• Journal of Communications and Networks
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• v.11 no.4
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• pp.390-405
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• 2009

Wireless sensor networks (WSNs) are envisioned to facilitate information gathering for various applications and depending on the application types they may require certain quality of service (QoS) guarantee for successful and guaranteed event perception. Therefore, QoS in WSNs is an important issue and two most important parameters that hinder the goal of guaranteed event perception are time-sensitive and reliable delivery of gathered information, while a minimum energy consumption is desired. In this paper, we propose an energy-aware, multi-constrained and multipath QoS provisioning mechanism for WSNs based on optimization approach. Hence, a detailed analytical analysis of reliability, delay and energy consumption is presented to formulate the optimization problem in an analytical way. A greedy algorithm is proposed to achieve the desired QoS guarantee while keeping the energy consumption minimum. Also, a simple but efficient retransmission mechanism is proposed to enhance the reliability further, while keeping the delay within delay bound. Simulation results demonstrate the effectiveness of our scheme.

• Fashion & Textile Research Journal
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• v.13 no.3
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• pp.299-308
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• 2011

The purpose of this study was to research the heroines' fashion styles in the opera, "La Boh$\`{e}$me." This article studied the representations of the grisettes in 1830's France and the characteristics of the grisettes appeared in the original novel, "Sc$\`{e}$nes de la Vie de Boh$\`{e}$me" and contemporary literatures and paintings. The one of the heroines, Mimi was figured a virtuous female despite poor environments, by contrast Musetta was described as cruel, greedy and vicious female in the opera. But, by analyzing the original novel and the representations of the grisettes in contemporary literatures, this study figured out clearly Mimi and Musetta have same origin and similar aspects, not contrast. Up to the present mimi's costumes were not sophisticated but too simple compared to Musetta's. Also Musetta's costume were too much luxury considering her status. This study proposed a new fashion style considering not only analysis result of the heroins' characteristics but contemporary costume design of the 1830's France.

• ETRI Journal
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• v.33 no.2
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• pp.210-218
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• 2011

Battiti's mutual information feature selector (MIFS) and its variant algorithms are used for many classification applications. Since they ignore feature synergy, MIFS and its variants may cause a big bias when features are combined to cooperate together. Besides, MIFS and its variants estimate feature redundancy regardless of the corresponding classification task. In this paper, we propose an automated greedy feature selection algorithm called conditional mutual information-based feature selection (CMIFS). Based on the link between interaction information and conditional mutual information, CMIFS takes account of both redundancy and synergy interactions of features and identifies discriminative features. In addition, CMIFS combines feature redundancy evaluation with classification tasks. It can decrease the probability of mistaking important features as redundant features in searching process. The experimental results show that CMIFS can achieve higher best-classification-accuracy than MIFS and its variants, with the same or less (nearly 50%) number of features.

• ETRI Journal
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• v.33 no.2
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• pp.184-193
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• 2011

Tailored for wireless local area networks, the present paper proposes a cross-layer resource allocation scheme for multiple-input multiple-output orthogonal frequency-division multiplexing systems. Our cross-layer resource allocation scheme consists of three stages. Firstly, the condition of sharing the subchannel by more than one user is studied. Secondly, the subchannel allocation policy which depends on the data packets' lengths and the admissible combination of users per subchannel is proposed. Finally, the bits and corresponding power are allocated to users based on a greedy algorithm and the data packets' lengths. The analysis and simulation results demonstrate that our proposed scheme not only achieves significant improvement in system throughput and average packet delay compared with conventional schemes but also has low computational complexity.

• The Journal of Society for e-Business Studies
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• v.19 no.1
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• pp.131-143
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• 2014

A triple database consisting of a number of three-column tables require high cost of query processing, whereby building a shortcut is known as an effective way to reduce the cost. It is important to figure out what shortcuts needs to be selectively built. Most shortcut selection algorithms make use of a benefit model that considers the query frequency. However they work poor to reflect the database update. In this paper, we consider a benefit model for triple databases. The model considers not only the profit of query response times but also the building and maintenance costs of the shortcuts. We apply the model to design a benefit function which can be plugged in a greedy-based shortcut selection algorithm. We perform the empirical experiments on a real-world dataset and analyze the effect of each factor employed in the benefit function.

• Journal of the Korean Data and Information Science Society
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• v.25 no.6
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• pp.1283-1291
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• 2014

In this paper, we propose forward stagewise algorithm when data are very large or coming in batches sequentially over time. In this situation, ordinary boosting algorithm for large scale data and data batch stream may be greedy and have worse performance with class noise situations. To overcome those and apply to large scale data or data batch stream, we modify the forward stagewise algorithm. This algorithm has better results for both large scale data and data batch stream with or without concept drift on simulated data and real data sets than boosting algorithms.

• Journal of Information Processing Systems
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• v.14 no.4
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• pp.961-979
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• 2018

For many years, matching in a bipartite graph has been widely used in various assignment problems, such as stable marriage problem (SMP). As an application of bipartite matching, the problem of stable marriage is defined over equally sized sets of men and women to identify a stable matching in which each person is assigned a partner of opposite gender according to their preferences. The classical SMP proposed by Gale and Shapley uses preference lists for each individual (men and women) which are infeasible in real world applications for a large populace of men and women such as matrimonial websites. In this paper, we have proposed an enhancement to the SMP by computing a weighted score for the users registered at matrimonial websites. The proposed enhancement has been formulated into profit maximization of matrimonial websites in terms of their ability to provide a suitable match for the users. The proposed formulation to maximize the profits of matrimonial websites leads to a combinatorial optimization problem. We have proposed greedy and genetic algorithm based approaches to solve the proposed optimization problem. We have shown that the proposed genetic algorithm based approaches outperform the existing Gale-Shapley algorithm on the dataset crawled from matrimonial websites.

• The Transactions of the Korea Information Processing Society
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• v.6 no.9
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• pp.2311-2319
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• 1999

We present two heuristic algorithms for the task allocation problem (NP-complete problem) in parallel computing. The problem is to find an optimal mapping of multiple communicating tasks of a parallel program onto the multiple processing nodes of a distributed-memory multicomputer. The purpose of mapping these tasks into the nodes of the target architecture is the minimization of parallel execution time without sacrificing solution quality. Many heuristic approaches have been employed to obtain satisfactory mapping. Our heuristics are based on genetic algorithms and simulated annealing. We formulate an objective function as a total computational cost for a mapping configuration, and evaluate the performance of our heuristic algorithms. We compare the quality of solutions and times derived by the random, greedy, genetic, and annealing algorithms. Our experimental findings from a simulation study of the allocation algorithms are presented.

• The Transactions of the Korea Information Processing Society
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• v.7 no.3
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• pp.943-952
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• 2000

The surface reconstruction problem from a set of wire-frame contours is very important in diverse fields such as medical imaging or computer animation. In this paper, surface triangulation method is proposed for solving the problem. Generally, many optimal triangulation techniques suffer from the large computation time but heuristic approaches may produce very unnatural surface when contours are widely different in shape. To compensate the disadvantages of these approaches, we propose a new heuristic triangulation method which iteratively decomposes the surface generation problem from a band (a pair of vertices chain) into tow subproblems from two sub-bands. Generally, conventional greedy heuristic contour triangulation algorithm, suffer from the drastic error propagation during surface modeling when the adjacent contours are different in shape. Our divide-and-conquer algorithm, called band partitioning algorithm, processes eccentric parts of the contours first with more global information. Consequently, the resulting facet model becomes more stable and natural even though the shapes are widely different. An interesting property of our method is hat it supports multi-resolution capability in surface modeling time. According to experiments, it is proved to be very robust and efficient in many applications.

• Journal of information and communication convergence engineering
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• v.9 no.4
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• pp.411-419
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• 2011

In this paper, we propose an Adaptive Regulating Drop (ARD) marker, as a novel dropping strategy at the ingressive edge router, to improve TCP fairness in assured services (ASs) without a decrease in the link utilization. To drop packets pertinently, the ARD marker adaptively changes a Temporary Permitted Rate (TPR) for aggregate TCP flows. The TPR is set larger than the current input IN packet rate of aggregate TCP flows while inversely proportional to the measured input OUT packet rate. To reduce the excessive use of greedy TCP flows by notifying droppings of their IN packets constantly to them without a decrease in the link utilization, the ARD marker performs random early fair remarking of their excessive IN packets to OUT packets at the aggregate flow level according to the TPR. In addition, an aggregate dropper is combined to drop some excessive IN packets fairly and constantly according to the TPR. Thus, the throughput of a TCP flow no more depends on only the sporadic and unfair OUT packet droppings at the RIO buffer in the core router. Then, the ARD marker regulates the packet transmission rate of each TCP flow to the contract rate by increasing TCP fairness, without a decrease in the link utilization.