• The KIPS Transactions:PartD
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• v.17D no.2
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• pp.147-156
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• 2010

Conformance testing for embedded software is to check whether software was correctly implemented according to software specification or not. In conformance testing, test scenarios must be extracted to cover every test cases of software. In a general way, test scenarios simply focus on testing all functions at least one time. But, test scenarios are necessary to consider efficiency of test execution. In this paper, we propose a test scenario extraction method by considering function's execution time and waiting time for user interaction. A test model is a graph model which is generated from state machine diagram and test cases in software specification. The test model is augmented by describing test execution time and user interaction information. Based on the test model, test scenarios are extracted by a modified Dijkstra's algorithm. Our test scenario approach can reduce testing time and improve test automation.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.5A
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• pp.325-338
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• 2012

In this paper, a radio resource allocation scheme for a multi-hop relay transmission in cognitive radio (CR) system is proposed to support the employment of relay nodes in IEEE 802.22 standard for wireless regional area network (WRAN). An optimization problem is formulated to maximize the number of serving secondary users (SUs) under system constraints such as time-divided frame structure for multiplexing and a single resource-unit to every relay-hop. However, due to mathematical complexity, the optimization problem is solved with a sub-optimal manner instead, which takes three steps in the order of user selection, relay/path selection, and frequency selection. In the numerical analysis, this proposed solution is evaluated in terms of service rate denoting as the ratio of the number of serving SUs to the number of service-requesting SUs. Simulation results show the condition of adopting multi-hop relay and the optimum number of relaying hops by comparing with the performance of 1-hop system.

• KIPS Transactions on Software and Data Engineering
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• v.5 no.10
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• pp.477-482
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• 2016

As being the advanced analytics indispensable on big data for agile decision-making and tactical planning in enterprises, distributed processing platforms, such as Hadoop and Spark which distribute and handle the large volume of data on multiple nodes, receive great attention in the field. In Spark platform stack, Spark SQL unveiled recently to make Spark able to support distributed processing framework based on SQL. However, Spark SQL cannot effectively handle advanced analytics that involves machine learning and graph processing in terms of iterative tasks and task allocations. Motivated by these issues, this paper proposes the design of SQL-based big data optimal processing engine and processing framework to support advanced analytics in Spark environments. Big data optimal processing engines copes with complex SQL queries that involves multiple parameters and join, aggregation and sorting operations in distributed/parallel manner and the proposing framework optimizes machine learning process in terms of relational operations.

• Journal of Navigation and Port Research
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• v.36 no.8
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• pp.637-641
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• 2012

In this paper, the method that reduce a computation time by optimizing computation process is proposed to realize low-power underwater acoustic communication system. At first, dependency of decision delay on tap length of linear equalizer was investigated. Variance is calculated based on this result, and the optimal decision delay bound is estimated. In addition to decide optimal tap length with decision delay, we extracted the MSE(Mean Square Error) graph. From the graph, we obtained variance value of the MSE-decision delay, and estimated the optimum decision delay range from the variance value. Also, using the extracted optimal parameters, we performed a simulation. According to the result, the simulation employing optimal tap length, which is only 40% of maximum tap length, showed a satisfactory performance comparable to simulation employing maximum tap length. We verified that the proposed method has 33% lower tap length than maximal tap length via sea trial.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.416-421
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• 2008

Recent high-speed trains around the world have achieved remarkable improvement in speed. In Korea, the new high-speed train with maximum speed of 400km/h has been developing through the 'Future High-Speed Rail System Project'. The improvement in train speed brings numerous aerodynamic problems such as strong aerodynamic resistance, noise, drastic pressure variation due to the crosswind or passing by, micro-pressure wave at tunnel exit, and so on. Especially, the nose shape of high-speed train is closely related to the most of the aerodynamic problems. Also the pantograph has to be considered for noise prevention and detachment problems. In this paper, the project, 'Research on the Aerodynamic Technology Advancement of the High-Speed EMU' is introduced briefly, which is one of the efforts for the speed improvement of the 'HEMU400x'. Finally, two main results of train nose and pantograph will be shown. First, the optimization of the cross-sectional area distribution of the high-speed train nose to reduce tunnel micro-pressure wave, and second, robust design optimization of the panhead shape of a pantograph.

• Journal of the Korea Society of Computer and Information
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• v.13 no.5
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• pp.27-35
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• 2008

The CTOC framework was implemented to efficiently perform analysis and optimization of the Java bytecode that is often being used lately. In order to analyze and optimize the bytecode from the CTOC, the eCFG was first generated. Due to the bytecode characteristics of difficult analysis, the existing bytecode was expanded to be suitable for control flow analysis. and the control flow graph was drawn. We called eCFG(extended Control Flow Graph). Furthermore, the eCFG was converted into the SSA Form for a static analysis. Many loops were found in the conversion program. The previous CTOC performed conversion directly into the SSA Form without processing the loops. However, processing the loops prior to the SSA Form conversion allows more efficient generation of the SSA Form. This paper examines the process of finding the loops prior to converting the eCFG into the SSA Form In order to efficiently process the loops, and exhibits the procedures for generating the loop tree.

• Culinary science and hospitality research
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• v.18 no.1
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• pp.15-26
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• 2012

The objective of this study is to optimize enzymatic hydrolysis of cooked krill by using Alcalase. To optimize krill hydrolysis on such dependent variables as TCA, DPPH-scavenging, and Fe-chelating activities by using Alcalase, independent variables of hydrolysis pH and temperature were investigated Their formulas and three dimensional graphs were obtained by using SAS and Maple softwares, respectively. For comparison of general composition of raw krill, its contents of moisture, crude protein, crude fat, and ash were 17.48%, 53.74%, 15.66%, and 10.21%, respectively, and for cooked krill, its contents were 4.80%, 71.84%, 5.26%, and 15.09%, respectively. The composition of fatty acids for cooked krill was similar to that of raw krill. The most abundant fatty acid was palmitic acid(16:0) and the following order was oleic acid(18:1), eicosapentaenoic acid (20:5), palmitoleic acid(16:1), and docosahexaenoic acid(22:6). For DH optimization of hydrolysates from cooked krill, its result was pH 8.5 and $66.6^{\circ}C$ hydrolysis temperature for the maximum DH of 29.4% For DPPH-antioxidative optimization of hydrolysates from raw krill, its maximum result of 27.1% was obtained in the hydrolysis condition of pH 7.4 and $67.5^{\circ}C$. For Fe-chelating optimization of hydrolysates from cooked krill, its maximum result of 24.9% was in the condition of pH 8.7 and $65.5^{\circ}C$. These results can be used for basic data for using krill products and other fish products as bioactive ingredients.

• Journal of KIISE:Computer Systems and Theory
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• v.34 no.5_6
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• pp.195-201
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• 2007

A minimum terminal path decomposition of a tree is defined as a partition of the tree into edge-disjoint terminal-to-terminal paths that minimizes the weight of the longest path. In this paper, we present an $O({\mid}V{\mid}^2$time algorithm to find a minimum terminal path decomposition of trees. The algorithm reduces the given optimization problem to the binary search using the corresponding decision problem, the problem to decide whether the cost of a minimum terminal path decomposition is at most l. This decision problem is solved by dynamic programing in a single traversal of the tree.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.8 s.179
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• pp.2131-2142
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• 2000

As recent production facilities are usually operated with unmanned material-handling system, the development of an efficient schedule with deadlock avoidance becomes a critical problem. Related researches on deadlock avoidance usually focus on real-time control of manufacturing system using deadlock avoidance policy. But little off-line optimization of deadlock-free schedule has been reported. This paper presents an optimization method for deadlock-free scheduling for Job-Shop system with no buffer. The deadlock-free schedule is acquired by the procedure that generates candidate lists of waiting operations, and applies a deadlock avoidance policy. To verify the proposed approach, simulation resultsare presented for minimizing makespan in three problem types. According to the simulation results the effect of each deadlock avoidance policy is dependent on the type of problem. When the proposed LOEM (Last Operation Exclusion Method) is employed, computing time for optimization as well as makespan is reduced.

• Proceedings of the Korea Information Processing Society Conference
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• 2003.11b
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• pp.713-716
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• 2003

현재 국내 LBS 가 중요한 서비스로 널리 확산되기 위해서는 서비스간의 상호운용성이 제공되어야 한다. 본 논문에서는 LBS 서비스간 상호운용성을 제공하는 개방형 LBS 를 위한 경로탐색 서비스에 대한 설계 및 구현기법을 제시한다. 최단경로문제(Shortest Path Problem)는 통신망 및 교통망의 분석, 생산라인의 품질 관리 등의 다양한 분야 등의 네트워크 흐름 최적화 문제 중에서 가장 많이 연구되고 있는 문제다. 도로 교통망에서는 교차로상에서의 회전 제약 문제 등의 제한조건이 존재한다. 본 논문에서 경로탐색은 듀얼 그래프(dual graph)를 이용하여 회전제약조건을 만족하는 경로를 구할 수 있었고, 사용자 경로탐색 기준에 따른 탐색기법도 제시한다. 또한, 구현된 서비스는OpenLS의 표준화된 인터페이스를 구현하여 상호운용성(interoperability)을 지원하며, 자바를 이용한 웹서비스로 구현되어 이식성, 운영체제 및 프로그래밍 언어 독립성을 제공할 수 있는 장점이 있다.