Production of Reliable Flight Crucial Software: Validation Methods Research for Fault Tolerant Avionics and Control Systems Sub-Working Group Meeting

The state of the art in the production of crucial software for flight control applications was addressed. The association between reliability metrics and software is considered. Thirteen software development projects are discussed. A short term need for research in the areas of tool development and software fault tolerance was indicated. For the long term, research in format verification or proof methods was recommended. Formal specification and software reliability modeling, were recommended as topics for both short and long term research

Double Langmuir probe measurements in a magnetized positive column

Single and double Langmuir probe measurements in magnetized and nonmagnetized positive columns in glow discharges of nitroge

B763: The Perceptions, Attitudes, and Reactions of Maine Commercial Fishermen Regarding Extended Jurisdiction and Fishery Management Practices

The enactment of the Fisheries Conservation and Management Act of 1976 (FCMA) on March 1, 1977 marked the beginning of a new era for the fishing industry of the United States. This act, commonly referred to as the 200 mile limit , has the potential of bringing about important institutional changes in the fishing industry. The legislation was necessitated by increased fishing pressure from both United States and foreign vessels, and the apparent inadequacy of existing fishery management practices and controls. The FCMA provides a framework of regulations which has the scope and flexibility needed to make wise decisions regarding our fishery resources. But if the potential significance of this act is to be fulfilled, careful analysis of the effects and implications of its policies must be made. It is the individual Maine fisherman who is presently feeling the initial direct impact of the FCMA and its regulations. The fishermen now have a greater expanse of ocean in which foreign vessels are restricted. They must limit their catches to prescribed quotas and follow regulations regarding closed seasons and closed areas, or risk fines. In order for many Maine fishermen to take advantage of the entire area of the 200 mile zone they may need to consider changing from the traditional small, family owned vessels to larger, more sophisticated vessels capable of negotiating the far offshore areas. Thus it is important to understand the perceptions and evaluations of Maine commercial fishermen regarding the FCMA, as they are present at the actual working level of this plan, and can see how the regulations and policies are carried out. The Maine fishermen should thus provide valuable insight in the application, impact, and effectiveness of the Fisheries Conservation and Management Act of 1976. The main objective of the study reported here was to determine the perceptions, attitudes, and reactions of Maine commercial fishermen regarding extended jurisdiction and fishery management practices.https://digitalcommons.library.umaine.edu/aes_bulletin/1129/thumbnail.jp

Some Observations of the Boiling Point of Ternary Liquid Mixtures

An exposition of an apparatus for the determination of the boiling points of liquid mixtures under constant pressure, and the results of preliminary investigations upon ternary mixtures of some common organic liquids

Building a Better Mousetrap: Enhanced Dollar Cost Averaging

This paper presents a simple, intuitive investment strategy that improves upon the popular dollarcost- averaging (DCA) approach. The investment strategy, which we call enhanced dollar-costaveraging (EDCA), is a simple, rule-based strategy that retains most of the attributes of traditional DCA that are appealing to most investors but yet adjusts to new information, which traditional DCA does not. Simulation results show that the EDCA strategy reliably outperforms the DCA strategy in terms of higher dollar-weighted returns about 90% of the time and nearly always delivers greater terminal wealth for reasonable values of the risk premium. EDCA is most effective when applied to high volatility assets, when cash flows are highly sensitive to past returns, and during secular bear markets. Historical back-testing on equity indexes and mutual funds indicates that investor dollar-weighted returns can be enhanced by between 30 and 70 basis points per year simply by switching from DCA to EDCA

Electro-optical characterization of GaAs solar cells

The electro-optical characterization of gallium arsenide p/n solar cells is discussed. The objective is to identify and understand basic mechanisms which limit the performance of high efficiency gallium arsenide solar cells. The approach involves conducting photoresponse and temperature dependent current-voltage measurements, and interpretation of the data in terms of theory to determine key device parameters. Depth concentration profiles are also utilized in formulating a model to explain device performance

Internal Motions in Starless Dense Cores

This paper discusses the statistics of internal motions in starless dense cores and the relation of these motions to core density and evolution. Four spectral lines from three molecular species are analyzed from single-pointing and mapped observations of several tens of starless cores. Blue asymmetric profiles are dominant, indicating that inward motions are prevalent in sufficiently dense starless cores. These blue profiles are found to be more abundant, and their asymmetry is bluer, at core positions with stronger $\rm N_2H^+$ line emission or higher column density. Thirty three starless cores are classified into four types according to the blue and red shifts of the lines in their molecular line maps. Among these cores, contracting motions dominate: 19 are classified as contracting, 3 as oscillating, 3 as expanding, and 8 as static. Contracting cores have inward motions all over the core with predominance of those motions near the region of peak density. Cores with the bluest asymmetry tend to have greater column density than other cores and all five cores with peak column density $> \rm 6\times 10^{21} cm^{-2}$ are found to be contracting. This suggests that starless cores are likely to have contracting motions if they are sufficiently condensed. Our classification of the starless cores may indicate a sequence of core evolution in the sense that column density increases from static to contracting cores: the static cores in the earliest stage, the expanding and/or the oscillating cores in the next, and the contracting cores in the latest stage.Comment: Accepted for publication in The Astrophysical Journal, 34 pages, and 14 figure