• Proceedings of the Korean Society Of Semiconductor Equipment Technology
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• 2003.05a
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• pp.80-87
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• 2003

On this study, an End-Effector for the 300mm wafer transfer robot System is newly suggested. It is a mechanical type with $180^{\circ}$ rotating ranges and is composed of 3-point arms, two plate springs and single-axis DC motor. It is controlled by microchip for the DC motor control. To design, relationships on the gripping force and the wafer deformation is analyzed by FEM analysis. Criterion on gripping force of a suggested End-Effector is confirmed as $255 ~ 274g_f$ from experimental results. From experimented results on repeatable position accuracy, gripping force and gripping cycle times in a wafer cleaning system, we confirmed that the suggested End-Effector is well satisfied on the required performance for 300mm wafer transfer robot system.

• Molecules and Cells
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• v.44 no.8
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• pp.549-556
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• 2021

Decoding the molecular mechanisms underlying axon guidance is key to precise understanding of how complex neural circuits form during neural development. Although substantial progress has been made over the last three decades in identifying numerous axon guidance molecules and their functional roles, little is known about how these guidance molecules collaborate to steer growth cones to their correct targets. Recent studies in Drosophila point to the importance of the combinatorial action of guidance molecules, and further show that selective fasciculation and defasciculation at specific choice points serve as a fundamental strategy for motor axon guidance. Here, I discuss how attractive and repulsive guidance cues cooperate to ensure the recognition of specific choice points that are inextricably linked to selective fasciculation and defasciculation, and correct pathfinding decision-making.

• International conference on construction engineering and project management
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• 2022.06a
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• pp.1250-1251
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• 2022

Measuring management is an important part of preventing the collapse of retaining walls in advance by evaluating their stability with a variety of measuring instruments. The current work of measuring management requires considerable human and material resources since measurement companies need to install measuring instruments at various places on the retaining wall and visit the construction site to collect measurement data and evaluate the stability of the retaining wall. It was investigated that the applicability of the current work of measuring management is poor at small and medium-sized urban construction sites(excavation depth<10m) where measuring management is not essential. Therefore, the purpose of this study is to develop a laser sensor-based hardware to support the wall displacement measurements and their control software applicable to small and medium-sized urban construction sites. The 2D lidar sensor, which is more economical than a 3D laser scanner, is applied as element technology. Additionally, the hardware is mounted on the corner strut of the retaining wall, and it collects point cloud data of the retaining wall by rotating the 2D lidar sensor 360° through a servo motor. Point cloud data collected from the hardware can be transmitted through Wi-Fi to a displacement analysis device (notebook). The hardware control software is designed to control the 2D lidar sensor and servo motor in the displacement analysis device by remote access. The process of analyzing the displacement of a retaining wall using the developed hardware and software is as follows: the construction site manager uses the displacement analysis device to 1)collect the initial point cloud data, and after a certain period 2)comparative point cloud data is collected, and 3)the distance between the initial point and comparison point cloud data is calculated in order. As a result of performing an indoor experiment, the analyses show that a displacement of approximately 15 mm can be identified. In the future, the integrated system of the hardware designed here, and the displacement analysis software to be developed can be applied to small and medium-sized urban construction sites through several field experiments. Therefore, effective management of the displacement of the retaining wall is possible in comparison with the current measuring management work in terms of ease of installation, dismantlement, displacement measurement, and economic feasibility.

• International Commerce and Information Review
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• v.14 no.3
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• pp.139-158
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• 2012

FTA is one of the most important trade policies for the motor car industry. Due to the large amount of employment and production the motor car industry provides in a country, in a lot of cases, the protective trade policies that countries employ are targeted for the motor car industry. In this point of view, it can be said that the Latin American FTA strategy such as the 'Korea-Columbia FTA', 'Korea-Peru FTA' and 'Korea-Chile FTA' has a large influence in the development of Korea's car industry. This paper analyses changes in factors influencing car export before and after the signing of the Korea-Chile FTA to forecast the export of motor cars to Latin America and aims to propose an action plan. Research shows that out of the variables 'exchange rate', 'GDP', and 'oil price, 'GDP' showed a strong corelation with export before and after the FTA. Regression analysis also showed that only 'GDP' has an impact on export rates and that its impact is most highest after the exhibition of FTA's effects. This suggests that FTA has an important effect in motor car export to Latin America but export is also strongly interlocked with the local country's economic condition which highlights the requirement for an action plan such as the establishment of local production systems.

• Korean Journal of Cognitive Science
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• v.22 no.2
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• pp.123-143
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• 2011

At what point in the process of speech production are gestures involved? According to the Lexical Retrieval Hypothesis, gestures are involved in the lexicalization in the formulating stage. According to the Information Packaging Hypothesis, gestures are involved in the conceptual planning of massages in the conceptualizing stage. We investigated these hypotheses, using the game situation in a TV program that induced the players to involve in both lexicalization and conceptualization simultaneously. The transcription of the verbal utterances was augmented with all arm and hand gestures produced by the players. Coverbal gestures were classified into two types of gestures: lexical gestures and motor gestures. As a result, concrete words elicited lexical gestures significantly more frequently than abstract words, and abstract words elicited motor gestures significantly more frequently than concrete words. The difficulty of conceptualization in concrete words was significantly correlated with the amount of lexical gestures. However, the amount of words and the word frequency were not correlated with the amount of both gestures. This result supports the Information Packaging Hypothesis. Most of all, the importance of motor gestures was inferred from the result that abstract words elicited motor gestures more frequently rather than concrete words. Motor gestures, which have been considered as unrelated to verbal production, were excluded from analysis in many gestural studies. This study revealed motor gestures seemed to be connected to the abstract conceptualization.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.23 no.2
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• pp.138-147
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• 2009

In this paper, improved direct torque control(DTC) system for five-phase squirrel-cage induction motor(IM) is proposed. Due to the additional degrees of freedom, five-phase 1M drives present unique characteristics. Also five-phase motor drives possess many other advantages compared with the traditional three-phase motor drive system, such as reducing an amplitude of torque pulsation and increasing the reliability. The DTC method is advantageous when it is applied to the five-phase IM, because the five-phase inverter provides 32 space vectors in comparison to 8 space voltage vectors into the three-phase inverter. However, five-phase motor has structural drawback of 3rd space-harmonics current component, it is necessary to controlled 3rd harmonic current. So to control 3rd harmonic current and enhance dynamic characteristics of five-phase squirrel-cage IM drive, modified DTC method should be demanded. The characteristics and dynamic performance of traditional five-phase DTC are analyzed and new DTC for five-phase IM is presented. A more precise flux and torque control algorithm for the drives can be suggested and explained For presenting the superior performance of the proposed direct torque control, experimental results are presented using a 32-[bit] fixed point TMS320F2812 digital signal processor with 2.2[kW] induction motor.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2001.04a
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• pp.399-404
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• 2001

In CNC machining, a 3D(3-dimension) linear segment and a 2D(2-dimension) circular arc are general forms given by CAD/CAM system. Generally, the 2D circular arc machining is processed using dividing into some linear segments. A 3D circular arc also don't exist in the standard form of NC data. This paper present a algorithm and method for real-time machining of a circular arc(not only the 2D one, but also the 3D one). The 3D circular arc machining is based on the 2D circular arc machining. It only needs making a new coordinate system, converting given 3D points(a start point, a end point, and a center point of a 3D circular arc) into points of the new coordinate system, and processing a inverse transformation about a interpolated point. The proposed algorithm was implemented and simulated on PC system. It was confirmed to give a gcod result.

• Journal of Advanced Navigation Technology
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• v.11 no.2
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• pp.209-216
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• 2007

In this paper, we embodied posture-stabilization and dynamic gait in a walking robot. 10 RC servo motors are used to operate joints. And the joints have enough moving ranges suitable in any walking pattern. Each joint trajectory is generated by cubic spline interpolation method and the stability of the trajectory is verified by using Zero Moment Point from the robot modeling. To avoid complex structure and expression, Zero Moment Point of the biped robot used angular acceleration is suggested. To measure the stability of the biped robot, Tilt sensor and gyro sensor are used. Finally, Personal Computer is used computer monitoring and data processing. Most of computation, such as 10 RC servo motor control, joint trajectory generating, ZMP compensation, sense measuring, etc, was used Digital Signal Processor.

• Korean Journal of Acupuncture
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• v.20 no.1
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• pp.71-90
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• 2003

The shoulder is the most flexible joint in human body, so many people suffer from the shoulder pain. In order to improve medical care about shoulder muscle disease, Myofascial Pain Syndrome(M.P.S) is compared with the oriental medical theory. The findings of this study are as follows; 1. Myofascial Pain Syndrome(M.P.S) is the sensory, motor, and autonomic symptoms caused by myofascial trigger points. For the objectivity of the oriental medical theory, practical application is necessary. 2. The meridian and meridian-muscle of the shoulder is su-sam-yang(手三陽), su-sam-um(手三陰). Meridian-muscle theory is similar to anatomical muscle and myofascia. 3. There is similarity in the trigger point and Ashi(阿是)-point, taut band and palpable tender-point(硬結), referred pain and Hangki(行氣). In this study, myofacial pain syndrome is similar to the oriental medical theory. If myofacial pain syndrome is applicated in treatment, the cure of shoulder pain and objectivity of the oriental medical theory is improved.

• Journal of Korea Foundry Society
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• v.26 no.1
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• pp.40-45
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• 2006

Most of the work reported concerned the semi-solid processing of low melting point alloys, and in particular light alloys of aluminum and magnesium. The purpose of this paper is to develop a semi-solid microstructure of Cu alloys using electromagnetic stirring applicable for squirrel cage rotor of induction motor. The size of primary solid particle and the degree of sphericity as a function of the variation in cooling rate, stirring speed, and holding time were observed. By applying electromagnetic stirring, primary solid particles became finer and rounder relative to as-cast sample. As the input frequency increased from 30 to 40 Hz, particle size decreased. The size of primary solid particle was found to be decreased with increasing cooling rate. Also, it decreased with stirring up to 3 minutes but increased above that point. The degree of sphericity became closer to be 1 with hold time. Semi-solid microstructure of Cu alloys, one of the high melting point alloys, could be controlled by electromagnetic stirring.