• Journal of Korea Technology Innovation Society
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• v.9 no.4
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• pp.627-653
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• 2006

The purpose of this study lies in understanding how the spectrum assigned for each mobile operator affects the consumers of mobile service. For this purpose, we have observed the change of path coefficient in the structural equation, using control variables. However, the structure of the mobile service market in Korea has become fixed. Considering this tendency and the conclusion of this study, the 'lock-in effect' occurs seriously in the mobile service market in Korea. It can be explained by the fact that CS(Customer Satisfaction) of the cellular subscribers little affects customer loyalty but the market dominance of the cellular service in the actual market has continued for a long time. In this study, we figured out a strong prejudice about call quality, which is caused by spectrum difference among competitors. Cellular subscribers tends to believe that call quality of their cellular service is better than that of PCS. In addition, we found that PCS operators can catch customer's retention by investment into network in order to increase call quality.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.11
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• pp.87-104
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• 2015

Currently the IoT (Internet of Things) environments and related technologies are being developed rapidly through the networks for connecting many intelligent objects. The IoT is providing artificial intelligent services combined with context recognition based knowledge and communication methods between human and objects and objects to objects. With the help of IoT technology, many research works are being developed using the C-ITS (Cooperative Intelligent Transport System) which uses road infrastructure and traveling vehicles as traffic control infrastructures and resources for improving and increasing driver's convenience and safety through two way communication such as bus-only lane and license plate recognition and road accidents, works ahead reports, which are eventually for advancing traffic effectiveness. In this paper, a system for deciding whether the traveling vehicle is possible or not to drive on bus-only lane in highway is researched using the lane and number plate recognition on the road in C-ITS traffic infrastructure environments. The number plates of vehicles on the straight ahead and sides are identified after the location of bus-only lane is discovered through the lane recognition method. Research results and experimental outcomes are presented which are supposed to be used by traffic management infrastructure and controlling system in future.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.6
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• pp.1169-1175
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• 2011

The soil chemical properties, microbial community structures and biochemical properties of lettuce or cucumber-cultivated greenhouse soil samples were analyzed to assess soil health and characterize microbial distribution in 8 locations in Korea. Although most of chemical properties were within the soil management guidelines, the available phosphate, and the contents of exchangeable potassium and calcium were higher than those of recommended levels. In the culture-dependent analysis, 841 bacterial strains were isolated from the greenhouse soils and were identified at the genus level by 16S rRNA gene sequences analysis. The dominant bacterial genera were Bacillus (35.7%), Microbacterium (9.3%), Arthrobacter (5.7%) and Lysobacter (5.1%). The abundance of pseudomonads was highly variable depending on the soil samples. In the culture-independent analysis, soil microbial community was investigated by using phospholipid fatty acid (PLFA) method. Principal component analysis (PCA) showed that a specific grouping for microbial community structure in the greenhouse soils was not observed based on cultivated crops and investigated sites. The results revealed that the greenhouses soils examined are relatively sound managed in terms of soil chemical contents and microbial properties.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.29 no.3
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• pp.147-153
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• 2011

What kinds of environmental adaptation did people during the Chosun era take when climate change due to drought was perceived and natural disasters occurred? Research hypotheses is 'More environmental improvement projects were conducted when climate disasters were experienced than rituals for rain calling. In this study, frequency samples for Rituals for Rain (RR, 祈雨祭) defined as abnormal climate of drought, Climate Disaster(CD) and Environmental Improvement Projects(EIP) were extracted from "Chosunwangjoshillok(朝鮮王朝實錄)". The analysis among RR, CD, and EIP were studied for a regression model. Research hypothesis was statistically tested. RR took placed the order of Sejong(世宗), Sukjong(肅宗) and Youngjo(英祖), while climate disasters were extracted under the Jungjong(中宗), Sungjong(成宗) and Taijong(太宗). EIP were most active under Youngjo(英祖), Sungjong(成宗) and Taijong(太宗). During the former part of the Chosun dynasty, abnormal climate was more seriously considered than climate disasters, while the opposite pattern was shown during the latter part. In a regression analysis between EIP and CD, the equation of EIP = 0.632CD was determined. As a test result, the study hypothesis the entire Chosun dynasty was dismissed. However, it is possible to statistically support that more EIP were conducted in order to adapt to the climate change during the latter part of the dynasty when climate disaster were experienced.

• The Journal of the Convergence on Culture Technology
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• v.8 no.2
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• pp.343-348
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• 2022

This study aims to analyze the user experience of unmanned checkout counters perceived by consumers using SNS big data. For this study, blogs, news, intellectuals, cafes, intellectuals (tips), and web documents were analyzed on Naver and Daum, and 'unmanned checkpoints' were used as keywords for data search. The data analysis period was selected as two years from January 1, 2020 to December 31, 2021. For data collection and analysis, frequency and matrix data were extracted through Textom, and network analysis and visualization analysis were conducted using the NetDraw function of the UCINET 6 program. As a result, the perception of the checkout counter was clustered into accessibility, usability, continuous use intention, and others according to the definition of consumers' experience factors. From a supplier's point of view, if unmanned checkpoints spread indiscriminately to solve the problem of raising the minimum wage and shortening working hours, a bigger employment problem will arise from a social point of view. In addition, institutionalization is needed to supply easy and convenient unmanned checkout counters for the elderly and younger generations, children, and foreigners who are not familiar with unmanned calculation.

• Journal of Korea Foundry Society
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• v.41 no.6
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• pp.550-557
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• 2021

With the advent of the fourth industrial revolution, the interest in the internet of things (IoT) in manufacturing is growing, even at foundries. There are several types of process data that can be automatically collected at a foundry, but considerable amounts of process data are still managed based on handwriting for reasons such as the limited functions of outdated production facilities and process design based on operator know-how. In particular, despite recognizing the importance of converting process data into big data, many companies have difficulty adopting these steps willingly due to the burden of system construction costs. In this study, the field applicability of IoT-based devices was examined by manufacturing devices and applying them directly to the site of a centrifugal foundry. For the centrifugal casting process, the temperature and humidity of the working site, the molten metal temperature, and mold rotation speed were selected as process parameters to be collected. The sensors were selected in consideration of the detailed product specifications and cost required for each process parameter, and the circuit was configured using a NodeMCU board capable of wireless communication for IoT-based devices. After designing the circuit, PCB boards were prepared for each parameter, and each device was installed on site considering the working environment. After the on-site installation process, it was confirmed that the level of satisfaction with the safety of the workers and the efficiency of process management increased. Also, it is expected that it will be possible to link process data and quality data in the future, if process parameters are continuously collected. The IoT-based device designed in this study has adequate reliability at a low cast, meaning that the application of this technique can be considered as a cornerstone of data collecting at foundries.

• Journal of Korea Entertainment Industry Association
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• v.14 no.1
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• pp.117-124
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• 2020

Chinese youth films fall into the dilemma of continuous development after experiencing rapid development from 2013 to 2017. How to update the creative ideas and methods of the films, arouse the audience's interest in watching and stimulate a new aesthetic experience has become a focal point for the creators who concern about the Chinese film market. "Us and Them" is a successful youth film in 2018. Its creative practice proves that defamiliarization can provide theoretical and methodological basis for the creation of Chinese youth films. Therefore, taking the current situation of Chinese youth film as the research background, treating "Us and Them" as the research object, the defamiliarization of narrative discourse and narrative content used in the film are analyzed. First, the defamiliarization of narrative discourse composed of scenes, characters and plots makes the film "stand out" from the real world. Second, the defamiliarization of narrative content composed of metropolis adoration, self-identity and hometown affection makes the film "stand out" from the existing context. These methods of creation not only meet the needs of the contemporary, but also provide an effective reference for the creation of other youth films. Research will be needed to utilize the elements of defamiliarization through the analysis of the successful case in spite of the time change.

• Journal of Korea Entertainment Industry Association
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• v.13 no.4
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• pp.385-400
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• 2019

We reviewed existing studies and proposed future research on the sustainability of short-term effects, and of the Yongin Emotion Management Training program (Y-EMT). In this study, we conducted Y-EMT to verify its effectiveness in relation to affective disorders associated with chronic schizophrenia. Thirty-five patients were assigned to the experimental group, and 35 to the control group. First, results of repeated-measures analysis supported the effectiveness of Y-EMT. Comparisons of the results on the pre-test with those for the 5-month and 1-year post-training tests showed significant differences in mean scores between the experimental and control groups. Furthermore, these differences persisted at the 2-year follow-up. Second, in the experimental group, interactions between emotional behavior and expression, self-efficacy, and changes in interpersonal relationships showed significant effects at 5 months after the program ended, and these effects continued to increase up to 1 year post-training. Taken together, the findings indicate that, to maintain the effects of therapy in patients with chronic schizophrenia, patients should undergo Y-EMT along with cognitive rehabilitation training and social skills training. Human relations training such as Y-EMT is most helpful for rehabilitation when it is paired with high levels of medication.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.4B
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• pp.383-392
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• 2008

It is not always easy to estimate the parameters in hydrologic models due to insufficient hydrologic data when hydraulic structures are designed or water resources plan are established. Therefore, uncertainty analysis are inevitably needed to examine reliability for the estimated results. With regard to this point, this study applies a Bayesian Markov Chain Monte Carlo scheme to the NWS-PC rainfall-runoff model that has been widely used, and a case study is performed in Soyang Dam watershed in Korea. The NWS-PC model is calibrated against observed daily runoff, and thirteen parameters in the model are optimized as well as posterior distributions associated with each parameter are derived. The Bayesian Markov Chain Monte Carlo shows a improved result in terms of statistical performance measures and graphical examination. The patterns of runoff can be influenced by various factors and the Bayesian approaches are capable of translating the uncertainties into parameter uncertainties. One could provide against an unexpected runoff event by utilizing information driven by Bayesian methods. Therefore, the rainfall-runoff analysis coupled with the uncertainty analysis can give us an insight in evaluating flood risk and dam size in a reasonable way.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.17 no.2
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• pp.53-64
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• 2022

The purpose of this study is to analyze the difference in importance and performance of the university start-up support system focusing on D university students to grasp the perception of the start-up support system provided the university from the perspective of students who are real users. Through this, a plan for qualitative growth and advancement of the university start-up system was derived using the IPA (importance-performance analysis) analysis. The findings are as follows. The importance of all elements of university start-up education and start-up support system is higher than the performance, which means that the start-up education and support programs currently implemented by universities are recognized as important, but do not play a big role in terms of performance for students. In addition, the highest priority factors for improvement in the importance-performance matrix were funding and investment support, start-up space and facilities support, management advisory, patent and intellectual property support, and entrepreneurship field practice. Therefore, This study can be used as objective data to identify the factors that universities should focus on and establish a start-up support system from a long-term perspective, and to build and operate a start-up support system that reflects the needs of students.