본 연구는 자신을 교과전문가로 인식하는 중학교 교사들에게 있어서 교장의 수업지도성은 교사의 교수효능감과 교직만족을 증대시키는 요인으로 작용할 수 있을 것이라는 가정 하에, 세 변인 간 구조적 관계를 밝힐 목적으로 수행되었다. 「학교교육 실태 및 수준 분석」 3주기 중학 교 데이터(2010년)의 교사 6,357명 자료를 기술통계, 확인적 요인분석, 구조방정식모형, 매개효 과 분석, 부트스트래핑을 활용하여 분석하였다. 연구결과, 첫째, 교장의 수업지도성과 교사의 교수효능감 및 교직만족도에 대한 교사들의 인식은 대체로 긍정적이었으나, 상대적으로 수업지 도성의 하위영역 중 ‘긍정적 학교 풍토 조성’과 교직만족도에 대한 인식은 상대적으로 덜 긍정 적이었다. 둘째, 교장의 수업지도성은 교사의 교수효능감과 교직만족도에 긍정적 영향을 미치 고, 교사의 교수효능감 역시 교직만족도에 긍정적 영향을 미치는 것으로 나타났다. 셋째, 교사 의 교수효능감은 교장의 수업지도성이 교사의 교직만족도에 미치는 영향을 부분매개하는 것으 로 확인되었다. 연구결과를 토대로 교장의 수업지도성과 교사의 교직만족 제고를 위한 지원이 필요하다는 내용을 위시한 정책적 제언을 제시하였다.
디지털 방사선촬영 기술은 영상 정보를 획득하는 원리에 따라 광도전체를 이용하는 직접 방식과 형광체를 이용하는 간접 방식으로 구분되지만, 모두 다양한 장단점을 내포하고 있다. 이에 본 연구에서는 X-ray 민감도를 개선하고자 형광체 및 광도전체를 병용한 Hybrid형 검출기의 구조에 대한 기초 연구를 수행하였다. 실험 결과, 조사 시간을 30 ms로 고정하고 관전압을 변화할 경우 전체적으로 직접 방식의 구조에서 우수한 민감도가 나타났으나, 조사 시간이 50 ms 이상에서는 Hybrid 구조의 경우가 더 우수한 것으로 나타났다. 이는 임상에서 다양한 검사를 수행할 경우에 일반적으로 50 ms 이상의 조사시간을 이용한다는 점에서 충분한 연구적 가치를 가질 것으로 사료된다.
This paper shows examples of damage cases for corrugated steel plate structures in Korea expressway. There are two representative types of damages. One is a water leak and the other is the deformation of inner section. The results of this study will be useful for future maintenance of corrugated steel plate structures.
Recently, the concern on the deterioration of concrete due to de-icing salts and its counter measurements has been increased. This paper discusses the results from investigation of pre-mature deteriorated existing road-subsidiary concrete structures and the specification of concrete quality.
The present study concerns a measurement of porosity at the nano-fibre interface in concrete. Concrete cast with a centrally located nano-fibre (Ø0.39 × 15.0 mm) was segmented for microscopic observation at a bascattered electron (BSE) image. As a result, it was found that the pores generated in the vicinity of the nano-fibre ranged from 5.40 to 11.45%, equivalent to 0.51 - 1.08% of air void in a bulk concrete.
In the current concrete structure of the highway is still the major problem most of concrete deterioration caused by the freeze-thaw and de-icing salt, which is of issues that are not completely resolved. In particular, a single freezing event does not cause much harm, durability of concrete under multi-deterioration environment by repeated freeze-thaw and de-icing salt is rapidly degraded and reduce its service life. In this study, to considering environmental characteristics when design and construction of concrete structures, the exposure environmental guidelines were established by investigation the application rates of de-icing salt, temperatures and snowfall characteristics during five years (2004∼2008) by regions. Also, damage condition and chloride content of the structural at regions of moderate and severe environmental exposures were investigated.
The purpose of this study is to evaluate the impact on flexural strength and compressive strength of the concrete, the mixing rate of the amorphous fibers.
Traditional methods for concrete structure demolition is not adequate specially for urban areas and historical places due to hazard of explosive and noise. Therefore, Soundless Chemical Demolition Agents (SCDA) is useful in urban area and historical places. In this study, a analysis for SCDA is performed depending on boundary conditions.
This study is corroborated as a fundamental resource to develop structural lightweight foamed concrete. Mortar using foaming agent decrease over 0.3 g/㎤ of weight of unit volume and increase over 27 MPa of compressive strength available structural purpose. After that, it is compared with Young's modulus of experiment and analysis from FEM analysis using SEM image.
This study investigated the applicability of synthetic resins as neutron shielding aggregates in cementitious materials with SEM analysis. Synthetic resins contain lots of hydrogen atoms, which is effective in neutron shielding by an elastic scattering because its mass is almost the same as that of the neutron. The SEM results showed that the binding force between HDPE/PP particles and cement matrix is very week compared to that of UPE particles so that additional treatment such as surface reforming should be needed.
A new approach to evaluate the durability of concrete structures was proposed in this study, which additionally considered the time-dependent and environmental effects, especially freezing-thawing and salt attack. This might have a potential for the reasonable durability evaluation with the systematic management of SOC facilities.
This study aimed to propose a reasonable performance evaluation process of freeze-thaw and carbonation depth on concrete structures, especially considering the time-dependent and environmental effects, to develop a long-term maintenance plan in Korea.
This experiment can maximize the decline of the heat on steel structure by using the magnesium hydroxide and aluminum hydroxide which generally used to resistant or retardant. These materials can delay a temperature rise due to the generation of vapors around the fire resistive covering, when reacting with heat by a creating moisture. Therefore, applicability of the fire resistance mortar used magnesium hydroxide and aluminum hydroxide was studied and experimented. As a result, in case of the workability is satisfied with the condition of site, but in case of the bonding strength is not satisfied with the standard with fire resistance mortar.
A state-of-the-art safety management system of water infrastructures based on ICT Technology is now under development by incorporating 1) real-time safety evaluation system, 2) disaster risk management support system based on GIS, and 3) decision-making support system for damage restoration equipped with multi sensor information acquisition system such as UAV and CCTV. This study includes development of practical natural disaster scenarios for flooding, typhoon and earthquake events based on recorded data, and standardization of disaster management platform.
Recently efficient maintenance technology has been rising because of the structural deterioration. Specific technology development and research related to the real-time monitoring has been conducted in various ways. All-in-one enclosure including GPS was fabricated to measure the displacement of the retaining wall structure exposed the extreme environment such as very high and low temperature. Also it measured the displacement of the structure under the phased construction.
Membrane structure is a system that is stabilized by maintaining a tensile state of the membrane material that originally cannot resist the bending or pressure. Thus, it is important to accurately understand the size of the membrane tension after the completion of the structure, for maintenance and management purposes. The author of this paper measured the tension of preexisting membrane structure for its maintenance purpose by using the developed portable measurement equipment. Through analyzing the measurement data, the author check the points that should be improved and the technical method for the new maintenance system of membrane tension.