Betweenness parameterized above tight lower bound

We study ordinal embedding relaxations in the realm of parameterized complexity. We prove the existence of a quadratic kernel for the Betweenness problem parameterized above its tight lower bound, which is stated as follows. For a set V of variables and set C of constraints “vi is between vj and vk”, decide whether there is a bijection from V to the set {1,…,|V|} satisfying at least |C|/3+κ of the constraints in C. Our result solves an open problem attributed to Benny Chor in Niedermeier's monograph “Invitation to Fixed-Parameter Algorithms”. The betweenness problem is of interest in molecular biology. An approach developed in this paper can be used to determine parameterized complexity of a number of other optimization problems on permutations parameterized above or below tight bounds.     

Study on the replication quality of micro-structures in the injection molding process with dynamical tool tempering systems

The injection molding of micro-structures is a promising mass-production method for a broad range of materials. However, the replication quality of these structures depends significantly on the heat flow during the filling stage. In this paper, the filling and heat transfer of v-groove and random structures below 5 μm is investigated with the help of an AFM (atomic force microscope) and thermo couples. A numerical model is developed to predict the filling of surface structures during the filling and packing stage. The model implies the use of simple fully developed flow models taking the power-law material model into account. This permits investigation into which ways several processing parameters affect the polymer flow in the surface structures. The mold wall temperature, which has significant effects on the polymer flow, is varied by using a variothermal mold temperature control system to validate the model proposed.     

Local closed world reasoning with description logics under the well-founded semantics

An important question for the upcoming Semantic Web is how to best combine open world ontology languages, such as the OWL-based ones, with closed world rule-based languages. One of the most mature proposals for this combination is known as hybrid MKNF knowledge bases (Motik and Rosati, 2010 [52]), and it is based on an adaptation of the Stable Model Semantics to knowledge bases consisting of ontology axioms and rules. In this paper we propose a well-founded semantics for nondisjunctive hybrid MKNF knowledge bases that promises to provide better efficiency of reasoning, and that is compatible with both the OWL-based semantics and the traditional Well-Founded Semantics for logic programs. Moreover, our proposal allows for the detection of inconsistencies, possibly occurring in tightly integrated ontology axioms and rules, with only little additional effort. We also identify tractable fragments of the resulting language.     

An experiment on the role of graphical elements in architecture visualization

The evolution and maintenance of large-scale software systems requires first an understanding of its architecture before delving into lower-level details. Tools facilitating the architecture comprehension tasks by visualization provide different sets of configurable, graphical elements to present information to their users. We conducted a controlled experiment that exemplifies the critical role of such graphical elements when aiming at understanding the architecture. In our setting, a different configuration of graphical elements had significant influence on program comprehension tasks. In particular, a 63% gain in effectiveness in architectural analysis tasks was achieved simply by changing the configuration of the graphical elements of the same tool. Based on the results, we claim that significant effort should be spent on the configuration of architecture visualization tools and that configurability should be a requirement for such tools.

Composite indicator for railway infrastructure management

Railway Engineering Science - The assessment and analysis of railway infrastructure capacity is an essential task in railway infrastructure management carried out to meet the required quality and...     

Josephson effect of a superconducting ferromagnet

A point contact tunneling technique has been used to investigate the existence of superconductivity in a long-range, magnetically ordered phase in the reentrant pseudoternary system (Er_{1 – x}Ho_x)Rh₄B₄ in the vicinity of the lower critical temperature T _{c 2}. In this experiment, Josephson-like current-voltage characteristics could be observed in a Nb-Nb oxide-(Er_0.58Ho_0.42)Rh₄B₄ junction even in a temperature region below T _{c 2} (1.8–1.96 K), that is, in the magnetically ordered phase.This work was carried out while on leave of absence.Sponsored by Suisse National Science Foundation.Work in La Jolla sponsored by the National Science Foundation under contract No. NSF/DMR77-08469.     

Are Reviews an Alternative to Pair Programming?

From the first presentation of extreme programming on, pair programming has attracted a wide range of programmers to work together in front of one display. The proposed advantages of pair programming are a faster development cycle and code with higher quality. However, the nearly doubled personnel cost when compared to single developers seems to outweigh these advantages. Instead of showing the superiority of pair programming, we seek an alternative. Can a single developer be assisted by an already known technique with which he produces the quality of pairs with only a fraction of the cost? The answer with some restrictions is: yes, he can. Reviews are a reasonable candidate with respect to code quality and cost.     

Topography simulation of sputtering using an algorithm with second order approximation in space

For the efficient simulation of topography evolution due to, e.g., focused ion beam processes, continuum surface advancement algorithms are commonly used. In this work we present a two-dimensional surface advancement algorithm that uses circular arcs between nodes and allows kinks in the surface. The algorithm is based on the method of characteristics, which yields the motion of the points and the slope of the surface. By the interpolation with circular arcs not only the final result is better represented, but also more accurate simulation is possible after insertion of new points as the surface evolves. Kinks in the surface (shocks) are detected by the generation of loops in the surface string or by a new criterion based on the analysis of infinitesimally separated characteristics. It requires the curvature of the surface, which may readily be determined from the radii of the circular arcs. The proposed algorithm uses a second order approximation in space and therefore requires fewer data points during calculation than first order methods. It is shown to converge with third order as a function of node number. The method is demonstrated by examples of trench formation including the effect of redeposition and of facet formation from a step-like surface.     

An Overview of the Latest Metabolomics Studies on Atopic Eczema with New Directions for Study

Atopic eczema (AE) is an inflammatory skin disorder affecting approximately 20% of children worldwide and early onset can lead to asthma and allergies. Currently, the mechanisms of the disease are not fully understood. Metabolomics, the analysis of small molecules in the skin produced by the host and microbes, opens a window to observe the mechanisms of the disease which then may lead to new drug targets for AE treatment. Here, we review the latest advances in AE metabolomics, highlighting both the lipid and non-lipid molecules, along with reviewing the metabolites currently known to reside in the skin.