• Proceedings of the KSR Conference
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• 2004.06a
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• pp.1259-1265
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• 2004

Railway is an important transportation tool for nation's industrial development and public daily life. These days the concern about railway has remarkably been rising due to the April 2004 opening of KTX, Korea High Speed Rail, together with Trans-Continental Railways linking North Korea, China, Russia, through European countries. In the meantime, the issues of train safety and efficiency, arising from the different on-board signaling systems installed on different kinds of trains, have been raised incessantly. In this paper CTCS(Continental Train Control System) is suggested, which can accommodate such various signaling functions as ATP, ATC, ATS, etc. into one single type of on-board signaling system and operate without changing ground signaling systems on the junctions of the Trans-Continental Railways. The development of this CTCS would cause speed-up of exiting lines and possession of railway core solutions for establishing Northeast Asia logistics center bases, which could be an important cornerstone for domestic railway improvements and Korea's role of Northeast Hub.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.53 no.12
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• pp.700-708
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• 2004

Flux-reversal machine (FRM) is a new doubly-salient stator-permanent magnet (PM) machine with flux linkage reversal in the stator concentrated windings. It can operate in both motoring and generating modes. In this paper, a novel design technique to improve the performance of FRM is proposed. Proposed techniques have a new stator winding and a magnet arrangement method. The stator and rotor shape with a concave type and a flux barrier are also proposed. According to the experimental results, it is shown that the proposed FRM have an improved performance.

• 제어로봇시스템학회:학술대회논문집
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• 1988.10a
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• pp.16-20
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• 1988

This paper presents a new algorithm for solving the inverse kinematics in real-time applications. The end-tip movement of each link can be resolved into the basic resolution unit, .DELTA.l, which depends on link length, reduction ratio and resolution of the incremental encoder attached to the joint. When x- and y-axis projection of the end-tip movement are expressed in .DELTA.l unit, projectional increments .DELTA.x and .DELTA.y become -1, 0 or I by truncation. By using the incremental computation with these ternary value and some simple logic rules, a coordinate transformation can be realized. Through this approach, it should be noted that the floating-point arithmetic and the manipulation of trigonometric functions are completely eliminated. This paper demonstrates the proposed method in a parallelogram linkage type, two-link arm.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.1402-1408
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• 2010

Interior Permanent Magnet Synchronous Motor(IPMSM) produces two kind of torque that Magnetic and Reluctance torque. The permanent magnet linkage flux Ψa and d-axis and q-axis inductance have an important influence on the torque characteristic of IPMSM. Thus their accurate prediction is essential for predicting performance aspect such as the torque and flux-weakening capabilities. In this paper, we compared the characteristic parameters and operation region of two type IPMSM which has different pole numbers.

• Journal of Institute of Control, Robotics and Systems
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• v.14 no.1
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• pp.62-69
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• 2008

A specialized anthropomorphic robot hand which can be attached to the biped humanoid robot MAHRU-R in KIST, has been developed. This built-in type hand consists of three fingers and a thumb with total four DOF(Degrees of Freedom) where the finger mechanism is well designed for grasping typical objects stably in human's daily activities such as sphere and cylinder shaped objects. The restriction of possible motions and the limitation of grasping objects arising from the reduction of DOF can be overcome by reflecting a typical human finger's motion profile to the design procedure. As a result, the developed hand can imitate not only human hand's shape but also its motion in a compact and efficient manner. Also this novel robot hand can perform various human hand gestures naturally and grasp normal objects with both power and precision grasping capability.

• Asian Journal of Innovation and Policy
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• v.7 no.1
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• pp.55-78
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• 2018

This paper investigates the linkage between the mode of transformation of entrepreneurial learning into outcomes and the subsequent impact of these learning outcomes in enhancing the survival of high-tech startups in India. The study uses data from 45 high-tech startups headquartered across different locations in India for the purpose of analysis. Survival Analysis of the data is conducted to determine which mode of learning transformation and what type of en trepreneurial decision making preference have a significant influence on the survival of Indian high-tech startups and to what extent do they impact their survival. The results indicate that entrepreneur's prior startup experience, explorative mode of learning transformation, causal decision making of the entrepreneur and availability of funding for the startup as the key factors that reduce the time to survival of Indian high-tech startups. They also provide key insights on how these factors impact the startup survival in this region.

• Journal of the korean Society of Automotive Engineers
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• v.12 no.4
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• pp.66-74
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• 1990

Friction between piston-ring assembly and cylinder wall of a spark ignition engine was evaluated under various engine operating conditions utilizing a grasshopper linkage system. The friction force was estimated by the force balance relation at the small end of connecting rod. Three forces were chosen to be measured for the objective. They were gas pressure inside the cylinder, inertia force of the piston-ring assembly, and the force exerted by the connecting rod. These forces were measured by a piezo type pressure sensor, an accelerometer and strain gauges, respectively. Comparisons were made with the frictional force evaluated by the conventional method where the assumption of constant rotational speed of engines was adopted. Due to the variation of rotational speed of engines, the conventional method was found to lead to a large error in the evaluation of the frictional force.

• Journal of the Korean Society for Railway
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• v.6 no.4
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• pp.300-307
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• 2003

Using a conventional railway, a tilting train was applied as a means of improving vehicle speed curve negotiation without any modification of infrastructure. In order to achieve the optimal car-body position control through the tilting mechanism, a dynamics analysis was required after the kinematics analysis of the tilting mechanism. For this, the geometric relationship of the linkage-type tilting mechanism was defined. Then, the equations of motion for the half car-body were derived. With the derived equations, the effect of the parameter change on performance was analyzed. The analysis result can be used in the optimum design of a tilting mechanism that considers the track environment, vehicle and operational conditions in which the tilting vehicle is applied.

• Journal of the Korean Society for Railway
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• v.6 no.4
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• pp.294-299
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• 2003

Using a conventional railway, a tilting train was applied as a means of improving vehicle speed during curve negotiation without any modification of infrastructure. As a study for the optimum design of the tilting mechanism of a tilting vehicle, the kinematics sensitivity of the tilting mechanism was analyzed. Using the geometric relationship of the linkage-type tilting mechanism, the relationship of the parameters and the performance index was defined using nonlinear algebraic equations. With the defined relation, the effect of change in the parameters on the performance was analyzed. The analysis result can be used in the optimum design of a tilting mechanism that considers the track environment, vehicle and operational condition in which the tilting vehicle is applied.

• Proceedings of the KIEE Conference
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• 1997.07a
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• pp.165-167
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• 1997

This paper centers on a method which can reduce calculating time and maintain accuracy of whole model FE analysis with one pole model for short secondary Permanent Magnet Linear Synchronous Motor(PMLSM). We use one pole model which considers the number of pole of stator and mover respectively in order to replace whole model to one pole model and calculate flux linkage and back e.m.f. with accuracy. Also we verify the validity of proposed method with comparision of results of whole and one pole model.