• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.57 no.4
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• pp.283-291
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• 2021

The Korean stow net is a fishing method that utilizes the changing direction of the net entrance with the tidal current. This study attempted to obtain basic data from the recent offshore stow net fisheries to improve the gear by analyzing the dynamic behavior of the nets affected by current speed and direction using computer simulations. A numerical calculation was performed at a current speed of 0.5 knot between 2.5 knot at each 0.5 knot. The time taken for the gear opening was the longest from 0.5 knot at 1,500 seconds and the shortest from 2.5 knot at 450 seconds in the simulations. In all cases, the net width and tension at net deployment gradually decreased as the current speed decreased. However, the net height tended to increase inversely proportional to the current speed. During the net rotation, the net height was maintained at all cases. The net width and tension fluctuated, but the regularity was very low. In this study, the calculated simulation data showed that the opening efficiency decreased proportional to the current speed. The opening efficiency is related to the catching efficiency; therefore, it is necessary to improve the gear to enhance its opening efficiency.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.391-394
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• 2002

This paper introduces that the lathe optimize for main and sub spindle's synchronous in Opening-CNC. In view of optimal design, the mathematical modelling and the frequency domain analysis of spindle's system are performed. For the compensation of synchronous error in compounded manufacture process, the optimization method of motor drive's control parameter and the related parameter is proposed. By the experiment in prototype machines using the server/client program, the validity of the proposed method is verified.

• Journal of Biomedical Engineering Research
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• v.14 no.4
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• pp.371-378
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• 1993

A new recognition algorithm which decides thge opening & the closing states of subject's eye and isn't affected by the subject's background is proposed. And it is tested in circumstances in which subject's motions are not restricted using the developed system. AERS (Automatic Eye opening & closing Recognition System) . The significant characteristic of the AERS is that it dosen't need any extra hardware except a formal CCD carmera and an image grabber but it works so well and so fast. The AFRS wcould be particularly well suited to a tray of communications of patients in a hospital, who can not communicate othertvise.

• Journal of Agricultural Extension & Community Development
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• v.12 no.1
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• pp.17-28
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• 2005

This study investigated structural changes of the Korea's agriculture and proposed the new direction of rural and agricultural policy in Korea after economic opening. The major results may be summarized as follows: Firstly, the study identified structural changes of the country's peasantry under the economic opening system. Korean agriculture has been deteriorated in population structure, arable land size, and income composition. Secondly, according to above analysis on these changes it suggested that the traditional rural communities were exposed to collapse and this unwanted disaster could result in serious adversities to the national economy. Thirdly, this study proposed preservation policies for small scale farming households and also administrative preparations of multi-dimensional approaches leading to successful rural and agricultural planning.

• Journal of the Korean Society of Industry Convergence
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• v.27 no.1
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• pp.71-76
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• 2024

Automatic production systems are constantly advancing technologies to improve productivity and safety. Specifically, liquid filling machines are primarily utilized to package products into drums after manufacturing process in the hazardous chemical industry. Most existing filling machines allow the operator to open the drum cap and inject the product directly or semi-automation. In this study, we have developed a cap opening and closing mechanism onto the existing drum filling machine, enabling automatic and safe cap manipulation while filling the product in the IBC tank. By applying the appropriate torque value through numerical analysis, we confirmed that the system worked without any problems during the process of opening and closing the cap. Therefore, it is expected that the developed machine will give more production and reduce human efforts without risk in the chemical packaging industry.

• Fire Science and Engineering
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• v.30 no.4
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• pp.59-64
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• 2016

The PSD (Platform Screen Door System) has been installed to enhance the passengers' safety. A total of 592 stations operate the PSD system, which is almost 71.8% of all stations in South Korea. This study compared the opening rate between the PSD and train door, and calculated the exact amount of passengers at peak time. In addition, the evacuation time was simulated by Pathfinder 2015 with the exact input data. Some of the high density stations have extremely high dangerous points about the passengers' evacuation at some situations by the PSD door opening rate. In particular, due to the interference of a fixed door, when it stops at 7 m less than the regular position, its opening rate becomes less than half of the normal state. To solve this problem, it should be made possible to open the fixed door by changing it to an emergency door or improving the PSD module system.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1999.04a
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• pp.295-302
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• 1999

This paper is the experimental and analytic of reinforced concrete hemisphere dome under vertical load. It is described that when the reinforced concrete hemispherical dome supported on cylindrical wall is loaded vertically, how the opening part of dome will behave mechanically The experimental and analytic model is a Hemispherical dome with opening and the meridian angle of opening is 76$^{\circ}$at the center of sphere under concentrated load around the opening, but this is reinforced by a ring is sufficient stiffness. The diagrams of crack development are represented to understand the behavior of the reinforced concrete hemispherical dome. The method of crack analysis will be applied the rigid element spring model. The rigid element spring model is a new discrete element analysis, each divided element is assumed by rigid elements without deformation which is interconnected with elasto-plastic spring system.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.10a
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• pp.609-614
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• 2000

This paper is an experimental study of the normal strength concrete beam and high strength concrete beam for the analysis of bending and shear behavior. In building structure, the story height can be minimized by providing openings in beams which serves for the utility equipments passing through. The dead space in false ceiling increase construction cost, the good ceiling system such as beam with opening give to economical merits because of a substantial reduction in materials and construction cost. For the analysis on the mechanical behavior of the reinforced high strength and normal strength concrete beams with circular opening in the web, the stress concentration of the circular opening, crack pattern and reinforcing methods were studied. Twenty test pieces with different reinforcing methods and difference concrete strength were tested and their resisting forces and load deflection curves were defined in this study.

• Journal of Mechanical Science and Technology
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• v.18 no.1
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• pp.114-121
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• 2004

In order to investigate the corrosion fatigue characteristics in the weld of multi-pass welded A 106 Gr B steel pipe, corrosion fatigue tests were performed under the various stress ratios and 3.5 wt% NaCl solution at room temperature. The corrosion fatigue characteristic curves were represented using crack closure concept. The obtained results are as follows : when the load frequency is 1.0 Hz, the crack opening point is transited in the region of $K_{max}$=20∼32 MPaㆍ $m^{1}$2/. In the low stress intensity factor range, the crack opening point is higher than that in air. However, in the high stress intensity factor range, it is lower than that in air. In the cases of 0.1 Hz and 0.01 Hz, the crack opening point gradually decreases to $K_{min}$ with $K_{max}$ increase.rease.

• Journal of Korean Society of Archives and Records Management
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• v.8 no.2
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• pp.105-125
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• 2008

In this study, system of opening of archival documents and providing reference services and archives web service in China have been reviewed. Throughout laws and regulations of archives management since found the People's Republic of China, related to opening of archival documents and providing reference services are analyzed. This paper also consider the present condition of archives web service in China and web service of Beijing archives.