• International Journal of Highway Engineering
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• v.11 no.3
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• pp.61-74
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• 2009

Traffic accident risk index Computation model's development apply traffic level of significance about area of road user group, road and street network area, population group etc.. through numerical formula or model by countermeasure to reduce the occurrence rate of traffic accidents. Is real condition that is taking advantage of risk by tangent section through estimation model and by method to choose improvement way to intersection from outside the country, and is utilizing being applied in part business in domestic. However, question is brought in the accuracy being utilizing changing some to take external model in domestic real condition than individual development of model. Therefore, selection intersection estimation element through traffic accidents occurrence present condition, geometry structure, control way, traffic volume, turning traffic volume etc. in 96 intersections in this research, and select final variable through correlation analysis of abstracted estimation elements. Developed intersection design model taking advantage of signal type, numeric of lane, intersection type, analysis of variance techniques through ANOVA analysis of three variables of intersection form with selected variable lastly, in signal crossing through three class intersection, distinction variable choice risk in model, no-signal crossing risk distinction analysis model and so on develop.

• Journal of Korean Society of Transportation
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• v.24 no.2 s.88
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• pp.101-112
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• 2006

Currently, highway design speed is determined by considering highway function, area type, and terrain type. Sometime it is pointed out that determining a reasonable design speed which is both efficient and safe is not an easy task and that Practicing engineers often select an unsuitable design speed on purpose, capitalizing on some ambiguous and discretionary expressions in describing the highway design speed. This undesirable Problem is arising mostly due to the fact, that the current geometric design standard fails to include rolling terrain type and can not reflect the whole characteristics of land use patterns adjacent to the design highway route. A recent research was Published considering this problem and it attempted to improve the highway design speed determining process. In this research Project, tn see the effects of this recently developed procedure, a new and reduced design speed was calculated based on the new Procedure and subsequently another highway design route was selected. The travel time. construction cost. and the expected degree of safety associated with the new route were assessed to be compared with the ones with the existing procedure. As a result. it was found that the new procedure was successful in reflecting the localities such as terrain type and area type into better determining highway design speed, eliminating much of highway engineers' discretion when applying engineering judgments. Also the new Procedure is keen to produce a more economical highway project. In other words, despite of producing reduced amount of user benefits accrued, in the new highway route, the construction cost has been cut significantly leading to higher values in B/C. NPV, and IRR. Also EMME-II output, which Provided the link assigned volumes, rendered only a slightly reduced Levels of Service along surrounding links in the study network. This reduction was believed to occur because of lower design speed and it had been expected from the beginning.

• Journal of KIISE:Computing Practices and Letters
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• v.7 no.5
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• pp.498-509
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• 2001

Collaborative systems allow users, who may be far removed from each other geographically, to do collaborative work such as 3D animation, computer game, and industrial design in a single virtual space. This paper describes our experience to develop a collaborative system framework that aims at expanding the some functions of a stand-alone visual modeling tool, called 3D Studio Max, into those of the distributed collaborative working environments. The paper mainly deals with design and implementation of a 3D shared-object Plug-In with respect to the 3D Studio Max Plug-In Software Development Kit in the distributed collaborative system developed by the authors. There are two major functions of the proposed scheme; one is to write 3D object-information to the shared memory after extracting it from the 3D Studio Max, the other is to create 3D objects after retrieving them from the shared memory. Also, the proposed scheme provides a simple way of storing 3D objects that have variable size, by means of shared memory which located in between the collaborative system clients and 3D studio Max. One of the remarkable virtures of the Plug-In is to reduce a considerable amount of shared object data which in consequence can mitigate the network overhead. This can be achieved by the fact that the system is able to extract a minimum amount of 3D objects that are required to transmit. Also, using the proposed scheme, user can facilitate 3D Studio Max into distributed collaborative working environments. This, in consequence give many benefits such as saving time as well as eliminating space constraints in the course of 3D modeling when we are under industrial design process.

• Journal of KIISE:Information Networking
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• v.29 no.3
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• pp.253-264
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• 2002

Recently, hierarchical architectures of databases for location management have been proposed in order to accommodate the increase in user population in future personal communication systems. In particular, a 3-level hierarchical database architecture is compatible with current cellular mobile systems. In the architecture, a newly developed additional databases, regional location database(RLR), are positioned between HLR and VLRs. We propose an efficient cache scheme, called the Double T-thresholds Location Cache Scheme. The cache scheme extends the existing T-threshold location cache scheme which is competent only under 2-level architecture of location databases currently adopted by IS-41 and GSM. The idea behind our scheme is to use two pieces of cache information, VLR and RLR serving called portables. The two pieces are required in order to exploit root only locality of registration area(RA) but also locality of regional registration area(RRA) which is the wide area covered by RLR. We also use two threshold values in order to determine whether the two pieces are obsolete. In order to model the RRA residence time, the branching Eralng-$\infty$ distribution is introduced. Our minute cost analysis shows that the double T-threshold location cache scheme yields significant reduction of network and database costs for molt patterns of portables.

• Journal of KIISE:Software and Applications
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• v.34 no.1
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• pp.79-94
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• 2007

In the ubiquitous computing age which uses a high quantity network, mobile devices such as wearable and hand-held ones with a small tamers and a wireless communication module will be widely used in near future. Thus, a lot of researches about an augmented game on mobile devices have been attempted recently. The existing augmented games used a traditional 'backpack' system and a pattern marker. The 'backpack' system is expensive, cumbersome and inconvenient to use, and because of the pattern marker, it is only possible to play the game in the previously installed palace. In this paper, we propose an augmented game called Flying Cake using a face region to create the virtual object(character) without the pattern marker, which manually indicates an overlapped location of the virtual object in the real world, on a small and mobile PDA instead of the cumbersome hardware. Flying Cake is an augmented shooting game. This game supplies us with two types: 1) a single player which attacks a virtual character on images captured by a camera in an outdoor physical area, 2) dual players which attack the virtual character on images which we received through a wireless LAN. We overlap the virtual character on the face region using a face detection technique, and users play Flying Cake though attacking the virtual character. Flying Cake supplies new pleasure to flayers with a new game paradigm through an interaction between the user in the physical world captured by the PDA camera and the virtual character in a virtual world using the face detection.

• Journal of KIISE:Databases
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• v.34 no.5
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• pp.448-464
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• 2007

Location-Based Services (LBSs) provide results to queries according to the location of the client issuing the query. In LBS, techniques such as caching and prefetching are effective approaches to reducing the data transmission from a server and query response time. However, they can lead to cache inefficiency and network overload due to the client's mobility and query pattern. To solve these drawbacks, we propose a semantic prefetching (SP) scheme using prefetching segment concept and improved cache replacement policies. When a mobile client enters a new service area, called semantic prefetching area, proposed scheme fetches the necessary semantic information from the server in advance. The mobile client maintains the information in its own cache for query processing of location-dependent data (LDD) in mobile computing environment. The performance of the proposed scheme is investigated in relation to various environmental variables, such as the mobility and query pattern of user, the distributions of LDDs and applied cache replacement strategies. Simulation results show that the proposed scheme is more efficient than the well-known existing scheme for range query and nearest neighbor query. In addition, applying the two queries dynamically to query processing improves the performance of the proposed scheme.

• Journal of Internet Computing and Services
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• v.15 no.5
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• pp.107-121
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• 2014

Distributed systems are collection of physically distributed computers linked by a network. General use of wired/wireless Internet enables users to make use of distributed service anytime and anywhere. The explosive growth of distributed services strongly requires functional verification of services as well as verification of non-functional elements such as service quality. In order to verify distributed services it is necessary to build a test environment for distributed systems. Because, however, distributed systems are composed of physically distributed nodes, efforts to construct a test environment are required more than those in a test environment for a monolithic system. In this paper we propose a test framework to verify functional and non-functional features of distributed systems. The suggested framework automatically generates test cases through the message sequence charts, and includes a test driver composed of the virtual nodes which can simulate the physically distributed nodes. The test result can be checked easily through the various graphs and the graphical user interface (GUI). The test framework can reduce testing efforts for a distributed system and can enhance the reliability of the system.

• Proceedings of the Korea Database Society Conference
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• 2008.05a
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• pp.389-403
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• 2008

As the information of web dramatically increase, the existing web reveals more and more limitations in information search because web pages are designed only for human consumption by mixing content with presentation. In order to improve this situation, the Semantic Web comes on the stage by W3C. Semantic web is based on ontology that defines relationships between resources and it is enough to bring a significant advancement in web search. But to do this, the Semantic Web must provide a novel search and visualization methods which can make users instantly and intuitively understand why and how the results are retrieved because ontology has formal explicit descriptions of meaning. In this paper, we propose a semantic association-based search methodology that consists of how to find relevant information for a given user's query in the ontology, that is, a semantic network of resources and properties and how to provide proper visualization and navigation methods on the results. From this work, users can search the semantically associated resources for their query and also navigate such associations between resources.

• Applied Microscopy
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• v.34 no.1
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• pp.13-21
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• 2004

The high voltage electron microscope (HVEM) newly installed in KBSI is an advanced transmission electron microscope capable of atomic resolution (${\leq}1.2{\AA}$ point-to-point resolution) together with high titling function (${\pm}60^{\circ}$), which are suitable to do 3-dimensional atomic imaging of a specimen. In addition, the instrument can be controlled by remote operation system, named as 'FasTEM' for the HVEM, which is favorable to overcome some environmental obstacles resulting from the direct operation. The FasTEM remote operation system has been established between the headquarter of KBSI in Daejeon and the Seoul branch. The server system in the headquarter has been connected with a portable client console system in the Seoul branch using an advanced internet resource, 'KOREN' of 155 Mbps grade. Most of the HVEM functions essential to do remote operation are available on the portable client console. The experiment to acquire the high resolution image of [001] Au has been achieved by excellent transmission of control signals and communication with the HVEM. Real-time reaction like direct operation, such as controls of the illumination and projection parameters, acquisition and adjustment of each detector signal, and electrical steering of each motor-driven system has been realized in remote site. It is positively anticipated that the first remote operation of HVEM in conjunction with IT infraengineering plays a important role in constructing the network based e-Science Grid in Korea for national user s facilities.

• Journal of the Korea Society for Simulation
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• v.26 no.1
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• pp.21-38
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• 2017

Information Centric Networking is changing the way how content is being transmitted. The shift from IP and host based networking towards content based networking scenario is growing day by day. Many researches have been done about different frameworks of ICN. Caching is an important part of ICN and many researchers have also proposed different ways for caching the data. With caching of data in intermediate devices like the network devices as well the user devices in some cases, the issue of content security as well as the role of the content producer becomes a major concern. A modified ICN architecture based on the current Content Centric Networking (CCN) model is presented in the paper. The architecture mainly focuses on involving the content producer in content delivery in the real time. The proposed architecture provides better security aspects for the CCN architecture. Apart from security the paper will also consider the issue of applicability of CCN architecture to replace the TCP/IP based architecture. The efficiency of the proposed architecture is compared with the previous CCN architecture based on the response time for a content delivery which shows very comparable level of efficiency. The paper than analyzes different beneficial aspects of the proposed architecture over the current architecture.