bluuebunny/crossref_metadata_2025 huggingface dataset:
Computer‐aided detection of breast masses on mammograms: Dual system approach with two‐view analysis
Authors: Wei Jun , Chan Heang‐Ping , Sahiner Berkman , Zhou Chuan , Hadjiiski Lubomir M. , Roubidoux Marilyn A. , Helvie Mark A.
Published: September 2009

Purpose:

The purpose of this study is to develop a computer‐aided detection (CAD) system that combined a dual system approach with a two‐view fusion method to improve the accuracy of mass detection on mammograms.

Methods:

The authors previously developed a dual CAD system that merged the decision from two mass detection systems in parallel, one trained with average masses and another trained with subtle masses, to improve sensitivity without excessively increasing false positives (FPs). In this study, they further designed a two‐view fusion method to combine the information from different mammographic views. Mass candidates detected independently by the dual system on the two‐view mammograms were first identified as potential pairs based on a regional registration technique. A similarity measure was designed to differentiate TP‐TP pairs from other pairs (TP‐FP and FP‐FP pairs) using paired morphological features, Hessian feature, and texture features. A two‐view fusion score for each object was generated by weighting the similarity measure with the cross correlation measure of the object pair. Finally, a linear discriminant analysis classifier was trained to combine the mass likelihood score of the object from the single‐view dual system and the two‐view fusion score for classification of masses and FPs. A total of 2332 mammograms from 735 subjects including 800 normal mammograms from 200 normal subjects was collected with Institutional Review Board (IRB) approval.

Results:

When the single‐view CAD system that was trained with average masses only were applied to the test sets, the average case‐based sensitivities were 50.6% and 63.6% for average masses on current mammograms and 22.6% and 36.2% for subtle masses on prior mammograms at 0.5 and 1 FPs/image, respectively. With the new two‐view dual system approach, the average case‐based sensitivities were improved to 67.4% and 83.7% for average masses and 44.8% and 57.0% for subtle masses at the same FP rates.

Conclusions:

The improvement with the proposed method was found to be statistically significant by JAFROC analysis.
Interindividual variability of arterial impulse response to intravenous injection of nonionic contrast agent (Iohexol) in DCE‐CT study
Authors: Kim S. M. , Haider M. A. , Milosevic M. , Yeung I. W. T.
Published: September 2009

Purpose:

It is known that the arterial input function (AIF) in dynamic contrast‐enhanced (DCE)‐CT differs among patients even for fixed contrast injection protocols. Therefore, a study has been performed to investigate the interindividual variability of the AIF with respect to patient factors (such as weight, height, and age). In addition, it has been demonstrated that the relations from the interindividual variability investigation can be further used for the estimation of AIF for a patient without the requirement of measurement.

Methods:

DCE‐CT data for a cohort of 34 patients with cervical carcinoma were used for the investigation of interindividual variability of the AIF. To dissociate the effect of different durations of contrast injection, the arterial impulse response (AIR) to intravenous contrast injection was calculated and examined for its correlations with these patient factors. An empirical functional form was proposed to model the AIR with temporal intensity of a first pass of contrast agent followed by recirculation and quasiequilibrium state of contrast concentration. Specific features (onset time, peak time, and amplitudes) of the AIR were tested for correlations with the patient factors. Linear regression was applied to cases that show significant strong correlation between the AIR amplitudes and patient factors. The results were then used to predict the AIR for any given patient based on the patient factors. It was shown that using the predicted AIR, the AIF of the patient can be estimated without the requirement of measurement given the injection protocol is known. The method of AIF estimation was tested in DCE‐CT data from another group of 14 patients. The efficacy of individually estimated AIF on pharmacokinetic analysis was assessed against the use of measured AIF and population‐averaged AIF as the latter is another possible strategy for AIF generation if AIF measurement is not available.

Results:

It was found that the amplitudes of AIR postonset time were significantly correlated with patient bodyweight at most time pointsexcept 8–17 s. When the adiabatic tissue homogeneity (ATH) and the Kety models were applied to the pharmacokinetic analysis, the mean percentage errors in kinetic parameter estimates induced by using the estimated AIF instead of the measured one for both models ranged from −4.98% to 11.19 %.

Conclusions:

It was found that there are strong linear relationships between AIR and patient weight; thereby the AIR of a patient can be estimated with patient weight. The proposed method of AIF estimation is potentially applicable in cases where AIF measurement is not possible.
Mixed motives, mixed outcomes when accused parents won’t agree to withdraw care
Authors: Appel J M
Published: September 2009

One of the basic tenets of paediatric ethics is that competent parents may render healthcare decisions for children who are too young or too incapacitated to make meaningful medical choices for themselves. In the USA, many jurisdictions have expanded this principle to include the right to terminate a child's life support, including nutrition and hydration, when that child enters a persistent vegetative state. However, this approach to the withdrawal of care in the paediatric setting has been put to the test by an increasing number of cases in which one or both parents are themselves accused of causing the child's life-threatening injuries. In such “mixed-motive” situations, parents may express a desire to keep a child on life support for religious or moral reasons; at the same time, forestalling the child's death may also prevent a murder charge against the accused parent. Principles need to be established for handling such tragic cases.
On how to interpret the role of the future within the abortion debate
Authors: Di Nucci E
Published: September 2009

In a previous paper, I had argued that Strong’s counterexamples to Marquis’s argument against abortion—according to which terminating fetuses is wrong because it deprives them of a valuable future—fail either because they have no bearing on Marquis’s argument or because they make unacceptable claims about what constitutes a valuable future. In this paper I respond to Strong’s criticism of my argument according to which I fail to acknowledge that Marquis uses “future like ours” and “valuable future” interchangeably. I show that my argument does not rely on not acknowledging that “future like ours” and “valuable future” are interchangeable; and that, rather, it is exactly by replacing “future like ours” with “valuable future” that I construct my argument against Strong. I conclude with some remarks on how Marquis’s concept of “future like ours” should be interpreted.
Severe food restriction induces myocardial dysfunction related to SERCA2 activity
Authors: Sugizaki Mário Mateus , Leopoldo André Soares , Okoshi Marina Politi , Bruno Alessandro , Conde Sandro José , Lima-Leopoldo Ana Paula , Padovani Carlos Roberto , Carvalho Robson Francisco , Nascimento André Ferreira do , Campos Dijon Henrique Salomé de , Nogueira Célia Regina , Cicogna Antonio Carlos
Published: September 2009

Previous studies have shown that food restriction promotes myocardial dysfunction in rats. However, the molecular mechanisms that are responsible are unclear. We investigated the role of sarcoplasmic reticulum Ca2+-ATPase (SERCA2) on myocardial performance in food-restricted rats. Male Wistar–Kyoto rats, 60 days old, were fed a control or restricted diet (daily energy intake reduced to 50% of the control) for 90 days. Expression of Serca2a, phospholamban (PLB), Na+/Ca2+exchanger (NCX), and thyroid hormone receptor (TRα1, TRβ1) mRNA was determined by quantitative PCR. SERCA2 activity was measured by using 20 µmol/L cyclopiazonic acid (CPA) in a left ventricular papillary muscle preparation during isometric contraction in basal conditions and during post-rest contraction. Serum concentrations of thyroxine (T4) and thyrotropin (TSH) were also determined. The 50%-restricted diet reduced body and ventricular weight and serum T4and TSH levels. The interaction of CPA and food restriction reduced peak developed tension and maximum rate of tension decline (–dT/dt), but increased the resting tension intensity response during post-rest contraction. PLB and NCX mRNA were upregulated and TRα1 mRNA was downregulated by food restriction. These results suggest that food restriction promotes myocardial dysfunction related to impairment of sarcoplasmic reticulum Ca2+uptake as a result of a hypothyroid state.
Tumor cells expressing tissue factor influence the migration of smooth muscle cells in a catalytic activity-dependent way
Authors: Brousseau Catherine , Morissette Guillaume , Fortin Jean-Philippe , Marceau François , Petitclerc Eric
Published: September 2009

The expression of tissue factor (TF) in tumors reportedly exacerbates the agressiveness of several types of cancers. The shedding of TF-containing membrane particles is believed to influence the ability of tumors to expand and metastasize, and these microparticles may also be harmful in the onset of disseminated intravascular coagulation in specific cancers. Futhermore, the intracellular signaling that is elicited after the formation of the TF / coagulation factor VIIa complex at the cell membane modulates the activity of adhesion molecules and mitogen-activated protein (MAP) kinases. To evaluate whether TF overexpression in tumor cells modulates its shedding and neighboring stromal cells by its catalytic or intracellular activity, TF-GFP (green fluorescent protein) and a tailless form (TFΔC-GFP) were stably expressed in the rat Morris hepatoma and human HT1080 fibrosarcoma cell lines. Both TF proteins were efficiently produced by tumor cells and functionally active, and their clotting activity could be blocked by the active site-inhibited factor VIIa (ASIS). TF-expressing tumorigenic cells produced a soluble factor that increased the migration of arterial smooth muscle cells in vitro. This effect was abrogated by ASIS and the PAR-1 receptor antagonist ATAP-2, showing that it is dependent on the proteolytic activity of the TF ligand factor VIIa and the thrombin-activated cell membrane receptor. We propose that TF-containing microparticles that are released in the culture medium by tumor cells influence the migratory behavior of neighboring stromal cells, thus aiding the cancer cell’s tumorigenic potential.
Encapsulation ability: Are all Drosophila species equally armed? An investigation in the obscura group
Authors: Havard S. , Eslin P. , Prévost G. , Doury G.
Published: September 2009

Unable to form cellular capsules around large foreign bodies, the species Drosophila subobscura Collin in Gordon, 1936 was previously shown devoid of lamellocytes, the capsule-forming hemocytes in Drosophila melanogaster Meigen, 1830. This unusual case of deficiency in encapsulation ability was remarkable enough to motivate further investigations in phylogenetically related species of the obscura group. Like D. subobscura, the species Drosophila azteca Sturtevant and Dobzhansky, 1936, Drosophila bifasciata Pomini, 1940, Drosophila guanche Monclus, 1976, Drosophila miranda Dobzhansky, 1935, Drosophila persimilis Dobzhansky and Epling, 1944, and Drosophila pseudoobcura Frovola and Astaurov, 1929 were found to be unable to encapsulate large foreign bodies and also to lack lamellocytes. Surprisingly, Drosophila affinis Sturtevant, 1916, Drosophila tolteca Patterson and Mainland, 1944, and Drosophila obscura Fallen, 1823 were capable of mounting cellular capsules, although their encapsulation abilities remained weak. These three species were free of lamellocytes but possessed small pools of never before described “atypical hemocytes” present in the hemolymph when capsules were formed.
Behavioral response of migrating wood frogs to experimental timber harvest surrounding wetlands
Authors: Rittenhouse Tracy A.G. , Semlitsch Raymond D.
Published: September 2009

Behavioral responses to ecological disturbances such as timber harvest, fire, or drought provide insight into wildlife habitat requirements. To determine the behavioral response of adult wood frogs ( Lithobates sylvatica (LeConte, 1825)) to timber harvest in oak–hickory forest, we conducted experimental timber harvest surrounding replicate breeding sites, monitored freely moving frogs using radiotelemetry, and tested the repeatability of behavioral responses with two experimental displacements. We found no evidence that wood frogs use recent oak–hickory clearcuts as habitat. Timber harvest was not a complete barrier to movement, as frogs surviving increased predation and desiccation risks reached drainages used as nonbreeding habitat. Frogs did not alter the direction of travel and traversed similar distances (i.e., total distance and net distance from breeding site) before and after timber harvest. However, rate of travel (i.e., maximum distance traversed in 1 day) increased following timber harvest and frogs displaced to the center of clearcuts exited the timber harvest array in one rainy night. Notably, wood frogs following displacement exhibited site fidelity to nonbreeding habitat. We suggest that deleterious effects of timber harvest on amphibians may be minimized through the use of small stand sizes placed in locations that do not separate breeding and nonbreeding habitat.
Diets and distributions of Leach’s storm-petrel (Oceanodroma leucorhoa) before and after an ecosystem shift in the Northwest Atlantic
Authors: Hedd A. , Montevecchi W. A. , Davoren G. K. , Fifield D. A.
Published: September 2009

The Grand Bank ecosystem has undergone significant shifts during the past two decades owing to oceanographic and fishing effects. Effects on upper trophic level seabirds (dietary shifts, reduced reproductive performance) have been mediated through changes in the biology and behaviour of capelin ( Mallotus villosus (Müller, 1776)), the focal forage species. To explore for effects at lower trophic levels, we combine dietary (1987–1988, 2003–2006) and distributional (1966–1990, 1998–1999) data for Leach’s storm-petrel ( Oceanodroma leucorhoa (Vieillot, 1818)), a small, abundant, and highly pelagic seabird. Fish and crustaceans formed the bulk of nestling diet at two colonies, with fish dominating in all sampling periods and years (occurrence >70%, reconstructed mass >75%). Five families were represented, but mature myctophids (glacier lanternfish ( Benthosema glaciale (Reinhardt, 1837)), horned lanternfish ( Ceratoscopelus maderensis (Lowe, 1839)), Protomyctophum arcticum (Lütken, 1892)) and sandlance (genus Ammodytes L., 1758) dominated. Crustaceans occurred frequently but typically comprised ≤10% by mass; Hyperia galba (Montagu, 1813) dominated this prey class. General diet composition was similar through time with birds relying heavily on myctophid fishes in 1987–1988 and 2003–2006. Crustacean diversity, however, declined with fewer species of hyperiid amphipods and no small euphausiids (genus Thysanoessa Brandt, 1851) consumed in 2003–2006. The latter parallels changes in spring diets of capelin and winter diets of murres (genus Uria Brisson, 1760) in the region. Associations of storm-petrels with deep water are consistent with the predominance of mesopelagic prey in their diets.
Butyric acid suppresses palatable food consumption in Siberian hamsters (Phodopus sungorus) housed in short, but not long, photoperiods
Authors: Workman Joanna L. , Johnson Eric M. , Martin Lynn B. , Nelson Randy J.
Published: September 2009

Short days induce winter-like adaptations in small mammals such as Siberian hamsters ( Phodopus sungorus (Pallas, 1773)). Specifically, hamsters adjust food consumption, metabolic processes, and immune function to optimize energetic needs and promote winter survival. One potentially inexpensive behavioral adaptation to increase survival is avoidance of infection. We tested the hypothesis that photoperiod affects avoidance of potentially infected food. In experiment 1, hamsters were weaned into either short or long days with ad libitum food. Three weeks later, hamsters were presented with either skim milk treated with butyric acid (2%), a bacterial product that serves as a potent cue of spoilage, or unadulterated skim milk; consumption was measured. After milk presentation, blood samples were obtained to assess cortisol. In experiment 2, skim-milk consumption was again assessed after 3 weeks in either short or long days. In experiment 3, we tested the hypothesis that food avoidance was due to photoperiod-induced differential neophobia. Short-day hamsters increased milk consumption, which was blocked by butyric acid. Short days increased cortisol concentrations; neither food restriction nor butyric acid affected cortisol concentrations. Photoperiod did not alter neophobic responses. These experiments suggest that short-day hamsters avoid food treated with butyric acid possibly as an adaptive trait to avoid costly winter infections.
Population genetic structure of raccoons (Procyon lotor) inhabiting a highly fragmented landscape
Authors: Dharmarajan Guha , Beasley James C. , Fike Jennifer A. , Rhodes Olin E.
Published: September 2009

The raccoon ( Procyon lotor (L., 1758)), a generalist mesocarnivore, has thrived in anthropogenically fragmented landscapes. In this study we utilized 13 microsatellites to analyze the population genetic structure in raccoons occupying an agriculturally fragmented habitat. Our analyses revealed low, but significant, levels of genetic structure (FST = 0.022, P < 0.001) among 645 raccoons inhabiting 29 spatially distinct habitat patches (neighborhoods). We found no evidence for the presence of either isolation by distance or barriers. However, spatial autocorrelation revealed evidence for social structure at the raccoon-neighborhood scale. About 30% of the variance in levels of social structure among raccoon neighborhoods was explained by effects of habitat-patch size and the percentage of land cover represented by forest around the individual habitat patch. We found strong evidence of sex-biased dispersal using direct (parentage analysis) and indirect (relatedness and assignment indices) genetic estimators. However, our analysis revealed that among dispersing raccoons there was no difference in dispersal distance between sexes and that dispersal events are randomly distributed with respect to distance. Our study provides evidence that demographic and behavioral processes affecting raccoon spatial organization may be most critical at very fine scales of biological organization, such as within individual habitat patches.
KOITER ESTIMATE REVISITED
Authors: DAUGE MONIQUE , FAOU ERWAN
Published: September 2009

We prove a general adimensional energy estimate between the solution of the three-dimensional Lamé system on a thin clamped shell and a displacement reconstructed from the solution of the classical two-dimensional Koiter model. This estimate only involves the thickness parameter ε, constants attached to the mid-surface S, the two-dimensional energy of the solution of the Koiter model and "wavelengths" associated with this latter solution. This bound is in the same spirit as Koiter's heuristic estimate in Ref. 26 and can be viewed as an a posteriori estimation of the modeling error by means of the two-dimensional solution. It is general with respect to the geometry of the mid-surface S which is an arbitrary smooth manifold with boundary. Taking boundary layer terms into account, we prove that our estimates are sharp in the cases of plates and elliptic shells.
THERMODYNAMIC STUDY OF CORROSION AND INHIBITOR ADSORPTION PROCESSES ONTO C38 STEEL/PIPERAZINES/PHOSPHORIC ACID SYSTEMS
Authors: OUSSLIM A. , OUNITI A. , BEKKOUCH K. , ELIDRISSI A. , HAMMOUTI B.
Published: September 2009

This paper describes the inhibition effect of 1-benzyl piperazine (P1) and bis(1-benzyl piperazine) thiuram disulfide (P2) towards the corrosion of C38 steel in 5.5 M H 3 PO 4 solution by potentiodynamic polarization and weight loss methods. The influence of inhibitor concentration and temperature on inhibitory behavior of P2 were investigated. The inhibition efficiency (IE) was found to be dependent on the type of piperazine and its concentration. The IE for 10-3 M P2 in 5.5 M H 3 PO 4 is greater than 98%. Polarization studies clearly revealed that both P1 and P2 act as mixed-type inhibitors. Adsorption isotherms were fitted by the Langmuir isotherm. Adsorption energies ([Formula: see text] and [Formula: see text]) were evaluated. Kinetic parameters were determined.
LIQUID–LIQUID INTERFACE STUDY OF HYDROCARBONS, ALCOHOLS, AND CATIONIC SURFACTANTS WITH WATER
Authors: SINGH MAN , MATSUOKA HIDEKI
Published: September 2009

Molecular interaction dynamics at liquid–liquid interface (LLI), involved nondispersive solution as compared with the interaction in bulk phase. Thereby, interfacial tension (IFT, mN/m) of LLI for four saturated hydrocarbons, six alcohols, and three cationic surfactants are reported at 298.15 K. The pentane, hexane, heptane, octane hydrocarbons and pentanol, hexanol, heptanol, 1-octanol, 2-octanol, and 1-decanol alcohols were used and IFT data were compared with 4 mm kg-1dodecyltrimethylammoniumbromide (DTAB), trimethylsulfoxoniumiodide (TMSOI), methyltrioctylammoniumchloride (MTOAC) surfactants studied in benzene–water LLI. The IFT data are noted as hydrocarbons > DTAB > TMSOI > alcohols > MTOAC. The hydrocarbons and alcohols decreased IFT within 16 to 49% and 87 to 92%, respectively, whereas the surfactants within 78.3 to 95.9%. The alcohols developed interaction similar to surfactants and are denoted as nonionic surfactants for making mixtures of low IFT with hydrophilic and hydrophobic interactions to the level of the surfactants. The pentanol and MTOAC caused similar decrease in IFT so the pentanol developed the hydrophilic and hydrophobic interactions of the strength of MTOAC. Comparatively, the hydrocarbons showed lower decrease but the octane showed 49% decrease in IFT. Thus, the hydrocarbon with longer alkyl chain and the alcohol with shorter behave as good surfactants. The hydrocarbons with inductive effect on sigma bond between carbon atoms in alkyl chain also weakened the IFT and influenced the hydrophobic interactions. The MTOAC with four octyl units reduced 96% IFT so inductive effects monitor LLI dynamics.
The Extended Opening Session of the Futures Market and Stock Price Behavior: Evidence from the Taiwan Stock Exchange
Authors: Lee Hsiu-Chuan , Chien Cheng-Yi , Chen Hsiang-Lan , Huang Yen-Sheng
Published: September 2009

This paper examines how the introduction of the extended opening session of the futures market affects stock price behavior around the market opening. On January 1, 2001, the Taiwan Futures Exchange (TAIFEX) extended the trading hours by opening earlier 15 minutes than the Taiwan Stock Exchange (TWSE). This change presents an opportunity to analyze how the extended opening session of futures market affects stock price behavior. Compared with the pre-extension period, the empirical results show that stock returns are less volatile and return autocorrelations are less positively correlated around the stock market opening. Moreover, overreaction for opening prices of the stock market is mitigated in the post-extension period. Finally, unexpected futures returns during the extended opening session can predict overnight stock returns. Overall, the empirical results are consistent with Foster and Viswanathan (1990) in that informed traders will trade aggressively at the market opening.
The Impact of Auditors' Opinions, Macroeconomic and Industry Factors on Financial Distress Prediction: An Empirical Investigation
Authors: Tsai Bi-Huei , Lee Cheng-Few , Sun Lili
Published: September 2009

This study investigates the usefulness of auditors' opinions, market factors, macroeconomic factors, and industry factors in predicting financial distress of Taiwanese firms. Specifically, two non-traditional auditors' opinions are evaluated: "long-term investment audited by other auditors" ("other auditor"), and "realized investment income based on non-audited financial statements" ("no auditor").

The results of the 22 discrete-time hazard models show that "other auditor" opinions have incremental contribution in predicting financial distress, in addition to "going concern" opinions. This suggests that "other auditor" opinions possess higher risk of overstating earnings and firms with such income items are more likely to fail. Besides, we find that the macroeconomic factors studied significantly explain financial distress. Particularly, the survivals of electronic firms are more sensitive to earnings due to higher earnings fluctuations in such firms. Finally, models with auditors' opinions, market factors, macroeconomic factors, and industry factors perform better than the financial ratio-only model in financial distress prediction.
Cash Holdings, Corporate Governance Structure and Firm Valuation
Authors: Lee Kin-Wai , Lee Cheng-Few
Published: September 2009

Firms with higher board independence, smaller boards, and lower expected managerial entrenchment, have lower cash holdings. We find that the positive association between cash holdings and managerial entrenchment is mitigated by stronger board structures. Specifically, in firms with higher expected managerial entrenchment, those with higher proportion of outside director on the board and smaller board size have lower cash holdings. We also find that firm value is negatively associated with cash levels. The negative association between firm value and cash holdings is more pronounced in firms with (i) lower proportion of outside directors, (ii) larger boards and (iii) higher expected managerial entrenchment. For firms with both high cash holdings and high expected managerial entrenchment, investors additionally discount the valuation of firms with lower proportion of outside directors and those with larger boards.
Are Structural VARs with Long-Run Restrictions Useful for Developing Monetary Policy Strategy in Egypt?
Authors: Hachicha Ahmed , Lee Cheng-Few
Published: September 2009

On the basis of SVAR models of monetary policy in Egypt for the period December 1976–May 2006, our paper explores a new empirical assessment for the interest rate channel in correcting trouble in the Egyptian economy by imposing contemporaneous and long run restrictions. It appears that after a monetary policy expansion, output is stable in the first period, rises temporarily reaching the baseline at t = 40, and the global monetary aggregate rises but not significantly. In addition, the price level rises with great difficulties in response to a negative interest rate shock to the global liquidity aggregate. The excess of money supply has a transitory effect on the Egyptian output but it causes inflation pressures.

SVAR Blanchard and Quah (1989) estimation reveals contradictory results to the previous findings. Last but certainly not least, this means that the effect of bank lending and the interest rate channels on the economy are limited in time.

The paper shows that the transmission of monetary policy through the interest rate channel has become weak in the short run but more important in the long run. Nonetheless, the bank lending channel through the commercial bank lending is not a potent monetary transmission mechanism.
Does Stock Misvaluation Differentiate the Motives for Takeovers?
Authors: Shih Yi-Cheng , Hsu Bai-Jia
Published: September 2009

We use pre-offer market valuations to examine the motives for takeovers under the misvaluation theory. According to previous literature, the motives for merger and acquisition consist of synergy, agency and hubris. We find that overvalued acquirers paying by cash have the motives of synergy and hubris. However, overvalued acquirers paying by stock have the motives of agency and hubris. On the other hand, the motive of undervalued acquirers paying by cash is only hubris. Lastly, the motives of those undervalued acquirers paying by stock are synergy and hubris. In this study, we provide the empirical evidence to show that acquirers' stock misevaluation and their payment methods will differentiate the motives for takeovers.
DISTRIBUTED ENERGY-EFFICIENT ALGORITHMS FOR COVERAGE PROBLEM IN ADJUSTABLE SENSING RANGES WIRELESS SENSOR NETWORKS
Authors: VU CHINH , CAI ZHIPENG , LI YINGSHU
Published: September 2009

Due to wide range of applications of Wireless Sensor Network (WSN), lots of effort has been dedicated to solve its various issues. Among those issues, coverage is one of the most fundamental ones of which a WSN has to watch over the environment such as a forest (area coverage) or set of subjects such as collection of precious renaissance paintings (target of point coverage) and collect environment parameters and maybe, further monitor the environment. With variable sensing range, the difficulties to cover a continuous space (where number of points is infinity) in the area coverage problem becomes somewhat harder than covering limited number of discrete points in the target coverage problem. Very few papers have paid effort for the former problem. In this paper, we consider the area coverage problem for WSN where sensors can arbitrarily change their sensing ranges under some upper bound. We first improve the work in [1] so that the boundary effect is ruled out and the monitored area can be completely covered at all cases. Next, we extend that improved algorithm by introducing two distributed scheduling algorithms which are trade-off in term of network lifetime and algorithms efficiency. The major objective of each of our 3 proposed algorithms in this paper is to balance energy consumption and to maximize network lifetime. Our proposed algorithm efficiency is shown by algorithms complexity analysis and extensive simulation. In compared with the work in [1], our proposed algorithms are not only better in providing coverage quality, they could also greatly lengthen network lifetime and greatly reduce the unnecessary coverage redundancy.
ODD GRACEFUL LABELINGS OF GRAPHS
Authors: GAO ZHEN-BIN , ZHANG XIAO-DONG , XU LI-JUAN
Published: September 2009

A graph G = (V(G), E(G)) with q edges is said to be odd graceful if there exists an injection f from V(G) to {0, 1, 2, …, 2q - 1} such that the edge labeling set is {1, 3, 5, …, 2q - 1} with each edge xy assigned the label |f(x) - f(y)|. In this paper, we prove that Pn × Pm (m = 2, 3, 4), generalized crown graphs Cn ⊙ K1,t and gear graphs are odd graceful.
Comparison of Jet Spray and Megasonic Module for a Cleaning of Aluminum Layer Surface
Authors: Min Jaewon , Kim Nackhoon , Yang Jichul , Park Youngkyou , Kim Taesung
Published: September 2009

Megasonic and jet spray cleaning in single wafer process have been used for many years for removing particulate contaminants from wafer surface. These methods were alternately used during manufacturing process. As the design rule of novel devices shrinks to the nanometer scale, particle contaminations caused significant drop in product yield. To increase the particle removal efficiency (PRE), we optimized the cleaning methods for each material surface. These optimized methods were evaluated for aluminum surface cleaning in terms of the PRE and pattern damage. We observed that jet spray cleaning is more effective than megasonic cleaning process for aluminum surface layer. Similarly the PRE in jet spray is high as compared with megasonic due to the effect of CO2 dissolved DI water.
Modeling Techniques for Strained CMOS Technology
Authors: Sverdlov Viktor , Baumgartner Oskar , Windbacher Thomas , Selberherr Siegfried
Published: September 2009

We review modeling techniques used to compute strain induced performance enhancement of modern MOSFETs. While p-channel MOSFETs were intensively studied, electron transport in strained structures received surprisingly little attention. A rigorous analysis of the subband structure in thin silicon films under stress is performed. Calculated subband effective masses are shown to strongly depend on shear strain and film thickness. A decrease of the transport effective mass under tensile stress in [110] direction and an additional splitting between the unprimed subbands with the same quantum number guarantees a mobility enhancement even in ultra-thin (001) silicon films. This increase of mobility and drive current combined with the improved channel control makes multi-gate MOSFETs based on thin films or silicon fins preeminent candidates for the 22nm technology node and beyond.
Ultrathin Body Effects in Multiple Gate SOI Transistors
Authors: Gamiz Francisco , Donetti Luca , Sampedro Carlos , Godoy Andres , Rodriguez Noel
Published: September 2009

We will review the electrostatics and transport properties of charge carriers in ultrathin multiple gate SOI transistors. Both electron and hole inversion layers will be studied and characterized as a function on the silicon thickness and for different crystallographic orientations.
Low-temperature Oxidation of Semiconductor Surfaces by use of a Novel High-density Microwave Plasma Apparatus
Authors: Gschwandtner Alexander , Lerch Wilfried
Published: September 2009

This paper describes a new microwave plasma oxidation apparatus with unique features addressing the near room temperature low temperature process for forming high quality dielectrics with minimum dopant deactivation and redistribution. With this new technique the oxide growth rate was studied as a function of time, gaseous ambient, pressure, applied microwave power and silicon substrate parameters to determine crystallographic oxidation rate anisotropy and dopant concentration dependent oxidation at temperatures much below 400 {degree sign}C. Furthermore, the plasma oxide was also electrically evaluated (C-V- and I-V curves) after as grown, a post plasma anneal up to maximum temperature of 700 {degree sign}C and a post-metallization forming gas anneal. The breakdown strength improved considerably up to 7 MV/cm and the interface trap density decreased much below 10^11 states/eVcm2 so that the oxide quality is comparable to thermal oxides.
Analysis of Remote Coulomb Scattering Limited Mobility in MOSFET with CeO2/La2O3 Gate Stacks
Authors: Mamatrishat Mamat , Kouda Miyuki , Kakushima Kuniyuki , Ahmet Parhat , Tsutsui Kazuo , Sugii Nobuyuki , Natori Kenji , Hattori Takeo , Iwai Hiroshi
Published: September 2009

Remote Coulomb Scattering (RCS) limited mobility in CeO2 capped La2O3 high-k MOSFETs was studied. The RCS mobility was calculated by quantum mechanical calculations. Experimental mobility data has been measured from nMOSFETs with ultrathin gate oxide with thickness of 1.5nm, and has been compared to the calculated RCS mobility. The result shows that the mobility degradation in CeO2 / La2O3 gate stack MOSFETs might be due to the RCS.
Comparison of the Electrochemical Polishing of Copper and Aluminum in Acid and Acid-free Media
Authors: Abdel-Fattah Tarek M. , Loftis Jon Derek
Published: September 2009

Electrochemical polishing of aluminum and copper was conducted in 1 M phosphoric acid and in acid-free ionic liquid electrolyte prepared from quaternary ammonium salt as a green polishing solution. Voltammetry tests were used to determine the optimum condition for electrochemical polishing of aluminum and copper samples in both phosphoric acid and ionic liquid media. Atomic force microscopy (AFM), digital microscopy, and surface morphology comparisons summarized electrochemical polishing efficiency in term of surface roughness of acid and acid-free treatments for copper and aluminum. The eco-friendly ionic liquid produced polished surfaces superior to those surfaces produced with standard industrial acidic solution.
Dopant Segregated Schottky (DSS) Source/Drain for Germanium p-MOSFETs with Metal Gate/High-k Dielectric Stack
Authors: Lim Phyllis S. , Chi Dong Zhi , Lo Guo Qiang , Yeo Yee-Chia
Published: September 2009

Dopant Segregated Schottky (DSS) Source/Drain (S/D) for Germanium p-MOSFETs with Metal Gate/High-k Dielectric Stack are demonstrated for the first time. The MOSFETs were fabricated using a CMOS-compatible process flow and 200 mm Ge-on-Si substrates. Dopant segregation induced by nickel germanide formation in the S/D was achieved using low process temperatures up to 400 degree celcius.
Physics of Nano-contact between Si Quantum Dots and Inversion Layer
Authors: Sakurai Yoko , Nomura Shintaro , Takada Yukihiro , Iwata Jun-ichi , Shiraishi Kenji , Muraguchi Masakazu , Endoh Tetsuo , Shigeta Yasuteru , Ikeda Mitsuhisa , Makihara Katsunori , Miyazaki Seiichi
Published: September 2009

Physics of nano-contact in metal-oxide-semiconductor field-effect transistors has been attracting interests of many researchers recently. Contacts are conventionally treated as a reservoir in thermal equilibrium, but behavior of contacts in ultra-small devices is still open questions. In this paper, we investigate electron tunneling between a two-dimensional electron gas (2DEG) and Siquantum dots (QDs) using Si-QDs floating gate metal-oxide-semiconductor (MOS) capacitor samples and found unexpected temperature dependence. This unusual tunneling behavior was phenomenologically explained by considering the wave functions of the 2DEG explicitly. The observed temperature dependence of tunneling currents is originated from the non-thermal-equilibrium nature of the 2DEG electrode.
Organic Semiconductor Lasers
Authors: Turnbull Graham A. , Yang Ying , Vasdekis Andreas E. , Ruseckas Arvydas , Samuel Ifor D.
Published: September 2009

We describe two examples of hybrid organic semiconductor lasers that integrate semiconducting polymers onto inorganic semiconductors. A compact, silicon-based organic semiconductor laser is demonstrated that integrates tunable red light emission to a silicon-on-insulator platform. We also demonstrate indirect electrical excitation of hybrid organic semiconductor lasers, using a polymer distributed feedback laser integrated onto an InGaN light-emitting diode.
Advanced Application of Resistivity and Hall Effect Measurements to Characterization of Silicon
Authors: Voronkov Vladimir V. , Voronkova Galina I. , Batunina Anna V. , Falster Robert
Published: September 2009

The resistivity measured in dependence of the temperature can be used to deduce the carrier concentration n(T) or p(T), and this technique is more reliable than the conventionally used Hall effect. Yet a parallel measurement of both the resisitivity and the Hall coefficient is desirable to determine the apparent Hall mobility, which is a useful tool to control the spatial uniformity of samples.
Electrical Characterization of Deep-Lying Donor Layers Created by Proton Implantation and Subsequent Annealing in N-Type Float Zone and Czochralski Silicon
Authors: Komarnitskyy Volodymyr , Hazdra Pavel
Published: September 2009

The deep-lying donor layers created by proton implantation and subsequent isochronal annealing were investigated in silicon substrates with oxygen concentration changing from 2x10^16 cm-3 to 1.4x10^18 cm-3. Implantation was performed with 700 keV and 1.8 MeV protons to fluence ranging from 1x10^10 to 1x10^15 cm-2. Results of C-V measurement showed that proton implantation introduces a Gaussian like distribution of shallow hydrogen donors that corresponds to the profile of implanted hydrogen obtained from the secondary ion mass spectroscopy measurement. Subsequent isochronal annealing leads to annealing out of hydrogen donors (~250{degree sign}C) and formation of a series of hydrogen thermal donors (250-350{degree sign}C). In substrates with enhanced concentration of oxygen, the radiation enhanced thermal donors and ordinary thermal donors (>400{degree sign}C) were registered. It was shown that the introduction rate of hydrogen and thermal hydrogen donor layers is enhanced in materials with higher oxygen concentration. However, low oxygen concentration is preferred when better control over spatial distribution of the excess donor profiles is required.
The Application of Differential Hall Effect Continuous Anodic Oxidation Technique for Ultra Shallow Structures
Authors: Prussin Simon , Reyes Jason
Published: September 2009

The differential Hall effect CAOT permits rapid, accurate measurements of mobility, resistivity, and carrier concentration. This permits us to extract defect scattering contributions to the mobility for comparison of doping and annealing techniques. The co-implantation of C with P was evaluated and showed that besides restricting the diffusion of P, the carrier concentration was significantly reduced. The application of DHE CAOT to the evaluation of doped polysilicon films permitted the evaluation of carrier concentration and mobility profiles. The latter has been correlated to grain size.
Characterization and Modeling of the Electrical Behavior and Threshold Voltage of the Nanocrystalline GZO Delta-doped ZnO TFTs
Authors: Hsiao Shih-Hua , Liu Kuang Chung , Chiang Hung-Li , Su Liang Yu , Peng Lung Han , Huang JianJang
Published: September 2009

A ZnO TFT with high operating current and adjustable threshold voltage is demonstrated by inserting a thin GZO layer within the ZnO layer. The TFTs of the proposed structure are fabricated, and the conventional TFTs are fabricated for comparison. The threshold voltage model of this TFT considering the device structure and the nanocrystalline property is developed and verified with the experimental results.
Comparison oF Electrical Measurements with Structural Analysis oF Thin High-k Hafnium-based Films
Authors: Hourdakis Emmanouel , Theodoropoulou M , Nassiopoulou Androula G. , Parisini Andrea , Reading Michael A. , Van den Berg Jaap , Conard T. , Degendt S.
Published: September 2009

We present a detailed characterization of thin high-k Hf-based dielectric/SiO2 stacks on Si by electrical measurements (capacitance - voltage (C-V) and current-voltage (I-V)), structural analysis using transmission electron microscopy (TEM) and compositional analysis using medium energy ion scattering (MEIS). We show that the electrical results are consistent with and can be explained by the structural and compositional results. Specifically, the structural results show that the effect of nitridation of the films using a decoupled plasma nitridation method is an increase in SiO2 thickness, which results in a capacitance and leakage current decrease, revealed by the electrical measurements. Nitridation also reduces the density of interface traps for these samples. The reduction is more effective in the case of nonstoichiometric hafnium silicate films (HfSiOx) than in the case of HfO2.
A Study of the Morphology of 3C-SiC Layers Grown at Different C/Si Ratios
Authors: Attolini Giovanni , Watts Bernard E. , Bosi Matteo , Rossi Francesca , Riesz Ferenc
Published: September 2009

A comparative study of the morphology of 3C-SiC films prepared with different C:Si ratios is presented. The silane precursor controls the growth rate at all values of C:Si ratio but combined observations using Atomic Force Microscopy and Scanning Electron Microscopy indicate that the C:Si ratio is critical in determining the grain size and faceting at C:Si values close to 1. Makyoh topography reveals various surface defects, a slight mesoscale roughness and bending of the epiwafers.
Investigations of the Surface Chemical Composition and Atomic Structure of ex-situ Sulfur Passivated Ge(100)
Authors: Fleischmann Claudia , Sioncke Sonja , Schouteden K. , Paredis Kristof , Beckhoff Burkhard , Mueller Matthias , Kolbe Michael , Meuris Marc , Van Haesendonck C. , Temst Kristiaan , Vantomme Andre
Published: September 2009

Using complementary surface analysis techniques, we have studied the chemical and structural properties of the S/Ge(100) passivation layer formed upon sulfidation in an aqueous (NH4)2S solution. Our experiments have revealed that only S-Ge bonds are formed upon the adsorption of S and that the surface is essentially free of other S-containing species (i.e. Sn or SOx). The passivation treatment was found to reduce, but not to fully inhibit Ge-O bonds on the surface. Moreover, we have shown that the top-layer of the passivated surface shows a high degree of disorder even though it is associated with a spotty (1x1) RHEED pattern. Based on our experimental findings, we conclude that the passivation layer can be best described as a thin amorphous GeSxOy film atop a partially ordered interfacial layer, a surface model that has been proposed previously in literature.
Progress in the Metal Supported Solid Oxide Fuel Cells and Stacks for APU
Authors: Szabo Patric , Arnold Johannes , Franco Thomas , Gindrat Malko , Refke Arno , Zagst Armin , Ansar Asif
Published: September 2009

DLR is one of the pioneer groups to introduce metal supported solid oxide fuel cells (MS-SOFC) in mid 90s and it is continuing the development of the concept towards a reliable light weight 1 kW stack for APU in a funded consortium with ElringKlinger, Plansee and Sulzer Metco. The joint work is an integrated approach incorporating improved materials for functional layers, advanced industrial scale manufacturing and an evolved stack design to define a pilot production set-up for large volume manufacturing. At laboratory scale, the latest generation button cells (12 to 15 cm² effective area) exhibited more than 750 and 520 mW/cm² respectively with hydrogen and simulated reformate gas as fuel at 800{degree sign}C. 2000 hours tests were performed with degradation rate of less than 1.5%/kh. Redox stability of these cells was demonstrated for 20 cycles during which the anodes were fully oxidized. Up-scaling to 85 cm² and 100 cm² effective area cells was accomplished and the cells showed 400 mW/cm² power density using simulated reformate gas at a fuel utilisation of 32%. Further improvements consisting of developing large scale industrial processes for the fabrication of functional layers including low pressure plasma spraying (LPPS) and atmospheric plasma spraying (APS) with TriplexPro are in progress. The aim is to get higher productivity and reproducibility. In addition, a new alloy for interconnects and substrates will be incorporated to further enhance the durability of cells.
Influence of Operating Conditions on the Reliable Performance of Stacks and Integrated Stack Modules
Authors: Mai Bjoern E. , Heller Thomas , Schimanke Danilo , Lawrence Jeremy , Wunderlich Christian
Published: September 2009

Reliable performance of SOFC stacks and Integrated Stack Modules (ISM) are determined by a robust stack design as well as an optimized operation regime. The following paper gives insight to some of the test methods Staxera has established to develop operation procedures that will allow a robust and long term stable performance of stacks and ISMs. As a result more than 12000h of operation and more than 50 thermal cycles could be demonstrated.
Recent Results in Solid Oxide Fuel Cell Development at Forschungszentrum Juelich
Authors: Steinberger-Wilckens Robert , Blum Ludger , Buchkremer Hans Peter , De Haart L.G.J. , Pap Michael , Steinbrech Rolf W. , Uhlenbruck Sven , Tietz Frank
Published: September 2009

The SOFC group at FZJ has assembled and tested more than 350 SOFC stacks rated between 100 W and 15 kW during the last 15 years. The research topics covered stretch from materials over stack design, manufacturing of cells, stacks and components, mechanical and electrochemical characterisation, up to system design and demonstration. Use of improved steels, cathodes and materials processing has resulted in reduced degradation rates around 6 mV (0.75%) per 1000 hours at 700{degree sign}C and 500 mA/cm² over tested stack lifetimes of over 15 000 hours. However, the target of development is directed at even further lowered degradation for commercial operation in stationary applications. A recent stack displays a degradation of approx. 3 mV (0.4%) per 1000 hours running at 800{degree sign}C and 500 m/cm². This paper gives an overview of some of long-term testing results.