Formal description, compression and transformation of digital pictures

This paper describes the application of vector spaces over Galois fields, for obtaining a formal description of a picture in the form of a very compact, non-redundant, unique syntactic code. Two different methods of encoding are described. Both these methods consist in identifying the given picture as a matrix (called picture matrix) over a finite field. In the first method, the eigenvalues and eigenvectors of this matrix are obtained. The eigenvector expansion theorem is then used to reconstruct the original matrix. If several of the eigenvalues happen to be zero this scheme results in a considerable compression. In the second method, the picture matrix is reduced to a primitive diagonal form (Hermite canonical form) by elementary row and column transformations. These sequences of elementary transformations constitute a unique and unambiguous syntactic code-called Hermite code—for reconstructing the picture from the primitive diagonal matrix. A good compression of the picture results, if the rank of the matrix is considerably lower than its order. An important aspect of this code is that it preserves the neighbourhood relations in the picture and the primitive remains invariant under translation, rotation, reflection, enlargement and replication. It is also possible to derive the codes for these transformed pictures from the Hermite code of the original picture by simple algebraic manipulation. This code will find extensive applications in picture compression, storage, retrieval, transmission and in designing pattern recognition and artificial intelligence systems.

Boosting the productivity and profitability of northern Australian beef enterprises: Exploring innovation options using simulation modelling and systems analysis

The financial health of beef cattle enterprises in northern Australia has declined markedly over the last decade due to an escalation in production and marketing costs and a real decline in beef prices. Historically, gains in animal productivity have offset the effect of declining terms of trade on farm incomes. This raises the question of whether future productivity improvements can remain a key path for lifting enterprise profitability sufficient to ensure that the industry remains economically viable over the longer term. The key objective of this study was to assess the production and financial implications for north Australian beef enterprises of a range of technology interventions (development scenarios), including genetic gain in cattle, nutrient supplementation, and alteration of the feed base through introduced pastures and forage crops, across a variety of natural environments. To achieve this objective a beef systems model was developed that is capable of simulating livestock production at the enterprise level, including reproduction, growth and mortality, based on energy and protein supply from natural C4 pastures that are subject to high inter-annual climate variability. Comparisons between simulation outputs and enterprise performance data in three case study regions suggested that the simulation model (the Northern Australia Beef Systems Analyser) can adequately represent the performance beef cattle enterprises in northern Australia. Testing of a range of development scenarios suggested that the application of individual technologies can substantially lift productivity and profitability, especially where the entire feedbase was altered through legume augmentation. The simultaneous implementation of multiple technologies that provide benefits to different aspects of animal productivity resulted in the greatest increases in cattle productivity and enterprise profitability, with projected weaning rates increasing by 25%, liveweight gain by 40% and net profit by 150% above current baseline levels, although gains of this magnitude might not necessarily be realised in practice. While there were slight increases in total methane output from these development scenarios, the methane emissions per kg of beef produced were reduced by 20% in scenarios with higher productivity gain. Combinations of technologies or innovative practices applied in a systematic and integrated fashion thus offer scope for providing the productivity and profitability gains necessary to maintain viable beef enterprises in northern Australia into the future.

Dynamic Instabilities in Slender Space Launch Vehicles under Propulsive Thrust and Aerodynamic Forces

A mechanics based linear analysis of the problem of dynamic instabilities in slender space launch vehicles is undertaken. The flexible body dynamics of the moving vehicle is studied in an inertial frame of reference, including velocity induced curvature effects, which have not been considered so far in the published literature. Coupling among the rigid-body modes, the longitudinal vibrational modes and the transverse vibrational modes due to asymmetric lifting-body cross-section are considered. The model also incorporates the effects of aerodynamic forces and the propulsive thrust of the vehicle. The effects of the coupling between the combustion process (mass variation, developed thrust etc.) and the variables involved in the flexible body dynamics (displacements and velocities) are clearly brought out. The model is one-dimensional, and it can be employed to idealised slender vehicles with complex shapes. Computer simulations are carried out using a standard eigenvalue problem within h-p finite element modelling framework. Stability regimes for a vehicle subjected to propulsive thrust are validated by comparing the results from published literature. Numerical simulations are carried out for a representative vehicle to determine the instability regimes with vehicle speed and propulsive thrust as the parameters. The phenomena of static instability (divergence) and dynamic instability (flutter) are observed. The results at low Mach number match closely with the results obtained from previous models published in the literature.

The new binary pulsar and the observation of gravitational spin precession

The possibility of observing gravitational spin precession due to spin-orbit coupling in a binary pulsar system is considered. An analysis is presented which can aid in delineating the relevant physical effects from pulse-structure data. In this analysis, it is assumed that the pulsar radiation emanates from a cone whose axis is tilted with respect to the axis of rotation. It is found that the time-averaged pulse width and polarization sweep vary periodically with time and that this variation has a periodicity of the order of the spin-precession frequency averaged over a complete revolution. It is concluded that for an orbital period of about 180 years, it suffices to measure polarization data with an accuracy of a few parts in 100 over a period of six months to a year in order to uncover the effects of spin precession. The consistency of the analysis is checked, and the calculations are applied to a recently discovered binary pulsar.

Die Ahnentafel der Klara Saar : Ein Versuch zur jüdischen Genealogie /

The family tree of Klara Saar: An essay about Jewish genealogy by Dr. Peter Trawnicek

Kehottomat sielut ja reinkarnaatio Filonin ajattelussa

Egyptin Aleksandriassa ajanlaskun taitteen molemmin puolin elänyt hellenistijuutalainen raamattufilosofi Filon korostaa laajassa tuotannossaan, että ihmisen on suuntauduttava pois kehon, aistinautintojen ja paheiden orjuudesta kohti hyveitä, oikeaa filosofiaa ja pelastusta: sielun transsendenttia päämäärää, Jumalaa. Filon selittää heprealaista Raamattua - lähinnä Tooraa - vertauskuvallisen menetelmän ja kreikkalaisen, etenkin Platonin, filosofian avulla. Filon samaistaa toisiinsa ihmisyksilön henkisen olemuspuolen eli sielun (????) tai mielen (????) ja alkuperäisen, Jumalan kuvan mukaan luodun ihmisen. Ihmisen sielu on Filoninin raamatunselityksessä olemassa ennen kuin se laskeutuu ihmiskehoon, ja sen on aktiivisesti pyrittävä vapautumaan tuosta "vankilastaan" tai "haudastaan" noustakseen jälleen taivaalliseen alkutilaansa. Tämä vastaa läheisesti Platonin etenkin dialogeissaan Faidros ja Timaios esittämää skeemaa, ja myös sanastolliset yhteydet Platoniin ovat merkittäviä. Filon on kuitenkin myös muokannut tämän suuresti arvostamansa filosofin ajatuksia esimerkiksi korostamalla Jumalan armon merkitystä ihmisen pelastumiselle. Ihmisen keho-vankeuden juuret juontavat Filon ajattelussa ensimmäisen maallisen ihmisen lankeemuksesta, jota - kuten paheellista elämää yleisemminkin - hän luonnehtii sielun kuolemaksi. Nautinto vietteli mielen aistien välityksellä, ja ihminen vaihtoi kuolemattomuutensa kuolevaiselämään kehossa. Vaihtokauppa on kuitenkin mahdollista purkaa ja kehosta vähittäin vapautua. Platonilla sielut reinkarnoituvat maan päälle, kunnes ne kykenevät lopullisesti jättämään kehon taakseen. Reinkarnoituminen johtuu yhtäältä sielujen maallista kohtaan tuntemasta vetovoimasta. Toisaalta on kyse paheellisen elämän pitkittämästä rangaistuksesta, jonka alkuperäinen syy Faidroksessa esitetyssä vertauksessa on taitamattomuus taivaallisessa, Zeuksen johtamassa valjakkoajelussa. Lopulta sielut kykenevät kasvattamaan siivet ja nousemaan takaisin taivaaseen. Ne voivat nopeuttaa prosessia suuntautumalla pois ruumiillisista asioista oikeanlaiseen filosofiaan. Filon mainitsee reinkarnaation suoraan vain muutaman kerran koko tuotannossaan. Unien selittämistä koskevan teoksensa De somniis kohdassa 1.138-1.139 hän tuo sen esiin kaikkein selvimmin: kehoista fyysisessä kuolemassa vapautuneista sieluista "yhdet kuolevaiselämän tavanomaisuuksia kaivaten palaavat takaisin". Exodusta selittävän Quaestiones in Exodum -teoksensa kohdassa 2.40 hän puolestaan kuvaa sieluja, joiden ei onnistu nousta taivaan tuolle puolen, Jumalaan: "siipien vähän matkaa niitä kannettua [ne] palaavat heti"; toisille se Jumalan armosta onnistuu: "Onnellisia ovat ne, jotka eivät palaa." Lisäksi teoksen De cherubim kohtaan 114 sisältyy mahdollinen viittaus reinkarnaatioon, maininta kuoleman jälkeen aineettomaan tilaan päätyneiden sielujen rientämisestä "uuteen syntymään". Tutkimuskirjallisuudessa ei reinkarnaatioteema ole saanut osakseen kovin suurta huomiota. Useat tutkijat sivuuttavat aiheen. Jotkut suhtautuvat Filonin reinkarnaatiouskoon epäillen ja jotkut jopa kiistävät sen, mutta näiden tutkijoiden perustelut joko puuttuvat kokonaan tai eivät kestä lähempää tarkastelua. Löytämistäni kannanotoista suuri enemmistö on sillä kannalla, että usko ihmissielun paluuseen maan päälle uuteen kehoon todellakin kuului Filonin ajatteluun. Sen lisäksi, että Filon mainitsee asian suoraan joitain kertoja, reinkarnaatio on myös loogisesti ottaen välttämätön osa hänen ajatteluaan: ihmisen tulee vapautua kehostaan, mutta Filon tekee selväksi, ettei kyse ole fyysisen kuoleman tavoittelusta.

Critical behaviour of electrical resistivity in 5 binary liquid systems

For five binary liquid systems CS2+CH3CN, CS2+CH3NO2, CS2+(CH3CO)2O, C6H12+(CH3CO)2O, n-C7H16+(CH3CO)2O, the electrical resistance has been measured near the critical solution temperatures. The behaviour is universal. Below Tc, the conductivities of the two phases follow σ1−σ2 β, where = T−Tc Tc with β≈0.35. In the one phase region with b≈0.35±0.1 and is positive in some cases and negative in others.

On the computation of two-dimensional compressible flow fields by the modified local stability scheme

The modified local stability scheme is applied to several two-dimensional problems—blunt body flow, regular reflection of a shock and lambda shock. The resolution of the flow features obtained by the modified local stability scheme is found to be better than that achieved by the other first order schemes and almost identical to that achieved by the second order schemes incorporating artificial viscosity. The scheme is easy for coding, consumes moderate amount of computer storage and time. The scheme can be advantageously used in place of second order schemes.

High pressure clamp for electrical measurements up to 8 GPa and temperature down to 77 K

A compact clamp-type high pressure cell for carrying out electrical conductivity measurements on small solid samples of size 1 mm or less at pressures upto 8 GPa (i.e., 80 kbar) and for use down to 77 K has been designed and fabricated. The pressure generated in the sample region has been calibrated at room temperature against the polymorphic phase transitions of Bismuth and Ytterbium. The pressure relaxation of the clamp at low temperatures has been estimated by monitoring the electrical conductivity behavior of lead. Review of Scientific Instruments is copyrighted by The American Institute of Physics.

An NAD(P)(+)-dependent secondary-alcohol dehydrogenase of Alcaligenes eutrophus: Purification, characterization and its application for the production of chiral alcohols

A soil micro-organism identified as Alcaligenes eutrophus capable of utilizing nerolidol, a sesquiterpene alcohol as the sole source of carbon, contains an inducible NAD(P)(+)-linked secondary-alcohol dehydrogenase (SADH), The enzyme was purified 252-fold from crude cell-free extract by a combination of salt precipitation, ion-exchange and affinity-matrix chromatography, Native and SDS/PAGE PAGE of the purified enzyme showed a single protein band and the enzyme appears to be a homotetramer having an apparent molecular mass of 139 kDa comprising four identical subunits of 38.5 kDa, The isoelectric point (pi) of SADH was determined to be 6.2, Depending on pH of the reaction media, the enzyme carried out both oxidation and reductions of various terpenoids and steroids, At pH 5.5, the enzyme catalysed the stereospecific reduction of prochiral ketones to optically active (S)-alcohols and the oxidation reaction was predominated over the former at pH 9.5, NADP(+) and NADPH were respectively preferred over NAD(+) and NADH for oxidation and reduction reactions, The K-m values for testosterone, NADP(+) and NAD(+) were 11.8, 55.6, and 122 mu M respectively, Neither enzyme was significantly inhibited by metal-binding agents, but some thiol-blocking compounds inhibited it, SADH tolerates moderate concentrations of water-miscible organic solvents such as ethanol, methanol, acetone and dioxan, Some of the properties of this enzyme were found to be significantly different from those thus far described.

Firing delay scheme for 3-Ï thyristor converters

A simple firing delay circuit for 3-φ fully controlled bridge using a phase locked loop is described. The circuit uses very few components and is an improved scheme over the existing methods. The use of this circuit in three-phase thyristor converters and 'circulating current free' mode dual converters is described.

Understanding teachers: The potential and possibility of discourse analysis

Understanding the ways in which teachers make sense of what they do and why is critical to a broader understanding of pedagogy. Historically, teachers have been understood through the thematic and content analysis of their beliefs or philosophies. In this paper, we argue that discourse analysis (DA) involves a much finer-grained analysis of the ‘lifeworlds’ of teachers and, in our view, provides a more detailed canvas from which inferences can be made. Our argument is structured in four parts. We begin by locating DA within the physical education (PE) literature and discuss what others have referred to as its relatively modest use. Following our location of DA, we outline a conceptual framework that we regard as useful, which contains six interrelated principles. We then introduce the idea of interpretive repertoires, which we consider to have particular explanatory power as well as being a sophisticated way to represent the subjectivities of PE teachers. Finally, we discuss the methodological strengths of interpretive repertoires. The paper concludes with a discussion on the theoretical and practical merits of adopting DA to analyse problems within PE.

Influence of Temperature and High Electric Field on Power Consumption by Piezoelectric Actuated Integrated Structure

The influence of electric field and temperature on power consumption of piezoelectric actuated integrated structure is studied by using a single degree of freedom mass-spring-damper system model coupled with a piezoactuator. The material lead zirconate titanate, is considered as it is capable of producing relatively high strains (e.g., 3000 mu epsilon). Actuators are often subject to high electric fields to increase the induced strain produced, resulting in field dependant piezoelectric coefficient d(31), dielectric coefficient epsilon(33) and dissipation factor delta. Piezostructures are also likely to be used across a wide range of temperatures in aerospace and undersea operations. Again, the piezoelectric properties can vary with temperature. Recent experimental studies by physics researchers have looked at the effect of high electric field and temperature on piezoelectric properties. These properties are used together with an impedance based power consumption model. Results show that including the nonlinear variation of dielectric permittivity and dissipation factor with electric field is important. Temperature dependence of the dielectric constant also should be considered.

Purification and some of the properties of a novel secondary alcohol dehydrogenase from Alcaligenes eutrophus

Alcaligenes eutrophus utilizing nerolidol, a sesquiterpene alcohol,as the sole source of carbon contains an inducible NAD(P)+-linked secondary alcohol dehydrogenase (SADH). The enzyme was purified to homogeneity by a combination of salt precipitation, ion exchange and affinity matri chromatographies. The apparent molecular mass of the enzyme was estimated to be 139 KDa with four identical subunits of 38.5 KDa. The enzyme carried out both oxidation and reduction reactions. At pH 5.5, enzyme catalyzed the stereospecific reduction of prochiral ketones to secondary alcohols. The pH optimum for the oxidation reaction was 9.5. NADP+ and NADPH were respectively preferred over NAD+ and NADH for oxidation and reduction reactions. Some of the properties of this enzyme were found to be significantly different from those thus far described.