• Journal of Drive and Control
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• v.17 no.1
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• pp.21-26
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• 2020

The load characteristics of a piston pump holder due to the squeeze effect are influenced by the surface shape and gap thickness of the holder (cradle). Therefore, the pressure distribution and the load capacity of the piston pump holder due to the squeeze effect are studied by using the CFD software and the surface shape and gap thickness of the piston pump holder are considered. In order to verify the accuracy of numerical results, the load capacities of a circular plate holder are numerically studied, and the accuracy of numerical results is verified by comparing with the theoretical results. Also, the pressure distribution and load capacity of the rectangular plate holder of a piston pump are obtained by using the CFD software. The results show that the load capacity of the square plate holder with grooves is slightly higher at a low gap thickness, but the effects of the number and arrangement of grooves on the load capacity of the holder are weak. We conclude that the load capacity and the maximum pressure are slightly affected due to the existence of grooves on the holder surface, and the fluid storing effect of the holder surface grooves during the operation is likely to prevent the dry-sticking phenomenon.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.38 no.6
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• pp.649-653
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• 2014

Although many reliability analysis and reliability-based design optimization (RBDO) methods have been developed to estimate system reliability, many studies assume the uncertainty of the design variable to be constant. In practice, because uncertainty varies with the design variable's value, this assumption results in inaccurate conclusions about the reliability of the optimum design. Therefore, uncertainty should be considered variable in RBDO. In this paper, we propose an RBDO method considering variable uncertainty. Variable uncertainty can modify uncertainty for each design point, resulting in accurate reliability estimation. Finally, a notable optimum design is obtained using the proposed method with variable uncertainty. A mathematical example and an engine cradle design are illustrated to verify the proposed method.

• Animal Systematics, Evolution and Diversity
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• v.20 no.2
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• pp.225-230
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• 2004

The egg, larva, and pupa of Paracycnotrachelus longiceps (Motschulsky) are described and illustrated. The species is a well-known forest pest and lives on such host plants as Quercus acutissima, Q. aliena, Q. mongolica, and Q. serrata. Taxonomic notes and cradle structure are also provided.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2002.11a
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• pp.228-233
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• 2002

In this study, Life Cycle Assessment method has been carried out the Corrugated board box in considering environmental aspects by quantifying the environmental emission and assessing its environmental impact potential. The system boundary in this study is selected from cradle to gate stage(raw material acquisition, raw material production and product manufacturing) of the paper product. To evaluate the environmental impact potential, impact categories are divided into 8 categories. As a results, abiotic resource depletion of the impact categories has the largest contribution to the total impact potential as 31.02% of total, Next were continued ecotoxicity having a contribution of 27.17%. In the life cycle, environmental impacts from law material production stage were contributed largely as 80.78%.

• Environmental Engineering Research
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• v.21 no.4
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• pp.355-364
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• 2016

Beijing, as a cradle of modern industry and the third largest metropolitan area in China, faces more responsibilities to adjust industrial structure and mitigate carbon emissions. The purpose of this study is aimed at predicting and comparing industrial carbon emissions of Beijing in ten scenarios under different policy focus, and then providing emission-cutting recommendations. In views of various scenarios issues, system dynamics has been applied to predict and simulate. To begin with, the model has been established following the step of causal loop diagram and stock flow diagram. This paper decomposes scenarios factors into energy structure, high energy consumption enterprises and growth rate of industrial output. The prediction and scenario simulation results shows that energy structure, carbon intensity and heavy energy consumption enterprises are key factors, and multiple factors has more significant impact on industrial carbon emissions. Hence, some recommendations about low-carbon mode of Beijing industrial carbon emission have been proposed according to simulation results.

• Journal of the Korean Society of Systems Engineering
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• v.7 no.1
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• pp.53-56
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• 2011

Configuration management plays a key role in systems engineering process for any project from earlier stage of development. It consists of five major activities, ie., configuration management planing, configuration identification, configuration control, configuration status accounting and configuration verification and audit, and is essential to control system design, development and operation throughout entire life cycle of the system development. And it is directly associated with other part of systems engineering management process, ie., technical data management which provides traceability of important decisions and changes during development. In this paper, we describe how to apply CASE(Computer-aided Systems Engineering) tool-Cradle for the configuration management to achieve effectiveness of Technical Management process.

• Journal of the Korean Society of Systems Engineering
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• v.9 no.2
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• pp.69-82
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• 2013

US DoD operated JCIDS(Joint Capability Integration and Development System) for top down requirement generation. Although the JCIDS can be a good practice for the countries which are trying to shift from bottom up to top down requirement generation, it contains many processes related with review and approval. In this study we structured a joint capability integration and development process from the JCIDS eliminating the organization dependent review or approval process so that it can be applied to any organization with some modification. Furthermore we implemented the process in the computer aided systems engineering tool, Cradle, for convenient use of the process. The result of this study can provide a basic process for top down capability development, and an efficient why of doing each element of the process using CASE tool.

• International Journal of Quality Innovation
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• v.8 no.2
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• pp.32-56
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• 2007

Life Cycle Assessment (LCA) aims to analyze possible impact upon manufacturing process and availability of products, and also study the environmental considerations and potential influence during entire life cycle ranging from procurement, production and utilization to treatment (namely, from cradle to tomb). Based on high-density polyethylene (HDPE) pipe manufacturing of company A, this case study would involve evaluation of environmental influence during the production process. When the manufacturing process has been improved during "production process" and "forming cooling" stage, it is found that capital input on "electric power" and "water supply" could be reduced, thus helping to sharpen the competitive power of company A, and also ensure sustainable economic and industrial development in accordance with national policies on environmental protection.

• Proceedings of the KSR Conference
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• 2005.05a
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• pp.1028-1032
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• 2005

Life cycle assessment(LCA) has been developed from the concept of life cycle thinking. Life cycle thinking implies that everyone in the whole chain of a product's life cycle, from cradle to grave, has a responsibility and a role to play, taking into account all the relevant external effects. LCA is an analytical tool for identifying environmental loads and assessing the environmental impact in the whole chain of a product's life cycle. In Europe and Japan, LCA and ecodesign study for railway industry have been actively carried out recently. However, LCA for railway industry in domestic is still infant. LCA is standardized in International Organization of Standardization(ISO), base on the ISO 14040 standards, 307 life cycle inventory(LCI) database for infrastructure and base materials have been established in total since 1999. Some of LCI database can use in performing LCA for trains and railway infrastructure, but still not enough to derive accurate LCA result. Therefore, railway oriented LCA methodology and LCI DB are needed to be developed.

• Journal of Korea Society of Digital Industry and Information Management
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• v.10 no.3
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• pp.107-117
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• 2014

The personal information extrusion accident(hacking, improper maintenance) by the internet has been increased rapidly during the last ten-year period. The personal information includes Korean resident registration number, name, cellphone number, home telephone number, E-mail address, home address, etc. Korean resident registration number is unchangeable from the cradle to the grave. Illegally accessed personal information can be wrongfully resoled or used at phishing scam. In this paper, we propose a alternative means of Korean resident registration number using the authorized certificate. The authorized certificate is in use safely in Internet. The authorized certificate(included Chinese name) is in used in offline service, the authorized certificate(included English name) is used in online(for government service) and the authorized certificate(not included name) is used in online(for private service). The authorized certificates are possible for discard, republication. The method can reduce the possibility of the personal information extrusion.