A simple rack for race tubes

A simple rack for race tube

Design techniques for revealing adolescent memory processes related to information seeking: A preliminary study

This study investigates the effectiveness of design techniques as a means for uncovering metamemory, an attribute of metacognition, and its role in information seeking. A focus group with four adolescents aged 13 and 14 used design techniques such as brainstorming and sketching, metaphorical design and fictional inquiry, to help express their thinking about their own memory processes during the information search process. Results showed that metaphorical design and fictional inquiry are both effective tools for revealing conceptual thinking about metamemory and information seeking. Coupling these techniques with brainstorming and sketching helped the teens to visualize and communicate their ideas. Results from this study will contribute to knowledge about adolescent thinking, metamemory, and information seeking behavior, broaden the range of methodological approaches used in the study of information seeking behavior, and will provide cognitive models for the design of information systems and tools that scaffold metacognition. © 2012 ACM

Integrated flight/propulsion control system design based on a centralized approach

An integrated flight/propulsion control system design is presented for the piloted longitudinal landing task with a modern, statically unstable, fighter aircraft. A centralized compensator based on the Linear Quadratic Gaussian/Loop Transfer Recovery methodology is first obtained to satisfy the feedback loop performance and robustness specificiations. This high-order centralized compensator is then partitioned into airframe and engine sub-controllers based on modal controllability/observability for the compensator modes. The order of the sub-controllers is then reduced using internally-balanced realization techniques and the sub-controllers are simplified by neglecting the insignificant feedbacks. These sub-controllers have the advantage that they can be implemented as separate controllers on the airframe and the engine while still retaining the important performance and stability characteristics of the full-order centralized compensator. Command prefilters are then designed for the closed-loop system with the simplified sub-controllers to obtain the desired system response to airframe and engine command inputs, and the overall system performance evaluation results are presented

Research Data Management Service Delivery Model for the ULS

This document presents a service delivery model for research data management at the University Library System (ULS). It presents three levels of participation and expertise around Research Data Management (RDM) services at the ULS. It outlines membership at each service level, level competencies and activities, and organizational support for service providers

IMPAC: An Integrated Methodology for Propulsion and Airframe Control

The National Aeronautics and Space Administration is actively involved in the development of enabling technologies that will lead towards aircraft with new/enhanced maneuver capabilities such as Short Take-Off Vertical Landing (STOVL) and high angle of attack performance. Because of the high degree of dynamic coupling between the airframe and propulsion systems of these types of aircraft, one key technology is the integration of the flight and propulsion control. The NASA Lewis Research Center approach to developing Integrated Flight Propulsion Control (IFPC) technologies is an in-house research program referred to as IMPAC (Integrated Methodology for Propulsion and Airframe Control). The goals of IMPAC are to develop a viable alternative to the existing integrated control design methodologies that will allow for improved system performance and simplicity of control law synthesis and implementation, and to demonstrate the applicability of the methodology to a supersonic STOVL fighter aircraft. Based on some preliminary control design studies that included evaluation of the existing methodologies, the IFPC design methodology that is emerging at the Lewis Research Center consists of considering the airframe and propulsion system as one integrated system for an initial centralized controller design and then partitioning the centralized controller into separate airframe and propulsion system subcontrollers to ease implementation and to set meaningful design requirements for detailed subsystem control design and evaluation. An overview of IMPAC is provided and detailed discussion of the various important design and evaluation steps in the methodology are included

The Bacterial Flora of the Antecubital Fossa: The Efficacy of Alcohol Disinfection of this Site, the Palm and the Forehead

The surface flora of the antecubital fossa (ACF) of 25 subjects comprised the same kinds of bacteria as are commonly found on the hands, arms, back and forehead. The population density was bimodal. Fifteen subjects had a sparse flora. After alcohol disinfection there were no surviving bacteria on these subjects. The other 10 subjects had a more abundant flora (310 to 10,000 per cm2) and after alcohol treatment there remained on 9 of these subjects a surviving population showing no quantitative correlation with the surface flora.On the palm (hypothenar eminence) of 5 subjects all bacteria were eliminated by alcohol disinfection despite initial surface populations equal to those of the 5 ACF subjects with the greatest alcohol resistant flora. On the forehead, bacterial population densities were much greater than on the palm or ACF. Alcohol disinfection reduced the surface population on the average, more than the subsurface populations, but did not eliminate either propionibacteria or gram positive cocci.Five ACF subjects with the highest alcohol resistant populations in the initial survey were retested several times over 7 mo (1 subject) or 2½ yr (4 subjects). On each person, the surviving bacteria in the initial test were of one particular species, Propionibacterium acnes, Peptococcus saccharolyticus, Staphylococcus epidermidis or an aerobic diphtheroid. In subsequent tests, S. epidermidis disappeared but the other 4 organisms continued to be present as alcohol resistant populations on both arms of their respective subjects throughout the study (22 of 25 tests positive).We suggest that the terms sheltered and exposed flora would be more accurate than transient and resident in discussing skin disinfection

Conidial harvest from solid media using fiberglass screening.

Conidial harvest from solid media using fiberglass screening

Dynamic Race Prediction in Linear Time

Writing reliable concurrent software remains a huge challenge for today's programmers. Programmers rarely reason about their code by explicitly considering different possible inter-leavings of its execution. We consider the problem of detecting data races from individual executions in a sound manner. The classical approach to solving this problem has been to use Lamport's happens-before (HB) relation. Until now HB remains the only approach that runs in linear time. Previous efforts in improving over HB such as causally-precedes (CP) and maximal causal models fall short due to the fact that they are not implementable efficiently and hence have to compromise on their race detecting ability by limiting their techniques to bounded sized fragments of the execution. We present a new relation weak-causally-precedes (WCP) that is provably better than CP in terms of being able to detect more races, while still remaining sound. Moreover it admits a linear time algorithm which works on the entire execution without having to fragment it.Comment: 22 pages, 8 figures, 1 algorithm, 1 tabl

On Verifying Causal Consistency

Causal consistency is one of the most adopted consistency criteria for distributed implementations of data structures. It ensures that operations are executed at all sites according to their causal precedence. We address the issue of verifying automatically whether the executions of an implementation of a data structure are causally consistent. We consider two problems: (1) checking whether one single execution is causally consistent, which is relevant for developing testing and bug finding algorithms, and (2) verifying whether all the executions of an implementation are causally consistent. We show that the first problem is NP-complete. This holds even for the read-write memory abstraction, which is a building block of many modern distributed systems. Indeed, such systems often store data in key-value stores, which are instances of the read-write memory abstraction. Moreover, we prove that, surprisingly, the second problem is undecidable, and again this holds even for the read-write memory abstraction. However, we show that for the read-write memory abstraction, these negative results can be circumvented if the implementations are data independent, i.e., their behaviors do not depend on the data values that are written or read at each moment, which is a realistic assumption.Comment: extended version of POPL 201

Investigating perceptions and support for transparency and openness in research: Using card sorting in a pilot study with academic librarians

This paper explores the role of academic librarians as advocates for research transparency and open research. We describe the design and piloting of a qualitative card-sorting research protocol that investigates academic librarians' attitudes, awareness and practices related to research transparency. We report on preliminary results from interviews with librarians, presenting their conceptualizations of research transparency and open research, existing library services that support and advocate for both concepts, and potential services that would augment this support and advocacy. Library activities they feel are most important to the advancement of transparency and openness are identified and perceptions of disciplinary differences are noted