Investigating Full-Waveform Lidar Data for Detection and Recognition of Vertical Objects

A recent innovation in commercially-available topographic lidar systems is the ability to record return waveforms at high sampling frequencies. These “full-waveform” systems provide up to two orders of magnitude more data than “discrete-return” systems. However, due to the relatively limited capabilities of current processing and analysis software, more data does not always translate into more or better information for object extraction applications. In this paper, we describe a new approach for exploiting full waveform data to improve detection and recognition of vertical objects, such as trees, poles, buildings, towers, and antennas. Each waveform is first deconvolved using an expectation-maximization (EM) algorithm to obtain a train of spikes in time, where each spike corresponds to an individual laser reflection. The output is then georeferenced to create extremely dense, detailed X,Y,Z,I point clouds, where I denotes intensity. A tunable parameter is used to control the number of spikes in the deconvolved waveform, and, hence, the point density of the output point cloud. Preliminary results indicate that the average number of points on vertical objects using this method is several times higher than using discrete-return lidar data. The next steps in this ongoing research will involve voxelizing the lidar point cloud to obtain a high-resolution volume of intensity values and computing a 3D wavelet representation. The final step will entail performing vertical object detection/recognition in the wavelet domain using a multiresolution template matching approach

Trophic status of inland lakes from LANDSAT

A first-cut assessment of the trophic status of inland lakes in Wisconsin was obtained from LANDSAT data. To satisfy the criteria of the project, a large and versatile computer program was developed to gain access to LANDSAT data. This analysis technique has proven to be a cost-effective method of classifying inland lakes in Wisconsin

Improving streamflow estimates through the use of LANDSAT

Estimates of low flow and flood frequency in several southwestern Wisconsin basins were improved by determining land cover from LANDSAT imagery. With the use of estimates of land cover in multiple-regression techniques, the standard error of estimate (SE) for the least annual 7-day low flow for 2- and 10-year recurrence intervals of ungaged sites were lowered by 9% each. The SE of flood frequency in the 'Driftless Area' of Wisconsin for 10-, 50-, and 100-year recurrence intervals were lowered by 14%. Four of nine basin characteristics determined from satellite imagery were significant variables in the multiple-regression techniques, whereas only 1 of the 12 characteristics determined from topographic maps was significant. The percentages of land cover categories in each basin were determined by merging basin boundaries, digitized from quadrangles, with a classified LANDSAT scene. Both the basin boundary X-Y polygon coordinates and the satellite coordinates were converted to latitude-longitude for merging compatibility

Analysis of multi-layered films

Dye densities of multi-layered films are determined by applying a regression analysis to the spectral response of the composite transparency. The amount of dye in each layer is determined by fitting the sum of the individual dye layer densities to the measured dye densities. From this, dye content constants are calculated. Methods of calculating equivalent exposures are discussed. Equivalent exposures are a constant amount of energy over a limited band-width that will give the same dye content constants as the real incident energy. Methods of using these equivalent exposures for analysis of photographic data are presented

Photographic quantification of water quality in mixing zones

A method was developed to quantitatively delineate waste concentrations throughout waste effluent mixing zones on the basis of densitometric measurements extracted from aerial photography. A mixing zone is the extent of a receiving water body ultilized to dilute a waste discharge to a concentration characteristic of a totally mixed condition. Simultaneously-acquired color infrared photography and suspended solids water samples were used to quantitatively delineate the mixing zone resulting from the discharge of a paper mill effluent. Digital scanning microdensitometer data was used to estimate and delineate suspended solids concentrations on the basis of a semi-empirical model. Photographic photometry, when predicated on a limited amount of ground sampling, can measure and delineate mixing zone waste distributions in more detail then conventional surface measuring techniques. The method has direct application to: (1) the establishment of definite and rational water quality guidelines; (2) the development of sampling and surveillance programs for use by governmental and private agencies; and (3) the development of design and location criteria for industrial and municipal waste effluent outfalls

Trophic classification of Tennessee Valley area reservoirs derived from LANDSAT multispectral scanner data

LANDSAT MSS data from four different dates were extracted from computer tapes using a semiautomated digital data handling and analysis system. Reservoirs were extracted from the surrounding land matrix by using a Band 7 density level slice of 3; and descriptive statistics to include mean, variance, and ratio between bands for each of the four bands were calculated. Significant correlations ( 0.80) were identified between the MSS statistics and many trophic indicators from ground truth water quality data collected at 35 reservoirs in the greater Tennessee Valley region. Regression models were developed which gave significant estimates of each reservoir's trophic state as defined by its trophic state index and explained in all four LANDSAT frames at least 85 percent of the variability in the data. To illustrate the spatial variations within reservoirs as well as the relative variations between reservoirs, a table look up elliptical classification was used in conjunction with each reservoir's trophic state index to classify each reservoir on a pixel by pixel basis and produce color coded thematic representations

Wetland mapping from digitized aerial photography

Computer assisted interpretation of small scale aerial imagery was found to be a cost effective and accurate method of mapping complex vegetation patterns if high resolution information is desired. This type of technique is suited for problems such as monitoring changes in species composition due to environmental factors and is a feasible method of monitoring and mapping large areas of wetlands. The technique has the added advantage of being in a computer compatible form which can be transformed into any georeference system of interest

The acquisition of resyllabification in Spanish by English speakers

How do second language learners produce and recognize words in continuous speech when speech segmentation strategies differ between languages? This thesis explores phrases that have been affected by the process of resyllabification of consonants across word boundaries, where syllable and word boundaries are misaligned (e.g. las alas `the wings' as [la.s#a.las] in Spanish). For production, learners must acquire a new gestural coordination pattern for producing these types of sequences across the word boundary, as well as avoid overmarking vowel-initial words with glottalization, which is the norm in some languages, such as English (Bissiri et al., 2011), but not Spanish (Hualde, 2005). For word recognition, models of speech segmentation that emphasize the consonant as a likely segment for the beginning of a word (such as the Possible Word Constraint (Norris et al., 1997) or the Syllable Onset Segmentation Heuristic (Dumay et al., 2001)) would correctly segment salas `rooms' out of a string of sounds [la.s_a.las], but would miss the possibility that alas is also a word. For languages with resyllabification, speakers must consider both segmenting the sequence into both V#CV and VC#V; that is, for /lasa/, both /s/ initial words and /a/ initial words must be activated equally in the lexicon. In English, where vowel-initial words are more likely to be accompanied by glottalization, for the same string /lasa/, /s/ initial words will be more strongly activated than /a/ initial words. Thus, English speakers learning Spanish must suppress their tendency to preclude the activation of lexical entries with different onsets (i.e. vowel initial words when preceded by a consonant). Additionally, English-speaking learners of Spanish must learn an additional language specific cue to word segmentation: the tap and trill contrast at the word boundary in Spanish. While both the tap and trill contrast between vowels word-medially (pero `but' vs. perro `dog'), at the word boundary, the tap is associated with a resyllabified /r/, as in ver ocas `to see geese', whereas the trill is obligatorily a word-initial segment, as in ve rocas `s/he sees rocks'. Several tasks were designed to test both the production and perception of resyllabification. In all cases, native Spanish speakers were compared with learners of Spanish whose first language was English at various proficiency levels. Production data is given from a laboratory read-speech task in both Spanish and English designed to elicit VC#V sequences with three consonants: /n/ and /s/ to test overall resyllabification, and /r/ to test the allophonic distribution of this phoneme at the word boundary. The results show that second language learners struggle overall to resyllabify consonants: they favor marking vowel-initial words with glottal stops, although they do so less than they do in English. They do not produce the tap and the trill in the appropriate positions at the word boundary either, although this is complicated by the difficulty in producing these segments in any position. Perception data is given in three different experiments: a word-monitoring task geared towards investigating /n/ and /s/ at the word boundary, a word-monitoring gating task investigating /r/, and finally a visual-world paradigm eye-tracking experiment investigating whether or not multiple lexical candidates are considered while listening to phrases where /n/, /s/, and /r/ straddle the word boundary. While ultimately perception results show that non-native speakers are able to successfully parse the intended word, even in resyllabification contexts, results show that they still have a bias towards consonant-initial words although this is lessened with increased proficiency. Additionally, native speakers appear to have this bias in perception as well, which is unreported in the literature. This finding calls into question the idea of complete resyllabification (Harris, 1983), wherein perception and production of V#CV and VC#V sequences are expected to be identical. Overall, this work adds descriptive contributions to word-juncture phenomena in Spanish and English and theoretical contributions to the ideas of lexical access and storage, phonological encoding, phonological universals in syllabification, and speech segmentation in a second language, as well as methodological concerns regarding eye tracking

Usefulness of preclinical models for assessing the efficacy of late-life interventions for sarcopenia

Caloric restriction and physical exercise have proven beneficial against age-associated changes in body composition and declining physical performance; however, little is known regarding what benefit these interventions might have when initiated late in life. The study of mimetics of diet and exercise and the combination thereof may provide additional treatments for a vulnerable elderly population; however, how and when to initiate such interventions requires consideration in developing the most safe and efficacious treatment strategies. In this review, we focus on preclinical late-life intervention studies, which assess the relationship between physical function, sarcopenia, and body composition. We provide a conceptual framework for the ever-changing definition of sarcopenia and a rationale for the use of an appropriate rodent model of this condition. We finish by providing our perspective regarding the implications of this body of work and future areas of research that may also contribute to the ultimate goal of extending healthspan. © 2011 The Author

Whole-genome and multisector exome sequencing of primary and post-treatment glioblastoma reveals patterns of tumor evolution

Glioblastoma (GBM) is a prototypical heterogeneous brain tumor refractory to conventional therapy. A small residual population of cells escapes surgery and chemoradiation, resulting in a typically fatal tumor recurrence ~7 mo after diagnosis. Understanding the molecular architecture of this residual population is critical for the development of successful therapies. We used whole-genome sequencing and whole-exome sequencing of multiple sectors from primary and paired recurrent GBM tumors to reconstruct the genomic profile of residual, therapy resistant tumor initiating cells. We found that genetic alteration of the p53 pathway is a primary molecular event predictive of a high number of subclonal mutations in glioblastoma. The genomic road leading to recurrence is highly idiosyncratic but can be broadly classified into linear recurrences that share extensive genetic similarity with the primary tumor and can be directly traced to one of its specific sectors, and divergent recurrences that share few genetic alterations with the primary tumor and originate from cells that branched off early during tumorigenesis. Our study provides mechanistic insights into how genetic alterations in primary tumors impact the ensuing evolution of tumor cells and the emergence of subclonal heterogeneity