• Journal of Korean Library and Information Science Society
• /
• v.45 no.2
• /
• pp.261-281
• /
• 2014

In light of the recent advancement in networking and information technology, the direct information request through website has increasingly proven to be the preferred means over visiting physical archives. Thus, the proper utilization of a communication tool capable of sufficiently capturing user feedback and requests is an absolute necessity. This paper examines the availability and utilization of alternative user participatory communication tools in government websites with particular focus on the archives in South Korea, the United States, the United Kingdom, Canada, China, and Japan. In assessing the use of alternative user participatory communication tools in these archives, we examined the availability of communication mediums other than the online forums, email, and telephone with particular focus on social media tools that may offer a degree of familiarity for the user. Our research indicates that the most frequently utilized social media tool is Facebook while the archive offering the greatest variety of alternative user participatory communication tools was the United States archive.

• Journal of KIISE:Databases
• /
• v.31 no.1
• /
• pp.30-38
• /
• 2004

In many scientific and commercial applications such as Earth Observation System (EOSDIS) and mobile Phone services tracking a large number of clients, it is a daunting task to archive and index ever increasing volume of complex data that are continuously added to databases. To efficiently manage multidimensional data in scientific and data warehousing environments, R-tree based index structures have been widely used. In this paper, we propose a scalable technique called seeded clustering that allows us to maintain R-tree indexes by bulk insertion while keeping pace with high data arrival rates. Our approach uses a seed tree, which is copied from the top k levels of a target R-tree, to classify input data objects into clusters. We then build an R-tree for each of the clusters and insert the input R-trees into the target R-tree in bulk one at a time. We present detailed algorithms for the seeded clustering and bulk insertion as well as the results from our extensive experimental study. The experimental results show that the bulk insertion by seeded clustering outperforms the previously known methods in terms of insertion cost and the quality of target R-trees measured by their query performance.

• The Journal of Society for e-Business Studies
• /
• v.22 no.1
• /
• pp.37-49
• /
• 2017

In order to maximize the efficiency and the quality of care in a hospital, hospitals in general operate by appointments. Patient no-shows or missed appointments waste the time of staffs who prepare for appointments, deprive patients of needed care, and increase burden on clinic capacity. The purpose of this study is to examine the importance and significance of factors that affect patient no-shows. The actual data of 50,000 outpatient appointments is compiled and analyzed from a VAMC in the United States with aims to identify the factors that contribute to outpatient no-shows and to draw meaningful implications. Random forest along with logistic regression analysis identify the factors affecting no-shows; appointment leadtime, show-up rate, travel distance, no-show rate in previous period, patient age, severity, complexity of disease, chronic pain, depression, drug dependence. The appointment leadtime, show-up rate, travel distance and previous no-show rate can be improved by enhancing SMS pre-notification and by improving afterwards telephone counseling. For other factors, it needs to study on the service differentiation with the characteristics of each patient group.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.23 no.5
• /
• pp.977-983
• /
• 2013

This paper presents result of researching personal information exposure of Korean twitter and facebook users. Personally identifiable information such as e-mail and phone numer is exposed in the accounts less than 1%. However there are many cases that a person is identified by non personally identifiable information. For example, 350 thousands accounts are distinguished with other accounts because its name is unique. Using combination of information such as name and high school, we can distinguish 2.97 millions accounts. We also found 170 thousands account pairs that are candidate of one users' own account. Linkability between two accounts in two different domains means that the person is identified. Currently, only personally identifiable information is protected by policy. This paper shows that the policy has limited effects under the circumstances that a person can be identified by non personally identifiable information and the account linking is possible.

• Journal of KIISE:Computing Practices and Letters
• /
• v.16 no.3
• /
• pp.289-300
• /
• 2010

Recently, diverse information which are location, call history, SMS history, photographs, and video can be collected constantly from mobile devices such as cellular phone, smart phone, and PDA. There are many researchers who study services for searching and abstraction of personal daily life with contextual information in mobile environment. In this paper, we introduce MyLifeBrowser which is developed in our previous work. Also, we explain LPS and correction of GPS coordinates as extensions of previous work and show LPS performance test and evaluate the performance of expanded keywords. MyLifeBrowser which provides searching personal information in mobile device and support of detecting related information according to a fragmentary keyword and common knowledge in ConceptNet. It supports the functionality of searching related locations using Bayesian network that is designed by the authors. In our experiment, we visualize real data through MyLifeBrowser and show the feasibility of LPS server and expanded keywords using both Bayesian network and ConceptNet.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2013.05a
• /
• pp.467-470
• /
• 2013

Telecommunication cost have been increasing successively in Korean hoseholds and its level is high now. Even though here are a lot of issues related to the high bill of mobile telecommunication services, plausible solutions have not been provided yet. 99% of Koreans use mobile phones and it is the highest rate in the world, but bill is relatively high. This situation may be brought by the government policy selection that it supports three mobile telecom companies systems. Thus least efficient company should be supported to sustain by pricing policy and MVNO cannot come into the market. The government can make mobile pricing system consider revenue and cost only in proper manner and constrain marketing cost in the rational level. And it can reduce mobile bill levels and selection rights of consumers by restraining too much complicated bill system. Fairness of mobile phone bill levels could be achieves by mobile telecommunication structure improvement through active MVNOs and reduction of excessive marketing costs. Mobile bills can be made more acceptable if the base is measured rate system.

• Journal of KIISE:Computing Practices and Letters
• /
• v.14 no.3
• /
• pp.261-265
• /
• 2008

As increasing the user of VoIP service using ITSP(Internet Telephony Service Provider), the VoIP spam becomes a big problem. The spam used in the existing public telephone is detected by using the pattern inspection of call behavior because it is difficult to filter contents for the characteristic of real-time voice communication. However there is a false-positive problem. The threat on spam remains where spam with low threshold can't be detected or users share one number. In this paper, we propose anti-spam for VoIP based on luring test. The proposed method gives a user luring test and he/she can connect to a receiver if passing turing test. A ticket is given to a user that pass luring test and it reduces overhead of luring test in re-dial. The proposed method is implemented on ASUS WL-500G wireless router and Asterisk IP-PBX. Experimental results show the effectiveness of the proposed method.

• Journal of the Korea Society of Computer and Information
• /
• v.13 no.4
• /
• pp.221-230
• /
• 2008

We Studied current Flight Information System everyone employing, and this paper designed a next generation Ubiquitous Flight Information System. Studied a Ubiquitous Flight Information System regarding AVOD, game TV, cellular phone, cabin Internet use for a customer, and airline and control of Air Traffic Service, Air Traffic Control, in seat reservation, transportation, ticketing and luggage back-tracking and airplanes in earthly service. We Designed for a Next Generation Ubiquitous Flight Information System and for necessary for network security, system security of information security system, and derived from comparative analysis of improvement point and difference to existing Ubiquitous Flight Information System and Next Generation Ubiquitous Flight Information as was based on result of research. Present vision to aerial the result of research world of this paper related industry, and ensure safety and communication efficiency and a customer and flight satisfaction, efficiency, and will reclaim the new horizon to the Flight Information Industry.

• The Journal of the Acoustical Society of Korea
• /
• v.18 no.6
• /
• pp.77-83
• /
• 1999

H.263 is an international standard of ITU-T that can makes the service such as video phone, video conference in the transmission line less than 64Kbps. This recommendation draft has used motion estimation/compensation, transform coding and quantizing methods. TMN5 used for the performance estimation of H.263 has fundamentally used DCT in transform coding method and presented quantizer for quantizing the DCT transform coefficient. This paper is presenting adaptive quantizer effectively able to quantize DCT coefficient considering the human visual sensitivity while the structure of TMN5 is maintaining. As quantizer that proposed DCT-based H.263 could make transmit more frame than TMN5 in a same transfer speed, it could lower the frame drop effect. And the luminance signal appeared the difference of -0.3 ～ +0.7dB in the average PSNR for the estimation of objective image quality and the chrominance signal appeared the improvement in about 1.5dB in comparision with TMN5. As a result it can attain the better image quality compared to TMN5 in the estimation of subjective image quality.

• Journal of Digital Contents Society
• /
• v.16 no.6
• /
• pp.917-925
• /
• 2015

WebRTC is one of the most recent technologies that supports browser-to-browser for voice calling, video chat, and P2P file sharing without the need of either internal or external plugins. However, there has some limitation which lets our development deal with many problems. This research will focus just on a small field of that problem which is bandwidth. While the bandwidth for downloading and uploading is fixed by service providers, but the number of users in a certain area is increasing largely by the time. In this paper, we propose a model to overcome the limitation of the bandwidth based on fuzzy control to adjust utilized bandwidth by changing frame rate and resolution of streaming video in the client itself.