• Journal of the Institute of Convergence Signal Processing
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• v.8 no.3
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• pp.192-198
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• 2007

In this paper, a new method to reduce the size of ROM in the direct digital frequency synthesizer(DDFS) is proposed. The new ROM compression method can reduce the ROM size by using the two ROM. The quantized value of sine is stored by the quantized-ROM(Q-ROM) and the differential ROM(D-ROM). To reduce the ROM size, we use the differential quantization technique with this two ROM. First, we quantize the quarter sine wave with the $2^L$ address and store the quantized value at the Q-ROM. Second, after the $2^L$ address are equally divided into $2^M$ sampling intervals, the sampling value is quantized. And the D-ROM store only the difference between this quantized value and the Q-ROM. So the total size of the ROM in the proposed DDFS is significantly reduced compared to the original ROM. The ROM compression ratio of 67.5% is achieved by this method. Also, the power consumption is affected mostly by this ROM reduction.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.41 no.5
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• pp.99-105
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• 2004

A shared-capacitor charge-sharing ROM (SCCS-ROM) using dummy bit lines is proposed. The SCCS-ROM reduces the bit line swing voltage using the charge-sharing technique of the conventional charge-sharing ROM (CS-ROM). Although the CS-ROM needs three small capacitors per output bit, the proposed SCCS-ROM shares the capacitors so that it needs only three capacitors. The SCCS-ROM implements the capacitors using dummy bit lines. This not only increases noise immunity but also reduces power. A SCCS-ROM with 8K${\times}$15bits implemented in a 0.35${\mu}{\textrm}{m}$ CMOS process. The SCCS-ROM consumes 8.63㎽ at 100MHz with 3.3V The simulation results show that the SCCS-ROM reduces 8.4% power compared to the CS-ROM.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.6 no.2
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• pp.126-137
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• 2007

In this paper, a new method to reduce the size of ROM in the direct digital frequency synthesizer(DDFS) is proposed. And we design the phase-to-sine converter using the phase accumulator of parallel type for generating the high frequency. The new ROM compression method can reduce the ROM size by using the two ROM. The quantized value of sine is saved by the quantized-ROM(Q-ROM) and the differential ROM(D-ROM). So the total size of the ROM in the proposed DDFS is significantly reduced compared to the original ROM. The ROM compression ratio of 67.5% is achieved by this method. Also, the power consumption is decreased according to the ROM size reduction.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.10a
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• pp.401-404
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• 2009

In this paper, a new method to reduce the size of ROM in the direct digital frequency synthesizer(DDFS) is proposed. The new parallel ROM compression method can reduce the ROM size by using the two ROM. The quantized value of sine is stored by the quantized-ROM and the differential ROM. To reduce the ROM size, we use the differential quantization technique with this two ROM. So the total size of the ROM in the proposed DDFS is significantly reduced compared to the original ROM. The ROM compression ratio of 67.5% is achieved by this method. Also, the power consumption is affected mostly by this ROM reduction.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.41 no.8
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• pp.99-104
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• 2004

This paper proposes a new error pattern ROM (EP-ROM) compression method for continuousdata. The EP-ROM reduces the ROM size by dividing the continuous data into coarse values and their errors and by storing the indices of error patterns instead of the non. This method significantly reduces the ROM size by exploiting the characteristic that the errors for continuous data possess the same patterns. The experiment results show that the EP-ROM achieves 60∼77% ROM size reductions for various continuous data.

• Journal of the Institute of Convergence Signal Processing
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• v.12 no.4
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• pp.291-297
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• 2011

In this paper, the differential quantized method and the parallel method to reduce the size of ROM in the direct digital frequency synthesizer(DDFS) is proposed And we design the DDFS by FPGA The new ROM compression method can reduce the ROM size by using the two ROM. The quantized value of sine is saved by the quantized-ROM(Q-ROM) and the differential ROM(D-ROM). Also we design the phase-to-sine converter using the phase accumulator of parallel type for generating the high frequency. So the total size of the ROM in the proposed DDFS is significantly reduced compared to the original ROM The ROM compression ratio of 67.5% is achieved by this method. Also, the power consumption is decreased according to the ROM size reduction and we can design the DDFS generating the high frequency.

• Journal of the Korean Society for Library and Information Science
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• v.35 no.4
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• pp.5-23
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• 2001

The purpose of this research is to survey the current status of CD-ROM acquisitions and use at public libraries. For this purpose, the questionnaires prepared to examine the information environments, CD-ROM acquisitions and use as well as the future plans for CD-ROM use were sent to seven public libraries in Daegu. This paper consists of the introduction, the characteristics and trends of CD-ROM publications, the present status of CD-ROM publishing in Korea, and the analyses of acquisitions and use of CD-ROMs at public libraries. It is intended to find out if there is any relationship between CD-ROM publishing and CD-ROM use at public libraries. It concludes that the CD-ROM collections of public libraries are related to the publishing of CD-ROM, but the use of CD-ROMs cannot be claimed to reflect the publishing. Some interpretations and recommendations for the results are suggested.

• Journal of Information Management
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• v.25 no.3
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• pp.1-27
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• 1994

CDLIB system, a CD-ROM network system constructed in the KTRC, made all the users connected with KTRC TRAN share the many CD-ROM drives and the massive information on the CD-ROM discs. The system is composed of CD-ROM network server, file server and the software which allows the users to retrieve CD-ROM discs through the network. This system has the following strong points : cost-effectiveness in the aspect of sharing the CD-ROM resources in the LAN environment and high system performance.

• Journal of Information Management
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• v.25 no.4
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• pp.36-55
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• 1994

This study discussed extensively the CD-ROM evaluation criteria that are necessary for library and information center to acquire the CD-ROM products. The evaluation criteria discussed in previous studies are divided into managerial and technical aspects, and especially the search software and user interface catagories in the technical aspect are investigated separately. Finally the basic checklist is suggested for the evaluation of CD-ROM product in appendix.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.10
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• pp.1179-1182
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• 2016

In this paper, a new method to reduce the size of ROM in the direct digital frequency synthesizer (DDFS) is proposed. This method use the sine-linear phase difference method and differential PCM. The new ROM compression method can reduce the ROM size by using the two ROM. The quantized value of sine-linear phase difference is saved by the ROM1 of the $2^N$ sample period. The ROM2 save the difference between the original sine-linear phase difference value and the saved sample value of the ROM1. The ROM compression ratio of 37% is achieved by this method. Also, the power consumption is decreased according to the ROM size reduction.