• 한국농촌건축학회논문집
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• 제21권4호
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• pp.53-60
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• 2019

The purpose of this study is to investigate the change of Hidden gates form with the times. Fortresses position is constructed on the Korea mountain ranges. Hidden gate, one of facilities to construct fortress among various factors, represents as route of supplies way, ask for rescue, or counterattack plan to come in. The shape of hidden gate changes depend on land form, function, and time period. Previous research partially based on archeology or history. This research analyze Namhan mountain Namhansansung, one of the highest hidden gates count in Korea, distributive by main fortress, Bong-am fortress, Hanbong fortress. Nahhan Mountain fortress repeatedly affected by King Injo in Joseon Dynasty. As a result, Nahhan Mountain fortress consist of hidden gates alternation depend on the time of establishment or extension which makes different shape or size.

• 드라이브 ㆍ 컨트롤
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• 제12권4호
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• pp.15-20
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• 2015

Unlike a typical metal spring, a gas spring uses compressed gas contained in a cylinder and compressed by a piston to exert a force. A common application includes automobiles where gas spring are incorporated into the design of open struts that support the weight of tail gate. They are also used in furniture such as office chairs, and in medical and aerospace applications. The gas spring works by the application of pressurized gas (nitrogen) contained in a cylinder. The internal pressure of the gas spring greatly exceeds atmospheric pressure. This differential in pressure exists at any rod position and generates an outward force on the rod, making the gas spring extend. In this paper, we investigated the dynamic characteristics of a gas spring on an automotive tail gate system.

• 대한기계학회논문집B
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• 제31권2호
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• pp.151-158
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• 2007

The mechanism of power transmission from motor torque to stem thrust and the operation characteristic of each stroke position are analyzed using the diagnostic signal, and effects of differential pressure on the performance of motor operated flexible wedge gate valve are investigated. Test facility consists of 76 mm motor operated valve(flexible wedge type), pump and pipe system. Static and dynamic test are performed separately, and two differential pressure conditions are applied in the dynamic test. To evaluate the performance of valve, test signals for the torque, thrust, current, voltage and stroke length are acquired by using UDS which is diagnosis device for motor operated valve, and each diagnostic signal is analyzed and compared. The characteristic of valve performance factors such as stem factor, rate of loading, valve factor, are evaluated, and these factors are found to be severely influenced by the fluid differential pressure.

• Journal of the Optical Society of Korea
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• 제19권3호
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• pp.222-227
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• 2015

We propose a new and potentially integrable scheme for the realization of an all-optical binary full adder employing two XOR gates, two AND gates, and one OR gate. The XOR gate is realized using a Mach-Zehnder interferometer (MZI) based on a semiconductor optical amplifier (SOA). The AND and OR gates are based on the nonlinear properties of a semiconductor optical amplifier. The proposed scheme is driven by two input data streams and a carry bit from the previous less-significant bit order position. In our proposed design, we achieve extinction ratios for Sum and Carry output signals of 10 dB and 12 dB respectively. Successful operation of the system is demonstrated at 10 Gb/s with return-to-zero modulated signals.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2001년도 추계학술대회 논문집
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• pp.286-290
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• 2001

This paper presents a full-digital low-level controller for a robotic material transfer system which has been developed for a computer-integrated manufacturing model plant. Compared to conventional analog or hybrid type controllers in current industrial environments, this controller system has some advantages such as strong noise-immunity, easy control algorithm implementation, etc The servo-controller consists of two modules, a position controller and a DC servo motor driver. The position controller operates position feedback routines by receiving position encoder data and sending control outputs to the driver. The position controller is implemented in a full-digital way using a recently introduced microcontroller. The DC servomotor driver controls speeds and torques. The driver consists of a micro-controller and insulated-gate-bipolar-transistors (IGBT). The micro-controller provides control signals, and the IGBT's amplifies the control signals and sends them to the motor.

• 한국방사선학회논문지
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• 제14권6호
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• pp.725-731
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• 2020

구(sphere)형의 섬광체를 사용한 방사선 스펙트로스코피 검출기를 설계하였고, 여러 대의 검출기를 사용하여 방사선원의 위치를 추적하는 시스템을 개발하였다. 방사선원의 위치 추적은 방사선의 수는 거리의 역자승 법칙에 따라 감소하는 이론을 바탕으로 위치 추적 알고리듬을 설계하였으며, 여러 위치의 방사선원에서 발생된 방사선의 수를 측정하여 알고리듬을 통해 위치를 계산하였다. 방사선원에서 발생되는 방사선은 각 검출기에서 서로 다른 계수로 검출되며, 이러한 검출되는 계수의 차이는 거리의 역자승에 비례하여 달라진다. 설계한 방사선원 위치 추적 시스템의 성능을 검증 및 평가하기 위해 Geant4 Application for Tomographic Emission (GATE) 시뮬레이션을 실시하였으며, 서로 다른 위치에 놓이 방사선원에서 발생된 방사선을 각 검출기로 계수하였다. 측정된 방사선의 수는 방사선원 위치 추적 알고리듬을 통해 위치가 추적되었으며, 실제 방사선원의 위치와 알고리듬으로 계산된 위치와의 오차를 평가하였다. 실제 방사선원의 위치와 계산된 위치와의 오차는 평균 X축 0.11%, Y축 0.37%로 측정되었으며, 매우 정확하게 위치를 측정할 수 있음이 검증되었다.

• Design & Manufacturing
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• 제12권2호
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• pp.27-33
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• 2018

Korea's automobile industry, which has grown rapidly to become the world's fifth-largest automobile producer, To cope with environmental pollution and energy problems in order to prevail competitive edge in global market We are investing a lot of research personnel and costs. Among them, for realizing alternative light weight It is a part of the automobile module system that has achieved the technological development before the breakthrough in the injection molding process in the press process. Door module PNL was the subject of research. The door module PNL is expected to cause warpage before the mold production due to the thin and flat product characteristics and fiber orientation characteristic of the material. In this paper, CAE analysis and reverse correction tool Design. CAE analysis to obtain the results of weld line position, bending position and deformation value Through the correction tool, think3, the original product was modified before the mold production to improve the completeness of the parts. In fiber orientation, the position and size of the cooling channel in the mold, the position and size of the gate, Temperature, pressure, time, and work environment. Compared with the result of CAE analysis, the product that was reverse-corrected by Think3 was manufactured, and injection molding was performed. Injection molding products were tested 24 hours later. 3.5 mm to 7.0 mm, and under the fixed condition, the deviation was from 1.1 mm to 1.5 mm. Unlike the CAE analysis, the deviation of the actual injection pressure and the cooling temperature, the fiber orientation of the material, In order to solve this problem, it is necessary to compare the injection conditions with the database, I knew I had to catch the standard.

• 한국산학기술학회논문지
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• 제16권11호
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• pp.7729-7735
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• 2015

플라스틱 사출성형제품은 금형을 제작하여 대량생산에 적합한 시스템으로서 두께가 두꺼운 자동차 핸들제품은 가스사출성형을 수행하는 것이 바람직하다. 가스사출성형은 용융된 원재료를 금형내로 충전시킨 후 질소가스를 주입하는 기술이다. 가스사출성형은 재료비절감, 품질향상 등 많은 장점을 가지고 있다. Moldflow소프트웨어를 활용하여 사출성형 공정을 해석하여 제품의 휨 변형을 최소하기 위한 게이트의 위치를 결정하였으며, 기존의 일반적인 PP재료로 가스사출 성형을 했을 경우 변형이 크게 발생되므로 미네랄이18% 함유된 PP 재료로 변경하여 사출제품의 휨 변형을 최소로 하는 것과 게이트의 위치를 변경하여 핑거링현상이 발생하는 트러블을 제거하는 것을 목적으로 하였다, 또한 가스 사출성형을 수행하였을 경우 원재료가 유입되고 난후 게이트를 기준으로 가스가 유입된 형상을 파악하기 위해 비교분석해 보았다. 본 연구를 통해 제품형상에 따른 두께의 변화와 가스사출성형을 수행하더라도 플라스틱의 재료에 따라 제품의 휨이 발생 될 수 있다는 것과 게이트의 위치가 제품의 트러블에 영향을 미친다는 것을 알 수 있었다.

• 한국세라믹학회지
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• 제46권3호
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• pp.229-233
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• 2009

This study has focused on manufacturing technique of powder injection molding of watch case made from zirconia powder. A series of computer simulation process was applied to prediction of the flow pattern in the inside of the mould to clarifying the change of sintering shrinkage depended on flow direction. The material properties of melted feedstock inclusive of the PVT graph and thermal viscosity flowage properties were measured for obtaining the input data in computer simulation. Also, molding experiment was conducted and the results of experiment showed that good agreement with simulation results for flow pattern and weld line location. On the other hand, gravity and inertia effect have an influence on velocity of melt front because of high density of ceramic powder particles in powder injection molding against the polymer injection molding process. In the experiment, the position of melt front was compared with upper gate and lower gate position. The gravity and inertia effect could be confirmed in the experimental results.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 추계학술대회 논문집
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• pp.275-278
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• 2005

This study has focused on manufacturing technique of powder injection molding of watch case which made from zirconia powder. A series of computer simulation process was applied to prediction of the flow pattern in the inside of the mould and defects as weld line. The material properties of melted feedstock inclusive of the PVT graph and thermal viscosity flowage properties were measured for obtaining the input data in computer simulation. Also, molding experiment was conducted and the results of experiment showed that good agreement with simulation results far flow pattern and weld line location. On the other hand, gravity and inertia effect have an influence on velocity of melt front because of high density of ceramic powder particles in powder injection molding against the polymer injection molding process. In the experiment, the position of melt front was compared with upper gate and lower gate position. The gravity and inertia effect could be confirmed in the experimental results.