• The Journal of Korean Institute of Communications and Information Sciences
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• v.38A no.4
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• pp.325-336
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• 2013

FlashLinQ, one of the typical D2D communication systems developed by Qualcomm, considers a single-tone communication based distributed channel-aware link scheduling method to realize the link scheduling process with low control overheads. However, considering the frequency selective fading effect of practical multi-path channel, the single-tone based SIR estimation causes a critical scheduling error problem because the received single-tone signal has quite different channel gain at each sub-carrier location. In order to overcome this problem, we propose a novel link scheduling method based on CAZAC (Constant Amplitude Zero Auto-Correlation) sequence for D2D communication system. In the proposed method, each link has a unique offset value set for the generation of CAZAC sequences. CAZAC sequences with the cyclic offsets are transmitted using multiple sub-blocks in the entire bandwidth, and then each device can obtain nearly full-band SIR using a good cyclic cross-correlation property of CAZAC sequence.

• Journal of the Korean Society for Library and Information Science
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• v.21
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• pp.103-140
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• 1991

Knowledge about career patterns of women In any profession and about factors which influence these career patterns becomes increasingly necessary because of the influx of ever-increasing numbers of women into the labor force, and the need for the development and utilization of the creative productivity of women. This study alms to investigate Korean female librarians' overall career patterns and verify relevant factors which might affect to their career patterns. As an instrument, self-reported questionnaires were sent to 1,251 full-time Korean female librarians throughout the country with regular librarian's certificate, currently engaging in public, college or university, and special libraries. Based on the data gathered, the interrelationship between their career pattern inclination and its influential factors were examined through hypothesis testing. Major findings of the survey are outlined in the following: 1). Female librarians' career patterns were classified into five categories with the group represented as Categories-2 (single; wishes to continue working after marriage; places an emphasis on the sense of occupational accomplishment and social prestige) accounted for the highest proportion$(33.4\%)$. 2). The result of the hypothesis testing revealed that there is no significant relationship statistically between social factors(parents' socio-economic status, etc.) and female librarians' career patterns. So the hypothesis concerning social factors were rejected. 3). In psychological factors(job satisfaction ; self-concept sex role attitude ; role conflict ; and achievement motivation), all except for self-concept were shown to be relevant with female librarians' stable career pattern. So the hypotheses concerning psychological factors were supported. 4). According to the result of multiple discriminant analysis conducted between the above four statistically significant psychological factors and career patterns, the most influential factor for female librarians' career patterns was job satisfaction and sex role. In conclusion, the following recommendations were made: For overall enhancement of Korean female librarianship, earlier career guidance and concrete sex role education for young women is urgent which enable them to establish correct viewpoint for their occupational career female librarians themselves' constant endeavor In maintaining positive attitude toward their job is required.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.2
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• pp.321-327
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• 2006

This paper presents low power and high frequency design of instructions using ad-hoc techniques at transistor level for full custom and semi-custom ASIC(Application Specific Integrated Circuit) designs. The proposed design has been verified at high level using Verilog-HDL and simulated using ModelSim for the logical correctness. It is then observed at the layout level using LASI using $0.25{\mu}m$ technology and analyzed for timing characteristic under Win-spice simulation environment. The result shows the significant reduction up to $35\%$ in the power consumption by any general purpose processor like RISC or CISC. A significant reduction in the propagation delay is also observed. increasing the frequency for the fetch and execute cycle for the CPU, thus increasing the overall frequency of operation.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.7 no.8
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• pp.1792-1801
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• 2003

In these days, image mosaic is getting interest in the field of advertisement, tourism, game, medical imaging, and so on with the development of internet technology and the performance of personal computers. The main problem of mage mosaic is searching corresponding points correctly in the overlapped area between images. However, previous methods requires a lot of CPU times and data processing for finding corresponding points. And they need repeated recording with a revolution of 360 degree around objects or background. This paper presents a new image mosaic method which generates a panorama image from a video sequence recorded by a general video camera. Our method finds the corresponding points between two successive images by using a new direction oriented 3­step block matching methods. Experimental results show that the suggested method is more efficient than the methods based on existing block matching algorithm, such as full search and K­step search algorithm.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.9
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• pp.2209-2215
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• 2014

This paper presents, a deinterlacing method by improving the Direction-Oriented Interpolation (DOI) technique. The technique is considered to be a very strong tool for intrafield-based deinterlacing. However, DOI has some problems such as long processing time, wrong edge detection in periodic pattern. To remedy this problem, we replace the full search in DOI by a two-step search to reduce processing time and introduces two additional processes to improve image quality. In the proposed method, the spatial direction vectors (SDVs) misread data are reconsidered to prevent them utilizing in the next interpolation step, resulting in an accurate deinterlacing method. We conduct experiments with ISO experimental images to compare the proposed method with the existing methods including line evarage (LA), edge-based line averaging (ELA), DOI, selective deinterlacing algorithm (SDA). Experimental results show the proposed method gives better performance in objective and subjective quality than existing deinterlacing methods.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.6A
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• pp.870-884
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• 2000

Among OLAP(On-Line Analytical Processing) approaches, ROLAP(Relational OLAP) based on the star, snowflake schema which offer the multidimensional analytical method has performance problem and MOLAP (Multidimensional OLAP) based on Multidimensional Database System has scalability problem. In this paper, to solve the limitaions of previous approaches, design and implementation of multidimensional data model based on Object-Relation DBMS was proposed. With the extensibility of Object-Relation DBMS, it is possible to advent multidimensional data model which more expressively define multidimensional concept and analysis functions that are optimized for the defined multidimensional data model. In addition, through the hierarchy between data objects supported by Object-Relation DBMS, the aggregated data model which is inherited from the super-table, multidimensional data model, was designed. One these data models and functions are defined, they behave just like a built-in function, w th the full performance characteristics of Object-Relation DBMS engine.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.17 no.11
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• pp.1320-1331
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• 1992

The error rate equation of FH/MFSK signal of repeated diversity received over m-distribution fading channel with partial-band interference has been derived and the error rate has been evaluated to show in figures as a function of signal to noise ratio, signal to interference ratio, fading figure, repeated number, partial-band interference fraction and power correlation coefficient between signal and interference. In this paper, we assumed that repeated diversity technique is used in transmitter against fading occurred in mobile radio channel. By comparing the error rate performance in diversity against fading and the obtainable degree of improvement of error performance with diversity technique has been found out. From the result, it is known that error rate performance deteriorates more as $\rho$ becomes small i.e., the partial-band interference gives more effect on error performance than full-band interference. Also when the values of $E_b/N_1$ and $\rho$ are small. as depth of fading diversity technique.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38A no.9
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• pp.810-816
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• 2013

In this paper, we propose a SSD (simultaneous single-band duplex) system using Digital Cancellation. Also, we propose a method for Digital Cancellation when RF Cancellation is effectively performed. The proposed system has estimation frame for effective self-interference channel estimation in time-domain. The proposed system calculates signal power for selection of optimal coefficient after digital cancellation. Then, the proposed system selects coefficient of minimum signal power. Further, the proposed system uses LDPC code to minimize the effects of remaining self-interference signal. The proposed system shows BER performance of at 20dB by cancelling self-interference and iterating LDPC code. That is, the proposed system shows that the SSD communication is possible in static self-interference channel.

• The KIPS Transactions:PartA
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• v.12A no.6 s.96
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• pp.531-538
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• 2005

In the high performance Analog Information Processing Systems(AIPS), gain boosting or additional gain stage is required when the gain is not sufficient with one stage amplification. This work shows that high gain is neatly obtained by enhancing the gain using the negative resistance element. Compared to the conventional techniques, the proposed scheme enjoys full output swing, small circuit area and power consumption, and the applications to various configurations of amplifiers. The negative resistance element is placed between the differential output nodes when used in the Op-Amp. The HSPICE simulation indicates that enhancement of more than 40 dB is readily obtained in this simple configuration when the negative resistance element is implemented in the form of cross-coupled CMOS inverters.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.8
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• pp.1774-1781
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• 1997

In this paper, we propose a full digital frequency and phase locked loop for CATV and HDTV receivers adopting VSB modulation. The CATV and HDTV receivers proposed by the Grand-Alliance in USA are ultilizing analog signal processing technology for carrier recovery. By the way, it is not a good architecture for the development of single chip ASIC operating in digital domain. To solve this problem while improving the performance, we first down convert the received r.f. signal to a near baseband signal for a low-rate AD converter and then we use digital signal processing techniques. The proposed system has the frequency pull-in range of -200 KHz +2.50 KHz. Moreover, it has the ability of adaptive loop bandwidth control according to the amount of frequency offset to improve the acquisition time while reducing the phase noise.