Doctorat en sciences sociales, politiques et économiques / info:eu-repo/semantics/nonPublished

This study investigated the physiological and psychological limitations to prolonged work performed at different relative intensities, through the use of an eclectic integrative methodology. Ten young male caucasian subjects (mean V0₂ max. 60,0 ml.kg⁻¹.min⁻¹ ± 7,9) were randomly exposed to treadmill runs at each of four relative intensities, namely 55%, 65%, 75% and 85% of V0₂ maximum, with the instruction to run to the point of subjective discomfort at which they were no longer willing to continue. Physiological measures of oxygen consumption (V0₂), heart rate (HR), respiratory exchange ratio (R) , minute ventilation volume (Vi), breathing frequency (Vf), tidal volume (Vt) and psychological measures of Ratings of Perceived Exertion (RPE), Perceived Thermal Comfo·rt (PTC), Perceived Pain and Perceived Fatigue were recorded throughout the protocol. The relative intensity was held constant by slight decreases in treadmill speed as subjects fatigued, and through feedback from an on-line oxygen consumption computer-aided data acquisition system. Significant increases in both physiological and psychological measures occurred with increases in relative intensity (p<0,05). HR and Vf increased overtime (p<0,05) whilst Rand Vt decreased over time (p < 0,05) . All psychological ratings increased in intensity over time (p < 0,05). Mean endurance times to exhaustion were 243 minutes ± 70 at 55% relative intensity, 159 minutes ±37 at 65%, 96 minutes ±25 at 75 % and 23 minutes +- 8 at 85%, being within the range reported by earlier researchers . A regression equation for prediction of endurance time given a known relative intensity was developed for this sample: % V0₂ max. = 117,8 + (-10,6 x LN (time)) (where r = -0,91) Convergence rankings indicate the greater contribution of local factors in the overall gestalt of perceived exertion, pain and fatigue, with biomechanical limitations to prolonged work (running) strongly implicated . High inter correlations between psychological rating scales suggest the use of the scale considered most applicable to the task at hand and the psychological response measure required. A coefficient of multiple correlation of 0,94 established the close interrelationship amongst the physiological and psychological parameters measured. Pre- and post-test Fatigue Cluster Analysis questionnaires indicated that the most important clusters contributing toward the sensation of fatigue and subsequent decision to cease activity were Task Aversion and General Fatigue (r = 0,96), followed by Leg Fatigue and Thirst. Motivation, the task at hand and an attainable goal appear to be important considerations in prolonged work performance. Relative intensity appears a valid tool for use in prolonged work studies due to its high predictive capacity for endurance performance times (r=-0,91). It is concluded that workloads considerably below 55% of maximal aerobic capacity are indicated as acceptable workloads for an 8 hour working day.

M.Comm. / Please refer to full text to view abstract

This work deals with the operational management of production in the selected section of the company. In the theoretical part explains the concepts of Lean Manufacturing, Toyota Production System, Kaizen, Productivity and related terms. Introduction The practical part of the thesis describes the production program production system and the organization of the production process in a selected section of the company. The next section is an analysis of workplace policy and pre-assembly lines. Followed by an analysis of work and identifying current shortcomings. The next section are designed to improve a specific solution of identified problems. The last part of the thesis deals with the evaluation of implemented improvements and their benefits.

This work deals with the measurement time frames and then balancing of assembly line in the company IFE-CR in segment drive units rail vehicles. The first part of thesis is focused on methods of work measurement, method improving quality eight disciplines problem solving and one of the many basic methods lean production 5S. The second part of thesis is introducing company, company's history, products and distribution drive units for rail vehicles. The following part is focused a distribution of production hall, description of workplaces and detailed description of assembly line. The practical part is focused on time frames of assembly operations and theirs compare before and after balancing of assembly line. The last part of the thesis deals evaluation of results balancing of assembly line with focus on productivity.

This master´s thesis focuses on possible rationalization of the testing operations the door drive units of the rail vehicles. The aim is to propose solutions to increase productivity and reduce operating costs. The first section briefly describes the history and basic principles of lean manufacturing. The following is the description of the assembly and testing of the door drive units including the analysis of the current state of testing workplaces. The following section identifies critical areas and reserves that could be used to increase productivity. In next chapters are proposed kinds of rationalization, their evaluations according to the cost of implementation and the possible achieved effects. Chosen variant is elaborated in more details. The last part deals with the economic evaluation and verification of the proposed method in conditions of the real production.

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Call number: LD2668 .T4 1984 C56 / Master of Science

The importance of employment in our society is unmistakable. The financial outcome of employment allows us to provide for ourselves and others. Furthermore, our employment status, and the work in which we engage, play a part in defining our self-concept. For many people, however, sustained employment remains elusive. The unemployment rate for individuals with disabilities is staggering, and the consequences of being without a job affects those who are unemployed, their families, and our society. There are many issues that directly challenge the employment status of people with disabilities. Some of these include funding for supported employment programs, employer bias, and the outcomes of our country's educational system. Another issue that affects the employment of individuals with disabilities is the manner in which they are prepared prior to employment and coached while on the job. The purpose of this investigation was to examine the effects of performance feedback delivered via covert audio coaching on the job performance of supported employees. A multiple baseline design across participants and work tasks was used to evaluate the effects of the intervention on the participants' work performance (accuracy and speed of task completion). The results demonstrated that the supported employees made substantial improvements on their accuracy and speed of completing the selected work tasks. The results also showed that the improvements maintained for 4-5 weeks following the removal of the intervention. / by Kyle D. Bennett. / Thesis (Ed.D.)--Florida Atlantic University, 2009. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2009. Mode of access: World Wide Web.