• Journal of Digital Convergence
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• v.3 no.1
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• pp.149-163
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• 2005

Researches for NN(nearest neighbor) query which is often used in LBS system, have been worked. However. Conventional NN query processing techniques are usually meaningless in moving object management system for LBS since their results may be invalidated as soon as the query and data objects move. To solve these problems, in this paper we propose a new nearest neighbor query processing technique, called CTNN, which is possible to meet continuous trajectory nearest neighbor query processing. The proposed technique consists of Approximate CTNN technique which has quick response time, and Exact CTNN technique which makes it possible to search accurately nearest neighbor objects. Experimental results using GSTD datasets shows that the Exact CTNN technique has high accuracy, but has a little low performance for response time. They also shows that the Approximate CTNN technique has low accuracy comparing with the Exact CTNN, but has high response time.

• Journal of Institute of Control, Robotics and Systems
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• v.7 no.12
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• pp.967-972
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• 2001

In this paper, an adaptive robust nonlinear predictive controller is developed for the continuous time nonlinear systems whose control objective is composed of the system output and its desired value. The basic control law is derived from the continuous time prediction model and its feedback dynamcis shows another from if input and output linearization. In order to cope with the parameter uncertainty, robust control is incorporated into the basic control law and the asymptotic convergence of tracking error to a certain bounded region is guaranteed. For stability and performance improvement within the bounded region, an adaptive control is introduced. Simulation tests for the motion control of an underwater wall-ranging robot confirm the performance improvement and the robustness of this controller.

• Journal of the Korean Mathematical Society
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• v.59 no.3
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• pp.595-619
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• 2022

The purpose of this paper is to introduce an iterative algorithm for approximating a solution of split equality variational inequality problem for pseudomonotone mappings in the setting of Banach spaces. Under certain conditions, we prove a strong convergence theorem for the iterative scheme produced by the method in real reflexive Banach spaces. The assumption that the mappings are uniformly continuous and sequentially weakly continuous on bounded subsets of Banach spaces are dispensed with. In addition, we present an application of our main results to find solutions of split equality minimum point problems for convex functions in real reflexive Banach spaces. Finally, we provide a numerical example which supports our main result. Our results improve and generalize many of the results in the literature.

• IEIE Transactions on Smart Processing and Computing
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• v.3 no.2
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• pp.65-73
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• 2014

An overall responding security-centered framework is necessary required for infringement accidents, failures, and cyber threats. On the other hand, the correspondence structures of existing administrative, technical, physical security have weakness in a system responding to complex attacks because each step is performed independently. This study will recognize all internal and external users as a potentially threatening element. To perform connectivity analysis regarding an action, an intelligent convergence security framework and road map is suggested. A suggested convergence security framework was constructed to be independent of an automatic framework, such as the conventional single solution for the priority defense system of APT of the latest attack type, which makes continuous reputational attacks to achieve its goals. This study suggested the next generation convergence security framework to have preemptive responses, possibly against an APT attack, consisting of the following five hierarchical layers: domain security, domain connection, action visibility, action control, and convergence correspondence. In the domain, the connection layer suggests a security instruction and direction in the domains of administrative, physical and technical security. The domain security layer has consistency of status information among the security domain. A visibility layer of an intelligent attack action consists of data gathering, comparison and decision cycle. The action control layer is a layer that controls the visibility action. Finally, the convergence corresponding layer suggests a corresponding system of before and after an APT attack. The administrative security domain had a security design based on organization, rule, process, and paper information. The physical security domain is designed to separate into a control layer and facility according to the threats of the control impossible and control possible. Each domain action executes visible and control steps, and is designed to have flexibility regarding security environmental changes. In this study, the framework to address an APT attack and load map will be used as an infrastructure corresponding to the next generation security.

• Journal of Digital Convergence
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• v.18 no.8
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• pp.133-149
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• 2020

The purpose of this study was to investigate the effect of perceived risk on continuous usage intention of Internet primary banks and to verify moderating effects of acceptance factors affecting customers' acceptance of Internet primary banks on the relationship between perceived risk and continuous usage intention. The study aims to find ways to cope with perceived risk and strategic measures of intention in order to increase the intention to continuous usage intention of Internet primary banks. For the analysis, interaction effect were conducted among a total of 457 surveys. As a results, First, perceived risks, acceptance factors and continuous usage intention of the customers of Internet primary banks were significantly correlated. Second, the types of perceived risks which have a significant effect on continued usage intention of Internet primary banks were found to be perceived financial and functional risks. Third, respect to moderating effects of moderator variables, usefulness was found to have a significant moderating effect on the relationship between perceived security risk and continuous usage intention. In addition, ease of use was shown to have a significant moderating effect on the relationship between each type of perceived risks and continuous usage intention. This study attempted to explore and seek strategies to reduce perceived risks and strategic plans for acceptance factors to increase continuous usage intention of Internet primary banks.

• Journal of Digital Convergence
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• v.20 no.5
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• pp.525-535
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• 2022

The purpose of this study is to identify the factors influencing the user's continuous usage intention of computer games. A research model was developed which shows that the independent variables of value, expectation confirmation, perceived enjoyment affect user satisfaction and continuous usage intention. To test the six hypotheses, survey data were collected from 104 respondents, and hypotheses tests as well as a confirmatory factor analysis were conducted using a partial least square analysis tool. The statistical analysis result showed that expectation confirmation had a significant positive effect on satisfaction, and satisfaction also had a strong positive effect on the game user's continuous usage intention. Perceived enjoyment showed a highly strong positive effect on satisfaction. In addition, satisfaction was found to have full mediation effects in the relationship between expectation confirmation and continuous usage intention, and perceived enjoyment and continuous usage intention respectively. This result provides an important implication that continuous usage intention occurs through user satisfaction, and also indicates the contribution of this study for the game industry. Another contribution of this study is to introduce critical independent variables from the marketing and information technology domains in order to explain continuous usage intention of computer games.

• Composites Research
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• v.29 no.6
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• pp.408-413
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• 2016

Commonly-used polymers are manufactured as versatile forms. Furthermore, continuous polymer fibers are recently manufactured using nylon or aramid fiber. One of common epoxy was also used to make polymer fibers. Bisphenol-A type was used as base epoxy whereas amine and anhydride were used as hardeners. Epoxy fibers was cured by stepping up the temperature to maintain the shape of epoxy fiber. Surface energy was measured to confirm the degree of interfacial adhesion by modified static contact angle method. After mechanical properties were measured via fiber tensile test, the evaluation of fiber fracture was proceeded. Tensile strength of epoxy fiber using amine type hardener was higher as 138 MPa than anhydride case as 70 MPa. Fractured surface exhibited different failure patterns at the cross-section.

• Asian-Australasian Journal of Animal Sciences
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• v.33 no.9
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• pp.1520-1532
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• 2020

Objective: Due to rapid economic return, mixed crop-swine farming systems in Korea have become more intensive. Intensive farming practices often cause nutrient surpluses and lead to environmental pollution. Nutrient budgets can be used to evaluate the environmental impact and as a regulatory policy instrument for nutrient management. This study was conducted to select a nutrient budgeting approach applicable to the mixed crop-swine farms in Korea and suggest an effective manure treatment method to reduce on-farm nutrient production. Methods: In this study, we compared current and ideal gross nutrient balance (GNB) approaches of Organisation for Economic Co-operation and Development and soil system budget (SSB) approach with reference to on-farm manure treatment processes. Data obtained from farm census and published literature were used to develop the farm nutrient budgets. Results: The average nitrogen (N) and phosphorus (P) surpluses were approximately 11 times and over 7 times respectively higher in the GNB approaches than the SSB. After solid-liquid separation of manure, during liquid composting a change in aeration method from intermittent to continuous reduced the N and P loading about 50% and 47%, respectively. Although changing in solid composting method from turning only to turning+aeration improved the N removal efficiency by 30.5%, not much improvement in P removal efficiency was observed. Conclusion: Although the GNB approaches depict the impact of nutrients produced in the mixed crop-swine farms on the overall agricultural environment, the SSB approach shows the partitioning among different nutrient loss pathways and storage of nutrients within the soil system; thus, can help design sustainable nutrient management plans for the mixed cropswine farms. The study also suggests that continuous aeration for liquid composting and turning+aeration for solid composting can reduce nutrient loading to the soil.

• Journal of Digital Convergence
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• v.19 no.10
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• pp.383-394
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• 2021

This study examines the determinants that affect the continuous intention to use of augmented reality applications by applying the technology acceptance model2(TAM2). A survey was conducted on 241 people, and the main results were derived by performing confirmatory factor analysis, correlation analysis, and path analysis using SPSS 21.0 and AMOS 21.0 programs. Presenting the results, it was found that the user's interface, interactivity, and relative advantage of the augmented reality application had a positive effect on perceived usefulness, and technological self-efficacy had a positive effect on perceived usefulness and perceived ease. Perceived ease of use had a positive effect on perceived usefulness, and both perceived usefulness and perceived ease had a positive effect on continuous intention to use of augmented reality applications. In future research, it will be necessary to verify the user effect of augmented reality applications by applying the fields of education or games.

• The KIPS Transactions:PartB
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• v.14B no.7
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• pp.541-548
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• 2007

Due to the mathematical convergence property, Simulated Annealing (SA) has been one of the most popular optimization algorithms. However, because of its problem of slow convergence in the practical use, many variations of SA like Fast SA (FSA) have been developed for faster convergence. In this paper, we propose and prove that Greedy SA (GSA) also finds the global optimum in probability in the continuous space optimization problems. Because the greedy selection does not allow the cost to become worse, GSA is expected to have faster convergence than the conventional FSA that uses Metropolis selection. In the computer simulation, the proposed method is shown to have as good performance as FSA with Metropolis selection in the viewpoints of the convergence speed and the quality of the found solution. Furthermore, the greedy selection does not concern the cost value itself but uses only dominance of the costs of solutions, which makes GSA invariant to the problem scaling.