• 교육시설
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• 제10권5호
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• pp.15-22
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• 2003

Deterioration of the educational facilities built before 1985 is a serious situation. The purpose of this study is to present the efficient remodeling method of old educational facilities. This paper, part II, presents the systemic and synthetic judgment method of deterioration grade of structural components. Deterioration grade of the whole structural components are judged by synthetic evaluation score which is the total of the score of ten evaluation items. And we added the importance coefficient of the viewpoint of four performance to each evaluation item.

• 교육시설
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• 제11권1호
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• pp.15-23
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• 2004

Deterioration of the educational facilities built before 1985 is a serious situation. The purpose of this study is to present the efficient remodeling method of old educational facilities. This paper, part III, presents the systemic and synthetic judgment method of deterioration grade of finished materials. Evaluation of the deterioration is carried out in every eight classrooms or building elements divided by the use. And classrooms are divided by several parts for example floor, wall and ceiling etc.. The whole deterioration of the building judges the result of every part collectively.

• 교육시설
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• 제13권4호
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• pp.15-23
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• 2006

The purpose of this study is to establish the objective deterioration grades and evaluation criteria of building equipment system of educational facilities available for reasonable maintenance and remodeling of them. For the purpose of it, the actual conditions of building equipment systems of the 148 buildings of 84 middle and high schools in Seoul 20 years after construction are investigated and surveyed through one-on-one interviews and questionnaires. And, deterioration grades of them are estimated by the evaluation criteria which is proposed in this study. As a result of this study, the 10 deterioration grades and the 4 evaluation criteria of the 6 performances of building equipment system, which are heating and cooling, water supply and drainage, hot water supply and electrical power performance, are suggested. And, as a result of the survey, it showed that 24% of the investigated school buildings were estimated C grade which needs partial remodelling, and 51% of the school buildings were estimated D grade which needs extensive remodelling. And, 25% of the school buildings were estimated E grade which needs overall remodelling or alteration of building equipment system.

• 한국산림과학회지
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• 제110권1호
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• pp.91-105
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• 2021

본 연구는 백두대간 마루금 선자령순환등산로 4.3 km에서 정성적으로 평가되는 훼손등급을 적용하여 숲길훼손이 발생된 구역의 구체적인 데이터와 조사방법을 제시하고, 조사항목간의 관계를 구명하고자 수행되었다. 그 결과, 선자령순환등산로의 평균 노폭(1.7 m)과 나지폭(1.4 m)은 지금까지 보고된 연구에 비해 매우 넓은 것으로 나타났으며, 훼손비율 또한 높은 것으로 확인되었다. 정성적인 기준으로 평가된 훼손등급에 대해 다음과 같이 구체적인 데이터를 확보할 수 있었다. 훼손등급 강의 경사도는 20.1%, 침식깊이는 평균 13.3 cm, 중앙 16.1 cm, 침식량 16.2 ㎠로 나타났으며 토양경도는 평균 12.3 kg/㎠(20.1 mm), 최대 39.3 kg/㎠(29.6 mm)로 나타났다. 훼손등급과 경사도는 양의 상관관계를 보였고, 능선보다 산복에서 평균과 중앙의 토양침식깊이가 깊어지는 것으로 나타났다. 그리고 토양경도는 횡단 측정위치와 방법에서 유의적인 차이가 있는 것으로 나타났다. 따라서 선자령순환등산로는 경사도가 20% 이상인 구간에서 훼손이 발생함에 따라 지속 가능한 이용을 위해서는 고정조사점에서의 지속적인 모니터링이 필요하다. 또한, 숲길설계와 관리에는 경사도가 우선적으로 고려되어야 한다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1994년도 봄 학술발표회 논문집
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• pp.243-248
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• 1994

The purpose of this study is to develop Deterioration Diagnosis System for the Reinforced Concrete Structure which can be used preliminary in determining the factors causing deterioration by simple inspection and mapping of the indicators of deterioration. Total 29 items compromising material, structural and constructional factors causing deterioration were considered in this system. Also the indicators of deterioration were subdivided into 54 items such as concrete crack pattern and steel corrosion etc. Each indicator of deterioration was quantatified by allocating and giving grade to each item which has extra weight according to its conscquence. Satisfactory results were obtatined by applying this Diagnosis system to the indicators of deterioration in ref. [3]. Further research was required on the indicators of deterioration in construction site to enhance the field applicability of this system.

• 한국도로학회논문집
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• 제18권1호
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• pp.85-90
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• 2016

PURPOSES : The objective of this paper is to understand the deterioration phenomenon and causes in the pavement of a ramp area. METHODS : Ramp areas need to be sloped because of the centrifugal force, which depends on the vehicle speed and grade of the ramp area. As a result, vertical and horizontal forces are applied on the pavement surface of the ramp area. Furthermore, the horizontal force depends on the vehicle speed and grade of the ramp area. In order to analyze the pavement structure of a ramp area, a multi-layered elastic analysis program was used to evaluate the weakest link of fatigue cracking deterioration, according to the simultaneously applied vertical and horizontal forces. RESULTS : From case studies related to the bonding conditions between the surface and base layer in a ramp area, it was found that the partially bonded cases resulted in a critical potential of fatigue cracking deterioration, in a comparison of 50%, 70%, and fully bonded cases. CONCLUSIONS : According to the results of the case studies, the pavement structure system should be reinforced by upgrading the material or increasing the thickness compared to the general pavement areas, in order to provide a performance life similar to the mainline pavements in the ramp areas.

• Smart Structures and Systems
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• 제33권4호
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• pp.313-323
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• 2024

Deterioration of buildings is one of the biggest problems in modern society, and the importance of a safety diagnosis for old buildings is increasing. Therefore, most countries have legal maintenance and safety diagnosis regulations. However, the reliability of the existing safety diagnostic processes is reduced because they involve subjective judgments in the data collection. In addition, unstructured tasks increase rework rates, which are time-consuming and not cost-effective. Therefore, This paper proposed the method that can calculate the safety grade of deterioration automatically. For this, a DNN structure is generated by using existing precision inspection data and precision safety diagnostic data, and an objective building safety grade is calculated by applying status evaluation data obtained with a UAV, a laser scanner, and reverse engineering 3D models. This automated process is applied to 20 old buildings, taking about 40% less time than needed for a safety diagnosis from the existing manual operation based on the same building area. Subsequently, this study compares the resulting value for the safety grade with the already existing value to verify the accuracy of the grade calculation process, constructing the DNN with high accuracy at about 90%. This is expected to improve the reliability of aging buildings in the future, saving money and time compared to existing technologies, improving economic efficiency.

• 보존과학회지
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• 제29권4호
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• pp.407-420
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• 2013

경복궁 석조조형물은 주로 화강암(884점, 96.7%)과 대리암(25점, 2.7%)으로 구성되었으며, 다양한 산지의 석재가 혼용되어 조성되었다. 이 석조조형물에서 나타나는 주요 손상은 균열(24%), 탈락(21%), 박리박락(36%), 입상분해(9%) 및 흑색변색(20%)으로써, 균열과 탈락은 높은 물리적 손상도에, 흑색변색은 높은 변색 손상도에 주로 기여하는 손상유형이다. 구역별로는 경회루(3등급 55%), 근정전(3등급 29%) 및 품계석(3등급 11%) 구역의 석조조형물에서 상대적으로 손상도가 높아 이들을 우선관리대상으로 설정하여 집중적으로 관리하고 정기모니터링 하는 것이 필요하다. 특히 품계석은 대리암으로 구성되어 외부환경에 노출될 시 풍화민감도가 크므로 강우와 일사를 제어할 수 있는 보호시설이 요구된다.

• Steel and Composite Structures
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• 제14권3호
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• pp.229-242
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• 2013

Corrosion is important reason for the deterioration of the bond between reinforcing steel and the surrounding concrete. Corrosion of the steel mainly depends on its microstructure. Smooth S220, ribbed S420 and S500 grade reinforcing steels were used in the experiments. Samples were subjected to accelerated corrosion. Pullout tests were carried out to evaluate the effects of corrosion on bond strength of the specimens. S500 grade steel which has tempered martensite microstructure showed lower corrosion rate in concrete than S220 and S420 steels which have ferrite+perlite microstructure. S500 grade steel showed highest bond strength among the other steel grades in concrete. Bond strength between reinforcing steel and concrete increased with increase in the strength of steel and concrete. It also depends on whether reinforcing bar is ribbed or not.

• 한국안전학회지
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• 제24권4호
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• pp.53-58
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• 2009

The importance of process for repair and reinforcement of the bridge is increasing because of the lack of the fatigue load and stress, a lowering of the bridge load carrying capacity owing to impact and oscillation, deterioration on cultivation periods of the bridge, etc. Typically the experimenter values the bridge load carrying capacity by the real rating factor and response modification factor in bridge load rating through static load test and dynamic load test. But the error occurred in reliability of response modification factor in bridge load rating according to experience of experimenter. so tests of connecting probability theory and valuation of the bridge recently. The study is to compute the real load carrying capacity of the bridge and the rating factor and response modification factor on grade of the bridge, and calculate the probability of over-loaded truck load from Weigh In Motion(WIM) Data in FORTRAN programming applying to Monte-Carlo Simulation. At the result of this study, it is acquired that the new grade is computed for the probability of over-loaded truck load and surface inspection. The A grade is over 1.95, B grade is $1.55{\sim}1.94$, C grade is $1.26{\sim}1.54$, D grade is $1.14{\sim}1.25$, E grade is under 1.13 of rating factor, respectively.