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Economic investigation of discount factors for agricultural greenhouse gas emission offsetsKim, Man-Keun 29 August 2005 (has links)
This dissertation analyzes the basis for and magnitudes of discount factors based on the characteristics of greenhouse gas emission (GHGE) offsets that are applied to the GHGE reduction projects, concentrating on agricultural projects. Theoretical approaches to discount factors, estimation and incorporation of discount factors procedures are developed. Discount factors would be imposed by credit purchasers due to noncompliance with regulatory program of the credits with GHG program including consideration of shortfall penalties and limited durations. Discount factors are proposed for (i) additionality, (ii) leakage, (iii) permanence, and (iv) uncertainty. Additionality arise when the region where an AO project is being proposed would have substantial adoption of the AO practice in the absence of GHG programs (business as usual GHGE offset). Leakage arises when the effect of a program is offset by an induced increase in economic activity and accompanying emissions elsewhere. The leakage effect depends on demand and supply elasticities. Permanence reflects the saturation and volatility characteristics of carbon sequestration. Carbon is stored in a volatile form and can be released quickly to the atmosphere when an AO practice is discontinued. The permanence discount depends on the project design including practice continuation after the program and the dynamic rate of offset. Also, consideration of multiple offsets is important. Uncertainty arises due to the stochastic nature of project quantity. The uncertainty discount tends to be smaller the larger the size of the offset contract due to aggregation over space and time. The magnitude of these discounts is investigated in Southeast Texas rice discontinuation study. The additionality and the leakage discounts are found to play an important role in case of rice lands conversion to other crops but less so for pasture conversions and yet less for forest conversions. The permanence discount is important when converting to other crops and short rotation forestry. When all discounts are considered, rice lands conversion to forest yields claimable credits amounting to 52.8% ~ 77.5% of the total offset. When converting rice lands to pasture, the claimable credits 45.1% ~ 64.2%, while a conversion of rice lands to other crops yields claimable credits 38.9% ~ 40.4%.
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Inverse modeling to predict effective leakage areaQi, Te 14 November 2012 (has links)
The purpose of this research is to develop a new approach to estimate the effective leakage area using the inverse modeling process as an alternative to the blower door test. An actual office building, which is the head quarter of Energy Efficiency Hub, was used as an example case in this study.
The main principle of the inverse modeling process is comparing the real monitor boiler gas consumption with the result calculated from the EnergyPlus model with a dynamic infiltration rate input to find the best estimation of the parameter of effective leakage area (ELA). This thesis considers only the feasibility of replacing the blower door test with the calibration approach, so rather than attempting an automated calibration process based on inverse modeling we deal with generating a first estimate and consider the role of model uncertainties that would make the proposed method less feasible.
There are five steps of the whole process. First, we need to customize our own actual weather data (AMY) needed by the energy model (EnergyPlus model), which can help increase our quality of the result. Second, create the building energy model in EnergyPlus. Third, create a multi-zone model using CONTAM with different ELA estimation of each facade to calculate the dynamic infiltration rate of each ELA estimate. Fourth, input the dynamic infiltration rate got from the CONTAM model to EnergyPlus model and output the boiler energy consumption. Fifth, compare the boiler gas consumption from the model and the real monitor data and find the best match between the two and the corresponding ELA, which gives the best estimate from the whole inverse modeling process.
From the simulation result comparison, the best estimation of the total building ELA from the inverse modeling process is the 23437cm2 at 4pa, while the result from the blower door test is 10483cm2 at 4pa. Because of the insufficient information of the building and also the uncertainty of the input parameters, the study has not led to a definite statement whether the proposed calibration of the ELA with consumption data can replace a blower door test to get an equally valid or even better ELA estimate, but it looks feasible. As this this case study is done in a deterministic context, the full feasibility test should be conducted under uncertainty. A first step towards this will talk be discussed in chapter 4.
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Air Leakage Diagnosis in Heavy Duty Truck Engines with EGR and VGT / Diagnos av Luftläckage på Lastbilsmotorer med EGR och VGTDagson, Josef, Nissilä Källström, Samuel January 2009 (has links)
Scania CV AB is a leading company within development and production of buses, trucks as well as industrial and marine engines. New environmental and safety legislations continuously demand higher quality from the products. An upcoming European legislation, Euro 6, implies that gas leakages from truck engines should be detected while driving. If the source of the leakage is not only detected, but also isolated, that is separated from other faults, the adjustments in the workshop goes faster since there is no need for leakage localisation. A faster reparation increases the up-time, i.e. the amount of time that the truck can be used. This master thesis work uses current methods developed at Scania for residual generation to perform model-based leakage diagnosis. In this work, measurements are gathered for dierent sensor faults and two leakages. The measurements are used to evaluate the actual performance of the resulting diagnosis system. The result, based on the residuals generated by the method, shows that leakages on the boost-side and the exhaust-side can be detected, and isolated from faults in the pressure sensors on the boost-side and the exhaust-side. The isolation of these four faults is considered the hardest to achieve among sensor faults and leakages why the full isolation performance is promising. Further measurements are needed to determine the full isolation performance of the diagnosis system. The resulting system is reasoned to be suitable for execution in real time on-board the truck. / Scania CV AB är en ledande koncern inom utveckling och produktion av bussar, lastbilar samt industri- och marinmotorer. Nya lagkrav för miljö och säkerhet ställer ständigt högre krav på de tillverkade produkterna. Ett nära förestående lagkrav för lastbilar, Euro 6, innebär att gasläckage från motorn ska detekteras under körning. Om läckaget förutom att detekteras också kan isoleras, det vill säga särskiljas från andra fel, går reparationen i verkstaden snabbare då man slipper lokalisera läckaget. En snabbare reparation ökar up-time, det vill säga tiden som lastbilen kan användas på åkeriet. I detta exjobb används befintliga metoder för residualgenerering framtagna på Scania för att åstadkomma modelbaserad läckagediagnos. Arbetet tar även fram mätdata för olika givarfel samt för två läckage i motorn. Denna mätdata används för att utvärdera det erhållna diagnossystemets faktiska prestanda. Resultatet, som bygger på residualerna som metoden genererat, visar att läckage går att detektera, och att läckagen går att isolera från fel på tryckgivarsensorer på laddluftssidan och avgassidan. Denna isolering anses vara den svåraste att uppnå av alla sensorfel samt läckage varvid övrig isoleringsprestande verkar lovande. Däremot behövs mer mätdata för att säkert kunna fastställa övrig isoleringsprestanda. Diagnosmetoden lämpar sig troligen för exekvering i realtid ombord på lastbilen.
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Tolerance to sub-zero temperatures in <i>Phaseolus acutifolius</i> and interspecies hybrids between <i>Phaseolus vulgaris</i> and <i>P. acutifolius</i>Martinez, Jocepascual 30 May 2011
Dry bean (Phaseolus vulgaris) is a sub-tropical crop severely affected by exposure to low temperatures during all of its growing stages. Cool spring temperatures and the risk of frost are major limiting factors for the early sowing of dry bean in Saskatchewan. Due to its economic importance; however, it has been introduced to Saskatchewan, but it needs to be made more cold tolerant to further expand acreage. The genes that can contribute some tolerance to low temperature stress in bean are not found within the primary gene pool, which limits the capability of breeders to generate a cultivar with such characteristics. Consequently studies have being done in order to find a possible source of genes that can induce tolerance to low temperature exposure. Phaseolus acutifolius is a relative of the domesticated dry bean and previous hybridizations with it have been successful. It is also known to be tolerant to abiotic stresses such as drought. For this reason the decision was taken to explore the level of resistance to low temperature stress exposure in several P. acutifolius accessions. Using whole plant freezing tests in controlled environment chambers, P. acutifolius W6 15578 was found to be more tolerant to exposure to sub-zero temperatures than were P. vulgaris genotypes. Interspecies hybrids were produced between P. vulgaris NY5-161 and W6 15578 and BC2 plants were produced using embryo rescue.
The whole plant freezing test is a destructive method that cannot be used with unique F1 and BC2 genotypes, so an alternative methodology to evaluate the hybrids was explored. An electrolyte leakage test was used and showed similar results to the whole plant freezing test with the parent plant controls. The F1 hybrids had an intermediate tolerance to low temperature stress and the further generations (BC1 and BC2) had a better level of tolerance to this kind of stress than the cultivated parent (NY5-161). This suggests that the genes that confer tolerance to low temperature exposure are being maintained through several generations of backcrossing and that these interspecies hybrids may offer a chance for the development of improved dry bean cultivars for the Saskatchewan environment.
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Leakage Resilience and Black-box Impossibility Results in CryptographyJuma, Ali 31 August 2011 (has links)
In this thesis, we present constructions of leakage-resilient cryptographic primitives, and we give black-box impossibility results for certain classes of constructions of pseudo-random number generators.
The traditional approach for preventing side-channel attacks has been primarily hardware-based. Recently, there has been significant progress in developing algorithmic approaches for preventing such attacks. These algorithmic approaches involve modeling side-channel attacks as {\em leakage} on the internal state of a device; constructions secure against such leakage are {\em leakage-resilient}.
We first consider the problem of storing a key and computing on it repeatedly in a leakage-resilient manner. For this purpose, we define a new primitive called a {\em key proxy}. Using a fully-homomorphic
public-key encryption scheme, we construct a leakage-resilient key proxy. We work in the ``only computation leaks'' leakage model, tolerating a logarithmic number of bits of polynomial-time computable leakage per computation and an unbounded total amount of leakage.
We next consider the problem of verifying that a message sent over a public channel has not been modified, in a setting where the sender and the receiver have previously shared a key, and where the adversary controls the public channel and is simultaneously mounting side-channel attacks on both parties. Using only the assumption that pseudo-random generators exist, we construct a leakage-resilient shared-private-key authenticated session protocol. This construction tolerates a logarithmic number of bits of polynomial-time computable leakage per computation, and an unbounded total amount of leakage. This leakage occurs on the entire state, input, and randomness of the party performing the computation.
Finally, we consider the problem of constructing a large-stretch pseudo-random generator given a one-way permutation or given a smaller-stretch pseudo-random generator. The standard approach for doing this involves repeatedly composing the given object with itself. We provide evidence that this approach is necessary. Specifically,
we consider three classes of constructions of pseudo-random generators from pseudo-random generators of smaller stretch or from one-way permutations, and for each class, we give a black-box impossibility result that demonstrates a contrast between the stretch that can be achieved by adaptive and non-adaptive black-box constructions.
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Leakage Resilience and Black-box Impossibility Results in CryptographyJuma, Ali 31 August 2011 (has links)
In this thesis, we present constructions of leakage-resilient cryptographic primitives, and we give black-box impossibility results for certain classes of constructions of pseudo-random number generators.
The traditional approach for preventing side-channel attacks has been primarily hardware-based. Recently, there has been significant progress in developing algorithmic approaches for preventing such attacks. These algorithmic approaches involve modeling side-channel attacks as {\em leakage} on the internal state of a device; constructions secure against such leakage are {\em leakage-resilient}.
We first consider the problem of storing a key and computing on it repeatedly in a leakage-resilient manner. For this purpose, we define a new primitive called a {\em key proxy}. Using a fully-homomorphic
public-key encryption scheme, we construct a leakage-resilient key proxy. We work in the ``only computation leaks'' leakage model, tolerating a logarithmic number of bits of polynomial-time computable leakage per computation and an unbounded total amount of leakage.
We next consider the problem of verifying that a message sent over a public channel has not been modified, in a setting where the sender and the receiver have previously shared a key, and where the adversary controls the public channel and is simultaneously mounting side-channel attacks on both parties. Using only the assumption that pseudo-random generators exist, we construct a leakage-resilient shared-private-key authenticated session protocol. This construction tolerates a logarithmic number of bits of polynomial-time computable leakage per computation, and an unbounded total amount of leakage. This leakage occurs on the entire state, input, and randomness of the party performing the computation.
Finally, we consider the problem of constructing a large-stretch pseudo-random generator given a one-way permutation or given a smaller-stretch pseudo-random generator. The standard approach for doing this involves repeatedly composing the given object with itself. We provide evidence that this approach is necessary. Specifically,
we consider three classes of constructions of pseudo-random generators from pseudo-random generators of smaller stretch or from one-way permutations, and for each class, we give a black-box impossibility result that demonstrates a contrast between the stretch that can be achieved by adaptive and non-adaptive black-box constructions.
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Lustgasläckage på operationssal, tandvårdssal och förlossningssal : arbetsmiljöaspekter för sjukvårdspersonal / Nitrousoxide leakage in operating theatre, dental treatment and delivery room : occupational aspects for healthcare personnelAhlsröd, Richard January 2012 (has links)
No description available.
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Diagnosis of a compressed air system in a heavy vehicle / Diagnos av tryckluftssystem i ett tungt fordonMartin, Kågebjer January 2011 (has links)
Compressed air has in the past been considered as a free resource in heavy vehicles.The recent years work to minimize fuel consumption has however made airconsumption an interesting topic for the manufactures to investigate further. Compressed air has many different applications in heavy vehicles. One importantconsumer of compressed air is the brake system, which would not work at allwithout compressed air. The compressed air is produced by a compressor attachedto the engine. A leakage in the system will force the compressor to work longer,which leads to an increased fuel consumption. It is of large interest to have a diagnosis system that can detect leakages, and ifpossible also provide information about where in the system the leakage is present.This information can then be used to repair the leakage at the next service stop. The diagnosis system that is developed in this thesis is based on model baseddiagnosis and uses a recursive least mean square method to estimate the leakagearea. The results from the validation show that the algorithm works well forleakages of the size 1-10 litres/minute. The innovative isolation algorithm givesfull fault isolation for a five circuit system with only three pressure sensors. / Tryckluft i lastbilar har tidigare ansetts vara en fri resurs. Den senaste tidens försökatt minimera bränsleförbrukningen har dock lett fram till att även användandetav tryckluft har börjat ses över. Tryckluft används i dagens lastbilar av flera olika förbrukare. En viktig förbrukareav tryckluft är bromsarna som inte fungerar överhuvudtaget utan tryckluft.Tryckluften produceras av en kompressor som sitter kopplad på förbränningsmotorn.Om det finns ett läckage i tryckluftsystemet leder detta till att kompressornmåste arbeta oftare vilket i sin tur leder till en ökad bränsleförbrukning. Det finns stort intresse av att kunna detektera dessa läckage och om möjligtäven avgöra var i systemet som läckaget finns. Informationen kan sedan användasvid nästa servicetillfälle för att laga läckaget. Diagnossystemet som utvecklats i detta examensarbete bygger på modellbaseraddiagnos och använder en rekursiv implementering av minstakvadratmetodenför att skatta läckagets storlek. Resultat från validering av algoritmen visar attdiagnossystemet fungerar bra för läckage i storleksordningen 1-10 liter/minut. Deninnovativa isoleringsalgoritmen ger full felisolerbarhet för ett system med fem kretsarmen bara tre tryckgivare.
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Tolerance to sub-zero temperatures in <i>Phaseolus acutifolius</i> and interspecies hybrids between <i>Phaseolus vulgaris</i> and <i>P. acutifolius</i>Martinez, Jocepascual 30 May 2011 (has links)
Dry bean (Phaseolus vulgaris) is a sub-tropical crop severely affected by exposure to low temperatures during all of its growing stages. Cool spring temperatures and the risk of frost are major limiting factors for the early sowing of dry bean in Saskatchewan. Due to its economic importance; however, it has been introduced to Saskatchewan, but it needs to be made more cold tolerant to further expand acreage. The genes that can contribute some tolerance to low temperature stress in bean are not found within the primary gene pool, which limits the capability of breeders to generate a cultivar with such characteristics. Consequently studies have being done in order to find a possible source of genes that can induce tolerance to low temperature exposure. Phaseolus acutifolius is a relative of the domesticated dry bean and previous hybridizations with it have been successful. It is also known to be tolerant to abiotic stresses such as drought. For this reason the decision was taken to explore the level of resistance to low temperature stress exposure in several P. acutifolius accessions. Using whole plant freezing tests in controlled environment chambers, P. acutifolius W6 15578 was found to be more tolerant to exposure to sub-zero temperatures than were P. vulgaris genotypes. Interspecies hybrids were produced between P. vulgaris NY5-161 and W6 15578 and BC2 plants were produced using embryo rescue.
The whole plant freezing test is a destructive method that cannot be used with unique F1 and BC2 genotypes, so an alternative methodology to evaluate the hybrids was explored. An electrolyte leakage test was used and showed similar results to the whole plant freezing test with the parent plant controls. The F1 hybrids had an intermediate tolerance to low temperature stress and the further generations (BC1 and BC2) had a better level of tolerance to this kind of stress than the cultivated parent (NY5-161). This suggests that the genes that confer tolerance to low temperature exposure are being maintained through several generations of backcrossing and that these interspecies hybrids may offer a chance for the development of improved dry bean cultivars for the Saskatchewan environment.
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Three Essays On Agricultural and Forestry Offsets In Climate Change MitigationFeng, Siyi 2012 May 1900 (has links)
This dissertation is composed of three essays, investigating two aspects of the role of agricultural sector in climate change mitigation: leakage and additionality.
Leakage happens when mitigation policies reduce net GHG emissions in one context, but increase (decrease) prices, which in turn causes production (demand) expansion resulting in an offsetting rise in emissions elsewhere. The first essay documents an integration of a US domestic agricultural sectoral model and a global agricultural sectoral model, with the aim to deliver better leakage assessment. The second essay investigates the trend of US crop yield growth and its implication on the international leakage effect. We find that the slowdowns have occurred to the growth rates of most US major crops. The implementation of climate change mitigation strategies, such as the expansion of bioenergy production, causes demand for the agricultural sector to increase substantially. The new demand would cause noticeable leakage effect if crop yields continue to grow at the current rates. Such effect may be potentially alleviated by higher crop yield growth rates; but the extent of alleviation depends on the mix of technological progress obtained across crops as well.
Additionality is often a concern in programs designed to incentivize the production of environmental services. Additionality is satisfied if payments are made to services that would not have occurred without the payment. However, because of the information asymmetry between service buyers and sellers, ensuring additionality poses a challenge to program designers. The third essay investigates how the pursuit of ensuring additionality would complicate environmental policy design with a theoretical model. Specifically, we examine 4 types of policy design, including 2 discriminating schemes and 2 simpler non-discriminating schemes. We found that under certain conditions, some of the non-discriminating schemes can be almost as good as the discriminating ones.
Findings in this dissertation contribute to inform policy makers about the potential impacts of climate change mitigation policies in the agricultural sector and also help to improve understanding of environmental program design.
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