Effect of the structure of the elementary filaments on the tension of complex viscose yarns during drying

Conclusions The effect of the structure of the elementary filaments on the tension of a complex viscose yarn during drying has been investigated.It has been found that the tension of viscose yarn during drying under isometric conditions is increased with increase in the proportion of skin in a transverse section of the elementary filaments.Translated from Khimicheskie Volokna, No. 1, pp. 27–28, January–February, 1986.     

Management of temporomandibular disorders in a restorative practice

Various disorders related to the masticatory muscles or to the temporomandibular joints may be encountered in a restorative dental practice. Most of them can be managed by the restorative dentist whose primary interest may not lie in the area of temporomandibular disorders. The term temporomandibular disorders is used in this discussion to denote the group of diseases of the masticatory system that involves primarily the temporomandibular joints, the masticatory muscles, and the occlusion of the teeth. The learning objective of this article is to describe temporomandibular disorders encountered in general practice. Managing these disorders in the general practice of restorative dentistry is not difficult and adds to the comfort of the patient and possibly to the success of the restorations.     

Adding a temporal dimension to a logic system

We introduce a methodology whereby an arbitrary logic system L can be enriched with temporal features to create a new system T(L). The new system is constructed by combining L with a pure propositional temporal logic T (such as linear temporal logic with Since and Until) in a special way. We refer to this method as adding a temporal dimension to L or just temporalising L. We show that the logic system T(L) preserves several properties of the original temporal logic like soundness, completeness, decidability, conservativeness and separation over linear flows of time. We then focus on the temporalisation of first-order logic, and a comparison is make with other first-order approaches to the handling of time.     

Trial and error

A pac-learning algorithm isd-space bounded, if it stores at mostd examples from the sample at any time. We characterize thed-space learnable concept classes. For this purpose we introduce the compression parameter of a concept classb and design our Trial and Error Learning Algorithm. We show: b isd-space learnable if and only if the compression parameter ofb is at mostd. This learning algorithm does not produce a hypothesis consistent with the whole sample as previous approaches e.g. by Floyd, who presents consistent space bounded learning algorithms, but has to restrict herself to very special concept classes. On the other hand our algorithm needs large samples; the compression parameter appears as exponent in the sample size. We present several examples of polynomial time space bounded learnable concept classes:

- all intersection closed concept classes with finite VC-dimension.

- convexn-gons in ?².

- halfspaces in ?ⁿ.

- unions of triangles in ?².

We further relate the compression parameter to the VC-dimension, and discuss variants of this parameter.     

Some features of viscose yarn take-up on the package on machines of the PNSh type

Conclusions In unwinding a yarn from a package, tension increases from the outer winding layer to the inner ones; this occurs most sharply in unwinding the last 500–600 g of yarn.On increasing the yarn winding speed, tension rises, due to additional yarn friction on the package surface.On removal from the package, a yarn experiences periodic fluctuations in tension which vary both in amplitude and wavelength, both in unwinding a double layer and also in unwinding a single turn.Regardless of the form of yarn winding on packages, the tension in unwinding rises from the outer layers to the inner ones by a factor of 10.Translated from Khimicheskie Volokna, No. 4, pp. 32–35, July–August, 1986.     

Co-Training by Committee: A Generalized Framework for Semi-Supervised Learning with Committees

Many data mining applications have a large amount of data but labeling data is often di cult, expensive, or time consuming, as it requires human experts for annotation.Semi-supervised learning addresses this problem by using unlabeled data together with labeled data to improve the performance. Co-Training is a popular semi-supervised learning algorithm that has the assumptions that each example is represented by two or more redundantly su cient sets of features (views) and additionally these views are independent given the class. However, these assumptions are not satis ed in many real-world application domains. In this paper, a framework called Co-Training by Committee (CoBC) is proposed, in which an ensemble of diverse classi ers is used for semi-supervised learning that requires neither redundant and independent views nor di erent base learning algorithms. The framework is a general single-view semi-supervised learner that can be applied on any ensemble learner to build diverse committees. Experimental results of CoBC using Bagging, AdaBoost and the Random Subspace Method (RSM) as ensemble learners demonstrate that error diversity among classi ers leads to an e ective Co-Training style algorithm that maintains the diversity of the underlying ensemble.     

Development of microcrystalline silicon carbide window layers by hot-wire CVD and their applications in microcrystalline silicon thin film solar cells

Microcrystalline silicon carbide (μc-SiC:H) thin films in stoichiometric form were deposited from the gas mixture of monomethylsilane (MMS) and hydrogen by Hot-Wire Chemical Vapor Deposition (HWCVD). These films are highly conductive n-type. The optical gap E₀₄ is about 3.0-3.2 eV. Such μc-SiC:H window layers were successfully applied in n-side illuminated n-i-p microcrystalline silicon thin film solar cells. By increasing the absorber layer thickness from 1 to 2.5 μm, the short circuit current density (j_SC) increases from 23 to 26 mA/cm² with Ag back contacts. By applying highly reflective ZnO/Ag back contacts, j_SC = 29.6 mA/cm² and η = 9.6% were achieved in a cell with a 2-μm-thick absorber layer.     

Traceable laser power measurements of diode laser radiation in the near infrared

We report a new calibration setup for laser radiometry at the Physikalisch-Technische Bundesanstalt, the German National Metrology Institute. Measurements of laser diode power of free beam diode lasers in the near infrared spectral range at a wavelength of 808 nm for powers up to 250 W and at wavelengths of 915 nm, 940 nm, and 980 nm for laser powers up to 25 W have been established. The calibration setup, the standard detector, the uncertainty budget and first calibration results will be presented and discussed. The standard uncertainty of the HLR302 standard detector is 0.2%. This uncertainty might be the main contribution to the overall uncertainty in customer calibrations, depending on the quality of the transfer detectors.     

The effects of native and light induced defects on optoelectronic properties of hydrogenated amorphous silicon–germanium (a-SiGe:H) alloy thin films

Effects of native and light induced defects states in hydrogenated amorphous silicon–germanium alloy thin films with different Ge concentrations have been investigated by using steady-state photoconductivity, dual beam photoconductivity (DBP), transmission spectroscopy and photothermal deflection spectroscopy (PDS) techniques. In the annealed state, sub-bandgap absorption spectra obtained from both PDS and DBP overlap very well at energies above 1.4 eV. However, differences in α (hν) spectrum exist in the lower energy part of absorption spectrum. The α (hν) value measured at 1.0 eV is the lowest for 10% Ge sample and increases gradually as Ge content of the sample increases. In the light soaked state, time dependence of photoconductivity decay obeys to t ^−x power law, where x changes from 0.30 to 0.60 for samples with low Ge content and 0.05–0.1 for samples with high Ge content. Correspondingly, the increase of the sub-bandgap absorption coefficient at lower energies obeys to t ^y power law, where y values are lower than the x value of the same sample. It can be inferred that sub-bandgap absorption and photoconductivity measurements are not controlled by the same set of defects created in the bandgap of alloys.