Quantitative analysis of the impacts of Croatia's agricultural trade policy on the agri-food sector

Croatia recently signed several trade liberalisation agreements. The cornerstones of its trade policy are WTO membership, the Stabilisation and Association Agreement with the EU and Croatia's application of membership as well as bilateral free trade agreements within the Stability Pact for South Eastern Europe. The objective of this paper is to quantify the impact of Croatia's agricultural trade policy on the agri-food sector. For the analysis, a partial equilibrium model based on 1999/2000 data is used. Trade between Croatia and Bosnia and Herzegovina, Hungary, Slovenia, the EU-15 and the rest of the world is modelled for 12 product groups. Three liberalisation scenarios are analysed for the years 2002 and 2005. The scenarios differ with regard to the tariff changes. In general, the model results indicate that reciprocal trade liberalisation is welfare improving for Croatia. The increase in consumer welfare is larger than the decline in farmers' profits and the loss of governmental tariff revenues. In conclusion, the continuation of trade liberalisation is to be recommended. However, trade policy alone will not solve the existing problems of the agri-food sector, and transitional compensation measures could be considered to avoid unacceptable hardship. The benefits of trade liberalisation are primarily to be seen in an improved access to international markets, which probably enables Croatian food processors to realise economies of scale. In addition, internationally binding commitments such as trade agreements are likely to foster the internal and international political credibility and reduce political risks. -- G E R M A N V E R S I O N: In den letzten Jahren hat Kroatien mehrere Handelsabkommen unterzeichnet. Die Hauptelemente der kroatischen Handelspolitik sind die Mitgliedschaft in der WTO, das Stabilisierungsund Assoziierungsabkommen mit der EU und der Antrag auf EU-Mitgliedschaft sowie die bilateralen Freihandelsabkommen innerhalb des Stabilitätspaktes für Südosteuropa. Ziel des vorliegenden Beitrages ist es, die Auswirkungen dieser Agrarhandelspolitik auf den kroatischen Agrar- und Ernährungssektor zu quantifizieren. Für die Analyse wird ein partielles Gleichgewichtsmodell verwendet, das auf Daten der Jahre 1999/2000 basiert. Für 12 Produktgruppen wird Kroatiens Handel mit Bosnien und Herzegowina, Ungarn, Slowenien, der EU-15 und dem Rest der Welt modelliert. Für die Jahre 2002 und 2005 werden drei Liberalisierungsszenarien untersucht, die sich bezüglich der Zolländerungen unterscheiden. Insgesamt zeigen die Modellergebnisse, das eine wechselseitige Handelsliberalisierung wohlfahrtssteigernde Effekte für Kroatien hat. Der Anstieg der Konsumentenwohlfahrt übersteigt den Einkommensrückgang der Landwirte und den Verlust an staatlichen Zolleinnahmen. Daher ist eine Fortsetzung der Handelsliberalisierung empfehlenswert. Allerdings kann die Handelspolitik alleine die existierenden Probleme im Agrar- und Ernährungssektor Kroatiens nicht lösen. Um unerwünschteHärten zu vermeiden, könnten für eine Übergangsphase Kompensationsmaßnahmen in Betracht gezogen werden. Der Nutzen einer Handelsliberalisierung ist vor allem in einem verbesserten Zugang zu internationalen Märkten zu sehen. Dies ermöglicht es kroatischen Verarbeitern wahrscheinlich, Skaleneffekte zu realisieren. Außerdem erhöhen international bindende Verpflichtungen wie Handelsabkommen die interne und internationale politische Glaubwürdigkeit und tragen damit dazu bei, politische Risiken zu reduzieren.Croatia,trade liberalisation,agri-food sector,partial equilibrium analysis,Kroatien,Handelsliberalisierung,Agrar- und Ernährungssektor,partielle Gleichgewichtsanalyse

Dynamic Occupancy Grid Mapping with Recurrent Neural Networks

Modeling and understanding the environment is an essential task for autonomous driving. In addition to the detection of objects, in complex traffic scenarios the motion of other road participants is of special interest. Therefore, we propose to use a recurrent neural network to predict a dynamic occupancy grid map, which divides the vehicle surrounding in cells, each containing the occupancy probability and a velocity estimate. During training, our network is fed with sequences of measurement grid maps, which encode the lidar measurements of a single time step. Due to the combination of convolutional and recurrent layers, our approach is capable to use spatial and temporal information for the robust detection of static and dynamic environment. In order to apply our approach with measurements from a moving ego-vehicle, we propose a method for ego-motion compensation that is applicable in neural network architectures with recurrent layers working on different resolutions. In our evaluations, we compare our approach with a state-of-the-art particle-based algorithm on a large publicly available dataset to demonstrate the improved accuracy of velocity estimates and the more robust separation of the environment in static and dynamic area. Additionally, we show that our proposed method for ego-motion compensation leads to comparable results in scenarios with stationary and with moving ego-vehicle.Comment: Accepted for presentation at the 2021 International Conference on Robotics and Automation (ICRA), May 30 - June 5, 2021, Xi'an, Chin

Motion Estimation in Occupancy Grid Maps in Stationary Settings Using Recurrent Neural Networks

In this work, we tackle the problem of modeling the vehicle environment as dynamic occupancy grid map in complex urban scenarios using recurrent neural networks. Dynamic occupancy grid maps represent the scene in a bird's eye view, where each grid cell contains the occupancy probability and the two dimensional velocity. As input data, our approach relies on measurement grid maps, which contain occupancy probabilities, generated with lidar measurements. Given this configuration, we propose a recurrent neural network architecture to predict a dynamic occupancy grid map, i.e. filtered occupancy and velocity of each cell, by using a sequence of measurement grid maps. Our network architecture contains convolutional long-short term memories in order to sequentially process the input, makes use of spatial context, and captures motion. In the evaluation, we quantify improvements in estimating the velocity of braking and turning vehicles compared to the state-of-the-art. Additionally, we demonstrate that our approach provides more consistent velocity estimates for dynamic objects, as well as, less erroneous velocity estimates in static area.Comment: Accepted for presentation at the 2020 International Conference on Robotics and Automation (ICRA), May 31 - June 4, 2020, Paris, Franc

Temporally Resolved Intensity Contouring (TRIC) for characterization of the absolute spatio-temporal intensity distribution of a relativistic, femtosecond laser pulse

Today's high-power laser systems are capable of reaching photon intensities up to $10^{22}$ W/cm^2, generating plasmas when interacting with material. The high intensity and ultrashort laser pulse duration (fs) make direct observation of plasma dynamics a challenging task. In the field of laser-plasma physics and especially for the acceleration of ions, the spatio-temporal intensity distribution is one of the most critical aspects. We describe a novel method based on a single-shot (i.e. single laser pulse) chirped probing scheme, taking nine sequential frames at framerates up to THz. This technique, to which we refer as temporally resolved intensity contouring (TRIC) enables single-shot measurement of laser-plasma dynamics. Using TRIC, we demonstrate the reconstruction of the complete spatio-temporal intensity distribution of a high-power laser pulse in the focal plane at full pulse energy with sub picosecond resolution.Comment: Daniel Haffa, Jianhui Bin and Martin Speicher are corresponding author

Zum Einfluß verbal-numerischer Antwortmodelle sowie der Frage-/ Aussageformulierung auf das Befragungsergebnis bei Meinungsindikatoren: (institutsinterner Forschungsbericht zur Methoden-Studie FB-72)

Ziel der Untersuchung ist es zu klären, inwieweit Ergebnisse zu gleichen Befragungsitems verglichen werden können, wenn ihnen unterschiedliche Antwortmodelle zugeordnet sind und welchen Einfluß die Formulierung eines Items als Frage oder als Aussage auf das Befragungsergebnis hat. Hierzu wurden Meinungsindikatoren mit politisch-staatsbürgerlichem Inhalt herangezogen. Die Analyse macht deutlich, daß sich verschiedenstufige Antwortmodelle gleicher Dimensionalität nicht nachteilig beeinflussen und hinsichtlich ihrer allgemeinen Differenzierungsfähigkeit und Meßgenauigkeit gleichwertig sind. Probleme treten bei der Trennschärfenbestimmung einzelner Stufen und deren Zusammenfassung auf. Die Formulierung von Items als Frage oder Aussage ergibt gleiche Häufigkeitsverteilungen und hat keinen Einfluß auf Trennschärfe und Meßgenauigkeit. (ICE

ADVANCED BRAKING SYSTEM CONTROL PROTOTYPING USING NETWORKED HARDWARE-IN-THE-LOOP TECHNIQUE

Control functions for the base-braking and emergency braking situations are important element of the vehicle active safety and have high requirements to robustness. The corresponding control algorithms should be reliable, provide sufficient level of system adaptiveness and be able to reject external disturbances. This demands not only the well-organized controller from the theoretical point of view, but also its systematic experimental validation. Moreover, effects and factors, which can potentially produce deterioration of braking system control functions, should be properly taken into account in the simulation and during the experiments. Another important factor is that brake control systems have a closed-loop operation with the tyre-road interaction, and its operation is accompanied by such complex effects like (i) variation of disc/pad friction coefficient and (ii) brake hysteresis. This produces strong demand on extension of the conventional testing facilities for the braking system control evaluation. Therefore, besides the part of the control system design, this paper represents possible advancement of hardware-in-the-loop testing procedure for development and validation of braking system control functions