The Cayun Builder and the Jiu-Jitsu Entrepreneur: A Narrative of the Making of an Entrepreneur in the Digital Age

This narrative describes the making of a German electrical engineer, Kurt Beyer, into a micro-entrepreneur. He set for himself the goal of sailing around the world in his own vessel – without being able to afford to buy such a ship. Many people in Germany have in recent years started to build their own sea-going vessels in order to escape from the creativity-stifling and restrictive patterns of their lives and work. Only a few of them have ever finished building their vessels. Firstly, this report describes the experiences of one of those few who have made it. Secondly, it tells the story of how this engineer himself turned into a micro-entrepreneur during the period of yacht-building and how later he started his own charter enterprise, centred around his yacht. Following the model of entrepreneurship described by Dassen-Housen in this issue of AI & Society, the narrative illustrates what it means to run such an enterprise in view of the international competition. Here follows the narrative of the engineer and ship-builder himself (translated by D. Brandt).     

Experimental and numerical analysis of sodium-carbonate salt gradient solar-pond performance under simulated solar-radiation

The objective of this study is to investigate experimentally and theoretically whether sodium carbonate (Na₂CO₃) salt is suitable for establishing a salinity gradient in a salt-gradient solar-pond (SGSP). For this purpose, a small-scale prismatic solar-pond was constructed. Experiments were conducted in the laboratory under the incident radiation from two halogen-lamps acting as a solar simulator. Furthermore, a one-dimensional transient mathematical model that describes the heat and mass transfer behaviour of the SGSP was developed. The differential equations obtained were solved numerically using a finite-difference method. It was found from the experiments that the density gradient, achieved using sodium carbonate salt, can suppress convection from the bottom to the surface of the pond.     

Effects of various phytase sources on phytic acid content,mineral extractability and protein digestibility of tarhana

Changes in phytic acid (PA), HCl-extractability (HCl-E) of some minerals and in vitro protein digestibility (IVPD) during the production of tarhana prepared with the addition of different phytase sources (bakers’ yeast, barley malt flour and microbial phytase) were investigated. PA content of tarhana decreased significantly (p < 0.01) after addition of the yeast, malt and phytase. With respect to wheat flour used as raw material, PA content of tarhana decreased by 95.3%. After tarhana production, average values of HCl-E of Ca, Mg, Zn and K, and also IVPD of tarhana increased up to 80.2%, 86.4%, 73.9% and 92.6%, and 91.9%, respectively. Significant negative correlation coefficients were found between the PA and HCl-E of the minerals, and also IVPD. Tarhana production processes, including fermentation, drying and grinding, were able to remove the antinutritional effects of PA. Each one of the phytase sources used alone decreased the PA content to a limited extend. The results show that tarhana has good potential in the total amounts and bioavailability of the minerals and proteins.     

Adolescents' theories about the development of their relationships with parents.

Assessed 100 undergraduates' developmental theories about their affective relationships with their parents, using a retrospective method. Ss used drawings and questionnaire ratings to portray their relationships with parents at 5 points between infancy and the present. From infancy to their current age, Ss portrayed their relationships in 2 major ways: They perceived themselves as gaining in responsibility, dominance, independence, and similarity from infancy to the present, whereas they portrayed their parents as experiencing a decline on these dimensions. For variables indicating closeness and love, however, there was a striking discontinuity in these linear trends: Although Ss perceived linear trends from infancy to adolescence, they depicted their current relationships as involving a great deal more love and closeness. They also portrayed their relationships with mothers and fathers somewhat differently. More responsibility was felt toward the mothers and they were portrayed as especially friendly, but Ss felt more similar to their fathers, whom they perceived as dominant. Results suggest that late adolescents construct theories of the affective components of their relationships with their parents to serve the needs of separation while maintaining a close affective tie to the parents. (24 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Zur Frage der Entstehung von Nitrosaminen bei der Reaktion von Monosacchariden mit Aminos?uren (Maillard-Reaktion)

Zusammeufassung Zur Überprüfung des Auftretens von Nitrosaminen [2] im Rahmen der Maillard-Reaktion wurden die flüchtigen Produkte verschiedener Glucose-Aminosäure-Modell-gemische durch Kombination von Gaschromatographie and Massenspektrometrie, Polarographie und Dünnschicht-Chromatographie untersucht. Das Auftreten von Nitrosaminen kann durch die Ergebnisse eindeutig ausgeschlossen werden.

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The problem of formation of nitrosamines by reacting monosaccharides with aminoacids (maillard-reaction)

Summary For proving the formation of nitrosamines applying maillardconditions [2] we tested the volatile reaction products of various glucose-aminoacid mixtures by coupling gas chromatography and mass spectrometry, polarography and thin-layer chromatography. The appearence of nitrosamines could undoubtedly be excluded according to the results.

     

Temperature gradients in the channels of a single‐screw extruder

We used a temperature‐sensitive fluorescent dye, perylene, to monitor the true resin temperature during extrusion of polycarbonate. The measurement involved doping polycarbonate with perylene and detecting fluorescence with an optical sensor that accesses a standard instrumentation port on a barrel of a single‐screw extruder. The sensor's confocal optics design permits fluorescence intensity measurements as a function of position. Using a previously established calibration function, temperature and temperature gradients were obtained from the measured fluorescence. Because the origin of the measurement is the fluorescent dye molecule that is soluble in the resin, this method allows temperature measurement of the polymer without interference from the surrounding metal parts. With the sensor looking over the screw, temperature profiles from the barrel wall to the core of the screw were obtained as a function of screw speed, screw design and resin melt flow rate. Polym. Eng. Sci. 44:2148–2157, 2004. © 2004 Society of Plastics Engineers.

1 This paper is a contribution from the National Institute of Standards and Technology, and, thus, is not subject to copyright in the United States.

     

Solid fuel combustion experiments in microgravity using a continuous fuel dispenser and related numerical simulations

The conventional way of determining the flammability characteristics of a material involves a number of tedious single-sample tests to distinguish flammable from non-flammable conditions. A novel test device and fuel configuration has been developed that permits multiple successive tests for indefinite lengths of thin solid materials. In this device, a spreading flame can be established and held at a fixed location in front of optimized diagnostics while continuous variations of test parameters are made. This device is especially well-suited to conducting experiments in space (e.g. aboard the International Space Station) where the limited resources of stowage, volume, and crew time pose major constraints. A prototype version of this device was tested successfully in both a normal gravity laboratory and during low-gravity aircraft trials. As part of this ongoing study of material flammability behavior, a numerical model of concurrent-flow flame spread is used to simulate the flame. Two and three-dimensional steady-state forms of the compressible Navier-Stokes equations with chemical reactions and gas and solid radiation are solved. The model is used to assist in the design of the test apparatus and to interpret the results of microgravity experiments. This paper describes details of the fuel testing device and planned experiment diagnostics. A special fuel, developed to optimize use of the special testing device, is described. Some results of the numerical flame spread model are presented to explain the three-dimensional nature of flames spreading in concurrent flow and to show how the model is used as an experiment design tool.     

Computer-assisted assessment of depression and function in older primary care patients

We wanted to test the psychometric reliability and validity of self-reported information on psychological and functional status gathered by computer in a sample of primary care outpatients. Persons aged 65 years and older visiting a primary care medical practice in Baltimore (n=240) were approached. Complete baseline data were obtained for 54 patients and 34 patients completed 1-week retest follow-up. Standard instruments were administered by computer and also given as paper and pencil tests. Test-retest reliability estimates were calculated and comparisons across mode of administration were made. Separately, an interviewer administered a questionnaire to gauge patient attitudes and feelings after using the computer. Most participants (72%) reported no previous computer use. Nevertheless, inter-method reliability of the GDS15 at baseline (0.719, n=47), intra-method reliability of the computer in time (0.797, n=31), inter-method reliability of the CESDR20 at baseline (0.740, n=53), and the correlation between the CESDR20 computer version at baseline and follow-up (0.849, n=34) were all excellent. The inter-method reliability of the CESDR20 at follow-up (0.615, n=37) was lower but still acceptable. Although 28% were anxious prior to using the computer testing system, that percent decreased to 19% while using the system. The efficiency and reliability in comparison to the paper instruments were good or better. Even though most participants had not ever used a computer prior to participating in the study, they had generally favorable attitudes toward the use of computers, and also reported having favorable experience with the computer testing system.     

Integrating Guidance into Relational Reinforcement Learning

Reinforcement learning, and Q-learning in particular, encounter two major problems when dealing with large state spaces. First, learning the Q-function in tabular form may be infeasible because of the excessive amount of memory needed to store the table, and because the Q-function only converges after each state has been visited multiple times. Second, rewards in the state space may be so sparse that with random exploration they will only be discovered extremely slowly. The first problem is often solved by learning a generalization of the encountered examples (e.g., using a neural net or decision tree). Relational reinforcement learning (RRL) is such an approach; it makes Q-learning feasible in structural domains by incorporating a relational learner into Q-learning. The problem of sparse rewards has not been addressed for RRL. This paper presents a solution based on the use of reasonable policies to provide guidance. Different types of policies and different strategies to supply guidance through these policies are discussed and evaluated experimentally in several relational domains to show the merits of the approach.