• Journal of KIISE:Computing Practices and Letters
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• v.15 no.6
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• pp.454-458
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• 2009

The technology of virtual environments has been developed with better-quality appearance on a computer display in mind, but without consideration for objects' precise measurements in physical units. With the increased application of computer graphics in a variety of areas, there is a need for precise measurement functionality in addition to visualization. This paper describes the definition of physical properties using measurement units for X3D based virtual objects, to provide their precise physical information in virtual environments. To this end, we have included the physical property node in the X3D specification. The physical measurement units, such as length, mass, time, temperature, etc., are based on SI units (International System of Units).

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2005.05a
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• pp.77-80
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• 2005

In this paper we write to the result of measuring human body shape method-ibs-2000 for human body shape measurement. The size measurement units and measuring speed is very inportant to efficiency of human body shape measurement units. By polygonal mirror system, the size measurement units and measuring time can be retrench.

• Journal of architectural history
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• v.25 no.4
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• pp.65-73
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• 2016

This paper aimed to identify the units of measuring scale in Hwangnyongsa temple planning with the published excavation survey reports. Hwangyongsa temple site was planned under Silla Capital's urban planning in 6~7C, its full size was $800{\times}800$, and main temple was $400{\times}515$ of Goguryeo's system of measurement. Main hall was located in the center of Hwangnyongsa temple site, and its location could be seen that there was the arrangement of main temple divided into 3 : 2. Building plan measuring units proved to be 351~356mm and 294~ 296mm by analyzing measured data of remains. Lecture hall and Wooden pagoda were rebuilt by using the ancestors' units of measuring scale again and Bell hall was not planned by Tang's system of measurement in middle of 8C. In this respect, it would be important to have a deliberate attitude and lay down stereotypes on research of the units of measuring scale in ancient architecture.

• The Mathematical Education
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• v.62 no.4
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• pp.457-471
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• 2023

Measurement is an imperative content area of early elementary mathematics, but it is reported that students' understanding of units in measurement situations is insufficient despite its importance. Therefore, this study examined lower-grade elementary students' quantitative reasoning of units in length measurement by identifying the levels of reasoning of units. For this purpose, we collected and analyzed the responses of second-grade elementary school students who engaged in a set of length measurement tasks using an open number line in terms of unitizing, iterating, and partitioning. As a result of the study, we categorized students' quantitative reasoning of unit levels into four levels: Iterating unit one, Iterating a given unit, Relating units, and Transforming units. The most prevalent level was Relating units, which is the level of recognizing relationships between units to measure length. Each level was illustrated with distinct features and examples of unit reasoning. Based on the results of this study, a personalized plan to the level of unit reasoning of students is required, and the need for additional guidance or the use of customized interventions for students with incomplete unit reasoning skills is necessary.

• Proceedings of the Korean Society for Quality Management Conference
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• 1998.11a
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• pp.345-352
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• 1998

Performance measurement is increasingly becoming a vital issue for promoting quality management within an organization. This research proposes a new performance measurement approach, called the Hierarchically Associated Performance Measurement, for the organizations which emphasize long term quality thrust through a balanced interface between the quality efforts of various units. The proposed approach is unique in that it considers relationships between internal quality activities and national quality award criteria and that it identifies and utilizes the quality responsibilities of functional units in order to encompass organizational roles in the evaluation process. The approach is illustrated via a numerical evaluation of a fictitious organization.

• Proceedings of the Safety Management and Science Conference
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• 2009.11a
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• pp.649-657
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• 2009

The paper presents the measurement split split-plot models for saving the time and cost. The split split-plot designs developed are efficiently used to estimating the gauge R&R(Reproducibility & Repeatability) when the completely randomized design of all factors(such as high pressure and temperature) is expensive and time consuming. The models studied include three split split-plots considering the type of experimental units.

• Journal of Electrical Engineering and Technology
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• v.10 no.1
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• pp.18-29
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• 2015

State Estimation (SE) is the basis of a variety of advanced applications used in most modern power systems. An SE problem formed with enough phasor measurement units (PMUs) data is simply a linear weighted least squares problem requiring no iterations. Thus, designing a minimum-cost placement of PMUs that guarantees observability of a power system becomes a worthy challenge. This paper proposes an equivalent integer linear programming method for substation-oriented optimal PMU placement (SOOPP). The proposed method uses an exhaustive search to determine a globally optimal solution representing the best PMU placement for that particular power system. To obtain a more comprehensive model, contingencies and the limitation of the number of PMU measurement channels are considered and embodied in the model as changes to the original constraints and as additional constraints. The proposed method is examined for applicability using the IEEE 14-bus, 118-bus and 300-bus test systems. The comparison between SOOPP results and results obtained by other methods reveals the excellence of SOOPP. Furthermore, practical large-scale power systems are also successfully analyzed using SOOPP.

• Korean Journal of Child Studies
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• v.25 no.1
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• pp.13-29
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• 2004

In this study of strategies used by young children in solving rectangular covering tasks before they have been taught area measurement, 75 5-, 6-, and 7-year-old children were asked to solve 3 rectangular covering tasks with a moveable unit. Three different sized units (4 cm., 2 cm., and 1 cm. cardboard squares) were provided and the children were asked to work out how many would be needed to cover a drawn rectangle. The resulting 5 developmental levels include incomplete covering, incomplete arrangement, complete covering, estimating, and measuring. Children using more advanced strategies were able to find correct number of units. While the tendency among older children was to use more advanced strategies, even 5-year-olds had an intuitive understanding of rectangular area measurement.

• Journal of Electrical Engineering and Technology
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• v.10 no.2
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• pp.474-486
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• 2015

This paper proposes a multi-objective optimal placement method of Phasor Measurement Units (PMUs) in large electric transmission systems. It is proposed for minimizing the number of PMUs for complete system observability and maximizing measurement redundancy of the buses, simultaneously. The measurement redundancy of the bus indicates that number of times a bus is able to monitor more than once by PMUs set. A high level of measurement redundancy can maximize the system observability and it is required for a reliable power system state estimation. Therefore, simultaneous optimizations of the two conflicting objectives are performed using a binary coded firefly algorithm. The complete observability of the power system is first prepared and then, single line loss contingency condition is added to the main model. The practical measurement limitation of PMUs is also considered. The efficiency of the proposed method is validated on IEEE 14, 30, 57 and 118 bus test systems and a real and large- scale Polish 2383 bus system. The valuable approach of firefly algorithm is demonstrated in finding the optimal number of PMUs and their locations by comparing its performance with earlier works.

• Proceedings of the KIEE Conference
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• 2001.05a
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• pp.92-94
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• 2001

This paper investigated the real-time generator swing prediction by some researchers. And the first swing stability assessment based on EAC(Equal-Area Criterion) by using phasor measurement unit is proposed. Also we proposed the multi-swing prediction techniques, which is to estimate system parameters by using least square method / extrapolation with phasor measurement units. And the multi-swing prediction is performed with the estimated parameters. Future works are necessary to verify the proposed approaches in this paper.