• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.14 no.5
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• pp.439-448
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• 2004

Magnetic bearing is an attractive device in precision engineering field because of its non-contacting nature and controllability of its dynamic characteristics. This paper provides a method of designing a sliding mode control for an active magnetic hearing(AMB) system which is used to support the elevation axis of a target tracking sight instead of mechanical bearings to eliminate the effect of mechanical friction. In such system, the axis should be levitated and supported within a predetermined air gap while AMB is excited by base motion. Experimental results showed that the sliding mode control is effective in disturbance rejection than conventional PID-control without any additive measurements.

• Journal of Information Technology Applications and Management
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• v.10 no.1
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• pp.111-125
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• 2003

This paper proposes a product data model that can express and enforce integrity constraints on product structure during engineering changes (ECs). The model adopts and extends an active object-oriented database model in order to Integrate IC data and their integrity constraints. Tightly integrated with product structure, It will enable designers to maintain and exchange consistent EC data throughout the product life cycle. In order to properly support operations for ECs, the model provides the data, operations, and Event-Condition-Action rules for nested ECs and simultaneous EC applications to multiple options. in addition, the EC objects proposed In the model integrate the data and Integrity constraints into a unified repository. This repository enables designers to access all EC data and integrity constraints through the product structure and relationships between EC objects. This paper also describes a prototype product data management system based on the proposed model In order to demonstrate its effectiveness.

• Proceedings of the Korea Information Processing Society Conference
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• 2002.04a
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• pp.381-384
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• 2002

This paper describes the motivation, design and performance of bi-active Load balancer in Linux Virtual Server. The goal of bi-active Load balancer is to provide a framework to build highly scalable, fault-tolerant services using a large cluster of commodity servers. The TCP/IP stack of Linux Kernel is extended to support three IP load balancing techniques, which can make parallel services of different kinds of server clusters to appear as a service on a single IP address. Scalability is achieved by transparently adding or removing a node in the cluster. and high availability is provided by detecting node or daemon failures and reconfiguring the system appropriately. Extensive simulation reveals that the proposed approach improves the reply rate about 20% compared to earlier design.

• The Journal of Korean Academic Society of Nursing Education
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• v.5 no.2
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• pp.191-205
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• 1999

The purpose of this study is to identify the influence of family support on hope of the patients with stroke. Subjects were 53 in-patients with stroke in two general hospitals and one oriental medicine hospital located in Seoul and Kwang-Ju. The instruments used for this study : The family support scale developed by Kang Hyun Suk(1985). The hope scale developed by Nowotny(1989). The Data were analyzed with descriptive statistics, t-test, ANOVA. Pearson's correlation and simple regression. Data had been collected from December 24, 1998 to January 31, 1999. The results of this study were as follows The mean score of family support was 43.94 and the mean score of the hope was 80.89. The relationship between family support and the hope of the patients with stroke revealed a significant correlation (r= .560, p= .0001). The variables influencing family support and the hope of the patients with stroke were as follows : There was significant difference between family support and general characteristic factor, which was family chief caregiver (p= .002). There was no significant difference between hope and general characteristic factors. but There were significant differences between one of the subscales of hope, 'confidence in the outcome' and general characteristic factors, which were age(p= .021), perceived disability effect(p= .027). There were significant differences between one of the subscales of hope 'possibility of future', and general characteristic factors, which were age(p= .016), education(p= .018). There was significant difference between one of the subscales of hope. 'spiritual belief', and general characteristic factors, which was religion(p= .002). There was significant difference between one of the subscales of hope, 'active involvement', and general characteristic factors, which was family chief caregiver (p= .012). It was found that the higher the degree of perceived family support, the higher the degree of hope. Clearly, the perceived family support can contribute significantly and positively to hope of the patients with stroke. Therefore, nurses should plan interventions to inspire hope level of patients with stroke by family support. The above results may be used as the basic data to seek more efficient way of elevating nursing practice and qualify for the patients with stroke.

• Journal of KIISE:Software and Applications
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• v.30 no.3_4
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• pp.347-357
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• 2003

The web is an important source of information and most of Web applications are based on form documents in HTML-based form documents only play a role as user interfaces, and they do not involve the procedures or rules if business process which form document designers assume. However, from documents imply methods for treating documents, and these embedded procedural knowledge can be utilized.actively in automation of business process. In this respect, we Investigate the activeness of documents with cognitive science to automate business processes based on from documents. Through this, we have a new concept and applicability of active documents. Our active documents include business rules and declarative knowledge to support the automation of document processing. Also, we propose a processing framework for the active documents. The framework has two phases: build-time and run-time. in order to demonstrate the usefulness of the proposed framework, a prototype called ActiveForm is designed and implemented for requisition processing them in an inference engine can enhance the intelligence of Internet applications.

• The Transactions of the Korea Information Processing Society
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• v.4 no.11
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• pp.2721-2731
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• 1997

Distributed programming can be greatly simplified by language support for distributed communication. Many web-browsers now offer some form of active objects and the number and types of them are growing daily in interesting and innovative ways. Java applets are well known as one kind of active object related to web-browser. This paper focuses in distributed active objects which is one kind of active objects that can communicate with other active objects located in different machines across the Internet. Java RMI and CORBA IDL are two major programming environments for distributed active objects which are non compatible with each other. To make discussion concrete, we introduce a single application as implemented on two environments : the HORM, adopting RMI mechanism, and the OrbixWeb2.0.1, adopting CORBA specification, respectively. Binding, inheritance, polymorphism, object passing and callbacks across the machine boundary in distributed programming environments are issued. The results show that some differences in the implementation of distributed active objects can have a significant impact on how distributed applications are structured. The comparison between two implementations on the programming environments will be the basis for building the translation system between HORB to OrbixWeb and vice versa.

• KIPS Transactions on Computer and Communication Systems
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• v.7 no.6
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• pp.145-154
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• 2018

A loosely coupled message broker system is a popular method for integrating distributed software components. Especially, a distributed broker structure with multiple brokers with active-standby or active-active message replicas are used to enhance availability as well as message processing performance. However, there are problems in both active-standby and active-active replica structure. The active-standby has relatively low processing performance and The active-active structure requires a high synchronization overhead. In this paper, we propose an active-active structure of replicas to increase the availability of the brokers without compromising its high fault-tolerancy. In the proposed structure, standby replicas process the requests of the active replicas so that load balancing is achieved without additional brokers, while the distributed coordinators are used for the synchronization process to decrease the overhead. We formulated the overhead incurred when synchronizing messages among replicas, and the formulation was used to support the experiment results. From the experiment, we observed that replicas of the active-active structure show better performance than the active stand-by structure with increasing number of users.

• Steel and Composite Structures
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• v.45 no.5
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• pp.715-728
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• 2022

Closed steel supports of different shapes are used in mining and underground constructions. The supports are prefabricated from rolled, usually robust, steel profiles. The load carrying capacity of a support is considerably influenced by the active loading and passive forces. The passive forces are induced by interactions between the support and the surrounding rock mass. The analysis herein comprises three parts: The first part consists of structural geometry processing. The second part involves finding the numerical solution of a statically indeterminate structure for a specified load. The third part is calculation of the load carrying capacity and the components of internal forces and deformations. For this, the force method and numerical integration are used. The Winkler model is applied when the support interacts with the surrounding environment. The load carrying capacity is limited by the slip resistance of the connected parts and it is limited by reaching the ultimate state of the profile. This paper serves as a comprehensive reference for the determination of the load carrying capacity of closed steel supports and includes stepwise derivations of the governing formulas.

• Asia pacific journal of information systems
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• v.32 no.2
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• pp.307-326
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• 2022

Currently, Mobile-commerce is active around the world, and consumers' online activities have changed significantly from pc-base to mobile-base. Unlike IT advanced countries such as the United States, which experienced PC-based online commerce (hereafter, PC-commerce) before Mobile-commerce, developing countries such as Vietnam have a relatively short history of PC-commerce. Consumers' experience with PC-commerce may affect their acceptance and use of Mobile-commerce. In this study, we tried to see if different online commerce histories differently affect consumers' online purchasing behavior. We selected the United States and Vietnam, with longer PC-commerce experience and shorter one, respectively. Data were collected for the following four groups: 1) the U.S. PC-commerce (n=256), 2) the U.S. Mobile-commerce (n=283), 3) the Vietnamese PC-commerce (n=159), and 4) the Vietnamese Mobile-commerce (n=225). As results, it was first confirmed that different e-commerce histories in developed and developing countries make the online shopping process different. Second, navigability has a huge impact on consumers' decision support satisfaction in Vietnam where PC-commerce history is shorter. Third, we identified that pre-purchase phase is more related with decision support satisfaction and that purchase phase is more related with task support satisfaction.

• Journal of Information Processing Systems
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• v.13 no.2
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• pp.256-267
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• 2017

An active research area in computer vision, stereo matching is aimed at obtaining three-dimensional (3D) information from a stereo image pair captured by a stereo camera. To extract accurate 3D information, a number of studies have examined stereo matching algorithms that employ adaptive support weight. Among them, the adaptive census transform (ACT) algorithm has yielded a relatively strong matching capability. The drawbacks of the ACT, however, are that it produces low matching accuracy at the border of an object and is vulnerable to noise. To mitigate these drawbacks, this paper proposes and analyzes the features of an improved stereo matching algorithm that not only enhances matching accuracy but also is also robust to noise. The proposed algorithm, based on the ACT, adopts the truncated absolute difference and the multiple sparse windows method. The experimental results show that compared to the ACT, the proposed algorithm reduces the average error rate of depth maps on Middlebury dataset images by as much as 2% and that is has a strong robustness to noise.