• Ocean Systems Engineering
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• v.6 no.3
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• pp.245-264
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• 2016

The iterative boundary element method (IBEM) developed originally before for cavitating two-dimensional (2-D) and three-dimensional (3-D) hydrofoils moving under free surface is modified and applied to the case of 2-D (two-dimensional) airfoils and 3-D (three-dimensional) wings over water. The calculation of the steady-state flow characteristics of an inviscid, incompressible fluid past 2-D airfoils and 3-D wings above free water surface is of practical importance for air-assisted marine vehicles such as some racing boats including catamarans with hydrofoils and WIG (Wing-In-Ground) effect crafts. In the present paper, the effects of free surface both on 2-D airfoils and 3-D wings moving steadily over free water surface are investigated in detail. The iterative numerical method (IBEM) based on the Green's theorem allows separating the airfoil or wing problems and the free surface problem. Both the 2-D airfoil surface (or 3-D wing surface) and the free surface are modeled with constant strength dipole and constant strength source panels. While the kinematic boundary condition is applied on the airfoil surface or on the wing surface, the linearized kinematic-dynamic combined condition is applied on the free surface. The source strengths on the free surface are expressed in terms of perturbation potential by applying the linearized free surface conditions. No radiation condition is enforced for downstream boundary in 2-D airfoil and 3-D wing cases and transverse boundaries in only 3-D wing case. The method is first applied to 2-D NACA0004 airfoil with angle of attack of four degrees to validate the method. The effects of height of 2-D airfoil from free surface and Froude number on lift and drag coefficients are investigated. The method is also applied to NACA0015 airfoil for another validation with experiments in case of ground effect. The lift coefficient with different clearance values are compared with those of experiments. The numerical method is then applied to NACA0012 airfoil with the angle of attack of five degrees and the effects of Froude number and clearance on the lift and drag coefficients are discussed. The method is lastly applied to a rectangular 3-D wing and the effects of Froude number on wing performance have been investigated. The numerical results for wing moving under free surface have also been compared with those of the same wing moving above free surface. It has been found that the free surface can affect the wing performance significantly.

• Journal of Korean Society of Rural Planning
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• v.23 no.1
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• pp.1-10
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• 2017

The community bridge node finder, based on the stochastic method of network analysis, can compute hubs spot, which would enable the use of network structures with limited information. However, applying this node finder to heterogeneity networks, which are efficient to analyze the main farm complex in fields and the spread of infectious disease, is difficult. These problems, The most connected point that is called hub is often a major role in the heterogeneity network. In this study, we therefore improved the community bridge node finder to enable it to be applied to heterogeneity networks. We attempted to calculate the bridge node quantitatively by using the modularity of cohesion analysis method and the community bridge node finder. Application of the improved method to the HPAI(Highly Pathogenic Avian Influenza) spread in Korea 2008 produced a quarantine coefficient that was 4 - 37% higher than the quarantine coefficient obtained with the centrality method for the first 14 days after the HPAI outbreak. We concluded that the improved method has the ability to successfully calculate the bridge node in heterogeneity networks based on network structures with scant information, such as those describing the spread of infectious disease in domestic animals. And Our method should be capable to find main farm complex in fields.

• Journal of The Geomorphological Association of Korea
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• v.20 no.4
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• pp.85-99
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• 2013

The objective of this paper is to analyze the spatial distribution of errors in the DEM generated using waterlines from multi-temporal remote sensing data and to assess flood vulnerability. Unlike conventional research in which only global statistics of errors have been generated, this paper tries to quantitatively analyze the spatial distribution of errors from a probabilistic viewpoint using geostatistical simulation. The initial DEM in Baramarae tidal flats was generated by corrected tidal level values and waterlines extracted from multi-temporal Landsat data in 2010s. When compared with the ground measurement height data, overall the waterline-based DEM underestimated the actual heights and local variations of the errors were observed. By applying sequential Gaussian simulation based on spatial autocorrelation of DEM errors, multiple alternative error distributions were generated. After correcting errors in the initial DEM with simulated error distributions, probabilities for flood vulnerability were estimated under the sea level rise scenarios of IPCC SERS. The error analysis methodology based on geostatistical simulation could model both uncertainties of the error assessment and error propagation problems in a probabilistic framework. Therefore, it is expected that the error analysis methodology applied in this paper will be effectively used for the probabilistic assessment of errors included in various thematic maps as well as the error assessment of waterline-based DEMs in tidal flats.

• Journal of Wetlands Research
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• v.24 no.1
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• pp.59-67
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• 2022

The interest in LID facilities is increasing worldwide for recovery of natural water cycle system to destroy by urbanization. However, problems are raised when installation of LID because comprehensive analysis about design capacity adequacy of LID facilities was not conducted completely. In this research, removal efficiency and design volume adequacy of LID facilities were analyzed based on rainfall monitoring data in four LID facilities(Vegetated Swale, Vegetative Filter Strip, Bio-Retention and Permeable Pavement). As a result, group of LID facility designed on WQV was shown higher flow(37%) and pollutants(TSS, BOD, TN and TP) removal efficiencies(20 ~ 37%) than group of LID facility designed on WQF. SA/CA graph was drawn for evaluation of design volume adequacy based on rainfall monitoring data. In this SA/CA graph, coefficient of determination show over 0.5 in all parameter, especially, Flow and TP were show over 0.95. And, 'SA/CA & L/CA' graph considering difference of structure mechanism in LID facility suggested in this research was confirmed that improved coefficient of determination in flow, TSS and TP than SA/CA graph. According to this research results, feasibility of applying 'SA/CA & L/CA' graph for evaluation of design volume adequacy in LID facility, and it is necessary to follow up research for generalization and normalization.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.4D
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• pp.351-360
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• 2010

In 2010, the number of registered vehicles reached almost at 17.48 millions in Korea. This dramatic increase of vehicles influenced to increase the number of traffic accidents which is one of the serious social problems and also to soar the personal and economic losses in Korea. Through this research, an enhanced intersection hazard prediction model by combining Genetic Algorithm and Artificial Neural Network will be developed in order to obtain the important data for developing the countermeasures of traffic accidents and eventually to reduce the traffic accidents in Korea. Firstly, this research has investigated the influencing factors of road geometric features on the traffic volume of each approaching for the intersections where traffic accidents and congestions frequently take place and, a linear regression model of traffic accidents and traffic conflicts were developed by examining the relationship between traffic accidents and traffic conflicts through the statistical significance tests. Secondly, this research also developed an intersection hazard prediction model by combining Genetic Algorithm and Artificial Neural Network through applying the intersection traffic volume, the road geometric features and the specific variables of traffic conflicts. Lastly, this research found out that the developed model is better than the existed forecasting models in terms of the reliability and accuracy by comparing the actual number of traffic accidents and the predicted number of accidents from the developed model. In conclusion, it is expect that the cost/effectiveness of any traffic safety improvement projects can be maximized if this developed intersection hazard prediction model by combining Genetic Algorithm and Artificial Neural Network use practically at field in the future.

• Korean Journal of Construction Engineering and Management
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• v.15 no.1
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• pp.28-38
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• 2014

Construction value engineering(VE) is often performed in the form of a short term review of designs, rather than during a regular workshop with a standardized work plan, and its application method is limited. Thus, tasks are performed by applying the method in reverse depending on the VE results, and function analysis, a key VE method, is omitted or only applied for the sake of formality. In addition, it is hard to expect great results from VE because of insufficient time and budget allowed to perform VE and a lack of understanding of VE procedures and methods. In particular, the methods used to store and reuse the tremendous amount of ideas and information created during the process of VE implementation is not systematic. Even the Korea Expressway Corporation, which has produced relatively systematic VE performance compared to other institutions, has had the above-mentioned problems. Therefore, this study aims to improve existing VE processes and suggest a method to efficiently store and retrieve VE information by analyzing the limitations of construction VE practice and the characteristics of VE for highway facilities as part of improving design VE performance.

• Journal of The Korean Association of Information Education
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• v.15 no.3
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• pp.483-492
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• 2011

'Learning with a robot' is now considered as one of the best candidates for STEAM education, which is recently growing its importance. Most of the 'learning with a robot' programs in elementary schools serve as afterschool classes. The students participating in the afterschool classes are mostly boys who are interested in science and robots. This paper mainly concerns that a robot can be helpful for improving students' interest in STEAM education. We divided the robot utilizable aspects into 5 areas with educational points of view; abstract concept understanding type, structure-oriented type, athletics-oriented type, intelligence-oriented type and value-orientated type. We extracted all robot utilizable subjects and units from elementary school curriculum, and developed lesson plans which can be applicable to regular classes. And we also verified them by applying into an elementary school for 5 months. As the result of the analysis, we can conclude that 'learning with a robot' can encourage students' interest in STEAM, and it is more effective for girls than boys. Finally, we discuss problems that teachers may face in using a robot for regular classes, and make suggestions about the use of a robot for STEAM education.

• Korean Business Review
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• v.19 no.2
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• pp.231-259
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• 2006

Performance-based budgeting(hereafter PB2) is supposed to improve efficiency and effectiveness of public organizations. Governmental PB2 is based on output flow rather than input flow. Since 1990s, many OECD nations including New Zealand and the United States have been changing their budget system to PB2. The Korean Government has been using input-based budgeting focusing on the size of expenditures. In 1999, The Ministry of Planning and Budget(hereafter MPB) conducted pilot projects for divisions or agencies of governmental departments for the purpose of improving efficiency in expenditure, rationalizing budget allotments, and inducing budget savings. However, performance budgeting may also have problems in terms of measurement and application. Due to the fact that public goals are abstract and may vary, it is difficult to induce performance indicators from public goals. There also seem not to be any performance indicators which correspond with the conditions of desirable indicators, such as validity, reliability, clarity, practicality, controllability and so on. In terms of applying an original budgeting plan, the difficulty of linking performance and budgeting, the appearance of unintended negative effect and externalities, and the repulsion of subordinated agencies are expected. Now days, local government is going to introduce PB2. Same problem may happen in the local government. And Therefore, the objectives of this paper are to introduce PB2 onlocal government and review a alternative strategy with the purpose of smoothly settling performance budgeting on local government. That is the linkage of Balanced Scorecard(BSC) and PB2.

• Journal of Acupuncture Research
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• v.18 no.2
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• pp.186-199
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• 2001

Objectives : Sa-am Acupucture(舍岩鍼法), Taeguk Acupucture(太極鍼法), and 8 Constitution-Acupuncture(八體質鍼法) are largely used acupuncture therapies which utilize Yin and Yang, The Five Elements, Interpromoting and Counteracting Relation(相生 相克 關係). We are here to compare and study each acupuncture methods in order to understand their fundamental principle and theory. Conclusion : 1. When prescribing Herb to patients, we can use the Differentiation of Syndromes method(辨證論治). As there is Constitutional Medicine prescription(四象醫學處方) using constitutional Large & Small Relation of Jang and Bu organs(臟腑大小 關係), in acupuncture treatment we can use the Differentiation of Syndromes method of Sa-am acupucture, applying constitutional Large & Small feature of Jang and Bu organs(臟腑大小) in Taeguk Acupucture and 8 Constitution Acupuncture we can derive a suitable prescriptions. 2. Taeguk Acupucture and 8 Constitution Acupuncture is an acupunture method created upon the constitutional theory. Taeguk Acupucture lacks a theory and has problems with its practical use. 8 Constitution-Acupuncture has a theory, thus it can give us the chance to make derived diverse prescriptions for each diseases. 3. Sa-am Acupucture uses exclusively Manual technique(手技法), breathing Posa method(呼吸補瀉法), YoungSu Posa method(迎隨補瀉法) and also retaining method(留鍼法). Taeguk Acupunctune is directed related with WonBang Posa method(圓方補瀉法), twirling method(撚鍼法) and uses retaining method. 8 Constitution-Acupuncture works only with YoungSu Posa method and also One-insertion method(單刺法). 4. If we apply The Five Elements of five Su points and Interpromoting and Counteracting Relation(相生 相克 關係), we can control discords between Jang and Bu organs. Sa-am Acupucture, Taeguk Acupture and 8 Constitution Acupuncture which use five Su points can make better results in Jang and Bu organs disease. 5. Sa-am Acupunture needs diverse applications of Organ picture theory(臟象論), Pathogenesis theory(病機學說) and an proper prescription studies by Differentiation of Syndromes(辨證). Taeguk Acupuncture and 8 Constitution Acupuncture has a organized prescription methods by constitutional Large & Small relation of Jang and Bu organs(臟腑大小), thus we need to focus on objectification in constitutional differentiation.

• Journal of Convergence for Information Technology
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• v.8 no.6
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• pp.367-374
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• 2018

The purpose of this research is to promote traditional markets, which are part of urban regeneration project, and to promote cultural and tourism market by applying characteristics and differentiated elements through story development through market-related resources in order to secure identity of the JeCheon Central market that lost function of the traditional market and regional aging of the traditional market. To this end, the basic survey and analysis of the Jecheon area and the current situation of the Jecheon Central Market were conducted to diagnose problems and to analyze keywords through surveys by local merchants and visitors. By drawing up measures to vitalize the Jecheon Central Market by floor and space, the Jecheon Central Market's design story is developed and applied so that it can restore the image of the local traditional market through regional and cultural elements and become a center of space and culture that can become a landmark for the region in the future. The storytelling designed for this purpose shall be linked to the spatial planning of each floor as well as the C.I. and exterior of the C.I. and the building of the Jecheon Central Market, and the identity of the Jecheon Central Market can be reestablishe.