One of the limiting factors in decreasing the systematic error of laser ranging is the influence of the atmospheric refraction. Two colour ranging may contribute useful information for more precise refraction factor modelling and calculation. We will describe two wavelength experiment using streak camera as a high resolution detector for ground target distance measurement.
Two closely related parasitoid wasp species with different host specificities were used for experimental studies on the biology of host finding, a crucial element of parasitoid life history: The habitat and host specialist Nasonia vitripennis and the habitat and host generalist Dibrachys microgastri (Chalcidoidea: Pteromalidae). The host finding parameters tested included reaction to olfactory cues, aspects of locomotor activity, ability to locate hidden hosts and day-night-activity. The results revealed distinct interspecific differences that match the respective host and habitat ranges of the two species. In N. vitripennis host finding is dominated by olfactory reaction to hosts and host habitat, i.e., fly puparia and birds' nests. In D. microgastri olfactory cues have only a minor role. Its host finding is characterized by rapid searching at random. Both species are able to locate hidden hosts. Although still incomplete, these insights into host finding by two parasitoid species with different life history strategies indicate they can be characterized by specific combinations of behavioural host finding features. and Ralph S. Peters.
The contemporary Platonists in the philosophy of mathematics argue that mathematical objects exist. One of the arguments by which they support this standpoint is the so-called Enhanced Indispensability Argument (EIA). This paper aims at pointing out the difficulties inherent to the EIA. The first is contained in the vague formulation of the Argument, which is the reason why not even an approximate scope of the set objects whose existence is stated by the Argument can be established. The second problem is reflected in the vagueness of the very term indispensability, which is essential to the Argument. The paper will remind of a recent definition of the concept of indispensability of a mathematical object, reveal its deficiency and propose an improvement of this definition. Following this, we will deal with one of the consequences of the arbitrary employment of the concept of indispensability of a mathematical theory. We will propose a definition of this concept as well, in accordance with the common intuition about it. Eventually, on the basis of these two definitions, the paper will describe the relation between these two concepts, in the attempt to clarify the conceptual apparatus of the EIA., Současní platonisté ve filozofii matematiky argumentují, že matematické objekty existují. Jedním z argumentů, které toto stanovisko podporují, je tzv. Enhanced Indispensability Argument (EIA). Cílem tohoto příspěvku je poukázat na obtíže spojené s EIA. První z nich je obsažena v vágní formulaci Argumentu, což je důvod, proč nelze stanovit ani přibližný rozsah nastavených objektů, jejichž existence je uvedena argumentem. Druhý problém se odráží v neurčitosti samotného pojmu nepostradatelnost, která je pro argument nezbytná. Příspěvek bude připomínat nedávnou definici pojmu nepostradatelnost matematického objektu, odhalit jeho nedostatek a navrhnout zlepšení této definice. Poté budeme se zabývat jedním z důsledků svévolného zaměstnávání konceptu nepostradatelnosti matematické teorie. Navrhneme také definici této koncepce v souladu se společnou intuicí. Nakonec, na základě těchto dvou definic, bude článek popsat vztah mezi těmito dvěma pojmy, ve snaze objasnit koncepční aparát EIA., and Vladimir Drekalović
A refined common generalization of known theorems (Arhangel’skii, Michael, Popov and Rančin) on the Fréchetness of products is proved. A new characterization, in terms of products, of strongly Fréchet topologies is provided.
In many natural language processing applications two or more models usually have to be involved for accuracy. But it is difficult for minor models, such as “backoff” taggers in part-of-speech tagging, to cooperate smoothly with the major probabilistic model. We introduce a two-stage approach for model selection between hidden Markov models and other minor models. In the first stage, the major model is extended to give a set of candidates for model selection. Parameters weighted hidden Markov model is presented using weighted ratio to create the candidate set. In the second stage, heuristic rules and features are used as evaluation functions to give extra scores to candidates in the set. Such scores are calculated using a diagnostic likelihood ratio test based on sensitivity and specificity criteria. The selection procedure can be fulfilled using swarm optimization technique. Experiment results on public tagging data sets show the applicability of the proposed approach.
In 2010, the body a Danish astronomer Tycho Brahe (1546-1601) was exhumed from a tomb in the Church of Our Lady before T9n in Old Town Square in Prague to authenticate the cause of his death. Brahe's death only eleven days after the onset of a sudden illness has been a mystery for over four hundred years. Over the centuries, a variety of myths and theories about his death were propounded. The most persistent theory has been that mercury poisoning caused Brahe's death. After studying samples for two years taken during the exhumation, the team of researchers from Aarhus University in Denmark, the University of Southern Denmark and the ASCR's Nuclear Physics Institute came to the unanimous conclusion that Brahe did not die of mercury poisoning. and Jan Kučera, Jan Kameník a Vladimír Havránek.
This conference took place 3-7 March 2008 and was held in the Emauzy Abbey. ALICE is the acronym for A Large Ion Collider Experiment, one of the largest experiments in the world devoted to research in the physics of matter on an infinitely small scale. Hosted at CERN, this project involves the international collaboratin of more than 1000 physicists, engineers and technicians from 300 countries. Together they are contributing to the resolution of one of the latest challenges in fundamental physics recounting the birth of matter. and Michal Šumbera, Vojtěch Petráček, Petr Závada.
Brain Awareness Week this year featured lectures by leading Czech neuroscientists and other brain scientists. It was the Czech Republic´s 18th observance, held on March 14-18, 2016 at the Czech Academy of Sciences main building. This issue of the Academic Bulletin presents an article by Dr. Alexandr Chvátal of the Institute of Experimental Medicine fo the CAS on what is known about glial cells at present. According to the general opinion, the central nervous system (CNS), whose principal purpose is the acquisition, processing and storage of information and response to external stimuli, to mainly composed of neurons that provide all of this above-mentioned functions. In fact, many glial cells are also involved in these functions. The aim of this brief overview is to correct some misconceptions about glial cells and to summarize some new insights about their role in nervous tissue functions. Many of the results were obtained by researchers from the Institute of Experimental Medicine of the Czech Academy of Sciences. and Autorem je redakce uvedená zkratkou red