• Journal of Korea Multimedia Society
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• v.17 no.8
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• pp.988-994
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• 2014

Software Defined Network (SDN) is a new technology in computer network area which enables user to centralize control plane. The security issue is important in computer network to protect system from attackers. SYN flooding attack is one of Distributed Denial of Service attack methods which are popular to degrade availability of targeted service on Internet. There are many methods to protect system from attackers, i.e. firewall and IDS. Even though firewall is designed to protect network system, but it cannot mitigate DDoS attack well because it is not designed to do so. To improve performance of DDOS mitigation we utilize another mechanism by using SDN technology such as OpenFlow and sFlow. The methodology of sFlow to detect attacker is by capturing and sum cumulative traffic from each agent to send to sFlow collector to analyze. When sFlow collector detect some traffics as attacker, OpenFlow controller will modify the rule in OpenFlow table to mitigate attacks by blocking attack traffic. Hence, by combining sum cumulative traffic use sFlow and blocking traffic use OpenFlow we can detect and mitigate SYN flooding attack quickly and cheaply.

• The Journal of Sustainable Design and Educational Environment Research
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• v.7 no.1
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• pp.1-14
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• 2008

Gyeonggi Province is trying to increase the number of public libraries from 100 as of December, 2006 to 150 in 2010. However most of existing public libraries preferred mid-to-large scale libraries, so they were restricted to be located in around a zone of life. For this reason most local residents have been excluded from right to use libraries and have difficulties to get library services for the knowledge and information society of the 21st century. The alternative to the small library is a school library. Both schools and public libraries are located in around a zone of life because residents can get an access to them easily. First, considering that small-scale public libraries of communities usually service about 10,000-20,000 people, I estimate that an open-style school library services 24class, 840people (24class*35people) of elementary school by 2003 Korean Library Standard (edited by Korean Library Association). Second, it requires systematic protection policies so that the open-style school of library can function as a local public library and a part of library cooperation system in accordance with local plans. All the open-style school libraries don't intend to open and we had better consider the suitable service areas. Third, it's desired for the management efficiency that the open-style school libraries being established afterward are divided into a branch-scale, a hall-scale and so on, not being uniform management model. And it also needs that one of them in the area enlarges the scale, and then supports other school libraries. According to these results of the research, as cooperation between the public library policy of a local government and school library policy, it needs a systematic support.

• The Korean Journal of Pain
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• v.10 no.1
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• pp.42-47
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• 1997

Background : This study was designed to evaluate the continuous effects of single intravenous injection of antiemetics on nausea and vomiting during continuous morphine injection for postoperative pain control. Methods : Prior to the study, we divided patients into two major groups according to the type of surgery performed intra-abdominal(Open: O) and non intra-abdominal(Close: C). When patients regained orientation after routine general anesthesia, enflurane-$O_2-N_2O$, we injected bolus dose of morphine and started continuous injection of morphine for postoperative pain control(Group I; Control). After bolus injection and just before continuous injection, we injected single dose of droperidol(Group II) or ondansetron(Group III). Mean arterial blood pressure, heart rate, pain score and symptom-therapy score were checked at 10 minutes, 4, 8, 16, 24, 36 hours after continuous morphine injection. Results : The pain score of group III was lower than group II(10 min.) and group I(24, 36 hours) in the open group. Symptom-therapy score of group III(10 min., 4, 24 hours) and group II(10 min.) were lower than group I in the open group. In the close group, symptom-therapy score of group III(8 hours) was lower than group I. Conclusions : Single intravenous injection of antiemetics have a tendency of lowering symptom-therapy score for 36 hours in spite of their relatively short elimination half-life.

• Journal of Chest Surgery
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• v.21 no.5
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• pp.850-855
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• 1988

From July 1983 to June 1988, twenty six patients underwent mitral valve repair for pure mitral stenosis[21 patient] or for mitral stenosis with a mild degree of regurgitation[5 patient] at Chonbuk National University Hospital. All patients underwent open mitral commissurotomy and 17 patients required to additional procedures for relief of obstructive subvalvular lesion. There was no operative death. The patients were followed from one to sixty months[mean 24. 1Mo.] One late death occurred due to cardiac and renal failure 10 month postoperatively. Of the 25 surviving patients at the time of follow-up, 17 patients[68%] were in NYHA functional class I and 8 patients[32%] were in class II.

• Informatization Policy
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• v.27 no.1
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• pp.72-91
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• 2020

In this study, we classified SNS into open and closed types, and empirically examined in which SNS activity the privacy paradox holds. The idea comes from the argument that privacy paradox may be observed differently in the open SNS, which is more vulnerable to the leakage of personal information due to public profiles, and the closed SNS, which is relatively less vulnerable by limiting the range of acquaintances, The results of the empirical analysis are as follows. First, in case of SNS usage, the privacy paradox holds in the overall SNS activities, but different conclusions are drawn according to open and closed SNS. In particular, it is found that as privacy concerns increase, individuals respond in a reasonable and desirable way to reduce SNS activity in the open SNS, which is more susceptible to infringement. Second, in the case of SNS activity intensity, (i) heavy users are more seriously aware of the probability of privacy infringement than light users, so there is a reasonable response to reducing the intensive margin with increasing privacy concerns, and (ii) this tendency is more clearly observed in open SNS, which is more vulnerable to privacy infringement. Accordingly, insisting that the privacy paradox is empirically established by observing only the overall SNS activities without distinguishing them into open and closed SNS may be interpreted as a "Fallacy of Composition."

• Journal of the Korean Institute of Telematics and Electronics A
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• v.33A no.3
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• pp.28-37
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• 1996

Syntax notation one (ASN.1) defined by ITU-T and ISO, is a formal abstrct specification language which has been widely used in international standards specifiation to inteconnect distributed open systems. It si necessary to have well defined encoder/decoder modules which taranslate ASN.1 datum to BER octets stream to interconnect distributed open systems. In this paper, we designed and implemented a new ASN.1-to-C compiler, called HYASNC (hanyang ASN.1-to-C), which atutomatically translates and ASN.1-to-C compiler, called HYASNC (hanyang ASN.1-to-C), which automatically translates an ASN.1 specification into C-language BER encoders and decoders with simple and neat I/F for the defined ASN.1 data types, and enhanced BER (basic encoding rules)encoding/decoding libraries, called HY(hanyang)BER library, and useful utility functions. And this paper discusses HYASNC compiler, HY BER runtime library's design and implementation principles, and also evaluates the perfomrance of HY BER library and the interoperability with other ASN.1 compilers.

• Proceedings of the Korean DIstribution Association Conference
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• 2007.11a
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• pp.155-178
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• 2007

The purpose of this study is to provide the strategic implication of the Korean open air market by examining the factors affecting their competitiveness. I have undertaken empirical research that uses the methodology of a mixture regression modeling, as a way to ascertain the determinants of competitiveness for the Korean open air market. I construct a mixture regression model which uses the proportions of merchandise categories as explanatory variables and the number of visitors as a dependent variable. The analysis of results show that competitive and non-competitive markets have different proportions of merchandise categories. The finding shows that stock farm products and home appliances are major influencers on the number of visitors in neighborhood markets. The finding also presents that stock farm products and processed foods are major influencers on the number of visitors in small & medium-sized city markets.

• Journal of Korea Entertainment Industry Association
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• v.15 no.4
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• pp.15-29
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• 2021

Many countries and companies are pursuing and developing Artificial intelligence as it is the core technology of the 4th industrial revolution. Global IT companies such as Apple, Microsoft, Amazon, Google and Samsung have all released their own AI assistant hardware products, hoping to increase customer loyalty and capture market share. Competition within the industry for AI agent is intense. AI assistant products that command the biggest market shares and customer loyalty have a higher chance of becoming the industry standard. This study analyzed the current status of major overseas and domestic IT companies in the field of artificial intelligence, and suggested future strategic directions for voice UI technology development and user satisfaction. In terms of B2B technology, it is recommended that IT companies use cloud computing to store big data, innovative artificial intelligence technologies and natural language technologies. Offering voice recognition technologies on the cloud enables smaller companies to take advantage of such technologies at considerably less expense. Companies also consider using GPT-3(Generative Pre-trained Transformer 3) an open source artificial intelligence language processing software that can generate very natural human-like interactions and high levels of user satisfaction. There is a need to increase usefulness and usability to enhance user satisfaction. This study has practical and theoretical implications for industry and academia.

• International Journal of Naval Architecture and Ocean Engineering
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• v.13 no.1
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• pp.433-449
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• 2021

In this study, a newly enhanced Fluid-Structure Interaction (FSI) model which incorporates mooring lines was used to simulate a floating structure. The model has two parts: a Computational Fluid Dynamics (CFD) model and a mooring model. The open-source CFD OpenFOAM® v1712 toolbox was used in the present study, and the convergence criteria and relaxation method were added to the computational procedure used for the OpenFOAM multiphase flow solver, interDyMFoam. A newly enhanced, tightly coupled solver, CoupledinterDyMFoam, was used to decrease the artificial added mass effect, and the results were validated through a series of benchmark cases. The mooring model, based on the finite element method, was established in MATLAB® and was validated against a benchmark analytical elastic catenary solution and numerical results. Finally, a model which simulates a floating structure with mooring lines was successfully constructed by connecting the mooring model to CoupledinterDyMFoam.

• 한국경영정보학회:학술대회논문집
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• 2008.06a
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• pp.17-22
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• 2008

The emergence of open source software (OSS) with its successful projects and its most prominent advantages creates a vast interest among academics and practitioners. However, it has been found that focusing on the developments of OSS to be successful is not adequate and the adoption of OSS by uses is also very important. Although there are a great number of useful and easy to use OSS has been developed, the adoption of OSS and usage in the market is very low. Based on the technology equity implementation model (EIM), this study examines user resistance in the adoption of OSS (i.e., switching from the current system to OSS). A survey has done regarding the adoption of Linux as the case of study. We have found that user resistance to change has negative effect on adoption intention, and switching benefits, switching costs and perceived value have significant relationships with user resistance to change.