• Journal of KIISE:Computing Practices and Letters
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• v.15 no.12
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• pp.913-917
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• 2009

Flash memories have asymmetric I/O costs for read and write in terms of latency and energy consumption. However, the ratio of these costs is dependent on the type of storage. Moreover, it is becoming more common to use two flash memories on a system as an internal memory and an external memory card. For this reason, buffer cache replacement algorithms should consider I/O costs of device as well as possibility of reference. This paper presents WWCLOCK(Write-Weighted CLOCK) algorithm which directly uses I/O costs of devices along with recency and frequency of cache blocks to selecting a victim to evict from the buffer cache. WWCLOCK can be used for wide range of storage devices with different I/O cost and for systems that are using two or more memory devices at the same time. In addition to this, it has low time and space complexity comparable to CLOCK algorithm. Trace-driven simulations show that the proposed algorithm reduces the total I/O time compared with LRU by 36.2% on average.

• Journal of KIISE:Computing Practices and Letters
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• v.15 no.12
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• pp.899-912
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• 2009

With greater utilization of web application and growth of its market, the function of such application is being expanded With today's increasing demand for high quality software, we see a sharp rise in the interest for web application test. The current trend is that web applications are being developed based on a framework of developmental environment. Hence, as the scope of that framework expands, each module of the entire web application is being configured by the combination of heterogeneous files. The distinctive characteristics of a web application are based on the fact that the framework that is provided in partially completed form controls the structure of all objects of development. The present study defines the web business logic as a minimal unit which has meaning as a unit of application for the web application. In this paper, we define web business logic as a least meaningful execution unit of web applications, propose how to generate automatically the BizUnit test code for it, and analyze the effectiveness of testing of the web application via the BizUnit test codes.

• Journal of KIISE:Computing Practices and Letters
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• v.14 no.7
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• pp.646-656
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• 2008

In this paper, the prototype of haptic-based NVE (networked virtual environment) QoE (quality of experience) is proposed. The proposed framework plays a role of providing users with realistic feeling by managing the system and network resources efficiently under time-varying networks and heterogeneous systems. Therefore, first IoPH (importance of presence for haptic interaction) is defined to quantitate the sense of real that the users feel now. Then we define the haptic-based NVE components required to satisfy the haptic interaction QoE requirements. Finally, QoE adaptation scheme is suggested, which adapts the haptic-based NVE components to current network and system constraints for better haptic interaction quality.

• Journal of KIISE:Computing Practices and Letters
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• v.8 no.2
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• pp.206-218
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• 2002

In this paper, we design and implement a system that presents a method for selecting and providing personalized services independently without unifying the existing system platform with shopping malls joined in the hub site. This system provides a mechanism for gathering information left behind by many clients visiting Web sites for analysis of customers property, vector model for selecting personalized services, and mechanism for providing them to customers who visited in a shopping mall joined to the hub site. In a position of shopping mall site, this kind of personalization system can provide target advertisement, point marketing, and point share service etc. without changing existing shopping mall's environment through wrapper web server. Hub site customers can get personalized services from many shopping mall sites with only once registration for the hub site.

• Spatial Information Research
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• v.11 no.4
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• pp.493-508
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• 2003

This study proposes a framework of a GIS service network to connect local governments'Land Management Information Systems(LMIS) together. Databases constructed far LMIS's are very crucial information on both administrative business and civil affairs administration. However, they did not give full play to their values because they could not be shared sufficiently. Local governments build their databases individually using diverse GIS solutions. It causes some problems on sharing them. To demonstrate their geniuses, they should be connected to each other within a network for the whole country, and are served whenever and wherever to people who require them. for this, there are two main problems to be solved. Firstly, a GIS service network that handles heterogeneous and distributed computing environments is organized to link every LMIS each other by the GIS service network vertically and horizontally. Secondly, a mechanism should be developed to access the GIS service network readily and to search GIS data efficiently. The needs from every types of user should be satisfied by the mechanism. As the result of investigation of the issues, one of the most possible solution was suggested in this study, which is a Web based approach. To take into account the advance of information technology in the future and the requirements of e-government, stepwise strategies that integrate the LMIS's into a Web based system was recommended.

• Journal of Internet Computing and Services
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• v.11 no.2
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• pp.41-48
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• 2010

It is essential to guarantee a smooth communication and data exchange in a PHD(Personal Healthcare Device) network for applications providing U-health services. In spite of that, most of PHDs are heterogeneous, so the heterogeneity of their protocols makes it difficult to develop an integrated gateway sending sensed healthcare data to U-health service providers. To solve this problem, we suggest the design and implementation of a device adapter model based on dynamic managed module in this paper. Our model were implemented to work on the OSGi-based gateway middleware and to have interoperability in connection with the HL7 system that is the standard of the Healthcare Information systems. In addition, our model has an architecture supporting a communication based on the object serialization in order to provide extensibility in the functional aspect of applications. Through the experiment on a test-bed which is an implementation of the device adapter module for electrocardiogram and blood-pressure/blood-sugar device having one channel, we have confirmed the accuracy of sensing and sending data.

• Journal of the Korea Computer Graphics Society
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• v.24 no.4
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• pp.11-20
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• 2018

Applications about systems integration of sensors and virtual environments have been developed increasingly. Accordingly, there is a need for the ability to represent, control, and manage physical sensors directly in a 3D virtual environment. In this research, a method of representing physical sensor devices in a 3D virtual environment has been defined using mixed and augmented reality, including virtual and real worlds, where sensors and virtual objects co-exist. The research is intended to control and manage various physical sensors through data sharing and interchange between heterogeneous computing environments. In order to achieve this, general sensor types have been classified, and a sensor based 3D scene graph for representing the functions of sensors has been defined. In addition, a sensor data model has been defined using the scene graph. Finally, a sensor 3D viewer has been implemented based on the scene graph and the data model so as to simulate the functions of sensors in indoor and outdoor 3D environments.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.10a
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• pp.435-438
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• 2012

Today, In all fields, As combination of ubiquitous computing-based technologies between electronic space and physical space, has been active trend research about wireless integration sensor network between sensors and wireless technology. Also, but in ship is underway research about Ship Area Network(SAN) of intelligent ship to integrate wireless technology, ship is required SAN-bridge technology of a variety of wired, wireless network integration and heterogeneous sensor and interoperability of the controller and SAN configuration management technology of remote control. Ship keep safe of all the surrounding environment including crew besides structural safety and freight management monitoring. In this paper, for monitoring design such as on climate change detection and temperature, pressure about various structures, there identify technology trends for routing and data aggregation to use energy efficiency in wireless sensor network. And to analyze self-organizing clustering method, study For wireless sensor network configuration in ship.

• Journal of KIISE:Software and Applications
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• v.36 no.1
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• pp.1-9
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• 2009

In heterogeneous and distributed computing environments, with an increasing number of Web services providing similar functionalities, the reliability of Web services is a critical decision factor. To fulfill the open business model such as cooperation among enterprises, several Web services can be composed into the upper level business transaction. In Web services composition, the reliability of services is more and more critical. Though each unit Web service can be reliable, the reliability of the composed service is not guaranteed. Thus a way to efficiently assess and select composed Web services is needed. In this paper, we define new metrics for measuring the trust value of Web services, and propose an evaluation method to predict the trustworthy degree of the composed services based on the metrics. We also define a conceptual framework to support optimal Web services selection based on the proposed trust evaluation method. By selecting using the quantitative measurement rather than intuitive selection of the service user, it allows the service users to select the high reliable service meeting their quality requirements well.

• Journal of Internet Computing and Services
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• v.10 no.4
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• pp.177-187
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• 2009

Typical RFID-device applications have provided users to each vendor-specific interface for supporting control and management of RF-tags and readers within their managed domain. Also, typical RFID-business applications have been implemented by using each event-data structure of RF-readers or RFID middlewares. RFID infrastructure managers, thus, are difficult to handle individual control and management specifications for managed RF-tags, devices and systems. Most RFID application services, also, are attached to providing visibility and traceability of an RF-tag item. To solve these problems, this paper proposes an RFID service management policy information model which supports to define unified control and management for heterogeneous RFID devices, middlewares and applications. This paper describes an example procedure that an RFID service management policy definition based on the proposed model is adaptively transformed and executed on a specific RFID sub-infrastructure.