• 한국안전학회지
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• 제27권2호
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• pp.42-48
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• 2012

The present study was motivated by the needs to make diversified scientific approaches toward influential factors like human, technical, organization, policy and environmental on the basis of the specialized information concerning the cause for industrial accidents in a measure to prevent the falling accident which has the biggest priority among the three major frequent industrial accidents. In this connection, diverse policies have been practiced in the meantime, with little effects in fact to reduce occurrence of industrial accidents, seemingly because such policies have been practiced on the direct dimension, instead of tries to nip in the bud of fundamental causes. This study was thus conducted with a view to determine the causes that have influence on falling accidents from the overall context and unearth the factors requiring management with priority. For this aim, "Fall from Height"(2003), a study by HSE, UK was applied to various conditions of korea as an experiment to search for fundamental causes for falling accidents. The major findings of this study might be summed up as exploring a main critical path that has influence upon falling accidents and suggesting effective ways to cut down through the critical path.

• 한국안전학회지
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• 제16권1호
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• pp.37-42
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• 2001

The severity of electric shock is entirely dependent on body resistance. When the human body becomes a part of electric circuit, the body resistance is given as a function of shock scenario. Factors which consist of applied voltage, shock duration, body current path and contact area, etc.. The body resistance is defined as the voltage applied to subjects divided by the body current. To secure safety of the subjects, the experiment is conducted on 10 subjects, the body current is limited to 4mA. And only three factors under many shock scenario conditions are used to determine the body resistance. The three factors are the applied voltage, the current pathway and the contact area. The object of this work is to estimate the dynamic resistance of the human body as a function of applied voltage using the body current at low-voltage levels. The data of the body current at low-voltage levels are extrapolated to high-voltage levels using two analytic functions with specified constants calculated by numerical method. Also we can provide permissible body voltage for various copper electrodes on the basis of the data determined with the dynamic resistance and the body current.

• 한국정보과학회논문지:소프트웨어및응용
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• 제41권7호
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• pp.523-532
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• 2014

본 논문에서는 래티스상의 구조적 분류에 기반한 한국어 형태소 분석 및 품사 태깅을 수행하는 방법을 제안한다. 제안하는 방법은 입력문이 주어질 때 어휘 사전(lexicon)을 참조하여, 형태소를 노드로 취하고 인접형태소간의 에지를 갖도록 래티스를 구성하며, 구성된 래티스상 가장 점수가 높은 경로상에 있는 형태소들을 분석 결과로 제시하는 방법이다. 실험 결과, ETRI 품사 부착 코퍼스에서 기존의 1차 linear-chain CRF에 기반한 방법보다 높은 어절 정확률 그리고 문장 정확률을 얻었다.

• 인지과학
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• 제15권4호
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• pp.49-59
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• 2004

한국어의 문법적 표지 중의성 해소 과정과, 한국어의 형태론적 정보 처리과정에 관한 길-혼동 의형과 제약-기반 모형의 예측을 비교 검토하기 위해 안구운동 추적 연구를 수행하였다. 최소부착원리에 따라 구문분석될 수 있는 복합 명사구 구조와, 첫 명사에 주격조사 (-가/이), 한정사(-만), 및 주제표지(-는/은)가 부착되는 삽입 관계절 구조를 비교하였다. 실험 결과, 한국어의 표지 중의성이 최소 부착의 원리에 따라 해소됨을 확인할 수 있었고, 주제표지는 재분석 과정에 영향을 끼침을 알 수 있었다. 안구 고정 시간의 양상은 길-혼동 모형과 더 일치했으며, 제약-기반 설명과는 일치하지 않았다. 추후 연구를 위한 제안을 논의하였다.

• 인터넷정보학회논문지
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• 제18권6호
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• pp.15-23
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• 2017

Wireless power transmission (WPT) for wireless charging is currently attracting much attention as a promising approach to miniaturize batteries and increase the maximum total range of an electric vehicle. The main advantage of the laser power beam (LPB) approach is its high power transmission efficiency (PTE) over long distance. In this paper, we present the design of a laser power beam based WPT system, which has a best WPT channel selection technique at the receiver end when multiple power transmitters and single power receiver are operated simultaneously. The transmitters send their transmission channel information via optically modulated laser pulses. The receiver uses the received signal strength indicator and digitized data to choose an optimum power transmission path. We modeled a vertical multi-junction photovoltaic cell array, and conducted an experiment and simulation to test the feasibility of this system. From the experimental result, the standard deviation between the mathematical model and the measured values of normalized energy distribution is 0.0052. The error between the mathematical model and measured values are acceptable, thus the validity of the model is verified.

• Nuclear Engineering and Technology
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• 제41권7호
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• pp.907-920
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• 2009

This study was performed to evaluate the prediction capability of a commercial CFD code and to investigate the effects of different geometries such as a 4.4 mm tube and an 8/10 mm annular channel on the detailed flow structures. A numerical simulation was performed for the conditions, at which the experimental data was produced by the test facility SPHINX. A 2-dimensional axisymmetric steady flow was assumed for computational simplicity. The RNG $\kappa-\varepsilon$ turbulence model (RNG) with an enhanced wall treatment option, SST $\kappa-\omega$ (SST) and low Reynolds Abid turbulence model (ABD) were employed and the numerical predictions were compared with the experimental data generated from the experiment. The effects of the geometry on heat transfer were investigated. The flow and temperature fields were also examined in order to investigate the mechanism of heat transfer near the wall. The local heat transfer coefficient predicted by the RNG model is very close to the measurement result for the tube. In contrast, the local heat transfer coefficient predicted by the SST and ABD models is closer to the measurement for the annular channel.

• 로봇학회논문지
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• 제15권3호
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• pp.277-285
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• 2020

A differential drive wheeled robot is a kind of mobile robot suitable for indoor navigation. Model predictive control is an optimal control technique with various advantages and can achieve excellent performance. One of the main advantages of model predictive control is that it can easily handle constraints. Therefore, it deals with realistic constraints of the mobile robot and achieves admirable performance for trajectory tracking. In addition, the intention of the robot can be properly realized by adjusting the weight of the cost function component. This control technique is applied to the local planner of the navigation component so that the mobile robot can operate in real environment. Using the Robot Operating System (ROS), which has transcendent advantages in robot development, we have ensured that the algorithm works in the simulation and real experiment.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2004년도 추계학술대회 논문집
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• pp.323-326
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• 2004

In this study, the inspection path which is considered to free collision is generated by offset surface. When the inspection is executed, the consideration of machine dynamic error increases a precision. Dynamic error is measured on CNC machine bed changing of weight work price. Offset surface is safety space about collision. Because the danger of probe-collision is excluded in Offset surface, it is possible to rapid feed of probe and reduced inspection time. The Program which is possible to simulate using CAIP and is confirmed through actual experiment.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2004년도 추계학술대회 논문집
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• pp.737-741
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• 2004

A mobile robot system is developed which is remotely controlled by a haptic master called ‘PHANTOM’. The mobile robot has 4 ultrasonic sensors and single CCD camera which detects the distance from a mobile robot to obstacles in the environment and sends this information to a haptic master. For more convenient remote control, haptic rendering process is performed like viscosity forces and obstacle avoidance forces. In order to show the effectiveness of the developed system, we experiment that the mobile robot runs through the maze and the time is checked to complete the path of the maze with/without the haptic information. Through this repeated experiments, haptic information proves to be useful for remote control of a mobile robot.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2001년도 가을 학술발표회 논문집
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• pp.471-476
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• 2001

Even though structural performance evaluation techniques for reinforced concrete structures have been improved, there are still many problems in the evaluation of structural performance for underground structures which interacts with surrounding soils. Since experimental evaluation of underground RC structures considering the interaction with the surrounding soil medium is quite difficult to be simulated, the evaluation for underground RC structures using an analytical method can be applied very usefully, For underground structures interacted with surrounding soils, it is important to consider path-dependent RC constitutive model, soil constitutive model, and interface model between structure and soil, simultaneously. In this paper, an elastoplastic interface model which consider thickness was proposed and importance of interface model is discussed. The effects of stiffness of structures to entire underground RC system are investigated through numerical experiment for underground RC structure for different reinforcement ratios and thickness of interfaces.