Representation of Boolean functions with ROBDDsAleš Časar
, Robert Meolic
, samostojni znanstveni sestavek ali poglavje v monografski publikaciji
Opis: This paper describes data structures and algorithms for representation of Boolean functions with reduced ordered binary decision diagrams (ROBDDs). A hash table is used for quick search. Additional information about variables and functions is stored in binary trees. Manipulations on functions are based on a recursive algorithm of ITE operation. The primary goal of this article is describe programming technics needed to realize the idea. For the first time here recursive algorithms for composing functions and garbage collection with a formulae counter are presented. This is better than garbage collection in other known implementations. The results of the tests show that the described representation is very efficient in applications which operate with Boolean functions.
Ključne besede: Reduced Ordered Binary Decision Diagram, Boolean function, logic functions, logic design verification, hash table
Objavljeno: 02.02.2018; Ogledov: 84; Prenosov: 4
Celotno besedilo (323,32 KB)
Wiener index of strong product of graphsIztok Peterin
, Petra Žigert
, 2018, izvirni znanstveni članek
Opis: The Wiener index of a connected graph ▫$G$▫ is the sum of distances between all pairs of vertices of ▫$G$▫. The strong product is one of the four most investigated graph products. In this paper the general formula for the Wiener index of the strong product of connected graphs is given. The formula can be simplified if both factors are graphs with the constant eccentricity. Consequently, closed formulas for the Wiener index of the strong product of a connected graph ▫$G$▫ with a cycle are derived.
Ključne besede: Wiener index, graph product, strong product
Objavljeno: 30.11.2017; Ogledov: 66; Prenosov: 3
Celotno besedilo (424,67 KB)
New perspectives for computer-aided discrimination of Parkinson's disease and essential tremorPetra Povalej
, J.A. Gallego
, J. P. Romero
, Vojko Glaser
, E. Rocon
, Julián Benito-León
, Félix Bermejo-Pareja
, Ignacio Posada
, Aleš Holobar
, 2017, izvirni znanstveni članek
Opis: Pathological tremor is a common but highly complex movement disorder, affecting ~5% of population older than 65 years. Different methodologies have been proposed for its quantification. Nevertheless, the discrimination between Parkinson's disease tremor and essential tremor remains a daunting clinical challenge, greatly impacting patient treatment and basic research. Here, we propose and compare several movement-based and electromyography-based tremor quantification metrics. For the latter, we identified individual motor unit discharge patterns from high-density surface electromyograms and characterized the neural drive to a single muscle and how it relates to other affected muscles in 27 Parkinson's disease and 27 essential tremor patients. We also computed several metrics from the literature. The most discriminative metrics were the symmetry of the neural drive to muscles, motor unit synchronization, and the mean log power of the tremor harmonics in movement recordings. Noteworthily, the first two most discriminative metrics were proposed in this study. We then used decision tree modelling to find the most discriminative combinations of individual metrics, which increased the accuracy of tremor type discrimination to 94%. In summary, the proposed neural drive-based metrics were the most accurate at discriminating and characterizing the two most common pathological tremor types.
Ključne besede: Parkinson's disease, essential tremor, electromyography, wrist movements, motor units, muscular excitation, decision tree
Objavljeno: 03.11.2017; Ogledov: 68; Prenosov: 3
Celotno besedilo (3,31 MB)
Implementation aspects of a BDD package supporting general decision diagramsRobert Meolic
, 2016, predavanje na tuji univerzi
Opis: General decision diagram is a loose term for a superset of different types of decision diagrams - we are interested in joining BDDs, FDDs, and different types of suppressed DDs, e.g. ZBDDs. I will present: The current state of our BDD package Biddy (functionalities and details about the original implementation aspects). Our ideas for efficient implementation of ZBDDs (which could be used for all types of suppressed DDs).New type od decision diagrams called ZFDD (somehow symmetric to ZBDD). A rough draft about the implementation of a package supporting general decision diagrams.
Ključne besede: Binary Decision Diagram, Zero-suppressed Binary Decision Diagram, Boolean function, Algorithm, BDD package, Biddy
Objavljeno: 26.10.2017; Ogledov: 171; Prenosov: 6
Celotno besedilo (1,07 MB)
The impact of wind-power generation on the planning of regulating reserveDunja Srpak
, Boštjan Polajžer
, 2017, izvirni znanstveni članek
Opis: This paper presents new approach to the optimal distribution of the regulating reserve (RR) in a set of available regulating generation units. It is developed using evolutionary computation for the transmission-loss minimization and power-flow computation by applying the iterative method with a reactive power correction for voltage control. The approach involves the use of actual operating data directly from the network’s dispatch centre as well as daily and hourly plans of wind and load power for determining the RR requirements for the load frequency control (LFC). By testing the proposed approach on a case study, the possibility of implementing it on real power systems is demonstrated. The obtained results of the testing with actual data from the Croatian control area indicate substantial savings in ancillary service costs for the LFC and the considerable impact of different variations from the plan of each individual wind-power plant on the optimal RR distribution.
Ključne besede: evolutionary computation, frequency control, optimization, power systems, wind power generation
Objavljeno: 24.10.2017; Ogledov: 67; Prenosov: 4
Celotno besedilo (1,52 MB)
Practicality of base load renewable generation in IndiaKarthik Subramanya Bhat
, Udo Bachhiesl
, objavljeni znanstveni prispevek na konferenci
Opis: India, among several other countries globally, now faces a unique situation where managing the energy transition process without hurting the economic development becomes the highlight of its policies. The Indian power sector is highly carbon intensive, with coal based power providing 70% of the total electricity generated. Renewable energy occupies around 15% of the capacity mix. Energy access along with several other
challenges, pose an obstacle to the needed transition to clean energy. As the seasonal load variations in India are not prominent, cheap coal based power supplies most of the load profile,while gas power plants are used for peak loads. The myth that renewable energy sources cannot meet baseload demand has become widely accepted and wide-spread, given their fluctuating nature. Several studies demonstrate an optimistic transition to 100% renewable sources might just be possible in the coming decades. In a carbon-rich power sector like India, the ‘base load’ mind set is a pretty big and powerful hurdle, as ensuring base load generation becomes a major issue with implications directly affecting the country’s economy. In this study, an effort has been made to discuss whether base load renewable generation in India is feasible, and the challenges involved.
Ključne besede: India, base load, renewable generation, energy transition, carbon intensive
Objavljeno: 11.10.2017; Ogledov: 55; Prenosov: 1
Celotno besedilo (970,31 KB)
What is it worth?Petra Gsodam
, Heinrich Stigler
, objavljeni znanstveni prispevek na konferenci
Opis: High lifetimes and high capital intensities characterize fixed assets of electric utilities. The historical cost concept implicate that long-lasting fixed assets are shown too low in balance sheets of electric utilities: the real value of long-lasting assets is not shown because of nominal price increases. An alternative to show the real value of longterm assets represents the capital stock concept based on replacement values less depreciations (net capital stock). To calculate the capital stock, information regarding the level of investment in each power plant at the time of construction (historical acquisition values) and with regard to a common base year (replacement values) is necessary. This paper shows how the not-standardized investments in hydropower plants can be estimated and how the capital stock of run-of-river and threshold hydropower plants can be calculated. Long-term assets in the form of run-of-river and threshold hydropower plants are compared based on historic costs and replacement values. The paper concludes that given nominal price increases for replacement investments, as is the case with long-lasting hydropower plants, only depreciations based on replacement values can ensure preservation of the company’s assets.
Ključne besede: fixed assets, electric utilities, balance sheet, capital stock, depreciation
Objavljeno: 11.10.2017; Ogledov: 60; Prenosov: 2
Celotno besedilo (1,51 MB)