• Journal of Communications and Networks
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• 제8권3호
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• pp.330-338
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• 2006

Many web cache systems and policies concerning them have been proposed. These studies, however, consider large objects less useful than small objects in terms of performance, and evict them as soon as possible. Even if this approach increases the hit rate, the byte hit rate decreases and the connections occurring over congested links to outside networks waste more bandwidth in obtaining large objects. This paper puts forth a client-cluster approach for improving the web cache system. The client-cluster is composed of the residual resources of clients and utilizes them as exclusive storage for large objects. This proposed system achieves not only a high hit rate but also a high byte hit rate, while reducing outgoing traffic. The distributed hash table (DHT) based peer-to-peer lookup protocol is utilized to manage the client-cluster. With the natural characteristics of this protocol, the proposed system with the client-cluster is self-organizing, fault-tolerant, well-balanced, and scalable. Additionally, the large objects are managed with an index based allocation method, which balances the loads of all clients well. The performance of the cache system is examined via a trace driven simulation and an effective enhancement of the proxy cache performance is demonstrated.

• KIPS Transactions on Software and Data Engineering
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• 제5권11호
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• pp.569-584
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• 2016

In this paper, we present a spatial knowledge extractor implemented in Hadoop MapReduce parallel, distributed computing environment. From a large spatial dataset, this knowledge extractor automatically derives a qualitative spatial knowledge base, which consists of both topological and directional relations on pairs of two spatial objects. By using R-tree index and range queries over a distributed spatial data file on HDFS, the MapReduce-enabled spatial knowledge extractor, MRSPAKE, can produce a web-scale spatial knowledge base in highly efficient way. In experiments with the well-known open spatial dataset, Open Street Map (OSM), the proposed web-scale spatial knowledge extractor, MRSPAKE, showed high performance and scalability.

• Steel and Composite Structures
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• 제45권1호
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• pp.51-66
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• 2022

This paper presents the axial compression behavior of partially encased composite (PEC) columns using H-shaped structural steel. In the experimental program, a total of eight PEC columns with H-shaped steel sections of different flange and web slenderness ratios were tested to investigate the interactive mechanism between steel and concrete. The test results showed that the PEC columns could sustain the load well beyond the peak load provided that the flange slenderness ratio was not greater than five. In addition, the previous analytical model was extended to predict the axial load-strain relationships of the PEC columns with H-shaped steel sections. A good agreement between the predicted load-strain relationships and test data was observed. Using the analytical model, the effects of compressive strength of concrete (21 to 69 MPa), yield strength of steel (245 to 525 MPa), slenderness ratio of flange (4 to 10), and slenderness ratio of web (10 to 25) on the interactive mechanism (K_h = confinement factor for highly confined concrete and K_w = reduction factor for steel web) and ductility index (DI = ratio between strain at peak load and strain at proportional load) were assessed. The numerical results showed that the slenderness of steel flange and yield strength of steel significantly influenced the compression behavior of the PEC columns.

• Journal of Korean Society for Quality Management
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• 제32권2호
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• pp.93-108
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• 2004

The purpose of this research is to summarize the methodological issues in internet survey and to suggest personalized internet survey system using data mining technique for enhancing the survey quality of internet survey as well as utilizing the benefit of interactive multimedia factors of internet survey. The data mining technique used in this paper is Case Based Reasoning for adopting individual design preference affecting survey quality. For achieving the research purpose, two surveys, pre & post survey, were performed. Pre survey was done for implementing CBR database to find individual index affecting survey quality and post survey was used for measuring the peformance of personalized internet survey system. The result shows that the survey quality of personalized web survey system is better than generalized web survey system.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제7권11호
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• pp.2913-2927
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• 2013

A data hiding scheme in HTML files is presented in this paper. Web pages are a very popular medium for broadcasting information and knowledge nowadays, and web pages are a good way to achieve the goal of secret message delivery because the different HTML coding codes will render the same screen in any of the popular browsers. The proposed method utilizes the HTML special space codes and sentence segmentation to conceal secret messages into a HTML file. The experimental results show that the stego HTML file generated by the proposed method is imperceptible. Also, the proposed method can conceal one more secret bit in every between-word location.

• Journal of Information Science Theory and Practice
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• 제3권4호
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• pp.62-77
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• 2015

This paper describes qualities of a library classification system that are commonly discussed in the LIS tradition and literature, and explains such a system’s three main functions, namely knowledge mapping, information retrieval, and shelf arrangement. In this vein, the paper states the functional requirements of bibliographic classifications, which broadly are subject collocation and facilitation of browsing the collection. It explains with details the components of a library classification system and their functions. The major components are schedules, notations, and index. It also states their distinguished features, such as generalia class, form divisions, book numbers, and devices for number synthesis which are not required in a knowledge classification. It illustrates with examples from the WebDewey good examples of added features of an online library classification system. It emphasizes that institutional backup and a revision machinery are essential for a classification to survive and remain relevant in the print and e-environment.

• Journal of Convergence for Information Technology
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• 제9권1호
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• pp.45-53
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• 2019

We face problems from excessive information served with websites in this rapidly changing information era. We find little information useful and much useless and spend a lot of time to select information needed. Many websites including search engines use web crawling in order to make data updated. Web crawling is usually used to generate copies of all the pages of visited sites. Search engines index the pages for faster searching. With regard to data collection for wholesale and order information changing in realtime, the keyword-oriented web data collection is not adequate. The alternative for selective collection of web information in realtime has not been suggested. In this paper, we propose a method of collecting information of restricted web sites by using Web crawling distributed monitoring system (R-WCMS) and estimating collection time through detailed analysis of data and storing them in parallel system. Experimental results show that web site information retrieval is applied to the proposed model, reducing the time of 15-17%.

• Informatization Policy
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• 제24권2호
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• pp.43-67
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• 2017

In 2015, Korea won the first place among 30 countries in Open, Useful, and Reusable (OUR) Data Index, which is an OECD's open government data indicator. On the other hand, Korea was ranked the 17th among 86 countries in Open Data Barometer (ODB) of World Wide Web Foundation. In this study, the research subject comes from two reasonable academic doubts on why the gap is wide between the two indicators of Korea and whether the OUR Data Index made proper evaluation on Korea's open government data. Based on the assumption that there may be some critical points in the measuring method of OUR Data Index, the study conducted a comparison of the two indicators. The result found that first, the two indicators almost had no correlation to each other; second, OUR Data Index had a more vague evaluation framework as well as less amount of government data for evaluation than ODB; third, while the government support takes a significant share in the OUR Data Index, it is considered as a mere input element; and fourth, the OUR Data Index does not evaluate the impact of open government data, whereas ODB includes the impact of open data on the government, economy, and society.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• 제8권6호
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• pp.141-146
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• 2008

Recently, it is studying to provide to users through internet in the SensorWeb of OGC(Open Geospatial Consortium) saving and maintaining data and image information gathered from sensor network. It is necessary to study about data convergence as binding audio and video for delivering the sensing data and image information to users with real-time system. In this article, it suggests how to convergence sensing data and moving picture collected from the sensor network using index. This program indicates both of them that collected sensing data and information identified of moving picture in the integration index and based on this program provides sensing data moving picture at the same time referencing integration index, if the user asks. To verify suggested method designing real-time multimedia service structure using sensor network and image installation and implementing Ubiquitous realtime multimedia system integrating moving picture and sensing data based on index. As a result of this program, it is confirmed providing real-time multimedia service to request information of application service using integration index collected image and sensing data from wireless sensor network and image installation suggested data convergence method.

• International Journal of Internet, Broadcasting and Communication
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• 제12권3호
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• pp.149-155
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• 2020

Air pollution is a problem of environmental health risk in big cities. Recently, researchers have proposed using various artificial intelligence technologies to predict air pollution. The proposed model is Cooperative of Artificial Neural Network (ANN) and Fuzzy Inference System (FIS), to predict air pollution of Korean cities using Python. Data air pollutant variables were collected and the Air Korean Web site air quality index was downloaded. This paper's aim was to predict on the health risks and the very unhealthy values of air pollution. We have predicted the air pollution of the environment based on the air quality index. According to the results of the experiment, our model was able to predict a very unhealthy value.