• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 1993년도 Proceedings of International Conference for Agricultural Machinery and Process Engineering
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• pp.291-296
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• 1993

Taking a bledes axle of rotary tiller as a example, this paper discusses influences of four loading essential factors, which are strengthened amplitude, cycle times, loading sequence and loading frequency. in fatigue life. Determination principles of above four factors and monitoring methods of fatigue damage by local strain are dealt with. The actual field testing check of farm machinery is rapidly simulated by laboratory program fatigue test can shorten the period of development and improvement of a product. In the time of in-door simulation test, damage monitoring and four loading essential factors, which are strengthened amplitude , cycle times, loading sequence and loading frequency, have to be dealt with . If these problems are solved successfully, it is possible to accelerated test speed, reduce costs and manhours, and raise accuracy of test result. However strengthening method, loading pattern and influence of loading frequency on test result have not so far been discu sed systematically, damage monitoring is even more a difficult problem. Authors have studied above problems with the object of blades axle of rotary tiller.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2004년도 가을 학술발표회 논문집
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• pp.517-526
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• 2004

In the resent years, the early evaluation of concrete quality, construction and maintenance has been considered as all is of major concern due to the increase of loading and the degradation of structures related with time. This paper presents evaluation of structural safety performance using measured data of construction, on the basis of a field measurements for the prevention of unreliable concrete works. Measurements analyzed in this paper are early quality condition and performance assessment, serviceability performance by cracks and deflection, rating performance by loading, durability performance by chloride attack and carbonation. Thus, a quantitative assessment model of resistance capacity was developed here to meet the requirement for deteriorated concrete structures. The model focuses on damage mechanical of concrete structures deteriorated by initial damage factors for concrete quality and environment factors such as chloride and carbonation attacks. These results could provide useful information for concrete structures interested in design, construction and maintenance.

• Toxicological Research
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• 제30권1호
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• pp.45-48
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• 2014

Helicobacter pylori (H. pylori) is the most important factor of gastric disease in clinical practice. Moreover, smoking, stress and a poor diet may be additive factors for gastric damage. With these factors, increasing infection of H. pylori triggers gastritis, gastric ulcers and gastric cancer. To develop a new protective agent, we are concerned with plant-derived extract. The extract of Coptis chinensis (C. chinensis) and its constituents were investigated to assess their protective activities against gastric damage. The C. chinensis extract showed a scavenging effect against 2, 2-diphenyl-1-picrylhydrazyl (DPPH) and superoxide radicals, inhibition of H. pylori colonization and antiulcerogenic activities in rat. In particular, palmatine derived from C. chinensis was found to be the novel protective agent. It is better than the C. chinensis extract, berberine, a well-known constituent of C. chinensis. We suggest that palmatine from the root cortex of C. chinensis may be a good candidate for the development of new pharmaceuticals to prevent gastric disease.

• Earthquakes and Structures
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• 제22권1호
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• pp.83-94
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• 2022

In recent years, some studies have identified and quantified factors that can increase or decrease the seismic vulnerability of buildings. These modifier factors, related to the building characteristics and condition, are taken into account in the vulnerability assessment, by means of a numerical estimation resulting from the quantification of these modifiers through vulnerability indexes. However, views have differed on the definition and the quantification of modifiers. In this study, modifier parameters and scores of the Risk-UE Level 1 method are adjusted based on the Algerian seismic code recommendations and the reviews proposed in the literature. The adjusted modifiers and scores are applied to reinforced concrete (RC) buildings in Boumerdes city, in order to assess probable seismic damage. Comparison between estimated damage and observed damage caused by the 2003 Boumerdes earthquake is done, with the objective to (i) validate the model involving influence of the modifier parameters on the seismic vulnerability, and (ii) to define the relationship between modifiers and damage. This research may help planners in improving seismic regulations and reducing vulnerability of existing buildings.

• 한국산림과학회지
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• 제97권6호
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• pp.656-660
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• 2008

본 연구는 숲가꾸기 작업을 위하여 개설된 작업로를 대상으로 노면피해에 영향을 미치는 요인을 평가하여 작업로 노면의 피해예방을 위한 적정 시설기준의 기초자료를 제공하고자 실시하였다. 작업로 노면피해에 영향을 크게 미치는 요인은 시설위치, 종단기울기, 겉보기토질, 산지사면형상, 노폭의 순으로 나타났다. 따라서 종단기울기, 노폭 등 도로 구조적인 요인과 시설위치, 산지사면형상 등 입지적 요인 그리고 겉보기 토질과 같은 도로 구성물질이 노면 피해 발생과 밀접한 연관이 있는 것으로 나타났다. 또한 작업로의 피해발생은 계곡부, 종단기울기 24%이상, 마사토 토질, 요형사면, 노폭 3.0 m이상에서 심한 것으로 나타났고, 안정성은 능선부, 종단기울기 4~24%, 토사지역, 직선형(-)사면, 노폭 3.0 m이하에서 큰 것으로 나타났다. 수량화II류의 판별식의 판별적중률은 79.4%로 상당히 양호한 값으로 나타나 작업로 노면의 양부판정에 활용이 가능할 것으로 사료된다.

• 한국콘텐츠학회논문지
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• 제21권12호
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• pp.573-584
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• 2021

본 연구는 지역아동센터 이용 아동 중에서 저소득층 아동의 차별피해에 영향을 미치는 요인을 알아보고자 하는 목적을 가지고 있다. 조사의 대상은 지역아동센터 아동패널조사 2기 3차의 응답자인 초등학교 6학년생이며, 이중에서 가정경제 수준이 기초생활수급대상, 차상위, 사각지대에 해당하는 아동 355명이다. SPSS Statistics 25.0을 이용하여 탐색적 요인분석, 신뢰도분석, 빈도분석, 기술통계, 상관관계분석, 다중회귀분석방법을 사용하였다. 연구결과, 한부모 가정, 부모 의논상대 존재 여부, 부모의 학대, 행복감이 지역아동센터 저소득층 아동의 차별피해에 유의미한 영향을 미치는 것으로 나타났다. 한부모 가정일수록, 부모가 의논상대 역할을 하지 못할수록, 부모 양육태도가 학대의 경향일수록 아동의 차별피해는 높아지는 것으로 나타났다. 대체로 부모 관련 요인들이 저소득층 아동의 차별피해에 영향을 미치고 있었다. 지역아동센터 및 관련 기관들은 이용 아동의 가족관계의 질을 향상시킬 수 있는 프로그램 개발과 실행에 역점을 두어야 한다.

• 한국지진공학회논문집
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• 제27권6호
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• pp.311-320
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• 2023

When an earthquake occurs, the severity of damage is determined by natural factors such as the magnitude of the earthquake, the epicenter distance, soil properties, and type of the structures in the affected area, as well as the socio-economic factors such as the population, disaster prevention measures, and economic power of the community. This study evaluated the direct economic loss due to building damage and the community's recovery ability. Building damage was estimated using fragility functions due to the design earthquake by the seismic design code. The usage of the building was determined from the information in the building registrar. Direct economic loss was evaluated using the standard unit price and estimated building damage. The standard unit price was obtained from the Korean Real Estate Board. The community's recovery capacity was calculated using nine indicators selected from regional statistical data. After appropriate normalization and factor analysis, the recovery ability score was calculated through relative evaluation with neighboring cities.

• Journal of Preventive Medicine and Public Health
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• 제40권1호
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• pp.16-22
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• 2007

Objective : The purpose of this study was to evaluate the levels of DNA damage in human lymphocytes caused by smoking and other lifestyle factors. Methods : The study population consisted of 173 normal healthy male adults from 21 to 59 years old. The demographic and lifestyle variables were obtained from administered questionnaires. The level of lymphocytic DNA damage in the peripheral blood was evaluated by the Comet assay. Statistical analyses were done by general linear model analysis and Dunnett's multiple comparison. Results : The difference in DNA damage between smokers and non-smokers was statistically significant. The means for the Tail%DNA were found to be 10.48 in the current smokers and 9.60 in the non-smokers (p < 0.05). The tail moment means were 1.58 and 1.45 (p < 0.05) for the current smokers and non-smokers, respectively. The number of cigarettes smoked per day did not result in a significant difference in the level of DNA damage among the smokers. Other lifestyle factors such as age, and drinking and exercise habits were not related to DNA damage. Conclusions : The DNA damage in the lymphocytes of smokers was found to be significantly higher than that for non-smokers. However, the number of cigarettes smoked per day was not related to DNA damage. Further study is needed to evaluate the relationship between the amount of smoking and level of damage to DNA. In addition, the status of DNA repair activities should be assessed.

• 한국조경학회지
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• 제35권4호
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• pp.71-80
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• 2007

The purpose of this study is to suggest the criteria for the damaged mountainous landscape based on the shape, location and ratio of damaged landscape. For the study, the preference and landscape adjectives were analyzed on visual images and simulations. The variables for analysis were the amount of the damaged ratio(10%, 30%, 50%), the location of the damage (upper, middle, lower) and the various forms of the damage(spot, line, area). According to the results of this study, in accordance with the amount of damage, the visual preference recorded its lowest with the a rate of 50%. As for the location of the damage, the lower-ridge of the mountain showed the highest preference, and the upper-ridge was recorded as the lowest. The linear damage type showed the highest preference. On the other hand, the spotted damage type showed lowest. The results indicate that the visual preference increases when there is a lower ratio of damage, as the damage locates at the lower-ridge, and also when there is a presence of linear formation development. The group of linear formation-the lower ridge-10% showed the highest preference, and the group of linear formation-the mid ridge-50% was the lowest with the results of 3-way ANOVA. The group of linear formation-lower ridge-10% in particular had virtually no differences of visual preference when it was compared with the original scene. The damage with the spotted formation, on the mid-upper location and the high ratio of damage were analyzed as factors that give negative influence on the mountainous landscape. The main features of mountainous landscape were reduced into two factors, 'total estimation' and 'spatial scale' by the factor analysis with total variance of 65.96%.

• 대한토목학회논문집
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• 제44권1호
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• pp.19-32
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• 2024

정밀안전진단보고서를 분석한 결과 국내 고속도로 교량은 결함, 열화, 물리력에 의한 손상이 주요하게 발생한다. 특히 열화는 시간이 경과함에 따라 다양한 환경 영향인자와 외부적 요인에 의해 발생하는 필연적인 손상이다. 교량 바닥판의 경우 열화가 가장 빠른 부재로, 균열부를 중심으로 철근부식, 박리/박락 등의 여러 가지 유형의 이종손상이 함께 발생하는 것으로 분석된다. 따라서 교량의 이종손상과 열화환경 간의 상관관계를 밝히고 이를 통해 교량의 이종손상 발생 원인을 규명해야 한다. 본 연구에서는 랜덤포레스트를 활용하여 교량의 이종손상 예측 모델을 개발하였으며, 개발된 모델을 통해 이종손상 발생에 영향을 미치는 상위 5가지 영향인자를 도출하였다. 이를 통해 장래 교량의 유지관리 및 예산을 추정하는 분야에 활용하는 기초자료가 될 수 있을 것으로 판단된다.