Comparison of Boolean Model and Model Based on Signature Files

Import 22/07/2015Cílem práce bylo porovnat booleovský model a model založený na signaturních souborech. Práce uvádí teoretické základy obou modelů, je zde tedy popsáno jak reprezentují dokumenty a jak přistupují k vyhodnocení dotazů zadaných uživatelem. Vytvořené aplikace byly použity pro srovnání, kde se porovnávalo vytváření indexu z hlediska času potřebného pro vytvoření, tak i paměti, kterou tento index zabírá na disku. Poté byly porovnány výsledky vyhodnocení pro různé dotazy a čas, který byl u obou modelů potřebný. Z důvodu, že signaturní soubory pro dotaz vybírají i ty dokumenty, které nejsou relevantní, bylo provedeno porovnání nastavovaných hodnot pro zjištění nejvhodnějšího nastavení, které by vykazovalo nejlepší výsledky.The aim of the study was to compare boolean model and model based on signature files. The study presents the theoretical foundations of both models, so here is described how they represent documents and how they approach to the evaluation of the queries entered by the user. Created applications were used for comparison, where the index creation was compared in terms of required time for the creation and the memory that index occupies on the disk. After that the evaluation results were compared for different queries and time, which was needed for evaluation in both models. For the reason, that signature files select for the query even those documents, that are not relevant, so a comparison of set values was made to determine the best settings, which showed the best results.460 - Katedra informatikyvelmi dobř

National economic policy simulations with global interdependencies : a sensitivity analysis for Germany

"Policy simulations for national economies with econometric models in general are done using a stand alone national model with exogenous export values and import prices. In a globalised world such an exercise is critical, since the policy in question may change the export prices and the import volumes of the particular country and induce via international trade a change of the economic activities of the global economy and a feed back to the export values and import prices of the particular country. The paper at hand presents a sensitivity analysis for Germany comparing the impacts of a shock on investment in a stand alone simulation using the multisector model INFORGE with the results, which occur, if the same model is linked to the global multicountry/multisector model GINFORS endogenising Germany's export values and import prices. The results are striking: The effect on real GDP is 50% higher in the global simulation than in the stand alone case. Because of the specialisation in trade the differences on the sector level are even stronger." (Author's abstract, IAB-Doku) ((en))Wirtschaftspolitik, Globalisierung - Auswirkungen, Export, Preisniveau, Importquote, Exportquote, Welthandel, Ökonometrie - Modell, Bruttoinlandsprodukt, volkswirtschaftliche Gesamtrechnung, Außenhandelspolitik, Außenhandelsentwicklung

Some Aspects of Territorial and State Legislative Control of the Municipal Government of Omaha (1857-1875)

A rapidly increasing urban population and a serious difference of opinion as to the method of controlling municipalities has given increasing important to the problem of city government. Since legal opinion has, almost without exception, placed cities under the control of state legislatures, the study of the government of any municipality may well begin with an examination of the role the legislature has played in its regulation. The study of laws of a community is of value for the indirect light they throw on existing political, economic, and social conditions. A knowledge of the laws governing a municipality is an effectual aid in the correct evaluation of source material, especially that found in newspapers

Politikberatung mit dem Simulationsmodell PACE-L : Möglichkeiten und Grenzen am Beispiel einer Senkung der Sozialabgaben

"Der Beitrag stellt das numerische allgemeine Gleichgewichtsmodell PACE-L (Policy Analysis based on Computable Equilibrium, Labour market module) in kompakter Form vor. Dieses quantitative gesamtwirtschaftliche Modell wird am IAB zur Beurteilung von beschäftigungsrelevanten Reformvorschlägen, insbesondere im Bereich der Steuerpolitik und Sozialen Sicherung, verwendet. Der Beitrag beschreibt erstens die PACE-L zugedachte Rolle im Rahmen der IAB-Forschung. Zweitens diskutiert er den dem Modell zugrunde liegenden Gleichgewichtsbegriff. Wir versuchen dabei zu verdeutlichen, warum ein Gleichgewichtsmodell zur Untersuchung von Arbeitslosigkeit und damit verbundenen Fragestellungen geeignet ist. Drittens präsentieren wir einige Simulationsrechnungen mit einer neueren Version von PACE-L. Schließlich vergleichen wir ausgewählte Ergebnisse von PACE-L mit zwei makroökonometrischen Modellen, dem IAB/ INFORGE- und dem IAB/RWI-Modell. Der Modellvergleich zeigt, dass die längerfristigen Wirkungen verminderter Sozialabgaben von allen drei Modellen insgesamt recht ähnlich quantifiziert werden. Allerdings deuten insbesondere die Ergebnisse mit dem IAB/INFORGE-Modell darauf hin, dass sich die kurzfristigen Effekte einer solchen Politik von den längerfristigen unterscheiden können." (Autorenreferat, IAB-Doku)Simulation - Methode, Makroökonomie - Modell, Modellentwicklung, Reformpolitik - Auswirkungen, Steuerpolitik, Sozialabgaben, Beschäftigungseffekte, Gleichgewichtstheorie, Arbeitsmarktgleichgewicht, Arbeitsmarkttheorie, Nachfrageentwicklung, Angebotsentwicklung, Preisentwicklung, Spieltheorie, Beschäftigungspolitik, IAB, Politikberatung

Volkswirtschaftliche Effekte einer Arbeitszeitverkürzung : eine Simulationsstudie für Westdeutschland mit dem makroökonometrischen Modell SYSIFO (Economic effects of a reduction in working hours : a simulation study for western Germany with the macro-economic model SYSIFO)

"Since the start of the high unemployment, there has been discussion in Germany of reductions in working hours, also for employment policy reasons, as a means of avoiding the threat of redundancies or - for lack of additional jobs - to spread the work available over more people to reduce unemployment. In addition to traditional concepts such as cuts in the statutory working week and increased part-time work, new forms of working time arrangements move into focus here which lead, for example via annual working time accounts, to operating hours and working hours being made more flexible and less closely bound, as well as to an increase in the time sovereignty of the employees. The economic effects of a reduction in working hours, in particular the effects on employment are, however, judged very differently, and not only by the two sides of industry. This article demonstrates economic connections of a general reduction in working hours. As a reduction in working hours influences the economy in several ways, some of which compensate for others, it is very difficult to deduce definite statements from economic theory, so macroeconomic simulation studies have to be used. For this reason a series of simulations were carried out on the effect of general reductions in annual working time, using the lAB/Westphal model, which was developed from the SYSIFO model. The following results can be deduced from the simulation experiments: - A reduction in working hours has a positive effect on employment, both with and without compensatory increases in wage rates, whereby, however, the employment effect is clearly less significant in the case of a reduction in working hours with full compensatory increases in wage rates. - The upswing in employment induced by the reduction in working hours is paid for with price increases and a loss of affluence and growth. - The effects of a reduction in working hours which increase employment, wages and prices, result in reduced state transfer payments and in the medium term also in additional tax revenue for the state. If this is then put back into the economic circulation, the positive employment impulse of a reduction in working hours increases and the losses in affluence and growth can begin to be compensated. - The most advantageous strategy from a employment policy point of view is a reduction in working hours under the following conditions: - without a compensatory increase in wage rates - use of the state's savings in expenditure and additional revenue to reduce taxes and non-wage labour costs To qualify this it must be stressed that the employment promoting impulses can only be deduced with the model for the national economic average. Disaggregation by trades or industries, regions, occupations or qualifications could result in differing effects. Also, the positive statements are valid only for reductions in working hours which do not differ greatly in type and scope from the previous development of annual working time observed in the past. More extensive drops in the average annual working.time could lead to reactions which cancel the connections deduced from the past and are therefore not taken into account in the model. Limitations for the extent of reductions in working hours also arise from the international competition connections. It can also be expected that in the case of a completely different pattern of reduction in working hours, such as a definite increase in voluntary transitions into part-time employment as well as more extensive flexibility and independence of operating and working hours, other effects will occur. There is something to be said for the fact that in the latter case the negative attendant circumstances could presumably be avoided to a large extent. As a result of its defensive character, an isolated reduction in working hours occurring purely for employment policy reasons due to a lack of sufficient jobs available elsewhere, and not embedded in a more extensive strategy of job creation, could hardly be suitable to solve the problems on the labour market permanently." (Author's abstract, IAB-Doku) ((en))Arbeitszeitverkürzung - Auswirkungen, Beschäftigungseffekte - Prognose, Preise, Wohlstand, Wirtschaftswachstum, Einkommen, Außenhandel, Investitionen, öffentlicher Haushalt

Atlantic Ocean Heat Transport Enabled by Indo-Pacific Heat Uptake and Mixing

The ocean transports vast amounts of heat around the planet, helping to regulate regional climate. One important component of this heat transport is the movement of warm water from equatorial regions toward the poles, with colder water flowing in return. Here, we introduce a framework relating meridional heat transport to the diabatic processes of surface forcing and turbulent mixing that move heat across temperature classes. Applied to a (1/4)° global ocean model the framework highlights the role of the tropical Indo‐Pacific in the global ocean heat transport. A large fraction of the northward heat transport in the Atlantic is ultimately sourced from heat uptake in the eastern tropical Pacific. Turbulent mixing moves heat from the warm, shallow Indo‐Pacific circulation to the cold deeper‐reaching Atlantic circulation. Our results underscore a renewed focus on the tropical oceans and their role in global circulation pathways