• The Journal of the Korean dental association
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• v.48 no.12
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• pp.893-918
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• 2010

This article is purposed of reviewing the development history of Japanese dental devices and instrument, and their related advertisement activities during the Japanese colonized period in Korea in early 20th century. Japanese dental devices and instrument were redesigned to accommodate their ergonomic shape above the simple imitation, and it implies the excessive desires brought them frustrations. The tragic earthquake on Sep. l, 1923, medical insurance law enforcement on Jan. 1, 1927, celebration of "Cavity prevention Day" started on Jun. 4, 1928, and the attack of Manchuria and China by Japan after 1931, all of these historical incidents become the preliminary requirement for the development of dental devices. On Nov. 1, 1937, Japanese government started to control dental materials, driving the campaigns for excluding foreign products and encourging the use of local products. In 1939, Nakajima dental manufacturers used this political and social atmosphere on their advertisement as saying "Our Nakajima's products have no compromise with the short raw materials, but only commitment to our quality". Since after 1940, the price and supply have been strongly under control, and the control group was appeared to manage all of supply and distribution of raw materials, regular price system, and specifications. At last, the Japanese national power were devastated in its production and distribution capacities, and get to the frustrated period. The main advertised dental devices and instruments in Korea during the Japanese colonized period were 1) dental chair, unit and cabinet, 2) dental x-ray, 3) compressors, 4) dental needles, 5) small instrument and carryon medical(emergency) kit, 6) oral hygiene and pyorrhea alveolaris, infrared rays, sunlight lamp, ultrashort wave treatment devices, 7)crown former, electric furnace, casting machine, articulator, electric lathe, and laboratory equipments, etc.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.3D
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• pp.457-468
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• 2011

Recently, the non-vibration mass excavation method is used on sewage pipes and road construction sites in Jeju. However, a construction cost estimation based on the unit quantity does not provide a proper unit price. In this study, a comparison of the productivity of the standard quantity-per-unit costing method and the one of the work crew combination method was made based on the site monitoring of the non-vibration mass excavation method that is used in construction sites near Jeju. For this, data of 35 sites were collected: a regression equation was derived from the 30 data, and verification was carried out through the remaining 5 data. The analysis concluded that a day's workload is $16.43m^3$. In addition, a combination of the equipment considering the site conditions and the amount of labor, which varies with the number of work crew was obtained in order to estimate the construction cost of the work crew combination method. The construction cost was calculated based on the one-day workload ($16.43m^3$) derived from the regression analysis. The cost then was analyzed and compared with the standard quantity-per-unit costing method.

• Korean Journal of Construction Engineering and Management
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• v.13 no.1
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• pp.67-76
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• 2012

There are index adjustment method and item adjustment method in estimation methods for price fluctuation rate of public constructions. A relevant regulation has put item adjustment method as a principle, but in most construction, contract sum adjustment has been made by index adjustment method. Hence, this study, by figuring out width and causes of the gap between index adjustment method and item adjustment method through direct comparative analysis, solved inequality caused by difference between them and suggested a rational way against irrationality of each method. For building operations of public housing construction, a detailed fluctuation rate by index adjustment method and item adjustment method of construction cost elements of the same construction, that is, direct material cost, direct labor cost and historical construction cost was estimated to analyze difference between two adjustments and establish its cause. Across the analysis, it was found that fluctuation rate by item adjustment method was estimated lower than that by index adjustment method and difference between methods for estimating fluctuation rate of quotation unit price and application of index unrelated to construction type and construction nature are main causes of the difference. This study has a significance in that, for smooth contract sum adjustment between contracting parties, it practically proved the real difference between adjustment methods by conducting comparative analysis of the difference in direct correspondence way.

• Korean Journal of Construction Engineering and Management
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• v.8 no.4
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• pp.155-166
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• 2007

The purpose of this research is to develop a conceptual model and prototype that establishes a new approach for building cost estimating in the schematic design phage. This research use the method that analyzes quantity and unit price separately to enhance schematic cost estimating through conducting literature review andi analyzing existing schematic cost estimating methods. In addition, this study proposes tile concept of cost breakdown structure including two more classifications: building element and floor compared to existing one only classified by trade. Thus, a Quantity Based Active Schematic cost Estimating(Q-BASE) model is developed founded on those two concepts. By applying proposed schematic cost estimating model, historical structure cost of residential complex building project is analyzed, and then, based on this analysis, prototype is implemented.