Variation aware analysis of bridging fault testing

This paper investigates the impact of process variation on test quality with regard to resistive bridging faults. The input logic threshold voltage and gate drive strength parameters are analyzed regarding their process variation induced influence on test quality. The impact of process variation on test quality is studied in terms of test escapes and measured by a robustness metric. It is shown that some bridges are sensitive to process variation in terms of logic behavior, but such variation does not necessarily compromise test quality if the test has high robustness. Experimental results of Monte-Carlo simulation based on recent process variation statistics are presented for ISCAS85 and -89 benchmark circuits, using a 45nm gate library and realistic bridges. The results show that tests generated without consideration of process variation are inadequate in terms of test quality, particularly for small test sets. On the other hand, larger test sets detect more of the logic faults introduced by process variation and have higher test quality

Investigation into voltage and process variation-aware manufacturing test

Increasing integration and complexity in IC design provides challenges for manufacturing testing. This thesis studies how process and supply voltage variation influence defect behaviour to determine the impact on manufacturing test cost and quality. The focus is on logic testing of static CMOS designs with respect to two important defect types in deep submicron CMOS: resistive bridges and full opens. The first part of the thesis addresses testing for resistive bridge defects in designs with multiple supply voltage settings. To enable analysis, a fault simulator is developed using a supply voltage-aware model for bridge defect behaviour. The analysis shows that for high defect coverage it is necessary to perform test for more than one supply voltage setting, due to supply voltage-dependent behaviour. A low-cost and effective test method is presented consisting of multi-voltage test generation that achieves high defect coverage and test set size reduction without compromise to defect coverage. Experiments on synthesised benchmarks with realistic bridge locations validate the proposed method.The second part focuses on the behaviour of full open defects under supply voltage variation. The aim is to determine the appropriate value of supply voltage to use when testing. Two models are considered for the behaviour of full open defects with and without gate tunnelling leakage influence. Analysis of the supply voltage-dependent behaviour of full open defects is performed to determine if it is required to test using more than one supply voltage to detect all full open defects. Experiments on synthesised benchmarks using an extended version of the fault simulator tool mentioned above, measure the quantitative impact of supply voltage variation on defect coverage.The final part studies the impact of process variation on the behaviour of bridge defects. Detailed analysis using synthesised ISCAS benchmarks and realistic bridge model shows that process variation leads to additional faults. If process variation is not considered in test generation, the test will fail to detect some of these faults, which leads to test escapes. A novel metric to quantify the impact of process variation on test quality is employed in the development of a new test generation tool, which achieves high bridge defect coverage. The method achieves a user-specified test quality with test sets which are smaller than test sets generated without consideration of process variation

Transcriptional and conformational changes of the tau molecule in Alzheimer's disease

Mutations in the tau gene cause frontotemporal dementia with parkinsonism, presumably by affecting the balance between tau isoforms (with either three or four microtubule-binding repeats) or by impairing tau-tubulin binding. Although to date no mutations have been found for Alzheimer's disease, it is plausible that tangle pathology in this disorder is also driven by similar molecular modifications. Investigations of Alzheimer brain tissue with new technologies such as laser capture microscopy, quantitative PCR and fluorescence lifetime imaging will shed light on whether transcriptional or conformational alterations play a role in Alzheimer pathogenesis

Level of confidence evaluation and its usage for Roll-back Recovery with Checkpointing optimization

Increasing soft error rates for semiconductor devices manu- factured in later technologies enforces the use of fault tolerant techniques such as Roll-back Recovery with Checkpointing (RRC). However, RRC introduces time overhead that increases the completion (execution) time. For non-real-time systems, research have focused on optimizing RRC and shown that it is possible to find the optimal number of checkpoints such that the average execution time is minimal. While minimal average execution time is important, it is for real-time systems important to provide a high probability that deadlines are met. Hence, there is a need of probabilistic guarantees that jobs employing RRC complete before a given deadline. First, we present a mathematical framework for the evaluation of level of confidence, the probability that a given deadline is met, when RRC is employed. Second, we present an optimization method for RRC that finds the number of checkpoints that results in the minimal completion time while the minimal com- pletion time satisfies a given level of confidence requirement. Third, we use the proposed framework to evaluate probabilistic guarantees for RRC optimization in non-real-time systems

Långsiktiga effekter av askåterföring och kvävegödsling på skogsmarkvegetationens sammansättning

Application of wood ash in forests is a method used to return (recycle) nutrients to the forest that is lost after forest harvesting. There are concerns that such application may influence pants and induce changes in species composition of the ground vegetation. Several studies have examined short-term effects of ash application on ground vegetation, but there few long-term studies have been conducted. The published studies examining the effects on ground vegetation show no consistent pattern in the response. Application of ash has been shown increased forest biomass production, but also influence some plants negatively, resulting in reduced cover of such species. My study is a continuation of a study completed in 2001. In that study, they had six treatments including a control. The various treatments consisted of 3, 6 and 9 tons of ash ha-1, 3 tons of ash + 150 kg N ha-1, 150 kg N ha-1 and 3 tons of pelletized ash ha-1. Inventory data from the study have been compared with inventory data in this study. Using statistical analyzes, my results address the long-term effects (17 yrs) of wood ash application on composition of forest ground vegetation. This shows whether species have increased or decreased after the application of ashes 17 years ago. My results show small differences in cover of plants between controls and plots exposed to wood ash application. Several species showed decreased cover as an initial response to wood ash application, but 17 years after application cover of almost all species had recovered from initial effects of the wood ash application. Some species, Vaccinium myrtillus and Hylocomium splendens even showed a tendency to have higher current cover in the ash treatments than in the controls. The only species that showed significant lower cover in the ash treatments, and showed no sign of recovery was Cladonia rangiferina. I suggest that this most likely is generated by changing competitive conditions. Based on how the ground vegetation responded I find no reason to stop or reduce return of wood ashes to the forestland. However, the long-lasting effects on the ground-living lichen Cladonia rangiferina imply that return of wood ash to areas utilized for reindeer husbandry (that is dependent on lichens as winter forage) should be avoided

Bridging fault test method with adaptive power management awareness

A key design constraint of circuits used in handheld devices is the power consumption, mainly due to battery life limitations. Adaptive power management (APM) techniques aim to increase the battery life of such devices by adjusting the supply voltage and operating frequency, and thus the power consumption, according to the workload. Testing for resistive bridging defects in APM-enabled designs raises a number of challenges due to their complex analog behavior. Testing at more than one supply voltage setting can be employed to improve defect coverage in such systems, however, switching between several supply voltage settings has a detrimental impact on the overall cost of test. This paper proposes a multi-Vdd automatic test generation method which delivers 100% resistive bridging defect coverage and also a way of reducing the number of supply voltage settings required during test through test point insertion. The proposed techniques have been experimentally validated using a number of benchmark circuits

Att planera för fickparker

Vid förtätning kan det i bland uppstå konflikter mellan prioritering av bebyggelse och grönska i våra städer. Även om bostäder, butiker och företag har stor betydelse för samhällets funktion ska man inte glömma vikten av grönskan för människans trivsel. Att anlägga fickparker är ett sätt att ge plats för grönska i våra städer eftersom fickparken tar en mindre yta i anspråk. Ofta placeras den mellan olika hus och vägar och blir därför en del av människors vardagsmiljö. Fickparkerna fungerar som platser där stadens invånare kan återhämta sig, träffa andra eller låta sig inspireras av planteringarna. En svensk kommun som idag är insatt i anläggandet av fickparker och behovet av dessa är Enköpings kommun. Staden Enköping är en växande pendlarstad med ett stort antal parker i relation till antalet invånare. Majoriteten av stadens parker ligger i tätorten nära centrum. Detta innebär att de som är bosatta i kransorterna inte kan ta del av stadens parker och därmed stadens parkidentitet i samma utsträckning som tätortens invånare eftersom de inte rör sig i tätorten lika ofta i sin vardag. I kommunens parkvision står det att alla kommunens stadsdelar och kransorter ska innehålla minst en egen fickpark. Under det här examensarbetet har vi i samarbete med Enköpings kommun, tagit fram en plan för placeringar av framtida fickparker inom kommunen utifrån dess mål och visioner samt utifrån våra egna erfarenheter och undersökningar. Vi har även valt ut två av dessa föreslagna platser (stadsdelen Galgvreten-Lillsidan och kransorten Lillkyrka) och tagit fram gestaltningsförslag på hur en fickpark på just dessa platser skulle kunna se ut. Arbetet innefattar också en bilaga som visar de platser vi föreslagit för etablering av nya fickparker i Enköpings kommun.Different priorities between buildings and greenery in our cities may sometimes arise during densification. Although homes, shops and businesses are important for the functioning of society, it is also important to take the urban green rooms into account. Pocket parks are a way to make room for greenery in small areas in our cities and they are often placed between houses and roads, and therefore becomes part of the everyday living environment. Pocket parks serve as places where the city’s residents can recover, meet others or be inspired. A Swedish municipality that is very familiar to the concept of pocket parks and the need for these is the municipality of Enköping. Enköping City is a growing commuter town with a high park density in relation to the number of inhabitants. But these parks are located in the urban area close to the city core, and local residents who are outside the center do not notice this high density of parks as much as those who live close to the city center. The municipal Park Vision states that all parts of the municipality should have at least one pocket park of their own. In this thesis, we have, by using inventory and by cooperation with Enköping, developed a plan for the placement of future pocket parks within the municipality based on their goals and visions, and our own experiences and investigations. Later we selected two of these proposed locations (Galgvreten-Lillsidan and Lillkyrka) and developed a design proposal on how a pocket park at these locations could look like. In this work we describe two design proposals for pocket parks in Enköping. The work also includes an appendix that shows the proposed sites for the establishment of new pocket parks in the municipality