• Journal of KIISE:Computer Systems and Theory
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• v.27 no.5
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• pp.464-474
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• 2000

All-to-all personalized communication, or complete exchange, is at the heart of numerous applications, such as matrix transposition, fast Fourier Transform(FFT), and distributed table lookup.We present an efficient all-to-all personalized communication algorithm for a 2D torus inwormhole-routed networks. Our complete exchange algorithm adopts divide-and-conquer approach toreduce the number of start-up latency significantly, which is a good metric for network performancein wormhole networks. First, we divide the whole network into 2x2 basic cells, After speciallydesignated nodes called master nodes have collected messages to transmit to the rest of the basic cell,only master nodes perform complete exchange with reduced network size, N/2 x N/2. When finishedwith this complete exchange in master nodes, these nodes distribute messages to the rest of the masternode, which results in the desired complete exchange communication. After we present our algorithms,we analyze time complexities and compare our algorithms with several previous algorithms. And weshow that our algorithm is efficient by a factor of 2 in the required start-up time which means thatour algorithm is suitable for wormhole-routed networks.

• The KIPS Transactions:PartA
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• v.9A no.3
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• pp.363-370
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• 2002

OPKFDD (Ordered Pseudo-Kronecker Functional Decision Diagram) is one of ordered-DDs (Decision Diagrams) in which each node can take one of three decomposition types : Shannon, positive Davio and negative Davio decompositions. Whereas OBDD (Ordered Binary Decision Diagram) uses only the Shannon decomposition in each node, OPKFDD uses the three decompositions and generates representations of functions with smaller number of nodes than other DDs. However, this leads to the extreme difficulty of getting an optimal solution for the minimization of OPKFDD. Since an appropriate decomposition type has to be chosen for each node, the size of the representation is decided by the selection of the decomposition type. We propose a heuristic method to generate OPKFDD efficiently from the OBDD of the given function and the algorithm of the decision of decomposition type for a given variable ordering. Experimental results demonstrate the performance of the algorithm.

• Journal of the Korea Society for Simulation
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• v.23 no.2
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• pp.65-72
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• 2014

Sensor nodes are easily compromised by attacker when which are divided in open environment. The attacker may inject false report and false vote attack through compromised sensor node. These attacks interrupt to transmission legitimate report or the energy of sensor node is exhausted. PVFS are proposed by Li and Wu for countermeasure in two attacks. The scheme use inefficiency to energy of sensor node as fixed report threshold and verification node. In this paper, our propose the next neighbor node selection scheme based on fuzzy logic system for energy improvement of PVFS. The parameter of fuzzy logic system are energy, hops, verification success count, CH select high the next neighbor node among neighbor nodes of two as deduction based on fuzzy logic system. In the experimental, our proposed scheme was improvement to energy of about 9% compare to PVFS.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.2B
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• pp.76-81
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• 2008

LEACH (Low Energy Adaptive Clustering Hierarchy) has been proposed as a routing protocol with a hierarchical structure, in order to achieve the energy efficiency that is of primary importance in the wireless sensor networks. A wireless sensor network adopting LEACH is composed of a few clusters, each of which consists of member nodes that sense the data, and head nodes that deliver the collected data from member nodes to a sink node that is connected to a backbone network. A head node in a cluster allocates TDMA slots to its member nodes without taking into account whether they have data to transmit or not, thus resulting in inefficiency of energy usage of head node that remains in active mode during the entire round time. This motivates us to propose a scheme to improve the energy efficiency of LEACH, by assigning TDMA slots only to those member nodes who have data to send. As a result, the head node can remain sleep during the period of no data transmission from member nodes, leading to the substantial energy saving. By using the ns-2 simulator, we evaluate the performance of the proposed scheme in comparison with the original LEACH. Experimental results validate our scheme, showing a better performance than original LEACH in terms of the number of outliving nodes and the quantity of energy consumption as time evolves.

• Convergence Security Journal
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• v.20 no.5
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• pp.33-39
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• 2020

In MANET consisting of only mobile nodes, all nodes serve as routes. However, the dynamic topology due to frequent movement of nodes degrades routing performance and is also cause of many security vulnerabilities. Therefore, security must be applied to routing techniques that can influence the performance of MANET. In this paper, we propose a technique for efficiently responding to various routing attacks and safe data transmission through application of zone-key based security routing techniques. A zone-based network structure was used, and a management node that manages member nodes in each zone was used in the proposed technique. In addition, the damage from the attacking node was minimized by issuing a key to each node and applying this to a routing technique. The zone management node issues a key for encryption routing information and manages the issuance information. A member node that wants to transmit data encrypts routing in formation using a key issued from the zone management node, and then performs path discovery using this. The improved performance of the proposed technique was confirmed through a comparative experiment with the CBSR and ARNA technique, excellent performance was confirmed through experiments.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.5
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• pp.1020-1030
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• 2016

This paper propose an improving relay node selection method for node-to-node connectivity. This concern with the mobility and analysis of deployed for masking operation using highest connectivity node. The major of Delay Tolerant Network (DTN) routing protocols make use of simple forwarding approach to transmit the message depend on the node's mobility. In this cases, the selection of the irrelevant mobile node induced the delay and packet delivery loss caused by limiting buffer size and computational power of node. Also the proposed algorithm provides the node connectivity considering the mobility and direction select the highest connectivity node from neighbor node using masking operation. From the simulation results, the proposed algorithm compared the packet delivery ratio with PROPHET and Epidemic. The proposed Enhanced Prediction-based Context-awareness Matrix(EPCM) algorithm shows an advantage packet delivery ratio even with selecting relay node according to mobility and direction.

• Fashion & Textile Research Journal
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• v.1 no.3
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• pp.252-258
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• 1999

The aims of this study is to classify the lower somatotype of adult women and appearance analysis on the shape of flare skirts by using the image processing. Also We have made skirts in order to analyze the various types of appearance of flare skirts by using the image processing. The subjects for our wear test lower somatotype, who were controlled in their waist, abdomen and hip shapes. The flare skirts used for wear test were 112 types(combinated 14 fabric type and 8 lower somatotype). The effect of lower somatotype on the shape of flare skirts was determined by the horizontally hem line section shape and the silhouette of flare skirts with image processing. The data were analyzed by using analysis of variance and Turkey, Duncan multiple range test. The results obtained are summarized as follows: It is shown that the fabric weight elongation differs in fabrics properties, in direction of textures. The shape horizontal section of flare skirt hem line has differed with the number of nodes, wave-height of nodes and breadth of silhouette by fabrics properties and lower somatotype. It is noticed that the breadth of flare skirts by the silhouette has high correlation with the drape ability of fabrics and lower somatotype. Results for our flare skirts show changes in amplitude and mean with fabrics, somatotype. Therefore we can say that gray-level histograms are correlated with changes in appearance, differences in drape spacing and related fabric properties and their somatotype.

• The KIPS Transactions:PartC
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• v.18C no.2
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• pp.97-102
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• 2011

Since the game theory provides a theoretical ground to distribute a shared resource between demanding users in a fair and efficient manner, it has been used for the bandwidth allocation problem in a network. However, the bandwidth allocation schemes with different game theory assign different amount of bandwidth in the same operational environments. However, only the mathematical framework is adopted when a bandwidth allocation scheme is devised without quantitatively comparing the results when they applied to the bandwidth allocation problem. Thus, in this paper, we compare the characteristics of the bandwidth allocation schemes using the bankrupt game theory and the bargaining game theory when they applied to the situation where nodes are competing for the bandwidth in a network. Based on the numerical results, we suggest the future research direction.

• Journal of the Korea Computer Industry Society
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• v.2 no.2
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• pp.203-210
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• 2001

To estimate relational models and test the theoretical hypotheses of binary tree search algorithms, we built binary search trees with random permutations of n (number of nodes) distinct numbers, which ranged from three to seven. Probabilities for building binary search trees corresponding to each possible height and balance factor were estimated. Regression models with variables of number of nodes, height, and average number of comparisons were estimated and the theorem of O(1g(n)) was accepted experimentally by a Lack of Test procedure. Analysis of Variance model was applied to compare the average number of comparisons with three groups by height and balance factor of the trees to test theoretical hypotheses of a binary search tree performance statistically.

• Journal of Digital Contents Society
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• v.6 no.1
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• pp.7-12
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• 2005

The purpose of this study is to study the relability of degree 2 ICR(Interleaved Cydic Ring) network and to compare with the other rings. Two node reliability is the probability that source node communicates with the destination node through a specified time interval for ICR network. The impact for change of failure rate is studied for ICR network for small size of network, the exact value of reliability is calculated but the approximation of average reliability general function from upper bound and lower bound reliability is obtained for large size of it. The reliability of ICR network is compared with it of the other rings according to changing the cycle value of ICR.