• Journal of Intelligence and Information Systems
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• v.17 no.4
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• pp.305-316
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• 2011

Recommender system is the system which, by using automated information filtering technology, recommends products or services to the customers who are likely to be interested in. Those systems are widely used in many different Web retailers such as Amazon.com, Netfix.com, and CDNow.com. Various recommender systems have been developed. Among them, Collaborative Filtering (CF) has been known as the most successful and commonly used approach. CF identifies customers whose tastes are similar to those of a given customer, and recommends items those customers have liked in the past. Numerous CF algorithms have been developed to increase the performance of recommender systems. However, the relative performances of CF algorithms are known to be domain and data dependent. It is very time-consuming and expensive to implement and launce a CF recommender system, and also the system unsuited for the given domain provides customers with poor quality recommendations that make them easily annoyed. Therefore, predicting in advance whether the performance of CF recommender system is acceptable or not is practically important and needed. In this study, we propose a decision making guideline which helps decide whether CF is adoptable for a given application with certain transaction data characteristics. Several previous studies reported that sparsity, gray sheep, cold-start, coverage, and serendipity could affect the performance of CF, but the theoretical and empirical justification of such factors is lacking. Recently there are many studies paying attention to Social Network Analysis (SNA) as a method to analyze social relationships among people. SNA is a method to measure and visualize the linkage structure and status focusing on interaction among objects within communication group. CF analyzes the similarity among previous ratings or purchases of each customer, finds the relationships among the customers who have similarities, and then uses the relationships for recommendations. Thus CF can be modeled as a social network in which customers are nodes and purchase relationships between customers are links. Under the assumption that SNA could facilitate an exploration of the topological properties of the network structure that are implicit in transaction data for CF recommendations, we focus on density, clustering coefficient, and centralization which are ones of the most commonly used measures to capture topological properties of the social network structure. While network density, expressed as a proportion of the maximum possible number of links, captures the density of the whole network, the clustering coefficient captures the degree to which the overall network contains localized pockets of dense connectivity. Centralization reflects the extent to which connections are concentrated in a small number of nodes rather than distributed equally among all nodes. We explore how these SNA measures affect the performance of CF performance and how they interact to each other. Our experiments used sales transaction data from H department store, one of the well?known department stores in Korea. Total 396 data set were sampled to construct various types of social networks. The dependant variable measuring process consists of three steps; analysis of customer similarities, construction of a social network, and analysis of social network patterns. We used UCINET 6.0 for SNA. The experiments conducted the 3-way ANOVA which employs three SNA measures as dependant variables, and the recommendation accuracy measured by F1-measure as an independent variable. The experiments report that 1) each of three SNA measures affects the recommendation accuracy, 2) the density's effect to the performance overrides those of clustering coefficient and centralization (i.e., CF adoption is not a good decision if the density is low), and 3) however though the density is low, the performance of CF is comparatively good when the clustering coefficient is low. We expect that these experiment results help firms decide whether CF recommender system is adoptable for their business domain with certain transaction data characteristics.

• The KIPS Transactions:PartD
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• v.12D no.3 s.99
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• pp.417-428
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• 2005

Today, IT organizations perform projects with vision related to marketing and financial profit. The objective of realizing the vision is to improve the project performing ability in terms of QCD. Organizations have made a lot of efforts to achieve this objective through process improvement. Large companies such as IBM, Ford, and GE have made over $80\%$ of success through business process re-engineering using information technology instead of business improvement effect by computers. It is important to collect, analyze and manage the data on performed projects to achieve the objective, but quantitative measurement is difficult as software is invisible and the effect and efficiency caused by process change are not visibly identified. Therefore, it is not easy to extract the strategy of improvement. This paper measures and analyzes the project performance, focusing on organizations' external effectiveness and internal efficiency (Qualify, Delivery, Cycle time, and Waste). Based on the measured project performance scores, an OT (Opportunity Tree) model was designed for optimizing the project performance. The process of design is as follows. First, meta data are derived from projects and analyzed by quantitative GQM(Goal-Question-Metric) questionnaire. Then, the project performance model is designed with the data obtained from the quantitative GQM questionnaire and organization's performance score for each area is calculated. The value is revised by integrating the measured scores by area vision weights from all stakeholders (CEO, middle-class managers, developer, investor, and custom). Through this, routes for improvement are presented and an optimized improvement method is suggested. Existing methods to improve software process have been highly effective in division of processes' but somewhat unsatisfactory in structural function to develop and systemically manage strategies by applying the processes to Projects. The proposed OT model provides a solution to this problem. The OT model is useful to provide an optimal improvement method in line with organization's goals and can reduce risks which may occur in the course of improving process if it is applied with proposed methods. In addition, satisfaction about the improvement strategy can be improved by obtaining input about vision weight from all stakeholders through the qualitative questionnaire and by reflecting it to the calculation. The OT is also useful to optimize the expansion of market and financial performance by controlling the ability of Quality, Delivery, Cycle time, and Waste.

• Journal of Internet Computing and Services
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• v.15 no.6
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• pp.133-144
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• 2014

As the Internet and smartphones prevail, this study investigated the purchasing factors of a new beauty marketing method, the social commerce, and verified the relationship of such purchasing factors to consumer satisfaction and repurchasing intentions. In order to verify the validity of purchasing factors, five sub-factors, such as service, price, interaction, convenience, and interest were classified, while consumer satisfaction and repurchasing intentions are grouped into one factor, using data about 20-39 years old. According to results of this study, purchasing factors in the beauty service markets through social commerce that had effects on the consumer satisfaction were price, service, convenience, and interest, but no relationship was found with interaction. We can predict that consumers buy not based on community activities among buyers or purchasing comments of others, but rather his/her own subjective thoughts and opinions about the services. As the result of repurchasing intention according to purchasing factors, affecting sub-factors were price, service, and convenience. Repurchasing intention is an positive response that reflects satisfactions. Since low price, satisfaction on the service, and convenience for busy modern people should be met, repurchasing intentions are not affected by interest, but rather systematic and professional service. Also, higher satisfaction on service raises repurchasing intention. In this study, it is clear that not only purchasing factors through social-commerce effect the satisfaction and the repurchasing intention, but also consumer satisfaction mediates partly purchasing factors and the repurchasing intention. And as sub-factors of purchasing factors, price, service, or convenience are more important to the consumer satisfaction than community or replies activities. Thus differentiated and professional customer service, the establishment and enhancement of trendy marketing should improve long term repurchasing intentions. This will lead to the increasing revenue of personal-shop and the developments of beauty markets, so strengthening product sourcing and promotion suitable for mobile shoppers are essential.

• International Commerce and Information Review
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• v.15 no.1
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• pp.3-34
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• 2013

This research, which was experimented by dividing tangible and intangible products, established the influence that affects recovery for consumers' complaint behavior and behavioral intention as per each different compensation program. In Experiment 1, the consumers, who experienced complaint behavior owing to company's mistake, have preferably recovered through the compensation program offered by the company. However, there was a significant difference in preference recovery between products that caused complaint behavior. According to the study result, the more clear preference recovery was shown in the case of purchasing laptop than the case of dining in family restaurant. Additionally, the consumers' emotion recovery was possible through compensation.; There was a emotion recovery disparity depending on product type between purchasing laptop case and dining in family restaurant case. The consumers, who experienced complaints, were only able to recover their preference, emotion, and behavioral intention through compensation of which recovery was greater in tangible product case than ordinary service. Meanwhile, there was no distinct difference between recovery compensation types even though the products were identical-type ones whereas it appeared that such tangible product which showed greater purchasing effort as laptop computer was more effective in stimulating emotion response. In Experiment 2, the purpose was to find out the difference between complaint behavior and its recovery process shown after purchase by Korean and Japanese college students, who have different consumer purchasing habits. The both consumers of the two countries, who experienced complaint behavior, demonstrated precise difference in preference recovery while the emotion and behavioral intention exhibited no disparity between the two consumer groups. In this experiment, it was learned that Korean college students were show-off purchase type consumers while on the other hand, the Japanese college students were famous product purchase type consumers. Thus, there was a clear difference in laptop computer purchase process and post-purchase evaluation between these two groups. In particular, the Korean college students had quicker preference recovery through compensation than the Japanese college students on account of their tendency to be consciousness of others. Nevertheless, there was no difference between the emotion recovery and re-purchase recovery and therefore, the compensation program for complaints was proven to affect the emotion and behavioral intention.

• Journal of Nutrition and Health
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• v.47 no.2
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• pp.145-156
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• 2014

Purpose: The purpose of this study was to establish accreditation systems of reliable educational materials for nutrition and dietary life which could be used in schools, workplace, and health promotion. Methods: The study was conducted from April 2011 to October 2011. Literature reviews, institutional visits, and telephone interviews were conducted. Expert meetings and advisory councils were held in order to receive feedback on development of the accreditation systems. A survey was conducted for the accreditation procedures on 143 professionals, including professors, researchers, health and medical experts, teachers, nutrition teachers, dietitians, and clinical nutritionists. Results: The final procedure of the developed accreditation system was finalized as follows: 1) receiving application twice per year 2) complete desk review (written evaluation) by three reviewers within two months, 3) board review (all board members) and decision, and 4) notification of results. The accreditation system is set for printed materials, web-site, and materials for activities. The certificate and accreditation mark is issued to the final certified educational materials. Expiration date is established only for the web-site form. The accreditation length lasts for two years, and can be extended by renewal application. Conclusion: The dietary and nutrition related materials, which are certificated by this accreditation system, could impart reliable information and knowledge to both learners and educators, and help them in effective selection of educational materials. Therefore, this accreditation system might be expected to increase satisfaction for teaching and learning about nutrition and healthy dietary life.

• Journal of the Korean Institute of Landscape Architecture
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• v.47 no.5
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• pp.41-48
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• 2019

Our daily lives are changing at a rapid pace and the concept of smart city is spreading, as the information communication technologies apply to various fields. However, efforts to prepare for changes in society due to technological evolution are insufficient in the field of landscape architecture. The purposes of this study are to explore the concept of smart parks, to investigate how smart technology has been applied to parks, and to identify the users' perception and satisfaction on smart park services. To this end, we conducted literature review, focus group interviews with experts, and a questionnaire survey with 180 users of the IoT See pilot smart park in Daegu. Smart parks can, as a result, be defined as sustainable parks that improve users' experience in parks and solve social and environmental problems faced by utilizing various high technology. Smart technologies introduced at the park so far have been mostly focused on safety and environmental areas, including AI CCTV, smart street lamp, and fine dust warning devices. The results of survey showed that not many users were aware of the smart services the park provided due to the lack of public communication as well as the nature of maintenance-oriented smart services. The survey also found that AR services for the education of historic parks were the least utilized, while solar power benches and WiFi service were most preferred by the park users. In conclusion, smart technologies need to be integrated with diverse park contents more centered user needs, providing services to enhance safety and environmental management in order to develop user-oriented smart parks.

• Journal of Nutrition and Health
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• v.56 no.4
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• pp.419-438
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• 2023

Purpose: This study examines the effectiveness of personalized goal setting and smartphone-based nutrition counseling among adults in their 20s and 30s. Methods: Nutrition counseling was conducted for a total of 30 adults through a 1:1 chat room of a mobile instant messenger, once a week for 8 weeks. The first week of counseling included a preliminary online questionnaire survey and a dietary intake survey. Based on the results of the preliminary survey, 2 dietary goals were set in the second week and the participants were asked to record their achievements on a daily checklist. From the third week onwards, counselors sent feedback messages based on the checklist and provided information on dietary guidelines in a card news format every week. Post-counseling questionnaires and dietary intake surveys were conducted in the seventh week. Changes in dietary habits during the counseling were reviewed in the eighth week, followed by a questionnaire survey on the evaluation of the counseling process. Results: The nutrition quotient (NQ) scores and self-efficacy scores were significantly higher after nutrition counseling. The NQ scores of consumption frequencies of fruits, milk and dairy products, nuts, fast food, Ramyeon, sweet and greasy baked products, sugarsweetened beverages, the number of vegetable dishes at meals, and breakfast frequency were significantly higher after nutrition counseling. The intake of protein, vitamin A, thiamin, riboflavin, folate, calcium, and iron, and the index of nutritional quality of vitamin A, riboflavin, folate, calcium, and iron were higher after nutrition education. The participants were satisfied with the nutrition counseling program and the provided nutrition information. Conclusion: Personalized goal setting and smartphone-based nutrition counseling were found to be effective in improving the quality of diet and self-efficacy in young adults. Similar results were obtained in both the underweight/normal weight and the overweight/obese groups.

• Korean Journal of Social Welfare Studies
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• v.41 no.4
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• pp.189-224
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• 2010

Nowadays Korean society has a fast growing population of North Korean immigrant youth. Especially, North Korean immigrant youth, who are discontinuing formal education, experience difficulties in social exclusion and adaptation. Therefore, the purpose of this study was to understand the experiences of adaptation and social support of North Korean immigrant youth discontinuing formal education, and to seek affirmative supporting plans and solutions for their adaptation. The methodology utilized for this study was a case study research. On the basis of the results and categorization, 'a network between overall categories and of early adaptation' was derived. The major findings of this study are summarized as follows. First, the participants of this study experienced major difficulties during 'economical adaptation', and their economical adaptation was strongly interrelated with their 'educational adaptation'. The discontinuing of their education resulting from their fleeing period caused 'academic differential and age disparity.' Thus they could not enroll in the formal education system, and their insufficient educational background resulted in low wages and overwork due to manual labor jobs. Second, participants recognized 'interpersonal relations' as the most essential factor in adaptation, and 'social support' from the interpersonal relations played an important role in adaptation to and comfort in Korean society. 'Interactions with South Koreans' was recognized as a significant resource for gaining informational and appraisal support, but was not activated satisfactorily. On the other hand, interaction with North Korean immigrants was avoided by the reason that 'there's nothing to learn', however emotional support from North Korean immigrants of close relationship played an important role in participants' adaptation, especially in all aspects of psychological adaptation. Third, participants experienced a lot of difficulties and stresses in their 'physical health and psychological adaptation'. Their chronic diseases worsened by remaining untreated, and female perceived symptoms were observed more often than in male. Meanwhile, excessive 'stresses' from the unfamiliar environment of South Korea negatively affected their psychological adaptation. However, they were satisfied with sense of liberty and security from living in a democratic society.

• Korean Journal of Agricultural and Forest Meteorology
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• v.25 no.4
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• pp.427-435
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• 2023

Changes in flowering time due to weather fluctuations impact plant growth and ecosystem dynamics. Accurate prediction of flowering timing is crucial for effective forest ecosystem management. This study uses a process-based model to predict flowering timing in 2023 for five major tree species in Korean forests. Models are developed based on nine years (2009-2017) of flowering data for Abeliophyllum distichum, Robinia pseudoacacia, Rhododendron schlippenbachii, Rhododendron yedoense f. poukhanense, and Sorbus commixta, distributed across 28 regions in the country, including mountains. Weather data from the Automatic Mountain Meteorology Observation System (AMOS) and the Korea Meteorological Administration (KMA) are utilized as inputs for the models. The Single Triangle Degree Days (STDD) and Growing Degree Days (GDD) models, known for their superior performance, are employed to predict flowering dates. Daily temperature readings at a 1 km spatial resolution are obtained by merging AMOS and KMA data. To improve prediction accuracy nationwide, random forest machine learning is used to generate region-specific correction coefficients. Applying these coefficients results in minimal prediction errors, particularly for Abeliophyllum distichum, Robinia pseudoacacia, and Rhododendron schlippenbachii, with root mean square errors (RMSEs) of 1.2, 0.6, and 1.2 days, respectively. Model performance is evaluated using ten random sampling tests per species, selecting the model with the highest R². The models with applied correction coefficients achieve R² values ranging from 0.07 to 0.7, except for Sorbus commixta, and exhibit a final explanatory power of 0.75-0.9. This study provides valuable insights into seasonal changes in plant phenology, aiding in identifying honey harvesting seasons affected by abnormal weather conditions, such as those of Robinia pseudoacacia. Detailed information on flowering timing for various plant species and regions enhances understanding of the climate-plant phenology relationship.

• Journal of Service Research and Studies
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• v.13 no.4
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• pp.97-112
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• 2023

Background: In modern society, the importance of Public Design has become increasingly significant in contributing to the enhancement of urban functionality and the quality of life of citizens. Smart Public Facilities have played a pivotal role in enriching user experience by improving accessibility, convenience, and safety, and in elevating the value of the city. This research recognizes the importance of Public Facilities and explores the potential of Smart Public Facilities in solving urban challenges and progressing towards sustainable and Inclusive cities. Method: The literature review comprehensively examines existing theories and research results on Smart Public Facilities. The case study analyzes actual examples of Smart Public Facilities implemented in cities both domestically and internationally, drawing out effects, user satisfaction, and areas for improvement. Through analysis and discussion, the results of the case studies are evaluated, discussing the potential development of Smart Public Facilities. Results: Smart Public Facilities have been found to bring positive changes in various aspects such as urban management, energy efficiency, safety, and information accessibility. In terms of urban management, they play a crucial role in optimization, social Inclusiveness, environmental protection, fostering citizen participation, and promoting technological innovation. These changes create a new form of urban space, combining physical space and digital technology, enhancing the quality of life in the city. Conclusion: This research explores the implications, current status, and functions of Smart Public Facilities in service and design aspects, and their impact on the urban environment and the lives of citizens. In conclusion, Smart Public Facilities have brought about positive changes in the optimization of urban management, enhancement of energy efficiency, increased information accessibility, User-Centric design, increased interaction, and social Inclusiveness. Technological innovation and the integration of Public Facilities have made cities more efficient and proactive, enabling data-based decision-making and optimized service delivery. Such developments enable the creation of new urban environments through the combination of physical space and digital technology. The advancement of Smart Public Facilities indicates the direction of urban development, where future cities can become more intelligent, proactive, and User-Centric. Therefore, they will play a central role in Public Design and greatly contribute to improving the urban environment and the quality of life of citizens.