• International journal of advanced smart convergence
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• v.5 no.4
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• pp.26-31
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• 2016

In a cloud computing environment, a cryptographic service allows an information owner to encrypt the information and send it to a cloud server as well as to receive and decode encrypted data from the server which guarantees the confidentiality of shared information. However, if an attacker gains a coded data and has access to an encryption key via cloud server, then the server will be unable to prevent data leaks by a cloud service provider. In this paper, we proposed a key management server which does not allow an attacker to access to a coded key of the owners and prevents data leaks by a cloud service provider. A key management server provides a service where a server receives a coded public key of an information user from an owner and delivers a coded key to a user. Using a key management server proposed in this paper, we validated that the server can secure the confidentiality of an encryption key of data owners and efficiently distribute keys to data users.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2008.11a
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• pp.557-562
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• 2008

In Korean construction industry, a public sector's ordering volume has been constantly increased after 2000. But, because a cost, schedule and quality control generally depends on a result-centric management form and a transparent management is not done during the construction in the Korean public business, it is recognized that this causes problems including an increase of cost and schedule, incomplete construction, a difficulty to find the problem in advance to establish measures, and an unclear locus of responsibility of constructor, supervisor and designer. Accordingly, this study is intended to derive the problems and the limit of management by identifying and analyzing the management state of the present government construction client for the client organization of public sector's government construction. Also, the study is intended to contribute to the client's efficient and actual project management by presenting the model of supplementing or improving the derived problem and limits to the client's organization.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.23 no.6
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• pp.637-644
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• 2019

In recent years, many public safety systems in the smart city are developed. These systems are taking responsibility to make a safe and comfortable city. In this paper, we propose vehicle tracking systems include a public safety system that enables the policeman to track the stolen vehicles more efficiently by providing the vehicle information in real time. When a vehicle is stolen, the vehicle owner can send a user emergency request. Then, the public safety server which supported by a geospatial query technique will give information such as time, distance, and routes to a policeman who is closest to the location of the vehicle to catch the thief. 300 simulations were performed to evaluate the performance of the system. We found that the average of times required when vehicle owner send a user emergency message on user application until policeman obtain a vehicle tracking request on police application below 1.2 seconds.

• Proceedings of the KIEE Conference
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• 1999.07f
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• pp.2537-2539
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• 1999

In order to widen the radius of electric vehicle (EV) travel recharging points must be provided in sufficient numbers and at convenient places. The cost of providing side an infrastructure is at preset, not well documented and this lack of information acts as a detersent to prospective insestors in EV technology. This paper acts as a preliminancy investigation into the cost of infrastructure is the different situation i.e for the private owner, the fleet owner or for the public. It provides an overview of the items required and this relative costs. Cost will however, vary from country to country and application to application, and this paper two acts purely as guide to the type of equipment and its relative costs.

• Land and Housing Review
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• v.4 no.4
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• pp.425-434
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• 2013

The Small and Medium Business Administration specified 123 construction materials mandatory to purchase directly and forced the public owners to provide the contractors with materials as required by related law. This study extensively reviewed various characteristics and management factors of the owner-providing materials consumed in the public apartment housing under Direct Buying System(DBS) from the public owner's perspective. Subsequently, the major managed materials were identified, and the proper response plan was developed along the material procurement process. The Procurement Management Load Indices (PMLI) of 43 materials were evaluated according to rating criteria with procurement path, project-specified level, user requirement level, supplier's responsibility, on-site work requirement, additional parts, and inspection standards. The tile and aluminum windows were classified in the group needing high-level procurement efforts to reduce the errors and ensure the efficiency. The accurate quantity estimation method, definite purchase details, management activity definition before and after production, additional quantity for rework, interference coordination were defined as the essential activities for effectively responding to DBS.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2007.11a
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• pp.509-512
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• 2007

In Domestic, the beginning of CM system was at December 1996 by 'Construction Industry fundamental law'. Today the needs of CM is more and more during 10 years. Although the time of CM's induction and high-quality human resources are insufficiency, various studies and developments's level through theoritical base and academic level is good which are compared by developed countries's. But still now the effort of CM product measure part, especially public sector is not enough. Besides, the existing check-list is for project owner so it needs to make up for balanced view as organized 4way-view of owner, CMr, designer, constructor. On this study, produce the list of check-list and then weight of each list by view of owner, CMr, designer, constructor. The completec check-list will be useful for CM product measure objectively .

• Korean Journal of Geomatics
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• v.3 no.2
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• pp.123-128
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• 2004

As the applied fields of GIS are expanded to the transportation, developing internet-based applications for transportation information is getting attention increasingly. Most applications developed so far are primarily focused on guidance systems for owner-driven cars. Although some recent ones are devoted to public transportation systems, they show limitations in dealing with the following aspects: (i) people may change transportation means not only within the same type but also among different modes such as between buses and subways, and (ii) the system should take into account the time taken in transfer from one mode to the other. This study suggest the framework for developing a public transportation guidance system that generates optimized paths in the transportation network of mixed means including buses, subways and other modes. For this study, the Genetic Algorithms are used to find the best routes that take into account transfer time and other service-time constraints.

• Journal of Korea Society of Digital Industry and Information Management
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• v.4 no.2
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• pp.21-28
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• 2008

There are some problems on the system that uses a password comprising a digital signature to identify the secret key owner under the public key infrastructure. For example, the password can be difficult to remember or easy to be disclosure, and users should make more complex password to protect it. A number of studies have been proceeded in order to overcome these defects using the fingerprint identification technologies, but they need to change the current standard of public key infrastructure. On the suggested private key escrow system, the private key can be withdrawn only through the enrollment and identification of a fingerprint template after it is saved to a reliable third system. Therefore, this new private key escrow system can remove previous inconveniences of managingthe private key on current public key infrastructure, and it exhibited superior results in terms of the evaluation items when compared with the integrated method of the existing fingerprint identification and public key infrastructure.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.6D
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• pp.645-653
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• 2012

The productivity management of highway construction is required to innovate the efficiency of investment The productivity management of highway construction is required to innovate the efficiency of investment cost for newly constructed projects and to improve the quality of these projects, as the maintenance and management expenses are steadily increasing for existing highways under operation. However, clear criteria, methods or requirements to measure the productivity and performance in the construction of highways have not been properly established yet. This study defined 5 major elements of the productive projects in terms of construction management which is one of major tasks of the owner. There were the 43 influential elements significantly affecting on the productivity and these elements were categorized into the hierarchical structure which was composed of 3 levels. Also, this study conducted a survey for Korea Expressway Corporation who is the largest owner in Korea's highway construction. As a result, major project performance indicators, which should be addressed for management, to execute the projects successfully, are presented through understanding the extent of the affection of productivity elements on the elements of project performance to attain the productive projects and through understanding the extent of demand to be improved.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2004.02a
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• pp.59-63
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• 2004

As the applied fields of GIS are expanded to the transportation, developing internet-based applications for transportation information is getting attention increasingly. Most applications developed so far are primarily focused on guidance systems for owner-driven cars. Although some recent ones are devoted to public transportation systems, they show limitations in dealing with the following aspects: (i) people may change transportation means not only within the same type but also among different modes such as between buses and subways, and (ii) the system should take into account the time taken in transfer from one mode to the other. This study suggest the framework for developing a public transportation guidance system that generates optimized paths in the transportation network of mixed means including buses, subways and other modes. For this study, the Genetic Algorithms are used to find the best routes that take into account transfer time and other service-time constraints.