• Title/Summary/Keyword: Performance indices

Search Result 973, Processing Time 0.041 seconds

The Use of Confidence Interval of Measures of Diagnostic Accuracy (진단검사 정확도 평가지표의 신뢰구간)

  • Oh, Tae-Ho;Pak, Son-Il
    • Journal of Veterinary Clinics
    • /
    • v.32 no.4
    • /
    • pp.319-323
    • /
    • 2015
  • The performance of diagnostic test accuracy is usually summarized by a variety of statistics such as sensitivity, specificity, predictive value, likelihood ratio, and kappa. These indices are most commonly presented when evaluations of competing diagnostic tests are reported, and it is of utmost importance to compare the accuracies of diagnostic tests to decide on the best available test for certain medical disorder. However, it is important to emphasize that specific point values of these indices are merely estimates. If parameter estimates are reported without a measure of uncertainty (precision), knowledgeable readers cannot know the range within which the true values of the indices are likely to lie. Therefore, when evaluations of diagnostic accuracy are reported the precision of estimates should be stated in parallel. To reflect the precision of any estimate of a diagnostic performance characteristic or of the difference between performance characteristics, the computation of confidential interval (CI), an indicator of precision, is widely used in medical literatures in that CIs are more informative to interpret test results than the simple point estimates. The majority of peer-reviewed journals usually require CIs to be specified for descriptive estimates, whereas domestic veterinary journals seem less vigilant on this issues. This paper describes how to calculate the indices and associated CIs using practical examples when assessing diagnostic test performance.

Analysis of the Indices for Economic Effects through Informatization According to Industry Types (정보화 효과지표의 업종별 분석)

  • Lee, Sang-Cheon;Hong, Jung-Wan
    • IE interfaces
    • /
    • v.14 no.4
    • /
    • pp.421-428
    • /
    • 2001
  • The economic effects of informatization are differently occurred according to industry types. Thus an evaluation methodology which reflects the industry type characteristics of informatization is needed. In this paper, we develop and analyze the indices for evaluating economic effects through informatization according to industry types, such as manufacturing, construction, financial services and marketing services. The factors related to performance of enterprise informatization can be defined as cost factors, effect factors, risk factors and influence factors. Effect factors are defined as quantitative or qualitative performance of informatization and classified into operational effect factors and strategic effect factors. The influence factor is defined as characteristics of informatization for industry types, that is, value chain of business and business products or services. Economic effect indices are classified according to the activity of business value chain. Economic effects indices of this research can be expected to play a role of general and standardized factors for economic evaluation of industry informatization.

  • PDF

Effects of EPS Assist Torque on On-center Steering Feel Indices (EPS 어시스트 토크에 의한 온 센터 조타감 성능지수 영향도 분석)

  • Kim, Sang Sup;Kyeong, Jin Sil
    • Transactions of the Korean Society of Automotive Engineers
    • /
    • v.22 no.3
    • /
    • pp.186-193
    • /
    • 2014
  • On-center handling feel indices are the important numerical factors that meaning performance of manuability and stability felt by drivers. They should be considered to suspension design. The major factor that affect to these indices is the shape of assist torque curve. This paper presents the variables that meaning the shape of the assist torque curve and analyze the effect of each variables. And using interaction formulas, it is proposed that the method to extract the variables that satisfy the goal indices. The result of simulation that applied assist torque curve extracted by the method demonstrate the capability of this method with error under 8%.

Comparative Analysis on Performance Indices of Obstacle Detection for an Overlapped Ultrasonic Sensor Ring (중첩 초음파 센서 링의 장애물 탐지 성능 지표 비교 분석)

  • Kim, Sung-Bok;Kim, Hyun-Bin
    • Journal of Institute of Control, Robotics and Systems
    • /
    • v.18 no.4
    • /
    • pp.321-327
    • /
    • 2012
  • This paper presents a comparative analysis on three different types of performance indices of obstacle detection for an overlapped ultrasonic sensor ring. Due to beam overlap, the entire sensing zone of each ultrasonic sensor can be divided into three smaller sensing subzones, which leads to significant reduction of positional uncertainty in obstacle detection. First, the positional uncertainty in obstacle detection is expressed in terms of the area of a sensing subzone, and type 1 performance index is then defined as the area ratio of side and center sensing subzones. Second, based on the area of a sensing subzone, type 2 performance index is defined taking into account the size of the entire range of obstacle detection as well as the degree of the positional uncertainty in obstacle detection. Third, the positional uncertainty in obstacle detection is now expressed in terms of the length of the uncertainty arc spanning a sensing subzone, and type 3 performance index is then defined as the average value of the uncertainty arc lengths over the entire range of obstacle detection. Fourth, using a commercial low directivity ultrasonic sensor, the changes of three different performance indices depending on the parameter of an overlapped ultrasonic sensor ring are examined and compared.

The Impact of Market Orientation Indices, Marketing Innovation, and Competitive Advantages on the Business Performance in Distributer Enterprises

  • Javanmard, Habibollah;Hasani, Hoda
    • The Journal of Industrial Distribution & Business
    • /
    • v.8 no.1
    • /
    • pp.23-31
    • /
    • 2017
  • Purpose - Market orientation is a key factor for business performance in today's fluctuating conditions. This study investigates whether the employment of innovation can improve the innovative capability and increase the performance by gaining competitive advantages or not. Therefore, this study aims to investigate the effects of market orientation on the performance of small and medium size distributer enterprises (SMDEs) in Iran. Research design, data, and methodology - Customer orientation, Competitor orientation, and Inter-functional coordination have been regarded as market orientation indices to determine the effects of these indices on marketing innovation, gaining competitive advantages, and companies' performance as well. Data were collected from managers and experts in SMDEs in Iran. The structural equations modeling are used for analysis. Results - The results indicated that marketing innovation has been improved in competitive companies that enjoyed a high level of Inter-functional coordination among the various units. Besides, marketing innovation resulted in gaining competitive advantages regarding cost management, concentration, and differentiation in these companies. In addition, it was observed that SMDEs that obtain competitive advantages are equipped to reap superior performance. Conclusions - With cost management, differentiation and concentration are more likely to enhance the enterprise efficiency and effectiveness than other companies. Additionally, competitiveness, inter-functional coordination, and marketing innovation in SMDEs have a positive impact on marketing innovation.

A Study of Forecast System for Clear-Air Turbulence in Korea, Part II: Graphical Turbulence Guidance (GTG) System (한국의 청천난류 예보 시스템에 대한 연구 Part II: Graphical Turbulence Guidance (GTG) 시스템)

  • Kim, Jung-Hoon;Chun, Hye-Yeong;Jang, Wook;Sharman, R.
    • Atmosphere
    • /
    • v.19 no.3
    • /
    • pp.269-287
    • /
    • 2009
  • CAT (clear-air turbulence) forecasting algorithm, the Graphical Turbulence Guidance (GTG) system developed at NCAR (national center for atmospheric research), is evaluated with available observations (e.g., pilot reports; PIREPs) reported in South Korea during the recent 5 years (2003-2008, excluding 2005). The GTG system includes several steps. First, 44 CAT indices are calculated in the domain of the Regional Data Assimilation and Prediction System (RDAPS) analysis data with 30 km horizontal grid spacing provided by KMA (Korean Meteorological Administration). Second, 10 indices that performed ten best forecasting scores are selected. Finally, 10 indices are combined by measuring the score based on the probability of detection, which is calculated using PIREPs exclusively of moderate-or-greater intensity. In order to investigate the best performance of the GTG system in Korea, various statistical examinations and sensitivity tests of the GTG system are performed by yearly and seasonally classified PIREPs. Performances of the GTG system based on yearly distributed PIREPs have annual variations because the compositions of indices are different from each year. Seasonal forecasting is generally better than yearly forecasting, because selected CAT indices in each season represent meteorological condition much more properly than applying the selected CAT indices to all seasons. Wintertime forecasting is the best among the four seasonal forecastings. This is likely due to that the GTG system consists of many CAT indices related to the jet stream, and turbulence associated with the jet stream can be activated mostly in wintertime under strong jet magnitude. On the other hand, summertime forecasting skill is much less than other seasons. Compared with current operational CAT prediction system (KITFA; Korean Integrated Turbulence Forecasting System), overall performance of the GTG system is better when CAT indices are selected seasonally.

On the asymptotic correlationship for some process capability indices Ĉp, Ĉpk and Ĉpm (공정능력지수 Ĉp, Ĉpk와 Ĉpm를 위한 점근적 상관성에 관한 연구)

  • Cho, Joong-Jae;Yu, Hye-Kyung
    • Journal of the Korean Data and Information Science Society
    • /
    • v.24 no.3
    • /
    • pp.465-475
    • /
    • 2013
  • Higher quality level is generally perceived by customers as improved performance by assigning a correspondingly higher satisfaction score. Usually, the quality level is measured by process capability indices. The index is used to determine whether a production process is capable of producing items within a specified tolerance. Some useful process capability indices $C_p$, $C_{pk}$ and $C_{pm}$ have been widely used in six sigma industries to assess process performance. Most evaluations on process capability indices focus on point estimates, which may result in unreliable assessments of process performance. It is necessary to investigate their asymptotic correlationship among process capability indices $\hat{C}_p$, $\hat{C}_{pk}$ and $\hat{C}_{pm}$. In this paper, we study their asymptotic correlationship for some process capability indices $\hat{C}_p$, $\hat{C}_{pk}$ and $\hat{C}_{pm}$ under the normal process.

Projecting the spatial-temporal trends of extreme climatology in South Korea based on optimal multi-model ensemble members

  • Mirza Junaid Ahmad;Kyung-sook Choi
    • Proceedings of the Korea Water Resources Association Conference
    • /
    • 2023.05a
    • /
    • pp.314-314
    • /
    • 2023
  • Extreme climate events can have a large impact on human life by hampering social, environmental, and economic development. Global circulation models (GCMs) are the widely used numerical models to understand the anticipated future climate change. However, different GCMs can project different future climates due to structural differences, varying initial boundary conditions and assumptions about the physical phenomena. The multi-model ensemble (MME) approach can improve the uncertainties associated with the different GCM outcomes. In this study, a comprehensive rating metric was used to select the best-performing GCMs out of 11 CMIP5 and 13 CMIP6 GCMs, according to their skills in terms of four temporal and five spatial performance indices, in replicating the 21 extreme climate indices during the baseline (1975-2017) in South Korea. The MME data were derived by averaging the simulations from all selected GCMs and three top-ranked GCMs. The random forest (RF) algorithm was also used to derive the MME data from the three top-ranked GCMs. The RF-derived MME data of the three top-ranked GCMs showed the highest performance in simulating the baseline extreme climate which was subsequently used to project the future extreme climate indices under both the representative concentration pathway (RCP) and the socioeconomic concentration pathway scenarios (SSP). The extreme cold and warming indices had declining and increasing trends, respectively, and most extreme precipitation indices had increasing trends over the period 2031-2100. Compared to all scenarios, RCP8.5 showed drastic changes in future extreme climate indices. The coasts in the east, south and west had stronger warming than the rest of the country, while mountain areas in the north experienced more extreme cold. While extreme cold climatology gradually declined from north to south, extreme warming climatology continuously grew from coastal to inland and northern mountainous regions. The results showed that the socially, environmentally and agriculturally important regions of South Korea were at increased risk of facing the detrimental impacts of extreme climatology.

  • PDF

Data Interpolation and Design Optimisation of Brushless DC Motor Using Generalized Regression Neural Network

  • Umadevi, N.;Balaji, M.;Kamaraj, V.;Padmanaban, L. Ananda
    • Journal of Electrical Engineering and Technology
    • /
    • v.10 no.1
    • /
    • pp.188-194
    • /
    • 2015
  • This paper proposes a generalized regression neural network (GRNN) based algorithm for data interpolation and design optimization of brushless dc (BLDC) motor. The procedure makes use of magnet length, stator slot opening and air gap length as design variables. Cogging torque and average torque are treated as performance indices. The optimal design necessitates mitigating the cogging torque and maximizing the average torque by varying design variables. The data set for interpolation and ensuing design optimisation using GRNN is obtained by modeling a standard BLDC motor using finite element analysis (FEA) tool MagNet 7.1.1. The performance indices of the standard motor obtained using FEA are validated with an experimental model and an analytical method. The optimal design is authenticated using particle swarm optimization (PSO) algorithm and the performance indices of the optimal design obtained using GRNN is validated using FEA. The results indicate the suitability of GRNN as an interpolation and design optimization tool for a BLDC motor.

Seismic Performance Assessment of Reinforced Concrete Bridge Piers using Damage Indices (손상지수를 이용한 철근콘크리트 교각의 내진성능평가)

  • 김태훈;정영수;신현목
    • Proceedings of the Korea Concrete Institute Conference
    • /
    • 2003.11a
    • /
    • pp.144-147
    • /
    • 2003
  • This paper presents a nonlinear finite element analysis procedure for the seismic performance assessment of reinforced concrete bridge piers using damage indices. The accuracy and objectivity of the assessment process may be enhanced by the use of sophisticated nonlinear finite element analysis program. A computer program, named RCAHEST(Reinforced Concrete Analysis in Higher Evaluation System Technology), for the analysis of reinforced concrete structures was used. Damage indices aim to provide a means of quantifying numerically the damage reinforced concrete bridge piers sustained under earthquake loading. The proposed numerical method for the seismic performance assessment of reinforced concrete bridge piers is verified by comparison with the reliable experimental results.

  • PDF