• Title/Summary/Keyword: running maximum

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Evaluation of Curving Performance and Running Safety of New High-Power Electric Locomotive (신형 고출력 전기기관차의 곡선추종성 및 주행안전성 평가)

  • Ham, Young Sam
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.37 no.6
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    • pp.827-832
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    • 2013
  • In this study, curve responsiveness was assessed based on the lateral force and running safety was evaluated based on the wheel unloading ratio and derailment coefficient, which is the ratio of the wheel load and the lateral force. The evaluation of the curving performance and running safety of the new high-power electric locomotive showed that the derailment coefficient appeared higher when the wheel-set was set to the front of the train instead of being placed backward, and the maximum value of the derailment coefficient was recorded as 0.572 on the Gyeongbu line. Furthermore, the lateral force increased in curved sections, and it appeared to be proportional to the curve radius. Meanwhile, a maximum axis lateral force of 77.6 kN was recorded on the Taebaek line, and the wheel unloading ratio was 47.6% on the Yeongdong line. Finally, the running safety at the maximum speed as well as the through-curve performance of the curve radius satisfied the required standards.

A Train Performance Simulation using Simulink for Generating Energy-efficient Speed Profiles (에너지 효율적인 속도 프로파일 생성을 위한 Simulink 기반 열차 성능 시뮬레이션)

  • Kang, Moon-Ho;Han, Moon-Seob
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.59 no.10
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    • pp.1816-1822
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    • 2010
  • In this research TPS (Train Performance Simulation) blocks are designed using Simulink and applied to generate speed profiles for energy-efficient train operation. With a train operation mode of maximum powering, coasting, and maximum breaking, a breaking point is calculated from forward-backward running profiles. Then, GA (Genetic Algorithm) is used to solve a running time constraint, and a coasting point is produced from the searching process of GA. With the breaking point and the coasting point a speed profile is plotted. Train performance under a speed limit and gradient variations is simulated and resultant speed profiles are analyzed.

Wheel flange Wear Reduction of Rolling Stock (철도차량의 차륜마모 저감)

  • 허현무;이찬우
    • Proceedings of the KSR Conference
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    • 2000.05a
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    • pp.143-150
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    • 2000
  • Like conventional railways, improving running performance of vehicle in curve is more effective than improving maximum speed to reduce traveling time. But some vehicles have problems concerning running performance in cure because of insufficient study for our conventional railway characteristics. So, these problems brought about increasement of maintenance cost. This study was started to deliberate several plans to solve problems concerning running performance in curve. Some modifications of primary suspension and tests were carried out to improve curve negotiation. Here, we describe some results.

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The Biomechanical Comparison of Running Shoes According to the Difference of Insole (인솔 차이에 따른 런닝화의 운동역학적 비교)

  • Jin, Young-Wan;Shin, Sung-Hwon
    • Korean Journal of Applied Biomechanics
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    • v.17 no.2
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    • pp.51-59
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    • 2007
  • These studies show that I applied to functional insole (a specific A company) for minimizing shocks and sprain people's ankle arising from running. How to an effect on human body which studied a kinematics and kinetics from 10 college students during experiments. This study imposes several conditions by barefoot, normal running shoes and put functional insole shoes ran under average $2.0{\pm}0.24\;m$/sec by motion analysis and ground reaction force that used to specific A company. First of all, motion analysis was caused by achilles tendon angle, angle of the lower leg, angle of the knee, initial sole angle and barefoot angle. The result of comparative analysis can be summarized as below. Motion analysis showed that statically approximates other results from achilles tendon angle (p<.01), initial ankle angle(p<.05), initial sole angle(p<.001) and barefoot angle(p<.001). Ground reaction force also showed that statically approximates other results from impact peak timing (p<.001), Maximum loading rate(p<.001), Maximum loading rate timing (p<.001) and impulse of first 20 percent (p<.001). Above experiment values known that there was statically difference between Motion analysis and Ground reaction force under absorbing of the functional insole shoes which was not have an effect on our body for kinetics and kinematics.

An Effect Analysis of Rearfoot Movement and Impact force by Different Design of Running Shoes Hardness (런닝화의 경도 차이가 후족 제어 및 충격력에 미치는 영향 분석)

  • Lee Dong-Choon;Lee Woo-Chang
    • Proceedings of the Society of Korea Industrial and System Engineering Conference
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    • 2002.05a
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    • pp.291-296
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    • 2002
  • The midsole hardness of athletic footwear affects capability of absorbing impact shock and controls rearfoot movement during running and walking. The prior studies were focused on examining the proper hardness of footwear for rearfoot movement or to finding effective hardness for absorbing impact shock. The displacements of maximal Achilles tendon angle described a amount of pronation motion is decreased when medial hardness of midsole is large more than lateral. Increasing hardness of footwear midsole are effected to reduce maximum and intial pronation angle, but declined the ability of impact shock during heelstrike. For determination of effectiveness hardness of midsole, therefore, the study that makes a compromise between rearfoot movement and absorbing impact during footstrike must be performed. The purpose of this study is to examine quantitative values of rearfoot control and absorbing impact shock with different hardness of medial and lateral midsole on heel portion. The results are useful to define biomechanical hardness of midsole for developing running shoes. As variable for impact shock, accelerations onto shank and knee are measured during 4 running speeds (5, 7, 9, 11km/h). Also, maximum and $10\%$ pronation angle (Achilles tendon angle) were measured using high-speed camera.

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Analysis on Running Safety for KTX Vehicle (KTX차량의 주행 안전성 해석)

  • Kim Jae-Chul;Lee Chan-Woo;You Won-Hee
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2005.06a
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    • pp.345-350
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    • 2005
  • KTX is the high speed train which is designed for 300km/h in maximum operation speed. But its long train set may cause unstable characters as swaying of the tail of a train and when the train is running on conventional line, its running safety is a point to be considered cautiously. In this study, we evaluated the running safety by the numerical analysis using VAMPIRE and compared the result with the test result of KHST, which is being in performance tests, for verifying the validity of analysis results

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Preview Control of High Mobility Tracked Vehicle Suspension

  • Kim, Yoon-Sun;Park, Young-Jin;Kwak, Byung-Hak
    • 제어로봇시스템학회:학술대회논문집
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    • 2001.10a
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    • pp.174.1-174
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    • 2001
  • The role of suspension system in tracked vehicles cannot be overestimated because the driving and running conditions of such vehicles are very severe. It reduces the vibration and shock which are generated by road profile in running condition. As the tracked vehicle's running speed increases, more undesired vibrations can be generated by road profile particularly in the situation of field running. Because, the excessive vibration can harm the operation ability of crewmen and stability of complex equipments, the maximum running speed is limited. In this study, to improve the performance of the tracked vehicle system, we examined the feasibility of using the active preview control for the tracked vehicle´s suspension system. First, we developed ...

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The Study on critical Value of Kinematical Evaluation Variables of Lower Extremity Pronation in Biomechanical Evaluation of Running Shoes (운동화의 생체역학적 평가시 하지 회내운동의 운동학적 평가변인에 대한 상해 기준치 연구)

  • Kwak, Chang-Soo;Jeon, Min-Ju;Kwon, Oh-Bok
    • Korean Journal of Applied Biomechanics
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    • v.16 no.4
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    • pp.175-187
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    • 2006
  • The purpose of this study was to find the relationship between Achilles tendon angle, angular velocity from 2D cinematography utilized to easily analyze the functions of shoes, ankle joint moment, knee joint moment, and hip joint moment from 3D cinematography utilized to predict the injury. Also, this study was to provide the optimal standard to analyze the injury related to the shoes. Subjects in this study were 30 university male students and 18 conditions (2 types of running speed, 3 of midsole hardness, 3 of midsole height) were measured using cinematography and force platform. The results were as following. 1) Hip joint abduction moment was effected by many variables such as running speed, midsole height, maximum achilles tendon angle, ground reaction force. 2) Knee joint rotational moment in running was approximately 1/10 - 1/4 times of the injury critical value and eversion moment was approximately 1/4 - 1/2 times of the injury critical value. 3) Ankle joint pronation moment in running was 1/3 - 1/2 times of the injury critical value. 4) Knee joint rotational moment was found to be irrelevant with maximum achilles tendon angle or angular velocity. 5) Pronation from running was thought to be relevant to rather eversion moment activity than rotational moment activity of knee joint. 6) Plantar flexion abductor of ankle showed significant relationship with the ground reaction force variable. 7) When the loading rate for ground reaction force in passive region increased, extensor tended to be exposed to the injury. Main variables in biomechanical analysis of shoes were impact absorption and pronation. Among these variables, pronation factor was reported to be relevant with knee injury from long duration exercise. Achilles tendon angle factor was utilized frequently to evaluate this. However, as the results of this study showed, the relationship between these variables and injury relating variable of knee moment was so important. Studies without consideration on this finding should be reconsidered and reconfirmed.

A JOINT DISTRIBUTION OF TWO-DIMENSIONAL BROWNIAN MOTION WITH AN APPLICATION TO AN OUTSIDE BARRIER OPTION

  • Lee, Hang-Suck
    • Journal of the Korean Statistical Society
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    • v.33 no.2
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    • pp.245-254
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    • 2004
  • This paper derives a distribution function of the terminal value and running maximum of two-dimensional Brownian motion {X($\tau$) = (X$_1$($\tau$), X$_2$ ($\tau$))', $\tau$ 〉0}. One random variable of the joint distribution is the terminal time value, X$_1$ (T). The other random variable is the maximum of the Brownian motion {X$_2$($\tau$), $\tau$〉} between time s and time t. With this distribution function, this paper also derives an explicit pricing formula for an outside barrier option whose monitoring period starts at an arbitrary date and ends at another arbitrary date before maturity.

Biomechanical Comparison Analysis of Popular Insole and Functional Insole of Running Shoes (런닝화의 일반인솔과 기능성인솔의 운동역학적 비교 분석)

  • Shin, Sung-Hwon;Jin, Young-Wan
    • Korean Journal of Applied Biomechanics
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    • v.16 no.3
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    • pp.9-18
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    • 2006
  • These studies show that I applied to functional insole (a specific S company) for minimizing shocks and sprain people's ankle arising from running. How to an effect on human body which studied a kinematics and kinetics from 10 college students during experiments. This study imposes several conditions by barefoot, normal running shoes and put functional insole shoes ran under average $2.0{\pm}0.24$ meter per second by motion analysis, ground reaction force and electromyography that used to specific A company. First of all, Motion analysis was caused by Achilles tendon angle, Angle of the lower leg, Angle of the knee, Initial sole angle and Barefoot angle. Second, Contact time, Vertical impact force peak timing, Vertical active force and Active force timing, and Maximum loading rate under impulse of first 20 percent and Value of total impulse caused Ground reaction force. Third. The tendon fo Quadriceps femoris, Biceps femoris, Tibialis anterior and gastronemius medials caused. electromyography. 1. Ground reaction force also showed that statically approximates other results from impact peak timing (p.001), Maximum loading rate(p<.001), Maximum loading rate timing (p<.001) and impulse of first 20 percent (p<.001). 2 Electromyography showed that averagely was distinguished from other factors, and did not show about that. Above experiment values known that there was statically difference between Motion analysis and Ground reaction force under absorbing of the functional insole shoes which was not have an effect on our body for kinetics and kinematics.