• Title/Summary/Keyword: 규모효율성

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Incorporating Social Relationship discovered from User's Behavior into Collaborative Filtering (사용자 행동 기반의 사회적 관계를 결합한 사용자 협업적 여과 방법)

  • Thay, Setha;Ha, Inay;Jo, Geun-Sik
    • Journal of Intelligence and Information Systems
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    • v.19 no.2
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    • pp.1-20
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    • 2013
  • Nowadays, social network is a huge communication platform for providing people to connect with one another and to bring users together to share common interests, experiences, and their daily activities. Users spend hours per day in maintaining personal information and interacting with other people via posting, commenting, messaging, games, social events, and applications. Due to the growth of user's distributed information in social network, there is a great potential to utilize the social data to enhance the quality of recommender system. There are some researches focusing on social network analysis that investigate how social network can be used in recommendation domain. Among these researches, we are interested in taking advantages of the interaction between a user and others in social network that can be determined and known as social relationship. Furthermore, mostly user's decisions before purchasing some products depend on suggestion of people who have either the same preferences or closer relationship. For this reason, we believe that user's relationship in social network can provide an effective way to increase the quality in prediction user's interests of recommender system. Therefore, social relationship between users encountered from social network is a common factor to improve the way of predicting user's preferences in the conventional approach. Recommender system is dramatically increasing in popularity and currently being used by many e-commerce sites such as Amazon.com, Last.fm, eBay.com, etc. Collaborative filtering (CF) method is one of the essential and powerful techniques in recommender system for suggesting the appropriate items to user by learning user's preferences. CF method focuses on user data and generates automatic prediction about user's interests by gathering information from users who share similar background and preferences. Specifically, the intension of CF method is to find users who have similar preferences and to suggest target user items that were mostly preferred by those nearest neighbor users. There are two basic units that need to be considered by CF method, the user and the item. Each user needs to provide his rating value on items i.e. movies, products, books, etc to indicate their interests on those items. In addition, CF uses the user-rating matrix to find a group of users who have similar rating with target user. Then, it predicts unknown rating value for items that target user has not rated. Currently, CF has been successfully implemented in both information filtering and e-commerce applications. However, it remains some important challenges such as cold start, data sparsity, and scalability reflected on quality and accuracy of prediction. In order to overcome these challenges, many researchers have proposed various kinds of CF method such as hybrid CF, trust-based CF, social network-based CF, etc. In the purpose of improving the recommendation performance and prediction accuracy of standard CF, in this paper we propose a method which integrates traditional CF technique with social relationship between users discovered from user's behavior in social network i.e. Facebook. We identify user's relationship from behavior of user such as posts and comments interacted with friends in Facebook. We believe that social relationship implicitly inferred from user's behavior can be likely applied to compensate the limitation of conventional approach. Therefore, we extract posts and comments of each user by using Facebook Graph API and calculate feature score among each term to obtain feature vector for computing similarity of user. Then, we combine the result with similarity value computed using traditional CF technique. Finally, our system provides a list of recommended items according to neighbor users who have the biggest total similarity value to the target user. In order to verify and evaluate our proposed method we have performed an experiment on data collected from our Movies Rating System. Prediction accuracy evaluation is conducted to demonstrate how much our algorithm gives the correctness of recommendation to user in terms of MAE. Then, the evaluation of performance is made to show the effectiveness of our method in terms of precision, recall, and F1-measure. Evaluation on coverage is also included in our experiment to see the ability of generating recommendation. The experimental results show that our proposed method outperform and more accurate in suggesting items to users with better performance. The effectiveness of user's behavior in social network particularly shows the significant improvement by up to 6% on recommendation accuracy. Moreover, experiment of recommendation performance shows that incorporating social relationship observed from user's behavior into CF is beneficial and useful to generate recommendation with 7% improvement of performance compared with benchmark methods. Finally, we confirm that interaction between users in social network is able to enhance the accuracy and give better recommendation in conventional approach.

The Study of Establishing the Multi-pass Eurasian Railroads (유라시아 철도의 다중경로 구축에 관한 연구)

  • Hahm, Beom-Hee;Huh, Nam-Kyun;Hurr, Hee-Young
    • Korean Business Review
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    • v.21 no.2
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    • pp.137-170
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    • 2008
  • This study is presenting the logistics strategy in the international logistics markets which makes competition and corporation among north-east Asian countries to establishing the multi-pass Eurasian railroads. The countries located in north-east area of Eurasia like China, Japan, Russia and Korea are paying higher costs and disutility to the transportations and communications due to repeated conflicts and confrontations causes from the politic problems. They are being used surface transportation for most of all logistics between Europe and Asia except special merchandises because of characteristic of cargo to be air, the Silk Road remains vestige only which was main logistic passage to this area since BC. So far the Trans-Siberian Railway is being used by Russia mostly as north of Eurasian transport because of difficulties of service. The Trans-China Railway built in 1992 is not accomplishing as a international logistic passages. It is expected to take a long lead time because of characteristic of resource development and poor logistic infrastructure to the countries like Uzbekistan, double landlocked country, Mongolia and Azerbaijan, the countries do not be adjacent to the sea, even they have great economic jump-up plans through the development of their own resources. The Shanghai Cooperation Organization(SCO) start to sail officially in 2001 is constructed with China, Russia, Tadzhikistan, Kyrgyzstan, Kazakhstan and Uzbekistan as regular members of 6 countries and Mongolia, India, Pakistan, Afghanistan and Iran as observers 5 countries. It is started as a military alliance to protect terror, but now, it is expended to cooperate with the traffic, transportation, trade and share of energies. The Russia is doing their best to activate TSR as a government target to developnorth area equivalently, and economic develop of far-east Siberia. And also it is agreed provisionally to improve and repair of rail road between Nahjin and Hassan to connect TSR and TKR( Trans-Korea Railroad) by Russia, North Korea and South Korea with Russian's aggressive efforts. The development plan of this area is over lapped with GTI(Greater Tumen Initiative) promoted by UNDP, and is a cooperated project by 5 countries of South Korea, Mongolia, China, Russia and North Korea, subject to review the appropriation of energy, tour, environment, rail road connection between Mongolia and China and establishing a ferry route to north-east Asia. It is Japanese situation to pay attention to Russia and China even they have been supplying large-scope of infrastructure in Mongol area without any charges, target to get East Asia Main Rail Road to connect Mongolia and Zalubino of Russia. In case of the program for the Denuclearization of North Korea is not creeping, it will be accelerated to connect the TKR and TSR, TKR and TCR by somehow attending United States, including developing program promoted by UN ESCAP. As the result, Korean peninsular will continue the central role of competition and cooperation as in the past, now and future of north-east Asia, as of geographical-economics and geographical-politics whether it is requested or not wanted by neighbor countries.

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Analysis of Critical Control Points through Field Assessment of Sanitation Management Practices in Foodservice Establishments (현장실사를 통한 급식유헝별 위생관리실태 분석)

  • Kwak Tong-Kyung;Lee Kyung-Mi;Chang Hye-Ja;Kang Yong-Jae;Hong Wan-Soo;Moon Hye-Kyung
    • Korean journal of food and cookery science
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    • v.21 no.3 s.87
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    • pp.290-300
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    • 2005
  • Increased sanitation management of foodservice establishments is required because most of the reported foodborne-disease outbreaks were in the foodservice industry. The purpose of this study was to determine the important control points for good sanitation. In this study, we inspected twenty foodservice establishments in Seoul, Kyunggi, Kyungnam with a self-developed monitoring tool. These foodservice establishments included secondary schools, universities, and industries. Six of them had appointed as the HACCP-certified establishments from the Korea Food and Drug Administration. The inspection was conducted from June to August in 2002. The inspection tool consisted of nine dimensions and sixty-five items. The dimensions were 'personal sanitation', 'supply of raw food', 'food storage', 'handling of raw food and ready-to-eat', 'cleaning and sterilization', 'waste control', 'pest control', and 'control of establishment and equipment' The highest possible score of this inspection tool is 105 points. Statistical data analysis was completed using the SPSS Package(11.0) for descriptive analysis Kruskal-Wallis. The score for the secondary schools (83.6 points) was higher than for the others and number of in compliance item was 50.9 on average. Therefore, we concluded that the secondary schools' sanitation condition was good. The foodservice establishments acquired HACCP certification was 89.7 points, which was significantly higher than that of establishments not applying foodservices in total score. Instituting the HACCP system in a foodservice is very effective for sanitation management. Many out of the compliance observations were found in the dimensions of 'waste control', 'control of establishment and equipment', and 'supply of raw food' 'Clean condition of refrigerator' item was $65\%$ out of the compliance that was the highest percent in this study. 'Notify and observance of heating/reheating temperature' was $45\%$ out of compliance. Items which were over $30\%$ out of compliance were 'sterilization of knifes and chopping boards in cooking', 'education of workers', 'maintain refrigerator temperature blow $5^{\circ}C$', and 'countermeasure of infection workers' In the results, most of the foodservice establishments were poorly managed in temperature control and cross-contamination. The important control points revealed in this study were preventing contamination, cooking temperature compliance, management of raw food and refrigerator. Therefore foodservice establishments should pay attention to education and training about important control points. The systematic sanitation management monitoring tool developed in this study can be effectively applied for conducting self-inspection and improving the sanitary conditions of their own foodservice operations.

Soil Surface Fixation by Direct Sowing of Zoysia japonica with Soil Improvement on the Dredged Soil Slope (해저준설토 사면에서 개량제 처리에 의한 한국들잔디 직파 지표고정 공법에 관한 연구)

  • Jeong, Yong-Ho;Lee, Im-Kyun;Seo, Kyung-Won;Lim, Joo-Hoon;Kim, Jung-Ho;Shin, Moon-Hyun
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.14 no.4
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    • pp.1-10
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    • 2011
  • This study was conducted to compare the growth of Zoysia japonica depending on different soil treatments in Saemangeum sea dike, which is filled with dredged soil. Zoysia japonica was planted using sod-pitching method on the control plot. On plots which were treated with forest soil and soil improvement, Zoysia japonica seeds were sprayed mechanically. Sixteen months after planting, coverage rate, leaf length, leaf width, and root length were measured and analyzed. Also, three Zoysia japonica samples per plot were collected to analyze nutrient contents. Coverage rate was 100% in B treatment plot(dredged soil+$40kg/m^3$ soil improvement+forest soil), in C treatment plots (dredged soil+$60kg/m^3$ soil improvement+forest soil), and D treatment plots (dredged soil+$60kg/m^3$ soil improvement), while only 43% of the soil surface was covered with Zoysia japonica on control plots. The width of the leaf on C treatment plots (3.79mm) was the highest followed by D treatment (3.49mm), B treatment (2.40mm) and control plots (1.97mm). Leaf and root length of D treatment was 30.18cm and 13.18cm, which were highest among different treatments. The leaf length of D treatment was highest followed by C, B, and A treatments. The root length of D treatment was highest followed by C, A, and B treatments. The nitrogen and phosphate contents of the above ground part of Zoysia japonica were highest in C treatment, followed by D, B, and A treatments. The nitrogen and phosphate contents of the underground part of Zoysia japonica were highest in D treatment, followed by C, A, and B treatments. C and D treatments showed the best results in every aspect of grass growth. The results of this study could be used to identify the cost effective way to improve soil quality for soil surface fixation on reclaimed areas using grass species.