Thesis (MScEng)--University of Stellenbosch, 2004. / ENGLISH ABSTRACT: The purpose of this study was to investigate the specification and use of appropriate seating systems to reduce whole-body vibration exposure in typical vehicles used in South African industry. As part of this study six suspension seats, which the manufacturers claim satisfy the requirements in ISO 7096 (2000), were tested. Six test subjects, three light and three heavy as specified in ISO 7096, were used to estimate the seat transmissibility functions in the vertical direction of the six different suspension seats. Transmissibility functions were measured in the laboratory using two excitation levels, 1m/s2 and 2 m/s2 r.m.s., of broadband frequency vibration and a spectrum approximating the EM5 spectral class in ISO 7096. SEA T values were calculated for operational vibration data measured in an articulated dump truck and a three-wheeled logger. It was shown that SEAT values for the EM1 spectral class could not be reliably estimated from seat transmissibility functions and need to be measured directly in the time-domain. The measurement procedures and seat selection criteria developed in this research project were used to compile a set of "Design Guidelines for Seat Selection for Whole-Body Vibration Control in Industrial Vehicles". These guidelines will provide manufacturers with an easy-to-implement methodology to control whole-body vibration transmitted to the operators of industrial vehicles and to comply with international regulations for whole-body vibration transmission. / AFRIKAANSE OPSOMMING: Die doel van die studie was om die spesifikasies en gebruike van geskikte sitplek stelsels van uit Suid Afrikaanse industriële voertuie, wat heel-liggaam vibrasies verminder, te ondersoek. Ses suspensiesitplekke, wat deur die vervaardigers voorgeskryf word, is getoets om te sien of hulle aan die ISO 7096 (2000) vereistes voldoen. Ses persone, waarvan drie lig en drie swaar is, soos in ISO 7096 voorgeskryf, is gebruik om die sitplek oordragsfunksies in die vertikale rigting vir die ses verskillende suspensiesitplekke te skat. Die oordragsfunksies is in die laboratorium gemeet deur twee opwekkingsvlakke, 1m/s2 en 2m/s2 w.g.k., van wyeband frekwensie vibrasie en n spektrum beraam tot die EMS spektrum soos in ISO 7096. 'SEA T' waardes was vanaf operationele vibrasie data wat in ge-artikuleerde vragmotors en driewiel- 'loggers' gemeet is bereken. Daar is gewys dat betroubare 'SEAT waardes vir die EM1 spektrum nie van sitplek oordragsfunksies geskat kan word nie, maar dat dit eerder direk van die tyd-gebied afgelees moet word. Die metings prosedures en die sitplek keuse vereistes wat in die navorsingsprojek ontwikkel is, is gebruik om "Ontwerp Riglyne vir Sitplek Keuse Vereistes vir Heel- Liggaam Vibrasie in Industriële Voertuie" saam te stel. Hierdie riglyne sal vervaardigers met maklik toepasbare metodes toerus om heel-liggaam vibrasie, wat oorgedra word na industriële voertuig operateurs, te beheer en om aan internasionale regulasies t.o.v. heel-liggaam vibrasie oordrag te kan voldoen.

This thesis' work has been conducted at and made possible by Autoliv Sverige AB in Vårgårda. The aim of this thesis is to study how the occupant experience of the belt changes when it is moved from a traditional installation point in the car's B-pillar, to the seat. This shall be studied in terms of how the perceived comfort is influenced by a belt in seat in an upright and a reclined seat back position of 20 and 45 degrees, for different sizes of occupants. Also how the ability to reach a belt in seat is affected by the size and mobility of the occupant. Based on this new knowledge, an optimal outlet position for a belt in seat shall be proposed, from a comfort perspective. The work has used a cross-sectional research approach to achieve its purpose. Through the cross-sectional approach, several different qualitative and quantitative methods have been used. Initially, a literature study where subjects relevant to the forthcoming study was studied. Meanwhile, a competitive analysis of existing belt in seat installations in new cars available on the market was planned and carried out. In the main element of this work, a two-part comfort and mobility study with a belt in seat was performed. The study combined the methods interview, survey and observation. Through the interview, qualitative questions were asked as a complement to the quantitative responses given by the test subjects on scales in the survey. Observations were used to observe the subjects' behavior and difficulties regarding the belt in seat. A major limitation of the results of the study is the deficient distribution of sitting heights and genders in the group of test subjects, which founded a certain bias in the results. This has been the reason why it has not been possible to draw any certain conclusions from the results, however, some trends have been seen. The comfort study revealed several different assessments of the belt that contributed to discomfort, including the perception of the belt being too close to the neck or too far out on the shoulder. Additionally, the discomfort significantly impaired when the seat was reclined to the relaxed state. The mobility study showed that more subjects felt limited by their own bodies in the movement than by the belt. In addition did the reversed belt geometry create large discomfort issues at the neck. An important conclusion of this thesis is that the seat's design is as important to the customer experience of discomfort of the belt as the positioning of the outlet. It has also become clear that the accessibility of a belt in seat is strongly limited, as it was tested in this study.

Master of Arts / Department of Geography / Jeffrey S. Smith / The county seat town holds an important role in American geography. Whether serving simply as a governmental or judicial meeting place for a specific political district, or acting as an economic hub for a county and its surrounding hinterlands, any given American county seat exists with a variety of different cultural meanings imposed upon it. This study analyzes the historical and cultural geographies of two rural counties in the heart of the American Great Plains which have, or at one time had, exceptionally small county seats of fewer than 250 residents. Both counties are adjacent to one another in western Kansas. One, Logan County, originally had its county seat located near its geographic center in the village of Russell Springs, but relocated its seat in the 1960s to the larger town of Oakley. Gove County, today maintains its original county seat of roughly 150 inhabitants near its geographic center despite the presence of more populated towns within the county’s boundaries. Both counties provide excellent material for a case study devoted to understanding what the role of the county seat is in rural America today. In this study I find that the discrepancies between these counties and their seats arise from the different ways in which distinct cultural groups understand or interact with the county seat. An individual’s age, ethnicity, land use or livelihood practices, and location within a county all have an effect on their interpretation of the role of the county seat. This thesis provides a glimpse into the complex cultural nature of rural Great Plains communities through the lens of historical and geographical change.

Today there is a shift from mass production to mass customisation due to changing customer needs in the global market. This thesis report analyses customisation in a modular system through a case study in the truck industry with focus on development of a new seat solution. The customer requests showed a demand for one to two additional seats in the cab. In order to answer to various customer needs, companies implement modular product development principals which enables them to produce in a rapid speed, minimize costs, increase performance and produce a high mix of products. The established RQ:s were: RQ1: How do companies improve competitiveness by translating customer needs into technical requirements? RQ2: What are the challenges and possibilities when making changes in a modular system? The thesis followed the first steps in the product development process due to delimitations in time, scope, and research quality. The data was collected through a literature study, interviews with customers and archival records and documentations at the case company. The study resulted in two final concepts, namely a seat solution and a bench solution which answered to the customer need of one to two additional seats in the cab. A conclusion was that it is crucial for companies to understand the in-depth customer needs to provide higher customer value, which in turn can contribute to strengthen the companies’ competitiveness. The correct translation of customer needs to technical requirements is essential for the development of a modular system. Challenges and possibilities when making changes in a modular system was found to be design complexity along with opportunity to reuse existing components. Both the translation of customer needs and design decisions regarding a modular system is achieved in the earlier stages of the product development process. It is thus of high importance to translate the customer needs correctly and make thoughtful decisions of the modules in the modular system to ensure company competitiveness.

The transfer of air travelers with disabilities between a mobility aid and an aircraft seat is a major source of injury for both the travelers and the airline personnel assisting in the transfer. The risk to both parties might be reduced through the biomechanical study of the transfer task. Such study requires that the contact forces acting on the body of the rear transferor be known, including the contact force between the rear transferor and the seat-back. A seat-back mounted force plate was designed and constructed to accurately measure the magnitude and the center of pressure location of normal forces applied to the seat-back. This force plate collects data from four preloaded single component force transducers. The force transducers are mechanically isolated from shear forces to protect them from damage. Testing of the force plate found a normal force magnitude accuracy of 0.19 %FS over the 890 Newton (200 lbf) calibrated range. The force plate was shown to have a horizontal and vertical center of pressure location accuracy of 2.66 and 1.58 millimeters (0.105 and 0.062 inches) RMS respectively over its 343 by 293 millimeter (13.5 by 11.5 inches) measurement range. By measuring forces that may have otherwise been ignored, the seat-back mounted force plate can improve the quality of the biomechanical analysis of aircraft transfers. / Graduation date: 2005

I denna uppsats har olika metoder för att göra prognoser för ekonomiska tidsserier med säsongsmönster jämförts och utvärderats. Frågan som undersökningen har kretsat kring är: Vilken metod är bäst lämpad för att göra prognoser av tidsserier med säsongsmönster? De metoder som jämförs är säsongsrensningsmetoderna Census II och TRAMO/SEATS, säsongsmodellerna SARIMA och ARIMA med dummyvariabler för säsong samt en metod där medelvärdena från de fyra första metoderna används som prognoser. För att genomföra undersökningen har dessa metoder tillämpats på fyra ekonomiska tidsserier, nämligen: konsumtion, BNP, export samt byggstarter. Resultatet från undersökningen är att säsongsmodellerna är bäst för konsumtionsserien, säsongsrensningsmetoderna är bäst för BNP- och exportserien och den ena säsongsmodellen (SARIMA) är bäst för byggstartsserien medan den andra (ARIMA-dummy) är den sämsta. Val av prognosmetod beror med andra ord på vilken serie som ska prognostiseras.

<p>The purpose with this master’s thesis, with Scania CV AB in Södertälje as job initiator, has been to develop three different passenger seat concepts with focus on modularisation, functionality and production. The different concepts are: a foldable passenger seat, which is possible to fold away completely, a bench for two passengers, and a resting seat for resting during breaks when the vehicle is parked.</p><p>The main tools used during the search for concept solutions have been brainstorming, morphological analyses, and evaluation matrixes. Prototypes have been made in order to visualise the ideas but also for the possibility to test them in a real truck cabin and by that find advantages but also flaws. Final product specifications has been made and with that guidelines for a continued development work.</p><p>Experiences gained during this thesis work has been that by using ergonomic data and theories, well thought through designs, and standardised interfaces a good result can be achieved, which fulfils the demands and wishes placed on the future product.</p>

The purpose with this master’s thesis, with Scania CV AB in Södertälje as job initiator, has been to develop three different passenger seat concepts with focus on modularisation, functionality and production. The different concepts are: a foldable passenger seat, which is possible to fold away completely, a bench for two passengers, and a resting seat for resting during breaks when the vehicle is parked. The main tools used during the search for concept solutions have been brainstorming, morphological analyses, and evaluation matrixes. Prototypes have been made in order to visualise the ideas but also for the possibility to test them in a real truck cabin and by that find advantages but also flaws. Final product specifications has been made and with that guidelines for a continued development work. Experiences gained during this thesis work has been that by using ergonomic data and theories, well thought through designs, and standardised interfaces a good result can be achieved, which fulfils the demands and wishes placed on the future product.

The purpose of the present study was to assess the pressure distribution responses to three hour seating bouts in a standard car seat condition compared to a Comfort Motion Technology (CMT) car seat condition. Twelve males participated in the study. Subjects came in for two separate sessions no more than one week apart. Pressure distribution on the backrest and seat pan was assessed in a three hour seating bout. Pressure variables associated with increased seating comfort were collected across six distinct 28 minute cycles and then averaged across these six cycles. The pressure variables were contact area, peak contact pressure, and force. The CMT car seat condition exhibited greater back contact area (p= .003) and less back peak pressure (p= .003) than the standard car seat condition. In addition, the CMT car seat condition had greater seat peak pressure (p< .001) and greater back force (p< .001) than the standard car seat condition. In conclusion, the CMT car seat condition is more comfortable than the standard car seat condition. / School of Physical Education, Sport, and Exercise Science

Made available in DSpace on 2014-06-11T19:28:56Z (GMT). No. of bitstreams: 0 Previous issue date: 2003-02-17Bitstream added on 2014-06-13T18:58:07Z : No. of bitstreams: 1 lopes_jfs_me_arafo.pdf: 1497511 bytes, checksum: 5cff0da20eacc454b65a7066c2aba9f6 (MD5) / O objetivo desta investigação foi determinar a resistência de união e limite de fadiga de nichos confeccionados em resina composta e ionômeros de vidro. Setenta e cinco corpos-de-prova (incisivos mandibulares humanos hígidos) com etiquetas adesivas com perfurações de 3,5mm de diâmetro foram adaptadas sobre a superfície lingual de cada dente. Esta delimitação tinha como objetivo padronizar a área da superfície de esmalte a ser condicionada e, posteriormente, mantida em contato com os materiais restauradores. Para realização dos nichos, matrizes foram realizadas para cada corpo-de-prova onde o material restaurador foi inserido. Os corpos-de-prova foram imersos em água destilada a 37ºC por um período de 30 dias. Para os ensaios de resistência à união, a máquina de testes mecânicos MTS modelo 810 foi calibrada utilizando uma velocidade de deslocamento de 0,5mm/min. Para os testes de limite de fadiga a máquina de testes foi calibrada para submeter cada corpo-de-prova a 10.000 ciclos constantes, com uma freqüência de 5 Hz, amplitude inicial de 0,5 mm e velocidade de rampa inicial de 100N/s. Os valores originais do experimento foram convertidos de N para MPa em função da área da base do nicho (circular) previamente calculada. Os corpos-de-prova após a fratura foram avaliados através de microscopia eletrônica de varredura com aumento de 500 vezes. A médias de resistência à união e limite de fadiga foram comparadas estatisticamente usando o teste de Análise de Variância a um Critério. Nos teste de cisalhamento, a resina composta Z-100 produziu maior valor de resistência de união (12,25 MPa) ao esmalte dentário que o ionômero de vidro convencional Fuji IX (7,21MPa). Não foram observadas diferenças entre os valores do material Fuji II LC (10,29MPa) e os demais materiais. Para todos os materiais, os corpos-de-prova testados por meio de ensaio dinâmico de... / The aim of this study was to determine the bond strength and fatigue limit of rest seats prepared with composite resin and glass ionomer cements. The lingual aspect of seventy-five specimens (intact human mandibular incisors) was delimited by adhesive tags with 3.5-mm diameter perforations. This delimitation aimed at standardizing the area of enamel surface to be etched and later kept in contact with the restorative materials. For preparation of the rest seats, matrixes were obtained for each specimen on which the restorative material was placed. The specimens were immersed in distilled water at 37ºC for a period of 30 days. For the bond strength assays, the mechanical assay machine MTS model 810 was calibrated at a displacement speed of 0.5mm/min. For the fatigue limit tests, the assay machine was calibrated so as to submit each specimen to 10,000 constant cycles, at a 5-Hz frequency with an initial range of 0.5mm and initial sloping speed of 100N/s. The original values of the experiment were converted from N to MPa according to the previously calculated circular area of the base of the rest seat. After fracture, the specimens were evaluated by means of scanning electron microscopy with magnification of 500x. The means of bond strength and fatigue limits were statistically compared through the one-way variance analysis. For the shear resistance test, the composite resin Z-100 yielded a higher value of bond strength (12.25 MPa) to the dental enamel than the conventional glass ionomer cement Fuji IX (7.21MPa). No differences could be found between Fuji II LC (10.29MPa) and the further materials. For all materials, the specimens submitted to dynamic fatigue assay tests yielded lower mean values than those achieved through static shear assays. Regarding the fatigue limit values, all materials presented different behaviors, being that Fuji II LC obtained the higher mean value (6.4MPa), ...(Complete abstract, click electronic access below)