226,460 research outputs found
Trying again to fail-first
No full textFor constraint satisfaction problems (CSPs), Haralick and Elliott [1] introduced the Fail-First Principle and defined in it terms of minimizing branch depth. By devising a range of variable ordering heuristics, each in turn trying harder to fail first, Smith and Grant [2] showed that adherence to this strategy does not guarantee reduction in search effort. The present work builds on Smith and Grant. It benefits from the development of a new framework for characterizing heuristic performance that defines two policies, one concerned with enhancing the likelihood of correctly extending a partial solution, the other with minimizing the effort to prove insolubility. The Fail-First Principle can be restated as calling for adherence to the second, fail-first policy, while discounting the other, promise policy. Our work corrects some deficiencies in the work of Smith and Grant, and goes on to confirm their finding that the Fail-First Principle, as originally defined, is insufficient. We then show that adherence to the fail-first policy must be measured in terms of size of insoluble subtrees, not branch depth. We also show that for soluble problems, both policies must be considered in evaluating heuristic performance. Hence, even in its proper form the Fail-First Principle is insufficient. We also show that the “FF” series of heuristics devised by Smith and Grant is a powerful tool for evaluating heuristic performance, including the subtle relations between heuristic features and adherence to a policy
Protective effect of resveratrol against renal oxidative stress in cholestasis
No full textThis experimental study was designed to evaluate histological changes of the kidney and renal tissue levels of malondialdehyde (MDA), reduced glutathione (GSH), and nitric oxide (NO) and the effect of resveratrol on these metabolites after bile duct ligation in rats. Methods. Secondary biliary cirrhosis was induced by bile duct ligation for 28 days. Swiss albino rats were divided into three groups. Group 1: Sham (n = 7), Group 2: Bile duct ligation (n = 7), Group 3: Bile duct ligation plus resveratrol (n = 7). Bile duct ligation (BDL) plus resveratrol group received 10 mgr/kg dose of resveratrol intraperitoneally daily throughout 28 days. Kidney tissues were harvested to determine the tissue levels of MDA, GSH, and NO activity. Liver and kidney tissues were removed for light microscopic evaluation. Results. Cholestasis was determined by biochemical and pathologic examination. In the resveratrol-treated rats, levels of MDA were significantly lower than those of the BDL group (p < 0.04). The levels of GSH in the resveratrol-treated rats were significantly higher than those in the BDL group (p < 0.01). The levels of NO in the resveratrol group were significantly lower than those in the BDL group (p < 0.01). Conclusion. The present study demonstrates that intraperitoneal administration of resveratrol in bile duct ligated rats maintains antioxidant defenses and reduces kidney oxidative damage. This effect of resveratrol may be useful in the preservation of renal oxidative stress in cholestasis
Banking in Japan: Will "Too Big To Fail" Prevail?
No full textThis paper reviews the evolution of the Japanese banking sector and the development of the banking crisis in Japan in the context of "too big to fail." It describes the deterioration of the Japanese financial sector caused by the bad loan problems and the failure of policymakers to get a grip on the underlying problems. Even at the start of the new century, Japanese policymakers still continue to struggle to find the right policy response to tackle the banking problems and how to avoid moral hazard behavior intertwined with "too big to fail" concerns. The increasing concentration in the Japanese banking industry, which is now dominated by five huge financial conglomerates, should make it more difficult to definitely end "too big to fail" in Japanese prudential policy. In this respect, we believe that the "too big to fail" policy in Japan will prevail.Too big to fail, Banking crisis, Japan
How much did banks pay to become too-big-to-fail and to become systematically important?
No full textThis paper estimates the value of the too-big-to-fail (TBTF) subsidy. Using data from the merger boom of 1991-2004, the authors find that banking organizations were willing to pay an added premium for mergers that would put them over the asset sizes that are commonly viewed as the thresholds for being TBTF. They estimate at least 100 billion in assets. In addition, the authors find that both the stock and bond markets reacted positively to these TBTF merger deals. Their estimated TBTF subsidy is large enough to create serious concern, particularly since the recently assisted mergers have effectively allowed for TBTF banking organizations to become even bigger and for nonbanks to become part of TBTF banking organizations, thus extending the TBTF subsidy beyond banking.Bank mergers
Damage Tolerance and Fail Safety of Welded Aircraft Wing Panels
No full textAn investigation is presented on fatigue crack growth behavior and fail safety
of integral stringer panels typified by welded aircraft fabrications. The
stringer panel is made of aluminum alloy 2024-T351 and fabricated by the
variable-polarity plasma-arc welding process. The sample simulates a part of the
lower-wing skin structures. Based on the linear elastic fracture mechanics,
numerical simulations are performed for two configurations, two-stringer and
nine-stringer panels, and three damage scenarios, in which welding-induced
longitudinal residual stresses are taken into account. A typical load spectrum
for large transport aircraft is employed for the analysis. For the two-stringer
panel life predictions have a reasonably good correlation with the test results.
Based on this validation, large-scale nine-stringer panels with three
manufacture options, that is, riveted, integrally machined, and welded integral,
are simulated for a skin crack under a broken central stringer propagating to
two-bay length. Useful comparisons are made among the three variants. Finally,
remedies to improve damage tolerance and fail safety of integral stringer panels
are explored. The incorporation of crack retarder straps bonded to the inner
surface of an integral panel has greatly improved the fail safety behavior of
the component with dramatically increased crack growth live
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Ending "Too Big To Fail": Government Promises vs. Investor Perceptions
No full textCan a government credibly promise not to bailout firms whose failure would have major negative systemic consequences? Our analysis of Korea's 1997-99 crisis, suggests an answer: No. Despite a general "no bailout" policy during the crisis, the largest Korean corporate groups (chaebol) – facing severe financial and governance problems – could still borrow heavily from households through issuing bonds at prices implying very low expected default risk. The evidence suggests "too big to fail" beliefs were not eliminated by government promises, presumably because investors believed that this policy was not time consistent. Subsequent government handling of potential and actual defaults by Daewoo and Hyundai confirmed the market view that creditors would be protected.
Are failproof banking systems feasible? Desirable?
No full textIn recent years, instability of the banking system has returned as a major problem in many countries, particularly in the developing world. In many cases, this instability has been so threatening to financial intermediation and the functioning of the payments system that governments have felt compelled to intervene and restructure banks, often at considerable cost to the public budget. One response to these problems has been a proposal to create failproof banking systems - to radically transform the structure, priorities, and operation of the banking and financial system. Banks would be limited to issuing deposits, holding essentially riskless portfolios, and operating the payments system. To minimize the resulting disruptions to the financial system, banks would be authorized (and encouraged) to set up holding companies and then transfer to holding company affiliates all the functions - including lending - that banks would no longer be permitted to perform. So while the failproof banking proposal would severely restrict the activity of banks, it would not restrict the activities of banking organizations that convert to a holding company form of organization. This proposal would produce major public benefits. It would assure a nation of a smoothly functioning banking and payments system, would substantially reduce the resources committed to banking supervision, would prevent bank-type regulation from expanding to the rest of the financial system, and would place banking and nonbanking organizations on a level playing field for the financial activities in which they compete. There are two major problems with the proposal. First, it might be difficult to implement because of too few riskless assets in a nation's financial system. (The author suggests several modifications that would alleviate this problem in some countries.) Second, the proposal might hurt the financial market by: (a) increasing interest rates for higher-risk borrowers, forcing them out of the market; and (b) transfering greater risk to the nonbank sector of the financial system, making it more susceptible to crisis. Although the proposal would benefit developing countries (more prone to banking instability) more than industrial countries, it would also be more difficult to implement in developing countries. And the adverse effects of the proposal would be felt more severely in the financial markets of developing countries than in industrial countries, which have deeper, more responsive financial markets.Banks&Banking Reform,Financial Intermediation,Financial Crisis Management&Restructuring,Banking Law,Settlement of Investment Disputes
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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