• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.23 no.2
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• pp.206-212
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• 2014

Liquid silicone rubber (LSR) has been widely used in automotive, electrical, and medical components. Thus, research on the use of LSR in the injection molding process is required to obtain high-quality and high-performance products. In this study, a mold was fabricated to examine the effects of the process parameters on the molding and mechanical properties of LSR parts. A computer-aided engineering analysis was used to optimize the air vent depth and curing temperature to decrease the flash at the air vents caused by the low viscosity of LSR. Temperature and pressure sensors were mounted in the mold to determine the effects of the process parameters on the temperature and pressure in the cavity. The tensile strength of the LSR parts was also examined in relation to the process parameters.

• Journal of Advanced Marine Engineering and Technology
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• v.38 no.3
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• pp.262-268
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• 2014

This research introduces the structural design and the validation results of the flexible high speed coupling for 2MW class wind turbine which transmit and cut off torque between gear box and generator. The high speed coupling requires electrical insulation to prevent electrical surface damages on gear box. Therefore glass fiber reinforced plastics is applied to absorb the vibration and deformation of power train and to transmit required torque. Finite element analysis was performed to optimize the thickness and accumulation number of glass fiber reinforced plastics. Torque limiter which cut off the abnormal torque is designed in frictional disc type. The design of the coupling was validated with the performance test of prototype.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.41 no.10
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• pp.975-981
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• 2017

Savings in weight using lightweight materials such as aluminum alloy can lead to increase fuel economy. However, compared to steel, aluminum alloys have a lower strength for an equivalent life cycle. To reduce the weight of automobiles, research is being performed on the fabrication of lighter and stronger torque struts without having to sacrifice the safety of automotive components. In this study, a weight reduction design process for torque struts is proposed that is based on varying von-Mises stress contours using an aluminum alloy (A356) having a tensile strength of 245 MPa, instead of STKM11A steels. The optimized design can reduce the weight of the original steel torque strut by over 42% and it can contribute to the design of light-weight components and to the safe design of torque struts.

• Archives of design research
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• v.9
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• pp.801-810
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• 1994

Design Problems are often both multidimensional and highly interactive. Very rarely does any part of a designed thing serve only one purpose. The activity of designing is thus a goal-directed activity and normally a goal-directed problem-solving activity. This means, problem solving is finding a way to get from some initial situation to a desired goal. Designers are transforming agents within a society whose goals are to improve the human condition through physical metamorphosis. Many theorist have agreed that designing involves problem solving or decision making. Accordingly evaluation plays an essential role in design activity. The evaluation factors include all attributes that have levels specified by quantitative and qualitative objectives Alternatives in multi-objective decision prOblems generally possess numerous attributes by which they can be described and compared. The evaluation factors include all attributes that have levels specified by quantitative and qualitative objectives. However since qualitative factors are difficult to quantify as numeral estimates, these factors have tended to be ignored without regard for their importance to human content. We adapted the Accumulative Evaluation Model as an evaluation algorithm for IDES. Industrial Design Evaluation System (IDES) consists of 3 major modules ( 1 Design Element, 2.Matrix, 3.Evaluation). It is intended to be an aid for design evaluation. The luther thinks IDES is a new design evaluation approach which could provide effective rating of design values to make value judgements. It is an attempt to provide industrial designers with access to design evaluation. The author's aim is to produce an Object-Oriented Evaluation System which can guide the designers and decision makers under complex design projects. It uses\ulcorner an Object-Oriented Programming for this prototype, Because of managing complexity (Flexibility and Reusability) and improving productivity(Extensibility & Maintainability and Programming by User) in software development process. The author has chose the C++ because it is a hybrid, rather than pure Object-Oriented Language.

• Nutrition Research and Practice
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• v.7 no.6
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• pp.503-509
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• 2013

There is little information on dietary vitamin K intake and nutritional status of daily requirements of vitamin K in Korea. The objective of this study was to investigate the vitamin K intake and major food sources of Vitamin K in Koreans. The survey data from the 2010-2011 Korean National Health and Nutrition Examination Survey of 7,792 subjects (aged 19-64 years) were examined. Total vitamin K intake was calculated from 24-hour dietary recall using a vitamin K food database, Computer Aided Nutritional analysis Program and the United States Department of Agriculture database. The geometric mean of vitamin K was estimated as $322.40{\pm}6.33ug/day$ for men and $271.20{\pm}4.92ug/day$ for women. Daily vitamin K intake increased significantly with age (p for trend < 0.001). The main food source of vitamin K was vegetables (72.84%), including cabbage kimchi (19.26%), spinach (17.38%), sesame leaves (7.11%), radish leaves (6.65%), spring onions (6.28%), and laver (4.82%), followed by seaweed, seasonings, and fat and oils. We observed that the vitamin K intake of Koreans was relatively higher than that reported by other studies in Western countries and differed depending on age.

• Journal of Engineering Education Research
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• v.3 no.2
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• pp.3-13
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• 2000

The paper has analyzed and summarized about the theoretical problem occurred in the CAQC, and has developed the learning model focused on the histogram as a case study. The range of study is to systematize the basic method of histogram generally used, and to make step by step procedures under the interactive relation with the improvement of the theory that must be added in case of the calculation by the aided of MS-Excel software. A histogram is the theory to understand the population distribution from which samples are extracted, so alternative methods are presented to estimate the population shape through an experiment and a practice. In order to enlarge the application area of the histogram in the factory, the theory of normal test, the criteria of process capability index and the probability calculation of PPM are added to the histogram. The learning model of CAQC education is proposed that is consistent with the target of histogram to control and search the cause of item defectives fast and correctly.

• Journal of the Korea Safety Management & Science
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• v.9 no.6
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• pp.39-46
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• 2007

In this paper we discuss the problems related with the existing electrical safety system that is influenced by all the socio-technical factors including the electrical safety law, government organizations, and their practicing rules and regulations. Sometimes intangible practices also affect the safety issues. It is our intention to incorporate all those factors effectively and systematically in improving the electrical safety system. Since, the problem in nature is so complex, an approach based on the systems engineering (SE) method could be a good candidate. Specifically, as a first step of the SE process we performed the requirements analysis of all the factors mentioned above and some recommendations from the experts in the field. In the work environment utilizing a computer-aided SE tool, the requirements are verified and managed efficiently although the data base is complicated in general in tracking the changes. Next, by analyzing the verified requirements, a functional architecture is developed to achieve an improved electrical safety system. We also did the reverse engineering of the existing electrical safety system to explore potential problems there. The result can also help improve the existing one. Overall, a systematic approach to constructing electrical safety system based on SE is proposed for the first time in this paper. Note that the method described here can be adopted in the study of other safety systems.

• Journal of the Korea Safety Management & Science
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• v.14 no.2
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• pp.23-33
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• 2012

Recent technological advances in the domestic railway industry have turned out to deliver a profound impact on the forefront of other industries as well. Furthermore, the introduction of the high-speed railway systems has made it possible to travel around our country in a day, thereby changing our life styles a lot. However, it has been well recognized that many factors can cause unanticipated accidents during the operation. One of the causes is known to be the human errors made by the train operators in locomotive cabs. The problem is getting more serious as the trains run at high speed. As such, the objective of this paper is on how to improve the work environment of the locomotive cabs. Our approach is based on the systems engineering methodology. Specifically, we first identify the context and scope of the problem to be solved. We then continue our effort in deriving the requirements set to accomplish the improvement. These results are utilized in constructing a computer-aided management system for test and evaluation intended for the improvement. The approach taken and the results obtained in this paper is expected to make a contribution on the route to keeping our nation's technologies on the competitive edges in the high-speed railway systems industry.

• Journal of the Korean Society for Railway
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• v.12 no.3
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• pp.382-387
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• 2009

When a system or service is realized, it needs to be verified by requirements. The process of verification is to check whether customers/stakeholders requirements have been property transformed into a system or service. A set of verification processes is described in the international or industrial standards. However, it is not appropriate to directly apply those verification processes in the national research and development projects. In particular, we noticed the problem in the development of safety systems, standards and process in the railway systems domain. As such, this paper is concerned with a detailed development of the verification process in that domain. Specifically, an effective and efficient verification process is presented regarding the safety systems and process, safety standards, and safety documents. Also, the verification process was modeled by a computer-aided systems engineering tool, Cradle(R). As a result, the outcomes of the verification process on be managed efficiently.

• Journal of the Korean Society for Railway
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• v.12 no.3
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• pp.376-381
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• 2009

While applying the systems engineering (SE) in systems development, a series of technical reviews play a critical role and is intended to monitor the status of the progress and outcomes of the project for which appropriate technical plans prepared earlier should be executed. It is noted however that during the technical review executed as planned, a lot of problems usually come out. Included are the ambiguity in the reports of the progress status and outcomes, discrepancies among the opinions from different participants, and the delay in carrying out the tasks. To solve those problems in an early stage, informal reviews are usually adopted before the formal technical reviews are held. A type of the informal reviews is the peer review. This paper is concerned with the peer review process model to make the later technical reviews more effective. Specifically, we first review the necessity and meaning of the peer reviews. We then study a model for the peer review process. To model the process, the methods of an IDEF modeling and schema definition have been applied using a computer-aided SE tool, Cradle(R), in the environment of the national research and development project. As a result, the implemented process model can show hew the peer review process is designed and managed to be utilized in the technical review. The documents related with the peer review process can also be generated automatically from the developed model Database. Finally, a general misunderstanding about the peer review and its improvement plan have also been mentioned.