• Journal of environmental and Sanitary engineering
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• v.7 no.2
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• pp.37-52
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• 1992

Since the first sewage treatment plant was constructed in 1976, the sewerage systems of Korea have been rapidly expanded. As of the end of 1991, 22 sewage treatment plants with total capacity of 5.4 million tons/day are in operation which is equivalent of 3395 total daily sewage generation. Total extension of sewer 39.534 km in 1990 which is 55% of the target extension for the year 2001. However, the most sewage treatment plants employ activated sludge process which may not be suitable for medium and/or small scale plants. The poor existing sewer systems do not effectively collect and transport sewage to adversely affect the function of sewage treatment plant. To select the appropriate treatment system, the cities are classified into 3 categories such as large and medium size inland cities, small size cities and coastal cities. Considering the criteria suggested during this study, appropriate treatment processes were selected for each category. Conventional activated sludge process and step aeration process were found to be the most appropriate for big inland cities while biological nutrient removal processes should be considered for the cities discharge the effluent to lakes or reservoirs. RBC or Oxidation Ditch process might be appropriate for the medium size cities while several processes which do not require skilled operation and maintenance were suggested for the small cities. Ocean discharge after primary treatment can be considered for some east coast cities, Appropriate methodology to rehabilitate the existing sewers and strategy to convert combined sewer system to separate sewer system were proposed. This paper also include the appropriate management system for industrial wastewater, sludge and nightsoil.

• The Journal of Sustainable Design and Educational Environment Research
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• v.15 no.1
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• pp.40-48
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• 2016

School appropriate scale refers to the size of the school to minimize students' educational deficits and ensure an appropriate level of students, the number of classes, class size, etc., and maximize educational effects. Difficult set of absolute standards appropriate scale school, contemporary social situations and educational effects, and seek a comprehensive and reasonable direction, considering this is required. School appropriate scale it is preferable to consider the effect of conditions in areas such as education, curriculum, but it is common to set the range in terms of school operational effectiveness, and efficiency of education funding, school environment. So the concept of the appropriate scale including the school's status changes associated with school size, is seeking a new direction is needed so that the school environment, etc. are considered.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.46 no.4
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• pp.272-280
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• 2023

For the past 70 years, an intense rivalry has persisted on the Korean Peninsula, and North Korea's nuclear and missile threats are becoming increasingly imminent. Facing a shortage of military resources, South Korea has pursued a national defense reform, significantly reducing the number of units and troops while focusing on ground forces. However, North Korea's strategic objective of unifying South Korea through surprise attacks, prompt responses, and combined nuclear and missile assaults remains unchanged. The central issue in this context revolves around determining the appropriate size of the Korean military's standing forces. This study employs the concept of net assessment as a novel method to ascertain the optimal size of the Korean military. Threats, strategic objectives, doctrine, and unit rotations are simultaneously considered from the enemy's perspective. In anticipation of security risks on the Korean Peninsula, an acceptable troop size will be proposed using the net assessment approach to calculate the appropriate standing force size.

• Communications for Statistical Applications and Methods
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• v.16 no.4
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• pp.669-673
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• 2009

When a social scientist prepares to conduct a survey, he/she faces the problem of deciding an appropriate sample size. Sample size is closely connected with cost, time, and the precision of the sample estimate. It is thus important to choose a size appropriate for the survey, but this may be difficult for survey researchers not skilled in a sampling theory. In this study we propose a method to determine a sample size under certain assumptions when the quantity of interest is measured by a Likert scale.

• Journal of the Korean Society of Clothing and Textiles
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• v.33 no.11
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• pp.1768-1773
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• 2009

This study determines the body size of preteen children and conducts questionnaire investigations into the awareness of real purchasers or parents of and satisfaction with children's clothes and fit, in order to provide the basic data for planning and setting up the size range for the preteens market in which the sales of children clothes are gradually increasing. The findings of this study are as follow: Analyzing the obesity of the children against the Rohrer index showed that almost 30% of the subjects were obese children and that it is necessary to research the sizes of the clothes for obese children. It was also found that older children selected a more appropriate clothe size. Investigations into the awareness of children on their body image found that there was a significant difference in the perception of body shape, body weight, shoulder breath, arm thickness, chest girt, waist girth, hip girth, and thigh thickness. Slim or standard type children had the greatest consideration for the length of clothes to purchase while obese children had the greatest consideration for bosom size and waist girth. However, in terms of the association between fitness and size selection, obese children did not select a bigger size but an appropriate one for their body. The findings show that it is imperative to develop appropriate size clothes for obese children.

• Journal of the Korean housing association
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• v.19 no.5
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• pp.111-120
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• 2008

The aim of this study is to present the design methods about manifold location being installed and size and to draw out the proper piping size as comparing the fluctuation of discharge with manifold size and residence size through the piping network analysis, when using the same faucet in accordance. The findings are summarized as follows, 1) an appropriate header main body pipe diameter was deemed to be $32{\sim}50\;mm$. 2) the research presented design measures for the application of appropriate water supply inlet pipe diameters according to residential buildings with various sizes. 3) the header direct branch piping method is ideal for small and medium-sized residential complexes, and the header branching and semi header methods are deemed to be more favorable for large residential complexes. 4) this study offered design measures for appropriate header system main body pipe diameters, water supply inlet pipe diameters, header system piping methods, application methods for functional auxiliary equipment units, and header system installation spaces and location.

• Journal of the Korean Society of Clothing and Textiles
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• v.24 no.3
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• pp.289-300
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• 2000

Stretchable textile materials are getting more widely used in clothing industry. Among others are two obvious reasons which make it so desirable to young female customers, i.e., better confort with motion and more closely fitted silhouette. But these two points cannot get along well always. If a manufacturer try hard to make his products too closely fit, then the products are even less comfortable than made of non-stretchable material. On the other hand, if a stretchable garment are developed to be too comfortable with plenty of size tolerance. it cannot attract customers who are looking for something closely fit. So the study was aimed to investigate appropriate size tolerances.

• Nuclear Engineering and Technology
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• v.51 no.4
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• pp.954-962
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• 2019

It is well known that the variance of tally is biased in a Monte Carlo calculation based on the power iteration method. Several studies have been conducted to estimate the real variance. Among them, the batch method, which was proposed by Gelbard and Prael, has been utilized actively in many Monte Carlo codes because the method is straightforward, and it is easy to implement the method in the codes. However, there is a problem when utilizing the batch method because the estimated variance varies depending on batch size. Often, the appropriate batch size is not realized before the completion of several Monte Carlo calculations. This study recognizes this shortcoming and addresses it by permitting selection of an appropriate batch size.

• Korean Journal of Agricultural Science
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• v.29 no.2
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• pp.135-148
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• 2002

In recent years, domestic market environment of rice production is confronted with the problems of excessive production and decrease in per capita consumption, resulting in steady decline of domestic rice price. Moreover, as new trade negotiations of WTO or FTA are being forwarded, cheap price of imported rice will also make the rice production environment being worse off. One of the possible production strategies to relieve this situation could be expanding farm size, which increases market competitiveness in terms of cost-saving. Since 1990's, one of the main agricultural policies for rice production in Korea has been expanding farm size. This study aims at 1)exploring brief history of Korean government's agricultural policy for expanding farm size, 2)examining economic effect of farming size expansion, and 3)discussing major role of government to promote appropriate programs for rice-farming and producers. Main conclusion suggests that appropriate farming size should be expanded upto at least five hectares per farm, with producers' effort to reduce farming costs and continuous investments on agricultural infrastructures including irrigation systems, etc. Continuous government's investment on operation and maintenance on water facility is also one of the important factors in expanding farm size.

• The Journal of the Korean dental association
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• v.54 no.8
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• pp.630-638
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• 2016

The appropriate sample size calculation in dental research is important to achieve the study purpose at the first step in study design. However, it cannot be easy to calculate sample size using standard formulas, because the several factors must be considered for calculation. This study introduced the graphic method for sample size calculation, which is called nomogram. The purpose of this study is to show the effectiveness of the nomogram using examples, expecting the researchers can easily use nomogram for sample size determination.