• Journal of Biosystems Engineering
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• v.30 no.4 s.111
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• pp.220-228
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• 2005

This study was conducted to investigate the main factors that contain a rotating velocity ratio between wheel and conveyor belt, a tilt angle of conveyor belt and a rotating velocity of a dick cutter for mechanization of Chinese leek harvest. In the survey on the cultivation of Chinese leek, row spacing of 350 m and cutting height of 10 mm from the ground were set up for field tests. Test equipment was designed to cut, pick up and convey Chinese leek one row by one row. From the results of material tests, pick-up height of conveyor belt was set up at $60\~90m$ from the bottom, and the strain and stress at rupture of Chinese leek was 0.487 m/m and 0.01078 MPa. An elastic coefficient of the rubber (Neoprene) of conveyor belts was 1.1077 under the strain of 0.3 nym. from the results of field tests, the tilt angle of conveyor belt was the range of $25^{\circ}\~30^{\circ}$ under consideration far space of container, the velocity ratio between vehicle and conveying belt was 1 to 2.4~1.7 at 0.1~0.3 m/s of vehicle, and optimum rotating velocity of the disk cutter was 34.8 m/s or more under consideration for soil friction.

• International journal of advanced smart convergence
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• v.12 no.2
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• pp.76-83
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• 2023

Squatting of agricultural work can cause musculoskeletal disorders due to excessive pressure and rotational force on the knee joint In order to improve the assistive chair used in squatting agricultural work so that it can be used in a narrow groove, it is intended to improve the musculoskeletal harm of squatting work by attaching a spring on the assistive chair. Therefore, in the presenty study, 3D drawing was done using ProEngineer (3D), and a mock-up was produced and tested. Using pro-Engineer, it was judged that it was rare for plastic to be broken by a spring, so the analysis was conducted with a focus on springs. It was found that the structure that can absorb the shock according to the rigidity of the tape spring and balance the body is that the power to withstand the load of the weight is distributed as a whole when five springs are used. Electromyography was measured using ME600 (Mega Electronics, Finland) Measuring equipment attached to the waist, thighs, calves, and shins. EMG values were measured and compared with the prototype in two ways, when the worker did not wear the product and when he wore an existing product on the market. As a result of the experiment when using the prototype, the maximum EMG value for each part is considered to be helpful in preventing musculoskeletal diseases as the amount of muscle used is reduced in the waist, thighs, calves, and shins.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2004.11a
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• pp.158-161
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• 2004

In order for better management of a medical linear accelerator, the records of the operational failures of Varian CL2100C over ten years were analyzed. The failures were classified according to the involved functional subunits and each class was rated into three levels depending on operational conditions. The relationship between the failure rate and working ratio was investigated. Among the recorded failures ( total 587 failures), the most frequent failure, which was 20% of the total. was observed in the parts related to the collimation system including monitor chamber. Regrading to the operational conditions, the 2nd level of failures, that temporally interrupted treatments, was the most frequent. The 3rd level of failures, that interrupted treatment for more than several hours, was mostly caused by the accelerating subunit. The average life-time of a Klystron and Thyratron became shorter as the working ratio increased, which was 42 and 83% of the expected values, respectively. Recording equipment problems and failures in detail over a long period of time can provide a good knowledge of equipment function as well as the capability to forecast future failure. More rigorous equipment maintenance is required for old medical linear accelerator to avoid the serious failure in advance, and improve the patient treatment quality.

• Korean Institute of Interior Design Journal
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• no.19
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• pp.45-52
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• 1999

This study is on Buckminster Fuller, who is generally known as a structure engineering architect, and his influences. Fuller's radical and utopian ideas and designs were regarded as 'paper architecture'. But considering today's high cost of energy and the limited natural resources, Fuller's Dymaxion theory must be re-evaluated. Fuller's influences on the contemporary architecture are summarized as follows. 1) His idea of controlling the environment through the use of technology influenced today's 'High-Tech' architects. Architecture is no-longer designed purely by its formal character, but becomes a tool of investigating environmental significance of modern technology. 2) Through systemizing mechanical equipment, Dymaxion House prototype, and aggregation of high-tech mechanical equipments, influenced Archigram & Metabolist's capsule idea. It is expressed as a plug-in module equipment of 'High-Tech' architecture which has flexible interior with mechanical exterior image. 3) Megastructure. The Manhattan dome project gave an influence to many engineer/architects who tried to achieve an ideal artificial environment. This is in connection to 1960's utopian projects. Today's megastructures show new possibilities in urbanism and architecture. Fuller's comprehensive idea of humans living in harmony in the universe shows possibilities not only in structural engineering, but in solving various problems that confront today's architecture.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.24 no.2
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• pp.182-192
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• 2014

Objectives: The aim of this study is to analyze the current status of possession of measurement and analytical instruments at work environment monitoring organizations and their relationships with human resources, including the number of professional engineers and evaluation scores resulting from evaluation programs in 2012. Materials: Data for measurement and analytical instruments were gathered by inspectors who had been assigned by the Korea Occupational Safety and Health Agency(KOSHA) and the Ministry of Employment and Labor(MoEL) during the evaluation program for 2012. Data for 11 monitoring instruments and nice pieces of analytical equipment were collected from 103 organizations. Additional data such as the type of service provides and the number of professional engineers employed were also recorded by the inspectors. Evaluation scores could be acquired from KOSHA. Results: Comprehensive Occupational Health Service Providers showed good operation quality, while University or Hospital Subsidiary and Work Environment Monitoring Organizations recorded relatively poor results. Evaluation scores correlated well with the possession of measurement instruments and human resources for each organization. High yields provided by professional engineers also showed statistically-associated contributions to evaluation scores and monitoring instrument possession. Compared with monitoring instruments, the amount of analytical equipment had little positive impact on organizations' competence. Conclusions: The evaluation results for domestic monitoring organizations revealed that human resources, possession of instruments, and the quality of employees were critical factors for operating the corporations. Each organization should give considerable effort to improving their ability to strengtheninternal quality, resulting in high-yield production for workers and employers by providing improved workplace monitoring services.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.6
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• pp.2472-2478
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• 2012

This research is aiming to develop Semiconductor equipment maintenance certification course to train qualified maintenance experts more effectively requested in related semiconductor industry. In the course of research, we adopted diverse research technique such as interview, on-spot investigation, documentary references to analyze current status of related training facilities, and forecast the population of test applicants. We analyzed similar certification course(Craftsman SMT, Industrial Engineer SMT, Craftsman Mechatronics, Industrial Enginee Mechatronics, et) as reference to set up job objectives and curriculum of semiconductor equipment maintenance certification. We conducted survey on expectations on newly created certificate, presented evaluation standard and objective of test, and preliminary writing test and demonstration test. Based on the result of various research, we were able to present training program for semiconductor equipment maintenance certification and set the assessment standard of qualification exam.

• Journal of the Korea Safety Management & Science
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• v.17 no.2
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• pp.117-127
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• 2015

This study investigated the smoke blocking and control systems for the safety of residents evacuation and for the prevention of smoke spread through the central corridor in the event of central corridor type of intelligent building fire. We offered additional ways of utilizing smoke ventilators and intake ventilation equipment and utilized CFD-based fire simulation program(FDS Ver.5.5.3) in order to analyze the effect. As a result, many differences in the smoke block effect, depending on the application of smoke ventilator and location of installation, was found. In addition, the result was found that larger effect was showed not in the case of application of smoke ventilator in central corridor only but application in fire room. The reason is that the smoke leakage is blocked primarily as air is flowed in the fire room through open door by operation of intake smoke ventilator in the public corridor and secondarily, the smoke leakage to the public corridor could be blocked as fire and smoke were released to the opened smoke ventilator continuously. Especially, the effect was maximized through complex interactions by applying smoke ventilator and intake ventilation equipment in corridor together rather than applying smoke ventilator and intake ventilation equipment independently. The proposed measure through this study shall be considered from architectural plan as one of ways for blocking from smoke spread to the central corridor in the central corridor type of intelligent building. In addition, flaws on regulation shall be established and supplemented.

• Land and Housing Review
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• v.2 no.2
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• pp.195-204
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• 2011

During mechanical demolition of RC structures, weights of dismantling equipment and demolition waste of building are applied to unexpected load which did not be considered during the design of structural member. Nevertheless, the loading of dismantling equipment and dismantling process are mainly dependent on field managers' field workers' or experiences without considering safety of structural member by a structural engineer. It is urgently required that reflecting actual circumstance of mechanical demolition, safety evaluation method to evaluate the safety and the guideline for appropriate capacity of structural member to support dismantling equipment weight, be provided. Through site investigation and questionnaire on field workers, this paper proposed demolition waste load, load factor, strength reduction factor, and so on. These are essential to safe evaluation of a building, ready to demolition. Considering actual circumstance of mechanical demolition, safety evaluation method of building and design method of slab and beam was suggested to a dilapidated building. An capability to loading of dismantling equipment was proposed, applied to RC slab and RC beam. Therefore, the suggested safety evaluation method and the guideline for an capability to loading of dismantling equipment weight can reasonably evaluate the capacity of structural member in demolition and use effectively as increasing efficiency and improving safety of demolition through proper management of dismantling equipments.

• Proceedings of the KIEE Conference
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• 2008.11a
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• pp.150-152
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• 2008

It is necessary to improve the time efficiency in the high power testing station because tests are mainly performed by high-priced equipment. Minimizing a human error through building the database of relevant standards is possible to expect reliable tests. And also, application program that is properly customized for the certain laboratory's power system will help test engineer to easily analyze the phenomenon that is happened in short-circuit and load switching tests. This paper introduces the several functions of the application program that is developed in order to realize these requirements.

• Journal of the Korean Professional Engineers Association
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• v.29 no.3
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• pp.94-104
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• 1996

When Broadband Integrated Services Digital Network(BISDN) becomes commercially available In public network, conventional Local Area Network(LAN)s will still be in use. The first wide spread application for B-ISDN will be the interconnection of LANs. The equipment providing the connection between the LAN and the BISDN will be given the general name Inter Working Unit(IWU). We addresses the congestion problem of many interworking issues. In this paper, Our study is concentrated on applying connectionless network protocol for interworking. We suggest a rate control method in the network layer to prevent a buffer overflow in the IWU. Since this rate control method can be applied to prevent buffer overflow in a congested IWU, We investigate the use of rate control to solve congestion problems of IWU and parallize network layer with rate control to lessen the congestion problem in IWU.