• Title/Summary/Keyword: Safe life

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A Study on the Design against Metal Fatigue (파로설계에 관한 소고)

  • Lee, Sun-Bok
    • 한국기계연구소 소보
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    • v.4 no.1
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    • pp.19-26
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    • 1981
  • Fatigue, the birth and growth of cracks in metal parts subjected to repeated loading, has been a problem plaguing engineers since the Industrial Revolution and the advent of rotating or reciprocating machinery. Designing against metal fatigue was studied briefly in several aspects. Examples of fatigue failures were shown. Fatigue was classified by loading: uniaxial Fatigue, multiaxial fatigue, cumulative fatigue da¬mage. Fatigue design criteria were discussed: Infinite-Life Design, Safe-Life Design, Fail-Safe Design, and Damage Tolerant Design. Mitigation of notch effects by design, improvement of fatigue strength of metal parts by residual stress and surface finishing were discussed. Relative fatigue beha¬vior was studied under various environmantal conditions. Especially the effects of corrosion, temperature, fretting, and irradiation were covered.

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Development of The Safe Driving Reward System for Truck Digital Tachograph using Hyperledger Fabric (하이퍼레저 패브릭을 이용한 화물차 디지털 운행기록 단말기의 안전운행 보상시스템 구현)

  • Kim, Yong-bae;Back, Juyong;Kim, Jongweon
    • Journal of Internet Computing and Services
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    • v.23 no.3
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    • pp.47-56
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    • 2022
  • The safe driving reward system aims to reduce the loss of life and property by reducing the occurrence of accidents by motivating safe driving and encouraging active participation by providing direct reward to vehicle drivers who have performed safe driving. In the case of the existing digital tachograph, the goal is to limit dangerous driving by recording the driving status of the vehicle whereas the safe driving reward system is a support measure to increase the effect of accident prevention and induces safe driving with financial reward when safe driving is performed. In other words, in an area where accidents due to speeding are high, direct reward is provided to motivate safe driving to prevent traffic accidents when safe driving instructions such as speed compliance, maintaining distance between vehicles, and driving in designated lanes are performed. Since these safe operation data and reward histories must be managed transparently and safely, the reward evidences and histories were constructed using the closed blockchain Hyperledger Fabric. However, while transparency and safety are guaranteed in the blockchain system, low data processing speed is a problem. In this study, the sequential block generation speed was as low as 10 TPS(transaction per second), and as a result of applying the acceleration function a high-performance network of 1,000 TPS or more was implemented.

A Study on Estimation of Infinite Fatigue Life in Cruciform Fillet Welded Joint (십자형 필릿 용접부에서의 무한 피로수명 평가에 관한 연구)

  • Lee, Yong-Bok
    • Journal of the Korean Institute of Gas
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    • v.17 no.1
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    • pp.19-25
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    • 2013
  • The joining methods of steel structures of gas facilities, bridges, ships etc. by welding are composed mostly of T-type or cruciform fillet welding and full penetration or partial penetration according to the uses and the shape of the structures. In this study, it was examined the characteristics of fatigue crack according to penetration depth in relation to material thickness in the cruciform fillet welded joints. From the results, it was investigated the safe design stresses within the range of infinite life. When the LOP length is long the range of infinite life is small with root failure and when the LOP length is short the range of infinite life is large with teo failure. For the specimen of material thickness, 20mm welded by 3 pass compared with 10mm, 15mm welded by 2 pass, the fatigue strength and the range of infinite life was more improved by increasing of notch toughness from formation of micro-ferrite acicular structure.

Regulatory roles of ginseng on inflammatory caspases, executioners of inflammasome activation

  • Yun, Miyong;Yi, Young-Su
    • Journal of Ginseng Research
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    • v.44 no.3
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    • pp.373-385
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    • 2020
  • Inflammation is an immune response that protects against pathogens and cellular stress. The hallmark of inflammatory responses is inflammasome activation in response to various stimuli. This subsequently activates downstream effectors, that is, inflammatory caspases such as caspase-1, 4, 5, 11, and 12. Extensive efforts have been made on developing effective and safe anti-inflammatory therapeutics, and ginseng has long been traditionally used as efficacious and safe herbal medicine in treating various inflammatory and inflammation-mediated diseases. Many studies have successfully shown that ginseng plays an anti-inflammatory role by inhibiting inflammasomes and inflammasome-activated inflammatory caspases. This review discusses the regulatory roles of ginseng on inflammatory caspases in inflammatory responses and also suggests new research areas on the anti-inflammatory function of ginseng, which provides a novel insight into the development of ginseng as an effective and safe anti-inflammatory herbal medicine.

Fatigue Safe Life Analysis of Helicopter Rotor Bearingless Hub System Composite Components (헬리콥터 로터 무베어링 허브 시스템 복합재 구성품 피로 안전수명 해석)

  • Kim, Taejoo;Kee, Youngjoong;Kim, Deog-Kwan
    • Aerospace Engineering and Technology
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    • v.13 no.1
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    • pp.10-19
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    • 2014
  • We designed bearingless rotor hub system which replace mechanical hinge/bearing with composite beam component and conducted fatigue analysis for flexbeam and torque tube. Extension/bending/torsional stiffness was calculated from 2D section analysis using VABS and 2D section structure analysis was applied for strain calculation. S-N curve of each composite material was generated using Wohler equation and fatigue analysis was conducted on weakness section which was decided from static structure analysis. CAMRAD II was used for load analysis and load analysis result was applied HELIX/FELIX standard load spectrum to generate bearingless rotor system load spectrum which was used fatigue safe life analysis.

Fatigue Safe Life Evaluation of Rotating Swashplate of Helicopter Main Rotor Control System (헬리콥터 주로터 조종 시스템 회전형 스와시플레이트 피로 안전수명 평가)

  • Kim, Dong-Chul;Lee, Pan-Ho;Kang, Shin-Hyun;Choi, Young-Don;Kim, Tae-Joo
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.36 no.2
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    • pp.203-210
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    • 2012
  • The main rotor control system is an important structural part of a helicopter that manages the thrust and control force of the helicopter. The main rotor control system consists of a swashplate assembly, scissor assembly, pitch rod assembly, guide, etc. The main rotor control system must endure various loads, such as the thrust and control force, and must meet the optimized fatigue safety life. The rotating swashplate is an important structure influenced by the pitch rod load and rotating scissor load. In this paper, the accuracy of a result about the rotating swashplate part of the main rotor control system is proven through comparison between fatigue test and FEM results. Based on this result, we estimate the lifetime and deduce the fatigue safe lifetime.

A Study on Weight Control Behavior by Female Consumers Eating Life Styles (여성 소비자의 식생활 라이프스타일에 따른 체중 조절 행위에 관한 연구)

  • Han, In-Kyung;Ha, Ae-Wha
    • The Korean Journal of Food And Nutrition
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    • v.22 no.2
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    • pp.177-184
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    • 2009
  • The study investigated the eating lifestyles of female consumers and whether they influenced weight control behavior. The findings of the study can be summarized as follows. First, the eating lifestyles of the subjects were presented four types: 'active eating life pursuit type', 'safe economical type', 'gourmet type' and 'passive negligence type'. In general, most cases were of the 'passive negligence type'. Second, weight control behavior was analyzed according to eating lifestyle. The results of the analysis indicated that the female consumers of the 'active eating life pursuit type' and 'safe economy type' had high behavior levels in each aspect of weight control attitude, subjective regulation, perceived behavior control, and behavior intention. Third, the 'gourmet type', with a strong preference for taste, and the 'passive negligence type', with fewer eating considerations in general, showed weaker attitudes towards weight control and the recognition of pressure from people around them. As such, the level of consideration for food or eating was correlated with weight control. These findings impliedy that the more active, safer, and economical women are in their general eating style, the stronger they perceive weight control issues.

The Factors Affecting Dining-out Expenses by Generation X and Generation MZ Based on Tobit Model (토빗분석을 적용한 X세대, MZ세대의 외식지출 영향요인)

  • Min, Ji Eun;Han, Kyung Soo
    • Journal of the Korean Society of Food Culture
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    • v.36 no.3
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    • pp.284-292
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    • 2021
  • The food service industry has grown larger with changes in the economic and socio-cultural environment. In this saturated food service industry, generation X and MZ are the main consumer forces that demand attention. That is because a generation is the main psychographic factor that reflects personal values and lifestyle based on one's life cycle. From such a perspective, a generation in marketing has been used as a variable to predict a market by supplementing demographic factors. Accordingly, this study classified generations into generation X and generation MZ with the use of the 2019 consumer behavior survey for food by Korea Rural Economic Institute (KREI) and then investigated the factors influencing group and personal dining-out expenses. The analysis was carried out applying the Tobit model using SPSS and R. The positively influential variables on generation X's personal dining-out expenditure were male, single person, high income and simple lifestyle, whereas housewives, personal ethical consciousness, behavioral ethical consciousness, and safe dietary life were negatively influential variables. The positively influential variables on generation MZ's personal dining-out expenditures were male, dual-income, high education level, corporate and governmental ethical consciousness, while the number of family members and safe dietary life were negatively influential variables.