• KIPS Transactions on Computer and Communication Systems
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• v.3 no.8
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• pp.261-270
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• 2014

As Internet traffic increases recently, much effort has been put on improving the performance of a web server. In addition to hardware side solutions such as replacement by high-end hardware or expansion of the number of servers, there are software side solutions to improve performance. Recent studies on these software side solutions have been actively performed. In this paper, we identify performance degradation problems occurring in a conventional TCP networking reception process and propose a way to solve them. We improve performance by combining three kinds of existing methods for Linux Networking Performance Improvement and two kinds of newly proposed methods in this paper. The three existing methods include 1) an allocation method of a packet flow to a core in a multi-core environment, 2) ITR(Interrupt Throttle Rate) method to control excessive interrupt requests, and 3) sk_buff data structure recycling. The two newly proposed methods are fd data structure recycling and epoll_event data structure recycling. Through experiments in a web server environment, we verify the effect of our two proposed methods and its combination with the three existing methods for performance improvement, respectively. We use three kinds of web servers: a simple web server, Lighttpd generally used in Linux, and Apache. In a simple web server environment, fd data structure recycling and epoll_event data structure recycling bring out performance improvement by about 7 % and 6%, respectively. If they are combined with the three existing methods, performance is improved by up to 40% in total. In a Lighttpd and an Apache web server environment, the combination of five methods brings out performance improvement by up to 36% and 20% in total, respectively.

• Journal of Power System Engineering
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• v.21 no.5
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• pp.79-85
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• 2017

Vickers hardness is an important material in the design and reliability is required. Therefore, these values are very important as the basic data for design, manufacture and development, and the identification of quantitative probability distribution characteristics such as mean and dispersion is a very important parameter in design. In this study, Vickers hardness was measured after artificially heat-treated in the temperature range 753K, where chrome depletion near the grain boundary occurred for three kinds of stainless steels, and the Vickers hardness were evaluated. From the results, Vickers hardness increased with increasing heat treatment temperature. In Weibull distribution for Vickers hardness, the dispersion of STS310S at 813K and 873K was small, and the dispersion of STS316L at 753K, 933K and 993K was small. Also, STS347H exhibited the lowest dispersion at 753K in three kinds of stainless steels. The scale parameter increased with increasing heat treatment temperature in three kinds of stainless steels.

• Proceedings of the Korea Concrete Institute Conference
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• 1998.10b
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• pp.637-642
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• 1998

This study was performed to develop effective management system of concrete structures in Nuclear Power Plants. This D/B system includes three kinds of data : 1)visual inspection data(cracking, spalling, etc.) 2) durability data carbonation, chloride attack, etc. 3) in-service inspection data(prestressing force. material properties, etc. ) By using the life management D/B System, the field engineers can easily acquire the information about the various inspection data. repair and accidental histories of structures. This system, will contribute to the efficient life management of concrete structures.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.32 no.3
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• pp.32-38
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• 2000

This study was carried out to determine the effect of the type of plastic pigment on the coat-ing structure and printability of coated paper. Three kinds of plastic pigments(solid-bead type binder type and hollow type) were used for hti purpose. IN this research it was observed that particle shape and structure of plastic pigment had influenced the rheology of coating color the state of packing and the properties of coated paper. Inorganic pigments used in this research were platelike kaolin clay and rhombic calcium carbonate. Three kinds of plastic pigments were blended with two inorganic pigments respec-tively. The combination of pigments were carried out(1) to determined the effect of particle structure of plastic pigment on the state of dispersion of coating color(2) to observe the effect of calendering temperature on the property of coated paper prepared with different plastic pigments. The data indicated that binder and hollow type plastic pigment gave the best results in improving the properties of coated paper such as paper gloss opacity and air pet-meability.

• Journal of Biosystems Engineering
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• v.11 no.1
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• pp.64-75
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• 1986

The objective of this study was to develop a mathematical model for optimum design of diversified farming systems which have the regional characteristics. For this purpose, the farming surveys were conducted for mainly 1984 agriculture. They were carried out on January and July 1985 for three villages of central region of Korea. The surveyed data were analyzed by systems analysis and the diversified farming systems were modeled. They consist of four and six croping patterns for paddy and upland, two and three kinds of fruit crop and livestock, and seven kinds of farm machinery for each work system. Then a mathematical model was developed by the multiple objective decision making (MODM) method in order to design optimum systems of diversified farming. It consists of 23 decision variables, two objective functions and nine constraint functions. The goals of objective function are maximization of agricultural incomes and power inputs of farm machinery, and the modeled factors for constraint function are arable land, available capital, labor, and land utilization.

• Journal of Plant Biology
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• v.25 no.2
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• pp.83-99
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• 1982

In this study, thirty-two stands in Kwangnung forest located in the central part of Korea were preferentially selected. In each stand, all stems for trees and shrubs were recorded by species and their girths were measured down to 5cm. In addition, several enviromental factors such as field soil pH, field soil moisture, soil compressibility, depth of soil, thickness of litter layer, elevation and basal area were measured. Three soil cores were sampled and various physical and chemcial properties was determined. The vegetational data were subjected to three kinds of multivariate ordination(PO, PCA, RA). The results suggested that Kwangnung forest was consisted of three forest types: coniferous, mixed and broad leaved forest communities. The relation between the stand scores of ordination and several environmental factors were investigated in terms of correlation analysis in order to examine the relationships between the vegetation and certain environmental factors. As a result of this analysis, the amount of sand content in A1 horizon decreased frm the coniferous to broad leaved forest, while maximum field capacity, pore space, exchangeable cations, loss on ignition, soil pH nad the amount of total nitrogen had a tendancy to increase significantly. However, easily soluble phosphorus appeared to have little to do with the forest types. The result of species ordination of centered-standardized PCA suggested that the major successional pathway in Kwangnung forest was; Pinus densifloralongrightarrowQuercus mongolica, Q. serrata, Q. alienalongrightarrowCarpinus laxifloralongrightarrowC. erosa in sequence. This trend is in good agreement with the past studies. In three kinds of ordination (centered PCA, centered-standardized PCA and RA) based on nineteen species and twenty-five stands, the total variances accounted for the first three axes were 77%, 46% and 63% respectively. The estimated beta diversity in Kwangnung forest assumed as a coenocline, was 1.5~1.8 HC. Increasing the effect of the sampling errors on ordination perfermance, this low heterogeneity seems to cause the poor concentration of the total variance. The results from the four kinds of ordination were in good agreement with each other, especially between PO, centered-standardized PCA and RA appeared robust. It seems to be worthy of applying multivariate method for analyzing other forest communities in Korea.

• Journal of the Korean Society of Costume
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• v.46
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• pp.159-170
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• 1999

This study was for reasonable gathering by a fabric and a skirt length. So the purpose of this study was to show the basic data to forecast the gathering effect of gathered skirt which was more aesthetical and suitable for a use in time of making pattern. To find the reasonable gathering amount by a length of gathered skirt and a fabric the methods of this study were divided on three types-five kinds of the gathering amounts three kinds of fabrics and three kinds of skirt ength-so forty five kinds of the samples were made. As the visual evaluation of the gathered skirt were practiced bgy these factors. The following are the results of this research. 1. For this research of fabrics the gathering amounts which were shown visually the most aesthetical silhouette in the same material and skirt length were decided on 1.5 times or 2.0 times. On the other side 0.5 times and 2.5 times of gathering amount were got a low estimation visually 2. Except in case the skirt length was 40cm and gathering amount were 1.0 times and 1.5 times in the same gathering amount and length of skirt it was estimated that wool fabric was most aesthetical silhouette fabric. On the other hand it was got low estimation which the cotton was not good for draping effect because it was got the lowest estimation level in all cases. 3. Considered as a whole in the same gathering amount and fabric the fabric widths for gathering which were shown the most aesthetical silhouette were estimated the length of 60cm in cotton fabric 80cm in polyester fabric and 40cm in wool fabric. Therefore as a fabric was weighty a length of a skirt was shorten so, it was estimated visually more beautiful.

• Journal of Korean Library and Information Science Society
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• v.16
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• pp.33-67
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• 1989

The purpose of this study is to analyze the three kinds of recarved books that were Wongak-Techam-Ryakbon, Kumkang-Banyakyung-Uiki, Sung-Yusikron-Sulki. the original edition of these recarved books were published by UiChon in Heungwang Temple with the Continued Edition of Tripitaka in the King Sukjong of the Koryo Dynasty. The continued edition was the collections of various and interpretations of Tripitaka, gathered from Song, Japan and Liao. This continued edition is not a imitation of any others but it is the original product of Koryo. The blocks were carved from the carefully proofread script of Koryo's best calligrapher. The results of this study can be summarized as follows: 1. The original edition of the Wongak-Yecham-Ryakbon was published at the third year of Suchang in Heungwang Temple. The names of two calligraphers and three proofreaders are recorded in the last part of the book. 2. The original edition of the Kumkang-Banyakyung-Uiki was also published at the fourth year of Suchang in Heungwang Temple. The publication data are recorded in the last part of the book that the calligrapher was ODaegong and the three proofreaders were Gakji, Jahyun and Dukyeon. 3. The Sung-Yusikron-Sulki is different from other recarved editions in physical format such as number of lines and letters in one printing page. The original edition of this book was published at Kwangkyowon in Kumsan Temple by Hyaedukwangsa. 4. The contents of these recarved editions are recently discovered.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1997.10a
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• pp.311-314
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• 1997

This paper presents recognition of high impedance fault patterns based of chaotic features using the Radial Basis Function Network(RBFN). The chaos attractor is reconstructed from the fault current data for pattern recognition. The RBFN successfully classifies the three kinds of fault pattems and one normal pattem.

• Korean Journal of Community Nutrition
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• v.16 no.2
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• pp.253-264
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• 2011

The objectives of this study were to investigate the current status of the Korean government-funded meal support program for low-income children through convenience stores and to evaluate the nutritional quality of the meal items available under the program. The POS data of three convenient stores where children had used their electronic meal cards most often in Seoul during January 2010 and the kinds and amounts of ingredients of the meal items available to the children were obtained from the headquarter of the convenient stores. A total of 5,081 transactions by 693 children included in the POS data was analyzed. In addition, nutritional contents of meal items, which were meal boxes (11 kinds), kimbab (13 kinds), rice balls (27 kinds), inari sushi (1 kind), and sandwiches (26 kinds), were analyzed with Can Pro 3.0. The results showed that children had purchased flavored-milk products most often. Children tended to purchase meal items together with drinks (60.9% of transactions), but some purchased drinks (27.6%) or meal items only (11.5%). Except for meal boxes, none of the meal items satisfied 1/3 of Estimated Energy Requirements of the 9-11 year-old boys per day. The average energy contents of different kinds of meal boxes, kimbabs, rice balls, and sandwiches were 619, 357, 200, and 380 kcal, respectively, and the energy content of a package of Inari sushi was 457 kcal. Vitamin C amount was found to be deficient in all the meal items, compared to 1/3 of Recommended Intake of the 9-11 year-old boys per day. The results of this study could be useful to develop nutritionally appropriate meal items for the convenient stores participating in the government-funded meal support program for children from lowincome families.