• Journal of the Korea institute for structural maintenance and inspection
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• v.17 no.4
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• pp.101-111
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• 2013

In this study, DEA (Data Envelopment Analysis) was carried out on the four bridges, which have the same extension (L=1,615m), in order to select the most superior, economical method of construction using the LCC concept of each bridge structure in the case of the Ulsan-Pohang double track railway which is scheduled to be constructed. DEA models were analyzed with the CCR model, which was designed for the evaluation of relative efficiency of each model. The initial construction costs, maintenance costs, indirect costs (user costs + indirect loss of social costs), and life cycle costs were used as input variables, and average duration was applied as the output variable. LCC was applied to calculate the input variables, and to get the costs of LCC, 100 years of period and 4.83% of real discount rate were applied, and the costs are classified into initial construction, maintenance, user, and indirect loss of social cost. The analysis results showed that the Method 2 and 3 were evaluated as the most efficient, and the other alternatives were evaluated as the following order; Method 1, the default, and Method 4.

• Journal of Korean Society of Steel Construction
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• v.23 no.2
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• pp.159-167
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• 2011

Steel structure construction is currently increasing on account of the many merits of steel structures. Due to numerous environmental factors, many cracks and extensive corrosion occur in steel structures, which cause the deterioration of the performance and life cycle of such structures. Maintenance of steel structures is thus strongly demanded, for safety control. The inspection methods that are currently being used, however, are very limited and can detect only local defects in steel structures. They also take much time to use and incur high maintenance costs. Moreover, such methods cannot be applied to huge steel structures, which men find unapproachable. They also require much time due to the need for periodic checks, and may lead to cost loss. Therefore, the development of a monitoring system that can detect defects in whole structures and can reduce the repair and strengthening costs at an early stage is very much needed. In this study, the generation and propagation of cracks were monitored via the electric-potential-drop method (EPDM).

• Journal of Korean Society of Transportation
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• v.24 no.5 s.91
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• pp.67-74
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• 2006

This paper proposes a way to a risk quantification of public sector comparator in the value-for-money test of the BTL (Build-Transfer-Lease) scheme in rail investment projects. Two principal risks that are project delay and budget increasing costs are identified and are empirically quantified with a case study of the Haman-Jinju link. The methodology suggested is expected to be a good reference for the similar research afterwards and also to help in settling down the scheme that is only an early stage.

• The KIPS Transactions:PartD
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• v.16D no.1
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• pp.123-132
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• 2009

Even support-and-management efforts by government are enforced with the growing international restrictions for complying with global standard, not a few private enterprises are still suffering software management problems from lack of understanding the software asset management and carelessness of the software management. This is due to the ambiguous scope of software asset management as well as characteristics of software property such as invisibility, easiness of copy and installation. In other words, it is not easy for software managers to comply all the information throughout the software life cycle; from purchasing, procurement. distribution, preservation to disposition. Therefore, Inspector which has been developed for resolving these problems are proposed in this study. The inspection service consists of search algorithms adapted for software characteristics, standardization of software right management information, and practical use of registry information. Inspection time for a PC by using inspector make the inspection time much shorter. It is also shown that effective software management enables the enterprise to curtail software acquisition cost and to help rationalizing its business management.

• Korean Journal of Construction Engineering and Management
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• v.22 no.4
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• pp.41-49
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• 2021

Domestic maintenance strategies are shifting from safety assessment to performance assessment, and related systems and laws are being restructured to meet those criteria. In order to introduce asset management based on performance evaluation, related evaluation methods such as performance measures and level of service should be made to evaluate performance according to the characteristics of the structure, but these are not well-prepared in Korea. In this study, we present a computerized model and system for implementing asset management that introduces techniques such as performance evaluation, life cycle cost analysis, performance measures, and level of service in conjunction with existing maintenance and safety diagnosis procedures. The features of this system consist of three modules to enable separate operations of existing maintenance, safety management and asset management. The system is designed to be used as a reference for public institutions to introduce asset management in the future.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.29 no.4
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• pp.885-895
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• 2019

As seen in recent cases of hacking in financial services, attackers are attempting to hacking trustee with poor security management, rather than directly hacking a financial company. As a result, the consignor is strengthening the security check and control of the trustee, but small trustee has difficulties to invest in information security with the lack of computer facilities and the excessive cost of security equipment. In this paper I investigate the vulnerability of personal information processing life cycle standards in order to enhance the security of small consignee that receive personal information form the credit card company. To solve the vulnerability the company should use litigation management system constructed on cloud computing service and install VPN to secure confidentiality and intergrity in data transfer section. Also, to enhance the security of users, it is suggested to protect personal credit information by installing PC firewall and output security on user PC.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.4
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• pp.9-14
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• 2019

Recently, container vessels are required to be applied various technologies to improve ship life-cycle and operating efficiency for the cost decreasing of logistics. The degradation of engine efficiency due to the increasing capacity of the ship and the related equipment of facilities are applied to large-scale ships without considering the condition of ship operation by increasing the ship size and feature. In this paper, the flow analysis is performed with existing gas pipe in large-scale container ship with the operation-condition of higher capacity engine and facilities, and the results were used on the new gas pipe design for ULCS (Ultra Large Container Ship). The newly designed gas pipe can be expected to increase the operating efficiency of ULCS.

• Journal of Mushroom
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• v.16 no.4
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• pp.331-333
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• 2018

The incorporation of Shiitake culture into sawdust is a widely utilized technique that can assist in reducing the cost and time consumption associated with oak cultivation. In sawdust cultivation, browning of the surface mycelia is an important stage with respect to the utility and longevity of the sawdust media. Surface browning forms a protective coating on the substrate, which can inhibit the invasion of pathogens and suppress water evaporation. Several different light sources (red LED, white LED, blue LED, and fluorescent light) were used and the intensity of illumination was carefully controlled (1.5, 10.5, $20.5{\mu}mol/m^2s$ for LEDs and 10, 100, 300 lux for the fluorescent light) to induce browning. The light sources were regulated via a 1 h on/off cycle in a controlled room environment at a temperature of $20^{\circ}C$, 60% humidity, and 1200 ppm $CO_2$ concentration for 60days. The browning effect varied depending on the source and the intensity of illumination. This effect was most effectively induced at $1.5{\mu}mol/m^2s$ for the red and blue LEDs. All light sources induced less browning at the highest intensity of illumination. This indicates that intensity values higher than $20.5{\mu}mol/m^2s$ in the case of the LEDs and 300 lux for the fluorescent light are not effective. After harvesting of the fruit bodies, we measured the weight, length, and width of the pileus and stipe in addition to their chromaticity and hardness. Treatment with $1.5{\mu}mol/m^2s$ blue LED produced the best harvest with the highest average chromaticity, weight (21.2 g), stipe length (30.8 mm), and hardness (377.9 g), with a fine length and width of the pileus.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.12
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• pp.90-98
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• 2018

An efficient R&D Methodology with minimized development period and cost needs to be developed due to advanced performance requirements of weapon systems. This will require the performance of logistics support analysis and design verification in the development stages of weapon systems through VR technology. VR technology has been applied to the Integrated Logistics Support (ILS) process as a part of collaborative system. In this study, we propose a development and application plan of ILS based on VR technology during the total life cycle of weapon systems. Moreover Digital Maintenance System (DMS) is introduced as a VR tool with key functions. finally, applications and improvement topics of DMS are suggested for use in ILS development.

• Plant Journal
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• v.14 no.4
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• pp.48-54
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• 2018

As the emission limits for NOx in power generation facilities were strengthened, HRSGs installed in the 1990s became necessary to install additional DeNOx system. However, since there is no space in the HRSG for installing the entire the catalyst and ammonia injection grid, as an alternative, the catalyst was installed inside of the HRSG and the ammonia injection device was installed in the exhaust duct of the gas turbine. Experiments were conducted in horizontal HRSG of Incheon combined cycle power plant. Experimental results show that the ammonia injection method in the gas turbine exhaust duct is 1.2 times higher than the HRSG internal ammonia injection method. However when operating a HRSG for 30 years as its life span, ammonia injection method in the gas turbine exhaust duct is more economical than the cost of new HRSG construction.