• Journal of the Korean Society of Industry Convergence
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• v.22 no.3
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• pp.251-257
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• 2019

This paper proposes a new measurement method using virtual power concept to measure the effective value of 3-phase voltage with variable frequency. The conventional effective value measurement method uses a method of integrating data sampled during one or half cycle of the power voltage and averaging it. In this method, since the effective voltage is calculated every cycle, a time delay occurs in the measured effective voltage and it is s a problem to measure the effective value of a device whose frequency varies from time to time, such as a generator. The proposed 3-phase voltage rms measurement method has an advantage that it can measure accurate voltage RMS value regardless of measurement frequency variation. In particular, there is an advantage in that it is possible to measure a 3-phase effective voltage rather than an average value of the effective voltage of each phase in a 3-phase unbalance voltage. In addition, the validity of the proposed method is verified by using the Psim simulation tool and the experimental results are analyzed by applying the proposed measurement algorithm to the actual three phase synchronous generator voltage measurement experiment.

• Korean Journal of Construction Engineering and Management
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• v.4 no.3 s.15
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• pp.137-145
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• 2003

The project control system based on the actual values of three objects shall be operated continuously in a timely manner. For collecting/tracking accurate actual performance data, a reasonable basis of measuring work performance and its related measuring methods are needed. Therefore, this research proposes a method of developing and operating the construction progress measurement system. The problem of the conventional method is the difficulty to construct control accounts and to define the basis of measuring the performance of each control account. Therefore, this research proposes the preferable, formal methodology that produces the progress value of the smallest work unit by surveying the installed quantities and estimates percent complete of groups of works or entire project by earned value concept. This research in connection with the hereafter research of the weight value of control accounts will contribute to apply in practice and to develop the scientific construction management technique in the construction industry. Further researches how to trend and forecast the project using the measured progress value are recommended for putting the prosed system of this research to practical use.

• The Korean Journal of Applied Statistics
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• v.34 no.1
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• pp.99-114
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• 2021

With the Fourth Industrial Revolution based on new technology, the semiconductor manufacturing industry researches various analysis methods such as detecting process abnormalities and predicting yield based on equipment sensor data generated in the manufacturing process. The semiconductor manufacturing process consists of hundreds of processes and thousands of measurement processes associated with them, each of which has properties that cannot be defined by chemical or physical equations. In the individual measurement process, the actual measurement ratio does not exceed 0.1% to 5% of the target product, and it cannot be kept constant for each measurement point. For this reason, efforts are being made to determine whether to manage by using equipment sensor data that can indirectly determine the normal state of each step of the process. In this study, the Functional Data Analysis (FDA) was proposed to define a process abnormality detection process based on equipment sensor data and compensate for the disadvantages of the currently applied statistics-based diagnosis method. Anomaly detection accuracy was compared using machine learning on actual field case data, and its effectiveness was verified.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.32 no.4
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• pp.456-464
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• 2022

Objectives: The Purpose of this study is to improve work environment measurement in construction industry by survey. Especially, this study focused on the defferences between construction staffs(safety manger, health manager) and work environment measurement institution workers. Methods: Survey targets are construction staffs(safety manger, health manager) and work environment measurement institution workers. Respondent was selected by respective councils and conferences. A questionnaire consisting of items on general characteristics and the improvement of work environment measurement in construction industry. Results: Total of 134 people(39 safety managers, 27 health managers, 68 work environment measurement institution workers) responded to survey. Overall, current work environment measurement was deemed unsuitable for construction industry. There was a significant difference between construction staff and work environment institution workers in some question. On the other hand, there was no noticeable significant difference in general characteristics. Conclusions: As a result of survey, current work environment measurement was deemed unsuitable for construction industry in terms of measurement method, measurement timing, and actual site improvement. In addition, there is a statistically significant differences in response between construction staff and work environment measurement institution workers, so it is necessary to reflect both opinions in order to improve work environment measurement in construction industry.

• Journal of KSNVE
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• v.11 no.1
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• pp.57-67
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• 2001

Proposed in this paper is a method of measurement of the flow rate in a pipe. The sound waves which are propagated within a pipe are characterized by that the wavenumber in the axial direction is changed according to the flow rate, and these characteristics are used in the present method of measurement of the flow rate. The amount of change in wavenumber of sound waves according to the flow rate can be obtained from the relationship among acoustic pressure signals within a pipe, which are measured by using a microphone array. The flow rate can be obtained by using the amount of change in wavenumber of sound waves and the relational equation of the flow rate. With respect to errors that can occur during the measurement of the flow rate, the types of errors and the method of correction of those errors are presented. This method of measurement of the flow rate has application limitation conditions due to the sensor interval, assumption of sound waves as plane waves, etc. The numerical simulation and experiments for measuring the flow rate of air in a pipe are performed in order to verify the applicability of this method of measurement of the flow rate. The experimental results are shown to be similar to those of the numerical simulation. And the flow rate measured is shown to be consistent with the actual value within 5% error bound.

• Journal of the Korea Society of Computer and Information
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• v.15 no.10
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• pp.137-145
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• 2010

This paper is proposed non-contact plant growth measurement system using infrared sensor based on USN(Ubiquitous Sensor Network) technologies. The proposed system has used noncontact sensors to reduce any potential damage when it measures the growth of the plant. In this system, plant growth parameters such as diameter, cross-sectional area and thickening form are measured in real-time non-contact method. The measured data are transmitted to remote server by using sensor network technologies, stored and analyzed at the server, and the analyzed data are finally provided for users. In this paper, the proposed plant growth measurement system has been designed and implemented using non-contact infrared sensor based measurement methods and devices, and its performances have been verified by actual measurement experiments at the fields.

• Journal of Electrical Engineering and Technology
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• v.10 no.3
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• pp.1328-1334
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• 2015

A new system for evaluating the voltage management errors of distribution equipment is presented in this paper. The main concept of the new system is to use real distribution live-line voltage to evaluate and correct the voltage measurement data from distribution equipment. This new approach is suitable for a new Distribution Management System (DMS) which has been developed for a distribution power system due to the connection of distributed generation growth. The data from distribution equipment that is installed at distribution lines must be accurate for the performance of the DMS. The proposed system is expected to provide a solution for voltage measurement accuracy assessment for the reliable and efficient operation of the DMS. An experimental study on actual distribution equipment verifies that this voltage measurement accuracy assessment system can assess and calibrate the voltage measurement data from distribution equipment installed at the distribution line.

• Journal of Korean Academy of Nursing Administration
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• v.11 no.4
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• pp.385-399
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• 2005

Objective: The objective was to extract a preliminary performance measurement indicators of nursing organizations in hospitals using the BSC(Balanced Score Card) developed by Kaplan and Norton, and to analyze the content validity and evaluation methods of the performance measurement indicators with actual nurses in the nursing organization as participants in the study. Methods: The preliminary performance measurement indicators was created through a literature review and had the content validity by a professional. This survey was sent via post to 316 nurse managers and nurses with more than 5 years of experience in seven secondary and tertiary hospitals in the Seoul Gyonggi district. The completed questionnaires were returned by mail. Results: Fourteen indicators for finances, 16 for customer services, 27 for internal business processes, and 13 for learning and growth were selected. Conclusion: Amidst a rapidly changing medical environment, a first step was taken towards developing a performance measurement from various perspectives for nursing organizations in hospitals from various perspectives, rather than just one or a past-oriented perspective. However, as the most important thing is to actually use these indicators, continuous interest in publicity and education must be developed.

• Journal of the Korean Society for information Management
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• v.28 no.1
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• pp.309-326
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• 2011

Most metadata quality measurement employ simple techniques by counting error records. This study presents a new quantitative measurement of metadata quality using advanced weighting schemes in order to overcome the limitations of exiting measurement techniques. Entropy, user tasks, and usage statistics were used to calculate the weights. Integrated weights were presented by combining these weights and were applied to actual journal article metadata. Entropy weights were found to reflect the characteristics of the data itself. User tasks presented the required metadata elements to solve user's information need. Integrated weights showed balanced measures without being affected by the influence of error elements, This finding indicates the new method being suitable for quantitative measurement of metadata quality.

• Journal of Biomedical Engineering Research
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• v.41 no.6
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• pp.219-227
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• 2020

In this study, we tried to quantify the actual cross-sectional area inside the bore when scanning by the MRI system with various bore sizes. To this end, a comparative analysis was conducted by both of blueprint of each MRI equipment and actual measurement in the field. As a result of analysis, ACSA(Actual Cross-Sectional Area) in Ingenia CX, Elition X, uMR 780, Omega, Vida, Lumina, Architect, Premier is recorded as 171230, 232150, 242100, 309332, 230760, 230760, 229380 and 235990 ㎟, respectively ACSA% was 60.6, 60.3, 73.0, 70.0, 60.0, 60.0, 59.6, and 61,3%. In addition, DTB (Distance from Table top to Bore top) recorded 400, 407, 445, 495, 405, 405, 405, 403, and 412 mm. Through this study, it was confirmed that there is a difference between the bore size according to each MRI system and the actual cross-sectional area during MRI scanning. Accordingly, if we consider the internal actual area just not bore size at the clinical site, useful diagnostic images can be obtained in the end with better convenience.