South Westphalia University of Applied Sciences
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Matthies B.,South Westphalia University of Applied Sciences
Pacific Asia Conference on Information Systems, PACIS 2016 - Proceedings | Year: 2016

Most project-based organizations possess extensive collections of diverse project documents. Exploring the knowledge codified in such project documents is specifically recommended by the common project management guidelines. In practice, however, project managers are faced with the problem of information overload when trying to analyze the extensive document collections. This paper addresses this problem by combining two approaches already established in other disciplines. The first involves the development of a Project Knowledge Dictionary (PKD) for the automated analysis of knowledge contents codified in project documents. The second involves the integration of a sentiment analysis where concrete opinion expressions (positive/negative) are identified in connection with the codified project knowledge. Building on this, three mutually complementary analyses are demonstrated, which provide the following contributions: (1) determining the volume and distribution of five project knowledge types in project documents; (2) determining the general sentiment (positive/negative) in conjunction with the textual description of the project knowledge; (3) classifying project documents by their sentiment. By this means, the proposed solution provides valuable insight into the emotional situation in projects and contributes to the emerging research issue of project sentiment analysis. Furthermore, the solution makes a contribution to overcoming the information overload by assessing and organizing the knowledge content of large document collections.

Matthies B.,South Westphalia University of Applied Sciences
Pacific Asia Conference on Information Systems, PACIS 2015 - Proceedings | Year: 2015

Project-based organizations invest a lot of time and effort into the extensive documentation of their projects. These project documents usually contain innovative knowledge and represent a significant source of information for the continual development of a learning organization. However, this codified project knowledge often remains untapped afterwards. A central problem in this context is the sheer information overload due to the often very large documentation stocks in project-based organizations. Against this background, this paper poses the following question: what can be done with the extensive project documentation after it has been created? To answer this question, two methodological approaches are combined. First, a literature review summarizes the current status quo of research in this special area. Then, expert interviews with IT project managers provide a deeper understanding of common practical problems. The combination of respective findings makes it possible to uncover research gaps and subsequently to define future needs for research. In sum, this paper formulates six research issues, which represent a starting point on the path to more comprehensive solutions for practically coping with large stocks of codified project knowledge.

Schulze H.,South Westphalia University of Applied Sciences
IET Optoelectronics | Year: 2017

The integrating sphere is the base for a physical model of the wireless optical indoor communication channel. The author has found that the approximate expression for the channel transfer function for the integrating sphere used in that model can be replaced by an exact expression. A comparison shows that the approximation is valid for a wide range of interest, however there are some differences for high frequency values. For the impulse response (obtained by the inverse Fourier transform), the author observes significant deviations in the time region where first order reflections contribute significantly to the curve shape. © The Institution of Engineering and Technology.

Sinsukthavorn W.,South Westphalia University of Applied Sciences | Ortjohann E.,South Westphalia University of Applied Sciences | Mohd A.,Enecsys Micro Inverter | Hamsic N.,South Westphalia University of Applied Sciences | Morton D.,University of Bolton
IEEE Transactions on Industrial Electronics | Year: 2012

Future power distribution requires advanced expandability and flexibility in the integration of distributed energy resources which normally require interfacing units to provide the necessary crossing point to the grid. The core of these interfacing units is power-electronics grid front end, namely, inverters. The inverter is the primary interface that provides not only their principal interfacing control function but also various utility functions. This paper presents the flexible control methodology of inverters as grid front end using an isochronous control function which is used by synchronous generators in conventional power systems to provide load sharing and control. © 2012 IEEE.

Mohd A.,South Westphalia University of Applied Sciences | Ortjohann E.,South Westphalia University of Applied Sciences | Morton D.,University of Bolton | Omari O.,Arab American University - Jenin
Electric Power Systems Research | Year: 2010

This paper presents state-of-the-art review of control methods applied currently to parallel power electronic inverters. Different system architectures, their modes of operation, management and control strategies will be analyzed; advantages and disadvantages will be discussed. Though, it is not easy to give a general view at the state of the art for the research area since it is rapid and going in different directions, this paper will focus on the main streams. This paper will start by briefly reviewing the current trends in power supply systems and the increasing importance for including power electronic devices. Next, the different techniques to parallel inverters suggested in the literature will be checked. These can be categorized to the following main approaches: master/slave control techniques, current/power sharing control techniques, and frequency/voltage droop control techniques. Finally, based on the reviewed state of the art, the study concludes by comparing the different approaches reported. In addition, their weaknesses and strengths are strained. © 2010 Elsevier B.V. All rights reserved.

Platte F.,IANUS Simulation GmbH | Heise H.M.,South Westphalia University of Applied Sciences
Journal of Molecular Structure | Year: 2014

Over recent years terahertz spectroscopy has become a new tool for the characterization of solid materials, in particular for investigating polymorphism and crystallinity in pharmaceutics. Search strategies have been tested for THz spectra of various organic compounds with their spectra taken from the Riken database (, using the GRAMS spectroscopy software. A subset of the entire database was used, which had been processed by removal of atmospheric water vapour lines and smoothing applied based on Savitzky-Golay convolution or time domain filtering. The spectral range available for all library substances was restricted to an interval from 0.9 to 4.5 THz (30-150 cm-1). The number of vibrational bands within this spectral range is much reduced compared with mid-infrared or Raman spectra. The appropriateness of spectral pre-treatment is demonstrated with regard to reliability and robustness of the search methods. In particular, time-domain filters for smoothing and pre-treatment by the removal of water lines and etalon effects have been successfully tested in combination with least squares and correlation methods. With these insights, applications for substance identification, especially for the pharmaceutical industry, may be enlarged. © 2013 Elsevier B.V. All rights reserved.

Schulze H.,South Westphalia University of Applied Sciences
IEEE Transactions on Communications | Year: 2016

The indoor wireless optical communication channel is characterised by the multiple reflections of the light from the surrounding walls. We present a new frequency-domain simulation method for this channel. In contrast to the known time-domain simulation techniques, our method is not restricted to a finite order of reflections. We show that the contributions of an infinite number of reflections can be summed up analytically to a formula that can be handled by standard numerical methods. We illustrate the method by comparing it to the results of previous time domain simulations, and we apply it to the numerical evaluation of some further model scenarios with more than one transmitter. © 2016 IEEE.

Schwung A.,South Westphalia University of Applied Sciences
IEEE International Conference on Automation Science and Engineering | Year: 2015

This paper presents a novel approach to cyber-physical modeling of compression systems. The proposed model covers both physical as well as virtual, i.e. control components. As the modeling framework we employ hybrid automata due to their ability to conveniently handle both continuous and discrete dynamics. Simulation results comparing the proposed model with a complex real world compression system model underline the effectiveness of the approach. © 2015 IEEE.

Schulze H.,South Westphalia University of Applied Sciences
2010 International ITG Workshop on Smart Antennas, WSA 2010 | Year: 2010

We apply the Monte-Carlo simulation model to a frequency selective fading channel including space-variance. This model is suited to simulate the performance of a multi-antenna system for a moving receiver (or transmitter). It takes into account that the time-variance of the channel due to this motion has its origin in the space-variance. We emphasize that for such a channel, time and frequency correlations cannot be separated. ©2010 IEEE.

Low-cost specialization, differentiation, and diversification are common business models of urban farms in developed countries. Similarities and differences between them as well as detailed insights into specific farm characteristics are widely absent in scientific discourses. This paper compares farm structures, success factors, obstacles, clients' expectations, and policy wishes between specialized, differentiated, and diversified farms as well as diversifiers into agriculture. A standardized questionnaire was used for 21 personal in-depth farm interviews located in metropolitan areas of North Rhine-Westphalia, Germany. Being located in a metropolitan area is the most often named Unique Selling Proposition (USP). This is also mentioned as most important success factor followed by sociability and personal contact to clients, which both underpin the importance of direct producer-consumer linkages in urban settings. Additionally, it is assumed that a single food criterion is not sufficient to be successful, but several have to be merged to meet clients' expectations. In terms of marketing, differentiated and diversified farmers prefer a multi-channel approach, while specialized farmers and diversifiers into agriculture focus mainly on one specific channel. While both specialized farmers and diversifiers into agriculture cultivate smaller areas of farmland, the latter one offers the greatest number of jobs including those outside agricultural production. The findings obtained are expected to support farms and agricultural advisory services in individual decision making of future business development strategies and increase knowledge of urban farming's main business models. © 2016 by the author licensee MDPI, Basel, Switzerland.

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