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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.
31

Investigation on seat structural integrity and occupant safety in coach rollover

Giahi, Hamid 30 January 2017 (has links)
Motor coaches are an integral part of the transportation system. It was observed that occupant fatalities and serious injuries occur in rollover more frequently than in any other type of accidents for these vehicles. Several regulations such as Economic Commission for Europe Regulation 66 (ECE R66) are issued to minimize the catastrophic consequences of rollover accidents. Passing “Motorcoach safety plan” which is based on a complete vehicle rollover test of ECE R66 will be mandatory in North America in the near future. However, the cost of a single physical test encourages researchers to perform numerical simulations prior to a complete vehicle rollover test. In this thesis, the integrity of a coach seat and the effects of different restraint configurations on the safety of passengers in rollover are numerically studied. To perform this research, a new modeling approach, which is computationally effective and highly suitable for parametric studies, is proposed. Firstly, a detailed model of two seats of a coach is developed and validated against experimental results. Anthropomorphic Test Devices are then introduced to the model and acceleration history of a physical rollover test is imposed on the system. The model is solved using non-linear explicit dynamic Finite Element code LS-DYNA®. Injury criteria values are extracted and compared to the experimental results. An acceptable level of correlation is achieved that confirms the validity of the model and the reliability of the modeling approach. The integrity of the seat in a rollover is analyzed showing the necessity of an anchorage test prior to a whole coach rollover test. The results of a parametric study on the safety of passengers reveal the high probability of partial ejection if the retractor does not lock properly in a rollover. It is also shown that the safety of occupants can be improved if retractor pretensioners be introduced to coaches. / February 2017
32

Application of Phase Change Materials to Improve the Thermal Performance of Buildings and Pavements

Pourakbar Sharifi, Naser 11 January 2017 (has links)
In recent decades, much research has investigated the efficiency of Phase Change Materials (PCMs) in improving the thermal performance of buildings and pavements. In buildings, increasing the thermal inertia of structural elements by incorporating PCMs decreases the energy required to keep the inside temperature in the comfort range. In concrete pavements, using PCMs decreases the number of freeze/thaw cycles experienced by the pavement and thus increases service life. However, PCMs cannot be added to cementitious binders directly, because they interfere with the hydration reactions between cement and water that produce strength-bearing phases. Therefore different carriers have been proposed to indirectly incorporate PCMs in cementitious materials. Lightweight Aggregate (LWA) is one of the materials that has been proposed as PCM carrier agent. However, it was not studied in depth before. Various experiments were conducted to investigate the problems associated with incorporating LWA presoaked in PCM in cementitious media. The results show that a portion of PCM leaks out of the LWA’s structure and subsequently affects different chemical, physical, and mechanical properties of the binder. In addition, the applicability of Rice Husk Ash (RHA), a common material never before used to encapsulate PCM, as a PCM carrier agent was investigated. The results show that RHA can absorb and contain liquids in its porous structure; and regarding its compatibility with the cementitious media, it can be used as PCM carrier. Different computational simulations using Typical Meteorological Year data were conducted to evaluate the efficiency of PCMs in improving the thermal performance of buildings. Utilizing PCM-incorporated gypsum boards was shown to be a promising strategy to achieve the governmental plans of “Zero Net Energy� buildings. The results show that using a PCM with a melting point near the occupant comfort zone delays and reduces the inside peak temperature, increases the duration of time during which the inside temperature stays in the comfort zone, and decreases the cost and energy required by HVAC system to keep the inside temperature in this range. However, PCMs’ efficiency is completely dependent on the input temperature profile.
33

Occupant Detection using Computer Vision

Klomark, Marcus January 2000 (has links)
<p>The purpose of this master’s thesis was to study the possibility to use computer vision methods to detect and classify objects in the front passenger seat in a car. This work presents different approaches to solve this problem and evaluates the usefulness of each technique. The classification information should later be used to modulate the speed and the force of the airbag, to be able to provide each occupant with optimal protection and safety.</p><p>This work shows that computer vision has a great potential in order to provide data, which may be used to perform reliable occupant classification. Future choice of method to use depends on many factors, for example costs and requirements on the system from laws and car manufacturers. Further, evaluation and tests of the methods in this thesis, other methods, the ABE approach and post-processing of the results should also be made before a reliable classification algorithm may be written.</p>
34

Occupant Detection using Computer Vision

Klomark, Marcus January 2000 (has links)
The purpose of this master’s thesis was to study the possibility to use computer vision methods to detect and classify objects in the front passenger seat in a car. This work presents different approaches to solve this problem and evaluates the usefulness of each technique. The classification information should later be used to modulate the speed and the force of the airbag, to be able to provide each occupant with optimal protection and safety. This work shows that computer vision has a great potential in order to provide data, which may be used to perform reliable occupant classification. Future choice of method to use depends on many factors, for example costs and requirements on the system from laws and car manufacturers. Further, evaluation and tests of the methods in this thesis, other methods, the ABE approach and post-processing of the results should also be made before a reliable classification algorithm may be written.
35

The Influence of Design, Operations, and Occupancy on Plug Loads in Student Housing

Collins, Thomas 18 August 2015 (has links)
Plug loads—traditionally viewed as behaviorally motivated and beyond the control of designers and operations—are now seen as an integral part of achieving low-energy building targets. Higher education institutions are increasingly recognizing the environmental impacts of campus facilities through holistic approaches to energy savings including energy efficient design and occupant engagement. Residence halls are a compelling example because students bring large numbers of electronics to their rooms and have unlimited access to power for an all-inclusive room rate and resource usage competitions and campaigns are commonplace. However, limited research exists on residence halls plug loads. This dissertation asked the following of residence halls: (1) What are the measured plug loads and how do they compare with design estimates? (2) What role do building design characteristics play in plug loads? (3) What are the specific occupant behaviors that could influence future design? (4) How can plug loads be better understood in terms of behavior, design, and operations? To answer these questions, a sequential mixed methods study included field measurements and student surveys in six residence halls on three Oregon campuses followed by 24 interviews with designers, operators, and students. Findings suggest that plug loads in occupied residence halls are higher and usage profiles differ from design predictions. Results do not show significant correlations between design characteristics and plug loads but suggest that some room/suite level features may play a somewhat stronger role. Survey responses indicated that students are doing more with fewer smart devices, which suggests opportunities for students sharing energy intensive devices. Lighting emerged as both a practical and a social consideration. Finally, the data revealed “balance of power” as a coherent process that explicates the relationships between design, operations, and behavior. Designers have the power to recommend plug load strategies and technologies but are limited by costs, maintenance, and political concerns; operations personnel have the power to impose limits on student power usage but are often reluctant to interfere with the overall living experience; and students have the power to use plug load electricity with few restrictions. This suggests that the balance may be skewed toward student behavior.
36

Investigating the Relationship between Energy Consumption, CO2 Emissions, and the Factors Affecting Them in the United States Building Sector: A Macro and Micro View

January 2018 (has links)
abstract: The United States building sector was the most significant carbon emission contributor (over 40%). The United States government is trying to decrease carbon emissions by enacting policies, but emissions increased by approximately 7 percent in the U.S. between 1990 and 2013. To reduce emissions, investigating the factors affecting carbon emissions should be a priority. Therefore, in this dissertation, this research examine the relationship between carbon emissions and the factors affecting them from macro and micro perspectives. From a macroscopic perspective, the relationship between carbon dioxide, energy resource consumption, energy prices, GDP (gross domestic product), waste generation, and recycling waste generation in the building and waste sectors has been verified. From a microscopic perspective, the impact of non-permanent electric appliances and stationary and non-stationary occupancy has been investigated. To verify the relationships, various kinds of statistical and data mining techniques were applied, such as the Granger causality test, linear and logarithmic correlation, and regression method. The results show that natural gas and electricity prices are higher than others, as coal impacts their consumption, and electricity and coal consumption were found to cause significant carbon emissions. Also, waste generation and recycling significantly increase and decrease emissions from the waste sector, respectively. Moreover, non-permanent appliances such as desktop computers and monitors consume a lot of electricity, and significant energy saving potential has been shown. Lastly, a linear relationship exists between buildings’ electricity use and total occupancy, but no significant relationship exists between occupancy and thermal loads, such as cooling and heating loads. These findings will potentially provide policymakers with a better understanding of and insights into carbon emission manipulation in the building sector. / Dissertation/Thesis / Doctoral Dissertation Civil, Environmental and Sustainable Engineering 2018
37

Envelope as Climate Negotiator: Evaluating adaptive building envelope's capacity to moderate indoor climate and energy

January 2013 (has links)
abstract: Through manipulation of adaptable opportunities available within a given environment, individuals become active participants in managing personal comfort requirements, by exercising control over their comfort without the assistance of mechanical heating and cooling systems. Similarly, continuous manipulation of a building skin's form, insulation, porosity, and transmissivity qualities exerts control over the energy exchanged between indoor and outdoor environments. This research uses four adaptive response variables in a modified software algorithm to explore an adaptive building skin's potential in reacting to environmental stimuli with the purpose of minimizing energy use without sacrificing occupant comfort. Results illustrate that significant energy savings can be realized with adaptive envelopes over static building envelopes even under extreme summer and winter climate conditions; that the magnitude of these savings are dependent on climate and orientation; and that occupant thermal comfort can be improved consistently over comfort levels achieved by optimized static building envelopes. The resulting adaptive envelope's unique climate-specific behavior could inform designers in creating an intelligent kinetic aesthetic that helps facilitate adaptability and resiliency in architecture. / Dissertation/Thesis / Ph.D. Environmental Design and Planning 2013
38

Domestic gas consumption, household behaviour patterns, and window opening

Conan, G. January 1982 (has links)
Domestic gas consumption for central heating is a function both of the efficiency of the heating system and the way in which it is used. While many studies have concentrated on the performance of systems and their controls, there have been few studies of occupant behaviour. The thesis therefore studies household behaviour patterns relating to domestic gas consumption. There are two main aims: firstly, to study a variety of these patterns and, secondly, to make a detailed investigation of one particular behaviour pattern, namely window opening. These two studies centre on 113 households on two local authority estates, where all the dwellings are of similar construction. The first study makes use of two main data sources: quarterly gas consumption readings and data obtained from an in-depth interview with each head of household. It identifies a variety of behaviour patterns and their underlying motivations. Additionally, this study shows that design heat loss and terrace position account for less than a third of the variance in winter consumption. A regression analysis using only behavioural and social variables resulted in a similar proportion of variance being explained. These two sets of independent variables could not justifiably be combined due to their inter-correlations. In conclusion, it was suggested that consumption may not be determined by a few variables of major significance but rather by a large number of inter-acting variables each with a small influence on consumption. The second study, window opening, makes use of three data sources: a series of systematic window observations, meteorological data and data obtained from postal questionnaires. The study identifies the objective correlates of estate-wide window opening, as well as the subjective motivations for the opening and closing of windows. It highlights the wide range of variation in window opening amongst householders. In addition, the study indicates that householders adopt characteristic window opening patterns which they can reliably report.
39

On the Effect of Occupant Behavior and Internal Heat Gains on the Building’s Energy Demand : A case study of an office building and a retirement home

Carlander, Jakob January 2021 (has links)
About 12% of the greenhouse gas emissions and 40% of the total energy use in the EU derive from the buildings. User behavior, construction, and HVAC systems has a significant impact on a building’s energy use. If a building is to be energy-efficient it is important to understand how all these parameters are connected. This study is motivated by the need to decrease the energy use in buildings to reach the goals of energy use and greenhouse gas emissions.  In this thesis, measurements of indoor climate and electricity use, together with time diaries was used to create input data for an energy simulation model of a retirement home. A parametric study was conducted to simulate how energy demand was affected by changes in five different parameters in an office building. Also, two different energy-efficiency indicators were used to see how indicators can affect the perceived energy-efficiency of buildings. High amount of airing and low electricity use had the most impact on the heating demand in the retirement home, and electricity use had the highest impact on the total energy demand in the office building. The model of the retirement home using data gathered on-site had 24% higher energy use than the model using standard user input data. In the office building, total energy demand for heating and cooling could be lowered with 12-31% by lowering the electricity use with 30% compared to standard user input data. For office buildings the most important thing to lower total energy demand seems to be lowering the electricity use. Using today’s standard user input data does not correspond well to using on-site gathered data in a retirement home and it is therefore important to develop the standard user input data further. The indicator kWh/m2, seems to promote buildings with low occupancy. This could lead to buildings being utilized in an in-efficient way. The indicator kWh/m2 should either be replaced or combined with an indicator that takes occupancy into consideration. / Runt 12% av utsläppen av växthusgaser och 40% av den totala energianvändningen i EU kommer från byggnader. Brukarbeteende, konstruktion och HVAC-system har signifikant påverkan på en byggnads energianvändning. Om en byggnad ska bli så energieffektiv som möjligt är det viktigt att förstå hur dessa parametrar hör ihop. Denna studie motiveras av behovet att minska energianvändning i byggnader för att nå målen för energianvändning och utsläpp av växthusgaser.  I denna avhandling användes mätningar av inomhusklimat och elanvändning, tillsammans med tidsdagböcker, för att skapa indata till en energisimuleringsmodell av ett ålderdomshem. En parameterstudie genomfördes för att simulera hur energibehovet påverkades av ändringar i fem olika parametrar i en kontorsbyggnad. Två olika indikatorer för energieffektivitet användes också, för att se hur olika indikatorer påverkar hur en byggnads energieffektivitet uppfattas. Hög grad av vädring och låg elanvändning hade störst påverkan av energibehovet i ålderdomshemmet, och i kontorsbyggnaden påverkades det totala energibehovet mest av elanvändningen. Modellen av ålderdomshemmet där data insamlad på plats användes hade 24% högre värmebehov än modellen som använde standardiserade brukarindata. Det totala energibehovet för värme och kyla i kontorsbyggnaden kunde sänkas med 12-31% genom att sänka elanvändningen med 30% jämfört med standardiserad brukarindata. Det viktigaste för att få ner det totala energibehovet i kontorsbyggnader verkar vara att sänka elanvändningen. Att använda dagens standardvärden för brukarindata överensstämmer inte väl med att använda data insamlad på plats för ett ålderdomshem. Det är därför viktigt att vidareutveckla standardiserad brukarindata. Indikatorn kWh/m2 verkar främja byggnader med låg beläggning. Detta skulle kunna leda till att byggnader utnyttjas på ett ineffektivt sätt. Indikatorn kWh/m2 skulle därför behöva ersättas eller kombineras med en indikator som även tar byggnadens beläggning i beaktande.
40

Parents' Knowledge of Child-Passenger Safety and Child-Passenger Restraint Usage

Cadore, Amanda 01 January 2019 (has links)
Although occupant protection laws exist, limited research has been conducted on how current child passenger safety (CPS) issues and CPS marketing strategies relate to child passenger safety seat (CPSS) usage. The purpose of this cross-sectional study was to analyze the relationship between parents' perception and knowledge of CPS issues and CPSS usage rates. The diffusion of innovation and the social marketing theories provided the frameworks for this study. The overall research question for the study examined the correlation between parents' knowledge of CPS issues and CPSS usage. Data (participants' surveys, car seat check-up information, and observational statistics) were collected from events that occurred in 3 locations across the county. The population consisted of a convenience sample of adults (parents of children 8-years-old and younger) from each of the locations. The study survey was distributed to 93 participants and only 71 surveys (76.34%) were received for analysis. Data analysis methods included deductive coding, Cronbach's alpha, descriptive statistics, hypotheses testing, linear regression, and Pearson Correlation. The overall test results showed that there were no significant relationships between the independent variable predictors (parents' knowledge of proper CPSS installation techniques, CPS laws and regulations, and marketing strategies) and the dependent variable (CPSS usage rates). The overall study was not statistically significant. The study should be replicated, however modified (on a larger scale for a longer period). Thus, having a stronger possibility to impact the community (producing noteworthy results and promoting social change).

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