• Journal of Communications and Networks
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• v.16 no.2
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• pp.140-145
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• 2014

In this paper, we propose an anti-interference cooperative spectrum sharing strategy for cognitive system, in which a secondary system can operate on the same spectrum of a primary system. Specifically, the primary system leases a fraction of its transmission time to the secondary system in exchange for cooperation to achieve the target rate. To gain access to the spectrum of the primary system, the secondary system needs to allocate a fraction of bandwidth to help forward the primary signal. As a reward, the secondary system can use the remaining bandwidth to transmit its own signal. The secondary system uses different bandwidth to transmit the primary and its own signal. Thus, there will be no interference felt at primary and secondary systems. We study the joint optimization of time and bandwidth allocation such that the transmission rate of the secondary system is maximized, while guaranteeing the primary system, as a higher priority, to achieve its target transmission rate. Numerical results show that the secondary system can gain significant improvement with the proposed strategy.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.5
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• pp.2015-2028
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• 2016

In this paper, we propose a sum transmission rate maximization based cooperative spectrum sharing protocol with quality-of-service (QoS) support for both of the primary and secondary systems, which exploits the situation when the primary system experiences a weak channel. The secondary transmitter ST_b which provides the best performance for the primary and secondary systems is selected to forward the primary signal. Specifically, ST_b helps the primary system achieve the target rate by using a fraction of its power to forward the primary signal. As a reward, it can gain spectrum access by using the remaining power to transmit its own signal. We study the secondary user selection and optimal power allocation such that the sum transmission rate of primary and secondary systems is maximized, while the QoS of both primary and secondary systems can be guaranteed. Simulation results demonstrate the efficiency of the proposed spectrum sharing protocol and its benefit to both primary and secondary systems.

• Journal of the Korean Society for Library and Information Science
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• v.33 no.1
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• pp.145-160
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• 1999

The literature may be divided into two broad categories : primary and secondary literature. Primary literature comprises documents which contain the full text of the author's work. On the other hand secondary literature, such as indexes, abstracts, bibliographies reviews and surveys, provides signposts to the primary literature. This paper intended to examine and analyze the relationship between primary and secondary literature through the previous research and the theory, and the actual study which compared it with the lists of journals in three secondary literatures: Library and Information Science Abstracts(LISA). 1998; Library Literature (LL), 1998; Information Science Abstracts (ISA), 1998. Some of the problem involved in the study of journal overlap and coverage patterns of secondary services are discussed. Conclusions are drawn about the impact on library and information science selection policies and organization of library collections.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.7 no.9
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• pp.2081-2100
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• 2013

In this paper, we propose a cooperative hybrid spectrum sharing protocol by jointly considering interweave (opportunistic) and underlay schemes. In the proposed protocol, secondary users can access the licensed spectrum along with the primary system. Our network scenario comprises a single primary transmitter-receiver (PTx-PRx) pair and a group of M secondary transmitter-receiver (STx-SRx) pairs within the transmission range of the primary system. Secondary transmitters are divided into two groups: active and inactive. A secondary transmitter that gets an opportunity to access the secondary spectrum is called "active". One of the idle or inactive secondary transmitters that achieves the primary request target rate $R_{PT}$ will be selected as a best decode-and-forward (DF) relay (Re) to forward the primary information when the data rate of the direct link between PTx and PRx falls below $R_{PT}$. We investigate the ergodic capacity and outage probability of the primary system with cooperative relaying and outage probability of the secondary system. Our theoretical and simulation results show that both the primary and secondary systems are able to achieve performance improvement in terms of outage probability. It is also shown that ergodic capacity and outage probability improve when the active secondary transmitter is located farther away from the PRx.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.6 no.10
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• pp.2455-2472
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• 2012

Although underlay spectrum sharing has been shown as a promising technique to promote the spectrum utilization in cognitive radio networks (CRNs), it may suffer bad secondary performance due to the strict power constraints imposed at secondary systems and the interference from primary systems. In this paper, we propose a two-phase based cooperative transmission protocol with the interference cancellation (IC) and best-relay selection to improve the secondary performance in underlay models under stringent power constraints while ensuring the primary quality-of-service (QoS). In the proposed protocol, IC is employed at both the secondary relays and the secondary destination, where the IC-based best-relay selection and cooperative relaying schemes are well developed to reduce the interference from primary systems. The closed-form expression of secondary outage probability is derived for the proposed protocol over Rayleigh fading channels. Simulation results show that, with a guaranteed primary outage probability, the proposed protocol can achieve not only lower secondary outage probability but also higher secondary diversity order than the traditional underlay case.

• The Korean Society of Law and Medicine
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• v.11 no.1
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• pp.117-143
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• 2010

Along with the development of digital technologies, the information obtained during the medical procedures was working as a source of valuable assets. Especially, the secondary use of personal health information gives the ordeal to privacy protection problems. In korea, the usage of personal medical information is basically regulated by the several laws in view of general and administrative Act like Medicine Act, Public institutions' personal information protection Act, Information-Network Act etc. There is no specific health information protection Act. Health information exchange program for the blood donor referral related with teratogenic drugs and contagious disease and medical treatment reporting system for income tax convenience are the two examples of recently occurred secondary use of health information in Korea. Basically the secondary use of protected health information is depend on the risk-benefit analysis. But to accomplish the minimal invasion to privacy, we need to consider collection limitation principle first. If the expected results were attained with alternative method which is less privacy invasive, we could consider the present method is unconstitutional due to the violation of proportionality rule.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.05a
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• pp.273-276
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• 2014

In 2014, the leakage of personal information from 3 credit card companies resulted in divulging approximately 10,000 customers' personal information. Although the credit card companies concluded that there was no secondary loss due to the leakage of personal information, secondary financial losses resulting from the leakage of personal information currently occur. In particular, hackers who employ smishing masquerade acquaintances by using the divulged personal information to ask payment for Ms. Kim's Sochi Olympics legal processing or exposed traffic violations. The hackers cause secondary financial losses through smartphones. This study aims to conduct a forensic analysis of smishing incidents in smartphones through the leakage of personal information, and to make a forensic analysis of financial losses due to the smishing incidents.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.33 no.4
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• pp.115-137
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• 2022

This research aims to suggest the way of activation of book curation in secondary school libraries by analyzing examples of book curation and the recognition of the persons in charge of secondary school libraries. A documentary research and a survey is conducted. 192 school librarians are chosen for that survey in Incheon region secondary school. 4 teacher librarians of Incheon region secondary school and a professor of library and information science are interviewed. Also an investigation is executed by visiting school libraries. Augmentation of the persons in charge of secondary school libraries, coordinating and information sharing with educational teachers, establishment of manual for book curation operation, publishing examples of subject selection are suggested for the measure of activation of book curation.

• Proceedings of the IEEK Conference
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• 2004.08c
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• pp.552-557
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• 2004

Mobile Ad Hoc Network (MANET) is a network architecture, which has no backbone network and is deployed temporarily and rapidly in emergency or war without fixed mobile infrastructures. All communications between network entities are carried in ad-hoc networks over the wireless medium. Due to the radio communications being extremely vulnerable to propagation impairments, connectivity between network nodes is not guaranteed. Therefore, previously developed routing algorithms in wired networks cannot be used. And many new algorithms have been undergone. This study proposes the secondary leader approach to the cluster based routing protocol(CBRP). In case, the primary leader becomes abnormal status so that the primary leader cannot participate the communications between network entities, the secondary leader immediately replaces the primary header without selecting process of the new primary leader. The performances of proposed algorithm ACBRP(Advanced Cluster. Based Routing Protocol;CBRP using secondary leader) are compared with CBRP and results are presented in order to show the effectiveness of the algorithm.

• Journal of information and communication convergence engineering
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• v.9 no.6
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• pp.641-646
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• 2011

In this paper, we investigate a power control problem which is very critical in underlay-based spectrum sharing systems. Although an underlay-based spectrum sharing system is more efficient compared to an overlay-based spectrum sharing system in terms of spectral utilization, some practical problems obstruct its commercialization. One of them is a real-time-based power adaptation of secondary transmitters. In the underlay-based spectrum sharing system, it is essential to adapt secondary user's transmit power to interference channel states to secure primary users' communication. Thus, we propose a practical power control scheme for secondary transmitters. The feedback overhead of our proposed scheme is insignificant because it requires one-bit signaling, while the optimal power control scheme requires the perfect information of channel states. In addition, the proposed scheme is robust to feedback delay. We compare the performance of the optimal and proposed schemes in terms of primary user's outage probability and secondary user's throughput. Our simulation results show that the proposed scheme is almost optimal in terms of both primary user's outage probability and secondary user's throughput when the secondary user's transmit power is low. As the secondary user's transmit power increases, the primary user's outage probability of the proposed scheme is degraded compared with the optimal scheme while the secondary user's throughput still approaches that of the optimal scheme. If the feedback delay is considered, however, the proposed scheme approaches the optimal scheme in terms of both the primary user's outage probability and secondary user's throughput regardless of the secondary user's transmit power.