• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.2
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• pp.275-280
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• 2016

In this paper, we propose a novel relay selection technique which utilizes a priori decoding information at relays for buffer-aided successive relaying networks. In the conventional relaying schemes, a single relay pair is selected for receiving data from the source and transmitting data to the destination. In the proposed technique, however, all relays except the relay selected for transmitting data to the destination try to decode the received signal from the source, and they store the data if they succeed decoding. The proposed technique selects the relay such that it can succeed its own transmission and it maximizes the number of relays successfully decoding the data from the source at the same time. It is shown that the proposed relaying technique significantly outperforms the conventional buffer-aided relaying schemes in terms of outage probability through extensive computer simulations.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.10
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• pp.1934-1936
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• 2015

This paper proposes an optimal relay selection and adaptive throughput enhancement scheme utilizing superposition modulation in cooperative communication. The optimal relay is selected and the channel state is estimated by utilizing superposition modulation. The source determines the number of superimposed signal in accordance with the estated channel state. As a result, throughput is increased in accordance with the channel state.

• Journal of Communications and Networks
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• v.13 no.4
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• pp.377-384
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• 2011

Cooperative beamforming has previously been proven to be an efficient way to improve the cooperative diversity. This method generally requires all relay nodes to participate in beamforming, which can be seen as "all participate" cooperative beamforming. However, not all relay nodes have constructive impacts on the end-to-end bit error rate (BER) performance. Based on this observation, we propose a new cooperative scheme which only selects those "appropriate" relay nodes to perform cooperative beamforming. Such relay nodes can be simply determined with mean channel gains. Therefore, the selection complexity is significantly reduced as global instantaneous channel state information is not required. This scheme guarantees that energy is only allocated to the "appropriate" relay nodes, and hence provides superior diversity. We also prove that power allocation among source and selected relay nodes is a convex problem, and can be resolved with lower computational complexity. Simulation results demonstrate that our scheme achieves an essential improvement in terms of BER performance for both optimal and limited feedback scenarios, as well as high energy-efficiency for the energy-constrained networks.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.9
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• pp.4658-4679
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• 2017

Android is now the most popular smartphone platform and remains rapid growth. There are huge number of sensitive privacy information stored in Android devices. Kinds of methods have been proposed to detect Android malicious applications and protect the privacy information. In this work, we focus on extracting the fine-grained features to maximize the information of Android malware detection, and selecting the least joint features to minimize the number of features. Firstly, permissions and APIs, not only from Android permissions and SDK APIs but also from the developer-defined permissions and third-party library APIs, are extracted as features from the decompiled source codes. Secondly, feature selection methods, including information gain (IG), regularization and particle swarm optimization (PSO) algorithms, are used to analyze and utilize the correlation between the features to eliminate the redundant data, reduce the feature dimension and mine the useful joint features. Furthermore, regularization and PSO are integrated to create a new joint feature mining method. Experiment results show that the joint feature mining method can utilize the advantages of regularization and PSO, and ensure good performance and efficiency for Android malware detection.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.5 no.7
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• pp.1252-1273
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• 2011

In Web Service Composition (WSC) area, services selection aims at selecting an appropriate candidate from a set of functionally-equivalent services to execute the function of each task in an abstract WSC according to their different QoS values. In despite of many related works, few of previous studies consider transactional constraints in QoS-aware WSC, which guarantee reliable execution of Composite Web Service (CWS) that is composed by a number of unpredictable web services. In this paper, we propose a novel global selection-optimal approach in WSC by considering both transactional constraints and end-to-end QoS constraints. With this approach, we firstly identify building rules and the reduction method to build layer-based Directed Acyclic Graph (DAG) model which can model transactional relationships among candidate services. As such, the problem of solving global optimal QoS utility with transactional constraints in WSC can be regarded as a problem of solving single-source shortest path in DAG. After that, we present Graph-building algorithms and an optimal selection algorithm to explain the specific execution procedures. Finally, comprehensive experiments are conducted based on a real-world web service QoS dataset. The experimental results show that our approach has better performance over other competing selection approaches on success ratio and efficiency.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.9
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• pp.4271-4294
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• 2018

Communication cost is the most important factor in Wireless Sensor Networks (WSNs), as exchanging control keying messages consumes a large amount of energy from the constituent sensor nodes. Time-based Dynamic Keying and En-Route Filtering (TICK) can reduce the communication costs by utilizing local time values of the en-route nodes to generate one-time dynamic keys that are used to encrypt reports in a manner that further avoids the regular keying or re-keying of messages. Although TICK is more energy efficient, it employs no re-encryption operation strategy that cannot determine whether a healthy report might be considered as malicious if the clock drift between the source node and the forwarding node is too large. Secure SOurce-BAsed Loose Synchronization (SOBAS) employs a selective encryption en-route in which fixed nodes are selected to re-encrypt the data. Therefore, the selection of encryption nodes is non-adaptive, and the dynamic network conditions (i.e., The residual energy of en-route nodes, hop count, and false positive rate) are also not focused in SOBAS. We propose an energy efficient selection of re-encryption nodes based on fuzzy logic. Simulation results indicate that the proposed method achieves better energy conservation at the en-route nodes along the path when compared to TICK and SOBAS.

• Journal of the Korea Fashion and Costume Design Association
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• v.15 no.3
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• pp.51-67
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• 2013

This study aims to examine impacts of the Internet shopping orientation of Korean and Chinese consumers on their selection criteria of shopping malls and apparel products, frequencies and amounts of purchase, and information search in the Internet shopping mall. A survey was carried out with Korean and Chinese female consumers in their 20s and 30s who have the Internet shopping experiences. The results of this study were as follows: First, the Internet shopping orientation of Korean and Chinese respondents clearly showed factorial structures including the pleasure-conscious, fashion-conscious, price-conscious, and convenience-conscious orientation. From a result of the cluster analysis on four factors of the Internet shopping orientation, Korean and Chinese respondents were classified into three groups of the Internet shopping-unconscious, the Internet shopping-loyalty, and pleasure convenience-conscious. Second, there were significant differences in selection criteria of both the Internet shopping mall and apparel products among three groups of the Internet shopping orientation in Korea and China. Third, significant differences were identified in visiting frequencies, apparel purchase frequencies and amounts, payment methods, and information sources during the Internet shopping among three groups of the Internet shopping orientation in Korea and China.

• Journal of Korea Society of Industrial Information Systems
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• v.21 no.6
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• pp.13-21
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• 2016

Feature selection is the one of important issue in the field of data mining and machine learning. It is the technique to find a subset of features which provides the best classification performance, from the source data. We propose a feature subset selection method using the neighborhood rough set model based on information granularity. To demonstrate the effectiveness of proposed method, it was applied to select the useful features associated with breast tumor diagnosis of 298 shape features extracted from 5,252 breast ultrasound images, which include 2,745 benign and 2,507 malignant cases. Experimental results showed that 19 diagnostic features were strong predictors of breast cancer diagnosis and then average classification accuracy was 97.6%.

• 한국공간정보시스템학회:학술대회논문집
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• 2004.05a
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• pp.275-278
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• 2004

This paper focused on problems of design, construction, and maintenance caused by construction implementation processes. They were analyzed through case study of structure safety diagnosis projects. From the case study, it is expected that the introduction of Construction Management from the first stage of procurement will improve construction cost increase or burden on small design company. It strengthens coherent management from design and source contractor selection to build review of responsibility. The coherency will prevent changes in designing or infirm unreliable construction. It is desirable that expert opinions are considered when structure changes and establishment occur and that, if necessary, actions such as source selection, periodic audits, and diagnosis arc checked and fed back to maintenance.

• Journal of Communications and Networks
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• v.14 no.4
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• pp.434-442
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• 2012

Several gateway selection schemes have been proposed that select gateway nodes based on a single Quality of Service (QoS) path parameter, for instance path availability period, link capacity or end-to-end delay, etc. or on multiple non-QoS parameters, for instance the combination of gateway node speed, residual energy, and number of hops, for Mobile Ad hoc NETworks (MANETs). Each scheme just focuses on the ment of improve only a single network performance, i.e., network throughput, packet delivery ratio, end-to-end delay, or packet drop ratio. However, none of these schemes improves the overall network performance because they focus on a single QoS path parameter or on set of non-QoS parameters. To improve the overall network performance, it is necessary to select a gateway with stable path, a path with themaximum residual load capacity and the minimum latency. In this paper, we propose a gateway selection scheme that considers multiple QoS path parameters such as path availability period, available capacity and latency, to select a potential gateway node. We improve the path availability computation accuracy, we introduce a feedback system to updated path dynamics to the traffic source node and we propose an efficient method to propagate QoS parameters in our scheme. Computer simulations show that our gateway selection scheme improves throughput and packet delivery ratio with less per node energy consumption. It also improves the end-to-end delay compared to single QoS path parameter gateway selection schemes. In addition, we simulate the proposed scheme by considering weighting factors to gateway selection parameters and results show that the weighting factors improve the throughput and end-to-end delay compared to the conventional schemes.