• Journal of Korean Library and Information Science Society
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• v.27
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• pp.61-95
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• 1997

The purpose of this paper is to overview a recent dispute of the library of the 21st century in Korea and to suggest a desirable model of the future library. There are two visions of the future of library. The first is an access based library model(digital library) emphasizing the digital resources that are networked and browsable electronically. The second is an ownership-based library model(paper library) which emphasize the use of traditional print collections stored locally and physically browsable. A points of dispute between the paper library as storehouse and the digital library as gateway are an electronic informations versus printed materials, access versus ownership, information professional versus librarians. The idea that library as physical place and as cyberspace are diametrically o n.0, pposed is a fallacy and surrealistic opinion. Future library has to acquire, organize, preserve, and make accessible the collections that users want and need. In other words, future libraries need both ownership and access. Access to remote electronic resources must serve as a reasonable substitute for holdings of older material. Therefore, it is a balanced solution that the more heavily used or important materials be considered for ownership and selective information resources for access. No doubt, the traditional library and the digital library will be coexist in the 21 century.

• The Transactions of the Korea Information Processing Society
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• v.4 no.12
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• pp.3123-3132
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• 1997

In this paper, we describe access control system for protection of pay TV program in digital DBS(Direct Broadcast satellite) system. We also propose a possible access control system and operation scenario for scrambling and descrambling which are important in access control system. Transport stream structure and option, entitlement checking message and entitlement management message for access control on digital broadcasting system are described in this paper. Especially, the authentication based on Flat-Shamir and Gulllou-Quisquater schemes required for verification of proper subscriber as access control is oriented to smart card number and subscriber ID(Identity). It has less restriction than scheme oriented to descrambler number.

• Journal of Communications and Networks
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• v.5 no.4
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• pp.374-385
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• 2003

The growing interest towards ultra-wideband (UWB) communications stems from its unique features such as baseband operation, ample multipath diversity, and the potential of enhanced user capacity. But since UWB has to overlay existing narrowband systems, multiple access has to be achieved in the presence of narrowband interference (NBI). However, existing baseband spreading codes for UWB multiple access are not flexible in handling NBI. In this paper, we introduce two novel spreading codes that not only enable baseband UWB multiple access, but also facilitate flexible NBI cancellation. We construct our codes using a single carrier or multiple carriers (SC or MC), which can be implemented with standard discrete-cosine transform (DCT) circuits. With our SC/MC codes, NBI can be avoided by simply nulling undesired digital carriers. Being digital, these SC/MC codes give rise to multiband UWB systems, without invoking analog carriers. In addition, our SC/MC codes enable full multipath diversity, and maximum coding gains. Equally attractive is their capability to reduce the number of interfering users, with simple matched filter operations. Comprehensive simulations are also carried out to corroborate our analysis.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.778-781
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• 2005

In this paper, we describe a development of a Bluetooth Access Point for the WAN connection of home network devices. Especially, users can access the PSTN at home instead of expensive digital cellular network through the AP, using the 'one-phone', which is the Bluetooth enabled cellular phone. The simultaneous benchmark test about telephone service and LAN access service shows the perfect compatibility and reasonable performance of the access point. The one-phone service can become a convergence of wired and wireless communication through the AP.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.33A no.7
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• pp.76-91
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• 1996

In this paper, we proposed the new medium access control protocol for the virtual token bus netowrk. The network is applied to inter-processor communication network of large capacity digital switching system and digital mobile system with distributed control architecture. in the virtual token bus netowrk, the existing medium access control protocols hav ea switchove rtime overhead when traffic load is light or asymmetric according ot arbitration address of node that has message to send. The proposed protocol optimized average message delay using cyclic bus access chain to exclude switchover time of node that do not have message to send. Therefore it enhanced bus tuilization and average message delay that degrades the performance of real time communication netowrks. It showed that the proposed protocol is more enhacned than virtual token medium access control protocol and virtual token medium access control protocol iwth reservation through performance analysis.

• Journal of Korea Society of Digital Industry and Information Management
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• v.7 no.4
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• pp.57-66
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• 2011

We implemented the document DRM applying role based access control(RBAC) mechanism for preventing the information leakage of a document which is transmitted in network environment. It must prevent to access document not related to user role and duty, and must allow operation to document for improving security, considering user role and security level according to a document importance. We improved the security of document DRM by adding to the access control module applying RBAC for satisfying security requirements. Though the user access document, our system allows operation authorizations to document by the user's role & security level and the security attribute of RBAC. Our system prevents indiscriminate access to the documents by user who is not associated with the role, and prevents damage the confidentiality and integrity.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.12
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• pp.5601-5613
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• 2011

The purpose of this paper is to better understand the socio-economic differentials of Internet access and use. Data from '2008 Korean Internet usage behavior' were used to conduct logistic regression analysis. The findings show that there are significant socio-economic(age, gender, educational attainment, employment situation, and Internet access type) disparity in Internet access(Internet access at home, broadband Internet access). Also socio-economic variables enter in as statistically significant in most specifications for Internet use intensity (Intensive internet use, frequent internet use, less frequent internet use). The gender, household income and education attainment explanations for large differential in Internet use intensity are generally very similar. It is shown that age, education attainment and household income level cause a large digital divide on Internet service use(information use, communication and community use, e-commerce use, Internet banking use).

• Journal of Communications and Networks
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• v.7 no.2
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• pp.135-143
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• 2005

This paper presents an investigation of satellite radio access technology for beyond IMT-2000 systems. Although we could not see any active role of a satellite system in the 3G networks, satellite system will provide strong advantages in future systems for certain applications. Because a satellite link has longer round trip delay than a terrestrial link, we need technologies that would make the satellite component especially efficient. After presenting the satellite radio interface of the 3G system, we suggest several points which need to be considered in the beyond 3G systems. We also suggest a few candidate technologies with various simulation results.

• Healthcare Informatics Research
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• v.24 no.4
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• pp.253-262
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• 2018

Objectives: We reviewed digital epidemiological studies to characterize how researchers are using digital data by topic domain, study purpose, data source, and analytic method. Methods: We reviewed research articles published within the last decade that used digital data to answer epidemiological research questions. Data were abstracted from these articles using a data collection tool that we developed. Finally, we summarized the characteristics of the digital epidemiological studies. Results: We identified six main topic domains: infectious diseases (58.7%), non-communicable diseases (29.4%), mental health and substance use (8.3%), general population behavior (4.6%), environmental, dietary, and lifestyle (4.6%), and vital status (0.9%). We identified four categories for the study purpose: description (22.9%), exploration (34.9%), explanation (27.5%), and prediction and control (14.7%). We identified eight categories for the data sources: web search query (52.3%), social media posts (31.2%), web portal posts (11.9%), webpage access logs (7.3%), images (7.3%), mobile phone network data (1.8%), global positioning system data (1.8%), and others (2.8%). Of these, 50.5% used correlation analyses, 41.3% regression analyses, 25.6% machine learning, and 19.3% descriptive analyses. Conclusions: Digital data collected for non-epidemiological purposes are being used to study health phenomena in a variety of topic domains. Digital epidemiology requires access to large datasets and advanced analytics. Ensuring open access is clearly at odds with the desire to have as little personal data as possible in these large datasets to protect privacy. Establishment of data cooperatives with restricted access may be a solution to this dilemma.

• ETRI Journal
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• v.26 no.3
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• pp.265-268
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• 2004

We develop a simple exact solution method for return link capacity allocation scheduling in a satellite interactive network using a hybrid code-division multiple access / time-division multiple access (CDMA/TDMA) scheme.