• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.20 no.2
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• pp.109-115
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• 2020

As the maritime targets that threaten allies become lower, smaller, and faster, the need for analysis and modeling of clutter according to sea state increases. Clutter according to the sea state has a great influence on radar performance, such as lowering the probability of detection of low-altitude small maritime targets. In this paper, to analyze the detection performance of a multi function radar for a ship, a sea clutter model suitable for the radar operating environment is selected from several sea clutter models, and analysis of low-altitude, small target detection under a clutter is performed. By using the actual data of the already mounted radar for maritime target detection, four known clutter models have been implemented for each sea state and compared with the actual data. Through this, by selecting a clutter model that best reflects the actual radar environment, reliability of the clutter model is improved. Subsequently, the selected model is used to detect the detectable distance to the low-altitude small target.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.48 no.1
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• pp.127-132
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• 2011

In this paper, we propose a novel method of adult image classification by combining skin color regions and edges in an input image. The proposed method consists of four steps. In the first step, initial skin color regions are detected by logical AND operation of all skin color regions detected by the existing methods of skin color detection. In the second step, a skin color probability map is created by modeling the distribution of skin color in the initial regions. Then, a binary image is generated by using threshold value from the skin color probability map. In the third step, after using the binary image and edge information, we detect final skin color regions using a region growing method. In the final step, adult image classification is performed by support vector machine(SVM). To this end, a feature vector is extracted by combining the final skin color regions and neighboring edges of them. As experimental results, the proposed method improves performance of the adult image classification by 9.6%, compared to the existing method.

• Journal of the Korean Society of Safety
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• v.32 no.5
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• pp.168-178
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• 2017

In order to prevent major and chemical accidents, some of the plants which would like to install and operate hazard chemicals handling facilities must submit Off-site Consequence Analysis due to recent arisen leak accidents since 2015. A lot of chemical industrials choose gas detectors as mitigation equipment to early detect gas vapor. The way of placement of gas detectors has two methods; Code-based Design(CBD) and Performance-based Design. The CBD has principles for gas detectors to be installed with consideration for the place that is expected to accumulate gas, and the leak locations according to legal standards and technical guidelines, and has a possibility to be unable to detect by these rules to locate gas detectors by vapor density information. The PBD has two methods; a Geographic Method and Scenario based Method. The Scenario-based Method has been suggested to make up for the Geographic Coverage Method. This Scenario-based Method draw the best optimum placement of gas detectors by considering leak locations, leak speed information, leak directions and etc. However, the domestic placement guidelines just refers to the CBD. Therefore, this study is to compare existing placement location of gas detectors by the domestic CBD with placement locations, coverages and the number of gas detectors in accordance with the Scenario-based Method. Also this study has measures for early detecting interest of Vapor Cloud and suitable placement of gas detectors to prevent chemical accidents. The Phast software was selected to simulate vapor cloud dispersion to predict the consequence. There are two cases; an accident hole size of leak(8 mm) from API which is the highst accident hole size less than 24.5 mm, and a normal leak hole size from KOSHA Guide (1.8 mm). Detect3D was also selected to locate gas detectors efficiently and compare CBD results and PBD results. Currently, domestic methods of gas detectors do not consider any risk, but just depend on domestic code methods which lead to placement of gas detectors not to make personnels recognize tolerable or intolerable risks. The results of the Scenario-based Method, however, analyze the leak estimated range by simulating leak dispersion, and then it is able to tell tolerable risks. Thus it is considered that individuals will be able to place gas detectors reasonably by making objectives and roles flexibly according to situations in a specific plant.

• The KIPS Transactions:PartD
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• v.12D no.4 s.100
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• pp.589-600
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• 2005

Application developers need effective reuseable methodology to meet rapidly changes and variety of users requirements. Product Line and CBD(Component Based Development) offer the great benefits on quality and productivity for developing the software that is mainly associate with reusable architectures and components in a specific domain and rapidly changing environments. Product line can dynamically focus on the commonality and variety feature model among the products. The product line uses the feature modeling for discovering, analyzing, and mediating interactions between products. Reusable architectures include many variety plans and mechanisms. In case of those architecture are use in product version for a long time, It is very important in architecture product line context for product line design phase. Application developer need to identify the proper location of architecture changing for variety expression. It is lack of specific variety managements to design the product line architecture until nowdays. In this paper, we define various variety types to identify the proper location of architecture changing for variety expression and to design the reusable architecture. We also propose architecture variety on feature model and describe variety expression on component relations. We implemented the web learning system based on the methodology. We finally describe how these methodology may assist in increasing the efficiency, reusability, productivity and quality to develop an application. In the future, we are going to apply the methodology into various domain and suggest international and domestic's standardization.

• International Journal of Highway Engineering
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• v.14 no.3
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• pp.151-162
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• 2012

It is not surprising to hear news about irresistible natural disasters all over the world due to climate change. Korean Government has focused on developing a variety of green technologies to reduce green house gasses, in particular, carbon dioxide. This study suggested 18 technology divisions for achieving green highway technology development in six different sub-sectors considering life-cycle of roadway and surveyed 29 highway and/or transportation professionals of three institutes using AHP(Analytical Hierarchy Process) analysis to construct "Green Highway"and realize carbon emission reductions and energy use efficiency in a road sector in Korea. Expert Choice Software was used to rank 18 technology divisions weighted by two-level choices. Transport Operating Infrastructure Improvement, Roadway Policy Implementation, Green Transportation(such as Pedestrian and Bicycle) were highly ranked by respondents according to results of the AHP modeling. Among the 18 divisions, technology policy for supporting R&D investments from development to commercialization was ranked as the most significant one to be focused. Green Transportation Facility Design/Construction/Operation and Eco-Friendly Roadway Plan were followed as expected since professionals have thought that the planning/design step of the life-cycle is a starting point to reduce carbon dioxide from roads more and more. Additionally, comparing the results with the Government investment trend 2006-2011 for the roads, it can be interpreted that the Government should invest to the R&D area more widely than before to promote element and core technology development for Green Highway Construction. Above all, small and mid-sized businesses have to be invested as well as encouraged to undertake green highwayrelated objects to accomplish the divisions which ranked high.

• Communications of Mathematical Education
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• v.29 no.1
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• pp.35-49
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• 2015

3D-Printing is one of the most innovative technologies that will be widely used in the 21st century. 3D-Printing also serves as an indispensable tool in STEAM education. In this article, we introduce what we have done in our mathematical modeling class in Uni. and recent R&E project under the support of Korean Foundation for the Advancement of Science and Creativity. We planned a model of STEAM education originating from our wish to make tangible models that use mathematical formulas to express the natural beauty of an object. We used a free, open-source software, Sage, to simulate these models online. Then, we created a program that generates a .STL file from these 3D images. This model can help students understand the natural beauty inherent in mathematics and use formulas and technology tools to simulate models in 3D. Finally, we were able to help students to create their own. STL files through a website we developed by adding Sage code into a Sage notebook. Then students can make and hold a 3D object of their very own. This process shows the possibility that mathematics, art and 3D-Printing can be effectively used to achieve the goals of STEAM education.

• Journal of radiological science and technology
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• v.38 no.4
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• pp.389-394
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• 2015

There is a progressive development in the medical imaging technology, especially of descriptive capability for anatomical structure of human body thanks to advancement of information technology and medical devices. But however maintenance of correct posture is essential for the medical imaging checkup on the shoulder joint requiring rotation of the upper limb due to the complexity of human body. In the cases of MRI examination, long duration and fixed posture are critical, as failure to comply with them leads to minimal possibility of reproducibility only with the efforts of the examiner and will of the patient. Thus, this study aimed to develop an auxiliary device that enables rotation of the upper limb as well as fixing it at quantitative angles for medical imaging examination capable of providing diagnostic values. An auxiliary device has been developed based on the results of precedent studies, by designing a 3D model with the CATIA software, an engineering application, and producing it with the 3D printer. The printer is Objet350 Connex from Stratasys, and acrylonitrile- butadiene-styrene(ABS) is used as the material of the device. Dimensions are $120{\times}150{\times}190mm$, with the inner diameter of the handle being 125.9 mm. The auxiliary device has 4 components including the body (outside), handle (inside), fixture terminal and the connection part. The body and handle have the gap of 2.1 mm for smooth rotation, while the 360 degree of scales have been etched on the handle so that the angle required for observation may be recorded per patient for traceability and dual examination.

• Journal of Korean Society on Water Environment
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• v.28 no.3
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• pp.347-358
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• 2012

The SWAT (Soil and Water Assessment Tool) should be calibrated and validated with observed data to secure accuracy of model prediction. Recently, the SWAT-CUP (Calibration and Uncertainty Program for SWAT) software, which can calibrate SWAT using various algorithms, were developed to help SWAT users calibrate model efficiently. In this study, three algorithms (GLUE: Generalized Likelihood Uncertainty Estimation, PARASOL: Parameter solution, SUFI-2: Sequential Uncertainty Fitting ver. 2) in the SWAT-CUP were applied for the Soyang-gang dam watershed to evaluate these algorithms. Simulated total streamflow and 0~75% percentile streamflow were compared with observed data, respectively. The NSE (Nash-Sutcliffe Efficiency) and $R^2$ (Coefficient of Determination) values were the same from three algorithms but the P-factor for confidence of calibration ranged from 0.27 to 0.81 . the PARASOL shows the lowest p-factor (0.27), SUFI-2 gives the greatest P-factor (0.81) among these three algorithms. Based on calibration results, the SUFI-2 was found to be suitable for calibration in Soyang-gang dam watershed. Although the NSE and $R^2$ values were satisfactory for total streamflow estimation, the SWAT simulated values for low flow regime were not satisfactory (negative NSE values) in this study. This is because of limitations in semi-distributed SWAT modeling structure, which cannot simulated effects of spatial locations of HRUs (Hydrologic Response Unit) within subwatersheds in SWAT. To solve this problem, a module capable of simulating groundwater/baseflow should be developed and added to the SWAT system. With this enhancement in SWAT/SWAT-CUP, the SWAT estimated streamflow values could be used in determining standard flow rate in TMDLs (Total Maximum Daily Load) application at a watershed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.8
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• pp.5550-5558
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• 2015

Recently, fuel cell with high energy efficiency and low CO2 emission is energetically interconnected with power system. Especially, FCGS(Fuel Cell Generation System) which usually operates at high temperature, is being developed and installed in the form of large scale system. However, it is reported that power system disturbances related to surge, harmonic and EMI have caused several problems such as malfunction of protection device and damage of control device in the large scale FCGS. In order to solve these problems, this paper presents a modeling of operation characteristics of FCGS by PSCAD/EMTDC, ETAP, P-SIM software. And also, this paper proposes countermeasure algorithms to prevent power system disturbances. From the simulation results, it is confirmed that the proposed algorithm is useful method for the stable operation of large scale FCGS.

• Journal of KIISE:Software and Applications
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• v.35 no.2
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• pp.70-80
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• 2008

Today, businesses have to respond with flexibility and speed to ever-changing customer demand and market opportunities. Service-oriented architecture (SOA) is the best methodology for minimizing the complexity and the cost of enterprise-level infrastructure and for maximizing the productivity and the flexibility of an enterprise. Most of the enterprise-level SOA delivery strategies deal with the top-down approach, which organization has to define the business processes, to model business services, and to find the required services or to develop new services. However, a lot of peoples want to maximally reuse legacy component-based systems as well as to deliver SOA into their organizations. In this paper, we propose a bottom-up approach for identifying business services with proper granularity. It can improve the reusability and maintenance of services by considering not data I/O of components of legacy applications but GUI event patterns. Our proposed method is applied to MIS with 129 GUIs and 13 components. As a result, the valiance of the coupling value of components is increased five times and three business services are distinctly exposed. It also provides a 49% improvement in reducing the relationship problems between services over a service identification method using only partitioning information of components.