• Asia pacific journal of information systems
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• v.6 no.1
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• pp.165-194
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• 1996

Data distribution is one of the most important steps in distributed database design. This paper proposes a methodology for distributing database by using a relational schema as an input. A design support system called DBDD (Database Distribution Design) is implemented within the framework of this methodology. The methodology consists of three phases such as (i) schema analysis, (ii) fragmentation, and (iii) allocation. In the schema analysis phase, all the table names are acquired from a global relational schema. In the fragmentation phase, fragments are generated according to transaction retrieval patterns. Furthermore, DBDD enhances the design quality by allocating fragments in a progressive manner. A real-life case is illustrated to demonstrate the practical usefulness of the DBDD.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.45-57
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• 2007

During the design phase of a system, which requires high reliability and safety such as aircraft, high speed train and nuclear power plant, reliability engineer must set up the target system reliability. To meet a reliability goal for the system, reliability allocation should be done gradually from the system to its element. For this end, first of all, we need to construct functional block diagram based on the design output and PWBS(Project Work Breakdown System). Another important input data for reliability allocation is the relationship between the cost and the reliability. In this study we investigate various reliability allocation models, which can be applicable to aircraft, vehicle, and power plant, and etc. And we suggest a proper reliability allocation model which can be effectively applicable to KTX-II high speed train to achieve the target system reliability.

• Journal of the Korean Society for Railway
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• v.10 no.3 s.40
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• pp.319-326
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• 2007

During the design phase of a system, which requires high reliability and safety such as aircraft, high speed train and nuclear power plant, reliability engineer must set up the target system reliability. To meet a reliability goal for the system, reliability allocation should be done gradually from the system to its element. For this end, first of all, we need to construct functional block diagram based on the design output and PWBS(Project Work Breakdown System). Another important input data for reliability allocation is the relationship between the cost and the reliability. In this study we investigate various reliability allocation models, which can be applicable to aircraft, vehicle, and power plant, and etc. And we suggest a proper reliability allocation model which can be effectively applicable to KTX-II high speed train to achieve the target system reliability.

• JSTS:Journal of Semiconductor Technology and Science
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• v.5 no.2
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• pp.89-101
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• 2005

Research on highly abstracted system modeling and simulation has received a great deal of attention as of the concept of platform based design is becoming ubiquitous. From a practical design point of view, such modeling and simulation must consider the following: (i) fast simulation speed and cycle accuracy, (ii) early availability for early stage software development, (iii) inter-operability with external tools for software development, and (iv) reusability of the models. Unfortunately, however, all of the previous works only partially addresses the requirements, due to the inherent conflicts among the requirements. The objective of this study is to develop a new system design methodology to effectively address the requirements mentioned above. We propose a new transaction-level system modeling methodology, called ViP (Virtual Platform). We propose a two-step approach in the ViP method. In phase 1, we create a ViP for early stage software development (before RTL freeze). The ViP created in this step provides high speed simulation, lower cycle accuracy with only minor modeling effort.(satisfying (ii)). In phase 2, we refine the ViP to increase the cycle accuracy for system performance analysis and software optimization (satisfying (i)). We also propose a systematic ViP modeling flow and unified interface scheme based on utilities developed for maximizing reusability and productivity (satisfying (ii) and (iv)) and finally, we demonstrate VChannel, a generic scheme to provide a connection between the ViP and the host-resident application software (satisfying (iii)). ViP had been applied to several System-on-a-chip (SoC) designs including mobile applications, enabling engineers to improve performance while reducing the software development time by 30% compared to traditional methods.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.3
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• pp.1054-1060
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• 2013

Fuel tank of a rotorcraft has a great influence on the survivability of crews. For a long time, US army has tried to develop the proper material for fuel cell of a military rotorcraft. As a result, the design specification of fuel cell, MIL-T-27422A, was issued for the first time on 1961. Through a few revisions, it has been developed to ML-DTL-27422D in 2007. It should be assured that fuel cell satisfies the requirement defined in MIL-DTL-27422D. The qualification test of this specification is classified into Phase I test for material and Phase II for fuel cell itself. This paper studies test conditions and procedures of slosh & vibration, gunfire resistance and crash impact test. They are considered as the most important tests which have a high possibility of failure. The rational consideration of this paper can improve the ability for estimating not only the validity of test procedure and test condition but test result. Based on the rational consideration, it is expected that the ability of the systematic development can be improved.

• Journal of Korean Traditional Oncology
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• v.20 no.1
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• pp.11-21
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• 2015

Objectives : The cancer incidence and cancer burden is increasing. In addition, the use of botanical agents in cancer care is increasing. This article aims to review a research strategy for botanical agents. Methods : The clinical studies of anticancer botanical agents and the papers about clinical research methodology of botanical agents were reviewed. Results : In phase I study, safety confirmation, optimal dose determination and drug interaction study are important. Most botanical agents have low toxicity and some have non-monotone dose response. Therefore, dose-response curve must be evaluated separately from the dose-toxicity curve to determine optimal dose. Although anticancer botanical agents can't shrink tumor size rapidly, they do extend survival. So, in phase II study, response should be evaluated by the survival. Conclusions : Clinical research of botanical agents in cancer is different from traditional methods and strategies. Considering the characteristics of botanical agents and experimental mechanism is necessary in conducting botanical based clinical trials.

• Educational Technology International
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• v.20 no.1
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• pp.25-55
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• 2019

The core purpose of the study is to develop and validate an ADDIE model based instructional model for English Language Teaching (ELT) in early childhood classroom in Bangladesh as an aid to teachers to reconstruct their knowledge and experience more strategically, and for them to design and implement their instruction more structurally. This study is developmental in nature which has been divided in five phases as follows. Phase I: Existing methods and instructional strategy review, Phase II: Instructional model development, Phase III: Delphi 1st round, Phase IV: Delphi 2nd round and Phase V: Model validation. After reviewing relevant literature and existing strategy in phase I, the 1st version of instructional model is made phase II. Next in phase III and phase IV, two rounds of Delphi have been conducted where experts related to different concerning areas of this study reviewed the 1st version and gradually the final version of the instructional model is made. Finally, the instructional model for English teachers of early childhood classroom in Bangladesh got validated by the same Delphi panelists in Phase V. In respect with each phases of ADDIE, the instructional model elaborates the 1) representative key points, 2) instructors' activities prescribed for the instructors, 3) supporting strategies. Both the conceptual and procedural models are included in this study for clearer identification of the whole process. Lastly the study provides some recommendations for instructors and practitioners on choosing the instructional model like doing prior need analysis, incorporating teacher training programs, training students, keeping on researching for finding effective teaching technique and tools and being open to changes etc. In addition, the study also acknowledges its limitations like not being able to consider the psychological factors due to time limitation. Finally, at the end the study points out the areas that welcome further research.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.39 no.11
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• pp.1077-1085
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• 2011

Various stakeholder's expectations and constraints are to be efficiently resolved into a program consensus prior to the beginning of its substantial design processes. This study focuses on the analysis of the stakeholder's expectations in determining the design requirements at the initial stage of space exploration programs including Naro launcher and currently on-going KSLV-II program. Naro program seems to unilaterally account for the government expectations of accelerating program phase speed without making any efforts to converge various expectations from related sectors. The planning of Naro launcher is also found lack of the concept of operations (ConOps), which is of critical importance by envisaging the operational applications of end products. Similarities are found in KSLV-II program regarding the lack of implementation for stakeholder's expectations. Moreover, the government plan for KSLV-II disclosed without considering all expectations and other comments. The increase in design conflicts and program uncertainties would be unavoidable, if the government plan for KSLV-II would be insisted. It is required to modify the government plan and to establish the ConOps with the convergence of stakeholder's expectations at this early stage of the program.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2001.10a
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• pp.231-236
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• 2001

The goal of multiphase optimization of machine structure is to obtain 1) light weight, 2) statically and dynamically rigid structure. The entire optimization process is carried out in two phases. In the first phase, multiple optimization problem with two objective functions is treated using pareto genetic algorithm. Two objective functions are weight of the structure, and static compliance. In the second phase, maximum receptance is minimized using genetic algorithm. The method is applied to design of quill type machine structure with back column.

• Journal of the Korean Society for Heat Treatment
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• v.8 no.1
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• pp.12-23
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• 1995

In this a set of constitutive equation relevant to the analysis of thermo-elasto-plastic materials with phase transformation during quenching process was presented on the basis of continuum thermo-dynamic. In calculating the transient thermal stresses, temperature between coolant and specimen(SM45C) surface was determined from the heat transfer coefficient. A calculation was made for specimen with 40mm in diameter quenched in coolant from $820^{\circ}C$ and the results are as follow. Stresses at starting point of transformation always show the maximum tensile value. Reverse of stresses takes place after completion of transformation of inner part at specimen.