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The operator Riccati equation associated with a distributed parameter quadratic cost-linear dynamics control process is considered.Making use of ideas from transport theory, a derivation of a generalized version of the X-Y functions of radiative transfer is given, and it is seen that, under commonly occurring conditions, the new equations may be easier to numerically resolve than the original Ricc
In this paper some of the numerical problems associated with computing the generalized inverse of a matrix are discussed and illustrated by a detailed analysis of an iteration of Ben-Israel and Cohen.
The problem of identifiability of processes using measurements obtained under closed loop operation is treated. Single input-single output systems are considered. It is assumed that the feedback is time invariant, linear and noise free. It is also assumed that no external input signal is injected. Conditions, which are simultaneously necessary and sufficient for identifiability are derived. The re
Tin whiskers are hair-like single crystals that spontaneously grow from tin-coated surfaces. Whiskers are commonly found in electronic components, where tin coatings are used in, e.g., soldering applications, and to protect components from corrosion. Whiskers are known to cause short-circuits leading to failure of electronic components. The exact mechanisms responsible for whisker formation and gr
In this paper five different recursive identification methods will be analyzed and compared, namely recursive versions of the least squares method, the instrumental variable method, the generalized least squares method, the extended least squares method and the maximum likelihood method. They are shown to be similar in structure and need of computer storage and time. Making use of recently develop
A class of identification methods, proposed in [3], are based on the instrumental variable principle. This correspondence contains a continued analysis of convergence of the parameter estimates of these methods. Alternative, sufficient conditions for convergence to correct values are given. It is also shown by construction of counter-examples that the methods do not converge under general conditio
ERP systems became popular with large organizations in the 1990s. In the 21st Century, these products were expanded by addition of supply chain management (SCM) and customer relationship management (CRM), as well as access through the Web, creating the ERP II concept. Efforts to increase the market led vendors to serve not only large organizations, but also focus more on small-to-medium sized ente
Applications of the generalized least squares method proposed by Clarke [1] have been reported by various authors. However, no analysis of the convergence of the method has been published. This correspondence gives examples for which the method converges to false solutions.
Convergence properties of the generalized least squares method are analyzed. The method can be interpreted as optimization of a likelihood function. The number of local maximum points of the likelihood function is examined. It is shown that this number is influenced by the signal to noise ratio. This theoretical result is illustrated by numerical examples using plant measurements. It is also prove
The current study demonstrates through experiment, the effect of solid lubricant assisted minimum quantity cooling lubrication (MQCL) when turning tempered (~60 HRC) alloyed steel Uddeholm Caldie with cemented carbide tools on the process performance. In MQCL application, nanosized graphite nanoplatelets (GnP) solid lubricant powder was dispersed (0.2% vol.) in rapeseed oil based lubricant “ECOLUB
The maximum likelihood method of identification is a powerful tool for obtaining mathematical models of dynamic processes. To apply this method a loss function has to be minimized. The aim of the paper is an investigation of the local minimum points of this loss function for a common structure of a general form. If the loss function has more than one local minimum point, numerical problems can occ
The presence of graphite particles in gray cast iron commonly implies a good machinability, especially if compared to common steels. However, increasing industrial demands have resulted in a new interest for high-speed machining of these materials with higher performing tool materials than the traditionally used. Thus, the research presented in this paper focuses on evaluating the active tool wearThe presence of graphite particles in gray cast iron commonly implies a good machinability, especially if compared to common steels. However, increasing industrial demands have resulted in a new interest for high-speed machining of these materials with higher performing tool materials than the traditionally used. Thus, the research presented in this paper focuses on evaluating the active tool wear
Aim of the Study. To assess the frequency of and identify contributing factors to wound dehiscence after posterior sagittal anorectoplasty (PSARP) in children born with anorectal malformations (ARM). Methods. Ethical approval was obtained (DNR 2017/191). Charts of all children with anorectal malformations (ARM) reconstructed with PSARP, limited PSARP, or PSARVUP at a tertiary centre of paediatric
Objective: In the 2016 American College of Rheumatology/European League Against Rheumatism classification criteria for primary Sjögren’s syndrome (pSS), pre-existing lymphoma is not an exclusion criterion for pSS diagnosis, as in earlier criteria. We aimed to explore whether there are differences between pSS patients with and without pre-existing lymphoma at pSS diagnosis. Method: Patients with IC
To Ask for the King’s Permission to Marriage: Applications for Marriage between Relatives in Eighteenth Century Sweden. In early modern Western society regulations against incestuous relationships were primarily justified by religion, and kinship by blood and kinship by marriage were treated equally. In the seventeenth and eighteenth centuries Swedish law was among the strictest in these matters,
In some cases of tomography we can only gain high resolution projections of the object with only partial coverage, whereas only a small part of the object – a given Region of Interest (ROI) – is fully covered by high resolution projections. In such cases the structures outside the region of interest cause artefacts to appear in the reconstructed image and degrade the image quality of the tomogram.
Känslor och känsloyttringar kan förefalla vara allmänmänskliga företeelser, men forskning visar att den generella inställningen till känslor har skiftat mellan olika kulturer såväl som inom en och samma kultur över olika tidsperioder. Under medeltiden värderades exempelvis kontroll och förnuft högre än känslosamhet i det västerländska samhället, men från och med sent 1700-tal kom känslor och kärleResearch has shown that the general attitudes towards emotions have shifted between different cultures as well as within one culture over different periods. During the Middle Ages, for example, control and reason were considered more desirable human qualities than emotions in Western societies. However, from the late 1700s emotions and empathy were described with increasingly positive terms. From
Evidence suggests that research benefits from diversity, yet science is concentrated to a small group of countries. Diversity in physical therapy research has so far not been studied thoroughly, and this is the first study to map physical therapy research geographically. The objective was to study the frequency and methodological quality of physical therapy-related randomized controlled trials (RC
