• Journal of KIISE:Software and Applications
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• v.34 no.8
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• pp.689-696
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• 2007

It is important issue for software architects to estimate performance of software in the early phase of the development process due to the need to verify non-functional requirements and estimation of performance in various stages of architectural design. In order to analyze performance of software, there are many approaches to translate software architecture represented by Unified Modeling Language, into analytical models. However, in the development of agent-based systems, these approaches ignore or simplify the crucial details of the underlying performance of the agent platform. In this paper, we propose performance prediction methodology for agent based system using formal semantic descriptions, and then, we transform the descriptions into queuing network model which model reflects performance of hardware and software platform. We prove the accuracy of proposed methodology using prototype implementation. The accuracy is summarized at 80%.

• Journal of KIISE:Information Networking
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• v.41 no.4
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• pp.151-166
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• 2014

The present method of measuring QoE (Quality of Experience) was to measure the whole block from the server that provides service to the terminal that the client gets the service. In this way, it was possible to simply determine whether the quality of QoE was good or not, and when the quality of QoE became bad, there was no way of presenting solutions. Also, as QoE metrics are numerous, there has been no strict regulation on how to use. This study analyzed QoE metrics in the viewpoints of network and clients, subdivided the whole service into three phases including one from the server providing the service to the router, another from the router to the terminal getting the service, and the third from the service router to the client router, and presented QoE metric frames appropriate for each phase. Through this, in the KOREN-CERNET environment, this study designed and embodied QoE network and demonstrated stability of QoE network, reduction in client complaint settlement time, and content adjustment effect according to the network change.

• 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.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.10A
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• pp.1571-1578
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• 1999

In this paper, we present the Modulator Channel Card and VLSI chip for the Radio Transceiver Unit (RTU) of direct sequence code division multiple access (DS-CDMA) Wireless Local Loop (WLL) System. The Modulator Channel Card is designed and implemented using ASIC's, FPGA's and DSP's. The ASIC, compliance with Common Air Interface specification proposed by ETRI, has 40K gates which is designed to operate at 32MHz, and is fabricated using $0.6\mu\textrm{m}$ CMOS process. The ASIC carries out for I- or Q- phase data channel signal processing at a time, where each data channel processing consists of channel coding, block interleaving, scrambling, Walsh modulation, Pseudo-Noise (PN) spreading, and baseband filtering. The Modulator Channel Card has been integrated as a part of RTU of WLL system and is confirmed that it meets all functional and performance requirements.

• Journal of Computational Design and Engineering
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• v.3 no.2
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• pp.161-177
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• 2016

In history based parametric CAD modeling systems, persistent identification of the topological entities after design modification is mandatory to keep the design intent by recording model creation history and modification history. Persistent identification of geometric and topological entities is necessary in the product design phase as well as in the re-evaluation stage. For the identification, entities should be named first according to the methodology which will be applicable for all the entities unconditionally. After successive feature operations on a part body, topology based persistent identification mechanism generates ambiguity problem that usually stems from topology splitting and topology merging. Solving the ambiguity problem needs a complex method which is a combination of topology and geometry. Topology is used to assign the basic name to the entities. And geometry is used for the ambiguity solving between the entities. In the macro parametrics approach of iCAD lab of KAIST a topology based persistent identification mechanism is applied which will solve the ambiguity problem arising from topology splitting and also in case of topology merging. Here, a method is proposed where no geometry comparison is necessary for topology merging. The present research is focused on the enhancement of the persistent identification schema for the support of ambiguity problem especially of topology splitting problem and topology merging problem. It also focused on basic naming of pattern features.

• Journal of Korea Game Society
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• v.6 no.4
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• pp.39-45
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• 2006

In game developments, the design results are often modified not only in the design phase but also in the implementation and test phases. The results of game design are consisted of the results of game rule design and the results of game contend design. The results of game rule design should be correctly understood to all the participants, be efficiently managed by the given configuration controls, and be accurately verified. In this study, we carry out a survey of representation methods of game rules in game design. We have the comparison analysis of the written representation, the UML representation, the Petri net representation, and script-language representation methods about the suitability of the representation method for game rule designs. The comparison analysis is about the representation scope, the visual representation, the automated verification, and the configuration management. The analysis results show that the UML representation is the best method but it needs more convenient automated verification method.

• The Transactions of the Korea Information Processing Society
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• v.4 no.3
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• pp.731-746
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• 1997

The usage of object models for the development of software has been frowung due to the prevalence of the ob-ject oriented paradigm.The object moedels produced as results of requirments analysis and design activities are vety veneficial to the implementation phase.It is even possible for source code to be genrated automatically if object models are concrete enough.Therefore system analyzers and desingners should make an dffort to refine theabstrace ogject model defined at.an early stage in order to achieve a more conrete object model.In general,re-fining an abstrace object model into a concrete model depends too much on the desigver's infromal experience.In this paper,we persent the refinement techniques required for concreting an abstract object model bassed on OMT(Object Modeling Technique)'s notation,We will discuss the definition of the abstraction level of an object model and the transformational rules of refinement.These transformational rules are currently applied to the design of a software tool,named Process Modeler,which is a major component of the software development process modeling system for ICS(Information Communication Service). Finally we can achieve a concrete object model which can easily be translated into C++ source code.

• Journal of the Korea Institute of Building Construction
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• v.10 no.1
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• pp.127-135
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• 2010

As the amount of construction information used in the growing construction field increases, the importance of efficient construction field management has been growing. Accordingly, this study aims to identifythe application situation and possibility of BIM through theoretical examinations and domestic & overseas case studies of BIM, and attempts to suggest an approach to the formulation of an efficient construction field management model through the implementation of phase-oriented and cooperation entity-oriented analysis in the construction field. In the future, the conclusions of this study should be used to formulate an actual construction field management model and apply it in the field.

• Korean Journal of Construction Engineering and Management
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• v.8 no.3
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• pp.57-65
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• 2007

Last Planner System (LPS) developed by Lean Construction Institute consists of four steps: Master Schedule, Phase Schedule, Lookahead Planning and Weekly Work Plan. This paper focuses on the process of measuring Percent of Plan Completed (PPC) at the weekly Work Plan stage. PPC means the percentage of weekly assignments completed. According to the results of the researches that deal with PPC from many other countries, we can assure the benefits or using PPC. However the concept of PPC is unfamiliar in Korea construction industry. This paper analyzes the cases in which PPC is applied in other countries and compares them with the production control system in Korean construction industry. The results of this research will provide the time management system for using PPC in Korea.

• Journal of the Korea Society for Simulation
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• v.21 no.1
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• pp.27-34
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• 2012

Proposed in the paper is an agent based and object-oriented methodology to create a virtual logistics support system model. The proposed virtual logistics support system model consists of three types of objects: the logistics force agent model(static model), the military supplies transport manager model(function model), the military supplies state manager model(dynamic model). A logistic force agent model consists of two agent: main function agent and function agent. To improve the reusability and composability of a logistics force agent model, the function agent is designed to adapt to different logistics force agent configuration. A military supplies transport manager is agent that get information about supply route, make decisions based on decision variables, which are maintained by the military supplies state manager, and transport military supplies. A military supplies state manager is requested military supplies from logistics force agent, provide decision variables such as the capacity, order of priority. For the implementation of the proposed virtual logistics force agent model, this paper employs Discrete Event Systems Specification(DEVS) formalism.