5,743 research outputs found

    Precedence relationship representations of mechanical assembly sequences

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    Two types of precedence relationship representations for mechanical assembly sequences are presented: precedence relationships between the establishment of one connection between two parts and the establishment of another connection, and precedence relationships between the establishment of one connection and states of the assembly process. Precedence relationship representations have the advantage of being very compact. The problem with these representations was how to guarantee their correctness and completeness. Two theorems are presented each of which leads to the generation of one type of precedence relationship representation guaranteeing its correctness and completeness for a class of assemblies

    The effect of flight line spacing on radioactivity inventory and spatial feature characteristics of airborne gamma-ray spectrometry data

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    Airborne Gamma Spectrometry (AGS) is well suited to the mapping of radioactivity in the environment. Flight parameters (e.g. speed and line spacing) directly affect the rate of area coverage, cost, and data quality of any survey. The influences of line spacing have been investigated for data from inter‐tidal, coastal and upland environments with a range of <sup>137</sup>Cs activity concentrations and depositional histories. Estimates of the integrated <sup>137</sup>Cs activity (‘inventory’) within specified areas and the shapes of depositional features were calculated for subsets of the data at different line spacings. Features with dimensions greater than the line spacing show variations in inventory and area of less than 3%, and features with dimensions less than the line spacing show larger variations and a decreased probability of detection. The choice of line spacing for a task is dependent on the dimensions of the features of interest and required edge definition. Options for line spacing for different tasks are suggested. It is noted that for regional mapping, even 5–10 km line spacing can produce useful data

    Task planning and control synthesis for robotic manipulation in space applications

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    Space-based robotic systems for diagnosis, repair and assembly of systems will require new techniques of planning and manipulation to accomplish these complex tasks. Results of work in assembly task representation, discrete task planning, and control synthesis which provide a design environment for flexible assembly systems in manufacturing applications, and which extend to planning of manipulatiuon operations in unstructured environments are summarized. Assembly planning is carried out using the AND/OR graph representation which encompasses all possible partial orders of operations and may be used to plan assembly sequences. Discrete task planning uses the configuration map which facilitates search over a space of discrete operations parameters in sequential operations in order to achieve required goals in the space of bounded configuration sets

    The VOICE Study: Valuing Opinions, Individual Communication and Experience: Building the evidence base for undertaking patient-centred family meetings in palliative care - a mixed methods study

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    Background: Despite family meetings being widely used to facilitate discussion among patients, families, and clinicians in palliative care, there is limited evidence to support their use. This study aims to assess the acceptability and feasibility of Patient-Centred Family Meetings in specialist inpatient palliative care units for patients, families, and clinicians and determine the suitability and feasibility of validated outcome measures from the patient and family perspectives. Methods: The study is a mixed-methods quasi-experimental design with pre-planned Patient-Centred Family Meetings at the intervention site. The patient will set the meeting agenda a priori allowing an opportunity for their issues to be prioritised and addressed. At the control site, usual care will be maintained which may include a family meeting. Each site will recruit 20 dyads comprising a terminally ill inpatient and their nominated family member. Pre- and post-test administration of the Distress Thermometer, QUAL-EC, QUAL-E, and Patient Health Questionnaire-4 will assess patient and family distress and satisfaction with quality of life. Patient, family, and clinician interviews post-meeting will provide insights into the meeting feasibility and outcome measures. Recruitment percentages and outcome measure completion will also inform feasibility. Descriptive statistics will summarise pre- and post-meeting data generated by the outcome measures. SPSS will analyse the quantitative data. Grounded theory will guide the qualitative data analysis. Discussion: This study will determine whether planned Patient-Centred Family Meetings are feasible and acceptable and assess the suitability and feasibility of the outcome measures. It will inform a future phase III randomised controlled trial. Trial registration: Australian New Zealand Clinical Trials Registry ACTRN12616001083482 on 11 August 201

    Richness and Abundance of Carabidae and Staphylinidae (Coleoptera), in Northeastern Dairy Pastures Under Intensive Grazing

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    Dairy cattle has become popular to dairy farmers in the Northeast looking for management schemes to cut production costs. Carabidae (ground beetles) and Staphylinidae (rove beetles) are indicators of habitat disturbances, such as drainage of wetlands, or grassland for grazing animals, and their monitoring could provide one measure of ecosystem sustainability if intensive management systems expand or intensify in the future. Our objective was assess the abundance and species richness of these two beetle families under intensive grazing throughout Pennsylvania, southern New York and Vermont. We collected 4365 ground beetles (83 species) and 4,027 rove beetles (79 species) by pitfall traps in three years in Pennsylvania. Nine ground beetle species, Amara aenea, Poecilus chalcites, Pterostichus melanarius, Bembidion quadrimaculatum oppositum, Amara familiaris, Poecilus lucublandus, Agonum muelleri, Bembidion obtusum and Bembidion mimus represented 80% of the Carabidae collected. Five other species were new to Pennsylvania. Four rove beetle species, Philonthus cognatus, Meronera venustula, Amischa analis, and Philonthus various = (carbonarius), comprised 74% of the total Staphylinidae collected. Yearly distributions of the dominant species did not change significantly in the three years with A. aenea and P. cognatus being most abundant every year. A parasitic rove beetle, Aleochara tristis, was recovered for the first time in Pennsylvania and Vermont since its release in the 1960\u27s to control face fly, Musca autumnalis. Similar results were found in New York and Vermont. We collected 1,984 ground beetles (68 species). Pterostichus melanarius was most abundant. Pterostichus vernalis was detected for the first time in the United States (Vermont). It was previously reported from Montreal, Canada. We collected 843 rove beetles (45 species). Philonthus cognatus was the most abundant rove beetle. In addition, Tachinus corticinus, previously known only from Canada, was discovered for the first time in the United States in Vermont. Pastures in Pennsylvania were diverse, containing 14 species of forage plants and 17 weed species. Botanical composition was similar in New York and Vermont. Sixteen species of grasses and legumes made up 90% of the plant composition and 36 species of weeds made up the remainder. This di­verse plant ecosystem may explain the richness of ground and rove beetles in northeastern U.S. pastures because the heterogeneity in the plant population provided additional resources which can support a rich assemblage of beetles. Monitoring richness and abundance of Carabidae and Staphylinidae over three years in Pennsylvania suggests intensive grazing systems are eco­logically sustainable

    Intake and Milk Production of Lactating Dairy Cows Grazing Diverse Forage Mixtures Over Two Grazing Seasons

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    Voluntary intake and stocking rate are key determinants of animal performance on pasture. Greater plant diversity in grassland plant communities has been linked to increased primary production, greater stability in response to disturbance, and reduced weed pressure. Thus, increasing plant diversity may be one approach to improving animal productivity. An experiment was conducted to determine the effects of forage diversity on intake and milk production of lactating dairy cows over two grazing seasons

    Vaccines to Combat Smoking

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    Background—Current U.S. FDA approved biological therapies for treating smoking target central nervous system processes. Although these therapies have had some success, relapse within a year is still high. Clearly additional strategies are needed to aid individuals in maintaining abstinence. Objective & Methods—We briefly discuss promising research using vaccines to combat smoking and then identify some potentially important directions for future research. Results & Conclusions—Immunization with a nicotine vaccine generates drug-specific antibodies that sequester some of the nicotine in peripheral circulation preventing it from entering the brain thus decreasing its addictive effects. Albeit promising, much more research is necessary to identify more efficacious vaccine designs and formulations, as well as optimal immunization regimens. A further understanding of the contributing factors to the substantial individual differences in immunogenicity to these vaccines and how to best use vaccines in combination with other treatment strategies will increase the success of intervention efforts

    Vaccines to Combat Smoking

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    Background—Current U.S. FDA approved biological therapies for treating smoking target central nervous system processes. Although these therapies have had some success, relapse within a year is still high. Clearly additional strategies are needed to aid individuals in maintaining abstinence. Objective & Methods—We briefly discuss promising research using vaccines to combat smoking and then identify some potentially important directions for future research. Results & Conclusions—Immunization with a nicotine vaccine generates drug-specific antibodies that sequester some of the nicotine in peripheral circulation preventing it from entering the brain thus decreasing its addictive effects. Albeit promising, much more research is necessary to identify more efficacious vaccine designs and formulations, as well as optimal immunization regimens. A further understanding of the contributing factors to the substantial individual differences in immunogenicity to these vaccines and how to best use vaccines in combination with other treatment strategies will increase the success of intervention efforts

    Corn Production Guide : A Summary of Recommendations

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    This publication provides tables and maps of South Dakota with recommendations for crop adaptation area, maturity range of hybrid, desirable population, seeding date, fertilizer application, and chemical pest control

    1964 Forage Crop Production Guide

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    This publication provides a table listing forage crops, varieties, area of best adaptation, seeding rate, chemical weed control, fertilizer, and insect and disease control recommendations
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