Search results for "msu"
showing 10 items of 63 documents
Zvaigžņotā Debess: 2013, Vasara (220)
2013
Saturs: Pēdējā "Apollo" ekspedīcija uz Mēnesi ; Vissavienības Astronomijas un ģeodēzijas biedrības Latvijas nodaļa ; M.Gills. ESON – astronomijas popularizēšanas tīkls ; S.Kropa. Dvēsele Atakamas tuksnesī ; M.G. Īsumā: ESO Astro Camp Eiropas vidusskolēniem 2013.gada decembrī ; A.Alksnis. Atklāta vēl viena no Saulei vistuvākajām kaimiņzvaigznēm ; A.Alksnis. Tuvēja zvaigzne, kas ir izveidojusies jau drīz pēc Lielā Sprādziena ; A.Alksnis. Čeļabinskas superbolīds – simtgades notikums ; A.Alksnis. Nevis pārsteidzoša nova, bet gan kvazāra uzliesmojums ; I.Eglītis. Orius – Baldones observatorijā atklātais centaurs ; R.Misa. Denisa Tito Marsa iedvesmas fonds ; A.A. Īsumā: Ap zvaigzni Gleznotāja Bet…
Estimation of Passenger Car Equivalents for single-lane roundabouts using a microsimulation-based procedure
2017
Calibration of microscopic traffic simulation models for single-lane roundabouts.Use of a meta-analytical estimation of critical and follow up headways.Use of a genetic algorithm-based procedure.Calculation of passenger car equivalents for single-lane roundabouts. Passenger car equivalents for heavy vehicles are required to carry out capacity calculations and perform operational analysis of any road entity (roadway segments or intersections). At single-lane roundabouts, the constraints to the vehicular trajectories imposed by the curvilinear geometric design and the driver's gap acceptance behaviour are expected to produce an impact of the heavy vehicles on the quality of traffic flow diffe…
Zvaigžņotā Debess: 2009, Pavasaris (203)
2009
Contents: E.R.Mustel, President of the Astronomical Council of the USSR Academy of Sciences. Congratulations to Editorial Board of “Zvaigžņotā debess” ; Z.Alksne. Gould’s Belt ; I.Daube. At the Radioastrophysical Observatory of the Latvian Academy of Sciences ; Z.Alksne, A.Alksnis. Lopsided Galaxies ; A.Alksnis. HII Region Gum 29 – a Stellar Nursery ; D.Docenko. On Collision of Asteroid 2008 TC3 with the Earth ; V.Lapoška. On „Leap Second” ; I.Vilks, M.Gills. Beginning of the International Year of Astronomy in Paris: Impressions by Latvian Delegates ; J.Jaunbergs. Equatorial Ridge on Iapetus ; M.Sudārs. Space Shuttle Is Not Likely to Retire Next Year ; I.Vilks. Planet Satellite Names in Lat…
Environmental Performance Evaluation at Urban Roundabouts
2021
Transformation toward greener, healthier and safer management of urban mobility demand is needed soon. Smart tools are available to assess the impact of new infrastructural projects and road facilities also from an environmental point of view. In this pilot study pollutant emissions at a sample of urban roundabouts were estimated employing the Vehicle Specific Power methodology which needs second-by-second speed profiles both gathered in the field and simulated in AIMSUN. The versatility of the micro-simulation model for a calibration aimed at improving accuracy of the emissions estimates was tested in order to ensure that second-by-second trajectories experienced in the field properly refl…
Zvaigžņotā Debess: 2021, Pavasaris (251)
2021
Zvaigžņotā Debess: 2006, Rudens
2006
Latvijas Zinātņu akadēmija, Latvijas Universitāte
Innovative Applications and Experiments for the Protection of Archaeological Sites
2020
Nowadays, the protection in situ, the enhancement and the fruition of archaeological sites are issues that are even more relevant, if we take into account the effects caused, in recent decades, by climate change both on the conservation of the most fragile artefacts and on the well-being of visitors. New questions related to the ‘recover of identity’ are raised by the relationships that the protection interventions establish with the environmental context (external) and with the ancient ruins (internal), imposing an interpretation of the project as a union of landscape, morphological, climatic, technical, use and management aspects, or by requiring a holistic and integrated approach, from a…
Genetic algorithm-based calibration of microscopic traffic simulation model for single-lane roundabouts
2017
A calibration procedure for microscopic simulation models based on a genetic algorithm is proposed. Focus is made on single-lane roundabouts for which many random factors such as gap- acceptance affect operations. A comparison is performed between the capacity functions based on a meta- analytic estimation of critical and follow up headways and simulation outputs of a roundabout built in Aimsun microscopic simulator. Aimsun parameters were optimized using the genetic algorithm tool in MATLAB® which automatically interacted with Aimsun through a Python interface. Results showed that applying the genetic algorithm in the calibration process of the microscopic simulation model, a good match to…
Zvaigžņotā Debess: 2017/18, Ziema (238)
2017
Contents: “ZVAIGŽŅOTĀ DEBESS” FORTY YEARS AGO: I.Vilka. Starry Sky and Birds’ Journeys (abridged) ; N.Cimahoviča. Spirals of Saturn’s Rings (abridged) ; I.Šmelds. V Readings of Friedrich Zander ; DEVELOPMENTS in SCIENCE: K.Schwartz. Most Distant Galaxy Clusters and 3D Structure of the Universe ; DISCOVERIES: M.Gills. The Day when Multi-Messenger Astronomy Was Announced ; I.Pundure. ESO Telescopes and Hubble Observe the Source of Gravitational Waves for the First Time ; I.Eglītis. Asteroid “Balklavs” ; SPACE RESEARCH and EXPLORATION: R.Misa. Mission of Cassini – Discoveries to the Very End ; J.Jaunbergs. The Icy World Tethys ; OBSERVATORIES and INSTRUMENTS: M.Gills. The Giant Radio Telescope…
Calibrating a microscopic traffic simulation model for roundabouts using genetic algorithms
2018
The paper introduces a methodological approach based on genetic algorithms to calibrate microscopic traffic simulation models. The specific objective is to test an automated procedure utilizing genetic algorithms for assigning the most appropriate values to driver and vehicle parameters in AIMSUN. The genetic algorithm tool in MATLAB® and AIMSUN micro-simulation software were used. A subroutine in Python implemented the automatic interaction of AIMSUN with MATLAB®. Focus was made on two roundabouts selected as case studies. Empirical capacity functions based on summary random-effects estimates of critical headway and follow up headway derived from meta-analysis were used as reference for ca…