Power supply for carbon dioxide lasers

An improved ac power supply for a CO2 laser which eliminates the need for ballast resistors to excite a stable discharge is disclosed. The method involves the connection of an inductance in front of the rectifier. This procedure provides a nondissapative positive resistance effect for cancelling the negative differential resistance exhibited by the tube at frequencies below 2 KHz. Such an inductance setup also increases the efficiency of the system

Computer-aided CO2 laser cavity-length selection for reduced line competition

The advantages of carbon dioxide lasers for space communications systems are considered. An attempt was made to predict the signature of CO2 lasers. It was found that this requires accurate data on the laser wavelengths (accuracy on the order of 10 MHz). The results of absolute frequency measurements of CO2 lines were utilized, and a list of accurate frequencies was calculated. A computer program was written for the signature prediction. A second program was written which searches through large ranges of cavity length and prints lists of regions where a particular line is well separated from adjacent lines in the signature. Lasers designed according to this list will have an undisturbed tuning profile for one or more lines

D-optimal plans for variable selection in data bases

This paper is based on an article of Pumplün et al. (2005a) that investigates the use of Design of Experiments in data bases in order to select variables that are relevant for classification in situations where a sufficient number of measurements of the explanatory variables is available, but measuring the class label is hard, e. g. expensive or time-consuming. Pumplün et al. searched for D-optimal designs in existing data sets by means of a genetic algorithm and assessed variable importance based on the found plans. If the design matrix is standardized these D-optimal plans are almost orthogonal and the explanatory variables are nearly uncorrelated. Thus Pumplün et al. expected that their importance for discrimination can be judged independently of each other. In a simulation study Pumplün et al. applied this approach in combination with five classification methods to eight data sets and the obtained error rates were compared with those resulting from variable selection on the basis of the complete data sets. Based on the D-optimal plans in some cases considerably lower error rates were achieved. Although Pumplün et al. (2005a) obtained some promising results, it was not clear for different reasons if D-optimality actually is beneficial for variable selection. For example, D-efficiency and orthogonality of the resulting plans were not investigated and a comparison with variable selection based on random samples of observations of the same size as the D-optimal plans was missing. In this paper we extend the simulation study of Pumplün et al. (2005a) in order to verify their results and as basis for further research in this field. Moreover, in Pumplün et al. D-optimal plans are only used for data preprocessing, that is variable selection. The classification models are estimated on the whole data set in order to assess the effects of D-optimality on variable selection separately. Since the number of measurements of the class label in fact is limited one would normally employ the same observations that were used for variable selection for learning, too. For this reason in our simulation study the appropriateness of D-optimal plans for training classification methods is additionally investigated. It turned out that in general in terms of the error rate there is no difference between variable selection on the basis of D-optimal plans and variable selection on random samples. However, for training of linear classification methods D-optimal plans seem to be beneficial. --

The Golden Passport - avagy a befektetési programmal elérhető állampolgárság aktuális kérdései az Európai Unióban

A growing number of States have been offering so-called citizenship by investment programs, where they offer residence and/or their nationality to foreigners willing to invest a considerable sum in their economies and/or to donate to their budget or other public funds. The main reason that EU institutions have criticised these practices relates to the fact that the EU has its own citizenship that is derived from the nationalities of the member states. According to Article 20 Treaty on the Functioning of the European Union „ Every person holding the nationality of a Member State shall be a citizen of the Union.” The European Commission adopted a report on investor citizenship and residence schemes within the EU in 2019, in which it argued that Member States must ensure ‘that nationality is not awarded absent any genuine link to the country or its citizens’. And on 20 October 2020 it launched legal proceedings against Cyprus and Malta regarding their investor citizenship schemes. It considers that ‘the granting of EU citizenship for predetermined payments or investments without any genuine link with the Member States concerned, undermines the essence of EU citizenship. Whether the genuine link requirement established by the International Court of Justice in Nottebohm justifies the position of the European Union

Az uniós polgárok védelme harmadik államokban - a statisztikák fényében

Az uniós polgárok egyre gyakrabban utaznak külföldre turistaként, illetve élnek külföldön munkavállalóként vagy diákként. Becslések szerint azonban az EU területén kívülre utazó uniós polgárok 8,7 %- a olyan országok területére utazik, ahol tagállamai nem rendelkeznek konzuli vagy diplomáciai képviselettel, ami azt jelenti, hogy a bajba jutott uniós polgár számára a saját országa nem, vagy csak különösen nagy erőfeszítések árán tud hathatós segítséget nyújtani. A képviselet hiányát csak tovább mélyíti, hogy 18 külországban, tehát olyan harmadik országban, amely nem tagja az Európai Uniónak semelyik tagállamnak nincs képviselete, 17-ben mindössze egy tagállam rendelkezik képviselettel. Ezek közé tartozik több, a turisták által kedvelt nyaralási célpont is például, így a Maldív-szigetek, Seychelle-szigetek is, de Közép-Amerikában, Közép-és Nyugat-Afrikában szintén nagyon alacsony a képviselettel rendelkező uniós tagállamok száma. Az elmúlt évek természeti katasztrófái; hurrikánok, a cunami (szökőár), de akár a válságterületeken kialakult polgárháborús helyzetek is azt bizonyították, hogy pont itt lenne szükség az uniós polgárok védelmére és a bekövetkezett események során elengedhetetlen a koordinált fellépés. Mégis a felmérések azt mutatják, hogy viszonylag alacsony a konzuli segítségnyújtásra irányuló kérelmek száma ezeken a területeken. Az uniós polgárokkal és tagállamokkal folytatott nyilvános konzultáció során kiderült, hogy ennek oka az, hogy a polgárok nem ismerik az Európai Unió Működéséről szóló Szerződés 23. cikkét. Az EUMSz 23.cikke ugyanis az uniós polgárok számára jogosultságot teremt bármelyik tagállam diplomáciai és konzuli képviseleteinek védelmére, arra az esetre, ha az uniós polgár harmadik ország területén kerül bajba, és saját tagállama nem rendelkezik képviselettel a helyszínen. European citizens travel abroad as tourists with increasing frequency, as well as work or study abroad. According to estimations 8.7 % of those European citizens who travel outside of the EU are going to such states where no Member State has diplomatic or consular representation, which means that the citizen’s own State cannot or only with significant challenges can provide effective protection to the injured person. The lack of representation is further burdened with the fact that in 18 third States, which are not members of the EU, no EU Member State has representation, and in 17 third States only one EU Member State has representation. Among these there are places of popular tourist resorts, such as the Maldives, the Seychelles, but also in CentralAmerica and Central- and West-Africa the number of EU Member States with representation is very low. The natural disasters of previous years, hurricanes, tsunamis, or the civil war-like situations have proved that these are exactly those places where European citizens need protection, and coordinated action is essential. However, studies have shown that request for consular assistance is relatively law at these places. Public consultation with European citizens and Member States has revealed that the reason behind this is that citizens are unaware of Article 23 of the Treaty on the Functioning of the European Union. Article 23 of the Treaty on the Functioning of the European Union guarantees the right of diplomatic protection and consular assistance by any Member State to European citizens, in case the citizen gets into trouble on the territory of a third State, provided his or her own State does not have representation there

Characterisation and identification of the navigational processes in homing pigeons

With the help of miniaturized GPS recorders I recorded 167 tracks of 48 individual pigeons during their flight from 6 different sites around Frankfurt. The experiments consisted of two main series of repeated releases from two sites 30 km north and south from the pigeons' home loft. From the site in the south the pigeons homed 12 times and from the site in the north 16 times. After the final release from these sites, the pigeons were released at 60 km distance from home. These additional sites were selected so that the pigeons would presumably fly over the previous release site with which they were highly familiar. After conclusion of the main series two additional releases were performed, one within the magnetic anomaly of the Vogelsberg and one in a magnetically quiet region. To make these releases comparable, both release sites were selected so that the distance from the home loft was 40 km. All data obtained during these experiments were subjected to a threefold analysis, mostly based on methods that I had developed by myself or adapted for this specific study. In the first step, data were analyzed traditionally, evaluating variables similar to those that can be found in current literature. I therefore calculated values that correspond to those obtained by visual observation, like virtual vanishing bearings and intervals after one minute and after 2.5 km. Additionally I calculated the efficiency of the flights and efficiencies for specific portions of each flight, to derive variables that describe the behavior after vanishing. In the second step, which served also as a preparation for the mathematical analysis, the flight of the pigeons was separated into distinctive phases of the flight by the so-called points of decision. The flight of the pigeon can usually be separated into an initial phase of flying about, a departure and/or final homing phase. In more complex cases, however, several points of decision and a multitude of intermediary phases can be defined. Yet, the initial phase, the departure phase and the final homing phase can be defined for all tracks and therefore have been selected as appropriate candidates for a thorough analysis. In the last step I employed the so-called method of time lag embedding to reconstruct the underlying navigational process of the pigeons' homing flight. This method is based on the principles of chaos theory and is regularly employed for the analysis of dynamic systems. Its application allows the reconstruction of the underlying processes from experimentally recorded data without any a priori knowledge of the underlying system itself. For these reconstructed systems I calculated characteristic properties which are unique for each system. These are the so-called correlation dimension, describing the complexity of the system, and the so-called largest Lyapunov exponent, describing its predictability. Based on the knowledge gathered from these reconstructions, I used a variation of the previous methods to identify navigational phases, by calculating the correlation dimension as a sliding mean over the complete track. From these data I then derived further characteristics of the underlying process, such as its precision and differences in complexity depending on the pigeon's current position. ...Mit Hilfe von miniaturisierten GPS-Rekordern habe ich 167 Flugwege von 48 Tauben bei ihren Flügen von 6 verschiedenen Auflassorten aufgezeichnet. Die Experimente bestanden dabei aus zwei Hauptserien, während derer die Tauben wiederholt von Orten in 30 km Entfernung vom Heimatschlag aufgelassen wurden. Insgesamt flogen die Tauben dabei 12 mal von einem Auflassort im Süden und 16 mal von einem Auflassort im Norden. Nach der letzten Auflassung vom jeweiligen Ort wurden die Tauben zusätzlich in 60 km Entfernung vom Heimatschlag aufgelassen. Diese zusätzlichen Auflassorte wurden dabei so gewählt, dass die Tauben aller Wahrscheinlichkeit nach über den vorherigen Auflassort, mit dem sie ja nun vertraut waren, flliegen würden. Nach Beendigung dieser beiden Hauptserien wurden noch zwei zusätzliche Versuche, einmal innerhalb der magnetischen Anomalie des Vogelsbergs und einmal in einer magnetisch normalen Region durchgeführt. Um sicherzustellen, dass auch diese Auflassungen vergleichbar sind, wurden die Auflassorte so gewählt, dass in beiden Fällen die Distanz zum Schlag ungefähr 40 km betrug. Alle so gewonnen Daten wurden im Folgenden einer dreischichtigen Analyse unterzogen. Die angewendeten Methoden sind dabei fast ausschliesslich von mir selbst entwickelt oder von mir speziell für diese Studie adaptiert worden. Im ersten Schritt wurden die Daten entsprechend der in der aktuellen Literatur verwendeten Methoden, sozusagen "auf traditionelle Weise", analysiert. Dabei wurden Werte ermittelt, die denen entsprechen die bei Beobachtung mit dem Fernglas gemacht werden, wie virtuelle Verschwinderichtungen nach einer Minute und in 2.5 km Entfernung vom Auflassort, sowie Verschwindezeiten in 2.5 km Entfernung vom Auflassort. Zusätzlich wurden Effizienzen für die einzelnen Flüge und einzelne Flugabschnitte bestimmt, um das Verhalten über das bei traditionellen Experimenten unzugängliche Verhalten nach dem Verschwinden zu erhalten. Im zweiten Schritt, der auch als eine Art Vorbereitung für den letzten Analyseschritt diente, wurden die Flugwege der Tauben durch Bestimmung sogenannter Entscheidungspunkte ("Points of Decision"), nach objektiven Kriterien, in charakteristische Phasen des Fluges aufgeteilt. Der Flug einer Taube lässt sich dabei üblicherweise in eine Anfangsphase ("Initial Phase"), während der die Vögel scheinbar ungezielt in der Nähe des Auflassortes umherfliegen, und eine Abflug ("Departure Phase") und/oder eine Heimkehrphase ("Final Homing Phase") aufteilen. In komplizierteren Fällen lassen sich jedoch auch mehrere "Zwischenphasen" definieren. Die Anfangsphase, die Abflugphase und die finale Heimkehrphase lassen sich jedoch für alle Flüge definieren und sind somit ideale Kandidaten für eine genauere Untersuchung. Im letzen Schritt wurden dann, basierend auf der Methode des sogenannten "Time Lag Embedding", die einzelnen Phasen des Fluges dazu verwendet, um den der Navigation zugrundeliegenden Prozess zu rekonstruieren. Die verwendete Methode basiert dabei auf den Prinzipien der Chaos-Theorie und wird oft dazu eingesetzt, dynamische Systeme zu charakterisieren. Sie erlaubt es, die zugrundeliegenden Prozesse eines Systems aus experimentellen Daten zu rekonstruieren, ohne dass genaueres Wissen über das Zusammenspiel der involvierten Faktoren vorhanden sein muss. Für den so rekonstruierten Prozess habe ich dann für das System charakteristische Eigenschaften bestimmt. Diese Eigenschaften beschreiben zum einem die Komplexität des Systems, die sogenannte "Korrealtions Dimension" und zum anderen die Vorhersagbarkeit des Systems, der sogenannte "größte Lyapunov Exponent". Basierend auf den so gewonnenen Erkenntnissen über die Eigenschaften des Systems, habe ich dann eine Variation der vorangehenden Methode entwickelt, um navigatorische Phasen im Flug der Tauben zu identifizieren. Hierzu wurde die Korrelations Dimension als gleitendes Mittel über den gesamten Flugweg der Taube berechnet. Aus diesen zusätzlichen Ergebnissen habe ich dann weitere Eigenschaften des Systems, wie die Genauigkeit der Kursbestimmung und die räumliche Abhängigkeit der Komplexität des Systems, abgeleitet. ..

A Rottmann-ügy öröksége, avagy az uniós polgárság elvesztésének új kérdései a JY v. Wiener Landesregierung ügy alapján

The Supreme Administrative Court of Austria has requested a preliminary ruling from the Court of Justice of the European Union (CJEU) in the case C-118/20 JY v. Wiener Landesregierung, concerning the revocation of a guarantee of the grant of Austrian nationality. Austria maintains a strict ‘single nationality’ policy, meaning that wherever possible, it requires that a person has only Austrian nationality and no other. Consequently, Austria requires that upon acquisition of its nationality all previous nationalities have to be relinquished. C-118/20 JY concerns the procedure for acquisition of Austrian nationality, and more specifically at which moment during the procedure the previous nationalities have to be lost, and whether this is in conformity with the rules on EU citizenship. One of the most important question, if the national authorities have to consider whether the revocation of the guarantee that prevented the recovery of citizenship of the Union is compatible with the principle of proportionality from the point of view of EU law in terms of its consequences for the situation of the person concerned. In the Rottmann and Tjebbes case the Court concerns the loss of the nationality of a Member State and of EU citizenship. In his decisions the Court listed multiple criteria which have to be observed in such cases. The case C-118/20 JY v. Wiener Landesregierung, concerning the revocation of a guarantee of the grant of Austrian nationality, is more than a case on loss of EU citizenship. It is the first case where the CJEU will have to rule on the acquisition of EU citizenship. The case will have an impact on the fundamental status of EU citizenship in the future