• 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.

• Asia-Pacific Journal of Business
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• v.10 no.4
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• pp.167-180
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• 2019

The purpose of this paper is to explore Laos mysterious 'Plain of Jars' area in a village. 'The Plain of Jars' site has been proposed for listing as a UNESCO World Heritage Monument. The study used convenience sampling and surveyed tourists who visited Tonghahin in Xieng Khouang. The results of this study are summarized as follows: First, Tonghahin is introduction stage from the tourism life cycle due to lack of basic infrastructure such as road condition, transportation, information service, etc,. Second, this study examined the ways to improve methods such as adminstration system and hospitality service manual for tourist site. Thereafter, third, to develop each attraction, they have come with better tourism products. These things are foresight-able to-do list for nomination as the UNESCO World Heritage. The recommendations and suggestions for future research are also discussed.

• International conference on construction engineering and project management
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• 2009.05a
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• pp.375-380
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• 2009

Gas & Oil plant construction projects are increasing recently all over oil-producing countries. An EPC (Engineering, Procurement and Construction) company, which participates in the plant projects, should possess pertinent engineering licenses and EPC management skills to create high added-value. Nonetheless, there exist various risks involved in the EPC life cycle process due to such characteristics of construction projects as long duration of construction time and complicated processes along with the procured goods or services subjected to various logistics. The objective of this paper is to analyze the overall EPC life cycle for proper process and to examine various information and document. Additionally, the principal data for the analysis of the EPC process are derived from personal interviews with experts and specialty contractors of the plant projects. The results of this study would be widely used as a guide for efficient and effective management of overseas gas plant projects.

• International conference on construction engineering and project management
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• 2005.10a
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• pp.748-753
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• 2005

In a super-highrise residence project, a project manager needs to form the long-term risk management plan which covers the problems from the beginning of project to the time of demolition. The cause and responsibility for a risk are clarified and quantitatively evaluated through the life cycle of a project. Development of the system which supports a risk strategy effectively is needed as a project becomes complex. In this paper, through the life cycle of a specific super-highrise residence project, a risk phenomenon is specified from a viewpoint of each participant, and the mathematical model is formulated choosing the combination of the optimal strategy against a risk quantitatively within a fixed risk strategy budget.

• Earthquakes and Structures
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• v.25 no.1
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• pp.69-78
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• 2023

Life-cycle performance analysis of a reinforced concrete box section bridge was generated. Moreover, Monte Carlo simulation with important sampling (IS) was used to simulate the bridge material and load uncertainties. The bridge deterioration model was generated with the basic probabilistic principles and updated according to the measurement data. A genetic algorithm (GA) with the response surface model (RSM) was used to determine the deterioration rate. The importance of health monitoring systems to sustain the bridge to give services economically and reliably and the advantages of fiber-optic sensors for SHM applications were discussed in detail. This study showed that the most effective loss of strength in reinforced concrete box section bridges is corrosion of the reinforcements. Due to reinforcement corrosion, the use of the bridge, which was examined, could not meet the desired strength performance in 25 years, and the need for reinforcement. In addition, it has been determined that long-term health monitoring systems are an essential approach for bridges to provide safe and economical service. Moreover the use of fiber optic sensors has many advantages because of the ability of the sensors to be resistant to environmental conditions and to make sensitive measurements.

• Parasites, Hosts and Diseases
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• v.55 no.2
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• pp.193-196
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• 2017

This study investigated the development characteristics of Dermacentor everestianus under laboratory conditions. The time taken for D. everestianus to complete the whole life cycle was 110.2 days on average, and the average developmental durations of larvae and nymphs were 17.1 days and 29.5 days, respectively. The summation of the prefeeding, feeding, and preoviposition periods of females was 17.8 days, and the oviposition and egg incubation lasted for 18.1 days and 27.7 days, respectively. A highly positive correlation was observed between the weight of engorged female and the number of egg mass laid (r=0.947). The reproductive efficiency index and the reproductive fitness index were 7.1 and 6.1, respectively.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.9
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• pp.61-67
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• 2017

Research into the selection of suitable materials and the development of fast processing methods for press die manufacturing is absolutely necessary to reduce the production time and cost. In particular, knowledge of its heat properties must be considered whendeveloping a long press die. Generally, as the main component materials of press dies, Cr, W low alloy tool steel, high carbon-high chrome steel, high speed steel, etc., are used as thetooling steel for the cold die. Machine tools and wire-cut electric discharge machining are mainly used for processing the press die parts. There are many differences in the machining time and life cycle of die parts depending on the machining process. The parts produced by milling and grinding have a high manufacturing time and cost with a long life cycle, while thosemade by milling and wire-cut discharge machining have areduced manufacturing time and cost,whereastheir die life cycle is reduced. Therefore, in this study, we will discuss amethod of improving the life cycle of the die parts by using heat treatment as a processing method that reduces the manufacturing time and cost. SEM, EDS analysis and the surface roughness analysis of the surface and center of the workpiece are used for analyzing the specimens produced by three machining methods, viz. milling - grinding, milling - wire cut discharge, and milling - wire cut discharge - heat treatment. A method of making die parts having the same life cycle as those produced by milling - grinding is developed with the milling - wire cut discharge - high temperature tempering method.

• Korean Journal of Construction Engineering and Management
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• v.16 no.4
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• pp.41-49
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• 2015

The amount of energy consumed in air ventilation systems of public facilities accounts for 40% of their total energy consumption. To reduce their energy consumption, applying variable speed operation controlled by an inverter with a high-efficiency motor is suggested. Since these methods require higher initial investment costs compared to the existing systems, economic evaluation should be conducted from a long-term perspective. While LCCA(Life Cycle Cost Analysis) model is useful to estimate net savings of alternatives that differs with respect to initial costs and operating costs, the environmental burdens are not considered. On the contrary LCA(Life Cycle Assesment) model is suitable to assess environmental impacts associated with the stages of a product's life but it does not consider costs. In this study, the high-efficient motors are introduced into the air ventilation system of a subway station and a comprehensive analysis on the economic and environmental impacts of the proposed method is conducted by using LCCA and LCA model.

• Journal of the Korean Wood Science and Technology
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• v.42 no.1
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• pp.1-12
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• 2014

This study carried out life cycle assessment for evaluating environmental impacts of timber Arch-Truss bridge by using domestic Pinus rigida Miller glued-laminated timber throughout life cycle such as extraction, manufacturing, transportation, construction, use, dismantlement, transportation of waste, disposal and recycling. The life cycle GHG (GreenHouse Gas) emissions of the target bridge are 192.56 ton $CO_2$ eq. in 50 years. Especially, the life cycle GHG emissions of concrete used in the target bridge are 82.84 ton $CO_2$ eq. which accounts for 53.02% of the GWP (Global Warming Potential) in extraction and manufacturing stages. The target bridge is constructed of $116.57m^3$ of domestic Pinus rigida Miller glued-laminated timber and used timber has stored 104.72 ton $CO_2$. If an effect of carbon storage in timber is applied to the total GHG emissions of the target bridge, the GHG emissions can be reduced by 54.38%. In the case of substitution effect, if domestic Pinus rigida Miller glued-laminated timber replaces steel manufactures used in other bridge which has the same structure and life span as the target bridge, the GHG emissions in extraction and manufacturing stages can be reduced by 10.26% to 23.91%.

• KIPS Transactions on Software and Data Engineering
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• v.6 no.12
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• pp.543-548
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• 2017

In recent years, the importance of the safety of medical device software has been emphasized because of the function and role of the software among components of the medical device, and because the operation of the medical device software is directly related to the life and safety of the user. To this end, various standards have been set up that provide activities that can effectively ensure the safety of medical devices and provide their respective requirements. The activities that standards provide to ensure the safety of medical device software are largely divided into the development life cycle of medical device software and the risk management process. These two activities should be concurrent with the development process, but there is a limitation that the risk management requirements to be performed at each stage of the medical device software development life cycle are not classified. As a result, developers must analyze the association of standards directly to develop risk management activities during the development of medical devices. Therefore, in this paper, we analyze the relationship between medical device software development life cycle and risk management process, and extract risk management requirement items. It enables efficient and systematic risk management during the development of medical device software by mapping the extracted risk management requirement items to the development life cycle based on the analyzed associations.