• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.11 no.5
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• pp.41-46
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• 2011

Mobile Ad-Hoc networks (MANET) has been getting the spotlight in the area of the wireless networks because of its flexibility and salability, and developing of many applications with it. As a consequence, MANETs are required to process not only simple data traffics, but also multimedia traffics, which has some constraints on the performances. However, unlike wired-networks, the wireless networks have frequent route-disconnections due to some reasons such as channel errors and mobility. Such frequent link disconnections makes the delivery of multimedia traffics difficult. Even though there many researches on multimedia transmissions on various environments, the performances of multimedia transmissions over fading channel and mobility even using various routing protocols have not been evaluated. Therefore, this paper extensively simulates the MPEG-4 video transmission over fading channel environment with node's mobility. In addition, the performances with two routing protocols such as AODV and DSR are compared. Finally, the simulation results shows that DSR protocol has the better performances to deliver MPEG-4 traffic.

• Korean Institute of Interior Design Journal
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• no.6
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• pp.45-52
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• 1995

The presentation of the method by which the furniture and the architecture can be unified in one category, and the study and the verification on the mutual relation in the shape and the function are having been consistently made till the late twenties. The change of the social structure such as increasing the unit dwelling space with the small scale comes to need the efficiency in using space and the open dwelling space by the systematic spa-cial formation. Therefore, the understanding of the mean-ing and the characteristics of system furnitures as the design method which can meet such needs will be made here in this study. The application of the systematic consideration as the method of interior design means the formation of the firm image on the spacial environment through the mix-ture and link of the heterogeneous factors, the organic connection of each surface, the establishment of the natu-ral relation by linking the heterogeneous materials mutu-ally. and the easiness of the entire plan in the end. This study aims at analyzing and studying the typical charac-teristics by understanding the historical background and methodical principle which enabled the appearance of this kind of thought, and the adapted cases of the wood and metal material system furniture. There may be difference between the structural sub-stance and formative consideration. Transformative furni-ture which consists of the factors is the concept for the encrease of the multi purpose value by mixing the unit cabinets. One system can be separated horizontally, verti-cally, and to the drawers, and it gives us the disengage-ment from the artificial environment, since all the heights and width can be transformed as per each situa-tion of the space. The factors which can not be found in the other existing furniture are as follows. 1. disengagement from the artificial environment. 2. establishing the new productiosn trend as freed from the customers' fashion trend. 3. presenting the producing condition which leads the exact technology. 4. flexibility of the furniture which enables the reduction and enlargement in each situation.

• ETRI Journal
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• v.40 no.1
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• pp.39-50
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• 2018

More people prefer using rail traffic for travel or for commuting owing to its convenience and flexibility. The railway scenario has become an important communication scenario in the fifth generation era. The communication system should be designed to support high-data-rate demands with seamless connectivity at a high mobility. In this paper, the channel characteristics are studied and modeled for the railway tunnel scenario with straight and curved route shapes. On the basis of measurements using the "Mobile Hotspot Network" system, a three-dimensional ray tracer (RT) is calibrated and validated for the target scenarios. More channel characteristics are explored via RT simulations at 25.25 GHz with a 500-MHz bandwidth. The key channel parameters are extracted, provided, and incorporated into a 3rd-Generation-Partnership-Project-like stochastic channel generator. The necessary channel information can be practically realized, which can support the link-level and system-level design of the communication system in similar scenarios.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 1997.11a
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• pp.392-403
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• 1997

There is a strong international move towards performance based fire regulations for buildings with New Zealand and Australia at the forefront of research in this fold. The reform of regulations is thought to offer more innovation and flexibility in building design and greater cost effectiveness in construction. An important part of the research in this area is related to the development of agreed approaches to fire safety design, such as the Fire Code Reform Centre's "Fire Engineering Guidelines" or New Zealand's "Fire Engineering Design Guide". Such design process documents have incorporated or referenced much of the latest research in areas such as: tenability criteria fire compartment models egress models risk assessment. Use of such design guidelines or equivalents in major projects in countries such as Hong Kong and Australia have highlighted where fro engineering can offer real benefits to building designers and ultimately building owners and operators. However, there is still much research to be done and use of a systematic, logical design approach clearly identifies where design data or modelling techniques are still urgently required. Such areas are: fire growth rates and peak heat release rates for non-residential occupancies pre-movement times related to egress experimental validation and limits of applicability of CFD and other compartment Ire models probability/reliability data on fire protection systems for risk based analysis. Examples from case studies will be shown where lack of such research and poor judgement can lead to inferior design solutions or where unnecessarily conservative designs can lead to cost excesses. In summary, the link between Ire engineering designers and the research community is very important to highlight areas of fire research that will have the most benefit to the building and construction industry.nstruction industry.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.14 no.1
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• pp.57-67
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• 2015

A large amount of work has been done in the areas of routing, MAC, QoS, capacity, location service, cooperative communication, fault tolerance, mobility models and various applications of mesh networks thanks to their merits of cost-effective way of deployment and flexibility in extending wireline services. Although multi-path routing protocols have been proposed to be used to provide QoS and fault-tolerance, there has not been any significant results discussed that support both in the literature to our best knowledge as they are often required in military and public safety applications. In this paper, we present a novel routing protocol for a mesh network based on the OFDM-TDMA collision-free MAC that discovers and maintains multiple paths that allows retransmitting and forwarding packets that have been blocked due to a link failure using an alternative next-hop node such that the delay-capacity tradeoff is reduced and the reliability is enhanced. Simulation results show that the proposed protocol performs well in terms of both the QoS and delivery ratio.

• Computers and Concrete
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• v.16 no.4
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• pp.503-529
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• 2015

Traditionally, multi-story buildings are designed to provide stiffer structural support to withstand lateral earthquake loading. Introducing flexible elements at the base of a structure and providing sufficient damping is an alternative way to mitigate seismic hazards. These features can be achieved with a device known as an isolator. This paper covers the design of base isolators for multi-story buildings in medium-risk seismicity regions and evaluates the structural responses of such isolators. The well-known tower building for police personnel built in Dhaka, Bangladesh by the Public Works Department (PWD) has been used as a case study to justify the viability of incorporating base isolators. The objective of this research was to establish a simplified model of the building that can be effectively used for dynamic analysis, to evaluate the structural status, and to suggest an alternative option to handle the lateral seismic load. A finite element model was incorporated to understand the structural responses. Rubber-steel bearing (RSB) isolators such as Lead rubber bearing (LRB) and high damping rubber bearing (HDRB) were used in the model to insert an isolator link element in the structural base. The nonlinearities of rubber-steel bearings were considered in detail. Linear static, linear dynamic, and nonlinear dynamic analyses were performed for both fixed-based (FB) and base isolated (BI) buildings considering the earthquake accelerograms, histories, and response spectra of the geological sites. Both the time-domain and frequency-domain approaches were used for dynamic solutions. The results indicated that for existing multi-story buildings, RSB diminishes the muscular amount of structural response compared to conventional non-isolated structures. The device also allows for higher horizontal displacement and greater structural flexibility. The suggested isolation technique is able to mitigate the structural hazard under even strong earthquake vulnerability.

• The Journal of the Korea Contents Association
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• v.10 no.8
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• pp.407-416
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• 2010

The purpose of this study was to examine the relationship among women's leisure dance participation, physical image and self-esteem. The subjects in this study were 300 female adults who were selected by cluster sampling from the population that consisted of women who were in their 20s to 50s. In the population, some women got leisure dance at fitness clubs, sport lovers' clubs and dance academies in Seoul and Gyeoggn Province as of 2009, and the others didn't. As for the reliability of the questionnaires used in the study, the Cronbach alpha coefficient of the questionnaires was above .70. The major statistical methods utilized in this study were Frequencies, reliability factor analysis, analysis covariate, regression analysis and path analysis. The findings of the study were as follows: First, the women who got leisuer dance evaluated their own physical image and self-esteem more favorably than the others who didn't. Second, the length of participation affected the body shape, satisfaction level and flexibility, and the intensity of participation impacted on the body shape and muscular power. Third, the length of participation had an impact on self-esteem, and the frequency of participation exerted a negative influence on that. Fourth, the degree of participation had a causal impact on physical image and self-esteem. In other words, the degree of getting leisure dance affected self-esteem in a firsthand manner and exerted a secondhand influence on that through physical image as well. The findings of the study suggested that physical image was one of major parameters to link participation in rhythmic exercise and self-esteem.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.16 no.5
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• pp.12-28
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• 2017

The core of the transportation service, so-called Mobility 4.0 is the flexibility of the entire mobility and its implementation. By doing so, the most essential element is to build a platform to link a supply and a demand simultaneously. In other word, a comprehensive analytical framework is to be set with a data repository which can be periodically updated. With such circumstances, the entire trip chain including pedestrian movements is required to be thoroughly investigated and constructed at the viewpoint of the intermodal transit station. A few studies, however, have been attempted. In this study, the comprehensive analytical framework with the integrated mobility at intermodal transit station was proposed, which consisted of the three modules; 1) Data Repository Extracting from Smart Card DB, 2) Framework of Analyzing Integrated Mobility, and 3) Interpretation of the Integrated Mobility with GIS information and the other factors. A case study with the seven railway stations (Sadang, Sindorom, Samseong, Gwanghwanoon, Gangnam, Jamsil, Seoul Nat'l Univ. of Education) was conducted. The stations of the case study were clustered by the three groups with the statistical ground, and it is most likely to understand the effect of a variety of factors and a comprehensive data-driven analyses with the entire trip stages.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.31 no.4
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• pp.173-181
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• 2018

Recently composite materials have dominated most engineering fields, owing to their better performance, increased durability and flexibility to be customized and designed for a specific required property. This has given them unprecedented superiority over conventional materials. With the help of the ever increasing computational capabilities of computers, researchers have been trying to develop accurate material models for the complex and integrated properties of these composites. This has led to advances in virtual testing of composite materials as a supplement or a possible replacement of laboratory experiments to predict the properties and responses of composite materials and structures. This paper presents a review on the complex multi-scale modelling framework of the virtual testing machines, which involve computational mechanics at various length-scales starting with nano-mechanics and ending in structure level computational mechanics, with a homogenization technique used to link the different length scales. In addition, the paper presents the features of some of the biggest integrated virtual testing machines developed for study of concrete, including a multiscale modeling scheme for the simulation of the constitutive properties of nanocomposites. Finally, the current challenges and future development potentials for virtual test machines are discussed.

• International Journal of Computer Science & Network Security
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• v.22 no.9
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• pp.35-42
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• 2022

The article deals with the role of extra-curricular work by means of multimedia technologies in order to improve the quality of training of future specialists. An important condition for achieving high results in training specialists is the optimal combination of classroom and independent extra-curricular work of students by means of multimedia technologies. Very significant is the development of student independence, the formation of skills of independent search activity, the ability to take responsibility, independently solve a problem, find constructive solutions, a way out of a crisis situation, and so on. Extra-curricular work forms students' ability to master the techniques of analysis, synthesis, generalization, comparison; develops flexibility of thinking; opens up opportunities for the development and stabilization of positive learning motives to activate the process of mastering knowledge by means of multimedia technologies as a means of forming the personality of a highly qualified specialist. The concept of multimedia as one of the priority areas of Information Technology, which plays a particularly important role in the process of informatization of education, is revealed, and its advantages in education are shown. The advent of multimedia systems optimizes transformations in education, in many areas of professional activity, science, art, etc. The necessity of distance learning to improve the quality of training of future specialists using multimedia technologies in extra-curricular work is justified. The effectiveness of pedagogical support in the process of distance learning is achieved by the following conditions, which is revealed in the article. Various forms and types of extra-curricular work of students that are used in the modern practice of the educational environment of a higher education institution are described. Scientific and informational activity is considered a key area of information activity. The analysis of scientific and information activities in the field of education allows us to identify its main functions, which emphasize the growing role of scientific information in the education system, in particular, extra-curricular work using multimedia technologies. Operational, complete, accurate, targeted information that meets objective and subjective needs becomes an important link between the field of management, science and practice.