• Proceedings of the Korean Geotechical Society Conference
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• 2006.10a
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• pp.515-520
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• 2006

Yano method had been used in predicting the settlement of self-weight consolidation of dredged soil in the construction of reclamating the dredged soil. Its estimation was found to show some different results from field measurements. The numerical analysis with PSDDF was peformed find such differences, considering the effect of desiccation on the consolidation during the remaining time after reclamation. For the parametric study, numerical analyses with/without consideration of desiccation were carried out with changing the conditions of desiccation such as the number of placing the fill and the time period between each placement. As results of analysis, estimations about consolidation settlement and distribution of water contents with consideration of desiccation was in good agreements with field measurements. It was also found that the number of placing the fill and the time period between each placement did not affect the behavior of self-weight consolidation as much as the effect of desiccation.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.10a
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• pp.705-710
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• 2000

Recently, use of sea-sand as fine aggregates in reinforced concrete structures is increasing because of lacking of supply due to destructive of environment caused by obtaining and exhausting of resource. It rise up issue, some field reconstruction, interrupted construction works occurring to the trouble on the site because sometimes engineer does not agree to use of corroded bar, even slighly corroded. This study investigates the properties of bond strength and the structural behavior of corroded bars before and after placement. The purpose of the study is to present the database estimating degree of damaged bond strength according to corrosion level and deciding on whether using corroded bars or not.

• International Journal of Concrete Structures and Materials
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• v.7 no.2
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• pp.165-174
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• 2013

Portland cement concrete exposed to high temperatures during mixing, transporting, casting, finishing, and curing can develop undesirable characteristics. Applicable requirements for such the hot weather concrete differ from country to country and government agencies. The current study is an attempt at evaluating the hardened properties of the concrete exposed to hot weather in fresh state. First of all, this study reviews the current state of understanding and practice for hot weather concrete placement in US and then roadway sites with suspected hot weather concrete problems were investigated. Core samples were obtained from the field locations and were analyzed by standard resonance frequency analysis and the boil test. Based on the results, there does not appear to be systematic evidence of frequent cracking problems related to high temperature placement. Thus, the suspicious deteriorations which are referable to hot weather concreting would be due to other factors.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2005.11a
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• pp.85-88
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• 2005

This study investigates influence on concrete adding beverage or detergent, by work man's mistakes during concrete placement in field. Overall, concrete adding beverage or detergent does not affect slump and air content, compared with control concrete. However concrete adding detergent resulted in significantly higher air content, due to inter facial activation ingredient. For the properties of setting time, concrete adding lactic acid beverage indicated the longest retarding properties, next was coffee and soft drink in order. Compressive strength of concrete, which retarded setting time. exhibited slightly improved value at 7 and 28 days respectively, while that of concrete adding detergent significantly decreased, due to higher air content.

• Journal of Electrical Engineering and Technology
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• v.5 no.1
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• pp.79-102
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• 2010

This paper presents exhaustive review of various methods/techniques for coordinated control between FACTS controllers in multi-machine power systems. It also reviews various techniques/methods for optimal choice and allocation of FACTS controllers. Authors strongly believe that this survey article will be very much useful to the researchers for finding out the relevant references in the field of placement and coordination of FACTS Controllers.

• Journal of the Korean Institute of Gas
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• v.17 no.2
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• pp.59-69
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• 2013

This study presents development of the ANN simulator for well placement of infill drilling in gas fields. The input data of the ANN simulator includes the production time, well location, all inter well distances, boundary inter well distance, infill well position, productivity potential, functional links, reservoir pressure. The output data includes the bottomhole pressure in addition to the production rate. Thus, it is possible to calculate the productivity and bottomhole pressure during production period simultaneously, and it is expected that this model could replace conventional simulators. Training for the 20 well placement scenarios was conducted. As a result, it was found that accuracy of ANN simulator was high as the coefficient of correlation for production rate was 0.99 and the bottomhole pressure 0.98 respectively. From the resultes, the validity of the ANN simulator has been verified. The term, which could produce Maximum Daily Quantity (MDQ) at the gas field and the productivity according to the well location was analyzed. As a result, the MDQ could be maintained for a short time in scenario C-1, which has the three infill wells nearby aquifer boundary, and a long time in scenario A-1. In conclusion, it was found that scenario A maintained the MDQ up to 21% more than those of scenarios B and C which include parameters that might affect the productivity. Thus, the production rate can be maximized by selecting the location of production wells in comprehensive consideration of parameters that may affect the productivity. Also, because the developed ANN simulator could calculate both production rate and bottomhole pressure, respectively, it could be used as the forward simulator in a various inverse model.

• Journal of Korean Society of Rural Planning
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• v.20 no.1
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• pp.77-89
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• 2014

This study intends to establish a system to investigate and analyze various impacting factors to Rural Housings such as the relationship of characteristics of Rural Housings located in a Rural Village to the Village and a Unit Housing, to the External and Internal Spaces inside the Unit Housing and the Village, and to Living Characteristics of the Residents and Space from an integrated point of view. The results of this study are largely summarized as following four kinds. Rural Housing Survey System can be largely classified into three stages, and they are a Preliminary Survey, Basic Survey and In-depth Survey. Along with these, the scope of the survey contents can be divided into a survey result by a unit of village, of land, of housing, and of resident's opinion survey. Secondly, the surveys by village unit are on location properties, Village Identity, Street Network, Land Use, Landscape Features and Public Facilities, and consist of Literature, Discussion and Field Survey. Thirdly, the land Unit Surveys are on a Driveway, Gate Location, Housing Placement, Outer Space Design in a Yard and Outer Space Use Characteristics, and consist of Questionnaire and Field Surveys. For the fourth, the Housing Unit Surveys are on an Internal Space Design and Placement, and consist of Questionnaire and Field Surveys. Finally, the Resident Questionnaire Survey consisted of Entire Discussion Survey and a Household one, and then the Entire Survey was on the Village's History, Village's Characteristics, Cultivation Characteristics and Community Activities while an individual one was on Main Living Characteristics, Satisfaction and Utilization Characteristics.

• Smart Structures and Systems
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• v.24 no.6
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• pp.709-721
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• 2019

This paper investigates the framework of vision-based dense displacement and strain measurement of miter gates with the approach for the quantitative evaluation of the expected performance. The proposed framework consists of the following steps: (i) Estimation of 3D displacement and strain from images before and after deformation (water-fill event), (ii) evaluation of the expected performance of the measurement, and (iii) selection of measurement setting with the highest expected accuracy. The framework first estimates the full-field optical flow between the images before and after water-fill event, and project the flow to the finite element (FE) model to estimate the 3D displacement and strain. Then, the expected displacement/strain estimation accuracy is evaluated at each node/element of the FE model. Finally, methods and measurement settings with the highest expected accuracy are selected to achieve the best results from the field measurement. A physics-based graphics model (PBGM) of miter gates of the Greenup Lock and Dam with the updated texturing step is used to simulate the vision-based measurements in a photo-realistic environment and evaluate the expected performance of different measurement plans (camera properties, camera placement, post-processing algorithms). The framework investigated in this paper can be used to analyze and optimize the performance of the measurement with different camera placement and post-processing steps prior to the field test.

• Korean journal of applied entomology
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• v.16 no.3 s.32
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• pp.155-161
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• 1977

During 1976 the effects of insecticide placement in the root zone of the rice plants were evaluated for control of rice insect pests in the screenhouse and in the paddy field at Suweon. The methods of insecticide placement included the use of encapsuled formulation and injection of liquid formulation. In screen house experiments, the root' zone placement of carbofuran was highly effective up to 30 days after treatment against the striped rice borers (Chilo sujppressalis) and up to 17 days after treatment against the small brown planthopper(Laodelphax xtriatellus) and the brown planthopper (Nilaparvata lugens), while the root-zone placement of omethoate and disyston were ineffective. In field experiments, the injection in every other row by the liquid applicator designed at IRRI was less effective for control of the striped "'rice borers and the small brown planthoppers than the caupsule placement. The single root·zone placement of liquid carbofuran, however, seemed to be equal in 'effectiveness to two broadcast applications of carbofuran and diazinon. In the plots treated at 5 days after transplanting, incidence of the dead hearts by the striped rice borers was much lower than in the plots treated at the 18 days after transplanting.

• Proceedings of the Korea Concrete Institute Conference
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• 1989.10a
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• pp.69-72
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• 1989

It is widely recognized that the strength of reinforced concrete members has characteristics of random variations due to the variability of the mechanical properties of concrete and steel, the dimensional error as well as incorrect placement of reinforcing bars. In those sources of randomness, variations in concrete strength may be the one affecting the strength of R.C. members most. The concrete strength is usually assumed to have large uncertainty due to the variations in many factors, such as material properties, proportions of the concrete mix, methods of mixing, transporting, placing and curing, etc. In this study, the random characteristics inherent in the strength of field-cast concrete have been examined based on the data collected by testing standard cylinders made of field-cast concrete and cured under in-situ condition.