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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
211

Skogsarbetets humanisering och rationalisering från 1900 och framåt

Ager, Bengt January 2014 (has links)
Rapporten belyser skogsarbetets förändring i storskogsbruket under perioden 1900 – 2013 under inflytande av rationalisering och humanisering som förändringsprocesser. Utgångsläget var ett ytterst slitsamt, riskabelt och lågbetalt säsongsarbete i kyla och snö, med bortaliggning i undermåliga kojor. I periodens början fullbordades en spontan rationalisering som inletts i slutet av 1800-talet och som bestod av att effektivare handredskap – olika typer av sågar, barkspadar och hanteringsdon - ersatte yxan som universalredskap. Organiserad rationalisering av skogsarbetet kom igång först i slutet på 30-talet. Den hämtade då sin inspiration från industrin som vid det laget hade anpassat amerikanen F W Taylors rationaliseringskoncept till den svenska arbetsmarknaden och kulturen. Arbetsstudier blev grund för effektivisering av det manuella skogsarbetet och för en rättvisare lön. Men skogsbruket kom sedan att finna egna vägar, som ledde till en världsunik teknisk och organisatorisk utveckling med början på 1950-talet och kulmen kring 1990. Under de senaste två årtiondena har rationaliseringen i skogsbruket anslutit sig till ”mainstream” i näringslivets utveckling, som styrs allt mera av dels den globaliserade marknadens mekanismer samt dels ”Lean”, ett hopkok av amerikanska och japanska organisationskoncept, och med ”outsourcing” som främsta verktyg. Under perioden 1940-2005 utvecklades produktiviteten kraftigt, med särskilt stora språng 1960-75 och 1990-2005. Efter 2005 skedde en stagnation. Humaniseringen av skogsarbetet inleddes med provinsialläkaren Hasslers larm 1907. Starten blev trög men skogsarbetarnas boende och mathållning kom att förbättras på många håll fram till 1930-talets slut. Då blev humanisering en integrerad del av den systematiska rationaliseringen, vilket innebar radikala förbättringar av det manuella skogsarbetet. När mekaniseringen tog fart under 50- och 60-talet kom människan i produktionssystemet bort ett tag, vilket ledde till omtag på humaniseringsprocessen. Ergonomin utvecklades som redskap och som vetenskap. Från slutet av 70-talet till slutet av 90-talet blev humaniseringen, stödd av flera aktörer, åter en integrerad del av rationaliseringen, nu underbyggd av det ”sociotekniska” organisationskoncept som utvecklats av engelska och norska arbetsforskare. Arbetets organisation kom i fokus. Den totala humankvaliteten kulminerade åren kring 1990. Skogsarbetet nådde då en höjdpunkt vad gäller mångsidighet, kontaktrikedom, variation, självbestämmande, ansvar och uppmärksamhet. Sedan inleddes en viss avhumanisering. Humaniseringsaktörerna försvagades eller försvann. Marknadens ”osynliga hand” tog alltmera över utvecklingen. Humankvaliteten försämrades på en rad punkter som i huvudsak kan hänföras till organisationsmiljön – färre personliga kontakter, längre arbetsresor, sämre skiftformer, kortare framförhållning och sämre kvalitet i planeringen samt sänkt relativ lönenivå. Försämringarna kompenseras delvis av att maskinernas förarmiljö och driftssäkerhet förbättrats avsevärt, men generellt har skogsarbetet förlorat i attraktivitet. Historiken summeras utförligt i kapitel 11.I kapitlet 12 om framtidens arbetsliv nationellt och i skogsbruket hävdar författaren att det behövs ett tidsanpassat humaniseringskoncept av samma dignitet som det på 60-talet lanserade sociotekniska konceptet. En skiss på ett sådant ”socioekonomiskt” koncept presenteras, inklusive en begreppsapparat som gör anspråk på att vara innovativ, samt en rad åtgärdsförslag. Därvid beaktas lärdomar från det förgångna / <p>Godkänd; 2014; 20140114 (andbra); Nedanstående person kommer att disputera för avläggande av filosofie doktorsexamen. Namn: Bengt Ager Ämne: Arbetsvetenskap/Human Work Science Avhandling: Skogsarbetets humanisering och rationalisering från 1900 och framåt Opponent: Professor emeritus Göran Olsson, Högskolan Väst, Trollhättan Ordförande: Professor Jan Johansson, Avd för Arbetsvetenskap, Institutionen för ekonomi, teknik och samhälle, Luleå tekniska universitet. Tid: Onsdag den 19 mars 2014, kl 13.00 Plats: F531, Luleå tekniska universitet</p>
212

Cognitive performance and restoration in open-plan office noise / Kognitiv prestation och återhämtning under buller i kontorslandskap

Jahncke, Helena January 2012 (has links)
This dissertation presents four experimental studies (in four papers) with the overall aim to investigate the effects of office noise on cognitive performance and restoration. In the first two papers the focus was on the effects of different sound levels (i.e., the mean level from all sound sources at an office, such as speech, phones, people walking) on performance, fatigue and stress. In the last two papers the focus was on the effects of background speech, as this has previously been shown to be the most disturbing noise source in open-plan offices. Paper I demonstrated decreased word memory performance, increased fatigue and motivational deficits when the background sound level increased by 12 dB, from 39 to 51 dB LAeq. Paper II showed that the sound level effects were more pronounced for individuals with a hearing impairment. Unexpectedly, no effects were found of acute noise exposure on the participant´s stress hormone levels (Paper I and Paper II).Regarding effects of irrelevant speech, Paper III showed that cognitive performance decreased as a function of background speech intelligibility, the higher the intelligibility depicted by the Speech Transmission Index (STI), the worse the performance. The results indicated that the STI-value must be less than 0.50, to avoid a negative influence on performance. Further, both Paper III and IV showed that performance is more impaired by background speech if the focal task requires episodic memory and rehearsal—such as word memory and information search. Interestingly, some tasks were insensitive for speech.The restorative effects of a break were addressed in Paper I and II (i.e., directly after the work sessions in noise). The break period differed in content between the participants. Paper I showed that a break with a nature movie with corresponding sound increased energy ratings compared to just listening to river sounds or office noise. Continued exposure to office noise gave the lowest ratings of motivation after the break. Paper II showed improved arithmetic performance and motivation after the break with a nature movie and decreased performance and motivation after continued noise exposure. For the hearing impaired participants, however, continued noise during the break increased motivation and performance, while the movie did not.Taken together, the current thesis demonstrates that open-plan office noise can have a negative impact on fatigue, motivation and performance. How much performance is impaired varies with the cognitive processes required by the tasks performed and hearing status. Moreover, continued noise exposure during a short break can further decrease motivation and subsequent performance. / <p>Godkänd; 2012; 20120831 (heljah); DISPUTATION Ämne: Teknisk psykologi/Engineering Psychology Opponent: Docent Mats Nilsson, Psykologiska institutionen, Stockholms universitet Ordförande: Professor Håkan Alm, Institutionen för ekonomi, teknik och samhälle, Luleå tekniska universitet Tid: Fredag den 23 november 2012, kl 10.30 Plats: F719J, Luleå tekniska universitet</p>
213

Adaptive Driver Information

Davidsson, Staffan January 2014 (has links)
New societal requirements and functional growth put new demand on future driver information. Simultaneously, new technology and IT capabilities makes it possible to constantly adapt the information given to the driver for different reasons. Therefore, the aim of this thesis was to obtain an improved understanding, strengthen knowledge of the adaptive control of driver information to understand if, for what reason, when and where to use adaptive driver information (ADI). Also some possible new means to support drivers were suggested.The main purpose of driver information is to support the driver in achieving goals such as a safer, more environmentally friendly, more efficient, legal and enjoyable transportation by providing correct information and feedback.ADI can support the driver throughout development of skill and when performing operational, tactical, and strategic level tasks. Also tasks related to setting goals for the driving task and encouraging good driving behaviour can be supported. ADI can, furthermore help drivers to stay within their comfort zone by visualizing risk or certainty, identify and thereafter adapt how a message is communicated to different personalities, maintain the driver’s mental workload within the safe task load area by reducing demand when it is too high, increase mental workload by extra stimulating task during too low a mental demand, and minimize the risk for mismatches between effort and real demand.ADI changes automatically that may cause new and unpredictable issues reducing the purpose of driver information. These may include: mode confusion, function allocation, over and under trust, locus of control issues, skill degeneration and too low/high mental workload. Research has suggested that the most efficient way to reduce these issues is to make the driver and the automation (the agents) get along together and become team players. The team players should share goals, show intention, show limits of performance, state etcetera. However, for cars, a consumer product, in which visual demand is high, an approach can be where information vanishes when agents have become a “team”. This approach may be called “team building”.Research and industrial contributions has been presented. Several examples of how ADI can be carried out have been suggested and some even illustrated. / <p>Godkänd; 2014; 20141006 (stadav); Nedanstående person kommer att disputera för avläggande av teknologie doktorsexamen. Namn: Staffan Davidsson Ämne: Teknisk Psykologi/Engineering Psychology Avhandling: Adaptive Driver Information Opponent: Docent Forskningsledare Björn Peters, Statens väg- och transportforskningsinstitut, Linköping Ordförande: Professor Håkan Alm, Institutionen för ekonomi, teknik och samhälle, Luleå Tekniska Universitet Tid: Tisdag 11 november 2014, kl. 10.00 Plats: E243, Luleå tekniska universitet</p>
214

Trivsel på arbetsplatsen : En kvalitativ studie om lärares trivsel på arbetsplatsen / Well-being in the workplace : A qualitative study on teachers well-being in the workplace

Andreasson, Frida, Johansson, Martin January 2017 (has links)
No description available.
215

Total quality management and performance in process engineering design firms in South Africa

Njenge, Lusanda 04 June 2014 (has links)
M.Phil. (Engineering Management) / Total Quality Management (TQM) as a management philosophy is driven by top management with employee participation. This encompasses all facets of an organisation, with the aim of producing products and services which meet the customer’s needs.TQM was adopted by project-based organisations in the 1990s in response to increasing global competition. Process engineering design firms are operating in a competitive, global business environment where outsourcing of process engineering design services from other countries is not an uncommon practice. It is argued that TQM is crucial for an organisation’s success and survival. Although various quality management techniques exist, TQM offers the holistic approach necessary to adequately manage design quality. The study investigates the effects of Total Quality Management (TQM) implementation on process engineering design firms. Secondly, the study investigates the extent of TQM adoption by South African process engineering design firms. Lastly, the study investigates the perceived importance of TQM principles. The research questions are: i. What is the effect of TQM on the performance of process engineering design firms? ii. To what extent has TQM been adopted by South African process engineering design firms? iii. What is the perceived importance of TQM principles in process engineering design? The first research question was answered by conducting a literature survey. The author was unable to find studies relating specifically to process engineering design firms. As a result, the literature study was done for engineering firms in general. The study indicates that TQM adoption has a favourable effect on engineering firms. The study reveals that TQM implementation improves employee satisfaction, customer satisfaction, and financial performance while providing a vision that channels the entire organisation towards improvements in product quality and customer-related performances. The second and third research questions were answered with the use of a questionnaire survey, which measured importance and adoption utilising a 5-point Likert scale. The study reveals that 70% of the firms which participated in the survey have formally adopted TQM while 30% have not. Eighty five per cent of the organisations that have adopted TQM are ISO9001 certified. An adoption rate of 70% indicates an above-average adoption of TQM by South African process engineering design firms. An ISO9001 certification of 85% indicates that South African process engineering design firms are conforming to international quality standards. The adoption of the TQM principles ranges from 66% to 80% (moderate to high). Customer Involvement and Management Commitment are the most highly adopted, while Supplier Quality Management and Continuous Improvement are the least adopted. The firms which have formally adopted TQM report 77% implementation rate, while the firms which have not formally adopted TQM report a 63% implementation rate. Although the firms which have not formally adopted TQM are implementing TQM principles, they have not been able to implement the principles as well as the firms which have formally adopted TQM. The perceived importance of the TQM principles ranges from 78% to 92% (“important” to “very important”). The most important principle is perceived to be Customer Involvement, while Continuous Improvement and Supplier Quality Management are perceived to be the least important. The firms which have formally adopted TQM rate the principles more highly in the importance scale (86%) compared to the firms which have not formally adopted TQM (80%). The results indicate that the firms which have formally adopted TQM find value in doing so. The mean score for the importance of TQM principles is 84%, while the mean score for the adoption of TQM principles is 73%. It is evident from the data that there is a gap between the perceived importance and adoption of the TQM principles. The data suggests that the policies and strategies of the organisation have not achieved full implementation of TQM and have room for improvement.
216

"Man vill ju inte vara den som säger det" : En kvalitativ undersökning om varför arbetsrelaterade förslitningsskador uppstår trots förebyggande arbetsmiljöarbete

Andreasson, Josefin, Stolt, Lisa January 2017 (has links)
No description available.
217

Effektivisering av lagerprocess kopplat till kundbehov / Efficiency of logistic process linked to customer needs

André, Felix January 2017 (has links)
No description available.
218

Mistura polimérica de poli(ácido lático)/poli(etileno-co-acetato de vinila) com incorporação de polietilenoglicol e quitosana como agentes modificadores de propriedades

Cavalli, Letícia Riboldi 15 December 2015 (has links)
O poli(ácido lático)(PLA) tem sido utilizado no campo das embalagens, contudo, visando melhorar as características processuais e a tenacidade deste polímero, misturas poliméricas de PLA com poli(etileno-co-acetato de vinila)(EVA), polietilenoglicol (PEG) e quitosana(QUI) foram desenvolvidas por processo de extrusão, injeção e por moldagem por compressão foram produzidos filmes, utilizados no estudo. As propriedades de mistura com PLA foram investigadas pelas propriedades morfológicas, térmicas e mecânicas e os filmes desenvolvidos foram aplicados a produtos alimentícios como pão de forma, sendo avaliadas as propriedades antimicrobianas, umidade, atividade de água, textura e cor, e em maçã minimamente processada, sendo avaliadas as propriedades antimicrobianas, atividade antioxidante, polifenóis, textura, pH, sólidos solúveis e cor. As misturas de PLA/EVA/PEG e PLA/EVA/PEG/QUI, quando comparadas ao PLA, mostraram miscibilidade parcial, diminuição na temperatura de transição vítrea (Tg), redução da resistência à flexão e do módulo de elasticidade, evidenciando a diminuição de rigidez molecular e aumento na capacidade de deformação do polímero, propriedades estas de interesse para processar PLA e para a produção de embalagens. A exposição do produto alimentício pão de forma às misturas poliméricas com quitosana promoveu efeito inibitório do crescimento de bolores e leveduras, em torno de 50% (com a mistura polimérica contendo 5 pcr de quitosana, quando comparado a mistura sem quitosana), sem afetar os teores de umidade, atividade de água e textura, do produto, e contribui para a manutenção da cor durante o armazenamento. A exposição de maçãs minimamente processadas às misturas poliméricas com quitosana promoveu uma diminuição no crescimento de bolores e leveduras, em torno de 54% (com a mistura polimérica contendo 5 pcr de quitosana, quando comparado a mistura sem quitosana), sem afetar a os teores de sólidos solúveis, pH, textura e perda de peso. A adição de quitosana também evitou o escurecimento enzimático, aumentou os teores de polifenóis totais, em torno de 20% e triplicou a atividade antioxidante, após 10 dias de armazenamento, nas frutas que ficaram em contato com a mistura polimérica PLA/EVA/PEG/5,0QUI. Conclui-se, por fim, que a mistura de EVA, PEG e quitosana ao PLA possibilitou a modificação das propriedades de rigidez e processabilidade e que o emprego da quitosana comprovou ter eficiente ação antimicrobiana e antioxidante, permitindo atender, com os resultados apresentados, o objetivo proposto no estudo. / Poly (lactic acid) (PLA) has been employed in the packaging area, however, in order to improve its processing features and tenacity. Polymer blends of PLA with poly(ethylene-co-vinyl-acetate) (EVA), polyethylene glycol (PEG) and chitosan (QUI) were developed by extrusion and injection process while films were obtained by compression on this work. Morphological, thermal and mechanical properties of PLA blends have been investigated and films have been developed and put in contact with a nutritional product, the loaf bread, analyzing then its antimicrobial properties, humidity, water activity, texture and color and on the minimally processed apple, analyzing then its antimicrobial properties, antioxidant activity, polyphenols, texture, pH, soluble solids as well as color. The PLA/EVA/PEG and PLA/EVA/PEG/QUI blends when compared to PLA, showed partial miscibility, reduction of glass transition temperature (Tg), lower flexural strength and of the modulus of elasticity, evidencing then a reduction in molecular hardness and an increase in the deformation ability of the polymer, properties of interest to process PLA and for packaging manufacture. The exposure to a nutritional product, the loaf bread, to the poly blends with chitosan promoted an inhibitory effect in the growing of molds and yeasts of around 50% (with poly blend containing 5 phr of chitosan when compared to chitosan-free blend), without affecting the humidity levels, water activity and texture of product, supporting the maintenance of the color during its storage. The contact of films with chitosan on minimally processed apples have promoted a decrease in the growing of molds and yeast of around 54% (with poly blends containing 5 phr of chitosan when it was compared to chitosan-free bled), without affecting the soluble solids levels, pH, texture and weight loss. It has contributed also to avoid the enzymatic browning and increased the total polyphenols levels by 20% and triplicated the antioxidant activity recorded after 10 days of storing the fruits that had been in contact with the poly blends PLA/EVA/PEG/QUI. Finally, it can be concluded that EVA/PEG and chitosan blends added to PLA have allowed modifications on the hardness and processability properties and that the application of chitosan proved to be an efficient action antimicrobial and antioxidant allowing the results obtained here and purpose of this study.
219

Estudo e secagem de argila vermelha utilizando um sensor magnetoelástico

Tormes, Claudia Daiane 11 April 2014 (has links)
Uma das grandes aplicações dos sensores magnetoelásticos está relacionada aos sistemas antifurto. Devido ao seu excelente desempenho e natureza passiva sem fio, também têm sido amplamente utilizados no sensoriamento ambiental em resposta às mudanças de temperatura, pressão atmosférica, velocidade de fluxo do fluido através da superfície do sensor, densidade e viscosidade de líquidos e variação de massa. O presente trabalho investiga a utilização de fitas magnetoelásticas, tais como Metglas®2826MB3, para estudar o comportamento de secagem de materiais cerâmicos. Duas argilas extraídas da região do Vale do Caí, principal produtor de materias cerâmicos para a construção civil, foram analisadas. Suspensões de argila foram preparadas e sua caracterização foi realizada por meio de técnicas tradicionais que considerou a cinética de secagem, a retração e o comportamento das trincas de acordo com a massa úmida do material depositado em um molde de alumínio. Posteriormente as suspensões foram depositadas sobre a superfície da fita sensora com auxílio de um dispositivo doctor blade. Aplicando um campo magnético variável, foi possível determinar a frequência de ressonância experimental do sensor. Essa frequência é inversamente proporcional ao comprimento da fita e dependente das propriedades físicas dos materiais. Um modelo matemático foi utilizado para relacionar a frequência de ressonância com as propriedades elásticas da cobertura da fita. Além das propriedades físicas dos materiais também foi incluído ao modelo, a dependência do módulo de elasticidade da fita em campo magnético, conhecido como efeito E. A tensão desenvolvida durante o processo de secagem pode gerar trincas e deformações no material quando não dissipadas. Essa tensão contribui para a anisotropia magnética e é introduzida no problema através do efeito E. A técnica do cantilever foi utilizada para verificar a presença de tensões durante a secagem. Medindo a deflexão do substrato é possível determinar a tensão gerada pela suspensão. As curvas da frequência de ressonância em função do tempo mostram várias regiões distintas. Na região que distingue os dois principais estágios de secagem da suspensão, caracterizada pela taxa de secagem que diminui aceleradamente, a medida da frequência se mostrou bastante sensível à presença de tensões. Portanto, as estruturas observadas nas curvas experimentais de frequência em função do tempo puderam ser reproduzidas pelo modelo, utilizando a distribuição de tensões experimentais e as propriedades elásticas do sensor e da suspensão de argila. Esse resultado promissor sugere que as tensões desenvolvidas durante a secagem de materiais cerâmicos poderiam ser determinadas por medidas da frequência de ressonância dos sensores. / An important application of magnetoelastic sensors is in antitheft systems. Because of their excellent performance and their passive wireless nature, they have also been extensively used in environmental sensing of changes in temperature, atmospheric pressure, flow speed of fluid over the sensor surface, density and viscosity of liquids and mass change. The present work investigates the use of magnetoelastic sensors based on Metglas®2826MB3 to study the drying behavior of ceramic materials. Two clays from the Vale do Caí region, the main producer of ceramic materials for the construction industry, were analyzed. Aqueous clay suspensions were prepared and their characterization was performed using traditional techniques that considered the drying kinetics, shrinkage and cracking behavior as a function of the wet weight of the material deposited into an aluminum mold. Subsequently, the suspensions were deposited on the sensor tape surface with a doctor blade device. Applying a variable magnetic field, it was possible to determine the experimental resonance frequency of the sensor. This frequency is inversely proportional to the ribbon length and dependent upon the physical properties of the materials. A mathematical model was used to correlate the resonance frequency with the elastic properties of the coating. Besides the physical properties of the materials, also included in model was the dependence of the tape's elastic modulus on magnetic field, known as the E effect. The stress developed during the drying process may cause cracks and deformations in the material when it is not dissipated. This stress contributes to the magnetic anisotropy which is introduced into the problem through the E effect. The cantilever technique was used to determine the presence of tensions during drying. Measuring the deflection of the substrate, it is possible to determine the stress generated by the suspension. The curves of resonance frequency versus time show several distinct regions. For the region that separates the two main rying stages of the suspension, the frequency measurement proved to be very sensitive to the presence of tension. Therefore, the structures observed in the experimental curves of frequency versus time could be modeled using the experimental distribution of stress and the elastic properties of the sensor and clay suspension. This promising result suggests that the tensions developed during the drying of ceramic materials could be determined by measurements of the resonance frequency of the sensors.
220

Fartyget och fartygsorganisationen som en komplex arbetsmiljö : om kvalitetsstyrning och säkerhet

Hansson, Kjell-Åke January 1996 (has links)
<p>Godkänd; 1996; 20080330 (ysko)</p>

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