610 research outputs found
Semicontinuity for representations of one-dimensional Cohen-Macaulay rings
We show that the number of parameters for CM-modules of prescribed rank is
semi-continuous in families of CM rings of Krull dimension 1. This transfers a
result of Knoerrer from the commutative to the not necessarily commutative
case. For this purpose we introduce the notion of ``dense subrings'' which
seems rather technical but, nevertheless, useful. It enables the construction
of ``almost versal'' families of modules for a given algebra and the definition
of the ``number of parameters''. The semi--continuity implies, in particular,
that the set of so-called ``wild algebras'' in any family is a countable union
of closed subsets. A very exciting problem is whether it is actually closed,
hence whether the set of tame algebras is open. However, together with the
results of a former paper of the authors the semi-continuity implies that tame
is indeed an open property for curve singularities (commutative CM rings). An
analogous procedure leads to the semicontinuity of the number of parameters in
other cases, like representations of finite dimensional algebras or finite
dimensional bimodules.Comment: LaTeX2
Оценки цены акций классическими методами: критика их надежности и влияние поведенческих финансов
При спробі з'ясувати, який метод використовувати для оцінки акцій у перший раз, більшість інвесторів швидко виявить величезну кількість методів оцінки, доступних їм сьогодні. Існують прості у використанні, такі як метод зіставлень, є більш привабливі методи, такі як модель дисконтування грошових потоків, але всі з них, мають свої власні проблеми та обмеження, а також вплив поведінкових фінансів. Компанії мають внутрішню цінність, і внутрішня вартість базується на кількості вільного грошового потоку, який вони можуть забезпечити протягом їхнього строку служби. Гроші пізніше коштують менше, ніж гроші зараз, проте, майбутні вільні грошові потоки будуть дисконтовані за відповідною ставкою. Теорія за більшістю методів оцінки акцій полягає в тому, що вартість бізнесу дорівнює сумі вартості всіх майбутніх вільних грошових потоків. Усі майбутні грошові потоки дисконтуються через часові гроші. Якщо ви об'єктивно знаєте всі майбутні грошові потоки компанії, і у вас є цільова норма прибутку на ваші гроші, то ви можете дізнатися точну суму грошей, яку ви повинні сплачувати за цю компанію. Під час підготовки до роботи були використані наступні методи: систематичний аналіз наукової літератури; Порівняльний аналіз; Систематизація, порівняння та підведення підсумків результатів. Поведінкові фінанси в теоретичному плані на основі сукупності та розвитку інституційної структури та практичних проявів стають все більш важливим елементом-каталізатором розвитку фінансових ринків. На жаль, немає жодного методу, який би найкраще підходив для кожної ситуації. Кожна акція різна, і кожен сектор промисловості має унікальні властивості, які можуть потребувати різних підходів до оцінки. У цій статті ми структуруємо і порівнюємо різні методи, їх сильні і слабкі сторони.When trying to figure out which valuation method to use to value a stock for the first time, most investors will quickly discover the overwhelming number of valuation techniques available to them today. There are the simple to use ones, such as the comparable method, and there are the more involved methods, such as the discounted cash flow model besides all of them have their own problems and limitations as well as impacted with behavioral finance. Companies have an intrinsic value, and that intrinsic value is based on the amount of free cash flow they can provide during their effective lifetime. Money later is worth less than money now, however, so future free cash flows have to be discounted at an appropriate rate. The theory behind most stock valuation methods is that the value of a business is equal to the sum value of all future free cash flows. All future cash flows are discounted due to the time value of money. If you objectively know all future cash flows of a company, and you have a target rate of return on your money, then you can know the exact amount of money you should pay for that company. Preparing the work, the following methods were used: Systematic analysis of the scientific literature; Comparative analysis; Systematization, comparison and summarizing of the results. Behavioral Finance in the theoretical plane based on a cumulative and develop the institutional framework and practical manifestations become increasingly important element-catalyst for the development of financial markets. Unfortunately, there is no one method that is best suited for every situation. Each stock is different, and each industry sector has unique properties that may require varying valuation approaches. In this article we structure and compare different methods, their strengths and weaknesses.При попытке выяснить, какой метод использовать для оценки акций в первый раз, большинство инвесторов быстро обнаружит подавляющее количество методов оценки, доступных им сегодня. Существуют простые в использовании, такие как метод сопоставлений, есть более привлекательные методы, такие как модель дисконтированных денежных потоков, но все они, имеют свои собственные проблемы и ограничения, а также влияние поведенческих финансов. Компании имеют внутреннюю ценность, и эта внутренняя ценность основана на количестве свободного денежного потока, который они могут предоставить в течение их эффективного срока службы. Однако деньги позже стоят меньше денег сейчас, поэтому будущие свободные денежные потоки должны быть дисконтировані по соответствующей ставке. Теория, лежащая в основе большинства методов оценки акций, заключается в том, что стоимость бизнеса равна сумме всех будущих свободных денежных потоков. Все будущие денежные потоки дисконтируются из-за временной стоимости денег. Если вы объективно знаете все будущие денежные потоки компании, и у вас есть целевая ставка прибыли на ваши деньги, то вы можете узнать точную сумму денег, которую вы должны заплатить за эту компанию. При подготовке работы использовались следующие методы: систематический анализ научной литературы; Сравнительный анализ; Систематизация, сравнение и обобщение результатов. Поведенческие финансы в теоретическом плане, основанные на накоплении и развитии институциональных рамок и практических проявлений, становятся все более важным элементом-катализатором развития финансовых рынков. К сожалению, нет ни одного метода, который бы лучше всего подходил для каждой ситуации. Каждая акция разная, и каждый сектор промышленности обладает уникальными свойствами, которые могут потребовать различных подходов к оценке. В этой статье мы структурируем и сравниваем различные методы, их сильные и слабые стороны
Lunar surface dynamics: Some general conclusions and new results from Apollo 16 and 17
Exposure ages of Apollo 17 rocks as measured by tracks and the Kr-Kr rare gas method are reported. Concordant ages of 22 - or + 1 million year (my) are obtained for the station 6 boulder sample 76315. This value is interpreted as the time when the station 6 boulder was emplaced in its present position. Reasonable agreement is also obtained by the two methods for another station 6 boulder, sample 76015. Discordant ages (respectively 5 and 28 my by the track and rare gas methods) are obtained for the station 7 boulder sample, 77135, indicating that the boulder was emplaced at least 5 my ago. The 72 my exposure age of 75035, in general agreement with previous measurements of approximately 85 my for another Camelot boulder, may well date the formation of Camelot. Rock 76015 was split and one surface exposed to the sky through a very small solid angle
Inorganic salts interact with organic di-acids in sub-micron particles to form material with low hygroscopicity and volatility.
Volatility and hygroscopicity are two key properties of organic aerosol components, and both are strongly related to chemical identity. Here we show that inorganic-organic component interactions typically not considered in atmospheric models may strongly affect aerosol volatility and hygroscopicity. In particular, bi-dentate binding of di-carboxylic acids (DCA) to soluble inorganic ions can lead to very strongly bound metal-organic complexes with largely undetermined hygroscopicity and volatility. These reactions profoundly impact particle hygroscopicity, transforming hygroscopic components into irreversibly non-hygroscopic material. While the hygroscopicities of pure salts, DCA, and DCA salts are known, the hygroscopicity of internal mixtures of hygroscopic salts and DCA, as they are typically found in the atmosphere, has not been fully characterized. We have studied the volatility of pure, dry organic salt particles and the hygroscopicity of internal mixtures of oxalic acid (OxA, the dominant DCA in the atmosphere) and a number of salts, both mono- and di-valent. The formation of very low volatility organic salts was confirmed, with minimal evaporation of oxalate salt particles below 75 C. Dramatic increases in the CCN activation diameter for particles with divalent salts (e.g. CaCl2) and relatively small particle mass fractions of OxA indicate that standard volume additivity rules for hygroscopicity do not apply. Thus small organic compounds with high O : C are capable of forming low volatility and very low hygroscopicity particles. Given current knowledge of the formation mechanisms of OxA and M-Ox salts, surface enrichment of insoluble M-Ox salts is expected. The resulting formation of an insoluble coating of metal-oxalate salts can explain low particle hygroscopicities. The formation of particles with a hard coating could offer an alternative explanation for observations of glass-like particles with very low viscosity
Structural phase transitions and their influence on Cu+ mobility in superionic ferroelastic Cu6PS5I single crystals
The structural origin of Cu+ ions conductivity in Cu6PS5I single crystals is
described in terms of structural phase transitions studied by X-ray
diffraction, polarizing microscope and calorimetric measurements. Below the
phase transition at Tc=(144-169) K Cu6PS5I belongs to monoclinic, ferroelastic
phase, space group Cc. Above Tc crystal changes the symmetry to cubic
superstructure, space group F-43c (a=19.528); finally at 274K disordering of
the Cu+ ions increases the symmetry to F-43m, (a=9.794). The phase transition
at 274K coincides well with a strong anomaly in electrical conductivity
observed in the Arrhenius plot. Diffusion paths for Cu+ ions are evidenced by
means of the atomic displacement factors and split model. Influence of the
copper stechiometry on the Tc is also discussed.Comment: conference pape
A study of the gravitational wave form from pulsars II
We present analytical and numerical studies of the Fourier transform (FT) of
the gravitational wave (GW) signal from a pulsar, taking into account the
rotation and orbital motion of the Earth. We also briefly discuss the
Zak-Gelfand Integral Transform. The Zak-Gelfand Integral Transform that arises
in our analytic approach has also been useful for Schrodinger operators in
periodic potentials in condensed matter physics (Bloch wave functions).Comment: 6 pages, Sparkler talk given at the Amaldi Conference on
Gravitational waves, July 10th, 2001. Submitted to Classical and Quantum
Gravit
Medication use in pregnancy: a cross-sectional, multinational web-based study
Objectives: Intercountry comparability between studies on medication use in pregnancy is difficult due to dissimilarities in study design and methodology. his study aimed to examine patterns and factors associated with medications use in pregnancy from a multinational perspective, with emphasis on type of medication utilised and indication for use. Design: Cross-sectional, web-based study performed within the period from 1 October 2011 to 29 February 2012. Uniform collection of drug utilisation data was performed via an anonymous online questionnaire. Setting: Multinational study in Europe (Western, Northern and Eastern), North and South America and Australia. Participants: Pregnant women and new mothers with children less than 1 year of age. Primary and secondary outcome measures: Prevalence of and factors associated with medication use for acute/short-term illnesses, chronic/long-term disorders and over-the-counter (OTC) medication use. Results: The study population included 9459 women, of which 81.2% reported use of at least one medication (prescribed or OTC) during pregnancy. Overall, OTC medication use occurred in 66.9% of the pregnancies, whereas 68.4% and 17% of women reported use of at least one medication for treatment of ute/short-term illnesses and chronic/long-term disorders, respectively. The extent of self-reported medicated illnesses and types of medication used by indication varied across regions, especially in relation to urinary tract infections, depression or OTC nasal sprays. Women with higher age or lower educational level, housewives or women with an unplanned pregnancy were those most often reporting use of medication for chronic/long-term disorders. Immigrant women in Western (adjusted OR (aOR): 0.55, 95% CI 0.34 to 0.87) and Northern Europe (aOR: 0.50, 95% CI 0.31 to 0.83) were less likely to report use of medication for chronic/long-term disorders during pregnancy than nonimmigrants. Conclusions: In this study, the majority of women in Europe, North America, South America and Australia used at least one medication during pregnancy. There was a substantial inter-region variability in the types of medication used
Characterization of Nanodiamondbased anti-HIV drug Delivery to the Brain
Human Immunodefciency Virus Type 1 (HIV-1) remains one of the leading causes of death worldwide. Present combination antiretroviral therapy has substantially improved HIV-1 related pathology. However, delivery of therapeutic agents to the HIV reservoir organ like Central nervous system (CNS) remains a major challenge primarily due to the inefective transmigration of drugs through Blood Brain Barrier (BBB). The recent advent of nanomedicine-based drug delivery has stimulated the development of innovative systems for drug delivery. In this regard, particular focus has been given to nanodiamond due to its natural biocompatibility and non-toxic nature–making it a more efcient drug carrier than other carbon-based materials. Considering its potential and importance, we have characterized unmodifed and surface-modifed (-COOH and -NH2) nanodiamond for its capacity to load the antiHIV-1 drug efavirenz and cytotoxicity, in vitro. Overall, our study has established that unmodifed nanodiamond conjugated drug formulation has signifcantly higher drug loading capacity than surfacemodifed nanodiamond with minimum toxicity. Further, this nanodrug formulation was characterized by its drug dissolution profle, transmigration through the BBB, and its therapeutic efcacy. The present biological characterizations provide a foundation for further study of in-vivo pharmacokinetics and pharmacodynamics of nanodiamond-based anti-HIV drugs
Synthesis and Characterization of LiFePO4 and LiTi0.01Fe0.99PO4 Cathode Materials
Nanocrystalline LiFePO4 and doped LiTi0.01Fe0.99PO4 powders were synthesized via a sol-gel preparation route. High-resolution tunneling electron microscopy observation and energy dispersive spectroscopy, mapping show the homogeneous distribution of dopant Ti cations in the crystals. Fe and O K -edge X-ray absorption near-edge structure (XANES) measurements show that Ti4+ doping induces an increased unoccupied d-state in LiFePO4, resulting in an enhanced p-type semiconductivity. In situ Fe K -edge XANES measurements of Ti-doped and undoped LiFePO4 electrodes have been performed to determine the change of Fe valence during the lithium intercalation and de-intercalation processes. Both LiFePO4 and doped LiTi0.01Fe0.99PO4 cathodes demonstrate good electrochemical performance
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