426 research outputs found
The Hierarchical System of Planning in a Socialist Society
For better understanding of the actual system of planning namely the vertical functioning of the hierarchical management, it is necessary to explain briefly some characteristics of it's evolution.
The planning system in the period of the past twenty years concerning the supplies of iron and steel, changed the form according to the development of methodology, increased production and demand. Characteristics of the period are a strict concentration, concerning production and sale, mainly in the beginning and after nationalizing all steel and iron plants in Czechoslovakia
Capacity Modeling in a Stripping Bay Simulation Study
The model of a steel plant with steel making, plate and sheet rolling and rod drawing facilities will be considered and described
Computer Based Management Systems
The purpose of this research is to identify the relative degree of centralization and integration of management within industrial sectors, in particular to clarify functions of the decision-making process based on planning. Special features of the hierarchy of a planned system and a short classification of plans and methods used is given. The main functions and objectives of Computer Based Management Systems are described with the typical structure of a production enterprise as a complex of subsystems having specific functions
The Role of Computer Simulation in Corporate Management: An Overview
This memorandum, prepared in support of a general study of integrated industrial systems, focuses on the growing use of computer simulation techniques (models) as a means of increasing the efficiency of management systems in large-scale industries. It first examines three significant generalized models or "business games," describing their important characteristics and evaluating their limitations as predictors of "real world" operations. It appears that models providing information feedback offer particular promise for realistic simulation of large-scale organizations.
Next, the author examines the use of simulation models in industry, noting that the most effective applications have been in the fields of transportation, communication, utilities, banking, and, particularly, manufacturing. An important characteristic of firms successfully using simulation techniques appears to be size: historically most practical applications have been in firms with sales in excess of 10 million. Typical costs for design and implementation appear to lie in range of 100,000, while elapsed times for full implementation range from six months to as much as three years.
To date, mathematical, rather than econometric modeling techniques have dominated, and have been used effectively in the fields of finance, marketing, production and inventory control. Although short-term forecasting techniques for projections of sales and revenue are in general use throughout industry, broader applications have suffered from a number of limitations in existing models, among the more significant being a lack of flexibility within the model itself and, in some cases, a lack of commitment to modeling on the part of high-level management. Despite these and other limitations, the high degree of risk and uncertainty characteristic of the current economic environment appears certain to lead to greater use of more complex simulation by managers at all levels
Microphone array signal processing for robot audition
Robot audition for humanoid robots interacting naturally with humans in an unconstrained real-world environment is a hitherto unsolved challenge. The recorded microphone signals are usually distorted by background and interfering noise sources (speakers) as well as room reverberation. In addition, the movements of a robot and its actuators cause ego-noise which degrades the recorded signals significantly. The movement of the robot body and its head also complicates the detection and tracking of the desired, possibly moving, sound sources of interest. This paper presents an overview of the concepts in microphone array processing for robot audition and some recent achievements
Rigorous Proof of a Liquid-Vapor Phase Transition in a Continuum Particle System
We consider particles in , interacting via attractive
pair and repulsive four-body potentials of the Kac type. Perturbing about mean
field theory, valid when the interaction range becomes infinite, we prove
rigorously the existence of a liquid-gas phase transition when the interaction
range is finite but long compared to the interparticle spacing.Comment: 11 pages, in ReVTeX, e-mail addresses: [email protected],
[email protected], [email protected]
Ordering and Demixing Transitions in Multicomponent Widom-Rowlinson Models
We use Monte Carlo techniques and analytical methods to study the phase
diagram of multicomponent Widom-Rowlinson models on a square lattice: there are
M species all with the same fugacity z and a nearest neighbor hard core
exclusion between unlike particles. Simulations show that for M between two and
six there is a direct transition from the gas phase at z < z_d (M) to a demixed
phase consisting mostly of one species at z > z_d (M) while for M \geq 7 there
is an intermediate ``crystal phase'' for z lying between z_c(M) and z_d(M). In
this phase, which is driven by entropy, particles, independent of species,
preferentially occupy one of the sublattices, i.e. spatial symmetry but not
particle symmetry is broken. The transition at z_d(M) appears to be first order
for M \geq 5 putting it in the Potts model universality class. For large M the
transition between the crystalline and demixed phase at z_d(M) can be proven to
be first order with z_d(M) \sim M-2 + 1/M + ..., while z_c(M) is argued to
behave as \mu_{cr}/M, with \mu_{cr} the value of the fugacity at which the one
component hard square lattice gas has a transition, and to be always of the
Ising type. Explicit calculations for the Bethe lattice with the coordination
number q=4 give results similar to those for the square lattice except that the
transition at z_d(M) becomes first order at M>2. This happens for all q,
consistent with the model being in the Potts universality class.Comment: 26 pages, 15 postscript figure
Non-coding nucleotides and amino acids near the active site regulate peptide deformylase expression and inhibitor susceptibility in Chlamydia trachomatis
Chlamydia trachomatis, an obligate intracellular bacterium, is a highly prevalent human pathogen. Hydroxamic-acid-based matrix metalloprotease inhibitors can effectively inhibit the pathogen both in vitro and in vivo, and have exhibited therapeutic potential. Here, we provide genome sequencing data indicating that peptide deformylase (PDF) is the sole target of the inhibitors in this organism. We further report molecular mechanisms that control chlamydial PDF (cPDF) expression and inhibition efficiency. In particular, we identify the σ66-dependent promoter that controls cPDF gene expression and demonstrate that point mutations in this promoter lead to resistance by increasing cPDF transcription. Furthermore, we show that substitution of two amino acids near the active site of the enzyme alters enzyme kinetics and protein stability
Transferable integrons of Gram-negative bacteria isolated from the gut of a wild boar in the buffer zone of a national park
The aim of this study was to determine the presence of integron-bearing Gram-negative bacteria in the gut of a wild boar (Sus scrofa L.) shot in the buffer zone of a national park. Five Gram-negative strains of Escherichia coli, Serratia odorifera, Hafnia alvei and Pseudomonas sp. were isolated. Four of these strains had class 2 integrase (intI2), and one harbored class 1 integrase (intI1). The integron-positive strains were multiresistant, i.e., resistant to at least three unrelated antibiotics. All of the integrons were transferred to E. coli J-53 (RifR) in a conjugation assay. The results showed that a number of multiresistant, integron-containing bacterial strains of different genera may inhabit a single individual of a wild animal, allowing the possibility of transfer of antimicrobial resistance genes
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