• Journal of the Korean Statistical Society
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• v.23 no.2
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• pp.403-420
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• 1994

An economic design of the $\bar{X}-R$ chart using variable sample size (VSS) scheme is proposed in this paper. In this design the sample size at each sampling time changes according to the values of the previous two sample statistics, sample mean and range. The VSS scheme uses large sample if the sample statistics appear near inside the control limits and smaller sample otherwise. The set of process parameters, such as the sampling interval, control limits and the sample sizes, are chosen to minimize the expected cost per hour. The efficiency of the VSS scheme is compared to the fixed sample size one for cases where there is multiple of assignable causes. Percent reductions of the expected cost in the VSS design are calculated for some given sets of cost parameters. It is shown that the VSS scheme improves the confidence of the procedure and performs statistically better in terms of the number of false alarms and the average time to signal, respectively.

• Journal of the Korean Home Economics Association
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• v.40 no.7
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• pp.119-127
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• 2002

Fitness of clothes becomes a major concern in apparel industry. In order to improve clothing fitness, it's very important to suggest a systematical sizing system. The Purpose of this study was to suggest a standard sizing system for junior-high school girls'lower clothes. The subjects were 402 middle-high school girls of 13 to 15 year-old. 4 clusters were categorized by cluster analysis and the sizing system was classified according to four lower body types. The size intervals of waist girth and hip girth were 3cm and 4cm respectively. The most frequent size were 64-86 in the short and small figure type 1,67-90 in the fattest figure type 2, 61-86 in the average size type 3 and 64-90 in type 4 taller than others types. The sizing system, which had frequencies more than 4%, was classified 9 cases, 11 cases, 8 cases and 9 cases respectively by lower body types. This result will contribute to clothing fitness of consumer and the amount of production.

• The KIPS Transactions:PartC
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• v.14C no.3 s.113
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• pp.285-292
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• 2007

In the adaptable bandwidth allocation technique, a transmission plan for variable rate video data is made by the CBA algorithm and the data is transmitted by considering network traffic. But the CBA algorithm produces a transmission plan where the size of the increasing interval of transmission rate is generally larger than the size of the decreasing interval. And the transmission rate in CBA algorithm is changed in overflow curve during the increasing interval of transmission rate. This ぉy cause many frames to be discarded when available transmission rate is small. In this paper, a smoothing algorithm is proposed, where transmission rate is changed in the middle of underflow curve and overflow curve, but the transmission rate increases at the minimum. In order to show the performance, the proposed algorithm and a CBA algorithm were applied to a transmission plan in the adaptable bandwidth allocation technique, and the minimum frame rates, the average frame rates, the variation of frame rates, and the numbers of discarded frames were compared in both algorithms.

• The KIPS Transactions:PartC
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• v.14C no.6
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• pp.475-480
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• 2007

Recently, wireless networking devices that depend on the limited Battery and power-saving of wireless hosts became important issue. Batteries can provide a finite amount of energy, therefore, to increase battery lifetime, it is important to design techniques to reduce energy consumption by wireless hosts. This paper improved power saying mechanism in Distributed Coordination Function(DCF) of IEEE 802.11. In the IEEE 802.11 power saving mechanism specified for DCF, time is divided into so-called beacon intervals. At the start of each beacon interval, each node in the power saving mode periodically wakes up during duration called the ATIM Window. The nodes are required to be synchronized to ensure that all nodes wake up at the same time. During the ATIM window, the nodes exchange control packets to determine whether they need to stay awake for the rest of the beacon interval. The size of the ATIM window has considerably affected power-saving. This paper can provide more power-saving than IEEE 802.11 power saving mode because ATIM window size is efficiently increased or decreased.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.18 no.10
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• pp.1181-1188
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• 2007

This paper presents the measured signal performances in the urban environment for the DVB-H parameters such as code rate, burst size, FFT mode and modulation technique to analyze the DVB-H signal performance avaible for the embodiment of single frequency network to improve the frequency efficiency. Measurements were performed for the case for applying and non-applying MPE-FEC technique simultaneously. Results show that the most outstanding performance are found in the case of QPSK modulation, 1/2 code rate, 2 k FFT mode and 512 burst size. In addition, the signal performance by the SFN with 1/8 guard interval becomes superiour in comparision with the measured data from each site and the data from SFN with 1/32 guard interval. The analysis of the results can be instructive for the improvement of the signal performance and broadcasting quality for the terrestrial digital mobile broadcasting service.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.4 no.3
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• pp.246-253
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• 1999

Grain size distributions of sediment samples were analyzed by the different methods, and the results were compared. Reported data of the bottom sediments from the Korean seas show significant deviations among the institutes, and the inter-lab comparison and calibration procedures are considered to be necessary. Grain size data by different methods show different results. Laser diffraction method provides good precision in replicate analysis, but underestimates the amounts of finer (smaller than 2-3 ${\mu}m$) fraction. Data from particle settling method, on the other hand, represent significant errors in the coarse silt (5-6 ${\phi}$) fraction, and slightly overestimate the clay fraction. In the sieve and pipette methods, best results were taken in 0.5 ${\phi}$ interval of analysis. Especially in the coarse silt fraction, pipette analysis is suggested to be made with 0.5 ${\phi}$ interval. During the dry sieving procedure in 1 ${\phi}$ interval, serious errors occur when large amounts of sample materials were concentrated in a particular sieve.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.9
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• pp.2326-2333
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• 2009

In the adaptable bandwidth allocation technique, a transmission plan for variable rate video data is made by smoothing algorithms such as CBA algorithm and the data is sent by the transmission plan considering network traffic. But the CBA algorithm, the MCBA algorithm, MVBA algorithm and the other smoothing algorithms produce a transmission plan where the size of the increasing interval of transmission rate is generally larger than the size of the decreasing interval. And the transmission rate in CBA algorithm, the MCBA algorithm, the MVBA algorithm is changed in overflow curve during the increasing interval of transmission rate. This may cause many frames to be discarded when available transmission rate is larger than transmission rate by the transmission plan. In this paper, the smoothing algorithm, where transmission rate is changed in the middle of underflow curve and overflow curve to decrease the number of discarded frames, but the transmission rate increases at the minimum, and the CBA algorithm, the MCBA algorithm, the MVBA algorithm are applied to a transmission plan in the adaptable bandwidth allocation technique, and the minimum frame rates, the average frame rates, the variation of frame rates, and the numbers of discarded frames are compared in among algorithms.

• Fashion & Textile Research Journal
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• v.6 no.5
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• pp.634-640
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• 2004

Nowadays, the use of apparel CAD system is important to the mass production of ready to wear. Especially, computer-based grading is the most important process to improve the fitness of clothes and to reduce the time needed to make various size pattern. The purpose of this study was to suggest a standard sizing system for high school boys' pants and to suggest a grading method according to the sizing systems. The subjects were 217 high school boys of 16 to 18 year-old. The size intervals of waist girth and hip girth were 3 cm and 4 cm respectively. The sizing system, which had frequencies more than 4%, was classified 8 cases. Among them, 71-92 and 71-88 size were the most frequent size and were adopted the basic size for the two types of grading. According to the sizing system, hand-made patterns were manufactured. By measure of the each part of the slacks, 4 size's new grading-rule patterns were developed by each size. This result will contribute to clothing fitness of consumer and the amount of production.

• Journal of the Korean Society of Clothing and Textiles
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• v.22 no.8
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• pp.1090-1098
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• 1998

The purpose of this study was to classify size specifications of the Korean adult male for the men's ready-made garments, especially jacket and dress shirts. By the stratified sampling method, data were collected by the real anthropometric measurement and by the photo-graphic sources. Sample size was 532 subjects as the sample and their age range was from 28 to 35 years old. 66 variables from the direct anthropometric data in total were applied to analyze. ANOVA in SPSS WIN package was applied to the data and the expected frequency distribution of 10.000 men was calculated by the extraction of density function. This study was performed to classify size specifications by the control dimensions and at the same interval of KS-K. The drop values of 15, 12 and 9 have the high coverage rate of 26.00%, 24.29% and 21.06% respectively and are composed of the majority of 71.35% of the subjects. According to the drop values, size specifications and distribution of control and reference dimensions are predicted. About 52.12% of the expected frequency distribution without stature were covered by 12 size specifications.

• Fashion & Textile Research Journal
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• v.21 no.5
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• pp.677-686
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• 2019

This study helps out-size consumers purchase ready-made clothes and improve fitness by classifying the lower bodies of abdomen-obese adult males in their 20s and older; in addition, it creates a size system based on each size interval of obesity type. The criteria for the 559 male subjects surveyed in this study were over $25kg/m^2$ of BMI, over 90 cm of waist, and over 0.85 waist hip ratio. The results are as follows. First, the higher the age group, the higher the degree of abdominal obesity in each age group. The degree of obesity then decreases somewhat as their age increases; however, the risk of abdominal obesity also increases. Second, 3 clusters were categorized by cluster analysis, into abdominal obesity, larger oval-type, trapezoid-type and small cylinder-type. Third, the size system establishment according to lower-body types resulted in basic body sizes and reference body sizes being different according to types even in commonly-appeared size names in the sections of respective types. The above research findings show it is necessary to understand obesity types according to waist and hip sizes that represent basic sizes and to design patterns in consideration of the characteristics of obese body shapes when lower-half body clothes are designed among obesity groups.