• Journal of Intelligence and Information Systems
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• v.25 no.4
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• pp.89-103
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• 2019

Recently, various approaches to recommendation systems have been studied in terms of the quality of recommendation system. A recommender system basically aims to provide personalized recommendations to users for specific items. Most of these systems always recommend the most relevant items of users or items. Traditionally, the evaluation of recommender system quality has focused on the various predictive accuracy metrics of these. However, recommender system must be not only accurate but also useful to users. User satisfaction with recommender systems as an evaluation criterion of recommender system is related not only to how accurately the system recommends but also to how much it supports the user's decision making. In particular, highly serendipitous recommendation would help a user to find a surprising and interesting item. Serendipity in this study is defined as a measure of the extent to which the recommended items are both attractive and surprising to the users. Therefore, this paper proposes an application of serendipity measure to recommender systems to evaluate the performance of recommender systems in terms of recommendation system quality. In this study we define relevant or attractive unexpectedness as serendipity measure for assessing recommendation systems. That is, serendipity measure is evaluated as the measure indicating how the recommender system can find unexpected and useful items for users. Our experimental results show that highly serendipitous recommendation such as item-based collaborative filtering method has better performance than the other recommendations, i.e. user-based collaborative filtering method in terms of recommendation system quality.

• International Journal of Highway Engineering
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• v.12 no.3
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• pp.87-92
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• 2010

As the Concept "how environmental friendly" becomes more and more important in road construction. However, so far there is no estimation method. Environmental friendly concept can be incorporated at the plan level in order to influence decision making, and support policies that affect environment. The overall goal of this study was to develop environmental friendly concept measures for the national highway and to develop a methodology to implement a more environmental friendly concept. The research identified 8 performance measures through a project analysis that could address environmental impact assessment system's ten strategic goals - Topography, Wildlife, hydrology, landuse, air quality, water quality, soil, waste, noise, landscape. The qualitatively and quantitatively evaluation approach was selected as the decision support framework and performance measure were investigated using the AHP(Analytic Hierarchy Process) and pilot corridor for a 10 section and calculate the index values. The methodology was applied to a pilot corridor comprised of a 120km section of national highway in korea. The methodology made it possible to identify the specific performance measures that need improvement to enhance the overall environmental friendly concept. It is fairly intuitive, based on readily available data, and is easy to apply. It provides a powerful tool for government to assess the relative environmental friendly conceptof their transportation corridors now and in the future. It allows for comparisons within a corridor and with other corridors and identifies the improvements needed to enhance the environmental friendly concept.

• International Journal of Highway Engineering
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• v.11 no.1
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• pp.117-126
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• 2009

Total number of recorded earthquakes in Korea is more than 2,000 of which 48 were catastrophic. The impacts from infrastructure damage due to an earthquake to production facilities and lifelines may spread across boundaries of several regions via import-export relationships and can bring serious economic impact to other regions. The economic impacts from unscheduled events stem not only from the damage and direct losses, but also from the indirect losses during the recovery and reconstruction periods. To recover and reconstruct the facilities and lifelines damaged by unexpected events through investment or government financial aid, both the direct and the indirect economic impacts from an event need to be measured in regional and interregional contexts. Direct economic impact is the direct change of production and demand due to the disruption of production facilities and lifelines from an unexpected event, and indirect economic impact is the change in other sectors due to inter-industry relationships. The purpose of the paper is to analyze various economic impacts of an earthquake, especially impacts on transportation networks in Korea. We collected spatial and economic data from Korea, and analyzed and estimated final demand loss and commodity flows from the unscheduled event.

• Korean Journal of Construction Engineering and Management
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• v.21 no.5
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• pp.3-10
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• 2020

Subcontracting of construction is essential to carry out public construction projects. Subcontractor of the construction work shall enter into a contract with the original contractor without directly entering into a contract with the owner. Subcontracts are therefore greatly affected by the original contract with the owner. To protect subcontractors, the Fair Trade Act is enacted and the construction company's standard subcontracting contract is in operation. However, subcontracts are not properly reflected in the Government contract system, which deals with the relationships between the owner and the original contractor. In particular, the subcontractor may complain of difficulties at the public construction site as such procedures are not properly reflected in the construction work standard subcontract, although various procedures shall be carried out depending on the amount when change order occurs in subcontracts. Thus, the direction of improvement of subcontracting systems was proposed in the case of change order at public construction project sites as follows: First, the rights of subcontractors should be strengthened. Second, in order to resolve the information non-identity, subcontractors should have access to information related to subcontracts. Third, the status of subcontractor shall be guaranteed by reflecting the characteristics of the subcontract when the original contract for public works is concluded. Fourth, the dispute settlement method should be prioritized over litigation in order to fair subcontracting.

• Korean Journal of Construction Engineering and Management
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• v.20 no.6
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• pp.57-65
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• 2019

If aging apartments are left unimproved through remodeling, the city will be eventually slum. As the government recognizes remodeling as an alternative to reconstruction, the law has been revised mainly to increase the housing area, increase the number of house and allow the vertical extension for making remodeling costs. However, the remodeling is still not activated yet in the market. Therefore, this study analyzes the decision factors of apartment remodeling in Seoul metropolitan area based on Heckman two-stage analysis considering sampling error. Research findings indicate that the decision for remodeling is determined by the characteristics of the household, housing, and time-lapse variables. And also the number of household members, net assets, housing satisfaction, the 11-20, 21-30, and more than 30 years of building are identified as the significant variables as a result of remodeling choice probability analysis. It is noteworthy that the significant variables from then remodeling cost analysis are net assets, area, more than 30 years of building, and unit housing price. It is also notable that the policy, which extend the housing area to cover remodeling cost, are not actually effective to activate the remodeling, and the age in the case of elderly people in Seoul and Gyeonggi-do who are expected to have high net assets and income is not significant variables. This study is expected to provide more objective and reliable implication to the policy makers, the home owner and the investors on the decision making process related to the remodeling project.

• Journal of Korea Port Economic Association
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• v.32 no.3
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• pp.123-137
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• 2016

In order to address the crisis of the regional employment structure caused by the recent restructuring of the shipbuilding industry, this study estimates the shipbuilding industry's Employment Linkage Effect(ELE) across regions and industries. Consequently, the study uses the hypothetical extraction method on the shipbuilding industry from the 2013 Regional Input-output Table. The analysis results are as follows. First, the shipbuilding industry's ELE across industries is estimated at its highest in wholesale and retail, followed by shipment, other manufacturing, project supporting service, machine and equipment manufacturing, and metal product manufacturing. These industries either have a high employment to GDP ratio or are directly related to the shipbuilding industry in terms of production activities. Second, the Southeastern Korea's ELE on South Jeolla Province is very low, and, accordingly, South Jeolla Province is isolated in the employment structure of the shipbuilding industry. Therefore, when the government establishes measures to tackle the crisis of employment caused by the shipbuilding industry's restructuring, it should prioritize identifying such regional employment structures, as demonstrated above, and incorporate them into the regional industry policy.

• Journal of the Korea Society of Computer and Information
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• v.15 no.9
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• pp.57-65
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• 2010

This paper describes the method of efficient container number recognition in colored container image with number plate at ATC(Automatic Transfer Crane) in container terminal yard. At the Sinseondae terminal gate in Busan, the container number recognition system is installed by "intelligent port-logistics system technology development", that is government research and development project. It is the method that it sets up the tunnel structure inside camera on the gate and it recognizes the container number in order to recognize the export container cargo automatically. However, as the automation equipment is introduced to the container terminal and the unmanned of a task is gradually accomplished, the container number recognition system for the confirmation of the object of work is required at ATC in container terminal yard. Therefore, the container number recognition system fitted for it is necessary for ATC in container terminal yard in which there are many intrusive of the character recognition through image including a sunlight, rain, snow, shadow, and etc. unlike the gate. In this paper, hardware components of the camera, illumination, and sensor lamp were altered and software elements of an algorithm were changed. that is, the difference of the brightness of the surrounding environment, and etc. were regulated for recognize a container number. Through this, a shadow problem, and etc. that it is thickly below hung with the sunlight or the cargo equipment were solved and the recognition time was shortened and the recognition rate was raised.

• Korean Journal of Construction Engineering and Management
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• v.22 no.6
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• pp.3-14
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• 2021

In the Chinese construction industry, the utilization of Building Information Modeling (BIM) aims to increase the total output of the construction industry by solving the problem of inefficient interoperability in the construction industry. In 2011, the Chinese Ministry of Housing and Urban-Rural Development despite the technical advantages of BIM and the government policy, the BIM adoption rate in China is lower than 45%. Meanwhile, as the South Korean construction industry is a step ahead of its Chinese counterpart in introducing and utilizing BIM, it is expected that BIM is more actively utilized and accepted in South Korea than in China. According to a comparative study based on the hype-cycle theory, South Korea is at a more advanced stage of introducing BIM, than in China. This study aimed to suggest how to increase BIM utilization rates in China. To this end, this study comparatively analyzed factors affecting BIM acceptance between China and South Korea. For the comparative analysis of the BIM acceptance factors between China and South Korea, literature reviews on the technology acceptance model (TAM) and BIM acceptance model were carried out, and based on that, the BIM acceptance factors were classified. Other BIM acceptance factors were also added and considered, as they reflected Chinese national characteristics and construction industry. As for the derived BIM acceptance factors, construction project participants, especially actual BIM users in China and South Korea, were targeted for the survey. A t-test using SPSS 22.00 was carried out to identify significant differences in data. Finally, based on the t-test results, this study suggested ways of improving the BIM utilization rate in China. Based on the findings, this study is expected to contribute to activating BIM adoption in the Chinese construction industry and also to set a theoretical foundation for future studies on BIM utilization in the industry.

• Journal of Conservation Science
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• v.37 no.5
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• pp.491-504
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• 2021

Gwanghwamun Gate of Gyeongbokgung Palace was dismantled and relocated during the Japanese colonial period, destroyed during the Korean War, reconstructed with reinforced concrete in 1968, and finally erected at its present location in 2010. A pair of Haechi statues located in front of Gwanghwamun was dismantled and relocated several times, and the statues have yet to be returned precisely to their original positions. This study assesses the historical accuracy of their current placement under the Gwanghwamun Square Restructuring Project of the Seoul Metropolitan Government and the Cultural Heritage Administration based on archival photos from the early 1900s, and proposes a method to estimate the original positions of the Haechi through image analysis of contemporary photographs and recent digital camera photos. We estimated the original position of the Haechi before the Japanese colonial period by identifying the shooting location of the archival photo and reproducing contemporary photographs by calculating the angle and distance to the Haechi from the shooting location. The leftmost and rightmost Haechi were originally located about 9.6 m to the east and 7.4 m to the north and about 1.9 m to the west and 8.0 m to the north, respectively, of their current location indicators. As the first attempt to determine the original location of a building and its accessories using archival photos, this study launches a new scientific methodology for the restoration of cultural properties.

• The Journal of the Korea Contents Association
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• v.21 no.9
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• pp.580-594
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• 2021

The purpose of this paper is to investigate the impact on self-reliance and satisfaction of participants participating in the self-sufficiency business program of the Ulsan Metropolitan Regional Self-Sufficiency Center. A self-filled questionnaire was surveyed on self-sufficiency participants in five Borough and Country in Ulsan for 4 weeks from September 1 to 30, 2020, and final 233 copies were used in the actual analysis. As a result of the study, first, the percentage of positive responses of the participants was found to be good at 71.7%, for questions on the degree of support to the government, local governments, and administrative welfare centers. Second, in response to a system or service that would like to be supported or needed in the future, support for living expenses and support for health and medical expenses appeared and as a result of gender difference analysis, it was confirmed that there was a significant difference between support for children's education expenses and support for housing funds. Among the factors of the participant's psychological self-reliance(self-control, confidence, and willingness to work), the factor of self-control was the most significant factor, followed by confidence and willingness to work. Overall satisfaction with work was the highest among 9 satisfaction items such as salary and working hours.