• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권2호
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• pp.1745-1748
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• 2007

First, thin-film photodevices are evaluated, and a p/i/n thin-film phototransistor (TFPT) is recommended because the photo-induced current is relatively high and independent of the applied voltage. Next, an artificial retina is developed using the p/i/n TFPTs, and it is found that it can detect photo illuminance profile with sensitivity control.

• 한국철도학회논문집
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• 제8권5호
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• pp.477-482
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• 2005

Through a year's commercial operation, Korea High Speed Railway has solved defectives from several breakages at the beginning and is going into the stage of stable operation. Among issues, wheel wear becomes a matter of primary concerns in view of vehicle's stability and maintenance. It was understood as above that wear status has been improved in the test by which railway system including vehicles and tracks was stabilized during a year's commercial operation, comparing to that with excessive wear in the trial operation prior to opening to the public. To make out wheel's wear status and characteristics of equivalent conicity at present when the service has been introduced a year ago and the average cumulative mileage of vehicles reach almost 500,000km, wheel's wear types were analyzed with the current vehicles in service.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2010년도 춘계학술대회 논문집
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• pp.1061-1067
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• 2010

In this paper, we propose a simulator for testing of the Navigation Control System(NCS) in Bimodal-tram. NCS uses values of all sorts of sensors installed in vehicle to decide current position, and to control speed and steering of vehicle to go to a next position. Major functions of simulator are input processing of the driver and generation of virtual sensor data and driving profile(navigation path, magnetic information), and the NCS function. Virtual sensor data is generated according to output data from the NCS, driving profile and input processing of the driver, and monitoring systems is operated separatedly to confirm of NCS operation. This paper discusses about the implementation of the simulator, and analyzes and evaluates the simulation results.

• 소성∙가공
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• 제25권2호
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• pp.136-140
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• 2016

Although the finite element method is a good tool to analyze skin-pass rolling, it is hard to be applied in the field because of its long calculation time. In the current study, simple numerical models were developed for the prediction of roll force and residual stress profiles along the strip width. These models are based on finite element analysis and a coupled solution of Sims’ equation and Hitchcock’s formula. The results indicate that plastic strains can be represented as in simple equations of the deformed roll profile and the initial thickness of the strip.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2003년도 춘계학술대회논문집
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• pp.592-597
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• 2003

To solve a problem of micro drive due to small size and portability, it is necessary to understand and to investigate micro drive widely ,deeply. So, we performed modal analysis of suspension of micro drive, and load/unload experiment for Input current to VCM coil and disk speed. To determine the effect of ramp profile, curve fitting of lateral speed is performed with equation of speed. The results indicate that small load/unload speeds decrease the number of head/disk contacts, and during unloading process, low disk speed increase the number of head/disk contacts.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 A
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• pp.257-259
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• 1998

The Switched Reluctance Motor (SRM) has good properties to the adjustable speed control. But, high torque ripple and noise decrease this merit and make unstable state. Also, because of the saturation in the magnetic circuit, it is difficult to predict the inductance profile. If the inductance pronto is known, it's possible to make flat-top torque by applying some control strategy. This paper suggests method to develope flat-top torque using a Artificial Neural Network(ANN) method that can calculate a nonlinear inductance profile.

• 암석학회지
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• 제17권4호
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• pp.231-237
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• 2008

아르헨티나의 대표적인 외국광산기업은 엑스트라타, 바릭 골드, 야마나 골드, 앵글로 골드의 4개 회사들이다. 본문에서는 이들 회사 중 첫 번째로 엑스트라타의 회사연혁, 현재와 미래의 광산프로젝트, 생산량, 재무현황의 개요를 소개하였는데 이는 좋은 협력파트너를 모색하려는 한국 광산기업들에게 심각한 투자실수를 피하기 위해서다.

• 한국표면공학회지
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• 제32권3호
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• pp.235-238
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• 1999

Silicon dioxide films were prepared by anodizing silicon wafers in an ethylene $glycol+HNO_3(0.04{\;}N)$ at 20 to $70^{\circ}C$. The voltage between silicon anode and platinum cathode was measured during this process. Under the constant current electrolysis, the voltage increased with oxide film growth. The transition time at which the voltage reached the predetermined value depended on the temperature of the electrolyte. After the time of electrolysis reached the transition time, the anodization was changed the constant voltage mode. The depth profile of oxide film/Si substrate was confirmed by XPS analysis to study the influence of the electrolyte temperature on the anodization. Usually, the oxide-silicon peaks disappear in the silicon substrate, however, this peak was not small at $45^{\circ}C$ in this region.

• Current Optics and Photonics
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• 제4권4호
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• pp.326-329
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• 2020

The Eaton lens, with spherical symmetry to its refractive index, was described by Eaton in 1952 and was found recently in the design of an invisible sphere for cloaking. In this paper, an Eaton lens for rotating 90° was designed using Luneburg theory, by which we found it was a fourth-order equation in the refractive index n. Therefore, the refractive index n has four roots. The equation in n was solved and studied using mathematical technology. The unsuitable complex roots of the equation should be dropped; consequently, only one of the four roots remained. To verify the refractive-index profile, the only root was solved for, before a simulation using finite-element analysis (FEA) was performed. The simulation showed that all rays will bend 90° to the right. The result of the simulation is identical to our expectation. This treatment provides a possible method for rotating light at many other angles.

• Current Optics and Photonics
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• 제6권4호
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• pp.359-366
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• 2022

In this paper, we present a new design for angle-sensitive pixels (ASPs). The proposed ASPs take advantage of subwavelength compound gratings to capture the light angle, which enables pixel size to reach the wavelength scale of 0.7 ㎛ × 0.7 ㎛. The subwavelength compound gratings are implemented by the wires of the readout circuit inherent to the standard complementary metal-oxide-semiconductor manufacturing process, thus avoiding additional off-chip optics or post-processing. This technique allows the use of two pixels for horizontal or vertical angle detection, and can determine the light's angle in the range from -45° to +45°. The proposed sensor enables surface-profile reconstruction of microscale samples using a lensless imaging system.