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Data manipulation of the LOFAR Long-Baseline Calibrator Survey (LBCS) and the Westerbork Northern Sky Survey (WENSS) catalogues are carried out in the present study. The aim of the study is to make calibrator classification statistics plots and estimations for further observations and upcoming stations. First, mean flux densities of LBCS calibrators against declination and observed station baseline length to the tied core station are plotted and the classified sources are marked. Second, we provide the designation – naming it the success rate – for the number of sources with the correlated signal against all the LBCS catalogue sources. Third, there is a trend in mean peak flux densities between stations – longer the baseline, higher mean peak flux density. Finally, estimations for upcoming and recent stations are made and some results are not encouraging.

The present paper describes reduction procedures and imaging of radio astronomical data from the gravitational lens system CLASS B0631+519 acquired by e-MERLIN interferometer. The source has been previously imaged with VLA, MERLIN and the VLBA interferometers. Data reduction and polarisation calibration procedures will provide data on Faraday effects such as Faraday rotation and depolarization between lensed images that in turn carry information on large and small-scale magnetic fields in the lensing galaxy. Reduction of data and imaging of the radio astronomical source have been achieved using Astronomical Image Processing System (AIPS) in conjunction with automatic data reduction pipelines that performed specific data processing steps. As a result, the sky map for the gravitational lens system has been successfully acquired and accuracy comparing the generated map to sky maps of the source produced by different authors has been confirmed.

Full list of authors: Jackson, N.; Badole, S.; Morgan, J.; Chhetri, R.; Prūsis, K.; Nikolajevs, A.; Morabito, L.; Brentjens, M.; Sweijen, F.; Iacobelli, M.; Orrù, E.; Sluman, J.; Blaauw, R.; Mulder, H.; van Dijk, P.; Mooney, S.; Deller, A.; Moldon, J.; Callingham, J. R.; Harwood, J.; Hardcastle, M.; Heald, G.; Drabent, A.; McKean, J. P.; Asgekar, A.; Avruch, I. M.; Bentum, M. J.; Bonafede, A.; Brouw, W. N.; Brüggen, M.; Butcher, H. R.; Ciardi, B.; Coolen, A.; Corstanje, A.; Damstra, S.; Duscha, S.; Eislöffel, J.; Falcke, H.; Garrett, M.; de Gasperin, F.; Griessmeier, J. -M.; Gunst, A. W.; van Haarlem, M. P.; Hoeft, M.; van der Horst, A. J.; Jütte, E.; Koopmans, L. V. E.; Krankowski, A.; Maat, P.; Mann, G.; Miley, G. K.; Nelles, A.; Norden, M.; Paas, M.; Pandey, V. N.; Pandey-Pommier, M.; Pizzo, R. F.; Reich, W.; Rothkaehl, H.; Rowlinson, A.; Ruiter, M.; Shulevski, A.; Schwarz, D. J.; Smirnov, O.; Tagger, M.; Vocks, C.; van Weeren, R. J.; Wijers, R.; Wucknitz, O.; Zarka, P.; Zensus, J. A.; Zucca, P., The Low-Frequency Array (LOFAR) Long-Baseline Calibrator Survey (LBCS) was conducted between 2014 and 2019 in order to obtain a set of suitable calibrators for the LOFAR array. In this paper, we present the complete survey, building on the preliminary analysis published in 2016 which covered approximately half the survey area. The final catalogue consists of 30 006 observations of 24 713 sources in the northern sky, selected for a combination of high low-frequency radio flux density and flat spectral index using existing surveys (WENSS, NVSS, VLSS, and MSSS). Approximately one calibrator per square degree, suitable for calibration of ≥200 km baselines is identified by the detection of compact flux density, for declinations north of 30° and away from the Galactic plane, with a considerably lower density south of this point due to relative difficulty in selecting flat-spectrum candidate sources in this area of the sky. The catalogue contains indicators of degree of correlated flux on baselines between the Dutch core and each of the international stations, involving a maximum baseline length of nearly 2000 km, for all of the observations. Use of the VLBA calibrator list, together with statistical arguments by comparison with flux densities from lower-resolution catalogues, allow us to establish a rough flux density scale for the LBCS observations, so that LBCS statistics can be used to estimate compact flux densities on scales between 300 mas and 2′′, for sources observed in the survey. The survey is used to estimate the phase coherence time of the ionosphere for the LOFAR international baselines, with median phase coherence times of about 2 min varying by a few tens of percent between theshortest and longest baselines. The LBCS can be used to assess the structures of point sources in lower-resolution surveys, with significant reductions in the degree of coherence in these sources on scales between 2′′ and 300 mas. The LBCS survey sources show a greater incidence of compact flux density in quasars than in radio galaxies, consistent with unified schemes of radio sources. Comparison with samples of sources from interplanetary scintillation (IPS) studies with the Murchison Widefield Array shows consistent patterns of detection of compact structure in sources observed both interferometrically with LOFAR and using IPS. © ESO 2022., Support for the operation of the MWA is provided by the Australian Government (NCRIS), under a contract to Curtin University administered by Astronomy Australia Limited. We acknowledge the Pawsey Supercomputing Centre which is supported by the Western Australian and Australian Governments. A.D. acknowledges support by the BMBF Verbundforschung under the grant 052020. L.K.M. is grateful for support from the UKRI Future Leaders Fellowship (grant MR/T042842/1). J. Moldón acknowledges financial support from the State Agency for Research of the Spanish MCIU through the “Center of Excellence Severo Ochoa” award to the Instituto de Astrofísica de Andalucía (SEV-2017-0709) and from the grant RTI2018-096228-B-C31 (MICIU/FEDER, EU). J.P.M. acknowledges support from the Netherlands Organization for Scientific Research (NWO, project number 629.001.023) and the Chinese Academy of Sciences (CAS, project number 114A11KYSB20170054).

Astronomy and astrophysics 658, A2 (2022). doi:10.1051/0004-6361/202140756, The Low-Frequency Array (LOFAR) Long-Baseline Calibrator Survey (LBCS) was conducted between 2014 and 2019 in order to obtain a set of suitable calibrators for the LOFAR array. In this paper, we present the complete survey, building on the preliminary analysis published in 2016 which covered approximately half the survey area. The final catalogue consists of 30 006 observations of 24 713 sources in the northern sky, selected for a combination of high low-frequency radio flux density and flat spectral index using existing surveys (WENSS, NVSS, VLSS, and MSSS). Approximately one calibrator per square degree, suitable for calibration of ≥200 km baselines is identified by the detection of compact flux density, for declinations north of 30° and away from the Galactic plane, with a considerably lower density south of this point due to relative difficulty in selecting flat-spectrum candidate sources in this area of the sky. The catalogue contains indicators of degree of correlated flux on baselines between the Dutch core and each of the international stations, involving a maximum baseline length of nearly 2000 km, for all of the observations. Use of the VLBA calibrator list, together with statistical arguments by comparison with flux densities from lower-resolution catalogues, allow us to establish a rough flux density scale for the LBCS observations, so that LBCS statistics can be used to estimate compact flux densities on scales between 300 mas and 2′′, for sources observed in the survey. The survey is used to estimate the phase coherence time of the ionosphere for the LOFAR international baselines, with median phase coherence times of about 2 min varying by a few tens of percent between theshortest and longest baselines. The LBCS can be used to assess the structures of point sources in lower-resolution surveys, with significant reductions in the degree of coherence in these sources on scales between 2′′ and 300 mas. The LBCS survey sources show a greater incidence of compact flux density in quasars than in radio galaxies, consistent with unified schemes of radio sources. Comparison with samples of sources from interplanetary scintillation (IPS) studies with the Murchison Widefield Array shows consistent patterns of detection of compact structure in sources observed both interferometrically with LOFAR and using IPS., Published by EDP Sciences, Les Ulis

Complex industrial systems are still very dependent on the operator’s human errors. Many automated control systems have been developed for the needs of rail transport. The safety of train movement directly depends on some of them. In case of a malfunction during the operation of such systems, they pass into a safe state and most traffic safety tasks are transmitted to the operator or station operator. To obtain quantitative values ​​of the probability of timely execution of operations by the duty officer at the station, a functional-semantic network and a corresponding model are proposed. This work investigates the connection between the probability of timely execution of operations and the psychophysiological state of the duty officer in case of complex industrial systems problems on the railway transport.

The paper provides a rationale for the effectiveness of the technology of lubrication of the rail roll surface in the curve by the locomotive in the train. The rational values of the friction constant on the roll surface of the inner rail are presented based on the results of computer simulation and field tests. The effect of reducing the lateral impact on the track by reducing the constant of friction on the roll surface of the inner rail and the side surface of the outer rail head is justified.

In the paper the fastening device of the railway rolling stock is described. The main idea of the construction was its simplicity and safety. The device consists of brake pads, which are mounted on the running rails with typical rail linings. Brake pads are put and removed from the heads of the running rails, using a track switch. Additional elements, namely laser and Parktronic, are built into the brake pads. Elements send the signal through the radio transmitter into the driver’s cabin, about the distance left to the complete rolling of the wheel pair on the brake shoe. Due to this device, the accuracy of the rolling stock fastening is increased. When the train departs, the driver receives a signal through the radio transmitter about whether the shoes remained under the wheel pairs.

Article considers the establishing requirements of digital signal processing in real-time systems with high risk of application on which execution the system has added by signs of safe system. In addition, article considers the analysis of a technical solution for the analog front end (AFE) for multi signal system and based on results of analysis designed a node of signals preprocessing in paralleled channel. Creation of AFE in relation to multi signal systems is considered. Article contains results of multi signal analysis and testing results of the specialized diagnostic measuring tool for the multi signal monitoring system used in railway automatic.

Article describes the method to reduce the time waiting of public transport and vehicles before the railway level crossing. One of the proposed methods — optimization of level crossing algorithm. The optimal level crossings time delay depends on the speed of the oncoming train. Time delay prediction algorithm based on track circuits primary parameters and other characteristics.

Diplomdarba tēmas nosaukums ir „Uzņēmuma Intra Serviss tirdzniecības paplašināšana izmantojot internetu”. Uzņēmumi, kas nodarbojas ar preču tirdzniecību arvien biežāk sāk izmantot internetu, lai reklamētu un izplatītu savu produkciju, jo tas sniedz daudz priekšrocību un ļauj ietaupīt līdzekļus. Diplomdarba izpētes daļā tiek analizētas produktu reklamēšanas metodes internetā un internetveikalu darbības principi, ar mērķi praktiskajā daļa izstrādāt uzņēmuma internetveikala projektu. Darba izstrādes rezultātā ir apkopoti secinājumi un izstrādāti konkrēti priekšlikumi uzņēmuma tirdzniecības paplašināšanai internetā. Diplomdarbs sastāv no ievada, četrām nodaļām ar apakšnodaļām, secinājumiem un priekšlikumiem. Diplomdarba apjoms 60 lappuses, 15 attēli, 2 tabulas un 52 literārais avots. Atslēgas vārdi: E-komercija, internetveikals, reklāma internetā, sociālie mediji, osCommerce., The title of a thesis subject is „Trading development in Intra Serviss comany using internet”. Companies, which are selling different products more often start to use internet to advertise and promote their products, because it has a lot of advantages and allow to reduce costs. In the research part of the study are analyzed advertising methods of product in internet and internet shop operation principles in order to organize project of internet shop in practical part. The research findings were summarized and drawn up proposals to develop product advertising and trading in internet. Thesis consists of and introduction, four chapters with subchapters, conclusions and proposals. Diploma volume is 60 pages, 15 images, 2 tables and 52 literary source. Key words: e-commerce, webshop, internet marketing, social media, osCommerce.

Maģistra darba nosaukums ir „Darba slodzes analīze autovadītājiem uzņēmumā SIA „GN””. Darbs sastāv no trīs daļām: 1) literatūras apskata daļas par psihoemocionālajiem faktoriem, nogurumu un to ietekmi uz autovadītāja profesiju, 2) pielietojamo novērtēšanas metožu apraksta daļas, 3) iegūto rezultātu analizēšanas daļas. Pētījumā secināts, ka uzņēmuma „GN” darbinieki ir pakļauti lielai psihoemocionālai slodzei (vairāk garīgai, nekā fiziskai), kas padara viņu darbu bīstamu. Darbiniekiem tika novērotas palielināta noguruma un miega traucējumu problēmas, kā arī samazinātas darbspējas. Pēc pētījuma tika izdarīti secinājumi, izstrādāti preventīvie pasākumi un sniegtas rekomendācijas darba vides uzlabošanai. Maģistra darbs izstrādāts latviešu valodā un sastāv no 86 lpp., 31 attēla, 9 tabulām, 57 literatūras avotiem, 5 pielikumiem. NOGURUMS, AUTOVADĪTĀJS, MIEGS, PSIHOEMOCIONĀLIE FAKTORI, SLODZE, Master thesis title is „The analysis of workload for drivers in „GN” Ltd.”. The work consists of three parts: 1) literature review part of psycho-emotional factors, fatigue and their impact on driver profession, 2) applied evaluation methods description part, 3) obtained results analyzing part. The study concludes, that employees in company „GN” are exposed to a great psycho-emotional load (more mental, than physical), which makes their work dangerous. Employees were reported increased fatigue and sleep disorder problems, as well as reduced workload. After the study was made conclusions, developed preventative measures and was given recommendations for improving the working environment. Master thesis is developed in the Latvian language and consists of: 86 pages, 31 pictures, 9 tables, 57 references, 5 attachments. FATIGUE, DRIVER, SLEEP, PSYCHO-EMOTIONAL FACTORS, LOAD

Diplomdarba mērķis ir aprakstīt lineāru vienādojumu sistēmas (LVS), izmantojot ģeometriskus jēdzienus, ka arī paskaidrot atbilstošas teorēmas „ģeometriska valodā”. Galvenais uzdevums bija izpētīt LVS atrisinājuma meklēšanas problēmu, ka arī parādīt, ka jebkurai LVS var atrast vienīgo normālo pseidoatrisinājumu. Darbs iepazīstina ar Gausa izslēgšanas metodi, ar ortogonālo projicēšanu uz apakštelpu, ar mazāku kvadrātu metodi, ar pseidoinversas matricas jēdzienu, ka arī ar dažām citām lietām. Un beigās ir dotas rekomendācijas, kā var atvieglot aprēķinus ar datorprogrammu palīdzību., The aim of the present graduation work is to describe Systems of Linear Algebraic Equations (SLAE) using geometric terms and also to explain corresponding theorems by the “geometric language”. The main task of the graduate work is to examine the problem of the SLAE solution finding and show that it is possible to find the only one normal pseudo-solution for any SLAE. The graduate work introduces the SLAE solution by the Gauss method, the orthogonal projection on subspace, the concept of pseudo-inverse matrix and also takes into account the other significant questions. At the end of the work some recommendations for the help in finding of SLAE solutions using computer programs are given.

Kvalifikācijas darba ietvaros tika apskatīta un aprakstīta SAP Hybris Commerce platformā izstrādātā lietotne, kas ir saistīta ar produkta uzglabāšanas un piedāvājuma ķēdes atspoguļojumu. Izmantojot doto lietotni, lietotājs var sekot produkta piegādes procesam sākot no noliktavas atrašanās vietas līdz veikalam kā arī līdz pašam pasūtītājam. Piegādes punkti un ķēdes tiek atspoguļotas uz pasaules kartes vektorgrafikas formātā, izmantojot klienta, noliktavas un veikala atrašanas vietas koordinātas. Dotā lietotne ir ļoti ērta, jo klientam ir iespēja redzēt un izvēlēties sev vispiemērotāko piegādēs iespēju no visām piedāvātām iespējām. Lietotne tika izstrādāta izmantojot SAP Hybris Commerce platformu, kas ir viena no pieprasītākajām e-komercijas realizācijas platformām. Tā tika realizēta kā daļa no internetveikala, kas dod iespēju integrēt to jebkuros e-komercijas projektos. Izstrādes laikā tika izmantotas HTML, LESS un JavaScript programmēšanas valodas., Within the framework of the qualification paper, the author reviewed and described the application developed by the SAP Hybris Commerce platform, related to the presentation of the product storage and supply chain. By using the given application, the user can track the delivery process of the product from the warehouse to the store as well as to the customer. Supply points and chains are depicted on the world map in vector graphic format, by using the coordinates of the customer, warehouse and store’s location. This application is very convenient because the customer has the opportunity to see and choose the most suitable delivery option from the all given choices. The application was developed on the SAP Hybris Commerce platform, which is one of the most sought after e-commerce platforms. It was implemented as part of an online store, which gives an opportunity to integrate it into any e-commerce project. The HTML, LESS and JavaScript programming languages were used during the development.

Lidzekļa “Pakalpojumu serviss: mājas lapas stāvokļa uzraudzība un atbildīgo personu brīdināšana par iespējamām un esošām problēmām” mērķis ir paatrināt servera un timekļa vietne problēmas identificēšanu un savlaicīgi brīdīnāt atbildīgus personus. Ilgstoši nodarbojoties ar projekta uzturu, izveidotas uz Magento platformas uzkrājam pieredzi un problemu risināšanu kas trauce saita darbibu. Problēmu atklāšana un tas risināšana aizniem pietiekoši daudz laika pat pieredzejušam īzstrādātājam. Kaut ko japarbauda regulāri, bet uz to nepietek laiks, bet ja konkrēta problēma ilgi neuzrādās, tad iespēja iemeslu atrast ātri uz izlabot problēmu mazā laika samazinās. Uzradās idēja automatizēt zinamo problemu atrašanu un izveidot instruments, kas paniems uz sevi automatisko un regularo servera un timekļa vietne darbošanas parbaudi un pazinojumu par atbildigiem darbiniekiem par problemam un risinašanas veidiem. Tas instruments ļaus saita ipašniekiem savlaicīgi reagēt uz izraisītam vai iespējāmam problēmam un padarīt minimālos zaudējūmus, kuri uzreiz uzradās at saita nedarbību. Līdzekļa merķis: ●vienmērīga veikala darbošanas nodrošināšana, kas stradā uz Magento vadošas sistēmas. uz 1 vai Magento 2; ●iespējamo problēmu prognozēšana uz savlaicīgs paziņojums saita ipasniekam; ●datu bāzeszinamo problēmu izveidošana un uzturēšana un veidi ka arisināt., Means services: “Website state monitoring service, predicted and existing issue notification of the person responsible" is to speed up the server and a web site problem identification and beforehand warning of the person responsible. Long time being engaged in support of the projects developed on the Magento platform have accumulated experience in the solution of the problems disturbing operability of the websites. Identification of the reasons of malfunctions and finding solutions takes a lot of time, even skilled developers. Something should be checked constantly, but for it there isn't enough time. And if a certain problem long didn't arise, then the chance to find the reason quickly and to correct a problem in adequate terms, decreases. There was an idea to automate search of the known problems and to make the tool which will undertake automatic and continuous check of operability of shop and the notification of ranking officers about a problem and ways of the decision. This tool will allow owners of the website to react in due time to the arisen or estimated problems and to minimize losses which by all means arise at not operability of the website. Tool targets: ●Providing of smooth operation of the shop working at management system of Magento 1 or Magento 2. ●Prediction of possible problems and timely annunciator of the owner of the website. ●Creation and maintenance of the database of widespread problems and methods of the decision