• Design & Manufacturing
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• v.16 no.4
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• pp.1-6
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• 2022

Fine blanking is a press processing technology that can process most of the product thickness into a smooth surface with a single stroke. In this fine blanking process, shear is an essential step. The punches and dies used in the shear are subjected to impacts of tens to hundreds of gravitational accelerations, depending on the type and thickness of the material. Therefore, among the components of the fine blanking mold (dies), punches and dies are the parts with the shortest lifespan. In the actual production site, various types of tool damage occur such as wear of the tool as well as sudden punch breakage. In this study, machine learning algorithms were used to predict these problems in advance. The dataset used in this paper consisted of the signal of the vibration sensor installed in the tool and the measured burr size (tool wear). Various features were extracted so that artificial intelligence can learn effectively from signals. It was trained with 5 features with excellent distinguishing performance, and the SVM algorithm performance was the best among 33 learning models. As a result of the research, the vibration signal at the time of imminent tool replacement was matched with an accuracy of more than 85%. It is expected that the results of this research will solve problems such as tool damage due to accidental punch breakage at the production site, and increase in maintenance costs due to prediction errors in punch exchange cycles due to wear.

• Journal of KIISE:Computing Practices and Letters
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• v.11 no.4
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• pp.312-333
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• 2005

SIP(Session Initiation Protocol) has been proposed for session control protocol of Internet multimedia communication system like VoIP(Voice over IP). SIP has complicated session control steps to support various kinds of audio and video formats and to assure service quality of real time data communication. Up until now, existing protocol analyzers can not provide such detailed information of SIP based communication system. In this paper, therefore, we propose a new protocol analyzer as a tool that can analyze and diagnose SIP based multimedia communication system throughout the session initiation, data exchange and session change steps. The propose traffic analyzer, which is called STAT(SIP based Traffic Analysis Tool), Is implemented on Winder's environment so that it is generally usable and extensible. Since STAT analyze low level packets captured via Ethernet broadcasting property, it is able to provide session status and real time traffic monitoring information without any affection to the communication system. The STAT which is implemented in this paper. therefore, is expected to be a useful tool for developing and managing of a SIP based multimedia communication system.

• Journal of the Korean housing association
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• v.21 no.1
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• pp.67-77
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• 2010

Citizen participation in local redevelopment has recently been regarded as essential, since progress in democracy and diversified public interests have contributed to more importance being placed on citizen participation in the implementation of public policies. While the importance of resident participation has been increasingly emphasized in principle, in reality more effort is still required in its application. We need to develop practical strategies of collecting community opinion in order to reflect it in public policy, if we are to achieve a resident and citizen-centered society. The purpose of this study is to develop an image map construction tool that can be applied to the "Maul-Mandulgi" projects as a visualized method to facilitate the exchange of opinions and work toward agreements. The tool is intended to assist public discussion by visualizing policies and plans and reducing the possibility of misunderstanding, so that residents can properly respond to the plans. Second, this study will verify the effectiveness of the tool in the application to local community workshops. The main research method is participant observation method and field study. Major findings are as follows, First, every resident who had participated in previous workshops gathered together, used the tool and represented their opinions unusually more than once. Each resident tried to make sure that other participants appropriately understood his or her opinion. The workshop finished when all participants agreed and produced a consensus. The workshop took much less time, which is in stark contrast to previous workshops in which it took significantly more time to collect opinions. Second, it proved that residents in the redevelopment area can strike a broad agreement by themselves on a method and direction for residential improvement. In previous workshops, conflicts between residents developed over the choice between the two methods, of local improvement and total demolition prior to multi-housing construction. In this study, opinions of residents were not limited to the two methods by finding a winwin solution. Third, the use of the tool kit for image map became efficient for inactive residents to develop their own opinions in regard to the direction and orientations of the residential improvement process. In addition, for those who have either no or a slight understanding of the residential improvement projects, the tool can provide access to information and knowledge. This study concludes that the developed tool for imaging of the redevelopment projection like a design game, rather than using forms of text and speech, can be a useful tool in collecting opinions and forming an agreed opinion for forthcoming residential improvement plans.

• Journal of the Korean Solar Energy Society
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• v.29 no.6
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• pp.45-55
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• 2009

Deterioration of the outdoor thermal environment in urban areas has become worse and worse due to the urbanization and overpopulation, etc. Most of existing researches about thermal environment are focused on the indoor environment in which the radiation heat exchange is relatively constant. However, the outdoor thermal environment is changed with time passages, because the thermal environment is highly effected by solar radiation. Thus, to simulate the outdoor thermal environment with accuracy, the solar radiation calculation should be considered, and the radiation heat exchange between building surface and ground surface should be calculated. The purpose of this study is to develop the simulator that can be possible to evaluate the outdoor thermal environment and pedestrian thermal comfort. In this paper, a new method which is coupled with convective heat transfer simulation and radiative heat transfer simulation will be proposed. And the coupled simulation method will be described through case study for outdoor thermal environment. From the results of simulation, the coupled simulation proposed in this study can assess the outdoor thermal environment with accuracy.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.4
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• pp.857-861
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• 2021

The study aims to find the asymmetric effect in National Stock Exchange in which the Nifty50 is considered as proxy for NSE. A return can be stated as the change in value of a security over a certain time period. Volatility is the rate of change in security value. It is an arithmetical assessment of the dispersion of yields of security prices. Stock prices are extremely unpredictable and make the investment in equities risky. Predicting volatility and modeling are the most profuse areas to explore. The current study describes the association between two variables, namely, stock yields and volatility in equity market in India. The volatility is measured by employing asymmetric GARCH technique, i.e., the EGARCH (1,1) tool, which was used in building the study. The closing prices of Nifty on day-to-day basis were used for analysis from the period 2011 to 2020 with 2,478 observations in the study. The model arrests the lopsided volatility during the mentioned period. The outcome of asymmetric GARCH model revealed the subsistence of leverage effect in the index and confirms the impact of conditional variance as well. Furthermore, the EGARCH technique was evidenced to be apt in seizure of unsymmetrical volatility.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.19 no.6
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• pp.23-35
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• 2009

Password-Authenticated Key Exchange (PAKE) Protocol is a useful tool for secure communication conducted over open networks without sharing a common secret key or assuming the existence of the public key infrastructure (PKI). It seems difficult to design efficient PAKE protocols using RSA, and thus many PAKE protocols are designed based on the Diffie-Hellman key exchange (DH-PAKE). Therefore it is important to design an efficient PAKE based on RSA function since the function is suitable for designing a PAKE protocol for imbalanced communication environment. In this paper, we propose a computationally-efficient key exchange protocol based on the RSA function that is suitable for low-power devices in imbalanced environment. Our protocol is more efficient than previous RSA-PAKE protocols, required theoretical computation and experiment time in the same environment. Our protocol can provide that it is more 84% efficiency key exchange than secure and the most efficient RSA-PAKE protocol CEPEK. We can improve the performance of our protocol by computing some costly operations in offline step. We prove the security of our protocol under firmly formalized security model in the random oracle model.

• The KIPS Transactions:PartD
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• v.16D no.4
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• pp.571-582
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• 2009

This paper provides a way to overcome limitations of general collaborative software development tools that completely restrict co-ownership of resources among individuals in a team oriented developmental environment. It also provides a solution for users to co-own resources and at the same time manage version control and collision problems that may occur due to the co-ownership of resources.The cooperative development support tool of developed software uses the conventional optimistic technique but employs the algorithm which is improved to reduce costs and efforts required for solving collision. The collaborative software development tool presented in this paper is made up of the classical client/server structure with the P2P(peer to peer) method which supports information exchange among individuals. This tool is developed based on open source software CVS(Concurrent Version System). Functional efficiency was confirmed by comparing it to the utility of prior existing collaborative software development tools.

• Journal of KIISE:Software and Applications
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• v.31 no.9
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• pp.1218-1225
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• 2004

S/KEY system was proposed to guard against intruder's password replay attack. But S/KEY system has vulnerability that if an attacker derive passphrase from his dictionary file, he can acquire one-time password required for user authentication. In this paper, we propose a correct S/KEY system mixed with EKE to solve the problem. Also, we specify a new S/KEY system with Casper and CSP, verify its secrecy and authentication requirements using FDR model checking tool.

• Journal of the Korea Fashion and Costume Design Association
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• v.14 no.4
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• pp.73-88
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• 2012

There are practicality, ornamentality and symbolic in a folding fan among Western accessories, and that is a little tool to enhance the overall harmony of a dress. The purpose of this study was to examine Western folding fans in an effort to shed light on the history, culture, fashion and life of different ages in which folding fans had been used. It's specifically meant to look into the mentality of people who had used folding fans. The meaning and function of folding fans were investigated, and their diverse types and characteristics were analyzed. As a result, it's found that in the West, a folding fan was one of major accessories that had an inseparable relation to popular clothes in each age and were necessary for a perfect coordination. Folding fans had been used as ornaments for Western noble women since the 16th century. After a certain period of time passed by, the 18th century became the heyday of folding fans. At that time, folding fans were one of aesthetic art works that even served as a means of mental exchange.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.9
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• pp.2105-2112
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• 2013

In this paper we implemented a web-based performance monitoring system for web mail server. For this system we derived performance monitoring items and fixed its threshold values for each measuring items. We used the SCOM 2007 server monitoring tool for collecting the performance data of web mail server and Exchange server management pack and server monitoring rules of SCOM 2007 to set the performance analysis parameters. We implemented this performance monitoring system using C# programming based on the ASP.NET framework. This system supports web-based performance report, failure report and resource availability report from the performance analysis results. Therefore the manager can easily detect the failures of web mail server in advance and decrease the number of failure over 60%. Also this system helps manager to minimize the recovery time when the failure occurs.