• 제목/요약/키워드: Factor of Safety

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A Study on the Infinite Slope Safty Factor Applied to the Roots Cohesion (뿌리 점착력을 적용한 무한사면 안전률에 관한 연구)

  • Choi, Won-Il;Choi, Eun-Hwa;Suh, Jin-Won;Jeon, Seong-Kon
    • Journal of the Korean Geosynthetics Society
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    • v.15 no.2
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    • pp.13-24
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    • 2016
  • The safety factor of an infinite slope tends to be analyzed as lower when the effects of root cohesion are not considered into the equation. Thus, it is essential to consider regional characteristics such as root cohesion and crown density in order to obtain a reasonable safety factor value. In this study, The safety factor of the landslide model, both before and after considering crown density and root cohesion, was calculated and a comparative analysis was carried out. The safety factor is increased by the effect of roots cohesion of the analysis results, the amount of increase in safety factor along the inclination of the slope angle has been analyzed with various things, the effect of reinforcing the roots cohesion, slope of the lower angle it was found that the higher the safety factor increase.

The Calculus of Variations Applied to Stability of Slopes (사면안정에 응용되는 여러가지 계산법)

  • 김경진
    • Journal of the Korean Professional Engineers Association
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    • v.16 no.2
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    • pp.11-17
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    • 1983
  • This work presents a method for the determination of the safety factor of a slope based on the theory of the calculus of variations. The method allows for the determination of the critical sliding line (The one giving the minimum safety factor) without the necessity of guessing about its shape, which leads to a considerable economy of time and effort. Furthermore it gives the actual safety factor of the slape and consequently a more complete knowledge of the safety of the slope is obtained.

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Structural Analysis of Hammering System for Pine Cone Harvest using Industrial Drone (산업용 드론을 이용한 잣수확용 해머링 시스템의 구조해석)

  • Ki-Hong Kim;Dae-Won Bae;Won-Sik Choi
    • Journal of the Korean Society of Industry Convergence
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    • v.26 no.2_2
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    • pp.285-291
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    • 2023
  • In this paper, in order to secure the safety and productivity of pine cone harvest, modeling and structural analysis of the hammering system for pine cone harvest drone that can easily access pine cone of Pinus koraiensis and collide with them to harvest them was performed. It calculate the equivalent stress for the structure of the hammering system and the yield strength of the applied material by applying the shear force of the stalk at which the pine cone is separated from the branch, and it is to verify the safety of the structure and propose an optimal design through appropriate factor of safety and design change. The shear force of the stalk at which the pine cone was separated from the branch was 468 N, and was applied to both ends of the hammering system. The yield strength of SS400 steel used in the hammering system is 245 ㎫, and the design change and structural analysis were performed so that the Von Mises stress could be less than 122.5 ㎫ by applying the factor of safety of 2.0 or more. As a result of the structural analysis of the frist modeling, the Von Mises stress was 220.3 ㎫, the factor of safety was 1.12, and the stress was concentrated in the screw fastening holes. As a result of the design change of the screw fastening holes, the Von Mises stress was 169.4 ㎫, the factor of safety was 1.45, and the stress was concentrated on the side part. As a result of the design change by changing screw fastening holes and adding ribs, the Von Mises stress was 121.6 ㎫, and the factor of safety was 2.02. The safety of the hammering system was secured with an optimal design with little change in mass. There was no deformation or damage as a result of experimenting on pine cone harvest by manufacturing the hammering system with an optimal design.

On the Countermeasure for Preventing the Accident of Cargo Handling in Port (항만하역관할의 원인분석 및 예방대책에 관하여)

  • 박용욱;이철영
    • Journal of the Korean Institute of Navigation
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    • v.17 no.3
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    • pp.57-68
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    • 1993
  • The economy of Korea has grown up significantly in its scale. It has, therefore, become imperative to develop countermeasures to prevent work related injuries and occupational illnesses resultining from haza-rdous working conditions and handling harmful substances. A lot of cargo handling accident in port have occurred due to the characteristics of poor working environment, diversity of working place and method, fluctuation of the amount of cargo and handling of heavy, long, harmful and dangerous cargo, etc. According to '91 industrial accident analysis carried out by the ministry of labour, the number of the stevedores injured by cargo handling accident in port were 1, 432 persons (the death accident : 22 per-sons), the amount of industrial accident compensation in port was 6.7 billion won (the amount of economic loss : 33.6 billion won), and the injury occurance rate of the stevedoring industry was higher than that of the whole industry. This paper, therefore, aims to the actual status of the stevedoring industry and to extract the main cau-ses of the accidents related to cargo handling in port through factor analysis using the data of the accide-nts in the whole habour from 1990 to 1992, and to suggest the countermeasures to prevent such accident. The main causes of the accident and countermeasures are found to be as follows through the factor analy-sis : Factor1, factor2, and factor3 related to a defect of human being and management, a defect of state and environment, and an insufficiency of education and law are extracted. The short-term countermeasures to prevent these accidents are 1) to consolidate the safety and health organization in the working spot, 2) to secure a safe condition in working spot before dock work, 3) to strengthen a dock worker's safety educa-tion. The long-term countermeasures are 1) to promote a decasualisation of dock workers, 2) to modernize the cargo working methods through constructing exclusive pier and introducing exclusive cargo handling equipment, 3) to establish a exclusive dock accident prevention organization and the dock workers law. Factor 4, factor5, factor6, and factor7 related to an unfitness, a deficiency of technical knowledge, a nonfu-lfilment of safety measures, and a bad arrangement are extracted. The countermeasures to prevent these accidents are 1) to perform a complete safety inspection of cargo handling equipments and tools and to carry out the dock work according to a working plan, 2) to publish and supply technical safety books, safety instruction book, safety check list, etc., 3) to strengthen the safety patrol at the working spot in habour and to activate a safety fund, 4) to maintain always a clean workshop with the safety consciousness in which the good arragement of the working spot is considered to be the beginning of safety.

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The Relationship of Food-Related Lifestyle Type and Fast Food Consumption Behaviors of the Middle School Students (일부 중학생의 패스트푸드 소비형태와 식생활 라이프스타일 유형과의 관계)

  • Oh, Sung-Cheon;Jang, Jae-Seon
    • The Korean Journal of Food And Nutrition
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    • v.28 no.1
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    • pp.119-125
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    • 2015
  • This study was analyzed to provide fundamental data on the relationship between fast food consumption behaviors and food-related lifestyle types. Data was collected from 268 middle students in the Incheon region through a self-administered questionnaire. A factor analysis extracted five comprising food-related lifestyle, which we named health seeking (factor 1), taste seeking (factor 2), easy seeking (factor 3), popularity seeking (factor 4) and safety seeking (factor 5). According to the results of the factor analysis, the food-related lifestyle showed that the average consumption was more than 2.95 and, 0.792 in Cronbach alpha coefficient. There were significant differences in the influence factor for the selection of fast food according to taste seeking and, popularity seeking types (p<0.05). Also, the easy seeking and safety seeking lifestyle types showed a significant differences for the reason the choosing criteria of fast food (p<0.05). Especially, the nutrition problem was of the highest importance for the health and safety seeking but an advertisement effect trend appealed more to the taste seeking, easy seeking and popularity seeking lifestyles. There were significant differences in fast food of intake frequency according to health seeking, easy seeking, popularity seeking and safety seeking types (p<0.05). A significant positive result of the internal characteristics of fast food consumption (p<0.05) was shown for the health seeking and safety seeking types. A significant positive result of the external characteristics of fast food consumption (p<0.05) was shown for the popularity seeking and safety seeking types.

A Study on the Safety Assessment of Zinc Plating Process (아연도금공정의 안전성평가)

  • Rhie, Kwang-Won;Park, Moon-Hee
    • Journal of the Korean Society of Safety
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    • v.18 no.4
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    • pp.148-154
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    • 2003
  • There are now the plating process that have many hazardous factor cause of the using numerous noxious chemical and bad working environments. The purpose of the study is to make a selection of suitable safety evaluation method that can analyze and righteously find with numerous hazardous factor of the plating process. And another purpose is to systematically adjust the risk of plating process by comprehension of the role of process, equipment, and source material. Therefore, these studies are carried out in the following three investigations of this report. The first research understands the injurious human health and environment by analyzing hazardous material based on the MSDS. To evaluate the safety of process and compartment, the second research is proposed the security secure counterproposal by using the FMEA and the HAZOP. The final research is devoted to systematically analyze the hazard by applying for reasonable guide word and doing the HAZOP for hazardous factor in specific process.

A Study on the Three-Dimensional Stability Analysis of the Slope (사면의 3차원 안정해석에 관한 연구)

  • Kim, Yeong-Su;Baek, Yeong-Sik;Seo, In-Seok
    • Geotechnical Engineering
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    • v.7 no.4
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    • pp.89-98
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    • 1991
  • This paper presents the three-dimensional stability analysis of the homogeneous, isotropic soil Slopes. Rotational slides are assumed with a cylindroid central part terminated with log-spiral curved ends. The ratio of threeiimensional minimum factor of safety to two 4imensional case is examined and factor of safety changes are showed for the ratio of cylinder length to slope height. On touch babes the following conclusions may be made 1. Factors of safety computed for 3-D geometry differ considerablely from ordir,arty 2-D factor of. safety. Sinoe Fn 1 Fa2 exceeds unity, threeiimensional effects tend to increase the factor of safety. 2. A,B LIU increase, the value of Fb3/ Fs2 decreases. 3. The ratio of Fr/Fs2 appears to be very sensitive to c and values.

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Factor Analysis and Intergroup Awareness Investigation of Workers' Safety in Logistic Center (물류센터 근로자의 안전인식에 대한 요인분석 및 집단간 인식 비교)

  • Choi, Hyunjoon;Moon, Sangyoung;Ok, Seung-Yong
    • Journal of the Korean Society of Safety
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    • v.30 no.4
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    • pp.113-119
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    • 2015
  • This study is to examine the workers' awareness of the safety in logistic centers. For that purpose, the exploratory factor analysis of workers' safety awareness in logistic centers was performed at first, and the 6 variables extracted from the factor analysis were then used to investigate the difference in intergroup awareness of the safety environment in the logistic centers. We administered a survey to 147 workers attending the logistic centers and collected data from them. The results of the study showed that the intergroup awareness of the safety environment turned out to be statistically different from each other in terms of working environment, safe behavior, work risk, safety knowledge and effort, risk justification and compromising attitudes. Experiences in industrial accidents influenced awareness of working environment, work risk and risk justification. The group who experienced accidents is more likely to feel risky and unsatisfied with working place, and their awareness toward risk justification was high as well. It was also observed that there exists awareness difference between manager group and worker group. The group who manages the working place showed more positive awareness of working environment, safe behavior, work risk, safety knowledge and effort, risk justification and compromising attitudes than the worker group. On the contrary, the worker group showed high recognition in risk of working place, and felt that they are willing to compromise on safety for increasing production. The scale of the logistic center produced negative influence on awareness of safety. The group in small logistic center showed the highest awareness in safety, whereas the group in large logistic center with more than 100 workers showed the highest awareness in risk. They are more likely to deviate from correct and safe work procedures due to over-familiarity with the job, as well. The findings suggest that there is a need for the safety management and education to change the workers' understanding and attitudes towards safety.

An IoT-based Traffic Safety Pedestrian System for the Elderly by Factor Analysis (요인분석을 통한 IoT 기반 고령자용 교통안전 보행자 시스템)

  • Lee, Kyung-Min;Lin, Chi-Ho
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.20 no.1
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    • pp.1-9
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    • 2021
  • In this paper, we propose an IoT-based traffic safety pedestrian system for the elderly by factor analysis. The proposed system performs a factor analysis of the elderly safety variables and uses the analysis results to provide an optimal path for the elderly. In order to verify the performance of this system, we experimented with performance measurements on elderly pedestrian paths. As a result, we confirm that it provides a better safety path than mobile navigation.

SEM-based study on the impact of safety culture on unsafe behaviors in Chinese nuclear power plants

  • Licao Dai;Li Ma;Meihui Zhang;Ziyi Liang
    • Nuclear Engineering and Technology
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    • v.55 no.10
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    • pp.3628-3638
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    • 2023
  • This paper uses 135 Licensed Operator Event Reports (LOER) from Chinese nuclear plants to analyze how safety culture affects unsafe behaviors in nuclear power plants. On the basis of a modified human factors analysis and classification system (HFACS) framework, structural equation model (SEM) is used to explore the relationship between latent variables at various levels. Correlation tests such as chi-square test are used to analyze the path from safety culture to unsafe behaviors. The role of latent error is clarified. The results show that the ratio of latent errors to active errors is 3.4:1. The key path linking safety culture weaknesses to unsafe behaviors is Organizational Processes → Inadequate Supervision → Physical/Technical Environment → Skill-based Errors. The most influential factors on the latent variables at each level in the HFACS framework are Organizational Processes, Inadequate Supervision, Physical Environment, and Skill-based Errors.