• Journal of Korean Society of Water and Wastewater
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• v.11 no.2
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• pp.50-64
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• 1997

Life cycle assessment (LCA) on total sewage sludge treatment system from thickening to incineration and melting was performed for estimating global environmental impact as $CO_2$. In general, the life cycles of actual treatment facilities consist of construction, operation and dismantlement. In this study, the amount of $CO_2$ produced from both whole and each life cycle step of currently used unit sludge treatment processes were calculated by inventory analysis. In addition, in the all processes investigated in this study, individual $CO_2$ production unit (CPU), i.e. total produced $CO_2$ by treating a unit weight of sludge was also calculated. By using the CPU matrix of the unit processes, it was possible to simulate the $CO_2$ production for any type of complex-system as well as to trace a dominant cause of $CO_2$ production in each process. Four selected alternatives examined here, each involve the same disposal way but differ substantially in the $CO_2$ exhaust.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2000.10a
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• pp.109-114
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• 2000

In this paper, an optimum design model for minimizing the life-cycle cost (LCC) of high-speed railway steel bridges is proposed The point is that it takes into account service life process as a whole, and thus the life-cycle costs include initial (design, testing, and construction) costs, maintenance costs, expected strength failure costs and expected serviceability failure costs. The problem is formulated as that of minimization of expected total life-cycle cost with respect to the design variables. By processing the optimum LCC design the effective and rational basis is proposed for calculating the total LCC and the sensitivity analysis of LCC is peformed. Based on a numerical example, it may be positively stated that the optimum LCC design of high-speed railway steel bridges proposed in this study provides a lot more rational and economical design, and thus the proposed approach will expedite the development of new concepts and design methodologies that may have important implications in the next generation performance-based design codes and standards.

• Journal of Power System Engineering
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• v.17 no.4
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• pp.131-138
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• 2013

The purpose of this study is to suggest the evaluation standard of cost-effectiveness analysis for renew of architectural equipment in public building. Evaluation items of cost-effectiveness analysis for renew of architectural equipment in public building were used life cycle cost, energy consumption(ton of oil equivalent), green house gas emissions(ton of carbon dioxide) and maximum power demand. Life cycle cost is the process of making an economic assessment of an item, area, system, or facility by considering all significant costs of ownership over an economic life, expressed in terms of equivalent costs. The essence of life cycle costing is the analysis of equivalent costs of various alternative proposals. The social concern with green house gas and maximum power demand of architectural equipment field has been growing for the last several years.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.1084-1091
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• 2011

The primary purpose of the safety management is to prevent the loss of lives or physical damages arising from potential hazards in the railway signaling system. Since such potential hazards may occur at any time during the system life-cycle from design and development to maintenance, safety management activities have to be continuously taken in the course of the system life-cycle. In this paper, presented for Safety Activity Process. (Phase, Methods, Documentation)

• Journal of the Korean Home Economics Association
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• v.48 no.9
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• pp.41-54
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• 2010

This study attempted to determine how the subjective knowledge related to a consumer's life cycle influences their information search in the decision making process. The data was collected using a total of 349 questionnaires for the final analysis of this study. SPSS 12.0 for windows was used for the data analysis and the detailed analyses included descriptive analysis, factor analysis, reliability tests, one way ANOVA, multiple regression analysis and t-tests. The results of this study showed that there are differences in the subdivisions of subjective knowledge of apparel according to the consumer's life cycle and there is a difference in the types of information searches according to the consumer's subjective knowledge, and the subdivisions of subjective knowledge of the consumers influence their information search. This study showed that although it affected the internal search, the media search, and the store search, it did not influence the personal search in the decision making process.

• Journal of the Korean housing association
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• v.14 no.5
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• pp.65-74
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• 2003

Recently, the environmental conservation has been emphasized over the world. Building industry should carefully reflected the development focused on the economic aspect as well as the environmental considerations. Therefore, it requires the technology development to mitigate the environmental pollution through the reducement of the energy and resources usage amount over the building life cycle. For these, it should be required to set up the analysis methodology to grasp the amount of the environmental pollution and energy and resources in each step of building life cycle. In this paper, it aimed at preparing the analysis process and analyzing the embodied energy and $CO_2$ and $SO_x$ emission according to the building work, field work, mechanical and electrical work on the new building and remodelling, utilizing the inventory analysis which is one of the LCA process.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.20 no.43
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• pp.365-379
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• 1997

Currently the problem of air pollution caused by the motor vehicle emission is of the most serious problems to be solved. Life Cycle Assessment is a process to evaluate the environmental burdens associated with a product or process by identifying and quantifying energy and materials used and wasters to the environment. This paper establishes a Life Cycle Assessment Systems which satisfies the criteria motor vehicle emission for the automobile producers who are currently producing the automobiles with catalytic convert. This plan also considered the constraint of the effective motor vehicle emission by way of the exhaust gas recirculation, electronic fuel injection, closed loop carburetor. In order to develope the performance of the LCA systems, the recent emissions test data have also been applied. The result of the development LCA systems has proved that the LCA plans presented in this paper satisfies the criteria motor vehicle emission and will be contributed to constrain the motor vehicle emission most effectively.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.5
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• pp.53-59
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• 2019

Continuous ship unloaders (CSUs) are used for the uninterrupted transport of material in processing industries, power plants, and harbors in accordance with the stream rate of the material. This study analyzed the structural integrity and fatigue life of a CSU structure using finite element structural analysis in ANSYS APDL software. The stress varied greatly depending on the luffing angle and the slew angle of the boom conveyor. The structural integrity of the CSU girder was evaluated by applying ASME BPVC Section VIII Division 2. The fatigue cycle at the angle with the greatest stress difference was calculated. The fatigue cycle was calculated by applying the JIS B 8821:2013 fatigue curve. It was confirmed that the fatigue cycle of the CSU satisfies the allowable fatigue of 200,000 cycles.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2006.11a
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• pp.99-105
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• 2006

A Launch vehicle which consists of many sub-systems is one sophisticated huge system. A lot of experience and system integration technique are needed for the launch vehicle to accomplish a mission successfully. The characteristics and complexity in the development of the launch vehicle depend on the size of that. However the systematic work flow is similar to each other. This paper introduces a standardized development process which is based on the whole program life cycles and experiences of NASA on the development of the launch vehicle. The development process can be categorized into 10 phases through the life cycle of the launch vehicle.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.14 no.1
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• pp.1-8
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• 2015

Productivity of machining using machine tools is affected by cutting conditions such as cutting speed, feedrate and depth. However, undesirable conditions that lengthen the machining cycle and shorten the tool life occur frequently because determination of cutting condition is known to depend on human experience. This paper presents a method of cycle reduction by removing undesirable conditions. For cycle reduction, maximum cutting load is determined using commercial FEM simulation code. The feedrate in the NC program is altered based on a predetermined cutting load value. To make a decision on the proposed effectiveness, a simulation is performed for the brake hub parts of an automobile. From the evaluation, it was found that the cycle reduction was under 15%.