226 research outputs found
Analysis of Unmanned Aerial System-Based CIR Images in Forestry—A New Perspective to Monitor Pest Infestation Levels
The detection of pest infestation is an important aspect of forest management. In the case of the oak splendour beetle (Agrilus biguttatus) infestation, the affected oaks (Quercus sp.) show high levels of defoliation and altered canopy reflection signature. These critical features can be identified in high-resolution colour infrared (CIR) images of the tree crown and branches level captured by Unmanned Aerial Systems (UAS). In this study, we used a small UAS equipped with a compact digital camera which has been calibrated and modified to record not only the visual but also the near infrared reflection (NIR) of possibly infested oaks. The flight campaigns were realized in August 2013, covering two study sites which are located in a rural area in western Germany. Both locations represent small-scale, privately managed commercial forests in which oaks are economically valuable species. Our workflow includes the CIR/NIR image acquisition, mosaicking, georeferencing and pixel-based image enhancement followed by object-based image classification techniques. A modified Normalized Difference Vegetation Index (NDVImod) derived classification was used to distinguish between five vegetation health classes, i.e., infested, healthy or dead branches, other vegetation and canopy gaps. We achieved an overall Kappa Index of Agreement (KIA) of 0.81 and 0.77 for each study site, respectively. This approach offers a low-cost alternative to private forest owners who pursue a sustainable management strategy
Auricular Acupuncture for Pain Relief after Ambulatory Knee Arthroscopy—A Pilot Study
Auricular acupuncture (AA) is effective in treating various pain conditions, but there have been no analyses of AA for the treatment of pain after ambulatory knee surgery. We assessed the range of analgesic requirements under AA after ambulatory knee arthroscopy. Twenty patients randomly received a true AA procedure (Lung, Shenmen and Knee points) or sham procedure (three non-acupuncture points on the auricular helix) before ambulatory knee arthroscopy. Permanent press AA needles were retained in situ for one day after surgery. Post-operative pain was treated with non-steroidal anti-inflammatory ibuprofen, and weak oral opioid tramadol was used for rescue analgesic medication. The quantity of post-operative analgesics and pain intensity were used to assess the effect of AA. The incidence of analgesia-related side effects, time to discharge from the anesthesia recovery room, heart rate and blood pressure were also recorded. Ibuprofen consumption after surgery in the AA group was lower than in the control group: median 500 versus 800 mg, P = 0.043. Pain intensity on a 100 mm visual analogue scale for pain measurement and other parameters were similar in both groups. Thus AA might be useful in reducing the post-operative analgesic requirement after ambulatory knee arthroscopy
Untersuchung zur automatisierten Bestimmung des IVS-Referenzpunktes am TWIN Radioteleskop Wettzell
Die Verknüpfung von geodätischen Raumtechniken wie GNSS, DORIS, SLR oder VLBI zur Ableitung eines geodätischen Referenzrahmens wie dem ITRF gelingt erst durch sogenannte Kolokationsstationen. Die geometrischen Beziehungen zwischen den betriebenen Raumtechniken sind dabei aus präzisen lokalen Vermessungen abzuleiten. Es wird ein Konzept zur automatisierten Bestimmung des IVS-Referenzpunktes am TWIN Radioteleskop Wettzell vorgestellt. Erste Untersuchungsergebnisse werden präsentiert
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