• Title/Summary/Keyword: Safety control

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Phase Portrait Analysis-Based Safety Control for Excavator Using Adaptive Sliding Mode Control Algorithm (적응형 슬라이딩 모드 제어를 이용한 위상 궤적 해석 기반 굴삭기의 안전제어 알고리즘 개발)

  • Oh, Kwang Seok;Seo, Ja Ho;Lee, Geun Ho
    • Journal of Drive and Control
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    • v.15 no.3
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    • pp.8-13
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    • 2018
  • This paper presents a phase portrait analysis-based safety control algorithm for excavators, using adaptive sliding mode control. Since working postures and material types cause the excavator's rotational inertia to vary, the rotational inertia was estimated, and this estimation was used to design an adaptive sliding mode controller for collision avoidance of the excavator. In order to estimate the rotational inertia, the recursive least-squares estimation with multiple forgetting was applied with the information of the swing velocity of the excavator. For realistic evaluation, an actual working scenario-based performance evaluation was conducted. Based on the estimated rotational inertia and an analysis of estimation errors, sliding mode control inputs were computed. The actual working scenario-based performance evaluation of the designed safety algorithm was conducted, and the results showed that the developed safety control algorithm can efficiently avoid a collision with an object in consideration of rotational inertia variations.

Antecedents of self-reported safety behaviors among commissioning workers in nuclear power plants: The roles of demographics, personality traits and safety attitudes

  • Tao, Da;Liu, Zhaopeng;Diao, Xiaofeng;Tan, Haibo;Qu, Xingda;Zhang, Tingru
    • Nuclear Engineering and Technology
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    • v.53 no.5
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    • pp.1454-1463
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    • 2021
  • Demographics, personality traits and attitudes are related to safety behaviors in varied workplaces, but their roles in nuclear power plants (NPPs) have not been fully understood. This study was conducted to explore the roles of a set of demographic, personality and attitudinal factors on self-reported safety behaviors (including safety participation and human errors) among NPP commissioning workers. Survey data were collected from 157 Chinese commissioning workers. Results showed that age and work experience were significantly associated with human errors, but not with safety participation. Neuroticism and conscientiousness were significantly related to human errors, while neuroticism, conscientiousness and agreeableness were significantly related to safety participation. Attitude towards questioning was observed as an antecedent of safety participation, and functioned as a mediating variable in the relation between conscientiousness and safety behaviors. The findings provide evidence-based implications on the design of diverse interventions and strategies for the promotion of safety behaviors in NPPs.

Effect of bamboo shoot dietary fiber on gel properties, microstructure and water distribution of pork meat batters

  • Li, Ke;Liu, Jun-Ya;Fu, Lei;Zhao, Ying-Ying;Zhu, He;Zhang, Yan-Yan;Zhang, Hua;Bai, Yan-Hong
    • Asian-Australasian Journal of Animal Sciences
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    • v.33 no.7
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    • pp.1180-1190
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    • 2020
  • Objective: To develop healthier comminuted meat products to meet consumer demand, the gel properties, rheological properties, microstructure and water distribution of pork meat batters formulated with various amounts of bamboo shoot dietary fiber (BSDF) were investigated. Methods: Different levels of BSDF (0% to 4%) were added to pork batters, and the pH, color, water-holding capacity, texture and rheological properties of pork batters were determined. Then, pork batters were analyzed for their microstructure and water distribution using scanning electron microscopy (SEM) and low-field nuclear magnetic resonance (LF-NMR). Results: Compared with the control, BSDF addition into meat batters showed a significant reduction in L*-value and a significant increase in b*-value (p<0.05). BSDF addition of up to 4% reduced the pH value of pork batters by approximately 0.15 units; however, the cooking loss and expressible water loss decreased significantly (p<0.05) with the increased addition of BSDF. The hardness and gel strength were noticeably enhanced (p<0.05) as the content of BSDF increased. The rheological results showed that BSDF added into pork batters produced higher storage modulus (G') and loss modulus (G") values. The SEM images suggested that the addition of BSDF could promote pork batters to form a more uniform and compact microstructure. The proportion of immobilized water increased significantly (p<0.05), while the population of free water was decreased (p<0.05), indicating that BSDF improved the water-holding capability of pork batters by decreasing the fraction of free water. Conclusion: BSDF could improve the gel properties, rheological properties and water distribution of pork meat batters and decrease the proportion of free water, suggesting that BSDF has great potential as an effective binder in comminuted meat products.

A Study on the Improvement of the Maritime Safety Supervisor System for the Reinforcement of Coastal Ship Safety Control (내항선 안전관리강화를 위한 해사안전감독관 제도 개선 연구)

  • Lee, Seok-Mal
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.24 no.1
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    • pp.43-55
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    • 2018
  • The biggest change in the field of coastal ship safety control since the accident of passenger ship Sewol has been the introduction of the maritime safety supervisor system. With its introduction, the safety control system in coastal passenger ships was changed from consisting of operation managers and marine police to operation managers and a newly-introduced maritime safety supervisor. The safety control system for coastal cargo ships was also converted from relying on ship inspection officers to having a maritime safety supervisor and ship inspection officers. However some negative elements have surfaced due to confusion related to the scope of work in the coastal cargo shipping field. These have been caused by dividing the supervisory agency, a lack of work continuity given non-permanent public official status, low supervisor qualifications overlooking reality, and limitations of the order for improvement to secure seaworthiness. It is essential that the maritime safety supervisor system be solidified to reinforce coastal ship safety control. Therefore, systematic safety control in the coastal cargo shipping industry should be conducted by a single, integrated government agency, and the area covered by the order for improvement to secure seaworthiness should be extended. Also limitations of the supervisor recruitment system due to non-permanent public official status should be simultaneously improved. In addition, it is necessary to upgrade supervisor qualifications to require experience with surveyors of international class, ship captains, and chief engineers.

A Case Study of National Food Safety Control System Assessment in the U.S. (미국의 국가식품안전관리체계 평가 사례연구)

  • Lee, Heejung
    • Journal of Food Hygiene and Safety
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    • v.32 no.3
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    • pp.179-186
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    • 2017
  • For more efficient and proactive safety control of imported food, new trend in U.S. is emerging, which assesses the food safety control systems of exporting countries using Systems Recognition Assessment Tool and helps ensure safety of imported foods. This study examines trends in development and application of assessmemnt tool and country assessment reports in U.S. where an active discussion on this issue is in progress. The expert interviews were also conducted. U.S. Systems Recognition Assessment Tool was developed by FDA to recognize the potential value in leveraging the expertise of foreign food safety systems and help ensure safety of imported food. The tool is comprised of ten standards and provides an objective framework for determining the robustness of trading partners' overall food safety systems. Using its own tool, the U.S. FDA conducted a preliminary assessment of the food safety control systems of New Zealand and Canada. According to the U.S.-New Zealand and the U.S.-Canada assessment reports, the overall structure of the systems was similar between the countries. In summarizing the opinions of experts, such a trend in National Food Safety Control System Assessment may be utilized in the sanitary assessment and the control of imported food border inspection frequency before importing food. It would contribute to more effective distribution of national budget and increased public trust. Additionally, international collaboration as well as securing of qualified experts and sufficient budget appear to be crucial to further increase the utility of National Food Safety Control Systems Assessment. In conclusion, firstly, it is critically important for the competent authority of South Korea to proactively respond to international trend in National Food Safety Control System Assessment by identifying the details of its background, assessment purpose, core assessment elements, and assessment procedures. Secondly, it is necessary to identify and complement the weaknesses of Korea's food safety control system by reviewing it with U.S. Systems Recognition Assessment Tool. Thirdly, by adapting the assessment results from imported countries' food safety control systems to the imported food inspection intensity, the resources previously used in inspecting the imported food from accredited countries can be redistributed to inspecting the imported food from unaccredited countries, and it would contribute to more efficient imported food safety control. Fourthly, the competent authority of South Korea should also consider developing its own assessment tool designed to reflect the unique characteristics of its food safety control system and international guidelines.

Effect of Apartment Residents' Safety Awareness on Fire Response Performance: Focusing on the Moderating Effect of Control Offices' Control Competence (아파트 거주자의 안전의식이 화재대응성과에 미치는 영향 : 관리사무소의 관리역량 조절효과를 중심으로)

  • Kim, Jong-Nam;Kong, Ha-Sung
    • The Journal of the Convergence on Culture Technology
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    • v.6 no.1
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    • pp.43-53
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    • 2020
  • The purpose of this study is to reduce the anxiety factors of fires by following evacuation tips in case of fire in an apartment household. This study analyzed the moderating effects of the control offices' competence in control on safety awareness and fire response. The study results were as follows. First, the residents and control staff's safety awareness had a positive effect on the fire response performance. This indicates that the higher the residents and control staff's safety awareness level, the higher the fire responsive performance. Second, the higher the control offices' control competence level, the better the apartment residents and control staff's safety awareness had a positive effect on the fire response performance. These results indicate that the higher the control office heads' leadership, the higher the apartment residents' housing satisfaction and that the more communicative the control office heads' attitude toward the residents, the better their attitude had a positive effect on the fire response performance. Lastly, the control offices' control competence was analyzed to have a moderating effects on the effect of the apartment residents and control staff's safety awareness level on the fire response performance. These results showed that the change in the model's R2 value showed an increasing trend in stages as the value increased more in the stage 2 than the stage 1 and even more in the stage 3 with the interaction terms of the moderating variables added. For this reason, the control offices' control competence which was a moderating variable was analyzed to have a moderating effect on the effect of residents and control staff's safety awareness level on the fire response performance.

A Study on Improvement of the Interface Control of NPP Construction and Operation Activities

  • Chung, Ku-Young;Lee, Woo-Ho;Lee, Jae-Hun
    • Proceedings of the Korean Nuclear Society Conference
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    • 2005.05a
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    • pp.1221-1222
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    • 2005
  • Interface control activities during the nuclear power plant (NPP) construction and operation have been reviewed for enhancing the safety of NPP. The primary focus of the study is given on analysis of lessons learned from the recent significant events of Korean Standard Nuclear Power plant (KSNP), such as a series of break-off of thermal sleeves at YGN 5 & 6 and radioactivity leak at YGN 5, in respect of interface control. Based on the results of the analysis, this study recommends measures for the improvement of interface control among utility and technical supporting organizations (TSO), and suggests new regulatory systems, such as reporting of safety significant non-conformances, to effectively verify the adequacy of interface control activities during construction and operation of NPPs.

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Research on Railway Safety Common Data Model and DDS Topic for Real-time Railway Safety Data Transmission

  • Park, Yunjung;Kim, Sang Ahm
    • Journal of the Korea Society of Computer and Information
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    • v.21 no.5
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    • pp.57-64
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    • 2016
  • In this paper, we propose the design of railway safety common data model to provide common transformation method for collecting data from railway facility fields to Real-time railway safety monitoring and control system. This common data model is divided into five abstract sub-models according to the characteristics of data such as 'StateInfoMessage', 'ControlMessage', 'RequestMessage', 'ResponseMessage' and 'ExtendedXXXMessage'. This kind of model structure allows diverse heterogeneous data acquisitions and its common conversion method to DDS (Data Distribution Service) format to share data to the sub-systems of Real-time railway safety monitoring and control system. This paper contains the design of common data model and its DDS Topic expression for DDS communication, and presents two kinds of data transformation case studied for verification of the model design.

A Mediating Effect of Job Stress Between Physical Environmental Risk and Safety Behavior, and Moderating Effect of Perceived Control (물리적 환경 위험도가 작업자의 안전행동에 미치는 영향, 직무 스트레스의 매개 효과 및 지각된 통제의 조절 효과)

  • Kim, Byung-Jik;Ji, Won-Koo;Jeon, Sang-Gil
    • Journal of the Korean Society of Safety
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    • v.32 no.2
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    • pp.105-111
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    • 2017
  • This research examined if job stress mediates the relationship between physical environmental risk and safety behavior of employees. In addition, we investigated whether perceived control moderates the physical environmental risk-job stress link. In order to test our hypotheses, 1005 employees in various fields of firms were participated. Using structural equation modeling(SEM), we conducted moderated mediation model analysis that elaborately test the hypotheses. The results demonstrated that job stress mediated the physical environmental risk-safety behavior link. Furthermore, the relationship between physical environmental risk and job stress was moderated by perceived control.

A Study on the Effect of Urban Freeway Traffic Control Strategies on Safety (도시고속도로 교통류 제어전략이 교통안전에 미치는 영향에 관한 연구)

  • 강정규
    • Journal of Korean Society of Transportation
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    • v.14 no.2
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    • pp.223-237
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    • 1996
  • Based on the traffic and accident data collected on a 4.2km (2.6mile) section of Interstate highway 35W in Minneapolis the relationship between traffic operation variables and safety measures is investigated. An aggregate specification that could be integrated into an urban freeway safety prediction methodology is proposed as a multiple regression model. The specification includes lane occupancy and volume data, which are the control parameters commonly used because they can be measured in real time. The primary variables that appear to affect the safety of urban freeway are : vehicle-miles of travel, entrance ramp volumes and the dynamic effect of queue building. The potential benefits of freeway traffic control strategies on freeway safety are also investigated via a simulation study. It was concluded that improvement of urban freeway safety is achievable by traffic control strategies which homogenize traffic conditions areound critical occupancy values.

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