• Title/Summary/Keyword: Small system

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A Study on Development of a Marine Docking System for Repair of a Small Coast-Boat (연안 소형선박 수리용 해상 상가시스템 개발)

  • Park, Chung-Hwan;Jang, Dong-Won;Yang, Hyang-Kweon;Jin, Jong-Ryung
    • Journal of Ocean Engineering and Technology
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    • v.22 no.4
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    • pp.78-83
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    • 2008
  • In recent years, small boats used for marine leisure have been steadily increasing because of the increase in national income and the desire for marine leisure. But the repair of such small boats in dry dock has pointed out many faults in small FRP-shipbuilding in terms if workspace and manpower. Lifting a boat from the water to land is done with a crane or by hand using a sling around the bottom of the boat. But dry dock work is limited by the scale of the boat, which corresponds to the crane capacity, with carelessness making it possible to capsize a boat and endanger life. The purpose of this study was the development of a marine docking system that would improve economical efficiency and safety, for which we carried out concept design, model tests, structural analysis, etc.

Design and Test Flash-based Storage for Small Earth Observation Satellites (소형 지구 관측 위성용 플래시 기반 저장장치 설계 및 시험)

  • Baek, Inchul;Park, Hyoungsic;Hwang, Kiseon
    • IEMEK Journal of Embedded Systems and Applications
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    • v.13 no.5
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    • pp.253-259
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    • 2018
  • Recently, small satellite industries are rapidly changing. Demand for high performance small satellites is increasing with the expansion of Earth Observation Satellite market. A next-generation small satellites require a higher resolution image storage capacity than before. However, there is a problem that the HW configuration of the existing small satellite image storage device could not meet these requirements. The conventional data storing system uses SDRAM to store image data taken from satellites. When SDRAM is used in small satellite platform of a next generation, there is a problem that the cost of physical space is eight times higher and satellite price is two times higher than NAND Flash. Using the same satellite hardware configuration for next-generation satellites will increase the satellite volume to meet hardware requirements. Additional cost is required for structural design, environmental testing, and satellite launch due to increasing volume. Therefore, in order to construct a low-cost, high-efficiency system. This paper shows a next-generation solid state recorder unit (SSRU) using MRAM and NAND Flash instead of SDRAM. As a result of this research, next generation small satellite retain a storage size and weight and improves the data storage space by 15 times and the storage speed by 4.5 times compare to conventional design. Also reduced energy consumption by 96% compared to SDRAM based storage devices.

Scaling analysis of the pressure suppression containment test facility for the small pressurized water reactor

  • Liu, Xinxing;Qi, Xiangjie;Zhang, Nan;Meng, Zhaoming;Sun, Zhongning
    • Nuclear Engineering and Technology
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    • v.53 no.3
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    • pp.793-803
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    • 2021
  • The small PWR has been paid more and more attention due to its diversity of application and flexibility in the site selection. However, the large core power density, the small containment space and the rapid accident progress characteristics make it difficult to control the containment pressure like the traditional PWR during the LOCA. The pressure suppression system has been used by the BWR since the early design, which is a suitable technique that can be applied to the small PWR. Since the configuration and operating conditions are different from the BWR, the pressure suppression system should be redesigned for the small PWR. Conducting the experiments on the scale down test facility is a good choice to reproduce the prototypical phenomena in the test facility, which is both economical and reasonable. A systematic scaling method referring to the H2TS method was proposed to determine the geometrical and thermohydraulic parameters of the pressure suppression containment response test facility for the small PWR conceptual design. The containment and the pressure suppression system related thermohydraulic phenomena were analyzed with top-down and bottom-up scaling methods. A set of the scaling criteria were obtained, through which the main parameters of the test facility can be determined.

System Identification of a Small Unmanned Rotorcraft (소형 무인 헬리콥터의 시스템 식별)

  • Ryu, Seong-Sook;Song, Yong-Kyu
    • Journal of Institute of Control, Robotics and Systems
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    • v.15 no.1
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    • pp.44-53
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    • 2009
  • In this paper, Recursive Least Squares (RLS) and Fourier Transform Regression (FTR) methods for estimating stability and control derivatives of small unmanned helicopter are evaluated together with MMLE technique. Flight data simulated by using a commercial small-scale helicopter model are exploited to estimate the parameters with accuracies for hover and cruise modes. The performances of the system identification methods are also compared by analyzing the responses of the reconstructed systems using estimated derivatives.

A study on systematic need analysis and sketch of production management system for Korean small and medium-sized firms (생산관리자동화 기술기반구축을 위한 니드분석 및 국내중소기업형 생산관리자동화 구상에 관한 연구)

  • 김형욱;신병현;최성빈
    • Korean Management Science Review
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    • v.13 no.3
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    • pp.1-21
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    • 1996
  • This study aims to systematize the needs of each area for computerized production management of small- and medium-sized firms and establish the basic design background of their common database. For this purpose, we surveyed the status, needs and appliable characteristics of the firms production system by the categories of industry, size and production type. On the base of these surveys the basic design concept and contents of automatic production system for small and medium-sized firms are proposed.

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DISJOINT SMALL CYCLES IN GRAPHS

  • Gao, Yunshu;Li, Guojun;Yan, Jin
    • Journal of applied mathematics & informatics
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    • v.27 no.3_4
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    • pp.809-817
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    • 2009
  • We call a cycle C be a small cycle if the length of C equals to 3 or 4. In this paper, we obtain two sufficient conditions to ensure the existence of vertex-disjoint small cycles in graph and propose several problems.

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A Case Study for Implementing HACCP in Small to Medium sized Company (현 중소기업에서의 HACCP시스템 구축 사례연구)

  • Son, Eun-Il;Seong, Chang-Mo
    • Journal of Industrial Convergence
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    • v.2 no.1
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    • pp.103-119
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    • 2004
  • This paper deals with a case analysis on the implementation of HACCP System. The intention is to provide some general guidelines, in particular, to small to medium sized companies that are planning to introduce the HACCP System. This paper is meaningful in regard to the actual implementation of HACCP System in small to medium sized company. It is very good result in this study because the law/guideline of HACCP is executed now.

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A study on the small sewerage system using SBR process (SBR을 이용한 소규모 오수처리시설에 관한 연구)

  • 박민정;김동석
    • Journal of Environmental Science International
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    • v.12 no.4
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    • pp.427-437
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    • 2003
  • An evaluation of the application of SBR and biofilm en small sewerage system was conducted. A newly developed small sewerage system, using SBR, was successfully applied to the nutrient treatment using municipal wastewater. The system was consisted of 6 compartments. Two systems, with SBR (A type) or without SBR (B type), were compared by several parameters (COD, SS, T-N, NH$_4$$\^$+/-N, NO$_3$$\^$-/-N, NO$_2$$\^$ -/-N, alkalinity, pH, DO) in all experimental periods. Also, the time variation of several parameters (DO, pH, NH$_4$$\^$+/-N, NO$_3$$\^$-/-N NO$_2$$\^$-/-N) was examined in a SBR applied sewerage system. T-N removal efficiency of B type Was higher than that Of A type by the effect of nitrification and denitrification even though the COD removal efficiencies were similar. In aeration stage, the pH was decreased from 6.4 to 6.3 within 1 h and increased to 6.65 at the end of aerobic stage, and pH was decreased to 6.2 in non-aeration stage, and these phenomena were explained. The effects of nitrification and denitrification were compared in A type and B type sewerage system, and the typical nitrification and denitrification were observed in B type sewerage system.

A Study on Development of Brake System of Light Eco-Friendly Car Considering Heat Load and Regenerative Braking Characteristic (열부하 및 회생 제동 특성을 고려한 경형 친환경차의 제동시스템 개발에 관한 연구)

  • Shim, J.H.;Shin, U.H.;Lee, J.H.;Hwang, S.R.;Yim, W.S.;Kim, B.C.
    • Journal of Auto-vehicle Safety Association
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    • v.12 no.2
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    • pp.7-13
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    • 2020
  • Recently, there is a big issue of downsizing on brake system according to fuel efficiency and regenerative braking cooperation control. Especially, small cars have improved in a variety ways such as electric vehicle and smart car compared to previous small cars. So, small brake system is strongly required in the car industry. A new small brake system for light compact vehicles was proposed in this paper. For this system, the solid type disc and caliper were newly developed. And the important design factors were considered to reduce brake size. First, we calculated the temperature rise of disc through heat capacity formula and CAE analysis. Second, we analyzed the housing and carrier stiffness of caliper to select the reasonable condition. Finally, the superiorities of the developed brake system were verified by heat capacity, consumption liquid level, braking feeling, judder, wear test and regenerative braking cooperation control analysis. A developed brake system is expected to be useful for brake system of light compact platform.

A Study on MMC System Furniture Design to use small living spaces effectively (소규모 주거공간의 효율적 활용을 위한 MMC System Furniture Design 연구)

  • Bae, Jee-Hoon;Yoon, Jong-Young
    • Proceedings of the Korean Institute of Interior Design Conference
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    • 2005.05a
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    • pp.237-240
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    • 2005
  • Nowadays living space has been small-sized due to a rise in the standard of living, change of recognition on the increase of housing for the singles, and frequent movements of duty place, etc. and the furnitures naturally evolved assembly and multi-functionality. However, it retuned with an economic charge in the consumers and lost the uniformity in a small-sized living space as well since the furniture depended on the each miscellaneous household goods or products and came to be used. Hereupon it was demanded the system where the various furnitures are to fit to here. This study aimed at this point firstly examined a new environment change which it follows till a small living space is demanded through lots of literature, after understanding the concept of the system furniture, I classified expressive types of system furniture in modern environment and analyzed the design quality and characteristics in it by selecting well-known furniture magazines inside and outside of the country and extracting and analyzing system furniture images which are recorded in advertisements or articles. The objective of this study is to present MMC(Multi Modular Coordination, a system furniture design based on this analysis that inquiring the problems with function, structure, assembly which other existing system furnitures are facing enabled to apply a basic data in unit-module planning and by sampling embodiment modeling by uses.

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