• 한국해양학회지
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• 제18권1호
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• pp.10-20
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• 1983

京畿灣의 三次元 流動 解析모델이 開發되었으며 이 모델을 利用하여 定常一風인 10dyne/$\textrm{cm}^2$의 剪斷强度를 갖는 北西風 및 西風에 의한 京畿灣의 反應을 數値實驗하였다. 算定된 바람 應力에 의한 三次元 海流分布가 檢討되었다. 모델은 또한 京畿灣의 主要한 物理現狀인 主太陰半日週潮(M$_{2}$)의 分布를 算定하는데 理容되었는데 潮流의 三次元 分布에 대한 初期缺課가 提示되고 討議되었다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 추계학술대회 논문집
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• pp.16-21
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• 2002

The high speed machining center(HMC) has been widely applied to manufacture a die and trial product in many machine industry. Because the evaluation fer the HMC is not sufficiently performed and the efficient cutting conditions aren't selected, a great loss has been caused in the cost aspect. In this study, the need of preliminary running time and unstable spindle speed is presented from the analysis of acceleration in idling. The Machinability fur the TiAlN coated flat end mill and STD11( $H_{R}$C60) is evaluated from the trends of tool wear and cutting force according to cutting conditions and slenderness ratio and a low response of tool dynamometer in high speed is proved. The resonance spindle speed is identified through the tool wear and natural frequency test.t.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2006년도 춘계학술대회논문집
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• pp.271-276
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• 2006

This paper shows the rotordynamic characteristics of a turbo-generator for a BOP of a fuel cell system. The rotor-bearing system consists of magnetic shaft and compressor-turbine shaft, and the two shafts are connected by spline coupling and supported by oil free air foil bearing. Preliminary design according to several parameter is considered in detail. Static and dynamic characteristics of the AFB are estimated by the soft elasto-hydrodynamic analysis technique and the perturbation method. The results of the natural frequencies, mode shape, and unbalance response analysis are presented.

• 아동학회지
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• 제26권1호
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• pp.107-121
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• 2005

The preliminary Korean Paternal Involvement Scale of 84 items was constructed from items collected from free-response surveys with 106 middle school students and 33 fathers followed by consultation with experts. Those items were tested on a sample of 339 middle school students. The 82 items selected through item analysis were analyzed by factor analysis. Of these, 54 items were categorized into seven factors : leisure-life, proffering information, discipline, academic support, tradition-inheritance, material support, and everyday life. Leisure-life, proffering information, and academic support correlated with grade level of adolescents and fathers' education. The alpha coefficients of this scale ranged from .68 to .90.

• Structural Engineering and Mechanics
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• 제31권5호
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• pp.527-544
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• 2009

In this study, the periodic seismic performance evaluation scheme is proposed using a structural health monitoring system in terms of seismic fragility. An instrumented highway bridge is used to demonstrate the evaluation procedure involving (1) measuring ambient vibration of a bridge under general vehicle loadings, (2) identifying modal parameters from the measured acceleration data by applying output-only modal identification method, (3) updating a preliminary finite element model (obtained from structural design drawings) with the identified modal parameters using real-coded genetic algorithm, (4) analyzing nonlinear response time histories of the structure under earthquake excitations, and finally (5) developing fragility curves represented by a log-normal distribution function using maximum likelihood estimation. It is found that the seismic fragility of a highway bridge can be updated using extracted modal parameters and can also be monitored further by utilizing the instrumented structural health monitoring system.

• International Journal of Naval Architecture and Ocean Engineering
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• 제6권4호
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• pp.763-774
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• 2014

A simple and efficient vibration analysis procedure for stiffened panels with openings and arbitrary boundary conditions based on the assumed mode method is presented. Natural frequencies and modes are determined by solving an eigenvalue problem of a multi-degree-of-freedom system matrix equation derived by using Lagrange's equations of motion, where Mindlin theory is applied for plate and Timoshenko beam theory for stiffeners. The effect of stiffeners on vibration response is taken into account by adding their strain and kinetic energies to the corresponding plate energies whereas the strain and kinetic energies of openings are subtracted from the plate energies. Different stiffened panels with various opening shapes and dispositions for several combinations of boundary conditions are analyzed and the results show good agreement with those obtained by the finite element analysis. Hence, the proposed procedure is especially appropriate for use in the preliminary design stage of stiffened panels with openings.

• 대한가정학회지
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• 제39권1호
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• pp.221-232
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• 2001

The purpose of this study was to develop a scale for evaluation of preschool children's peer competence and to examine its validity and reliability. The 15 items of the preliminary scale were completed by teachers, and peer rating scale for assessment of peer acceptance was administered to 365 children 5 to 6 years of age. The methods for data analysis included item analysis, factor analysis for construct validity, Pearson correlations between teacher's ratings of peer competence and children's ratings of peer acceptance for concurrent validity, and Cronbach's u for reliability. The 15 items of the scathe were found be satisfactory in terms of item response distribution and item discrimination. Factor analysis revealed that a 3-factor solution was the best fit: sociability, prosocial behavior, leadership in peer relations. Correlations between teacher's ratings and children's ratings were as significant. Cronbach'so ranged from .88 to .93 for three subscales and .93 for the total scale. It was concluded that the psychometric properties of the peer competence scale in general were acceptable for use.

• 한국해양공학회지
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• 제2권2호
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• pp.27-36
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• 1988

For the purposes of drilling oil field and extracting oil deep water in more rough weather, the size of drilling rigs must be estimated. In this paper, the three dimensional source distribution method is used and we assume 10 deg. heeling and trimming condition of the drilling rig(SR-192). Also, the effects of the hydrodynamic forces which include the drift forces for field method, and the motion responses are studied with changing the incident wave direction in the assumed inclining condition. The theory and numerical codes used in this thesis appeared to be very useful for the preliminary design of drilling rigs.

• 음성과학
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• 제10권4호
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• pp.229-239
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• 2003

The purposes of this study are; to investigate the swallowing mechanism of stroke patients with different consistencies through the modified barium swallowing(MBS); and to establish preliminary data on the differences in swallowing durations. 4 different kinds of consistency-water, nectar, pudding, and crackers-were given to 6 stroke patients and their swallowing durations recorded through the fluoroscopy were measured in 1/100 second units. The results show that first swallowing time(FST), the oral preparatory duration(OPD), and the pharyngeal response duration(PRD) were delayed in swallowing thicker consistencies. However, water exhibited delayed oral and pharyngeal phase relative to its consistency and 50% of subjects showed oral loss of water. The relationship between consistencies and swallowing durations and the clinical issues on the stroke population were discussed.

• 한국전산유체공학회지
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• 제16권3호
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• pp.1-7
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• 2011

As a preliminary design study to achieve target aerodynamic performance, this work was conducted on an original nozzle with 9 flutes in order to design a fluted nozzle with 12 flutes. The thrust and rolling moment of the nozzle with 12 flutes were analyzed using a CFD code according to the depth and rotation angle of the flutes. Based on this, a fluted nozzle with 12 flutes was optimized to yield the same thrust as that of the original nozzle with 9 flutes. The response surface method was applied for shape optimization of the fluted nozzle and design variables were selected to determine the depth angle and rotation angle of the flutes. An optimized shape that led to a thrust as strong as that of the original nozzle was obtained.