• Journal of Communications and Networks
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• v.17 no.4
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• pp.428-439
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• 2015

In this study, we present an approach for reducing the information inaccuracy of existing star aggregation based on bypass links when there are multi-constraint QoS parameters in asymmetric networks. In our approach, bypass links with low similarity are selected. Links that are not chosen as bypass links are included in each group depending on the star's link characteristics. Moreover, each link group is aggregated differently according to the similarity of the links that make up the group. The selection of a bypass link by using link similarity reduces the existing time complexity of O($N^3$) to O(N) by virtue of the simplification of the selection process. In addition, the adaptive integration according to the characteristics of the links in each group is designed to reduce the information inaccuracy caused by static aggregation. Simulation results show that the proposed method maintains low information distortion; specifically, it is 3.8 times lower than that of the existing method, even when the number of nodes in a network increases.

• Journal of the Korean Society of Food Culture
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• v.30 no.5
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• pp.674-681
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• 2015

The purpose of this study was to analyze factors affecting acceptance of four kinds of dak-jjim samples in third year school-aged children (n=100). Soy sauce, red pepper paste, Vietnam fish sauce, and star anise were applied to samples for their familiar and exotic characteristics. Significant differences among samples were observed in odor, taste, and acceptance (p<0.001). Soy (Soy sauce sample), RPPaste (Red pepper paste sample), and Soy_FishS (Soy sauce and Vietnam fish sauce sample) samples scored higher than Soy_StarA (Soy sauce and star anise sample) sample. On the other hand, there were no significant differences in intensities of saltiness, sweetness, and hot spicy flavor (p>0.05). Liked attributes in samples were saltiness, sweetness, chicken flavor, potato flavor, moistness of chicken, hot spicy flavor, and color. Disliked attributes in samples were hot spicy flavor, saltiness, and ginger flavor. Significant differences among samples were observed in familiar intensity and willing to try again (p<0.001). Soy, RPPaste, and Soy_FishS samples scored higher than Soy_StarA sample. Panels considered taste (46%) and nutrition (45%). Higher familiar intensity of sample was associated with higher acceptance in samples. In other words, familiarity of food affects acceptance of food. Therefore, familiar ingredients such as soy sauce and chicken can be used for development of Korean menu items considering taste and nutrition with enhanced Korean food acceptance in school-aged children.

• Journal of Internet Computing and Services
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• v.21 no.4
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• pp.59-68
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• 2020

The present study aims to explore the influence of BTS, which is popular around the world. Specifically, it aims to look at differences between Korean and Chinese BTS female fandom. Besides, it also explores factors affecting fandom's daily happiness. The study conducted a survey with Korean and Chinese female fans. Findings from surveys suggest that first, there are differences on star attributes, fandom activity and illusory romance between Korean and Chinese female fandom. Specifically, Chinese female fandom's professionalism and artistic attractiveness which are included in star attributes, and illusory romance which is gained in fandom activity are higher than Korean. In addition, Korean female fans actively participated in offline fandom activities, while Chinese female fans actively participated in online fandom activities. Second, it is found that fandom activity, star identification and illusory romance have positive effects on daily happiness. Based on these findings, implication, limitations, and topics for future research are discussed.

• Journal of Digital Convergence
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• v.18 no.8
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• pp.1-9
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• 2020

This study aims to find new attributes by analyzing Korea and China duty free store online reviews and examine the influence of these attributes on star ratings(satisfaction)of duty free store. For study, we used Dazhong Dianping that largest online review site in China. Using R, we analyzed 5,659 reviews of Korea duty free store and 4,051 reviews of China duty free store. According to the analysis, Sale, Food and Membership attributes had a positive effect on star rating of Korea duty free store. Sale, Product, Airport, Food and Membership had a positive effect on star rating of China duty free store. This study has identified new factors such as food that showed the importance of providing space of restaurants while shopping at duty free store. This study has contributed to the existing literature by finding new attribute such as food. Practically, this finding will help to duty free industry workers better understand the impact of providing space of restaurants on duty free store.

• Journal of Computing Science and Engineering
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• v.1 no.2
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• pp.177-194
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• 2007

Index selection is one of the most important decisions to take in the physical design of relational data warehouses. Indices reduce significantly the cost of processing complex OLAP queries, but require storage cost and induce maintenance overhead. Two main types of indices are available: mono-attribute indices (e.g., B-tree, bitmap, hash, etc.) and multi-attribute indices (join indices, bitmap join indices). To optimize star join queries characterized by joins between a large fact table and multiple dimension tables and selections on dimension tables, bitmap join indices are well adapted. They require less storage cost due to their binary representation. However, selecting these indices is a difficult task due to the exponential number of candidate attributes to be indexed. Most of approaches for index selection follow two main steps: (1) pruning the search space (i.e., reducing the number of candidate attributes) and (2) selecting indices using the pruned search space. In this paper, we first propose a data mining driven approach to prune the search space of bitmap join index selection problem. As opposed to an existing our technique that only uses frequency of attributes in queries as a pruning metric, our technique uses not only frequencies, but also other parameters such as the size of dimension tables involved in the indexing process, size of each dimension tuple, and page size on disk. We then define a greedy algorithm to select bitmap join indices that minimize processing cost and verify storage constraint. Finally, in order to evaluate the efficiency of our approach, we compare it with some existing techniques.

• The KIPS Transactions:PartC
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• v.18C no.5
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• pp.361-368
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• 2011

In this study, we present a method for efficiently aggregating networks state information required to determine feasible paths in transport networks that uses the source routing algorithm for hierarchical QoS routing. It is proposed to transform the full mesh topology whose Service Boundary Line serves as its logical link into the star topology. This is an aggregation method that can be used when there are two or more QoS parameters for the link to be aggregated in an asymmetric network, and it improves the information accuracy of the star topology. For this purpose, the Service Boundary Line's 3 attributes, splitting, joining and integrating, are defined in this study, and they are used to present a topology transformation method. The proposed method is similar to space complexity and time complexity of other known techniques. But simulation results showed that aggregated information accuracy and query response accuracy is more highly than that of other known method.

• The KIPS Transactions:PartD
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• v.19D no.1
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• pp.1-14
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• 2012

As the size of the data warehouse is large, the selection of indices on the data warehouse affects the efficiency of the query processing of the data warehouse. Indices induce the lower query processing cost, but they occupy the large storage areas and induce the index maintenance cost which are accompanied by database updates. The bitmap join indices are well applied when we optimize the star join queries which join a fact table and many dimension tables and the selection on dimension tables in data warehouses. Though the bitmap join indices with the binary representations induce the lower storage cost, the task to select the indexing attributes among the huge candidate attributes which are generated is difficult. The processes of index selection are to reduce the number of candidate attributes to be indexed and then select the indexing attributes. In this paper on bitmap join index selection problem we reduce the number of candidate attributes by the data mining techniques. Compared to the existing techniques which reduce the number of candidate attributes by the frequencies of attributes we consider the frequencies of attributes and the size of dimension tables and the size of the tuples of the dimension tables and the page size of disk. We use the mining of the frequent itemsets as mining techniques and reduce the great number of candidate attributes. We make the bitmap join indices which have the least costs and the least storage area adapted to storage constraints by using the cost functions applied to the bitmap join indices of the candidate attributes. We compare the existing techniques and ours and analyze them in order to evaluate the efficiencies of ours.

• Culinary science and hospitality research
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• v.14 no.3
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• pp.1-15
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• 2008

The purpose of this study was to examine the structural relationship where the job satisfaction of chefs who directly handle the food materials in the hotel restaurants influences their purchase and management of the food materials. For this, 350 chefs of 11 five-star hotels were surveyed with a questionnaire about the process and consciousness in managing food materials. 293 copies of the questionnaire were used in the empirical study by excluding unanswered and insincere ones. Before verifying the hypothesis, the reliability and propriety of the concepts suggested by the study model were analyzed through structural equation model using AMOS 5.0 to analyze concepts and verify the hypothesis. As the result of, the job satisfaction of five-star hotel restaurant chefs appeared to have positive influence on the chefs' purchase attitude, food material satisfaction, food material management performance. Also, the supplier satisfaction increased when the cooking and purchase departments communicate well with each other. Therefore, for the efficient purchase of food materials, the purchase and cooking departments shall survey the market periodically, increase communication between departments to obtain food material satisfaction, organization satisfaction and job satisfaction.

• The Journal of Industrial Distribution & Business
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• v.14 no.1
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• pp.21-28
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• 2023

Purpose: This study aims to analysis the difference by Michelin rating in customer satisfaction of restaurant listed in the Korea Michelin Guide. There are opinions that the Michelin Guide's rating system and evaluation criteria are somewhat ambiguous. Research design, data, and methodology: This study collected 145 actual online reviews published on TripAdvisor to examine how the effect of the content attributes of reviews on consumer satisfaction varies according to the Michelin grade. Based on this, two studies were conducted. Study 1 examined the effect of strong and weak positive reviews on consumer satisfaction according to the rating. Study 2 examined the effect of image information on consumer satisfaction. Results: The results revealed that the lower the Michelin rating, the more positive review had a significant effect on consumer satisfaction. The higher the rating, the more image information had an effect on consumer satisfaction. Expectations for Michelin three-star restaurants are higher than those of two-star restaurants, so customers are more likely to be used negatively when writing reviews. Conclusions: Accurate information on Michelin selection criteria should be delivered so as not to form high expectations and not to disappoint. For consumers to be satisfied with the name Michelin, the standards should be stricter.

• Journal of Power Electronics
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• v.15 no.1
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• pp.256-267
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• 2015

Grid-connected transformerless photovoltaic (PV) inverters (TPVIs) are increasingly dominating the market due to their higher efficiency, lower cost, lighter weight, and reduced size when compared to their transformer based counterparts. However, due to the lack of galvanic isolation in the low voltage grid interconnections of these inverters, the PV systems become vulnerable to leakage currents flowing through the grounded star point of the distribution transformer, the earth, and the distributed parasitic capacitance of the PV modules. These leakage currents are prohibitive, since they constitute an issue for safety, reliability, protection coordination, electromagnetic compatibility, and module lifetime. This paper investigates a wide range of multi-kW range power rating TPVI topologies and classifies them in terms of their leakage current attributes. This systematic classification places most topologies under a small number of classes with basic leakage current attributes. Thus, understanding and evaluating these topologies becomes an easy task. In addition, based on these observations, new topologies with reduced leakage current characteristics are proposed in this paper. Furthermore, the important efficiency and cost determining characteristics of converters are studied to allow design engineers to include cost and efficiency as deciding factors in selecting a converter topology for PV applications.