Optimization-based control of cooling plant with dissimilar chillers

Statkraft drifter kjølestasjonen på Øya, som leverer kjøling til Universitetssykehuset i Trondheim. En masteroppgave er skrevet i samarbeid med Statkraft i et forsøk på å forbedre styringen av kjølestasjonen. Det ble lagt mest innsats i modellutvikling, siden fornuftige modeller er essensielt for modellbasert styring. Modellkompleksiteten ble minimert for å begrense beregningstiden. En optimaliseringsbasert regulator som bruker modellene ble designet og justert, med fokus på heuristikker for å begrense beregningstiden og motvirke modellfeil. Regulatoren ble brukt til en demonstrasjon av et operatørstøttesystem (OSS) fordi regulatoren bør testes av operatørene i sanntid før den installeres, og et OSS kan være nyttig for operatørene uavhengig av om regulatoren blir installert. OSS-et kunne bare demonstreres med historiske data fordi henting av data i sanntid ikke ble implementert i tide for dette prosjektet. Modellene, regulatoren og OSS-et presenteres i denne rapporten. En oppdatering av beskrivelsen gitt i spesialiseringsprosjektet for denne masteroppgaven er også inkludert, sammen med anbefalinger for hvordan driften av kjølestasjonen kan forbedres. Denne masteroppgaven er relevant for delmål 9.4 av FNs bærekraftsmål, som er å oppgradere infrastruktur og omstille næringslivet til å bli mer bærekraftig med mer effektiv bruk av ressurser. OSS-et minimerer energikostnadene når kjølestasjonens krav er oppfylt, noe som vil bidra til å øke ressursutnyttelsen til kjølestasjonen hvis det installeres.Statkraft operates the cooling plant at Øya, which provides cooling to Trondheim University Hospital. A master's thesis has been written in cooperation with Statkraft in an attempt to improve the cooling plant control. Most of the effort was put into model development, as reasonable models are fundamental to model-based control while the model complexity was minimized to limit computation time. An optimization-based controller using the models was designed and tuned, with a focus on heuristics to limit computation time and mitigate model errors. The controller was used for a demonstration of an operator support system (OSS) because the controller should be tested by the operators in a real-time environment before it is deployed and an OSS could be helpful to the operators independent of the controller deployment. The OSS could only be demonstrated with historical data, as real-time data collection was not implemented in time for this project. The models, controller and OSS are presented in this report. An update of the description given in the specialization project for this master's thesis is also included, along with recommendations on how the operation of the cooling plant can be improved. This master's thesis is relevant to target 9.4 of the United Nations Sustainable Development Goals, which is to upgrade infrastructure and retrofit industries to increase sustainability by increasing resource efficiency. The OSS minimizes energy costs when the cooling plant requirements are met, which would help increase the resource efficiency of the cooling plant if it is deployed

Practical extremum-seeking control for gas-lifted oil production

We present a distributed extremum seeking algorithm for the problem of production optimization of multiple gas lifted wells. The algorithm is based on “synchronization” of production performance gradients for all individual wells. It mimics the manual optimization method employed by production engineers in industry. Thus due to better understanding by industrial specialists, this method may have higher chances of being accepted in the oil and gas industry compared to other data-driven optimization methods. Performance of the proposed algorithm is illustrated by simulations.acceptedVersion© 2017 IEEE. This is the author's accepted manuscript of the article. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works

Ensemble learning in the estimation of flow types and velocities of individual phases in multiphase flow using non-intrusive accelerometers' and process pressure data

Multiphase flows with oil/ gas/ water are common in oil and gas industries. Accurately identifying flow types and estimating flow velocities of the individual phases are crucial for different purposes, such as observing the process status and providing inputs to control systems. This paper presents a solution for identifying flow contents and estimating flow rates in single-phase or each phase in multiphase flows by using pressure measurements and pipe vibrations caused by the flows. The necessary experiments were performed using the multiphase flow rig with three-inch diameter pipelines transporting natural gas, water, and crude oil in a closed loop with a separator tank as source and sink. A series of tree-based ensemble machine learning models have been developed and tested with the data collected from accelerometers, differential pressure transmitters, and upstream- and downstream pressure transmitters. With these inputs, the developed models can identify volume ratios of individual phases (such as water cut) and can estimate the flow velocity of each phase in the flow loop, including the open/close status of the choke valve. After describing briefly, the P&ID diagram of the multiphase flow rig, the paper focuses on exploratory data analysis of the data from three accelerometers and three pressure sensors using three submodels cascaded to perform ensemble learning.acceptedVersio

Phase Fractions and Velocities in Multiphase Flow – Estimation using Sensor Data Fusion and Machine Learning

There is a strong interest in quantifying the amount of gas and its flow rate to facilitate better control of the processes involved in many industries. There are usually many sensors monitoring these processes, both intrusive and invasive, as well as non-invasive sensors which are usually clamped on to the process pipelines in which the multiphase flow occurs. In the multiphase flow rigs at Equinor and the University of South-Eastern Norway, experiments have been performed with different combinations and velocities of the phases and multiple sensors have been logged. The data from these sensors have been used to estimate volume fractions of the phases as well as their flow rates. This paper presents the estimated results of volume fractions and velocities of selected phases, obtained by fusing data from multiple sensors that monitor density, differential pressure, temperature, and acoustic emission using machine learning (ML) algorithms. These ML algorithms use neural networks with the non-linear input-output type with Levenberg-Marquardt training and provide estimates of volume fractions and phase velocities with RMSE values in the range of 4.6 to 16 m3/h, with the lowest RMSE for gas and the highest for multiphase flow. The total flow rate for the multiphase flow was in the range 30 to 120 m3/h. Results are compared with ML models using data from non-invasive sensors

Advances in european sea bass genomics and future perspectives

Only recently available sequenced and annotated teleost fish genomes were restricted to a few model species, none of which were for aquaculture. Application of Marker Assisted Selection for improved production traits had been largely restricted to the salmon industry and genetic and Quantitative Trait Loci (QTL) maps were available for only a few species. With the advent of Next Generatio Sequencing the landscape is rapidly changing and today the genomes of several aquaculture species have been sequenced. The European sea bass, Dicentrarchus labrax, is a good example of a 17 commercially important aquaculture species in Europe for which in the last decade a wealth of genomic resources, including a chromosomal scale genome assembly, physical and linkage maps as well as relevant QTL have been generated. The current challenge is to stimulate the uptake of the resources by the industry so that the full potential of this scientific endeavour can be exploited and produce benefits for producers and the public alike

Interventions for treating proximal humeral fractures in adults.

Background Fracture of the proximal humerus, often termed shoulder fracture, is a common injury in older people. The management of these fractures varies widely. This is an update of a Cochrane Review first published in 2001 and last updated in 2012. Objectives To assess the effects (benefits and harms) of treatment and rehabilitation interventions for proximal humeral fractures in adults. Search methods We searched the Cochrane Bone, Joint and Muscle Trauma Group Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, and other databases, conference proceedings and bibliographies of trial reports. The full search ended in November 2014. Selection criteria We considered all randomised controlled trials (RCTs) and quasi-randomised controlled trials pertinent to the management of proximal humeral fractures in adults. Data collection and analysis Both review authors performed independent study selection, risk of bias assessment and data extraction. Only limited meta-analysis was performed. Main results We included 31 heterogeneous RCTs (1941 participants). Most of the 18 separate treatment comparisons were tested by small single-centre trials. The main exception was the surgical versus non-surgical treatment comparison tested by eight trials. Except for a large multicentre trial, bias in these trials could not be ruled out. The quality of the evidence was either low or very low for all comparisons except the largest comparison. Nine trials evaluated non-surgical treatment in mainly minimally displaced fractures. Four trials compared early (usually one week) versus delayed (three or four weeks) mobilisation after fracture but only limited pooling was possible and most of the data were from one trial (86 participants). This found some evidence that early mobilisation resulted in better recovery and less pain in people with mainly minimally displaced fractures. There was evidence of little difference between the two groups in shoulder complications (2/127 early mobilisation versus 3/132 delayed mobilisation; 4 trials) and fracture displacement and non-union (2/52 versus 1/54; 2 trials). One quasi-randomised trial (28 participants) found the Gilchrist-type sling was generally more comfortable than the Desault-type sling (body bandage). One trial (48 participants) testing pulsed electromagnetic high-frequency energy provided no evidence. Two trials (62 participants) provided evidence indicating little difference in outcome between instruction for home exercises versus supervised physiotherapy. One trial (48 participants) reported, without presentable data, that home exercise alone gave better early and comparable long-term results than supervised exercise in a swimming pool plus home exercise. Eight trials, involving 567 older participants, evaluated surgical intervention for displaced fractures. There was high quality evidence of no clinically important difference in patient-reported shoulder and upper-limb function at one- or two-year follow-up between surgical (primarily locking plate fixation or hemiarthroplasty) and non-surgical treatment (sling immobilisation) for the majority of displaced proximal humeral fractures; and moderate quality evidence of no clinically important difference between the two groups in quality of life at two years (and at interim follow-ups at six and 12 months). There was moderate quality evidence of little difference between groups in mortality in the surgery group (17/248 versus 12/248; risk ratio (RR) 1.40 favouring non-surgical treatment, 95% confidence interval (CI) 0.69 to 2.83; P = 0.35; 6 trials); only one death was explicitly linked with the treatment. There was moderate quality evidence of a higher risk of additional surgery in the surgery group (34/262 versus 16/261; RR 2.06, 95% CI 1.18 to 3.60; P = 0.01; 7 trials). Although there was moderate evidence of a higher risk of adverse events after surgery, the 95% confid

Nordic Innovative Trials to Evaluate osteoPorotic Fractures (NITEP) Collaboration: The Nordic DeltaCon Trial protocol-non-operative treatment versus reversed total shoulder arthroplasty in patients 65 years of age and older with a displaced proximal humerus fracture: a prospective, randomised controlled trial

Introduction The proximal humerus fracture (PHF) is one of the most common fractures in the elderly. The majority of PHFs are treated non-operatively, while 15%-33% of patients undergo surgical treatment. Recent randomised controlled trial (RCT) and meta-analyses have shown that there is no difference in outcome between non-operative treatment and locking plate or hemi-arthroplasty. During the past decade, reverse total shoulder arthroplasty (RTSA) has gained popularity in the treatment of PHF, although there is a lack of RCTs comparing RTSA to non-operative treatment.Methods This is a prospective, single-blinded, randomised, controlled, multicentre and multinational trial comparing RTSA with non-operative treatment in displaced proximal humeral fractures in patients 65-85 years. The primary outcome in this study is QuickDASH-score measured at 2 years. Secondary outcomes include visual analogue scale for pain, grip strength, Oxford shoulder score, Constant score and the number of reoperations and complications. The hypothesis of the trial is that operative treatment with RTSA produces better outcome after 2 and 5 years measured with QuickDASH.Ethics and dissemination In this protocol, we describe the design, method and management of the Nordic DeltaCon trial. The ethical approval for the trial has been given by the Regional Committee for Medical and Health Research Ethics, Norway. There have been several examples in orthopaedics of innovations that result in failure after medium-term follow-ups. In order to prevent such failures and to increase our knowledge of RSTA, we feel a large-scale study of the effects of the surgery on the outcome that focuses on the complications and reoperations is warranted. After the trial 2-year follow-up, the results will be disseminated in a major orthopaedic publication

Nordic Innovative Trials to Evaluate osteoPorotic Fractures (NITEP) Collaboration : The Nordic DeltaCon Trial protocol-non-operative treatment versus reversed total shoulder arthroplasty in patients 65 years of age and older with a displaced proximal humerus fracture: a prospective, randomised controlled trial

Introduction The proximal humerus fracture (PHF) is one of the most common fractures in the elderly. The majority of PHFs are treated non-operatively, while 15%-33% of patients undergo surgical treatment. Recent randomised controlled trial (RCT) and meta-analyses have shown that there is no difference in outcome between non-operative treatment and locking plate or hemi-arthroplasty. During the past decade, reverse total shoulder arthroplasty (RTSA) has gained popularity in the treatment of PHF, although there is a lack of RCTs comparing RTSA to non-operative treatment. Methods This is a prospective, single-blinded, randomised, controlled, multicentre and multinational trial comparing RTSA with non-operative treatment in displaced proximal humeral fractures in patients 65-85 years. The primary outcome in this study is QuickDASH-score measured at 2 years. Secondary outcomes include visual analogue scale for pain, grip strength, Oxford shoulder score, Constant score and the number of reoperations and complications. The hypothesis of the trial is that operative treatment with RTSA produces better outcome after 2 and 5 years measured with QuickDASH. Ethics and dissemination In this protocol, we describe the design, method and management of the Nordic DeltaCon trial. The ethical approval for the trial has been given by the Regional Committee for Medical and Health Research Ethics, Norway. There have been several examples in orthopaedics of innovations that result in failure after medium-term follow-ups. In order to prevent such failures and to increase our knowledge of RSTA, we feel a large-scale study of the effects of the surgery on the outcome that focuses on the complications and reoperations is warranted. After the trial 2-year follow-up, the results will be disseminated in a major orthopaedic publication.Peer reviewe

Identification and characterisation of novel SNP markers in Atlantic cod: Evidence for directional selection

<p>Abstract</p> <p>Background</p> <p>The Atlantic cod (<it>Gadus morhua</it>) is a groundfish of great economic value in fisheries and an emerging species in aquaculture. Genetic markers are needed to identify wild stocks in order to ensure sustainable management, and for marker-assisted selection and pedigree determination in aquaculture. Here, we report on the development and evaluation of a large number of Single Nucleotide Polymorphism (SNP) markers from the alignment of Expressed Sequence Tag (EST) sequences in Atlantic cod. We also present basic population parameters of the SNPs in samples of North-East Arctic cod and Norwegian coastal cod obtained from three different localities, and test for SNPs that may have been targeted by natural selection.</p> <p>Results</p> <p>A total of 17,056 EST sequences were used to find 724 putative SNPs, from which 318 segregating SNPs were isolated. The SNPs were tested on Atlantic cod from four different sites, comprising both North-East Arctic cod (NEAC) and Norwegian coastal cod (NCC). The average heterozygosity of the SNPs was 0.25 and the average minor allele frequency was 0.18. <it>F</it>_{<it>ST </it>}values were highly variable, with the majority of SNPs displaying very little differentiation while others had <it>F</it>_{<it>ST </it>}values as high as 0.83. The <it>F</it>_{<it>ST </it>}values of 29 SNPs were found to be larger than expected under a strictly neutral model, suggesting that these loci are, or have been, influenced by natural selection. For the majority of these outlier SNPs, allele frequencies in a northern sample of NCC were intermediate between allele frequencies in a southern sample of NCC and a sample of NEAC, indicating a cline in allele frequencies similar to that found at the Pantophysin I locus.</p> <p>Conclusion</p> <p>The SNP markers presented here are powerful tools for future genetics work related to management and aquaculture. In particular, some SNPs exhibiting high levels of population divergence have potential to significantly enhance studies on the population structure of Atlantic cod.</p

Surgical versus non-surgical treatment of humeral SHAFT fractures compared by a patient-reported outcome:the Scandinavian Humeral diAphyseal Fracture Trial (SHAFT)—a study protocol for a pragmatic randomized controlled trial

Background: The outcome of non-surgical treatment is generally good, but the treatment course can be long and painful with approximately a quarter of the patients acquiring a nonunion. Both surgical and non-surgical treatment can have disabling consequences such as nerve injury, infection, and nonunion. The purpose of the study is to compare patient-reported outcomes after surgical and non-surgical treatment for humeral shaft fractures. Methods: A pragmatic randomized controlled trial (RCT) is planned with two study groups (SHAFT-Young and SHAFT-Elderly). A total of 287 eligible acute humeral shaft fractures are scheduled to be recruited and randomly allocated to surgical or non-surgical treatment with the option of early crossover due to delayed union. The surgical method within the allocation is decided by the surgeon. The primary outcome is the Disability of Arm, Shoulder, and Hand (DASH) score at 52 weeks, and is assessor blinded. The secondary outcomes are DASH score, EQ-5D-5L, pain assessed by visual analog score, Constant-Murley score including elbow range of motion, and anchor questions collected at all timepoints throughout the trial. All complications will be reported including; infection, nerve or vascular injury, surgical revisions (implant malpositioning, hardware failure, aseptic loosening, and peri-implant fracture), major adverse cardiovascular events, and mortality. Discussion: The SHAFT trial is a pragmatic multicenter RCT, that will compare the effectiveness of the main strategies in humeral shaft fracture treatment. This will include a variety of fracture morphologies, while taking the dilemmas within the population into account by splitting the population by age and providing the orthopedic society with an interval for early crossover surgery. Trial registration: Clinicaltrials.govNCT04574336. Registered on 5 October 2020.</p