Long-term traffic forecasting in optical networks using Machine Learning

Knowledge about future traffic in backbone optical networks may greatly improve a range of tasks that Communications Service Providers (CSPs) have to face. This work proposes a procedure for long-term traffic forecasting in optical networks. We formulate a long-term traffic forecasting problem as an ordinal classification task. Due to the optical networks’ (and other network technologies’) characteristics, traffic forecasting has been realized by predicting future traffic levels rather than the exact traffic volume. We examine different machine learning (ML) algorithms and compare them with time series algorithms methods. To evaluate the developed ML models, we use a quality metric, which considers the network resource usage. Datasets used during research are based on real traffic patterns presented by Internet Exchange Point in Seattle. Our study shows that ML algorithms employed for long-term traffic forecasting problem obtain high values of quality metrics. Additionally, the final choice of the ML algorithm for the forecasting task should depend on CSPs expectations

Comorbidity of mental disorders - epidemiological data

W artykule przedstawiono koncepcję współchorobowości z perspektywy epidemiologicznej. Dokonano przeglądu badań z całego świata, o najwyższych standardach metodologicznych (opierających się na standaryzowanych narzędziach, co najmniej kilkutysięcznych próbach, dobieranych losowo). Mimo kontrowersji związanych z samym pojęciem współchorobowości (w całym obszarze psychiatrii), pewne wnioski powtarzają się, skłaniając do rozważenia możliwości ich wykorzystania na przykład w organizacji opieki zdrowotnej. Psychiatria 2010; 7, 1: 1-10This paper presents the concept of comorbidity in a perspective of epidemiology. A review of surveys from all over the world of the highest methodological standards has been done (which are: standardized diagnostic instruments, samples of at least few thousands participants and random selection). Despite of many controversies, connected with the idea of comorbidity (in the whole field of psychiatry), some of the conclusions are the same and, by that, they lead to reflections on, for example, health care organization. Psychiatry 2010; 7, 1: 1-1

Data Stream Classification Using Classifier Ensemble

For the contemporary business, the crucial factor is making smart decisions on the basis of the knowledge hidden in stored data. Unfortunately,m traditional simple methods of data analysis are not sufficient for efficient management of modern enterprizes, because they are not appropriate for the huge and growing amount of the data stored by them. Additionally data usually comes continuously in the form of so-called data stream. The great disadvantage of traditional classification methods is that they assume that statistical properties of the discovered concept are being unchanged, while in real situation, we could observe so-called concept drift, which could be caused by changes in the probabilities of classes or/and conditional probability distributions of classes. The potential for considering new training data is an important feature of machine learning methods used in security applications (spam filtering or intrusion detection) or decision support systems for marketing departments, which need to follow the changing client behavior. Unfortunately, the occurrence of concept drift dramatically decreases classification accuracy. This work presents the comprehensive study on the ensemble classifier approach applied to the problem of drifted data streams. Especially it reports the research on modifications of previously developed Weighted Aging Classifier Ensemble (WAE) algorithm, which is able to construct a valuable classifier ensemble for classification of incremental drifted stream data. We generalize WAE method and propose the general framework for this approach. Such framework can prune an classifier ensemble before or after assigning weights to individual classifiers. Additionally, we propose new classifier pruning criteria, weight calculation methods, and aging operators. We also propose rejuvenating operator, which is able to soften the aging effect, which could be useful, especially in the case if quite ”old” classifiers are high quality models, i.e., their presence increases ensemble accuracy, what could be found, e.g., in the case of recurring concept drift. The chosen characteristics of the proposed frameworks were evaluated on the basis of the wide range of computer experiments carried out on the two benchmark data streams. Obtained results confirmed the usability of proposed method to the data stream classification with the presence of incremental concept drift

On the potential for a bottom active layer below coastal permafrost: the impact of seawater on permafrost degradation imaged by electrical resistivity tomography (Hornsund, SW Spitsbergen)

This paper presents the results of two-dimensional electrical resistivity tomography (ERT) of permafrost developed in coastal zone of Hornsund, SW Spitsbergen. The measurements were made using the Wenner-Schlumberger electrode array with an electrode spacing 5 m for overview and 1.5 or 1 m spacing for detailed imaging. Using the ERT inversion results, we studied the ‘sea influence’ on deeper parts of the frozen ground. During the investigations we tested hypotheses that the operation of seawater on shoreface may cause changes in the shape of the coastal permafrost base, and that the impact of seawater on more inland permafrost depends on the shape of the shoreline (differently in the embayment, and differently in a headland exposed to the open sea). Our study was inspired by previous ground temperature measurements conducted in several boreholes located in study area which captured the propagation of ground heat waves from the base of permafrost. Our resistivity models indicate a major differentiation in terms of resistivity of permafrost in the coastal zone. The resistivity measures obtained in deeper layers of ground were so low (< 100 Ω·m) that in the ‘warm permafrost’ conditions they exclude a possibility of freezing the coastal sediments and bedrock from the side of the sea. Low values continue further inland, going down under the surface layer of permafrost with higher resistivity. We interpret this situation as an influence of seawater's temperature and salinity on deeper parts of permafrost. Based on the measurements conducted within two years, we stated a change in the distribution of resistivity, both in the active layer, and in coastal front of permafrost in deeper parts of the ground. As observed in the inverse models, the geometric arrangement between the fields of extreme resistivity indicates the existence of a bottom active layer by the permafrost base, depending on thermal and chemical characteristics of seawater. The measurements conducted in the embayment, as well as on the headland exposed to the operation of storm waves, proved strong differences in the scale of the impact of seawater on permafrost

Immunohistochemical and hybridocytochemical study on ghrelin signalling in the rat seminiferous epithelium.

The results of presented study demonstrate expression of ghrelin, its functional receptor GHSR-1a and their genes in spermatogenic cells of rat testis suggesting their functioning within seminiferous epithelium. The immunohistochemical and hybrydocytochemical expression, of proteins and transcripts, was estimated taking into account the cycle of seminiferous epithelium and phases of spermatogenesis. Both transcripts and ghrelin was found to show nuclear expression and scarcely cytoplasmic. Expression of genes for ghrelin and GHSR-1a was shown in early spermatocytes and round spermatids representing transcriptional phases of meiosis and spermiogenesis. Ghrelin was evidenced to show nuclear expression in two stage-specific windows, in late spermatogonia, in spermatocytes up to early pachytenes, and again in spermatids of acrosome and early maturation phase of spermiogenesis. In late pachytenes, secondary spermatocytes, round spermatids, maturing spermatids and spermatozoa the reaction is lacking. With two types of antibodies against the GHSR-1a used the two different patterns of immunostaining was evidenced suggesting two isoforms of GHSR-1a. The first evidenced GHSR-1a in cytoplasm of spermatocytes, cell membrane and acrosomes of spermatids, Sertoli cell processes and heads of spermatozoa. With second type of antibodies the immunostaining marks all steps of evolution of acrosome in spermatids. It is believed that site of ghrelin expression in seminiferous epithelium may indicate its role in local regulations, not excepting the intracellular signalling. Immunostaining pattern for GHSR-1a seems to suggest both its participation in the cross-talk among the cells and also process of furnishing gametes with GHSR-1a for its response to ghrelin in seminal plasma or female reproductive tract

Fusion of morphological data obtained by coronary computed tomography angiography with quantitative echocardiographic data on regional myocardial function

Background: Three-dimensional (3D) fusion of morphological data obtained by coronary computed tomography angiography (CCTA) with functional data from resting and stress echocardiography could potentially provide additional information compared to examination results analyzed separately and increase the diagnostic and prognostic value of non-invasive imaging in patients with suspected coronary artery disease (CAD). Using vendor-independent software developed in our institution, we aimed to assess the feasibility and reproducibility of 3D fusion of morphological CCTA data with echocardiographic data regarding regional myocardial function. Methods: Thirty patients with suspected CAD underwent CCTA and resting transthoracic echocardiography. From CCTA we obtained 3D reconstructions of coronary arteries and left ventricle (LV). Offline speckle-tracking analysis of the echocardiographic images provided parametric maps depicting myocardial longitudinal strain in 17 segments of the LV. Using our software, 3 independent investigators fused echocardiographic maps with CCTA reconstruc­tions in all patients. Based on the obtained fused models, each segment of the LV was assigned to one of the major coronary artery branches. Results: Mean time necessary for data fusion was 65 ± 7 s. Complete agreement between independent investigators in assignment of LV segments to coronary branches was obtained in 94% of the segments. The average coefficient of agreement (kappa) between the investigators was 0.950 and the intra-class correlation coefficient was 0.9329 (95% CI 0.9227–0.9420). Conclusions: Three-dimensional fusion of morphological CCTA data with quantitative echocardiographic data on regional myocardial function is feasible and allows highly repro­ducible assignment of myocardial segments to coronary artery branches

Mild therapeutic hypothermia for patients with acute coronary syndrome and cardiac arrest treated with percutaneous coronary intervention (UNICORN). The design and rationale for the prospective, observational, multicenter study

Introduction. Cardiac arrest constitutes the most frequent reason for sudden death in developed countries. Out-of-hospital cardiac arrest (OHCA) survivors are at high risk of death or neurologic deficits. The existing data regarding effectiveness and safety of mild therapeutic hypothermia (MTH) for treatment of OHCA survivors are inconsistent and ambiguous. Moreover, a uniform protocol of treatment by means of MTH is lacking. Methods. The UNICORN study is a phase IV, prospective, international, multi-centre, observational study designed to assess the effectiveness of MTH in patients after OHCA with shockable rhythm presenting with acute coronary syndrome (ACS). The trial is expected to include up to 500 patients. Depending on the availability of MTH in each study centre, besides the routine treatment of ACS in OHCA survivors, patients will either undergo MTH according to a uniform protocol or will not undergo MTH (250 patients per group). The primary end-point of the study is all cause mortality at 180 days after enrolment. Secondary end-points include: neurological outcome at discharge, stent thrombosis at 30 days, bleeding according to the BARC criteria, infectious complications at 180 days, and rhythm and conduction disorders at 180 days. Ethics and dissemination. The study received approval from the Local Ethics Committee to conduct the study (Komisja Bioetyczna Uniwersytetu Mikołaja Kopernika w Toruniu przy Collegium Medicum im. Ludwika Rydygiera w Bydgoszczy; study approval reference number KB 615/2015). The study results will be disseminated through conference presentations and publications in peer-reviewed journals. Trial registration. ClinicalTrials.gov identifier: NCT02611934 (18 November 2015).