• Korean Journal of Construction Engineering and Management
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• v.9 no.2
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• pp.182-189
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• 2008

In private and public construction works, cost estimation and site productivity management are based on designed labor quantities calculated by the Standard Quantities per Unit (SQU). The designed labor quantities are regarded as the basis for insurance costs and safety and environmental costs and also affect the progress measurement of construction works. Even though the designed labor quantities from the SQU has been considered to be different from actual labor quantities put to construction works, there is no research that empirically analyzes the statistical differences. This study analyzes actual labor quantities of form workers, steel-bar fabricators, concrete pourers in reinforced concrete works of the 43 apartment projects, and compares the actual labor quantities to labor quantities from the SQU. It goes further to scrutinize the critical reasons underlying the differences through a survey on 65 practitioners and interviews with 32 site managers and supervisors. The regression models of labor quantities of the apartment concrete work produced by the present study will contribute to reasonable construction contracts based on the past actual costs and practical site management by the actual labor quantities.

• Journal of the Korean Society of Safety
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• v.37 no.6
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• pp.9-17
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• 2022

Qualifying quantities (upper tier (UT) and lower tier (LT)) are designated for the regulation of toxic substances. In this study, we aimed to establish systematic criteria for the qualifying quantities by comparing the South of Korea chemical control act with the European Seveso III Directive (Seveso III). In Seveso III, qualifying quantities are defined as "hazard categories" applying GHS (Globally Harmonized System of Classification and Labelling of Chemicals), and LTR (lower-tier requirements) and UTR (upper-tier requirements) are determined. The Pro HC (proposed hazard categories) were relevant to the GHS classification of toxic substances and were compared with the currently regulated qualifying quantities. Furthermore, we estimated the Pro LTR (proposed lower-tier requirements) and Pro UTR (proposed upper-tier requirements) corresponding to each Pro HC. Consequently, it was supposed that LT and UT were selected based on GHS like those of Seveso III. Therefore, designation criteria for qualifying quantities should be established by setting the Pro HC such as in Seveso III, rather than designating the qualifying quantities of toxic substances by itself individually. In addition, qualifying quantities should not be delegated to GHS classifications (H302, H341, H411) that do not meet the criteria for the designation of toxic substances, and the corresponding substances should be excluded from classification as toxic substances. This study provides insights into the selection of hazard categories and criteria for qualifying quantities of toxic substances.

• Korean Management Science Review
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• v.27 no.2
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• pp.31-44
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• 2010

It is very important to forecast demand and determine the optimal procurement quantities of spare parts. The Army has been forecasting demand not with actual usage of spare parts but with request quantities. However, the Army could not purchase all of forecasted demand quantities due to budget limit. Thus, the procurement quantities depend on the item managers' intuition and their meetings. The system currently used contains many problems. This study suggests a new determination procedure; 1) forecasting demand method based on actual usage, 2) determining procurement method through LP model with budge and other constraints. The newly determined quantities of spare parts is verified in the simulation model, that represents the real operational and maintenance situation to measure the operational availability. The result shows that the new forecasting method with actual usage improves the operational availability. Also, the procurement determination with LP improves the operational availability as well.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.23 no.5
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• pp.383-387
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• 2010

The response characteristics of AE (acoustic emission) sensors with a coupled vibration mode and a non-coupled vibration mode were investigated according to PD(partial discharge) quantities in XLPE (cross linked polyethylene) sheets and craft papers immersed in insulating oil. The response voltages of a coupled vibration mode AE sensor were linearly proportional to the PD quantities up to 1,000 pC in XLPE sheets, while a non-coupled vibration mode AE sensor did not show the similar linearity. In case of a test of craft papers immersed in insulating oil, a linearity between response voltages and PD quantities was observed up to 550 pC, but after that, similar linearity between response voltage of any types of AE sensor and PD quantities was not shown.

• Korean Journal of Logic
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• v.14 no.3
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• pp.137-176
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• 2011

Bob Hale recently proposed a theory of real numbers based on abstraction principles. In his theory, real numbers are regarded as ratios of quantities and the criteria of identities of ratios of quantities are given by an Eudoxan ratio principle. The reason why Hale defines real numbers as ratios of quantities is that he wants to satisfy Frege's requirement that arithmetical concepts should be defined to be adequate for their universal applicability. In this paper I show why Hale's explanation of applications of real numbers fails to satisfy Frege's requirement, and I propose an alternative explanation. At first I show that there are some gaps between his explanation of the concept of quantity and his stipulation of domains of quantities, and that those gaps give rise to some difficulties in his explanation of applications of real numbers. Secondly I introduce a new ratio principle which can be applied to any kinds of quantities, and I argue that it allows us an adequate explanation of the reason why real numbers as ratios of quantities can be universally applicable. Finally I enquire into some procedures of the measurement of quantities, and I propose some principles which we should presuppose in order to successfully apply real numbers to the measurement of quantities.

• Journal of Korean Library and Information Science Society
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• v.39 no.4
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• pp.445-460
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• 2008

The objective of this study is to examine the correlation of reading quantities in various media(magazines, books, comic books) and different developmental phases of women high school students. I surveyed reading quantities in developmental periods, by questionnaires. As a methodology of empirical study, data was collected from 198 students at the Jeonju Girls' High School. Statistical techniques of a Pearson Correlation Test were employed according to my hypotheses. The results of this survey are as follows: 1) Reading quantities of specific media of specific period is correlated with reading quantities of same media of other period 2) Reading quantities of books is correlated with reading quantities of comic books.

• Journal of the Korea Institute of Building Construction
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• v.23 no.4
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• pp.497-508
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• 2023

Manual estimation of rebar quantities by contractors often yields discrepancies between projected and actual amounts used in the construction phase, leading to cost inaccuracies and potential logistical challenges. To address these issues, there is a clear need for a method that allows precise estimation of rebar quantities during the design phase. Such a method would enhance contractor competitiveness during project bids, promote accurate cost calculations, and avert superfluous rebar purchases on-site. Given that columns are the primary structural components in reinforced concrete(RC) buildings and necessitate considerable amounts of rebar, this study focuses on creating an automated algorithm for estimating column rebar quantities. An analysis of the accurate quantities obtained via the study and those derived from manual estimation reveals a discrepancy of 0.346 tons or 2.056%. This comparison affirms the proposed algorithm's efficacy in eliminating errors from overestimation or underestimation of rebar quantities. The practical implications of this study are significant for construction companies as it fosters efficient and precise estimation of rebar quantities, ensuring compliance with related specifications and governing regulations.

• Journal of Elementary Mathematics Education in Korea
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• v.20 no.1
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• pp.1-15
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• 2016

In this paper, the following three issues are discussed in connection with intensive quantities. (1) Is there any relationship among intensive quantity, per unit quantity, and ratio? (2) Which intensive quantities obtained by two same extensive quantities are handled? And How are they handled? (3) Which intensive quantities obtained by two different extensive quantities are handled? And How are they handled? Based on the results of this discussions, three implications are suggested as conclusions to explore the direction for the development of handling intensive quantities in elementary math textbooks and workbooks. Firstly, it is necessary to systematize the systemize a series of processes to handle intensive quantities. There is a need to rethink to use terms like speed and velocity before handling the ratio. Secondly, there is a need to rethink the definition of intensive quantities which have the particular names. For example, it is necessary to rethink using average distance in the definition of speed and the average population in the definition of density of population. Thirdly, it is necessary to consider the limiting the kinds of intensive quantities obtained by two same extensive quantities handled in the elementary math. There is a need to set limit to them which are used in daily life, and there is a need to rethink to use them which are used in the specialized area. There is a need to rethink the using hitting ratio in the form of %.

• Journal of Korean Library and Information Science Society
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• v.38 no.2
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• pp.147-164
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• 2007

The objective of this study is to examine the correlation of reading quantities in different developmental phases and various media(magazines, books, comic books). I surveyed reading quantifies in developmental periods, by questionnaires. As a methodology of empirical study, data was collected from 187 students at the Chonbuk National University. Statistical techniques of a Pearson Correlation Test were employed according to my hypotheses. The results of this survey are as follows: 1) reading quantities of general book of specific period is correlated with general book reading quantities of specific period. 2) reading quantities of magazine of specific period is correlated with magazine reading quantities of other period 3) reading quantities of comic book of specific period is correlated with comic book reading quantities of other period 4) correlation among reading quantity of middle school period and high school period is high.

• Korean Journal of Construction Engineering and Management
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• v.24 no.5
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• pp.83-94
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• 2023

In order to devise a rebar usage optimization algorithm, it is necessary to calculate the exact rebar length and revise the arrangement of rebars into special lengths. However, the process of rearranging numerous rebars and manually calculating their quantities is time-consuming and requires significant human resources. To address this challenge, it is necessary to develop an algorithm that can automatically estimate the length of rebars and calculate their quantities. This study aims to create an automatic estimation algorithm that improves work efficiency while ensuring accurate and reliable calculations of rebar quantities. The algorithm considers various factors such as concrete cover, hook length, development length, and lapping length, mandated by the building codes, to calculate the quantity of rebars for wall structures. The effectiveness of the proposed method is validated by comparing the rebar quantities generated by the algorithm with manually calculated quantities, resulting in a difference rate of 1.14% for the hook case and 1.37% for the U-bar case. The implementation of this method enables fast and precise estimation of rebar quantities, adhering to relevant regulatory codes.