• Communications for Statistical Applications and Methods
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• v.27 no.2
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• pp.211-224
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• 2020

Sensitivity and specificity are popular measures described by the receiver operating characteristic (ROC) curve. There are also two other measures such as the positive predictive value (PPV) and negative predictive value (NPV); however, the PPV and NPV cannot be represented by the ROC curve. Based on the total operating characteristic (TOC) curve suggested by Pontius and Si (International Journal of Geographical Information Science, 97, 570-583, 2014), explanatory methods are proposed to geometrically describe the PPV and NPV by the TOC curve. It is found that the PPV can be regarded as the slope of the right-angled triangle connecting the origin to a certain point on the TOC curve, while 1 - NPV can be represented as the slope of the right-angled triangle connecting a certain point to the top right corner of the TOC curve. When the neutral zone exists, the PPV and 1-NPV can be described as the slopes of two other right-angled triangles of the TOC curve. Therefore, both the PPV and NPV can be estimated using the TOC curve, whether or not the neutral zone is present.

• Transactions of the Korean Society of Automotive Engineers
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• v.7 no.9
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• pp.89-96
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• 1999

This paper presents the optimization design technique on the joint stiffness and section characteristic factors of chassis frame, by using beam and spring elements in a given design package. Two correction methods are used for the optimization design of chassis frame. First is the equivalent inertia of moment method in relation to the section characteristic factors of joint zones, which are thickness , width and height of frame channel section. Second is the rotational spring element with joint stiffness of joint zones. The CAE example shows that the relationship of section characteristic factors and joint stiffness can effectively be used in designing chassis frame. In this point, if static and dynamic targets are given, the joint-zone and section characteristic factors of chassis frame intended may be designed and defined by using beam and rotational spring elements.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.4
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• pp.699-704
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• 2007

In this paper, optimized model was designed for the starting characteristic of the Single-Phase Line-Start Permanent Magnet Synchronous Motor by using the Design of Experiment. A field pole angle, thickness and distance from center axis of permanent magnet were selected as design factor. We executed the transient state characteristic analysis of 8 test models. The transient state characteristic analysis was executed by using the 2 dimensional Finite Element Method and the Time Difference Method. We checked the fact that the selected design factor affected starting characteristic of the Line-Start Permanent Magnet Synchronous Motor. Depend on this result we found the optimized design point by using the response optimization.

• Journal of the Korea Institute of Building Construction
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• v.4 no.3
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• pp.153-159
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• 2004

The brand value of apartment which affects not only sale percent and profit but also the worth of real estate is raised as an important point of sale competition in the apartment market. But now the market is occupied by a few construction companies, which have well recognized brand. So it's difficult for a construction company without brand to enter the apartment market because of consumer's ignorance. domestic construction companies are spending lots of money and effort to advertise their characteristic brandapartment based on classified consumer's desire and offer consumers what they want. Therefor, This study investigated the factors of recently characteristic brandapartment focusing on design, environment, materials, home automation and surveyed residents preference of a brand by P.O.E methods. Based on such results of survey, this study suggest the basically reference information on characteristic strategy of an brandapartment.

• Transactions of the Korean Society of Automotive Engineers
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• v.9 no.4
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• pp.139-147
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• 2001

2 DOF half-car model with 6 semi-active suspension units is utilized to evaluate the tracked vehicle dynamic performance simulated by several suspension control algorithms. The target of this research is to improve the ride comfort to maintain operator's handling capability when the tracked vehicle travels fast on the rough road. The control algorithms for suspension systems, such as full state feedback active, full state feedback semi-active, sky-hook active, sky-hook semi-active, and on-off systems, are evaluated and analyzed in view point of ride comfort. The dynamic performances of vehicle are expressed and evaluated by vibratory characteristic evaluation curves, performance indices and frequency characteristic curves. The simulation results show that the performances of sky-hook algorithms for ride comfort nearly follow those of full state feedback algorithms and on-off algorithm is recommendatory when the vehicle runs relatively fast.

• Proceedings of the Korean Institute of Interior Design Conference
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• 2004.11a
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• pp.122-127
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• 2004

This study is about a relationship of architecture and polyphony music. In the field of interior architecture, there have been many tries of applying characteristics of music, such as abstraction and nature of time for users of space to have new experience. It has been possible because architecture and music have similarities in many ways. Regarding using proportional characteristic in architecture and music, the both fields are enormously related in some ways. The purpose of this study is explaining of possibility of architectural expression in music and suggesting a way of analysing architectural design based on musical elements emphasizing proportional characteristic. Therefore, it is going to analyse Counterpoint of Bach, which is well expressed in music and compare it with proportional characteristic of space through this study.

• Proceedings of the KIEE Conference
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• 2004.11a
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• pp.306-309
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• 2004

Recently, the environmental problem has received considerable attention. so, many lamps have been developing for environmental requirement and energy efficiency. also, at glow discharge lamp researchers try to reduce energy spending that is power saving lamp. this kind requirement agree with strong points of electrodeless fluorescent lamp has received to now lighting sauce. At low pressure as mTorr I.C.P make high density plasma easily, is good to maintain discharge, has high ionization and does not have failing lighting and losing ability of electron radiation by oxidation and volatilization of electrodes, because this tape does not have electrodes. This point of I.C.P can use at electrodeless fluorescent lamp in this study ICP display elements and Ar, Ne, Kr are researched for optical characteristic. each gas is looked into optical characteristic, also mixed gases is experiment for optical characteristic.

• Journal of Korean Association for Spatial Structures
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• v.19 no.4
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• pp.69-76
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• 2019

A stadium roof that uses the pin-jointed spatial truss system has to be designed by taking into account the unstable phenomenon due to the geometrical non-linearity of the long span. This phenomenon is mainly studied in the single-free-node model (SFN) or double-free-node model (DFN). Unlike the simple SFN model, the more complex DFN model has a higher order of characteristic equations, making analysis of the system's stability complicated. However, various symmetric conditions can allow limited analysis of these problems. Thus, this research looks at the stability of the DFN model which is assumed to be symmetric in shape, and its load and equilibrium state. Its governing system is expressed by nonlinear differential equations to show the double Duffing effect. To investigate the dynamic behavior and characteristics, we normalize the system of the model in terms of space and time. The equilibrium points of the system unloaded or symmetrically loaded are calculated exactly. Furthermore, the stability of these points via the roots of the characteristic equation of a Jacobian matrix are classified.

• Proceedings of the KSME Conference
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• 2001.06a
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• pp.345-350
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• 2001

In order to perform elastic-plastic fracture mechanical analyses, fracture resistance curves for concerned materials are required. 1T-CT specimen was used to obtain fracture resistance curves. But the fracture resistance curve by the 1T-CT specimen was very conservative to evaluate the integrity of the structure. And fracture resistance curve was affected by the specimen geometry and crack plane orientation. The objective of this paper is to be certain the conservativeness of the fracture resistance curve by the 1T-CT specimen and to provide the additional safety margin. For these, the fracture tests using the real pipe specimen and standard 1T-CT specimen test were performed. 4-point bending jig was manufactured for pipe test and direct current potential drop method was used to measure the crack extension and length for pipe test. From the pipe and the 1T-CT specimen test results, it was observed that the J-integral of the 1T-CT specimen test at the crack initiation point was very small compare to that of the pipe specimen test.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2009.10a
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• pp.63-64
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• 2009