Risk assessment of credit portfolios is of pivotal importance in the banking industry. The bank that has the most accurate view of its credit risk will be the most profitable. One of the main pillars in the assessing credit risk is the estimated probability of default of each counterparty, ie the probability that a counterparty cannot meet its payment obligations in the horizon of one year. A credit rating system takes several characteristics of a counterparty as inputs and assigns this counterparty to a rating class. In essence, this system is a classifier whose classes lie on an ordinal scale.
In this paper we apply linear regression ordinal logistic regression, and support vector machine techniques to the credit rating problem. The latter technique is a relatively new machine learning technique that was originally designed for the two-class problem. We propose two new techniques that incorporate the ordinal character of the credit rating problem into support vector machines. The results of our newly introduced techniques are promising.
Self-organization in a polymer system appears when a balance is achieved between long-range repulsive and short-range attractive forces between the chemically different building blocks. Block copolymers forming supramolecular assemblies in aqueous media represent materials which are extremely useful for the construction of drug delivery systems especially for cancer applications. Such formulations suppress unwanted physicochemical properties of the encapsulated drugs, modify biodistribution of the drugs towards targeted delivery into tissue of interest and allow triggered release of the active cargo. In this review, we focus on general principles of polymer selforganization in solution, phase separation in polymer systems (driven by external stimuli, especially by changes in temperature, pH, solvent change and light) and on effects of copolymer architecture on the self-assembly process., M. Hrubý, S. K. Filippov, P. Štěpánek., and Obsahuje bibliografii
One hundred years ago Heike Kamerlingh Onnes arrived to one of the most important breakthroughs of 20th century physics - he discovered superconductivity. His finding as in many other cases in the history of science had been a result of use of a very new experimental technique. He used the cryogenic equipment in his Leiden's laboratory with the liquid helium cryocooler and measured electrical properties of metals near the absolute zero temperature. When cooled down to extremely low temperatures, near 4 Kelvin, very pure mercury suddenly lost its electrical resistance completely. Many major physicists of 20th century, experimentalists as well as theorists, devoted their life efforts to exploration of the mysterious properties of superconductors. Superconductivity has been shown to be one of the rare cases where quantum physics is observed on a macroscopic scale. Many chemical elements and thousands of compounds have been found to be superconducting. Fifty years after the discovery important practical applications such as strong magnets for laboratories and magnetic-resonance-imaging in hospitals came to the market. But more than seventy five years the superconducting materials had been functioning only at extreme cold, below 23 K (-250°C). In 1986 the "hightemperature superconductor's" era started with materials superconducting at -100°C. This paper surveys the history and the latest research into one of today's most fascinating physics and promising technologies., Peter Samuely., and Obsahuje bibliografii
On Bartle-Graves Theorem in the category of quotient bornological spaces. We prove Bartle-Graves Theorem in the category of quotient bornological spaces (L. Waelbroeck, 1986). Also, this permits us to define some spaces of functions taking their values in quotient bornological spaces. Résumé. On se propose d’établir le Théorème de Bartle-Graves dans la catégorie des quotients bornologiques. Aussi, cela nous permet de définir certains espaces de fonctions à valeurs dans des quotients bornologiques. and On se propose d’établir le Théor`eme de Bartle-Graves dans la catégorie des quotients bornologiques. Aussi, cela nous permet de définir certains espaces de fonctions a` valeurs dans des quotients bornologiques.
Soit G l’ensemble des points rationnels d’un groupe algébrique réductif non connexe p-adique de caractéristique 0. Soit G 0 la composante neutre de G. On suppose que G/G0 est commutatif et fini. Notre motivation pour cette note est de rejoindre le cas connexe d’un papier précédent, Betta¨ıeb, (2003). Autrement dit, de retrouver une analogue à notre classification des représentations irréductibles tempérées de G, lorsque G est connexe. C’està-dire que toute représentation irréductible tempérée de G est irréductiblement induite d’une limite de série discr`ete d’un sous-groupe de Lévi cuspidal de G.
Let $p_1\equiv p_2\equiv 1 \pmod 8$ be primes such that $(\frac {p_1}{p_2})=-1$ and $(\frac {2}{a+b})=-1$, where $p_1p_2=a^2+b^2$. Let ${\rm i}=\sqrt {-1}$, $d=p_1p_2$, $\Bbbk =\mathbb {Q}(\sqrt {d},{\rm i})$, $\Bbbk _2^{(1)}$ be the Hilbert 2-class field and $\Bbbk ^{(*)}=\mathbb{Q} (\sqrt {p_1},\sqrt {p_2},{\rm i})$ be the genus field of $\Bbbk $. The 2-part ${\bf C}_{{\Bbbk },2}$ of the class group of $\Bbbk $ is of type $(2,2,2)$, so $\Bbbk _2^{(1)}$ contains seven unramified quadratic extensions $\mathbb K_j/\Bbbk $ and seven unramified biquadratic extensions $\mathbb {L}_j/\Bbbk $. Our goal is to determine the fourteen extensions, the group ${\bf C}_{{\Bbbk },2}$ and to study the capitulation problem of the 2-classes of $\Bbbk $. \medskip {\it Résumé. Soient $p_1\equiv p_2\equiv 1\pmod 8$ des nombres premiers tels que, $(\frac {p_1}{p_2})=-1$ et $(\frac {2}{a+b})=-1$, où $p_1p_2=a^2+b^2$. Soient ${\rm i}=\sqrt {-1}$, $d=p_1p_2$, $\Bbbk =\mathbb {Q}(\sqrt {d},{\rm i})$, $\Bbbk _2^{(1)}$ le 2-corps de classes de Hilbert de $\Bbbk $ et $\Bbbk ^{(*)}=\mathbb{Q} (\sqrt {p_1},\sqrt {p_2},{\rm i})$ le corps de genres de $\Bbbk $. La 2-partie ${\bf C}_{{\Bbbk },2}$ du groupe de classes de $\Bbbk $ est de type $(2, 2, 2)$, par suite $\Bbbk _2^{(1)}$ contient sept extensions quadratiques non ramifiées $\mathbb K_j/\Bbbk $ et sept extensions biquadratiques non ramifiées $\mathbb {L}_j/\Bbbk $. Dans ce papier on s'intéresse à déterminer ces quatorze extensions, le groupe ${\bf C}_{{\Bbbk },2}$ et à étudier la capitulation des 2-classes d'idéaux de $\Bbbk $ dans ces extensions. and Soient $p_1\equiv p_2\equiv1\pmod8$ des nombres premiers tels que, $(\frac{p_1}{p_2})=-1$ et $(\frac2{a+b})=-1$, où $p_1p_2=a^2+b^2$. Soient $ i=\sqrt{-1}$, $d=p_1p_2$, $\Bbbk=\mathbb{Q}(\sqrt{d}, i)$, $\Bbbk_2^{(1)}$ le 2-corps de classes de Hilbert de $\Bbbk$ et $\Bbbk^{(*)}=\mathbb Q(\sqrt{p_1},\sqrt{p_2}, i)$ le corps de genres de $\Bbbk$. La 2-partie $ C_{{\Bbbk},2}$ du groupe de classes de $\Bbbk$ est de type $(2, 2, 2)$, par suite $\Bbbk_2^{(1)}$ contient sept extensions quadratiques non ramifiées $\mathbb K_j/\Bbbk$ et sept extensions biquadratiques non ramifiées $\mathbb{L}_j/\Bbbk$. Dans ce papier on s'intéresse à déterminer ces quatorze extensions, le groupe $ C_{{\Bbbk},2}$ et à étudier la capitulation des 2-classes d'idéaux de $\Bbbk$ dans ces extensions.
The effect of suramin, an inhibitor of G protein regulated signalling, was studied on the membrane currents induced by noxious heat and by capsaicin in cultured dorsal root ganglia neurones isolated from neonatal rats. Whole-cell responses induced by a heat ramp (24-52 °C) were little affected by suramin. The noxious heat-activated currents were synergistically facilitated in the presence of 0.3 µM capsaicin 13.2-fold and 6.3-fold at 40 °C and 50 °C, respectively. In 65% of neurones, the capsaicin-induced facilitation was inhibited by 10 µM suramin to 35±6 % and 53±6 % of control at 40 °C and 50 °C (S.E.M., n=15). Suramin 30 µM caused a significant increase in the membrane current produced by a nearly maximal dose (1 µM) of capsaicin over the whole recorded temperature range (2.4-fold at 25 °C and 1.2-fold at 48 °C). The results demonstrate that suramin differentially affects the interaction between capsaicin and noxious heat in DRG neurones and thus suggest that distinct transduction pathways may participate in vanilloid receptor activation mechanisms., V. Vlachová, A. Lyfenko, L. Vyklický, † R.K. Orkand., and Obsahuje bibliografii
To apply surgery theory to the problem of classifying pairs of closed manifolds, it is necessary to know the subgroup of the group $LP_*$ generated by those elements which are realized by normal maps to a pair of closed manifolds. This closely relates to the surgery problem for a closed manifold and to the computation of the assembly map. In this paper we completely determine such subgroups for many cases of Browder-Livesay pairs of closed manifolds. Moreover, very explicit results are obtained in the case of an elementary fundamental group. Then we generalize them, and obtain several further results about the realization of elements in the Browder-Quinn surgery obstruction groups by means of normal maps to a closed manifold filtered by closed submanifolds.
The use of sensor networks has been proposed for military surveillance and environmental monitoring applications. Those systems are composed of a heterogeneous set of sensors to observe the environment. In centralised systems the observed data will be conveyed to the control room to process the data. Human operators are supposed to give a semantic interpretation of the observed data. They are searching for suspicious or unwanted behaviour. The increase of surveillance sensors in the military domain requires a huge amount of human operators which is far beyond available resources. Automated systems are needed to give a context sensitive semantic interpretation of the observed kinematic data. As a proof of concept two automatic surveillance projects will be discussed in this paper. The first project is about a centralised system based on the AISAutomated Identification System which will be used to monitor ship movements automatically. The second project is about a decentralised system composed of a network of cameras installed at a military area. There is a need for a surveillance system along the coast of Europe. There is an increase of illegal drugs transport from the open sea, intrusion of boat refuges, illegal fishing, pollution of the sea by illegal chemical and oil pollution by ships. An automated sensor system is needed to detect illegal intruders and suspicious ship movements. Vessels fitted with AIS transceivers and transponders can be tracked by AIS base stations located along coast lines or, when out of range of terrestrial networks, through a growing number of satellites that are fitted with special AIS receivers. AIS data include a unique identifier of a vessel and kinematic data such as its position, course and speed. The proposed system enables identification, and tracking of vessels and to detect unwanted or illegal behaviour of ship movements. If ships violate traffic rules, enter forbidden areas or approach a critical infrastructure an alert will be generated automatically in the control room. Human operators start an emergency procedure. The second project is about a network of cameras installed at a military area. The area is monitored by multiple cameras with non-overlapping field of views monitored by human operators. We developed an automated surveillance system. At the entrance gate the identity of visitors will be checked by a face recognition system. In case of intruders, unwanted behaviour, trouble makers the emotional state of the visitor will be assessed by an analysis of facial expressions using the Active Appearance model. If unwanted behaviour is detected an alert is send the control room. Also license place of cars will be recognized using a system based on Neocognitron Neural Networks. Moving objects as persons and vehicles will be detected, localized and tracked. Kinematic parameters are extracted and a semantic interpretation of their behaviour is automatically generated using a rule based system and Bayesian networks. Cars violating the traffic rules or passing speed limits or entering forbidden areas or stopping/parking at forbidden places will be detected. A prototype of a system has been developed which is able to monitor the area 24 hours a day, 7 days a week.