• Journal of KIISE:Computer Systems and Theory
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• v.35 no.9_10
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• pp.485-496
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• 2008

As the complexity of SoC (System-on-Chip) design increases dramatically. traditional system performance analysis and verification methods based on RTL (Register Transfer Level) are no more valid for increasing time-to-market pressure. Therefore a new design methodology is desperately required for system verification in early design stages. and hardware software (HW-SW) cosimulation at TLM (Transaction Level Modeling) level has been researched widely for solving this problem. However, most of HW-SW cosimulators support few restricted ion levels only, which makes it difficult to integrate HW-SW cosimulators with different ion levels. To overcome this difficulty, this paper proposes a multipurpose framework for HW SW cosimulation to provide systematic SoC design flow starting from software application design. It supports various design techniques flexibly for each design step, and various HW-SW cosimulators. Since a platform design is possible independently of ion levels and description languages, it allows us to generate simulation models with various ion levels. We verified the proposed framework to model a commercial SoC platform based on an ARM9 processor. It was also proved that this framework could be used for the performance optimization of an MJPEG example up to 44% successfully.

• Journal of Navigation and Port Research
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• v.41 no.3
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• pp.137-148
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• 2017

Port service level is a metric of competitiveness among ports for the operating/managing bodies such as the terminal operation company (TOC), Port Authority, or the government, and is used as an important indicator for shipping companies and freight haulers when selecting a port. Considering the importance of metrics, we developed software to objectively define and manage six important service indicators exclusive to container and bulk terminals including: berth occupancy rate, ship's waiting ratio, berth throughput, number of berths, average number of vessels waiting, and average waiting time. We computed the six service indicators utilizing berth 1 through berth 5 in the container terminals and berth 1 through berth 4 in the bulk terminals. The software model allows easy computation of expected ship's waiting ratio over berth occupancy rate, berth throughput, counts of berth, average number of vessels waiting and average waiting time. Further, the software allows prediction of yearly throughput by utilizing a ship's waiting ratio and other productivity indicators and making calculations based on arrival patterns of ship traffic. As a result, a TOC is able to make strategic decisions on the trade-offs in the optimal operating level of the facility with better predictors of the service factors (ship's waiting ratio) and productivity factors (yearly throughput). Successful implementation of the software would attract more shipping companies and shippers and maximize TOC profits.

• Journal of the Korean Society for Railway
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• v.15 no.1
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• pp.9-16
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• 2012

The dynamic stability of railway vehicle has been one of the important issues in railway safety. The dynamic simulator has been used in the study about the dynamic stability of railway vehicle and wheel/rail interface optimization. Especially, a small scale simulator has been widely used in the fundamental study in the laboratory instead of full scale roller rig which is not cost effective and inconvenient to achieve diverse design parameters. But the technique for the design of the small scale simulator about the dynamic characteristics of the wheel-rail system and the bogie system has not been well developed in Korea. Therefore, the research using the small-scaled derailment simulator and the 1/5 scaled bogie has been conducted. In this paper, we did running stability test of 1/5 scaled bogie using small-scaled derailment simulator. Also, for the operation of the small scaled simulator, it is required to investigate the performance and characteristics of the simulator system. This could be achieved by a comparative study between an analysis and an experiment. This paper presented the analytical model which could be used for verifying the test results and understanding of the physical behavior of the dynamic system comprising the small- scaled derailment simulator and the 1/5 scaled bogie.

• Journal of Korea Water Resources Association
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• v.44 no.9
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• pp.695-710
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• 2011

Manning's roughness coefficients for the Han River, the Nakdong River and the Geum River were determined by the hydraulic models using their field measurements. The roughness coefficients of present study were compared with the ones of the conventional references. The hydraulic models, such as HEC-2, HEC-RAS and FLDWAV models, are usually applied to a river flow analysis. In order to compute the accurate flood level with the numerical models, accurate information about river sections, the upstream and downstream boundary conditions, and the appropriate roughness coefficients are indispensable. It is hard to obtain the reasonable roughness coefficient of the river, in the other hand the river cross sectional data and the boundary conditions are relatively easy to acquire. The coefficient values from the references are applied in many applications without considering the variation of locations and discharges of the river, or the values are unreasonably estimated. The final results from this study will give a reasonable and important data to perform the flood routing in the Korea river.

• Journal of the military operations research society of Korea
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• v.32 no.2
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• pp.131-142
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• 2006

Nowadays, most enterprises have introduced both EA methodology to optimize an entire enterprise and CBD methodology to improve a software reusability. The Korea Government not only have developed many EA guiding products such as EA framework, Reference Model, Guideline, etc. but also have instituted a law to optimize a government-wide enterprise. The Minister of National Defense(MND) have developed the MND-AF as a standard methodology for EA and the ADDMe as a standard methodology for CBD. But it is possible to develop products of WD-AF and ADDMe redundantly because the process of MND-AF and ADDMe is not quitely aligned. The purpose of this paper is to present a scheme that ADDMe can reuse the artifacts of MND-AF by analyzing the relationships between two processes. In order to identify the relationships between two processes, we first identify the relation of a 'definition' part of two processes and then identify the relation of an 'attribute' part based on the relation of a 'detailed definition' part. As a result we found that 113 attributes of MND-AF are related to 49 attributes of ADDMe. Therefore the proposed study will decrease the development cost and time and will be a good example for aligning the process of EA and CBD methodology.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.28 no.2
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• pp.111-117
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• 2006

An area of current research is investigating the app1ication of human mesenchymal stem cells or hMSCs as a cell-based regenerative therapy. In order to achieve effective bone regeneration, appropriate matrices functioning as cell-carriers must be identified and optimized in terms of function, efficacy and biocompatibility. Two methods of approaching optimization of matrices are to facilitate adhesion of the donor hMSCs and furthermore to facilitate recruitment of host progenitor cells to osteoblastic differentiation. Pleiotrophin is an extracellular matrix protein that was first identified in developing rat brains and believed to be associated with developing neuronal pathways. A recent publication by Imai and colleagues demonstrated that transgenic mice with upregulated pleiotrophin expression developed a greater volume of cortical as well as cancellous bone. The proposed mechanism of action of pleiotrophin is demonstrated here. Through either environmental stresses and/or intracellular regulation, there is an increase in pleiotrophin production. The pleiotrophin is released extracellularly into areas requiring bone deposition. A receptor-mediated process recruits host osteoprogenitor cells into these areas. Therefore, the aim of our study was to investigate the osteoconductive properties of pleiotrophin. We wanted to determine if pleiotrophin coating facilitates cellular adhesion and furthermore if this has any effect on hMSCs derived bone formation in an animal model. The results showed a dose dependent response of cellular adhesion in fibronectin samples, and cellular adhesion was facilitated with increasing pleiotrophin concentrations. Histologic findings taken after 5 weeks implantation in SCID mouse showed no presence of bone formation with only a dense fibrous connective tissue. Possible explanations for the results of the osteogenesis assay include inappropriate cell loading.

• Journal of the Korea Society of Computer and Information
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• v.15 no.10
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• pp.229-237
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• 2010

Recently, forest management objectives become more complex and complicated, and spatial constraints were necessarily considered for ecological stability. Now forest planning is required to provide an optimized solution that is able to achieve a number of management objectives and constraints. In this study, we developed a decision supporting system based on the one of dynamic planning techniques, Tabu Search (TS) heuristic algorithm, which enable one to generate an optimized solution for given objectives and constraints. For this purpose, we analyzed the logical flow of the algorithm and designed the subsequence of processes. To develop a high-performance computing system, we examined a number of strategy to minimize execution time and workloads in each process and to maximize efficiency of using system resources. We examined two model based on the original TS algorithm and revised version of TS algorithm and compared their performance in optimization process. The results showed high performance of the developed system in providing feasible solutions for several management objectives and constraints. Moreover, the revised version of TS algorithm was appeared to be more stable for providing results with minimum variation. The developed system is expected to use for developing forest management plans in Korea.

• Journal of the Korean Chemical Society
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• v.54 no.3
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• pp.269-274
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• 2010

The solubility and the physicochemical property (refractive index) in the NaCl-$CaCl_2$-$H_2O$ and KCl-$CaCl_2$-$H_2O$ systems were determined at $50^{\circ}C$ and the phase diagrams and the diagrams of physicochemical property vs composition were plotted. One invariant point, two univariant curves, and two crystallization zones, corresponding to sodium Chloride (or potassium chloride), dihydrate ($CaCl_2{\cdot}2H_2O$) showed up in the phase diagrams of the ternary systems. The mixing parameters ${\theta}_{M,Ca}$ and ${\Psi}_{M,Ca,Cl}$ (M = Na or K) and equilibrium constant $K_{sp}$ were evaluated in NaCl-$CaCl_2-H_2O$ and KCl-$CaCl_2-H_2O$ systems by least-squares optimization procedure, in which the single-salt Pitzer parameters of NaCl, KCl and $CaCl_2$ ${\beta}^{(0)}$, ${\beta}^{(1)}$, ${\beta}^{(2)}$ and $C^{\Phi}$ were directly calculated from the literature. The results obtained were in good agreement with the experimental data.

• Nuclear Engineering and Technology
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• v.52 no.7
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• pp.1386-1395
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• 2020

High fidelity nuclear reactor fuel assembly simulation using CFD method is an effective way for the structure design and optimization. The validated models and user practice guidelines play critical roles in achieving reliable results in CFD simulations. In this paper, the international benchmark MATiS-H is studied carefully and the best user practice guideline is achieved for the rod bundles simulation. Then a 5 × 5 rod bundles model in the advanced pressurized water reactor (PWR) is established and the detailed three-dimensional thermal-hydraulic characteristics are investigated. The influence of spacer grids and mixing vanes on the flow and hear transfer in rod bundles is revealed. As the coolant flows through the spacer grids and mixing vanes in the rod bundles, the drastic lateral flow would be induced and the pressure drop increases significantly. In addition, the heat transfer is enhanced remarkably due to the strong mixing effects. The calculation results could provide meaningful guidelines for the design of advanced PWR fuel assembly.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.2
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• pp.179-187
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• 2010

The use of high frequency band, broad band and MIMO antenna is expected in the next generation mobile communication system. By the rapid increase of demand for wireless communications and the explosive increase of the mobile communication services, researches for optimization of next-generation mobile communication system are required. In the existing MIMO channel models, propagation-environments are commonly classified into urban, suburban, rural area, etc. However such approaches can have drawbacks in that many different morphologies may exist even in the urban area, for example. In this paper, we introduced path morphology concept, and proposed the method of morphology classification considering the building height, density, etc. Delay spread(DS), angular spread(AS) of AoD and AoA analyzed for each environment using the ray tracing technique. Based on the analysis, a MIMO channel model appropriate in domestic environment was suggested.