• Title/Summary/Keyword: 범위주기

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A Study on Tranquility by the Development of New Type Floating Breakwater (신형식부방파제의 개발과 정온도에 관한 연구)

  • Lee, Hyun Jin;Kim, Do Sam;Shin, Moon Seup
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.25 no.3
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    • pp.154-164
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    • 2013
  • In this study, a new type floating breakwater was proposed to improve the capability of wave attenuation compared with the existing floating breakwater in Wonjun Port, which is located in Masan City, Korea. In order to develop the optimal design, many different configurations considering the shape and location of vertical barrier and horizontal plate were examined based on the shape of existing floating breakwaters in Wonjun and Tongyeong Port. The analytical and numerical results of the new type floating breakwater showed better performance in long-period wave attenuation than the existing floating breakwater in Wonjun. Therefore, the new type floating breakwater can improve harbor tranquility in Wonjun Port.

A Study on the Design of High Gain and Wideband Microstrip Array Antenna for Satellite Communications (위성통신용 고이득 광대역 마이크로스트립 배열 안테나의 설계연구)

  • 윤현보;임계재
    • The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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    • v.2 no.3
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    • pp.32-40
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    • 1991
  • A modified transmission line model is proposed for input impedance analysis of a square microstip antenna with single-circularly-polarized. Alog-periodic arrangement with microstrip antenna (LPMA) which consists of 3 resonant element ($3\times1$) is designed for broadband operation ranging from 11.2 GHz to 12.4 GHz, based on this pro- posed model from transmission line model. Aplanar array ($3\times4$array), in which 4sets of the above LPMA are in the same plane, is fabricated for high gain X-band satellite communication antennas. The optimum spacing between each LPMA is determined using computer simulation for the minimum bariation of far field pattern and null. This $3\times4$array has a measured values of gain greater than 8dBi, VSWR les then 2.3, and bandwidth greater than 7% respectively.

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[ ${\mu}TMO$ ] Model based Real-Time Operating System for Sensor Network (${\mu}TMO$ 모델 기반 실시간 센서 네트워크 운영체제)

  • Yi, Jae-An;Heu, Shin;Choi, Byoung-Kyu
    • Journal of KIISE:Computer Systems and Theory
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    • v.34 no.12
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    • pp.630-640
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    • 2007
  • As the range of sensor network's applicability is getting wider, it creates new application areas which is required real-time operation, such as military and detection of radioactivity. However, existing researches are focused on effective management for resources, existing sensor network operating system cannot support to real-time areas. In this paper, we propose the ${\mu}TMO$ model which is lightweight real-time distributed object model TMO. We design the real-time sensor network operation system ${\mu}TMO-NanoQ+$ which is based on ETRI's sensor network operation system Nano-Q+. We modify the Nano-Q+'s timer module to support high resolution and apply Context Switch Threshold, Power Aware scheduling techniques to realize lightweight scheduler which is based on EDF. We also implement channel based communication way ITC-Channel and periodic thread management module WTMT.

A Conceptual Model Study For J.I.T(Just In Time) Construction Managemaent On High-rise Building-Concerned On Resource Life Cycle Of Concrete Construction- (고층건축공사 적시생산을 위한 관리모델 사례 -콘크리트 자재의 Life Cycle을 중심으로-)

  • Song Young-Suk;Lim Hyung-Chul;Choi Yun-Ki
    • Korean Journal of Construction Engineering and Management
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    • v.2 no.4 s.8
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    • pp.127-134
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    • 2001
  • Effectiveness of Just in time managing system can be obtained by removing unexpected lead-time and maintaining consistency on the physical transportation of construction resource. Construction resource management is essential on checking on load data from production of shop to field, and it is based on building resource life cycle information. In this study, production, transportation, and assembly disciplines of concrete construction should real time communications exchanging information related to shop-field with each other, Establishing information support system is an important initial step for promoting active cooperations among these resource life cycle on data flow. To achieve this, on suitable using management point, we suggest a concrete construction control model.

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A study on RF characteristics of fishbone-type transmission line on PES substrate for application to flexible wireless communication device (플렉시블 무선통신소자 응용을 위한 PES 박막상의 Fishbone 형태의 전송선로에 대한 RF 특성연구)

  • Yun, Young
    • Journal of Advanced Marine Engineering and Technology
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    • v.38 no.3
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    • pp.302-311
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    • 2014
  • In this work, a FTTL (fishbone-type transmission line) structure was fabricated on PES (polyether sulfone) for a realization of transparent flexible wireless communication device, and its RF characteristics were investigated. According to the results, the FTTL on PES showed a short wavelength characteristic compared with conventional coplanar waveguide. Concretely, the wavelength of the FTTL was 2.23 mm at 50 GHz, which was 56.6 % of the conventional coplanar waveguide. According to the bandwidth extraction result, the passband of the FTTL on PES was 608 GHz. Unlike conventional periodic structures, the characteristic impedance of the FTTL on PES showed a very low frequency dependency, which means that the FTTL on PES can be used for application to transmission line and distributed passive components with a broadband operation frequency.

Real-Time Support on the Tablet PC Platform (태블릿 PC 환경의 실시간 처리 기능 지원)

  • Park, Ji-Yoon;Jo, Ah-Ra;Kim, Hyo-Joung;Choi, Jung-Hyun;Heo, Yong-Kwan;Jo, Han-Moo;Lee, Cheol-Hoon
    • The Journal of the Korea Contents Association
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    • v.13 no.11
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    • pp.541-550
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    • 2013
  • Generally in case of tablet PC's, the Windows 8 is used to support various functions or development convenience, however it cannot support real-time processing. In addition, existing commercial solutions and RTiK has a problem to support real-time processing due to impossibility of getting APIC timer count value which is used to generate timer interrupt separated from that of Windows. Thus, in this paper, we set the initial APIC count value using MSR_FSB_FREQ to support real-time processing on the Windows 8-based tablet PC's. Additionally, we deal with designing and implementing RTiK+ providing real-time processing to guarantee interrupt periods by controlling C-State which is used for low power techniques. To evaluate the performance of the proposed RTiK+, we measured the periods of generated real-time threads using RDTSC instructions which return the number of CPU clock ticks, and verified that RTiK+ operates correctly within the error ranges of 1ms.

Optimization of Design Variables of Detection Algorithm for Loss of Balance Using a Linear Internal Model (균형상실의 검출 성능 향상을 위한 내부 모델의 설계변수 선정 및 민감도 평가)

  • Kim, Kwang-Hoon;Kim, In-Su;Son, Kwon
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.34 no.9
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    • pp.1153-1160
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    • 2010
  • The detection algorithm for loss of balance had three main parts: one for processing data, another for constructing an internal model, and a third for detecting the loss of balance. The part related to the internal model is the most important part of the algorithm. The purpose of this study is to evaluate the effect of variables associated with the internal model on the success rate of the algorithm. The internal model depends on the type of linearization adopted and the operating period of the algorithm. The design variables were evaluated by performing sensitivity analysis of the variables of the internal model in order to obtain the success rate of the algorithm. The results showed that the most sensitive variable was the period and the period of 0.3 s yielded the highest success rate of 97.1%. Further, the ranges of the design variables that can facilitate a success rate of over 95% are presented.

A Study of Seismic Resistant Design for Base-Isolated Bridges(I) (지진에 대비한 기초분리 교량의 설계법에 관한 연구(I))

  • Lee, Sang Soo
    • Journal of Korean Society of Steel Construction
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    • v.9 no.4 s.33
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    • pp.625-635
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    • 1997
  • The base isolation technique and its benefits in reducing the transmitted earthquake energy into a structure have gained increasing recognition during the last two decades. Unfortunately, the current available design procedures, especially for base-isolated bridges, seem inadequate and too restrictive. As a result, practical design procedure still relies upon a series of deterministic time history analyses. In this study, the evaluation of the possibility of the normal mode method to predict the nonlinear seismic responses of base isolated bridges has been performed. The applicability has been examined through the numerical approach with isolator's elastic or plastic states of the base isolated bridges. Numerical results show that the 1st. mode period and the various responses are varied with the state but are conversed. And, the result show that the normal mode method is applicable to predict the seismic responses and to design the babe isolated bridge. Various analysis method to bridges with bilinearized hysteresis isolator and various pier heights are evalulated.

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On The Towing Speed and Warp Tension of the Stern Trawler in the Atlantic Coast of Africa (대서양 아프리카 연안 트로올의 예망속도와 끌줄의 장력에 관하여)

  • 김진건
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.13 no.2
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    • pp.21-26
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    • 1977
  • The author operated with a six seam trawl net by the stern trawler, No. 85 Parto, 499 GT, 2,200ps, in the Atlantic coast of Africa, from June, 1975 to October, 1977. In the term, towing speed and warp tension were determined, and trawling condition was observed. 1. The condition of trawling was good when the tension was less than 7.5ton. 2. 290 RPM, $13.5^{\circ}\;to\;13.8^{\circ}$ of pitch angle, and 3.5 to 4 knots of towing speed was considered as optimum for the trawler in the relation to the engine condition.

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A Study of Ultra Wideband Impulse Radio Systems for Multiple Access Communication (다원접속 통신을 위한 초광대역 임펄스 무선 전송 시스템 연구)

  • 이양선;강희조;문용규;양승인
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.28 no.3C
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    • pp.224-231
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    • 2003
  • In this paper we proposed system parameter values of ultra-wideband Impulse Radio systems for the frequency band(3.1~10.6GHz), which is allocated by Federal Communications Commission(FCC). We also analyzed performance of the proposed system in the multiple access interference environment. According to result, application of possible pulse duration($t_{n}$) is very limited by 0.04~0.0326 ns in permission frequency range that establish in FCC. In the case of the same pulse signal power, we could know that system performance was changed by pulse repetition number($N_{s}$ ) regardless of pulse duration. Thus, We could know that we have to need duration of monocycle pulse and setting of frame un it time(Τ$_{f}$ ) according to multi user numbers and design proper pulse repetition number by transfer rate in multiple access systems design. In the IR system that needs high speed transmission more than 50 Mbps in multiple access interference environment, we could know that very serious performance decrease by multiple access interference happens. Therefore, as the design of high speed multiple access IR system, it should be designed to additional improvement techniques that can remove multiple access interference at the same time.