• Proceedings of the Korea Information Processing Society Conference
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• 2010.04a
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• pp.119-122
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• 2010

본 논문에서는 Xen 가상 머신에 연성 실시간 기능을 제공하기 위한 방안을 제시한다. 현재 실시간 하이퍼바이저(hypervisor)는 대부분 경성 실시간(hard real-time) 보장을 위하여 자원을 파티션(partition)하고 고정된 태스크에 대한 수행을 지원한다. 본 연구에서는 오픈 환경을 위한 조합적 실시간 프레임워크에 기반한 계층형 실시간 스케줄링 시스템을 제안하고 있다. 제안하는 시스템은 오픈 환경에서 동적으로 태스크 및 컴포넌트의 유입이 가능하게 설계되었다. 제안하는 시스템에 대한 사전 연구 결과로써 Xen 플랫폼의 오버헤드 분석 결과를 제시하고 있다.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.19 no.1
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• pp.253-259
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• 2019

The wedding seating problem(WSP) is to finding a minimum loss of guest relations(sit together preference) with restricted seats of a table for complex guest relation network. The WSP is NP-hard because of the algorithm that can be find the optimal solution within polynomial-time is unknown yet. Therefore we can't solve the WSP not computer-assisted programming but by hand. This paper suggests min-cut rule theory that the two guests with maximum preference can't separate in other two tables because this is not obtains minimum loss of preference. As a result of various experimental, this algorithm obtains proper seating chart meet to the seats of a table constraints.

• Journal of the Korean Geotechnical Society
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• v.15 no.5
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• pp.241-257
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• 1999

Subsurface contamination of industrial hazardous organic substances is a serious social issue. Decomposing the hydrophobic organic compounds in the subsurface is technically difficult and the compounds can last as long-term contaminant sources of groundwater once they are sorbed on the soil. Although the danger of contaminated subsurface has long been recognized little was known about the effective remediation technique. Focusing on the remediation of the p-Cresol and 3, 5-Dichlorobiphenyl among subsurface contaminants, this paper studies the surfactant-enhanced desorption technique. Nonionic surfactant(Triton X-100) and anionic surfactant(SDS ) were used as desorbing solvents for extracting organic compound sorbed on soil particles. Sorption characteristics of soils and organic compounds were analyzed and the applications of surfactant solution were studied through batch tests and the flexible-wall permeameter tests. As a result of the sorption isotherm tests, a log-log linear relation was obtained between the linear-partition coefficient, $K_p$ and the octanol-water partition coefficient, $K_{ow}$ of each organic compound. The result of the batch test also showed that Triton X-100 at 0.5% of solution desorbs the 3, 5-Dichlorobiphenyl 28 times more than the water in the batch tests. The surfactant-enhanced subsurface remediation technique becomes more effective when the contaminants are hydrophobic and hard to be decomposed.

• Journal of Educational Research in Mathematics
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• v.8 no.2
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• pp.565-586
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• 1998

Like many other school subjects, terminology is a starting point of mathematical thinking, and plays a key role in mathematics learning. Among several areas in mathematics, geometry is the area in which students usually have the difficulty of learning, and the new terms are frequently appeared. This is why we started to investigate geometric terms first. The purpose of this study is to investigate geometric terminology in school mathematics. To do this, we traced the historical transition of geometric terminology from the first revised mathematics curriculum to the 7th revised one, and compared the geometric terminology of korean, english, Japanese, and North Korean. Based on this investigation, we could find and structuralize the following four issues. The first issue is that there are two different perspectives regarding the definitions of geometric terminology: inclusion perspective and partition perspective. For example, a trapezoid is usually defined in terms of inclusion perspective in asian countries while the definition of trapezoid in western countries are mostly based on partition perspective. This is also the case of the relation of congruent figures and similar figures. The second issue is that sometimes there are discrepancies between the definitions of geometric figures and what the name of geometric figures itself implies. For instance, a isosceles trapezoid itself means the trapezoid with congruent legs, however the definition of isosceles trapezoid is the trapezoid with two congruent angles. Thus the definition of the geometric figure and what the term of the geometric figure itself implies are not consistent. We also found this kind of discrepancy in triangle. The third issue is that geometric terms which borrow the name of things are not desirable. For example, Ma-Rum-Mo(rhombus) in Korean borrows the name from plants, and Sa-Da-Ri-Gol(trapezoid) in Korean implies the figure which resembles ladder. These terms have the chance of causing students' misconception. The fourth issue is that whether we should Koreanize geometric terminology or use Chinese expression. In fact, many geometric terms are made of Chinese characters. It's very hard for students to perceive the ideas existing in terms which are made of chines characters. In this sense, it is necessary to Koreanize geometric terms. However, Koreanized terms always work. Therefore, we should find the optimal point between Chines expression and Korean expression. In conclusion, when we name geometric figures, we should consider the ideas behind geometric figures. The names of geometric figures which can reveal the key ideas related to those geometric figures are the most desirable terms.

• Journal of the Korean Institute of Intelligent Systems
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• v.20 no.2
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• pp.165-172
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• 2010

In clinical data minig, choosing the optimal subset of features is such important, not only to reduce the computational complexity but also to improve the usefulness of the model constructed from the given data. Moreover the threshold values (i.e., cut-off points) of selected features are used in a clinical decision criteria of experts for differential diagnosis of diseases. In this paper, we propose a fuzzy discretization approach, which is evaluated by measuring the degree of separation of redundant attribute values in overlapping region, based on spatial distribution of data with continuous attributes. The weighted average of the redundant attribute values is then used to determine the threshold value for each feature and rough set theory is utilized to select a subset of relevant features from the overall features. To verify the validity of the proposed method, we compared experimental results, which applied to classification problem using 668 patients with a chief complaint of dyspnea, based on three discretization methods (i.e., equal-width, equal-frequency, and entropy-based) and proposed discretization method. From the experimental results, we confirm that the discretization methods with fuzzy partition give better results in two evaluation measures, average classification accuracy and G-mean, than those with hard partition.

• The Korean Journal of Quaternary Research
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• v.22 no.1
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• pp.1-12
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• 2008

We investigated metal concentrations and oceanic environment changes that have occurred over the past several years by studying the hard coral Porites lutea, which inhabits tropical and subtropical areas. Soft X-radiographs clearly showed distinctive annual bands within 71 mm coral sample, which reflect changes in the oceanic environment over this period. There were large fluctuations in the major and minor element concentrations. Considering the physicochemical partition coefficient, some elements accumulated in the aragonite matrix in a mechanical manner, while others were affected by environmental factors. The concentrations of some heavy metals varied over a wide range, implying local environmental effects. The variation of Sr/Ca and Mg/Ca in coral skeleton clearly showed large-scale fluctuation over the specific intervals, implying environmental changes during this period. The concentrations of heavy metals also show high fluctuations, and roughly accord with Mg/Ca variation. In addition, Cu and Zn seem to show cyclicity-like peaks, coincide with Mg/Ca variation over the specific intervals. Such variation might be related to local pollution and oceanographic changes. More detailed investigation is necessary, including the pretreatment of coral skeleton sediment.

• Journal of Digital Convergence
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• v.12 no.4
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• pp.277-283
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• 2014

Fuzzy modeling is generally using the given data and the fuzzy rules are established by the input variables and the space division by selecting the input variable and dividing the input space for each input variables. The premise part of the fuzzy rule is presented by selection of the input variables, the number of space division and membership functions and in this paper the consequent part of the fuzzy rule is identified by polynomial functions in the form of linear inference and modified quadratic. Parameter identification in the premise part devides input space Min-Max method using the minimum and maximum values of input data set and C-Means clustering algorithm forming input data into the hard clusters. The identification of the consequence parameters, namely polynomial coefficients, of each rule are carried out by the standard least square method. In this paper, membership function of the premise part is dividing input space by using trapezoid-type membership function and by using gas furnace process which is widely used in nonlinear process we evaluate the performance.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.11
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• pp.5379-5388
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• 2012

In fuzzy modeling for nonlinear process, the fuzzy rules are typically formed by selection of the input variables, the number of space division and membership functions. The Generation of fuzzy rules for nonlinear processes have the problem that the number of fuzzy rules exponentially increases. To solve this problem, complex nonlinear process can be modeled by generating the fuzzy rules by means of fuzzy division of input space. Therefore, in this paper, rules of non-fuzzy inference systems are generated by partitioning the input space in the scatter form using HCM clustering algorithm. The premise parameters of the rules are determined by membership matrix by means of HCM clustering algorithm. The consequence part of the rules is represented in the form of polynomial functions and the consequence parameters of each rule are identified by the standard least-squares method. And lastly, we evaluate the performance and the nonlinear characteristics using the data widely used in nonlinear process. Through this experiment, we showed that high-dimensional nonlinear systems can be modeled by a very small number of rules.

• Journal of the Korean Operations Research and Management Science Society
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• v.30 no.3
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• pp.119-135
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• 2005

Design of location erea(LA) in a cellular network is to partition the network into clusters of cells so as to minimize the cost of location updating and paging. Most research works dealing with the LA design problem assume that the call. arrival rate and mobile flow rate are fixed parameters which can be estimated independently. In this aspect, most Problems addressed so far are deterministic LA design problems(DLADP), known to be NP hard. The mobile flow and call arrival rate are, however, varying with time and should be treated simultaneously because the call arrival rate in a cell during a day is influenced by the change of a population size of the cell. This Paper Presents a new model on IA design problems considering the time-dependent call arrival and mobile flow rate. The new model becomes a stochastic LA design problem(SLADP) because It takes into account the possibility of paging waiting and blocking caused by the changing call arrival rate and finite paging capacity. Un order to obtain the optimal solution of the LA design problem, the SIADP is transformed Into the DLADP by introducing the utilization factor of paging channels and the problem is solved iteratively until the required paging quality is satisfied. Finally, an illustrative example reflecting the metropolitan area, Seoul, is provided and the optimal partitions of a cell structure are presented.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.20 no.2
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• pp.209-214
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• 2020

The equitable partitioning problem(EPP) is classified as [0/1] binary skill existence or nonexistence and integer skill levels such as [1,2,3,4,5]. There is well-known a polynomial-time optimal solution finding algorithm for binary skill EPP. On the other hand, tabu search a kind of metaheuristic has apply to integer skill level EPP is due to unknown polynomial-time algorithm for it and this problem is NP-hard. This paper suggests heuristic greedy algorithm with polynomial-time to find the optimal solution for integer skill level EPP. This algorithm descending sorts of skill level frequency for each field and decides the lower bound(LB) that more than the number of group, packing for each group bins first, than the students with less than LB allocates to each bin additionally. As a result of experimental data, this algorithm shows performance improvement than the result of tabu search.