Occupation, Dispersal, and Economic Impact of Major Invasive Plant Species in Southern U.S. Forests

Invasive alien plants have impacted southern U.S. forests. This study focuses on quantifying current distribution, rate of dispersals, and economic losses caused by four major invaders — Chinese tallow (Triadica sebifera (L.) Small), Chinese Privet (Ligustrum sinense Lour.), European Privet (Ligustrum vulgare L.), and Japanese Honeysuckle (Lonicera japonica Thunb.). Using data from USDA Forest Service’s Forest Inventory and Analysis (FIA), National Oceanic and Atmospheric Administration (NOAA), and USGS Land Use and Land Cover (LULC), I first used logistic regressions to build occupation models for these four species. Second, I used VB.NET© (Microsoft, 2003) and Environment System Research Institute (ESRI) Arc View® 9.2 Geographical Information System (GIS) to model spatially explicit dispersal dynamics of these species. Finally, I evaluated economic losses associated with these invasions. The results of occupation models showed that landscape features, climatic conditions, forest and site conditions, forest management activities and disturbances, and forest ownership have statistically significant impacts on current distributions of all four species. The results of dispersal models showed that invasions of Chinese tallow, Chinese and European privets, and Japanese honeysuckle will be likely to appear on approximately 6.65 million acres of forest land in East Texas and Louisiana, 3.81 million acres in Mississippi and Alabama, and 12.55 million acres in Mississippi and Alabama, respectively, during the next 20 years. The estimated timber losses resulting from the invasion with no control for the next 20 years at 5% discount rate is 518 million dollars for Chinese tallow, 2.72 billion dollars for Chinese and European privets, and 11.05 billion dollars for Japanese honeysuckle. From an economic point of view, it would be most cost effective to execute high intensity control for these invasive species. Based on these findings, strategies for monitoring and mitigating these invasive species are proposed

Improving Automatic Jazz Melody Generation by Transfer Learning Techniques

In this paper, we tackle the problem of transfer learning for Jazz automatic generation. Jazz is one of representative types of music, but the lack of Jazz data in the MIDI format hinders the construction of a generative model for Jazz. Transfer learning is an approach aiming to solve the problem of data insufficiency, so as to transfer the common feature from one domain to another. In view of its success in other machine learning problems, we investigate whether, and how much, it can help improve automatic music generation for under-resourced musical genres. Specifically, we use a recurrent variational autoencoder as the generative model, and use a genre-unspecified dataset as the source dataset and a Jazz-only dataset as the target dataset. Two transfer learning methods are evaluated using six levels of source-to-target data ratios. The first method is to train the model on the source dataset, and then fine-tune the resulting model parameters on the target dataset. The second method is to train the model on both the source and target datasets at the same time, but add genre labels to the latent vectors and use a genre classifier to improve Jazz generation. The evaluation results show that the second method seems to perform better overall, but it cannot take full advantage of the genre-unspecified dataset.Comment: 8 pages, Accepted to APSIPA ASC(Asia-Pacific Signal and Information Processing Association Annual Summit and Conference ) 201

Location-based Data Analysis of Visitor Structure for Recreational Area Management

This work presents a location-based data analysis framework for profiling visitors structures. In terms of recreational area management, understanding visitors’ structure and popularity is important. Traditionally, visitors monitoring with automatic counting devices has drawbacks of inaccurate visitors counting. In this work, compared to automatic counting devices, we use Wi-Fi tracking as the main method to count visitors, which provides a fairly precise picture of visitor structures. Moreover, we deliver rich analytic functions in this framework and we present the functionality with visitor data collected from Guanyinshan Visitor Center. This framework not only standardizes visitor counting process but also facilitates a profound analysis of visitor structures. Key Words: Guanyinshan Visitor Center, Wi-Fi trackin

Global-Local Finite Element Analysis

114 σ.Η αναλυτική επίλυση πολύπλοκων προβλημάτων της μηχανικής στις μέρες μας καθίσταται δυσχερής εως αδύνατη χωρίς την εφαρμογή αριθμητικών μεθόδων και τη χρήση ηλεκτρονικού υπολογιστή. Η μέθοδος των πεπερασμένων στοιχείων αποτελεί σήμερα ένα ισχυρό εργαλείο για την επίλυση τέτοιων προβλημάτων και εξελίσσεται με μεγάλη ταχύτητα τόσο σε ακαδημαϊκό όσο και σε επαγγελματικό επίπεδο. Ενδεικτικά, αν και επινοήθηκε και χρησιμοποιήθηκε για τη στατική ανάλυση φορέων, έχει καθολικότερη εφαρμογή σε μια ευρύτερη κατηγορία προβλημάτων του μηχανικού, όπως στη ρευστομηχανική, στη μεταφορά θερμότητας, στην ακουστική, στον ηλεκτρομαγνητισμό και στην εμβιομηχανική. Επιπλέον, η εξέλιξη στων Η/Υ με τις ολοένα μεγαλύτερες δυνατότητες διαχείρισης όγκου δεδομένων αλλά και με την αύξηση της ταχύτητας εκτέλεσης των αριθμητικών πράξεων κατέστησε εφικτή την επίλυση σύνθετων προβλημάτων τα οποία θεωρούνταν απροσπέλαστα πριν μερικά χρόνια. Στην κατηγορία αυτή, των προβλημάτων αυξημένου υπολογιστικού κόστους, ανήκει και η καταστατική περιγραφή πολυφασικών υλικών. Είναι γεγονός ότι το μεγαλύτερο μέρος των παραγώμενων δομικών υλικών σήμερα, παρουσιάζει κάποιο είδος ανομοιογένειας, διακριτή ή μη στην κλίμακα δομικών έργων. Χαρακτηριστικά παραδείγματα αποτελούν τα κράματα μετάλλων, τα πορώδη, τα πολυκρυσταλλικά και τα σύνθετα υλικά στα οποία το μέγεθος, το σχήμα και οι ιδιότητες των συστατικών τους μερών καθορίζουν άμεσα τη συνολική τους μηχανική συμπεριφορά. Διάφορες τεχνικές έχουν αναπτυχθεί για την προσομοίωση και την περιγραφή της απόκρισης ανομοιογενών υλικών. Η παρούσα εργασία επικεντρώνεται στη μέθοδο ομογενοποίησης πολλαπλών κλιμάκων η οποία συνίσταται στην επίλυση δύο εμφωλευμένων προβλημάτων συνοριακών τιμών, για τη μακροκλίμακα και τη μικροκλίμακα αντίστοιχα. Τα βασικά χαρακτηριστικά μιας τέτοιας μεθόδου είναι ότι - Δεν απαιτείται η περιγραφή των καταστατικών νόμων του μακροφορέα. - Παρέχει τη δυνατότητα ενσωμάτωσης μεγάλων παραμορφώσεων και στροφών τόσο στην προσομοίωση της μικροκλίμακας όσο και του μακροφορέα. - Παρέχει τη δυνατότητα λεπτομερούς προσομοίωσης των συστατικών μερών της μικροκλίμακας. - Επιτρέπει οποιαδήποτε τεχνική επίλυσης στην κλίμακα του μικροφορέα. Αναλυτικά, σύμφωνα με τη μέθοδο αυτή. υπολογίζεται το διάνυσμα ανηγμένων παραμορφώσεων σε κάθε υλικό σημείο του μακροφορέα το οποίο στη συνέχεια χρησιμοποιείται για τη μόρφωση των συνοριακών συνθηκών του αντιπροσωπευτικού μικροφορέα στο αντίστοιχο σημείο. Μετά την επίλυση του προβλήματος συνοριακών τιμών της μικροκλίμακας, το διάνυσμα των τάσεων του μακροφορέα υπολογίζεται μέσα από τη διαδικασία ομογενοποίησης του πεδίου των τάσεων και κατά τον τρόπο αυτό υπολογίζεται η σχέση τάσεων ανηγμένων παραμορφώσεων για κάθε υλικό σημείο Ωστόσο, υπάρχουν κάποιοι περιορισμοί στην εφαρμογή της εν λόγω υπολογιστικής τεχνικής. Συγκεκριμένα, παρά το ότι κατά την προσομοίωση λαμβάνονται υπ' όψην οι διάφορες παράμετροι της μικροκλίμακας όπως το ποσοστό όγκου, η κατανομή και η μορφολογία των συστατικών μερών του υλικού, τα αποτελέσματα της μεθόδου είναι ανεξάρτητα από το απόλυτο μέγεθος του αντιπροσωπευτικού όγκου της μικροκλίμακας. Παρ' όλα αυτά, η τεχνική ομογενοποίησης στα πλαίσια ανάλυσης πολλαπλών κλιμάκων αποτελεί ένα σημαντικό εργαλείο για τον υπολογισμό των καταστατικών σχέσεων πολυφασικών υλικών στα οποία είναι αδύνατη η εφαρμογή οποιασδήποτε άλλης μεθόδου.Nowadays, analysis of complicated problems in the domain of mechanics consti- tutes a hard and even impossible task without the implementation of numerical methods and the employment of computational machines. Finite element method is a powerful tool for the solution of such problems and is rapidly developed in an academic and professional sense. Even if it was developed and implemented for structural analysis, it is widely employed in several domains such as in fluid mechanics, heat transfer, acoustics and electromagnetism. Furthermore, the development of computer hardware in terms of data processing, has significantly contributed to the solution of problems that were considered inaccessible a few years ago. Most of the materials produced in industry are heterogeneous on one or another spatial scale. Typical examples include metal alloy systems, porous media and polycrystalline materials and composites. The overall response of these micro heterogeneous materials depends strongly on the size, shape properties and spatial distribution of the microstructural components. Several techniques have been developed for the prediction of the macroscopic behavior of such materials. The present work is concentrated on the first order homogenization technique in the framework of a multi-scale approach which consists of the solution of two nested boundary value problems, for the macro-scale and the micro-scale respectively. Methods of this type - Do not require any constitutive assumption with respect to the overall ma- terial behavior. - Enable the incorporation of large deformations and rotations on both micro and macrolevel. - Provide the possibility to introduce detailed microstructural information. - Allow the use of any modelling technique at the microlevel. Concretely, according to this approach, the macroscopic deformation tensor is calculated for every integration point of the macrostructure and then is used to formulate the kinematic boundary conditions for the associated microstructural representative volume element (RVE). After the solution of the microstructural boundary value problem, the macroscopic stress tensor is computed by averaging the resulting microstructural stress field over the volume of the RVE and as a result, we obtain the stress-strain relation at every macroscopic point. However, there is a major disadvantage of the existing first-order computational homogenization. More specifically, this technique can account for the volume fraction, distribution and morphology of the micro-components however, it cannot take into account the absolute size of the microstructure making it thus impossible to treat microstructural size effects. Nevertheless, computational homogenization provides a significant strategy to obtain micro-macro structure-property relations for materials for which the overall macroscopic response cannot be computed by any other method.Κωνσταντινος Ε. Τατση

Species Distribution Model for Management of an Invasive Vine in Forestlands of Eastern Texas

Invasive plants decrease biodiversity, modify vegetation structure, and inhibit growth and reproduction of native species. Japanese honeysuckle (Lonicera japonica Thunb.) is the most prevalent invasive vine in the forestlands of eastern Texas. Hence, we aimed to identify potential factors influencing the distribution of the species, quantify the relative importance of each factor, and test possible management strategies. We analyzed an extensive dataset collected as part of the Forest Inventory and Analysis Program of the United States Department of Agriculture (USDA) Forest Service to quantify the range expansion of Japanese honeysuckle in the forestlands of eastern Texas from 2006 to 2011. We then identified potential factors influencing the likelihood of presence of Japanese honeysuckle using boosted regression trees. Our results indicated that the presence of Japanese honeysuckle on sampled plots almost doubled during this period (from 352 to 616 plots), spreading extensively, geographically. The probability of invasion was correlated with variables representing landscape conditions, climatic conditions, forest features, disturbance factors, and forest management activities. Habitats most at risk to invasion under current conditions occurred primarily in northeastern Texas, with a few invasion hotspots in the south. Estimated probabilities of invasion were reduced most by artificial site regeneration, with habitats most at risk again occurring primarily in northeastern Texas

Range expansion of invasive shrubs: implication for crown fire risk in forestlands of the southern USA

Non-native plant invasions and changing management activities have dramatically altered the structure and composition of forests worldwide. Invasive shrubs and fire suppression have led to increased densification and biomass accumulation in forest ecosystems of the southeastern USA. Notably, Chinese and European privets are rapid growing, shade-tolerant shrubs which number among the most aggressive invasive species in these forests. Privet encroachment has caused losses of native diversity, alteration of ecosystem processes and changes in community structure. The latter has become manifest through decreases in fine herbaceous fuels concurrent with increases in coarse woody fuels in forest understoreys. These alterations in fuel structure will potentially lead to less frequent, but more severe forest fires, which threaten important forest resources during extreme weather conditions. Drawing on extensive data sets compiled by the US Forest Service, we integrated statistical forecasting and analytical techniques within a spatially explicit, agent-based, simulation framework to predict potential range expansion of Chinese and European privet (Ligustrum sinense and L. vulgare) and the associated increase in crown fire risk over the next two decades in forestlands of Mississippi and Alabama. Our results indicate that probability of invasion is positively associated with elevation, adjacency (within 300 m) to water bodies, mean daily maximum temperature, site productivity and private land ownership, and is negatively associated with slope, stand age, artificial regeneration, distance to the nearest road and fire disturbance. Our projections suggest the total area invaded will increase from 1.36 to ≈31.39% of all forestlands in Mississippi and Alabama (≈7 million hectares) and the annual frequency of crown fires in these forestlands will approximately double within the next two decades. Such time series projections of annual range expansions and crown fire frequency should provide land managers and restoration practitioners with an invasion chronology upon which to base proactive management plans

Potential Range Expansion of Japanese Honeysuckle (Lonicera japonica Thunb.) in Southern U.S. Forestlands

Japanese honeysuckle is one of the most aggressive invasive vines in forestlands of the southern United States. We analyzed field data collected by the U.S. Forest Service to identify potential determinants of invasion and to predict likelihood of further invasion under a variety of possible management strategies. Results of logistic regression, which classified 74% of the field plots correctly with regard to species presence and absence, indicated probability of invasion is correlated positively with adjacency to water bodies, temperature, site productivity, species diversity, and private land ownership, and is correlated negatively with slope, stand age, artificial regeneration, distance to the nearest road, and fire disturbance. Habitats most at risk to further invasion under current conditions occur throughout Mississippi, stretching northward across western Tennessee and western Kentucky, westward across southern Arkansas, eastward across north-central Alabama, and also occur in several counties scattered within Virginia. Invasion likelihoods could be increased by global climate change and reduced most by conversion to public land ownership, followed by artificial regeneration, and fire disturbance. While conversion of land ownership may not be feasible, this result suggests the opportunity for decreasing the likelihood of invasions on private lands via using selected management practices

Measurements and Correlations of MTBE and BETX in Traffic Tunnels

ABSTRACT In this study, the concentrations of five volatile organic compounds (VOCs), including BTEX and methyl tertiary-butyl ether (MTBE), were investigated in five different traffic tunnels (including Liangshan, Yueguangshan, Zoying, Guogang and Zhongliao tunnels) in southern Taiwan. Results showed that Guogang Tunnel was the most polluted with the highest average levels of both MTBE and BTEX while ethylbenzene had the lowest levels. The range of measured concentration of toluene in Liangshan, Yueguangshan, Zoying, Guogang and Zhongliao tunnels were from 5.6 to 6.2 (mean = 1.6), from 0.0 to 62.3 (mean = 17.6), from 2.7 to 26.7 (mean = 13.1), from 15.2 to 125.5 (mean = 57.5), and from 43.7 to 197.1 (mean = 115.8) g/m 3 , respectively. In Guogang Tunnel, the average MTBE-BTEX ratios at two peak rush periods were (5.0:1, 5:3, 4:1, 0:1, 5:1.1) and (5.7:1, 3:3, 2:1, 0:1, 4:1.1). From morning till night, the ratios at different sampling periods in the five different tunnels suggest the existence of both different traffic flow and variations in traffic fleet type in different tunnels. T/B ratio ranged from 0 to 2.3, from 0 to 1.9, from 0.6 to 2.5, from 0.9 to 2.6 and from 0 to 10.5 in Liangshan, Yueguangshan, Zoying, Guogang and Zhongliao tunnels, respectively. We also observed a wide range of (m+p+o)-xylenes/ethylbenzene ( X/E) or m,p-X/E ratio in all five tunnels. The m,p-xylene/ethylbenzene ratio ranged from 2.2 to 5.7, from 1.4 to 3.3, from 2.0 to 7.7, from 1.4 to 1.5 and from 5.5 to 8.1 in Liangshan, Yueguangshan, Zoying, Guogang and Zhongliao Tunnels, respectively. Notably, those high X/E ratios in all tunnels reflect a fresh air parcel in the tunnels due to the enclosed/half-enclosed environment. Nevertheless, it is important that the characteristics of X/E in different traffic tunnels are explored

Nervous Necrosis Virus Replicates Following the Embryo Development and Dual Infection with Iridovirus at Juvenile Stage in Grouper

Infection of virus (such as nodavirus and iridovirus) and bacteria (such as Vibrio anguillarum) in farmed grouper has been widely reported and caused large economic losses to Taiwanese fish aquaculture industry since 1979. The multiplex assay was used to detect dual viral infection and showed that only nervous necrosis virus (NNV) can be detected till the end of experiments (100% mortality) once it appeared. In addition, iridovirus can be detected in a certain period of rearing. The results of real-time PCR and in situ PCR indicated that NNV, in fact, was not on the surface of the eggs but present in the embryo, which can continue to replicate during the embryo development. The virus may be vertically transmitted by packing into eggs during egg development (formation) or delivering into eggs by sperm during fertilization. The ozone treatment of eggs may fail to remove the virus, so a new strategy to prevent NNV is needed