• 한국철도학회논문집
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• 제7권4호
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• pp.367-373
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• 2004

The investigation of running stability of the train for curved track is necessary in view of preventing the train from derailment caused by unbalanced forces transferred from the wheel and guaranteeing moderate level of running safety in curve sections. This paper carried out an analysis of running stability of tilting trains in conventional line which the test operation of tilting trains under development are scheduled. For this purpose, the wheel load and lateral pressure to the rail are evaluated. The criteria for the calculated wheel load and derailment coefficient are compared to the design criteria for running stability. It is founded that the running stability of tilting trains for curved track is guaranteed to have sufficient safety and the train speed in curve is governed by the geometric layout of track rather than the criteria for running stability.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 추계학술대회 논문집
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• pp.1622-1627
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• 2008

A suspension is a core part, determining running stability and riding quality of vehicles and its stiffness is essential parameters in the process of vehicle designing. Suspension stiffness shall be adjusted to meet requirements of running stability and curve running performance, as adding stiffness to primary suspension for running stability in high-speed running results running performance degradation in curved track. The purpose of the report lies in utilization of usable data for optimization of suspension via analyzing running performance through changing stiffness of railway vehicle suspension.

• 한국생활과학회지
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• 제16권3호
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• pp.577-585
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• 2007

This research aimed for 20 latter man whose body shape of torso alters remarkably to develop nipper pattern of running type considered characteristic of body shape of 20 latter man to keep rather balanced body shape against middle age when body shape changes extremely. 1. running type nipper pattern design. Pattern of running, lining and nipper were designed by flattening surface shell. A basis line of running pattern is completed by applying reduction ratio after 3 times of modification & complement based on surface shell. Nipper pattern is designed with design line set by a plaster cast based on running pattern line. Lining pattern is designed with lining design line set by a plaster cast based on running type outside material and nipper pattern. 2. Functional evaluation of research and commercial nipper. Functional inspection through dress test was applied 5point evaluation method and the result of functional inspection on the sight of a wearer is that research nipper(running reduction ratio 15%, nipper reduction ratio 18%) averaged more 4.8point but commercial nipper averaged less 1.8point in the aspect of 20 items such as wear sensibility, motional function and external appearance aesthetic. Research running type nipper scored high in order of motional function, looks of side, back, front and whole and wear sensibility. Functional inspection in the point of view of an observer is that research nipper(running reduction ratio 15%, nipper reduction ratio 18%) averaged over 4.8point and commercial nipper averaged under 1.9point in 17 items of external appearance beauty. Research running type nipper marked high in order of looks of back, whole, front and side.

• Tribology and Lubricants
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• 제15권3호
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• pp.257-264
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• 1999

Recently as electronics and semi-conductor industry develop, ultra-precision machine tools that use air-spindle with externally pressurized air bearing appear in need of ultra-precision products which demand high precision property. Effects of air compressibility absorbs the vibration of shaft, this is called averaging effect, however, the higher running accuracy is demanded by degrees, the more important factor is machining errors that affect running accuracy of shaft. Actually, it would be very important in the view points of running accuracy to understand effects of machining errors on the running accuracy of the spindle system quantitatively to design and manufacture precision spindle system in the aspect that efficiency in manufacturing spindle system and performance in operation. So fu, there are some researches on the effects that machining error affect running accuracy. However, because these researches deal with one bearing of spindle system, these results aren't enough to explain how much machining errors affect running accuracy in the typical spindle system overall. In this study, we investigate the effects of the perpendicularity error of bearing and shaft on running accuracy of spindle system that consists of journal and thrust bearing theoretically, and suggest design guideline about shape tolerances.

• 한국정밀공학회지
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• 제30권10호
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• pp.1023-1029
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• 2013

Water running animals such as basilisk lizards have an advantage of high-speed movement and high power efficiency on water; so researchers in robotic fields have been interested in the water running locomotion. This paper presents prototype-design and experimental study on the fourand six-legged water running robot. Based on the previously proposed quadruped water running robot, we assemble a hexapedal water running robot. The legs of the water running robot are designed based on four-bar parallel link for repeated motion along to pre-defined path. Stability performance of the quadruped and hexapedal water running robot are investigated by experiments on rolling criterion. As a result, hexapedal robot performs better stability than quadruped robot. Based on the hexapedal robot design, we are planning to optimize the position of legs and operating frequency.

• Journal of Korean Neurosurgical Society
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• 제57권2호
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• pp.82-87
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• 2015

Objective : The aim of this study was to investigate voluntary wheel running behavior in the unilateral 6-hydroxydopamine (6-OHDA) rat model. Methods : Male Sprague-Dawley rats were assigned to 2 groups : 6-OHDA group (n=17) and control group (n=8). The unilateral 6-OHDA rat model was induced by injection of 6-OHDA into unilateral medial forebrain bundle using a stereotaxic instrument. Voluntary wheel running activity was assessed per day in successfully lesioned rats (n=10) and control rats. Each behavioral test lasted an hour. The following parameters were investigated during behavioral tests : the number of running bouts, the distance moved in the wheel, average peak speed in running bouts and average duration from the running start to the peak speed. Results : The number of running bouts and the distance moved in the wheel were significantly decreased in successfully lesioned rats compared with control rats. In addition, average peak speed in running bouts was decreased, and average duration from the running start to the peak speed was increased in lesioned animals, which might indicate motor deficits in these rats. These behavioral changes were still observed 42 days after lesion. Conclusion : Voluntary wheel running behavior is impaired in the unilateral 6-OHDA rat model and may represent a useful tool to quantify motor deficits in this model.

• 한국소음진동공학회논문집
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• 제23권3호
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• pp.199-208
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• 2013

So far today, there is a speed limit by the radius of curve based on operation regulation in domestic railway, however a study for the maximum running speed at the curved section without any derailment would be necessary. The two major factors related to the running safety of railway vehicle are classified as the railway vehicle condition and the track condition. In terms of the rail inclination among many other factors, the determination of rail inclination within the possible limit is necessary for the geometrical structure of the optimum track. The disregard of the geometrical parameter related to the rail inclination may cause a serious problem to the running safety of railway vehicle. This study is focusing on the analyzing of running safety regard to the change of rail inclination among the many other parameters to improve derailment safety, so that there is an affection analysis of the running safety regard to the change of rail inclination in the ideal and geometric track condition. Also There is an affection analysis of the running safety regard to the simultaneous change of rail inclination and the running speed at the curved section. According to analysis results of running safety, In case that the left and right rail inclination are 1/40, the running safety of this condition defined than other conditions. Also, the rail inclination of conventional lines is 1/40, Therefore, the railway vehicle passing through curve is safe when the railway vehicle runs in conventional lines.

• 한국운동역학회지
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• 제30권3호
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• pp.197-204
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• 2020

Objective: The purpose of this study was to investigate the effect of increased running speed on the magnitude of impact shock attenuation in high frequency (9~20 Hz) at support phase on the treadmill running. Method: Twenty-four healthy male heel-toe runners participated in this study. Average age, height, mass, and preference running speed were 23.43±3.78 years, 176.44±3.38 cm, 71.05±9.04 kg, and 3.0±0.5 m/s, respectively. Three triaxial accelerometer (Noraxon, USA) were mounted to the tuberosity of tibia, PSIS (postero-superior iliac spine), and forehead to collect acceleration signals, respectively. Accelerations were collected for 20 strides at 1,000 Hz during treadmill (Bertec, USA) running at speed of 2.5, 3.0, 3.5, and 4.0 m/s. Power Spectrum Density (PSD) of three acceleration signals was calculated to use in transfer function describing the gain and attenuation of impact shock between the tibia and PSIS, and forehead. One-way ANOVA were performed to compare magnitude of shock attenuation between and within running speeds. The alpha level for all statistical tests was .05. Results: No significant differences resulted for magnitude of the vertical and resultant impact shock attenuation between the tibia and PSIS, and forehead between running speeds. However, significant differences within running speed were found in magnitude of the vertical shock attenuation between tibia and PSIS, tibia and forehead at speed of 2.5, 3.0 m/s, respectively. Conclusion: In conclusion, it might be conjectured that muscles covering the knee and ankle joints and shoe's heel pad need to strengthen to keep the lower extremities from injuries by impact shock at relatively fast running speed that faster than preferred running speed.

• 한국운동역학회지
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• 제19권3호
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• pp.581-592
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• 2009

본 연구는 일반운동화와 스프링신발의 운동역학적 분석을 통해 일상적인 보행에서 스프링신발이 갖는 특성을 알아보기 위해 실시하였다. 이를 위해 정상족궁인 30-40대 여성 12명을 대상으로 2종류의 실험용 신발(스프링신발)과 비교용 신발(일반운동화)을 착용시킨 후 1.7m/s의 보행속도에서 지면반력기와 EMG, 적외선 카메라를 이용한 운동 역학적 분석을 실시하였다. 분석 결과 지면반력 분석에서는 제 1정점과 제 2정점에서 실험용신발이 일반운동화에 비해 큰 전후성분값을 나타냈다. 근전도분석에서는 대퇴직근의 활동이 스프링 신발을 신었을 때 증가하는 것으로 나타났다. 후족각에서 스프링 신발이 착지 시와 제1정점간에 일반화보다 크며 발목 관절을 중심으로 내측으로 회전하는 회내 운동을 적절하게 제어 하면서 이지 시에 후족 각의 감소에 영향을 미치는 것으로 나타났다. 따라서 스프링신발은 일반 신발에 비해 보행 시 무릎 신전근들의 근력 향상에는 도움을 줄 수 있을 것으로 판단된다.

• Journal of Computing Science and Engineering
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• 제5권4호
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• pp.283-287
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• 2011

Due to the proliferation of software parallelization on multi-core CPUs, the number of concurrently executing processes is rapidly increasing. Unlike processes running in a server environment, those executing in a multi-core desktop or a multi-core mobile platform have various correlations. Therefore, it is crucial to consider correlations among concurrently running processes. In this paper, we exploit the property that for a given created location in the binary image of the parent process, the average running time of child processes residing in the run-queue differs. We claim that this property can be exploited to improve the overall system performance by running processes that have a relatively short running time before those with a longer running time. Experimental results verified that the running time was actually improved by 11%.