• Journal of the Korean Institute of Gas
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• v.20 no.6
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• pp.16-22
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• 2016

Coating pipe(PLP) has been generally used in buried site for protecting the corrosion. To prevent the damage by occurring the defect, other construction or execution works, an anti-oxidation environment was forcibly made by using protective potential. Coating and protective potential are applied simultaneously, but corrosion rate or defects are not easy to observe because soil composition has many uncertainty. Also, defect of coating pipe can not be directly observed. A corrosion coupon can easily measure a corrosion rate directly. The corrosion rate was measured with 6 scenarios using corrosion coupon during about 1 year(6 scenarios are based on soil type and protective potential or not in this research. Resultingly, the corrosion coupon has not occurred in the case of protected by potential current, but corrosion has occurred in a non-protected site. The corrosion rate was measured at least in the clay, and the propensity of corrosion rate was similar in other soil(sand and loams). The local corrosion has occurred in the clay because of high water content. On the other hand, general corrosion was occurred in sand and loams. Commonly, sand is not to corrosive soil. Although, corrosion occurred in sand can be estimated by chemical component and valid with chemical analysis report.

• Journal of Intelligence and Information Systems
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• v.20 no.1
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• pp.121-131
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• 2014

Traffic speed is an important measure in transportation. It can be employed for various purposes, including traffic congestion detection, travel time estimation, and road design. Consequently, accurate speed prediction is essential in the development of intelligent transportation systems. In this paper, we present an analysis and speed prediction of a certain road section in Busan, South Korea. In previous works, only historical data of the target link are used for prediction. Here, we extract features from real traffic data by considering the neighboring links. After obtaining the candidate features, linear regression, model tree, and k-nearest neighbor (k-NN) are employed for both feature selection and speed prediction. The experiment results show that k-NN outperforms model tree and linear regression for the given dataset. Compared to the other predictors, k-NN significantly reduces the error measures that we use, including mean absolute percentage error (MAPE) and root mean square error (RMSE).

• Information Systems Review
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• v.23 no.3
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• pp.159-176
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• 2021

Obviating user churn is a prominent strategy to capitalize on online games, eluding the initial investments required for the development of another. Extant literature has examined factors that may induce user churn, mainly from perspectives of motives to play and game as a virtual society. However, such works largely dismiss the service aspects of online games. Dissatisfaction of user needs constitutes a crucial aspect for user churn, especially with online services where users expect a continuous improvement in service quality via software updates. Hence, we examine the relationship between a game's quality management and its user base. With text mining and survival analysis, we identify complaint factors that act as key predictors of user churn. Additionally, we find that enjoyment-related factors are greater threats to user base than usability-related ones. Furthermore, subsequent quasi-experiment shows that improvements in the complaint factors (i.e., via game patches) curb churn and foster user retention. Our results shed light on the responsive role of developers in retaining the user base of online games. Moreover, we provide practical insights for game operators, i.e., to identify and prioritize more perilous complaint factors in planning successive game patches.

• The KIPS Transactions:PartD
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• v.8D no.4
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• pp.313-326
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• 2001

The XML that was proposed as a next-generation standard for describing Web documents is widely used in various Web-based applications. In addition, XML documents on the Web link each other by hyperlinks. The current works on XML focus on the XML storage system that can efficiently store, manage, and retrieve XML documents. However, the research on the query language that supports the XML links and on the XML retrieval systems to process the XML links, is little conducted until now. In this paper, we propose an extension of an XML query language for expressing the XML link query and its processing scheme. A link query is to retrieve contents from an XML document (a query document) and from the XML documents (referenced documents) that are referred to by the links in the query document. As far as retrieving from the referenced documents is concerned, the current practice is to manually generate queries to get the partial results, and to repeat such a procedure. The purpose of link query processing in this paper is to eliminate the manual work altogether in getting the complete query result. The performance analysis shows that our link query processing strategy outperforms the conventional approach including the manual tasks. The more links to the referenced documents and the more referenced documents there are in the site storing the query document, the more query processing time decreases.

• Journal of The Korean Association For Science Education
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• v.38 no.2
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• pp.187-202
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• 2018

This study posits that a more equitable science education is possible through analyzing the sociocultural mechanisms that operate in the participation and marginalization in science learning process, and therefore aims to review research trends in this area of science education. To do so, the study analyzed 85 articles that adopted a sociocultural approach to science learning identity in major international journals. The review was organized into 1) overall trends such as the number of articles by year, country, learner's sociocultural background, research context and research methods, and 2) a more in-depth analysis of the main research problems and conceptual frameworks along with concrete research examples. The study found that the current research works in this area have contributed to broadening the idea of legitimate learners in science education by considering learners' various sociocultural identities as the positive resource for learning based on the premise that science learning occurs as identity formation through participating communities of practice, and critiquing the culture or discourses that oppress such identity formation. The studies in this area also brought up the equity issue in science education in ways which embrace various learners that had been marginalized in the traditional science class and facilitate their agency. Based on these findings, the study made a case for analyzing various sociocultural mechanisms relating to the participation and marginalization in science learning to realize 'science education for all Koreans' and proposed future research direction.

• Transactions of the KSME C: Technology and Education
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• v.5 no.2
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• pp.135-143
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• 2017

The domestic unique research reactor, HANARO (Hi-flux Advanced Neutron Application ReactOr), has been constructed with the open-pool, the core is submerged in, for the multi-purpose neutron application. The reactor has a primary cooling system to remove the fission heat from the core and its connected fluidic systems. Since the works are required at the reactor pool top as a characteristic of the research reactor, the radiation shall be minimized with the operation of the hot water layer system to avoid unnecessary radiation exposure on the workers during work at the pool top. Moreover, the pool water management system is connected to the reactor pool to maintain the pool temperature below $50^{\circ}C$ to minimize the uprising radioactive gas or impurity from the colder pool bottom. For the efficient flow rate of the PWMS, the thermal capacity of heat exchanger is selected with 260 kW in the normal operation condition. In this paper, the modeling is formulated to figure out whether or not each pool temperature maintains below the temperature limit and the calculation results show that the designed PWMS heat exchanger has enough capacity with the design margin regardless of the reactor operation mode.

• 한국사회정책
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• v.24 no.4
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• pp.113-150
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• 2017

This study analyzes how workers become impoverished and have their jobs less stabilized after they suffer from non-job-related sickness. Given that South Korea lacks sickness benefits, which most of OECD member states legislate and implement except US and Switzerland, this study examines its impact on laborers' job stability and povertization in Korea. The researchers have conducted in-depth interviews with nine former or present laborers who have the experiences and four experts on the issue in July-September, 2017 for the qualitative analysis. It is found that laborers, after becoming aware of their sickness, at first endure their pain without informing their employers not to lose their jobs. The attititude is observed especially among non-standard laborers, because sickness more often leads to job loss for them than for standard laborers. After workers have to leave their jobs due to their sickness in the end, they have no choice but to keep working in less stable jobs to compensate for income losses. They become gradually impoverished with their social capital like family bond declining. We observe laborers who are eligible for industrial accident insurance compensation could not benefit from the system because some employers refrain from the legal reporting duty. Due to this illegal practices, some industrial accident victims unduly lose their jobs due to "non-job-related sickness". Second, some employers report to the authority that their sick laborers have left their jobs 'voluntarily' even when they have quitted it without their volition, in which case the newly unemployed are not eligible for unemployment benefits. Large holes in Korea's safety nets for those suffering from multiple risks of sickness and unemployment.

• The Journal of the Korea Contents Association
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• v.8 no.12
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• pp.91-97
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• 2008

What if the memory is not erased but continues to exist in the head as it was before? The typical answer to this question would be summarized as the "love for memory". It is almost unbearable that the memory is erased, forgotten or replaced with others. Even though three episodes may be understood as separate things, they have a different image when they are seen under one subject . he three episodes impresses the people with their unique fantastic images and artistic air. In the episode of , we can see a woman who is so much concerned with her past memory so that she does not love the present. In this episode, we can realize how much destructive the bad past memory gives effect on a woman and how memory can give bad effect on a person if that does not connect the past and the present. The work criticizes the society whichdoes not understand the current problems by depicting a person who is so preoccupied with the thing near that person only. shows that the dream is meaningless if people have the future dream without understanding what they really want. Theaudience is absorbed to each hero or heroin who is so obsessed with the past, present and future. What we can feel from these three works is the doubt about the human society which is so much preoccupied with the pessimism and the individuals who do not recognize the importance of the present because they are so much obsessed with their superficial past, present and future as well as the society where they live.

• Korean Journal of Agricultural and Forest Meteorology
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• v.2 no.4
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• pp.204-208
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• 2000

Little information is available for the temporal variation in air temperature profile within rice canopies under development, while much works have been done for a fully developed canopy. Fine wire thermocouples of 0.003 mm diameter (chromel-constantan) were installed at 10 vertical heights by a 10 cm step in a paddy rice field to monitor the air temperatures over and within the developing rice canopy from one month after transplanting (June 29) to just before heading (August 24). According to a preliminary analysis of the data, we found neither the daytime temperature maximum nor the night time minimum at the active radiation surface (the canopy height with maximum leafages) during this period, which is a typical profile of a fully developed canopy. Air temperature within the canopy never exceeded that above the canopy at 1.5 m height during the daytime. Temporal march of the within-canopy profile seemed to be controlled mainly by the ambient temperature above the canopy and the water temperature beneath the canopy, and to some extent by the solar altitude, resulting in alternating isothermal and inversion structures.

• KIISE Transactions on Computing Practices
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• v.21 no.10
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• pp.658-669
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• 2015

The paradigm of game development changes with technological trends. If the system can analyze and determine undefined inputs, users' input choices are not restricted. Therefore, game scenarios can have multifarious flows depending upon the user's input data. In this paper, we propose a method of including an output plan in the game system that is based on the user's input but is not restricted to predefined choices. We have implemented an experimental game on the Android platform by combining network communication and APIs. The game interface works as follows: first, the user's input data is transmitted to the server using HTTP protocol; then, the server carries out an analysis on the input data; and finally, the server returns the decision result to the game device. The game can provide users a scenario that corresponds to the decision results. In this paper, we used an image file for the user's input data format. The server calculates similarities between the user's image file and reference images obtained from the Naver Image Search API and then returns determination results. We have confirmed the value of integrating the game development framework with other computing technologies demonstrating the potential of the proposed methods for application to various future game interfaces.