• International Journal of Highway Engineering
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• v.18 no.1
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• pp.33-41
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• 2016

PURPOSES : This study primarily focused on evaluating the performance characteristics of 4.75-mm nominal maximum aggregate size (NMAS) asphalt mixtures for their more effective implementation to a layered flexible pavement system. METHODS : The full-scale pavements in the FDOT's accelerated pavement testing (APT) program, including 4.75-mm mixtures at the top with different thicknesses and asphalt binder types, were considered for the faster and more realistic evaluation of the rutting performance. The results of superpave indirect tensile (IDT) tests and hot-mix asphalt fracture mechanics (HMA-FM) based model predictions were used for cracking performance assessments. RESULTS : The results indicated that the rutting performance of pavement structures with 4.75-mm mixtures may not be as good as to those with the typical 12.5-mm mixtures, and pavement rutting was primarily confined to the top layer of 4.75-mm mixtures. This was likely due to the relatively higher mixture instability and lower shear resistance compared to 12.5-mm mixtures. The energy ratio (ER) and HMA-FM based model performance prediction results showed a potential benefit of 4.75-mm mixtures in enhanced cracking resistance. CONCLUSIONS : In relation to their implementation, the best use of 4.75-mm mixtures seem to be as a surface course for low-traffic-volume applications. These mixtures can also be properly used as a preservation treatment that does not necessarily last as long as 12.5-mm NMAS structural mixes. It is recommended that adequate thicknesses and binder types be considered for the proper application of a 4.75-mm mixture in asphalt pavements to effectively resist both rutting and cracking.

• International Journal of Highway Engineering
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• v.7 no.3 s.25
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• pp.1-10
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• 2005

In this study, accelerated pavement tester(APT) was performed on long-life asphalt pavements that can save maintenance and user costs by increasing the design life twice longer than conventional asphalt pavements. Basic material testings are first conducted on a high modulus base(HMB) mixture developed in this study. Four different pavement sections including thin and thick conventional and thin and thick HMB courses are constructed to compare the load-carrying capacities and to investigate the fatigue and rutting performances using an accelerated pavement tester. Tensile strain values at the bottom of base courses under the various loading levels are measured. The tensile strain values of the HMB sections are lower than those of the conventional sections. It is observed from the APT performed on the thin pavement sections that no significant cracks are developed up to the 180,000 cycles of a wheel load. In terms of rutting, only 3mm of rutting is developed in the thick HMB section while 5.3mm of rutting is developed in the thick conventional section at the 90,000 cycles of the wheel load. The HMB material developed in this study can be successfully used in the long-life asphalt pavements because of its excellent fatigue and rutting performances. It is estimated from a series of structural analysis that the use of the HMB material instead of the conventional base materials may reduce the asphalt thickness at least 5cm because of its better load-carrying capacity.

• Journal of Environmental Impact Assessment
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• v.6 no.1
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• pp.67-76
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• 1997

The purpose of this research is to draw out the factors affecting the residents' evaluation on valuable animal and vegetation and the naturality of vegetation seen near regional environment. With this purpose, Questionnaire research and vegetation survey focusing on area of types of vegetation and species of big trees were made in 30 points of midstream of Tama River, Tokyo, Japan. The questionnaire research was based on basin environment units in order to be reflective of regional natural environment. The vegetation was classified into 5 types according to its flora and observed the covering area of each points and types through the aerial photograph. In addition, the species of big trees in habitat were listed by the survey. Results as below came out by analyzing the outcome of the questionnaire research and vegetation survey by multiple regression. First, residents are most likely not to distinguish precisely between the quantitative and qualitative aspects of vegetation. Both of the researches are apt to be influenced by quantitative factors of vegetation. Second, residents are assumed to consider forest of big trees, inhabitant of groups of big trees, highly natural.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 2008.10b
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• pp.96-103
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• 2008

The information systems audit is an proactive action to find out the predicted issues on proceeding the business beforehand, to make out whether the information systems satisfies the user's demand or not and to check up the result of the project with complementing the capabilities of self-diagnostics for the complicated and advanced information system. However, the results of the audited project are apt to be regarded as a failure in a case that an opinion of the audit area evaluation is described as 'insufficient' or 'negative' in the audit report that is submitted as the result of the audit. It makes a lot of arguments among the board of audit, the institution ordering the audit and the auditor. In this study, we made an attempt to finding out the factors affecting the audit area evaluation and verifying them objectively. A study model and hypothesis including the improvement type of the recommended subject to be improved, the importance, the audit time, the business scale of the audited object and the auditing company as a factor variable were established and the hypothesis was verified by analyzing the correlation between the factor variables and the audit area evaluation.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.12
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• pp.8908-8914
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• 2015

The Internet continues to grow and develop, but there are going to generate a variety of Internet attacks that exploit it. In the initial Internet environment, the attackers maliciously exploited Internet environments for ostentations and hobbies. but these days many malicious attempts purpose the financial gain so systematic and sophisticated attacks that are associated with various crimes are occurred. The structures, such as viruses and worms were present in the form of one source multi-target before. but recently, APT(Advanced Persistent Threat, intelligent continuous attacks) in the form of multi-source single target is dealing massive damage. The performance evaluation analyzed whether to generate audit data and detect integrity infringement, and false positives for normal traffic, process detecting and blocking functions, and Agent policy capabilities with respect to the application availability.

• Convergence Security Journal
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• v.17 no.1
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• pp.31-38
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• 2017

As the cyber-attacks through the networks advance, it is difficult for the intrusion detection system based on the simple rules to detect the novel type of attacks such as Advanced Persistent Threat(APT) attack. At present, many types of research have been focused on the application of machine learning techniques to the intrusion detection system in order to detect previously unknown attacks. In the case of using the machine learning techniques, the performance of the intrusion detection system largely depends on the feature set which is used as an input to the system. Generally, more features increase the accuracy of the intrusion detection system whereas they cause a problem when fast responses are required owing to their large elapsed time. In this paper, we present a network intrusion detection system based on artificial neural network, which adopts a multi-objective genetic algorithm to satisfy the both requirements: accuracy, and fast response. The comparison between the proposing approach and previously proposed other approaches is conducted against NSL_KDD data set for the evaluation of the performance of the proposing approach.

• Journal of Internet Computing and Services
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• v.22 no.1
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• pp.13-22
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• 2021

Recently network based attack technologies are rapidly advanced and intelligent, the limitations of existing signature-based intrusion detection systems are becoming clear. The reason is that signature-based detection methods lack generalization capabilities for new attacks such as APT attacks. To solve these problems, research on machine learning-based intrusion detection systems is being actively conducted. However, in the actual network environment, attack samples are collected very little compared to normal samples, resulting in class imbalance problems. When a supervised learning-based anomaly detection model is trained with such data, the result is biased to the normal sample. In this paper, we propose to overcome this imbalance problem through One-Class Anomaly Detection using an auto encoder. The experiment was conducted through the NSL-KDD data set and compares the performance with the supervised learning models for the performance evaluation of the proposed method.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.2D
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• pp.285-292
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• 2006

The objective of this study is to introduce the development of the first Korean full-scale APT(Accelerated Pavement Tester) and to compare the performances of general dense grade asphalt mixture and modified asphalt mixtures as the first running of the tester. The tests evaluated the rutting resistance for dense grade mixture and three different modified asphalt mixture under three different temperature conditions (25-30, 40, $50^{\circ}C$). The results of the testing were compared with the laboratory test results. Results of the tests indicated that the all the modified asphalt sections showed higher rutting resistance than the dense grade section. Especially, the difference was more noticeable at higher temperature condition. Additionally, $G^*/sin{\delta}$ is found out to be an important factor for permanent deformation prediction whereas the resilient modulus was not.

• Journal of Internet Computing and Services
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• v.19 no.1
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• pp.49-66
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• 2018

This research explores a value chain structure of VR-AR media including user's perception, uses, and evaluation. The purpose of this research focused on factor analysis and the relationship among user's VR-AR adoption motivations and utilities. This research explores correlation between personal value and using motivation. This study was to identify the value structure of respondent on VR-AR usages based on means-end chain theory. The research used structured APT laddering questions and 251 data was analysed. Through such analysis, category difference by stage and relationship difference were identified and hierarchical value map was compared. There are four different value ladders: first is attributes, functional consequences, psychological consequences, and final value. This study is based on the analysis of the value chain structure factors that affect VR and AR use behavior (attributes, functional benefits, psychological benefits, use value), 'Hierarchical Value Map' between users' The purpose of the model is to construct a model. For this, 'means-end chain theory' was applied to measure the causal relationship between personal value and VR related use behavior. In order to solve this research problem, 135 people were analyzed through the structured questionnaire using the AR and VR content fitness measure and the second APT laddering, and the use of VR-AR : 1) Functional benefits; 2) Psychological benefits; 3) Means to reach value, 4) Objective value chain structure was identified. The results show that VR users tried to smooth the social life through the new virtual reality audiovisual element, the newness of experience, fun, and pleasure through the departure of reality, vividness of experience, and leading fashion. The AR fitness was a game and a new program, and the value of interacting with other people and the value of 'periwinkle' played an important role through the vividness and peripheral interaction of AR, It was an important choice. The important basic values of users' VR and AR selection were correlated with psychological attributes of interaction with others, achievement, happiness and favorable values.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.7
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• pp.1-8
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• 2017

As the IT environment becomes more sophisticated, various threats and their associated serious risks are increasing. Threats such as DDoS attacks, malware, worms, and APT attacks can be a very serious risk to enterprises and must be efficiently managed in a timely manner. Therefore, the government has designated the important system as the main information communication infrastructure in consideration of the impact on the national security and the economic society according to the 'Information and Communication Infrastructure Protection Act', which, in particular, protects the main information communication infrastructure from cyber infringement. In addition, it conducts management supervision such as analysis and evaluation of vulnerability, establishment of protection measures, implementation of protection measures, and distribution of technology guides. Even now, security consulting is proceeding on the basis of 'Guidance for Evaluation of Technical Vulnerability Analysis of Major IT Infrastructure Facilities'. There are neglected inspection items in the applied items, and the vulnerability of APT attack, malicious code, and risk are present issues that are neglected. In order to eliminate the actual security risk, the security manager has arranged the inspection and ordered the special company. In other words, it is difficult to check against current hacking or vulnerability through current system vulnerability checking method. In this paper, we propose an efficient method for extracting diagnostic data regarding the necessity of upgrading system vulnerability check, a check item that does not reflect recent trends, a technical check case for latest intrusion technique, a related study on security threats and requirements. Based on this, we investigate the security vulnerability management system and vulnerability list of domestic and foreign countries, propose effective security vulnerability management system, and propose further study to improve overseas vulnerability diagnosis items so that they can be related to domestic vulnerability items.