• Korean Journal of Occupational Health Nursing
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• v.14 no.2
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• pp.93-107
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• 2005

Purpose: The purpose of this study is to identify the trends of studies on work-related musculoskeletal disorder and to suggest the direction of future research. Method: 144 research thesis for a degree on work-related musculoskeletal disorder were systematic reviewed and published from Jan. 1990 to Mar. 2005. The analyzed using descriptive statistics, an actual number, percentage. Result: As its result the work-related musculoskeletal disorder research which is announced from domestic the doctorate dissertation at the 2004 year 42 the most many 144 dissertation middle most to be 129 in master degree dissertation was 15 in Ph D degree. Dissertation contents character the contents against the result relation that it analyzes especially and a condition and an obstacle was many most at 84. Research plan in most description investigation research 121 the dissertation field to be the especially public health (hygiene, industry and environment) at this 57 most many research object person distribution manufacturing industry in the research object one dissertation was many most at the 40. The tools which are used in each measurement in the question tool which it uses most the question price of land which uses the condition investigation ticket which it made from the NIOSH and the ANSI most many 33, the hazard which analyzes a work attitude in the tool which it uses the RULA was many most at 14. In the stress test tool social psychological healthy measurement PWI (Psychological Wellbeing Index) the dissertation which uses the Job Strain of the Karasek Model to be many most at 19 PWI (Psychological Wellbeing Index) 7 easy use. Work-related musculoskeletal disorder measurement hazard in physiological index and the machinery and tools which it uses there were 9 researches to use an electromyogram most plentifully. With the effect goes to a work-related musculoskeletal disorder they are 33 where the age is many most from general quality. From healthy act with the relation of smoking the year to be many from 16 dissertations. Work of the corpse an attitude (the attitude which is inappropriate) with 5 and the work market the work burglar is many most at 9, the society-support of 36 where the stress is many psychologically most, the stress and service also the most many duty discretion (authority and autonomy) is 6 at the duty demand boat song 9. The service career to be many is 22 of extraordinarily with relation of service. Conclusion: It is recommended the research which it sees being limited in only domestic thesis for a degree the international comparative study to become accomplished. It comes to think with the fact that it will be necessary to make the protocol which it conforms in the civil official guide the test researches for the protocol or arbitration program which is standardized are necessary. Prevention and the civil official of work relation bones and sinews standing total disease hazard scientific base one program is necessary with base.

• Journal of the Korean Society of Safety
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• v.23 no.2
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• pp.81-86
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• 2008

Experimental studies have been performed to examine the influences of wall obstructions in a rectangular confinement. Three wall obstacles with blockage ratios ranging from 10 to 30% were used. Temporally resolved flame front images were recorded by a high-speed video camera to investigate the interaction between a propagating flame and the obstacle. The local flame displacement speed and its probability density functions(PDFs) were obtained for the wall obstructions. During the interaction with the sharp-edges of the wall obstacles, the local propagation speed increased. The increase of local speed became larger as the obstruction ratio increased. However, the averaged flame displacement speeds with different blockage ratios were not significantly different within the chamber as shown in the paper of Park et al. The flame front interaction investigated in this work was less dependent of the obstacle obstructions compared to that published in the literature for large L/D.

• Journal of Electrical Engineering and Technology
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• v.12 no.2
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• pp.918-925
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• 2017

This paper presents a path planning problem for multi-robot system in the environment with dynamic obstacles. In order to guide the robots move along a collision-free path efficiently and reach the goal position quickly, a navigation method based on fuzzy logic controllers has been developed by using proximity sensors. There are two kinds of fuzzy controllers developed in this work, one is used for obstacle avoidance and the other is used for orientation to the target. Both static and dynamic obstacles are included in the environment and the dynamic obstacles are defined with no type of restriction of direction and velocity. Here, the environment is unknown for all the robots and the robots should detect the surrounding information only by the sensors installed on their bodies. The simulation results show that the proposed method has a positive effectiveness for the path planning problem.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.20 no.8
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• pp.2593-2600
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• 1996

A modified k-$\varepsilon$ turbulence model having a generality is proposed in the present study, in which the constant $C_{\varepsilon2}$in the $\varepsilon$-equation is simply changed as a functional form of a new parameter both satisfying the tensor invariant condition and representing the extra straining effect on complex shear flows. With this model turbulent shear flows over two-dimensional obstacles placed in a channel are numerically studied for different blockage ratios and aspect ratios. Comparing with the available experimental data, the predicted results with the present model provide definite improvements over the standard model's results and work fairly well with the experimental data on the size of the recirculation zone, as well as mean velocity, wall static pressure, turbulent kinetic energy and Reynolds stresses.

• Journal of the Korean Society for Nondestructive Testing
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• v.29 no.6
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• pp.586-590
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• 2009

Poisson's ratio, one of elastic constants of elastic solids, has not attracted attention due to its narrow range and difficult measurement. Transverse wave velocity as well as longitudinal wave velocity should be measured for nondestructive measurement of Poisson's ratio. Rigid couplants for transverse wave is one of obstacle for scanning over specimen. In the present work, a novel measurement of Poisson's ratio distribution was applied. Immersion method was employed for the scanning over the specimen. Echo signals of normal beam longitudinal wave were collected, and transverse wave modes generated by mode conversion were identified. From transit time of longitudinal and transverse waves, Poisson's ratio was determined without the information of specimen thickness. Poisson's ratio distribution of the carbon steel weldment was mapped. Heat affected zone of the weldment was clearly distinguished from base and filler metals.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.13 no.2
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• pp.32-38
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• 1999

An autonomous mobile vehicle for transport system must plan optimal path in work envimnrent without human supervision and obstacle collision. This is to reach a destination without getting lost. In this paper, a genetic algorithm for globaI and local path planning and collision avoidance is proposed. The genetic algorithm searches for a path in the entire and continuous free space and unifies global path planning and local path planning. The sinmulation shows the proposed method is an efficient and effective method when compared with the traditional collision avoidance algorithms.rithms.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.832-835
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• 2004

In this paper, we implement a sensor which can perceive obstacles. We constructed it with a laser emitting a structured light and a small pc camera. It is cheap and can measure the precise sizes of the obstacles. Ultrasonic arrays and laser scanners are used generally to perceive obstacles in the autonomous mobile robot until now. However we knew that they can perceive big obstacles well, but cannot perceive small obstacles on the ground by experiments. We mounted this equipment to our robot and use it to perceive the obstacles of the front side. Our robot can recognize the obstacles of 10mm height. We expect that this equipment will be useful because it is cheap but work well.

• Proceedings of the Korean Information Science Society Conference
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• 2011.06a
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• pp.352-354
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• 2011

The performance of multihop cognitive radio networks (CRN) can be improved significantly by using multiple channels in spectrum underlay fashion. However, interference due to the sharing of common radio channel and congestion due to the contention among those flows that share the same links become an obstacle to meet this challenge. How to control efficiently congestion and allocate power optimally to obtain a high end-to-end throughput is a key objective in this work. We reexamined the Network Utility Maximum (NUM) problem with a new primary outage constraint and proposed a novel resource allocation strategy to solve it effectively and efficiently.

• Journal of the Korean Professional Engineers Association
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• v.42 no.5
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• pp.29-31
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• 2009

A general practice in software ordering behavior in public sector has been an enormous obstacle standing in development path of Korea's software industry. Standard on software development cost estimation is supposedly based on Function Point, but in general, it is on headcounting (a number of people involved in a project). Moreover, it is difficult to change a contract in an on-going project, since statement of work is not precisely and carefully described. But it has a simple solution. Design and Implementation should be a separate project, as in construction industry, and both power and responsibility for design should be given to an expert with a national-level qualification. Here, there is a simple way for Korea to reborn as one of the strongest software country.

• Proceedings of the KSR Conference
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• 2003.10b
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• pp.176-181
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• 2003

Damages by vibration and noise due to the construction performance are increasing. The rise of construction demand and enlargement of equipments are major reasons of this damage. As a result, the enmity of the people is provoked and this appears to be an obstacle of construction work. Especially, in case of ground improvement construction. Casing pipe is inserted into the Sand Drain, Sand Compaction Pile and Vibrated Crushed-stone Pile by vibration power when carrying out. Hence, a pillar is formed and it creates vibration and noise. This causes a lot of restrictions to construction condition. The low Vibration and low noise construction equipments uses earth auger and hydrulic cylinder for insertion and chopping operation instead of vibro hammer, which is the source of vibration and noise. This minimize ground disturbanceand decrease vibration and noise successfully, but increase chopping effect greatly. Thus, this new equipment is not only suitable for environment but also excellent engineering method of construction.