• Journal of Korean Society of Industrial and Systems Engineering
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• v.43 no.4
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• pp.48-58
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• 2020

Naval weapons systems of the Republic of Korea are acquired through the Defense Planning Management System. Recently, acquisition of some naval ships have been delayed, and the causes of the delays have been recognized as inappropriate project management at the Execution Phase. However, we argue that the delay problem in naval ships acquisition should be approached, with due regard for the entire Defense Planning Management System. That is, We should try to investigate from Planning Phase to those of Programming, Budgeting and Execution Phases. Therefore, in this study, we investigated the actual cases of the delay in naval acquisition at all phases of the Defense Planning Management System. Based on the investigation, we tried to identify the naval ship Acquisition Delay Factors and find out the Weights of those factors. As the next step, we calculated the Influence Measures on the naval missions, including the Cost of Naval Capability Gap derived from the delays in acquisition of naval ships. As a final step, we calculated the Acquisition Delay Measures based on the interrelationship between the Acquisition Delay Factors and the Influence Measures. Then we evaluated and analyzed what the results stand for. Finally, we made suggestions for future improvement. The improvement suggestions we made for preventing delay in acquisition of naval ships in this study are as follows. First, we need a shift in perception. It is necessary to measure the Acquisition Delay Factors in acquiring naval ships and manage them from the Planning Phase. Second, resolution must be concerted efforts. All relevant agencies, not just a few, should work together to resolve the problems of acquisition delay. Third, analysis must be based on the accumulation of data. This allows the elaborating of naval ship Acquisition Delay Factors and Delay Measures. If this research method is applied to other military weapons systems in the future, we may be able to not just identify the Acquisition Delay Factors in acquisition of other military weapons systems, but also pursue improvement in those cases.

• Journal of Intelligence and Information Systems
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• v.15 no.1
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• pp.1-14
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• 2009

The Capacitated Vehicle Routing Problem (CVRP) is the problem that the vehicles stationed at central depot are to be optimally routed to supply customers with demands, satisfying vehicle capacity constraints. The CVRP is the NP-hard as it is a natural generalization of the Traveling Salesman Problem (TSP). In this article, we propose the heuristic algorithm, called the bisection seed detection method, to solve the CVRP. The algorithm is composed of 3-phases. In the first phase, we work out the initial cluster using the improved sweep algorithm. In the next phase, we choose a seed node in each initial cluster by using the bisection seed detection method, and we compose the rout with the nearest node from each seed. At this phase, we compute the regret value to decide the list of priorities for the node assignment. In the final phase, we improve the route result by using the tabu search and exchange algorithm. We compared our heuristic with different heuristics such as the Clark-Wright heuristic and the genetic algorithm. The result of proposed heuristic show that our algorithm can get the nearest optimal value within the shortest execution time comparatively.

• Korean Journal of Construction Engineering and Management
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• v.10 no.3
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• pp.13-21
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• 2009

The ideas created by the execution of Value Engineering(VE) during design phase are usually proposed in a scattered way due to the characteristic of brainstorming. Because of this process, it is likely that similar ideas are proposed duplicatedly, and the created similar overlapping ideas may lead to different analyses and evaluations respectively. The efficient analysis/evaluation of the such similarly created ideas are not easy and the verification of the adequacy and objectivity of the ideas becomes harder and the objective evaluation gets more difficult as well as consumes much time. In spite of the perfect executions of preparatory step for idea creation, the difficulties in managing the similarly created ideas in quantity systematically result in the reduced reliability of the VE activities during design phase. Thus, this study proposes a process model for the efficient idea creation and management of the VE activities during design phase.

• The Transactions of the Korea Information Processing Society
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• v.2 no.5
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• pp.733-745
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• 1995

This study is aimed at construction of a translator for a functional programming language. For this goal we define a functional programming language which has lazy semantics and develop a translator for it. The execution model selected is the G-machine-based combinator graph reduction. The translator is composed of 4 phases and translates a source program to a C program. The first phase of the translator translates a source program to a enriched lambda- calculus graph, the second phase transforms a lambda-calculus graph into supercombinators, the third phase translates supercombiantors to a G program and the last phase translates the G program to a C program. The final result of the translator, a C program, is compiled to an executable program by C compiler. The translator is implemented in C using compiler development tools such as TACC and Lex, under the UNIX environments. In this paper we present the design and implementation techniques for developing the translator and show results by executing some test problems.

• Journal of KIISE:Databases
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• v.36 no.2
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• pp.123-138
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• 2009

In recent years, the web services composition search has become an issue of great interest. The web services composition search is the process of integrating individual web services to yield desired behavior. Through the web services composition search, more sophisticated functionalities can be provided. Current solutions can be classified into three main classes: forward chaining approach, backward chaining approach and two-phase approach. However one-way chaining approaches, such as forward chaining approach and backward chaining approach have limitations of searching irrelevant web services. And two-phase approach has limitations of including redundant web services. In this paper, we propose an unredundant web services composition search based on the two-phase algorithm. The algorithm consists of a forward phase and a backward phase. In the forward phase, the candidate web services participating composition will be found efficiently by searching the Link Index. In the backward phase, unredundant web services compositions will be generated from candidate web services by using the Token Manager. The experimental results show that our proposed algorithm is more efficient than one-way chaining approaches. The experimental results also show that our algorithm can provide more solutions than previous two-phase approach and is comparable to previous one in execution time.

• 한국디지털정책학회:학술대회논문집
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• 2006.06a
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• pp.39-44
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• 2006

The purport of this paper is to deduce political implication and significance of the proposed redress scheme of 'Consumer Collective Lawsuit (hereinunder "CCL")' under way to be introduced by the Korean government via various assessments per each phase of policy implementation process. To this end, the paper classifies the subject policy (referring to CCL) implementation process into 4 phases: policy origination, policy enactment, policy advertisement, and policy execution. Based on the said classification, assessments per each phase together with pros and cons analysis have been conducted. Through the aforementioned analysis, the paper concludes the following political implication and significance of CCL under way of introduction: - 1. In the case of policy origination led by external parties, a social consensus by and from involved parties with various interests is the most critical; 2. Prior feasibility and/or suitability study is also crucial in the policy implementation procedure; 3. To mitigate inter-ministerial conflicts that might arise from the due policy making procedure, democratization of conflict settlement mechanism, and institutionalization of participation in and disclosure of policy making process are cal led upon; and 4. Prior planning wi th respect to the public relation and advertisements of the subject policy on the table poses substantial significance.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.18 no.3
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• pp.425-438
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• 1993

Due to the producer-consumer dependency of shared variables, the potential parallelism embeded in the logic programming language has not been fully examined. The method proposed in this paper eliminates the dependency of shared variables by introducing number-sequenced variables in expanding an AND-OR proof tree. Basically, the execution of a logic program can be divided into two phases : expanding an AND-OR tree and proving the tree by matching facts with leaf nodes. In the course of the first phase, a set of number-sequenced variables are produced by expanding an AND-OR tree in the breadth-first searching. Based on the information of number-sequence, each of them is verified in the second phase in order to prove the tree. Consequently, the proposed algorithm can explore more parallelism without the dependency of shared variables.

• Journal of Internet Computing and Services
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• v.7 no.6
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• pp.79-86
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• 2006

Many of concurrency control for client-sewer database systems have been proposed and studied in the literature. However, commonly known schemes do not manage to the case of dramatic changes in data contention because the data contention of database systems is changed for each cases. In this paper, we propose o hybrid concurrency control. The proposed scheme uses a optimistic scheme for the first-run transactions and a pessimistic scheme for the second-run transactions. By pre-claiming locks in the second phase, deadlocks which ore possible in pessimistic based concurrency control are prevented in our approach. In addition, the scheme ensures at most one re-execution even if the validation in the optimistic phase fails. By a detailed simulation, this paper examines the behaviors of the Distributed Optimistic Concurrency Control and the proposed scheme. The simulation study shows our scheme outperforms Distributed Optimistic Concurrency Control in our experimental result.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2007.11a
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• pp.13-18
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• 2007

The construction by the ministry of health and welfare support of the first special hospital for only children in busan and gyeong-nam is under building with YPNUH(Yangsan Pusan National University Hospital) for the best medical treatment town and is to improve the productivity and efficiency by eliminating unproductive and inefficient fact through the construction management, systemic and scientific management technique. So in this study we would like to suggest the generated effect to apply project management technique to all stage such as from pre-design phase, turn-key enterprise choice, construction, design VE(Value Engineering), PMIS (Project Management Information System) construction to maintenance phase and cost and schedule reduction effect through basic, execution design VE by using engineer of field.

• Journal of Power Electronics
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• v.4 no.2
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• pp.102-111
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• 2004

This paper is concerned with a deadbeat current control implementation of shunt-type three-phase active power filter (APF). Although the one-dimensional deadbeat control method can attain time-optimal response of APF compensating current, one sampling period is actually required fur its settling time. This delay is a serious drawback for this control technique. To cancel such a delay and one more delay caused by DSP execution time, the desired APF compensating current has to be predicted two sampling periods ahead. Therefore an adaptive predictor is adopted for the purpose of both predicting the control error of two sampling periods ahead and bringing the robustness to the deadbeat current control system. By adding the adaptive predictor output as an adjustment term to the reference value of half a source voltage period before, settling time is made short in a transient state. On the other hand, in a steady state, THD (total harmonic distortion) of the utility grid side AC source current can be reduced as much as possible, compared to the case that ideal identification of controlled system could be made.