• Journal of Navigation and Port Research
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• v.38 no.6
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• pp.689-694
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• 2014

The Korean government has introduced and enforced maritime traffic safety assessment to secure traffic safety since 2010. The maritime traffic safety assessment is needed by law to design a new port or modify an existing one. According to Korea Maritime Safety Act, in the assessment the propriety of marine traffic system consists of the safety of channel transit and berthing/unberthing maneuver, safety of mooring, and safety of marine traffic flow. The safety of channel transit and berthing/unberthing maneuver can be evaluated only by ship-handling simulation. The ship-handling simulation is carried out by sea pilots working with the port concerned. The vessel's proximity measure is an important factor to evaluate traffic safety. The proximity measure is composed of vessel's closest distance to channel boundary and probability of grounding/collision. What is more, the probability of grounding becomes important. According to central limit theorem, a sample has a normal distribution on condition that its size is more than 30. However, more than 30 simulation runs bring about the increase of assessment period and difficulty of employing sea pilots. Therefore this paper is to find out minimum sample size for evaluating vessel's proximity. First sample sets of size of 3, 5, 7, 9 etc. are selected randomly on the basis of normal distribution. And then KS test for goodness of fit and t-test for confidence interval are applied to each sample set. Finally this paper decides the minimum sample size. As a result this paper suggests the minimum sample size of 5, that is, the simulation of more than five times.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.11
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• pp.5627-5635
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• 2013

The purpose of this study was to determine factors of women's satisfaction of hospital environment following childbirth. Data were collected using a structured questionnaire from 783 women visited at 101 hospitals for delivery and frequencies, t-test, ANOVA, Pearson's correlation, and multiple regression analyses were performed. Women's satisfaction was significantly related with personal and environmental factors. Specifically, a kind of patient room, using a shared room regardless of their preference, using family delivery room, planned hospitalization, gestational week at delivery, and hospital locations significantly predicted the variance of women's satisfaction. Therefore, hospital user satisfaction should be carefully understood as a consequence of interaction of person and environment and the level of satisfaction can be represented by the degree of congruency between personal and environmental characteristics. Furthermore, healthcare providers should develop strategies to reduce gaps between personal preferences/will/control and environmental situations, contributing to women's satisfaction with hospital following childbirth.

• Environmental and Resource Economics Review
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• v.14 no.1
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• pp.1-24
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• 2005

One of the most important factors that determine the quality of a stated preference study is questionnaire design. This study introduces strategies for enhancing the rationality and testing for the validity of choice experiments(CE) using "example" choice questions that mimic the main choice questions. From the case study of WTP for reduced radon radiation exposures in the home, the study found that screening out irrational responses, 12% of the effective responses, resulted in a meaningful increase in model fit. Meanwhile the study tested for anchoring effects, as a way of confirming the divergent validity of the study, by looking at equality of models estimated for two subsamples. The overall test results were mixed. The pros and cons of the questionnaire design strategy employed are also reported.

• Journal of the Korean Society of Clothing and Textiles
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• v.32 no.1
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• pp.99-109
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• 2008

The purpose of this study was to survey sizing system and preferable ease and to decide the body measuring items for pattern making in a men's dress shirt for mass customization industry that is rising to the surface as a new production system. For this, it had a survey subjects were 254 males between 25 to 44 years old who wear dress shirt frequently and the relevant on line companies, and analyzed the garment sizing system and preferable ease. Collected data were analysed by frequency analysis, t-test, $X^2-test$, and ANOVA using SPSS 12.0 for window. Garment pattern making should reflect the sizes of the body parts well, and simplification of the ordering process would work as an important variable. In relation to the preferable ease, older people preferred more ease while younger people preferred fit ease. In relation to the sizes, people wearing the size of '110' preferred more ease than the size of '90'. And people weighing over 90kg preferred sufficient ease than less weighing. People height over 170cm people preferred sufficient ease for the length between shoulders than height under 170cm. In case of the companies had no consistent sizing system. Significant difference was found in the sizes, except for the size of '100', among those companies, there was significant difference in the length between shoulders and the length of the shirt among those companies and those sizes. Significant body parts for a garment pattern making was height, the circumference of the neck, the chest circumference, the length between biacromion, the arms length, and the waist circumference.

• Korean Journal of Applied Biomechanics
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• v.19 no.3
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• pp.603-610
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• 2009

The purpose of this study was to determine how spandex pants affect impact force and muscle activities in the lower extremity. Seven pairs of surface electrodes were attached to the right-hand side of the body. Paired t-test was performed to test if significant difference exist between two conditions(p< .05). The average IEMG activities in the TA, BF, and GM during the landing phase reduced significantly with spandex pants compared to regular pants. All peak IEMG activities except the RF in wearing spandex pants group were significantly greater than the corresponding values in wearing regular pants one. The greater muscle activity recorded in wearing spandex pants can be attributed to the greater motor unit recruitment needed to decelerate and stabilized their bodies. Impact force and loading rate were not significantly decreased with wearing spandex pants. Since the spandex pants used in this study were not custom-fit based on girth of each participants thigh and shank, compression and elasticity for the pants could not be optimized.

• Journal of Korea Water Resources Association
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• v.32 no.3
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• pp.265-279
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• 1999

In this study, one of the techniques on the extension of low flow series has been developed, in which the daily streamflows were simulated by the Tank model with the input of extended daily rainfall series which were stochastically generated by the Markov chain model. The annual lowest flow serried for each of the given durations were formulated form the simulated daily streamflow sequences. The frequency of the estimated annual lowest flow series was analyzed. The distribution types to be used for the frequency analysis were two-parameter and three-parameter log-normal distribution, two-parameter and three-parameter Gamma distribution, three-parameter log-Gamma distribution, Gumbel distribution, and Weibull distribution, of which parameters were estimated by the moment method and the maximum likelihood method. The goodness-of-fit test for probability distribution is evaluated by the Kolmogorov-Sminrov test. The fitted distribution function for each duration series is applied to frequency analysis for developing duration-low flow-frequency curves at Yongdam Dam station. It was shown that the purposed technique in this study is available to generate the daily streamflow series with fair accuracy and useful to determine the probabilistic low flow in the watersheds having the poor historic records of low flow series.

• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.15 no.2
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• pp.19-30
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• 2019

In this study, to evaluate conservatism of various fatigue life evaluation procedures, fatigue tests were conducted using compact tension (CT) specimens with a round notch, made of A516 Gr.70 carbon steel and A240 TP304 stainless steel, under load-controlled cyclic condition. Experimental fatigue failure cycles were measured and compared with predicted fatigue lives using two different life evaluation methods; (1) Design-By-Analysis (DBA) procedure given in ASME B&PV Code, Sec. III, Div. 1, Subsec. NB-3200 and (2) structural stress-based approach provided in ASME B&PV Code, Sec. VIII, Div. 2, Part 5. To predict fatigue failure cycles, three-dimensional elastic finite element analysis was conducted. Fatigue lives were predicted by both design fatigue curve given in ASME B&PV Code, Sec. III, Div. 1, Appendices and best-fit fatigue curve suggested in NUREG/CR-6815 for the DBA procedure. Finally, fatigue lives evaluated by various methods were compared with test results, and then conservatism between each evaluation procedure was discussed.

• Journal of the Korean Society of Clothing and Textiles
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• v.34 no.2
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• pp.189-199
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• 2010

This study develops a coverall design for the body shape and movement of infants. This research analyzed these processes: 1. The current coverall styles preferred for infants. 2. The appropriate products for the real size, body shape, movement, and fit of infants. 3. The observations of the 6 months to 9 months movement and development of infants. 4. The design and creation of a new coverall base in this study, and to check the suitable test the developed coverall design for the infant. The result of this study are: A coverall for infants that lie or crawl on the floor must avoid opening in the center front and a gore has to be added at the crotch of the pants for the better movement of infants. These ways provide infants a neat appearance and easy movement. The test of developed designs shows that the developed coverall design covers the size gap of the trunk loop according to the growth of the infant and the movement of the legs; in addition it provides a positive aesthetic effect. The waistline in the developed coverall (a waistline that should exist lower than the body waistline of the infant) can reduce seam stress because the pressure of the seam line can be absorbed in a dipper. It is one of the suitable design points for infants lying prone all day long in this study.

• Korean Journal of Veterinary Research
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• v.44 no.3
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• pp.323-327
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• 2004

The purpose of the present experiment was to investigate the micronuclei(MN) frequency in cytokinesis-blocked(CB) cells after various doses of gamma-rays in pig (Landrace, male, 3-month-old) and so to contribute to the clarification of the question whether these species are suitable as a target organism in the test system. The frequencies of binucleated cells, and gamma-ray-induced MN in CB cells at several doses were measured in three donors. The peaks of binucleated lymphocyte formation(22%) were found at a concentration of 2% phytohaemagglutinin(PHA) and $4{\mu}g/ml$ Cytochalasin B(Cyt-B) in pig at 72 hours after incubation. Measurements performed after irradiation showed a dose-related increases in MN frequency in each of the donors studied. When analysed by linear-quadratic model the line of best fit was $y=0.0183D+0.0124D^2+0.0133$(y = number of MN/CB cells and D=irradiation dose in Gy). In conclusion, the results demonstrate that it appears feasible to use pig as target organisms in the micronucleus test to estimate the cytogenetic damage caused by ionizing radiations or, potentially, chemical compounds.

• Journal of the Institute of Convergence Signal Processing
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• v.10 no.3
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• pp.170-175
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• 2009

In this paper, we propose real time automatic speaker verification (ASV) system to protect personal information on personal digital assistant (PDA) device. Recently, the capacity of PDA has extended and been popular, especially for mobile environment such as mobile commerce (M-commerce). However, there still exist lots of difficulties for practical application of ASV utility to PDA device because it requires too much computational complexity. To solve this problem, we apply the method to relieve the computational burden by performing the preprocessing such as spectral subtraction and speech detection during the speech utterance. Also by applying the hidden Markov model (HMM) optimal state alignment and the sequential probability ratio test (SPRT), we can get much faster processing results. The whole system implementation is simple and compact enough to fit well with PDA device's limited memory and low CPU speed.