• Journal of the Korean Society of Industry Convergence
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• v.10 no.3
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• pp.171-177
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• 2007

It is well known that mobile phones have been a indispensable communication tool for human life. The spiral springs are used as the main component of the semi-auto sliding mechanism of mobile phones. The characteristic of axiomatic approach is scientific and analytical method, and axiomatic approach is different from other design methods in offering the systematic method at an early stage of design. The axiomatic approach could determine design parameter and arrange the order of design and estimate the optimum design in good order. In axiomatic approach, the composition is divided by customer requirement, functional requirement, design parameter, and design matrix in large portion. This paper presents design in sliding mechanism for mobile phones by finite element method and axiomatic design.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.8
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• pp.1461-1471
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• 2002

Linear motor has a lot of advantages in comparison with conventional feed mechanisms: high velocity, high acceleration, good positioning accuracy and a long lifetime. An important disadvantage of linear motor is its high power loss and heating up of motor and neighboring machine components in operation. For the application of the linear motors to precision machine tools an effective cooling method and thermal optimizing measures are required. In this paper Finite-Element-Method for the thermal behavior of synchronous linear motor is introduced, which is useful for the design and manufacturing of linear motors. By modeling the linear motor the orthotropic physical properties of the sheet metal and windings were considered and convective coefficient in the water cooler and to the surroundings was defined by analytical and experimental method. The calculated isothermal lines could analyze the heat flow in the linear motor.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.15 no.8 s.101
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• pp.975-979
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• 2005

The analysis of a mechanical system, body traveling along the elastic structure, has been a topic of interest. The establishment of analytical method for the development and control of this system is required in the fields of many machine operations such as modern weapons and high-speed feed drive system for a machine tool. The dynamic equations are derived on the torsion of a cantilever hollow shaft induced by the spin-up of a moving mass and the displacement of the mass. Influences of design parameters such as the inertia ratio, the mass moving speed and the friction coefficient are discussed on the transient response of the system.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.05a
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• pp.941-944
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• 2005

Asymmetry of rotor systems is an important factor for identification of dynamic characteristics including the stability and response of rotors and for condition monitoring. In this work, asymmetry of rotors is identified by applying curve-fitting method to the directional frequency response functions (dFRFs), which are known as a powerful tool for detecting the presence and degree of asymmetry. This method minimizes least square error between analytical and measured dFRFs by iteratively updating physical parameters associated with rotor asymmetry. The effectiveness of the identification method is demonstrated by experiments with a laboratory test rotor.

• Progress in Superconductivity and Cryogenics
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• v.13 no.1
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• pp.46-50
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• 2011

The electrical insulation design of high voltage superconducting fault current limiters (SFCLs) should be confirmed to be applied for the stabilization of the power grid. This paper describes numerical analysis and AC dielectric experiments for developing high voltage SFCLs. The electric field distributions between applied high voltage part and ground were calculated by finite element method (FEM) simulation tool and AC criterion of liquid nitrogen at 200 kPa was calculated from correlation between the field utilization factor and FEM simulation results. This paper deals with ceonceptual insulation design of a 154 kV class single-phase no-inductively wound solenoid type SFCL which was focused on gap distance between the cryostat and superconducting coils. Furthermore, the shield ring effect was confirmed to reduce maximum electric field at applied high voltage part.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.11 no.2
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• pp.71-79
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• 2002

In this paper, an oil hydraulic pipeline is terminated by both rotary sinusoidal flow generator at upstream oriffice at down stream. The pulsating pressure wave from generated by the rotary sinusoidal flow generator, is measured by using sensor. In the analysis of this paper, a component of the fundamental frequency is obtained by using Laplace transformation.. The experimental and analytical results make clear that (1) viscosity is significant role in hydraulic pipe. (2) When pulsating frequency is matched with the natural frequency, resonance frequency occured periodically. According to the study proposed here, dynamic pressure in a circular oil pipe is expressed in propagation of pressure wave with respect to frequency and Bessel function. The resonance at oil temperature $20^{\circ}$$0^{\circ}C$ in this study. The abrupt change of gain value is due to effect of resonance frequency. The results of experiment are compared with the calculated results, and agreement of both results is fairly good.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.11 no.2
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• pp.59-64
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• 2002

This paper presets experimental and analytical studies of ultimate strength of [$[30_2/-30_2/90]_S$ carbon/epoxy laminates with free-edge delamination under uniaxial tension. We performed tensile teat far laminates with Telflon inserted on interfaces to simulate initial free-edge delamination, The experiment reveals that extensional stiffness of the laminate decreases by the initiation of the delamination, and that strength of the laminate without delamination is smaller than that of the laminates with delamination. Generalized quasi-three delamination finite element analysis, which employs energy release rate and maximum stress criteria, predicts the ultimate strength of the laminates with sufficient accuracy.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2000.10a
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• pp.268-271
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• 2000

In these days, the technical advances and complexities have generated much of the difficulties in managing the project resources, both time and costing to accomplish the project in the most efficient manner. The project manager is frequently required to render judgements concerning the schedule and resource adjustments. This research develops an analytical model for a schedule-cost and risk analysis based on visual PERT/CPM. We used a two-step approaches ：in the step 1, a deterministic PERT/CPM model for the critical path and estimating the project time schedule and related resource planning, In the second step, we developed a heuristic model for crash and stretch out analysis based upon a time-cost trade-off associated with the crash and stretch out of the project. Computer implementation of this model is provided based on GUI-Type objective-oriented programming for the users and provided displays of all the inputs and outputs in the form of visual graphical. Also developed GUI-type program, Dongeui Visual-PERT/CPM. The results of this research will provide the project managers with an efficient management tool.

• Korean Institute of Interior Design Journal
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• v.13 no.3
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• pp.162-170
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• 2004

The purpose of this study is to analyze the emotional color of home office and the trendy color with special comparison of office and library colors, and to suggest the harmony of color combination of home office based on the emotional color of this analytical data. this study, the Color Syntax Program, digital tool for color analysis of images is used. The results of this study are as follows. Firstly, the main color of home office images shows three color classifications of YR-Y, Y-GY, R-YR, and with relatively high ratios of YR-Y in the color of home offices, and B-PB, GY-G in offices and libraries. Secondly, from the point of emotional aspect, the trendy color of the home office can be classified into four color image categories: 'natural', 'peaceful', 'mild', and 'noble'. Under those categories this paper proposes 10 color harmony scheme that can be applied to color of home office interior design.

• Journal of Korean Institute of Industrial Engineers
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• v.12 no.1
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• pp.107-118
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• 1986

A heuristic algorithm (SIMICOM) has been designed and tested for optimizing simulated stochastic systems whose performances are functions of several discrete decision variables. The approach adopted utilizes an integer complex method coupled with techniques of establishing confidence intervals for the system's responses. It can handle a general class of optimization problems that could be constrained or unconstrained. In constrained cases, the constraints could either be explicit analytical functions of decision variables or be expressed as other responses of the simulation model. In addition to obtain a reasonably accurate solution, the economic aspect of obtaining the solution has also been taken into consideration.