• 한국소음진동공학회논문집
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• 제14권3호
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• pp.224-229
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• 2004

In order to control the railway noise, the radiation characteristic of the noise when the train passes by should be analyzed. Generally, the major noise sources of the Korea Train Express are the rolling noise and power unit noise up to 300km/h. In this paper, a train model that is considered to be a row of point sourcesis introduced to analyze the radiation characteristic. The analysis results are compared with the measurement ones. It is shown that the propagation characteristic of the rolling noise is a dipole type and the noise generated by the power unit is radiated as a cosine type. With increasing of the train speed, the noise level at a receiving point is increased in the direction of motion and reduced in the direction opposite to the motion. The analysis results including the moving effect of the noise source at 300km/h show good agreement with the measurement results.

• 한국정밀공학회지
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• 제26권6호
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• pp.59-67
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• 2009

This paper addresses the control method for skating motion with a nonholonomic constraint. In order to generate a human-like skating motion, the behaviors of motion are distinctively analyzed into transient state and steady state. A close investigation of the behaviors evolved the characteristic of successive motions with transient state and steady state. Simulation results were intuitively comprehensible, and the effectiveness of control method was demonstrated for skating motion.

• 대한토목학회논문집
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• 제26권2A호
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• pp.273-284
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• 2006

본 연구에서는 근거리지진의 일반적인 특성에 대해 고찰한 후, 탄성응답스펙트럼이 제공하지 못하는 구조물의 비탄성거동에 따른 응답을 연성도 및 항복강도계수의 변화를 이용하여 평가하기 위해 비탄성응답스펙트럼을 작성하였다. 근거리지진의 특성을 가장 잘 반영할 수 있는 장주기의 대상 구조물을 선정하여 탄성 및 비탄성시간이력해석을 수행하였으며, 입력지진동에 대한 응답 분포 양상을 검토하였다. 또한 구조물의 비탄성거동을 명확하게 파악할 수 있도록 소성힌지 발생여부를 검토하여 구조물의 응답특성을 비교 분석하였다.

• 반도체디스플레이기술학회지
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• 제7권2호
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• pp.29-33
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• 2008

LCD panels are increasingly used to show moving image material, for example in LCD television sets. However, moving images become blurred on LCD panels. One of the causes of motion blur is the slow reaction of LC(liquid crystal) cell to change in the pixel value. Another cause of motion blur is the hold-type characteristic of the LCD panel, during the frame time the image is shown continuously. This type of motion blur can be reduced with a scanning backlight. We have designed and fabricated a scanning backlight system that solves the hold-type characteristic problem in a way that Flat fluorescent lamp divided 6 blocks was scanned 60Hz.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1986년도 한국자동제어학술회의논문집; 한국과학기술대학, 충남; 17-18 Oct. 1986
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• pp.251-255
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• 1986

Some missiles using canards as control device adopt rollerons to reduce roll motion due to aerodynamically induced rolling moment. This paper presents equations of motion of these missiles including the gyroscopic effect of rolleron rotors. Some linearized analysis results and simulation results are shown to coincide, thus some characteristic motions of missiles and rollerons can be seen.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2010년도 춘계학술대회 논문집
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• pp.937-938
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• 2010

• 한국의학물리학회지:의학물리
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• 제28권4호
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• pp.164-170
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• 2017

One of the methods to consider the effect of respiratory motion of a tumor target in radiotherapy is to establish a treatment plan with the internal target volume (ITV) created based on an accurate analysis of the target motion displacement. When this method is applied to intensity modulated radiotherapy (IMRT), it is expected to yield a different treatment dose distribution under the motion condition according to the IMRT method. In this study, we prepared ITV-based IMRT plans with conventional IMRT using fixed gantry angle beams, RapidArc using volumetric modulated arc therapy, and tomotherapy using helical therapy. Then, the variation in dose distribution caused by the target motion was analyzed by the dose measurement in the actual motion condition. A delivery quality assurance plan was prepared for the established IMRT plan and the dose distribution in the actual motion condition was measured and analyzed using a two-dimensional diode detector placed on a moving phantom capable of simulating breathing movements. The dose measurement was performed considering only a uniform target shape and motion in the superior-inferior (SI) direction. In this condition, it was confirmed that the error of the dose distribution due to the target motion is minimum in tomotherapy. This is thought to be due to the characteristic of tomotherapy that treats the target sequentially by dividing it into several slices. When the target shape is uniform and the main target motion direction is SI, it is considered that tomotherapy for the ITV-based IMRT method has a characteristic which can reduce the dose difference compared with the plan dose under the target motion condition.

• International Journal of Advanced Culture Technology
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• 제12권2호
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• pp.345-352
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• 2024

We are designed to solve cyber motion sickness, an important task that must be addressed for the growth of the virtual reality content industry. Not only the industry but also academia are paying a lot of attention. However, despite long interest and research on the phenomenon of cyber motion sickness, a solution has not been drawn. This is deeply related to the lack of tools that can effectively measure cyber motion sickness. Therefore, in this paper, prior studies on cyber motion sickness were analyzed to develop a tool that can effectively measure cyber motion sickness when users experience immersive virtual reality. The measurement method of cyber motion sickness used in previous studies, each characteristic and limitation, and common factors related to cyber motion sickness were analyzed. Each of the related factors was derived as sub-factors. Based on the analyzed contents, an effective cyber motion sickness measurement evaluation tool model in immersive virtual reality was presented. It is expected that the evaluation tool model can be used for the study of cyber motion sickness.

• 한국전산구조공학회논문집
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• 제28권1호
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• pp.29-37
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• 2015

본 연구에서는 BWIM(Bridge Weigh-in-Motion) 시스템을 기반으로 주행차량의 총중량 및 축중량 추정을 수행하였다. BWIM 시스템의 개발을 위해 차량 주행시험은 필수적이지만 그 비용과 시간이 많이 소요되고, 다양한 차량 주행 조건의 적용이 어렵다. 따라서 차량 주행시험의 비용 및 시간적 문제점을 보완하고, 주행 조건에 따른 다양한 교량응답의 확보할 수 있는 수치 시뮬레이션이 현장실험과 병행되어야한다. 본 연구에서는 교량의 동적특성을 반영하는 수치 시뮬레이션을 수행하여 교량의 응답을 획득하고, 통행 차량의 중량을 산출하는 BWIM 시스템에 적용하여 총중량 및 축중량 추정을 수행하고 정밀해석모델기반 과적단속기술에 대하여 제안하였다.

• Journal of information and communication convergence engineering
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• 제16권1호
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• pp.12-16
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• 2018

In this work, a voltage controlled oscillator (VCO) monolithic microwave integrated circuit (MMIC) was demonstrated for 10-GHz band motion detecting sensors. The VCO MMIC was fabricated using a $2-{\mu}m$ InGap/GaAs HBT process, and the tuning of the oscillation frequency is achieved by changing the internal capacitance in the HBT, instead of using extra varactor diodes. The implemented VCO MMIC has a micro size of $500{\mu}m{\times}500{\mu}m$, and demonstrates the value of inserting the VCO into a single chip transceiver. The experimental results showed that the frequency tuning characteristic was above 30 MHz, with the excellent output flatness characteristic of ${\pm}0.2dBm$ over the tuning bandwidth. And, the VCO MMIC exhibited a phase noise characteristic of -92.64 dBc/Hz and -118.28 dBc/Hz at the 100 kHz and 1 MHz offset frequencies from the carrier, respectively. The measured values were consistent with the design values, and exhibited good performance.