• Journal of the Korea Society for Simulation
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• v.28 no.3
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• pp.65-74
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• 2019

For many years, it has been widely studied on fork-join production systems but there is not much literature focusing on the finite buffer(s) of either individuals or shared, and generally distributed processing times. Usually, it is difficult to handle finite buffer(s) through a standard queueing theoretical approach. In this study, by using the max-plus algebraic approach we studied buffer-shared fork-join production systems with general processing times. However, because it cannot provide proper computational ways for performance measures, we developed simulation models using @RISK software and the expressions derived from max-plus algebra. From the simulation experiments, we compared some properties on waiting time with respect to a buffer capacity under two blocking policies: BBS (Blocking Before Service) and BAS (Blocking After Service).

• KIPS Transactions on Software and Data Engineering
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• v.9 no.12
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• pp.411-418
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• 2020

In the field of information security, IDS(Intrusion Detection System) is normally classified in two different categories: signature-based IDS and anomaly-based IDS. Many studies in anomaly-based IDS have been conducted that analyze network traffic data generated in cyberspace by machine learning algorithms. In this paper, we studied pre-processing methods to overcome performance degradation problems cashed by rare classes. We experimented classification performance of a Machine Learning algorithm by reconstructing data set based on rare classes and semi rare classes. After reconstructing data into three different sets, wrapper and filter feature selection methods are applied continuously. Each data set is regularized by a quantile scaler. Depp neural network model is used for learning and validation. The evaluation results are compared by true positive values and false negative values. We acquired improved classification performances on all of three data sets.

• KIPS Transactions on Software and Data Engineering
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• v.10 no.2
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• pp.65-72
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• 2021

Recently, attacks on the network environment have been rapidly escalating and intelligent. Thus, the signature-based network intrusion detection system is becoming clear about its limitations. To solve these problems, research on machine learning-based intrusion detection systems is being conducted in many ways, but two problems are encountered to use machine learning for intrusion detection. The first is to find important features associated with learning for real-time detection, and the second is the imbalance of data used in learning. This problem is fatal because the performance of machine learning algorithms is data-dependent. In this paper, we propose the HSF-DNN, a network intrusion detection model based on a deep neural network to solve the problems presented above. The proposed HFS-DNN was learned through the NSL-KDD data set and performs performance comparisons with existing classification models. Experiments have confirmed that the proposed Hybrid Feature Selection algorithm does not degrade performance, and in an experiment between learning models that solved the imbalance problem, the model proposed in this paper showed the best performance.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.1
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• pp.457-470
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• 2021

The banking system provides a number of important functions for the economy and is also the lifeblood and financier of the economy in each country. Large amounts of idle money have not been exploited by banks; however, banks still depend on loans, including loans from foreign banks, to meet the growing demand, as such, for banks, the cost of capital is high, the stability and business efficiency are low and banks have not promoted their internal resources to grow steadily. To achieve the goal, this research analyzes the factors affecting the choice of bank for the deposit decisions of customers in Vietnam. The study used a sample data of 250 individuals and SPSS software was used to analyze the data. The results showed that customer policy has a positive effect on customers' deposit decisions in a bank, and this is new evidence regarding behavioral theory in the case of Vietnam. Results further demonstrated that other factors such as employee image, brand, interest rate, relative influencing, and transaction time positively impact the choice of bank for the deposit decisions of customers. However, the bank's promotion strategies had no impact on the choice of bank for the deposit decisions of customers. Besides, employee image is the most influential factor in the deposit decisions, followed by the bank's brand and interest rate.

• Journal of Convergence for Information Technology
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• v.10 no.12
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• pp.22-30
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• 2020

With the development of information and communication technology, DDoS and DRDoS continue to become security issues, and gradually develop into advanced techniques. Recently, IT companies have been threatened with DRDoS technology, which uses protocols from normal servers to exploit as reflective servers. Reflective traffic is traffic from normal servers, making it difficult to distinguish from security equipment and amplified to a maximum of Tbps in real-life cases. In this paper, after comparing and analyzing the DNS amplification and Memcached amplification used in DRDoS attacks, a countermeasure that can reduce the effectiveness of the attack is proposed. Protocols used as reflective traffic include TCP and UDP, and NTP, DNS, and Memcached. Comparing and analyzing DNS protocols and Memcached protocols with higher response sizes of reflective traffic among the protocols used as reflective traffic, Memcached protocols amplify ±21% more than DNS protocols. The countermeasure can reduce the effectiveness of an attack by using the Memcached Protocol's memory initialization command. In future studies, various security-prone servers can be shared over security networks to predict the fundamental blocking effect.

• The Journal of the Convergence on Culture Technology
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• v.7 no.1
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• pp.533-538
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• 2021

The purpose of this study is to consider the perception, which education-related workers and parents have, associated with guaranteeing the right to learn for youth migrants in Korea. The study was especially intended to analyze the opportunities and adaptions of youth migrants and make policy suggestions accordingly. To this purpose, this study implemented one-on-one in-depth interviews with research participants to collect and analyze data. This research yielded four categories: initial settlement, social security support as a fundamental right, learning rights guarantees, and psychological support. Also, seven subcategories were elicited. The suggestions based on results are followings: first, the legal basis for learning support for middle-aged adolescents; second, curriculum composition for school maladjusted middle-aged adolescents; third, individualized support system; fourth, the active promotion of support systems such as information provision; fifth, the diversification of policy for psychological stability.

• Journal of The Korean Society of Integrative Medicine
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• v.9 no.1
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• pp.101-108
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• 2021

Purpose : The purpose of this study is to verify the effect of selective muscle strengthening of the knee joint extensor muscles using a pressure biofeedback unit to improve knee extensor strength and the balance ability of total knee replacement patients. Through this, we tried to provide clinical information. Methods : In this study, 12 patients with total knee replacement were recruited from a rehabilitation hospital. They were divided into two groups: a feedback group (n=6) and a control group (n=6). All patients received 30 minutes of continuous passive motion and leg-strengthening exercises for 15 minutes five times a week for two weeks. Subjects performed knee extension exercises with or without biofeedback units in the sitting position. The knee extensor strength and balance ability were measured before and after exercise. Knee extensor strength was measured by Biodex system 3 and balance ability was measured by Balancia software. Results : Both the experimental group and the control group showed a significant difference in the muscle strength of the knee joint extensor muscles after intervention (p<.05). In comparison, the experimental group showed a significant difference than the control group (p<.05). Both the experimental group and the control group showed a significant difference in the velocity average, path length, area 95 % center of pressure (COP), weight distribution, five times sit to stand test (FTSST) after intervention. In comparison, the experimental group showed a significant difference in velocity average, area 95 % COP, and FTSST than the control group (p<.05). Conclusion : In order to strengthen the knee extensor muscle and improve the balance ability in total knee replacement patients, it is necessary to consider providing pressure biofeedback unit during leg strengthening exercises.

• Journal of Korean Library and Information Science Society
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• v.51 no.4
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• pp.231-247
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• 2020

As artificial intelligence (AI) has emerged as a promising future technology among the fourth industrial revolution, we are trying to apply artificial intelligence technology across all area of society, including libraries. This study investigated the effects, issues, and implications of artificial intelligence on university library services. As a research method, in-depth interviews were conducted with IT experts of university libraries in North America, and conclusions and discussion were drawn from interview results and related documents. Research results revealed that university libraries in North America were trying to build an infrastructure that facilitates information access and retrieval based on artificial intelligence systems and to provide new services in collaboration with AI research institutes in universities. This study raised issues regarding the expansion of the role of libraries and librarians, privacy, and data quality. It was also discussed that the need for re-education of university librarians to become software engineers who play a role in disseminating knowledge. In addition, this study suggested the investment for the establishment of the information system and an artificial intelligence research center in the library. The study discussed limitations of research due to changes in the research environment and suggestions for future research.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.8
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• pp.1006-1014
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• 2020

Consumer expectations for drama VFX increased as the influx of overseas dramas increased due to the growth of OTT service, but the current production time of the drama production system has a negative effect on the quality and completion of work. This paper proposes a background rendering using a game engine and a subject rendering using background HDRI as environmental lighting. The proposed workflow is expected to reduce the production time of VFX and improve the quality of VFX. The proposed workflow was verified in 3 steps. Comparing game engine and rendering software according to the same lighting environment and camera distance, comparing rendering with existing rendering method and background HDRI generation, and validating the proposed workflow. For verification, quantitative evaluation was performed using Structual similarity index and histogram. This study is expected to be one of the options to improve the quality of VFX and improve the risk.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.2
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• pp.244-251
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• 2020

This paper presents a design of the Meta-Class Repository (MCR) which maintain syntactically analyzed and structured meta-class information from UML diagrams, and then proposes 'meta-class,' also known as super-class, to construct structured information analyzed syntactically. The MCR is a collection of these meta-classes which contains the information extracted from diagrams. This paper also presents a design of the Code Generation Engine (CGE) which roles generating codes corresponding classes from UML diagrams based on the MCR maintaining a collection of meta-classes which is syntactically-analyzed and constructed in previous process. The logics of CGE are designed to generate codes collaborated with MCR and CGE with integration. The logics of CGE mechanism is presented with the form of finite state machine to present the algorithms of code generation formally and have the advantages of simplicity and easiness in development.