• 산업공학
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• 제11권3호
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• pp.89-101
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• 1998

The randomness of the input variables in simulation experiments produce output responses which are also realizations of random variables. The random responses make necessary the use of statistical inferences to adequately describe the stochastic nature of the output. The analysis of the simulation output of non-terminating simulations is frequently complicated by the autocorrelation of the output data and the effect of the initial conditions that produces biased estimates. The regenerative method has been developed to deal with some of the problems created by the random nature of the simulation experiments. It provides a simple solution to some tactical problems and can produce valid statistical results. However, not all processes can he modeled using the regenerative method. Other processes modeled as regenerative may not return to a given demarcating state frequently enough to allow for adequate statistical analysis. This paper shows how the state transformation concept was successfully used in a queueing model and a job shop model. Although the first example can be analyzed using the regenerative method. it has the problem of too few recurrences under certain conditions. The second model has the problem of no recurrences. In both cases, the state transformation increase the frequency of the demarcating state. It was shown that time state transformations are regenerative and produce more cycles than the best typical discrete demarcating state in a given run length.

• 한국해양공학회지
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• 제27권1호
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• pp.67-73
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• 2013

This paper presents the results of a numerical study on the towing stability of barges. Towing simulations were carried out by using two different numerical models (MMG model and cross-flow model). Stability criteria are also suggested based on the analysis of the linearized governing equations for towed vessel motion. In order to validate the present numerical models, the experimental data of Yasukawa et al. (2006) were used. Simulations were conducted for single and double barges under constant towing speed and direction conditions. The time histories of the heading angle, yaw rate, and towline tension were compared between the numerical results and experiments. The effects of the towline length on the slewing frequency and maximum heading angle were also observed. In addition, a series of numerical simulations using variable hydrodynamic coefficients were performed to investigate the effects of the hydrodynamic forces on the towing stability.

• 대한전자공학회논문지SD
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• 제41권11호
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• pp.1-6
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• 2004

RFIC를 위한 Nanoscale MOSFET에서의 유효 게이트 저항을 직접 추출법으로 추출하여 다양한 게이트 길이에 대해 분석하였다. 추출된 유효 게이트 저항은 비교적 정확하면서 간소화된 모델을 통한 측정결과와 비교하여 10GHz 대역까지 잘 일치함을 확인하였다. 같은 공정기술로 제작된 소자들 중에서 reverse short channel 효과가 생기지 않는 긴 채널 MOSFET 소자의 경우에 일반적인 유효 게이트 저항에서와는 다른 인가전압 및 주파수 종속성을 가짐을 확인하였다. 특히, 문턱전압을 전후하여 주파수에 따라 상이한 결과를 나타내고 있으며, 게이트 인가전압이 문턱전압에 가까울 때 비이상적으로 큰 유효 게이트 저항값을 나타내었다. 이러한 특성은 직접추출법을 사용하는 RF MOSFET 모델링에 있어서 참고해야 할 중요한 특성이 될 것이다.

• 성인간호학회지
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• 제23권2호
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• pp.170-179
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• 2011

Purpose: The purpose of this study was to identify the effect of combined Western and Oriental medicine headache massage program for chronic headache patients. Methods: This study was designed using the Nonequivalent control group pretest-posttest design. The forty nine patients were divided into an experimental group (25 patients) and a control group (24 patients). Collected data were analyzed by Chi-test, t-test, Fisher's exact test, Repeated measures ANOVA using SPSS/WIN 14.0 program. Results: After treatment in this program, the experimental group had no significan difference in scores for headache intensity and frequency as the length of time in treatment increased compared to the control group. But there were significant decreases in the use of medication (F=4.209, p=.046) and disturbances in the quality of life related to headaches (F=13.097, p=.001) after providing the combined Western-Oriental massage program. Conclusion: This program could have a positive effect on using medication for pain controllers and headache related quality of life. Based on the results of this study, further research focusing on the effectiveness of unique nursing intervention for chronic headache patients is suggested.

• The Journal of the Acoustical Society of Korea
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• 제16권3E호
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• pp.50-55
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• 1997

Based on the anthropometric data of Korea male adults, a head and torso simulator(HATS) is constructed to measure its head related transfer functions (HRTFs) which can be used for three dimensional (3-D) sound localization. The HRTFs binaural impulse responses, are measured in an anechoic chamber using a burst maximum length sequence (MLS) signal of 65,535 samples and 32,768 samples acquisition at the sampling rate of 75.47kHz. Also measured are the impulse responses of a driving loudspeaker and some headphones for sound reproduction to get the exact HRTF of the HATS-alone. Through a post-processing procedure, the impulse-version HRTFs at the sampling frequency of 44.1 kHz, which have filter lengths of 512 points, are finally obtained. As an application of the measured HRTFs, a 3-D sound processor for headphone reproduction has been developed. The signal intervals to be processed can be selected and each interval is manipulated to have its diretionality and distance information by using corresponding HRTF and energy control.

• 패션비즈니스
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• 제10권4호
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• pp.45-54
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• 2006

This study analyzed the purchasing behavior for underwear, with the subjects of pregnant women, and the trend of its fit preference and thereby looks into the practices of their clothing life to provide the basic data for the formation of maternity clothing industry, focusing on the underwear development in response to pregnant women's body type features. The conclusion were as follows: 1. The analysis of underwear wearing practices for the women in the pregnancy of eight months or longer and those after the delivery within one month showed that about 80-90% of them wore panties or brassieres and about 70% of them did not wear girdles, thus with a lower level for girdles than for panties or brassieres. 2. The surveys of the satisfaction and fit for two designs each with the high wearing frequency did not show any relatively significant difference in assessment by the design. The analysis of the satisfaction by the part with the maternity underwear indicated that in the case of panties the respondents were dissatisfied with the length as to be long, and also dissatisfied with waist circumference, abdomen circumference, private parts, and groin as to be small, reflecting that the circumference coverage of the panties in the market was not effectively managed.

• 한국공간구조학회논문집
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• 제8권2호
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• pp.95-103
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• 2008

주파수영역과 시간영역의 두가지 방법을 통하여 감쇠율을 분석하였다. 11층${\sim}$19층 범위의 철근콘크리트 건물에 대하여 주파수 영역에서의 해석을 위한 상시진동과 시간영역에서의 해석을 위한 인력가진을 실시하였다. 하프파워법의 적용성을 검토하기 위하여 1024, 2048, 4096 세가지 앙상블 샘플사이즈에 대하여 분석하였다. 인력가진법에 의한 장변과 단변의 감쇠율은 각각 1.05%${\sim}$1.22%과 1.16%${\sim}$1.50%이다. 하프파워법은 감쇠율을 약간 과대평가할 수 있지만, 계측데이터의 길이를 가능한 길게 하여 bandwidth를 작게 하면 감쇠율 평가의 정밀도를 향상할 수 있었다.

• 한국의류산업학회지
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• 제13권4호
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• pp.624-634
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• 2011

The purpose of this study is to develop the pattern of safety clothes used at flat or mountainous areas and to identify the pattern of safety clothes by conducting experimental evaluation of virtual wear. Three subjects were selected, based on fire fighters' physical constitution. A prototype design for safety clothing was determined after in-depth interviewing of professionals and surveying of Forest service staff and related agency. Wearing test should be carried out in the order of pattern making, virtual and real wearing evaluation. For data analysis, technical statistical values should be obtained by using body measurements of subject, frequency analysis and T-test. The jacket is designed to have a front extension and the entire length of clothing enough for wearer to put on it over ordinary shirts or sweater. The collar of jacket is of round type. Cyber reality enables to identify the movement and activity of virtual fitting model and to find out errors or problems in safety clothing prior to on-the-spot wear test, thus raising the precision level of pattern. There was significant difference between real and virtual fit preference. The results show that the virtual try-on system need the development of a specific style.

• 한국정보통신학회논문지
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• 제5권5호
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• pp.1001-1010
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• 2001

TLM 법에서 이산 그린함수 흡수경계는 광대역에서 정밀한 수치해석에 사용되어왔다. 그러나 이산 그린함수 흡수경계는 이산 그린함수를 얻는 수치해석이 부가적으로 요구되기 때문에 흡수경계를 적용하는 과정이 복잡하다. 그러므로 흡수경계를 적용하는 과정의 간소화를 위해서 본 논문에서는 새로운 그린 흡수층을 제안한다. 제안된 그린 흡수층은 이산 그린함수의 손실처리 방법을 응용하여 구현하였으며 최적의 흡수 상태를 그린 흡수층의 길이에 대응하는 손실 증가율과 감쇠상수리 관계로 얻을 수 있었다. 또한 최적의 흡수상태가 되는 그린 흡수층을 적용하여 도파관 대역통과필터를 해석하였다. 그 결과, 기존의 그린함수 흡수경계와 제안된 그린 흡수층을 적용한 해석 결과가 정확히 일치하였다.

• 대한가정학회지
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• 제43권5호
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• pp.93-105
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• 2005

This study focused on the development of scales measuring the characteristics related to appearance management behaviors of businessmen for on-line image consulting. The purposes of this study were, 1) to develop a tool which can measure the ideal image, 2) to develop a tool which can measure personality, and 3) to develop a scale measuring the physical characteristics and body cathexis. The data were collected from 380 businessmen in Seoul, Korea and were analyzed by frequency, factor analysis, reliability test, cluster analysis, correlation analysis, one-wav ANOVA and Duncan test. The results from this study were as follows .1)Five factors of the ideal image were identified: stylish, able, active, neat/confident and easy. The total variance was 74.29$\%$ and Cronbach's alpha of the 5 factors ranged from .74-.90. One item was selected to represent each factor. 2) Five factors of personality were identified: preference of social function, sociable, dynamic, achievement-motivated, and success-oriented. The totai variance was 60.63$\%$ and Cronbach's alpha ranged from .56-.83. One item was selected to represent each factor. 3) Five factors of body cathexis were identified: satisfaction with girth, length, physique, nose and eyes. The total variance was 73_46$\%$ and Cronbach's alpha ranged from .68-.85.