• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.28 no.7
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• pp.299-304
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• 2016

In recent years, heat source systems which have a principal effect on the performance of buildings are difficult to design optimally as a great number of design factors and constraints in large and complicated buildings need to be considered. On the other hand, it is necessary to design an optimum system combination and operation planning for energy efficiency considering Life Cycle Cost (LCC). This study suggests a multi-level and multi-objective optimization method to minimize both LCC and investment cost using a genetic algorithm targeting an office building which requires a large cooling load. The optimum method uses a two stage process to derive the system combination and the operation schedule by utilizing the input data of cooling and heating load profile and system performance characteristics calculated by dynamic energy simulation. The results were assessed by Pareto analysis and a number of Pareto optimal solutions were determined. Moreover, it was confirmed that the derived operation schedule was useful for operating the heat source systems efficiently against the building energy requirements. Consequently, the proposed optimization method is determined by a valid way if the design process is difficult to optimize.

• Journal of the Korean Institute of Intelligent Systems
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• v.16 no.4
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• pp.416-422
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• 2006

Most of the existing statistical models of software manpower profile are based on the assumptions of the usage and development process. Therefore, there is no universally applicable estimation and prediction model. To develop a prediction model, this paper suggests the predictive filter as a prediction model for software manpower profile. Firs of all, we investigate the software manpower profile and we suggest the input-output of predictive filter and method for parameter determination. Then, its usefulness is empirically verified by analyzing the actual data obtained from the software projects. Based on the average relative prediction error and Pred(0.25), the suggested predictive filter is compared with other well-known statistical estimation models. As a result, the predictive filter generally has a simple structure and on the other hand, it adapts the software manpower profile very well.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2012.05a
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• pp.53-54
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• 2012

This study is aimed at utilizing LCA processor with BIM LOD, eliciting the problems of the existing environmental assessment by constructing the database for environmental values of green buildings. For these objects, environmental load database of BIM construction material and evaluation process are presented, after matching BIM family based environmental load database which is available during evaluation stage, input-output tables and Korea LCI database to standard item code of public procurement service. It is a important factor in environmental assessment of building to develop database unit of standard item code for BIM and construction material. Thus, the results of this study are expected to provide basic data for improving effectiveness of construction through BIM based environmental load evaluation database. Furthermore, the provided environmental load database unit for construction material is considered to be available as basic information for BIM study by suggesting a processor connecting BIM with LCA and along with this, continuous examination on the connection process is needed.

• Journal of the Korean Society for Railway
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• v.10 no.4
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• pp.438-443
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• 2007

This paper proposes an integrated SE process for the development of railway systems with safety assessment included. Although the safety assessment process must be performed with SE process properly with good coordination, the interfaces between the two processes have not been clear. Thus, in many of safety critical system developments in Korea, it is difficult to assess safety in proper development phase. The process model proposed in this paper is based on both the concept of system life cycle and the repetitive use of SE process. In each of development phases, appropriate safety assessment methods are described. Also the evaluation of the integrated system incorporating safety factors is described. The resultant process model is expressed by the Enhanced Functional Flow Block Diagram (EFFBD) using a CASE tool. The model also allows timeline analysis for identifying activity flow and data flow, resulting in the effective management of process. In conclusion, the integrated process enable both the SE process and safety assessment process to cooperate with each other from early development phase throughout the whole system life cycle.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.20 no.4
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• pp.280-286
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• 2008

In this study, characteristics simulation of heat pump system is investigated for heating and cooling using sewage water as a heat source. A simulation program for preestimate operation characteristics of heat pump system is developed. The performance of this system is resolved by several variables and the characteristics which is based on actual air and sewage temperature data. The simulation results agree well with the experimental values of COP. In the analysis of system characteristics, the COP is changed between $3\sim5$ in winter season for heating load, $4\sim6$ in summer season for cooling load. As the results of Life Cycle Cost analysis over a 15 year life cycle, the energy cost could be reduced by 250 million won if a heat pump system was used instead of a conventional boiler and an absorbtion refrigerator on the office building.

• Proceedings of the CALSEC Conference
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• 2003.09a
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• pp.72-77
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• 2003

Visual inspection works are very important part of facility maintenance and management life cycle as a step of creating base data for decision making and maintenance and repair. But currently, visual inspection works have been performed unefficiently and unreliably as works on hand, duplication of works, decisions of defect state, unutilization of inspection history, lack of professional and so on. In this research, we developed visual inspection system that processes inspection work efficiently and provides reliability of inspection output, as a target of bridges, tunnels, underground roadway on national road. We defined problems through visual inspection work analysis, examined the solutions and reflected to functional design of system. We will plan to utilize this system in HMCS(Highway Maintenance and Construction Service).

• Journal of Fisheries and Marine Sciences Education
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• v.28 no.4
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• pp.1014-1023
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• 2016

The purpose of this study is to suggest improvement directions and strategies for the minimization of ex-post damage and prevention of the generation of derelict fishing gear which lead to decreased fisheries resources and deteriorated marine ecosystem through ghost fishing and damaging spawning and growth grounds. Current problems related to derelict fishing gear in Korea are lack of reliable data on the generation amount of derelict fishing gear, absence of life-cycle monitoring and management system, insufficient supports for derelict fishing gear collection programs and R&D investment in environmentally friendly fishing gear, etc. Thus, this study suggests three basic improvement directions to prevent the generation and minimize the damage of derelict fishing gear. Such improvement directions contain more detailed strategies such as establishment of fishing gear management law and life-cycle management system, strengthening entry regulations on fisheries causing serious ghost fishing problems, increased supports for R&D investment and dissemination of bio-degradable fishing nets, and promotion of voluntary agreements among competing fishermen's groups.

• Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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• 2003.08a
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• pp.376-381
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• 2003

The reliability analysis of overtopping probability is proposed. In order to estimate the expected overtopping probability of the rubble mound breakwater, the experimental results of individual wave runup height is applied for the analysis of irregular wave system. The joint distribution of wave heights and periods is used for the input data of runup calculation because the runup height depends on the wave height and period. The runup heights during the one event that the design wave attacks the rubble mound breakwater extend to the one life cycle of 60 years. Utilizing the Monte-Carlo method, the one life cycle is tried more about 60 times for obtaining the expected value of overtopping probability. It is found that the inclusion of the variability of wave tidal and wave steepness has great influence on the computation of the expected overtopping probability of rubble mound breakwater. The previous design disregarding the tidal fluctuation largely overestimates or underestimates the expected overtopping probability depending on tidal range and wave steepness.

• Journal of Information Technology Applications and Management
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• v.20 no.2
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• pp.69-87
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• 2013

The expanded spiral model in this paper consists of five processes of architecture design, architectural construction, architectural maintenance, operation, and architectural management. The former four processes are executed alternatively, while the latter architectural management process is executed continuously interacting with the other processes during the whole life cycle of the system. The expanded spiral model provides a conceptual framework to sort discussions of architectural degeneration into those of product-oriented processes and those of management processes, making it possible to incorporate the models and body of knowledge about project and program management especially those of Project Management Institute, into discussions of architectural degeneration. A good architecture decomposes the software-intensive system into components mutually interacting in a well-formed structure. The architecture design process and the architectural construction process together create the object system with well-designed architecture. The architectural maintenance process prevents the implemented architecture deviate from the designed architecture. The architectural management process monitors the changes of requirements including architecturally significant requirements, supports the other processes to be executed reflecting various perspectives of stake-holders, and creates and documents the reasons of architectural decisions, which is considered as a key element of the architecture.

• Journal of Navigation and Port Research
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• v.34 no.3
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• pp.189-194
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• 2010

As the seriousness of the global environment is gaining our attention recently, studies on application of LCA(Life Cycle Assessment) to ship are being carried out dynamically in various industrial fields. This study was carried out to examine the application of LCA to ships and was focused on the inventory analysis on global warming gas from merchant cargo ships. Two merchant cargo ships were adopted as ship models. Actual voyage data of at last several years was used to analysis the ship's exhaust gas inventory. The analysis shows how many weight of global warming gas being exhausted to transport 1 ton of each cargo per 1 nautical mile.