Scientific CCD technology at JPL

Charge-coupled devices (CCD's) were recognized for their potential as an imaging technology almost immediately following their conception in 1970. Twenty years later, they are firmly established as the technology of choice for visible imaging. While consumer applications of CCD's, especially the emerging home video camera market, dominated manufacturing activity, the scientific market for CCD imagers has become significant. Activity of the Jet Propulsion Laboratory and its industrial partners in the area of CCD imagers for space scientific instruments is described. Requirements for scientific imagers are significantly different from those needed for home video cameras, and are described. An imager for an instrument on the CRAF/Cassini mission is described in detail to highlight achieved levels of performance

Report of the sensor readout electronics panel

The findings of the Sensor Readout Electronics Panel are summarized in regard to technology assessment and recommended development plans. In addition to two specific readout issues, cryogenic readouts and sub-electron noise, the panel considered three advanced technology areas that impact the ability to achieve large format sensor arrays. These are mega-pixel focal plane packaging issues, focal plane to data processing module interfaces, and event driven readout architectures. Development in each of these five areas was judged to have significant impact in enabling the sensor performance desired for the Astrotech 21 mission set. Other readout issues, such as focal plane signal processing or other high volume data acquisition applications important for Eos-type mapping, were determined not to be relevant for astrophysics science goals

Low-degree multi-spectral p-mode fitting

We combine unresolved-Sun velocity and intensity observations at multiple wavelengths from the Helioseismic and Magnetic Imager and Atmospheric Imaging Array onboard the Solar Dynamics Observatory to investigate the possibility of multi-spectral mode-frequency estimation at low spherical harmonic degree. We test a simple multi-spectral algorithm using a common line width and frequency for each mode and a separate amplitude, background and asymmetry parameter, and compare the results with those from fits to the individual spectra. The preliminary results suggest that this approach may provide a more stable fit than using the observables separately

Early postglacial hunter-gatherers show environmentally driven “false logistic” growth in a low productivity environment

Studies that employ probability distributions of radiocarbon dates to study past population size often use exponential increase in radiocarbon dates with time as a standard of comparison for detecting population fluctuations. We show that in the case of early postglacial interior Scandinavia, however, the summed probability distribution of radiocarbon dates has best fit with a S-shaped logistic growth curve. Despite the logistic growth model having solid grounding in ecological theory, we further argue that what our data indicate is not logistic growth in the population ecological sense but “false logistic” growth that mainly follows from climatic and environmental forcing. In the initial postglacial phase, 9500–7500 BCE, human settlement was located almost exclusively along the Scandinavian Atlantic coast and the use of the mountainous interior remained low. Thereafter the formation of separate inland adaptations resulted in population growth in tandem with increasing climatic warming and environmental productivity. Some millennia later, when environmental productivity started to decrease after the Holocene Thermal Maximum, hunter-gatherer population size in interior Scandinavia reached a plateau that lasted at least 2000 years. Lowering productivity prevented any population growth that would be detectable in the available archaeological record.Peer reviewe

An Evaluation of the Usability of a Computerized Decision Support System for Nursing Homes

Background: Computerized decision support systems (CDSSs) have the potential to significantly improve the quality of nursing care of older people by enhancing the decision making of nursing personnel. Despite this potential, health care organizations have been slow to incorporate CDSSs into nursing home practices. Objective: This study describes facilitators and barriers that impact the ability of nursing personnel to effectively use a clinical CDSS for planning and treating pressure ulcers (PUs) and malnutrition and for following the suggested risk assessment guidelines for the care of nursing home residents. Methods: We employed a qualitative descriptive design using varied methods, including structured group interviews, cognitive walkthrough observations and a graphical user interface (GUI) usability evaluation. Group interviews were conducted with 25 nursing personnel from four nursing homes in southern Norway. Five nursing personnel participated in cognitive walkthrough observations and the GUI usability evaluation. Text transcripts were analyzed using qualitative content analysis. Results: Group interview participants reported that ease of use, usefulness and a supportive work environment were key facilitators of CDSS use. The barriers identified were lack of training, resistance to using computers and limited integration of the CDSS with the facility’s electronic health record (EHR) system. Key findings from the usability evaluation also identified the difficulty of using the CDSS within the EHR and the poorly designed GUI integration as barriers. Conclusion: Overall, we found disconnect between two types of nursing personnel. Those who were comfortable with computer technology reported positive feedback about the CDSS, while others expressed resistance to using the CDSS for various reasons. This study revealed that organizations must invest more resources in educating nursing personnel on the seriousness of PUs and poor nutrition in the elderly, providing specialized CDSS training and ensuring that nursing personnel have time in the workday to use the CDSS

Confidence Calculation with AMV+

The iterative advanced mean value algorithm (AMV+), introduced nearly ten years ago, is now widely used as a cost-effective probabilistic structural analysis tool when the use of sampling methods is cost prohibitive (Wu et al., 1990). The need to establish confidence bounds on calculated probabilities arises because of the presence of uncertainties in measured means and variances of input random variables. In this paper an algorithm is proposed that makes use of the AMV+ procedure and analytically derived probability sensitivities to determine confidence bounds on calculated probabilities

Teaching clinical reasoning and decision-making skills to nursing students: Design, development, and usability evaluation of a serious game

Background Serious games (SGs) are a type of simulation technology that may provide nursing students with the opportunity to practice their clinical reasoning and decision-making skills in a safe and authentic environment. Despite the growing number of SGs developed for healthcare professionals, few SGs are video based or address the domain of home health care. Aims This paper aims to describe the design, development, and usability evaluation of a video based SG for teaching clinical reasoning and decision-making skills to nursing students who care for patients with chronic obstructive pulmonary disease (COPD) in home healthcare settings. Methods A prototype SG was developed. A unified framework of usability called TURF (Task, User, Representation, and Function) and SG theory were employed to ensure a user-centered design. The educational content was based on the clinical decision-making model, Bloom’s taxonomy, and a Bachelor of Nursing curriculum. A purposeful sample of six participants evaluated the SG prototype in a usability laboratory. Cognitive walkthrough evaluations, a questionnaire, and individual interviews were used for the usability evaluation. The data were analyzed using qualitative deductive content analysis based on the TURF framework elements and related usability heuristics. Results The SG was perceived as being realistic, clinically relevant, and at an adequate level of complexity for the intended users. Usability issues regarding functionality and the user–computer interface design were identified. However, the SG was perceived as being easy to learn, and participants suggested that the SG could serve as a supplement to traditional training in laboratory and clinical settings. Conclusions Using video based scenarios with an authentic COPD patient and a home healthcare registered nurse as actors contributed to increased realism. Using different theoretical approaches in the SG design was considered an advantage of the design process. The SG was perceived as being useful, usable, and satisfying. The achievement of the desired functionality and the minimization of user–computer interface issues emphasize the importance of conducting a usability evaluation during the SG development process

Delta-doped hybrid advanced detector for low energy particle detection

A delta-doped hybrid advanced detector (HAD) is provided which combines at least four types of technologies to create a detector for energetic particles ranging in energy from hundreds of electron volts (eV) to beyond several million eV. The detector is sensitive to photons from visible light to X-rays. The detector is highly energy-sensitive from approximately 10 keV down to hundreds of eV. The detector operates with milliwatt power dissipation, and allows non-sequential readout of the array, enabling various advanced readout schemes