• Journal of Korea Society of Industrial Information Systems
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• v.16 no.4
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• pp.45-52
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• 2011

In the real-field of control cases for robot manipulators, there always exists a modeling error, which results the model has the uncertainties in its parameters and/or structure. In many modem applications, digital computers are extensively used to implement control algorithms to control such systems. The discretization of the nonlinear dynamic equations of such systems results in a complicated discrete dynamic equations. Therefore, it will be difficult to design a discrete-time controller to give good tracking performances in the presence of certain uncertainties. In this paper, a discrete-time sliding mode control algorithm for nonlinear and time varying robot manipulators with uncertainties is presented. Sufficient conditions for guaranteeing the convergence of the discrete-time SMC system are derived. As example simulations, the proposed SMC algorithm is applied to a two-link robotic manipulator with unknown dynamics. The results of the simulation indicate that the developed control scheme is effective in manipulators and electro-mechanical system control.

• Korean Journal of Geomatics
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• v.2 no.2
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• pp.115-122
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• 2002

Since geographic information systems (GIS) began to emerge as an effective spatial information processing technology, there also has been growing interest in integrated use of GIS with other decision support systems. As various spatial-related problems such as urban development planning and natural resource management require more analytical and interpretive solutions, it is viewed that the supportive role of GIS to complement or reinforce the counterpart decision tools will be increased. This study examines the major situations that have needed the integration methodologies in the past decade to derive research trends relating to this integration agenda and, hence, to elicit the possible underlying principles from those experiences. According to the kinds of decision tools linked with GIS, alternative methodologies and viewpoints are categorized and compared.

• Management & Information Systems Review
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• v.24
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• pp.25-44
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• 2008

Small business have very different characteristics from large business; notable, small business suffer from resource and capacity poverty. Without knowing the relative importance of limited resources and capacity in small business, it have limited practical contribution to e-business implementation success. This paper develops an exploratory resource-based model of e-business implementation for small business with 42 sample companies. The results show that three types of resource factors; IS/IT vender supports, the level of IS/IT knowledge, and financial support. The implication for research is that the resource-based view of the firm and the test an exploratory framework of resource factors are useful theories to ground future work on e-business implementation in small business.

• Journal of Korea Society of Industrial Information Systems
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• v.12 no.5
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• pp.133-145
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• 2007

This study investigated the relationship between introduction characteristics of ERP system, innovation diffusion and business performance in public enterprise. This study tried to suggest plans that can adapt and use critical impact factors on public enterprise performance though diffusion of ERP systems. This study suggests that introduction characteristics affect on vertical innovation diffusion and organizational performance, directly and indirectly.

• Journal of Korea Society of Industrial Information Systems
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• v.4 no.1
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• pp.97-101
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• 1999

The most important technical problem in EC is about secure electronic payment systems. Electronic payment systems come three different types distinguished by the payment method: electronic cash, electronic check, and creditcard. In these types, electronic cash payment system is popular and practical as in real commerce. But electronic cash can be copied easily, then it is infeasible to prevent user from double-spending a coin. In this paper, we overview several requirements for secure electronic payment system and present other proposed additions to the results. At last we present a model system which considers requirements above examined.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.12
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• pp.1577-1586
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• 2018

The emergence of the Smart Grid is an integrated solution for the next generation power system that combines IT technology in the power system to create optimal energy utilization and various services. However, these convergence technologies (power systems and information communications) are not only improving the related technologies but also producing various problems especially exposure to cyber risk. In particular, the intelligent power grid has security vulnerabilities through real-time information sharing among various organically linked systems, and it is more complicated than the cyber risk problem in the existing IT field and is directly connected to national disaster accidents. Therefore, in order to construct and operate a more stable smart grid, this paper analyzes the system of power system control system in Korea, and proposes a cyber security element definition and a countermeasure establishment method of power monitoring & control systems based on security standards of smart grid (No. SPS-SGSF-121-1-1).

• International conference on construction engineering and project management
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• 2024.07a
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• pp.335-342
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• 2024

This research developed an urban information platform to enable holistic urban design across multiple disciplines and regions, addressing Japan's urban challenges. By aggregating a wide range of urban data into a geographic database, the study emphasizes data-driven decision-making in urban planning. The platform supports the visualization and analysis of critical domains like medical and water supply, enhancing decision-making processes. Key contributions include the creation of evaluation indicators and the demonstration of the platform's application in urban design discussions.

• Journal of Biomedical Engineering Research
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• v.32 no.3
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• pp.237-244
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• 2011

In this paper, a feature-based registration technique is proposed for pre-contrast and post-contrast lung CT images. It utilizes three dimensional(3-D) features with their descriptors and estimates feature correspondences by nearest neighborhood matching in the feature space. We design a transformation model between the input image pairs using a free form deformation(FFD) which is based on B-splines. Registration is achieved by minimizing an energy function incorporating the smoothness of FFD and the correspondence information through a non-linear gradient conjugate method. To deal with outliers in feature matching, our energy model integrates a robust estimator which discards outliers effectively by iteratively reducing a radius of confidence in the minimization process. Performance evaluation was carried out in terms of accuracy and efficiency using seven pairs of lung CT images of clinical practice. For a quantitative assessment, a radiologist specialized in thorax manually placed landmarks on each CT image pair. In comparative evaluation to a conventional feature-based registration method, our algorithm showed improved performances in both accuracy and efficiency.

• Journal of Electrical Engineering and Technology
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• v.13 no.6
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• pp.2227-2235
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• 2018

Under the current policies and compensation rules in South Korea, Photovoltaic (PV) generation supplier can maximize the profit by combining PV generation with Energy Storage System (ESS). However, the existing operational strategy of ESS is not able to maximize the profit due to the limitation of ESS capacity. In this paper, new ESS scheduling algorithm is introduced by utilizing the System Marginal Price (SMP) and PV generation forecasting to maximize the profits of PV generation supplier. The proposed algorithm determines the charging time of ESS by ranking the charging schedule from low to high SMP when PV generation is more than enough to charge ESS. The discharging time of ESS is determined by ranking the discharging schedule from high to low SMP when ESS energy is not enough to maintain the discharging. To compensate forecasting error, the algorithm is updated every hour to apply the up-to-date information. The simulation is performed to verify the effectiveness of the proposed algorithm by using actual PV generation and ESS information.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.6 no.11
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• pp.2901-2919
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• 2012

Recent research in MEMS (Micro-Electro-Mechanical Systems) and wireless communication has enabled tracking of continuous objects, including fires, nuclear explosions and bio-chemical material diffusions. This paper proposes an energy-efficient scheme that detects and tracks different dynamic shapes of a continuous object (i.e., the inner and outer boundaries of a continuous object). EBCO (Efficient Boundary detection and tracking of Continuous Objects in WSNs) exploits the sensing capabilities of sensor nodes by automatically adjusting the sensing range to be either a boundary sensor node or not, instead of communicating to its neighboring sensor nodes because radio communication consumes more energy than adjusting the sensing range. The proposed scheme not only increases the tracking accuracy by choosing the bordering boundary sensor nodes on the phenomenon edge, but it also minimizes the power consumption by having little communication among sensor nodes. The simulation result shows that our proposed scheme minimizes the energy consumption and achieves more precise tracking results than existing approaches.