1. Using statistical analysis of an acceleration-based bridge weigh-in-motion system for damage detectionEugene J. O'Brien, Muhammad Arslan Khan, Daniel Patrick McCrum, Aleš Žnidarič, 2020, izvirni znanstveni članek Povzetek: This paper develops a novel method of bridge damage detection using statistical analysis of data from an acceleration-based bridge weigh-in-motion (BWIM) system. Bridge dynamic analysis using a vehicle-bridge interaction model is carried out to obtain bridge accelerations, and the BWIM concept is applied to infer the vehicle axle weights. A large volume of traffic data tends to remain consistent (e.g., most frequent gross vehicle weight (GVW) of 3-axle trucks); therefore, the statistical properties of inferred vehicle weights are used to develop a bridge damage detection technique. Global change of bridge stiffness due to a change in the elastic modulus of concrete is used as a proxy of bridge damage. This approach has the advantage of overcoming the variability in acceleration signals due to the wide variety of source excitations/vehicles–data from a large number of different vehicles can be easily combined in the form of inferred vehicle weight. One year of experimental data from a short-span reinforced concrete bridge in Slovenia is used to assess the effectiveness of the new approach. Although the acceleration-based BWIM system is inaccurate for finding vehicle axle-weights, it is found to be effective in detecting damage using statistical analysis. It is shown through simulation as well as by experimental analysis that a significant change in the statistical properties of the inferred BWIM data results from changes in the bridge condition.
Ključne besede: bridge health monitoring, bridge WIM, structural dynamics, damage detection, vehicle-bridge interaction
Objavljeno v DiRROS: 12.09.2023; Ogledov: 56; Prenosov: 22
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2. First record of the northern spruce bark beetle, Ips duplicatus (Sahlberg, 1836), in SloveniaAndreja Kavčič, Zina Devetak, Barbara Piškur, Eva Groznik, Maarten De Groot, 2023, izvirni znanstveni članek Povzetek: The northern spruce bark beetle, Ips duplicatus (Sahlberg), has invaded Central Europe in the past century and continues to spread southwards and westwards. It has caused damage in some parts of Europe in recent decades and poses a serious threat to spruce forests across the continent. From 2018 to 2021, we conducted intensive monitoring to determine the status of I. duplicatus in Slovenia. We used different types of traps and pheromone lures that attract I. duplicatus beetles and took bark samples from bark beetle-infested trees. Of the 26 traps used during the four years of monitoring, I. duplicatus was found in 16 traps in the central part of Slovenia in 2020. Adult beetles were caught in traps containing both I. typographus and I. duplicatus lures. The identity of this species was confirmed using morphological keys and molecular methods. One to five I. duplicatus beetles were found per trap, totaling 25 specimens. However, we did not confirm any I. duplicatus in samples taken from trees in 2021. We conclude that I. duplicatus is present in Slovenia, but our results suggest that the species is only present locally and that the population is small.
Ključne besede: biological invasions, forest pests, temperate forests, conifers, damage, forest pest monitoring, confirmation
Objavljeno v DiRROS: 05.09.2023; Ogledov: 68; Prenosov: 30
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3. Phenological variability and resistance to late spring frost of common beech in the international provenance test in Bosnia and HerzegovinaMirzeta Memišević Hodžić, Almedin Hebibović, Dalibor Ballian, 2021, izvirni znanstveni članek Povzetek: The research aimed to determine the start, end and duration of leafing phases, the degree of plant damage caused by late spring frost, and the retention of leaves in autumn. The research was conducted in the international common beech provenance test in Bosnia and Herzegovina. The test contains eight provenances from Bosnia and Herzegovina, four from Germany, three from Serbia, two each from Croatia, Romania and Switzerland, and one from Hungary. Leafing phenology, canopy damage caused by late spring frost, and leaf retention were assessed in 2019. Most provenances started opening buds on 17 April 2019. Complete canopy damage affected the highest percentage of plants in provenance BW Bad Wildbad, Germany (68 %), and the lowest in provenance Konjuh Kladanj, Bosnia and Herzegovina (3.2 %). Provenance Herzogenbuchsee from Switzerland had the highest percentage of winter leaf retention (37.5 % of plants). The results can be used in choosing provenances that are resistant to low temperatures in zones of late spring and early autumn frost.
Ključne besede: common beech, international provenance test, leafing phenophases, frost damage, winter leaf retention
Objavljeno v DiRROS: 01.12.2021; Ogledov: 2965; Prenosov: 1723
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4. Windstorm restoration efficiency using the Kidričevo windstorm (29 June, 2006) as a case studyGoran Paulinič, Janez Krč, 2008, izvirni znanstveni članek Povzetek: Economic efficiency is one of the many essential demands regarding the technical management of windstorms. The main goal of this paper is to analyze a hypothetical scenario in which a forest owner works independently on windstorm restoration, using his own equipment and work power. Managing windstorm damage is a difficult and dangerous task, although a potentially lucrative endeavour as our investigation shows. A windstorm represents an opportunity for instant profit for forest owners who are independent of regular forest income. Economic damage is greater and longer lasting for owners with large forest properties and for farm households, which depend on regular forest income. We compared two potential scenarios in a wind-damaged area within the 2000-2010 forestry management period. First, we include a hypothetical scenario in which the windstorm did not occur. An inventory of regular thinning as well as simulation of future events based on past dynamics was done. We also performed a second scenario in which we assumed that private owners carry out windstorm restoration alone, although in reality felling has been carried out with short-wood technology (mechanized cutting). The results section presents the possibilities to attain reasonably high yield by dealing with the consequences of a minor windstorm.
Ključne besede: cost analysis, production effects, scenarios, windstorm, storm damage, forest
Objavljeno v DiRROS: 12.07.2017; Ogledov: 3564; Prenosov: 1735
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5. Norway spruce (Picea abies (L.) Karst.) damage in the Zasavje district of Slovenia evaluated by two methodsNatalija Vidergar-Gorjup, Andrej Strniša, Franc Batič, 2000, izvirni znanstveni članek Povzetek: The Zasavje district has been heavily affected by air pollution due to mining,the presence of a coal-fired power plant, and industry. The extent of forest damage differs according to location because of specific climatic and orographic characteristics. Norway spruce damage was estimated by two methods at 10 locations in the Zasavje district using the Slovenian forestry method for the estimation of forest damage (KOVA et al. 1995), and a Czech method forestimation of damage to the branching system and needle loss and discoloration (CUDLIN & CHMELIKOVA 1995). Comparison of the results obtained by the two methods gave similar damage assessments at heavily polluted sites, although the data obtained by the two methods differ due to several environmental parameters. The Czech method did not give as good results as wasexpected. A possible reason might be that spruce trees in the investigated locations are less damaged than those in the Czech Republic, where the method was developed.
Ključne besede: air pollution, Norway spruce, Picea abies (L.), tree damage, Zasavje, propadanje gozda, poškodovanost drevja, gozdno drevje, onesnaženost zraka, Zasavje, smreka, Picea abies (L.) Karst.
Objavljeno v DiRROS: 12.07.2017; Ogledov: 4230; Prenosov: 1810
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