• IE interfaces
• /
• v.11 no.3
• /
• pp.89-101
• /
• 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.

• Journal of Ocean Engineering and Technology
• /
• v.27 no.1
• /
• pp.67-73
• /
• 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.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.41 no.11
• /
• pp.1-6
• /
• 2004

Effective gate resistance, extracted by direct extraction method, is analyzed among various gate length, in nanoscale MOSFET for RFIC. Extracted effective gate resistance is compared to measured data and verified with simplified model. Extracted parameters are accurate to 10GHz. In the same process technology effect has a different kind of gate voltage dependency and frequency dependency compared with general effective gate resistance. Particularly, the characteristic of effective gate resistance before and after threshold voltage is noticeable. When gate voltage is about threshold voltage, effective gate resistance is abnormally high. This characteristic will be an important reference for RF MOSFET modeling using direct extraction method.

• Korean Journal of Adult Nursing
• /
• v.23 no.2
• /
• pp.170-179
• /
• 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
• /
• v.16 no.3E
• /
• pp.50-55
• /
• 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.

• Journal of Fashion Business
• /
• v.10 no.4
• /
• pp.45-54
• /
• 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.

• Journal of Korean Association for Spatial Structures
• /
• v.8 no.2
• /
• pp.95-103
• /
• 2008

This paper is concerned with the damping ratios of two methods, which are frequency domain and time domain approach. Ambient vibrations and synchronized human excitation test were conducted to three reinforced concrete buildings ranging from eleven to nineteen stories. The performance of the half power bandwidth method was investigated using three kinds of sample size, 1024, 2048, and 4096. The damping ratio by synchronized human excitation ranges from 1.05% to 1.22% in the long direction and from 1.16% to 1.50% in short direction. Damping by half power bandwidth method is slightly more overestimated than the synchronized human excitation due to insufficient record length. Damping evaluation by half power bandwidth method was found to be enhanced by using the narrower bandwidth with long recorded data.

• Fashion & Textile Research Journal
• /
• v.13 no.4
• /
• pp.624-634
• /
• 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.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.5 no.5
• /
• pp.1001-1010
• /
• 2001

In TLM method, Discrete Green's function ABC have been used when improved the exactness of analyzing in wide frequency band. But this technology has a complicated process to apply absorbing boundary, which means it needs additional numerical analyzing process to obtain discrete Green's function data. so, In this paper, we propose new Green's absorbing layer for simple process to apply absorbing boundary. newly proposed Green's absorbing layer is produced by applying of loss operation, loading discrete Green's function with attenuation. A state of optimum absorbing would be obtained by relation between increasing rate of loss, attenuation constant and length of green's absorbing layer. and then Analysts of waveguide BPF is carried out using Green's absorbing layer within state of optimum absorbing, then this result is in corrective agreement with the result applying traditional discrete Green's function ABC.

• Journal of the Korean Home Economics Association
• /
• v.43 no.5 s.207
• /
• pp.93-105
• /
• 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.