low extremities with old adults were generally significant difference in ramp ascending. In swing phase, rectus femoris and biceps femoris activity in old adults generally more increased during stairs ascending and tibialis anterior and gastrocnemius activity in old adults generally increased during ramp ascending. Conclusion: These results indicate that stair and ramp climbing is different muscle recruit pattern to level walking.

• The Journal of Korean Physical Therapy
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• v.22 no.6
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• pp.21-28
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• 2010

Purpose: The purpose of this study was to investigate the kinematic adaptation of head and trunk to ascend stairs and a ramp. Subjects were healthy young adults. Three-dimensional kinematic patterns of head and trunk movements were examined during stair climbing and steeper ramp climbing. Methods: Fourteen young subjects with no history of chronic or acute musculoskeletal, cardiovascular or respiratory disorders took part in this experiment. Kinematic data were collected using a 6 camera Vicon system (Oxford Metrix, Oxford, England). Repeated measures ANOVA analyses were used to investigate the effect of gait mode on kinematics of the head and trunk. Results: The angle of the trunk while ascending stairs or a ramp was modified in three human planes (p<0.05). The angle of head and neck during the ascending of stairs or a ramp was not changed in the sagittal plane but was changed in the frontal and transverse planes (p<0.05). Conclusion: This study describes and discusses some basic kinematic mechanisms underlying the pattern of head and trunk changes during stair and ramp climbing and showed that postural adaptation of the head and trunk is necessary to maintain balance.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.2653-2660
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• 2011

Facilities for disabled person are currently required for rolling stock and its requirements are increased. Researching and development to meet these requirements must be necessary. One of them, ramp between platform and train for wheelchair user was developed and applied in real project, the case is described as per the result. The main contents of this paper is for double leaves type wheelchair ramp development operated by manual. This ramp is fixed at floor area of interior with locking device. So operating is allowed for authorized person only. Beside of this, brief comparison with other types will be mentioned.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.15 no.6
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• pp.102-115
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• 2016

In this study, a scheme of ramp metering that uses Off-ramp Exit Percentage instead of the O/D table required for systems of integrated control of ramps at the target freeway segment is presented. The segment from Gyeyang IC to Jangsu IC on the Seoul Outer Ring Expressway was selected for the study because the segment frequently shows large volume of traffic on the short distance between the two ICs requiring an integrated on-ramp control by taking the traffic situation on an entire expressway into account despite an unavailability of O/D data. Thus the information of Off-ramp Exit Percentage at each IC were collected instead of securing the O/D table through actual survey, and the congestion on the segment was analyzed to identify the validity of the use of off-ramp traffic instead of O/D data. In addition, the scheme of ramp metering that exploits the off-ramp traffic information was prepared through simulations conducted in a way supporting the traffic control for respective access roads thereof by taking traffic situations and queues on each ramp into account. The results obtained from the simulation analyses revealed an improved level of travel speed and traffic volume on the main line and validated the use of off-ramp traffic instead of the O/D table for the ramp metering.

• Journal of Welding and Joining
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• v.11 no.3
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• pp.34-47
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• 1993

Finite element models were developed for thermal and residual stress analysis for the specific welding problems. They were used to evaluate the effectiveness of the various welding heat input models, such as ramp heat input function and lumped pass models. Through the parametric studies, thermal-mechanical modeling sensitivity to the ramp function and lumping techniques was determined by comparing the predicted results with experimental data. The kinetics for residual stress formation during welding can be developed by iteration of various proposed mechanisms in the parametric study. A ramp heat input function was developed to gradually apply the heat flux with variable amplitude to the model. This model was used to avoid numerical convergence problems due to an instantaneous increase in temperature near the fusion zone. Additionally, it enables the model to include the effect of a moving arc in a two-dimensional plane. The ramp function takes into account the variation in the out of plane energy flow in a 2-D model as the arc approaches, travels across, and departs from each plane under investigation. A lumped pass model was developed to reduce the computation cost in the analysis of multipass welds. Several weld passes were assumed as one lumped pass in this model. Recommendations were provided about ramp lumping techniques and the optimum number of weld passes that can be combined into a single thermal input.

• Nuclear Engineering and Technology
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• v.41 no.2
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• pp.187-198
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• 2009

In this paper, three power ramp tests performed on high burn-up Re-crystallized Zircaloy2 - UO2 BWR fuel rods (56 to 63 MWd/kgU) within the SCIP project are simulated with METEOR and ALCYONE 3D. Two of the ramp tests are of staircase type up to Linear Heat Rates of 420 and 520 W/cm and with long holding periods. Failure of the 420 W/cm fuel rod was observed after 40 minutes. The third ramp test consisted of a more standard ramp test with a constant power rate of 80 W/cm/min up to 410 W/cm with a short holding time. The tests were first simulated with the METEOR 1D fuel rod code, which gave accurate results in terms of profilometry and fission gas releases. The behaviour of a fuel pellet fragment and of the cladding piece on top of it was then investigated with ALCYONE 3D. The size and the main characteristics of the ridges after base irradiation and power ramp testing were recovered. Finally, the failure criteria validated for PWR conditions and fuel rods with low-to-medium burn-ups were used to analyze the failure probability of the KKL rodlets during ramp testing.

• The Journal of Korean Physical Therapy
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• v.22 no.5
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• pp.77-82
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• 2010

Purpose: The purpose of this study was to compare the pathway of COP and plantar foot pressure and to determine the correlation between plantar regions during the ascending and descending of a ramp. Methods: Fifteen healthy adults who had no musculoskeletal problems participated in our study. They were asked to walk on a level surface and on an ascending and descending ramp in their bare feet. Pathway of COP and plantar foot pressures were recorded using the Matscan system (Tekscan, Boston, USA). For pressure measurements, the plantar foot surface was divided into seven regions: two toe regions, three forefoot regions, a midfoot region, and a heel region. To determine whether there was a statistically significant difference between pathway of COP and plantar foot pressures during walking, we used repeated measuremes ANOVA. Results: In comparison to results for a level walking, pathway of COP while ascending a ramp had a tendency to be shifted medially in the forefoot and became longer till the big toe. Pathway of COP while descending a ramp also was shifted medially, but ended in the forefoot. Plantar foot pressure of the second and third metatarsal head and the fourth and fifth metatarsal heads was significantly decreased while descending the ramp. Conclusion: These results indicated that plantar foot pressure is changed while ascending and descending a ramp and demonstrated that ramp walking can affect the structure and function of the foot. Therefore, gait environment is associated with significant changes in foot characteristics, which contribute to altered plantar loading patterns during gait.

• Journal of the Korean Institute of Intelligent Systems
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• v.21 no.2
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• pp.186-191
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• 2011

Ramp metering has been used to solve recurrent or non-recurrent congestion on many highways. However, the existing ramp metering methods cannot control non-recurrent congestion like incident and don't have any methods to solve congestion after congestion. In addition, the methods cannot solve congestion quickly because ramp metering operates independently for each ramp. In this study, we developed SARAM which is ramp metering technique with shockwave theory in order to solve the problems. In simulation from Jangsoo IC to Joongdong IC, we confirmed that speed increased by 7.32km/h and delay time reduced by 39.14sec.

• Journal of the Korean Society of Propulsion Engineers
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• v.2 no.2
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• pp.47-55
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• 1998

Steady-state and transient performance for the medium scale civil aircraft turbofan engine was analyzed. Steady-state performance was analyzed on maximum take-off condition, maximum climb condition, and cruise condition. At 90％RPM of the low pressure compressor, the partload performance was economized. The transient performance was analyzed with cases of the step increase, the ramp increase, the ramp decrease, and the step increase and ramp decrease for the input fuel flow. For the transient performance analysis, work matching between compressor and turbine was needed. Modified Euler method was used the integration of residual torque in work matching equation. At all flight condition, the overshoot of the high pressure turbine inlet temperature was appeared in the step and ramp increase case, and the surge of high pressure compressor was appeared in the step increase case and the ramp increase case within 5.5 seconds of maximum climb condition.