• Journal of the Korean Society for Precision Engineering
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• v.12 no.9
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• pp.115-125
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• 1995

부품가공에 있어서 생산성향상을 위하여 버제거를 위한 고도의 기술이 더욱 중요하게 되었다. 특히 CIM 체제에서는 버제거의 자동화를 위하여 가공중에 발생하는 버형성과 파단현상을 정량적으로 예측할 필요성이 더욱 커졌다. 이미 연구된 2차원절삭에서의 버형성 모델을 실제적인 3차원절삭에 적용하기 위하여 기존의 모델을 수정하는 작업이 이루어졌다. 3차원 절삭모델로는 절삭인선에 수직한 면에서의 칩과 공구의 상대운동에 의해서 결정된다고 하는 Rubenstein의 가정이 사용되었다. 본연구에서 다루에되는 롤오버(roll-over) 버는 항상 공구진행방향으로 발생하기 때문에 3차원절삭에서의 버형성을 공구진행방향의 평면내에서의 2차원 절삭의 집합 으로 가정하였다. 공구의 기울림각(inclination angle)이 커질수록 버형성의 크기나 파단면의 크기가 감소하였다. 두종류의 파단이 버형성중에 관찰되었다. 하나는 가공물 끝면에 평행하게 파단면이 발생하였으며 다른 하나는 이에대하여 기울어진 파단이 일어났다. 가공물 끝면에 평행한 경우는 수정된 모델로부터 등가초기공구위치( equivalent initial tool distance)로부터 예측이 가능하며 기울어진 경우는 이결과와 공구의 기울림각으로부터 파단위치를 예측할 수 있다.

• Transactions of Materials Processing
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• v.20 no.3
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• pp.214-221
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• 2011

In recent years, automotive seat components have been manufactured by the fine blanking process, allowing an improvement of dimensional accuracy at sheared surface in series production. However, the rollover has increased and die failures have occurred more frequently when manufacturing gears by fine blanking. Consequently, important goals for manufacturing seat recliner parts with gears have been to decrease the rollover as well as to improve the tool life. In this study, the half blanking and shaving processes were introduced to improve aforementioned problems for the lower tooth, the main component of a seat recliner. For this purpose, the half blanking process was optimized using the finite element (FE) analysis and design of experiment (DOE). The optimized conditions resulting from this study were an offset of 0.2 mm, a clearance of 0.1 mm and a penetration depth of 4.5 mm. Fine blanking experiment conducted under the optimal condition resulted in a rollover depth decrease from 1.9 to 1.3 mm, and no die failure occurrence.

• Journal of the Korean Society for Precision Engineering
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• v.18 no.2
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• pp.199-205
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• 2001

Burr makes troubles on manufacturing process due to deburring cost, quality of products and productivity. This paper described the results of experimental study on the influence of the cutting parameters on the formation of exit burrs in face milling. Using the results of experimental study, burr types are classified and data bases are developed to predict burr formation result. From the CAD file for work geometry and the NC data for tool path, the exit angles are calculated at every edges. This program predicts the burr geometry at exit edges using the prediction algorithm and data bases which are developed experimentally. Simulation results on deformation strain and temperature are also available in specific 2-dimensional cutting conditions. Also algorithm which can determine the exit angle is proposed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.11
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• pp.483-490
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• 2016

Automobile door latch is a fine design and assembly techniques are required in order to produce them in a small component assembly shape such as a spring, injection products, a small-sized motor. The door latch is fixed to not open the door of the car plays an important role it has a direct impact on the driver's safety. In this study, during trimming of the terminals of the connector main components of the car door latch, reduce rollover and conducted a research to find a suitable effective shear surface. Using the Taguchi method with orthogonal array of Finite Element Analysis and optimal Design of Experiments were set up parameters for the shear surface quality of the car door latch connector terminals. The design parameters used in the analysis is the clearance, the radius, and the blank holding force, the material of the connector terminal is a C2600. Trimming process optimum conditions suggested by the analysis has been verified by experiments, the shear surface shape and dimensions of a final product in good agreement with forming analysis results.Taguchi method from the above results in the optimization for the final rollover and effective shear surface improved for a vehicle door latch to the connector terminal can be seen that the applicable and useful for a variety of metal forming processes other than the trimming process is determined to be applicable.

• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.7
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• pp.1278-1284
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• 1992

In plate rolling, it is desired to reduce the trimming loss by controlling the formation of defective end shapes. For this reason, edge rolling is frequently performed in the plate mill. In this paper, the effect of various process variables on the deformation of plate ends in edge rolling is examined by conducting experiments and finite element computer simulation. A focus is given to investigating the effect of edging on the width of the deformed plate trimming-free plate rolling.

• Archives of design research
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• v.19 no.1 s.63
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• pp.129-140
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• 2006

In this study, I would like to suggest a new model of web navigation design which can enhance old-aged users web usability. I would like to prove that when users enjoy web navigation design, older-users access information much more effectively. Using a survey, suggest some types of web navigation designed for old-aged users. After that, based on the result of the prepatory survey, I conducted an experiment with 4 types of web navigation designs, which have been developed to reflect varying stages of comprehensibility. My survey focused three points. First I tested whether they lost their way while searching for information. Secondly, if they did lose their way, I checked whether they could recover from their errors and find their way back. Thirdly, I investigated whether layout, location and size of the web navigation design factors affected usability. The results of my survey indicated that old-aged users spend the shortest time, have the easiest interface, and have least error incidence under the web navigation design to enhance old-aged users web usability.Thus, developing a web navigation design for old-aged users can encourage older people to be more involved with the internet, especially in the aging society.

• The Journal of Korean Association of Computer Education
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• v.13 no.1
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• pp.9-18
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• 2010

The purpose of this study is to determine the differences in menu-layout preference for learners based on their demographics. The experiment was conducted in this manner: three class second grade and three class sixth grade elementary school students were separated by sex, grade, age and cognitive style such as field-dependent and field-independent. They were asked to choose which menu layouts they preferred or did not prefer out of 6 different types. The results of the research are as follows: First, there were no differences in sex, grade and cognitive style for preferences in the menu layout but there were meaningful differences with regard to age. Second grade students preferred map-type layout, but sixth grade students preferred the type having a main menu across the top with a sub menu in roll over. Second, there was a difference with regard to age as to what they do not prefer. Overall, the results of this study suggest that the menu layout for a learning web site on the internet needs to be different according to their age.

• Journal of Digital Contents Society
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• v.10 no.4
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• pp.587-595
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• 2009

Domestic competition of Internet shopping malls is becoming more intense everyday. Users prefer an convenient and reliable shopping mall. Thus the design of Internet shopping malls with a strengthened convenience in usage will not only increase the desire of users to purchase, but will also encourage the users to revisit to the website, and it will increase the competitive power of the shopping mall. In this paper, I examined the interface design which users can use conveniently to purchase products, and proposed a design for an Internet shopping mall in which product information is conveniently provided to the user and the convenience in usage for guiding product selection and purchase is strengthened. The results of this study show that the navigation designs which allowed users to conveniently find products on Internet shopping malls included a roll-over menu in which a subdirectory was presented with a large area. If the navigation that guides products to users were designed more conveniently, users would be able to find and purchase products more easily. Since a web interface design with strengthened convenience in usage helps users to satisfactorily select and purchase products on an Internet shopping mall, it would increase the reliability of the shopping mall.

• Archives of design research
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• v.19 no.4 s.66
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• pp.101-110
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• 2006

In this study, I suggested a new model of universal web navigation design which can enhance users' web usability. I would like to prove that when users enjoy web navigation design, they access information much more effectively. Using a survey, I suggest some types of web navigation design for users. After that, I conducted an experiment with 4 types of web navigation designs, which have been developed to reflect varying stages of comprehensibility. My survey focused on three points. First I measured the time they spent to search for information. Second, I tested whether they lost their way while searching for information and if they did lose their way, I checked whether they could recover from their errors and find their way back. Third, I investigated whether layout, location and size of the web navigation design factors affected usability. The results of my survey indicated that users spend the shortest time, have the easiest interface, and have least error incidence under the web navigation design to enhance old-aged users' web usability. Thus, developing a universal web navigation design can encourage people to be more involved with the internet.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.2
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• pp.37-41
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• 2018

As individuals generate and share various content anytime and anywhere, new networking architectures, such as content-centric networking (CCN) using the content name as a packet identifier, have been in the spotlight recently. However, the current CCN hardly takes into account node mobility problems, especially the mobility of content sources. The movement of content sources causes long delivery latency and long service disruptions. To solve that, the tunneling-based redirection scheme was proposed. However, the tunneling-based scheme requires a location-update procedure whenever the network changes, which creates many control messages and causes long latency. So, this paper presents hierarchical mobility management of mobile CCN to reduce the number of control messages and handoff latency. Performance evaluation shows that the proposed scheme can provide low control overhead, which results in network scalability.