• Proceedings of the KSR Conference
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• 2009.05a
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• pp.581-588
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• 2009

With the development of IT industry and formation of web-based knowledge sharing platform, a variety of railway-related information services on the web have emerged, ranging from personal blogs to dedicated portal sites, as in the other sectors. These services are contributing to advancing railway industry after all. As far as it is concerned with specific areas such as railway sector, the internet users are hardly expected to avail satisfactory results in acquiring customized information from the access, as the information served varies on the intension of the web site operator or relevant agency, and indexing categories and sub-categories is not easy to work out in a straight manner. This study will review on the feasibility of standardizing categories and sub-categories for railway industry information on the web, and present optimum categorization and sub-categorization approach for the most satisfactory results when searched, ultimately aiming at laying a foundation to satisfy the wide spectrum of users' need for railway information.

• 한국IT서비스학회:학술대회논문집
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• 2006.11a
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• pp.261-270
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• 2006

The present study analyzes the social equilibrium of wireless internet platform market before and after the adoption of WIPI(Wireless Internet Platform for Interoperability). When market prevails operator ownership, as opposed to manufacturer ownership, with heterogenous platforms becomes a more likely and desirable solution. After the adoption of WIPI, social equilibrium is achieved only if operators perceive that the cost reduction and the interoperability effects from investing in WIPI fully offset the appropriation effect from investing in heterogenous platforms.

• Journal of Distribution Science
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• v.19 no.7
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• pp.113-121
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• 2021

Purpose: Technology induces the virtual distribution channel to exist, especially for booking a room online. This situation, indeed, provides an alternative for the customers to book based on their budget through digital platforms. One platform offering competitive prices is virtual hotel operators, such as Airbnb, OYO, RedDoorz, and Airy Rooms. Preferably, after using their platform, the user should be satisfied and loyal. Hence, this investigation aims to prove some associations. The first is between e-satisfaction and e-loyalty. The second is between website quality and e-satisfaction. The final is between website quality and e-loyalty. Research design, data, and methodology: This study is quantitatively designed with the sample of 350 users of the virtual hotel operator applications in Bandar Lampung: Airbnb, OYO, RedDoorz, and Airy, as the samples. Therefore, by denoting this sample size, the structural equation model based on covariance is utilized to examine the three hypotheses proposed. Also, to get the responses, this study uses a survey through a questionnaire. Result: This investigation demonstrates the positive relationship between e-satisfaction and e-loyalty. Additionally, website quality positively associates with e-satisfaction and e-loyalty. Conclusion: The virtual hotel operators must have the superiority on their website-based application to update the information based on the room availability and price, ensure online transaction safety, and facilitate its utilization to maintain long-term satisfaction and loyalty virtually.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.10
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• pp.2180-2186
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• 2010

As the substantial increase in battlefield density, multiple and complex weapon systems, Ensuring the Survivability of the platform has been emphasized. Most of platforms have equipped with ASE (Aircraft Survivability Equipment) system in order to protect the platform and operator against at modernized hostile weapon. ASE system enhance the survivability of the platform through providing accurate situation awareness information by detecting and countermeasuring hostile threats. One of Key factor of the AE system performance is handling multiple and complex threats. In this study, it describes the fact that the performance of ASE system with proposed threat integration algorithm is verified in the developed threat emulation system and also, suggests system verification method before deployment by dealing with complex threat situation.

• Journal of KIISE:Computing Practices and Letters
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• v.10 no.3
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• pp.259-272
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• 2004

This paper suggests a new security architecture for facilitating secure OSGi service platform environment. The security architecture includes 1) user authentication mechanism, 2) bundle authentication mechanism, 3) key sharing mechanism, and 4) authorization mechanism. The user authentication mechanism supplies SSO(single sign-on) functions which are useful for safe and easy user authentications. The bundle authentication mechanism utilizes both PKI-based and MAC-based digital signatures for efficiently authenticating service bundles. The key sharing mechanism, which is performed during bootstrapping phase of a service gateway, supplies a safe way for sharing secret keys that are required for authentication mechanisms. Finally, the authorization mechanism suggests distributed authorization among service providers and an operator by establishing their own security policies. The main contributions of the parer are twofold. First, we examine several security requirements of current OSGi specification when its security functions can be applied in real OSGi environments. Second, we describe the ways to resolve the problems by means of designing and implementing concrete security mechanisms.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.7
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• pp.1417-1426
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• 2011

Radiofrequency ablation through cardiac catheterization is one of minimally invasive intervention procedures used in drug resistant arrhythmia treatment. To facilitate more accurate and precise catheter navigation, systems for robotic cardiac catheter navigation have been developed and commercialized. The authors have been developing a novel robotic catheter navigation system. The system is a network-based master-slave configuration 3-DOF (Degree-Of-Freedom) robotic manipulator for operation with conventional cardiac ablation catheter. The catheter manipulation motion is composed of the translation (forward/backward) and the roll movements of the catheter and knob rotation for the catheter tip articulation. The master manipulator comprises an operator handle compartment for the knob and the roll movement input, and a base platform for the translation movement input. The slave manipulator implements a robotic catheter platform in which conventional cardiac catheter is mounted and the 3-DOF motions of the catheter are controlled. The system software that runs on a realtime OS based PC, implements the master-slave motion synchronization control in the robot system. The master-slave motion synchronization performance tested with step, sinusoidal and arbitrarily varying motion commands showed satisfactory results with acceptable level of steady state error. The developed system will be further improved through evaluation of safety and performance in in vitro and in vivo tests.

• Korean Chemical Engineering Research
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• v.58 no.4
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• pp.565-572
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• 2020

This study developed a software platform using machine learning of artificial intelligence to optimize the distillation column system. The distillation column is representative and core process in the petrochemical industry. Process stabilization is difficult due to various operating conditions and continuous process characteristics, and differences in process efficiency occur depending on operator skill. The process control based on the theoretical simulation was used to overcome this problem, but it has a limitation which it can't apply to complex processes and real-time systems. This study aims to develop an empirical simulation model based on machine learning and to suggest an optimal process operation method. The development of empirical simulations involves collecting big data from the actual process, feature extraction through data mining, and representative algorithm for the chemical process. Finally, the platform for the distillation column was developed with verification through a developed model and field tests. Through the developed platform, it is possible to predict the operating parameters and provided optimal operating conditions to achieve efficient process control. This study is the basic study applying the artificial intelligence machine learning technique for the chemical process. After application on a wide variety of processes and it can be utilized to the cornerstone of the smart factory of the industry 4.0.

• ETRI Journal
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• v.23 no.4
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• pp.190-198
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• 2001

The performance of Motion Compensated Discrete Cosine Transform (MC-DCT) video coding is improved by using the region adaptive subband image coding [18]. On the assumption that the video is acquired from the camera on a moving platform and the distance between the camera and the scene is large enough, both the motion of camera and the motion of moving objects in a frame are compensated. For the compensation of camera motion, a feature matching algorithm is employed. Several feature points extracted using a Sobel operator are used to compensate the camera motion of translation, rotation, and zoom. The illumination change between frames is also compensated. Motion compensated frame differences are divided into three regions called stationary background, moving objects, and newly emerging areas each of which is arbitrarily shaped. Different quantizers are used for different regions. Compared to the conventional MC-DCT video coding using block matching algorithm, our video coding scheme shows about 1.0-dB improvements on average for the experimental video samples.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.11
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• pp.2237-2244
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• 2002

This research develops a low-cost and high accuracy kinematic calibration method based on the following principles: 1) the platform locations are accurately measured by a constrained movement to inspect a calibration target; 2) the constrained movement is chosen to guarantee the parameter observability; 3) the mechanical fixture to constrain the movement and the sensor to check the constrained movement are implemented by low-cost and high-accuracy devices; 4) the calibration is easily done at an industrial environment. The kinematic parameters calibrated with respect to a single plane aren't influenced due to the misalignment of the plane. A parameter observability is successfully obtained even through one planar constraint, which guarantees that all kinematic parameters are estimated by minimizing the cost function.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.753-756
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• 2005

Rapid prototyping (RP) technologies are mainly performed by layered manufacturing (LM) process which manufactures 3D physical objects by depositing 2D sections in a direction. Thus, deformations are apt to occur in overhanging area of the RP processed part. Also, excessive adhesion between part and platform of the RP apparatus is generated. In order to prevent these problems, most of the RP technologies adopt support structure. Main element to support a part in the support structure is strand. In actual field, however, the number of strand is determined by the software operating reference guide or RP system operator's experience. In this paper, a methodology to determine the optimal strand spacing is presented through experiments and measurements for the SL part deformation by change of strand spacing and part weight in the support structure of the stereolithography.