• Journal of the Korean Society of Marine Environment & Safety
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• v.29 no.7
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• pp.971-979
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• 2023

Small ships (<499 GT) constitute 46% of the existing ships, therefore, it can be concluded that they produce relatively high CO₂ gas emissions. Operating in optimal trim conditions can reduce the resistance of the ship, which results in fewer greenhouse gases. An affordable way for trim optimization is to adjust the weight distribution to obtain an optimum longitudinal center of gravity (LCG). Therefore, in this study, the effect of LCG changes on the resistance of a small planing ship is studied using empirical and numerical analyses. The Savitsky method employing Maxsurf resistance and the STAR-CCM+ commercial computational fluid dynamics (CFD) software is used for the empirical and numerical analyses, respectively. Finally, the total resistance from the ship design process is compared to obtain the optimum LCG. To summarize, using numerical analysis, optimum LCG is achieved at the 46.2% length overall (LoA) at Froude Number 0.56, and 43.4% LoA at Froude Number 0.63, which provides a significant resistance reduction of 41.12 - 45.16% compared to the reference point at 29.2% LoA.

• Journal of the Society of Naval Architects of Korea
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• v.50 no.4
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• pp.240-247
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• 2013

Hydrodynamic characteristics of a planing craft are very sensitive to the hull form variations, especially when the craft navigates with high-speed. Therefore, we need to verify hydrodynamic performances of the craft during the process of hull form design. In this paper, motion performances of a 40ft class cruise leisure boat are evaluated by both model tests and theoretical analyses using two different methods. Model tests are carried out at calm sea and regular wave conditions using high speed towing carriage installed in SNU towing tank. Theoretical methods used are a empirical method proposed by Martin (1976) and a potential method based on Rankine panel (DNV, 2010). The results from the theoretical methods are compared with and verified by those of model tests. Results of empirical formula showed somewhat larger motion RAOs and resonant frequencies than those of model tests. Potential based method showed even larger discrepancies with the model test results. From the analyses of comparison results, we could confirm the limitation of each theoretical method and suggest the way of improvement for the better prediction of motion performances.

• Journal of the Korean Institute of Landscape Architecture
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• v.20 no.4
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• pp.12-25
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• 1993

The purpose of this study is to interpret the landscape meaning of village grove and then combines this interpretations with landscape planing if it is possible. So we chose four village groves among seven villlage interpretations with landscape planing if it is possible. So we chose four village groves among seven village groves in HAMPYUNG & YOUNGKWANG Province(CHONRANAMDO, KOREA). The reason why we did it is that the meaning of korean groves is divided into three types(Confucianism, Feng-shui, Native belief etc.) according to original planting reasons. This study was done mainly by both referring to the regional character of those types and examining the nature of grove meanings. As a result of this process, we are able to find three demensions which were explained by physical-ecological, user's behavioral and cultural meaning. 1. Physical landscape of village grove is composed with ecological meaning that is related with people's land use not only inside but outside of it. So this kind of ecological meaning is the mutual relation among physical elements of village groves, for example old high trees, surface, user's facilities, land use around a grove and soon. 2. User's behavior meaning of grove shows that it has high relation with physical dimension, for example distance and accessiblity to a grove, linkage with open space around a village and so on. User's behavior inside of grove is usually divided into three types(recreation, play, ritual services). Especially, we were able to find a tendency to have numerous people use in the case of a village grove well to preserve its ritual service. 3. Cultural meaning of grove has the holistic character which usually defines the regional theme of each village and village grove(Confucianism, Feng-shui, Native belief etc.). So, the Landscape meaning of village grove is not only a physical shape but a certain concept existing inside of village grove. This diversed meaning existing in a grove have a direct effect on good fortune or misfortune of a village and its dwellers.

• KIEAE Journal
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• v.13 no.6
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• pp.77-82
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• 2013

Light environment in the school building is one of the most important elements of the plan in order to improve student's ability to learn and the healthy growth. Thus, the window plan of the school building is a great addition to improve environmental-friendly performance through the daylight control. Daylight is highly beneficial for improving the indoor environmental quality and reducing building energy consumption, daylighting applications are scarcely considered, especially during the school building design process, because of lack of previous studies on the light environment of student and complex simulation process. Therefore, daylighting process were performed using ECOTECT, which has various advantage such as easy user interface and simple simulation processes. ECOTECT simulation were performed using weather data. As a result, ECOTECT simulation are performed for daylight autonomy and useful daylight illuminance. Using this data, Window planing is to propose and effective method in the early stages of design.

• Journal of Ocean Engineering and Technology
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• v.11 no.3
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• pp.200-211
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• 1997

Most recently, offshore Engineering & Construction field is concerned about integration management technology such as CIM(Computer Integrated Manufacturing), PDM(Product Data Management) and Enterprise Information Engineering in order to cope with the rapid change of engineering and manufacturer specification as per owner's requirement during construction stage of the project. System integration and integrated data modeling with relational database in integration management technology improve the quality of product and reduce the period of the construction project by reason of owing design information jointly. This paper represents the design methodology of system integration using Business Process Reengineering by the case study. The case study is about the offshore plant material information process from front end engineering design to detail engineering for the construction and the basis of monitoring system by integrating and sharing the design information between the 2D intelligent P&ID and 3D plant modeling using relational database. As a result of the integrated data modeling and system integration, it is possible to maintain the consistency of design process in point of view of the material balancing and reduce the design assumption/duration. Near future, this system will be expanded and connected with the MRP(Material Requirement Planing) and the POR (Purchase Order Requisition) system.