bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis and Approximated Crystal and Electronic Structure of a Proposed New Tantalum Oxide Nitride Ta3O6N
Authors: Nakhal Suliman , Lumey Marck‐Willem , Bredow Thomas , Dronskowski Richard , Lerch Martin
Published: March 2010

In the quasibinary system Ta2O5/Ta3N5 we prepared a new oxide nitride phase, Ta3O6N, by the reaction of 1T–TaS2 with water‐saturated ammonia gas. The determination of the unit cell metric and the crystal structure indicated that Ta3O6N is structurally related to the TiNb2O7‐type. Quantum‐chemical calculations on DFT level were used to rank the relative stabilities of possible N/O distributions and to provide a plausible structural model of the ground state with a minimum in the total energy. In agreement with Paulings 2nd rule, nitrogen ions prefer sites with high coordination numbers.
Nitrides with Inverse K2[NiF4] Structure: (R1–xCa3+xN1–x/3)Bi2 with R = Rare‐Earth Metal
Authors: Gäbler Frank , Bräunling Daniel , Senyshyn Anatoliy , Schnelle Walter , Niewa Rainer
Published: March 2010

The novel nitrides (R1–xCa3+xN1–x/3)Bi2 (with R = La, Ce, Pr) crystallize in the K2[NiF4] structure type (I4/mmm, No. 139, Z = 2). Samples (La1–xCa3+xN1–x/3)Bi2 with x = 0.10, 0.05, 0.00, (Ce1–xCa3+xN1–x/3)Bi2 with x = 0.30, and (PrCa3N)Bi2 were obtained as single phase microcrystalline powders according to X‐ray diffraction and the crystal structure details were derived from Rietveld refinements based on X‐ray and neutron diffraction powder patterns. A partial order of R3+/Ca2+ on two crystallographic sites is governed by different ionic radii and charges. (La1–xCa3+xN1–x/3)Bi2 and (Ce1–xCa3+xN1–x/3)Bi2 exhibit small homogeneity ranges and typically a nitrogen deficiency. In contrast, for (PrCa3N)Bi2 no indications for a significant homogeneity range or deficiency of nitrogen was observed. (La1–xCa3+xN1–x/3)Bi2 with x = 0.05 is a diamagnet. X‐ray absorption spectroscopy at the CeL3‐edge as well as magnetic susceptibility measurements evidence that (Ce1–xCa3+xN1–x/3)Bi2 with x = 0.30 contains Ce3+ in the 4f1 configuration. According to electrical resistivity data, samples from all three systems are heavily doped semiconductors.
A Study on AB2O6 Compounds: Part I, Synthesis, Structure, Magnetic Properties and 151Eu Mössbauer Spectroscopic Data of EuNb2O6
Authors: Beck Horst P. , Seup‐Ra Hyun , Haberkorn Robert , Kohlmann Holger , Eul Matthias , Harmening Thomas , Pöttgen Rainer
Published: March 2010

The synthesis and crystal structure of EuNb2O6 is reported. The compound is isotypic with SrNb2O6 and crystallizes with the space group P21/c and lattice parameters a = 7.7050(1) Å, b = 5.5781(1) Å, c = 11.0032(1) Å and β = 90.35(1)°. Susceptibility measurements show no magnetic ordering down to the lowest measured temperature of 3 K. 151Eu Mössbauer spectra clearly indicate divalent europium only.
Synthesis, Crystal Structure and Lithium Motion of Li8SeN2 and Li8TeN2
Authors: Bräunling Daniel , Pecher Oliver , Trots Dmytro M. , Senyshyn Anatoliy , Zherebtsov Dmitry A. , Haarmann Frank , Niewa Rainer
Published: March 2010

The compounds Li8EN2 with E = Se, Te were obtained in form of orange microcrystalline powders from reactions of Li2E with Li3N. Single crystal growth of Li8SeN2 additionally succeeded from excess lithium. The crystal structures were refined using single‐crystal X‐ray diffraction as well as X‐ray and neutron powder diffraction data (I41md, No. 109, Z = 4, Se: a = 7.048(1) Å, c = 9.995(1) Å, Te: a = 7.217(1) Å, c = 10.284(1) Å). Both compounds crystallize as isotypes with an anionic substructure motif known from cubic Laves phases and lithium distributed over four crystallographic sites in the void space of the anionic framework. Neutron powder diffraction pattern recorded in the temperature range from 3 K to 300 K and X‐ray diffraction patterns using synchrotron radiation taken from 300 K to 1000 K reveal the structural stability of both compounds in the studied temperature range until decomposition. Motional processes of lithium atoms in the title compounds were revealed by temperature dependent NMR spectroscopic investigations. Those are indicated by significant changes of the 7Li NMR signals. Lithium motion starts for Li8SeN2 above 150 K whereas it is already present in Li8TeN2 at this temperature. Quantum mechanical calculations of NMR spectroscopic parameters reveal clearly different environments of the lithium atoms determined by the electric field gradient, which are sensitive to the anisotropy of charge distribution at the nuclear sites. With respect to an increasing coordination number according to 2 + 1, 3, 3 + 1, and 4 for Li(3), Li(4), Li(2), and Li(1), respectively, the values of the electric field gradients decrease. Different environments of lithium predicted by quantum mechanical calculations are confirmed by 7Li NMR frequency sweep experiments at low temperatures.
Reaktionen des metalloiden Clusteranions {Ge9[Si(SiMe3)3]3}– in der Gasphase. Oxidations‐ und Reduktionsschritte geben Einblicke in den Bereich zwischen metalloiden Clustern und Zintl‐Ionen
Authors: Schenk Christian , Henke Florian , Neumaier Marco , Olzmann Matthias , Schnöckel Hansgeorg , Schnepf Andreas
Published: March 2010

The cluster anion {Ge9[Si(SiMe3)3]3}– (1) is transferred intact into the gas phase via the electro spray method. Subsequently the fragmentation of 1 after resonant excitation as well as the oxidation reaction with O2 and Cl2 are investigated in an FT‐ICR mass spectrometer (Fourier Transform Ion Cyclotron Resonance). Unlike former results with off‐resonant excitation the fragmentation leads mainly to the end‐product Ge9–. Moreover, applying an on‐resonant excitation the dissociation experiment can be quantified; 2.0 ± 0.15 eV (193 ± 15kJ·mol–1) for the elimination of the first two ligands and 2.7 ± 0.15 eV (261 ± 15 kJ·mol–1) for all ligands, respectively. Particular attention is turned on the first step, where sterically encumbered Si2(SiMe3)6 molecules are formed in a concerted reaction. This result, which is also important for elemental reactions on metal surfaces in catalyses, is based on experimentally determined threshold energies, DFT calculations and calculations on the lifetime of the involved species., In contrast to the high reactivity of crystalline 1·Li(THF)4, gaseous 1 is inert against oxygen. The analogy to recently published spin forbidden reactions of Al13– with O2 hints to a general importance of spin conversion during gas phase reactions of larger cluster molecules. The oxidation of 1 with Cl2 proceeds through different reaction channels. DFT calculations give a first insight on the complex primary oxidation steps. These calculations also reveal that the delocalized bonding situation in the Ge9 core is distorted upon oxidation. This result together with the dissociation experiments shed more light on differences and similarities between metalloid clusters and Zintl ions.
Synthesis, Crystal and Electronic Structure of the Nitridoaluminosilicate Ca5[Si2Al2N8]
Authors: Ottinger Frank , Cuervo‐Reyes Eduardo , Nesper Reinhard
Published: March 2010

Ca5[Si2Al2N8] was synthesized from elementary aluminum and silicon with phase‐pure tricalcium dinitride at 1280 K under dry argon in a sealed niobium ampoule. Ca3N2 was freshly prepared from distilled calcium metal in a dry nitrogen atmosphere. The compound crystallizes in form of transparent yellow distorted octahedra. In air and under moisture Ca5[Si2Al2N8] undergoes hydrolysis. The structure was determined from a single crystal to be orthorhombic (space group Pbcn – no. 60, a = 925.5, b = 614.0 and c = 1557.8 pm). The nitridoaluminate and ‐silicate substructures are separated into planes of edge and corner‐shared aluminate tetrahedra, which are linked by edge‐sharing double tetrahedral pillars of the silicate. The structure was confirmed by electrostatic and quantum mechanical analysis.
Risk factors for major morbidity after hepatectomy for hepatocellular carcinoma in 293 recent cases
Authors: Sadamori Hiroshi , Yagi Takahito , Matsuda Hiroaki , Shinoura Susumu , Umeda Yuzo , Yoshida Ryuichi , Satoh Daisuke , Utsumi Takasi , Ohnishi Teppei
Published: March 2010

Background/Purpose

The purpose of this study was to identify risk factors for major morbidity after hepatectomies for hepatocellular carcinoma (HCC).

Methods

Univariate and multivariate analyses of risk factors for major morbidity were performed in 293 patients who underwent hepatectomy for HCC between 2001 and 2008.

Results

Two hundred and forty‐three patients (82.9%) underwent an anatomic hepatectomy, and a repeat hepatectomy was performed in 50 patients (17.1%). The prevalences of bile leakage and intraabdominal abscess were 12.9% and 9.2%, respectively. The risk factor for bile leakage was an operative time ≥ 300 min and the risk factor for intraabdominal abscess was a repeat hepatectomy (odds ratios = 4.9 and 5.3, respectively). The main cause of bile leakage that made endoscopic therapy or percutaneous transhepatic biliary drainage necessary was a latent stricture of the biliary anatomy that had existed preoperatively, caused by previous treatments for HCC. Methicillin‐resistantStaphylococcus aureus was the main causative bacteria of intraabdominal abscess after repeat hepatectomies.

Conclusions

Our recent series revealed that prolonged operative time and repeat hepatectomy were independent risk factors for bile leakage and intraabdominal abscess, respectively, after hepatectomies for HCC. Preoperative assessment of the biliary anatomy should be considered for patients who have had previous multiple treatments for HCC, including hepatectomy, to reduce bile leakage that makes invasive treatment necessary.
Patient allocation based on preoperative assessment of pancreatic fibrosis to secure pancreatic anastomosis performed by trainee surgeons: a prospective study
Authors: Tajima Yoshitsugu , Kuroki Tamotsu , Kitasato Amane , Adachi Tomohiko , Isomoto Ichiro , Uetani Masataka , Kanematsu Takashi
Published: March 2010

Background

A fragile or non‐fibrotic pancreas increases the risk of postoperative pancreatic fistula (POPF) after pancreatic head resection, whereas pancreatic fibrosis decreases the risk. The degree of pancreatic fibrosis can be estimated using the time‐signal intensity curve (TIC) of the pancreas, obtained with dynamic magnetic resonance imaging (MRI). We have investigated whether trainee surgeons can perform pancreatic anastomosis safely, without the occurrence of POPF, when patients are selected carefully based on a preoperative assessment of pancreatic fibrosis.

Methods

Seventy‐two consecutive patients who underwent pancreatic head resection were enrolled in this prospective trial. Dynamic contrast‐enhanced MRI of the pancreas was performed preoperatively in all patients who, based on their pancreatic TIC profile, were then allocated to one of two groups: Group A comprised patients with type I pancreatic TIC, signifying a normal pancreas without fibrosis (n = 46); Group B comprised patients with type II or III pancreatic TIC, signifying a fibrotic pancreas (n = 26). An end‐to‐side duct‐to‐mucosa pancreaticojejunostomy was performed in all patients, with all patients in Group A operated on by two experienced surgeons, and all patients in Group B operated on by one of eight trainee surgeons at various stages of training.

Results

There was no operative mortality. POPF developed in 19 patients: 12 patients with grade A POPF and seven with grade B. All except one of the POPF occurred in Group A patients. The POPF in the one patient from Group B was grade A (p < 0.001).

Conclusions

A trainee surgeon can perform a secure pancreatic anastomosis without the occurrence of POPF in patients with a pancreas displaying a fibrotic pancreatic TIC on dynamic MRI scans.
A Constrained Linear Estimator for Multiple Regression
Authors: Davis-Stober Clintin P. , Dana Jason , Budescu David V.
Published: March 2010

“Improper linear models” (see Dawes, Am. Psychol. 34:571–582, 1979), such as equal weighting, have garnered interest as alternatives to standard regression models. We analyze the general circumstances under which these models perform well by recasting a class of “improper” linear models as “proper” statistical models with a single predictor. We derive the upper bound on the mean squared error of this estimator and demonstrate that it has less variance than ordinary least squares estimates. We examine common choices of the weighting vector used in the literature, e.g., single variable heuristics and equal weighting, and illustrate their performance in various test cases.
Gene Expression Profiles of Soybeans with Mid‐Oleic Acid Seed Phenotype
Authors: Upchurch Robert G. , Ramirez Martha E.
Published: March 2010

Seeds of the mid‐oleic acid soybean mutant M23 accumulate higher levels of oleic acid (50–60% oleate) by virtue of a deletion of GmFAD2‐1A, an allele of the microsomal omega‐6 oleate desaturase gene. In other less well characterized soybean varieties that are phenotypically mid‐oleic, little is known about the expression levels of omega‐6 desaturase GmFAD2 genes and other candidate genes that determine seed oleic acid content. We compared the steady‐state transcript abundance during seed development of the oleate‐ACP thioesterase (GmFATB1a), delta‐9 stearoyl acyl carrier protein desaturase (GmSACPD) and the omega‐6 fatty acid desaturase (GmFAD2) genes in five natural mid‐oleic varieties and mutant M23 to gene expression data for the conventional non mid‐oleic cultivar Dare. We found that, relative to Dare, there were instances where lower expression of GmFATB1a, GmFAD2‐1A, GmFAD2‐1B, GmFAD2‐2, and GmFAD2‐3 and higher expression of the GmSACPD‐C might be associated with the mid‐oleic seed phenotype. This finding suggests that of the several soybean genomic loci known or suspected to be involved in oleic acid phenotype, some are likely to encode genes involved in regulation of transcription of the oleate biosynthetic genes.
Pediatric Rehabilitation: 2. Environmental Factors Affecting Participation
Authors: Murphy Nancy , Trovato Melissa , Kim Heakyung , Kim Chong Tae , Moberg‐Wolff Elizabeth
Published: March 2010

Objective

This self‐directed learning module highlights the environmental factors that influence the participation of children and youth with disabilities in life situations, including activities of self‐care, mobility, socialization, education, recreation, and community life. It is part of the study guide on pediatric rehabilitation in the Self‐Directed Physiatric Education Program for practitioners and trainees in physical medicine and rehabilitation and pediatric medicine. This module emphasizes the participation of children with disabilities in adapted sports and reviews mobility devices to promote function, in the context of the International Classification of Functioning and in reference to the Americans with Disabilities Act. It provides the physiatrist with strategies to promote community participation, functional independence and healthcare transitions for children with disabilities as they approach adulthood. The goal of this article is to improve the learner's treatment strategies to maximize the participation of children and youth with disabilities in all settings, particularly schools and communities.
Pediatric Rehabilitation: 3. Facilitating Family‐Centered Treatment Decisions
Authors: Moberg‐Wolff Elizabeth , Kim Chong Tae , Murphy Nancy , Trovato Melissa , Kim Heakyung
Published: March 2010

Objective

This self‐directed learning module focuses on the role of accurate diagnosis, psychological support, and family integration of children who have chronic impairments such as pain, spasticity, or cognitive disability. It is part of the study guide on pediatric rehabiliation in the Self‐Directed Physiatric Education Program for practitioners and trainees in physical medicine and rehabilitation and pediatric medicine. The role of therapeutic, medical (traditional and nontraditional) and psychological interventions that improve family and individual function are emphasized. The goal of this article is to refine a learner's knowledge of the impact family‐centered care can have on the medical, psychological, financial, and functional capabilities of families to improve treatment decisions in the context of children with disability.
Postinjury Personality and Outcome in Acquired Brain Injury: The Millon Behavioral Medicine Diagnostic
Authors: Beck Kelley D. , Franks Susan F. , Hall James R.
Published: March 2010

Objective

To examine the relationship between postinjury personality and outcome in individuals with acquired brain injury. It was hypothesized that patients with differing levels of Introversive, Dejected, and Oppositional coping styles as described by Millon's Theory of Personality would show different outcomes after completion of a rehabilitation program.

Design

A retrospective chart review and completion of an outcome assessment was undertaken to examine study hypotheses.

Setting

A postacute brain injury rehabilitation program.

Participants

Fifty patients who completed the rehabilitation program between 2005 and 2008, who were 18 years of age or older, who possessed at least a sixth‐grade reading level, and who completed a valid Millon Behavioral Medicine Diagnostic (MBMD) were selected. Rehabilitation therapists who worked with these patients were also recruited to assess patient outcomes.

Methods

Charts of patients that met inclusion criteria were reviewed. Rehabilitation therapists completed the outcome measure retrospectively. The MBMD was used to predict outcome. The MBMD is a self‐report questionnaire designed to assess psychosocial factors that relate to the course of medical treatment in chronic illness.

Main Outcome Measurements

The Mayo‐Portland Adaptability Inventory (MPAI‐4) was used to assess patient outcome. It is a 29‐item assessment designed to evaluate the common physical, cognitive, emotional, behavioral, and social issues after acquired brain injury.

Results

Findings supported our hypotheses that patients with differing levels of Introversive and Oppositional Coping Styles would have significantly different outcomes after rehabilitation. Thus, individuals with mild/moderate to moderate/severe limitations had significantly greater scores on the Introversive and Oppositional coping compared with individuals with more successful outcomes.

Conclusions

The results of this study support the idea that postinjury personality is an important factor in understanding outcome after completion of a brain‐injury rehabilitation program. Personality variables accounted for significant variance above and beyond variance accounted for by the severity of the injury alone. These findings have important implications for the development and implementation of rehabilitation treatment planning.
The Diagnostic Validity of Hip Provocation Maneuvers to Detect Intra‐Articular Hip Pathology
Authors: Maslowski Erin , Sullivan William , Forster Harwood Jeri , Gonzalez Peter , Kaufman Marla , Vidal Armando , Akuthota Venu
Published: March 2010

Objective

To determine which hip provocation maneuvers best predict the presence of an intra‐articular hip pathology.

Design

Prospective diagnostic study.

Setting

Musculoskeletal clinic at a university‐based multispecialty group practice.

Participants

Fifty subjects referred for intra‐articular hip injection under fluoroscopic guidance.

Interventions

Subjects were examined with 4 pain provocation maneuvers before and after anesthetic intra‐articular hip injection administered under fluoroscopic guidance.

Main Outcome Measurements

Presence of intra‐articular hip pain generator was confirmed by ≥80% improvement on visual analog scale after intra‐articular hip injection.

Results

The most sensitive tests were flexion abduction external rotation (FABER) test and internal rotation over pressure (IROP) maneuver. For the FABER test, sensitivity was 0.82 (95% CI 0.57‐0.96); sensitivity for the IROP maneuver was 0.91 (95% CI 0.68‐0.99). The most specific test was the Stinchfield maneuver, with specificity at 0.32 (95% CI 0.14‐0.55). FABER and IROP had the highest positive predictive value, with 0.46 (95% CI 0.28‐0.65) and 0.47 (95% CI 0.29‐0.64), respectively. IROP had the highest negative predictive value at 0.71 (95% CI 0.25‐0.98).

Conclusions

IROP and FABER may be worthwhile components of the clinical evaluation of hip pain to determine intra‐articular hip pathology. These tests are nonspecific and therefore not necessarily negative in the absence of intra‐articular hip pathology. These hip provocation maneuvers are a useful part of an evaluation that includes history, further examination findings, and other diagnostic studies.
How does evaluation ‘Work’? A case study of homeless services in Ireland
Authors: Rhodes Mary Lee , Brooke Simon
Published: March 2010

This paper describes how the processes of evaluation interact with the complex processes of policy and implementation, with a view to exploring the implications relating to the nature of evidence, the impact of evaluation on policy and practice and the challenges inherent in evaluation activities. Recent studies of evaluation and evidence-based policy have suggested that there are significant issues and complexities in determining ‘what works’ specifically with regard to the impact of evaluations and the evidence bases for policy and/or practice. The aim of this paper is to examine a detailed case in which these three activities of policy formulation, implementation and evaluation have evolved and interacted in a particular policy domain over time. To this end we examine homeless policy, implementation, outcomes and evaluation in Ireland between 1988, the year ‘homelessness’ was defined first in legislation, and 2008, the year of launching the second national homeless strategy.
Late Quaternary glaciation history of isla de los Estados, southeasternmost South America
Authors: Möller Per , Hjort Christian , Björck Svante , Rabassa Jorge , Ponce Juan Federico
Published: March 2010

Isla de los Estados is a mountainous island southeast of Tierra del Fuego, in southernmost South America. Its central and eastern parts have an alpine topography, transected by U-shaped valleys, small, partly over-deepened fjords, and a multitude of abandoned cirques, all associated with extensive former local glaciations. Traces of glacial erosion generally reach 400–450 m a.s.l., and above that trimline a distinct sharp-edged nunatak derived landscape is present. The westernmost part of the island has a lower, more subdued topography, reflecting its "softer" geology but possibly also over-running and erosion by mainland-derived ice streams. The present study concentrated on glacigenic sediment sequences exposed along coastal erosional cliffs. A combination of OSL and 14C datings show that these sediments mostly date from the latest (Wisconsinan/Weichselian) glacial cycle, i.e. from the last ca. 100 ka with the oldest (glaciolacustrine) deposits possibly as old as 90–80 ka. The upper parts of overlying tills, with associated lateral and terminal moraines from glaciers that expanded onto an eustatically exposed dry shelf north of the island, date from the last global glacial maximum (LGM). Radiocarbon ages of peat and lake sediments indicate that deglaciation began 17–16 cal ka BP.
The Tragedy of the Middle East
Authors: Rubin Barry
Published: March 2010

The Middle East has changed clearly, substantially, and dramatically during the last decade. Yet scholarly and public understanding lags far behind these events. This book explains why the previous era came to end, giving an historical and political summation of the region. Three interlinked themes are crucial to the book. First, a reinterpretation of the era of upheaval the Middle East has just passed through. During that period, many Arabs believed that some leader, country, or radical movement would unite the region, solving all its problems. Second, an evaluation of how the historical experience of the period between the 1940s and the 1990s undermined the old system, making change necessary. Third, an analysis of the region today that helps explain future developments, in what the author terms the Era of Reluctant Pragmatism, as the Middle Eastern societies decide their relationships to the West.
Peasant Rebellions of the Caspian Region during the Iranian Constitutional Revolution, 1906–1909
Authors: Afary Janet
Published: March 2010

Despite a growing literature on peasant movements in the early 20th century, the story of the peasant rebellions of the Caspian region at the time of the Iranian Constitutional Revolution of 1906–11 has been little studied.1 A close look at three sets of materials—the newspapers of the Constitutional Revolution, among them Majlis (1906–1908), Anjuman (1906–1909), Habl al-Matīn (1907–1909), and Sūr-i Isrāfīl (1907–8); British diplomatic reports; and several regional studies and memoirs of the period—reveal that, during the First Constitutional Period of 1906–1908, a number of strikes and sit-ins were carried out by the peasants, often with the support of craftsmen and workers, who had initiated trade union activity. Such revolts were considerably more sustained and prominent in the northern areas of Gilan and Azerbayjan, which were directly influenced by the flow of radical ideas from the Russian Caucasus; they also benefited from a long history of social struggle among the craftsmen and small shopkeepers (pīshahvarāns), who maintained their guilds, and a tradition of alliances among the craftsmen, the urban poor, and the poor peasants.2
Fund Flow Volatility and Performance
Authors: Rakowski David
Published: March 2010

This paper provides a detailed analysis of the impact of daily mutual fund flow volatility on fund performance. I document a significant negative relationship between the volatility of daily fund flows and cross-sectional differences in risk-adjusted performance. This relationship is driven by domestic equity funds, as well as small funds, well-performing funds, and funds that experience inflows over the sample period. My results are consistent with performance differences arising from the transaction costs of nondiscretionary trading driven by daily fund flows, but not with performance differences arising from the suboptimal cash holdings that arise from fund flows.
Pharmaceutical R&D Spending and Threats of Price Regulation
Authors: Golec Joseph , Hegde Shantaram , Vernon John A.
Published: March 2010

Do threats of pharmaceutical price regulation affect subsequent research and development (R&D) spending? This study uses the Clinton administration’s Health Security Act (HSA) of 1993 as a natural experiment to study this issue. We link events surrounding the HSA to pharmaceutical stock price changes and then examine the cross-sectional relation between firms’ stock price changes and their subsequent unexpected R&D spending changes. Results show that the HSA had significant negative effects on stock prices and firm-level R&D spending. Conservatively, the HSA reduced R&D spending by about $1 billion even though it never became law.
Disagreement, Portfolio Optimization, and Excess Volatility
Authors: Duchin Ran , Levy Moshe
Published: March 2010

Disagreement, a key factor inducing trading, has been receiving ever increasing attention in recent years. Most research has focused on disagreement about the expected returns. Several authors have shown that if the average belief coincides with the true expected return, in the portfolio context prices are unaffected by disagreement. In this paper we study the pricing effects of disagreement about return variances. We show that i) disagreement about variances has systematic and significant pricing effects—more disagreement leads to higher prices, and ii) prices are very sensitive to the degree of disagreement: Even if the average belief about the variance is constant, tiny fluctuations in the disagreement about the variance lead to substantial price fluctuations. This second result may offer an explanation for the excess volatility puzzle: When small changes in the degree of disagreement occur, they induce relatively large price changes. Yet, the changes in disagreement may be hard to directly detect empirically, leading to apparent “excess volatility.”
Friend or Foe? The Role of State and Mutual Fund Ownership in the Split Share Structure Reform in China
Authors: Firth Michael , Lin Chen , Zou Hong
Published: March 2010

The recent split share structure reform in China involves the nontradable shareholders proposing a compensation package to the tradable shareholders in exchange for the listing rights of their shares. We find that state ownership (the major owners of nontradable shares) has a positive effect on the final compensation ratio. In contrast, mutual fund ownership (the major institutional owner of tradable shares) has a negative effect on the compensation ratio and especially in state-owned firms. The evidence is consistent with our predictions that state shareholders have incentives to complete the reform quickly and exert political pressure on mutual funds to accept the terms without a fight.
Dynamic Factors and Asset Pricing
Authors: He Zhongzhi (Lawrence) , Huh Sahn-Wook , Lee Bong-Soo
Published: March 2010

This study develops an econometric model that incorporates features of price dynamics across assets as well as through time. With the dynamic factors extracted via the Kalman filter, we formulate an asset pricing model, termed the dynamic factor pricing model (DFPM). We then conduct asset pricing tests in the in-sample and out-of-sample contexts. Our analyses show that the ex ante factors are a key component in asset pricing and forecasting. By using the ex ante factors, the DFPM improves upon the explanatory and predictive power of other competing models, including unconditional and conditional versions of the Fama and French (1993) 3-factor model. In particular, the DFPM can explain and better forecast the momentum portfolio returns, which are mostly missed by alternative models.
A Longer Look at the Asymmetric Dependence between Hedge Funds and the Equity Market
Authors: Kang Byoung Uk , In Francis , Kim Gunky , Kim Tong Suk
Published: March 2010

This paper reexamines, at a range of investment horizons, the asymmetric dependence between hedge fund returns and market returns. Given the current availability of hedge fund data, the joint distribution of longer-horizon returns is extracted from the dynamics of monthly returns using the filtered historical simulation; we then apply the method based on copula theory to uncover the dependence structure therein. While the direction of asymmetry remains unchanged, the magnitude of asymmetry is attenuated considerably as the investment horizon increases. Similar horizon effects also occur on the tail dependence. Our findings suggest that nonlinearity in hedge fund exposure to market risk is more short term in nature, and that hedge funds provide higher benefits of diversification, the longer the horizon.
Stokes' cradle: normal three-body collisions between wetted particles
Authors: DONAHUE C. M. , HRENYA C. M. , DAVIS R. H. , NAKAGAWA K. J. , ZELINSKAYA A. P. , JOSEPH G. G.
Published: March 2010

In this work, a combination of experiments and theory is used to investigate three-body normal collisions between solid particles with a liquid coating (i.e. ‘wetted’ particles). Experiments are carried out using a Stokes' cradle, an apparatus inspired by the Newton's cradle desktop toy except with wetted particles. Unlike previous work on two-body systems, which may either agglomerate or rebound upon collision, four outcomes are possible in three-body systems: fully agglomerated, Newton's cradle (striker and target particle it strikes agglomerate), reverse Newton's cradle (targets agglomerate while striker separates) and fully separated. Post-collisional velocities are measured over a range of parameters. For all experiments, as the impact velocity increases, the progression of outcomes observed is fully agglomerated, reverse Newton's cradle and fully separated. Notably, as the viscosity of the oil increases, experiments reveal a decrease in the critical Stokes number (the Stokes number that demarcates a transition from agglomeration to separation) for both sets of adjacent particles. A scaling theory is developed based on lubrication forces and particle deformation and elasticity. Unlike previous work for two-particle systems, two pieces of physics are found to be critical in the prediction of a regime map that is consistent with experiments: (i) an additional resistance upon rebound of the target particles due to the pre-existing liquid bridge between them (which has no counterpart in two-particle collisions), and (ii) the addition of a rebound criterion due to glass transition of the liquid layer at high pressure between colliding particles.
Should Christians do Natural Theology?
Authors: Moore Andrew
Published: March 2010

Natural theology is enjoying something of a resurgence at present but this article seeks to question its place in Christian philosophy and theology. Antecedent natural theology accepts that it is necessary for Christian beliefs to be rationally warranted. Romans 1:18ff. is often cited in favour of natural theology. However, examination of this text shows that Paul argues here on the basis of a prior revelation. Not only does he not endorse natural theology but what he does say implies that arguments for a God's existence are not likely to lead to the God revealed in Jesus Christ. Such arguments are in any case tainted by the noetic effects of sin. It is therefore not clear that these arguments lead to the God of Christian belief who calls us to simple discipleship. Consequent natural theology holds that Christians are under an epistemological obligation to their surrounding culture to show that they are reflectively rational. But the arguments put up for this by Michael Sudduth ignore theological arguments which should bear on Christian epistemology. Apart from God's self-revelation we find ourselves sceptics, and natural theology is unable to overcome this. Historical research has shown the damaging effects that arguing from nature has had on Christian theology. So, for both theological and historical reasons, Christians need not accept the epistemological obligations imposed on them by unbelievers which lead them to do natural theology.
An analysis of several configuration design systems
Authors: Balkany Alan , Birmingham William P. , Tommelein Iris D.
Published: March 2010

Design has been extensively studied by artificial intelligence researchers for many years. These studies have resulted in a large number of design tools that perform interesting tasks. Understanding the capabilities of these tools is, however, very difficult, which seriously impedes progress in the field. A better understanding of different tools can be achieved by analyzing the knowledge use of existing tools. Such an analysis of six configuration design tools is presented. This results in a model of configuration design that shows significant similarity in the tasks performed by these tools.
A systematic approach for design and planning of mechanical assemblies
Authors: Chen C. L. Philip , Wichman C. A.
Published: March 2010

A system that integrates design and planning for mechanical assemblies is presented. The system integrates neural network computing that captures designer's design concept and rule-based system to generate a task-level assembly plan automatically. The design concept is expressed by a standard pattern format representing qualitative assembly information. A neural network model together with feature-based model translates the input pattern into a preliminary boundary representation (B-rep). Based on a refinement B-rep assembly representation, assembly plans are generated for practical use in a single-robot assembly workcell. A feasible assembly plan that minimizes tool changes and subassembly reorientations is generated from the system. A robust part collision detection algorithm to generate the precedence relationships among the assembly's components is included in the system. By contrast with many assembly planning systems that used a prolonged question-and-answering session or required knowledge beyond what is typically available in the design database, an automated assembly planning system presented here draws input relationships directly from the conceptual design and the geometry of the assembly. The system developed under this study extracts all reasoning information from the product model and permits the components to be assembled in a multitude of directions. Several experiments illustrate the effectiveness of the designed assembly planning system.
Qualitative dynamic diagnosis of circuits
Authors: Fanni Alessandra , Diana Paolo , Giua Alessandro , Perezzani Marco
Published: March 2010

We describe ACDS, an automatic diagnostic system. ACDS is capable of diagnosing faults on analog circuits in dynamic conditions. The circuit's dynamic behavior is studied by means of a series of intrastate simulations during which the qualitative state of the circuit does not change. An acquistion board collects the value of a set of quantities corresponding to accessible test points. These measurements are converted into qualitative values and are used for two purposes: first, to determine the state of the circuit components; second, to trigger the diagnostic procedure whenever a discrepancy between observed and predicted behavior is found. The main difficulty in this phase of measurement interpretation is in obtaining meaningful numerical-qualitative data conversion for values of quantities approaching a boundary between two different qualitative intervals. System performance has been verified through a number of simulations, which have shown the proposed approach to be efficient both in terms of localized faults and of flexibility in adapting to different circuits.
Model/heuristic-based alarm processing for power systems
Authors: Pfau-Wagenbauer Monika , Nejdl Wolfgang
Published: March 2010

This paper describes an intelligent alarm processing expert system which is integrated in a large Supervisory Control and Data Acquisition system for power distribution networks. The expert system works as an operator support tool by diagnosing network disturbances and device malfunctions. The expert system is based on a hierarchic, multi-level problem-solving architecture, integrating both model-based and heuristic techniques acting upon an object-oriented data structure. Several enhancements have been designed and implemented to enable the system to perform its task online and real-time. The expert system covers online processing of real-time data and intelligent alarm processing, as well as the automatic creation and update of the knowledge base. It consists of approximately 25000 objects (units) and 190 rules. The system uses the expert system tool KEE, runs on SUN workstations, and is integrated in the Supervisory Control and Data Acquisition system via LAN. The expert system was implemented for the Public Utilities Board Singapore controlling its 22 kV distribution network and has been online since November 1990.
Using artificial intelligence techniques to support project management
Authors: Levitt Raymond E. , Kunz John C.
Published: March 2010

This paper develops a philosophy for the use of Artificial Intelligence (AI) techniques as aids in engineering project management.

First, we propose that traditional domain-independent, ‘means–and’ planners, may be valuable aids for planning detailed subtasks on projects, but that domain-specific planning tools are needed for work package or executive level project planning. Next, we propose that hybrid computer systems, using knowledge processing techniques in conjunction with procedural techniques such as decision analysis and network-based scheduling, can provide valuable new kinds of decision support for project objective-setting and project control, respectively. Finally we suggest that knowledge-based interactive graphics, developed for providing graphical explanations and user control in advanced knowledge processing environments, can provide powerful new kinds of decision support for project management.

The first claim is supported by a review and analysis of previous work in the area of automated AI planning techniques. Our experience with PLATFORM I, II and III, a series of prototype AI-leveraged project management systems built using the IntelliCorpKnowledge Engineering Environment(KEE™), provides the justification for the latter two claims.
Modifiable combining functions
Authors: Cohen Paul R. , Shafer Glenn , Shenoy Prakash P.
Published: March 2010

Modifiable combining functions are a synthesis of two common approaches to combining evidence. They offer many of the advantages of these approaches and avoid some disadvantages. Because they facilitate the acquisition, representation, explanation, and modification of knowledge about combinations of evidence, they are proposed as a tool for knowledge engineers who build systems that reason under uncertainty, not as a normative theory of evidence.
Expert database concepts for engineering design
Authors: Nguyen G. T. , Rieu D.
Published: March 2010

The specific semantics of CAD objects are analysed concerning their nature their dynamicity and their consistency during the design process. The nature of CAD objects is concerned with their structure and relationships. The dynamicity is concerned with the evolving nature of the objects, i.e. their behavior. The consistency is concerned with their completeness and relationships with integrity constraints.

A new methodology for semantic constraints management and control is defined. It relies extensively on database and expert system technologies for the implementation of new concepts, e.g. logical prototypes of objects and object equivalence class.

It provides a sound and unified basis for modelling the dynamic nature of complex objects, concerning both the management of their structure and the certification of the update operations, i.e. the control of their correctness.

The functionalities of CADB, a prototype expert database system that supports these features, are detailed. CADB is currently implemented in Prolog on VAX™ 11/785 and APOLLO™ workstations.
A machine learning approach to the automatic synthesis of mechanistic knowledge for engineering decision-making
Authors: Lu Stephen C.-Y. , Chen Kaihu
Published: March 2010

Inductive learning is proposed as a tool for synthesizing domain knowledge from data generated by a model-based simulator. In order to use an inductive engine to generate decision rules, the pre-classification process becomes more complicated in the presence of multiple competing objectives. Instead of relying on a domain expert to perform this pre-classification task, a clustering algorithm is used to eliminate human biases involved in the selection of a classification function for pre-classification. It is shown that the use of a clustering algorithm for pre-classification not only further automates the process of knowledge by synthesizing, but also improves the quality of the rules generated by the inductive engine.
On research methodology towards a scientific theory of engineering design
Authors: Dixon John R.
Published: March 2010

The goal of this paper is to raise awareness and generate discussion about research methodology in engineering design. Design researchers are viewed as a single communicating community searching for scientific theories of engineering design; that is, theories that can be tested by formal methods of hypothesis testing. In the paper, the scientific method for validating theories is reviewed, and the need for operational definitions and for experiments to identify variables and meaningful abstractions is stressed. The development of a design problem taxonomy is advocated. Generating theories is viewed as guided search. Three types of design theories are described: prescriptive, cognitive descriptive, and computational. It is argued that to seek prescriptions is premature and that, unless the human and institutional variables are reduced to knowledge and control, cognitive descriptive theories will be impossibly complex. A case is made for a computational approach, though it also shown that computational and cognitive research approaches can be mutually supportive.
Building an expert system for the preliminary design of ships
Authors: Akagi Shinsuke , Fujita Kikuo
Published: March 2010

An expert system for the preliminary design of ships developed. The design process is understood as determining design variables and the relationships among design parameters. The relationships among the elements of design knowledge are represented by a network model. The object-oriented knowledge representations are introduced in the computer system to manipulate design variables such as the principle particulars of a ship in the network model. The expert system based on the above concept provides the following functions: (1) flexibility for building a model and easy modification of the model; (2) effective diagnosis of the design process by using rule-based knowledge representations; (3) hybrid function with both symbolic treatment of the design knowledge and numerical computations by coupling the systems programmed in LISP and FORTRAN and (4) a supporting method for determination of the design variables.

Finally the system's validity and effectiveness is ascertained by applying it to the preliminary design of a bulk carrier ship.
Engineering design synthesis: a domain independent representation
Authors: Maher Mary Lou
Published: March 2010

The knowledge used in the design of engineering systems includes: understanding systems and their components, and the understanding implications of design decisions on other decisions and further problem decomposition This paper presents design as a process and then characterizes the knowledge used in synthesizing design alternatives. A knowledge based approach to design synthesis is proposed, followed by a description of the implementation of a domain independent synthesis framework. The implementation is further illustrated by an example application to structural design.
Introduction: Preliminary stages of engineering analysis and modeling
Authors: Finn Donal
Published: March 2010

On June 20th, 1992, a workshop entitled the “Preliminary Stages of Engineering Analysis and Modeling” was held at Carnegie Mellon University, Pittsburgh, U.S.A. The workshop was organized in conjunction with the 2nd International Conference on Artificial Intelligence in Design (AID ’92), and aimed to provide a forum for engineers and computer scientists to examine how AI techniques could be exploited effectively in assisting engineers with the preliminary stages of engineering analysis and modeling. This report has two objectives; firstly it serves as a summary of the workshop and secondly it introduces four of the workshop papers that have been rewritten and extended for this issue.
Engineering design is a computable function
Authors: Fitzhorn Patrick A.
Published: March 2010

Computational abstraction of engineering design leads to an elegant theory defining (1) the process of design as an abstract model of computability, the Turing machine; (2) the artifacts of design as enumerated strings from a (possibly multidimensional) grammar; and (3) design specifications or constraints as formal state changes that govern string enumeration. Using this theory, it is shown that engineering design is a computable function. A computational methodology based on the theory is then developed that can be described as a form follows function design paradigm.