• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.10 no.4
• /
• pp.1892-1903
• /
• 2016

Mobile social network is becoming more and more popular with respect to the development and popularity of mobile devices and interpersonal sociality. As the amount of social data increases in a great deal and cloud computing techniques become developed, the architecture of mobile social network is evolved into cloud-based that mobile clients send data to the cloud and make data accessible from clients. The data in the cloud should be stored in a secure fashion to protect user privacy and restrict data sharing defined by users. Ciphertext-policy attribute-based encryption (CP-ABE) is currently considered to be a promising security solution for cloud-based mobile social network to encrypt the sensitive data. However, its ciphertext size and decryption time grow linearly with the attribute numbers in the access structure. In order to reduce the computing overhead held by the mobile devices, in this paper we propose a new Outsourcing decryption and Match-then-decrypt CP-ABE algorithm (OM-CP-ABE) which firstly outsources the computation-intensive bilinear pairing operations to a proxy, and secondly performs the decryption test on the attributes set matching access policy in ciphertexts. The experimental performance assessments show the security strength and efficiency of the proposed solution in terms of computation, communication, and storage. Also, our construction is proven to be replayable choosen-ciphertext attacks (RCCA) secure based on the decisional bilinear Diffie-Hellman (DBDH) assumption in the standard model.

• Journal of the Korean housing association
• /
• v.20 no.4
• /
• pp.31-38
• /
• 2009

In our country, the application of the design method of face to face dimension in wall-slab apartment has passed 10 years. So MC(Modular Coordination) design method has fixed in the design step to some degree. In Design and Work Execution of House the exclusive area of the apartment was calculated by face to face dimension. And the term of face to face dimension was known broadly to clients, construction company, etc. But design method of face to face dimension is not to simply extend the room size so far as wall depth in design process but to ensure the actual space should be considered with efficient use and assembly of building components. That is to say, Design method of face to face dimension is not to be defined by design step but to be related with construction and maintenance. However in construction process the point of face to face design method was not understood even now. So the purpose of this study was to extract the effect and question of face to face design method in construction process by survey of actual condition of structure and construction quality, and compare this result with existing construction method. The following project of this study is to survey of actual condition of interior components such as gypsum board, windows & doors etc. Therefore this study is to induce architectural long-life through architectural standardization construction and component's exchange, and, by the subject of the study on Apartment to have design guideline and basis for joining part between Gypsumboard and windows.

• Proceeding of Spring/Autumn Annual Conference of KHA
• /
• 2009.04a
• /
• pp.230-235
• /
• 2009

In our country, the application of the design method of face to face dimension in wall-slab apartment has passed 10 years. So MC design method has fixed in the design step to some degree. In Design and Work Execution of House the exclusive area of the apartment was calculated by face to face dimension. And the term of face to face dimension was known broadly to clients, construction company, etc. But design method of face to face dimension is not to simply extend the room size so far as wall depth in design process but to ensure the actual space should be considered with efficient use and assembly of building components. That is to say, Design method of face to face dimension is not to be defined by design step but to be related with construction and maintenance. However in construction process the point of face to face design method was not understood even now. So the purpose of this study was to extract the effect and question of face to face design method in construction process by survey of actual condition of structure and construction quality, and compare this result with existing construction method. The following project of this study is to survey of actual condition of interior components such as gypsum board, windows & doors etc. Therefore this study is to induce architectural long-life through architectural standardization construction and component's exchange, and, by the subject of the study on Apartment to have design guideline and basis for joining part between Gypsumboard and windows.

• Korean Journal of Construction Engineering and Management
• /
• v.7 no.2 s.30
• /
• pp.62-70
• /
• 2006

As buildings are changing variously from the side of use, efficiency and size, the construction qualities are more importantly recognized. Supervision system was enacted in the Residential Building Law in 1990 and responsibility supervision system in the Construction Engineering Management Law in 1994, respectively. However, recently revised supervision system in 2003 has some limitations: the present problems of appointing supervisor, disposing the supervisors, supervisor's works. Therefore, the aim of this study is to improve the present supervision system for mix-use residential building. By implementing the proposed revised supervision system, it will be able to expect quality improvement, confidence of the owner and the user, development of construction technology, and increase international competitiveness of supervision company.

• Proceedings of the Korean Institute Of Construction Engineering and Management
• /
• autumn
• /
• pp.468-473
• /
• 2002

The pursuit of strategic infomatization plays a critical role in increasing the competitiveness of domestic companies in this rapidly changing era. In particular, infomatization of small and medium construction companies is lower than that of large companies in terms of company size and the range of infomatization. Also, the environment for the infomatization is very unfavorable. Thus, to ensure effective infomatization of small and medium construction companies, it is critical to assess the current level of infomatization, and ensuing initiatives should start by gaining an accurate understanding of the level that should be reached in the future by each stage. This paper purports to develop indices which are needed for the diagnosis of current level of infomatization and for the understanding of current realities, problems and requirements that the small and medium construction companies face while pursuing infomatization today.

• Corrosion Science and Technology
• /
• v.14 no.2
• /
• pp.47-53
• /
• 2015

Recently, the bending process is greatly applied to fabricate the pipe line. Bending process can reduce welding joints and then decrease the number of inspection. Thus, the maintenance cost will be reduced. Induction heat bending process is composed of bending deformation by repeated local heat and cooling. By this thermal process, corrosion properties and microstructure can be affected. This work focused on the effect of induction heating bending process on the properties of ASME SA106 Gr. C low carbon steel pipes. Microstructure analysis, hardness measurements, and immersion corrosion test were performed for base metal and bended area including extrados, intrados, crown up, and down parts. Microstructure was analyzed using an optical microscope and SEM. Hardness was measured using a Rockwell B scale. Induction heat bending process has influenced upon the size and distribution of ferrite and pearlite phases which were transformed into finer structure than those of base metal. Even though the fine microstructure, every bent area showed a little lower hardness than that of base metal. It is considered that softening by the bending process may be arisen. Except of I2, intrados area, the others showed a similar corrosion rate to that of base metal. But even relatively high rate of intrados area was very low and acceptable. Therefore, it is judged that induction heat bending process didn't affect boric acid corrosion behaviour of carbon steel.

• Journal of the Korean Society for information Management
• /
• v.28 no.3
• /
• pp.83-101
• /
• 2011

The international standards, ISO 15489 and Family Code, recommend using functional classification method both in public and private organizations. In this study made a comparative analysis of the details of classification systems through case studies on records classification systems of a total of seven comprehensive construction companies in Korea including three large corporations and four small and medium-size businesses. Findings of this study suggester the direction of developing construction records classification system and its methodology. By summarizing classification standards derived from these case studies, key construction records classification standards were presented.

• Journal of Korean Institute of Industrial Engineers
• /
• v.42 no.4
• /
• pp.270-279
• /
• 2016

A glass product manufacturing company transports a large number of flat glass products from a manufacturing firm to a building construction site. The products are transported using specially designed racks, which assure fewer glass breakages during the deliveries. This study determines the sizes of the racks which minimize the total logistics cost including costs for rack purchasing, handling, transportation, and inventory costs. The determination of the rack size should consider tradeoff relationships between the amount of glasses piled in a rack and the number of racks loaded on a truck, and affects the required number of racks and the truck operational cost. A truck loading algorithm is proposed to maximize a high truck utilization, and an enumeration method is proposed to determine the optimal combination of rack sizes considering the total logistics cost. The numerical example is solved by using a real data.

• Journal of architectural history
• /
• v.30 no.3
• /
• pp.7-20
• /
• 2021

Since 1939, Bupeyong was rapidly urbanized and industrialized for the purpose of constructing military logistics base of the empire of Japan. Based on Kyungin urban planning of 1940 and industrial land development plan of Kyeonggido, many military factories and arsenal were constructed, and great amount of housing were also built for their workers from 1939 to 1944. Although the initial urban planning was unfinished, urban change from rural area to military industrial city in the late Japanese colonial era, made identity of city of Bupyeong. Workers houses which built during five years vary in different size and type, and somewhat reflects discussions about housing attempts to solve the housing shortage. This study aims to analyze architectural characteristics of workers housing related with discussions of housing, and to evaluate its value as an industrial heritage which constitute the urban landscape of the industrial city of Bupyeong. Workers houses in Bupyeong were constructed by military factories, construction company, and Chosun housing administration, with land readjustment planning. As the war became serious, workers housing became smaller and simpler. Construction of workers housing was essential part of modern military industrial city, bupyeong, and many of workers housing are still remained whereas most of factories were demolished, thus workers housing of bupyeong has significant meaning as industrial heritage of Bupyeong.

• Journal of the Korean Society of Safety
• /
• v.10 no.2
• /
• pp.97-104
• /
• 1995

To evaluate readily the effect of unconfined vapor cloud explosion(UVCE) having high possibility of accident and risk in chemical industries, the expert system of UVCE was developed and its applicability on a real accident was analyzed. We found that the hazard of UVCE could be well evaluated from the TNT equivalency model and the empirical loss data produced by overpressure for chemical facilities. By using the developed expert system, the size of vapor cloud, the quantity of vaporization, the released energy, the overpressure range from explosion point, and the impact damage of each installation could be estimated respectively. Also, probable maximum loss and catastrophic loss potential for real accident( cyclohexane release in Flixborough Nypro company) were estimated and compared with damages of the accident. As a result, the developed expert system could be well applicable to real accident.