• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 춘계학술대회 논문집
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• pp.554-559
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• 2011

Braking performance of a trainset that consists of a locomotive and several coaches and/or wagons is influenced by that of the locomotive as well as each coach or wagon. For trains to safely travel on a railway, trains must be provided with sufficient distance where to stop. Thus, replacing coaches or wagons needs calculating, measuring the braking performance such as a stopping distance or a deceleration. The task is further complicated if there are many kinds of trains with different braking performance characteristics. The accurate calculation is subject to acquire accurate information on the existing cars. Moreover, the initiation of braking by a driver or the geometry of the track affects as complicated factors. In this paper, based on the braking performance test conducted for US-SCRRA coaches, introduced several factors assumed to influence the result and the compensating methodology.

• 한국조리학회지
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• 제6권3호
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• pp.119-147
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• 2000

This Study is performed to research a customer satisfaction to a Franchisee on the food franchise industry. In future, the food industry will be complicated and various. So customer needs also will be complicated. Consequently. a study of customer satisfaction will be researched continuously for corresponding an industrial transfiguration and a customer variety. The result of this study, a Franchisee satisfaction on the food franchise industry is evaluated below the average. This result can be happened by the scale of food franchise industry. However actually it has caused by the lack of Franchisee management mind, the capability of head office, and the lack of competitive power. The mind of service for customer, hygiene and cleanness mind, and the lack of marketing strategies and strategic management can not be satisfied of customer. Also customer value creation can not be made. So the education training and marketing strategies for Franchisee on the food franchise industry have to be requested. And a continuous study for customer satisfaction that correspond with the characteristics of industrial classification be raised.

• 대한기계학회논문집
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• 제18권7호
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• pp.1789-1798
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• 1994

This paper aimed for numerical simulation of complicated gas turbine combustor with swirler. For the convenience of numerical analysis, fuel nozzle and air linear hole areas of secondary and dilution zone, which are issued to jet stream, were simplified to equivalent areas of annular type. In other to solve these problems, imaginary source terms which are corresponded to supplied fuel amount were added to those of governing equation. Chemical equilibrium model of infinite reaction rate and $k-{\epsilon}-g$ model with the consideration of density fluctuation were applied. As the result, swirl intensity contributed to mixing of supplied fuel and air, and to speed up the flame velocity than no swirl condition. Temperature profiles were higher than experimental results at the upstream and lower at the downstream, but total energy balance was accomplished. As these properties showed the similar trend qualitatively, simplified simulation method was worth to apply to complicated combustor for predicting combustion characteristics.

• 대한임베디드공학회논문지
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• 제9권1호
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• pp.53-59
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• 2014

In multiple object tracking, accurate detection for each of objects that appear sequentially and effective tracking in complicated cases that they are overlapped with each other are very important. In this paper, we propose a multiple object tracking system that has a concrete detection and tracking characteristics by using multi-lateral histogram and SIFT feature extraction algorithm. Especially, by limiting the matching area to object's inside and by utilizing the location informations in the keypoint matching process of SIFT algorithm, we advanced the tracking performance for multiple objects. Based on the experimental results, we found that the proposed tracking system has a robust tracking operation in the complicated environments that multiple objects are frequently overlapped in various of directions.

• 전기학회논문지
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• 제57권5호
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• pp.821-826
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• 2008

Recently as a progress of electric technology, modern electric systems become more and more complicated. Thus, it is difficult to use a classical method to analyze responses of the systems in complicated electromagnetic environments because there are so many coupling phenomena. The electromagnetic topology (EMT) is a helpful solution to analyze electromagnetic interference / electromagnetic compatibility (EMI/EMC) of the large complex system. In this paper, EMT is applied to analyze an active element. And then to prove the validity of this analysis, a detector circuit including Schottky barrier diode is analyzed by EMT when input power is given directly.

• 대한전기학회논문지:시스템및제어부문D
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• 제50권3호
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• pp.143-148
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• 2001

A lot of robot trajectory tracking methods are proposed to enhance the tracking error, but irregular tracking errors are always accompanied and very hard to reduce it. Up to now, these irregular tracking errors are reduced by introducing more complicated control algorithms. But, it is intuitively obvious to reduce only the big errors selectively in the irregular ones for the better performance instead of using more complicated control algorithms. By the characteristics of the robot, big tracking errors of the end-effector are generated mostly due to the fast moving of joint. So, in this paper, we introduce a new method which reduce the big tracking errors by clippings the joint velocity with the constraint of given path. Using this method, desired trajectory tracking is obtained within the far reduced error bound. Also, this method is successfully applied to generate the path-constrained error reducing trajectories for 2-axis SCARA type robot.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제48권6호
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• pp.316-321
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• 1999

Disk type single phase switched reluctance motor which is a simple robust construction, simple control circuit and low manufacturing cost, has a characteristics of axial and radial flux machines. However, because this DSPSRM has a complicated magnetic circuit, it is difficult to analyze the design characteristics.. In this study, the calculation of design parameter based on the conventional design theory of electric machine and the characteristics analysis by computer simulation was performed. As the DSPSRM has the characteristics of both AFM and RFM, it is difficult to analyze its characteristics by the 2D FEM. 3D FEM was applied in the analysis of energy distribution and approximated calculation of torque characteristics with rotor positions. With analysis results, prototype of DSPSRM is manufactured.

• 한국자동차공학회논문집
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• 제16권2호
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• pp.99-105
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• 2008

Multi-leaf springs are widely used for a major suspension component in many commercial vehicles. The modeling technique of multi-leaf springs is one of the most difficult problems in suspension modeling as the elements have complicated nonlinear characteristics such as a hysteresis behavior due to the friction. In this paper, hysteretic characteristics with the static and dynamic test are modeled and are simulated with three links and joints in MSC.ADAMS. Simulation results showed good agreements with test results. Using this methodology, it is expected that dynamic characteristics of suspension system with multi-leaf spring can be more accurately evaluated in vehicle dynamics.

• 한국생산제조학회지
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• 제19권6호
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• pp.746-752
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• 2010

Rib structure has been used to bed and column of machine tool to heighten weight stiffness ratio, cost performance and weight saving. In this paper the bed rib structure was estimated with thermal characteristics. Using superposition principle, machine tool designer can describe every complicated heat generation in the machine tool thermal source. As thermal characteristics, thermal deformation of guide rail and column and Maximum-minimum temperature variation were selected. The size, configuration and direction against the thermal loading surface operated to the thermal characteristics. The DB chart was made following rib structure estimating thermal characteristics. With superposition principle and DB chart, machine tool designer can prognosticate the thermal characteristics without FEM analysis to every bed rib structure.

• 한국생산제조학회지
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• 제22권4호
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• pp.740-746
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• 2013

Angular contact ball bearings are often adopted for a high-speed spindle owing to their durability against axial and radial loads. The dynamic characteristics of an angular contact ball bearing, however, are very complicated because they are dependent on the applied loads as well as on the system configuration. This study systematically analyzes the radial-load-dependent characteristics of spindles as well as angular contact ball bearings. Toward this end, a spindle dynamic model along with the bearing dynamics model is established. An iterative solution algorithm is implemented to resolve the statically indeterminate problem associated with spindle-bearing systems subjected to radial load. Two numerical examples are provided to investigate the spindle and bearing characteristics as a function of radial load with regard to the system configuration.