Analysis of Morphological Features of Sargalu Region in Sulaymaniyah Governorate, North of Iraq, by using Geographic Information System

It is an ideal area of research to examine related indicators to anticipate relative tectonic activities, where there is a broad range of geological formations with elements of different sedimentary rocks. This study includes assessing and evaluating the relative tectonic activities within the Sargalu area by using a morphometric approach, which involved the use of different indices that can explain and help understanding the geometry, development level, lithology, and structural disturbance on a sub-basinal level. The research was accomplished by using ArcGIS 10.5 hydrology tools to design the drainage system of each studied stream. The Advanced Spaceborne Thermal Emission Radiometer (ASTER) satellite imagery data and the Digital Elevation Model (DEM 90m) were used. Moreover, Global Mapper and Statistical Package for the Social Sciences (SPSS) were applied. DEM datasets of ASTER were used for watershed delineation. Also, 14 sub-basins were delineated in the Sargalu area. Morphometric indices used include Shape Related Indices, such as Rc, Bs, Rf, Ls, Re, T, and Af. Basin asymmetry factor (Af) and several geomorphic indices were also utilized. Based on the shape related indices (Rc, Rf, Re, Ls, and Cc), the results were found to be similar and, for most sub-basins, had an elongated nature. The elongated basins are connected with tectonically active areas, while the circulated basins are connected with the tectonically undisturbed environment.

A geometric approach to structural model matching by output feedback in linear impulsive systems

This paper provides a complete characterization of solvability of the problem of structural model matching by output feedback in linear impulsive systems with nonuniformly spaced state jumps. Namely, given a linear impulsive plant and a linear impulsive model, both subject to sequences of state jumps which are assumed to be simultaneous and measurable, the problem consists in finding a linear impulsive compensator that achieves exact matching between the respective forced responses of the linear impulsive plant and of the linear impulsive model, by means of a dynamic feedback of the plant output, for all the admissible input functions and for all the admissible sequences of jump times. The solution of the stated problem is achieved by reducing it to an equivalent problem of structural disturbance decoupling by dynamic feedforward. Indeed, this latter problem is formulated for the so-called extended linear impulsive system, which consists of a suitable connection between the given plant and a modified model. A necessary and sufficient condition for the solution of the structural disturbance decoupling problem is first shown. The proof of sufficiency is constructive, since it is based on the synthesis of the compensator that solves the problem. The proof of necessity is based on the definition and the geometric properties of the unobservable subspace of a linear impulsive system subject to unequally spaced state jumps. Finally, the equivalence between the two structural problems is formally established and proven.

THE REGIME-SWITCHING VOLATILITY OF EURO AREA BUSINESS CYCLES

We document the strong evidence of time variation in the volatility of Euro Area business cycles since 1970. Then we provide the quantitative sources of these changes using a medium-scale DSGE model allowing time variation in structural disturbance variances. We show that (1) the size of different types of shock oscillates, in a synchronized manner, between two regimes over time, with the high-volatility regime prevailing predominantly in the 1970s, sporadically in the 1980s and 1990s, and during the Great Recession; (2) their relative importance remains, however, unchanged across regimes, where neutral technology shocks and marginal efficiency of investment shocks are the dominant sources of business cycle fluctuations; and 3) these investment shocks, which affect the transformation of savings into productive capital, can be interpreted as an indicator of credit conditions.

Comparisons of the composition of foliage-dwelling spider assemblages in apple orchards and adjacent deciduous forest

Previous studies have shown that annual crops have different spider (Araneae) assemblages than adjacent relatively natural habitats, suggesting that spider recolonization of crops occurs via long-distance ballooning and that spider species in crops are mainly agrobionts. However, in perennial crops, e.g., apple (Malus domestica Borkhausen (Rosaceae)), which are subject to less physical disturbance than annual crops, overlap in spider species has been observed between tree foliage and adjacent habitats, suggesting that spiders colonize orchards from adjacent vegetation. The objective of this study was to compare the species composition of assemblages of foliage-dwelling spiders in apple orchards with that in adjacent deciduous forest and to determine whether spider assemblages in orchards are dominated by agrobiont species. Spiders were collected from four apple orchards and adjacent deciduous forest in southern Quebec from May until August 2004. The similarity of assemblages between the orchard and forest habitats was evaluated using nonmetric multidimensional scaling and multiresponse permutation procedures and spider species richness in the two habitat types was compared using rarefaction. Although spider species richness was higher in the forest than in the orchards, the composition of the spider assemblages in apple orchards was not significantly different from that in adjacent deciduous forest at three of the four sites. Therefore, adjacent deciduous forest, which is similar to orchards in vegetation structure and frequency of structural disturbance, is likely the main source of spiders found in apple orchards.