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  • 1
    Electronic Resource
    Electronic Resource
    The importance of attribute selection measures in decision tree induction (1994)
    Springer
    Machine learning 15 (1994), S. 25-41 
    Details
    ISSN: 0885-6125
    Keywords: decision trees ; noisy data ; induction ; attribute selection
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract Recent work by Mingers and by Buntine and Niblett on the performance of various attribute selection measures has addressed the topic of random selection of attributes in the construction of decision trees. This article is concerned with the mechanisms underlying the relative performance of conventional and random attribute selection measures. The three experiments reported here employed synthetic data sets, constructed so as to have the precise properties required to test specific hypotheses. The principal underlying idea was that the performance decrement typical of random attribute selection is due to two factors. First, there is a greater chance that informative attributes will be omitted from the subset selected for the final tree. Second, there is a greater risk of overfitting, which is caused by attributes of little or no value in discriminating between classes being “locked in” to the tree structure, near the root. The first experiment showed that the performance decrement increased with the number of available pure-noise attributes. The second experiment indicated that there was little decrement when all the attributes were of equal importance in discriminating between classes. The third experiment showed that a rather greater performance decrement (than in the second experiment) could be expected if the attributes were all informative, but to different degrees.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01000407
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  • 2
    Electronic Resource
    Electronic Resource
    Focusing of multiply charged energetic ions using solenoidal B and radial E lenses (1987)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 58 (1987), S. 220-222 
    Details
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: Several large-solid-angle devices for collecting, at a common focus, multiply charged heavy ions from nuclear reactions have been studied. These devices use axial magnetic fields (solenoids), radial electric fields (coaxial lenses), or a combination of these. Although each system has particular advantages and disadvantages, several designs appear promising for use as practical devices.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1139311
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    Paper (German National Licenses)
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  • 3
    Electronic Resource
    Electronic Resource
    Tests of a large air-core superconducting solenoid as a nuclear-reaction-product spectrometer (1987)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 58 (1987), S. 1682-1693 
    Details
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: An air-core superconducting solenoid, with a diameter of 0.2 m and a length of 0.4 m, has been configured for use as a heavy-ion reaction-product spectrometer (E/A≤5 MeV/u) near θ=0 °. The spectrometer has a large solid angle (10–35 msr) and properties suitable for time-of-flight measurements with flight paths (approximately-greater-than) 2 m. The performance of the spectrometer was established using α-particle sources and nuclear-reaction products from heavy-ion collisions. The characteristics of air-core magnets are compared to those of steel-yoke magnets. The simplicity and ease of operation of the air-core magnet, without significant problems from the (axial) fringe fields, suggests that larger air-core magnets with dΩ≥20 msr and capable of focusing ions with E/A≥30 MeV/u are feasible. Other applications of solenoids and combinations of solenoids with radial electric-field lenses (ELCO lenses) are also discussed, including designs which focus more than one charge state simultaneously.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1139368
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  • 4
    Electronic Resource
    Electronic Resource
    Large-aperture, axially symmetric ion-optical lens systems using new types of electrostatic and magnetic elements (1989)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 60 (1989), S. 1228-1232 
    Details
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: We have developed new types of ion-optical systems having larger solid angles (i.e., collecting power) and flexibility than many existing designs. They use relatively simple axially symmetric elements, namely solenoids, axial magnetic dipoles, and radial electric field lenses. The systems can focus, with good optical properties, energetic ions in the range of tens of keV up to tens of MeV kinetic energy and are capable of operating in nondispersive, achromatic modes. The key elements for the latter are new types of defocusing magnetic and electrostatic correction lenses. The lens systems have applications in any existing devices used to collect and focus energetic ions (including electrons). Typical devices are: mass spectrometers, leak detectors and gas analyzers, ion sources, accelerators and ion implantation systems, nuclear particle spectrometers, electron microscopes, ion microprobes, and ion-beam lenses for cancer therapy.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1140295
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  • 5
    Electronic Resource
    Electronic Resource
    A multicentre study on eradication of Helicobacter pylori using four 1-week triple therapies in China (2001)
    Oxford UK : Blackwell Science Ltd
    Alimentary pharmacology & therapeutics 15 (2001), S. 0 
    Details
    ISSN: 1365-2036
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Short-term proton pump inhibitor-based triple therapies for the eradication of Helicobacter pylori are used widely. The eradication rates vary greatly from country to country and from region to region.〈section xml:id="abs1-2"〉〈title type="main"〉Aim:To assess the efficacy at eradicating H. pylori of 1-week regimens containing three medications: omeprazole (O) or colloidal bismuth subcitrate (B), furazolidone (F) or metronidazole (M), and amoxicillin (A) or clarithromycin (C).〈section xml:id="abs1-3"〉〈title type="main"〉Methods:A multicentre study involving 20 hospitals in different regions of China. A total of 892 patients with H. pylori-positive non-ulcer dyspepsia or healed duodenal ulcer confirmed by endoscopy were recruited to receive, randomly, one of four regimens: OMC, OFC, OFA, and BFC, b.d. for 7 days. 13C-urea breath test was performed 4–8 weeks after completion of treatment.〈section xml:id="abs1-4"〉〈title type="main"〉Results:The eradication rates with per protocol/intention-to-treat analyses were: OMC (n=217/219) 66%/65%; OFC (n=227/229) 69%/69%; OFA (n=223/225) 87%/86%; and BFC (n=214/219) 80%/78%. The eradication rate (per protocol analysis) in duodenal ulcer (79%) was higher than that in non-ulcer dyspepsia (73%, P=0.033). Patient compliance was good. The adverse events of the four regimens were mild, and mainly gastrointestinal.〈section xml:id="abs1-5"〉〈title type="main"〉Conclusions:The omeprazole, furazolidine and amoxicillin regimen achieves a high H. pylori eradication rate in different geographical regions of China.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1365-2036.2001.00895.x
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  • 6
    Electronic Resource
    Electronic Resource
    Superstitious learning and induction (1995)
    Springer
    Artificial intelligence review 9 (1995), S. 3-18 
    Details
    ISSN: 1573-7462
    Keywords: induction ; superstition ; learning ; behaviourism ; obsessive-compulsive disorder
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract The behaviourist perspective on superstition is explained and an analogy is drawn between superstitious behaviour and the phenomenon of excessive branching in tree-based inductive learning algorithms operating under uncertainty. The argument is then extended to include cognitive aspects of learning and superstition. Further analogies are made with obsessive-compulsive disorder. Ways in which these phenomena might be simulated are indicated.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00857651
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