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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.
11

Effects of Intervention on Booster Seat Purchase: A Field Study

Stevens, Suzanne L. 26 May 2000 (has links)
Motor vehicle crashes remain a leading cause of death and injury for US children, despite improved crashworthiness of vehicles and effective restraint systems for children of all ages. Children who are too large for child safety seats (a child restraint system for children from birth to 4 years old) are often restrained improperly or not at all. These children should be restrained in a booster seat which is a type of child safety seat designed for children who have out grown their convertible seat and are not large enough to fit properly in an adult seat belt. For this reason, the use and correct use of occupant protection for 4-9 year old children in particular needs to be addressed. For proper restraint, children who have outgrown child safety seats require booster seats used with vehicle lap/shoulder belts. This present study attempted to determine if raising risk perception and/or lowering cost of compliance would influence more parents to purchase booster seats for their children who should be restrained in them. A field study with 128 participants with four treatment groups was conducted to test the following two hypotheses. 1) Informational pamphlets and dollars off coupons will reduce compliance cost and thereby induce the purchase of booster seats, 2) informational pamphlets will increase risk perception. Of the 128 participants, 37 (from various treatment groups) purchased booster seats, and 100% of those who purchased, reported that they use them each time their child rides in a vehicle. Unlike previous studies on risk perception of consumers, this study went beyond post measures of attitude change and assessed actual purchase behavior through self-reports from the participants. In so doing, this study was able to draw inferences about the effects of the interventions on purchase behavior. The analyses indicated that intervention of any kind was more effective than no intervention in influencing the purchase of a booster seat. Thus, the intervention encouraged adoption of a safety product. This study hopes to achieve a change in people's perception of booster seats regarding the safety of children in vehicles. In addition, possibly influencing future legislation regarding child passenger safety. / Master of Science
12

A decision making model for aircraft resources management

鄭德建, Cheng, Tak-kin. January 1996 (has links)
published_or_final_version / Business Administration / Master / Master of Business Administration
13

Sezónní očišťování časových řad

Eisler, Jan January 2006 (has links)
Tato diplomová práce je zaměřená na problematiku týkající se sezónního očišťování časových řad založené na Boxově-Jenkinsově metodologii. Její nedílnou součástí je aplikace dvou nejpoužívanějších metod (X12 ARIMA, TRAMO/SEATS) na konkrétních datech ? čtvrtletní hodnoty HDP vybraných zemí EU - 25 a čtvrtletní míra nezaměstnanosti v populaci 15 - 24 let u vybraných zemí EU - 25.
14

Säsongsrensning : En komparativ studie av TRAMO/SEATS och X-12 ARIMA

Odencrants, Martin, Rahm, Fredrik January 2007 (has links)
<p>Ett syfte med tidserieteori är att dekomponera en observerad tidsserie i en summa icke observerbara komponenter. Dessa komponenter är Trend, Cykel, Säsong, Kalendereffekter, Extremvärden samt Irreguljära effekter.</p><p>Det finns två olika teorier för dekomponering av tidsserier, modellbaserad dekomponering och icke modellbaserad dekomponering. De två olika teorierna skiljer sig åt i grunden. Den här uppsatsen syftar till att utvärdera de två säsongsrensningsmetoderna TRAMO/SEATS och X-12 ARIMA samt att säsongsrensa tidsserien över den totala lönesumman, vilken är en del av statistikprodukten Lönesummor arbetsgivaravgifter och preliminär A-skatt (LAPS) producerad av SCB.</p>
15

Säsongsrensning : En komparativ studie av TRAMO/SEATS och X-12 ARIMA

Odencrants, Martin, Rahm, Fredrik January 2007 (has links)
Ett syfte med tidserieteori är att dekomponera en observerad tidsserie i en summa icke observerbara komponenter. Dessa komponenter är Trend, Cykel, Säsong, Kalendereffekter, Extremvärden samt Irreguljära effekter. Det finns två olika teorier för dekomponering av tidsserier, modellbaserad dekomponering och icke modellbaserad dekomponering. De två olika teorierna skiljer sig åt i grunden. Den här uppsatsen syftar till att utvärdera de två säsongsrensningsmetoderna TRAMO/SEATS och X-12 ARIMA samt att säsongsrensa tidsserien över den totala lönesumman, vilken är en del av statistikprodukten Lönesummor arbetsgivaravgifter och preliminär A-skatt (LAPS) producerad av SCB.
16

An evaluation of the Virginia 2002 Child Passenger Safety Law determining if the law reduced motor vehicle crash injuries and fatalities /

Connell, Petra Maria Menzel, January 1900 (has links)
Thesis (Ph. D.)--Virginia Commonwealth University, 2009. / Prepared for: Dept. of Public Policy and Administration. Title from title-page of electronic thesis. Bibliography: leaves 128-141.
17

Stability of the Infant Car Seat Challenge and Risk Factors for Oxygen Desaturation Events

DeGrazia, Michele 13 April 2006 (has links)
Research suggests that infants with poor neck and upper torso muscle tone experience lateral slouching and a compromised airway when placed in the semi-upright seating position. Studies reveal that 4-60% of premature infants (born at less than 3-7 weeks gestation) may experience oxygen desaturation events when in their child safety seats (CSS), potentially resulting in adverse neurodevelopmental outcomes. Therefore, the American Academy of Pediatrics recommends that premature infants be tested in their CSS prior to hospital discharge. However, neonatal healthcare providers are concerned that this method of testing might not be reliable. No formal studies have investigated the outcomes of repeat testing of premature infants, and little is known about the risk factors for oxygen desaturation events. Therefore, the purpose of this descriptive, non-experimental, observational study was to explore the stability of the one-point Infant Car Seat Challenge (ICSC) and risk factors that may be associated with oxygen desaturation events. A sample of 49 premature infants was used to explore the following variables: 1) pass/fail rates following two (ICSC) observation points, 2) oxygen saturation and desaturation patterns, sleep/wake activity, and a measure of head lag (using the pull-to-sit maneuver) during two ICSCs, and 3) the association between head lag, chronological age, time spent sleeping in the CSS and oxygen desaturation events. Data were analyzed by descriptive and nonparametric statistical tests. This study's findings indicated that 86% of premature infants had stable results, 8% passed rcsc 1 but not ICSC 2, and 6% failed ICSC l and passed ICSC 2. In addition the odds for oxygen desaturation events increased in infants that are born at a gestational age ≤ 34 weeks, were discharged home at a chronological age of > 7 days and had a corrected gestational age of ≤ 37 weeks. Neither head lag or sleep time influenced the ICSC outcomes. Furthermore the ICSC success rate for identifying at risk infants was equal to or better than that of other screening tests for newborn medical conditions. These findings will assist neonatal healthcare providers in making appropriate recommendations for safe travel.
18

'n Aanpasbare energieabsorbeerder vir 'n helikoptersitplek

Coetzee, Gerhard 16 September 2014 (has links)
M.Ing. (Mechanical Engineering) / The development of crashworthy seats for helicopters during the past three decades is discussed. The primary design criteria is mentioned and the disadvantages of crashworthy seats that are currently in use are highlighted. An hydraulic energy absorber which automatically compensates for the mass of the seat occupant was designed and a simulation model was developed. The concept for the control valve used was obtained from WARRICK [25]. Results of the simulations correlated well with those of WARRICK. A prototype of a mechanical/hydraulic accelerometer was designed, manufactured and tested. The results obtained from the experiments compared favourably with simulation values. The simulated and experimental results indicate that the concept of using an hydraulic energy absorber, in a crashworthy seat, is very satisfactory. Future crashworthy seat designs could be enhanced by incorporating this promising device.
19

Modeling viscoelastic responses of the head/neck system during pilot ejection

Deuel, Christopher R. 04 December 2009 (has links)
The effect of added head mass during pilot ejection from an aircraft is currently being studied at the Wright Patterson Air Force Base in Ohio. The Articulated Total Body model, a FORTRAN computer program capable of simulating three-dimensional human body motion using rigid body dynamics, has been chosen to simulate the response of the head and neck to an ejection-like acceleration. The present Viscoelastic configuration of the head/neck model, which is capable of head rotation and axial neck deformation, was validated with experimental head acceleration data from live human volunteers subjected to a 10G<sub>Z</sub> deceleration in the Vertical Deceleration Tower at Wright Patterson Air Force Base. Experimental head z-direction acceleration data from a first subject, L7, was reproduced accurately using the ATB model. However, Simulated head z-direction acceleration profiles for a second subject, B9, could not match experimental data for this subject, even after numerous variations of parameters controlling the head/neck response of the ATB model. Two of these parameters were determined to be time-varying for subject B9, and regression equations were developed describing the parameters as functions of time. Because the current ATB program does not allow time-varying parameters, the program code was modified to include two new subroutines in which the values of the parameters are calculated with each time increment. Modifications to the ATB model resulted in an improved simulated head z-direction acceleration profile for subject B9 when compared with previous simulations using constant value parameters. / Master of Science
20

The verification of seat effective amplitude transmissibility (SEAT) value as a reliable metric to evaluate dynamic seat comfort

Van der Westhuizen, Anriette 12 1900 (has links)
Thesis (MScIng)--University of Stellenbosch, 2004. / ENGLISH ABSTRACT: A rough road vibration stimulus was reconstructed on a shaker platform to assess the dynamic comfort of seven seats by six human subjects. The virtual seat method was combined with a paired comparison procedure to assess subjective dynamic seat comfort. The psychometric method of constants, 1-up-1-down Levitt procedure and a 2-up-1-down Levitt procedure were compared experimentally to find the most accurate and efficient paired comparison scheme. A two-track interleaved, 2-up-1-down Levitt procedure was used for the subjective dynamic seat comfort assessment. SEAT value is an objective metric and has been widely used to determine seat vibration isolation efficiency. There was an excellent correlation (R2 = 0.97) between the subjective ratings and estimated SEAT values on the seat top when the values are averaged over the six subjects. This study suggests that the SEAT values, estimated from averaged seat top transmissibility of six carefully selected subjects, could be used to select the best seat for a specific road vibration input. / AFRIKAANSE OPSOMMING: Ses persone het deelgeneem aan ‘n eksperiment, om die dinamiese ritgemak van sewe stoele te karakteriseer. ‘n Rowwe padvibrasie is vir die doel op ‘n skudplatform geherkonstrueer. Subjektiewe ritgemak is bepaal deur die virtuelestoel metode met ‘n gepaarde, vergelykingstoets te kombineer. Die psigometriese metode van konstantes, die 1-op-1-af Levitt procedure en die 2-op- 1-af Levitt procedure is vergelyk om die mees effektiewe en akkurate vergelykingstoets te vind. ‘n Tweebaan, vervlegde , 2-op-1-af Levitt prosedure het die beste resultate gelewer en is gekies vir die subjektiewe evaluasie van dinamiese ritgemak. SEAT-waarde is ‘n objektiewe maatstaf, wat gebruik word om te bepaal hoe effektief ‘n stoel die insittende van voertuigvibrasie isoleer. Daar was ‘n uitstekende korrelasie (R2 = 0.97) tussen subjektiewe dinamiese ritgemakevaluesies en SEAT-waardes in die vertikale rigting op die stoelkussing as die gemiddelde oor die ses persone bereken word. Uit die resultate van hierdie studie blyk dit dat SEAT-waardes, wat bereken is vanaf die gemiddelde sitplektransmissie van die ses persone, wat verteenwoordigend van die teikenbevolking is, gebruik kan word om die beste stoel vir ‘n spesifieke vibrasieinset te kies.

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