Search results for "Abstract"
showing 10 items of 1959 documents
An Encoding in Metaheuristics for the Minimum Communication Spanning Tree Problem
2009
Problem-specific encodings can improve the performance of metaheuristics, such as genetic algorithms or simulated annealing. This paper studies the link-biased (LB) encoding, which is a tree representation, and applies metaheuristics using this encoding to the minimum communication spanning tree (MCST) problem. Given the communication requirements of the nodes, the MCST problem seeks a communication spanning tree with minimum total cost. Optimal solutions for MCST problems are similar to minimum spanning trees (MSTs), and the LB encoding exploits this property by encoding trees similar to MSTs with higher probability. The paper investigates how to systematically design problem-specific enc…
Extraction of Endmembers from Spectral Mixtures
1999
Abstract Linear spectral mixture modeling (LSMM) divides each ground resolution element into its constituent materials using endmembers which represent the spectral characteristics of the cover types. However, it is difficult to identify and estimate the spectral signature of pure components or endmembers which form the scene, since they vary with the scale and purpose of the study. We propose three different methods to estimate the spectra of pure components from a set of unknown mixture spectra. Two of the methods consist in different optimization procedures based on objective functions defined from the coordinate axes of the dominant factors. The third one consists in the design of a neu…
Internal Time and Innovation
2003
Consider a physical system that may be observed through time-varying quantities x t , where t stands for time that may be discrete or continuous. The set x t may be a realization of a deterministic system, e.g. a unique solution of a differential equation, or a stochastic process. In the latter case each x t is a random variable. We are interested in the global evolution of the system, not particular realizations x t , from the point of view of innovation. We call the evolution innovative if the dynamics of the system is such that there is a gain of information about the system as time increases. Our purpose is to associate the concept of internal time with such systems. The internal time w…
Review of Knowledge Management Models for Implementation within Advanced Product Quality Planning
2014
The purpose of this paper is to review different Knowledge Management Models (KMM) based on their strengths and weaknesses and to ascertain their possible implementation within the scope of the Advanced Product Quality Planning (APQP) procedure. The KMM listed are selected based on an extensive literature review. They are presented in a visual manner and analyzed based on their structure and features, versus a predetermined set of criteria. This study offers an overview and a critical discussion of the merits and faults of a number KMM and suggests possible improvement avenues.
Further Developments and Tests of a Progressive Algorithm for Multiple Criteria Decision Making
1993
P. Korhonen, H. Moskowitz, and J. Wallenius (1986) developed a progressive algorithm and the supporting theory for modeling and solving multiple criteria decision problems with discrete alternatives. A special feature of the algorithm is that it relaxes the usual assumption of a fixed set of available decision alternatives and complete knowledge of a decision maker's (DM's) preference structure or value function. The algorithm is based on progressively sampling the decision space, obtaining preference information from the DM, determining the likelihood of finding possibly/surely better alternatives, and based on this information, continuing the search or terminating it by making the final …
Cloud and Fog Effects and Their Parameterisation in Regional Air Quality Models
1997
For the special purpose of cloud chemistry a tool ASOCC was developed which is able to generate a differential equation system from a given set of chemical kinetics equations. Sensitivity and structure analysis have been performed to evaluate the great number of investigated reactions in the liquid phase and to derive a condensed mechanism for use in regional chemistry-transport models.
A High Level Language for Pyramidal Architectures
1986
In the paper are described the syntax and some implementation features of a high level language for pyramidal architectures called Pyramid B Language (PCL). The language is an extension of the B and include data type, set of instructions and builtin functions oriented to the pyramidal architectures. Some notes on the implementation for the PAPIA machine are also given.
Stability of the performance of thin film modules during one year of operation
2012
At the University of Agder in Grimstad, Southern Norway, a test bench for photovoltaic modules is in operation since December 2010. Currently, various c-Si as well as aSi, CIS and HIT modules are under investigation. This project is part of the Norwegian contribution to IEA PVPS Task13. The paper focuses on the stability of the modules' MPP-performance in the course of one year. For this purpose, data on the DC response are logged together with irradiance and module temperature at one-minute intervals. Data analysis is performed in monthly blocks. The modeling involves two steps. First, the short-circuit current is expressed as function of irradiance and module temperature. Then, the MPP po…
A multiple layered functional data model to support multiple representations and interoperability of GIS
2001
This paper presents a multi-layered functional data model to support multiple representation and information sharing among distributed spatial information systems. The key idea is that a geographical space (foe example an urban space) can be viewed as a set of abstract spatial functionalities on which different application classes can be derived to manipulate objects of the same geographical space and share the same abstract generic functionalities. The object classes define multiple views or representations of a domain. For example in urban management, transportation systems, water supply and sewage systems applications can share generic network functionalities defined by graph treversal o…
A Novel Multidimensional Scaling Technique for Mapping Word-Of-Mouth Discussions
2009
The techniques which utilize Multidimensional Scaling (MDS) as a fundamental statistical tool have been well developed since the late 1970’s. In this paper we show how anMDS scheme can be enhanced by incorporating into it a Stochastic Point Location (SPL) strategy (one which optimizes the former’s gradient descent learning phase) and a new Stress function. The enhanced method, referred to as MDS SPL, has been used in conjunction with a combination of the TF-IDF and Cosine Similarities on a very noisy Word-Of-Mouth (WoM) discussion set consisting of postings concerning mobile phones, yielding extremely satisfying results.