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International Telemetering Conference Proceedings / October 17-20, 1994 / Town & Country Hotel and Conference Center, San Diego, California / An increasing number of satellite users and manufacturers are looking to lightweight, inexpensive satellites as substitutes to traditional large, expensive satellites with multiple payloads. Neither the Department of Defense nor the commercial sector can bear the financial or reputational consequences associated with massive program failures. With the low cost and weight of these new satellites, users can achieve mission success without great risk. One example of this new class of inexpensive spacecraft is the RADCAL (RADar CALibration) satellite. Detachment 2, Space & Missile Systems Center at Sunnyvale, CA operates the satellite. RADCAL is a 200-pound polar orbiting satellite with an average altitude of 450 miles. It is primarily used by 77 worldwide radars to calibrate their systems to within five meter accuracy. Also flying on board RADCAL is a communication payload for remote field users with small radios. The RADCAL program has satisfied all mission requirements. However, with the limited size and cost come certain challenges, both in the satellite and on the ground. Pre-launch testing was not as comprehensive as with more expensive programs; anomalies have arisen that require extensive workarounds. Data management is not a straightforward task, and it is sometimes difficult and inexact to track satellite performance. These challenges are presented with their solutions in the following discussion; this paper addresses the functional, operational, and testing aspects associated with the RADCAL satellite.

International Telemetering Conference Proceedings / October 26-29, 1998 / Town & Country Resort Hotel and Convention Center, San Diego, California / Optical trackers are often used at the Air Force Flight Test Center (AFFTC) and at other Department of Defense (DoD) ranges to collect video and trajectory data for real-time display and postflight processing. When optical trackers are used in remote areas, pointing data from radar is utilized to enable the trackers to initially acquire targets. To enable the trackers to use radar-pointing data, offsets to true north must first be known. This offset is taken into account given the current position of the optical tracker. During postflight processing, when determining the trajectory of the target, the offsets are also taken into account to produce an accurate trajectory solution. Current methods of determining offsets to true north are time consuming and involve a lot of guesswork. Typically, a map and a known landmark are used to determine the offsets to true north. Another method is to look for the North Star (Polaris) and input an estimated offset. This paper will describe an inexpensive, stand-alone system that utilizes the Global Positioning System (GPS) to determine these offsets. This device may be modified and integrated with other systems that may need to point accurately. For example, a gun barrel on a tank may need to point accurately to within a degree. This device may also be used to accurately position telemetry antennas.

The rate of data growth in many domains is straining our ability to manage and analyze it. Consequently, we see the emergence of computing systems that attempt to efficiently process data-intensive applications or I/O bound applications with large data. Cloud computing offers “infinite” resources on demand, and on a pay-as-you-go basis. As a result, it has gained interest for large-scale data processing. Given this supposedly infinite resource set, we need a provisioning process to determine appropriate resources for data processing or workload execution. We observe that the prevalent data processing architectures do not usually employ provisioning techniques available in a public cloud, and existing provisioning techniques have largely ignored data-intensive applications in public clouds. In this thesis, we take a step towards bridging the gap between existing data processing approaches and the provisioning techniques available in a public cloud, such that the monetary cost of executing data-intensive workloads is minimized. We formulate the problem of provisioning and include constructs to exploit a cloud’s elasticity to include any number of resources to host a multi-tenant database system prior to execution. The provisioning is modeled as a search problem, and we use standard search heuristics to solve it. We propose a novel framework for resource provisioning in a cloud environment. Our framework allows pluggable cost and performance models. We instantiate the framework by developing various search algorithms, cost and performance models to support the search for an effective resource configuration. We consider data-intensive workloads that consist of transactional, analytical or mixed workloads for evaluation, and access multiple database tenants. The workloads are based on standard TPC benchmarks. In addition, the user preferences on response time or throughput are expressed as constraints. Our propositions and their results are validated in a real public cloud, namely the Amazon cloud. The evaluation supports our claim that the framework is an effective tool for provisioning database workloads in a public cloud with minimal dollar cost. / Thesis (Ph.D, Computing) -- Queen's University, 2013-11-30 19:30:39.427

Noise is a pervasive workplace hazard that varies spatially and temporally. Hazard mapping is a useful way to communicate intensity and distribution of noise sources in the workplace. These maps can be created using a stationary network of sensors, although the cost of noise measurement instruments has prohibited their use in such a network. The objectives for this work were to (1) develop an inexpensive noise sensor (<$100) that measures A-weighted sound pressure levels within ±2 dBA of a Type 2 sound level meter (SLM, ~$1,800); and (2) evaluate 50 noise sensors before field deployment as part of an inexpensive sensor network. The inexpensive noise sensor consists of an electret condenser microphone, an amplifier circuit, and a microcontroller with a small form factor (28mm by 47 mm by 9 mm) than can be operated as a stand-alone unit. Laboratory tests were conducted to evaluate 50 of the new sensors at 5 test levels. The testing levels were (1) ambient noise in a quiet office, (2) a pink noise test signal from 65 to 85 dBA in 10 dBA increments, and, (3) 94 dBA using a SLM calibrator. The difference between the output of the sensor and SLM were computed for each level and overall. Ninety-four percent of the noise sensors (n=46) were within ± 2 dBA of the SLM for noise levels from 65 dBA to 94 dBA. As noise level increased, bias decreased, ranging from 18.3% in the quiet office to 0.48% at 94 dBA. Overall bias of the sensors was 0.83% across the 75 dBA to 94 dBA range. These sensors are available for a variety of uses and can be customized for many applications, including incorporation into a stationary sensor network for continuously monitoring noise in manufacturing environments.

Pulses (common beans and cowpeas) provide a major alternative source of protein, and the rapid rise in food prices has led to an increase in the consumption of inexpensive pulses. The slow growth in pulse production has, however, led to a decline in availability. Thus, to overcome this decline in production, this study concern in expanding pulse production in Mozambique by using the agricultural research survey known as TIA. In addition, this study identified and analysed the critical drivers influencing production, as well as constraints and opportunities to expand pulse production in Mozambique. In studying the participation of smallholder farmers in pulse markets, the Heckman two-step approach was applied to avoid sample selection bias. In the first step a Probit model was estimated to capture the household’s decision of whether or not to participate in the market. The second step comprised of an OLS estimation to determine the significance of variables that contribute to the level of pulse sold. At national level, results indicate that the majority of households receive price information, but few households receive information on fertilizers and improved seed use. Most households also have poor access to credit and improved extension services, and low levels of membership of agricultural associations. A very small percentage of household farmers are engaged in pulse production, with male farmers more dedicated to the production of common beans and female farmers more dedicated to the production of cowpeas. In terms of market participation, the results reveal that female-headed households are less likely to participate in pulse markets. The critical factors that discourage entry into the pulse market are distance to the market and yield loss. The factors that give incentives to smallholders to participate in the pulse market are land size, price information and pulse price. The trade volume of common beans is relatively high and is affected by land size, pulse price and price information. In contrast, the trade volume of cowpeas is highly affected by bicycle ownership and ownership of livestock for animal traction. Cowpea prices also have a positive effect on the volume of cowpeas sold. Yield loss is a major factor that negatively affects the pulse trade, while land size has a negative effect on the volume of cowpeas sold. Land availability and price information provide good opportunities, in Mozambique, for expanding pulse production. The expansion of pulse production is however constrained by household access to public goods and services such as extension services, credit and membership to an agricultural association. Moreover, the expansion of pulse production in the country is also constrained by the absence of the use of productive technologies such as improved seed and fertilizer. Based on the results of the study, the recommendations are to expand extension services, improve access to improved technology, facilitate access to agricultural finance, and improve infrastructure and storage facilities. This would facilitate and give incentive to smallholder to expanding pulse production in Mozambique. / Dissertation (MSc Agric)--University of Pretoria, 2013. / gm2014 / Agricultural Economics, Extension and Rural Development / unrestricted

Encouraging greater implementation of conservation agriculture practices such as reduced tillage and cover crops may require better understanding of the effect of these practices on soil health. The overall objective of this study was to quantify soil health dynamics due to conservation agriculture practices and address methodological gaps in terms of measuring soil health parameters. We developed five sites across the state of Virginia; each site had replicated plots with combinations of reduced tillage versus disk tillage and wintertime cover crops versus no cover crops as experimental treatments. Soil and plant samples were collected 1-2 times per year for 3 years, and were analyzed for 30 soil health parameters. The parameters were first evaluated to determine if any consistently detected treatment differences. We then quantified the temporal dynamics of the eight most responsive soil health parameters, while considering influences of soil water content at time of tillage, cover crop biomass, and previous land management history. Of the analyzed parameters, only 2-4 mm aggregate stability and magnesium showed high responsiveness and consistency in identifying tillage and cover crop effects. None of the parameters detected treatment differences in all sites or at all times, yet samples collected after high biomass cover crops or after tillage in wet conditions tended to show significant treatment differences for multiple indicators. The previous history of management in each site may have affected trends in aggregate stability, but did not appear to influence other indicators. As soil aggregate stability was found to be the most important soil health parameter, our third study developed an improved method for measuring soil aggregate stability. This new method, Integrated Aggregate Stability (IAS), interprets aggregate stability using a laser diffraction machine. Overall, IAS showed higher correlation with the wet sieving method (R2 = 0.49 to 0.59) than widely used median aggregate size (d50) (R2 = 0.09 to 0.27). IAS can also quantify stability of macro- and micro-sized aggregates, which d50 cannot. When comparing between IAS and wet sieving, IAS requires considerably less time and sample amounts. Our fourth study focused on creating an inexpensive yet accurate tool for measuring soil respiration, as microbial assessments based on respiration rates have great potential for detecting rapid changes in soil health. Using an Arduino-based infrared gas analyzer (IRGA) sensor, we developed the Soil Microbial Activity Assessment Contraption (SMAAC) for less than $150. Our results show that SMAAC provided consistent readings with a commercial IRGA unit when tested using three different configurations. Altogether, the research presented in this dissertation identifies important soil health parameters and quantifies their temporal and between-site dynamics. Using this narrower set of indicators can help producers and practitioners save resources when conducting measurements to assess soil health effects of agricultural practices. Further, this work also provides improved measurement techniques for useful soil health parameters like aggregate stability and soil respiration. These findings and innovations should help to encourage greater adoption of agricultural management practices that build and preserve soil health. / Doctor of Philosophy / If we want to make sure that ample and safe food is available to future generations, then it is time that we produce food without damaging the soil. Many widely used soil management techniques like tillage and leaving the field bare can harm the soil and decrease productivity in the long run. One potential technique to produce food while protecting the soil and environment is conservation agriculture, which can include reduced tillage and cover cropping. Reduced tillage is a technique in which we grow food without majorly disturbing the soil, while cover crops are planted when cash crops are not in the field in order to improve or sustain the soil. Understanding the soil-related benefits of conservation agriculture practices is important to encourage farmers to adopt these practices. In this study we tested the effects on soils of reduced tillage and cover crop practices versus conventional tillage and bare soil practices, using five locations across Virginia. We also developed improved methods for measuring two informative soil parameters. We found that, when looking at all of our five sites, the stability of soil aggregates, the rate at which water enters soil, and the nutrients in surface soils were all affected by the type of management that the soils were subjected to. Reduced tillage increased stability of soil aggregates when compared with conventional till. This increased stability of aggregates indicators lower potential for surface water runoff, erosion, and flooding when we practice reduced tillage. Cover cropping also increased stability of soil aggregates, especially when the cover crops attained substantial above-ground mass. Soil nutrients (which are essential for plants to grow) were also overall higher in the surface soil layers under no-till. Since the stability of soil aggregates was found to be an important benefit of CA practices, we also perceived a need for a better method for measuring stability of these aggregates. In response, we developed a new index called Integrated Aggregate Stability (IAS). IAS was found to give similar results as established methods, but the time required to get IAS result is about 10 minutes, whereas the time required for established methods like wet sieving is around 2 days. IAS measurements are therefore both accurate and quick to perform. We also focused on developing an inexpensive tool for measuring soil respiration. Soil respiration-based measurements help us to understand the activity of microbes in the soil. These microbes are very important for soils to function. Our tool, Soil Microbial Activity Assessment Contraption (SMAAC), was very consistent with a currently used tool and shows high potential for future use. Altogether, we found that no-tillage and cover cropping can increase stability of soil aggregates even within 1-3 years of starting those practices. No-till can also increase nutrient concentrations in the top soil layer. The tools and innovations developed in this study have the potential to increase the ability of farmers to assess soil health and also encourage greater adoption of conservation agriculture practices.

Redundant Arrays of Inexpensive Disks or RAID is a popular method of improving the reliability and performance of disk storage. Of various levels of RAID, mirrored or RAID1 and rotating parity or RAID5 configurations have become moat popular. Mirrored or RAID1 provides best overall performance and is easier to configure, but has 100 percent storage overhead for the redundancy. Rotating parity or RAID5, on the other hand, is quite inexpensive for the redundancy it provides, shorn impressive performance for reads and full-stripe writes in normal mode, but the small write performance is poor due to the read-modify-write cycle involved. The performance drops drastically when one of the disks fails and the system enters degraded mode. Also RAID5 is relatively difficult to configure. Typical non-scientific system disk access patterns exhibit very high locality of reference. This thesis presents the design and implementation of an Adaptive Hierarchical RAID array to exploit this high locality. Frequently accessed data is migrated towards the top of the hierarchy and not so frequently acee88ed data is moved down the hierarchy, thus adaptively rearranging itself to the access patterns. Previous work on Adaptive Hierarchical RAID such as HP AutoRAID has explored one part of the design space, namely design of configurable storage at the SGSI level with no interaction with higher level layers like volume manager. This thesis explores a different design point: namely, one that is centered at the volume manager layer. This is important also for the reason that with fibre channel disks and SCSI-3, Storage Area Networks (SAN) no longer need a conventional controller but a modified version of a controller that is more close to a volume manager.

A link between eye movement mechanics and the mental processing associated with text reading has been established in the past. The pausing of an eye gaze on a specific word within a sentence reflects correctness or fluency of a translated text. A cognitive translation system has been built employing a single, inexpensive web camera without the use of infrared illumination. It was shown that the system translates the text, detects rarely occurring and out-of-context words from eye gaze information, and provides solutions in real time while the user is still reading. The solutions are in form of a translation, definition or synonym for the word in question. The only effort required is that of reading.

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