• Title/Summary/Keyword: Mechanic

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The Impact of Redundancy and Teamwork on Resilience Engineering Factors by Fuzzy Mathematical Programming and Analysis of Variance in a Large Petrochemical Plant

  • Azadeh, Ali;Salehi, Vahid;Mirzayi, Mahsa
    • Safety and Health at Work
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    • v.7 no.4
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    • pp.307-316
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    • 2016
  • Background: Resilience engineering (RE) is a new paradigm that can control incidents and reduce their consequences. Integrated RE includes four new factors-self-organization, teamwork, redundancy, and fault-tolerance-in addition to conventional RE factors. This study aimed to evaluate the impacts of these four factors on RE and determine the most efficient factor in an uncertain environment. Methods: The required data were collected through a questionnaire in a petrochemical plant in June 2013. The questionnaire was completed by 115 respondents including 37 managers and 78 operators. Fuzzy data envelopment analysis was used in different ${\alpha}$-cuts in order to calculate the impact of each factor. Analysis of variance was employed to compare the efficiency score means of the four abovementioned factors. Results: The results showed that as ${\alpha}$ approached 0 and the system became fuzzier (${\alpha}=0.3$ and ${\alpha}=0.1$), teamwork played a significant role and had the highest impact on the resilient system. In contrast, as ${\alpha}$ approached 1 and the fuzzy system went toward a certain mode (${\alpha}=0.9$ and ${\alpha}=1$), redundancy had a vital role in the selected resilient system. Therefore, redundancy and teamwork were the most efficient factors. Conclusion: The approach developed in this study could be used for identifying the most important factors in such environments. The results of this study may help managers to have better understanding of weak and strong points in such industries.

A Study on the Actual Wearing Conditions of Working Uniform for the Aircraft Mechanic (항공정비복 착용실태에 관한 연구)

  • Lim, Hyun-Ju;Choi, Hei-Sun;Lee, Kyung-Mi;Kim, Soo-A
    • Journal of the Korean Society of Clothing and Textiles
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    • v.30 no.9_10 s.157
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    • pp.1344-1353
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    • 2006
  • The purpose of this research is to investigate the actual wearing conditions of working uniform and identify problems for the aircraft mechanic. For this study, questionnaire surveys were conducted dividing according to styles of clothing; one-piece and two-piece styles. Subjects were 343 men working in flight line. Questionnaire of 159 two-piece styles and 184 one-piece ones were used in analysis. The results of the study are as follows; The result about wearing each type of working uniform showed that the two-piece one is always as the air force uniform, whereas the one-piece one is worn only a few times. They felt inconvenience during all operations except in the sitting position, crawling position, and positions in which they were using tools. Accordingly, the result of the functionality reported dissatisfaction on all question items. Therefore, uniform of two-piece style achieved better results on all questions related to motional flexibility and functionality. Questions on changes to finishing methods showed that each airline employed different methods for both two-pieced and one-pieced uniforms. The answers about the unstitched or worn-out parts of the two-piece garments showed that pants were unstitched on the inner seam of the trouser leg and hip regions, but the upper one was not. In case of the one-pieced uniform, the parts of wearing out is the seam of hip and the unstitched parts are knee region and hem line of pants. Questions concerning their satisfaction with the material of uniforms indicated a high rate of dissatisfaction, particularly in its ventilation and absorbency. Questions concerning the preferred design of working uniform indicated a preference for two-piece uniform rather than one-piece ones.

Study on the way how to make the recruiting Examination of 'Machinery·Metal' Subject in Technical High School. (중등임용시험 '기계·금속' 과목의 출제방안 연구)

  • Choi, Jun-Seop;Lee, Seoung-Won;Kim, Jong-Chan;Jung, Bong-Kyoon;Park, Sang-Jin;Kwon, Cha-Mi
    • 대한공업교육학회지
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    • v.31 no.2
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    • pp.111-127
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    • 2006
  • The purpose of this study is to analyze current recruiting examination and to categorize and construct test item that assess a variety of Mechanic Metal teachers in technical high school for appointing new Mechanic Metal teacher. The future developmental directions in this study are as follows: First, the examination for appointing secondary school new Mechanic Metal Teacher reflects the curriculum of the teacher education and technical high school, must be nomalize. Second, the rational readjustment of the basic necessary subjects for Machinery Metal recruiting examination is required. Third, the Mechanic Metal recruiting examination must prepare the criteria for the domain ratio of presenting problems and improve with level of presenting the question items which demands a knowledge, application and critical thinking. Fourth, in order to avoid the bias of the some subject tendency with committee making questions of different domain, more participation of a committee making questions is required. Fifth, the practical evaluation must be executed by the effective method to be able to make up for the limit of paper and pencil tests Sixth, as the long-term prospect to secure the professionalism of teacher, the recruiting examination of teachers must be carried out with the Machinery and Metal subject, respectively.

Analysis and Improvement of Wasted Film

  • Chung Kyun Mo;Ahn Chin Shin
    • Journal of The Korean Radiological Technologist Association
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    • v.25 no.1
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    • pp.24-24
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    • 1999
  • In order to establish reasonable concept and background on repititive films, we analyzed factors due to wasted films grouping into three major factors as 1) artificial factor from exposure and positioning. 2) mechanical factor as mechanic error and jammin

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Vibration control parameters investigation of the Mega-Sub Controlled Structure System (MSCSS)

  • Limazie, Toi;Zhang, Xun'an;Wang, Xianjie
    • Earthquakes and Structures
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    • v.5 no.2
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    • pp.225-237
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    • 2013
  • Excessive vibrations induced by earthquake excitation and wind load are an obstacle in design and construction of tall and super tall buildings. An innovative vibration control structure system (Mega-Sub Controlled Structure System-MSCSS) was recently proposed to further improve humans comfort and their safeties during natural disasters. Preliminary investigations were performed using a two dimensional equivalent simplified model, composed by 3 mega-stories. In this paper, a more reasonable and realistic scaled model is design to investigate the dynamical characteristics and controlling performances of this structure when subjected to strong earthquake motion. The control parameters of the structure system, such as the modulated sub-structures disposition; the damping coefficient ratio (RC); the stiffness ratio (RD); the mass ratio of the mega-structure and sub-structure (RM) are investigated and their optimal values (matched values) are obtained. The MSCSS is also compared with the so-called Mega-Sub Structure (MSS) regarding their displacement and acceleration responses when subjected to the same load conditions. Through the nonlinear time history analysis, the effectiveness and the feasibility of the proposed mega-sub controlled structure system (MSCSS) is demonstrated in reducing the displacement and acceleration responses and also improving human comfort under earthquake loads.

A Study of Formative Characteristics of Steampunk Fashion (스팀펑크(steampunk) 패션의 표현 특성 연구)

  • Choi, Yoo-Jin
    • Journal of the Korean Society of Costume
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    • v.63 no.8
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    • pp.58-75
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    • 2013
  • Steampunk is a term generally used for one of the S. F. subgenre in literature, arts, fashion styles, and lifestyles. This study clarifies formative characteristics as well as the meanings of steampunk fashion style based on its attributes in movies and animations. Attributes of the steampunk are blending time, blending technology, and introspection against science development. In order to have an objective research, this study researched frequency of the fashion item, color, accessory of the collected fashion image, and after interpreted that consequence. Men's steampunk fashion was composed of men's basic outfit such as shirts, vest, jacket, pants, and coats of the 19th century. Black color took up the largest proportion for color. In accessory, top hat, goggle, and steam-powered weapons, in order, were most commonly used. Women's steampunk fashion was composed of shirts and long one-piece dresses, long skirt simply applied 19th victorian style fashion. Yellow, brown, and black color took up the largest proportion of fashion color. In accessory, top hat, belt trimming, corset, and boots, in order, were most commonly used. It is the characteristics of the steampunk fashion that represents retro-future fashion, as it features steam-powered mechanic esthetics, a kind of DIY subculture and transcending division of nationality, class, and gender.

Glass powder admixture effect on the dynamic properties of concrete, multi-excitation method

  • Kadik, Abdenour;Boutchicha, Djilali;Bali, Abderrahim;Cherrak, Messaouda
    • Structural Engineering and Mechanics
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    • v.74 no.5
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    • pp.671-678
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    • 2020
  • In this work, the dynamic properties of a high performance concrete containing glass powder (GP) was studied. The GP is a new cementitious material obtained by recycling waste glass presenting pozzolanic activity. This eco-friendly material was incorporated in concrete mixes by replacing 20 and 30% of cement. The mechanical properties of building materials highly affect the response of the structure under dynamic actions. First, the resonant vibration frequencies were measured on concrete plate with free boundary conditions after 14, 28 and 90 curing days by using an alternative vibration monitoring technique. This technique measures the average frequencies of several excitations done at different points of the plate. This approach takes into account the heterogeneity of a material like concrete. So, the results should be more precise and reliable. For measuring the bending and torsion resonant frequencies, as well as the damping ratio. The dynamic properties of material such as dynamic elastic modulus and dynamic shear modulus were determined by modelling the plate on the finite element software ANSYS. Also, the instantaneous aroused frequency method and ultrasound method were used to determine the dynamic elastic modulus for comparison purpose, with the results obtained from vibration monitoring technique.

A Structured Analysis Model of Customer Loyalty in Online Games (고객 충성도(Customer Loyalty)에 영향을 미치는 온라인 게임의 중요 요소에 대한 LISREL 모델 분석)

  • Choi, Dong-Seong;Park, Sung-June;Kim, Jin-Woo
    • Asia pacific journal of information systems
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    • v.11 no.3
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    • pp.1-21
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    • 2001
  • In recent years, the market for online computer games has become an important part in the entertainment industry. New online games have been introduced every month and the numbers of game players who are playing online games have grown rapidly. However, only a few online games have been successful in making a good profit among many online games. Why are most players playing only a few online games repeatedly? To answer the question, this research focuses on the customer loyalty and their optimal experience(flow) in playing specific online games. This research hypothesizes that customer loyalty for specific online game can be increased by customers' optimal experience(flow) in playing it, and they would feel optimal experience because of mechanic and social interaction in online games. In order to validate the hypothesis, this research analyzes online survey data of players of various online games. According to this survey results, players' optimal experience is affected by their mechanic interaction between a player and an online game system, and their social interaction with other players who participated in the online game. And their optimal experience during playing the online game affects the degree of customer loyalty to the game. This paper ends with conclusions of the survey results and study limits.

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