• KIISE Transactions on Computing Practices
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• v.21 no.7
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• pp.506-511
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• 2015

IOV is a technology that supports one or more virtual desktops, and can share a single physical device. In general, the virtual desktop uses the virtual IO devices which are provided by virtualization SW, using SW emulation technology. Virtual desktops that use the IO devices based on SW emulation have a problem in which service quality and performance are declining. Also, they cannot support the high-end application operations such as 3D-based CAD and game applications. In this paper, we propose a physical network separation system using Virtual Desktop Service based on HW direct assignments to overcome these problems. The proposed system provides independent desktops that are used to access the intranet or internet using server virtualization technology in a physical desktop computer for the user. In addition, this system can also support a network separation without network performance degradation caused by inspection of the network packet for logical network separations and additional installations of the desktop for physical network separations.

• Journal of KIISE:Databases
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• v.29 no.4
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• pp.321-333
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• 2002

As web-based services are becoming more and more popular, concurrent updates of spatial data should be possible in the web-based environments in order to use the various services. Web-based GIS applications are characterized by large quantity of data providing and these data should be continuously updated according to various user's requirements. Faced with such an enormous data providing system, it is inefficient for a server to do all of the works of updating spatial data requested by clients. Besides, the HTTP protocol used in the web environment is established under the assumption of 'Connectionless'and 'Stateless'. Lots of problems may occur if the scheme of transaction processing based on the LAN environment is directly applied to the web environment. Especially for long transactions of updating spatial data, it is very difficult to control the concurrency among clients and to keep the consistency of the server data. This paper proposes a solution of keeping consistency during updating directly spatial data in the client-side by resolving the Dormancy Region Lock problem caused by the 'Connectionless'and 'Stateless'feature of the HTTP protocol. The RX(Region-eXclusive) lock and the periodically sending of ALIVE_CLIENTi messages can solve this problem. The protocol designed here is verified as effective enough through implementing in the main memory spatial database system, called CyberMap.

• KIPS Transactions on Computer and Communication Systems
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• v.3 no.8
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• pp.261-270
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• 2014

As Internet traffic increases recently, much effort has been put on improving the performance of a web server. In addition to hardware side solutions such as replacement by high-end hardware or expansion of the number of servers, there are software side solutions to improve performance. Recent studies on these software side solutions have been actively performed. In this paper, we identify performance degradation problems occurring in a conventional TCP networking reception process and propose a way to solve them. We improve performance by combining three kinds of existing methods for Linux Networking Performance Improvement and two kinds of newly proposed methods in this paper. The three existing methods include 1) an allocation method of a packet flow to a core in a multi-core environment, 2) ITR(Interrupt Throttle Rate) method to control excessive interrupt requests, and 3) sk_buff data structure recycling. The two newly proposed methods are fd data structure recycling and epoll_event data structure recycling. Through experiments in a web server environment, we verify the effect of our two proposed methods and its combination with the three existing methods for performance improvement, respectively. We use three kinds of web servers: a simple web server, Lighttpd generally used in Linux, and Apache. In a simple web server environment, fd data structure recycling and epoll_event data structure recycling bring out performance improvement by about 7 % and 6%, respectively. If they are combined with the three existing methods, performance is improved by up to 40% in total. In a Lighttpd and an Apache web server environment, the combination of five methods brings out performance improvement by up to 36% and 20% in total, respectively.

• The KIPS Transactions:PartD
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• v.11D no.2
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• pp.371-380
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• 2004

E-commerce is in wide use with the rapid advance of internet technology. The main component of an e-commerce application is a Web-based database application. Currently, it takes a lot of time in developing Web applications since developers should write codes manually or semi-automatically for user interface forms and query processing of an application. Therefore, the productivity increase of Web-based database applications has been demanded. In this paper, we introduce a software tool, which we call the WebSiteGen2, that automatically generates the forms that we used as user interfaces and the EJB/JSP components that process the query made through the forms for an application that needs a new database or uses an existing database. The WebSiteGen2 thus increases the productivity, reusability, expandibility, and portability of an application by automatically generating a 3-tier application based on component technology. Moreover, one user interface form that are generated by the WebSiteGen2 provides information on an interested entity as well as information on all the directly or indirectly related entities with the interested one. In this paper, we explain the functionality and implementation of the WebSiteGen2 and then show the merits by comparing the WebSiteGen2 to the other commercial Web application generators.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.4
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• pp.694-699
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• 2017

In accordance with the development of information and communications technology, a network user has to be able to use quality of service (QoS)-based multimedia services easily. Thus, information and communications operators began to focus on a technique for providing multimedia services. The IP Multimedia Subsystem (IMS) is a platform based on Internet Protocol (IP) as a technology for providing multimedia services and application services. The emerging 5G networks are described as having massive capacity and connectivity, adaptability, seamless heterogeneity, and great flexibility. The explosive growth in network services and devices for 5G will cause excessive traffic loads. In this paper, software-defined networking (SDN) is applied as a kind of virtualization technology for the network in order to minimize the traffic load, and Simple Network Management Protocol (SNMP) is used to provide more efficient network management. To accomplish these purposes, we suggest the design of a dynamic routing algorithm to be utilized in the IMS network using SDN and an SNMP private management information base (MIB). The proposal in this paper gives information and communications operators the ability to supply more efficient network resources.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.6 no.4
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• pp.315-324
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• 2005

VOD(video on demand) is a video service by users' order, that is, a video service on demand. That means the users can select and watch the video content that has been saved on sewer, out of broadcasting in the usual process like TV. At present the client of VOD system bases on PC. As the PC-based client uses the software MPEG decoder, the main processor specification has an effect on the capacity. Also people, who don't know how to use their PC, cannot be provided the VOD service. The purpose of this paper is to show the process of the development the VOD client system Into the embedded type with hardware MPEG-4 decoder. The main processor is the SC1200 of x86 Family in National Semiconductor with a built-in video processor and the memory is 128Mbyte SDRAM. Also, in order that the VOD service can be provided using the Internet, the Ethernet controller is included. As the hardware MPEG-4 decoder is used in the embedded VOD client system, which is developed, it can make the low capacity of the main processor. Therefore it is able to be developed as a low-price system. The embedded VOD client system is easy for anyone to control easily with the remote control and can be played through TV.

• Journal of Distribution Research
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• v.7 no.1
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• pp.105-127
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• 2002

This paper presents an analysis of how the business models of organizations are getting transformed in the Marketspace created by the Internet. We use a research model comprising the transformation scores of four Ps(Product, Price, Promotion, and Place) as dependent variables and three dimensions, Demographics, Technology, and Community elements on the Websites, as explaining variables about the Cyber Transformation of the 4Ps. While most existing literatures have focused on Website's technology, our research model includes 22 five-point-scale items; 10 Demographics /Technology items and 12 Community items. To measure the 4P's transformation scores, the authors selected 14 workable items from the Marketspace Model by Dutta, Kwan, & Segev(1997). A sample of 123 shopping mall Websites comprising three categories(grocery, jewelry/accessory, and cosmetics) from the 100hot.co.kr list are evaluated and the data is analyzed by SPSSWIN 8.0 version. The result shows that there are five significant factors, Technology, Interaction, Connectedness, Business Features, and Domain, while the average transformation scores of 4Ps are at very low level. The factor scores are used in regression analysis for each P. Two factors, Technology and Interaction are influencing all four Ps; Connectedness is influencing only two, Product and Place. Organizations must not simply take their existing business models. They have to adopt the Technology items(navigation, logo, e-mail, guide, graphics) and to facilitate the Interaction items(consulting, number/quality of bulletin boards, participation, offline events) and Connectedness(club activation, contents, partner/site link, entertainment contents) in order to get transformed in the Marketspace successfully in the near future.

• KIPS Transactions on Computer and Communication Systems
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• v.3 no.11
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• pp.393-402
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• 2014

We have experienced an explosive increase of the IoT(Internet of Things) technology based devices including smart phones and the wireless communications. Also the growing power consumption in IEEE 802.11 WLANs(Wireless LANs) driven by these dramatic increases in not only mobile users and but also wireless APs(Access Points). To reduce the power consumption, this paper proposes a wireless AP power saving algorithm, which minimizes the transmission power without decrease the transmission and carrier sense ranges. A wireless AP which is use in our algorithm checks its own original coverage periodically for whether there is a new STA(Station) or not when its transmission power is decreased. Moreover, if there are no signaling message to connect the wireless AP, it changes its operation mode Wake-up to sleep. A Result shows that the proposed AP algorithm can reduce the total power consumption of the wireless AP approximated 18% and 35% compared to the conventional wireless AP with and without the existing power saving algorithm, respectively.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.10
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• pp.259-269
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• 2019

The purpose of this study is to investigate the necessity and activation plan of trial work to increase the re-employment of injured industrial workers. This study applied an internet and paper questionnaire method to 1,058 employers listed in the Korea Workers' Compensation and Welfare Services. The employers were asked about their experiences with trial work and their preferences for supports. From September 2018, the survey was conducted for 6 weeks and a total of 201 questionnaires were analyzed. Descriptive analysis and t-tests were applied. The results of the study showed that the trial work system satisfied the employers who participated in it. In order for this system to operate smoothly for injured workers, it is necessary to simplify the system's procedures, increase the amount of the trial work subsidy, and improve the amount of support after the workers convert to full time employment. In order for employers to use the new system, $750 per month will be provided for 8 months when hiring one injured worker. Eighty percent of employers stated that they would hire injured workers if the subsidy and application period are accepted. Future study and suggestions for applying the trial work system for injured industrial workers are also discussed.

• Journal of the Korea Society for Simulation
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• v.30 no.3
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• pp.1-9
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• 2021

Commander and staffs on the battlefield are aware of the situation and, based on the results, they perform military activities through their military decisions. Recently, with the development of information technology, the demand for artificial intelligence to support military decisions has increased. It is essential to identify, collect, and pre-process the data set for reinforcement learning to utilize artificial intelligence. However, data on enemies lacking in terms of accuracy, timeliness, and abundance is not suitable for use as AI learning data, so a training model is needed to collect AI learning data. In this paper, a methodology for learning artificial intelligence was presented using the constructive wargame model exercise data. First, the role and scope of artificial intelligence to support the commander and staff in the military decision-making process were specified, and to train artificial intelligence according to the role, learning data was identified in the Chang-Jo 21 model exercise data and the learning results were simulated. The simulation data set was created as imaginary sample data, and the doctrine of ROK Army, which is restricted to disclosure, was utilized with US Army's doctrine that can be collected on the Internet.