• 제목/요약/키워드: Performance Technique

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Transmission Performance of Half-Symbol-Rate-Carrier Offset QPSK Modulation in Band-limited Channels

  • Yeo, Hyeop-Goo
    • Journal of information and communication convergence engineering
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    • 제7권2호
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    • pp.152-156
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    • 2009
  • This paper examines the BER performance of the recently proposed half-symbol-rate-carrier (HSRC) offset quadrature phase-shift-keying (OQPSK) receiver for high-speed data communication. A modified demodulation technique using a bit-time period signal integration, the bit-error-rate (BER) performance of the HSRC-OQPSK signal improves more than 4dB compared to that of a demodulation technique using a symbol-time period integration. This paper also examines the BER performance of modified demodulation with various band-limited channels modeled using low-pass filters, and the three different data-rate systems are simulated and compared with the performance of the system using the conventional demodulation technique.

통합 모델 설계 방식 기반 통신 프로토콜 개발을 위한 SDL-OPNET 모델 변환 기법 (SDL-OPNET Model Conversion Technique for the Development of Communication Protocols with an Integrated Model Design Approach)

  • 김재우;김태형
    • 대한임베디드공학회논문지
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    • 제5권2호
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    • pp.67-76
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    • 2010
  • Although both functional verification and performance evaluation are necessary for the development of effective and reliable communication systems, they have been often performed independently; by functional modeling with formal language tools and by performance modeling with professional network performance evaluation tools, respectively. Separate and repeated modeling of one system, however, would often result in cost increase and inconsistency between the models. This paper proposes an integrated model design approach in order to overcome this problem that evaluates the performance of a communication protocol designed in SDL with SDL-OPNET model conversion. The proposed technique generates OPNET skeleton code from Tau-generated C code of the SDL model by analyzing the relations between SDL and OPNET models. IEEE 802.2 LLC protocol was used as an example of model conversion to show the applicability and effectiveness of the proposed technique.

옥외 장기폭로에 따른 UHPC 패널의 표면 특성 평가 연구 (A study on the Evaluation of Surface Properties of UHPC Panels following long-term outdoor exposure)

  • 김태익;최병걸;박용규;최상훈;윤기원;이대식
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2022년도 봄 학술논문 발표대회
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    • pp.176-177
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    • 2022
  • In this study, surface performance evaluation was conducted according to the fiber and surface finishing technique of the exterior material using Ultra High Performance Concrete(UHPC), whitch is spotlighted as a highly durable exterior material. As a result of outdoor exposure, the initial performance of the UHPC Panel using organic fibers was maintained without being affected by the surface finishing technique. In the specimen using steel fiber, the surface performance was maintained when the water repellent treatment was performed in the plain specimen, but fiber corrosion occurred in the specimen to which the surface finishing technique was applied.

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소수력발전소의 성능예측 기법 (A Study on the Performance Prediction Technique for Small Hydro Power Plants)

  • 박완순;이철형
    • 한국수소및신에너지학회논문집
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    • 제14권1호
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    • pp.61-68
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    • 2003
  • This paper presents the methodology to analyze flow duration characteristics and performance prediction technique for small hydro power(SHP) Plants and its application. The flow duration curve can be decided by using monthly rainfall data at the most of the SHP sites with no useful hydrological data. It was proved that the monthly rainfall data can be characterized by using the cumulative density function of Weibull distribution and Thiessen method were adopted to decide flow duration curve at SHP plants. And, the performance prediction technique has been studied and development. One SHP plant was selected and performance characteristics was analyzed by using the developed technique, Primary design specfications such as design flowrate, plant capacity, operational rate and annual electricity production for the SHP plant were estimated, It was found that the methodology developed in this study can be a useful tool to predict the performance of SHP plants and candidate sites in Korea.

A Nexus among Strategy Type, Market Orientation, Strategic Costing and Financial Sector Performance of Private Universities in Indonesia

  • SRIYONO, Sriyono
    • The Journal of Asian Finance, Economics and Business
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    • 제7권10호
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    • pp.1035-1046
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    • 2020
  • This study aims to find empirical evidence of causal relationship between strategy type, market orientation, strategic management accounting (SMA) strategic costing technique, and financial sector performance of private universities in Indonesia. The research object in this study are private universities in Yogyakarta, Indonesia. Yogyakarta is chosen because universities there are one of the barometers of higher education in Indonesia, and the city has quite a number of universities. The respondents in this study are the leader (manager) of private universities in Yogyakarta, Indonesia. The data analysis is done using SEM-PLS with WarpPLS 3.0 software. The results of this study show that market orientation has significant influence on the development and implementation of SMA strategic costing technique, while strategy type does not have significant influence on the development and implementation of SMA strategic costing technique. This study also finds that the implementation of SMA strategic costing technique significantly influences the financial sector performance of private universities in Yogyakarta, Indonesia. This study provides theoretical implication regarding SMA development in universities that consider that contingency factors (market orientation) can encourage increased organizational performance. It indicates support for contingency theory that states there are no general principles that apply to all situations.

에너지 효율적인 멀티코어 임베디드 시스템을 위한 부하 불균형 스케줄링 방법 (Load Unbalancing Scheduling Method for Energy-Efficient Multi-core Embedded Systems)

  • 최영진
    • 대한임베디드공학회논문지
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    • 제11권1호
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    • pp.1-8
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    • 2016
  • We proposed a load unbalancing scheduling method for energy-efficient multi-core embedded systems considering DVFS (Dynamic Voltage/Frequency Scaling) power consumption and task characteristics. It is a new kind of scheduler which combines load balancing and load unbalancing technique. The purpose of the method is to effectively utilize energy without much effect in performance. In this paper, we conduct experiments on energy consumption and performance using the previous load balancing and unbalancing techniques and our proposed technique. The proposed technique reduced energy consumption more than 13.7% when compared to other algorithms. As a result, the proposed technique shows low energy consumption without much decline in the performance and is adequate for energy-efficient multi-core embedded systems.

2.4 GHz WLAN InGaP/GaAs Power Amplifier with Temperature Compensation Technique

  • Yoon, Sang-Woong;Kim, Chang-Woo
    • ETRI Journal
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    • 제31권5호
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    • pp.601-603
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    • 2009
  • This letter presents a high performance 2.4 GHz two-stage power amplifier (PA) operating in the temperature range from $-30^{\circ}C$ to $+85^{\circ}C$ for IEEE 802.11g, wireless local area network application. It is implemented in InGaP/GaAs hetero-junction bipolar transistor technology and has a bias circuit employing a temperature compensation technique for error vector magnitude (EVM) performance. The technique uses a resistor made with a base layer of HBT. The design improves EVM performance in cold temperatures by increasing current. The implemented PA has a dynamic EVM of less than 4%, a gain of over 26 dB, and a current less than 130 mA below the output power of 19 dBm across the temperature range from $-30^{\circ}C$ to $+85^{\circ}C$.

MRRC 안테나 기법을 이용한 MC-DS-CDMA 전송방식의 성능 분석 (Performance Evaluation of MC-DS-CDMA Transmission Technique using MRRC Antenna Scheme)

  • 최승국
    • 한국정보통신학회논문지
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    • 제14권4호
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    • pp.817-823
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    • 2010
  • MC-DS-CDMA 전송 방식에서는 서로 직교성이 있는 여러 개의 부반송파들을 사용함으로서 주파수 다이버시티 효과를 얻을 수 있어 우수한 성능의 전송이 가능하다. 본 논문에서는 파일럿 심볼을 이용하여 채널을 추정하는 MC-DS-CDMA 시스템에 MRRC 안테나 다이버시티 기법을 적용할 때의 시스템 성능을 분석한다. 이러한 다중 반송파 전송 방식에서는 채널 추정 에러, 비선형 전력 증폭기 및 송수신간 반송 주파수 편차 등에 의하여 시스템 성능이 열화 된다. 그러므로 위와 같은 영향들을 모두 고려하여 송신 신호가 다중경로 페이딩 채널을 통하여 전송될 때의 데이터 비트 오류율 성능을 분석한다.

선박 백본 네트워크의 논리 토폴로지 재구성 기법 (A Reconfiguration Technique of Logical Topology in a Ship Backbone Network)

  • 탁성우
    • 한국정보통신학회논문지
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    • 제16권5호
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    • pp.922-931
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    • 2012
  • 본 논문에서는 연속적인 트래픽 요구 변화에 대처할 수 있는 선박 백본 네트워크의 논리 토폴로지 재구성 방안을 연구하였다. 제안한 기법은 트래픽 포워딩 경로의 변경을 최소화하며, 동시에 트래픽 포워딩 경로의 평균 홉 수를 최소화하여 선박 백본 네트워크의 성능을 향상시킨다. 제안한 재구성 기법의 성능 분석을 수행한 결과, 연속적인 재구성 처리 과정에서 우수한 성능을 보여 주었다.

Microcontroller-Based Improved Predictive Current Controlled VSI for Single-Phase Grid-Connected Systems

  • Atia, Yousry;Salem, Mahmoud
    • Journal of Power Electronics
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    • 제13권6호
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    • pp.1016-1023
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    • 2013
  • Predictive current control offers the potential for achieving more precise current control with a minimum of distortion and harmonic noise. However, the predictive method is difficult to implement and has a greater computational burden. This paper introduces a theoretical analysis and experimental verification for an improved predictive current control technique applied to single phase grid connected voltage source inverters (VSI). The proposed technique has simple calculations. An ATmega1280 microcontroller board is used to implement the proposed technique for a simpler and cheaper control system. To enhance the current performance and to obtain a minimum of current THD, an improved tri-level PWM switching strategy is proposed. The proposed switching strategy uses six operation modes instead of four as in the traditional strategy. Simulation results are presented to demonstrate the system performance with the improved switching strategy and its effect on current performance. The presented experimental results verify that the proposed technique can be implemented using fixed point 8-bit microcontroller to obtain excellent results.