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Search Results: 1 - 10 of 297505 matches for " Jürgen; "
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Operator Splitting Method for Coupled Problems:Transport and Maxwell Equations  [PDF]
Jürgen Geiser
American Journal of Computational Mathematics (AJCM) , 2011, DOI: 10.4236/ajcm.2011.13019
Abstract: In this article a new approach is considered for implementing operator splitting methods for transport problems, influenced by electric fields. Our motivation came to model PE-CVD (plasma-enhanced chemical vapor deposition) processes, means the flow of species to a gas-phase, which are influenced by an electric field. Such a field we can model by wave equations. The main contributions are to improve the standard discretization schemes of each part of the coupling equation. So we discuss an improvement with implicit Runge- Kutta methods instead of the Yee’s algorithm. Further we balance the solver method between the Maxwell and Transport equation.
Development of a computer vision system to monitor pig locomotion  [PDF]
Jrgen Kongsro
Open Journal of Animal Sciences (OJAS) , 2013, DOI: 10.4236/ojas.2013.33038
Abstract: Avoiding lameness or leg weakness in pig production is crucial to reduce cost, improve animal welfare and meat quality. Detection of lameness detection by the use of vision systems may assist the farmer or breeder to obtain a more accurate and robust measurement of lameness. The paper presents a low-cost vision system for measuring the locomotion of moving pigs based on motion detection, frame-grabbing and multivariate image analysis. The first step is to set up a video system based on web camera technology and choose a test area. Secondly, a motion detection and data storage system are used to build a processing system of video data. The video data are analyzed measuring the properties of each image, stacking them for each animal and then analyze these stacks using multivariate image analysis. The system was able to obtain and decompose information from these stacks, where components could be extracted, representing a particular motion pattern. These components could be used to classify or score animals according to this pattern, which might be an indicator of lameness. However, further improvement is needed with respect to standardization of herding, test area and tracking of animals in order to have a robust system to be used in a farm environment.
The Motley World of “International Values”: Modes of Production on the World Market  [PDF]
Jrgen Sandemose
Theoretical Economics Letters (TEL) , 2016, DOI: 10.4236/tel.2016.63058
Abstract: I venture to describe the world market from the viewpoint of those different extant modes of production which deliver commodities in “foreign” trade. The world market is, then, understood strictly in its basic feature, as a market for material products, all called commodities. The term “exchange”, which has to be used with some indeterminacy to begin with, is explained in greater detail as I proceed. In this regard, the most important sections are nos. 2 and 3. The term “modes of production” will also be clarified in due place, and primarily in Sections 9 and 10. I find such a concept necessary for an adequate background description of the products which are poured onto any market. I primarily analyze the capitalist mode of production through the concept of intensity of labour (cf. 4 and 9), which plays a main role even in Marx’s theory of the “modifications” of the law of value on the world market. Also, I find what is often labelled “Karl Marx’s theory of international values” to be correct in its foundations, and I will take a point of departure in it—especially apparent in sections 1, 2 and 3. A target for criticism in this article is the modern mainstream theory of “factors of production” in so far as it is found feasible for an analysis of the movements on the world market. This is briefly done in Section 8. In Section 6, I consider David Ricardo’s theory of “comparative advantages” as a counter-example to that theory. I use some terrain to show that the real historical and social background of the economic functioning of the so-called “factors”—capital, land and labour—must be a measuring rod for whether a factor theory is viable or not. To do this, I depend (cf. again Sections 9 and 10) to a high degree of Marx’s theory of those factors considered as forms of organized class forces—a viewpoint which played a central role in his preparing of the three volumes of Capital. While the Marxian theory insofar is adequate, it is also useful in analyzing the aborted or undeveloped state of those modes of production which, beneath the advanced capitalist one, supply the world market with material products. This ought to become clear especially in Sections 10 and 11. As my text expands, I try to show how the said inconsistency in the Ricardian model is based on
On the Exposition of the Transformation of Commodity-Values into Production Prices in the Third Volume of Capital—A Textual Analysis  [PDF]
Jrgen Sandemose
Theoretical Economics Letters (TEL) , 2016, DOI: 10.4236/tel.2016.65098
Abstract: The article is about the exposition of the Karl Marx’s concept of production prices in his main work Capital. It focuses on the structure of the central text in question, Chapter 9 of the third volume, on “transformation [Verwandlung] of commodity-values into production prices”. The actual content and structure of the chapter has to some degree been overlooked or distorted in the literature. The aim of the article is to establish (or re-establish) a sound view of the chapter, freed from prejudices nurtured by—especially—a theory of price formation which, albeit “modernized” by i.a. Walras, dates back to Steuart and Ricardo. These prejudices have had an immense significance for misunderstandings of the Marxian theory of measure of value and standard of prices reflected in the text of the chapter mentioned. For this reason, the article is furnished with an Appendix, underlining the difficult situation for Marxist-minded research today. It should be noted that it is not an objective of the article to discuss any extant interpretation of Marx’s exposition. However, the paradigm of criticism that was introduced early in the 20th century by Ladislaus von Bortkiewicz is used as a perspective. Specific references—other than to Marx’s own texts—are held at a minimum in the article proper. I have chosen such a mode of approach because I find that misunderstandings of the chapter are evenly distributed among authors regardless of how their views on the “transformation” collide. On the other hand, such a consciousness of “misunderstandings” among commentators certainly does imply that the author should at least shortly clarify his own view of the main problems in the paradigmatic criticism mentioned above. In the first section, I point out the importance of Marx’s way of presenting his concept of the composition of capital. In the next, I make some remarks on the concept of the socially necessary labour time and its relation to abstract labour. In the third and fourth, I investigate Marx’s different models of analysis. In the fifth section, it will be shown how Marx, contrary to
Paradoxes, Self-Referentiality, and Hybrid Systems: A Constructive Approach  [PDF]
Jürgen Klüver
Open Journal of Philosophy (OJPP) , 2017, DOI: 10.4236/ojpp.2017.71004
Abstract:
Since the discovery of the paradoxes of self-referentiality or self-reference respectively logicians and mathematicians tried to avoid self-reference when constructing formal systems. Yet “real” complex systems like the mind are characterized by self-reference and can accordingly only be modeled by formal systems that are also basically self-referential. In this article I show that and how self-referential computer programs, understood as algorithmic formal systems, are not only possible but also since some time quite common in special branches of computer science. Examples for this argument are neural networks and so-called hybrid systems, i.e. combination of different sub systems. The hybrid system SOCAIN, a combination of a cellular automaton, a neural network and a genetic algorithm is an example for the fruitfulness of using self-reference in a systematic way. In particular, such systems consist of mutually dependent sub systems, i.e. form no static hierarchy.
Treatment of chronic vulvovaginal candidiasis with posaconazole and ciclopiroxolamine  [PDF]
Hans-Jürgen Tietz
Health (Health) , 2010, DOI: 10.4236/health.2010.26077
Abstract: Therapy of chronic recurrent vulvovaginal can- didiasis (VVC) caused by Candida glabrata is still rare in comparison to C. albicans infection, but therapy remains more difficult. Combination therapy with topical antifungals may improve therapy outcome, but still standard agents as fluconazole or itraconazole often fail. Posaconazole is a new systemic triazole with a wide antifungal spectrum including rare Candida species. Up to now, no clinical trials with posa- conazole in chronic recurrent VVC have been undertaken. Here, first results of the application of a new therapy regimen consisting of oral posaconazole in combination with topical ciclopiroxolamine are presented. 15 patients with chronic recurrent VVC caused by C. glabrata have been treated. 14 of these patients experienced successful therapy, clinical and mycological cure 30 days after begin of therapy has been observed. Long-term results are promising, as in 4 patients clinical and mycologic cure persists for more than 1 year up to now.
Periodic Signals of the Milky Way Concealed in Terrestrial Sedimentary Basin Fills and in Planetary Magmatism?  [PDF]
Heinz-Jürgen Brink
International Journal of Geosciences (IJG) , 2015, DOI: 10.4236/ijg.2015.68067
Abstract: Long periodic geodynamic processes with durations between 150 and 600 Million years appear to be in phase with similar galactic cycles, caused by the path of the solar system through the spiral arms of the Milky Way. This path is assumed by some authors to cause climate change due to cosmic ray fluctuations, affecting the cloud formation and the related albedo of the Earth, which periodically lead to glaciations every 150 Ma. With the glaciations, the sea level fluctuates accordingly. Subsequently, the varying sizes of shallow seas are causing periodic changes of the Moon’stidal dissipation, which affects presumably other geodynamic processes on the Earth. The Moonmay therefore synchronize directly or indirectly long periodic Phanerozoic cycles (sea level, orogeny, magmatism, sedimentation, etc.) with the Milky Way. As sea level fluctuations, orogeny, sedimentation and magmatism can be described as members of a geodynamic feedback system; no apparent reasons appear to be required to assign a cause of the cyclicity to agents outside of thegalactic-climatically synchronized Earth-Moon system. However, recent observations of youngvolcanism on the near Earth terrestrial planets may require a new understanding. Magmatic/volcanic episodes on Venus, Mars and Mercury as well as on the Earth’s Moon are apparently contemporaneous thermal events accompanying increased magmatic/volcanic activities on theEarth,following a 300 myr cycle. Therefore, a collateral galactic thermal source within the Milky Way
Magnesium intervention and blood pressure—A study on risk groups  [PDF]
Ragnar Rylander, Tommi Tallheden, Jürgen Vormann
Open Journal of Preventive Medicine (OJPM) , 2012, DOI: 10.4236/ojpm.2012.21004
Abstract: Hypothesis: Although mineral deficiency in particular magnesium is a known risk factor for cardiovascular disease intervention experiments with magnesium show only modest results. Previously published data suggest that there may be particular risk groups in the population. The study was undertaken to investigate if such risk groups could be identified. Experimental design: Subjects (n = 31) were 50 - 79 years old with no disease. The 24 hour urinary excretion of urea (proxy for acidity), magnesium, calcium, and potassium was measured at two week intervals, with and without intervention with mineral water. Intervention with mineral water comprised 75 mL daily, supplying 3.1 mmol Mg, 2.3 Ca, and 0.02 K. Major results: There was a significant relation between acidity and excretion of magnesium, calcium, and potassium, both at one occasion and regarding changes over time. Among subjects with a high secretion of urea there was an inverse relation between the excretion of magnesium and systolic blood pressure. After intervention with mineral water, there was a strong tendency to a decrease in the systolic blood pressure among those with an initial high excretion of urea and a low excretion of magnesium. Conclusions: The results demonstrate the importance of acid-base conditions for mineral homeostasis and suggest the presence of risk groups in the population, related either to a low intake or to a disorder in the reabsorbtion mechanisms. Mineral water decreased the systolic blood pressure in that particular risk group.
Small and Mid-Size Pump-Turbines with Variable Speed  [PDF]
Jürgen Krenn, Helmut Keck, Manfred Sallaberger
Energy and Power Engineering (EPE) , 2013, DOI: 10.4236/epe.2013.52A007
Abstract:

The stability of the grid is jeopardized with the large percentage of non-dispatchable renewables like wind power and also with increasing solar power. This creates various problems because these forms of energy are very volatile and difficult to predict. In most countries the in-feed of these sources must not be curtailed. In addition most of the renewables do not provide short circuit capacity and inertia in the same way as classical units and so further worsen the stability of the grid. The growing exploitation of wind and solar might be limited due to grid stability problems. In order to compensate those problems a large amount of reserve capacity is needed and therefore new technologies for electricity storage are required. Hydraulic pumped storage—the classical storage technology—has some disadvantages. These plants are in mountain regions often far away from wind farms. The distance to the wind farms mean additional loading for the already stressed grid and additional transmission losses. To compensate the very volatile wind energy, the pump input power should be varied continuously. This is so far only possible with variable speed units. Up to now double-fed asynchronous motor-generators are used which are rather expensive. In order to provide a solution for the described situation, ANDRITZ HYDRO has developed a new innovative concept of decentralized pump storage plants. Small standardized pump turbines are combined with a synchronous motor-generator and a full size converter which allows speed variation in pump and turbine mode over a wide range. These plants can be built locally close to wind farms and other sources to be balanced, allowing the increase of renewable energy without increasing the transmission line capacity. For the future smart grids this will be a key storage technology. This concept is reliable, innovative and more economic than other storage technologies.

In vivo prediction of intramuscular fat in pigs using computed tomography  [PDF]
Jrgen Kongsro, Eli Gjerlaug-Enger
Open Journal of Animal Sciences (OJAS) , 2013, DOI: 10.4236/ojas.2013.34048
Abstract:

One hundred and four pure-bred Norwegian Duroc boars were CT (computed tomography) scanned to predict the in vivo intramuscular fat percentage in the loin. The animals were slaughtered and the loin was cut commercially. A muscle sample of the m. Longissimus dorsi was sampled and analyzed by the use of near-infrared spectroscopy. Data from CT images were collected using an in-house MATLAB script. Calibration models were made using PLS (partial least square) regression, containing independent data from CT images and dependent data from near-infrared spectroscopy. The data set used for calibration was a subset of 72 animals. The calibration models were validated using a subset of 32 animals. Scaling of independent data and filtering using median filtering were tested to improve predictions. The results showed that CT is not a feasible method for in vivo prediction of intramuscular content in swine.

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