• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.11
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• pp.5671-5693
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• 2017

With the rapid development of cloud computing, more and more data owners are motivated to outsource their data to cloud for various benefits. Due to serious privacy concerns, sensitive data should be encrypted before being outsourced to the cloud. However, this results that effective data utilization becomes a very challenging task, such as keyword search over ciphertexts. Although many searchable encryption methods have been proposed, they only support exact keyword search. Thus, misspelled keywords in the query will result in wrong or no matching. Very recently, a few methods extends the search capability to fuzzy keyword search. Some of them may result in inaccurate search results. The other methods need very large indexes which inevitably lead to low search efficiency. Additionally, the above fuzzy keyword search methods do not support access control. In our paper, we propose a searchable encryption method which achieves fuzzy search and access control through algorithm design and Ciphertext-Policy Attribute-based Encryption (CP-ABE). In our method, the index is small and the search results are accurate. We present word pattern which can be used to balance the search efficiency and privacy. Finally, we conduct extensive experiments and analyze the security of the proposed method.

• 제어로봇시스템학회:학술대회논문집
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• 1995.10a
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• pp.319-322
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• 1995

As a trend toward multi-product batch processes is increasing in Chemical Process Industry (CPI), multi-product batch scheduling has been actively studied. But the optimal production scheduling problems for multi-product batch processes are known as NP-complete. Recently Ku and Karimi [5] have studied Simulated Annealing(SA) and Jung et al.[6] have developed Modified Simulated Annealing (MSA) method which was composed of two stage search algorithms for scheduling of batch processes with UIS and NIS. Jung et al.[9] also have studied the Common Intermediate Storage(CIS) policy which have accepted as a high efficient intermediate storage policy. It can be also applied to pipeless mobile intermediate storage pacilities. In spite of these above researches, there have been no contribution of scheduling of CIS policy for chemical batch processes. In this paper, we have developed another MSA for scheduling chemical batch processes with searching the suitable control parameters for CIS policy and have tested the this algorithm with randomly generated various scheduling problems. From these tests, MSA is outperformed to general SA for CIS batch process system.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.27 no.2
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• pp.171-191
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• 2016

This research was examined to evaluate whether the websites of 6 policy research institutes provide web resources which were collected and provided as information resources, and that they were sure that the web resources had value as policy information by content analysis method. Web resources provided as policy information in policy research institutes were classified into and evaluated by 4 categories. Evaluation had been conducted on 10 items in the 4 categories of content, design, accessibility and meta data. From the result, the information content have been found to be reliable and up-to-date although more thorough description is required. Navigation and the search function in the design category were found to be excellent, but dead links were present in all of the institutions. The accessibility was proven to be great as it was able to access information with only three clicks. However, it has been found that a comprehensive review of the meta data is required in order to improve the accuracy of search functions. In conclusion, improvements to the dead link problems, quality control of the meta data, systematic and professional management plan of policy research information, and the establishment of a comprehensive policy research information portal system have been proposed.

• Journal of Information Management
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• v.26 no.1
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• pp.80-98
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• 1995

Search strategies is a means to make an efficient search. Among several studies of search strategy, Bates' $\ulcorner$Search Tactics$\lrcorner$ has been often cited and introduced, but their studies have been superficial. In this paper, the contents of Bates' $\ulcorner$Search Tactics$\lrcorner$ are examined in detail, and we try to represent the actual online search process based upon Bates' $\ulcorner$Search Tactics$\lrcorner$. The following three kinds of survey are made in order to clarify which and how tactics are used: (1) Interview with 7 searchers who belong to different types of organizations, and use different kinds of databases (2) Analysis of some online search records. (3) Analysis of written applications for a newspaper database during one year. In conclusion, Bates' tactics falls into categories and new several tactics which often used are added. The following five factors affect online search activities, search strategy, and search tactics. (1) the difficulty of search requests (2) the kinds of databases (3) the charging policy for each online search (4) the presence of the user during the search (5) the searcher' online experience In the limited condition, typical tactics are suggested, but in order to generalize the pattern of using tactics, further investigation is necessary.

• Health Policy and Management
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• v.27 no.1
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• pp.18-29
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• 2017

Background: In Korea, the problem of physician workforce imbalances has been a debated issue for a long time. This study aimed to draw key lessons and policy implications to Korea by analyzing projection models of physician demand/supply among five countries. Methods: We adopted theoretical framework and analyzed detail indicators used in projection models of demand/supply comparatively among countries. A systematic literature search was conducted using PubMed and Google Scholar with key search terms and it was complimented with hand searching of grey literature in Korean or English. Results: As a results, Korea has been used a supply-based traditional approach without taking various variables or environmental factors influencing on demand/supply into consideration. The projection models of USA and Netherlands which considered the diversity of variables and political issues is the most closest integrated approach. Based on the consensus of stakeholder, the evolved integrated forecasting approach which best suits our nation is needed to minimize a wasteful debate related to physician demand/supply. Also it is necessary to establish the national level statistics indices and database about physician workforce. In addition, physician workforce planning will be discussed periodically. Conclusion: We expect that this study will pave the way to seek reasonable and developmental strategies of physician workforce planning.

• KDI Journal of Economic Policy
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• v.37 no.1
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• pp.1-18
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• 2015

A reduction in search costs is generally believed to make markets more competitive. However, the effect may be mitigated or amplified if consumers must pay costs for switching products. This paper investigates how search costs affect prices in the presence of switching costs using U.S. domestic airfare data for 2000-2010. The airline industry experienced a dramatic decrease in search costs with increasing Internet use in the 2000s. At the same time, the industry is known for its frequent flyer programs (FFPs), which increase switching costs for consumers. We use the average network size of airlines in a market as a proxy for switching costs related to FFPs and Internet usage as a proxy for (the inverse of) search costs. The results show that increasing Internet usage lowers airfares but that the effect is smaller for markets with a larger average network size.

• Journal of KIISE:Computer Systems and Theory
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• v.33 no.6
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• pp.337-343
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• 2006

The Stack Resource Policy (SRP) is a real-time synchronization protocol with some distinct properties. One of such properties is early blocking; the execution of a job is delayed instead of being blocked when requesting shared resources. If SRP is used with dynamic priority scheduling such as Earliest Deadline First (EDF), the early blocking requires that a scheduler should select the highest-priority job among the jobs that will not be blocked, incurring runtime overhead. In this paper, we analyze the runtime overhead of EDF scheduling when SRP is used. We find out that the overhead of job search using the conventional implementations of ready queue and job search algorithms becomes serious as the number of jobs increases. To solve this problem, we propose an alternative data structure for the ready queue and an efficient job-search algorithm with O([log$_2n$]) time complexity.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.17 no.5
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• pp.119-124
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• 2017

In 1997, IBM's DeepBlue won the world chess championship, Garry Kasparov, and recently, Google's AlphaGo won all three games against Ke Jie, who was ranked 1st among all human Baduk players worldwide, interest in deep running has increased rapidly. DeepPurple, proposed in this paper, is a AI chess engine based on deep learning. DeepPurple Chess Engine consists largely of Monte Carlo Tree Search and policy network and value network, which are implemented by convolution neural networks. Through the policy network, the next move is predicted and the given situation is calculated through the value network. To select the most beneficial next move Monte Carlo Tree Search is used. The results show that the accuracy and the loss function cost of the policy network is 43% and 1.9. In the case of the value network, the accuracy is 50% and the loss function cost is 1, respectively.

• Journal of Broadcast Engineering
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• v.25 no.6
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• pp.854-860
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• 2020

Deep neural networks have shown remarkable performance in various areas, including image classification and speech recognition. The variety of data generated by augmentation plays an important role in improving the performance of the neural network. The transformation of data in the augmentation process makes it possible for neural networks to be learned more generally through more diverse forms. In the traditional field of image process, not only new augmentation methods have been proposed for improving the performance, but also exploring methods for an optimal augmentation policy that can be changed according to the dataset and structure of networks. Inspired by the prior work, this paper aims to explore to search for an optimal augmentation policy in the field of sound data. We carried out many experiments randomly combining various augmentation methods such as adding noise, pitch shift, or time stretch to empirically search which combination is most effective. As a result, by applying the optimal data augmentation policy we achieve the improved classification accuracy on the environmental sound classification dataset (ESC-50).

• Journal of Digital Convergence
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• v.11 no.2
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• pp.271-277
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• 2013

Typical semantic search query for Semantic search promises to provide more accurate result than present-day keyword matching-based search by using the knowledge base represented logically. Existing keyword-based retrieval system is Preference for the semantic interpretation of a user's query is not the meaning of the user keywords of interconnect, you can not search. In this paper, we propose a method that can provide accurate results to meet the user's search intent to user preference based evaluation by ranking search. The proposed scheme is Integrated ontology-based knowledge base built on the formal structure of the semantic interpretation process based on ontology knowledge base system.