| 1. |
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| 2. |
- Gunnarsson, Mikael, et al.
(author)
-
No radiation protection reasons for restrictions on C-14 urea breath tests in children.
- 2002
-
In: British Journal of Radiology. - : British Institute of Radiology. - 1748-880X .- 0007-1285. ; 75:900, s. 982-986
-
Journal article (peer-reviewed)abstract
- Traditional 14C urea breath tests are normally not used for younger children because the radiation exposure is unknown. High sensitivity accelerator mass spectrometry and an ultra-low amount (440 Bq) of 14C urea were therefore used both to diagnose Helicobacter pylori (HP) infection in seven children, aged 3–6 years, and to make radiation dose estimates. The activity used was 125 times lower than the amount normally used for older children and 250 times lower than that used for adults. Results were compared with previously reported biokinetic and dosimetric data for adults and older children aged 7–14 years. 14C activity concentrations in urine and exhaled air per unit administered activity for younger children (3–6 years) correspond well with those for older children (7–14 years). For a child aged 3–6 years who is HP negative, the urinary bladder wall receives the highest absorbed dose, 0.3 mGy MBq-1. The effective dose is 0.1 mSv MBq-1 for the 3-year-old child and 0.07 mSv MBq-1 for the 6-year-old child. For two children, the 10 min and 20 min post-14C administration samples of exhaled air showed a significantly higher amount of 14C activity than for the rest of the children, that is 6% and 19% of administered activity exhaled per hour compared with 0.3–0.9% (mean 0.5%) of administered activity exhaled per hour indicating that these two children that is were HP positive. For a 3-year-old HP positive child, absorbed dose to the urinary bladder wall was 0.3 mGy MBq-1 and effective dose per unit of administered activity was 0.4 mSv MBq-1. Using 55 kBq, which is a normal amount for older children when liquid scintillation counters are used for measurement, the effective dose will be approximately 6 µSv to a 3-year-old HP negative child and 20 µSv to a HP positive child. Thus there is no reason for restrictions on performing a normal 14C urea breath test, even on young children.
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| 3. |
- Abul-Kasim, Kasim, et al.
(author)
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Low-dose helical computed tomography (CT) in the perioperative workup of adolescent idiopathic scoliosis.
- 2009
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In: European Radiology. - : Springer Science and Business Media LLC. - 0938-7994 .- 1432-1084. ; 19, s. 610-618
-
Journal article (peer-reviewed)abstract
- The study aims were to estimate the radiation dose in patients examined with low dose spine CT and to compare it with that received by patients undergoing standard CT for trauma of the same region, as well as to evaluate the impact of dose reduction on image quality. Radiation doses in 113 consecutive low dose spine CTs were compared with those in 127 CTs for trauma. The inter- and intraobserver agreement in measurements of pedicular width, and vertebral rotation, measurements of signal-to-noise ratio and assessment of hardware status were the indicators in the evaluation of image quality. The effective dose of the low dose spine CT (0.37 mSv) was 20 times lower than that of a standard CT for trauma (13.09 mSv). This dose reduction conveyed no impact on image quality. This low dose spine CT protocol allows detailed evaluation that is necessary for preoperative planning and postoperative evaluation.
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| 4. |
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| 5. |
- Abul-Kasim, Kasim, et al.
(author)
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Optimization of Radiation Exposure and Image Quality of the Cone-beam O-arm Intraoperative Imaging System in Spinal Surgery.
- 2012
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In: Journal of Spinal Disorders and Techniques. - 1539-2465. ; 25:1, s. 52-58
-
Journal article (peer-reviewed)abstract
- STUDY DESIGN: Retrospective study. OBJECTIVES: To optimize the radiation doses and image quality for the cone-beam O-arm surgical imaging system in spinal surgery. SUMMARY OF BACKGROUND: Neurovascular compromise has been reported after screw misplacement during thoracic pedicle screw insertion. The use of O-arm with or without navigation system during spinal surgery has been shown to lower the rate of screw misplacement. The main drawback of such imaging surgical systems is the high radiation exposure. METHODS: Chest phantom and cadaveric pig spine were examined on the O-arm with different scan settings: 2 were recommended by the O-arm manufacturer (120 kV/320 mAs, and 120 kV/128 mAs), and 3 low-dose settings (80 kV/80 mAs, 80 kV/40 mAs, and 60 kV/40 mAs). The radiation doses were estimated by Monte Carlo calculations. Objective evaluation of image quality included interobserver agreement in the measurement of pedicular width in chest phantom and assessment of screw placement in cadaveric pig spine. RESULTS: The effective dose/cm for 120 kV/320 mAs scan was 13, 26, and 69 times higher than those delivered with 80 kV/80 mAs, 80 kV/40 mAs, and 60 kV/40 mAs scans, respectively. Images with 60 kV/40 mAs were unreliable. Images with 80 kV/80 mAs were considered reliable with good interobserver agreement when measuring the pedicular width (random error 0.38 mm and intraclass correlation coefficient 0.979) and almost perfect agreement when evaluating the screw placement (κ value 0.86). CONCLUSIONS: The radiation doses of the O-arm system can be reduced 5 to 13 times without negative impact on image quality with regard to information required for spinal surgery.
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| 6. |
- Abul-Kasim, Kasim, et al.
(author)
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Radiation dose optimization in CT planning of corrective scoliosis surgery. A phantom study.
- 2008
-
In: The Neuroradiology Journal. ; 21:3, s. 374-382
-
Journal article (peer-reviewed)abstract
- The aim of the study was to explore the possibility of obtaining a helical CT scan of a long segment of vertebral column, optimally reduce the radiation dose, compare the radiation dose of the low dose helical CT with that of some of the CT protocols used in clinical practice and finally assess the impact of such a dose reduction on the image quality. A chest phantom was examined with a 16-slice CT scanner. Six scans were performed with different radiation doses. The lowest radiation dose which had no impact on image quality with regard to the information required for surgical planning of patients with scoliosis, was 20 times lower than that of routinely used protocol for CT examination of the spine in children (0.38 mSv vs 7.76 mSv). Patients with scoliosis planned for corrective spinal surgery can be examined with low dose helical CT scan. The dose reduction systems (DRS) available in modern CT scanners contribute to dose reduction and should be used.
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| 7. |
- Al-Okshi, Ayman, et al.
(author)
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Effective dose of cone beam computed tomography (CBCT) of the facial skeleton : a systematic review
- 2015
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In: British Journal of Radiology. - : British Institute of Radiology. - 0007-1285 .- 1748-880X. ; 88:1045
-
Research review (peer-reviewed)abstract
- Objective: To estimate effective dose of cone beam CT (CBCT) of the facial skeleton with focus on measurement methods and scanning protocols. Methods: A systematic review, which adhered to the preferred reporting items for systematic reviews (PRISMA) Statement, of the literature up to April 2014 was conducted. Data sources included MEDLINE®, The Cochrane Library and Web of Science. A model was developed to underpin data extraction from 38 included studies. Results: Technical specifications of the CBCT units were insufficiently described. Heterogeneity in measurement methods and scanning protocols between studies made comparisons of effective doses of different CBCT units and scanning protocols difficult. Few studies related doses to image quality. Reported effective dose varied across studies, ranging between 9.7 and 197.0 mSv for field of views (FOVs) with height #5cm, between 3.9 and 674.0 mSv for FOVs of heights 5.1–10.0 cm and between 8.8 and 1073.0 mSv for FOVs .10 cm. There was an inconsistency regarding reported effective dose of studies of the same CBCT unit with the same FOV dimensions. Conclusion: The review reveals a need for studies on radiation dosages related to image quality. Reporting quality of future studies has to be improved to facilitate comparison of effective doses obtained from examinations with different CBCT units and scanning protocols. A model with minimum data set on important parameters based on this observation is proposed. Advances in knowledge: Data important when estimating effective dose were insufficiently reported in most studies. A model with minimum data based on this observation is proposed. Few studies related effective dose to image quality.
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| 8. |
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| 9. |
- Alegret, Joan, 1977, et al.
(author)
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Plasmonic properties of silver trimers with trigonal symmetry fabricated by electron-beam lithography
- 2008
-
In: Journal of Physical Chemistry C. - : American Chemical Society (ACS). - 1932-7447 .- 1932-7455. ; 112:37, s. 14313-14317
-
Journal article (peer-reviewed)abstract
- We investigate the dipolar plasmon modes of nanoparticle trimers formed by three equal silver disks of diameter D = 100 nm located on the vertexes of an equilateral triangle. Samples were fabricated by electron-beam lithography and studied experimentally by dark-field spectroscopy. The results are found to be in good agreement with electrodynamical simulations based on the discrete dipole approximation (DDA). Similar to nanoparticle dimers, the trimer system exhibits two hybridized dipole resonances to the red and to the blue of the single particle resonance. However, the far-field spectra are polarization-insensitive for light incident normal to the plane of the trimer, and the peak shifts, which occur as the edge-to-edge distance d between the particles decrease, are smaller than for dimers. Moreover, we find that the dipolar displacement patterns are well described by linear combinations of bonding and antibonding symmetry adapted coordinates obtained through symmetry analysis based on the ideal D-3h point-group.
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| 10. |
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| 11. |
- Andersson, Magnus, et al.
(author)
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A Simulation and Animation Tool for Studying Multivariable Control
- 2002
-
In: Proceedings of the 15th IFAC World Congress. - 9783902661746 ; , s. 1432-1432
-
Conference paper (peer-reviewed)abstract
- A simulation and animation tool for education in multivariable control is presented. The purpose of the tool is to support studies of various aspects of multivariable dynamical systems and design of multivariable feedback control systems. Different ways to use this kind of tool in control education are also presented and discussed.
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| 12. |
- Azevedo Costa, Marcelo, et al.
(author)
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Failure detection in robotic arms using statistical modeling, machine learning and hybrid gradient boosting
- 2018
-
Reports (other academic/artistic)abstract
- Modeling and failure prediction is an important task in manyengineering systems. For this task, the machine learning literaturepresents a large variety of models such as classification trees,random forest, artificial neural networks, fuzzy systems, amongothers. In addition, standard statistical models can be applied suchas the logistic regression, linear discriminant analysis, $k$-nearestneighbors, among others. This work evaluates advantages andlimitations of statistical and machine learning methods to predictfailures in industrial robots. The work is based on data from morethan five thousand robots in industrial use. Furthermore, a newapproach combining standard statistical and machine learning models,named \emph{hybrid gradient boosting}, is proposed. Results show thatthe a priori treatment of the database, i.e., outlier analysis,consistent database analysis and anomaly analysis have shown to becrucial to improve classification performance for statistical, machinelearning and hybrid models. Furthermore, local joint information hasbeen identified as the main driver for failure detection whereasfailure classification can be improved using additional informationfrom different joints and hybrid models.
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| 13. |
- Bauer, Brigitte, 1978, et al.
(author)
-
Metal nanoparticles amplify photodynamic effect on skin cells in vitro
- 2011
-
In: Progress in Biomedical Optics and Imaging - Proceedings of SPIE. Optical Interactions with Tissue and Cells XXII; San Francisco, CA; 24-26 January 2011. - : SPIE. - 1605-7422. - 9780819484345 ; 7897
-
Conference paper (other academic/artistic)abstract
- We report on an investigation aimed to increase the efficiency of photodynamic therapy (PDT) through the influence of localized surface plasmon resonances (LSPR's) in metal nanoparticles. PDT is based on photosensitizers that generate singlet oxygen at the tumour site upon exposure to visible light. Although PDT is a well-established treatment for skin cancer, a major drawback is the low quantum yield for singlet-oxygen production. This motivates the development of novel methods that enhance singlet oxygen generation during treatment. In this context, we study the photodynamic effect on cultured human skin cells in the presence or absence of gold nanoparticles with well established LSPR and field-enhancement properties. The cultured skin cells were exposed to protoporphyrin IX and gold nanoparticles and subsequently illuminated with red light. We investigated the differences in cell viability by tuning different parameters, such as incubation time and light dose. In order to find optimal parameters for specific targeting of tumour cells, we compared normal human epidermal keratinocytes with a human squamous skin cancer cell line. The study indicates significantly enhanced cell death in the presence of nanoparticles and important differences in treatment efficiency between normal and tumour cells. These results are thus promising and clearly motivate further development of nanoparticle enhanced clinical PDT treatment.
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| 14. |
- Becker, Petra, et al.
(author)
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Selfcare Strategies Shown to Be Useful in Daily Life for Adults Diagnosed with Attention Deficit Hyperactivity Disorder – A Systematic Review
- 2023
-
In: Issues in Mental Health Nursing. - : Taylor & Francis Group. - 0161-2840 .- 1096-4673. ; 44:9, s. 825-833
-
Journal article (peer-reviewed)abstract
- Adults with ADHD experience a wide range of difficulties in daily life, and RNs and other healthcare professionals need to know how to support them. The aim was to conduct a systematic review of which selfcare strategies adults with ADHD use and need in order to manage daily life. A literature review based on the PRISMA model was performed, and seven articles with a qualitative design were found. Data were analyzed with thematic analysis. The analysis generated one major theme Enabling ways to manage the consequences of disability in daily life based on three subthemes; Establishing ways of acting to help yourself, Finding encouraging and helping relationships, and Using external aids for managing daily life. Professionals may benefit from knowing about these selfcare strategies when meeting people with ADHD.
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| 15. |
- Bridel, Claire, et al.
(author)
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Diagnostic Value of Cerebrospinal Fluid Neurofilament Light Protein in Neurology : A Systematic Review and Meta-analysis
- 2019
-
In: JAMA Neurology. - : American Medical Association (AMA). - 2168-6149 .- 2168-6157. ; 76:9, s. 1035-1048
-
Research review (peer-reviewed)abstract
- Importance Neurofilament light protein (NfL) is elevated in cerebrospinal fluid (CSF) of a number of neurological conditions compared with healthy controls (HC) and is a candidate biomarker for neuroaxonal damage. The influence of age and sex is largely unknown, and levels across neurological disorders have not been compared systematically to date.Objectives To assess the associations of age, sex, and diagnosis with NfL in CSF (cNfL) and to evaluate its potential in discriminating clinically similar conditions.Data Sources PubMed was searched for studies published between January 1, 2006, and January 1, 2016, reporting cNfL levels (using the search terms neurofilament light and cerebrospinal fluid) in neurological or psychiatric conditions and/or in HC.Study Selection Studies reporting NfL levels measured in lumbar CSF using a commercially available immunoassay, as well as age and sex.Data Extraction and Synthesis Individual-level data were requested from study authors. Generalized linear mixed-effects models were used to estimate the fixed effects of age, sex, and diagnosis on log-transformed NfL levels, with cohort of origin modeled as a random intercept.Main Outcome and Measure The cNfL levels adjusted for age and sex across diagnoses.Results Data were collected for 10 059 individuals (mean [SD] age, 59.7 [18.8] years; 54.1% female). Thirty-five diagnoses were identified, including inflammatory diseases of the central nervous system (n = 2795), dementias and predementia stages (n = 4284), parkinsonian disorders (n = 984), and HC (n = 1332). The cNfL was elevated compared with HC in a majority of neurological conditions studied. Highest levels were observed in cognitively impaired HIV-positive individuals (iHIV), amyotrophic lateral sclerosis, frontotemporal dementia (FTD), and Huntington disease. In 33.3% of diagnoses, including HC, multiple sclerosis, Alzheimer disease (AD), and Parkinson disease (PD), cNfL was higher in men than women. The cNfL increased with age in HC and a majority of neurological conditions, although the association was strongest in HC. The cNfL overlapped in most clinically similar diagnoses except for FTD and iHIV, which segregated from other dementias, and PD, which segregated from atypical parkinsonian syndromes.Conclusions and Relevance These data support the use of cNfL as a biomarker of neuroaxonal damage and indicate that age-specific and sex-specific (and in some cases disease-specific) reference values may be needed. The cNfL has potential to assist the differentiation of FTD from AD and PD from atypical parkinsonian syndromes.
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| 16. |
- Carvalho Bittencourt, André, 1984-, et al.
(author)
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A data-driven approach to diagnostics of repetitive processes in the distribution domain : Applications to gearbox diagnosticsin industrial robots and rotating machines
- 2014
-
In: Mechatronics (Oxford). - : Elsevier. - 0957-4158 .- 1873-4006. ; 24:8, s. 1032-1041
-
Journal article (peer-reviewed)abstract
- This paper presents a data-driven approach to diagnostics of systems that operate in a repetitive manner. Considering that data batches collected from a repetitive operation will be similar unless in the presence of an abnormality, a condition change is inferred by comparing the monitored data against an available nominal batch. The method proposed considers the comparison of data in the distribution domain, which reveals information of the data amplitude. This is achieved with the use of kernel density estimates and the Kullback–Leibler distance. To decrease sensitivity to disturbances while increasing sensitivity to faults, the use of a weighting vector is suggested which is chosen based on a labeled dataset. The framework is simple to implement and can be used without process interruption, in a batch manner. The approach is demonstrated with successful experimental and simulation applications to wear diagnostics in an industrial robot gearbox and for diagnostics of gear faults in a rotating machine.
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| 17. |
- Carvalho Bittencourt, André, 1984-
(author)
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Modeling and Diagnosis of Friction and Wear in Industrial Robots
- 2014
-
Doctoral thesis (other academic/artistic)abstract
- High availability and low operational costs are critical for industrial systems. While industrial equipments are designed to endure several years of uninterrupted operation, their behavior and performance will eventually deteriorate over time. To support service and operation decisions, it is important to devise methods to infer the condition of equipments from available data.The monitoring of industrial robots is an important problem considered in this thesis. The main focus is on the design of methods for the detection of excessive degradations due to wear in a robot joint. Since wear is related to friction, an important idea for the proposed solutions is to analyze the behavior of friction in the joint to infer about wear. Based on a proposed friction model and friction data collected from dedicated experiments, a method is suggested to estimate wear-related effects to friction. As it is shown, the achieved estimates allow for a clear distinction of the wear effects even in the presence of large variations to friction associated to other variables, such as temperature and load.In automated manufacturing, a continuous and repeatable operation of equipments is important to achieve production requirements. Such repetitive behavior of equipments is explored to define a data-driven approach to diagnosis. Considering data collected from a repetitive operation, an abnormality is inferred by comparing nominal against monitored data in the distribution domain. The approach is demonstrated with successful applications for the diagnosis of wear in industrial robots and gear faults in a rotating machine.Because only limited knowledge can be embedded in a fault detection method, it is important to evaluate solutions in scenarios of practical relevance. A simulation based framework is proposed that allows for determination of which variables affect a fault detection method the most and how these variables delimit the effectiveness of the solution. Based on an average performance criterion, an approach is also suggested for a direct comparison of different methods. The ideas are illustrated for the robotics application, revealing properties of the problem and of different fault detection solutions.An important task in fault diagnosis is a correct determination of presence of a condition change. An early and reliable detection of an abnormality is important to support service, giving enough time to perform maintenance and avoid downtime. Data-driven methods are proposed for anomaly detection that only require availability of nominal data and minimal/meaningful specification parameters from the user. Estimates of the detection uncertainties are also possible, supporting higher level service decisions. The approach is illustrated with simulations and real data examples including the robotics application.
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| 18. |
- Chen, Si, 1985, et al.
(author)
-
Ultrahigh sensitivity made simple : nanoplasmonic label-free biosensing with an extremely low limit-of-detection for bacterial and cancer diagnostics.
- 2009
-
In: Nanotechnology. - : Institute of Physics (IOP). - 0957-4484 .- 1361-6528. ; 20:43
-
Journal article (peer-reviewed)abstract
- We present a simple and robust scheme for biosensing with an ultralow limit-of-detection down to several pg cm(-2) (or several tens of attomoles cm(-2)) based on optical label-free biodetection with localized surface plasmon resonances. The scheme utilizes cost-effective optical components and comprises a white light source, a properly functionalized sensor surface enclosed in a simple fluidics chip, and a spectral analyzer. The sensor surface is produced by a bottom-up nanofabrication technique with hole mask colloidal lithography. Despite its simplicity, the method is able to reliably detect protein-protein binding events at low picomolar and femtomolar concentrations, which is exemplified by the label-free detection of the extracellular adherence protein (EAP) found on the outer surface of the bacterium Staphylococcus aureus and of prostate-specific antigen (PSA), which is believed to be a prostate cancer marker. These experiments pave the way towards an ultra-sensitive yet compact biodetection platform for point-of-care diagnostics applications.
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| 19. |
- Costa, Marcelo Azevedo, et al.
(author)
-
Failure detection in robotic arms using statistical modeling, machine learning and hybrid gradient boosting
- 2019
-
In: Measurement. - : ELSEVIER SCI LTD. - 0263-2241 .- 1873-412X. ; 146, s. 425-436
-
Journal article (peer-reviewed)abstract
- Modeling and failure prediction are important tasks in many engineering systems. For these tasks, the machine learning literature presents a large variety of models such as classification trees, random forest, artificial neural networks, among others. Standard statistical models such as the logistic regression, linear discriminant analysis, k-nearest neighbors, among others, can be applied. This work evaluates advantages and limitations of statistical and machine learning methods to predict failures in industrial robots. The work is based on data from more than five thousand robots in industrial use. Furthermore, a new approach combining standard statistical and machine learning models, named hybrid gradient boosting, is proposed. Results show that the hybrid gradient boosting achieves significant improvement as compared to statistical and machine learning methods. Furthermore, local joint information has been identified as the main driver for failure detection, whereas failure classification can be improved using additional information from different joints and hybrid models. (C) 2019 Elsevier Ltd. All rights reserved.
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| 20. |
- Dahlin, Andreas, 1980, et al.
(author)
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High-Resolution Microspectroscopy of Plasmonic Nanostructures for Miniaturized Biosensing
- 2009
-
In: Analytical Chemistry. - : American Chemical Society. - 0003-2700 .- 1520-6882. ; 81:16, s. 6572-6580
-
Journal article (peer-reviewed)abstract
- In this article, we demonstrate how to perform microscale spectroscopy of plasmonic nanostructures in order to minimize the noise when determining the resonance peak wavelength. This is accomplished using an experimental setup containing standard optical components mounted on an ordinary light microscope. We present a detailed comparison between extinction spectroscopy in transmission mode and scattering spectroscopy under dark field illumination, which shows that extinction measurements provide higher signal-to-noise in almost all situations. Furthermore, it is shown that rational selection of nanostructure, hardware components, and data analysis algorithms enables tracking of the particle plasmon resonance wavelength from a 10 mu m x 50 mu m area with a resolution of 10(-3) nm in transmission mode. We investigate how the temporal resolution, which can be improved down to 17 Ins, affects, the noise characteristics. In addition, we show how data can be acquired from an area as small as 2 mu m x 10 mu m (similar to 240 particles) at the expense of higher noise on longer time scales. In comparison with previous work on macroscopic sensor designs, this represents a sensor miniaturization of 5 orders of magnitude, without any loss in signal-to-noise performance. As a model system, we illustrate biomolecular detection using gold nanodisks prepared by colloidal lithography. The microextinction measurements of nanodisks described here provide detection of protein surface coverages as low as 40 pg/cm(2) (less than0.1% of saturated binding). In fact, the miniaturized system provides a detection limit in terms of surface coverage comparable to state of the art macroscopic sensors, while simultaneously being as close to single protein molecule detection as sensors based on a single nanoparticle.
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| 21. |
- Dahlstrand, Ursula, et al.
(author)
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TEP under general anesthesia is superior to Lichtenstein under local anesthesia in terms of pain 6 weeks after surgery : results from a randomized clinical trial
- 2013
-
In: Surgical Endoscopy. - : Springer Science and Business Media LLC. - 0930-2794 .- 1432-2218. ; 27:10, s. 3632-3638
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Journal article (peer-reviewed)abstract
- Persistent pain is common after inguinal hernia repair. The methods of surgery and anesthesia influence the risk. Local anesthesia and laparoscopic procedures reduce the risk for postoperative pain in different time perspectives. The aim of this study was to compare open Lichtenstein repair under local anesthesia (LLA) with laparoscopic total extraperitoneal repair (TEP) with respect to postoperative pain. Between 2006 and 2010, a total of 389 men with a unilateral primary groin hernia were randomized, in an open-label study, to either TEP (n = 194) or LLA (n = 195). One patient in the TEP group and four in the LLA group were excluded due to protocol violation. Details about the procedure and patient and hernia characteristics were registered. Patients completed the Inguinal Pain Questionnaire (IPQ) 6 weeks after surgery. [The study is registered in ClinicalTrials.gov (No. NCT01020058)]. A total of 378 (98.4 %) patients completed the IPQ. One hundred forty-eight patients (39.1 %) reported some degree of pain, 22 of whom had pain that affected concentration during daily activities. Men in the TEP group had less risk for pain affecting daily activities (6/191 vs. 16/187; odds ratio [OR] 0.35; 95 % CI 0.13-0.91; p = 0.025). Pain prevented participation in sporting activities less frequently after TEP (4.2 vs. 15.5 %; OR 0.24; 95 % CI 0.09-0.56; p < 0.001). Twenty-nine patients (7.7 %) reported sick leave exceeding 1 week due to groin pain, with no difference between the treatment groups. Patients who underwent the laparoscopic TEP procedure suffered less pain 6 weeks after inguinal hernia repair than those who underwent LLA. Groin pain affected the LLA patients' ability to perform strenuous activities such as sports more than TEP patients.
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| 22. |
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| 23. |
- Ekelund, L, et al.
(author)
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Imaging of Four-Corner Fusion (SLAC Arthrodesis) of the Wrist with 64-Slice Computed Tomography.
- 2007
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In: Acta Radiologica. - : SAGE Publications. - 1600-0455 .- 0284-1851. ; 48:1, s. 76-79
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Journal article (peer-reviewed)abstract
- Purpose: To find out whether it is possible to evaluate the healing of wrist arthrodesis, carried out with a metallic spider plate, by means of 64-slice computed tomography (CT). Material and Methods: 18 CT examinations were performed in 12 patients 2 weeks to 37 months following scapholunate advanced collapse (SLAC) arthrodesis fixed with a metallic plate. Ten patients also had plain films of the wrist. Radiation doses were estimated. Results: Plain films were difficult to evaluate due to overprojection of the spider plate. With 64-slice CT, however, it was possible to evaluate the healing process in all patients in spite of metallic artifacts. Radiation doses were low. Conclusion: The healing of SLAC arthrodesis of the wrist is difficult to evaluate with conventional radiography due to the metallic plate. By means of 64-slice CT, however, it was possible to “see under” the plate in all 12 patients.
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| 24. |
- Eklund, Mona, et al.
(author)
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Effectiveness of an intervention to improve day centre services for people with psychiatric disabilities
- 2014
-
In: Australian Occupational Therapy Journal. - : John Wiley & Sons. - 0045-0766 .- 1440-1630. ; 61:4, s. 268-275
-
Journal article (peer-reviewed)abstract
- Background/aim: Day centres for people with psychiatric disabilities need to be evaluated for effectiveness in order to provide the best possible support. This study aimed at investigating the effectiveness of a tailor-made intervention to improve day centre services for people with psychiatric disabilities.Methods: The intervention was devised to bridge identified gaps in the services and lasted for 14 months. Eight centres were allotted to the intervention (55 attendees) or comparison condition (51 attendees). Fidelity to the intervention and major events in the day centres were assessed. The outcomes were degree of meaningfulness found in the day centre occupations, satisfaction with the rehabilitation received, satisfaction with everyday occupations and quality of life.Results: The fidelity to the intervention was good, but more positive events, such as new occupational opportunities, had taken place in the comparison units. No differences were identified between the intervention and the comparison group regarding changes from baseline to the 14-month follow-up in perceived meaningfulness among day centre occupations, satisfaction with everyday occupations or quality of life.Conclusions: The intervention seemed ineffective, but the positive events in the comparison group resembled the measures included in the tailor-made interventions. This first intervention study in the day centre context has hopefully helped to generate hypotheses and methods for future research.
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| 25. |
- Ekvall, Mikael T., et al.
(author)
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Nanoplastics formed during the mechanical breakdown of daily-use polystyrene products
- 2019
-
In: Nanoscale Advances. - : Royal Society of Chemistry (RSC). - 2516-0230. ; 1:3, s. 1055-1061
-
Journal article (peer-reviewed)abstract
- Large amounts of plastics are released into the environment every day. These released plastics have a clearly documented negative effect on wildlife. Much research attention has been given to large plastic pieces and microplastics. However, if the breakdown of plastics is a continous process, eventually nanoplastics will be produced. Nanoplastics will affect wildlife differently from larger plastic pieces. We have studied the products formed by the mechanical breakdown of two commonly used polystyrene products, takeaway coffee cup lids and expanded polystyrene foam. After breakdown using a food processor, we characterized the breakdown products using seven different methods and found nanosized polystyrene particles with different shapes and negative or nearly neutral surface charges. These results clearly demonstrate that daily-use polystyrene products can break down into nanoparticles. Model polystyrene particles with different sizes and surface modifications have previously been shown to have different negative effects on wildlife. This indicates that breakdown nanoparticles might have the potential to cause cocktail effects in nature.
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| 26. |
- Enqvist, Martin, 1976-, et al.
(author)
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The CDIO Initiative from an Automatic Control Project Course Perspective
- 2005
-
In: Proceedings of the 16th IFAC World Congress. - 9783902661753 ; , s. 2283-2283
-
Conference paper (peer-reviewed)abstract
- The CDIO (Conceive Design Implement Operate) Initiative is explained, and some of the results at the Applied Physics and Electrical Engineering program at Linköping University, Sweden, are presented. A project course in Automatic Control is used as an example. The projects within the course are carried out using the LIPS (Linköping interactive project steering) model. An example of a project, the golf playing industrial robot, and the results from this project are also covered.
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| 27. |
- Enqvist, Martin, 1976-, et al.
(author)
-
The CDIO Initiative from an Automatic Control Project Course Perspective
- 2004
-
Reports (other academic/artistic)abstract
- The CDIO (Conceive Design Implement Operate) Initiative is explained, and some of the results at the Applied Physics and Electrical Engineering program at Linköping University, Sweden, are presented. A project course in Automatic Control is used as an example. The projects within the course are carried out using the LIPS (Linköping interactive project steering) model. An example of a project, the golf playing industrial robot, and the results from this project are also covered.
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| 28. |
- Fujimori, Atsushi, et al.
(author)
-
A Gain Scheduling Control of Nonlinear Systems along a Reference Trajectory
- 2005
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In: Proceedings of the 16th IFAC World Congress. - 9783902661753 ; , s. 609-609
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Conference paper (peer-reviewed)abstract
- This paper presents a gain scheduling control of a nonlinear system in which the reference trajectory is given in advance. Multiple frozen operating times are chosen on the reference trajectory and a linear time invariant model is obtained at each operating time. A linear parameter varying model is then constructed by interpolating the region between the neighbor frozen operating times. A gain scheduling state feedback law is designed by a linear matrix inequality formulation. The effectiveness is demonstrated in a numerical simulation of a traing control of a two-link robot arm.
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| 29. |
- Fujimori, Atsushi, et al.
(author)
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A Gain Scheduling Control of Nonlinear Systems along a Reference Trajectory
- 2004
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Reports (other academic/artistic)abstract
- This paper presents a gain scheduling control of a nonlinear system in which the reference trajectory is given in advance. Multiple frozen operating times are chosen on the reference trajectory and a linear time invariant model is obtained at each operating time. A linear parameter varying model is then constructed by interpolating the region between the neighbor frozen operating times. A gain scheduling state feedback law is designed by a linear matrix inequality formulation. The effectiveness is demonstrated in a numerical simulation of a traing control of a two-link robot arm.
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| 30. |
- Geber, Therese, et al.
(author)
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Eye lens dosimetry for interventional procedures - Relation between the absorbed dose to the lens and dose at measurement positions
- 2011
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In: Radiation Measurements. - : Elsevier BV. - 1350-4487 .- 1879-0925. ; 46:11, s. 1248-1251
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Conference paper (peer-reviewed)abstract
- This study investigated the relationship between the absorbed dose to the lens of the eye and the absorbed dose at different measurement positions near the eye of interventional radiologists. It also visualised the dose distribution inside the head, both when protective eyewear were used and without such protection. The best position for an eye lens dosimeter was found to be at the side of the head nearest to the radiation source, close to the eye. Positioning the dosimeter at the eyebrow could lead to an underestimation of the lens dose of as much as 45%. The measured dose distribution showed that the absorbed dose to the eye lenses was high compared to the other parts of the head, which stresses the importance of wearing protective eyewear. However, many models of eyewear were found to be deficient as the radiation could slip through at several places, e.g. at the cheek. The relationship between the absorbed dose to the lens and the kerma-area-product (P-KA) delivered to the patient was also studied. (C) 2011 Elsevier Ltd. All rights reserved.
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| 31. |
- Gidlöf-Gunnarsson, Anita, 1957, et al.
(author)
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Comparative studies on railway and road traffic noise annoyances and the importance of number of trains
- 2011
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In: 11th International Congress on Noise as a Public Health Problem (ICBEN), 24-28 July, 2011, London, UK.
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Conference paper (peer-reviewed)abstract
- Railway noise is perceived as less annoying than road traffic noise, both in terms of general annoyance and sleep disturbances according to dose-response relationships from meta-analyses. However, findings in recent years from Japanese studies show, unlike most European studies, that railway noise is perceived as more annoying than road traffic noise at sound levels >LAeq,24h 55 dB. This applies particularly to the Japanese Shinkansen express trains as well as conventional trains. Several of the Japanese studies have been done in areas with a very large number of trains (about 500-800 trains/day). In the present study, the following research questions were asked: How does a large number of trains affect noise annoyance and can the differences between Japanese studies (railway noise more annoying than road traffic noise) and European studies (railway noise less annoying than road traffic noise) in part be due to major differences in the number of trains? Socio-acoustic surveys (n=1689) were conducted in residential areas exposed to railway noise with different number of trains (124 trains/day vs. 481 trains/day) and road traffic noise (LAeq,24h 45-65 dB in all areas) The findings show that the number of trains/day, and not only the equivalent sound levels influence how railway noise is perceived. When the number of trains is very large, (481 trains/day), the proportion who are annoyed and report disturbed activities is significantly higher than in a situation with fewer trains (124 trains/day) at equal sound levels and in comparison to road traffic noise >LAeq,24h 55 dB.
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| 32. |
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| 33. |
- Gidlöf-Gunnarsson, Anita, 1957, et al.
(author)
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Good sound environment in green areas modify road-traffic noise annoyance at home
- 2009
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In: Proceedings of the 8th European Conference on Noise Control 2009 (EURONOISE 2009). - uo : Curran Associates, Inc.. ; , s. 1579-1587
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Conference paper (pop. science, debate, etc.)abstract
- There has been a growing recognition among noise researchers that natural elements and natural areas of the built environment have potentials to reduce annoyance due to traffic noise. It has been suggested that presence of vegetation (e.g., trees, bushes, grass, flowers) contributes to an aesthetically pleasing environment, which influence overall residential satisfaction and people?s perception of the noise. Other expected benefits of natural elements/areas are prevention or modification of adverse effects of work-, personal-, or environmental stress (e.g., noise) through restoration processes. Within the large TVANE-project, the present study examined the effect of green areas (park or similar at walking distance) on noise responses in residential settings (n=468) exposed to road traffic noise (LAeq,24h 45 to 65 dB). A binary multiple logistic regression analysis, with sound exposure as the prime variable assumed to predict general noise annoyance at home, indicated that presence of green areas, a closer distance to it from the subject?s home, and perceived green-area characteristics (good sound environment, high attractiveness and potentials for recreational activities) significantly lowered noise annoyance. The results suggest that the exposure-response relationship between noise and annoyance is influenced by access to nearby green areas provided that they have good environmental quality, particularly regarding the perceived sound environment
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| 34. |
- Gidlöf-Gunnarsson, Anita, 1957, et al.
(author)
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Noise annoyance and restoration in different courtyard settings: Laboratory experiments on audio-visual interactions
- 2007
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In: Proceedings of Inter Noise 2007, Istanbul 28-31 August, Paper no IN07_117 (Available on CD)..
-
Conference paper (peer-reviewed)abstract
- Having access to restorative, natural environments in urban residential areas is important for health and wellbeing. However, previous research on restorative environments is mainly focused on the visual impression. Knowledge is needed on the interaction between the acoustic/perceived soundscape and the visual appearance in residential settings intended for restoration and recreation. The present study examines audio-visual interactions in two laboratory settings – an attractive vs. unattractive courtyard. At each courtyard setting, six sound conditions were presented in a randomised order during 4 minutes each: only sounds from road traffic at LAeq 43, 50 and 55 dB, and these traffic sound levels together with birdsong. 24 subjects (12 men, 12 women) participated in the experiment. The results indicate that visual courtyard perception, road traffic noise annoyance, perceived soundscape (e.g., soothing, stressing), emotional reactions, and possibilities to rest/relax were affected by courtyard setting, sound levels, and birdsong. For example, noise annoyance decreased with the attractive courtyard setting and presence of birdsong. However, about 35 to 50% and 75 to 90% were annoyed at 50 and 55 dB, respectively. At these sound levels, few of the participants reported that they would like to visit the courtyards, even if it was the attractive one.
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| 35. |
- Gidlöf-Gunnarsson, Anita, 1957, et al.
(author)
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Railway noise annoyance and the importance of number of trains, ground vibration, and building situational factors
- 2012
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In: Noise & Health. - : Medknow. - 1463-1741. ; 14:59, s. 190-201
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Journal article (peer-reviewed)abstract
- Internationally accepted exposure-response relationships show that railway noise causes less annoyance than road traffic and aircraft noise. Railway transport, both passenger and freight transport, is increasing, and new railway lines are planned for environmental reasons. The combination of more frequent railway traffic and faster and heavier trains will, most probably, lead to more disturbances from railway traffic in the near future. To effectively plan for mitigations against noise and vibration from railway traffic, new studies are needed to obtain a better basis of knowledge. The main objectives of the present study was to investigate how the relationship between noise levels from railway traffic and general annoyance is influenced by (i) number of trains, (ii) the presence of ground borne vibrations, and (iii) building situational factors, such as orientation of balcony/patio and bedroom window. Socio-acoustic field studies were executed in residential areas; (1) with relatively intense railway traffic; (2) with strong vibrations, and; (3) with the most intense railway traffic in the country. Data was obtained for 1695 respondents exposed to sound levels ranging from LAeq,24h 45 to 65 dB. Both number of trains and presence of ground-borne vibrations, and not just the noise level per se, are of relevance for how annoying railway noise is perceived. The results imply that, for the proportion annoyed to be equal, a 5 - 7 dB lower noise level is needed in areas where the railway traffic causes strong ground-borne vibrations and in areas with a very large number of trains. General noise annoyance was twice as high among residents in dwellings with balcony / patio oriented towards the railway and about 1.5 times higher among residents with bedroom windows facing the railway.
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| 36. |
- Gunnarsson, Bengt, 1954, et al.
(author)
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A functional relationship between species richness of spiders and lichens in spruce
- 2004
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In: Biodiversity and Conservation. - 0960-3115. ; 13:4, s. 685-693
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Journal article (peer-reviewed)abstract
- Modern forestry has created stands with even age distribution of trees and fragmentation of the habitat. In boreal forests, the effects on biodiversity within many taxa need to be examined. We tested the hypothesis that species richness of foliose and fruticose lichens and spiders is positively related in the lower canopy of spruce (Picea abies) in forests with, or without, management in central Sweden. High species richness of lichens may increase the structural complexity of the microhabitat on spruce branches, and bring a higher species richness also in the spider community. In six areas, spruce branches were sampled in old-growth and managed boreal forest stands, respectively. Forest management did not affect the species richness of spiders or lichens, but an effect due to sampling area was found in the latter taxon. There was a significant covariation between species richness of lichens and spiders, and the hypothesised positive correlation was confirmed by separate analyses for each area and combining the probabilities. Moreover, regression analysis on mean values from each site revealed a positive relationship. We conclude that species richness of lichens and spiders covary on spruce branches for functional reasons, i.e. more lichen species promotes a more diverse spider community by increasing the structural heterogeneity. Our results might provide a 'shortcut' for assessing biodiversity in boreal forests.
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| 37. |
- Gunnarsson, Gunnar, 1965, et al.
(author)
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Continuous ST-segment monitoring of patients with left bundle branch block and suspicion of acute myocardial infarction
- 2004
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In: J Intern Med. - 0954-6820. ; 255:5, s. 571-8
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Journal article (peer-reviewed)abstract
- OBJECTIVES: Patients with left bundle branch block comprise 5-9% of all patients with acute myocardial infarction. Limited data exist on the usefulness of continuous electrocardiographic monitoring of these patients. We have investigated prospectively the usefulness of real-time continuous vectorcardiography for monitoring patients with left bundle branch block and suspicion of acute myocardial infarction. DESIGN: A prospective multi-centre study. SETTING: Fourteen Swedish coronary care units. SUBJECTS: Patients with left bundle branch block and suspicion of acute myocardial infarction with <6-h symptom duration were included. MAIN OUTCOME MEASURES: All patients were monitored with continuous vectorcardiography for 12-24 h. RESULTS: One hundred thirty-three patients were included, 47% had acute myocardial infarction. Patients with acute myocardial infarction showed a marked relative decrease in ST-vector than those without (P = 0.0002). These changes were most marked in the first 90 min. When comparing patients with acute myocardial infarction receiving thrombolytic therapy or not, those treated with thrombolytics showed more marked decline in ST-vector magnitude (P < 0.0001) and in shorter time (P = 0.0017). All patients showed STC-vector magnitude changes that were more marked in patients with acute myocardial infarction (P = 0.0002). An STC-vector magnitude cut-off value of 65 microV after 90 min of monitoring gave 54% sensitivity and 72% specificity for diagnosis of acute myocardial infarction. CONCLUSION: Real-time continuous vectorcardiographic monitoring of patients with left bundle branch and suspicion of acute myocardial infarction shows significant differences between those with and without acute myocardial infarction and could be of use for early diagnosis and subsequent monitoring.
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| 38. |
- Gunnarsson, Gunnar, 1965, et al.
(author)
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Continuous ST-segment monitoring of patients with right bundle branch block and suspicion of acute myocardial Infarction
- 2005
-
In: Ann Noninvasive Electrocardiol. - 1082-720X. ; 10:2, s. 161-8
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Journal article (peer-reviewed)abstract
- BACKGROUND: Patients with right bundle branch block comprise 5-9% of all patients with acute myocardial infarction. In spite of this, limited data exist on early diagnosis or the usefulness of continuous electrocardiographic monitoring in these patients. METHODS: A prospective multicenter study with 14 Swedish coronary care units. Patients with right bundle branch block and suspicion of acute myocardial infarction with less than 6 hours symptom duration were included. All patients were monitored with continuous vectorcardiography for 12-24 hours. RESULTS: Seventy-nine patients were included, 43% had acute myocardial infarction. Patients with acute myocardial infarction had significantly higher initial ST-vector magnitude values (P = 0.0014) compared to patients without acute myocardial infarction. Patients with acute myocardial infarction also showed gradual regression of ST-vector magnitude over time that was not seen for patients without acute myocardial infarction (P = 0.005). ST-vector magnitude measured at the J-point differentiated best between patients with and without acute myocardial infarction. A cutoff value of 125 microV for initial ST-vector magnitude resulted in 55% sensitivity and 87% specificity for the diagnosis of acute myocardial infarction. Over time, patients with acute myocardial infarction showed greater changes in QRS-vector difference compared to patients without acute myocardial infarction (P = 0.052). CONCLUSION: Vectorcardiographic monitoring shows good diagnostic abilities for patients with right bundle branch block and clinical suspicion of acute myocardial infarction and could be useful for continuous monitoring of these patients.
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| 39. |
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| 40. |
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| 41. |
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| 42. |
- Gunnarsson, Helene, et al.
(author)
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Solving a multi-period supply chain problem for a pulp company using heuristics—An application to Södra Cell AB
- 2008
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In: International Journal of Production Economics. - : Elsevier. - 0925-5273 .- 1873-7579. ; 116:1, s. 75-94
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Journal article (peer-reviewed)abstract
- In this paper, the integrated planning of production and distribution for a pulp company is considered. The tactical decisions included regard transportation of raw materials from harvest areas to pulp mills; production mix and contents at pulp mills; inventory; distribution of pulp products from mills to customers and the selection of potential orders and their levels at customers. The planning period is one year and several time periods are included. As a solution approach we make use of two different heuristic approaches. The main reason to use heuristics is the need for quick solution times. The first heuristic is based on a rolling planning horizon where iteratively a fixed number of time periods is taken into consideration. The second heuristic is based on Lagrangian decomposition and subgradient optimization. This provides optimistic bounds of the optimal objective function value that are better than the LP relaxation value, which can be used as a measure of the heuristic (pessimistic) solution quality. In addition, we apply the proposed rolling horizon heuristic in each iteration of the subgradient optimization. A number of cases based on real data is analysed which shows that the proposed solution approach is simple and provides high quality solutions.
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| 43. |
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| 44. |
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| 45. |
- Gunnarsson, Helene, 1968-, et al.
(author)
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Supply chain modelling of forest fuel
- 2003
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In: Systems analysis in forest resources. - : Kluwer. - 140201256X ; , s. -326
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Book chapter (other academic/artistic)abstract
- Systems analysis in forestry has continued to advance in sophistication and diversity of application over the last few decades. The papers in this volume were presented at the eighth symposium in the foremost conference series worldwide in this subject area. Techniques presented include optimization and simulation modelling, decision support systems, alternative planning techniques, and spatial analysis. Over 30 papers and extended abstracts are grouped into the topical areas of (1) fire and fuels; (2) networks and transportation; (3) forest and landscape planning; (4) ecological modeling, biodiversity, and wildlife; and (5) forest resource applications. This collection will be of interest to forest planners and researchers who work in quantitative methods in forestry.
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| 46. |
- Gunnarsson, Jonas, et al.
(author)
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Effects of eutrophication on contaminant cycling in marine benthic systems
- 2000
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In: Ambio. - 0044-7447 .- 1654-7209. ; 29:4-5, s. 252-259
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Journal article (peer-reviewed)abstract
- Effects of inputs of organic matter were studied on bioavailability and cycling of hydrophobic organic contaminants (HOCs) in benthic ecosystems of the Baltic and Kattegat Seas. In laboratory experiments, effects of microalgae additions were studied on the bioaccumulation of HOCs (PCBs and PAHs) by the blue mussel Mytilus edulis, the brittle star Amphiura filiformis, and the polychaete Nereis diversicolor. Contrary to the equilibrium partitioning theory, bioaccumulation was proportional to the concentrations of algae and organic carbon. This was attributed to the high nutritional quality of the algal organic carbon and suggests that feeding rather than equilibrium partitioning governed bioaccumulation in these species. In the field, annual mass fluxes of PCBs in blue mussels and in brittle stars were estimated, as well as contaminant transfer to higher trophic levels. Our results suggest that: I) Eutrophication processes may contribute to increase HOC accumulation in benthic species. ii) Temporal variation in the quantity and quality of organic carbon needs to be considered when assessing contamination of benthic systems. ill) Macrofaunal feeding activities are important for the benthic-pelagic coupling of HOCs. iv) Bioturbation enhances the release of HOCs from sediment to overlying water.
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| 47. |
- Gunnarsson, Linda K, 1971, et al.
(author)
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Confined Plasmons in Nanofabricated Single Silver Particle Pairs: Experimental Observations of Strog Interparticle Interactions
- 2005
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In: Journal of Physical Chemistry B. - : American Chemical Society (ACS). - 1520-5207 .- 1520-6106. ; 109:3, s. 1079-1087
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Journal article (peer-reviewed)abstract
- We report on the optical properties of single isolated silver nanodisks and pairs of disks fabricated by electron beam lithography. By systematically varying the disk size and surface separation and recording elastic scattering spectra in different polarization configurations, we found evidence for extremely strong interparticle interactions. The dipolar surface plasmon resonance for polarization parallel to the dimer axis exhibited a red shift as the interdimer separation was decreased; as expected from previous work, an extremely strong shift was observed. The scattering spectra of single particles and pairs separated by more than one particle radius can be well described by the coupled dipole approximation (CDA), where the particles are approximated as point dipoles using a modified dipole polarizability for oblate spheroids. For smaller particle separations (d
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| 48. |
- Gunnarsson (Lidestam), Helene, et al.
(author)
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A combined terminal location and ship routing problem
- 2006
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In: Journal of the Operational Research Society. - : Informa UK Limited. - 0160-5682 .- 1476-9360. ; 57:8, s. 928-938
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Journal article (peer-reviewed)abstract
- In this paper, we consider a combined terminal location and ship routing problem at Södra Cell AB. The purpose is to supply the customers' annual demand for pulp products while minimizing the distribution costs. Customers are supplied with various pulp products from pulp mills in Scandinavia by ships, trains, or lorries. The ship routes go from the pulp mills to terminals in Europe. From each terminal, the products are transported to customers by lorry, train, or barge. Some customers can be supplied directly from the pulp mills by trains or lorries. We have developed a mathematical model to select which terminals to use and, at the same time, determine the shipping routes. The mixed integer programming model was solved directly using a commercial solver. When the number of routes generated is large, the time required to obtain an optimal solution is too long. Hence, we have developed heuristics in order to obtain an acceptable solution in reasonable time. In addition to the basic case, five different scenarios were tested. Our heuristics provide solutions that are within 0.12% of the optimal ones.
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| 49. |
- Gunnarsson Lidestam, Helene, et al.
(author)
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Integrated production and distribution planning for S¨odra Cell AB
- 2007
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In: Journal of Mathematical Modelling and Algorithms. - : Springer Science and Business Media LLC. - 1570-1166 .- 1572-9214. ; 6:1, s. 25-45
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Journal article (peer-reviewed)abstract
- In this paper we consider integrated planning of transportation of raw material, production and distribution of products of the supply chain at Södra Cell AB, a major European pulp mill company. The strategic planning period is one year. Decisions included in the planning are transportation of raw materials from harvest areas to pulp mills, production mix and contents at pulp mills, distribution of pulp products from mills to customer via terminals or directly and selection of potential orders and their levels at customers. Distribution is carried out by three different transportation modes; vessels, trains and trucks. We propose a mathematical model for the entire supply chain which includes a large number of continuous variables and a set of binary variables to reflect decisions about product mix and order selection at customers. Five different alternatives regarding production mix in a case study carried out at Södra Cell are analyzed and evaluated. Each alternative describes which products will be produced at which pulp mills.
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| 50. |
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