• International conference on construction engineering and project management
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• 2005.10a
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• pp.1262-1267
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• 2005

It is still difficult to share and utilize the information generated at each phase of a steel box girder production process due to the spatial gap and different level of management information. The physical distance results in the inefficiency of the information transmission, the accidental omission and typos of the relative information, and so on. Various levels of management information make it difficult to embody a new management system. Eventually, these factors incur the loss of cost and schedule and interrupt development of a new management system. This paper analyzes a current process and presents graphical process flow by using IDEF0. Based this analysis, the research for new production process and work breakdown structure (WBS) is conducted. At the end of this paper, the conceptual design of this system is suggested. Through new management system, it is expected that the model proposed in this study will improve the management process in the steel box production, and the improved process will reduce the redundant cost and schedule information, transmission and deposit generated by manual paper.

• Journal of Biosystems Engineering
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• v.36 no.1
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• pp.9-14
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• 2011

This study was carried out to develop a vine crusher for harvesting sweet potato. The experimental two-row vine crusher attachable to agricultural tractor composed of vine crushing part with frail type vine crushing blades and vine lifting blades, power transmission part with chain and gear transmission mechanism, crushing height control part with two control wheels and manual levers, and implement frames, was designed and fabricated. And this vine crushing performance was also analyzed. From vine crushing tests, backward travel direction (i.e., rotational direction of the vine crushing blades) showed better vine crushing performance than forward travel direction. Crushing ratio of remained vine was increased, and length of remained vine and length of crushed vine were decreased as working speed was decreased and rotational speed of vine crushing blades was increased. At a working speed of 0.27 m/s and rotational speed of vine crushing blades of 800 rpm, crushing ratio of remained vine was 98%, length of remained vine was 104 mm, and length of crushed vine was 327 mm. But, when crushing vine on irregular ridges, vines and mulching vinyl were wound in the vine crushing part. Therefore, change of location of power transmission chain mechanism, and an automatic control device for controlling crushing height were needed.

• Journal of the FoodService Safety
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• v.1 no.1
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• pp.37-44
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• 2020

The virus isolated from patients with severe pneumonia of unknown etiology in Wuhan City, Hubei province in China was termed SARS-CoV-2 and the World Health Organization (WHO) named the disease caused by this virus as coronavirus disease 2019 (COVID-19). The COVID-19 infection has spread rapidly and become a pandemic. In July 2020, there were 13.25 million infected patients and over 570,000 deaths worldwide, and 13,711 infected patients and 294 deaths were reported in South Korea. Since the primary mode of transmission of COVID-19 is through respiratory droplets, the importance of preventive measures, including social distancing, has become important in daily life. In response to the continuous spread of COVID-19, this study developed three guidelines for preventing COVID-19 for the food service industry including childcare centers, institutional foodservices and restaurants by the integration of the manual of controlling foodborne illness. These are included the COVID-19 prevention action methods for food deliverers, for food service administrator, for foodservice works and for customers. All guidelines were designed for easy understanding using illustrations and have been systematically explained subject wise. Thus, these COVID-19 prevention guidelines can be appropriately applied depending on the specific situation and workplace. In addition, they are worthy as educational materials that contribute to the food safety.

• (The)Study of the Eastern Classic
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• no.67
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• pp.203-236
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• 2017

The objective of this study is to suggest the transmission direction and tasks of Ssireum, and the conclusions are like below. First, Ssireum has been designated as a national intangible cultural heritage(No.131) in December 2016. Second, in the current status of preservation and spread of Ssireum, there is no system related to the transmission of Ssireum such as cultivation of professional manpower, and facilities, programs, and administration/finance for transmitting Ssireum. Third, based on the "Intangible Cultural Heritage Preservation & Promotion Act", the transmission direction of Ssireum was suggested. (1)The designation of a college to transmit Ssireum would be needed. (2)The Ssireum curriculum should be established. (3) It would be necessary to secure trainees for transmitting Ssireum. (4)The production of teaching materials for transmitting Ssireum would be needed. (5)It would be needed to secure training institutes designated in each region and also teaching personnels for transmitting Ssireum. (6)The research direction for the correct transmission of Ssireum should be set up. Fourth, based on the "Ssireum Promotion Act", the transmission direction of Ssireum was suggested. (1)It is urgent to complement provisions for transmitting Ssireum. (2)For the transmission of Ssireum, instead of the transmission direction of Ssireum as a national intangible cultural heritage in the standardized perspective, it would be necessary to seek for the joint transmission direction between South & North Korea for research & documentation of Ssireum that could be systematized/shared between South & North Korea, development/spread of contents for discovering the original form of Ssireum, and the establishment of a base of transmission system for the preservation/promotion of Ssireum through the academic/institutional exchanges regarding Ssireum between South and North Korea. Moreover, the overall and fundamental transmission measures for the education, transmission, research, record, and informatization of Ssireum, and the cultivation of professional manpower should be established. Fifth, the contents of institutional tasks for Ssireum are like following. (1)The institutional complementation of the "Ssireum Promotion Act" should be done for the domestic/foreign promotion of Ssireum. (2)For the integration of Ssireum organizations, the administrative system should be unified. (3)The standard technical system manual for Ssireum should be produced. (4)The 'Ssireum Transmission Center' should be built for the preservation and systematic transmission of Ssireum. (5)The selection of a college for transmitting Ssireum and the establishment of a system to cultivate Ssireum successors should be done. (6)It would be necessary to establish database(DB) for the use of Ssireum techniques essential for the transmission of Ssireum.

• Journal of Mechanical Science and Technology
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• v.16 no.8
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• pp.1064-1071
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• 2002

Stainless steel pipe of type 304 the with a wall thickness of 26.9 mm and the outer diameter 406.4 mm is welded by manual arc welding process. Mechanical properties and fracture toughness of type 304 stainless steel are investigated in the temperature ranging from room temperature to -162$^{\circ}C$ The results obtained are summarized as follows. The tensile strength noticeably increases as the temperature becomes lower while the yield strength is relatively insensitive to temperature. The Charpy impact energy and CTOD values become higher in the case that crack propagation direction is aligned to the transverse axis upon the rolling direction than longitudinal direction. The drop of fracture toughness is associated with the noticeable diminution of plastic component as temperature seduces from room temperature to -162$^{\circ}C$ .

• Proceedings of the KIEE Conference
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• 2004.11c
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• pp.43-45
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• 2004

A remote monitoring system was developed to improve inconveniences of manual work such as monitoring street lights by using current sensors, microprocessor and RF communication system. In order to control the street lights on the roads effectively and monitor them in real time, we can attach current sensor to the street lights which monitors Lamp, the broken part and state of the Balast, and the amount of an electric leak precisely we developed a system which makes it possible to transmit the data on monitoring results in breakdown of street lights and Balasts to the central monitoring computer without setting up extra data transmission line. The system we devised can transmit data through Power Line Modem and RF communication using relay method to the central controlling computer without any loss of data.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1997.10a
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• pp.292-297
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• 1997

The rattle noise is the most significant in many kinds of manual gearbox noises, which is generated at the idle stage of the engine operation. The main torsional vibration source of the driveline is the fluctuation of the engine torque. The gear rattle is impacts generating in the backlash of the free gear due to this torsional vibration. Many researchers reported the clutch torsional characteristic optimization method to reduce the idle gear rattle but only few of them give sufficient consideration to the system parameters like gear backlash, drag torque, system inertia, inertia distribution, engine torque fluctuation, idle engine rotation speed, and accessory load. This paper pays attention to the gear impact mechanism and system design parameters to reduce the idle gear rattle with computer simulation.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.58 no.1
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• pp.56-61
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• 2009

In this paper, A telemetering control system for the HDTV SMPS Aging System is developed. Manual Aging System is usually used to measurement of a produced SMPS. But in this system, the respective operator is arranged and monitoring the test cycle visually- According to an excess of the test time and mistakes of an operator, the reliability makes come to be low. Therefore as using the telemetering control system, it improves a productivity and a reliability of the HDTV SMPS. In the developed system, elec1rical signal is measured from aging system, and converted into the digital signal. Also the telemetering control system is composed of many units - telemetering control units for collecting the data, data relay units for the digital transmission service, data division for the multichannel realization.

• Tribology and Lubricants
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• v.22 no.4
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• pp.196-202
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• 2006

This paper presents a case study on the tribological failure analysis of a clutch system for a manual transmission car. The clutch systems are composed of clutch disk, clutch pressure plate, flywheel rubbing surface, coil and diaphragm springs, release bearing and lever, clutch spline and shaft. The purpose of a clutch system is to transmit and disconnect the driving power of engines by frictional farce from a rubbing surface of a flywheel to a clutch disk and clutch pressure plate with a minimum power loss. In this study, many tribological failure cases based on the wear phenomena and thermal distortions have been presented, which are collected from the car repair shop and maintenance center. The triboiogicai failures are mostly come from the driving conditions, overloading of a car, and especially driving style and personal habit of a car driver.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1994.10a
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• pp.217-224
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• 1994

변속기에서 발생하는 치타음을 클러치를 통하여 해결하려는 방법으로 자동차 중립시와 주행시 각기 다른 비틀림특성을 갖는 클러치를 대상으로 한 실험으로부터 엔진플라이휠, 인풋기어, 변속기 케이스의 진동을 측정하고 분석함으로써 다음과 같은 결론을 얻었다. 자동차 중립시나 주행시에 수동변속기에서 발생하는 치타음은 클러치를 통하여 해결될 수 있음을 알 수 있었다. 클러치의 프리댐퍼와 메인댐퍼의 비틀림강성과 히스테리시스는 중립시와 주행시 치타음에 대해 각기 다른 특성을 갖게 되는데 메인 댐퍼만으로 구성된 클러치는 주행시에는 치타음을 제거하는데 효과적이지만 중립시에는 인풋기어의 비틀림 공진에 의하여 변속기가 가진되어 치타음이 발생하였다. 주행시 변속기 치타음 제거효과를 감소시키지 않고 중립시 변속기에서 발생하는 치타음을 제거하기 위해 메인댐퍼만으로 이루어진 클러치디스크에 프리댐퍼 부분을 첨가하여 보았는데 자동차 주행시의 치타음 제거효과를 유지하면서 중립시의 치타음을 제거시킬 수 있다는 것을 확인하였다.