• The Journal of Korea Robotics Society
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• v.9 no.1
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• pp.28-38
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• 2014

This paper verifies the performance of Extended Kalman Filter(EKF) and MCL(Monte Carlo Localization) approach to localization of an underwater vehicle through experiments. Especially, the experiments use acoustic range sensor whose measurement accuracy and uncertainty is not yet proved. Along with localization, the experiment also discloses the uncertainty features of the range measurement such as bias and variance. The proposed localization method rejects outlier range data and the experiment shows that outlier rejection improves localization performance. It is as expected that the proposed method doesn't yield as precise location as those methods which use high priced DVL(Doppler Velocity Log), IMU(Inertial Measurement Unit), and high accuracy range sensors. However, it is noticeable that the proposed method can achieve the accuracy which is affordable for correction of accumulated dead reckoning error, even though it uses only range data of low reliability and accuracy.

• Korean Journal of Construction Engineering and Management
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• v.5 no.2 s.18
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• pp.202-210
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• 2004

Under the current competitive business environment, the complexity of procurement method, and the lack of engineering capacity in the construction engineering industry, a construction engineering firms require the business strategy and its performance measurement system. This study suggests a performance measurement model that could follow 'H' construction engineering firm's vision and strategy. The model utilizes the concept of Balanced Scorecard. The study proposes the four main performance perspectives such as financial, growth, internal efficiency, and improvement & learning through the long-term strategy analysis, SWOT analysis, and interviews of the employees. Also the study develops the critical success factor and the key performance indicators. The usefulness of the performance measurement model is validated through the gap analysis such as alignment analysis and consensus analysis.

• Smart Structures and Systems
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• v.30 no.3
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• pp.287-301
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• 2022

The machine-vision based structural displacement measurement methods are widely used due to its flexible deployment and non-contact measurement characteristics. The accuracy of vision measurement is directly related to the image resolution. In the field of computer vision, super-resolution reconstruction is an emerging method to improve image resolution. Particularly, the deep-learning based image super-resolution methods have shown great potential for improving image resolution and thus the machine-vision based measurement. In this article, we firstly review the latest progress of several deep learning based super-resolution models, together with the public benchmark datasets and the performance evaluation index. Secondly, we construct a binocular visual measurement platform to measure the distances of the adjacent corners on a chessboard that is universally used as a target when measuring the structure displacement via machine-vision based approaches. And then, several typical deep learning based super resolution algorithms are employed to improve the visual measurement performance. Experimental results show that super-resolution reconstruction technology can improve the accuracy of distance measurement of adjacent corners. According to the experimental results, one can find that the measurement accuracy improvement of the super resolution algorithms is not consistent with the existing quantitative performance evaluation index. Lastly, the current challenges and future trends of super resolution algorithms for visual measurement applications are pointed out.

• International conference on construction engineering and project management
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• 2009.05a
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• pp.1294-1299
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• 2009

Best value in value engineering has relation to cost and performance. But a severe problem in VE study of a project is to reduce value due to loss of performance, caused by focusing on cost reduction. Also a lack of understanding performance concept, no trial VE workshop as well as cost saving-based policy have not satisfied customer needs. A efficient and practical methodology for accomplishing best value in construction projects is proposed. This study developed a more objective approach for performance measurement approach of mega projects and suggested a systematic process of performance quantitative analysis verifying value improvement. The proposed performance measurement method would be very useful for better communication and consensus between stakeholders and VE team especially through value engineering.

• The Journal of Korea Robotics Society
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• v.2 no.3
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• pp.270-274
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• 2007

In this paper, we present a Sound Source Localization (SSL) based GCC (Generalized Cross Correlation)-PHAT (Phase Transform) and new measurement method of angle with robot auditory system for a network-based intelligent service robot. The main goal of this paper is to analysis performance of TDOA and GCC-PHAT sound source localization method and new angle measurement method is compared. We use GCC-PHAT for measuring time delays between several microphones. And sound source location is calculated by using time delays and new measurement method of angle. The robot platform used in this work is wever-R2, which is a network-based intelligent service robot developed at Intelligent Robot Research Division in ETRI.

• Current Optics and Photonics
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• v.2 no.2
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• pp.153-164
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• 2018

In semiconductor manufacturing, critical dimensions indicate the features of patterns formed by the semiconductor process. The purpose of measuring critical dimensions is to confirm whether patterns are made as intended. The deposition process for an organic light emitting diode (OLED) forms a luminous organic layer on the thin-film transistor electrode. The position of this organic layer greatly affects the luminescent performance of an OLED. Thus, a system for measuring the position of the organic layer from outside of the vacuum chamber in real-time is desired for monitoring the deposition process. Typically, imaging from large stand-off distances results in low spatial resolution because of diffraction blur, and it is difficult to attain an adequate industrial-level measurement. The proposed method offers a new superresolution single-image using a conversion formula between two different optical systems obtained by a deep learning technique. This formula converts an image measured at long distance and with low-resolution optics into one image as if it were measured with high-resolution optics. The performance of this method is evaluated with various samples in terms of spatial resolution and measurement performance.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.8
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• pp.113-121
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• 1999

It is necessary to calibrate measurement systems to enhance its measurement accuracy. The visual sensing system that is presented in our previous work has to be calibrated, too. It is a multiple mirror system for three-dimensional measurement, which is composed of a camera and a series of mirrors. It is important to calibrate the positions and orientations of the mirrors relative to the camera because they have direct influence on the relationship between the image plane and the task space. This paper presents the calibration method for the visual sensing system. To confirm the measurement performance of the implemented system. its measurement accuracy in measuring the locations in three-dimensional space is investigated. A series of experiments for measuring the locations of the circle-shaped marks are performed. Experimental results show that the sensing system can be effectively used for three-dimensional measurement.

• Journal of Digital Convergence
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• v.11 no.1
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• pp.99-106
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• 2013

Personal information protection has become one of the most impending business issues because leakage of personal information can cause tremendous financial losses and image degradation. Consequently, personal information protection initiatives have been recognized widely in business. To invigorate personal information protection investments, performance measurement method such as cost benefits analysis or qualitative analyses are needed, which have not been studied enough in the previous studies. This study proposes a performance measurement model which can include quantitative and qualitative analyses in the context of personal information protection investments. A comparative analysis has been performed on security investment and IT investment performance measurements, which leads to choose the WiBe method (developed by the German Interior Ministry), considering the privacy characteristics and the method's applicability. In particular, the quantitative effect measured how proactive threat assessment based on the way according to the nature of the businesses and organizations of privacy and possible investment decisions. This study proposes the 16 performance indicators, which turn out to be meaningful in terms of their materiality and feasibility by conducting focus group interviews of 25 experts on personal information protection.

• Journal of the Korean Society of Propulsion Engineers
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• v.5 no.1
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• pp.69-75
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• 2001

Linear GPA(Gas Path Analysis) and non-linear GPA programs for performance diagnostics of a turboprop engine were developed, and a study for selection of optimal measurement variables was performed. Simultaneous faults in the compressor, the compressor turbine and the power turbine, which occur damage of the engine, were assumed. The non-linear GPA analysis was carried out with an iterative method, where the performance degradation rate of independent parameters was divided into same intervals. It was compared with the result by the Newton-Raphson method for observing the effect of an iterative method. According to the analysis result, it was found that performance of non-linear GPA can be influenced on the type of the iterative method. For showing effects of the number of measurement variables both the linear and non-linear GPAs were analyzed with 10, 8 and 6 measurement sets, respectively. RMS error between them were compared each other. It was realized that the more measurement parameters are used, and the more accurate result may be obtained. However much better result can be obtained with measurement parameters selected properly Moreover, RMS error by using non-linear GPA was less than that by using linear GPA.

• Journal of the Korea Society of Computer and Information
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• v.28 no.9
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• pp.93-104
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• 2023

In modern society, the service method is tended to prefer the non-face-to-face method rather than the face-to-face method. However, services that recommend products such as shoes will inevitably be face-to-face method. In this paper, for the purpose of non-face-to-face service, a system that a foot size is automatically measured and some shoes are recommended based on the measurement result is proposed. To analyze the performance of the proposed method, size measurement error rate and recommendation performance were analyzed. In the recommendation performance experiments, a total of 10 methods for similarity calculation were used and the recommendation method with the best performance among them was applied to the system. From the experiments, the error rate the foot size was small and the recommendation performance was possible to derive significant results. The proposed method is at the laboratory level and needs to be expanded and applied to the real environment. Also, the recommendation method considering design could be needed in the future work.