• The Journal of the Acoustical Society of Korea
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• v.29 no.2
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• pp.118-124
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• 2010

In this paper, design parameters of dynamic vibration absorber, which is used to reduce bending vibrations of a vehicle drive line, is optimized. For obtaining the correct dynamic response characteristics, a flexible-body drive line is made by applying the flexibility data extracted from vibration analysis of propeller shafts to the drive line dynamic model. Inner tube mass, rubber stiffness and rubber damping coefficient of the dynamic vibration absorber are taken as design parameters for optimization. To minimize the vertical acceleration of the drive line, a second-order regression equation of the objective function is generated by performing the central composite experimental design with 3 factors, 2 levels and 15 test runs. And the design parameters of the dynamic vibration absorber are determined by using optimization program. The vehicle model with optimized dynamic vibration absorber reduces the vertical acceleration peak of the drive line by 17.1 % in compared with the initial model.

• Journal of Ocean Engineering and Technology
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• v.26 no.4
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• pp.77-85
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• 2012

A study was performed on the design of a mooring line to maintain the position of a floating WEC (wave energy conversion) system. The procedure to design a mooring line is set up and the safety of the designed mooring system is evaluated using commercial software, Orcaflex. The characteristics curve for one line is analyzed to determine the properties and pretension of a mooring line. While considering the ocean environmental condition and importance of a floating WEC system, a multi-line layout is determined. A 4-point mooring system with 4 lines shows the instability in the yaw motion of the floating WEC system under a designed ocean environmental condition. The redesigned 4-point mooring system with 8 lines is found to be safe on the condition of a harsh ocean environment. The floating WEC system with the redesigned mooring system also shows stable motion in surge and pitch under operating conditions. From a parametric study on the mooring line length, the extreme value of the mooring line tension is found to be very sensitive to the pretension and length of mooring line. The results of this study can contribute to the establishment of a design procedure for mooring lines.

• Transactions of Materials Processing
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• v.28 no.2
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• pp.83-88
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• 2019

This paper introduces a new concept - on-line FE model, as applied to metal rolling. The new technology allows for completion of process simulation within a tiny fraction of a second without loss of high-level prediction accuracy inherent to FEM. The three steps of an on-line FE model design namely, process metamorphosis, mesh design, and process variable design, are described in detail. The procedure is demonstrated step by step through designing actual on-line models for the prediction of the dog-bone profile in edge rolling. The validity and prediction accuracy of the on-line FE models are analyzed and discussed.

• Journal of Ocean Engineering and Technology
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• v.27 no.6
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• pp.22-26
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• 2013

The purpose of this study was to improve the design of a mooring line by attaching a lumped mass to it on the seabed. A numerical analysis of the redesigned mooring system is performed to analyze the effect of the weight of the attached lumped mass using the commercial software Orcaflex. The ultimate tension of the mooring system with the lumped mass is compared with that of a bare mooring line in the original design. An appropriately designed weight for the lumped mass is found to induce a critical lifted point in the mooring line by floater motion in the ultimate condition to move toward the floater position from the anchor point, while maintaining a similar safety factor for the mooring line. On the other hand, it is shown that excess weight for the lumped mass induces snapping in a mooring line, resulting in low safety factor for the mooring system. The distance between lumped weights is shown to be a minor parameter affecting the safety of a mooring line, although a shorter line has an advantage from an economic point of view. Using the optimal weight for the lumped mass attached to the mooring line on a seabed reduces the mooring line length and installation area occupied by a mooring system under real sea conditions.

• Journal of Electrical Engineering and Technology
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• v.1 no.4
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• pp.490-495
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• 2006

In this research, the design procedure and the design method of a single-phase line-start permanent magnet motor (LSPM) are proposed. In the design procedure, the permanent magnet is designed first and the windings and capacitors are designed later. As well, the points of design of each design parameter are explained. In the design of the single-phase LSPM, the equivalent circuit method is combined with the finite element method (FEM) because it has a shorter analysis time than FEM. The 400 watts single-phase LSPM is designed and manufactured. The characteristics of the manufactured single-phase LSPM are analyzed and experimented. From the analysis result and the experiment result, it is verified that the design procedure and the design method of the single-phase LSPM is valid.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.10
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• pp.123-129
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• 2010

During the past 2 decades, many electric power companies have been searching various solutions in order to supply power with economical and more efficiency in the present transmission utilities. Most interesting method to increase the line capacity of overhead transmission lines without constructing any new line might be to adapt Dynamic Line Rating(DLR). Specified rating is normally determined by any current level, not by conductor temperature. Although specified rating is essential to design transmission line, dip may be the most important factor in limiting transmission capacity. Transmission lines built by the oldest dip criterion among the 3 different design criteria for conductor dip are nearly over one-half of all Kepco's transmission lines. This paper describes an up-rating method for those transmission lines in order to apply DLR technique. Based on limit dip conductor temperature and current of the transmission lines, limitation performance and effectiveness in applying DLR with weather model are analyzed. As a result of analysis, it can be shown that an improved method could be effectively used for increasing the line rating of old transmission line which was built by the design criterion with low dip margin.

• Journal of Navigation and Port Research
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• v.31 no.1 s.117
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• pp.71-79
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• 2007

This study is intended to investigate the superyacht exterior design style from the viewpoint of marine architectural design. Especially it is focused on the exterior profile design of superyachts. Superyachts are passenger vessels whose hull exceeds 24m. They are a kind of luxurious leisure ships. Marine architectural designer can contribute in the field of exterior and interior design of superyachts. In this study we analyze outboard profile of 32 superyachts and extract key design elements of exterior profiles. Those are sheer line, stem line, bow line, house line and windows.

• Journal of the Korea Fashion and Costume Design Association
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• v.14 no.2
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• pp.101-111
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• 2012

The purpose of this study is to evaluate the differences of visual image on variations in the length and princess line, in a silhouette of a one-piece dress with the application of the 3D Virtual Clothing System known as i-designer. Eight sample were examined: 2 variations of the length and 2 variations of the princess line, 2 variations of the form of a silhouette. The data was obtained from 66 fashion design majors. The data was assessed by a t-test and a multi-way ANOVA and factor analysis. The results were as follows; The visual image according to the design variables, four factors were selected; the attractiveness factor, the activeness factor, the practicality factor, the elegance factor. In these factors, the attractiveness factor is estimated by the most important factor. As a result of analyzing the effect of the interaction in the visual image according to the design variables, the influence of the main effect was found to be great in each factor. In the activeness factor, a significant difference was noted in the two-way interaction between the length and the princess line, the length and the silhouette. In the elegance factor, a significant difference was noted in the two-way interaction between the length and the silhouette. However, the influence on three-way interaction among the length, the princess line, and the silhouette was not significant.

• Journal of the Korean Society of Clothing and Textiles
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• v.15 no.2 s.38
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• pp.103-113
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• 1991

The purpose of this study was to investigate the effect of physical type and age on preference for line in women's clothing design. Line preference in clothing design was concerned with varying in length, direction, division, and shape. All of the preference measures were devised specifically for this study. Furthermore, items on height and weight for physical type as well as age of the subjects were included in the questionnaire. Data were obtained by means of structured interviews and self-administered questionnaires from 588 women ($20\~60$ years of age) in Seoul. Analysis was by One·way ANOVA, Chi-square ($X^{2}$), and Scheffe test. It was found that 4 categories of line preference were affected by both body type and height. An age effect was found on 3 categories of design lines; however, preference for 2 categories of design lines in clothing styles were unaffected by either physical type or age. It was concluded that body type, height, and age are powerful predictive variables for line preference in clothing design. Generally, there was some similarities in preference for lines among slim body types, tall figures, and younger age group as well as heavy body types, short figures, and older age group.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.1743-1753
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• 2011

Seoul Metropolitan Government has performed alternative transit system, light rail transit(LRT), for settling the problems of urban public transit system based on conventional bus service and heavy rail transit(HRT). LRT projects of total 8 lines(about 73.6km), including Ui-Sinseol line, have been planned as Build-Transfer-Operate(BTO) projects. For the first LRT, Ui-Sinseol line, however, design of structure had met standard for design of HRT, because of no domestic design code for LRT when participates of Ui-Sinseol project submitted the design proposal. This case study reports a successful example of LRT design minimizing the scale of stations designed in base of HRT code. The problems, like oversized structures compared with LRT vehicles, excessive costs for construction, had been resolved through negotiations with the participates of Ui-Sinseol line. Result suggests that present and future costs for construction and maintenance of the LRT projects in Seoul be considerably reduced in advance.