• Journal of the Korean Institute of Telematics and Electronics
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• v.25 no.12
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• pp.1618-1624
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• 1988

In this paper, a robust discrete model reference adaptive controller is proposed using a generalized model reference adaptive algorithm for single-input single-output discrete systems. A signal dependent time-varying dead-zone is employed in a generalized adaptive control structure. This adaptive controller is shown to assure the boundedness of the signals of the system even in the presence of bounded external disturbance.

• Korean Journal of Human Ecology
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• v.23 no.2
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• pp.317-328
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• 2014

In this study, differences of texture image and preference for men's suit fabrics according to mechanical properties, hand and fabric information were investigated. 55 subjects evaluated texture image and preference of 12 kinds of wool blended fabrics. For statistical analysis, t-test and pearson correlation coefficients were used. The results were as follows: Most of mechanical properties effected on texture images, and bending property and shearing property were effected on tactile preference and purchasing preference. For hand, objective hand values showed correlations with subjective texture images and preferences, but THV had almost no correlations. In sensory images according to presence of fabric information, fabrics were evaluated thinner, lighter, more pliable and smooth by cognition of wool blending ratio. For sensibility images, fabrics were evaluated more refined, intellectual, dignified and less practicable after recognize of wool blending ratio. In preferences, tactile preference was increased and purchasing preference was decreased after recognize fabric information. Therefore, significant differences of texture image and preference were observed according to presence of fabric information.

• Asia pacific journal of information systems
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• v.25 no.3
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• pp.473-499
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• 2015

The limited literature on Open Source Software (OSS) customers' adoption does not provide explanations on how OSS services are adopted by customers in the presence of functionally superior commercially licensed software (CLS). This paper aims to uncover the process that shapes customer satisfaction of OSS services in comparison to CLS. Expectation Disconfirmation Theory (EDT) is adapted and integrated with pre implementation factor model that influences software customers' expectations including cost, reputation, and experience. The constructed research model is empirically validated using a field survey of OSS and CLS database management system (DBMS) customers in Korea. The theoretical contribution of the paper lies on the application of EDT to explain the wide adoption of OSS DBMS services in the presence of functionally superior CLS DBMSs. Furthermore, this paper integrates EDT with pre-implementation factors for customers' expectations, which has been considered a limitation of the theory. Among the practical contributions, this study draws attention to the substantive differences between OSS and CLS customers' expectations. Additionally, it offers initial explanations for the differences in customer behavior for OSS and CLS and the way that customers' expectations and actual performance are mingled together to form customer satisfaction.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.4C
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• pp.453-459
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• 2009

Due to its capability to resist jamming signals, chirp spread spectrum (CSS) technique has attracted much attention in the field of wireless communications. However, there has been little rigorous analysis for the performance of CSS systems in the presence of jamming signals. In this paper, thus, we present analytic results on the performance of a CSS system: specifically, symbol error rate (SER) expressions are derived for a CSS M-ary phase shift keying (MPSK) system in the presence of broadband and tone jamming signals, respectively. The numerical results show that the empirical SER closely agree with the analytic result.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.9B
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• pp.867-875
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• 2009

The reliability of wireless body area networks is an important research issue since it may jeopardize the vital human life, unless managed properly. In this article, a new modeling and analysis of node misbehaviors in wireless body area networks is presented, in the presence of multi-type failures. First, the nodes are classified into types in accordance with routing capability. Then, the node behavior in the presence of failures such as energy exhaustion and/or malicious attacks has been modeled using a novel Semi-Markov process. The proposed model is very useful in analyzing reliability of WBANs in the presence of multi-type failures.

• The KIPS Transactions:PartD
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• v.10D no.6
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• pp.999-1010
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• 2003

Program slicing is s method to extract the statements from the program which have an influence on the value of a variable at a paricular point of the program. Program slicing is applied for many applications, such as program degugging, program testing, program integration, parallel program execution, software metrics, reverse engineering, and software maintenance, etc. This paper is the study to create the exact slice in the presence of Object Reference State Graph to generate more exactly static analysis information of objects in the program of the presence of complicated data structure.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.10
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• pp.4223-4249
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• 2015

A novel jamming detection technique to detect the presence of jamming in the downstream direction for cluster based wireless sensor networks is proposed in this paper. The proposed technique is deployed in base station and in cluster heads. The proposed technique is novel in two aspects: Firstly, whenever a cluster head receives a packet it verifies whether the source node is legitimate node or new node. Secondly if a source node is declared as new node in the first step, then this technique observes the behavior of the new node to find whether the new node is legitimate node or jammed node. In order to monitor the behavior of the existing node and new node, the second step uses two metrics namely packet delivery ratio (PDR) and received signal strength indicator (RSSI). The rationality of using PDR and RSSI is presented by performing statistical test. PDR and RSSI of every member in the cluster is measured and assessed by the cluster head. And finally the cluster head determines whether the members of the cluster are jammed or not. The CH can detect the presence of jamming in the cluster at member level. The base station can detect the presence of jamming in the wireless sensor network at CH level. The simulation result shows that the proposed technique performs extremely well and achieves jamming detection rate as high as 99.85%.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.6
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• pp.2128-2147
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• 2021

Cognitive radio systems are being implemented recently to tackle spectrum underutilization problems and aid efficient data traffic. Spectrum sensing is the crucial step in cognitive applications in which cognitive user detects the presence of primary user (PU) in a particular channel thereby switching to another channel for continuous transmission. In cognitive radio systems, the capacity to precisely identify the primary user's signal is essential to secondary user so as to use idle licensed spectrum. Based on the inherent capability, a new spectrum sensing technique is proposed in this paper to identify all types of primary user signals in a cognitive radio condition. Hence, a spectrum sensing algorithm using improved convolutional neural network and long short-term memory (CNN-LSTM) is presented. The principle used in our approach is simulated annealing that discovers reasonable number of neurons for each layer of a completely associated deep neural network to tackle the streamlining issue. The probability of detection is considered as the determining parameter to find the efficiency of the proposed algorithm. Experiments are carried under different signal to noise ratio to indicate better performance of the proposed algorithm. The PU signal will have an associated modulation format and hence identifying the presence of a modulation format itself establishes the presence of PU signal.

• Journal of Distribution Science
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• v.13 no.5
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• pp.45-52
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• 2015

Purpose - Augmented reality (AR) content used in mobile media today can accommodate a wide variety of contextual information. This indicates that making people experience a sense of presence and flow is a very significant factor in augmented reality content. Flow represents a rich immersion potential as representing the progress of emotion and the means to facilitate the operation of the smart phone. Therefore, users will have friendly relational continuance behavior with products and brands that supply this experience. Based on that, the purpose of this study is to investigate the relationships among smart phone AR application traits, presence, flow experience, and relational continuance behavior. First, AR application traits are defined as three categories sensory immersion, navigation, and manipulation, based on preceding studies. This study then examines the influence of AR application traits on the presence and flow experience and looks into the relation among presence, flow experience, and relational continuance behavior. This analysis suggests more detailed and concentrated strategic implications. Research design, data, and methodology - A research model is designed to examine the relation among AR application traits, presence, flow experience, and relational continued behavior. For data collection, questionnaire surveys were composed of multi-items for each component and the direct interview method was used for the interviews. To collect the data, after running the smart phone AR applications, the consumer behaviors of the respondents were generally determined. The questionnaire surveys were conducted for one month, October 2014. A total of 300 questionnaires were distributed with 278 questionnaires used for analysis, excluding the unanswered and insincere questionnaires. The data were analyzed using SPSS ver. 20.0 and LISREL ver. 8.51. Results - The following results are found: First, AR application traits have a significantly positive effect on presence with sensory immersion, navigation, and manipulation all having a significantly positive effect. Second, sensory immersion and manipulation among the AR application traits have a significantly positive effect on flow. However, navigation did not have a significantly positive effect on flow. Third, presence has a significantly positive effect on flow and has a significantly positive effect on relational continuance behavior. Moreover, flow also has a significantly positive effect on relational continuance behavior. This behavior tends to be formed since brands want to encourage relational continuance behavior and positive emotions with the brands being used. Relational continuance behavior accompanies repeat purchasing, positive word-of-mouth and recommendation activities, and forms of trust with the brand. Conclusions - The research results showed that smart phone AR traits had significantly positive effect on presence, flow, and relational continuance behavior. Based on this, smart phone AR application providers should establish an aggressive marketing strategy to accommodate more realistic problems in order to positively influence user behavior. Additionally, the marketers should make efforts to provide fun or convenience in the AR application operation process of the user.

• Proceedings of the IEEK Conference
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• 1998.10a
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• pp.959-962
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• 1998

In this paper, we propose an efficient vehicle detection and classification algorithm for an electronic toll collection, which is based on shadow robust vehicle presence test. In order to improve the performance of vehicle presence test, we use correlation coefficients between wavelet transformed input and reference images, which takes advanage of textural similarity. We compare the performance of the vehicle presence test with those of some conventional approaches that use variance of frame difference. Experimental results from field test show that the proposed vehicl detection and classification algorithm performs well even under abrupt intensity change due to the characteristics of sensor and occurrence of shadow.