• Proceedings of the KSR Conference
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• 2005.05a
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• pp.14-19
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• 2005

An accelerated life test (ALT) is used to estimate the reliability of machinery parts and system with a design specification as soon as possible. However, accelerated life test results with simple and severe conditions are inconsistent with physical phenomena in real service condition. Therefore, to assure the safety of the machinery system, it is necessary to establish the appropriate test condition of the ALT of machinery element. In this study, fatigue analysis of the spur gear as a part of the gear box system in the rolling stock was performed. Moreover, based on the results, appropriate test condition of the ALT is developed using both the probabilistic model of the linear damage rule and accelerated durability analysis simulation.

• Journal of the Korean Society for Precision Engineering
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• v.28 no.6
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• pp.709-715
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• 2011

Chattering in cutting operations are usually a cumbersome part of the manufacturing process in mechanical. Particular, machining performance such as that of the boring process is limited by cutting condition at the movable components. Among various sources of chatter vibration, detrimental point in cutting condition is found a mechanical condition on overhang. It limits cutting speed, depth, surface roughness and tool wear failure as result because the all properties are varying with the metal removal process. In this case, we have to observe the resonance frequencies of a boring bar for continuous cutting. In the established research, boring bar vibration of cutting system has been measured with the aid of accelerometer. However, the inherent parameters of internal turning operations are severely limit for the real time monitoring on accelerometers. At this point, this paper is proposed other method for real time monitoring during continuous cutting with optical fiber at the inside of boring bar. This method has been used a plastic fiber in the special jig on boring bar by based on experimental modal analysis. In this study, improvement of monitoring system on continuous internal cutting was attempted using optical fiber sensor of inside type because usually chattering is investigated experimentally measuring the variation in chip thickness. It is demonstrated that the optical fiber sensor is possibility to measure of chattering with real time in boring process.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.23 no.6 s.165
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• pp.881-894
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• 1999

Cylindrical plunge grinding is widely used for final machining process of precision parts such as automobile, aircraft, measurement units. But in order to make parts which have high precision accuracy and high surface integrity, it is necessary to consider grinding characteristics due to accumulation phenomena of grinding wheel in plunge grinding process. In this study, in order to examine closely plunge grinding process, grinding power, grinding force, real depth of cut are monitored in transient state, steady state and spark out state. As the result, it is shown that grinding power and force are affected by dressing condition, depth of cut and speed ratio and that there exist threshold grinding force and it also affected by dressing condition. Also considered effects of grinding conditions on surface roughness and roundness of workpiece

• 한국연소학회:학술대회논문집
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• 2012.11a
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• pp.29-30
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• 2012

The objectives of this study are to examine the variation of flame chemiluminescence on flame condition and to evaluate the possibility to apply the optical sensor for air/fuel ratio control. Flame chemiluminescence is one of the most important factor to judge the real time flame condition like a air/fuel ratio. In this paper, it is experimentally found that a strong relationship between the air/fuel ratio and optical element output (i.e., photo diode) should be existed. This is verified through the flame spectral analysis for various PD output signal.

• Journal of the Korea Safety Management & Science
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• v.3 no.3
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• pp.1-9
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• 2001

To keep an enterprise's competitiveness on the condition of the automatic manufacturing system such as FA, FMS and CIM, all the maintenance problems should be considered seriously In not only in production and maintenance but also in related industrial safety. As we analyze in the surveys the maintenance management of domestic enterprises and the causes of Industrial accident, there will be necessity of drawing up countermeasures for preventing industrial accidents and for ensuring expertise maintenance technologies. Based on these analyses, the safety information system, maintenance management information system, and the machinery condition diagnosis technique are studied by using of the knowledge-based system under the real-time computer-operating environment and using fuzzy linguistic variable. This computer system based knowledge-based diagnosis can easily provide not only the knowledge of expert system about deterioration phenomenon of industrial robots, but also the knowledge of relating safety and facility all the time. Therefore, it is expected to improve the efficiency of business processes in the production and safety when we use this system.

• Journal of Fashion Business
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• v.19 no.4
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• pp.75-91
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• 2015

There is an increased interest in having beauty regardless of ages and sex with improvement of the national income level and increase in social activities. Competition within the beauty service industry is increasing rapidly because of global impact within Korea wave. Thus, active public relations and offering distinguished service in the beauty service industry are important. Also, uniforms play an important role in providing an image differentiated from other brands and presents professionalism to the customer. Therefore, we determined function and design of uniforms required in beauty service industry by researching wearing realities, satisfaction, preferred designs and functions of uniforms from hair shop staff. Functional and aesthetic uniforms play an important role to enhance the staffs' sense of belonging. In addition, it is good for the image of hair shop. Special design mirroring job characteristics with expression of differentiated personalities is needed. However, the research was conducted only in the hair shop in Seoul, Daejeon, and Gyeonggi-do. Further studies on much wider areas will be needed.

• Journal of Institute of Control, Robotics and Systems
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• v.16 no.2
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• pp.140-144
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• 2010

In the case of a linear time-varying system, it is difficult to apply the conventional stability conditions of RHC (Receding Horizon Control) to real physical systems because of computational complexity comes from time-varying system and backward Riccati equation. Therefore, in this study, a frozen time RHC for a linear discrete time-varying system is proposed. Since the proposed control law is obtained by time-invariant Riccati equation solved by forward iterations at each control time, its stability can be ensured by matrix inequality condition and the stability condition based on horizon for a time-invariant system, and they can be applied to real physical systems effectively in comparison with the conventional RHC.

• Journal of the Korean Society for Railway
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• v.5 no.2
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• pp.70-76
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• 2002

In this study, performance of reinforced railroad roadbeds with the reinforced roadbed materials were investigated through the real scale roadbed tests. It was also found that the reinforced roadbed with reinforced roadbed materials has less elastic and plastic settlement than the one with soil. The slag roadbed was more effective than the crushed stone roadbed with the same condition for load distribution. Therefore considering overall characteristics of reinforced roadbed material, the optimum thickness was recommended as 50 cm. Furthermore the real scale model test under the simulated rainfall condition, the settlement in the slag roadbed was about 8 times smaller than the settlement in the soil roadbed.

• Fire Science and Engineering
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• v.27 no.2
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• pp.18-24
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• 2013

Goverment and enterprises have been devoting a lot of dffort in order to prevent the loss of human and property due to a large, diversified fire, explosion, global warming and disasters caused by natural phenomena. But Enterprises came forward and running in the economy priority policy for profit-seeking until now in order to meet the macro purpose of quality improvement of national life and welfare promotion in company with National growth, as a result of lax risk management have had to endure the loss of precious lives and property. According to the '2007 Survey of public safety for the activation of the safety culture' of National Emergency Management Agency [NEMA], a insensitivity of safety in our society was surveyed 'a serious level'. In this study, surveyed need of 'step-by-step fire protection safety management system builds' in order to prevent fire safety accident and improvement of safety awareness level through a systematic management and real condition estimation of not only large business that can control risk management, but also small business that has a big risk to occur accident easily according to small budget and organization.

• Journal of the Korean Society of Costume
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• v.56 no.5 s.104
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• pp.75-88
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• 2006

The conception of uniform is changing from function and economical efficiency of the past to symbolism and aesthetic sense So, in such a management strategical point of view as enterprises' PR, scouting talent, organization revitalization etc, this is required to settle uniform culture which is proper to each enterprise and design development. The purpose of this thesis is, first, to study to help distribution enterprises' CI or PR by examining the present condition of uniform design in domestic fashion distribution enterprise and planning uniform design on the base of real case and finally making a real thing in person. Second is to suggest to fashion enterprise security of competitive ability of uniform-producing enterprise by developing article design of worth. Third is to present academic area with how to do design education in a wide range not based on trend article development. Following is how and what to study to carry out these purposes. Details about necessity and how and what to study are in an introduction, the conception of uniform in theory through precedential records examination in chapter 2, the present condition of uniform design based on Changwon city in chapter 3, planning uniform design and making a real thing suitable for F enterprise in chapter 4, and the conclusion is in chapter 5. Through this study, I became to know that uniform in distribution enterprise who treats visitors face to face is very important. I supply material and information concluded from this study to uniform industry and hope this will be helpful in developing uniform. It is significant in that this study as being related with enlarged uniform and enterprise, beyond such a uniform area as school uniform and hospital one, expanded the study range of clothing. I already tell you that this study is based on visual expression of uniform and wearer's feeling in clothes is not included.