• International Journal of Computer Science & Network Security
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• 제23권7호
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• pp.16-22
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• 2023

Enhanced radio access technologies (RAT) are deployed in Next Generation Convergence Networks by the service providers so as to satisfy the basic requirements of end-users for e.g. QoS. Whenever the available resources are being shared simultaneously and dynamically by multiple users or distribution of allocated channels randomly, the deficiency of spectral resources and dynamic behavior of Network traffic in real time Networking, we may have problem. In order to evaluate the performance of our proposed algorithm, computer simulation has been performed on NS-2 simulator and a comparison with the existing algorithms has been made.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권5호
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• pp.1976-1997
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• 2016

This paper investigates the problem of co-tier interference mitigation for dynamic small- cell networks, in which the load of each small-cell varies with the number of active associated small-cell users (SUs). Due to the fact that most small-cell base stations (SBSs) are deployed in an ad-hoc manner, the problem of reducing co-tier interference caused by dynamic loads in a distributed fashion is quite challenging. First, we propose a new distributed channel allocation method for small-cells with dynamic loads and define a dynamic interference graph. Based on this approach, we formulate the problem as a dynamic interference graph game and prove that the game is a potential game and has at least one pure strategy Nash equilibrium (NE) point. Moreover, we show that the best pure strategy NE point minimizes the expectation of the aggregate dynamic co-tier interference in the small-cell network. A distributed dynamic learning algorithm is then designed to achieve NE of the game, in which each SBS is unaware of the probability distributions of its own and other SBSs' dynamic loads. Simulation results show that the proposed approach can mitigate dynamic co-tier interference effectively and significantly outperform random channel selection.

• 한국자동차공학회논문집
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• 제10권5호
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• pp.214-222
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• 2002

Computer simulations are widely used to analyze passenger safety in simulated traffic accidents. ATB, Articulated Total Body, is a computer simulation model developed to predict gross human body response to such dynamic environments as vehicle crashes and pilot ejections. ATB, whose code is open, has high flexibility and application capability that users can easily insert defined modules and functions. ATB is, however, inconvenient as it was coded in FORTRAN and it needs a formated input file. Moreover, it takes much time to make input files and to modify coding errors. This study aims to increase user friendliness by adding a preprocessor program, WINATB(WINdows ATB), to the conventional ATB. WINATB, programmed in Visual C＋＋ and OpenGL, uses ATB IV as a dynamic solver. The preprocessor helps users prepare input files through graphic interface and dialog box. An additional postprocessor makes the graphical presentation of simulated results. In these case of the frontal crash, the rear impact and the side impact, the simulation results obtained by WINATB and MADYMO(MAthematical Dynamic Model) are compared to validate the effectiveness of WINAIB.

• 정보처리학회논문지A
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• 제8A권3호
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• pp.261-268
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• 2001

With the rapid growth of the Internet, various web-based businesses are creating a new environment in an imaginary space. However, this expanding Internet and user increase cause an overflow of transmission and numerous subordinate problems. To solve these problems, a parallel cluster system is produced using different methods. This thesis recommends a multi0distribution cluster group. It constructs a MPP dynamic distribution sub-cluster group using numerous low-priced and low-speed systems. This constructed sub-cluster group is then connected with a singular virtual IP to finally serve the needs of clients (users). This multi-distribution cluster group consists of an upper structure based on LVS and a dynamic serve cluster group centered around an SC-server. It conducts the workloads required from users in a parallel process. In addition to the web service, this multi-distribution cluster group can efficiently be utilized for the calculations which require database controls and a great number of parallel calculations as well as additional controls with result from the congestion of service.

• Journal of Communications and Networks
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• 제17권4호
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• pp.406-418
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• 2015

Cognitive radio networks (CRNs) have emerged as a promising solution to the problem of spectrum under utilization and artificial radio spectrum scarcity. The paradigm of dynamic spectrum access allows a secondary network comprising of secondary users (SUs) to coexist with a primary network comprising of licensed primary users (PUs) subject to the condition that SUs do not cause any interference to the primary network. Since it is necessary for SUs to avoid any interference to the primary network, PU activity precludes attempts of SUs to access the licensed spectrum and forces frequent channel switching for SUs. This dynamic nature of CRNs, coupled with the possibility that an SU may not share a common channel with all its neighbors, makes the task of multicast routing especially challenging. In this work, we have proposed a novel multipath on-demand multicast routing protocol for CRNs. The approach of multipath routing, although commonly used in unicast routing, has not been explored for multicasting earlier. Motivated by the fact that CRNs have highly dynamic conditions, whose parameters are often unknown, the multicast routing problem is modeled in the reinforcement learning based framework of learning automata. Simulation results demonstrate that the approach of multipath multicasting is feasible, with our proposed protocol showing a superior performance to a baseline state-of-the-art CRN multicasting protocol.

• Journal of Information Processing Systems
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• 제6권3호
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• pp.403-412
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• 2010

Multi-Relay Networks should accommodate mobile users of various speeds. The cellular system should meet the minimum residency time requirements for handover calls while considering an efficient use of available channels. In this paper, we design speed-sensitive handover under dynamic hierarchical cellular systems, in which mobile users are classified according to the mean speed of mobile users and each class has its cellular layer. In order to meet the minimum residency time, the cell size of each cellular layer is dynamically determined depending on the distributions of mean speeds of mobile users. Since the speed-dependent non-preferred cell can provide a secondary resource, overflow and take-back schemes are adopted in the system. We develop analytical models to study the performance of the proposed system, and show that the optimal cell size improves the blocking probability.

• 한국군사과학기술학회지
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• 제15권4호
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• pp.442-449
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• 2012

Cognitive Radio(CR) is the technology that allocates the frequency by using dynamic spectrum access. We proposed a model to calculate the optimal level of the cognitive radiotelegraph, where secondary users opportunistically share the spectrum with primary users through the spectrum sensing. When secondary user with cognitive radio detects the arrival of a primary user in its current channel, the secondary user moves to the idle channel or be placed in the virtual queue. We assume that the primary users have finite buffers and the population of secondary users is finite. Using a two-dimensional Makov model with preemptive priority queueing, we could derive the blocking and waiting probability as well as the optimal level of cognitive radiotelegraph under a various range of parameter circumstances.

• 한국의류산업학회지
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• 제21권4호
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• pp.420-431
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• 2019

This paper evaluates the potential of dynamic graphical patterns in future-driven fashion design using computer graphics that enables changes to the visual appearance of a textile for aesthetic, expressive or communicative purposes. In particular, it focuses on experimenting with the possibility of creating digitalized dynamic fashion garments that are illustrated digitally using motion graphics developed collaboratively in a virtual space. Three objectives were formed and addressed. First, a dynamic graphical pattern was defined that also investigated the cases of tangible and virtual dynamic patterns in textiles and garments to identify current situations and future prospects in terms of functional techniques and expressive effects. Ten digital fashion illustrations were then created in collaboration with a group of graphic designers and motion artists to visualize dynamic graphical patterns changing over time. Four types of dynamic fashion illustrations were also introduced in their methodological and expressive aspects. Last, some findings resulted from digital works that led to implications for future studies on tangible dynamic fashion designs. This study proposed that computer graphics and digital imaging technologies integrated into a virtual fashion that creates eye-catching and futuristic dynamic fashion designs that can customize colors and patterns according to the desires of wearers or users.

• 한국정보과학회논문지:데이타베이스
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• 제36권6호
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• pp.411-421
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• 2009

블로그 연결망 내에는 다른 사용자들이 블로그 서비스를 활발하게 이용하도록 유도하는 특별한 사용자들이 존재한다. 본 논문에서는 이러한 사용자들 가운데 블로그 내의 컨텐츠가 다른 사용자에게 큰 영향을 끼치는 사용자들을 컨텐츠 파워 유저라고 정의하고 이들을 파악하는 기법에 대하여 논의한다. 우선, 각 사용자가 소유하고 있는 각 게시글들의 컨텐츠 영향력을 계량화하는 방법을 제안하고, 이 값들의 합을 이용하여 해당 사용자의 컨텐츠 영향력을 계산하는 방법을 제안한다. 끝으로, 실제 블로그 연결망에서 제안하는 기법과 기존의 기법들을 이용하여 컨텐츠 파워 유저들을 파악하는 실험을 수행하고, 이 결과를 비교 및 분석한다.

• 한국CDE학회논문집
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• 제8권1호
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• pp.35-40
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• 2003

In this paper, we present the methods to develop a Web-based CAM system that is capable to simulate machining processes in solid model form through internet. The methods include the dynamic representation on Web of machining operation, workpiece definition on the request of users, interpretation technique of NC par programs through CORBA, and algorithm for efficient machining simulation. Based on the methods, a Web-based CAM system it implemented at http://virtual.ulsan.ac.kr. Using the Web-based CAM system, public users tan simulate machining processes by own NC part programs.