• Computers and Concrete
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• v.29 no.2
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• pp.69-79
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• 2022

For long underground box utility tunnels, post-tensioned precast concrete is often used. Between precast tunnel segments, sealed waterproof flexible joints are often specified. Fault displacement can lead to excessive deformation of the joints, which can lead to reduction in waterproofing due to diminished contact pressure between the sealant strip and the tunnel segment. This paper authenticates utilization of a finite element model for a prefabricated tunnel fault-crossing founded on ABAQUS software. In addition, material parameter selection, contact setting and boundary condition are reviewed. Analyzed under normal fault action are: the influence of fault displacement; buried depth; soil friction coefficient, and angle of crossing at the fault plane. In addition, distribution characteristics of the utility tunnel structure for vertical and longitudinal/horizontal relative displacement at segmented interface for the top and bottom slab are analyzed. It is found that the effect of increase in fault displacement on the splice joint deformation is significant, whereas the effects of changes in burial depth, pipe-soil friction coefficient and fault-crossing angle on the overall tunnel and joint deformations were not so significant.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.16 no.9
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• pp.3043-3067
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• 2022

With the mobile traffic in the network increases exponentially, multi-access edge computing (MEC) develops rapidly. MEC servers are deployed geo-distribution, which serve many mobile terminals locally to improve users' QoE (Quality of Experience). When the cache space of a MEC server is full, how to replace the cached videos is an important problem. The problem is also called the cache replacement problem, which becomes more complex due to the dynamic video popularity and the varied video sizes. Therefore, we proposed a new cache replacement scheme based on local video popularity and video size to solve the cache replacement problem of MEC servers. First, we built a local video popularity model, which is composed of a popularity rise model and a popularity attenuation model. Furthermore, the popularity attenuation model incorporates a frequency-dependent attenuation model and a frequency-independent attenuation model. Second, we formulated a utility based on local video popularity and video size. Moreover, the weights of local video popularity and video size were quantitatively analyzed by using the information entropy. Finally, we conducted extensive simulation experiments based on the proposed scheme and some compared schemes. The simulation results showed that our proposed scheme performs better than the compared schemes in terms of hit rate, average delay, and server load under different network configurations.

• International Journal of Precision Engineering and Manufacturing
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• v.1 no.1
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• pp.133-145
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• 2000

Plastic molding designers are frequently faced with optimizing multiple defects in injection molded parts. these defects are usually in conflict with each other, and thus a tradeoff needs to be made reach a final compromised solution. In this study, an automated injection molding design methodology has been developed to optimize multiple defects of injection molded parts. Two features of the proposed methodology are as follows: one is to apply the utility theory to transform the original multiple objective optimization problem into single objective optimization problem with utility as objective function, the other is an implementation of a direct search-based injection molding optimization procedure with automated consideration of process variation. The modified complex method is used as a general optimization tool in this research. The developed methodology was applied to an actual molding design and the results showed that the methodology was useful through the CAE simulation using a commercial injection molding software package. Applied to production, this study will be of immense value to industry in reducing the product development time and enhancing the product quality.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.11
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• pp.5731-5754
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• 2019

In this paper, we redesign, implement, and evaluate ShareSafe (Based on SecGraph), an open-source secure graph data sharing/publishing platform. Within ShareSafe, we propose De-anonymization Quantification Module and Recommendation Module. Besides, we model the attackers' background knowledge and evaluate the relation between graph data privacy and the structure of the graph. To the best of our knowledge, ShareSafe is the first platform that enables users to perform data perturbation, utility evaluation, De-A evaluation, and Privacy Quantification. Leveraging ShareSafe, we conduct a more comprehensive and advanced utility and privacy evaluation. The results demonstrate that (1) The risk of privacy leakage of anonymized graph increases with the attackers' background knowledge. (2) For a successful de-anonymization attack, the seed mapping, even relatively small, plays a much more important role than the auxiliary graph. (3) The structure of graph has a fundamental and significant effect on the utility and privacy of the graph. (4) There is no optimal anonymization/de-anonymization algorithm. For different environment, the performance of each algorithm varies from each other.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.9
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• pp.210-221
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• 2000

Plastic mold designers and frequently faced with optimizing multi-quality issues in injection molded parts. These issues are usually in conflict with each other and thus tradeoff needs to be made to reach a final compromised solution. in this study an automated injection molding design methodology has been developed to optimize multi-quality characteristics of injection molded parts. The features of the proposed methodology are as follows : first utility theory is applied to transform the original multi-objective problem into single-objective problem. Second is an implementation of a direct search-based injection molding optimization procedure with automated consideration of robustness against process variation. The modified complex method is used as a general optimization tool in this study. The developed methodology was applied to an actual mold design and the results showed that the methodology was useful through the CAE simulation using a commercial injection molding software package. Applied to production this study will be of immense value to companies in reducing the product development time and enhancing the product quality.

• Proceedings of the Korea Association of Information Systems Conference
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• 1996.11a
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• pp.145-155
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• 1996

This paper is to describe the development of nesting software for the materials cutting plan of footwear manufacturing processes. In shoes cutting process, almost of the materials cutting plan is dependent upon worker's experience. Thus, the pattern nesting by worker's experience for materials cutting is different from the real cutting results and also different from the error size of yield in degree of worker's skill. Recently, a few of domestic shoes' makers make use of oversee's nesting software. But the nesting software unfits for the domestic actual circumstances, and is complex to use, and is expensive, and is not to be interfaced with the auto cutting machine. Therefore, we have developed the economic nesting systems that are easier for novice to use and fit for the domestic circumstances, which can syncronize with the development of the auto cutting machine. The system comprises interrelated modules for materials information, nesting simulation, utility. The architecture of system, the functions of each module, and the information processing procedures of each function are discussed.

• Journal of Korea Society of Industrial Information Systems
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• v.1 no.1
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• pp.203-217
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• 1996

This paper is to describe the development of nesting software for the materials cutting plan of footwear manufacturing processes. In shoes cutting process, almost of the materials cutting plan is dependent upon worker's experience. Thus, thepattern nesting by worker's experience for materials cutting is different form the real cutting results and also different form the error size of yield in degree of worker's skill. Recently, a few of domestic shoes' makers make use of oversee's nesting software.But the nesting software unfits for the domestic actual circumstances , and is complex to use , and is expensive , and is not to be interfaced with the auto cutting machine. Therefore , we have developed the economic nesting systems that are easier for novice to use and fit for the domestic circumstances, which can synchronize with the development of the auto cutting machine. The system comprises interrelated modules for materials information, nesting simulation, utility. The architecture of system, the function of each module, and the information processing proceduresof each function are discussed.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 1996.10a
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• pp.145-155
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• 1996

This paper is to describe the development of nesting software for, the materials cutting plan of footware manufacturing processes. In shoes cutting process, almost of the materials cutting plan is dependent upon worker's experience. Thus the pattern nesting by worker's experience for materials cutting is different form the real cutting results and also different from the error size of yield in degree of worker's skill. Recently, a few of domestic shoes makers use of oversee's nesting software. But the nesting software unfits for the domestic actual circumstances, and is complex to use, and is expensive, and is not to be interfaced with the auto cutting machine. Therefore, we have developed the economic nesting systems that are easier for novice to use and fit for the domestic circumstances , which can syncronize with the development of the auto cutting machine. The system comprises interrelated modules for materials information, nesting simulation, utility . The architecture of system, the functions of each module and the information processing procedures of each function are discussed.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2007.05a
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• pp.200-202
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• 2007

In recent years, equipment and network standards have been increasing in both number and complexity. Two standards that will soon be introduced to KOREA are the HV standards for assessing distorting and fluctuating loads, IEC 61000-3-6. Utility engineers, being under increasing time constraints, are turning more and more to software to quickly solve problems. This paper describes the methodology used to implement the above standards in Microsoft Excel in order to assist utility engineers to readily apply these standards in practical situations.

• Proceedings of the KIEE Conference
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• 1996.07b
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• pp.916-918
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• 1996

We have an urgent matter that is lack of energy resource. So we have to accomplish the design of economical energy utility systems and to develop energy facilities with high efficiency. Cogeneration system is one of them. It has high efficiency and can solve unbalanced electricity and heat demand in Summer & Winter concurrently. Recently, to increase the efficiency and stability of the total system, it is applying automatic control and monitoring software to the hardware facilities in industrial control systems. Therefore, these systems has been researched and developed in the advanced countries. It also has been researched and developed in the domestic since '60. But the control and monitoring software in cogeneration system has been hardly developed and has been imported expensive products from the advanced countries. In this study, we have developed the software of operating control, status monitoring, operating data managing and tele-controlling. We have confirmed usefullness of developed software by applying to gas turbine cogeneration system.