Coloring intersection graphs of arc-connected sets in the plane

A family of sets in the plane is simple if the intersection of its any subfamily is arc-connected, and it is pierced by a line $L$ if the intersection of its any member with $L$ is a nonempty segment. It is proved that the intersection graphs of simple families of compact arc-connected sets in the plane pierced by a common line have chromatic number bounded by a function of their clique number.Comment: Minor changes + some additional references not included in the journal versio

Evaluation of diagnostic classifiers using artificial clinical cases

Evaluation of classifiers in diagnosis support systems is a non-trivial task. It can be done in a form of controlled and blinded clinical trial, which is often difficult and costly. We propose a new method for generating artificial medical cases from a knowledge base, utilizing the concept of so-called medical diamonds. Cases generated using this method have features analogous to that of double-blinded trial and, thus, can be used for measuring sensitivity and specificity of diagnostic classifiers. This is easy and low-cost method of evaluation and comparison of classifiers in diagnosis support systems. We demonstrate that this method is able to produce valuable results when used for evaluation of similarity-based classifiers as well as shallow and deep neural networks

Przedkontraktowe obowiązki informacyjne kredytodawcy wobec kredytobiorcy w ustawie o odwróconym kredycie hipotecznym

Artykuł porusza problematykę obowiązku informacyjnego poprzedzającego zawarcie umowy odwróconego kredytu hipotecznego. Usługa ta z założenia adresowana jest do osób starszych, które poszukują sposobu na zwiększenie dochodów ponad środki uzyskiwane ze świadczeń emerytalnych. W opracowaniu poddano analizie regulacje ustawowe normujące przedkontraktowe obowiązki informacyjne kredytodawcy wobec potencjalnego kredytobiorcy, które ograniczają się w zasadzie do przekazania formularza informacyjnego. Rozważania prowadzą do wniosku, że ustawowy obowiązek informacyjny jest niedostosowany do specyfiki kredytobiorców

Triangle-free geometric intersection graphs with large chromatic number

Several classical constructions illustrate the fact that the chromatic number of a graph can be arbitrarily large compared to its clique number. However, until very recently, no such construction was known for intersection graphs of geometric objects in the plane. We provide a general construction that for any arc-connected compact set $X$ in $\mathbb{R}^2$ that is not an axis-aligned rectangle and for any positive integer $k$ produces a family $\mathcal{F}$ of sets, each obtained by an independent horizontal and vertical scaling and translation of $X$, such that no three sets in $\mathcal{F}$ pairwise intersect and $\chi(\mathcal{F})>k$. This provides a negative answer to a question of Gyarfas and Lehel for L-shapes. With extra conditions, we also show how to construct a triangle-free family of homothetic (uniformly scaled) copies of a set with arbitrarily large chromatic number. This applies to many common shapes, like circles, square boundaries, and equilateral L-shapes. Additionally, we reveal a surprising connection between coloring geometric objects in the plane and on-line coloring of intervals on the line.Comment: Small corrections, bibliography updat

The first record of a potential pest Orientus ishidae (Matsumura, 1902) (Hemiptera: Cicadellidae) in Poland

This study provides the first data on the occurrence of the mosaic leafhopper Orientus ishidae (Matsumura, 1902) (Hemiptera: Cicadellidae) in Poland. This species is native to Southeast Asia, adventive in Europe and feeds on cultivated plants. Orientus ishidae is a well-known carrier of Grapevine flavescence doree phytoplasma which causes the grapevine yellows disease. Symptoms of phytoplasma diseases of grapevine include deformations, leaf chlorosis and withering of plants. The appearance of this species in Poland might be caused by observed climate variations and insufficient plant health controls in the international trade of plants

Calibrated Simplex Mapping Classification

We propose a novel supervised multi-class/single-label classifier that maps training data onto a linearly separable latent space with a simplex-like geometry. This approach allows us to transform the classification problem into a well-defined regression problem. For its solution we can choose suitable distance metrics in feature space and regression models predicting latent space coordinates. A benchmark on various artificial and real-world data sets is used to demonstrate the calibration qualities and prediction performance of our classifier.Comment: 24 pages, 8 figures, 7 table

Cliquewidth and dimension

We prove that every poset with bounded cliquewidth and with sufficiently large dimension contains the standard example of dimension $k$ as a subposet. This applies in particular to posets whose cover graphs have bounded treewidth, as the cliquewidth of a poset is bounded in terms of the treewidth of the cover graph. For the latter posets, we prove a stronger statement: every such poset with sufficiently large dimension contains the Kelly example of dimension $k$ as a subposet. Using this result, we obtain a full characterization of the minor-closed graph classes $\mathcal{C}$ such that posets with cover graphs in $\mathcal{C}$ have bounded dimension: they are exactly the classes excluding the cover graph of some Kelly example. Finally, we consider a variant of poset dimension called Boolean dimension, and we prove that posets with bounded cliquewidth have bounded Boolean dimension. The proofs rely on Colcombet's deterministic version of Simon's factorization theorem, which is a fundamental tool in formal language and automata theory, and which we believe deserves a wider recognition in structural and algorithmic graph theory

Obesity as a multidimensional problem in the health care system - literature review

Awareness among medical professionals and patients about the impact of obesity on health is currently at a good level. Medical recommendations often include the recommendation of weight reduction, and there are increasing numbers of dieticians on wards educating patients about a healthy diet and physical activity. Special programs are also being developed to provide pharmacological and surgical treatment for obesity. New drugs that reduce body fat are becoming available. Unfortunately, as statistics show, the problem is still global and the number of obese people is increasing over the years. Currently, there is a huge emphasis on treating and reversing the effects of obesity, rather than preventing it. Scientific and technological advances are lagging behind in the face of the challenges posed by the large obese population.  In this work, we present the radiological, anesthesiological and surgical problems and limitations associated with obesity, which may not be obvious to those who do not deal with obese patients on a daily basis as well as the patients themselves

Problematyka wyliczania wysokości emerytury żołnierzy pełniących służbę w czasie wojny lub w strefie działań wojennych – przyczynek do dyskusji

The basis for considerations included in this article – which is designed to trigger a discussion on rules of calculating soldiers’ pensions – is the judgement of February 16, 2018 of the District Court in Łódź (VIII U 2407/17). The court ruled that for the purpose of calculating soldiers’ pension, each part of the service of soldiers who served during the war or in the war zone should be recalculated into months. Judges decided that summing individual separate periods of service calculated in days and recalculating them in full months is inconsistent with the law. The judgement of February 16, 2018 depicts well discrepancies in practice of courts and the Army Pension Bureaus. Moreover, that decision relates to the problem of the compatibility of the secondary legislation with the 1993 act on professional soldiers and their families pensions act.Kanwą dla niniejszych rozważań – które w swym założeniu sprowokować mają dyskusję na temat zasad ustalania emerytury żołnierskiej – jest wyrok Sądu Okręgowego w Łodzi z dnia 16 lutego 2018 r. (VIII U 2407/17). W orzeczeniu tym przyjęto, że wyliczając wysokość emerytury żołnierzy pełniących służbę na froncie w czasie wojny lub w strefie działań wojennych, należy poszczególne okresy przeliczać osobno na miesiące. Sumowanie poszczególnych, odrębnych okresów służby w strefie działań wojennych w dniach i zamiana ich na pełne miesiące w końcowym podsumowaniu uznane zostały przez sąd za niezgodne z obowiązującym prawem. Orzeczenie to dobrze obrazuje rozbieżności, jakie pojawiają się w praktyce stosowania przepisów przez sądy oraz Wojskowe Biura Emerytalne, a także odnosi się do problemu zgodności rozporządzeń wykonawczych wydawanych w oparciu o przepisy ustawy z dnia 10 grudnia 1993 r. o zaopatrzeniu emerytalnym żołnierzy zawodowych oraz ich rodzin (tekst jedn. Dz.U. 2017 poz. 2225) z tą właśnie ustawą

Spatch based active partitions with linguistically formulated energy

The present paper shows the method of cognitive hierarchical active partitions that can be applied to creation of automatic image understanding systems. The approach, which stems from active contours techniques, allows one to use not only the knowledge contained in an image, but also any additional expert knowledge. Special emphasis is put on the effcient way of knowledge retrieval, which could minimise the necessity to render information expressed in a natural language into a description convenient for recognition algorithms and machine learning