• Geomechanics and Engineering
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• v.32 no.1
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• pp.35-47
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• 2023

Deformability of road pavements in the form of ruts represent a safety risk for road users. In the procedures for dimensioning the pavement structure, the requirement that such deformations do not occur is imperatively included, which results in the appropriate selection of elements (material, geometry) of the pavement structure. Deformability and functionality, will depend of the correct design of pavement structure during exploitation period. Nevertheless, there are many examples where deformations are observed on the pavement structure, in the form of rutting at parts of the road with relatively short length, realised in the same climatic and the same geoenvironmental conditions. The performed analysis of deformability led to the conclusion that the level of deformation is a function of the speed of traffic. This effect is observed on city roads, but also outside of urban areas at roads with speed limits are significant, due to the traffic management, traffic jams (intersections, etc.). Still, the lower speed cause greater deformations. The authors tried to describe the deformability of flexible pavement structures, from the aspects of geotechnical problems, as a function of driving speed. Outcome of the analysis is a traffic load correction coefficient, in terms of using the existing methods of flexible pavement structures design.

• Information Systems Review
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• v.8 no.1
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• pp.141-158
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• 2006

Recently, developing U-City as an integrated set of ubiquitous space services has been regarded as a promising field in realizing ubiquitous computing technology. However, well organized requirement analyses of U-City to declare what kinds of ubiquitous space services are needed and which ubiquitous computing technology should be incorporated to come up with the needs are still insufficient. Hence, the aims of this paper are to propose a set of unique U-City construction philosophies and to analyze which services should be offered in the ubiquitous space services in U-Cities. A field survey to the citizens who are potential end users of the ubiquitous space services was conducted to analyze the success factors of U-City using CSF methodology. Focused group interview with professionals in the field of ubiquitous computing technology in Korea was then performed to identify the relationship of the ubiquitous space services and the critical success factors.

• KIPS Transactions on Computer and Communication Systems
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• v.3 no.12
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• pp.463-478
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• 2014

Portal site is not only providing search engine and e-mail service but also various services including blog, news, shopping, and others. The fact that average number of daily login for Korean portal site Naver is reaching 300 million suggests that many people are using portal sites. With the increase in number of users followed by the diversity in types of services provided by portal sites, the attack is also increasing. Most of studies of password authentication is focused on threat and countermeasures, however, in this study, we analyse the security threats and security requirement of membership, login, password reset first phase, password reset second phase. Also, we measure security score with common criteria of attack potential. As a result, we compare password authentication system of domestic and abroad portal sites.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.28 no.3
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• pp.681-694
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• 2018

This paper studied the effects of risk cognition of personal information and self-expression information on conation of privacy protection. In the first study, 88 college students who volunteered for this research were surveyed about risk cognition of personal information and conation to protect it. In the second study, after an information-seeking expert collected and organized the self-expression information that 88 volunteers had expressed on SNS, and then showed the organized self-expression information to 88 volunteers, and then 88 volunteers were surveyed about risk cognition of self-expression information and conation to protect it. As results of the first data analysis, the risk cognition of personal information had the greatest influence on non-disclosure of personal information, followed by reduction of the disclosure scope and law institutionalization requirement. As results of the second data analysis, SNS users openly expressed their opinion or life-style, but when they realized that self-expression information can be accumulated and become sensitive information, they had conation to protect their self-expression information such as non-disclosure, reduction of disclosure scope, and law institutionalization requirement. The implication of this study is that we have overcome the limitations of existing researches that can not explain information protection behavior on SNS.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.6B
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• pp.508-516
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• 2006

The explosive growth of wireless network users and the existence of various wireless services have demanded high rate throughput as well as user's QoS guarantees. Towards this, this paper proposes QoS-oriented subcarrier allocation scheme considering the QoS provisioning of multiple users, which is major requirement for wireless network design point of view. This paper introduces joint RR/K&H combined with M-LWDF(Modified Largest Weighted Delay First) scheme throughout observing statistical channel behavior and real time queuing analysis for appropriate resource allocation tightly connected to multiuser scheduling. Accordingly, the system throughput can be enhanced, and the QoS demanded for delay sensitive services can be satisfied. Furthermore, the proposed scheme is applied for OFDMA(Orthogonal Frequency Division Multiple Access) systems to allocate sub-carriers in optimal way. The simulation results verify plausible performances of proposed resource allocation scheme via showing superior effective capacity under time-varying physical-layer channel behaviors.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.6A
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• pp.484-493
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• 2009

For the flexible frequency utilization, cognitive radio technique has been prominently considered. The most important requirement in cognitive radio networks is to protect the communications of primary users. Spectrum sensing task by secondary users should be seriously considered in cognitive radio networks, since the spectrum sensing process makes their current quality of service worse. In this paper, we propose the channel sensing scheduling method that keeps the requirements for protecting the primary and guarantee the secondary user's quality of service as possible. The quality of service of secondary user is analyzed in terms of packet delay and loss while the protection-requirements in terms of sensing interval and sensing time predefined. In numerical analysis, we can get appropriate parameters which guarantee QoS in various environment. And simulation results show that this method can improve the performance, delay and the number of transmitted packets against consecutive sensing method.

• Journal of the Korean Institute of Educational Facilities
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• v.24 no.6
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• pp.37-44
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• 2017

This study is about user satisfaction of the Junior College Library based on its characteristics of space composition. For this, we studied characteristics of space composition targeting the libraries in colleges in Seoul and Gyeonggi-do. First, in case of study of characteristics of space composition for books and library data, student satisfaction for traditional and normal library areas was high. It means that the service based on library areas should start from normal library areas as well as there is a change about space as the type of data in libraries change to electric data and multimedia. Second, If we look at the space for a reader and a user, satisfaction for a normal reading room was high. we can also see that satisfaction for a computer room and a multimedia reading room was not higher but still high. Also, the reason why satisfaction for a multimedia reading room that provides various activities was high was that the complex of a library space is needed to provide users with various activities. Third, in case of space for programme function and meeting, satisfaction for the room of video information and the group study room was high. we can see that user satisfaction for the space got high basically when a user is satisfied with the proper information technology based on interaction Fourth, as a result of variance analysis of 3 spaces of Junior College Library and the services, the size of the space of service does not influence user satisfaction directly. Even the space is small, if it decorates variously like with a lighting for a user, a window seat to meet the nature of users and has specific factors such as space reservation using internet, user satisfaction is high. If we summarise the result of this study, to make user satisfaction for speace in a Junior College Library higher, not just we need to try to make it extend as a educational, a cultural place but we also need to accept the student's requirement that the space also needs to be extend as a complex cultural space.

• Journal of Navigation and Port Research
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• v.40 no.3
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• pp.89-95
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• 2016

S-Mode is a concept involving a standardized navigation display with accompanying standardized functionality and interfaces for navigational equipment. It was proposed by the International Federation of Shipmasters' Associations at IMO NAV $54^{th}$ session in 2008. The IMO e-Navigation Strategy Implementation Plan(SIP) addresses, S-Mode and the IMO MSC at its $95^{th}$ session in 2015 approved an output 1 to develop S-Mode guidance. In this study, it has been carried out survey of user needs for adopting S-Mode guideline on ECDIS which is core navigational equipment. It is conducted with a questionnaire survey, targeting deck officers and masters who will be the primary users of the equipment related to the e-Navigation system. In this research, users' opinion survey regarding the necessity of development, the scope of standardization, and priorities was conducted. This survey result could be contributed to development S-Mode guideline and specify the concept of S-Mode. It would be derived from standardizing component through providing elements to be considered for its development.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.9
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• pp.3274-3297
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• 2021

Permission delegation is an important research issue in access control. It allows a user to delegate some of his permissions to others to reduce his workload, or enables others to complete some tasks on his behalf when he is unavailable to do so. As an ideal solution for controlling read access on outsourced data objects on the cloud, Ciphertext-Policy Attribute-Based Encryption (CP-ABE) has attracted much attention. Some existing CP-ABE schemes handle the read permission delegation through the delegation of the user's private key to others. Still, these schemes lack the further consideration of granularity and traceability of the permission delegation. To this end, this article proposes a flexible and fine-grained CP-ABE key delegation approach that supports white-box traceability. In this approach, the key delegator first examines the relations between the data objects, read permission thereof that he intends to delegate, and the attributes associated with the access policies of these data objects. Then he chooses a minimal attribute set from his attributes according to the principle of least privilege. He constructs the delegation key with the minimal attribute set. Thus, we can achieve the shortest delegation key and minimize the time of key delegation under the premise of guaranteeing the delegator's access control requirement. The Key Generation Center (KGC) then embeds the delegatee's identity into the key to trace the route of the delegation key. Our approach prevents the delegatee from combining his existing key with the new delegation key to access unauthorized data objects. Theoretical analysis and test results show that our approach helps the KGC transfer some of its burdensome key generation tasks to regular users (delegators) to accommodate more users.

• The Journal of Sustainable Design and Educational Environment Research
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• v.3 no.2
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• pp.1-21
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• 2003

This study will focus on analysing changes in subject content, teaching and learning methods, teaching model, and evaluation which have been brought about by the introduction of the 7th education curriculum, and on considering how many kinds of science labs are needed, and on proposing the desirable direction of building them. Methods for studying the goals above are as follows: First, considerations were given on how science labs must be structured and on which equipment are needed, which were done by analysing change of science education for future society, science subjects in the 7th educational curriculum, current situation of science labs, and science educational materials. Second, based on the need of students, it was examined how many science classes were needed, and through this the number of labs needed and users' requirement were analysed. Third, on the basis of the analysis above, existing conditions in planning science labs and the example of existing labs were examined.