• Journal of the Korean Society for Precision Engineering
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• v.11 no.6
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• pp.185-199
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• 1994

This study has been performed to present a new automatic tool wear measurement by digital image processing. The purpose of this paper is to develop an automatic tool wear measuring system based on the image processing which can be applied to the quasi-real time measurement of the characteristics of insert tip in turning. Tool wear monitoring is one of the key-problems, for the development of control systems of modern unmanned factory which are not completely solved now. In oredr words at present complete qualitative and quantitative information on tool wear morphology is required, at least on the following aspects : flank wear, its dimensions and distribution on the maximum and mean values on VB pqrqmeter in the various zones of the wearland. crater wear, its main dimensions and values of KT parameters. This research has been performed to this technique made possible by designing a proper lighting system to the worn tool with following features : The flank wear is measured by observing the active cutting part from a proper direction and by lighting the wearland by a diffuser optic system. The crater wear is visualized by lighting the tool by a He-Ne gas laser system developed in this study. By means of this system it is research to evaluate classical parameters of tool wear and to have complete information about tool wear morphology.

• Proceedings of the KIEE Conference
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• 1998.11c
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• pp.764-766
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• 1998

An evaluation method for oxygen permeable characteristics of the membrane covering to each cathode of multiple cathode - single anode type dissolved oxygen sensor, which has high reproducibility and is capable of measuring multiple components in solutions. For this purpose, a measuring circuit for the multiple cathode type DO sensor was designed to lower the noise signal by adapting a digital LPF to readout the sensor output accurately. Digital LPF is designed by setting up the transfer function to set the cutoff frequency to 10Hz, and the transfer function is programmed by C language, and then the filtering characteristics are evaluated with the simulation and experiments. Using this LPF added measuring circuit for the multiple cathode type DO sensor, we have obtained the calibration factor for each cathode to calibrate the variation of the output signals. The calibration factor was obtained by measuring the sensor output signal followed by oxygen partial pressure, using the same oxygen permeable membrane at each cathode of the multiple cathode type DO sensor.

• Journal of Arbitration Studies
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• v.9 no.1
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• pp.367-390
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• 1999

The basic requirements for conducting electronic commerce include confidentiality, integrity, authentication and authorization. Cryptographic algorithms, make possible use of powerful authentication and encryption methods. Cryptographic techniques offer essential types of services for electronic commerce : authentication, non-repudiation. The oldest form of key-based cryptography is called secret-key or symmetric encryption. Public-key systems offer some advantages. The public key pair can be rapidly distributed. We don't have to send a copy of your public key to all the respondents. Fast cryptographic algorithms for generating message digests are known as one-way hash function. In order to use public-key cryptography, we need to generate a public key and a private key. We could use e-mail to send public key to all the correspondents. A better, trusted way of distributing public keys is to use a certification authority. A certification authority will accept our public key, along with some proof of identity, and serve as a repository of digital certificates. The digital certificate acts like an electronic driver's license. The Korea government is trying to set up the Public Key Infrastructure for certificate authorities. Both governments and the international business community must involve archiving keys with trusted third parties within a key management infrastructure. The archived keys would be managed, secured by governments under due process of law and strict accountability. It is important that all the nations continue efforts to develop an escrowed key in frastructure based on voluntary use and international standards and agreements.

• Journal of Digital Convergence
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• v.12 no.12
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• pp.293-301
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• 2014

In this paper, we propose a new measure based on the confidence of Bayesian posterior probability so as to reduce unimportant information in the clustering process. Because the performance of clustering is up to selecting the important degree of attributes within the databases, the concept of information entropy is added to posterior probability for attributes discernibility. Hence, The same value of attributes in the confidence of the proposed measure is considerably much less due to the natural logarithm. Therefore posterior probability-based clustering algorithm selects the minimum of attribute reducts and improves the efficiency of clustering. Analysis of the validation of the proposed algorithms compared with others shows their discernibility as well as ability of clustering to handle uncertainty with ACME categorical data.

• Proceedings of the Korean Geotechical Society Conference
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• 2005.03a
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• pp.439-444
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• 2005

Shotcrete lining is likely to be deteriorated due to the ground water which the lining is exposed to. Some tunnel collapses seemed to be affected by shotcrete degradation were reported. But there isn't any assessment method of shotcret long-term degradation. So, Experimental technology for shotcrete long-term degradation modeling was developed in this study. The shotcrete long-term degradation modeling, developed in other study in Korea Institute of Construction Technology, require the time-history of volume change. Digital strain observation system was used to acquire the time-history of volume change. To verify the Strain Observation Digital System, the measurement using the system was compared to the one using a micrometer. Through this process, The experiment for shotcrete long-term degradation modeling was set up.

• Journal of Digital Contents Society
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• v.19 no.8
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• pp.1489-1497
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• 2018

The importance of comments is constantly growing as a participation of individual in Online News that being invigorated. The 'Best Comments', which strongly related by major participants are recognized as a primary public opinion, and obtains the power. Thus this study is aimed to analyze the characteristics of the 'Best Comments' by utilizing the data of comments on Online News. For this study, a possible element that may reveal the difference between 'general' comments and 'best' comments were set up, digitalized the data, and examined the difference between 'general' and 'best' comments. This study is expected to provide a clue for the problematic issues, such as 'online comment rigged scandal' in recent; also as a basic data that subjected by the individual, academic society, government, and etc.

• Journal of Korea Society of Digital Industry and Information Management
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• v.11 no.1
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• pp.27-35
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• 2015

Increasing the number of GPU (Graphic Processor Unit) cores, the studies on High Performance Computing Platform using GPU have actively been made in recent. This trend has led to the development of GPGPU (General Purpose GPU) and CUDA (Compute Unified Device Architecture) Framework. In this paper, we explain the many benefits of the GPU based system, and propose the ICIDF(Identify Compute-Intensive Data set and Function) methodology to apply GPU technology to legacy military information system for performance improvement. To demonstrate the efficiency of this methodology, we applied this method to AES CPU based program obtained from the Internet web site. Simply changing the data structure made improved the performance of AES program. As a result, the performance of AES based GPU program is improved gradually up to 10 times. Depending on the developer's ability, additional performance improvement can be expected. The problem to be solved is heat issue, but this problem has been much improved by the development of the cooling technology.

• Journal of Korea Society of Digital Industry and Information Management
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• v.10 no.3
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• pp.71-85
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• 2014

This study proposes the future strategy of semiconductor companies corresponding to the growth of cloud computing. Cloud computing is the delivery of IT resources such as hardware and software as a service rather than a product, and it is expected to significantly change the IT market. By employing the scenario planning method, this study develops a total of eight scenario cases, and presents the three possible scenarios including the best market, the worst market, and the neutral market scenario. This study suggests the future strategy of semiconductor companies based on the best market scenario (increasing firms' IT expenditure, increasing the complexity and performance of devices, the frequent replacement of devices). The suggested future strategy of semiconductor includes that the semiconductor companies need to strengthen their price competitiveness, secure the next generation technologies, and develop the better capability for market prediction with the growth of cloud computing. This study will help semiconductor companies set up the strategy direction of technology development, and understand the connections between cloud computing and the memory semiconductor industry. This study has practical implications for semiconductor industry to prepare for the future of cloud computing.

• Journal of Digital Contents Society
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• v.16 no.3
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• pp.407-415
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• 2015

Offline English Zone refers to a physical environment in which the learners can check the results while they practice speaking and listening in English, and look up the vocabulary and information on their own. However, offline English zone is inevitably dependent on limited and artificial environment and its operation is greatly limited in having to provide an environment in which the students can spontaneously experience role play in an artificial space set in a small-scale English village consisting of shopping, restaurant, and hospital zones. The purpose of this study is to analyze the problems of the environmental restrictions in educational methodology utilizing offline English zone programs. Moreover, based on the ubiquitous concept. It is to provide a strategy for utilizing online English zone programs which utilize multimedia tools, wireless internet, and SNS.

• Journal of Digital Convergence
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• v.9 no.5
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• pp.157-173
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• 2011

This study is to find out how the activities of Corporate Citizenship based on Economics, Law, Ethics, Philanthropy affect the purchase intention of comsumer. The survey used a random sample of more than 400 people across Seoul and Kyunggi-do. The coding data selected was analyzed by Cronbach's alpha and factor analysis. And then the multi-regression analysis carried out and these results were impacted on all assumptions we set up originally.