• Journal of the Korean Institute of Rural Architecture
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• v.20 no.1
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• pp.1-10
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• 2018

In order to give back-to-farm residents the stable settlement environment in the rural area, the 'community village' is desirable as the village type and its village planning guideline should be supported as well. The purpose of this study was to develop a guideline for the planning of back-to-farm community village in the living and social environmental aspects, based on the comprehensive comparative analysis about items that field survey and literature suggested. The guideline for the living environment was developed for 6 items; village structure(adequate size, lot, outer space for household), village landscape(allocation, space composition), road system and transportation(parking lot in village, placement of bus stops, village trail, public transportation, road and pedestrian system), common living facilities and common space(number, size, location & placement, plan type, planning type of common facilities), transfer space, individual housing(type, size, planning type). The guideline for the social environment was developed for 3 items; village making and establishment(resident participation type, resident participation tool, residents' construction participation) and resident education in the course of planning, resident participation(gathering resident opinion, decision making, composition of construction committee, community newsletter).

• Smart Structures and Systems
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• v.18 no.4
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• pp.819-837
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• 2016

The quality of vibration pattern reproduction of elastic structures by the modal expansion method is influenced by the modal expansion method and the sensor placement as well as the accuracy of measured natural modes and the total number of vibration sensors. In this context, this paper presents an improved numerical method for reproducing the vibration patterns by introducing a block-wise modal expansion method (BMEM), together with the genetic algorithm (GA). For a given number of vibration sensors, the sensor positions are determined by an evolutionary optimization using GA and the modal assurance criterion (MAC). Meanwhile, for the proposed block-wise modal expansion, a whole frequency range of interest is divided into several overlapped frequency blocks and the vibration field reproduction is made block by block with different natural modes and different modal participation factors. A hollow cylindrical tank is taken to illustrate the proposed improved modal expansion method. Through the numerical experiments, the proposed method is compared with several conventional methods to justify that the proposed method provides the improved results.

• International Journal of Highway Engineering
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• v.7 no.3 s.25
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• pp.23-30
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• 2005

Predicting distribution and variation of humidity inside concrete is essential to improve curing quality of concrete at field. The concrete humidity is predicted by numerical analysis using surface humidity as boundary condition. However, ambient humidity has been used instead of the surface humidity because the surface humidity could not be ccurately measured. Because it is hard to accurately measure the surface humidity, owever, the ambient humidity has been used instead of the surface humidity in the numerical analysis. In this paper, a methodology to accurately measure the surface humidity is suggested, and the ambient humidity and the humidity at the surface and inside the concrete measured by a series of laboratory tests are presented. The cause of low concrete humidity immediately after placement was investigated by a separately performed test. A surface humidity prediction model was developed using the measured humidity, and consequently validated through an additional test.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2006.05a
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• pp.1-4
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• 2006

A down construction method is frequently used in these days to reduce popular discontent and to assure sufficient working space at early stage in downtown area. There are two main problems in the existing down construction method. One is a confliction between frame works and excavation works, and the other is a cold joint in retaining wall which is unavoidable due to a sequence of concrete placement and induces a water leakage. Therefore, a new method is needed to overcome these problems. The CWS (buried wale Continuous Wall System) method was developed by authors. By replacing RC perimeter beam with embedded steel wale, the steel frame works of substructure can be simplified and the water leakage can be prevented using continuous retaining wall. Consequently, the improved duality and reduction of construction period can be obtained from CWS method.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.05a
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• pp.105-106
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• 2019

In this research, considering the practical conditions at field, thermal cracking method was suggested based on the comparative analysis between predicted value and actual value obtained from the actual structure member with optimum mix design. The optimum mix design was deduced from the various mix designs with various proportions of cementitious binder for upper and lower placement lifts of mat-foundation mass concrete. Therefore, it can be stated that applying low heat mix design and different heating technique between upper and lower placement lifts for mass concrete are efficient to control the thermal cracking. As future issues, based on the interpretation result value, we will select the optimal combination that is applied specifically to the actual site, and deeply analyze the correlation between the measured value and the analysis value through the combination and the test of the actual structure.

• Wind and Structures
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• v.32 no.1
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• pp.1-9
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• 2021

Vortex generators are commonly used in mechanical engineering and the aerospace industry to suppress flow separation owing to their advantages of simple structure, economic viability, and high level of efficiency. Owing to the flow separation of the incoming wind on the leading edge, a suction area is formed on the roof surface, which results in a lifting effect on the roof. In this research, vortex generators were installed on the windward surface of a flat roof and used to disturb to roof flow field and reduced suction based on flow control theory. Computational fluid dynamics (CFD) simulations were performed in this study to investigate the effects of vortex generators on reduce suction. It was determined that when the vortex generator was installed on the top of the roof on the windward surface, it had a significant control effect on reduce suction on the roof leading edge. In addition, the influence of parameters such as size, placement interval, and placement position of the vortex generator on the control effect of the roof's suction is also discussed.

• The Journal of Korean Society for School & Community Health Education
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• v.18 no.1
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• pp.99-110
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• 2017

Objectives: The purpose of this study was to examine the effect of the field practice of health science majors on their career attitude maturity in our country in an effort to determine influential factors. Methods: The subjects in this study were 220 selected health science majors in three different colleges located in North Gyeongsang Province and South Chungcheong Province. A survey was conducted with structured questionnaires from September 1 to 10, 2016. As for statistical analysis. a statistical package SPSS 20.0 was used. Results: The factors of the field practice of the health science majors that affected their career attitude maturity were the career of people in charge(${\beta}=.145$, p-.034) and the content of field practice(${\beta}=.233$, p=.015), which were the factors of the institution for field practice, and the relationship between people in charge and trainees(${\beta}=.299$, p=.008) and satisfaction with field placement(${\beta}=-.262$, p=.013) that were the factors of field practice tasks were also influential. The influence of these factors were statistically significant. Conclusions: Institutions that provide health science majors with the opportunity of field practice should try to improve the competencies of people in charge, to ensure the substantiality of field practice in content and to develop standardized manuals for field practice. In schools, professors who are in charge of field practice should offer intensive guidance and feedback on problems with field practice. These efforts are expected to elevate the career attitude maturity of students.

• Journal of the Korea Institute of Building Construction
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• v.9 no.4
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• pp.55-61
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• 2009

Recently, the number of high-rise buildings being built in Korea by major construction companies for residential and commercial use has been increasing. When constructing a high-rise building, it is necessary to apply massive amounts of concrete to form a mat foundation that can withstand the huge load of the upper structure. However, it is of increasing concern that due to limitations in terms of the amount of placing equipment, available job-sites and systems for mass concrete placement in the construction field, it is not always possible to place a great quantity of concrete simultaneously in a large-scale mat foundation, and for this reason consistency between placement lift cannot be secured. In addition, a mat foundation Is likely to crack due to the stress caused by differences inhydration heat generation time. To derive a solution for these problems, this study provides test results of a hydration heat crack reduction method by applying placement lift change and setting time control with a super retarding agent for mass concrete in a large-scale mat foundation. Mock-up specimens with different mixtures and placement liftswere prepared at the job-site of a newly-constructed high-rise building. The test results show that slump flow of concrete before and after adding the super retarding agent somewhat Increases as the target retarding time gets longer, while the air content shows no great difference. The setting time was observed to be retarded as the target retarding time gets longer. As the target retarding time gets longer, compressive strength appears to be decreased at an early stage, but as time goes by, compressive strength gets higher, and the compressive strength at 28 days becomes equal or higher to that of plain concrete without a super retarding agent. For the effect of placement lift change and super retarding agent on the reduction of hydration heat, the application of 2 and 4 placement lifts and a super retarding agent makes it possible to secure consistency and reduce temperature difference between placement lifts, while also extending the time to reach peak temperature. This implies that the possibility of thermal crack induced by hydration heat is reduced. The best results are shown in the case of applying 4 placement lifts.

• Journal of the Korean Society of Safety
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• v.30 no.1
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• pp.79-86
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• 2015

This research proposed a design direction for the ambulance interior storage space based on the placement and access to the equipment to facilitate an emergency medical practice taking into account the safety and efficiency by the emergency medical technician ergonomic factors. Therefore, through a field survey for the current derivation of the storage space problem 'placement', 'enable', 'management' like these three items resulting clarity, accessibility, simplicity and functionality of the four functional elements by targeting ambulances in operation in this country. First, there is a need to improve standardized of cabinet sizes fit to loaded meet emergency equipment standards. Currently, the equipment designed to use a simple storage cabinet has had problems in the usability. Second, it must be located in the continuous exposure in progress to the user's traffic line. Third, the problem was the insufficient function of the cabinet to ensure the safety of patients by paramedics from the emergency rescue equipment and due to the leaning of the ambulance driving. Besides, it was pointed out that in addition to the proposed alternatives, including the agenda, states that safety belt replacement equipment, emergency personnel and patients with the handle of a guardian for the efficient use storage space within the 119 ambulance. However, in the present study suggest that there is a state proceeds mainly limited usability in the field, having been installed.

• Korean journal of applied entomology
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• v.17 no.2 s.35
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• pp.99-103
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• 1978

Population density of the spiders (Micryphantidae and Lycosidae) in the two Paddy field at Suweon and Iri was studied following single root-zone application of carbofurans encapsulea and liquid-formulated and two to four paddy water applications of carbofuran to rice plants. In two field tests, the spider populations were reduced In all insecticide treatments. Among them, the reduction was greater in the capsule placement of carbofuran than in the liquid injection and broadcast of carbofuran. Their reduction was also enlarged with the increase of application rate of insecticide. The significant reduction of spider population in root-tone appliration of carbofuran was considered due to the food-chain toxicity on the spider-hopper system.