• Journal of Biosystems Engineering
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• v.23 no.5
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• pp.481-490
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• 1998

A computer vision system to measure low flow rate of solid particles was developed and tested to examine its performance with various sized 7 kinds of seeds, perilla, mung bean, paddy, small red bean, black soybean, Cuba bean and small potato tuber. The test was performed for two types of particle flow, continuous and discontinuous. For the continuous flow tested with perilla, mung bean and paddy, the tests resulted correlation coefficients for the flow rates measured by the computer vision and direct method about 0.98. Average errors of the computer vision measurement were in a range of 6∼9%. For the discontinuous flow tested with small red bean, black soybean, Cuba bean and small potato tuber, the tests resulted correlation coefficients for the flow rates measured by the computer vision and direct method 0.98∼0.99. Average errors of the computer vision measurement were in a range of 5∼10%. Performance of the computer vision system was compared with that of the conventional optical sensor to count particles in discontinuous flow. The comparison was done with black soybean, Cuba bean and small potato tuber, and resulted that the computer vision has much better performance than the optical sensor in a sense of precision of the measurement.

• Journal of the Korea Institute of Military Science and Technology
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• v.21 no.1
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• pp.61-68
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• 2018

In this paper, we described about methods and results to verify the Tx/Rx beam characteristics of a planar active phased array antenna as using a near-field measurement. The near-field system can effectively measure multiple beams and predict the performance degradation due to the partial failure of individual elements. Also, it can accurately predict the EIRP relating to detection performance of the active phased array radar. We briefly described the near-field measurement method to verify the Tx/Rx beam characteristics, and then verified the effectiveness of measurement method by analyzing the measured results.

• Journal of Korea Society of Industrial Information Systems
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• v.10 no.2
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• pp.87-101
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• 2005

Many studies on the SCM related topics have been carried out during the last decade. However, most of research focused on identifying critical success factors of SCM with collaborations between partners. There have been a need for the integrated SCM success model and for identifying indicators of SCM performance measurement. In this study, we suggest the SCM success model classifying 5 aspects with key indicators for measurement. The suggested model can be applied to the measurement of SCM success.

• Journal of the Korean Operations Research and Management Science Society
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• v.16 no.2
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• pp.109-109
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• 1991

We have recognized that an organization should be viewed from a multifaceted perspective necessitating a sophisticated analytical and systematic approach to monitor and improve organizational performance. Although some performance measurement systems have been proposed and are currently being used in many organizations, no performance measurement system has presented a mechanism for integrating all of the information of performance measures in a way that considers relationships between them. This paper introduces the implementation of the performance information integration method(PIIM) which synthesizes all useful information of performance measures with consideration of the relationship and generates a single, global, organizational performance score. The PIIM was empirically validated by implementing in one of Missouri Veterans Homes

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.2
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• pp.255-260
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• 2006

Safety-critical navigation systems have to provide 'reliable' position solutions, i.e., they must detect and exclude measurement or system faults and estimate the uncertainty of the solution. To obtain more accurate and reliable navigation systems, various filtering methods have been employed to reduce measurement noise level, or integrate sensors, such as global navigation satellite system/inertial navigation system (GNSS/INS) integration. Recently, particle filters have attracted attention, because they can deal with nonlinear/non-Gaussian systems. In most GNSS applications, the GNSS measurement noise is assumed to follow a Gaussian distribution, but this is not true. Therefore, we have proposed a fault detection and exclusion method using particle filters assuming non-Gaussian measurement noise. The performance of our method was contrasted with that of conventional Kalman filter methods with an assumed Gaussian noise. Since the Kalman filters presume that measurement noise follows a Gaussian distribution, they used an overbounded standard deviation to represent the measurement noise distribution, and since the overbound standard deviations were too conservative compared to the actual distributions, this degraded the integrity-monitoring performance of the filters. A simulation was performed to show the improvement in performance of our proposed particle filter method by not using the sigma overbounding. The results show that our method could detect smaller measurement biases and reduced the protection level by 30% versus the Kalman filter method based on an overbound sigma, which motivates us to use an actual noise model instead of the overbounding or improve the overbounding methods.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.11
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• pp.2191-2198
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• 2017

The PME(precision measurement equipment) used in the measurement to check the performance of the equipment in military weapon system is periodically calibrated to maintain measurement reliability during the life cycle. Previous studies suggest that reliability models are determined by considering sample size and characteristics of equipment. However, it may not be fit well to apply a single model assuming the same characteristic distribution for the maintenance date of many kinds of PMEs. This paper proposes that the most suitable calibration interval for maintenance data is selected through the F-test and the performance index evaluation among the calibration intervals estimated from the measurement reliability models assuming the characteristic of the bath-tub curve during the life cycle of various PMEs. The research results show that the reliabilities of various types of equipment are maintained during calibration intervals.

• The Mathematical Education
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• v.58 no.2
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• pp.283-298
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• 2019

Among the measurement attributes included in the elementary school mathematics curriculum, perimeter, area, volume and surface area are intensively covered in fifth and sixth graders. However, not much is known about the level of student performance and difficulties in this area. The purpose of this study is to examine the understanding and performance of sixth-grade elementary school students on some ideas of measurement and ultimately to give some suggestions for teaching measurement and the development of mathematics textbooks. For this, diagnosis questions were developed in relation to the following parts: measurement of perimeter and area of plane figure, measurement of surface area and volume of solid figure, and the relationships between perimeter and area, and the relationships between surface area and volume. The performances of 95 sixth graders were analyzed for this study. The results showed children's low performance in the measurement area, especially measurement of perimeter and surface area, and relationship of the measurement concepts. Finally, we proposed the introduction order of the measurement concepts and what should be put more emphasis on teaching measurement. Specifically, it suggested that we consider placing a less demanding concept first, such as the area and volume, and dealing more heavily with burdensome tasks such as the perimeter and surface area.

• Journal of the Korea institute for structural maintenance and inspection
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• v.28 no.3
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• pp.1-9
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• 2024

This study proposes a multi-scale template matching technique with image pyramids (TMI) to measure structural dynamic displacement using a vision sensor under atmospheric turbulence conditions and evaluates its displacement measurement performance. To evaluate displacement measurement performance according to distance, the three-story shear structure was designed, and an FHD camera was prepared to measure structural response. The initial measurement distance was set at 10m, and increased with an increment of 10m up to 40m. The atmospheric disturbance was generated using a heating plate under indoor illuminance condition, and the image was distorted by the optical turbulence. Through preliminary experiments, the feasibility of displacement measurement of the feature point-based displacement measurement method and the proposed method during atmospheric disturbances were compared and verified, and the verification results showed a low measurement error rate of the proposed method. As a result of evaluating displacement measurement performance in an atmospheric disturbance environment, there was no significant difference in displacement measurement performance for TMI using an artificial target depending on the presence or absence of atmospheric disturbance. However, when natural targets were used, RMSE increased significantly at shooting distances of 20 m or more, showing the operating limitations of the proposed technique. This indicates that the resolution of the natural target decreases as the shooting distance increases, and image distortion due to atmospheric disturbance causes errors in template image estimation, resulting in a high displacement measurement error.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.1
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• pp.348-354
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• 2012

This paper presents a framework for quantitative software development performance measurement and analysis based on characteristics of software in System on Chip (SoC) industry, one of the semiconductor businesses. In this paper, we propose a measurement model based on not only theoretical model (Performance Pyramid) but also characteristics of SoC embedded software. Quantitative software development performance measurement is not just collecting indicators but analyzing quality, cost, and delivery (QCD) of collected indicators. Externally, it is possible for programmers to develop software meeting customers' needs. Internally, more efficient software development can be possible through the visible productivity increase. Using the proposed framework, the paper quantitatively measures embedded software development performance.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.32 no.9
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• pp.122-129
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• 2004

An accurate thrust measurement is one of the critical paths to the successful test and evaluation program of small liquid propulsion engines. This study describes the design factors for the development of thrust measurement system (TMS) as well as manufacturing practice of TMS hardware. We investigate characteristics of the TMS and its performance through hot-firing test of small liquid engine in a vacuum test cell which is capable of simulating 100,000 ft of altitude or higher. For performance test of TMS, we measure thrusts by changing propellant injection pressure at steady state firing mode as well as at pulse firing mode. Measured eigen frequency of the TMS is 67 Hz. Linearity test of the TMS shows good performance with less than 0.5% of linearity error.