988 research outputs found
Autonomous prealignment of a docking mechanism
Proposed future space exploration, such as lunar and Martian expeditions, will require autonomous docking of space vehicles. One proposed candidate method of autonomous docking utilizes a actively controlled parallel manipulator. Operation of the proposed docking manipulator can be segmented into four successive events: prealignment, capture/latching, attenuation, and structural rigidization. This paper discusses the development and testing of a digitally controlled, six-degree-of-freedom (6-DOF), parallel manipulator for the prealignment segment of a docking spacecraft
Enabling an effective knowledge and information flow between the phases of building construction and facilities management
Purpose The purpose of this study is to investigate ways of transferring knowledge and information during the life-cycle phases of construction projects, particularly between the construction and occupancy phases, and to find an approach to minimise knowledge and information gaps during the handover process. Design/methodology/approach The study applied a qualitative approach involving a literature review and an archival analysis of information flow in the studied cases of a construction project, followed by a cross-cases analysis and expert interviews. Data on information flow were collected from three cases of building construction projects in Perth, Western Australia. In addition, a total of 18 local facilities management experts were interviewed to identify the key reasons of knowledge and information gaps and to propose an effective knowledge flow model. Findings The findings of this study indicated a significant knowledge and information gap, which exists during the handover process in construction projects in Western Australia. The findings of case analysis and expert interviews identified that the project handover guidelines were often ignored in construction projects in Western Australia, and the handover phase was not given the same priority as the design and construction phases by most of the project stakeholders, which led to information and knowledge gaps between the project construction and post-occupancy phases. The study conducted, integrated knowledge and information flow modelling to analyse the knowledge and information gaps followed by mapping the gaps against existing knowledge sharing frameworks (KSFs) before proposing an integrated knowledge sharing conceptual model to improve current practice and to enhance the information flow during the various phases of the construction project life cycle. Research limitations/implications The study is based on three cases in Perth, Western Australia, and thus the findings and recommendations are contextual. Whilst laying a good foundation to do so, further research is needed to investigate more cases in Western Australia and beyond to fully generalise the findings from this study. Originality/value The study contributes to improve the handover process and information flows in project life-cycle phases in Western Australia and develop an information flow model followed by bringing together existing KSFs, namely, the open communication channel (OCC), soft landing framework (SLF) and building information modelling (BIM), to propose an integrated knowledge sharing conceptual model. The methodology used here to analyse the information flow in a diagrammatic manner, the mapping of FM issues against the KSFs’ capabilities and a conceptual model to facilitate change in the industry’s silo mindset are the main contributions of this paper
Satellite-matrix-switched, time-division-multiple-access network simulator
A versatile experimental Ka-band network simulator has been implemented at the NASA Lewis Research Center to demonstrate and evaluate a satellite-matrix-switched, time-division-multiple-access (SMS-TDMA) network and to evaluate future digital ground terminals and radiofrequency (RF) components. The simulator was implemented by using proof-of-concept RF components developed under NASA contracts and digital ground terminal and link simulation hardware developed at Lewis. This simulator provides many unique capabilities such as satellite range delay and variation simulation and rain fade simulation. All network parameters (e.g., signal-to-noise ratio, satellite range variation rate, burst density, and rain fade) are controlled and monitored by a central computer. The simulator is presently configured as a three-ground-terminal SMS-TDMA network
Novel Space Alters Theta and Gamma Synchrony Across the Longitudinal Axis of the Hippocampus.
Hippocampal theta (6–10 Hz) and gamma (25–50 Hz and 65–100 Hz) local field potentials (LFPs) reflect the dynamic synchronization evoked by inputs impinging upon hippocampal neurons. Novel experience is known to engage hippocampal physiology and promote successful encoding. Does novelty synchronize or desynchronize theta and/or gamma frequency inputs across the septotemporal (long) axis of the hippocampus (HPC)? The present study tested the hypothesis that a novel spatial environment would alter theta power and coherence across the long axis. We compared theta and gamma LFP signals at individual (power) and millimeter distant electrode pairs (coherence) within the dentate gyrus (DG) and CA1 region while rats navigated a runway (1) in a familiar environment, (2) with a modified path in the same environment and (3) in a novel space. Locomotion in novel space was related to increases in theta and gamma power at most CA1 and DG sites. The increase in theta and gamma power was concurrent with an increase in theta and gamma coherence across the long axis of CA1; however, there was a significant decrease in theta coherence across the long axis of the DG. These findings illustrate significant shifts in the synchrony of entorhinal, CA3 and/or neuromodulatory afferents conveying novel spatial information to the dendritic fields of CA1 and DG targets across the long axis of the HPC. This shift suggests that the entire theta/gamma-related input to the CA1 network, and likely output, receives and conveys a more coherent message in response to novel sensory experience. Such may contribute to the successful encoding of novel sensory experience
Coupling ammonia-N production with ammonia-N uptake in the rumen
Abstract only availableMicrobial efficiency is defined as a measure of microbial yield in the rumen per unit of organic matter fermented. Because the ruminant is dependant on microbial mass for its supply of amino acids, the nutritional goal is to maximize microbial efficiency. However, an excessive supply of nutrients to rumen microbes can result in waste. Excessive waste can have negative economic and environmental consequences. A study was conducted to determine if prediction of ammonia-N release could be optimized with bacterial ammonia uptake in the rumen. The hypothesis of this research was that a diet could be formulated such that ammonia-N release would match the ammonia uptake by rumen microflora. To test this hypothesis, a continuous culture system of twenty fermentors placed in a 39ÂşC water bath was used. Dietary treatments were basal, 0.33X, 0.66X, X, and 1.33X. The optimal diet (diet X) was formulated using substrates with complementary degradation rates in order to maintain an optimal ammonia level of 2 mM (Satter & Slyter, 1973). Following an acclimation period of 4 days, samples were collected for 3 days. Collected samples were analyzed for organic matter digestibility (OMD), concentration of volatile fatty acids (VFA), pH, and microbial efficiency. Microbial efficiency was maximized for diet X. As the degradable protein level increased in the diet, VFA increased and pH decreased. The degradable protein level did not influence OMD. Conclusions from this data were that increasing degradable protein increased fermentative activity but not microbial yield. We further deduced that previous research conducted in our laboratory was valid in concluding that ammonia-N requirements could be modeled. This will enhance diet formulation for ruminants.F.B. Miller Animal Sciences Summer Undergraduate Research Progra
Lattice modules having small cofinite irreducibles
We introduce the concept of small cofinite irreducibles in Noetherian lattice modules and obtain several characterizations of this property
Texas and Southwestern Cattle Raisers Association Members\u27 Preferred Sources of Animal Health Information
The nation’s agriculture and food infrastructure is vulnerable to significant social disruption and economic loss from hazards. Biological hazards, such as animal disease epidemics, have resulted in millions of dollars of economic loss and the death of millions of livestock in the past, and it will happen again unless infrastructure stakeholders adopt proper preventative measures. From farm to plate, defense starts on the farm with producers. With the multitude of potential hazards, many factors influence livestock producers’ protective action decision process. A major factor in the decision to take a protective action is from where or from whom the threat information originates. By identifying preferred sources, perceived credible sources, and preferred formats of animal health information by producers, risk communicators can more effectively develop critical animal health warnings and messages to promote rapid detection of hazards. This study targeted 7,661 members of the Texas and Southwestern Cattle Raisers Association. An online questionnaire developed from previous research with similar populations allowed TSCRA members to respond to questions related to the objectives of this study. A representative sample of TSCRA members from Texas, Oklahoma, and New Mexico responded and identified high levels of perceived trust and reliability in local veterinarians as a source of information along with livestock associations and county extension offices. TSCRA members also indicated they have multiple preferred formats for receiving animal health information. By using this information when communicating possible hazards, protective action from such threats will become more probable in this population
Art for Life: Jakarta Urban Community Efforts Peace with Mental Disorders through Art (Case Study in Indonesian Schizophrenia Community Care)
This paper describes concerning the efforts of Jakarta urban community to peace with mental disorders caused by many factors, one of which is the hard life in Jakarta demanding society able to adapt the rapid changes. The impact of rapid changes in the community mental health can be seen in the presence of: school dropping out, fighting between students, or fighting between ethnic village, the violence on woman and children, crime, psychosomatic disorder, acute anxiety, depression and other mental health problems. Indonesian Schizophrenia Community Care (KPSI) tries to peace with mental illness disorder through art therapy. Various activities are explored to determine the response on persons with schizophrenia to therapy sessions and its psychological impacts. Art therapy here is not intended to replace medical treatment and does not offer instant recovery, but rather act as a supportiing therapy of pharmacotherapy. Some of the activities that have been implemented include: drawing, painting, creating murals, painting batik and making collages. These activities are carried out by a group thematic format with a semi-structural approach. With the gradual flexible implementation strategy, therapy sessions show the contribution to the development of more well developed self-esteem, self-confidence, fluency to respond stimulus, imagination and problem-solving abilities, being able to interact and socialize with others in a positive way, as well as their fine motoric develop more skilled. Development themes that is explored has more orientation to provide comfortable, enjoyable sensory and aesthetic experience and satisfy personal to build confidence and openness in sharing life experiences. The art works they create and exhibitions held by KPSI is an effort to reduce negative stigma attached to them. The progress report of the development of individual and group potential in writing give special attention to personal and interpersonal abilities related art work activities. Data for the report was obtained through observation participation, in-depth interviews, the study on documents related to art therapy session held from February to May 2013. The report results constitutes a feed-back concerning strengths and weaknesses of persons with schizophrenia and also serves as an evaluation instrument for the implementation of art therapy sessions that have been taking place. Efforts to peace with mental illness through art therapy program is a real contribution form of the art to the Jakarta urban life. Keywords: Art, urban society, Jakarta, peace, mental disorder
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