• Journal of KIISE:Computer Systems and Theory
• /
• v.31 no.9
• /
• pp.536-542
• /
• 2004

An architecture of direct digital frequency synthesizers (DDFS) is studied in this paper The Direct digital frequency synthesizers (DDFS) provide fast frequency switching with high spectral purity and are widely used in modern spread spectrum wireless communication systems. ROM-based DDFS uses a ROM lookup table to store the amplitude of a sine wave. In this paper, we suggest three new techniques to reduce the ROM size. One new technique uses more number of hierarchical levels in ROM structures. Another techniques use simple interpolation techniques combined with hierarchical ROM structures. A 12 bit sine wave is generated by using these techniques. Experimental results show that the new proposed techniques can reduce the required ROM size by up to 24%, when compared to that of a resent method[1].

• Proceedings of the IEEK Conference
• /
• 1999.11a
• /
• pp.267-270
• /
• 1999

In this paper, a new method to reduce the size of ROM in the direct digital frequency synthesizer (DDFS) is proposed. In the case that ROM is used for sinusoidal value calculation, reducing the size of ROM is significant. So the power consumption is affected mostly by its bit width. In the proposed method, the ROM bit width is reduced by 1 bit using the phase subtraction and the approximation. The spurious level is better than 80㏈c and the power consumption estimated is 510㎼/MHz.

• Proceedings of the Korean Information Science Society Conference
• /
• 2000.04a
• /
• pp.415-417
• /
• 2000

ARM 프로세서는 이동 단말기의 표준으로 채택된 32 비트 범용 마이크로프로세서이다. 이동 단말기 내에서 ARM 프로세서는 실시간 운영체제 커널과 운영체제 그리고 API 로 구성되며 소형의 단말기에서 응용 프로그램을 운용하기 위해서는 ROM 에 응용 프로그램을 상주시켜 실행시켜야 한다. 이러한 ROM 상주를 위해서는 ROM 영역에 적재하기 위한 메모리 구성이 중요하다. 본 논문은 메모리 구성을 위한 메모리 이미지의 형성과 메모리의 맵을 통한 ROM 상주 프로그램의 적재 그리고 시스템 초기화를 통해서 응용 프로그램의 수행을 보장하는 방법론에 대해 분석한다.

• Proceedings of the KAIS Fall Conference
• /
• 2000.10a
• /
• pp.194-198
• /
• 2000

최근 저장 장치로 많이 사용되고 있는 IBM PC의 CD-ROM(Compact Disc Read Only Memory)과 MP3(MPEG-1 Layer Ⅲ Audio) 디코더 칩을 이용하여 PC 작동과 관계없이 독립적으로 작동하는 CD-ROM 기반의 MP3 Player를 구현하였다. 여기서는 CD-ROM의 규격과 CD-ROM에 사용되는 ATAPI(AT Attachment Packet Interface) Format, MPEG-1 Layer Ⅲ의 오디오 부분에 대하여 알아보고 MP3 디코더 칩을 사용하여 CD-ROM에서 읽은 MP3 데이터즐 재생하는 방법을 취하였다. 이리하여 PC 자체로 MP3를 작동시키는 부하를 경감시키는 효과를 얻었다.

• Journal of the Korean Society for information Management
• /
• v.7 no.2
• /
• pp.138-149
• /
• 1990

The present study is aimed at the comparative evaluation of several CD-ROM MEDLINE versions for biomedical information retrieval and searching. The CD-ROM MEDLINE has recently been introduced in Korea and is actively using for health and medical professionals as an effective delivery tool of biomedical information. And this evaluative study revealed some different advantages and disadvantages in searching information among several CD-ROM MEDLINE versions. The present study also provides some findings of CD-ROM user's information seeking behaviors.

• Journal of the Korean Society for Library and Information Science
• /
• v.34 no.1
• /
• pp.17-37
• /
• 2000

This study aims to provide a guide to the selection and purchase of a good CD-ROM encyclopedia by establishing evaluation criteria for CD-ROM encyclopedia. This study first divided evaluation criteria into the following rune categories: reviews available, print version, availability of trial disc, hardware requirements and ease of software installation, database contents, retrieval software, standalone/network version, standard/deluxe version, costs. Next, it suggested evaluation points and items in detail under each category.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.25 no.3B
• /
• pp.584-591
• /
• 2000

In distributed arithmetic-based architecture for an inner product between two length-N vectors, the size of the ROM increases exponentially with N. Moreover, the ROMs are generally the bottleneck of speed, especially when their size is large. In this paper, a ROM size reduction technique for DA( distributed arithmetic ) is proposed. The proposed method is based on modified OBC( offset binary coding) and control circuit reduction technique. by simulations, it is shown that the use of the proposed technique can result in reduction in the number of gates up to 50%.

• Journal of the Korean Society for information Management
• /
• v.9 no.1
• /
• pp.1-23
• /
• 1992

The purpose of this study is to answer a question as to "How much does CD-ROM improve thefunction of library\ulcorner" and, then, to build up an analytical framework to analyze the above question.The hypothesis is statistically tested with the responses of 282(70.5%) librarians in the libraries whichare currently using CD-ROM. The hypothesis is positively or vigorously supported by four steps.Therefore, the researcher suggests strongly at a plan to utilize CD-ROM be forwarded to improvelibrary functions. library functions.

• Journal of Korea Water Resources Association
• /
• v.33 no.6
• /
• pp.745-755
• /
• 2000

The dam operation system of KOWACO for flood control doesn't have capability to account for the downstream hydrologic conditions and any feasible index to decide the pre-release from the forecasted rainfall and inflow. In this study, a dam operation model for flood control was developed to account for the flood flow condition of its downstream to give users the dam release schedules. Application test of EV ROM to Keum River showed that EV ROM is superior to the Rigid ROM and Technical ROM which are currently used by KOWACO. EV ROM developed in this study provides a release schedule accounting for the cumulative lateral flow hydrograph at the downstream control points where the discharge does not depend only on the dam operation. but also on lateral inflow from the tributaries. In order to reduce the peak discharge at the control points, it suggests the preliminary release during the early rising phase of the predicted hydrograph, holding the flood flow inside the dam during a peak phase, and afterward resuming the release. Three case studies of flood control by the operation of Daechung Multipurpose Dam in Geum River Basin show that the EV ROM is superior to the Rigid ROM and Technical ROM. This must be due to its nature to account for the downstream flow condition as well as the inflow and water level of the dam. It was also conceived that further case studies of EV ROM and more accurate rainfall prediction would improve the dam operation for flood control.ontrol.

• The Journal of Korean Physical Therapy
• /
• v.32 no.4
• /
• pp.238-244
• /
• 2020

Purpose: This study compared the effects of the fascial distortion model (FDM), foam rolling (FR), and self-stretching (SS) on the ankle dorsiflexion range of motion (ROM). Methods: Thirty subjects who had no more than 30° of ankle dorsiflexion ROM at the weight-bearing lunge test were recruited in this study. They were divided into three groups: (FDM, FR, and SS), and underwent each intervention for five minutes. Before and after the intervention, the ankle dorsiflexion ROM in the supine (the open-) and standing (the closed-kinetic chain) of the subjects were tested. The changes in the ROM between pre- and post-intervention and among the groups were analyzed. Results: All groups showed increased ankle dorsiflexion ROM after the intervention in both positions. In the position of the open kinetic chain, the changes in the ROM between pre- and post-intervention had significant differences among the groups, and the FDM was higher than the FR and SS. In the position of the closed kinetic chain, the ROM after the interventions and the changes in the ROM had significant differences among the groups, and FDM was higher than the FR (ROM after the intervention, the change in ROM) and SS (the change in ROM). Conclusion: These findings showed that FDM had more efficiency than the FR and SS as FDM had a stronger effect on increasing ankle dorsiflexion in a short, limited time. Clinicians who have limited time to treat their patients, particularly trying to increase ankle dorsiflexion ROM, should consider the application of FDM.