University of Paderborn

About: University of Paderborn is a education organization based out in Paderborn, Nordrhein-Westfalen, Germany. It is known for research contribution in the topics: Computer science & Context (language use). The organization has 6684 authors who have published 16929 publications receiving 323154 citations.

MDHT: a hierarchical name resolution service for information-centric networks

Abstract: Information-centric network architectures are an increasingly important approach for future Internet architectures. Several approaches are based on a non-hierarchical identifier (ID) namespace that requires some kind of global Name Resolution Service (NRS) to translate the object IDs into network addresses. Building a world-wide NRS for such a namespace with 1015 expected IDs is challenging because of requirements such as low latency, efficient network utilization, and anycast routing. In this paper, we present an NRS called Multi-level Distributed Hash Table (MDHT). It provides name-based anycast routing, can support constant hop resolution, and fulfills the afore mentioned requirements. A scalability assessment shows that our system can scale to the Internet level, managing 1015 objects with today's storage technology and 1/10th of today's DNS nodes. The evaluation indicates that a non-hierarchical namespace can be adopted on a global scale, opening up several design alternatives for information-centric network architectures.

A fuzzy hybrid project portfolio selection method using Data Envelopment Analysis, TOPSIS and Integer Programming

Abstract: Project portfolio selection is a complex and difficult task in fuzzy environments.A three-stage hybrid method is used to select an optimal combination of projects.Data Envelopment Analysis is used to screen the available projects.TOPSIS is used to rank the potentially promising projects.Linear Integer Programming is used to select the most suitable project portfolio. Project selection and resource allocation are critical issues in project-based organizations. These organizations are required to plan, evaluate, and control their projects in accordance with the organizational mission and objectives. In this study, we propose a three-stage hybrid method for selecting an optimal combination of projects. We obtain the maximum fitness between the final selection and the project initial rankings while considering various organizational objectives. The proposed model is comprised of three stages and each stage is composed of several steps and procedures. We use Data Envelopment Analysis (DEA) for the initial screening, the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) for ranking the projects, and linear Integer Programming (IP) for selecting the most suitable project portfolio in a fuzzy environment according to organizational objectives. Finally, a case study is used to demonstrate the applicability of the proposed method and exhibit the efficacy of the algorithms and procedures.

Energy and nutrient intake of young-old, old-old and very-old elderly in Germany.

Abstract: Background: Reliable information about the nutritional status of elderly people in Germany is lacking. Objective: To describe energy and nutrient intake of elderly people living in private households in Germany with special focus on age-related differences in the elderly. Design: Descriptive nationwide cross-sectional study. Setting: Germany, 1998. Subjects: A random sample of 4020 elderly men and women living independently in private households stratified in three age groups (65–74, 75–84, 85+ y), of which 1550 participated and 1372 (789 female subjects) provided reliable 3-day estimated dietary records. Results: The median daily energy intake was 2207 kcal (9.2 MJ) in men and 1994 kcal (8.3 MJ) in women without difference between the age groups. Protein intake amounted to 91 and 81 g/day, respectively, corresponding to 1.2 g/kg body weight per day. The median intake was well above the recommended amount for all nutrients except dietary fibre, calcium, vitamin D and folate, where 38, 35, 75 and 37% did not reach two-thirds of the recommended amount. An age-related decline was observed for calcium intake in male and for dietary fibre, water, calcium, magnesium, iron, vitamins A, E, C and thiamin intake in female participants; however, the overall picture was unaffected by these differences. Conclusions: Dietary intake in these independently living elderly, including the very-old, is adequate for most of the evaluated nutrients. Increased intake of foods rich in dietary fibre, calcium, vitamin D and folate as well as regular sunlight exposure is recommended in order to optimize nutrient supply in this population group. Sponsorship: German Ministry of Health.

Optimal FPGA module placement with temporal precedence constraints

Abstract: We consider the optimal placement of hardware modules in space and time for FPGA architectures with reconfiguration capabilities, where modules are modeled as three-dimensional boxes in space and time. Using a graph-theoretic characterization of feasible packings, we are able to solve the following problems. (a) Find the minimal execution time of the given problem on an FPGA of fixed size, (b) Find the FPGA of minimal size to accomplish the tasks within a fired time limit. Furthermore, our approach is perfectly suited for the treatment of precedence constraints for the sequence of tasks, which are present in virtually all practical instances. Additional mathematical structures are developed that lead to a powerful framework for completing optimal solutions. The usefulness is illustrated by computational results.