Neuro-fuzzy knowledge processing in intelligent learning environments for improved student diagnosis

In this paper, a neural network implementation for a fuzzy logic-based model of the diagnostic process is proposed as a means to achieve accurate student diagnosis and updates of the student model in Intelligent Learning Environments. The neuro-fuzzy synergy allows the diagnostic model to some extent "imitate" teachers in diagnosing students' characteristics, and equips the intelligent learning environment with reasoning capabilities that can be further used to drive pedagogical decisions depending on the student learning style. The neuro-fuzzy implementation helps to encode both structured and non-structured teachers' knowledge: when teachers' reasoning is available and well defined, it can be encoded in the form of fuzzy rules; when teachers' reasoning is not well defined but is available through practical examples illustrating their experience, then the networks can be trained to represent this experience. The proposed approach has been tested in diagnosing aspects of student's learning style in a discovery-learning environment that aims to help students to construct the concepts of vectors in physics and mathematics. The diagnosis outcomes of the model have been compared against the recommendations of a group of five experienced teachers, and the results produced by two alternative soft computing methods. The results of our pilot study show that the neuro-fuzzy model successfully manages the inherent uncertainty of the diagnostic process; especially for marginal cases, i.e. where it is very difficult, even for human tutors, to diagnose and accurately evaluate students by directly synthesizing subjective and, some times, conflicting judgments

Advisor Choice in Asia-Pacific Property Markets

This paper examines advisor choice decisions by publicly traded REITs and listed property companies in Asia-Pacific real estate markets. Using a sample of 168 firms, we find robust evidence that firms strategically evaluate and compare the increased agency costs associated with external advisement against the potential benefits associated with collocating decision rights with location specific soft information. Our empirical results reveal real estate companies tend to hire external advisors when they invest in countries: 1) that are more economically and politically unstable, 2) whose legal system is based on civil law, 3) where the level of corruption is perceived to be high, and 4) when disclosure is relatively poor. Additionally, we find the probability of retaining an external advisor is directly related to the expected agency costs. Lastly, we find evidence of return premiums in excess of 13 % for firms whose organizational structure matches their investment profile. As such, we conclude that the decision to hire an external advisor represents a value relevant trade-off between the costs and benefits of this organizational arrangement

Capital Structure and Political Risk in Asia-Pacific Real Estate Markets

This study investigates the determinants of capital structure decisions by real estate firms, with a specific focus on the impact of political risk on leverage. Using a sample of Asia-Pacific REITs and listed property trusts, we find those firms with properties located in countries characterized by relatively high degrees of political risk, such as political instability, and/or greater uncertainty in the ability to repatriate and monetize profits from international investment activities, employ less debt than their counterparts operating in more politically stable environments. This core finding remains robust to alternative sample selection criteria including the division of the sample into high versus low market-to-book value firms, and also holds within the subset of organizations that are active in raising additional capital in the secondary markets

Observation of surface charge screening and Fermi level pinning on a synthetic, boron-doped diamond

Spectroscopic current-voltage (I-V) curves taken with a scanning tunneling microscope on a synthetic, boron-doped diamond single crystal indicate that the diamond, boiled in acid and baked to 500 °C in vacuum, does not exhibit ideal Schottky characteristics. These I-V curves taken in ultrahigh vacuum do not fit the traditional theory of thermionic emission; however, the deviation from ideal can be accounted for by charge screening at the diamond surface. At ambient pressure, the I-V curves have a sharp threshold voltage at 1.7 eV above the valence band edge indicating pinning of the Fermi energy. This measurement is in excellent agreement with the 1/3 band gap rule of Mead and Spitzer [Phys. Rev. 134, A713 (1964)]

Summary of Workshop to Review an OMB Report on Regulatory Risk Assessment and Management

Summary of the results of an invitational workshop conducted to peer review the 1990 OMB report, CURRENT REGULATORY ISSUES IN Risk ASSESSMENT AND Risk MANAGENMENTIN REGULATORY PROGRAM OF THE UNITED STATES GOVERNMENT, APRIL 1, 1990 - MARCH 31, 1991

The Impact of Geographic and Cultural Dispersion on Information Opacity

This paper investigates the influences of intrafirm geographic and cultural dispersion, the distance between the location of a firm’s investments and its headquarters, on the firm’s information environment. Specifically, using a sample of publicly traded real estate companies across the Asia-Pacific region, we examine how intrafirm geographic and cultural distance impacts a firm’s capital acquisition costs. As a consequence of both the heavily regulated operating environment faced by these firms, as well as the capital intensive nature of this industry, funding costs should be of pronounced importance to firms within this sector. Consistent with this paradigm, we find that firms with geographically disperse investments exhibit enhanced informational opacity. Specifically, firms with more geographically disperse investments exhibit higher capital acquisition costs than their more geographically concentrated counterparts. Similarly, firms with more culturally disparate investments also exhibit enhanced informational opacity, as evidenced by increased capital costs. Additionally, we present evidence that the impact of both physical and cultural distance is increasing following the global financial crisis. Taken together, our results provide strong evidence that both intrafirm geographic and cultural dispersion materially impact both an organization’s information environment and funding costs

Extrasolar Planets in the Classroom

The field of extrasolar planets is still, in comparison with other astrophysical topics, in its infancy. There have been about 300 or so extrasolar planets detected and their detection has been accomplished by various different techniques. Here we present a simple laboratory experiment to show how planets are detected using the transit technique. Following the simple analysis procedure describe we are able to determine the planetary radius to be 1.27 +/- 0.20 R_{J} which, within errors agrees with the establish value of 1.32 +/- 0.25 R_{J}.Comment: 7 pages, 2 figures, published in Physics Educatio