• Title/Summary/Keyword: Waterfall

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Analysis of Relationship between Structure and Acoustic Character of Natural Waterfall (자연폭포의 강조와 청각적 특성의 관계분석)

  • 정성관;박정길
    • Journal of the Korean Institute of Landscape Architecture
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    • v.18 no.1
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    • pp.19-32
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    • 1990
  • The perception of landscape structure can he formed mode clearly, with including an auditory stimulus to a visual aspect. The waterfall, as an landscape element, will be considered of not only it's function and structure in landscape architecture designing but also harmony with environment which it has been situated, and contribution to the public goad. The purpose of this study was to establish more 7rational and practical design theory for the construction of waterfall. The number of subjects investigated were 47 of waterfall located in Mt. Palgong. In this study, the acoustic character of the waterfalls were investigated as an excellent effect to mask easily sensible noises. The correlations between the structure of waterfalls and water 1a17ing sound, which were useful for waterfall design and construction, were examined. It was discovered that the position of double distance of waterfall height From the waterfall is significant in the visual and acoustic perception of waterfall.

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LDPC Codes' Upper Bounds over the Waterfall Signal-to-Noise Ratio (SNR) Region

  • Chung, Kyu-Hyuk
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.33 no.11C
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    • pp.880-882
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    • 2008
  • This paper presents LDPC codes' upper bounds over the waterfall SNR region. The previous researches have focused on the average bound or ensemble bound over the whole SNR region and showed the performance differences for the fixed block size. In this paper, the particular LDPC codes' upper bounds for various block sizes are calculated over the waterfall SNR region and are compared with BP decoding performance. For different block sizes the performance degradation of BP decoding is shown.

A study on waterfall classification by form and processes (폭포의 지형학적 분류에 관한 연구)

  • PARK, Kyeong;KIM, Ji Young
    • Journal of The Geomorphological Association of Korea
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    • v.21 no.4
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    • pp.85-96
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    • 2014
  • A waterfall is a channel unit with steep bedrock. No strict criteria for height, water volume, gradient to define waterfalls exist in Korea. The goal of our study is to classify waterfalls based on morphological forms which are the outcomes of developmental processes. The genesis of waterfall depends upon erosional properties of waterfall. The height, gradient, bedrock strength and stream power of waterfalls are regarded as the main factors, by which waterfalls can be classified. We find out that the most important factor for the development of waterfalls is joint system. Development of joint system varies depending on bedrocks. Flow directions and erosional types are decided by the density and direction of joint system in the bedrock, which also decide the height and gradient of stream bed. Joint type decides the gradients of the bed, gradient and height of waterfalls, therefore, decides morphological forms.

A Method for Inferring Development Progress in a Waterfall Model-based Software Development Environment

  • Seong-Hoon Lee;Dong-Woo Lee
    • International journal of advanced smart convergence
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    • v.12 no.2
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    • pp.187-192
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    • 2023
  • Currently, our society is showing many changes due to the influence of information and communication technology (ICT). At the center of these information and communication technologies are software, intelligence, and sensing technologies. The software-related industry is steadily developing due to various software development policies implemented by the government and related organizations. Software development is desirable, but on the other hand, some negative aspects are also appearing. In this study, we proposed an objective way to infer the progress of software development for reasonable resolution of cases when a dispute related to the progress of development occurred during the software development process. The proposed solution was based on the waterfall model. The outputs generated in each process of the waterfall model are contents excluded from subjectivity. Therefore, it can be used as an objective method for calculating software development progress.

Disturbance Analysis in an Optical Disk Drive Using Model Based Disturbance Observer and Waterfall Technique (모델 기반 외란 관측기와 Waterfall 해석을 이용한 광 디스크 외란 분석)

  • Choi, Jin-Young;Lee, Kwang-Hyun;Jun, Hong-Gul;Lee, Moon-Noh;Yang, Hyun Seok;Park, No-Cheol;Park, Young-Pil
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.16 no.1 s.106
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    • pp.40-49
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    • 2006
  • A novel disturbance measurement method, model based disturbance observer (MBDO) for optical disk drives (ODDs), is proposed and the disturbance analysis using the proposed method is performed under various conditions. In ODDs, the quantitative and qualitative analysis for the generated disturbance during normal operation is very important to successful servo loop design. However, the disturbance measurement is difficult, and high precision measurement is necessary. Furthermore, the conventional disturbance measurement method using a LDV (laser Doppler vibrometer) has many difficulties in eccentricity direction due to the vertical movement of an optical disk. To solve this problem, the MBDO is proposed. First, the relationship between the servo loop for ODDs and the generated disturbance are briefly reviewed. Second, the principle of the MBDO is introduced, and the disturbance measurement results, which are measured by the MBDO and a LDV, are compared. In these experiments, test DVD-ROM disks are used to generate quantitative/qualitative disturbance. Then, the disturbance analysis under various conditions is performed using waterfall technique. This technique clearly shows the disturbance trend from the inner part of an optical disk to the outer part of it. Finally, the various disturbances measurement results are summarized and some remarks for it are commented.

Study of Information Hiding Methods for SONAR Images in the Naval Combat System (정보은닉기법을 적용한 함정 전투체계 소나 영상의 정보관리 방안 연구)

  • Lee, Joon-Ho;Shin, Sang-Ho;Jung, Ki-Hyun;Yoo, Kee-Young
    • Journal of the Korea Institute of Military Science and Technology
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    • v.18 no.6
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    • pp.779-788
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    • 2015
  • The SONAR waterfall image(SWI) is used typically to target detection in SONAR operation and is managed with additional data linked in the naval combat system. The SWI and additional data are very important to classify a kind of target. Although additional data of the SWI is essential and must be kept together with the SWI, it was stored separately in the current system. In this paper, we propose an improved information management method in the naval combat system, where additional data can be contained in the SWI together by using information hiding techniques. The experimental results show that the effectiveness of information hiding techniques in the naval combat system. It is demonstrated that the information hiding techniques can be applied to the SWI that can make the naval combat system to be robust and secure.

A Case Study of Information System Auditing of CBD Project (CBD프로젝트의 정보시스템감리 사례연구)

  • 조남재;박기호;전순천;박준호
    • Journal of Information Technology Applications and Management
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    • v.11 no.2
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    • pp.167-178
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    • 2004
  • Different from traditional development methodologies like waterfall model, the CBD (component based development) methodology relies on a building block approach in the design and development of information system. The audit procedure and checklist for the traditional IS development methodology are required to be modified to be suitable for CBD. This research reviewed IS audit guidelines for the existing development process and analyzed multiple projects that employed the by component based development process. For the purpose of this study, we chose a governmental project and a next-generation IS project of a financial agency as sample cases. By comparing existing IS audit checklists and items actually reviewed in audit projects, this study identified appropriate check items for the CBD-centric audit program. New items were proposed as additional items such as project control in management phase, usage case and conceptual model establishment, component evaluation and design, in implementation phase, and so forth. The result of the research provides new guidelines for the audit CBD projects for the purposed of increased efficiency and qualify of application development projects.

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A Study on the methodology for Web-based Maintenance System Development of Light Rail Transit (웹기반의 경량전철 유지보수 정보화시스템 개발방법론에 대한 연구)

  • Lee, Ho-Yong;Han, Seok-Yoon;Cho, Hong-Shik;Cho, Bong-Kwan
    • Proceedings of the KSR Conference
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    • 2007.05a
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    • pp.722-729
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    • 2007
  • The methodology for maintenance system development should overall be considered with all of task characteristic, schedule, and the technical condition of investment sources. This research applies Waterfall model to methodology for the development and construction of maintenance system through customizing the CD (Custom Development) procedure of "HSDM (Hyundai System Development Methodology)" based on information engineering. The waterfall model called as classic life cycle paradigm is defined for the sequent development procedure, which make progress a next step after that a previous step is admitted with thorough review. This model which is popular and the oldest paradigm is used for system development by four steps; demands analysis, design, construction, and maintenance. This methodology advances higher abstract step from higher lower step using top-down approach from concept definition to construction, which notices the end of a step whenever a step is over. Therefore, each step is exactly divided, and consequently the output is clearly yielded.

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Noise reduction of a high precision gearbox based on experimental study (실험적 방법을 통한 고정밀 감속기의 소음 저감)

  • Lee, Kyu-Ho;Kim, Woo-Hyung;Chung, Jin-Tai
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2006.05a
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    • pp.266-270
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    • 2006
  • Noise reduction the noise of a high precision multi-stage gearbox applied at the industrial robot is investigated by experiment such as the modal test and the signal analysis. The signal analysis performed with the waterfall plot representing the power spectrum as a function of the rotating speed. An eccentric load is installed at the gearbox in order to organize similar condition used in the industrial robot. Exciting sources are found out by the waterfall plot, and then the main factor to make the noise is distinguish. For the low-noise gearbox, the gear design parameter is modified and this gearbox is experimented in the same procedure. The results of the test show the noise level of gearbox reduced.

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A Study on the Noise and Vibration Diagnostic of the Industrial Robot Reducer (산업용 로봇 감속기의 소음 진동 평가에 대한 연구)

  • Kim, Woo-Hyung;Chung, Jin-Tai
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2004.11a
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    • pp.875-878
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    • 2004
  • The noise and vibration diagnostic of the industrial robot reducer is ultimately the purpose. We evaluated a noise and vibration tendency of the industrial robot reducer to be made in the outside (RV reducer) through the experiment. Also, we compared the RV reducer to the industrial robot reducer (RD reducer) in the domestic. We measured the noise level with the sound level meter and analyzed the vibration tendency with the waterfall plot. Through the comparison of RV reducer and RD reducer diagnose the industrial robot reducer. We guessed the improvement direction of RD reducer. (The domestic's industrial robot reducer).

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