• Journal of The Korean Society of Agricultural Engineers
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• v.49 no.5
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• pp.3-9
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• 2007

In this study, the effect of the purification materials is analyzed and tested by Flow 3D and Hydraulic model test. Three dimension numerical analysis led from the research that sees abnormal form and the size back of the water purification material conferred the flowing water conduct inside the test channel against the test condition. Comparison it analyzed the flux distribution, a water depth of the channel which establishes the water purification materials the cross section, an interval of the water purification material, a conference with general channel, it change executed. As a result, the cross section ratio of the purification materials against and a flux change from the test which it sees. The interval of the purification materials in order to prevent three dimension that follows in decrease of increase and flux must decide an interval.

• Journal of Communications and Networks
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• v.12 no.1
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• pp.43-51
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• 2010

IEEE 802.11 defines distributed coordination function (DCF), which is characterized by CSMA/CA and binary exponential backoff (BEB) algorithm. Most modifications on DCF so far have focused on updating of the contention window (CW) size depending on the outcome of own frame transmission without considering freezing periods experienced in the backoff interval. We propose two simple but novel schemes which effectively utilize the number of freezing periods sensed during the current backoff interval. The proposed schemes can be applied to DCF and its family, such as double increment double decrement (DIDD). Saturation throughput of the proposed schemes is analyzed by means of Bianchi's Markovian model. Computer simulation validates the accuracy of the analysis. Numerical results based on IEEE 802.11b show that up to about 20% improvement of saturation throughput can be achieved by combining the proposed scheme with conventional schemes when applied to the basic access procedure.

• Journal of the Korean Data and Information Science Society
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• v.21 no.6
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• pp.1109-1115
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• 2010

In this paper, exact confidence interval of hyper-geometric parameter, that is the probability of success p in the population is discussed. Usually, binomial distribution is a well known discrete distribution with abundant usage. Hypergeometric distribution frequently replaces a binomial distribution when it is desirable to make allowance for the finiteness of the population size. For example, an application of the hypergeometric distribution arises in describing a probability model for the number of children attacked by an infectious disease, when a fixed number of them are exposed to it. Exact confidence interval estimation of hypergeometric parameter is reviewed. We consider the performance of exact confidence interval estimates of hypergeometric parameter in terms of actual coverage probability by small sample Monte Carlo simulation.

• Development and Reproduction
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• v.16 no.3
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• pp.205-217
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• 2012

The ovarian cycle, the biological minimum size, and artificial spawning frequency by artificial spawning induction of the female hard clam, Meretrix petechialis, were investigated by histological observations and morphometric data. The ovarian cycle of this species can be classified into five successive stages: early active stage, late active stage, ripe stage, partially spawned stage, and spent/inactive stage. The spawning period was from June to September, and the main spawning occurred between July and August when the seawater temperature exceeds over $20^{\circ}C$. The biological minimum size (shell length at 50% of first sexual maturity) in females were 40.39 mm in shell length (considered to be two years of age), and all clams over 50.1 mm in shell length sexually matured. In this study, the mean number of the spawned eggs by spawning induction increased with the increase of size (shell length) classes. In case of artificial spawning induction for the clams > 40.39 mm, the number of spawned eggs from the clams of a sized class was gradually decreased with the increase of the number of the spawning frequencies (the first, second, and third spawning). In the experiments of artificial spawning induction during the spawning season, the interval of each spawning of this species was estimated to be 15-18 days (approximately 17 days).

• Journal of the Korean Society of Clothing and Textiles
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• v.31 no.5 s.164
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• pp.742-752
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• 2007

The purpose of this study is the image of clothing according to the change of the dots' size was analyzed and its influence on the formation of the image of polka dots clothing was investigated. White waterdrop patterns were designed on the 12 kinds of black texture using Photoshop and CAD program in regular arrangement of diamond figure, composed of white waterdrop(0.5cm, 1.0cm, 1.5cm and 2cm in diameter) and interval(diameter : interval-1 : 1, 1 : 2, 1 : 4). Applying above specification, the photograph stimulus of 12 kinds of X-line one-piece dress with wide square neckline and without sleeve or detailed ornament was presented on a screen in the same size as when putting it on. The image of polka dots clothes was investigated by questionnaire survey. The object of the study was 320 females aged between 16 and 29. Factor analysis, one-way ANOVA, $Scheff\acute{e}$ verification and two-way ANOVA using SPSS 10.0 were carried out for data analysis. Followings are the results: 1) The image of polka dots clothing consists of 4 factors as aesthetics, brevity, dynamism and lightweight. 2) The size of the dot has a great influence on the formation of the image of polka dots clothing. 3) The evaluations of the image of polka dots clothing were different depending on the age and physical image, the personal characteristics of the object of investigation.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.1D
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• pp.43-50
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• 2011

The monitoring system for link travel speed using taxi probe is one of key sub-systems of ITS. Link travel speed collected by taxi probe has been widely employed for both monitoring the traffic states of urban road network and providing real-time travel time information. When sample size of taxi probe is small and link travel time is longer than a length of time interval to collect travel speed data, and in turn the missing state is inevitable. Under this missing state, link travel speed data is real-timely not collected. This missing state changes from single to multiple time intervals. Existing single interval prediction techniques can not generate multiple future states. For this reason, it is necessary to replace multiple missing states with the estimations generated by multi-interval prediction method. In this study, a multi-interval prediction method to generate the speed estimations of single and multiple future time step is introduced overcoming the shortcomings of short-term techniques. The model is developed based on Non-Parametric Regression (NPR), and outperformed single-interval prediction methods in terms of prediction accuracy in spite of multi-interval prediction scheme.

• The Mathematical Education
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• v.55 no.3
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• pp.317-334
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• 2016

Knowledge and data interpretation on statistical estimation was important to have statistical literacy that current curriculum was said not to satisfy. The author investigated mathematics teachers' MKT on statistical estimation concerning interpretation of confidence interval by using questionnaire and interview. SMK of teachers' confidence was limited to the area of textbooks to be difficult to interpret data of real life context. Most of teachers wrongly understood SMK of interpretation of confidence interval to have influence upon PCK making correction of students' wrong concept. SMK of samples and sampling distribution that were basic concept of reliability and confidence interval cognized representation of samples rather exactly not to understand importance and value of not only variability but also size of the sample exactly, and not to cognize appropriateness and needs of each stage from sampling to confidence interval estimation to have great difficulty at proper teaching of statistical estimation. PCK that had teaching method had problem of a lot of misconception. MKT of sample and sampling distribution that interpreted confidence interval had almost no relation with teachers' experience to require opportunity for development of teacher professionalism. Therefore, teachers were asked to estimate statistic and to get confidence interval and to understand concept of the sample and think much of not only relationship of each concept but also validity of estimated values, and to have knowledge enough to interpret data of real life contexts, and to think and discuss students' concepts. So, textbooks should introduce actual concepts at real life context to make use of exact orthography and to let teachers be reeducated for development of professionalism.

• Fashion & Textile Research Journal
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• v.9 no.3
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• pp.278-285
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• 2007

The purpose of this study is the image of clothing according to the change of the dots' interval was analyzed and its influence on the formation of the image of polka dots clothing was investigated. White waterdrop patterns were designed on the 12 kinds of black texture using Photoshop and CAD program in regular arrangement of diamond figure, composed of white waterdrop(0.5 cm, 1.0 cm, 1.5 cm and 2 cm in diameter) and interval(diameter : interval - 1 : 1, 1 : 2, 1 : 4). Applying above specification, the photograph stimulus of 12 kinds of X-line one-piece dress with wide square neckline and without sleeve or detailed ornament was presented on a screen in the same size as when putting it on. The image of polka dots clothes was investigated by questionnaire survey. The object of the study was 320 females aged between 16 and 29. Factor analysis, one-way ANOVA, Scheff$\acute{e}$ verication and two-way ANOVA using SPSS 10.0 were carried out for data analysis. The research finding are as follows. First, the image of polka dots clothing consists of 4 factors as aesthetics, brevity, dynamism and lightweight. Secondly, the interval of the dot has a great influence on the formation of the image of polka dots clothing. Lastly, the evaluations of the image of polka dots clothing were different depending on the age and physical image, the personal characteristics of the object of investigation.

• Journal of Korean Society for Quality Management
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• v.18 no.1
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• pp.77-83
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• 1990

A model for the economic design of an pn control charts with an assignale cause is presented and the loss-cost function for control schemes using these charts is derived. By minimizing this function with respect to the three control variables, namely, the sample size, the sampling interval and acceptance number, the economically optimal control plan can be optained. The article shows what influence increasing or decreasing condition, according to changeability of the size of these factors, of expected cost can have on the economy when an attribute control chart is used.

• Journal of the Korean Society of Clothing and Textiles
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• v.26 no.6
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• pp.923-934
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• 2002

The aim of this study is to suggest a Sizing System which has following points:- 1. In order to satisfy children of diverse figure shapes, we developed sizing system for three different figure type. Figure types are categorized into slim, normal, fat type based on the Rohrer Index. 2. For each figure types, we developed size chart using height bust circumference and hip circumference as basic measurements. The size codes are presented as the height-bust circumference or height-hip circumference. The size interval of height is 5cm for all figure types, such as 120,125,130 ‥‥ we developed a size allocation program, which is helpful when a customer doesn't know exact measurement of some body dimension. If a customer input measurements as much as he/she hows, the program allocates the nearest. At the end of the study, the sizing interaction sites were developed to present the results of the study clear.