141 research outputs found

    Spontaneous strategies

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    My thesis body of work combines sculptures and paintings which are visual essays reflecting the interrelationships of color and form. The sculptures are simplified geometric shapes integrated with brilliant saturated color fields. This thesis is an investigation into the process of making art and the condition of receiving it. I have explored ideas produced through the experience of chance, color, movement, rhythm, and form with a cohesive vision evolving into a personal direction that enables experimentation without the loss of integrity

    Improving Control in a Joule-Thomson Refrigerator

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    A report discusses a modified design of a Joule-Thomson (JT) refrigerator under development to be incorporated into scientific instrumentation aboard a spacecraft. In most other JT refrigerators (including common household refrigerators), the temperature of the evaporator (the cold stage) is kept within a desired narrow range by turning a compressor on and off as needed. This mode of control is inadequate for the present refrigerator because a JT-refrigerator compressor performs poorly when the flow from its evaporator varies substantially, and this refrigerator is required to maintain adequate cooling power. The proposed design modifications include changes in the arrangement of heat exchangers, addition of a clamp that would afford a controlled heat leak from a warmer to a cooler stage to smooth out temperature fluctuations in the cooler stage, and incorporation of a proportional + integral + derivative (PID) control system that would regulate the heat leak to maintain the temperature of the evaporator within a desired narrow range while keeping the amount of liquid in the evaporator within a very narrow range in order to optimize the performance of the compressor. Novelty lies in combining the temperature- and cooling-power-regulating controls into a single control system

    Rural residence is not a risk factor for frequent mental distress: a behavioral risk factor surveillance survey

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    BACKGROUND: Residents of rural areas may be at increased risk of mental health problems. If so, public health programs aimed at preventing poor mental health may have to be customized for delivery to rural areas. The purpose of this study was to examine the relationship between residing in a rural area and frequent mental distress, which is one indicator of poor mental health. METHODS: The Behavioral Risk Factor Surveillance System (BRFSS) survey for the state of Texas was the source of information about obesity, demographic characteristics, and frequent mental distress (FMD). FMD was defined as poor self-rated mental health during at least half of the days in the last month. Adjusted odds for FMD were computed for rural and suburban respondents relative to urban respondents. RESULTS: FMD was found to be independently associated with lower education, being younger, being non-Hispanic, being unmarried, and being female. FMD also was associated with being obese or underweight and suburban residence (relative to metro-central city). FMD was not more common among rural respondents than in the metro-central city. CONCLUSION: Rural respondents were not at greater risk of frequent mental distress than urban respondents in this sample. Programs seeking to improve community mental health should target persons with less education and extremes in body weight, along with women and single persons, regardless of whether they live in rural or urban areas

    Fault-Tolerant, Multiple-Zone Temperature Control

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    A computer program has been written as an essential part of an electronic temperature control system for a spaceborne instrument that contains several zones. The system was developed because the temperature and the rate of change of temperature in each zone are required to be maintained to within limits that amount to degrees of precision thought to be unattainable by use of simple bimetallic thermostats. The software collects temperature readings from six platinum resistance thermometers, calculates temperature errors from the readings, and implements a proportional + integral + derivative (PID) control algorithm that adjusts heater power levels. The software accepts, via a serial port, commands to change its operational parameters. The software attempts to detect and mitigate a host of potential faults. It is robust to many kinds of faults in that it can maintain PID control in the presence of those faults

    Planck sorption cooler engineering breadboard test report

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    In order to validate the sorption cooler flight design, an Engineering Breadboard (EBB) cooler was developed. Testing of the EBB cooler began in January, 2002, and ended in May, 2003. Throughout this period, the cooler was operated for a total of 4300 hours, during which its performance was verified with respect to the flight requirements. Prior to its construction, all of its components and sub-assemblies were tested individually. Interaction among these subsystems was yet to be validated. The EBB provided this system test prior to the construction of the flight models. In addition, operation of the EBB was used to develop robust operational algorithms, which were implemented in the flight prototype electronics. The prototype electronics were validated by testing with the EBB cooler. All the components for the flight cooler have been built to be functionally equivalent to those of the EBB, with a few exceptions. For this reason, the subassembly interactions and performance in the EBB are considered to be representative of those expected of the flight models. The impact of the differences between the EBB and flight models will be assessed in the following sections. All lessons learned from the EBB tests were implemented in the design and operation of the flight cooler

    The mini-conference: Teaching professionalism through student involvement

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    Professional orientation courses typically provide important knowledge about professional organizations, standards, credentials, and roles. Knowledge alone, however, may not instill a sense of professionalism in counseling students. This article describes one teaching method that seems to foster behaviors and attitudes that characterize professionalism

    Surrogate: A Body-Dexterous Mobile Manipulation Robot with a Tracked Base

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    Robotics platforms in accordance with various embodiments of the invention can be utilized to implement highly dexterous robots capable of whole body motion. Robotics platforms in accordance with one embodiment of the invention include: a memory containing a whole body motion application; a spine, where the spine has seven degrees of freedom and comprises a spine actuator and three spine elbow joints that each include two spine joint actuators; at least one limb, where the at least one limb comprises a limb actuator and three limb elbow joints that each include two limb joint actuators; a tracked base; a connecting structure that connects the at least one limb to the spine; a second connecting structure that connects the spine to the tracked base; wherein the processor is configured by the whole body motion application to move the at least one limb and the spine to perform whole body motion

    Supervised Remote Robot with Guided Autonomy and Teleoperation (SURROGATE): A Framework for Whole-Body Manipulation

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    The use of the cognitive capabilities of humans to help guide the autonomy of robotics platforms in what is typically called “supervised-autonomy” is becoming more commonplace in robotics research. The work discussed in this paper presents an approach to a human-in-the-loop mode of robot operation that integrates high level human cognition and commanding with the intelligence and processing power of autonomous systems. Our framework for a “Supervised Remote Robot with Guided Autonomy and Teleoperation” (SURROGATE) is demonstrated on a robotic platform consisting of a pan-tilt perception head, two 7-DOF arms connected by a single 7-DOF torso, mounted on a tracked-wheel base. We present an architecture that allows high-level supervisory commands and intents to be specified by a user that are then interpreted by the robotic system to perform whole body manipulation tasks autonomously. We use a concept of “behaviors” to chain together sequences of “actions” for the robot to perform which is then executed real time

    Robotics Platforms Incorporating Manipulators Having Common Joint Designs

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    Manipulators in accordance with various embodiments of the invention can be utilized to implement statically stable robots capable of both dexterous manipulation and versatile mobility. Manipulators in accordance with one embodiment of the invention include: an azimuth actuator; three elbow joints that each include two actuators that are offset to allow greater than 360 degree rotation of each joint; a first connecting structure that connects the azimuth actuator and a first of the three elbow joints; a second connecting structure that connects the first elbow joint and a second of the three elbow joints; a third connecting structure that connects the second elbow joint to a third of the three elbow joints; and an end-effector interface connected to the third of the three elbow joints
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