• Journal of the Korean Institute of Telematics and Electronics
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• v.15 no.1
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• pp.23-26
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• 1978

The circuit which generates full-wave is designed throught only simple formula, and full wave is used for square-wave of which duty ratio is variable but period constant.

• Journal of information and communication convergence engineering
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• v.9 no.6
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• pp.647-651
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• 2011

In this letter, non-regenerative Amplify-and-Forward (AF) relay systems based on half and full duplex schemes are investigated and their performance is analyzed and compared in terms of outage probability. Although the AF relay systems have been widely investigated in many previous literatures, most of them adopted a half duplex scheme due to hardware limitation and mathematical tractability. To the best of our knowledge, this letter is the first study to investigate the performance of the full duplex AF relay system considering practical hardware limitations. In full duplex AF relay systems, it is important to secure the isolation between transmit and receive antennas. Our numerical and simulation results show that there exists a threshold point of the isolation gain that the full duplex relay system outperforms the half duplex relay system.

• Journal of Korean Library and Information Science Society
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• v.24
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• pp.45-79
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• 1996

Rising publication costs and declining financial resources have resulted in renewed interest among librarians in resource sharing. Although the idea of sharing resources is not new, there is a sense of urgency not seen in the past. Driven by rising publication costs and static and often shrinking budgets, librarians are embracing resource sharing as an idea whose time may finally have come. Resource sharing in electronic environments is creating a shift in the concept of the library as a warehouse of print-based collection to the idea of the library as the point of access to need information. Much of the library's material will be delivered in electronic form, or printed. In this new paradigm libraries can not be expected to su n.0, pport research from their own collections. These changes, along with improved communications, computerization of administrative functions, fax and digital delivery of articles, advancement of data storage technologies, are improving the procedures and means for delivering needed information to library users. In short, for resource sharing to be truly effective and efficient, however, automation and data communication are essential. The possibility of using full-text online databases as a su n.0, pplement to interlibrary loan for document delivery is examined. At this point, this article presents possibility of using full-text online databases as a means to interlibrary loan for document delivery. The findings of the study can be summarized as follows : First, turn-around time and the cost of getting a hard copy of a journal article from online full-text databases was comparable to the other document delivery services. Second, the use of full-text online databases should be considered as a method for promoting interlibrary loan services, as it is more cost-effective and labour saving. Third, for full-text databases to work as a document delivery system the databases must contain as many periodicals as possible and be loaded on as many systems as possible. Forth, to contain many scholarly research journals on full-text databases, we need guidelines to cover electronic document delivery, electronic reserves. Fifth, to be a full full-text database, more advanced information technologies are really needed.

• Human Ecology Research
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• v.51 no.5
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• pp.513-526
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• 2013

In an effort to protect consumers' rights to information and to promote their freedom of choice, the South Korean government has been enforcing a policy called the cosmetics full ingredients list system since 2008, which requires cosmetics manufacturers to list all of the ingredients used in their products. This policy aims to assist consumers in identifying the causes of possible side effects of cosmetic products. This study uses consumers' demographic information addition to their cosmetics purchase and usage characteristics to learn about consumers' attitudes and utilization intentions and the influence of information from the cosmetics full ingredients list. This study was conducted through a questionnaire based survey administered to women above the age of 20 years across South Korea who use cosmetic products. The questionnaire was distributed to 300 members on the panel of M Brain, an online research institute. The findings of this study are as follows: (1) The level of knowledge on cosmetics' ingredients positively affected the consumers' attitude and utilization intention of information on the cosmetics full ingredients list. (2) The higher the utilization intention for information, the more often consumers checked the packaging of goods. This implies that habitual behavior, such as checking information, leads to increasing intention to utilize of new information. (3) The brand, as a decision-making factor, negatively affected consumers' attitudes regarding information.

• Journal of the Korean Society for information Management
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• v.15 no.3
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• pp.73-93
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• 1998

Conventional full-text information retrieval system has been proved with high recall ratio and low precision ratio. One of the disadvantages of full-text IR system is that it is not designed to reflect the user's information need. It is due to the fact that full-text IR system has been designed based on physical and logical structure of document without considering the content of document. The purpose of the study is to develop more effective full-text IR system by resolving such disadvantages of conventional system. The study has developed new method of designing full-text IR system by using Content Structure Markup Language(CSML) other than conventioanal SGML.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.1
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• pp.16-33
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• 2019

In this paper, a full-duplex NOMA relaying based underlay device-to-device (D2D) communication scheme is proposed, in which D2D transmitter assists cellular downlink transmission as a full-duplex relay. Specifically, D2D transmitter receives signals from base station and transmits the superposition signals to D2D receiver and cellular user in NOMA scheme simultaneously. Furthermore, we investigate the power allocation under the proposed scheme, aiming to maximize D2D link's achievable transmit rate under cellular link's transmit rate constraint and total power constraint. To tackle the power allocation problem, we first propose a power allocation method based on linear fractional programming. In addition, we derive closed-form expressions of the optimal transmit power for base station and D2D transmitter. Simulation results show that the performance of two solutions matches well and the proposed full-duplex NOMA relaying based underlay D2D communication scheme outperforms existing full-duplex relaying based D2D communication scheme.

• Journal of the Korean Society for Library and Information Science
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• v.17
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• pp.49-83
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• 1989

A Full text retrieval system is a natural language document retrieval system in which the full text of all documents in a collection is stored on a computer so that every word in every sentence of every document can be located by the machine. This kind of IR System is recently becoming rapidly available online in the field of legal, newspaper, journal and reference book indexing. Increased research interest has been in this field. In this paper, research on full text databases and retrieval systems are reviewed, directions for research in this field are speculated, questions in the field that need answering are considered, and variables affecting online full text retrieval and various role that variables play in a research study are described. Two obvious research questions in full text retrieval have been how full text retrieval performs and how to improve the retrieval performance of full text databases. Research to improve the retrieval performance has been incorporated with ranking or weighting algorithms based on word occurrences, combined menu-driven and query-driven systems, and improvement of computer architectures and record structure for databases. Recent increase in the number of full text databases with various sizes, forms and subject matters, and recent development in computer architecture artificial intelligence, and videodisc technology promise new direction of its research and scholarly growth. Studies on the interrelationship between every elements of the full text retrieval situation and the relationship between each elements and retrieval performance may give a professional view in theory and practice of full text retrieval.

• Journal of the Korean Society for Library and Information Science
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• v.32 no.1
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• pp.129-154
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• 1998

In these days the online full-text database are increasing, but conventional full-text information retrieval system has been proved with high recall ratio and low precision ratio. One of the disadvantages of full-text IR system is that it is not designed to reflect the user's information need it is due to the fact that full-text IR system has been designed based on physical and logical structure of document without considering the content of document. Therefore, the purpose of the study examined feasibility of document content structure in full-text IR system by resolving such disadvantages of conventional system. 180 Journal articles have been analyzed to find common structure of document content and finally general model of the structure of journal articles were developed. The result shows that have relation to between user's cogntive schema structure, user's information need and contents structure of document. Thus it is concluded that full-text IR system need to be designed by using document content structure in order to meet user's information need more effectively.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.3
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• pp.451-458
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• 2015

The deployment density of AP increases as well as the density WLAN stations due to increase of WLAN use and the real performance of WLAN is degraded. To improve the performance, there are many PHY/MAC technologies and OFDMA and full duplex are promising technologies among them. In conventional OFDMA WLAN MAC relate works, there are some limitations in terms of channel utilization and collision probability. Thus, it need to research for effective channel allocation protocol. Full duplex can transmit data on the same time and same frequency resource so it can allocate channel more flexible than half duplex. In this paper, we prose the OFDMA FD-MAC(Full Duplex MAC) protocol that it allocates the sub-channels based on the idle channel information for full duplex pair. In addition, it shows the throughput improvement by performance analysis.

• Journal of Communications and Networks
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• v.18 no.6
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• pp.913-925
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• 2016

In-band wireless full-duplex is a promising technology that enables a wireless node to transmit and receive at the same time on the same frequency band. Due to the complexity of self-interference cancellation techniques, only base stations (BSs) are expected to be full-duplex capable while user terminals remain as legacy half-duplex nodes in the near future. In this case, two different nodes share a single subchannel, one for uplink and the other for downlink, which causes inter-node interference between them. In this paper, we investigate the joint problem of subchannel assignment and power allocation in a single-cell full-duplex orthogonal frequency division multiple access (OFDMA) network considering the inter-node interference. Specifically, we consider two different scenarios: i) The BS knows full channel state information (CSI), and ii) the BS obtains limited CSI through channel feedbacks from nodes. In the full CSI scenario, we design sequential resource allocation algorithms which assign subchannels first to uplink nodes and then to downlink nodes or vice versa. In the limited CSI scenario, we identify the overhead for channel measurement and feedback in full-duplex networks. Then we propose a novel resource allocation scheme where downlink nodes estimate inter-node interference with low complexity. Through simulation, we evaluate our approaches for full and limited CSIs under various scenarios and identify full-duplex gains in various practical scenarios.