• 제목/요약/키워드: System Performance Index

검색결과 1,494건 처리시간 0.031초

다중 모드를 사용하는 OFDM-CDIM 시스템 설계와 성능 평가 (Design and Performance Evaluation of OFDM-CDIM System Using Multiple Modes)

  • 안창영;유흥균
    • 한국전자파학회논문지
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    • 제29권7호
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    • pp.515-522
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    • 2018
  • 본 논문에서는 기존 OFDM(Orthogonal Frequency Division Multiplexing) 시스템보다 높은 성능과 스펙트럼 효율를 달성할 수 있는 OFDM-CDIM(Coded Direct Index Modulation) 시스템을 제안한다. 기존 OFDM-IM(Index Modulation) 및 DM(Dual Mode)-OFDM-IM 시스템은 높은 복잡도를 갖는 조합연산을 통해 각 부반송파의 인덱스에 추가적인 데이터를 할당하여 전송한다. 그러나 제안하는 시스템은 모드를 선택하는 정보를 각 부반송파에 추가 연산 없이 직접 할당하고, 선택된 모드 내에서 하나의 심볼을 선택하여 전송한다. 더욱이 부반송파의 인덱스에 할당되는 데이터에만 부호화를 수행하여 높은 부호율과 함께 우수한 성능 개선 효과를 얻는다. 시뮬레이션 결과를 통해 4개를 모드를 사용하는 4M(Four Modes)-OFDM-CDIM 시스템은 기존 4QAM(Quadrature Amplitude Modulation)을 사용하는 OFDM 시스템과 비교하여 AWGN(Additive White Gaussian Noise)과 Rayleigh 페이딩 환경에서 BER(Bit Error Rate) 성능과 전송 효율을 향상시킬 수 있음을 정량적으로 확인할 수 있다.

가치산정법에 의한 전력품질비용 산정 및 단일화지수의 개발 (Evaluation of Power Quality Cost Based on Value-Based Methodology and Development of Unified Index)

  • 이범;김경민
    • 전기학회논문지
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    • 제60권7호
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    • pp.1293-1298
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    • 2011
  • This paper presents an Unified Index which can evaluate a performance of a distribution system based on value-based methodology. Reliability cost and voltage sags cost are calculated for each load point using Reliability Sector Customer Damage Function(SCDF). Aging cost is calculated for each load point using Aging SCDF. Power loss cost and operation cost are calculated for the system. By summation of each cost of load point and system, power quality cost can be obtained. Finally, this paper developed an unified index which can show the performance of a distribution system. Presented method has been applied to a real system, the usefulness of the method has been verified.

게이지 R&R과 성능지수를 이용한 측정시스템과 공정능력 평가 방법 (Evaluation Method for Measurement System and Process Capability Using Gage R&R and Performance Indices)

  • 주영돈;이동주
    • 산업경영시스템학회지
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    • 제42권2호
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    • pp.78-85
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    • 2019
  • High variance observed in the measurement system can cause high process variation that can affect process capability badly. Therefore, measurement system analysis is closely related to process capability analysis. Generally, the evaluation for measurement system and process variance is performed separately in the industry. That is, the measurement system analysis is implemented before process monitoring, process capability and process performance analysis even though these analyses are closely related. This paper presents the effective concurrent evaluation procedure for measurement system analysis and process capability analysis using the table that contains Process Performance (Pp), Gage Repeatability & Reproducibility (%R&R) and Number of Distinct Categories (NDC). Furthermore, the long-term process capability index (Pp), which takes into account both gage variance and process variance, is used instead of the short-term process capability (Cp) considering only process variance. The long-term capability index can reflect well the relationship between the measurement system and process capability. The quality measurement and improvement guidelines by region scale are also described in detail. In conclusion, this research proposes the procedure that can execute the measurement system analysis and process capability analysis at the same time. The proposed procedure can contribute to reduction of the measurement staff's effort and to improvement of accurate evaluation.

주파수 형태의 성능지수를 고려한 능동형 현가장치 제어 (Actrve Suspension Control using aFrequency-Shaped Performance Index)

  • 김희수;기창두;황원걸
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 1993년도 추계학술대회 논문집
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    • pp.299-304
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    • 1993
  • A 1/4 car model(2 DOF system) is employed to evaluate the performance included a quadratic cost functional in frequency domain. The design procedure of feedback control to optimize the performance index results in a modified Linear-Quadratic-Gaussian problem and cultivates a quite simple control algorithm. Computer simulation result is shown that the LQG method using frequency shaped performance index is outstanding in ride comfort and its response converges to the steady state very rapidly in comparison with the known passive suspension, classical design methods LQR/ and LQG.

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균형성과표를 활용한 전자의무기록시스템의 성과측정 모형개발 (Development of the Performance Measurement Model of Electronic Medical Record System - Focused on Balanced Score Card -)

  • 이경희;김영훈;부유경
    • 한국병원경영학회지
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    • 제21권4호
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    • pp.1-12
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    • 2016
  • The purpose of this study are suggest to performance measurement model of Electronic Medical Record(EMR) and Key Performance Index(KPI). For data collection, 665 questionnaires were distributed to medical record administrators and insurance reviewers at 31 hospitals, and 580 questionnaires were collected(collection rate: 87.2%). Regarding methodology, Critical Success Factor(CSF) and index of the information system were derived based on previous studies, and these were set as performance measurement factors of EMR system. The performance measurement factors were constructed by perspective using BSC, and analysis on causal relationship between factors was conducted. A model of causal relationship was established, and performance measurement model of EMR system was proposed through model validation. Analysis on causal relationship between performance management factors revealed that utility cognition of the learning & growth perspective factor had causal relationship with job efficiency(${\beta}=0.20$) and decision support(${\beta}=0.66$) of the internal process perspective factors, and security had causal relationship with system satisfaction(${\beta}=0.31$) of the customer perspective factor. System quality had causal relationship with job efficiency(${\beta}=0.66$) and decision support(${\beta}=0.76$) of the internal process perspective factors, all of which were statistically significant(P<0.01). Job efficiency of the internal process perspective had causal relationship with system satisfaction(${\beta}=0.43$), and decision support had causal relationship with decision support satisfaction(${\beta}=0.91$) and job satisfaction (${\beta}=0.74$), all of which were statistically significant(P<0.01). System satisfaction of the customer perspective had causal relationship with job satisfaction(${\beta}=0.12$), job satisfaction had causal relationship with cost reduction(${\beta}=0.53$) of the financial perspective, and decision support satisfaction had causal relationship with productivity improvement(${\beta}=0.40$)of the financial perspective(P<0.01). Also, cost reduction of the financial perspective had causal relationship with productivity improvement(${\beta}=0.37$), all which were statistically significant(P<0.05). Suitability index verification of the performance measurement model whose causal relationship was found to be statistically significant revealed that $X^2/df=2.875$, RMR=0.036, GFI=0.831, AGFI=0.810, CFI=0.887, NFI=0.838, IFI=0.888, RMSEA=0.057, PNFI=0.781, and PCFI=0.827, all of which were in suitable levels. In conclusion, the performance measurement indices of EMR system include utility cognition, security, and system quality of the learning & growth perspective, decision support and job efficiency of the internal process perspective, system satisfaction, decision support satisfaction, and job satisfaction of the customer perspective, and productivity improvement and cost reduction of the financial perspective. In this study, it is expected that the performance measurement indices and model of EMR system which are suggested by the author, will be a measurement tool available for system performance measurement of EMR system in medical institutions.

병렬 공간 색인을 위한 검색 기법 (Search scheme for parallel spatial index)

  • 서영덕
    • 한국공간정보시스템학회 논문지
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    • 제7권2호
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    • pp.81-89
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    • 2005
  • 디클러스터링과 병렬 색인 구조는 효과적인 대용량 데이터의 검색을 위한 데이터베이스의 중요한 연구 분야이다. 기존의 연구에서 다중 디스크에서 다양한 방법들을 이용하여 R-tree등의 색인을 위한 다양한 방법들이 제시되었으나, 이에 적절한 검색 기법에 관한 연구는 거의 없었다. 이 연구에서는 기존의 연구에서 제시된 병렬 공간 색인 구조에서 검색 성능을 향상시킬 수 있는 새로운 검색 기법을 제시한다. 제시된 기법은 디스크로부터 동시에 여러 개의 노드를 읽어 들일 수 있는 병렬 디스크의 장점을 최대한 활용한 기법이다. 기존의 한번에 한 노드를 읽는 알고리즘을 개선하여 여러 노드를 동시에 접근하기 위한 최적화된 기법이다 실험을 통하여 제시된 기법은 기존의 연구에서 제시된 알고리즘들을 검색 기법의 변경을 통하여 최대 40%이상의 성능 향상을 유발함을 입증하였다.

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링 레이저 자이로 기반 함정용 관성항법장치 성능규격 결정에 대한 연구 (A Study on Determining the Performance Requirements of Ship's Inertial Navigation System Based on Ring Laser Gyroscope)

  • 김천중;유해성;유기정;박찬주;이상정
    • 한국군사과학기술학회지
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    • 제21권6호
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    • pp.731-743
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    • 2018
  • In this paper, a study result to decide the accuracy specifications of inertial sensors satisfying the performance requirements of SINS(ship's inertial navigation system) is proposed. To do this, the performance specifications of overseas SINS is surveyed and the detailed error analysis of SINS at stationary condition is performed. Also, a new performance index to indicate the performance of SINS is derived. Modelling and simulation results show that the accuracy specifications of inertial sensors to meet the performance requirements of SIGMA40XP, a typical overseas SINS, can be determined through the newly derived performance index in this paper.

Parametric analysis of hybrid outrigger system under wind and seismic loads

  • Neethu Elizabeth Johna;Kiran Kamath
    • Structural Engineering and Mechanics
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    • 제86권4호
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    • pp.503-518
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    • 2023
  • In tall constructions, the outriggers are regarded as a structural part capable of effectively resisting lateral loads. This study analyses the efficacy of hybrid outrigger system in high rise RCC building for various structural parameters identified. For variations in α, which is defined as the ratio of the relative flexural stiffness of the core to the axial rigidity of the column, static and dynamic analyses of hybrid outrigger system having a virtual and a conventional outrigger at two distinct levels were conducted in the present study. An investigation on the optimal outrigger position was performed by taking the results from absolute maximum inter storey drift ratio (ISDmax), roof acceleration (accroof), roof displacement (disproof), and base bending moment under both wind and seismic loads on analytical models having 40, 60 and 80 storeys. An ideal performance index parameter was introduced and was utilized to obtain the optimal position of the hybrid outrigger system considering the combined response of ISDmax, accroof, disproof and, criteria required for the structure under wind and seismic loads. According to the behavioural study, increasing the column area and outrigger arm length will maximise the performance of the hybrid outrigger system. The analysis results are summarized in a flowchart which provides the optimal positions obtained for each dependent parameter and based on ideal performance index which can be used to make initial suggestions for installing a hybrid outrigger system.

이동체의 관성을 이용한 궤적 색인의 병렬화 기법 (Parallelization scheme of trajectory index using inertia of moving objects)

  • 서영덕;홍봉희
    • 한국공간정보시스템학회 논문지
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    • 제8권1호
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    • pp.59-75
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    • 2006
  • 최근 가장 활발하고 많은 연구가 이루어지는 시스템중의 하나는 교통 제어 시스템이다. 이 시스템을 효과적으로 지원하기 위해서는 이동체를 효과적으로 저장하고, 시간 혹은 시공간 질의를 효과적으로 수행하기 위하여 높은 성능을 가진 이동체 데이터베이스 시스템이 필요하다. 빠른 이동체 데이터베이스 시스템의 성능은 병렬 색인을 이용하여 구축될 수 있다. 이 논문에서는 시공간 인접성과 이동체 특성에 기반한 디클러스터링 정책을 제시한다. 이동체의 진행 방향에 대한 예측을 통하여 색인의 노드에 대한 성장을 예측하고, 이를 토대로 병렬 색인을 구축한다. 실험 결과 제시된 기법은 기존의 다른 정책에 비하여 최대 15%이상의 성능 향상이 있다. 이 결과는 단일 디스크를 사용할 때에 비하여 디스크 당 50%이상의 성능향상 결과이다.

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동적 인텍스 매핑을 이용한 벡터 양자화 시스템에서의 비트율 감축 (Bitrate Reduction in Vector Quantization System Using a Dynamic Index Mapping)

  • 이승준;양경호;김철우;이충웅
    • 전자공학회논문지B
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    • 제32B권8호
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    • pp.1091-1098
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    • 1995
  • This paper proposes an efficient noiseless encoding method of vector quantization(VQ) index using a dynamic index mapping. Using high interblock correlation, the proposed index mapper transforms an index into a new one with lower entropy. In order to achieve good performance with low computational complexity, we adopt 'the sum of differences in pixel values on the block boundaries' as the cost function for index mapping. Simulation results show that the proposed scheme reduces the average bitrate by 40 - 50 % in ordinary VQ system for image compression. In addition, it is shown that the proposed index mapping method can be also applied to mean-residual VQ system, which allows the reduction of bitrate for VQ index by 20 - 30 %(10 - 20 % reduction in total bitrate). Since the proposed scheme is one for noiseless encoding of VQ index, it provides the same quality of the reconstructed image as the conventional VQ system.

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