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Sample records for model-determined segmental duration

  1. Segmental duration in Parkinsonian French speech.

    PubMed

    Duez, Danielle

    2009-01-01

    The present study had 2 main objectives: (1) examine the effect of Parkinson's disease (PD) on vowel and consonant duration in French read speech and (2) investigate whether the durational contrasts of consonants and vowels are maintained or compromised. The data indicated that the consonant durations were shortened in Parkinsonian speech (PS), compared to control speech (CS). However, this shortening was consonant dependent: unvoiced occlusives and fricatives were significantly shortened compared to other consonant categories. All vowels were slightly longer in PS than in CS, however, the observed differences were below the level of significance. Despite significant shortening of some consonant categories, the general pattern of intrinsic duration was maintained in PS. There was slightly less agreement for vowels with the normal contrast of intrinsic durations, possibly because vowel durational contrasts are more sensitive to PD disorders. Most PD patients tended to maintain the intrinsic duration contrasts of both vowels and consonants, suggesting that low-level articulatory constraints operate in a similar way and with the same weight in PS and CS. Copyright 2009 S. Karger AG, Basel.

  2. Genetic Determinants of P Wave Duration and PR Segment

    PubMed Central

    Verweij, Niek; Leach, Irene Mateo; van den Boogaard, Malou; van Veldhuisen, Dirk J.; Christoffels, Vincent M.; Hillege, Hans L.; van Gilst, Wiek H.; Barnett, Phil; de Boer, Rudolf A.; van der Harst, Pim

    2014-01-01

    Background The PR interval on the electrocardiogram reflects atrial depolarization and AV nodal delay which can be partially differentiated by P wave duration and PR segment, respectively. GWAS have identified a number of genetic loci for PR interval but it remains to be determined whether this is driven by P wave duration, PR segment or both. Methods and Results We replicated 7 of the 9 known PR interval loci in 16,468 individuals of European ancestry. Four loci were unambiguously associated with PR segment while the others were shared for P wave duration and PR segment. Next, we performed a genome-wide analysis on P wave duration and PR segment separately and identified five novel loci. SNPs in KCND3 (P=8.3×10−11) and FADS2 (P=2.7×10−8) were associated with P wave duration, whereas SNPs near IL17D (P=2.3×10−8), in EFHA1 (P=3.3×10−10) and LRCH1 (P=2.1×10−8) were associated with PR segment. Analysis on DNA elements indicated that genome-wide significant SNPs were enriched at genomic regions suggesting active gene transcription in the human right atrium. Quantitative-PCR showed that genes were significantly higher expressed in the right atrium and AV-node compared to left ventricle (P=5.6×10−6). Conclusions Genetic associations of PR interval appear to be mainly driven by genetic determinants of the PR segment. Some of the PR interval associations are strengthened by a directional consistent effect of genetic determinants of P wave duration. Through genome-wide association we also identified genetic variants specifically associated with P wave duration which might be relevant for cardiac biology. PMID:24850809

  3. Domain-General Mechanisms for Speech Segmentation: The Role of Duration Information in Language Learning

    PubMed Central

    2016-01-01

    Speech segmentation is supported by multiple sources of information that may either inform language processing specifically, or serve learning more broadly. The Iambic/Trochaic Law (ITL), where increased duration indicates the end of a group and increased emphasis indicates the beginning of a group, has been proposed as a domain-general mechanism that also applies to language. However, language background has been suggested to modulate use of the ITL, meaning that these perceptual grouping preferences may instead be a consequence of language exposure. To distinguish between these accounts, we exposed native-English and native-Japanese listeners to sequences of speech (Experiment 1) and nonspeech stimuli (Experiment 2), and examined segmentation using a 2AFC task. Duration was manipulated over 3 conditions: sequences contained either an initial-item duration increase, or a final-item duration increase, or items of uniform duration. In Experiment 1, language background did not affect the use of duration as a cue for segmenting speech in a structured artificial language. In Experiment 2, the same results were found for grouping structured sequences of visual shapes. The results are consistent with proposals that duration information draws upon a domain-general mechanism that can apply to the special case of language acquisition. PMID:27893268

  4. Domain-general mechanisms for speech segmentation: The role of duration information in language learning.

    PubMed

    Frost, Rebecca L A; Monaghan, Padraic; Tatsumi, Tomoko

    2017-03-01

    Speech segmentation is supported by multiple sources of information that may either inform language processing specifically, or serve learning more broadly. The Iambic/Trochaic Law (ITL), where increased duration indicates the end of a group and increased emphasis indicates the beginning of a group, has been proposed as a domain-general mechanism that also applies to language. However, language background has been suggested to modulate use of the ITL, meaning that these perceptual grouping preferences may instead be a consequence of language exposure. To distinguish between these accounts, we exposed native-English and native-Japanese listeners to sequences of speech (Experiment 1) and nonspeech stimuli (Experiment 2), and examined segmentation using a 2AFC task. Duration was manipulated over 3 conditions: sequences contained either an initial-item duration increase, or a final-item duration increase, or items of uniform duration. In Experiment 1, language background did not affect the use of duration as a cue for segmenting speech in a structured artificial language. In Experiment 2, the same results were found for grouping structured sequences of visual shapes. The results are consistent with proposals that duration information draws upon a domain-general mechanism that can apply to the special case of language acquisition. (PsycINFO Database Record

  5. The relationship between speech segment duration and vowel centralization in a group of older speakers.

    PubMed

    Fletcher, Annalise R; McAuliffe, Megan J; Lansford, Kaitlin L; Liss, Julie M

    2015-10-01

    This study examined the relationship between average vowel duration and spectral vowel quality across a group of 149 New Zealand English speakers aged 65 to 90 yr. The primary intent was to determine whether participants who had a natural tendency to speak slowly would also produce more spectrally distinct vowel segments. As a secondary aim, this study investigated whether advancing age exhibited a measurable effect on vowel quality and vowel durations within the group. In examining vowel quality, both flexible and static formant extraction points were compared. Two formant measurements, from selected [ɐ:], [ i:], and [ o:] vowels, were extracted from a standard passage and used to calculate two measurements of vowel space area (VSA) for each speaker. Average vowel duration was calculated from segments across the passage. The study found a statistically significant relationship between speakers' average vowel durations and VSA measurements indicating that, on average, speakers with slower speech rates produced more acoustically distinct speech segments. As expected, increases in average vowel duration were found with advancing age. However, speakers' formant values remained unchanged. It is suggested that the use of a habitually slower speaking rate may assist speakers in maintaining acoustically distinct vowels.

  6. Optimized adaptation algorithm for HEVC/H.265 dynamic adaptive streaming over HTTP using variable segment duration

    NASA Astrophysics Data System (ADS)

    Irondi, Iheanyi; Wang, Qi; Grecos, Christos

    2016-04-01

    Adaptive video streaming using HTTP has become popular in recent years for commercial video delivery. The recent MPEG-DASH standard allows interoperability and adaptability between servers and clients from different vendors. The delivery of the MPD (Media Presentation Description) files in DASH and the DASH client behaviours are beyond the scope of the DASH standard. However, the different adaptation algorithms employed by the clients do affect the overall performance of the system and users' QoE (Quality of Experience), hence the need for research in this field. Moreover, standard DASH delivery is based on fixed segments of the video. However, there is no standard segment duration for DASH where various fixed segment durations have been employed by different commercial solutions and researchers with their own individual merits. Most recently, the use of variable segment duration in DASH has emerged but only a few preliminary studies without practical implementation exist. In addition, such a technique requires a DASH client to be aware of segment duration variations, and this requirement and the corresponding implications on the DASH system design have not been investigated. This paper proposes a segment-duration-aware bandwidth estimation and next-segment selection adaptation strategy for DASH. Firstly, an MPD file extension scheme to support variable segment duration is proposed and implemented in a realistic hardware testbed. The scheme is tested on a DASH client, and the tests and analysis have led to an insight on the time to download next segment and the buffer behaviour when fetching and switching between segments of different playback durations. Issues like sustained buffering when switching between segments of different durations and slow response to changing network conditions are highlighted and investigated. An enhanced adaptation algorithm is then proposed to accurately estimate the bandwidth and precisely determine the time to download the next

  7. [Nonstationarity and duration of the R-R-segment in the diagnostics of functional states of operators].

    PubMed

    Mashin, V A

    2007-01-01

    The effect of the nonstationarity of R-R interval series on the diagnostics of functional states of operators has been analyzed. The functional states were diagnosed by means of a factor model of heart rate variability. The heart rate was recorded in the supine position, before the performance of an important task, and after its completion. A high resistance of the diagnostics of functional states to nonstationarity was found for all periods. Indices of heart rate variability resistant to nonstationarity were defined. Also, the effect of R-R segment duration on functional states diagnostics was explored. The results obtained allow one to conclude that the diagnostics of functional states based on the three-factor model of heart rate variability can be used on short segments within a range of 256 divided 32 R-R intervals. The indices of the factor model of heart rate variability must be normalized for corresponding R-R segment duration before diagnostics. In addition, the effect of the duration of R-R segment on the indices of heart rate variability was analyzed for different functional states. The indices resistant to the duration of R-R segments and conditions necessary for heart rate recording were defined.

  8. Acoustic predictors of intelligibility for segmentally interrupted speech: temporal envelope, voicing, and duration.

    PubMed

    Fogerty, Daniel

    2013-10-01

    Temporal interruption limits the perception of speech to isolated temporal glimpses. An analysis was conducted to determine the acoustic parameter that best predicts speech recognition from temporal fragments that preserve different types of speech information-namely, consonants and vowels. Young listeners with normal hearing previously completed word and sentence recognition tasks that required them to repeat word and sentence material that was temporally interrupted. Interruptions were designed to replace various portions of consonants or vowels with low-level noise. Acoustic analysis of preserved consonant and vowel segments was conducted to investigate the role of the preserved temporal envelope, voicing, and speech duration in predicting performance. Results demonstrate that the temporal envelope, predominantly from vowels, is most important for sentence recognition and largely predicts results across consonant and vowel conditions. In contrast, for isolated words the proportion of speech preserved was the best predictor of performance regardless of whether glimpses were from consonants or vowels. These findings suggest consideration of the vowel temporal envelope in speech transmission and amplification technologies for improving the intelligibility of temporally interrupted sentences.

  9. Cross-linguistic differences in the use of durational cues for the segmentation of a novel language.

    PubMed

    Ordin, Mikhail; Polyanskaya, Leona; Laka, Itziar; Nespor, Marina

    2017-03-13

    It is widely accepted that duration can be exploited as phonological phrase final lengthening in the segmentation of a novel language, i.e., in extracting discrete constituents from continuous speech. The use of final lengthening for segmentation and its facilitatory effect has been claimed to be universal. However, lengthening in the world languages can also mark lexically stressed syllables. Stress-induced lengthening can potentially be in conflict with right edge phonological phrase boundary lengthening. Thus the processing of durational cues in segmentation can be dependent on the listener's linguistic background, e.g., on the specific correlates and unmarked location of lexical stress in the native language of the listener. We tested this prediction and found that segmentation by both German and Basque speakers is facilitated when lengthening is aligned with the word final syllable and is not affected by lengthening on either the penultimate or the antepenultimate syllables. Lengthening of the word final syllable, however, does not help Italian and Spanish speakers to segment continuous speech, and lengthening of the antepenultimate syllable impedes their performance. We have also found a facilitatory effect of penultimate lengthening on segmentation by Italians. These results confirm our hypothesis that processing of lengthening cues is not universal, and interpretation of lengthening as a phonological phrase final boundary marker in a novel language of exposure can be overridden by the phonology of lexical stress in the native language of the listener.

  10. The perception of lexical stress in German: effects of segmental duration and vowel quality in different prosodic patterns.

    PubMed

    Kohler, Klaus J

    2012-01-01

    Several decades of research, focusing on English, Dutch and German, have set up a hierarchy of acoustic properties for cueing lexical stress. It attributes the strongest cue to criterial-level f0 change, followed by duration, but low weight to energy and to stressed-vowel spectra. This paper re-examines the established view with new data from German. In the natural productions of the German word pair Kaffee 'coffee' - Café 'locality' (with initial vs. final stress in a North German pronunciation), vowel duration was manipulated in a complementary fashion across the two syllables in five steps, spanning the continuum from initial to final stress on each word. The two base words provided different vowel qualities as the second variable, the intervocalic fricative was varied in two values, long and short, taken from Café and Kaffee, and the generated test words were inserted in a low f0 tail and in a high f0 hat-pattern plateau, which both eliminated f0 change as a cue to lexical stress. The sentence stimuli were judged in two listening experiments by 16 listeners in each as to whether the first or the second syllable of the test word was stressed. The results show highly significant effects of vowel duration, vowel quality and fricative duration. The combined vowel-quality and fricative variable can outweigh vowel duration as a cue to lexical stress. The effect of the prosodic frame is only marginal, especially related to a rhythmic factor. The paper concludes that there is no general hierarchy with a fixed ranking of the variables traditionally adduced to signal lexical stress. Every prosodic embedding of segmental sequences defines the hierarchy afresh. Copyright © 2012 S. Karger AG, Basel.

  11. Segments.

    ERIC Educational Resources Information Center

    Zemsky, Robert; Shaman, Susan; Shapiro, Daniel B.

    2001-01-01

    Presents a market taxonomy for higher education, including what it reveals about the structure of the market, the model's technical attributes, and its capacity to explain pricing behavior. Details the identification of the principle seams separating one market segment from another and how student aspirations help to organize the market, making…

  12. Maximising diagnostic information by relating temporal variations in parameter sensitivity to different segments of the flow duration curve

    NASA Astrophysics Data System (ADS)

    Guse, Björn; Pfannerstill, Matthias; Strauch, Michael; Reusser, Dominik; Volk, Martin; Fohrer, Nicola

    2015-04-01

    Parameter sensitivity analysis is a well-known method to detect the most relevant parameters to reproduce the modelled discharge. In contrast to classical approaches, a temporally resolved analysis provides daily sensitivities and detects dominant model parameters for each time step. Relating the dominant parameters to the corresponding processes enables the investigation of the process relevance in a high temporal resolution and thus, improves the understanding of the dominant processes in the model structure. For this, we used a Fourier Amplitude Sensitivity Test (FAST) which is efficient compared to other sensitivity test by requiring only a small number of 315 model runs for nine model parameters. In order to maximize the diagnostically relevant information with low computational demand, the interpretation of the temporal resolved parameter analysis is extended by extracting additional information. We present a model framework consisting of three steps, which was applied to a lowland and a upland catchment in Germany to check its plausibility in two hydrological contrasting catchments. The results of one temporal sensitivity analysis are used in an efficient way to provide three different visualization types with a different focus and aggregation levels. In a first step, the temporal dynamic is analysed in a high resolution with daily time series of parameter sensitivities (TEDPAS). TEDPAS detects the temporal variations in dominant model parameters. Secondly, these results are related to the flow duration curve (FDC) (TEDPAS-FDC) to identify parameter dominances in relation to discharge magnitudes. TEDPAS-FDC emphasizes that high sensitivities of model parameters are related to certain discharges. These relationships are explained by looking at the role of the parameters in the model concept. Thirdly, the parameter sensitivities are monthly averaged and investigated separately for five segments of the FDC (TEDPAS-FDC PATTERN) to detect typical monthly process

  13. Segmentation of dual-axis swallowing accelerometry signals in healthy subjects with analysis of anthropometric effects on duration of swallowing activities.

    PubMed

    Sejdić, Ervin; Steele, Catriona M; Chau, Tom

    2009-04-01

    Dysphagia (swallowing difficulty) is a serious and debilitating condition that often accompanies stroke, acquired brain injury, and neurodegenerative illnesses. Individuals with dysphagia are prone to aspiration (the entry of foreign material into the airway), which directly increases the risk of serious respiratory consequences such as pneumonia. Swallowing accelerometry is a promising noninvasive tool for the detection of aspiration and the evaluation of swallowing. In this paper, dual-axis accelerometry was implemented since the motion of the hyolaryngeal complex occurs in both anterior-posterior and superior-inferior directions during swallowing. Dual-axis cervical accelerometry signals were acquired from 408 healthy subjects during dry, wet, and wet chin tuck swallowing tasks. The proposed segmentation algorithm is based on the idea of sequential fuzzy partitioning of the signal and is well suited for long signals with nonstationary variance. The algorithm was validated with simulated signals with known swallowing locations and a subset of 295 real swallows manually segmented by an experienced speech language pathologist. In both cases, the algorithm extracted individual swallows with over 90% accuracy. The time duration analysis was carried out with respect to gender, body mass index (BMI), and age. Demographic and anthropometric variables influenced the duration of these segmented signals. Male participants exhibited longer swallows than female participants (p=0.05). Older participants and participants with higher BMIs exhibited swallows with significantly longer (p=0.05) duration than younger participants and those with lower BMIs, respectively.

  14. Significant relationship between local angle at fused segments and C2-7 angle: Average duration of longer than 20 years after anterior cervical discectomy and fusion

    PubMed Central

    Nagata, T.; Takami, T.; Yamagata, T.; Uda, T.; Naito, K.; Ohata, K.

    2011-01-01

    Background: The authors have focused their attention to the radiological durability of cervical sagittal alignment after anterior cervical discectomy and fusion (ACDF) using autologous bone grafting. Materials and Methods: Among the patients who underwent ACDF with trans-unco-discal (TUD) approach between 1976 and 1997, 22 patients (16 males and 6 females) made return visits for a clinical evaluation. Patients with trauma or previously treated by anterior cervical fusion or by posterior decompression were excluded from the present study. Clinical evaluation included adjacent segment degeneration (ASD), osseous fusion, local angle at the fused segments and C2-7 angle of cervical spine. Results: The duration after ACDF ranged from 13 to 34 years with an average of 21.3 ± 7.0 years. A single level fusion was done on 8 patients, 2 levels on 11 patients, 3 levels on 2 patients, and 4 levels on 1 patient. Imaging studies indicated that 12 of the 22 patients (54.5%) were graded as having symptomatic ASD. Osseous bony fusion at ACDF was recognized in all cases. None of the patients demonstrated kyphotic malalignment of the cervical spine. Average degrees of local angle at the fused segments and the C2-7 angle were 7.06 and 17.6, respectively. Statistical analysis indicated a significant relationship between the local at the fused segments and C2-7 angles. Conclusions: Sagittal alignment of the cervical spine was durable long after ACDF when the local angle at the fused segments was well stabilized. PMID:23125490

  15. Interglacial Durations

    NASA Astrophysics Data System (ADS)

    Mangili, Clara; McManus, Jerry F.; Raynaud, Dominique

    2014-05-01

    In the context of future global warming induced by human activities, it is essential to assess the role of natural climatic variations. Precise knowledge of the duration of past interglacial periods is fundamental to the understanding of the potential future evolution of the Holocene. Past ice age cycles provide a natural laboratory for exploring the progression and duration of interglacial climate. Palaeorecords from ice, land and oceans extend over the last 800 ka, revealing eight glacial-interglacial cycles, with a range of insolation and greenhouse gas influences. The interglacials display a correspondingly large variety of intensity and duration, thus providing an opportunity for major insights into the mechanisms involved in the behaviour of interglacial climates. A comparison of the duration of these interglacials, however, is often difficult, as the definition of an interglacial depends on the archive that is considered. Therefore, to compare interglacial length and climate conditions from different archives, a consistent definition of interglacial conditions is required, ideally one that is not bound to the method nor to the archive under consideration. Here we present a method to identify interglacials and to calculate their length by mean of a simple statistical approach. We based our method on ~ 400 ka windows of time to determine mean climatic conditions while allowing for the possibility of long term evolution of the climatic baseline. For our study of interglacials of the past 800 ka, we used two windows that largely align with the pre- (800-430 ka ago) and post- (430-0 ka ago) mid-Brunhes event (MBE), although the resulting conclusions are not sensitive to this particular division. We applied this method to the last 800 ka of a few palaeoclimate records: the deuterium ice core (EDC) record as a climatic proxy, the benthic δ18O stack (LR04) as a proxy for sea level/ice volume, ice core (Vostok, EDC) atmospheric CO2 and additional records. Although

  16. Measurement of transit disorders in different gastrointestinal segments of patients with diabetes mellitus in relation to duration and severity of the disease by use of the metal-detector test.

    PubMed

    Folwaczny, C; Hundegger, K; Volger, C; Sorodoc, J; Kühn, M; Tatsch, K; Landgraf, R; Karbach, U

    1995-09-01

    The existence of gastrointestinal transit disorders in other intestinal segments beside the stomach in Type-1 diabetes mellitus (DM) and occurrence in Type-2 DM and in uremia has yet been confirmed only in few studies. Eleven healthy volunteers, 34 patients with Type-1, 32 patients with Type-2 DM in different stages of their disease and 34 non-diabetic patients with endstage-renal disease were investigated by use of the metal detector test. Patients were divided in three subgroups, depending on the duration of their disease: < 1 year: "Short", 1 - 10 years: "Middle", > 10 years: "Long". For comparison with the metal detector test scintigraphic studies of esophageal and gastric transit were performed in 17 patients and small intestinal transit was studied by use of the H2-lactulose breath test in 20 patients with long-standing DM Type-1. In Type-1 DM there is an increase of gastric (135 +/- 18, p < 0.01; 218 +/- 26, p < 0.0001 vs. 73 +/- 7 min.) and large intestinal transit times (79 +/- 18, P < 0.02; 76 +/- 11, p < 0.04 vs. 40 +/- 5 h) in patients with middle or long standing DM. In Type-2 DM similar transit disturbances occur (gastric emptying, long group: 120 +/- 15 min., p < 0.02; colonic transit, long group: 80 +/- 13 h, p < 0.01). In uremia transit disturbances were only found in patients with chronic ambulatory peritoneal dialysis (colonic transit: 71 +/- 9 h, p < 0.05). In 65% gastric scintigraphy and in 55% of cases the H2-lactulose breath test showed a prolongation of gastric emptying or a prolonged mouth-to-cecum transit. Transit disorders can occur in every stage of DM with preferential involvement of the stomach and the colon. These findings are of clinical relevance, since transit disturbances can result in instable metabolic condition.

  17. Active Segmentation

    PubMed Central

    Mishra, Ajay; Aloimonos, Yiannis

    2009-01-01

    The human visual system observes and understands a scene/image by making a series of fixations. Every fixation point lies inside a particular region of arbitrary shape and size in the scene which can either be an object or just a part of it. We define as a basic segmentation problem the task of segmenting that region containing the fixation point. Segmenting the region containing the fixation is equivalent to finding the enclosing contour- a connected set of boundary edge fragments in the edge map of the scene - around the fixation. This enclosing contour should be a depth boundary. We present here a novel algorithm that finds this bounding contour and achieves the segmentation of one object, given the fixation. The proposed segmentation framework combines monocular cues (color/intensity/texture) with stereo and/or motion, in a cue independent manner. The semantic robots of the immediate future will be able to use this algorithm to automatically find objects in any environment. The capability of automatically segmenting objects in their visual field can bring the visual processing to the next level. Our approach is different from current approaches. While existing work attempts to segment the whole scene at once into many areas, we segment only one image region, specifically the one containing the fixation point. Experiments with real imagery collected by our active robot and from the known databases 1 demonstrate the promise of the approach. PMID:20686671

  18. EVENT SEGMENTATION

    PubMed Central

    Zacks, Jeffrey M.; Swallow, Khena M.

    2012-01-01

    One way to understand something is to break it up into parts. New research indicates that segmenting ongoing activity into meaningful events is a core component of ongoing perception, with consequences for memory and learning. Behavioral and neuroimaging data suggest that event segmentation is automatic and that people spontaneously segment activity into hierarchically organized parts and sub-parts. This segmentation depends on the bottom-up processing of sensory features such as movement, and on the top-down processing of conceptual features such as actors’ goals. How people segment activity affects what they remember later; as a result, those who identify appropriate event boundaries during perception tend to remember more and learn more proficiently. PMID:22468032

  19. Segmentation precedes face categorization under suboptimal conditions

    PubMed Central

    Van Den Boomen, Carlijn; Fahrenfort, Johannes J.; Snijders, Tineke M.; Kemner, Chantal

    2015-01-01

    Both categorization and segmentation processes play a crucial role in face perception. However, the functional relation between these subprocesses is currently unclear. The present study investigates the temporal relation between segmentation-related and category-selective responses in the brain, using electroencephalography (EEG). Surface segmentation and category content were both manipulated using texture-defined objects, including faces. This allowed us to study brain activity related to segmentation and to categorization. In the main experiment, participants viewed texture-defined objects for a duration of 800 ms. EEG results revealed that segmentation-related responses precede category-selective responses. Three additional experiments revealed that the presence and timing of categorization depends on stimulus properties and presentation duration. Photographic objects were presented for a long and short (92 ms) duration and evoked fast category-selective responses in both cases. On the other hand, presentation of texture-defined objects for a short duration only evoked segmentation-related but no category-selective responses. Category-selective responses were much slower when evoked by texture-defined than by photographic objects. We suggest that in case of categorization of objects under suboptimal conditions, such as when low-level stimulus properties are not sufficient for fast object categorization, segmentation facilitates the slower categorization process. PMID:26074838

  20. Path planning by querying persistent stores of trajectory segments

    NASA Technical Reports Server (NTRS)

    Grossman, Robert L.; Mehta, S.; Qin, Xiao

    1993-01-01

    We introduce an algorithm for path planning (long duration) paths of dynamical systems, given a persistent object store containing suitable collections of short duration trajectory segments. We also describe experimental results from a proof-of-concept implementation of the algorithm. The basic idea is to interpret a path planning algorithm as a suitable query on a persistent object store consisting of short duration trajectory segments. The query returns a concatenation of short duration trajectory segments which is close to the desired path. The needed short duration segments are computed by using a divide and conquer algorithm to break up the original path into shorter paths; each shorter path is then matched to a nearby trajectory segment which is part of the persistent object store by using a suitable index function.

  1. Just Noticeable Differences for Segment Duration in Natural Speech

    ERIC Educational Resources Information Center

    Huggins, A. W. F.

    1972-01-01

    Revised version of a paper presented at the 77th Meeting of the Acoustical Society of America, Philadelphia, Pennsylvania, April 8-11, 1969; research supported in part by the Science Research Council (U.K.) and by the National Institutes of Health. (RS)

  2. Icon Duration and Development.

    ERIC Educational Resources Information Center

    Gummerman, Kent; And Others

    In this study, developmental changes in duration of the icon (visual sensory store) were investigated with three converging tachistoscopic tasks. (1) Stimulus interuption detection (SID), a variation of the two-flash threshold method, was performed by 29 first- and 32 fifth-graders, and 32 undergraduates. Icon duration was estimated by stimulus…

  3. [Sleep duration and metabolism].

    PubMed

    Viot-Blanc, V

    2015-12-01

    Sleep duration has gradually diminished during the last decade while obesity and type 2 diabetes have become epidemics. Experimental sleep curtailment leads to increased appetite, hormonal disturbances and, especially, insulin resistance. Numerous epidemiological studies have therefore examined whether habitual short sleep is associated with obesity and type 2 diabetes. A large majority of cross-sectional studies have confirmed an association between short, and also long sleep duration and obesity in adults more than in the elderly. Short sleep is strongly associated to obesity in children and adolescents. Prospective studies, including studies in children, are not conclusive with regard to the effect of short sleep on the incidence of obesity. Both short and long sleep durations are associated with diabetes, but only short sleep duration seems predictive of future diabetes. Insomnia seems to be a strong contributor to short sleep duration but the association of insomnia with obesity is not clear. Insomnia is associated with type 2 diabetes and also predictive of a higher incidence. Other studies have shown that short sleep duration and insomnia are associated with, and sometime predictive of, other components of the metabolic syndrome, especially hypertension and the risk of coronary disease. The treatment of short sleep duration and insomnia with regard to their effects on the metabolic syndrome merits further study.

  4. Background music as a quasi clock in retrospective duration judgments.

    PubMed

    Bailey, Nicole; Areni, Charles S

    2006-04-01

    The segmentation-change model of time perception proposes that individuals engaged in cognitive tasks during a given interval of time retrospectively estimate duration by recalling events that occurred during the interval and inferring each event's duration. Previous research suggests that individuals can recall the number of songs heard during an interval and infer the length of each song, exactly the conditions that foster estimates of duration based on the segmentation-change model. The results of a laboratory experiment indicated that subjects who solved word-search puzzles for 20 min. estimated the duration of the interval to be longer when 8 short songs (<3 min.) as opposed to 4 long songs (6+ min.) were played in the background, regardless of whether the musical format was Contemporary Dance or New Age. Assuming each song represented a distinct segment in memory, these results are consistent with the segmentation-change model. These results suggest that background music may not always reduce estimates of duration by drawing attention away from the passage of time. Instead, background music may actually expand the subjective length of an interval by creating accessible traces in memory, which are retrospectively used to infer duration.

  5. Flow-duration curves

    USGS Publications Warehouse

    Searcy, James Kincheon

    1959-01-01

    The flow-duration curve is a cumulative frequency curve that shows the percent of time specified discharges were equaled or exceeded during a given period. It combines in one curve the flow characteristics of a stream throughout the range of discharge, without regard to the sequence of occurrence. If the period upon which the curve is based represents the long-term flow of a stream, the curve may be used to predict the distribution of future flows for water- power, water-supply, and pollution studies. This report shows that differences in geology affect the low-flow ends of flow-duration curves of streams in adjacent basins. Thus, duration curves are useful in appraising the geologic characteristics of drainage basins. A method for adjusting flow-duration curves of short periods to represent long-term conditions is presented. The adjustment is made by correlating the records of a short-term station with those of a long-term station.

  6. Inductively stabilized, long pulse duration transverse discharge apparatus

    DOEpatents

    Sze, Robert C.

    1986-01-01

    An inductively stabilized, long pulse duration transverse discharge apparatus. The use of a segmented electrode where each segment is attached to an inductive element permits high energy, high efficiency, long-pulsed laser outputs to be obtained. The present apparatus has been demonstrated with rare-gas halide lasing media. Orders of magnitude increase in pulse repetition frequency are obtained in lasing devices that do not utilize gas flow.

  7. Durational Patterning at Syntactic and Discourse Boundaries in Mandarin Spontaneous Speech

    ERIC Educational Resources Information Center

    Fon, Janice; Johnson, Keith; Chen, Sally

    2011-01-01

    This study focused on durational cues (i.e., syllable duration, pause duration, and syllable onset intervals (SOIs)) at discourse boundaries in two dialects of Mandarin, Taiwan and Mainland varieties. Speech was elicited by having 18 participants describe events in "The Pear Story" film. Recorded data were transcribed, labeled, and segmented into…

  8. Durational Patterning at Syntactic and Discourse Boundaries in Mandarin Spontaneous Speech

    ERIC Educational Resources Information Center

    Fon, Janice; Johnson, Keith; Chen, Sally

    2011-01-01

    This study focused on durational cues (i.e., syllable duration, pause duration, and syllable onset intervals (SOIs)) at discourse boundaries in two dialects of Mandarin, Taiwan and Mainland varieties. Speech was elicited by having 18 participants describe events in "The Pear Story" film. Recorded data were transcribed, labeled, and segmented into…

  9. Segmentation and segment connection of obstructed colon

    NASA Astrophysics Data System (ADS)

    Medved, Mario; Truyen, Roel; Likar, Bostjan; Pernus, Franjo

    2004-05-01

    Segmentation of colon CT images is the main factor that inhibits automation of virtual colonoscopy. There are two main reasons that make efficient colon segmentation difficult. First, besides the colon, the small bowel, lungs, and stomach are also gas-filled organs in the abdomen. Second, peristalsis or residual feces often obstruct the colon, so that it consists of multiple gas-filled segments. In virtual colonoscopy, it is very useful to automatically connect the centerlines of these segments into a single colon centerline. Unfortunately, in some cases this is a difficult task. In this study a novel method for automated colon segmentation and connection of colon segments' centerlines is proposed. The method successfully combines features of segments, such as centerline and thickness, with information on main colon segments. The results on twenty colon cases show that the method performs well in cases of small obstructions of the colon. Larger obstructions are mostly also resolved properly, especially if they do not appear in the sigmoid part of the colon. Obstructions in the sigmoid part of the colon sometimes cause improper classification of the small bowel segments. If a segment is too small, it is classified as the small bowel segment. However, such misclassifications have little impact on colon analysis.

  10. Speed tuning of motion segmentation and discrimination

    NASA Technical Reports Server (NTRS)

    Masson, G. S.; Mestre, D. R.; Stone, L. S.

    1999-01-01

    Motion transparency requires that the visual system distinguish different motion vectors and selectively integrate similar motion vectors over space into the perception of multiple surfaces moving through or over each other. Using large-field (7 degrees x 7 degrees) displays containing two populations of random-dots moving in the same (horizontal) direction but at different speeds, we examined speed-based segmentation by measuring the speed difference above which observers can perceive two moving surfaces. We systematically investigated this 'speed-segmentation' threshold as a function of speed and stimulus duration, and found that it increases sharply for speeds above approximately 8 degrees/s. In addition, speed-segmentation thresholds decrease with stimulus duration out to approximately 200 ms. In contrast, under matched conditions, speed-discrimination thresholds stay low at least out to 16 degrees/s and decrease with increasing stimulus duration at a faster rate than for speed segmentation. Thus, motion segmentation and motion discrimination exhibit different speed selectivity and different temporal integration characteristics. Results are discussed in terms of the speed preferences of different neuronal populations within the primate visual cortex.

  11. Speed tuning of motion segmentation and discrimination

    NASA Technical Reports Server (NTRS)

    Masson, G. S.; Mestre, D. R.; Stone, L. S.

    1999-01-01

    Motion transparency requires that the visual system distinguish different motion vectors and selectively integrate similar motion vectors over space into the perception of multiple surfaces moving through or over each other. Using large-field (7 degrees x 7 degrees) displays containing two populations of random-dots moving in the same (horizontal) direction but at different speeds, we examined speed-based segmentation by measuring the speed difference above which observers can perceive two moving surfaces. We systematically investigated this 'speed-segmentation' threshold as a function of speed and stimulus duration, and found that it increases sharply for speeds above approximately 8 degrees/s. In addition, speed-segmentation thresholds decrease with stimulus duration out to approximately 200 ms. In contrast, under matched conditions, speed-discrimination thresholds stay low at least out to 16 degrees/s and decrease with increasing stimulus duration at a faster rate than for speed segmentation. Thus, motion segmentation and motion discrimination exhibit different speed selectivity and different temporal integration characteristics. Results are discussed in terms of the speed preferences of different neuronal populations within the primate visual cortex.

  12. Segment interdependency and gaze anchoring during manual two-segment sequences.

    PubMed

    Rand, Miya K

    2014-09-01

    This study examined two-segment pointing movements with various accuracy constraints to test whether there is segment interdependency in saccadic eye movements that accompany manual actions. The other purpose was to examine how planning of movement accuracy and amplitude for the second pointing influences the timing of gaze shift to the second target at the transition between two segments. Participants performed a rapid two-segment pointing task, in which the first segment had two target sizes, and the second segment had two target sizes and two movement distances. The results showed that duration and peak velocity of the initial pointing were influenced by altered kinematic characteristics of the second pointing due to task manipulations of the second segment, revealing segment interdependency in hand movements. In contrast, saccade duration and velocity did not show such segment interdependency. Thus, unlike hand movements, saccades are planned and organized independently for each segment during sequential manual actions. In terms of the timing of gaze shift to the second target, this was delayed when the initial pointing was made to the smaller first target, indicating that gaze anchoring to the initial target is used to verify the pointing termination. Importantly, the gaze shift was delayed when the second pointing was made to the smaller or farther second target. This suggests that visual information of the hand position at the initial target is important for the planning of movement distance and accuracy of the next pointing. Furthermore, timings of gaze shift and pointing initiation to the second target were highly correlated. Thus, at the transition between two segments, gazes and hand movements are highly coupled in time, which allows the sensorimotor system to process visual and proprioceptive information for the verification of pointing termination and planning of the next pointing.

  13. Long duration flights management

    NASA Astrophysics Data System (ADS)

    Sosa-Sesma, Sergio; Letrenne, Gérard; Spel, Martin; Charbonnier, Jean-Marc

    Long duration flights (LDF) require a special management to take the best decisions in terms of ballast consumption and instant of separation. As a contrast to short duration flights, where meteorological conditions are relatively well known, for LDF we need to include the meteorological model accuracy in trajectory simulations. Dispersions on the fields of model (wind, temperature and IR fluxes) could make the mission incompatible with safety rules, authorized zones and others flight requirements. Last CNES developments for LDF act on three main axes: 1. Although ECMWF-NCEP forecast allows generating simulations from a 4D point (altitude, latitude, longitude and UT time), result is not statistical, it is determinist. To take into account model dispersion a meteorological NCEP data base was analyzed. A comparison between Analysis (AN) and Forecast (FC) for the same time frame had been done. Result obtained from this work allows implementing wind and temperature dispersions on balloon flight simulator. 2. For IR fluxes, NCEP does not provide ascending IR fluxes in AN mode but only in FC mode. To obtain the IR fluxes for each time frame, satellite images are used. A comparison between FC and satellites measurements had been done. Results obtained from this work allow implementing flux dispersions on balloon flight simulator. 3. An improved cartography containing a vast data base had been included in balloon flight simulator. Mixing these three points with balloon flight dynamics we have obtained two new tools for observing balloon evolution and risk, one of them is called ASTERISK (Statistic Tool for Evaluation of Risk) for calculations and the other one is called OBERISK (Observing Balloon Evolution and Risk) for visualization. Depending on the balloon type (super pressure, zero pressure or MIR) relevant information for the flight manager is different. The goal is to take the best decision according to the global situation to obtain the largest flight duration with

  14. Long Duration Sorbent Testbed

    NASA Technical Reports Server (NTRS)

    Howard, David F.; Knox, James C.; Long, David A.; Miller, Lee; Cmaric, Gregory; Thomas, John

    2016-01-01

    The Long Duration Sorbent Testbed (LDST) is a flight experiment demonstration designed to expose current and future candidate carbon dioxide removal system sorbents to an actual crewed space cabin environment to assess and compare sorption working capacity degradation resulting from long term operation. An analysis of sorbent materials returned to Earth after approximately one year of operation in the International Space Station's (ISS) Carbon Dioxide Removal Assembly (CDRA) indicated as much as a 70% loss of working capacity of the silica gel desiccant material at the extreme system inlet location, with a gradient of capacity loss down the bed. The primary science objective is to assess the degradation of potential sorbents for exploration class missions and ISS upgrades when operated in a true crewed space cabin environment. A secondary objective is to compare degradation of flight test to a ground test unit with contaminant dosing to determine applicability of ground testing.

  15. Segmented trapped vortex cavity

    NASA Technical Reports Server (NTRS)

    Grammel, Jr., Leonard Paul (Inventor); Pennekamp, David Lance (Inventor); Winslow, Jr., Ralph Henry (Inventor)

    2010-01-01

    An annular trapped vortex cavity assembly segment comprising includes a cavity forward wall, a cavity aft wall, and a cavity radially outer wall there between defining a cavity segment therein. A cavity opening extends between the forward and aft walls at a radially inner end of the assembly segment. Radially spaced apart pluralities of air injection first and second holes extend through the forward and aft walls respectively. The segment may include first and second expansion joint features at distal first and second ends respectively of the segment. The segment may include a forward subcomponent including the cavity forward wall attached to an aft subcomponent including the cavity aft wall. The forward and aft subcomponents include forward and aft portions of the cavity radially outer wall respectively. A ring of the segments may be circumferentially disposed about an axis to form an annular segmented vortex cavity assembly.

  16. Station Tour: Russian Segment

    NASA Image and Video Library

    Expedition 33 Commander Suni Williams concludes her tour of the International Space Station with a visit to the Russian segment, which includes Zarya, the first segment of the station launched in 1...

  17. Production of anterior segment ischemia.

    PubMed Central

    Hiatt, R L

    1977-01-01

    Anterior segment ischemic changes can occur without detachment of any muscles. The most common cause of such ischemic changes of the anterior segment is the removal of too many rectus muscles in one operation. Twenty dog eyes and eight monkey eyes were subjected to the disinsertion and detachment of various combinations of extraocular muscles. The dogs were sacrificed at intervals from 30 to 90 days. During the observation period, they were observed for gross and slit-lamp changes. The enucleated eyes were studied microscopically for signs of ischemic and necrotic changes. Two patients who were studied, observed, and treated for anterior segment ischemia following muscle surgery are described. The changes which occur after extraocular muscle surgery are extensive and include corneal edema, cataract, chemosis, corneal changes, decreases in intraocular pressure, decreases in outflow or glaucoma, and frank necrosis. The variables which lead to this reaction are described in detail. Also, some unanswered queries, such as the duration of the reaction and the time interval of the reaction after multiple muscle operations are discussed. Images FIGURE 1 A FIGURE 1 B FIGURE 1 C FIGURE 2 A FIGURE 2 B FIGURE 2 C FIGURE 2 D FIGURE 3 FIGURE 4 PMID:418549

  18. Long duration ash probe

    DOEpatents

    Hurley, John P.; McCollor, Don P.; Selle, Stanley J.

    1994-01-01

    A long duration ash probe includes a pressure shell connected to a port in a combustor with a sample coupon mounted on a retractable carriage so as to retract the sample coupon within the pressure shell during sootblowing operation of the combustor. A valve mounted at the forward end of the pressure shell is selectively closeable to seal the sample coupon within the shell, and a heating element in the shell is operable to maintain the desired temperature of the sample coupon while retracted within the shell. The carriage is operably mounted on a pair of rails within the shell for longitudinal movement within the shell. A hollow carrier tube connects the hollow cylindrical sample coupon to the carriage, and extends through the carriage and out the rearward end thereof. Air lines are connected to the rearward end of the carrier tube and are operable to permit coolant to pass through the air lines and thence through the carrier tube to the sample coupon so as to cool the sample coupon.

  19. Long duration ash probe

    DOEpatents

    Hurley, J.P.; McCollor, D.P.; Selle, S.J.

    1994-07-26

    A long duration ash probe includes a pressure shell connected to a port in a combustor with a sample coupon mounted on a retractable carriage so as to retract the sample coupon within the pressure shell during soot blowing operation of the combustor. A valve mounted at the forward end of the pressure shell is selectively closeable to seal the sample coupon within the shell, and a heating element in the shell is operable to maintain the desired temperature of the sample coupon while retracted within the shell. The carriage is operably mounted on a pair of rails within the shell for longitudinal movement within the shell. A hollow carrier tube connects the hollow cylindrical sample coupon to the carriage, and extends through the carriage and out the rearward end thereof. Air lines are connected to the rearward end of the carrier tube and are operable to permit coolant to pass through the air lines and thence through the carrier tube to the sample coupon so as to cool the sample coupon. 8 figs.

  20. Color image segmentation

    NASA Astrophysics Data System (ADS)

    McCrae, Kimberley A.; Ruck, Dennis W.; Rogers, Steven K.; Oxley, Mark E.

    1994-03-01

    The most difficult stage of automated target recognition is segmentation. Current segmentation problems include faces and tactical targets; previous efforts to segment these objects have used intensity and motion cues. This paper develops a color preprocessing scheme to be used with the other segmentation techniques. A neural network is trained to identify the color of a desired object, eliminating all but that color from the scene. Gabor correlations and 2D wavelet transformations will be performed on stationary images; and 3D wavelet transforms on multispectral data will incorporate color and motion detection into the machine visual system. The paper will demonstrate that color and motion cues can enhance a computer segmentation system. Results from segmenting faces both from the AFIT data base and from video taped television are presented; results from tactical targets such as tanks and airplanes are also given. Color preprocessing is shown to greatly improve the segmentation in most cases.

  1. Extended duration lunar lander

    NASA Astrophysics Data System (ADS)

    Babic, Nikola; Carter, Matt; Cosper, Donna; Garza, David; Gonzalez, Eloy; Goodine, David; Hirst, Edward; Li, Ray; Lindsey, Martin; Ng, Tony

    1993-05-01

    Selenium Technologies has been conducting preliminary design work on a manned lunar lander for use in NASA's First Lunar Outpost (FLO) program. The resulting lander is designed to carry a crew of four astronauts to a prepositioned habitat on the lunar surface, remain on the lunar surface for up to 45 days while the crew is living in the habitat, then return the crew to earth via direct reentry and land recovery. Should the need arise, the crew can manually guide the lander to a safe lunar landing site, and live in the lander for up to ten days on the surface. Also, an abort to earth is available during any segment of the mission. The main propulsion system consists of a cluster of four modified Pratt and Whitney RL10 rocket engines that use liquid methane (LCH4) and liquid oxygen (LOX). Four engines are used to provide redundancy and a satisfactory engine out capability. Differences between the new propulsion system and the original system include slightly smaller engine size and lower thrust per engine, although specific impulse remains the same despite the smaller size. Concerns over nozzle ground clearance and engine reliability, as well as more information from Pratt and Whitney, brought about this change. The power system consists of a combination of regenerative fuel cells and solar arrays. While the lander is in flight to or from the moon, or during the lunar night, fuel cells provide all electrical power. During the lunar day, solar arrays are deployed to provide electrical power for the lander as well as electrolyzers, which separate some water back into hydrogen and oxygen for later use by the fuel cells. Total storage requirements for oxygen, hydrogen, and water are 61 kg, 551 kg, and 360 kg, respectively. The lander is a stage-and-a-half design with descent propellant, cargo, and landing gear contained in the descent stage, and the main propulsion system, ascent propellant, and crew module contained in the ascent stage. The primary structure for both

  2. Extended duration lunar lander

    NASA Technical Reports Server (NTRS)

    Babic, Nikola; Carter, Matt; Cosper, Donna; Garza, David; Gonzalez, Eloy; Goodine, David; Hirst, Edward; Li, Ray; Lindsey, Martin; Ng, Tony

    1993-01-01

    Selenium Technologies has been conducting preliminary design work on a manned lunar lander for use in NASA's First Lunar Outpost (FLO) program. The resulting lander is designed to carry a crew of four astronauts to a prepositioned habitat on the lunar surface, remain on the lunar surface for up to 45 days while the crew is living in the habitat, then return the crew to earth via direct reentry and land recovery. Should the need arise, the crew can manually guide the lander to a safe lunar landing site, and live in the lander for up to ten days on the surface. Also, an abort to earth is available during any segment of the mission. The main propulsion system consists of a cluster of four modified Pratt and Whitney RL10 rocket engines that use liquid methane (LCH4) and liquid oxygen (LOX). Four engines are used to provide redundancy and a satisfactory engine out capability. Differences between the new propulsion system and the original system include slightly smaller engine size and lower thrust per engine, although specific impulse remains the same despite the smaller size. Concerns over nozzle ground clearance and engine reliability, as well as more information from Pratt and Whitney, brought about this change. The power system consists of a combination of regenerative fuel cells and solar arrays. While the lander is in flight to or from the moon, or during the lunar night, fuel cells provide all electrical power. During the lunar day, solar arrays are deployed to provide electrical power for the lander as well as electrolyzers, which separate some water back into hydrogen and oxygen for later use by the fuel cells. Total storage requirements for oxygen, hydrogen, and water are 61 kg, 551 kg, and 360 kg, respectively. The lander is a stage-and-a-half design with descent propellant, cargo, and landing gear contained in the descent stage, and the main propulsion system, ascent propellant, and crew module contained in the ascent stage. The primary structure for both

  3. Impact assisted segmented cutterhead

    DOEpatents

    Morrell, Roger J.; Larson, David A.; Ruzzi, Peter L.

    1992-01-01

    An impact assisted segmented cutterhead device is provided for cutting various surfaces from coal to granite. The device comprises a plurality of cutting bit segments deployed in side by side relationship to form a continuous cutting face and a plurality of impactors individually associated with respective cutting bit segments. An impactor rod of each impactor connects that impactor to the corresponding cutting bit segment. A plurality of shock mounts dampening the vibration from the associated impactor. Mounting brackets are used in mounting the cutterhead to a base machine.

  4. Variation in vowel duration among southern African American English speakers

    PubMed Central

    Holt, Yolanda Feimster; Jacewicz, Ewa; Fox, Robert Allen

    2015-01-01

    Purpose Atypical duration of speech segments can signal a speech disorder. This study examined variation in vowel duration in African American English (AAE) relative to White American English (WAE) speakers living in the same dialect region in the South in order to characterize the nature of systematic variation between the two groups. The goal was to establish whether segmental durations in minority populations differ from the well-established patterns in mainstream populations. Method Participants were 32 AAE and 32 WAE speakers differing in age who, in their childhood, attended either segregated (older speakers) or integrated (younger speakers) public schools. Speech materials consisted of 14 vowels produced in hVd-frame. Results AAE vowels were significantly longer than WAE vowels. Vowel duration did not differ as a function of age. The temporal tense-lax contrast was minimized for AAE relative to WAE. Female vowels were significantly longer than male vowels for both AAE and WAE. Conclusions African Americans should be expected to produce longer vowels relative to White speakers in a common geographic area. These longer durations are not deviant but represent a typical feature of AAE. This finding has clinical importance in guiding assessments of speech disorders in AAE speakers. PMID:25951511

  5. Variation in Vowel Duration Among Southern African American English Speakers.

    PubMed

    Holt, Yolanda Feimster; Jacewicz, Ewa; Fox, Robert Allen

    2015-08-01

    Atypical duration of speech segments can signal a speech disorder. In this study, we examined variation in vowel duration in African American English (AAE) relative to White American English (WAE) speakers living in the same dialect region in the South to characterize the nature of systematic variation between the 2 groups. The goal was to establish whether segmental durations in minority populations differ from the well-established patterns in mainstream populations. Participants were 32 AAE and 32 WAE speakers differing in age who, in their childhood, attended either segregated (older speakers) or integrated (younger speakers) public schools. Speech materials consisted of 14 vowels produced in hVd-frame. AAE vowels were significantly longer than WAE vowels. Vowel duration did not differ as a function of age. The temporal tense-lax contrast was minimized for AAE relative to WAE. Vowels produced by females were significantly longer than vowels produced by males for both AAE and WAE. African American speakers should be expected to produce longer vowels relative to White speakers in a common geographic area. These longer durations are not deviant but represent a typical feature of AAE. This finding has clinical importance in guiding assessments of speech disorders in AAE speakers.

  6. An Approach with Hybrid Segmental Mechanics.

    PubMed

    Mishra, Harsh Ashok; Maurya, Raj Kumar

    2016-06-01

    Present case report provides an insight into the hybrid segmental mechanics with treatment of 13-year-old male, considering the side effects of sole continuous arch wire sliding mechanics. Patient was diagnosed as a case of skeletal class I jaw relationship, low mandibular plane angle, class II molar relation on right and class I molar relation on left side, anterior cross bite, crowding of 12mm in upper, 5mm in lower arch. He also had proclined upper and lower anteriors by 2mm, convex profile and incompetent lips. Total treatment duration was 20 months, during which segmental canine retraction was performed with TMA (Titanium, Molybdenum, Aluminum) 'T' loop retraction spring followed by consolidation of spaces with continuous arch mechanics. Most of the treatment objectives were met with good intraoral and facial results within reasonable framework of time. This approach used traditional twin brackets, which offered the versatility to use continuous arch-wire mechanics, segmental mechanics and hybrid sectional mechanics.

  7. Phonological Encoding and Phonetic Duration

    ERIC Educational Resources Information Center

    Fricke, Melinda Denise

    2013-01-01

    Studies of connected speech have repeatedly shown that the contextual predictability of a word is related to its phonetic duration; more predictable words tend to be produced with shorter duration, when other factors are controlled for (Aylett & Turk, 2004, 2006; Bell et al., 2003; Bell, Brenier, Gregory, Girand, & Jurafsky, 2009; Gahl,…

  8. Phonological Encoding and Phonetic Duration

    ERIC Educational Resources Information Center

    Fricke, Melinda Denise

    2013-01-01

    Studies of connected speech have repeatedly shown that the contextual predictability of a word is related to its phonetic duration; more predictable words tend to be produced with shorter duration, when other factors are controlled for (Aylett & Turk, 2004, 2006; Bell et al., 2003; Bell, Brenier, Gregory, Girand, & Jurafsky, 2009; Gahl,…

  9. Hospital benefit segmentation.

    PubMed

    Finn, D W; Lamb, C W

    1986-12-01

    Market segmentation is an important topic to both health care practitioners and researchers. The authors explore the relative importance that health care consumers attach to various benefits available in a major metropolitan area hospital. The purposes of the study are to test, and provide data to illustrate, the efficacy of one approach to hospital benefit segmentation analysis.

  10. Pancreas and cyst segmentation

    NASA Astrophysics Data System (ADS)

    Dmitriev, Konstantin; Gutenko, Ievgeniia; Nadeem, Saad; Kaufman, Arie

    2016-03-01

    Accurate segmentation of abdominal organs from medical images is an essential part of surgical planning and computer-aided disease diagnosis. Many existing algorithms are specialized for the segmentation of healthy organs. Cystic pancreas segmentation is especially challenging due to its low contrast boundaries, variability in shape, location and the stage of the pancreatic cancer. We present a semi-automatic segmentation algorithm for pancreata with cysts. In contrast to existing automatic segmentation approaches for healthy pancreas segmentation which are amenable to atlas/statistical shape approaches, a pancreas with cysts can have even higher variability with respect to the shape of the pancreas due to the size and shape of the cyst(s). Hence, fine results are better attained with semi-automatic steerable approaches. We use a novel combination of random walker and region growing approaches to delineate the boundaries of the pancreas and cysts with respective best Dice coefficients of 85.1% and 86.7%, and respective best volumetric overlap errors of 26.0% and 23.5%. Results show that the proposed algorithm for pancreas and pancreatic cyst segmentation is accurate and stable.

  11. Keypoint Transfer Segmentation

    PubMed Central

    Toews, M.; Langs, G.; Wells, W.; Golland, P.

    2015-01-01

    We present an image segmentation method that transfers label maps of entire organs from the training images to the novel image to be segmented. The transfer is based on sparse correspondences between keypoints that represent automatically identified distinctive image locations. Our segmentation algorithm consists of three steps: (i) keypoint matching, (ii) voting-based keypoint labeling, and (iii) keypoint-based probabilistic transfer of organ label maps. We introduce generative models for the inference of keypoint labels and for image segmentation, where keypoint matches are treated as a latent random variable and are marginalized out as part of the algorithm. We report segmentation results for abdominal organs in whole-body CT and in contrast-enhanced CT images. The accuracy of our method compares favorably to common multi-atlas segmentation while offering a speed-up of about three orders of magnitude. Furthermore, keypoint transfer requires no training phase or registration to an atlas. The algorithm’s robustness enables the segmentation of scans with highly variable field-of-view. PMID:26221677

  12. Keypoint Transfer Segmentation.

    PubMed

    Wachinger, C; Toews, M; Langs, G; Wells, W; Golland, P

    2015-01-01

    We present an image segmentation method that transfers label maps of entire organs from the training images to the novel image to be segmented. The transfer is based on sparse correspondences between keypoints that represent automatically identified distinctive image locations. Our segmentation algorithm consists of three steps: (i) keypoint matching, (ii) voting-based keypoint labeling, and (iii) keypoint-based probabilistic transfer of organ label maps. We introduce generative models for the inference of keypoint labels and for image segmentation, where keypoint matches are treated as a latent random variable and are marginalized out as part of the algorithm. We report segmentation results for abdominal organs in whole-body CT and in contrast-enhanced CT images. The accuracy of our method compares favorably to common multi-atlas segmentation while offering a speed-up of about three orders of magnitude. Furthermore, keypoint transfer requires no training phase or registration to an atlas. The algorithm's robustness enables the segmentation of scans with highly variable field-of-view.

  13. Segmented ion thruster

    NASA Technical Reports Server (NTRS)

    Brophy, John R. (Inventor)

    1993-01-01

    Apparatus and methods for large-area, high-power ion engines comprise dividing a single engine into a combination of smaller discharge chambers (or segments) configured to operate as a single large-area engine. This segmented ion thruster (SIT) approach enables the development of 100-kW class argon ion engines for operation at a specific impulse of 10,000 s. A combination of six 30-cm diameter ion chambers operating as a single engine can process over 100 kW. Such a segmented ion engine can be operated from a single power processor unit.

  14. Image segmentation survey

    NASA Technical Reports Server (NTRS)

    Haralick, R. M.

    1982-01-01

    The methodologies and capabilities of image segmentation techniques are reviewed. Single linkage schemes, hybrid linkage schemes, centroid linkage schemes, histogram mode seeking, spatial clustering, and split and merge schemes are addressed.

  15. CPCs with segmented absorbers

    SciTech Connect

    Keita, M.; Robertson, H.S. )

    1991-01-01

    One of the most promising means of improving the performance of solar thermal collectors is to reduce the energy lost by the hot absorber. One way to do this, not currently part of the technology, is to recognize that since the absorber is usually not irradiated uniformly, it is therefore possible to construct an absorber of thermally isolated segments, circulate the fluid in sequence from low to high irradiance segments, and reduce loss by improving effective concentration. This procedure works even for ideal concentrators, without violating Winston's theorem. Two equivalent CPC collectors with single and segmented absorber were constructed and compared under actual operating conditions. The results showed that the daily thermal efficiency of the collector with segmented absorber is higher (about 13%) than that of the collector with nonsegmented absorber.

  16. GPS Control Segment Improvements

    DTIC Science & Technology

    2015-04-29

    Systems Center GPS Control Segment Improvements Mr. Tim McIntyre GPS Product Support Manager GPS Ops Support and Sustainment Division Peterson...hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and...DATE 29 APR 2015 2. REPORT TYPE 3. DATES COVERED 00-00-2015 to 00-00-2015 4. TITLE AND SUBTITLE GPS Control Segment Improvements 5a. CONTRACT

  17. Squaring a Circular Segment

    ERIC Educational Resources Information Center

    Gordon, Russell

    2008-01-01

    Consider a circular segment (the smaller portion of a circle cut off by one of its chords) with chord length c and height h (the greatest distance from a point on the arc of the circle to the chord). Is there a simple formula involving c and h that can be used to closely approximate the area of this circular segment? Ancient Chinese and Egyptian…

  18. Squaring a Circular Segment

    ERIC Educational Resources Information Center

    Gordon, Russell

    2008-01-01

    Consider a circular segment (the smaller portion of a circle cut off by one of its chords) with chord length c and height h (the greatest distance from a point on the arc of the circle to the chord). Is there a simple formula involving c and h that can be used to closely approximate the area of this circular segment? Ancient Chinese and Egyptian…

  19. Segmented pyroelector detector

    DOEpatents

    Stotlar, S.C.; McLellan, E.J.

    1981-01-21

    A pyroelectric detector is described which has increased voltage output and improved responsivity over equivalent size detectors. The device comprises a plurality of edge-type pyroelectric detectors which have a length which is much greater than the width of the segments between the edge-type electrodes. External circuitry connects the pyroelectric detector segments in parallel to provide a single output which maintains 50 ohm impedance characteristics.

  20. Geometry Guided Segmentation

    NASA Astrophysics Data System (ADS)

    Dunn, Stanley M.; Liang, Tajen

    1989-03-01

    Our overall goal is to develop an image understanding system for automatically interpreting dental radiographs. This paper describes the module that integrates the intrinsic image data to form the region adjacency graph that represents the image. The specific problem is to develop a robust method for segmenting the image into small regions that do not overlap anatomical boundaries. Classical algorithms for finding homogeneous regions (i.e., 2 class segmentation or connected components) will not always yield correct results since blurred edges can cause adjacent anatomical regions to be labeled as one region. This defect is a problem in this and other applications where an object count is necessary. Our solution to the problem is to guide the segmentation by intrinsic properties of the constituent objects. The module takes a set of intrinsic images as arguments. A connected components-like algorithm is performed, but the connectivity relation is not 4- or 8-neighbor connectivity in binary images; the connectivity is defined in terms of the intrinsic image data. We shall describe both the classical method and the modified segmentation procedures, and present experiments using both algorithms. Our experiments show that for the dental radiographs a segmentation using gray level data in conjunction with edges of the surfaces of teeth give a robust and reliable segmentation.

  1. Comprehensive Gravity and Dynamics Model Determination of Binary Asteroid Systems

    NASA Astrophysics Data System (ADS)

    Fahnestock, Eugene G.

    2009-09-01

    I present the development of additional tools within the framework of JPL's in-house Mirage / Orbit Determination Program (ODP) software to allow the determination of a comprehensive gravity and dynamics model for any binary asteroid system potentially visited by a spacecraft rendezvous mission. This involves a concurrent global solution for the gravity fields of both components, sufficient parametric description of their fully-coupled translational and rotational dynamics, the spacecraft state, and all other relevant force model parameters. This estimation process primarily uses spacecraft radio tracking data (range and Doppler measurements), supplemented by in-situ imaging observations data types. A solution for the gravity field (gravity analysis) and a simultaneous solution for the spacecraft motion and other system properties has been performed before using the ODP for solitary irregular small solar system bodies (e.g. Eros, visited by the NEAR mission), but never for any closely gravitationally bound pair of irregular small solar system bodies. I am expanding NASA's tool set to allow the latter, in preparation for potential future spacecraft rendezvous missions. This is nontrivial, because of the need to incorporate propagation of the binary system's fully-coupled rigid-body dynamical model either along with the spacecraft state within Mirage/ODP or "offline", followed by interpolating an appropriate "binary dynamics ephemeris” representation. Further, this model optionally incorporates formulations for body gravity fields not previously used in this context, and it can be computationally very expensive. However, successfully performing this model determination at a binary asteroid yields valuable science results concerning internal mass distributions and structures of the components and insight into the system's formation and evolution. In this poster I present my current progress in the development of this capability and results for the quality of science

  2. Duration of general practitioner contracts.

    PubMed

    Abelsen, Birgit; Gaski, Margrete; Brandstorp, Helen

    2015-12-01

    The regular GP scheme is intended to promote continuity in the relationship between doctor and patient. The duration of GP contracts is therefore a key factor in the success of the scheme. This study examines how long the GP contracts last and whether their duration varies according to doctors' gender and age, municipality size and list size. The study encompasses 7,359 GP contracts throughout Norway, entered into between municipalities and doctors in the period 1 May 2001 - 1 May 2014. Duration is measured as the time from which the contract was signed until its expiry or the end of the study period. The material was analysed with measures of central tendencies and dispersion, Kaplan-Meier survival curve analysis and Cox proportional hazards regression. Median duration of a GP contract at the time of the study was 5.91 years. It varied between 2.75 years in the smallest municipalities and 8.37 years in the largest ones. The duration of a GP contract increased significantly if the doctor was a woman, or with the doctor's age at the start of the contract, increased municipality size and increased list size. If it is assumed that continuity in the doctor-patient relationship provides a qualitatively better GP service, the results indicate that patients in small municipalities are generally offered a lower-quality service than patients in large municipalities.

  3. Rediscovering market segmentation.

    PubMed

    Yankelovich, Daniel; Meer, David

    2006-02-01

    In 1964, Daniel Yankelovich introduced in the pages of HBR the concept of nondemographic segmentation, by which he meant the classification of consumers according to criteria other than age, residence, income, and such. The predictive power of marketing studies based on demographics was no longer strong enough to serve as a basis for marketing strategy, he argued. Buying patterns had become far better guides to consumers' future purchases. In addition, properly constructed nondemographic segmentations could help companies determine which products to develop, which distribution channels to sell them in, how much to charge for them, and how to advertise them. But more than 40 years later, nondemographic segmentation has become just as unenlightening as demographic segmentation had been. Today, the technique is used almost exclusively to fulfill the needs of advertising, which it serves mainly by populating commercials with characters that viewers can identify with. It is true that psychographic types like "High-Tech Harry" and "Joe Six-Pack" may capture some truth about real people's lifestyles, attitudes, self-image, and aspirations. But they are no better than demographics at predicting purchase behavior. Thus they give corporate decision makers very little idea of how to keep customers or capture new ones. Now, Daniel Yankelovich returns to these pages, with consultant David Meer, to argue the case for a broad view of nondemographic segmentation. They describe the elements of a smart segmentation strategy, explaining how segmentations meant to strengthen brand identity differ from those capable of telling a company which markets it should enter and what goods to make. And they introduce their "gravity of decision spectrum", a tool that focuses on the form of consumer behavior that should be of the greatest interest to marketers--the importance that consumers place on a product or product category.

  4. Fast tip-tilt segment alignment for segmented mirrors

    NASA Astrophysics Data System (ADS)

    Skvarč, Jure

    2016-07-01

    A method for fast identification of segments and alignment of the segmented mirrors has been developed and applied for the deformable mirror of the WHT AO system (NAOMI) and for the GTC 36-segment primary mirror. By moving each segment by a known but different amount and in a different direction it is possible to identify many segments simultaneously using a pattern-matching algorithm which finds spots that have moved by a segment-specific vector from one image to another. The method does not need any special optical setup. The applicability of the method for the segmented primary mirrors of future telescopes is discussed.

  5. Scorpion image segmentation system

    NASA Astrophysics Data System (ADS)

    Joseph, E.; Aibinu, A. M.; Sadiq, B. A.; Bello Salau, H.; Salami, M. J. E.

    2013-12-01

    Death as a result of scorpion sting has been a major public health problem in developing countries. Despite the high rate of death as a result of scorpion sting, little report exists in literature of intelligent device and system for automatic detection of scorpion. This paper proposed a digital image processing approach based on the floresencing characteristics of Scorpion under Ultra-violet (UV) light for automatic detection and identification of scorpion. The acquired UV-based images undergo pre-processing to equalize uneven illumination and colour space channel separation. The extracted channels are then segmented into two non-overlapping classes. It has been observed that simple thresholding of the green channel of the acquired RGB UV-based image is sufficient for segmenting Scorpion from other background components in the acquired image. Two approaches to image segmentation have also been proposed in this work, namely, the simple average segmentation technique and K-means image segmentation. The proposed algorithm has been tested on over 40 UV scorpion images obtained from different part of the world and results obtained show an average accuracy of 97.7% in correctly classifying the pixel into two non-overlapping clusters. The proposed 1system will eliminate the problem associated with some of the existing manual approaches presently in use for scorpion detection.

  6. Robust vessel segmentation

    NASA Astrophysics Data System (ADS)

    Bock, Susanne; Kühnel, Caroline; Boskamp, Tobias; Peitgen, Heinz-Otto

    2008-03-01

    In the context of cardiac applications, the primary goal of coronary vessel analysis often consists in supporting the diagnosis of vessel wall anomalies, such as coronary plaque and stenosis. Therefore, a fast and robust segmentation of the coronary tree is a very important but challenging task. We propose a new approach for coronary artery segmentation. Our method is based on an earlier proposed progressive region growing. A new growth front monitoring technique controls the segmentation and corrects local leakage by retrospective detection and removal of leakage artifacts. While progressively reducing the region growing threshold for the whole image, the growing process is locally analyzed using criteria based on the assumption of tubular, gradually narrowing vessels. If a voxel volume limit or a certain shape constraint is exceeded, the growing process is interrupted. Voxels affected by a failed segmentation are detected and deleted from the result. To avoid further processing at these positions, a large neighborhood is blocked for growing. Compared to a global region growing without local correction, our new local growth control and the adapted correction can deal with contrast decrease even in very small coronary arteries. Furthermore, our algorithm can efficiently handle noise artifacts and partial volume effects near the myocardium. The enhanced segmentation of more distal vessel parts was tested on 150 CT datasets. Furthermore, a comparison between the pure progressive region growing and our new approach was conducted.

  7. Cooperative processes in image segmentation

    NASA Technical Reports Server (NTRS)

    Davis, L. S.

    1982-01-01

    Research into the role of cooperative, or relaxation, processes in image segmentation is surveyed. Cooperative processes can be employed at several levels of the segmentation process as a preprocessing enhancement step, during supervised or unsupervised pixel classification and, finally, for the interpretation of image segments based on segment properties and relations.

  8. Segmented heterochromia in scalp hair.

    PubMed

    Yoon, Kyeong Han; Kim, Daehwan; Sohn, Seonghyang; Lee, Won Soo

    2003-12-01

    Segmented heterochromia of scalp hair is characterized by the irregularly alternating segmentation of hair into dark and light bands and is known to be associated with iron deficiency anemia. The authors report the case of an 11-year-old boy with segmented heterochromia associated with iron deficiency anemia. After 11 months of iron replacement, the boy's segmented heterochromic hair recovered completely.

  9. Cooperative processes in image segmentation

    NASA Technical Reports Server (NTRS)

    Davis, L. S.

    1982-01-01

    Research into the role of cooperative, or relaxation, processes in image segmentation is surveyed. Cooperative processes can be employed at several levels of the segmentation process as a preprocessing enhancement step, during supervised or unsupervised pixel classification and, finally, for the interpretation of image segments based on segment properties and relations.

  10. Criteria for the Segmentation of Vowels on Duplex Oscillograms.

    ERIC Educational Resources Information Center

    Naeser, Margaret A.

    This paper develops criteria for the segmentation of vowels on duplex oscillograms. Previous vowel duration studies have primarily used sound spectrograms. The use of duplex oscillograms, rather than sound spectrograms, permits faster production (real time) at less expense (adding machine paper may be used). The speech signal can be more spread…

  11. Head segmentation in vertebrates

    PubMed Central

    Kuratani, Shigeru; Schilling, Thomas

    2008-01-01

    Classic theories of vertebrate head segmentation clearly exemplify the idealistic nature of comparative embryology prior to the 20th century. Comparative embryology aimed at recognizing the basic, primary structure that is shared by all vertebrates, either as an archetype or an ancestral developmental pattern. Modern evolutionary developmental (Evo-Devo) studies are also based on comparison, and therefore have a tendency to reduce complex embryonic anatomy into overly simplified patterns. Here again, a basic segmental plan for the head has been sought among chordates. We convened a symposium that brought together leading researchers dealing with this problem, in a number of different evolutionary and developmental contexts. Here we give an overview of the outcome and the status of the field in this modern era of Evo-Devo. We emphasize the fact that the head segmentation problem is not fully resolved, and we discuss new directions in the search for hints for a way out of this maze. PMID:20607135

  12. Segmented annular combustor

    DOEpatents

    Reider, Samuel B.

    1979-01-01

    An industrial gas turbine engine includes an inclined annular combustor made up of a plurality of support segments each including inner and outer walls of trapezoidally configured planar configuration extents and including side flanges thereon interconnected by means of air cooled connector bolt assemblies to form a continuous annular combustion chamber therebetween and wherein an air fuel mixing chamber is formed at one end of the support segments including means for directing and mixing fuel within a plenum and a perforated header plate for directing streams of air and fuel mixture into the combustion chamber; each of the outer and inner walls of each of the support segments having a ribbed lattice with tracks slidably supporting porous laminated replaceable panels and including pores therein for distributing combustion air into the combustion chamber while cooling the inner surface of each of the panels by transpiration cooling thereof.

  13. [Pulmonary segmental mediolytic arteriopathy].

    PubMed

    Müller, A M; Kullmann, H J

    2006-03-01

    Segmental mediolytic arteriopathy (SMA) is defined as non-inflammatory arteriopathy with mediolysis due to segmental loss of media and consecutive formation of vascular gaps. Up to now, less than 40 cases of visceral and cerebral SMA and, to our knowledge, only one case of pulmonary SMA have been reported. We present the history of a 21 year old female patient, admitted to hospital with hemoptysis, but without other symptoms. Apart from two lesions in the sixth and tenth pulmonary segment, documented by CT and interpreted as colliquations, there were no other clinical and laboratory findings. Repeated bronchoscopy supplied no further information. Histomorphology of the resected lesion revealed SMA without evidence of vasculitis. Wegener's disease could be excluded. The aetiology of the disease is still unknown. Acute vasospasm (due to inappropriate reactions to catecholamine or endothelial dysfunction), as well as SMA as a precursor or subtype of fibromuscular dysplasia, are two theories still under discussion.

  14. Segmental curvilinear distraction osteogenesis.

    PubMed

    Zhou, Libin; Shang, Hongtao; Feng, Zhihong; Liu, Chen; Ye, Wenmin; Ma, Qin; Wu, Wei; Liu, Yanpu

    2012-10-01

    Curvilinear distraction is currently under investigation to reconstruct curved maxillofacial bone defects. However, previous studies have revealed the discrepancy between the contour of the regenerated bone in the distraction gap and the curvilinear pathway of the transport disc. We hypothesize that the discrepancy is because of the conflict of the distraction vector and the strain vector during the consolidation. In curvilinear distraction osteogenesis, the distraction vector varies, while the strain vector during the consolidation phase is fixed-linear, from the beginning to the end of the distraction pathway. Here we bring forward a solution of segmental curvilinear distraction osteogenesis to divide the curvilinear distraction into several segments, with respective consolidation for each distraction gap. If this hypothesis is verified, the segmental distraction curvilinear distraction will benefit the reconstruction of complicated long-range maxillofacial bone defects. Copyright © 2012 Elsevier Ltd. All rights reserved.

  15. Duration of an Elastic Collision

    ERIC Educational Resources Information Center

    de Izarra, Charles

    2012-01-01

    With a pedagogical goal, this paper deals with a study of the duration of an elastic collision of an inflatable spherical ball on a planar surface suitable for undergraduate studies. First, the force generated by the deformed spherical ball is obtained under assumptions that are discussed. The study of the motion of the spherical ball colliding…

  16. Duration of an Elastic Collision

    ERIC Educational Resources Information Center

    de Izarra, Charles

    2012-01-01

    With a pedagogical goal, this paper deals with a study of the duration of an elastic collision of an inflatable spherical ball on a planar surface suitable for undergraduate studies. First, the force generated by the deformed spherical ball is obtained under assumptions that are discussed. The study of the motion of the spherical ball colliding…

  17. Automatic measurement of vowel duration via structured prediction.

    PubMed

    Adi, Yossi; Keshet, Joseph; Cibelli, Emily; Gustafson, Erin; Clopper, Cynthia; Goldrick, Matthew

    2016-12-01

    A key barrier to making phonetic studies scalable and replicable is the need to rely on subjective, manual annotation. To help meet this challenge, a machine learning algorithm was developed for automatic measurement of a widely used phonetic measure: vowel duration. Manually-annotated data were used to train a model that takes as input an arbitrary length segment of the acoustic signal containing a single vowel that is preceded and followed by consonants and outputs the duration of the vowel. The model is based on the structured prediction framework. The input signal and a hypothesized set of a vowel's onset and offset are mapped to an abstract vector space by a set of acoustic feature functions. The learning algorithm is trained in this space to minimize the difference in expectations between predicted and manually-measured vowel durations. The trained model can then automatically estimate vowel durations without phonetic or orthographic transcription. Results comparing the model to three sets of manually annotated data suggest it outperformed the current gold standard for duration measurement, an hidden Markov model-based forced aligner (which requires orthographic or phonetic transcription as an input).

  18. Automatic measurement of vowel duration via structured prediction

    NASA Astrophysics Data System (ADS)

    Adi, Yossi; Keshet, Joseph; Cibelli, Emily; Gustafson, Erin; Clopper, Cynthia; Goldrick, Matthew

    2016-12-01

    A key barrier to making phonetic studies scalable and replicable is the need to rely on subjective, manual annotation. To help meet this challenge, a machine learning algorithm was developed for automatic measurement of a widely used phonetic measure: vowel duration. Manually-annotated data were used to train a model that takes as input an arbitrary length segment of the acoustic signal containing a single vowel that is preceded and followed by consonants and outputs the duration of the vowel. The model is based on the structured prediction framework. The input signal and a hypothesized set of a vowel's onset and offset are mapped to an abstract vector space by a set of acoustic feature functions. The learning algorithm is trained in this space to minimize the difference in expectations between predicted and manually-measured vowel durations. The trained model can then automatically estimate vowel durations without phonetic or orthographic transcription. Results comparing the model to three sets of manually annotated data suggest it out-performed the current gold standard for duration measurement, an HMM-based forced aligner (which requires orthographic or phonetic transcription as an input).

  19. [Segmental testicular infarction].

    PubMed

    Ripa Saldías, L; Guarch Troyas, R; Hualde Alfaro, A; de Pablo Cárdenas, A; Ruiz Ramo, M; Pinós Paul, M

    2006-02-01

    We report the case of a 47 years old man previously diagnosed of left hidrocele. After having a recent mild left testicular pain, an ultrasonografic study revealed a solid hipoecoic testicular lesion rounded by a big hidrocele, suggesting a testicular neoplasm. Radical inguinal orchiectomy was made and pathologic study showed segmental testicular infarction. No malignancy was found. We review the literature of the topic.

  20. Segmentation and Impoverished Youth.

    ERIC Educational Resources Information Center

    Friedman, Judith J.; Friedman, Samuel R.

    1986-01-01

    The following characteristics of jobs held by impoverished youth who applied for a job training program were examined: (1) benefits; (2) skills; (3) career ladders; and (4) unionization. Results imply that segmentation models are not fruitful as guides to labor market experiences of youth at the bottom of wage scale. Other studies were also…

  1. Cast segment evaluation

    NASA Technical Reports Server (NTRS)

    Diem, H. G.; Studhalter, W. R.

    1971-01-01

    Evaluation program to determine feasibility of fabricating segmented rocket engine thrust chambers using low cost, lightweight castings extends state of the art in areas of casting size and complexity, and in ability to provide thin sections and narrow, deep, cooling channels. Related developments are discussed.

  2. Segmentation in Tardigrada and diversification of segmental patterns in Panarthropoda.

    PubMed

    Smith, Frank W; Goldstein, Bob

    2016-10-31

    The origin and diversification of segmented metazoan body plans has fascinated biologists for over a century. The superphylum Panarthropoda includes three phyla of segmented animals-Euarthropoda, Onychophora, and Tardigrada. This superphylum includes representatives with relatively simple and representatives with relatively complex segmented body plans. At one extreme of this continuum, euarthropods exhibit an incredible diversity of serially homologous segments. Furthermore, distinct tagmosis patterns are exhibited by different classes of euarthropods. At the other extreme, all tardigrades share a simple segmented body plan that consists of a head and four leg-bearing segments. The modular body plans of panarthropods make them a tractable model for understanding diversification of animal body plans more generally. Here we review results of recent morphological and developmental studies of tardigrade segmentation. These results complement investigations of segmentation processes in other panarthropods and paleontological studies to illuminate the earliest steps in the evolution of panarthropod body plans.

  3. Effects of september 11th terrorism stress on estimated duration.

    PubMed

    Anderson, Matthew J; Reis-Costa, Kathleen; Misanin, James R

    2007-06-01

    Previous research has suggested that the duration of stressful video material is estimated to be longer than one containing less stressful material. The current study sought to examine what effects viewing news coverage of the September 11th 2001 terrorist attacks might have on estimated duration of exposure. 16 participants were recruited from Saint Joseph's College of Maine psychology courses and viewed two 3-min. video clips. One clip contained coverage of the 9-11 terrorist attacks; the other, a nonstressful control, was taken from a familiar segment of The Wizard of Oz. Participants estimated the length of the clip and rated stress experienced while viewing the clip. Analysis showed the September 11th footage was rated as more stressful and was estimated as longer than the control clip.

  4. Segmentation of stereo terrain images

    NASA Astrophysics Data System (ADS)

    George, Debra A.; Privitera, Claudio M.; Blackmon, Theodore T.; Zbinden, Eric; Stark, Lawrence W.

    2000-06-01

    We have studied four approaches to segmentation of images: three automatic ones using image processing algorithms and a fourth approach, human manual segmentation. We were motivated toward helping with an important NASA Mars rover mission task -- replacing laborious manual path planning with automatic navigation of the rover on the Mars terrain. The goal of the automatic segmentations was to identify an obstacle map on the Mars terrain to enable automatic path planning for the rover. The automatic segmentation was first explored with two different segmentation methods: one based on pixel luminance, and the other based on pixel altitude generated through stereo image processing. The third automatic segmentation was achieved by combining these two types of image segmentation. Human manual segmentation of Martian terrain images was used for evaluating the effectiveness of the combined automatic segmentation as well as for determining how different humans segment the same images. Comparisons between two different segmentations, manual or automatic, were measured using a similarity metric, SAB. Based on this metric, the combined automatic segmentation did fairly well in agreeing with the manual segmentation. This was a demonstration of a positive step towards automatically creating the accurate obstacle maps necessary for automatic path planning and rover navigation.

  5. Segmental arterial mediolysis.

    PubMed

    Chao, Christine P

    2009-09-01

    Segmental arterial mediolysis (SAM) is a nonatherosclerotic, noninflammatory arteriopathy, which is characterized by dissecting aneurysms resulting from lysis of the outer media of the arterial wall. The most common presentation is abdominal pain and hemorrhage in the elderly. Computed tomography (CT) and angiography imaging findings overlap with various vasculitides and include segmental changes of aneurysm and stenosis. A key distinguishing feature is the presence of dissections, the principle morphologic expression of SAM. Differentiation and exclusion of an inflammatory arteritis is crucial in appropriate management, as immunosuppressants generally used for treatment of vasculitis may be ineffective or even worsen the vasculopathy. Although the disease can be self-limiting without treatment or with conservative medical therapy, the acute process carries a 50% mortality rate and may necessitate urgent surgical and/or endovascular therapy. Prompt recognition and diagnosis are therefore of utmost importance in appropriate management of this rare entity.

  6. ABL beam control segment

    NASA Astrophysics Data System (ADS)

    Kelchner, Bryan L.; Dauk, Ronald C.

    1998-09-01

    The U.S. Air Force Airborne Laser consists of four primary subsystem segments; aircraft, battle management and C4I, laser device, and beam control segment (BCS). The BCS performs two major function, beam control and fire control, using three primary products, turret assembly, beam transfer assembly, and fire control hardware and software. The fire control sequence involves slewing the turret to the target coordinates as received from the battle management segment, centering the target in the acquisition sensor, acquiring the plume in the coarse track sensor, acquiring the hard body of the missile with the track illuminator laser, and establishing active tracking of the nose of the target theater ballistic missile. The beam control sequence begins after established active nose track by firing another beacon illuminator laser (BILL) to establish the aim point on the missile for the high energy laser. The resulting spot on the missile is imaged in the wavefront sensor and compared with the outgoing sample of the BILL. By applying the conjugate of the wavefront difference from the beacon to a deformable mirror then the atmosphere serves to correct the arriving wavefront on target. At this point the HEL is fired along the same path with similar wavefront correction, and dwells on target until the missile skin is weakened and rips open or buckles.

  7. Example based lesion segmentation

    NASA Astrophysics Data System (ADS)

    Roy, Snehashis; He, Qing; Carass, Aaron; Jog, Amod; Cuzzocreo, Jennifer L.; Reich, Daniel S.; Prince, Jerry; Pham, Dzung

    2014-03-01

    Automatic and accurate detection of white matter lesions is a significant step toward understanding the progression of many diseases, like Alzheimer's disease or multiple sclerosis. Multi-modal MR images are often used to segment T2 white matter lesions that can represent regions of demyelination or ischemia. Some automated lesion segmentation methods describe the lesion intensities using generative models, and then classify the lesions with some combination of heuristics and cost minimization. In contrast, we propose a patch-based method, in which lesions are found using examples from an atlas containing multi-modal MR images and corresponding manual delineations of lesions. Patches from subject MR images are matched to patches from the atlas and lesion memberships are found based on patch similarity weights. We experiment on 43 subjects with MS, whose scans show various levels of lesion-load. We demonstrate significant improvement in Dice coefficient and total lesion volume compared to a state of the art model-based lesion segmentation method, indicating more accurate delineation of lesions.

  8. Modelling total duration of traffic incidents including incident detection and recovery time.

    PubMed

    Tavassoli Hojati, Ahmad; Ferreira, Luis; Washington, Simon; Charles, Phil; Shobeirinejad, Ameneh

    2014-10-01

    Traffic incidents are key contributors to non-recurrent congestion, potentially generating significant delay. Factors that influence the duration of incidents are important to understand so that effective mitigation strategies can be implemented. To identify and quantify the effects of influential factors, a methodology for studying total incident duration based on historical data from an 'integrated database' is proposed. Incident duration models are developed using a selected freeway segment in the Southeast Queensland, Australia network. The models include incident detection and recovery time as components of incident duration. A hazard-based duration modelling approach is applied to model incident duration as a function of a variety of factors that influence traffic incident duration. Parametric accelerated failure time survival models are developed to capture heterogeneity as a function of explanatory variables, with both fixed and random parameters specifications. The analysis reveals that factors affecting incident duration include incident characteristics (severity, type, injury, medical requirements, etc.), infrastructure characteristics (roadway shoulder availability), time of day, and traffic characteristics. The results indicate that event type durations are uniquely different, thus requiring different responses to effectively clear them. Furthermore, the results highlight the presence of unobserved incident duration heterogeneity as captured by the random parameter models, suggesting that additional factors need to be considered in future modelling efforts.

  9. Segmenting the Adult Education Market.

    ERIC Educational Resources Information Center

    Aurand, Tim

    1994-01-01

    Describes market segmentation and how the principles of segmentation can be applied to the adult education market. Indicates that applying segmentation techniques to adult education programs results in programs that are educationally and financially satisfying and serve an appropriate population. (JOW)

  10. Market Segmentation for Information Services.

    ERIC Educational Resources Information Center

    Halperin, Michael

    1981-01-01

    Discusses the advantages and limitations of market segmentation as strategy for the marketing of information services made available by nonprofit organizations, particularly libraries. Market segmentation is defined, a market grid for libraries is described, and the segmentation of information services is outlined. A 16-item reference list is…

  11. Segmenting the Adult Education Market.

    ERIC Educational Resources Information Center

    Aurand, Tim

    1994-01-01

    Describes market segmentation and how the principles of segmentation can be applied to the adult education market. Indicates that applying segmentation techniques to adult education programs results in programs that are educationally and financially satisfying and serve an appropriate population. (JOW)

  12. Market Segmentation for Information Services.

    ERIC Educational Resources Information Center

    Halperin, Michael

    1981-01-01

    Discusses the advantages and limitations of market segmentation as strategy for the marketing of information services made available by nonprofit organizations, particularly libraries. Market segmentation is defined, a market grid for libraries is described, and the segmentation of information services is outlined. A 16-item reference list is…

  13. Functional Segments in Tongue Movement

    ERIC Educational Resources Information Center

    Stone, Maureen; Epstein, Melissa A.; Iskarous, Khalil

    2004-01-01

    The tongue is a deformable object, and moves by compressing or expanding local functional segments. For any single phoneme, these functional tongue segments may move in similar or opposite directions, and may reach target maximum synchronously or not. This paper will discuss the independence of five proposed segments in the production of speech.…

  14. Functional Segments in Tongue Movement

    ERIC Educational Resources Information Center

    Stone, Maureen; Epstein, Melissa A.; Iskarous, Khalil

    2004-01-01

    The tongue is a deformable object, and moves by compressing or expanding local functional segments. For any single phoneme, these functional tongue segments may move in similar or opposite directions, and may reach target maximum synchronously or not. This paper will discuss the independence of five proposed segments in the production of speech.…

  15. Some effects of duration on vowel recognition.

    PubMed

    Hillenbrand, J M; Clark, M J; Houde, R A

    2000-12-01

    This study was designed to examine the role of duration in vowel perception by testing listeners on the identification of CVC syllables generated at different durations. Test signals consisted of synthesized versions of 300 utterances selected from a large, multitalker database of /hVd/ syllables [Hillenbrand et al., J. Acoust. Soc. Am. 97, 3099-3111 (1995)]. Four versions of each utterance were synthesized: (1) an original duration set (vowel duration matched to the original utterance), (2) a neutral duration set (duration fixed at 272 ms, the grand mean across all vowels), (3) a short duration set (duration fixed at 144 ms, two standard deviations below the mean), and (4) a long duration set (duration fixed at 400 ms, two standard deviations above the mean). Experiment 1 used a formant synthesizer, while a second experiment was an exact replication using a sinusoidal synthesis method that represented the original vowel spectrum more precisely than the formant synthesizer. Findings included (1) duration had a small overall effect on vowel identity since the great majority of signals were identified correctly at their original durations and at all three altered durations; (2) despite the relatively small average effect of duration, some vowels, especially [see text] and [see text], were significantly affected by duration; (3) some vowel contrasts that differ systematically in duration, such as [see text], and [see text], were minimally affected by duration; (4) a simple pattern recognition model appears to be capable of accounting for several features of the listening test results, especially the greater influence of duration on some vowels than others; and (5) because a formant synthesizer does an imperfect job of representing the fine details of the original vowel spectrum, results using the formant-synthesized signals led to a slight overestimate of the role of duration in vowel recognition, especially for the shortened vowels.

  16. An Approach with Hybrid Segmental Mechanics

    PubMed Central

    Mishra, Harsh Ashok

    2016-01-01

    Present case report provides an insight into the hybrid segmental mechanics with treatment of 13-year-old male, considering the side effects of sole continuous arch wire sliding mechanics. Patient was diagnosed as a case of skeletal class I jaw relationship, low mandibular plane angle, class II molar relation on right and class I molar relation on left side, anterior cross bite, crowding of 12mm in upper, 5mm in lower arch. He also had proclined upper and lower anteriors by 2mm, convex profile and incompetent lips. Total treatment duration was 20 months, during which segmental canine retraction was performed with TMA (Titanium, Molybdenum, Aluminum) ‘T’ loop retraction spring followed by consolidation of spaces with continuous arch mechanics. Most of the treatment objectives were met with good intraoral and facial results within reasonable framework of time. This approach used traditional twin brackets, which offered the versatility to use continuous arch-wire mechanics, segmental mechanics and hybrid sectional mechanics. PMID:27504427

  17. Risk stratification for malignant progression in Barrett's esophagus: Gender, age, duration and year of surveillance.

    PubMed

    Gatenby, Piers; Bhattacharjee, Santanu; Wall, Christine; Caygill, Christine; Watson, Anthony

    2016-12-28

    To clarify risk based upon segment length, diagnostic histological findings, patient age and year of surveillance, duration of surveillance and gender. Patients registered with the United Kingdom Barrett's Oesophagus Registry from 9 United Kingdom centers were included. The outcome measures were (1) development of all grades of dysplasia; (2) development of high-grade of dysplasia or adenocarcinoma; and (3) development of adenocarcinoma. Prevalent cases and subjects with < 1 year of follow-up were excluded. The covariates examined were segment length, previous biopsy findings, age at surveillance, duration of surveillance, year of surveillance and gender. One thousand and one hundred thirty six patients were included (total 6474 patient-years). Fifty-four patients developed adenocarcinoma (0.83% per annum), 70 developed high-grade dysplasia/adenocarcinoma (1.1% per annum) and 190 developed any grade of dysplasia (3.5% per annum). High grade dysplasia and adenocarcinoma increased with age and duration of surveillance. The risk of low-grade dysplasia development was not dependent on age at surveillance. Segment length and previous biopsy findings were also significant factors for development of dysplasia and adenocarcinoma. The risk of development of low-grade dysplasia is independent of age at surveillance, but high-grade dysplasia and adenocarcinoma were more commonly found at older age. Segment length and previous biopsy findings are also markers of risk. This study did not demonstrate stabilisation of the metaplastic segment with prolonged surveillance.

  18. Speaking Rate Affects the Perception of Duration as a Suprasegmental Lexical-Stress Cue

    ERIC Educational Resources Information Center

    Reinisch, Eva; Jesse, Alexandra; McQueen, James M.

    2011-01-01

    Three categorization experiments investigated whether the speaking rate of a preceding sentence influences durational cues to the perception of suprasegmental lexical-stress patterns. Dutch two-syllable word fragments had to be judged as coming from one of two longer words that matched the fragment segmentally but differed in lexical stress…

  19. The ATIC Long Duration Balloon Project

    NASA Technical Reports Server (NTRS)

    Guzik, T. G.; Adams, J. H.; Ahn, H. S.; Bashindzhagyan, G.; Chang, J.; Christl, M.; Fazely, A. R.; Ganel, O.; Granger, D.; Gunasingha, R.

    2003-01-01

    Long Duration Balloon (LDB) scientific experiments, launched to circumnavigate the south pole over Antarctica, have particular advantages compared to Shuttle or other Low Earth Orbit (LEO) missions in terms of cost, weight, scientific 'duty factor' and work force development. The Advanced Thin Ionization Calorimeter (ATIC) cosmic ray astrophysics experiment is a good example of a university-based project that takes full advantage of current LDB capability. The ATIC experiment is currently being prepared for its first LDB science flight that will investigate the charge composition and energy spectra of primary cosmic rays over the energy range from about 10(exp 10) to 10(exp 14) eV. The instrument is built around a fully active, Bismuth Germanate (BGO) ionization calorimeter to measure the energy deposited by the cascades formed by particles interacting in a thick carbon target. A highly segmented silicon matrix, located above the target, provides good incident charge resolution plus rejection of the 'backscattered' particles from the interaction. Trajectory reconstruction is based on the cascade profile in the BGO calorimeter, plus information from the three pairs of scintillator hodoscope layers in the target section above it. A full evaluation of the experiment was performed during a test flight occurring between 28 December 2000 and 13 January 2001 where ATIC was carried to an altitude of approx. 37 km above Antarctica by an approx. 850,000 cu m helium filled balloon for one circumnavigation of the continent. All systems behaved well, the detectors performed as expected, more than 43 gigabytes of engineering and cosmic ray event data was returned and these data are now undergoing preliminary data analysis. During the coming 2002-2003 Antarctica summer season, we are preparing for a ATIC science flight with approx. 15 to 30 days of continuous data collection in the near-space environment of LDB float altitudes.

  20. Acceptability for temporal modification of single vowel segments in isolated words.

    PubMed

    Kato, H; Tsuzaki, M; Sagisaka, Y

    1998-07-01

    Few perceptual studies of the temporal aspects of speech have investigated the influence of changes in segmental durations in terms of acceptability. Aiming to contribute to the assessment of rules for assigning segmental durations in speech synthesis, the current study measured the perceptual acceptability of changes in the segmental duration of vowels as a function of the segment attributes or context, such as base duration, temporal position in a word, vowel quality, and voicing of the following segment. Seven listeners estimated the acceptability of word stimuli in which one of the vowels was subjected to a temporal modification from -50 ms (for shortening) to +50 ms (for lengthening) in 5-ms steps. The temporal modification was applied to vowel segments in 70 word contexts; their durations ranged from 35-145 ms, the mora position in the word was first or third, the vowel quality was /a/ or /i/, and the following segment was a voiced or an unvoiced consonant. The experimental results showed that the listeners' acceptable range of durational modification was narrower for vowels in the first moraic position in the word than for those in the third moraic position. The acceptable range was also narrower for the vowel /a/ than for the vowel /i/, and similarly narrower for vowels followed by unvoiced consonants than for those followed by voiced consonants. The vowel that fell into the least vulnerable class (the third /i/, followed by a voiced consonant) required 140% of the modification of that which fell into the most vulnerable class (the first /a/, followed by an unvoiced consonant) to yield the same acceptability decrement. In contrast, the effect of the original vowel duration on the acceptability of temporal modifications was not significant despite its wide variation (35-145 ms).

  1. Storing Tooth Segments for Optimal Esthetics.

    PubMed

    Tuzuner, Tamer; Turgut, Sedanur; Ozen, Bugra; Kılınç, Hamiyet; Bagiş, Bora

    2016-01-01

    A fractured whole crown segment can be reattached to its remnant; crowns from extracted teeth may be used as pontics in splinting techniques. We aimed to evaluate the effect of different storage solutions on tooth segment optical properties after different durations. Sixty central incisor crowns were divided into 6 groups (n = 10); Group 1 was kept dry; Groups 2, 3, 4, 5, and 6 were placed in an isotonic solution, water, milk, saliva, and casein-phosphopeptide-amorphous-calcium-phosphate (CPP-ACP), respectively, for 30 min, 12 h, 1 day, 1 week, and 3 weeks. Color values were measured using a colorimeter. Data were analyzed with Kruskal-Wallis tests, Mann-Whitney U-tests, and Friedman Wilcoxon tests with Bonferroni stepwise corrections (p < 0.05). ΔE* values varied from 0.3 to 15.3 over the 3 week period. Group 1 demonstrated the greatest color changes over all durations; Group 6 exhibited the least. L*, a*, b*, and ΔE* values varied between time periods in all groups; the differences were significant (p < 0.01), except for L* and ΔE* values in Group 2 and a* values in Group 6 (p > 0.01). Comparing ΔE* values, Group 6 was significantly different from the other groups for all durations (p < 0.01), except Group 4. A CPP-ACP complex solution seems a good choice for tooth fragment storage. Milk and saliva solutions may cause perceptible color changes if tooth fragments are stored for 3 weeks before use.

  2. Cohabitation Duration and Transient Domesticity

    PubMed Central

    GOLUB, ANDREW; REID, MEGAN; STRICKLER, JENNIFER; DUNLAP, ELOISE

    2013-01-01

    Research finds that many impoverished urban Black adults engage in a pattern of partnering and family formation involving a succession of short cohabitations yielding children, a paradigm referred to as transient domesticity. Researchers have identified socioeconomic status, cultural adaptations, and urbanicity as explanations for aspects of this pattern. We used longitudinal data from the 2001 Survey of Income and Program Participation to analyze variation in cohabitation and marriage duration by race/ethnicity, income, and urban residence. Proportional hazards regression indicated that separation risk is greater among couples that are cohabiting, below 200% of the federal poverty line, and Black but is not greater among urban dwellers. This provides empirical demographic evidence to support the emerging theory of transient domesticity and suggests that both socioeconomic status and race explain this pattern. We discuss the implications of these findings for understanding transient domesticity and make recommendations for using the Survey of Income and Program Participation to further study this family formation paradigm. PMID:24273358

  3. Cohabitation Duration and Transient Domesticity.

    PubMed

    Golub, Andrew; Reid, Megan; Strickler, Jennifer; Dunlap, Eloise

    2013-01-01

    Research finds that many impoverished urban Black adults engage in a pattern of partnering and family formation involving a succession of short cohabitations yielding children, a paradigm referred to as transient domesticity. Researchers have identified socioeconomic status, cultural adaptations, and urbanicity as explanations for aspects of this pattern. We used longitudinal data from the 2001 Survey of Income and Program Participation to analyze variation in cohabitation and marriage duration by race/ethnicity, income, and urban residence. Proportional hazards regression indicated that separation risk is greater among couples that are cohabiting, below 200% of the federal poverty line, and Black but is not greater among urban dwellers. This provides empirical demographic evidence to support the emerging theory of transient domesticity and suggests that both socioeconomic status and race explain this pattern. We discuss the implications of these findings for understanding transient domesticity and make recommendations for using the Survey of Income and Program Participation to further study this family formation paradigm.

  4. Segmentation of Unstructured Datasets

    NASA Technical Reports Server (NTRS)

    Bhat, Smitha

    1996-01-01

    Datasets generated by computer simulations and experiments in Computational Fluid Dynamics tend to be extremely large and complex. It is difficult to visualize these datasets using standard techniques like Volume Rendering and Ray Casting. Object Segmentation provides a technique to extract and quantify regions of interest within these massive datasets. This thesis explores basic algorithms to extract coherent amorphous regions from two-dimensional and three-dimensional scalar unstructured grids. The techniques are applied to datasets from Computational Fluid Dynamics and from Finite Element Analysis.

  5. SEGMENTAL CLAVICLE FRACTURE

    PubMed Central

    Grossi, Evander Azevedo

    2015-01-01

    The aim here was to present an unusual case of segmental clavicle fracture associated with ipsilateral rib fracture. Although the clavicle is very superficial, undetected cases of both types of fracture may occur, because these patients usually suffer multiple trauma. The case of a patient with a fracture of the diaphysis and lateral extremity of the clavicle is described: the patient was treated surgically and an excellent result was achieved. Similar cases in the literature are reviewed and their management is discussed. PMID:27047835

  6. Segmented Target Design

    NASA Astrophysics Data System (ADS)

    Merhi, Abdul Rahman; Frank, Nathan; Gueye, Paul; Thoennessen, Michael; MoNA Collaboration

    2013-10-01

    A proposed segmented target would improve decay energy measurements of neutron-unbound nuclei. Experiments like this have been performed at the National Superconducting Cyclotron Laboratory (NSCL) located at Michigan State University. Many different nuclei are produced in such experiments, some of which immediately decay into a charged particle and neutron. The charged particles are bent by a large magnet and measured by a suite of charged particle detectors. The neutrons are measured by the Modular Neutron Array (MoNA) and Large Multi-Institutional Scintillation Array (LISA). With the current target setup, a nucleus in a neutron-unbound state is produced with a radioactive beam impinged upon a beryllium target. The resolution of these measurements is very dependent on the target thickness since the nuclear interaction point is unknown. In a segmented target using alternating layers of silicon detectors and Be-targets, the Be-target in which the nuclear reaction takes place would be determined. Thus the experimental resolution would improve. This poster will describe the improvement over the current target along with the status of the design. Work supported by Augustana College and the National Science Foundation grant #0969173.

  7. Segmental arterial mediolysis.

    PubMed

    Pillai, Anil Kumar; Iqbal, Shams I; Liu, Raymond W; Rachamreddy, Niranjan; Kalva, Sanjeeva P

    2014-06-01

    Segmental arterial mediolysis (SAM) is an uncommon, nonatherosclerotic, noninflammatory, large- to medium-sized arteriopathy first described in 1976. It is characterized histologically by vacuolization and lysis of the outer arterial media leading to dissecting aneurysms and vessel rupture presenting clinically with self-limiting abdominal pain or catastrophic hemorrhages in the abdomen. Patients of all ages are affected with a greater incidence at the fifth and sixth decades. There is a slight male predominance. Imaging findings overlap with inflammatory vasculitis, collagen vascular disease, and fibromuscular dysplasia. The presence of segmental dissections involving the celiac, mesenteric, and/or renal arteries is the key distinguishing features of SAM. Inflammatory markers, genetic tests for collagen vascular disorders, and hypercoagulable studies are negative. Anti-inflammatory agents and immunosuppressants are not effective. A mortality rate of 50 % has been attributed to the acute presentation with aneurysmal rupture necessitating urgent surgical or endovascular treatments; in the absence of the acute presentation, SAM is a self-limiting disease and is treated conservatively. There are no established guidelines on medical therapy, although optimal control of blood pressure is considered the main cornerstone of medical therapy. The long-term prognosis is not known.

  8. Trunk segment numbers and sequential segmentation in myriapods.

    PubMed

    Fusco, Giuseppe

    2005-01-01

    Sequential segmentation from a posterior "proliferative zone" is considered to be the primitive mechanism of segmentation in arthropods. Several studies of embryonic and post-embryonic development and gene expression suggest that this occurs in all major arthropod taxa. Sequential segmentation is often associated with the idea of posterior production of body units that accumulate along the main body axis. However, the precise mechanism of sequential segmentation has not been identified yet, and, while searching for the genetic circuitry able to generate a first periodic pattern in the embryo, we can at least outline the distinctive role in segmentation of a proliferative zone. A perusal of myriapod segmentation patterns suggests that these patterns result from multi-layered developmental processes, where gene expression and epigenetic mechanisms interact in a nonstrictly hierarchical way. The posterior zone is possibly a zone of periodic signal production, but, in general, the resulting segmental pattern is not completely attributable to the activity of the signal generator. In this sense, a posterior proliferative zone would be more a "segmental organizer" than a "segment generator."

  9. Extended Duration Orbiter Medical Project

    NASA Technical Reports Server (NTRS)

    Sawin, Charles F. (Editor); Taylor, Gerald R. (Editor); Smith, Wanda L. (Editor); Brown, J. Travis (Technical Monitor)

    1999-01-01

    Biomedical issues have presented a challenge to flight physicians, scientists, and engineers ever since the advent of high-speed, high-altitude airplane flight in the 1940s. In 1958, preparations began for the first manned space flights of Project Mercury. The medical data and flight experience gained through Mercury's six flights and the Gemini, Apollo, and Skylab projects, as well as subsequent space flights, comprised the knowledge base that was used to develop and implement the Extended Duration Orbiter Medical Project (EDOMP). The EDOMP yielded substantial amounts of data in six areas of space biomedical research. In addition, a significant amount of hardware was developed and tested under the EDOMP. This hardware was designed to improve data gathering capabilities and maintain crew physical fitness, while minimizing the overall impact to the microgravity environment. The biomedical findings as well as the hardware development results realized from the EDOMP have been important to the continuing success of extended Space Shuttle flights and have formed the basis for medical studies of crew members living for three to five months aboard the Russian space station, Mir. EDOMP data and hardware are also being used in preparation for the construction and habitation of International Space Station. All data sets were grouped to be non-attributable to individuals, and submitted to NASA s Life Sciences Data Archive.

  10. Sentence durations and accentedness judgments

    NASA Astrophysics Data System (ADS)

    Bond, Z. S.; Stockmal, Verna; Markus, Dace

    2003-04-01

    Talkers in a second language can frequently be identified as speaking with a foreign accent. It is not clear to what degree a foreign accent represents specific deviations from a target language versus more general characteristics. We examined the identifications of native and non-native talkers by listeners with various amount of knowledge of the target language. Native and non-native speakers of Latvian provided materials. All the non-native talkers spoke Russian as their first language and were long-term residents of Latvia. A listening test, containing sentences excerpted from a short recorded passage, was presented to three groups of listeners: native speakers of Latvian, Russians for whom Latvian was a second language, and Americans with no knowledge of either of the two languages. The listeners were asked to judge whether each utterance was produced by a native or non-native talker. The Latvians identified the non-native talkers very accurately, 88%. The Russians were somewhat less accurate, 83%. The American listeners were least accurate, but still identified the non-native talkers at above chance levels, 62%. Sentence durations correlated with the judgments provided by the American listeners but not with the judgments provided by native or L2 listeners.

  11. Tilt changes of short duration

    USGS Publications Warehouse

    McHugh, Stuart

    1976-01-01

    Section I of this report contains a classification scheme for short period tilt data. For convenience, all fluctuations in the local tilt field of less than 24 hours duration will be designated SP (i.e., short period) tilt events. Three basic categories of waveshape appearance are defined, and the rules for naming the waveforms are outlined. Examples from tilt observations at four central California sites are provided. Section II contains some coseismic tilt data. Fourteen earthquakes in central California, ranging in magnitude from 2.9 to 5.2, were chosen for study on four tiltmeters within 10 source dimensions of the epicenters. The raw records from each of the four tiltmeters at the times of the earthquakes were photographed and are presented in this section. Section III contains documentation of computer programs used in the analysis of the short period tilt data. Program VECTOR computes the difference vector of a tilt event and displays the sequence of events as a head-to-tail vector plot. Program ONSTSP 1) requires two component digitized tilt data as input, 2) scales and plots the data, and 3) computes and displays the amplitude, azimuth, and normalized derivative of the tilt amplitude. Program SHARPS computes the onset sharpness, (i.e., the normalized derivative of the tilt amplitude at the onset of the tilt event) as a function of source-station distance from a model of creep-related tilt changes. Program DSPLAY plots the digitized data.

  12. Icing Encounter Duration Sensitivity Study

    NASA Technical Reports Server (NTRS)

    Addy, Harold E., Jr.; Lee, Sam

    2011-01-01

    This paper describes a study performed to investigate how aerodynamic performance degradation progresses with time throughout an exposure to icing conditions. It is one of the first documented studies of the effects of ice contamination on aerodynamic performance at various points in time throughout an icing encounter. Both a 1.5 and 6 ft chord, two-dimensional, NACA-23012 airfoils were subjected to icing conditions in the NASA Icing Research Tunnel for varying lengths of time. At the end of each run, lift, drag, and pitching moment measurements were made. Measurements with the 1.5 ft chord model showed that maximum lift and pitching moment degraded more rapidly early in the exposure and degraded more slowly as time progressed. Drag for the 1.5 ft chord model degraded more linearly with time, although drag for very short exposure durations was slightly higher than expected. Only drag measurements were made with the 6 ft chord airfoil. Here, drag for the long exposures was higher than expected. Novel comparison of drag measurements versus an icing scaling parameter, accumulation parameter times collection efficiency was used to compare the data from the two different size model. The comparisons provided a means of assessing the level of fidelity needed for accurate icing simulation.

  13. Does knowing speaker sex facilitate vowel recognition at short durations?

    PubMed

    Smith, David R R

    2014-05-01

    A man, woman or child saying the same vowel do so with very different voices. The auditory system solves the complex problem of extracting what the man, woman or child has said despite substantial differences in the acoustic properties of their voices. Much of the acoustic variation between the voices of men and woman is due to changes in the underlying anatomical mechanisms for producing speech. If the auditory system knew the sex of the speaker then it could potentially correct for speaker sex related acoustic variation thus facilitating vowel recognition. This study measured the minimum stimulus duration necessary to accurately discriminate whether a brief vowel segment was spoken by a man or woman, and the minimum stimulus duration necessary to accuately recognise what vowel was spoken. Results showed that reliable vowel recognition precedesreliable speaker sex discrimination, thus questioning the use of speaker sex information in compensating for speaker sex related acoustic variation in the voice. Furthermore, the pattern of performance across experiments where the fundamental frequency and formant frequency information of speaker's voices were systematically varied, was markedly different depending on whether the task was speaker-sex discrimination or vowel recognition. This argues for there being little relationship between perception of speaker sex (indexical information) and perception of what has been said (linguistic information) at short durations.

  14. Probabilistic retinal vessel segmentation

    NASA Astrophysics Data System (ADS)

    Wu, Chang-Hua; Agam, Gady

    2007-03-01

    Optic fundus assessment is widely used for diagnosing vascular and non-vascular pathology. Inspection of the retinal vasculature may reveal hypertension, diabetes, arteriosclerosis, cardiovascular disease and stroke. Due to various imaging conditions retinal images may be degraded. Consequently, the enhancement of such images and vessels in them is an important task with direct clinical applications. We propose a novel technique for vessel enhancement in retinal images that is capable of enhancing vessel junctions in addition to linear vessel segments. This is an extension of vessel filters we have previously developed for vessel enhancement in thoracic CT scans. The proposed approach is based on probabilistic models which can discern vessels and junctions. Evaluation shows the proposed filter is better than several known techniques and is comparable to the state of the art when evaluated on a standard dataset. A ridge-based vessel tracking process is applied on the enhanced image to demonstrate the effectiveness of the enhancement filter.

  15. Partially segmented deformable mirror

    DOEpatents

    Bliss, E.S.; Smith, J.R.; Salmon, J.T.; Monjes, J.A.

    1991-05-21

    A partially segmented deformable mirror is formed with a mirror plate having a smooth and continuous front surface and a plurality of actuators to its back surface. The back surface is divided into triangular areas which are mutually separated by grooves. The grooves are deep enough to make the plate deformable and the actuators for displacing the mirror plate in the direction normal to its surface are inserted in the grooves at the vertices of the triangular areas. Each actuator includes a transducer supported by a receptacle with outer shells having outer surfaces. The vertices have inner walls which are approximately perpendicular to the mirror surface and make planar contacts with the outer surfaces of the outer shells. The adhesive which is used on these contact surfaces tends to contract when it dries but the outer shells can bend and serve to minimize the tendency of the mirror to warp. 5 figures.

  16. Partially segmented deformable mirror

    DOEpatents

    Bliss, Erlan S.; Smith, James R.; Salmon, J. Thaddeus; Monjes, Julio A.

    1991-01-01

    A partially segmented deformable mirror is formed with a mirror plate having a smooth and continuous front surface and a plurality of actuators to its back surface. The back surface is divided into triangular areas which are mutually separated by grooves. The grooves are deep enough to make the plate deformable and the actuators for displacing the mirror plate in the direction normal to its surface are inserted in the grooves at the vertices of the triangular areas. Each actuator includes a transducer supported by a receptacle with outer shells having outer surfaces. The vertices have inner walls which are approximately perpendicular to the mirror surface and make planar contacts with the outer surfaces of the outer shells. The adhesive which is used on these contact surfaces tends to contract when it dries but the outer shells can bend and serve to minimize the tendency of the mirror to warp.

  17. Bone image segmentation.

    PubMed

    Liu, Z Q; Liew, H L; Clement, J G; Thomas, C D

    1999-05-01

    Characteristics of microscopic structures in bone cross sections carry essential clues in age determination in forensic science and in the study of age-related bone developments and bone diseases. Analysis of bone cross sections represents a major area of research in bone biology. However, traditional approaches in bone biology have relied primarily on manual processes with very limited number of bone samples. As a consequence, it is difficult to reach reliable and consistent conclusions. In this paper we present an image processing system that uses microstructural and relational knowledge present in the bone cross section for bone image segmentation. This system automates the bone image analysis process and is able to produce reliable results based on quantitative measurements from a large number of bone images. As a result, using large databases of bone images to study the correlation between bone structural features and age-related bone developments becomes feasible.

  18. Segmented heat exchanger

    DOEpatents

    Baldwin, Darryl Dean; Willi, Martin Leo; Fiveland, Scott Byron; Timmons, Kristine Ann

    2010-12-14

    A segmented heat exchanger system for transferring heat energy from an exhaust fluid to a working fluid. The heat exchanger system may include a first heat exchanger for receiving incoming working fluid and the exhaust fluid. The working fluid and exhaust fluid may travel through at least a portion of the first heat exchanger in a parallel flow configuration. In addition, the heat exchanger system may include a second heat exchanger for receiving working fluid from the first heat exchanger and exhaust fluid from a third heat exchanger. The working fluid and exhaust fluid may travel through at least a portion of the second heat exchanger in a counter flow configuration. Furthermore, the heat exchanger system may include a third heat exchanger for receiving working fluid from the second heat exchanger and exhaust fluid from the first heat exchanger. The working fluid and exhaust fluid may travel through at least a portion of the third heat exchanger in a parallel flow configuration.

  19. Segmented rail linear induction motor

    DOEpatents

    Cowan, Jr., Maynard; Marder, Barry M.

    1996-01-01

    A segmented rail linear induction motor has a segmented rail consisting of a plurality of nonferrous electrically conductive segments aligned along a guideway. The motor further includes a carriage including at least one pair of opposed coils fastened to the carriage for moving the carriage. A power source applies an electric current to the coils to induce currents in the conductive surfaces to repel the coils from adjacent edges of the conductive surfaces.

  20. Segmented rail linear induction motor

    DOEpatents

    Cowan, M. Jr.; Marder, B.M.

    1996-09-03

    A segmented rail linear induction motor has a segmented rail consisting of a plurality of nonferrous electrically conductive segments aligned along a guideway. The motor further includes a carriage including at least one pair of opposed coils fastened to the carriage for moving the carriage. A power source applies an electric current to the coils to induce currents in the conductive surfaces to repel the coils from adjacent edges of the conductive surfaces. 6 figs.

  1. Multiple-Segment Climbing Robots

    NASA Technical Reports Server (NTRS)

    Kerley, James; May, Edward; Eklund, Wayne

    1994-01-01

    Multiple-segment climbing robots developed to perform such tasks as inspection, sandblasting, welding, and painting on towers and other structures. Look and move like caterpillars. Video camera mounted on one of segments rotated to desired viewing angle. Used in remote inspection of structure, to view motion of robot and/or provides video feedback for control of motion, and/or to guide operation of head mounted on foremost segment with motorized actuators.

  2. Acoustic Predictors of Intelligibility for Segmentally Interrupted Speech: Temporal Envelope, Voicing, and Duration

    ERIC Educational Resources Information Center

    Fogerty, Daniel

    2013-01-01

    Purpose: Temporal interruption limits the perception of speech to isolated temporal glimpses. An analysis was conducted to determine the acoustic parameter that best predicts speech recognition from temporal fragments that preserve different types of speech information--namely, consonants and vowels. Method: Young listeners with normal hearing…

  3. Development of Perception of Second Language Japanese Geminates: Role of Duration, Sonority, and Segmentation Strategy

    ERIC Educational Resources Information Center

    Hardison, Debra M.; Saigo, Miki Motohashi

    2010-01-01

    This study explored the second language perceptual accuracy of Japanese geminates (moraic units) by English-speaking learners at three proficiency levels: beginner (28), low-intermediate (42), and advanced (15). Stimuli included singleton and geminate /t/, /k/, /s/ followed by /a/ or /u/ produced by a native speaker in isolated words and carrier…

  4. Acoustic Predictors of Intelligibility for Segmentally Interrupted Speech: Temporal Envelope, Voicing, and Duration

    ERIC Educational Resources Information Center

    Fogerty, Daniel

    2013-01-01

    Purpose: Temporal interruption limits the perception of speech to isolated temporal glimpses. An analysis was conducted to determine the acoustic parameter that best predicts speech recognition from temporal fragments that preserve different types of speech information--namely, consonants and vowels. Method: Young listeners with normal hearing…

  5. Speech Production in Parkinson's Disease: II. Acoustic and Electropalatographic Investigation of Sentence, Word and Segment Durations

    ERIC Educational Resources Information Center

    McAuliffe, Megan J.; Ward, Elizabeth C.; Murdoch, Bruce E.

    2006-01-01

    Previous investigations employing electropalatography (EPG) have identified articulatory timing deficits in individuals with acquired dysarthria. However, this technology is yet to be applied to the articulatory timing disturbance present in Parkinson's disease (PD). As a result, the current investigation aimed to use EPG to comprehensively…

  6. High volume ULE segment production

    NASA Astrophysics Data System (ADS)

    Hobbs, Thomas; Edwards, Mary; Fox, Andrew

    2016-07-01

    It is expected that many of the next generation large ground based telescopes will utilize a segmented design for the primary mirror and, in some cases, the secondary mirror. Corning Incorporated (Corning) presents a process to manufacture segment mirror blanks from Corning ULE titania silicate glass in segment sizes ranging from 1.0 m to 1.8 m flat to flat. This paper will review ULE properties and describe the facilities, equipment, resources, and processes required to produce a few hundred to a few thousand mirror segment blanks for extremely large telescope (ELT) applications.

  7. Automated medical image segmentation techniques

    PubMed Central

    Sharma, Neeraj; Aggarwal, Lalit M.

    2010-01-01

    Accurate segmentation of medical images is a key step in contouring during radiotherapy planning. Computed topography (CT) and Magnetic resonance (MR) imaging are the most widely used radiographic techniques in diagnosis, clinical studies and treatment planning. This review provides details of automated segmentation methods, specifically discussed in the context of CT and MR images. The motive is to discuss the problems encountered in segmentation of CT and MR images, and the relative merits and limitations of methods currently available for segmentation of medical images. PMID:20177565

  8. Asteroid Redirect Mission: Robotic Segment

    NASA Image and Video Library

    This concept animation illustrates the robotic segment of NASA's Asteroid Redirect Mission. The Asteroid Redirect Vehicle, powered by solar electric propulsion, travels to a large asteroid to robot...

  9. Compatibility of segmented thermoelectric generators

    NASA Technical Reports Server (NTRS)

    Snyder, J.; Ursell, T.

    2002-01-01

    It is well known that power generation efficiency improves when materials with appropriate properties are combined either in a cascaded or segmented fashion across a temperature gradient. Past methods for determining materials used in segmentation weremainly concerned with materials that have the highest figure of merit in the temperature range. However, the example of SiGe segmented with Bi2Te3 and/or various skutterudites shows a marked decline in device efficiency even though SiGe has the highest figure of merit in the temperature range. The origin of the incompatibility of SiGe with other thermoelectric materials leads to a general definition of compatibility and intrinsic efficiency. The compatibility factor derived as = (Jl+zr - 1) a is a function of only intrinsic material properties and temperature, which is represented by a ratio of current to conduction heat. For maximum efficiency the compatibility factor should not change with temperature both within a single material, and in the segmented leg as a whole. This leads to a measure of compatibility not only between segments, but also within a segment. General temperature trends show that materials are more self compatible at higher temperatures, and segmentation is more difficult across a larger -T. The compatibility factor can be used as a quantitative guide for deciding whether a material is better suited for segmentation orcascading. Analysis of compatibility factors and intrinsic efficiency for optimal segmentation are discussed, with intent to predict optimal material properties, temperature interfaces, and/or currentheat ratios.

  10. Automated medical image segmentation techniques.

    PubMed

    Sharma, Neeraj; Aggarwal, Lalit M

    2010-01-01

    Accurate segmentation of medical images is a key step in contouring during radiotherapy planning. Computed topography (CT) and Magnetic resonance (MR) imaging are the most widely used radiographic techniques in diagnosis, clinical studies and treatment planning. This review provides details of automated segmentation methods, specifically discussed in the context of CT and MR images. The motive is to discuss the problems encountered in segmentation of CT and MR images, and the relative merits and limitations of methods currently available for segmentation of medical images.

  11. Compatibility of segmented thermoelectric generators

    NASA Technical Reports Server (NTRS)

    Snyder, J.; Ursell, T.

    2002-01-01

    It is well known that power generation efficiency improves when materials with appropriate properties are combined either in a cascaded or segmented fashion across a temperature gradient. Past methods for determining materials used in segmentation weremainly concerned with materials that have the highest figure of merit in the temperature range. However, the example of SiGe segmented with Bi2Te3 and/or various skutterudites shows a marked decline in device efficiency even though SiGe has the highest figure of merit in the temperature range. The origin of the incompatibility of SiGe with other thermoelectric materials leads to a general definition of compatibility and intrinsic efficiency. The compatibility factor derived as = (Jl+zr - 1) a is a function of only intrinsic material properties and temperature, which is represented by a ratio of current to conduction heat. For maximum efficiency the compatibility factor should not change with temperature both within a single material, and in the segmented leg as a whole. This leads to a measure of compatibility not only between segments, but also within a segment. General temperature trends show that materials are more self compatible at higher temperatures, and segmentation is more difficult across a larger -T. The compatibility factor can be used as a quantitative guide for deciding whether a material is better suited for segmentation orcascading. Analysis of compatibility factors and intrinsic efficiency for optimal segmentation are discussed, with intent to predict optimal material properties, temperature interfaces, and/or currentheat ratios.

  12. Segmenting Words from Natural Speech: Subsegmental Variation in Segmental Cues

    ERIC Educational Resources Information Center

    Rytting, C. Anton; Brew, Chris; Fosler-Lussier, Eric

    2010-01-01

    Most computational models of word segmentation are trained and tested on transcripts of speech, rather than the speech itself, and assume that speech is converted into a sequence of symbols prior to word segmentation. We present a way of representing speech corpora that avoids this assumption, and preserves acoustic variation present in speech. We…

  13. Correlates of Long Sleep Duration

    PubMed Central

    Patel, Sanjay R.; Malhotra, Atul; Gottlieb, Daniel J.; White, David P.; Hu, Frank B.

    2012-01-01

    Study Objective Sleeping more than 7 to 8 hours per day has been consistently associated with increased mortality. Whether this association is causal and what pathways explain this association are unknown. We sought to identify factors that could potentially explain the association between long sleep and mortality. Design Cross-sectional epidemiologic survey. Participants Middle-aged women (n = 60,028) participating in the Nurses Health Study II who reported a habitual sleep duration of 7 hours or more. Results Multiple sclerosis (odds ratio [OR] = 3.7, 95% confidence interval [3.0–4.5]), antidepressant use (OR = 3.1, [2.9–3.3]), benzodiazepine use (OR = 3.0 [2.6–3.3]), and systemic lupus erythematosus (OR = 2.9, [2.3–3.6]) were the factors most strongly associated with prolonged sleep. Combining these data with prevalence information and a range of plausible associations with mortality, the confounding rate ratio was estimated. This parameter is the ratio of the unadjusted long sleep–mortality rate ratio to the rate ratio adjusted for the factor and measures the extent that the factor can alter the long sleep—mortality association, either through confounding or as a causal intermediate. Based on this parameter, psychiatric and socioeconomic factors have the greatest potential to influence the long sleep–mortality relationship. Assuming each factor doubles mortality risk, the confounding rate ratios for depression, antidepressant use, and unemployment were 1.10, 1.18, and 1.12. Lesser influential factors were benzodiazepine use, poverty, low societal status, sedentary lifestyle, and obesity. Conclusion Depression and low socioeconomic status are strong candidates for producing the statistical association between long sleep and mortality, either as confounders or as causal intermediates. Future causal research on the effects of long sleep should include a detailed assessment of psychiatric disease and socioeconomic status. PMID:16895254

  14. Sleep Duration and Adolescent Obesity

    PubMed Central

    Rodriguez, Daniel; Schmitz, Kathryn H.; Audrain-McGovern, Janet

    2013-01-01

    OBJECTIVES: Short sleep has been associated with adolescent obesity. Most studies used a cross-sectional design and modeled BMI categories. We sought to determine if sleep duration was associated with BMI distribution changes from age 14 to 18. METHODS: Adolescents were recruited from suburban high schools in Philadelphia when entering ninth grade (n = 1390) and were followed-up every 6 months through 12th grade. Height and weight were self-reported, and BMIs were calculated (kg/m2). Hours of sleep were self-reported. Quantile regression was used to model the 10th, 25th, 50th, 75th, and 90th BMI percentiles as dependent variables; study wave and sleep were the main predictors. RESULTS: BMI increased from age 14 to 18, with the largest increase observed at the 90th BMI percentile. Each additional hour of sleep was associated with decreases in BMI at the 10th (–0.04; 95% confidence interval [CI]: –0.11, 0.03), 25th (–0.12; 95% CI: –0.20, –0.04), 50th (–0.15; 95% CI: –0.24, –0.06), 75th (–0.25; 95% CI: –0.38, –0.12), and 90th (–0.27; 95% CI: -0.45, -0.09) BMI percentiles. The strength of the association was stronger at the upper tail of the BMI distribution. Increasing sleep from 7.5 to 10.0 hours per day at age 18 predicted a reduction in the proportion of adolescents >25 kg/m2 by 4%. CONCLUSIONS: More sleep was associated with nonuniform changes in BMI distribution from age 14 to 18. Increasing sleep among adolescents, especially those in the upper half of the BMI distribution, may help prevent overweight and obesity. PMID:23569090

  15. Sleep duration and adolescent obesity.

    PubMed

    Mitchell, Jonathan A; Rodriguez, Daniel; Schmitz, Kathryn H; Audrain-McGovern, Janet

    2013-05-01

    Short sleep has been associated with adolescent obesity. Most studies used a cross-sectional design and modeled BMI categories. We sought to determine if sleep duration was associated with BMI distribution changes from age 14 to 18. Adolescents were recruited from suburban high schools in Philadelphia when entering ninth grade (n = 1390) and were followed-up every 6 months through 12th grade. Height and weight were self-reported, and BMIs were calculated (kg/m(2)). Hours of sleep were self-reported. Quantile regression was used to model the 10th, 25th, 50th, 75th, and 90th BMI percentiles as dependent variables; study wave and sleep were the main predictors. BMI increased from age 14 to 18, with the largest increase observed at the 90th BMI percentile. Each additional hour of sleep was associated with decreases in BMI at the 10th (-0.04; 95% confidence interval [CI]: -0.11, 0.03), 25th (-0.12; 95% CI: -0.20, -0.04), 50th (-0.15; 95% CI: -0.24, -0.06), 75th (-0.25; 95% CI: -0.38, -0.12), and 90th (-0.27; 95% CI: -0.45, -0.09) BMI percentiles. The strength of the association was stronger at the upper tail of the BMI distribution. Increasing sleep from 7.5 to 10.0 hours per day at age 18 predicted a reduction in the proportion of adolescents >25 kg/m(2) by 4%. More sleep was associated with nonuniform changes in BMI distribution from age 14 to 18. Increasing sleep among adolescents, especially those in the upper half of the BMI distribution, may help prevent overweight and obesity.

  16. Vowel and Consonant Durations in Falling Nuclei.

    ERIC Educational Resources Information Center

    Baird, A. J.

    This paper focuses on British English. Such rules as might be devised for specification of segment length would have to take into account, among other factors, the lenis/fortis nature of the segments at syllable margins, degree of stress, the relation between a given syllable and others in the same rhythm group, the same relations within the word,…

  17. The Importance of Marketing Segmentation

    ERIC Educational Resources Information Center

    Martin, Gillian

    2011-01-01

    The rationale behind marketing segmentation is to allow businesses to focus on their consumers' behaviors and purchasing patterns. If done effectively, marketing segmentation allows an organization to achieve its highest return on investment (ROI) in turn for its marketing and sales expenses. If an organization markets its products or services to…

  18. Automatic segmentation of the colon

    NASA Astrophysics Data System (ADS)

    Wyatt, Christopher L.; Ge, Yaorong; Vining, David J.

    1999-05-01

    Virtual colonoscopy is a minimally invasive technique that enables detection of colorectal polyps and cancer. Normally, a patient's bowel is prepared with colonic lavage and gas insufflation prior to computed tomography (CT) scanning. An important step for 3D analysis of the image volume is segmentation of the colon. The high-contrast gas/tissue interface that exists in the colon lumen makes segmentation of the majority of the colon relatively easy; however, two factors inhibit automatic segmentation of the entire colon. First, the colon is not the only gas-filled organ in the data volume: lungs, small bowel, and stomach also meet this criteria. User-defined seed points placed in the colon lumen have previously been required to spatially isolate only the colon. Second, portions of the colon lumen may be obstructed by peristalsis, large masses, and/or residual feces. These complicating factors require increased user interaction during the segmentation process to isolate additional colon segments. To automate the segmentation of the colon, we have developed a method to locate seed points and segment the gas-filled lumen with no user supervision. We have also developed an automated approach to improve lumen segmentation by digitally removing residual contrast-enhanced fluid resulting from a new bowel preparation that liquefies and opacifies any residual feces.

  19. Segmentation: Slicing the Urban Pie.

    ERIC Educational Resources Information Center

    Keim, William A.

    1981-01-01

    Explains market segmentation and defines undifferentiated, concentrated, and differentiated marketing strategies. Describes in detail the marketing planning process at the Metropolitan Community Colleges. Focuses on the development and implementation of an ongoing recruitment program designed for the market segment composed of business employees.…

  20. Market Segmentation: An Instructional Module.

    ERIC Educational Resources Information Center

    Wright, Peter H.

    A concept-based introduction to market segmentation is provided in this instructional module for undergraduate and graduate transportation-related courses. The material can be used in many disciplines including engineering, business, marketing, and technology. The concept of market segmentation is primarily a transportation planning technique by…

  1. Market segmentation using perceived constraints

    Treesearch

    Jinhee Jun; Gerard Kyle; Andrew Mowen

    2008-01-01

    We examined the practical utility of segmenting potential visitors to Cleveland Metroparks using their constraint profiles. Our analysis identified three segments based on their scores on the dimensions of constraints: Other priorities--visitors who scored the highest on 'other priorities' dimension; Highly Constrained--visitors who scored relatively high on...

  2. Segmentation: Slicing the Urban Pie.

    ERIC Educational Resources Information Center

    Keim, William A.

    1981-01-01

    Explains market segmentation and defines undifferentiated, concentrated, and differentiated marketing strategies. Describes in detail the marketing planning process at the Metropolitan Community Colleges. Focuses on the development and implementation of an ongoing recruitment program designed for the market segment composed of business employees.…

  3. Risk segmentation in Chilean social health insurance.

    PubMed

    Hidalgo, Hector; Chipulu, Maxwell; Ojiako, Udechukwu

    2013-01-01

    The objective of this study is to identify how risk and social variables are likely to be impacted by an increase in private sector participation in health insurance provision. The study focuses on the Chilean health insurance industry, traditionally dominated by the public sector. Predictive risk modelling is conducted using a database containing over 250,000 health insurance policy records provided by the Superintendence of Health of Chile. Although perceived with suspicion in some circles, risk segmentation serves as a rational approach to risk management from a resource perspective. The variables that have considerable impact on insurance claims include the number of dependents, gender, wages and the duration a claimant has been a customer. As shown in the case study, to ensure that social benefits are realised, increased private sector participation in health insurance must be augmented by regulatory oversight and vigilance. As it is clear that a "community-rated" health insurance provision philosophy impacts on insurance firm's ability to charge "market" prices for insurance provision, the authors explore whether risk segmentation is a feasible means of predicting insurance claim behaviour in Chile's private health insurance industry.

  4. Optimal segmentation and packaging process

    DOEpatents

    Kostelnik, Kevin M.; Meservey, Richard H.; Landon, Mark D.

    1999-01-01

    A process for improving packaging efficiency uses three dimensional, computer simulated models with various optimization algorithms to determine the optimal segmentation process and packaging configurations based on constraints including container limitations. The present invention is applied to a process for decontaminating, decommissioning (D&D), and remediating a nuclear facility involving the segmentation and packaging of contaminated items in waste containers in order to minimize the number of cuts, maximize packaging density, and reduce worker radiation exposure. A three-dimensional, computer simulated, facility model of the contaminated items are created. The contaminated items are differentiated. The optimal location, orientation and sequence of the segmentation and packaging of the contaminated items is determined using the simulated model, the algorithms, and various constraints including container limitations. The cut locations and orientations are transposed to the simulated model. The contaminated items are actually segmented and packaged. The segmentation and packaging may be simulated beforehand. In addition, the contaminated items may be cataloged and recorded.

  5. On the Regulation of Consonant Duration in the Speech Perception and Production of Adults and 5 to 7 Year Old Children.

    ERIC Educational Resources Information Center

    Hawkins, Sarah; Tatham, M. A. A.

    The perception of duration in consonant segments is compared with their produced durations, and adults' and children's performance in this respect are compared. The temporal organization imposed by adults on initial consonant clusters was often not imposed by children from four to eight years of age, even though the cluster was produced…

  6. IDF relationships for short duration rainfall

    NASA Astrophysics Data System (ADS)

    Montesarchio, Valeria; Napolitano, Francesco; Russo, Fabio; Spina, S.

    2013-10-01

    The intensity-duration-frequency (IDF) relationships bound rainfall intensity to duration and return period. These relationships are commonly used as an input in design of many hydraulic structures and drainage systems. Empirical IDF are estimated on the basis of recorded maximum annual precipitation of given durations, often ranging from 1 h to 24 h. For shorter durations, extrapolations are applied. In this paper, maximum annual precipitation for durations shorter than 1 h (namely, 30 min and 10 min) are evaluated using a rainfall disaggregation model and then used for the evaluation of the IDF relationship. A comparison of values obtained with the extrapolated values is then performed, and the results are discussed. Keywords: intensity-duration-frequency curves, rainfall disaggregation, entropy.

  7. The LOFT ground segment

    NASA Astrophysics Data System (ADS)

    Bozzo, E.; Antonelli, A.; Argan, A.; Barret, D.; Binko, Pavel; Brandt, S.; Cavazzuti, E.; Courvoisier, T.; den Herder, J. W.; Feroci, M.; Ferrigno, C.; Giommi, P.; Götz, D.; Guy, L.; Hernanz, M.; in't Zand, J. J. M.; Klochkov, D.; Kuulkers, Erik; Motch, C.; Lumb, D.; Papitto, A.; Pittori, Carlotta; Rohlfs, R.; Santangelo, A.; Schmid, C.; Schwope, A. D.; Smith, P. J.; Webb, N. A.; Wilms, J.; Zane, S.

    2014-07-01

    LOFT, the Large Observatory For X-ray Timing, was one of the ESA M3 mission candidates that completed their assessment phase at the end of 2013. LOFT is equipped with two instruments, the Large Area Detector (LAD) and the Wide Field Monitor (WFM). The LAD performs pointed observations of several targets per orbit (~90 minutes), providing roughly ~80 GB of proprietary data per day (the proprietary period will be 12 months). The WFM continuously monitors about 1/3 of the sky at a time and provides data for about ~100 sources a day, resulting in a total of ~20 GB of additional telemetry. The LOFT Burst alert System additionally identifies on-board bright impulsive events (e.g., Gamma-ray Bursts, GRBs) and broadcasts the corresponding position and trigger time to the ground using a dedicated system of ~15 VHF receivers. All WFM data are planned to be made public immediately. In this contribution we summarize the planned organization of the LOFT ground segment (GS), as established in the mission Yellow Book1. We describe the expected GS contributions from ESA and the LOFT consortium. A review is provided of the planned LOFT data products and the details of the data flow, archiving and distribution. Despite LOFT was not selected for launch within the M3 call, its long assessment phase ( >2 years) led to a very solid mission design and an efficient planning of its ground operations.

  8. Evolution of segmented strings

    NASA Astrophysics Data System (ADS)

    Gubser, Steven S.

    2016-11-01

    I explain how to evolve segmented strings in de Sitter and anti-de Sitter spaces of any dimension in terms of forward-directed null displacements. The evolution is described entirely in terms of discrete hops which do not require a continuum spacetime. Moreover, the evolution rule is purely algebraic, so it can be defined not only on ordinary real de Sitter and anti-de Sitter but also on the rational points of the quadratic equations that define these spaces. For three-dimensional anti-de Sitter space, a simpler evolution rule is possible that descends from the Wess-Zumino-Witten equations of motion. In this case, one may replace three-dimensional anti-de Sitter space by a noncompact discrete subgroup of S L (2 ,R ) whose structure is related to the Pell equation. A discrete version of the Bañados-Teitelboim-Zanelli (BTZ) black hole can be constructed as a quotient of this subgroup. This discrete black hole avoids the firewall paradox by a curious mechanism: even for large black holes, there are no points inside the horizon until one reaches the singularity.

  9. 5 CFR 890.1302 - Duration.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... EMPLOYEES HEALTH BENEFITS PROGRAM Department of Defense Federal Employees Health Benefits Program Demonstration Project § 890.1302 Duration. The demonstration project will run from January 1, 2000,...

  10. LSM: perceptually accurate line segment merging

    NASA Astrophysics Data System (ADS)

    Hamid, Naila; Khan, Nazar

    2016-11-01

    Existing line segment detectors tend to break up perceptually distinct line segments into multiple segments. We propose an algorithm for merging such broken segments to recover the original perceptually accurate line segments. The algorithm proceeds by grouping line segments on the basis of angular and spatial proximity. Then those line segment pairs within each group that satisfy unique, adaptive mergeability criteria are successively merged to form a single line segment. This process is repeated until no more line segments can be merged. We also propose a method for quantitative comparison of line segment detection algorithms. Results on the York Urban dataset show that our merged line segments are closer to human-marked ground-truth line segments compared to state-of-the-art line segment detection algorithms.

  11. A Segmental Framework for Representing Signs Phonetically

    ERIC Educational Resources Information Center

    Johnson, Robert E.; Liddell, Scott K.

    2011-01-01

    The arguments for dividing the signing stream in signed languages into sequences of phonetic segments are compelling. The visual records of instances of actually occurring signs provide evidence of two basic types of segments: postural segments and trans-forming segments. Postural segments specify an alignment of articulatory features, both manual…

  12. A Segmental Framework for Representing Signs Phonetically

    ERIC Educational Resources Information Center

    Johnson, Robert E.; Liddell, Scott K.

    2011-01-01

    The arguments for dividing the signing stream in signed languages into sequences of phonetic segments are compelling. The visual records of instances of actually occurring signs provide evidence of two basic types of segments: postural segments and trans-forming segments. Postural segments specify an alignment of articulatory features, both manual…

  13. Multiatlas Segmentation as Nonparametric Regression

    PubMed Central

    Awate, Suyash P.; Whitaker, Ross T.

    2015-01-01

    This paper proposes a novel theoretical framework to model and analyze the statistical characteristics of a wide range of segmentation methods that incorporate a database of label maps or atlases; such methods are termed as label fusion or multiatlas segmentation. We model these multiatlas segmentation problems as nonparametric regression problems in the high-dimensional space of image patches. We analyze the nonparametric estimator’s convergence behavior that characterizes expected segmentation error as a function of the size of the multiatlas database. We show that this error has an analytic form involving several parameters that are fundamental to the specific segmentation problem (determined by the chosen anatomical structure, imaging modality, registration algorithm, and label-fusion algorithm). We describe how to estimate these parameters and show that several human anatomical structures exhibit the trends modeled analytically. We use these parameter estimates to optimize the regression estimator. We show that the expected error for large database sizes is well predicted by models learned on small databases. Thus, a few expert segmentations can help predict the database sizes required to keep the expected error below a specified tolerance level. Such cost-benefit analysis is crucial for deploying clinical multiatlas segmentation systems. PMID:24802528

  14. Direct volume estimation without segmentation

    NASA Astrophysics Data System (ADS)

    Zhen, X.; Wang, Z.; Islam, A.; Bhaduri, M.; Chan, I.; Li, S.

    2015-03-01

    Volume estimation plays an important role in clinical diagnosis. For example, cardiac ventricular volumes including left ventricle (LV) and right ventricle (RV) are important clinical indicators of cardiac functions. Accurate and automatic estimation of the ventricular volumes is essential to the assessment of cardiac functions and diagnosis of heart diseases. Conventional methods are dependent on an intermediate segmentation step which is obtained either manually or automatically. However, manual segmentation is extremely time-consuming, subjective and highly non-reproducible; automatic segmentation is still challenging, computationally expensive, and completely unsolved for the RV. Towards accurate and efficient direct volume estimation, our group has been researching on learning based methods without segmentation by leveraging state-of-the-art machine learning techniques. Our direct estimation methods remove the accessional step of segmentation and can naturally deal with various volume estimation tasks. Moreover, they are extremely flexible to be used for volume estimation of either joint bi-ventricles (LV and RV) or individual LV/RV. We comparatively study the performance of direct methods on cardiac ventricular volume estimation by comparing with segmentation based methods. Experimental results show that direct estimation methods provide more accurate estimation of cardiac ventricular volumes than segmentation based methods. This indicates that direct estimation methods not only provide a convenient and mature clinical tool for cardiac volume estimation but also enables diagnosis of cardiac diseases to be conducted in a more efficient and reliable way.

  15. Multiatlas segmentation as nonparametric regression.

    PubMed

    Awate, Suyash P; Whitaker, Ross T

    2014-09-01

    This paper proposes a novel theoretical framework to model and analyze the statistical characteristics of a wide range of segmentation methods that incorporate a database of label maps or atlases; such methods are termed as label fusion or multiatlas segmentation. We model these multiatlas segmentation problems as nonparametric regression problems in the high-dimensional space of image patches. We analyze the nonparametric estimator's convergence behavior that characterizes expected segmentation error as a function of the size of the multiatlas database. We show that this error has an analytic form involving several parameters that are fundamental to the specific segmentation problem (determined by the chosen anatomical structure, imaging modality, registration algorithm, and label-fusion algorithm). We describe how to estimate these parameters and show that several human anatomical structures exhibit the trends modeled analytically. We use these parameter estimates to optimize the regression estimator. We show that the expected error for large database sizes is well predicted by models learned on small databases. Thus, a few expert segmentations can help predict the database sizes required to keep the expected error below a specified tolerance level. Such cost-benefit analysis is crucial for deploying clinical multiatlas segmentation systems.

  16. The influence of movement segment difficulty on movements with two-stroke sequence.

    PubMed

    Rand, M K; Alberts, J L; Stelmach, G E; Bloedel, J R

    1997-06-01

    Arm movements in the horizontal plane consisting of two segments were examined to determine whether the difficulty of the second segment influenced the kinematic characteristics of the first segment. The direction of the first segment was an elbow extension movement away from the trunk and remained constant throughout the experiment. The direction of the second segment varied between forearm extension and flexion movements. Based on Fitts' law, two different indexes of difficulty (ID) of the second segment were utilized by changing target size and movement amplitude. The effects of changing ID were examined for two different movement amplitudes. All movements were single-joint movements employing elbow flexion/extension and were recorded by an x-y digitizer. Variations in the ID of the second segment produced context-dependent kinematic changes in the performance of the initial segment. Movement duration increased when the ID was increased by reducing target size for both extension-extension sequence and extension-flexion sequences. Peak velocity also decreased for higher ID targets in the extension-flexion sequence. However, there was an interaction between the ID and movement amplitude in the extension-flexion sequence. In this sequence the duration of movement for the high ID/large movement amplitude condition increased substantially compared with the low ID/small movement amplitude condition. In addition, changing ID of the second segment influenced the time between the two segments (intersegment interval) in the extension-flexion sequence. Collectively, these data suggest that the planning of complex movements is based in part on the accuracy demands of multiple segments of the sequence.

  17. Word Durations in Non-Native English

    PubMed Central

    Baker, Rachel E.; Baese-Berk, Melissa; Bonnasse-Gahot, Laurent; Kim, Midam; Van Engen, Kristin J.; Bradlow, Ann R.

    2010-01-01

    In this study, we compare the effects of English lexical features on word duration for native and non-native English speakers and for non-native speakers with different L1s and a range of L2 experience. We also examine whether non-native word durations lead to judgments of a stronger foreign accent. We measured word durations in English paragraphs read by 12 American English (AE), 20 Korean, and 20 Chinese speakers. We also had AE listeners rate the `accentedness' of these non-native speakers. AE speech had shorter durations, greater within-speaker word duration variance, greater reduction of function words, and less between-speaker variance than non-native speech. However, both AE and non-native speakers showed sensitivity to lexical predictability by reducing second mentions and high frequency words. Non-native speakers with more native-like word durations, greater within-speaker word duration variance, and greater function word reduction were perceived as less accented. Overall, these findings identify word duration as an important and complex feature of foreign-accented English. PMID:21516172

  18. 12 CFR 1252.2 - Effective duration.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 12 Banks and Banking 7 2010-01-01 2010-01-01 false Effective duration. 1252.2 Section 1252.2 Banks and Banking FEDERAL HOUSING FINANCE AGENCY ENTERPRISES PORTFOLIO HOLDINGS § 1252.2 Effective duration. This part shall be in effect for each Enterprise so long as— (a) This part has not been...

  19. Duration Sensitivity Depends on Stimulus Familiarity

    ERIC Educational Resources Information Center

    Morewedge, Carey K.; Kassam, Karim S.; Hsee, Christopher K.; Caruso, Eugene M.

    2009-01-01

    When people are asked to assess or compare the value of experienced or hypothetical events, one of the most intriguing observations is their apparent insensitivity to event duration. The authors propose that duration insensitivity occurs when stimuli are evaluated in isolation because they typically lack comparison information. People should be…

  20. Stimulus Intensity and the Perception of Duration

    ERIC Educational Resources Information Center

    Matthews, William J.; Stewart, Neil; Wearden, John H.

    2011-01-01

    This article explores the widely reported finding that the subjective duration of a stimulus is positively related to its magnitude. In Experiments 1 and 2 we show that, for both auditory and visual stimuli, the effect of stimulus magnitude on the perception of duration depends upon the background: Against a high intensity background, weak stimuli…

  1. 18 CFR 430.33 - Duration.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 18 Conservation of Power and Water Resources 2 2014-04-01 2014-04-01 false Duration. 430.33 Section 430.33 Conservation of Power and Water Resources DELAWARE RIVER BASIN COMMISSION SPECIAL REGULATIONS GROUND WATER PROTECTION AREA: PENNSYLVANIA § 430.33 Duration. The delineation and declaration of...

  2. 18 CFR 430.33 - Duration.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 18 Conservation of Power and Water Resources 2 2013-04-01 2012-04-01 true Duration. 430.33 Section 430.33 Conservation of Power and Water Resources DELAWARE RIVER BASIN COMMISSION SPECIAL REGULATIONS GROUND WATER PROTECTION AREA: PENNSYLVANIA § 430.33 Duration. The delineation and declaration of the...

  3. 18 CFR 430.33 - Duration.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 18 Conservation of Power and Water Resources 2 2012-04-01 2012-04-01 false Duration. 430.33 Section 430.33 Conservation of Power and Water Resources DELAWARE RIVER BASIN COMMISSION SPECIAL REGULATIONS GROUND WATER PROTECTION AREA: PENNSYLVANIA § 430.33 Duration. The delineation and declaration of...

  4. Stimulus Intensity and the Perception of Duration

    ERIC Educational Resources Information Center

    Matthews, William J.; Stewart, Neil; Wearden, John H.

    2011-01-01

    This article explores the widely reported finding that the subjective duration of a stimulus is positively related to its magnitude. In Experiments 1 and 2 we show that, for both auditory and visual stimuli, the effect of stimulus magnitude on the perception of duration depends upon the background: Against a high intensity background, weak stimuli…

  5. Accounting for segment correlations in segmented gamma-ray scans

    SciTech Connect

    Sheppard, G.A.; Prettyman, T.H.; Piquette, E.C.

    1994-08-01

    In a typical segmented gamma-ray scanner (SGS), the detector`s field of view is collimated so that a complete horizontal slice or segment of the desired thickness is visible. Ordinarily, the collimator is not deep enough to exclude gamma rays emitted from sample volumes above and below the segment aligned with the collimator. This can lead to assay biases, particularly for certain radioactive-material distributions. Another consequence of the collimator`s low aspect ratio is that segment assays at the top and bottom of the sample are biased low because the detector`s field of view is not filled. This effect is ordinarily countered by placing the sample on a low-Z pedestal and scanning one or more segment thicknesses below and above the sample. This takes extra time, however, We have investigated a number of techniques that both account for correlated segments and correct for end effects in SGS assays. Also, we have developed an algorithm that facilitates estimates of assay precision. Six calculation methods have been compared by evaluating the results of thousands of simulated, assays for three types of gamma-ray source distribution and ten masses. We will report on these computational studies and their experimental verification.

  6. Potential application of Raman spectroscopy for determining burial duration of skeletal remains.

    PubMed

    McLaughlin, Gregory; Lednev, Igor K

    2011-11-01

    Raman spectroscopy was used to study trends in chemical composition of bones in a burial environment. A turkey bone was sectioned and buried for short intervals between 12 and 62 days. Buried sections were analyzed using Raman microspectroscopy with 785 nm excitation. The results indicate that chemical changes in bone due to soil bacteria are time-dependent. Spectroscopic trends within buried bone segments were correlated to burial duration. A preliminary model was constructed using peak integration of Raman bands. Data collected within buried bone segments fit very well in this model. The model constructed is sensitive to changes in bone composition in a scale of days. This study illustrates the great potential of Raman spectroscopy as a non-destructive method for estimating the burial duration of bone for forensic purposes.

  7. Autonomic Recovery after Long-Duration Spaceflight

    NASA Astrophysics Data System (ADS)

    Couckuyt, Kurt; Verheyden, Bart; Liu, Jiexin; Aubert, Andre E.

    2008-06-01

    In this study, the recovery of cardiovascular autonomic modulation after long-duration spaceflight (6 months) is evaluated over a period of 30 days. Results from long-duration spaceflight were compared with the results obtained in astronauts who spent about 10 days in space. It is expected that cardiovascular recovery after spaceflight takes longer when the time spent in weightlessness is extended. Six male astronauts who spent 6 months in space in the ISS participated in the study. It was found that after long duration spaceflight, there is a sympathetic autonomic dominance resulting in post-flight orthostatic tachycardia. Surprisingly, no differences were found in autonomic changes and post-flight recovery after long-duration spaceflight compared to post-flight autonomic control after short-duration spaceflight.

  8. Ensemble segmentation using efficient integer linear programming.

    PubMed

    Alush, Amir; Goldberger, Jacob

    2012-10-01

    We present a method for combining several segmentations of an image into a single one that in some sense is the average segmentation in order to achieve a more reliable and accurate segmentation result. The goal is to find a point in the "space of segmentations" which is close to all the individual segmentations. We present an algorithm for segmentation averaging. The image is first oversegmented into superpixels. Next, each segmentation is projected onto the superpixel map. An instance of the EM algorithm combined with integer linear programming is applied on the set of binary merging decisions of neighboring superpixels to obtain the average segmentation. Apart from segmentation averaging, the algorithm also reports the reliability of each segmentation. The performance of the proposed algorithm is demonstrated on manually annotated images from the Berkeley segmentation data set and on the results of automatic segmentation algorithms.

  9. Sleep Duration and Biomarkers of Inflammation

    PubMed Central

    Patel, Sanjay R.; Zhu, Xiaobei; Storfer-Isser, Amy; Mehra, Reena; Jenny, Nancy S.; Tracy, Russell; Redline, Susan

    2009-01-01

    Introduction: Extremes of sleep duration have been associated with adverse health outcomes. The mechanism is unclear but may be related to increased inflammation. We sought to assess the association between sleep duration and inflammatory biomarkers. Methods: A total of 614 individuals from the Cleveland Family Study completed questionnaires about sleep habits and underwent polysomnography. A morning fasting blood sample was assayed for 5 inflammatory cytokines. Results: In this cohort, mean (SD) habitual sleep duration based on self-report was 7.6 (1.6) h and mean sleep duration by polysomnography (PSG) on the night prior to blood sampling was 6.2 (1.3) h. After adjusting for obesity and apnea severity, each additional hour of habitual sleep duration was associated with an 8% increase in C-reactive protein (CRP) levels (P = 0.004) and 7% increase in interleukin-6 (IL-6) levels (P = 0.0003). These associations were independent of self-reported sleepiness. In contrast, PSG sleep duration was inversely associated with tumor necrosis factor alpha (TNFα) levels. For each hour reduction in sleep, TNFα levels increased by 8% on average (P = 0.02). Sleep duration was not associated with IL-1 or IL-10. Conclusions: Increases in habitual sleep durations are associated with elevations in CRP and IL-6 while reduced PSG sleep duration is associated with elevated TNFα levels. Activation of pro-inflammatory pathways may represent a mechanism by which extreme sleep habits affect health. Citation: Patel SR; Zhu X; Storfer-Isser A; Mehra R; Jenny NS; Tracy R; Redline S. Sleep duration and biomarkers of inflammation. SLEEP 2009;32(2):200–204. PMID:19238807

  10. Metrology of IXO Mirror Segments

    NASA Technical Reports Server (NTRS)

    Chan, Kai-Wing

    2011-01-01

    For future x-ray astrophysics mission that demands optics with large throughput and excellent angular resolution, many telescope concepts build around assembling thin mirror segments in a Wolter I geometry, such as that originally proposed for the International X-ray Observatory. The arc-second resolution requirement posts unique challenges not just for fabrication, mounting but also for metrology of these mirror segments. In this paper, we shall discuss the metrology of these segments using normal incidence metrological method with interferometers and null lenses. We present results of the calibration of the metrology systems we are currently using, discuss their accuracy and address the precision in measuring near-cylindrical mirror segments and the stability of the measurements.

  11. Texture segmentation by genetic programming.

    PubMed

    Song, Andy; Ciesielski, Vic

    2008-01-01

    This paper describes a texture segmentation method using genetic programming (GP), which is one of the most powerful evolutionary computation algorithms. By choosing an appropriate representation texture, classifiers can be evolved without computing texture features. Due to the absence of time-consuming feature extraction, the evolved classifiers enable the development of the proposed texture segmentation algorithm. This GP based method can achieve a segmentation speed that is significantly higher than that of conventional methods. This method does not require a human expert to manually construct models for texture feature extraction. In an analysis of the evolved classifiers, it can be seen that these GP classifiers are not arbitrary. Certain textural regularities are captured by these classifiers to discriminate different textures. GP has been shown in this study as a feasible and a powerful approach for texture classification and segmentation, which are generally considered as complex vision tasks.

  12. Reduplication facilitates early word segmentation.

    PubMed

    Ota, Mitsuhiko; Skarabela, Barbora

    2017-02-06

    This study explores the possibility that early word segmentation is aided by infants' tendency to segment words with repeated syllables ('reduplication'). Twenty-four nine-month-olds were familiarized with passages containing one novel reduplicated word and one novel non-reduplicated word. Their central fixation times in response to these as well as new reduplicated and non-reduplicated words introduced at test showed that familiarized reduplicated words were segmented better than familiarized non-reduplicated words. These results demonstrate that infants are predisposed to segment words with repeated phonological elements, and suggest that register-specific words in infant-directed speech may have evolved in response to this learning bias.

  13. Morphing of Segmented Bimorph Mirrors

    NASA Astrophysics Data System (ADS)

    Rodrigues, Gonçalo; Bastaits, Renaud; Preumont, André

    2010-08-01

    Atmospheric turbulence compensation for the next generation of terrestrial telescopes (30-40 m diameter) will require deformable mirrors of increasing size and a number of actuators reaching several thousands. However, the mere extrapolation of existing designs leads to complicated and extremely expensive mirrors. This article discusses an alternative solution based on the use of segmented identical hexagonal bimorph mirrors. This allows to indefinitely increase the degree of correction while maintaining the first mechanical resonance at the level of a single segment, and shows an increase in price only proportional to the number of segments. Extensive simulations using random turbulent screens show that the segmentation produces only moderate reductions of the Strehl number, compared to a monolithic bimorph mirror with the same number of actuators (S = 0.86 instead of S = 0.89 in this study).

  14. Image Segmentation Using Affine Wavelets

    DTIC Science & Technology

    1991-12-12

    2-4 2.7 Artificial Neural Network Radial Basis Function Classifiers . . . 2-5 2.7.1 Localized Receptive Fields...used a radial 1-3 basis function artificial neural network, which accomplishes the segmentation based on the multiresolution features. 1.7 Objectives...as the features? "* Can the Radial Basis Function (RBF) artificial neural network be trained to au- tonomously segment SAR and FLIR imagery using the

  15. Non-Orthogonal Iris Segmentation

    DTIC Science & Technology

    2005-05-09

    pixels ( eyelashes , eyelids, etc.). For example, if all three quality bounds are close in proximity, the iris pattern that was segmented...iris pattern that was segmented by the algorithm contains eyelashes and additional extraneous information. If all automatically generated “test” mask...orthogonal iris images (see Figs. 25-28). This is primarily explained by the increased presence of eyelashes in the non-orthogonal iris masks. As the angle

  16. Neural network for image segmentation

    NASA Astrophysics Data System (ADS)

    Skourikhine, Alexei N.; Prasad, Lakshman; Schlei, Bernd R.

    2000-10-01

    Image analysis is an important requirement of many artificial intelligence systems. Though great effort has been devoted to inventing efficient algorithms for image analysis, there is still much work to be done. It is natural to turn to mammalian vision systems for guidance because they are the best known performers of visual tasks. The pulse- coupled neural network (PCNN) model of the cat visual cortex has proven to have interesting properties for image processing. This article describes the PCNN application to the processing of images of heterogeneous materials; specifically PCNN is applied to image denoising and image segmentation. Our results show that PCNNs do well at segmentation if we perform image smoothing prior to segmentation. We use PCNN for obth smoothing and segmentation. Combining smoothing and segmentation enable us to eliminate PCNN sensitivity to the setting of the various PCNN parameters whose optimal selection can be difficult and can vary even for the same problem. This approach makes image processing based on PCNN more automatic in our application and also results in better segmentation.

  17. The Envisat-1 ground segment

    NASA Astrophysics Data System (ADS)

    Harris, Ray; Ashton, Martin

    1995-03-01

    The European Space Agency (ESA) Earth Remote Sensing Satellite (ERS-1 and ERS-2) missions will be followed by the Polar Orbit Earth Mission (POEM) program. The first of the POEM missions will be Envisat-1. ESA has completed the design phase of the ground segment. This paper presents the main elements of that design. The main part of this paper is an overview of the Payload Data Segment (PDS) which is the core of the Envisat-1 ground segment, followed by two further sections which describe in more detail the facilities to be offered by the PDS for archiving and for user servcies. A further section describes some future issues for ground segment development. Logica was the prime contractor of a team of 18 companies which undertook the ESA financed architectural design study of the Envisat-1 ground segment. The outputs of the study included detailed specifications of the components that will acquire, process, archive and disseminate the payload data, together with the functional designs of the flight operations and user data segments.

  18. Attentional entrainment and perceived event duration

    PubMed Central

    McAuley, J. Devin; Fromboluti, Elisa Kim

    2014-01-01

    This study considered the contribution of dynamic attending theory (DAT) and attentional entrainment to systematic distortions in perceived event duration. Three experiments were conducted using an auditory oddball paradigm, in which listeners judged the duration of a deviant (oddball) stimulus embedded within a series of identical (standard) stimuli. To test for a role of attentional entrainment in perceived oddball duration, oddballs were presented at either temporally expected (on time) or unexpectedly early or late time points relative to extrapolation of the context rhythm. Consistent with involvement of attentional entrainment in perceived duration, duration judgements about the oddball were least distorted when the oddball occurred on time with respect to the entrained rhythm, whereas durations of early and late oddballs were perceived to be shorter and longer, respectively. This pattern of results was independent of the absolute time interval preceding the oddball. Moreover, as expected, an irregularly timed sequence context weakened observed differences between oddballs with on-time and late onsets. Combined with other recent work on the role of temporal preparation in duration distortions, the present findings allot at least a portion of the oddball effect to increased attention to events that are more expected, rather than on their unexpected nature per se. PMID:25385779

  19. Repetition enhancement and memory effects for duration.

    PubMed

    Wiener, Martin; Thompson, James C

    2015-06-01

    A remarkable aspect of conscious perception is that moments carryover from one to the next, also known as temporal continuity. This ability is thus crucial for detecting regularities, such as in speech and music, and may rely on an accurate perception of time. Investigations of human time perception have detailed two electroencephalographic (EEG) components associated with timing, the contingent negative variation (CNV) and late positive component of timing (LPCt); however, the precise roles of these components in timing remain elusive. Recently, we demonstrated that the perception of duration is influenced by durations presented on prior trials, which we explained by the creation of an implicit memory standard that adapts to local changes in sequence presentation. Here, we turn to the neural basis of this effect. Human participants performed a temporal bisection task in which they were required to classify the duration of auditory stimuli into short and long duration categories; crucially, the presentation order was first-order counterbalanced, allowing us to measure the effect of each presented duration on the next. EEG recordings revealed that the CNV and LPCt signals both covaried with the duration presented on the current trial, with CNV predicting reaction time and LPCt predicting choice. Additionally, both signals covaried with the duration presented in the prior trial but in different ways, with the CNV amplitude reflecting the change in the memory standard and the LPCt reflecting decision uncertainty. Furthermore, we observed a repetition enhancement effect of duration only for the CNV, suggesting that this signal additionally indexes the similarity of successive durations. These findings demonstrate dissociable roles for the CNV and LPCt, and demonstrate that both signals are continuously updated on a trial-by-trial basis that reflects shifts in temporal decisions. Copyright © 2015 Elsevier Inc. All rights reserved.

  20. Methods to shorten the duration of an external fixator in the management of tibial infections

    PubMed Central

    Emara, Khaled M; Ghafar, Khaled Abd Al; Al Kersh, Mohamed Ahmed

    2011-01-01

    Massive segmental bone loss due to chronic osteomyelitis represents a considerable challenge to orthopedic surgeons and is a limb threatening condition. The only option available in such a clinical situation is segment transport using the Ilizarov technique of distraction osteogenesis; yet the most common problem in cases of bone transport with the Ilizarov technique in massive bone loss, is the long duration of the fixator. In addition to autologous bone grafting, several mechanical, biologic, and external physical treatment modalities may be employed to promote bone formation and maturation during segment transport in osteomyelitis patients. Mechanical approaches include compressive loading of the distraction regenerate, increased frequency of small increments of distraction, and compression-distraction. Intramedullary nailing and hemicorticotomy can reduce the time in external fixation; however, these techniques are associated with technical difficulties and complications. Exogenous application of low-intensity pulsed ultrasound or pulsed electromagnetic fields may shorten the duration of external fixation. Other promising modalities include diphosphonates, physician-directed use (off-label use) of bone morphogenetic proteins, and local injection of bone marrow aspirate and platelet gel at the osteotomy site. Well-designed clinical studies are needed to establish safe and effective guidelines for various modalities to enhance new bone formation during distraction osteogenesis after segment transfer. PMID:22474640

  1. Risk stratification for malignant progression in Barrett’s esophagus: Gender, age, duration and year of surveillance

    PubMed Central

    Gatenby, Piers; Bhattacharjee, Santanu; Wall, Christine; Caygill, Christine; Watson, Anthony

    2016-01-01

    AIM To clarify risk based upon segment length, diagnostic histological findings, patient age and year of surveillance, duration of surveillance and gender. METHODS Patients registered with the United Kingdom Barrett’s Oesophagus Registry from 9 United Kingdom centers were included. The outcome measures were (1) development of all grades of dysplasia; (2) development of high-grade of dysplasia or adenocarcinoma; and (3) development of adenocarcinoma. Prevalent cases and subjects with < 1 year of follow-up were excluded. The covariates examined were segment length, previous biopsy findings, age at surveillance, duration of surveillance, year of surveillance and gender. RESULTS One thousand and one hundred thirty six patients were included (total 6474 patient-years). Fifty-four patients developed adenocarcinoma (0.83% per annum), 70 developed high-grade dysplasia/adenocarcinoma (1.1% per annum) and 190 developed any grade of dysplasia (3.5% per annum). High grade dysplasia and adenocarcinoma increased with age and duration of surveillance. The risk of low-grade dysplasia development was not dependent on age at surveillance. Segment length and previous biopsy findings were also significant factors for development of dysplasia and adenocarcinoma. CONCLUSION The risk of development of low-grade dysplasia is independent of age at surveillance, but high-grade dysplasia and adenocarcinoma were more commonly found at older age. Segment length and previous biopsy findings are also markers of risk. This study did not demonstrate stabilisation of the metaplastic segment with prolonged surveillance. PMID:28082811

  2. Medical image segmentation by MDP model

    NASA Astrophysics Data System (ADS)

    Lu, Yisu; Chen, Wufan

    2011-11-01

    MDP (Dirichlet Process Mixtures) model is applied to segment medical images in this paper. Segmentation can been automatically done without initializing segmentation class numbers. The MDP model segmentation algorithm is used to segment natural images and MR (Magnetic Resonance) images in the paper. To demonstrate the accuracy of the MDP model segmentation algorithm, many compared experiments, such as EM (Expectation Maximization) image segmentation algorithm, K-means image segmentation algorithm and MRF (Markov Field) image segmentation algorithm, have been done to segment medical MR images. All the methods are also analyzed quantitatively by using DSC (Dice Similarity Coefficients). The experiments results show that DSC of MDP model segmentation algorithm of all slices exceed 90%, which show that the proposed method is robust and accurate.

  3. Communicative functions integrate segments in prosodies and prosodies in segments.

    PubMed

    Kohler, Klaus J

    2011-01-01

    This paper takes a new look at the traditionally established divide between sounds and prosodies, viewing it as a useful heuristics in language descriptions that focus on the segmental make- up of words. It pleads for a new approach that bridges this reified compartmentalization of speech in a more global communicative perspective. Data are presented from a German perception experiment in the framework of the Semantic Differential that shows interdependence of f0 contours and the spectral characteristics of a following fricative segment, for the expression of semantic functions along the scales questioning - asserting, excited - calm, forceful - not forceful, contrary - agreeable. The results lead to the conclusion that segments shape prosodies and are shaped by them in varying ways in the coding of semantic functions. This implies that the analysis of sentence prosodies needs to integrate the manifestation of segments, just as the analysis of segments needs to consider their prosodic embedding. In communicative interaction, speakers set broad prosodic time windows of varying sizes, and listeners respond to them. So, future phonetic research needs to concentrate on speech analysis in such windows.

  4. Integrated segmentation of cellular structures

    NASA Astrophysics Data System (ADS)

    Ajemba, Peter; Al-Kofahi, Yousef; Scott, Richard; Donovan, Michael; Fernandez, Gerardo

    2011-03-01

    Automatic segmentation of cellular structures is an essential step in image cytology and histology. Despite substantial progress, better automation and improvements in accuracy and adaptability to novel applications are needed. In applications utilizing multi-channel immuno-fluorescence images, challenges include misclassification of epithelial and stromal nuclei, irregular nuclei and cytoplasm boundaries, and over and under-segmentation of clustered nuclei. Variations in image acquisition conditions and artifacts from nuclei and cytoplasm images often confound existing algorithms in practice. In this paper, we present a robust and accurate algorithm for jointly segmenting cell nuclei and cytoplasm using a combination of ideas to reduce the aforementioned problems. First, an adaptive process that includes top-hat filtering, Eigenvalues-of-Hessian blob detection and distance transforms is used to estimate the inverse illumination field and correct for intensity non-uniformity in the nuclei channel. Next, a minimum-error-thresholding based binarization process and seed-detection combining Laplacian-of-Gaussian filtering constrained by a distance-map-based scale selection is used to identify candidate seeds for nuclei segmentation. The initial segmentation using a local maximum clustering algorithm is refined using a minimum-error-thresholding technique. Final refinements include an artifact removal process specifically targeted at lumens and other problematic structures and a systemic decision process to reclassify nuclei objects near the cytoplasm boundary as epithelial or stromal. Segmentation results were evaluated using 48 realistic phantom images with known ground-truth. The overall segmentation accuracy exceeds 94%. The algorithm was further tested on 981 images of actual prostate cancer tissue. The artifact removal process worked in 90% of cases. The algorithm has now been deployed in a high-volume histology analysis application.

  5. The remembering of auditory event durations.

    PubMed

    Boltz, M G

    1992-09-01

    Three experiments examined the incidental remembering of event durations. In each study, Ss engaged in an initial learning phase in which they performed a set of perceptual ratings on events for a varying number of trials. These events consisted of tonal sequences or ecological sounds that varied in their internal structure and ending. Ss were then given a surprise memory task in which they were asked to recognize the duration of each event (Experiments 1 and 3) or extrapolate its completion (Experiment 2). Results showed that in contrast to irregularly timed events, those filled with regularly timed or continuous pitch information yielded high levels of accuracy that increased with greater learning experience. In addition, durations marked by a nonarbitrary ending were more accurately remembered than those marked by an arbitrary ending which, in fact, were misremembered as shorter than their actual duration. These findings are discussed in terms of an approach that emphasizes the role of event structure on perceiving and remembering activities.

  6. 18 CFR 430.33 - Duration.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... REGULATIONS GROUND WATER PROTECTION AREA: PENNSYLVANIA § 430.33 Duration. The delineation and declaration of the Southeastern Pennsylvania Ground Water Protected Area made pursuant to this regulation, and...

  7. 18 CFR 430.33 - Duration.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... REGULATIONS GROUND WATER PROTECTION AREA: PENNSYLVANIA § 430.33 Duration. The delineation and declaration of the Southeastern Pennsylvania Ground Water Protected Area made pursuant to this regulation, and...

  8. A progressive-duration schedule of reinforcement.

    PubMed

    Gulotta, Kara B; Byrne, Tom

    2015-12-01

    We describe a schedule of reinforcement involving systematic, within-session increases in response-duration requirements. Rats received access to appetitive reinforcers for depressing and holding down a response lever. Duration requirements increased after each reinforcer delivery. Sessions ended when reinforcement criteria were unmet for a period of ten minutes. Breaking points, defined as the terminal duration requirement in effect prior to the end of the session, stabilized when environmental conditions were held constant. Breaking points were sensitive to manipulations of both food deprivation and reinforcer quality. Analogous to progressive-ratio schedules, progressive-duration schedules may provide an assay for measuring the amount of behavior an organism will emit for a given reinforcer under current motivational conditions.

  9. Detrended fluctuation analysis of intertrade durations

    NASA Astrophysics Data System (ADS)

    Jiang, Zhi-Qiang; Chen, Wei; Zhou, Wei-Xing

    2009-02-01

    The intraday pattern, long memory, and multifractal nature of the intertrade durations, which are defined as the waiting times between two consecutive transactions, are investigated based upon the limit order book data and order flows of 23 liquid Chinese stocks listed on the Shenzhen Stock Exchange in 2003. An inverse U-shaped intraday pattern in the intertrade durations with an abrupt drop in the first minute of the afternoon trading is observed. Based on a detrended fluctuation analysis, we find a crossover of power-law scaling behaviors for small box sizes (trade numbers in boxes) and large box sizes and strong evidence in favor of long memory in both regimes. In addition, the multifractal nature of intertrade durations in both regimes is confirmed by a multifractal detrended fluctuation analysis for individual stocks with a few exceptions in the small-duration regime. The intraday pattern has little influence on the long memory and multifractality.

  10. 14 CFR 420.43 - Duration.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... TRANSPORTATION LICENSING LICENSE TO OPERATE A LAUNCH SITE License Terms and Conditions § 420.43 Duration. A license to operate a launch site remains in effect for five years from the date of issuance...

  11. [Duration of antibiotic therapy in bacterial meningitis].

    PubMed

    Pereira, P Ricardo; Borges, Fernando; Mansinho, Kamal

    2013-01-01

    The duration of antibiotic therapy in bacterial meningitis is a controversial issue. Antibiotic regimens have changed over time along with the criteria used to determine the ideal antibiotic therapy duration. The authors aim to make an historical overview on this matter and simultaneously add the evidence of recent studies, pointing out some issues in results interpretation, namely, their design and the associated demographic and epidemiological questions. Clinical assays on this subject, with statistically significant results, are quite recent. Most of the scientific knowledge has been acquired empirically through the times. The actual investigation paradigm, in what concerns to antibiotic therapy in bacterial meningitis, lays on the dichotomy: "short versus long duration regimens". Nevertheless, so far, the existing studies have not completely cleared this doubt. Thus, despite some evidence suggests that short duration antibiotic regimens are effective for some patients, in patients with severe disease presentations or with other morbidities its use may be questioned.

  12. Duration of breast-feeding in Bangladesh.

    PubMed

    Giashuddin, M S; Kabir, M

    2004-06-01

    The duration of exclusive breast-feeding in Bangladesh is low. Though several studies have been carried out on breast-feeding in Bangladesh, the factors influencing the duration of breast-feeding are not studied. The purpose of this study was to assess the duration of breast-feeding among children in Bangladesh and to study socio-economic and demographic factors affecting the duration. The study included 5068 mother-child pairs, selected on the basis of Bangladesh Demographic Health Survey (BDHS) of 1999-2000. The risk of giving supplementary food at different ages was estimated by life table survival method. Independent effects of total duration of breast-feeding of each of the study variables were estimated by using Cox's regression model. The median duration of full breast-feeding was 3.67 months whereas mean and median durations of total breast-feeding was 31.3 and 30 months respectively. Life table analysis showed that 69.9 per cent women gave supplementary food to their babies before reaching six months of age. Cox's regression analysis revealed that women who had lived in rural areas were less likely to terminate breast-feeding than those living in urban areas. Women who had completed at least secondary education were more likely to stop breast-feeding than less or uneducated mothers. Children born in high economic status families had higher risk of stopping breast-feeding compared to those in low economic status families. Further, the deliveries assisted by the relatives had lower risk of terminating breastfeeding than by the health professionals. According to the study results, women with higher education, high economic level, lower birth interval and delivery assisted by health personnel had lower duration of breastfeeding. Future breast-feeding programme in Bangladesh should give special attention to these women since they breast-feed relatively shorter periods of time.

  13. Sex and race differences in QRS duration.

    PubMed

    Hnatkova, Katerina; Smetana, Peter; Toman, Ondrej; Schmidt, Georg; Malik, Marek

    2016-12-01

    The study investigated healthy subjects to study sex and race differences in QRS durations and the dependency of QRS durations on heart rates and other physiologic correlates. QRS duration and its heart rate dependency were evaluated in 420 615 electrocardiograms obtained in 523 healthy subjects including 111 females of African origin, 130 Caucasian females, 125 males of African origin, and 129 Caucasian males. The distributions of QRS/RR slopes and QRS durations at RR intervals of 1 and 0.5 s were compared between sex- and race-defined subgroups. At high heart rates, QRS duration was increased in ∼35% of all subjects, while in the others, QRS was shortened (no differences between the subgroups). At RR interval of 1 s, the QRS duration was 97.4 ± 4.6, 99.8 ± 6.0, 101.6 ± 5.3, and 104.8 ± 6.3 ms in African females, Caucasian females, African males, and Caucasian males, respectively (all differences P < 0.001). Similar statistical differences were found at an RR of 0.5 s. When accounting for the differences in lean body mass, the difference between African and Caucasian subjects was as large as the difference between females and males. Within each subgroup, the normal QRS durations differed by 15-20 and 18-25 ms at RR intervals of 1 and 0.5 s, respectively. The QRS widths are heart rate dependent and different not only between women and men but also between African and Caucasian individuals. Difference in cardiac resynchronization therapy efficacy might be expected between patients of African and Caucasian origin stratified by QRS duration. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For permissions please email: journals.permissions@oup.com.

  14. Interaction of Factors Related to Lactation Duration

    PubMed Central

    Boettcher, Joan P; Chezem, Jo Carol; Roepke, Judith; Whitaker, Tracy Adams

    1999-01-01

    Perceived social support and interpersonal dependency were studied as potential factors associated with lactation duration based upon previous breastfeeding experience. Inexperienced breastfeeding mothers perceived more social support than experienced breastfeeding mothers did. Perceived social support was not significantly correlated with lactation duration. An ancillary finding was that women providing a combination of breast milk and human milk substitutes had significantly lower social self-confidence than did mothers providing breast milk exclusively. PMID:22945984

  15. Perceived duration of chromatic and achromatic light.

    PubMed

    Kojima, Haruyuki; Kawabata, Yasuhiro

    2012-01-15

    Luminance and color information are considered to be processed in parallel systems. The integration of information from these two separate systems is crucial for the visual system to produce a coherent percept. To investigate how luminance and color lights are perceived in time, we measured the perceived duration of light stimuli with and without colors in a paradigm involving simultaneous perception with presentation of two successive stimulus frames. Luminance contrast and color contrast of the stimuli were set with a chromatic substitution technique. In Experiment 1, the perceived duration of both chromatic stimuli and achromatic stimuli increased as the luminance contrast decreased. Experiment 2 tested if the duration of the percept was influenced by color contrast which was defined by colorimetric purity of the stimuli, when luminance contrast was set as low as practically possible. The result showed that the duration of the percept decreased with increasing color contrast of the stimuli. Moreover, Experiment 3 demonstrated that the trend of perceived duration was consistent with the four primary colors, provided that the effective color contrast of stimulus was corrected based on the contrast sensitivity to the color. These experiments indicate that, with a high luminance contrast level, perceived duration of a stimulus is predominantly defined by luminance contrast, whereas in low luminance contrast conditions, the duration depends on the color contrast. The perceived duration of color stimuli showed an "inverse color contrast effect", similar to the well-known "inverse intensity effect" for luminance stimuli. The similarities and the differences between the two systems, as well as their priorities in processing temporal information of visual stimuli are further discussed.

  16. Segmentation cues in conversational speech: robust semantics and fragile phonotactics.

    PubMed

    White, Laurence; Mattys, Sven L; Wiget, Lukas

    2012-01-01

    Multiple cues influence listeners' segmentation of connected speech into words, but most previous studies have used stimuli elicited in careful readings rather than natural conversation. Discerning word boundaries in conversational speech may differ from the laboratory setting. In particular, a speaker's articulatory effort - hyperarticulation vs. hypoarticulation (H&H) - may vary according to communicative demands, suggesting a compensatory relationship whereby acoustic-phonetic cues are attenuated when other information sources strongly guide segmentation. We examined how listeners' interpretation of segmentation cues is affected by speech style (spontaneous conversation vs. read), using cross-modal identity priming. To elicit spontaneous stimuli, we used a map task in which speakers discussed routes around stylized landmarks. These landmarks were two-word phrases in which the strength of potential segmentation cues - semantic likelihood and cross-boundary diphone phonotactics - was systematically varied. Landmark-carrying utterances were transcribed and later re-recorded as read speech. Independent of speech style, we found an interaction between cue valence (favorable/unfavorable) and cue type (phonotactics/semantics). Thus, there was an effect of semantic plausibility, but no effect of cross-boundary phonotactics, indicating that the importance of phonotactic segmentation may have been overstated in studies where lexical information was artificially suppressed. These patterns were unaffected by whether the stimuli were elicited in a spontaneous or read context, even though the difference in speech styles was evident in a main effect. Durational analyses suggested speaker-driven cue trade-offs congruent with an H&H account, but these modulations did not impact on listener behavior. We conclude that previous research exploiting read speech is reliable in indicating the primacy of lexically based cues in the segmentation of natural conversational speech.

  17. Collective behaviors of book holding durations

    NASA Astrophysics Data System (ADS)

    Li, Ren-De; Guo, Qiang; Han, Jing-Ti; Liu, Jian-Guo

    2016-10-01

    Duration can directly reflect the collective reading behaviors of library user book holding. In this paper, by introducing the burstiness and memory coefficients, we empirically investigate the collective book holding behavior of three university libraries. The statistical results show that there are similar properties among the students with different backgrounds, presenting the burstiness < B > = - 0.2 and memory < M > = 0.5 for three datasets, which indicates that memory and random effects coexist in student book holding durations. In addition, we analyze the behavior patterns without duplicate durations by merging a series of books borrowed and returned at the same time. The results show the average burstiness B increases to -0.16 and memory M drops to 0.16 for three datasets, which indicates that both duplicate behavior and student's preference affect the memory effect. Furthermore, we present a model which assumes student's next book holding duration follows the previous one with probability p, and with probability 1 - p, the student would hold the book independently. The experimental results show that the presented model can reproduce the burstiness and memory effect of student book holding durations when p = 0.5 for empirical datasets and p = 0.2 for de-duplicate datasets, which indicate that the student's preferential holding behavior occurs with the probability p. This work helps in deeply understanding the regularity of duration-based human behaviors.

  18. Strong motion duration and earthquake magnitude relationships

    SciTech Connect

    Salmon, M.W.; Short, S.A.; Kennedy, R.P.

    1992-06-01

    Earthquake duration is the total time of ground shaking from the arrival of seismic waves until the return to ambient conditions. Much of this time is at relatively low shaking levels which have little effect on seismic structural response and on earthquake damage potential. As a result, a parameter termed ``strong motion duration`` has been defined by a number of investigators to be used for the purpose of evaluating seismic response and assessing the potential for structural damage due to earthquakes. This report presents methods for determining strong motion duration and a time history envelope function appropriate for various evaluation purposes, for earthquake magnitude and distance, and for site soil properties. There are numerous definitions of strong motion duration. For most of these definitions, empirical studies have been completed which relate duration to earthquake magnitude and distance and to site soil properties. Each of these definitions recognizes that only the portion of an earthquake record which has sufficiently high acceleration amplitude, energy content, or some other parameters significantly affects seismic response. Studies have been performed which indicate that the portion of an earthquake record in which the power (average rate of energy input) is maximum correlates most closely with potential damage to stiff nuclear power plant structures. Hence, this report will concentrate on energy based strong motion duration definitions.

  19. Automatic segmentation of psoriasis lesions

    NASA Astrophysics Data System (ADS)

    Ning, Yang; Shi, Chenbo; Wang, Li; Shu, Chang

    2014-10-01

    The automatic segmentation of psoriatic lesions is widely researched these years. It is an important step in Computer-aid methods of calculating PASI for estimation of lesions. Currently those algorithms can only handle single erythema or only deal with scaling segmentation. In practice, scaling and erythema are often mixed together. In order to get the segmentation of lesions area - this paper proposes an algorithm based on Random forests with color and texture features. The algorithm has three steps. The first step, the polarized light is applied based on the skin's Tyndall-effect in the imaging to eliminate the reflection and Lab color space are used for fitting the human perception. The second step, sliding window and its sub windows are used to get textural feature and color feature. In this step, a feature of image roughness has been defined, so that scaling can be easily separated from normal skin. In the end, Random forests will be used to ensure the generalization ability of the algorithm. This algorithm can give reliable segmentation results even the image has different lighting conditions, skin types. In the data set offered by Union Hospital, more than 90% images can be segmented accurately.

  20. Optimal segmentation and packaging process

    DOEpatents

    Kostelnik, K.M.; Meservey, R.H.; Landon, M.D.

    1999-08-10

    A process for improving packaging efficiency uses three dimensional, computer simulated models with various optimization algorithms to determine the optimal segmentation process and packaging configurations based on constraints including container limitations. The present invention is applied to a process for decontaminating, decommissioning (D and D), and remediating a nuclear facility involving the segmentation and packaging of contaminated items in waste containers in order to minimize the number of cuts, maximize packaging density, and reduce worker radiation exposure. A three-dimensional, computer simulated, facility model of the contaminated items are created. The contaminated items are differentiated. The optimal location, orientation and sequence of the segmentation and packaging of the contaminated items is determined using the simulated model, the algorithms, and various constraints including container limitations. The cut locations and orientations are transposed to the simulated model. The contaminated items are actually segmented and packaged. The segmentation and packaging may be simulated beforehand. In addition, the contaminated items may be cataloged and recorded. 3 figs.

  1. Feature extraction for MRI segmentation.

    PubMed

    Velthuizen, R P; Hall, L O; Clarke, L P

    1999-04-01

    Magnetic resonance images (MRIs) of the brain are segmented to measure the efficacy of treatment strategies for brain tumors. To date, no reproducible technique for measuring tumor size is available to the clinician, which hampers progress of the search for good treatment protocols. Many segmentation techniques have been proposed, but the representation (features) of the MRI data has received little attention. A genetic algorithm (GA) search was used to discover a feature set from multi-spectral MRI data. Segmentations were performed using the fuzzy c-means (FCM) clustering technique. Seventeen MRI data sets from five patients were evaluated. The GA feature set produces a more accurate segmentation. The GA fitness function that achieves the best results is the Wilks's lambda statistic when applied to FCM clusters. Compared to linear discriminant analysis, which requires class labels, the same or better accuracy is obtained by the features constructed from a GA search without class labels, allowing fully operator independent segmentation. The GA approach therefore provides a better starting point for the measurement of the response of a brain tumor to treatment.

  2. 47 CFR 95.853 - Frequency segments.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Frequency segments. 95.853 Section 95.853... SERVICES 218-219 MHz Service Technical Standards § 95.853 Frequency segments. There are two frequency segments available for assignment to the 218-219 MHz Service in each service area. Frequency segment A is...

  3. 47 CFR 95.853 - Frequency segments.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 5 2012-10-01 2012-10-01 false Frequency segments. 95.853 Section 95.853... SERVICES 218-219 MHz Service Technical Standards § 95.853 Frequency segments. There are two frequency segments available for assignment to the 218-219 MHz Service in each service area. Frequency segment A is...

  4. 47 CFR 95.853 - Frequency segments.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 5 2011-10-01 2011-10-01 false Frequency segments. 95.853 Section 95.853... SERVICES 218-219 MHz Service Technical Standards § 95.853 Frequency segments. There are two frequency segments available for assignment to the 218-219 MHz Service in each service area. Frequency segment A is...

  5. 47 CFR 95.853 - Frequency segments.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 5 2013-10-01 2013-10-01 false Frequency segments. 95.853 Section 95.853... SERVICES 218-219 MHz Service Technical Standards § 95.853 Frequency segments. There are two frequency segments available for assignment to the 218-219 MHz Service in each service area. Frequency segment A is...

  6. 47 CFR 95.853 - Frequency segments.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 5 2014-10-01 2014-10-01 false Frequency segments. 95.853 Section 95.853... SERVICES 218-219 MHz Service Technical Standards § 95.853 Frequency segments. There are two frequency segments available for assignment to the 218-219 MHz Service in each service area. Frequency segment A is...

  7. Identifying Benefit Segments among College Students.

    ERIC Educational Resources Information Center

    Brown, Joseph D.

    1991-01-01

    Using concept of market segmentation (dividing market into distinct groups requiring different product benefits), surveyed 398 college students to determine benefit segments among students selecting a college to attend and factors describing each benefit segment. Identified one major segment of students (classroomers) plus three minor segments…

  8. U.S. Army Custom Segmentation System

    DTIC Science & Technology

    2007-06-01

    segmentation is individual or intergroup differences in response to marketing - mix variables. Presumptions about segments: •different demands in a...product or service category, •respond differently to changes in the marketing mix Criteria for segments: •The segments must exist in the environment

  9. Identifying Benefit Segments among College Students.

    ERIC Educational Resources Information Center

    Brown, Joseph D.

    1991-01-01

    Using concept of market segmentation (dividing market into distinct groups requiring different product benefits), surveyed 398 college students to determine benefit segments among students selecting a college to attend and factors describing each benefit segment. Identified one major segment of students (classroomers) plus three minor segments…

  10. Image Information Mining Utilizing Hierarchical Segmentation

    NASA Technical Reports Server (NTRS)

    Tilton, James C.; Marchisio, Giovanni; Koperski, Krzysztof; Datcu, Mihai

    2002-01-01

    The Hierarchical Segmentation (HSEG) algorithm is an approach for producing high quality, hierarchically related image segmentations. The VisiMine image information mining system utilizes clustering and segmentation algorithms for reducing visual information in multispectral images to a manageable size. The project discussed herein seeks to enhance the VisiMine system through incorporating hierarchical segmentations from HSEG into the VisiMine system.

  11. Durations required to distinguish noise and tone: Effects of noise bandwidth and frequency.

    PubMed

    Taghipour, Armin; Moore, Brian C J; Edler, Bernd

    2016-05-01

    Perceptual audio coders exploit the masking properties of the human auditory system to reduce the bit rate in audio recording and transmission systems; it is intended that the quantization noise is just masked by the audio signal. The effectiveness of the audio signal as a masker depends on whether it is tone-like or noise-like. The determination of this, both physically and perceptually, depends on the duration of the stimuli. To gather information that might improve the efficiency of perceptual coders, the duration required to distinguish between a narrowband noise and a tone was measured as a function of center frequency and noise bandwidth. In experiment 1, duration thresholds were measured for isolated noise and tone bursts. In experiment 2, duration thresholds were measured for tone and noise segments embedded within longer tone pulses. In both experiments, center frequencies were 345, 754, 1456, and 2658 Hz and bandwidths were 0.25, 0.5, and 1 times the equivalent rectangular bandwidth of the auditory filter at each center frequency. The duration thresholds decreased with increasing bandwidth and with increasing center frequency up to 1456 Hz. It is argued that the duration thresholds depended mainly on the detection of amplitude fluctuations in the noise bursts.

  12. Psychological distance to reward: Segmentation of aperiodic schedules of reinforcement

    PubMed Central

    Leung, Jin-Pang

    1993-01-01

    College students responded for monetary rewards in two experiments on choice between differentially segmented aperiodic schedules of reinforcement. On a microcomputer, the concurrent chains were simulated as an air-defense video game in which subjects used two radars for detecting and destroying enemy aircraft. To earn more cash-exchangeable points, subjects had to shoot down as many planes as possible within a given period of time. For both experiments, access to one of two radar systems (terminal link) was controlled by a pair of independent concurrent variable-interval 60-s schedules (initial link) with a 4-s changeover delay always in effect. In Experiment 1, the appearance of an enemy aircraft in the terminal link was determined by a variable-interval (15 s or 60 s) schedule or a two-component chained variable-interval schedule of equal duration. Experiment 2 was similar to Experiment 1 except for the segmented schedule, which had three components. Subjects preferred the unsegmented schedule over its segmented counterpart in the conditions with variable-interval 60 s, and preference tended to be more pronounced with more components in the segmented schedule. These findings are compatible with those from previous studies of periodic and aperiodic schedules with pigeons or humans as subjects. PMID:16812691

  13. Bronchopulmonary segments approximation using anatomical atlas

    NASA Astrophysics Data System (ADS)

    Busayarat, Sata; Zrimec, Tatjana

    2007-03-01

    Bronchopulmonary segments are valuable as they give more accurate localization than lung lobes. Traditionally, determining the segments requires segmentation and identification of segmental bronchi, which, in turn, require volumetric imaging data. In this paper, we present a method for approximating the bronchopulmonary segments for sparse data by effectively using an anatomical atlas. The atlas is constructed from a volumetric data and contains accurate information about bronchopulmonary segments. A new ray-tracing based image registration is used for transferring the information from the atlas to a query image. Results show that the method is able to approximate the segments on sparse HRCT data with slice gap up to 25 millimeters.

  14. Speaking Rate from Proximal and Distal Contexts Is Used during Word Segmentation

    ERIC Educational Resources Information Center

    Reinisch, Eva; Jesse, Alexandra; McQueen, James M.

    2011-01-01

    A series of eye-tracking and categorization experiments investigated the use of speaking-rate information in the segmentation of Dutch ambiguous-word sequences. Juncture phonemes with ambiguous durations (e.g., [s] in "eens (s)peer," "once (s)pear," [t] in "nooit (t)rap," "never staircase/quick") were…

  15. How Does Sequence Structure Affect the Judgment of Time? Exploring a Weighted Sum of Segments Model

    ERIC Educational Resources Information Center

    Matthews, William J.

    2013-01-01

    This paper examines the judgment of segmented temporal intervals, using short tone sequences as a convenient test case. In four experiments, we investigate how the relative lengths, arrangement, and pitches of the tones in a sequence affect judgments of sequence duration, and ask whether the data can be described by a simple weighted sum of…

  16. Distribution Metrics and Image Segmentation

    PubMed Central

    Georgiou, Tryphon; Michailovich, Oleg; Rathi, Yogesh; Malcolm, James; Tannenbaum, Allen

    2007-01-01

    The purpose of this paper is to describe certain alternative metrics for quantifying distances between distributions, and to explain their use and relevance in visual tracking. Besides the theoretical interest, such metrics may be used to design filters for image segmentation, that is for solving the key visual task of separating an object from the background in an image. The segmenting curve is represented as the zero level set of a signed distance function. Most existing methods in the geometric active contour framework perform segmentation by maximizing the separation of intensity moments between the interior and the exterior of an evolving contour. Here one can use the given distributional metric to determine a flow which minimizes changes in the distribution inside and outside the curve. PMID:18769529

  17. The segmentation of hadron calorimeters

    NASA Astrophysics Data System (ADS)

    Chen, He Sheng

    1987-05-01

    Optimization of the segmentation of large hadron calorimeters is important in order to obtain good resolution for jet physics at minimum construction cost for the next generation of high energy experiments. The principles of the segmentation of hadron calorimeters are discussed. As an example, the Monte Carlo optimization of the segmentation of the L3 hadron calorimeter barrel at CERN is described. Comparisons of results for the reconstructed jet shapes show that the optimum number ADC channels is about 20K for the readout of 450K wires of the proportional chambers. The matching between the sandwiched φ towers and Z towers is the dominant factor for angular resolution. Based on these Monte Carlo simulations, an optimized tower structure is obtained.

  18. Segmental Rescoring in Text Recognition

    DTIC Science & Technology

    2014-02-04

    ttm № tes/m, m* tmvr mowm* a Smyrna Of l δrtA£ACf02S’ A w m - y i p m AmiKSiS € f № ) C № № m .. sg6#?«rA fiθN ; Atφ h Sft№’·’Spxn mm m fim f№b t&m&mm...applying a Hidden Markov Model (HMM) recognition approach. Generating the plurality text hypotheses for the image forming includes generating a first...image. Applying segmental analysis to a segmentation determined by a first OCR engine, such as a segmentation determined by a Hidden Markov Model (HMM

  19. Unsupervised segmentation with dynamical units.

    PubMed

    Rao, A Ravishankar; Cecchi, Guillermo A; Peck, Charles C; Kozloski, James R

    2008-01-01

    In this paper, we present a novel network to separate mixtures of inputs that have been previously learned. A significant capability of the network is that it segments the components of each input object that most contribute to its classification. The network consists of amplitude-phase units that can synchronize their dynamics, so that separation is determined by the amplitude of units in an output layer, and segmentation by phase similarity between input and output layer units. Learning is unsupervised and based on a Hebbian update, and the architecture is very simple. Moreover, efficient segmentation can be achieved even when there is considerable superposition of the inputs. The network dynamics are derived from an objective function that rewards sparse coding in the generalized amplitude-phase variables. We argue that this objective function can provide a possible formal interpretation of the binding problem and that the implementation of the network architecture and dynamics is biologically plausible.

  20. Keep Your Eyes on the Road: Young Driver Crash Risk Increases According to Duration of Distraction

    PubMed Central

    Simons-Morton, Bruce; Guo, Feng; Klauer, Sheila G; Ehsani, Johnathon P; Pradhan, Anuj K

    2014-01-01

    Purpose Secondary task engagement that distracts the driver is a contributing factor to motor vehicle crashes among adults. However, the association between eye glance duration and crash risk with novice teenage drivers has not been determined. Methods Vehicles of 42 newly-licensed teenage drivers were instrumented with cameras, accelerometers, GPS, and other devices. Data were collected continuously for 18 months. Crashes and near crashes (CNCs) were identified by examining highly elevated gravitational force events. Video footage of the 6 seconds prior to each CNC and randomly sampled non-CNC road segments were coded for the duration of eye glances off the forward roadway and the presence of secondary task engagement. The likelihood (odds ratios) of CNC due to eye glance behavior was calculated by comparing the prevalence of secondary task engagement and duration of eyes off road prior to CNC with the prevalence and duration of eyes off road during non-CNC road segments. Results Crash risk increased with the duration of single longest glance during all secondary tasks (OR=3.8 for >2s) and wireless secondary task engagement (OR=5.5 for >2s). Single longest glance provided a more consistent estimate of crash risk than total time eyes off the forward roadway. Conclusions Eyes glances away from forward roadway involving secondary tasks increased the likelihood of CNC. The longer the duration of eye glance away from the road the greater the risk, regardless of type of secondary task. Education and policy discouraging secondary task engagement, particularly for prolonged periods, is warranted. PMID:24759443

  1. Effects of pulse duration on magnetostimulation thresholds

    SciTech Connect

    Saritas, Emine U.; Goodwill, Patrick W.; Conolly, Steven M.

    2015-06-15

    Purpose: Medical imaging techniques such as magnetic resonance imaging and magnetic particle imaging (MPI) utilize time-varying magnetic fields that are subject to magnetostimulation limits, which often limit the speed of the imaging process. Various human-subject experiments have studied the amplitude and frequency dependence of these thresholds for gradient or homogeneous magnetic fields. Another contributing factor was shown to be number of cycles in a magnetic pulse, where the thresholds decreased with longer pulses. The latter result was demonstrated on two subjects only, at a single frequency of 1.27 kHz. Hence, whether the observed effect was due to the number of cycles or due to the pulse duration was not specified. In addition, a gradient-type field was utilized; hence, whether the same phenomenon applies to homogeneous magnetic fields remained unknown. Here, the authors investigate the pulse duration dependence of magnetostimulation limits for a 20-fold range of frequencies using homogeneous magnetic fields, such as the ones used for the drive field in MPI. Methods: Magnetostimulation thresholds were measured in the arms of six healthy subjects (age: 27 ± 5 yr). Each experiment comprised testing the thresholds at eight different pulse durations between 2 and 125 ms at a single frequency, which took approximately 30–40 min/subject. A total of 34 experiments were performed at three different frequencies: 1.2, 5.7, and 25.5 kHz. A solenoid coil providing homogeneous magnetic field was used to induce stimulation, and the field amplitude was measured in real time. A pre-emphasis based pulse shaping method was employed to accurately control the pulse durations. Subjects reported stimulation via a mouse click whenever they felt a twitching/tingling sensation. A sigmoid function was fitted to the subject responses to find the threshold at a specific frequency and duration, and the whole procedure was repeated at all relevant frequencies and pulse durations

  2. Four segment piezo based micropump

    NASA Astrophysics Data System (ADS)

    Haldkar, Rakesh Kumar; Sheorey, Tanuja; Gupta, Vijay Kumar; Ansari, M. Zahid

    2017-06-01

    In recent years, micropumps have been investigated by various researchers as drug delivery and disease diagnostic devices. Many of these micropumps have been designed, considering available micro fabrication technologies rather than appropriate pump performance analysis. Piezoelectric based micro pumps are more popular as compared to other smart materials being explored. In this paper, four segment piezoelectric bimorph actuator (FSPB) are compared with circular disc piezoelectric bimorph actuator (CDPB) based pump. The static and transient behaviors under various electric fields have been analyzed by using ANSYS 12.1(R) finite element software. Simulation results show that dividing the actuator in segment can amplify the deflection and improve the performance of the pump.

  3. SExSeg: SExtractor segmentation

    NASA Astrophysics Data System (ADS)

    Coe, Dan

    2015-08-01

    SExSeg forces SExtractor (ascl:1010.064) to run using a pre-defined segmentation map (the definition of objects and their borders). The defined segments double as isophotal apertures. SExSeg alters the detection image based on a pre-defined segmenation map while preparing your "analysis image" by subtracting the background in a separate SExtractor run (using parameters you specify). SExtractor is then run in "double-image" mode with the altered detection image and background-subtracted analysis image.

  4. Document segmentation via oblique cuts

    NASA Astrophysics Data System (ADS)

    Svendsen, Jeremy; Branzan-Albu, Alexandra

    2013-01-01

    This paper presents a novel solution for the layout segmentation of graphical elements in Business Intelligence documents. We propose a generalization of the recursive X-Y cut algorithm, which allows for cutting along arbitrary oblique directions. An intermediate processing step consisting of line and solid region removal is also necessary due to presence of decorative elements. The output of the proposed segmentation is a hierarchical structure which allows for the identification of primitives in pie and bar charts. The algorithm was tested on a database composed of charts from business documents. Results are very promising.

  5. Impact of response duration on multisensory integration.

    PubMed

    Ghose, Dipanwita; Barnett, Zachary P; Wallace, Mark T

    2012-11-01

    Multisensory neurons in the superior colliculus (SC) have been shown to have large receptive fields that are heterogeneous in nature. These neurons have the capacity to integrate their different sensory inputs, a process that has been shown to depend on the physical characteristics of the stimuli that are combined (i.e., spatial and temporal relationship and relative effectiveness). Recent work has highlighted the interdependence of these factors in driving multisensory integration, adding a layer of complexity to our understanding of multisensory processes. In the present study our goal was to add to this understanding by characterizing how stimulus location impacts the temporal dynamics of multisensory responses in cat SC neurons. The results illustrate that locations within the spatial receptive fields (SRFs) of these neurons can be divided into those showing short-duration responses and long-duration response profiles. Most importantly, discharge duration appears to be a good determinant of multisensory integration, such that short-duration responses are typically associated with a high magnitude of multisensory integration (i.e., superadditive responses) while long-duration responses are typically associated with low integrative capacity. These results further reinforce the complexity of the integrative features of SC neurons and show that the large SRFs of these neurons are characterized by vastly differing temporal dynamics, dynamics that strongly shape the integrative capacity of these neurons.

  6. Estimating magnitude and duration of incident delays

    SciTech Connect

    Garib, A.; Radwan, A.E.; Al-Deek, H.

    1997-11-01

    Traffic congestion is a major operational problem on urban freeways. In the case of recurring congestion, travelers can plan their trips according to the expected occurrence and severity of recurring congestion. However, nonrecurring congestion cannot be managed without real-time prediction. Evaluating the efficiency of intelligent transportation systems (ITS) technologies in reducing incident effects requires developing models that can accurately predict incident duration along with the magnitude of nonrecurring congestion. This paper provides two statistical models for estimating incident delay and a model for predicting incident duration. The incident delay models showed that up to 85% of variation in incident delay can be explained by incident duration, number of lanes affected, number of vehicles involved, and traffic demand before the incident. The incident duration prediction model showed that 81% of variation in incident duration can be predicted by number of lanes affected, number of vehicles involved, truck involvement, time of day, police response time, and weather condition. These findings have implications for on-line applications within the context of advanced traveler information systems (ATIS).

  7. Power supplies for long duration balloon flights

    NASA Astrophysics Data System (ADS)

    Lichfield, Ernest W.

    Long duration balloon flights require more electrical power than can be carried in primary batteries. This paper provides design information for selecting rechargeable batteries and charging systems. Solar panels for recharging batteries are discussed, with particular emphasis on cells mounting suitable for balloon flights and panel orientation for maximum power collection. Since efficient utilization of power is so important, modern DC to DC power conversion techniques are presented. On short flights of 1 day or less, system designers have not been greatly concerned with battery weight. But, with the advent of long duration balloon flights using superpressure balloons, anchor balloon systems, and RACOON balloon techniques, power supplies and their weight become of prime importance. The criteria for evaluating power systems for long duration balloon flights is performance per unit weight. Instrumented balloon systems have flown 44 days. For these very long duration flights, batteries recharged from solar cells are the only solution. For intermediate flight duration, say less than 10 days, the system designer should seriously consider using primary cells. The National Center for Atmospheric Research is sponsored by the National Science Foundation. Any opinions, findings and conclusions or recommendations expressed in this publication are those of the authors and do not necessarily reflect the views of the National Science Foundation.

  8. Duration of immunity to norovirus gastroenteritis.

    PubMed

    Simmons, Kirsten; Gambhir, Manoj; Leon, Juan; Lopman, Ben

    2013-08-01

    The duration of immunity to norovirus (NoV) gastroenteritis has been believed to be from 6 months to 2 years. However, several observations are inconsistent with this short period. To gain better estimates of the duration of immunity to NoV, we developed a mathematical model of community NoV transmission. The model was parameterized from the literature and also fit to age-specific incidence data from England and Wales by using maximum likelihood. We developed several scenarios to determine the effect of unknowns regarding transmission and immunity on estimates of the duration of immunity. In the various models, duration of immunity to NoV gastroenteritis was estimated at 4.1 (95% CI 3.2-5.1) to 8.7 (95% CI 6.8-11.3) years. Moreover, we calculated that children (<5 years) are much more infectious than older children and adults. If a vaccine can achieve protection for duration of natural immunity indicated by our results, its potential health and economic benefits could be substantial.

  9. Sleep duration, cardiovascular disease, and proinflammatory biomarkers

    PubMed Central

    Grandner, Michael A; Sands-Lincoln, Megan R; Pak, Victoria M; Garland, Sheila N

    2013-01-01

    Habitual sleep duration has been associated with cardiometabolic disease, via several mechanistic pathways, but few have been thoroughly explored. One hypothesis is that short and/or long sleep duration is associated with a proinflammatory state, which could increase risk for cardiovascular and metabolic diseases. This hypothesis has been largely explored in the context of experimental sleep deprivation studies which have attempted to demonstrate changes in proinflammatory markers following acute sleep loss in the laboratory. Despite the controlled environment available in these studies, samples tend to lack generalization to the population at large and acute sleep deprivation may not be a perfect analog for short sleep. To address these limitations, population based studies have explored associations between proinflammatory markers and habitual sleep duration. This review summarizes what is known from experimental and cross-sectional studies about the association between sleep duration, cardiovascular disease, and proinflammatory biomarkers. First, the association between sleep duration with both morbidity and mortality, with a focus on cardiovascular disease, is reviewed. Then, a brief review of the potential role of proinflammatory markers in cardiovascular disease is presented. The majority of this review details specific findings related to specific molecules, including tumor necrosis factor-α, interleukins-1, -6, and -17, C-reactive protein, coagulation molecules, cellular adhesion molecules, and visfatin. Finally, a discussion of the limitations of current studies and future directions is provided. PMID:23901303

  10. Computer-aided liver volumetry: performance of a fully-automated, prototype post-processing solution for whole-organ and lobar segmentation based on MDCT imaging.

    PubMed

    Fananapazir, Ghaneh; Bashir, Mustafa R; Marin, Daniele; Boll, Daniel T

    2015-06-01

    To evaluate the performance of a prototype, fully-automated post-processing solution for whole-liver and lobar segmentation based on MDCT datasets. A polymer liver phantom was used to assess accuracy of post-processing applications comparing phantom volumes determined via Archimedes' principle with MDCT segmented datasets. For the IRB-approved, HIPAA-compliant study, 25 patients were enrolled. Volumetry performance compared the manual approach with the automated prototype, assessing intraobserver variability, and interclass correlation for whole-organ and lobar segmentation using ANOVA comparison. Fidelity of segmentation was evaluated qualitatively. Phantom volume was 1581.0 ± 44.7 mL, manually segmented datasets estimated 1628.0 ± 47.8 mL, representing a mean overestimation of 3.0%, automatically segmented datasets estimated 1601.9 ± 0 mL, representing a mean overestimation of 1.3%. Whole-liver and segmental volumetry demonstrated no significant intraobserver variability for neither manual nor automated measurements. For whole-liver volumetry, automated measurement repetitions resulted in identical values; reproducible whole-organ volumetry was also achieved with manual segmentation, p(ANOVA) 0.98. For lobar volumetry, automated segmentation improved reproducibility over manual approach, without significant measurement differences for either methodology, p(ANOVA) 0.95-0.99. Whole-organ and lobar segmentation results from manual and automated segmentation showed no significant differences, p(ANOVA) 0.96-1.00. Assessment of segmentation fidelity found that segments I-IV/VI showed greater segmentation inaccuracies compared to the remaining right hepatic lobe segments. Automated whole-liver segmentation showed non-inferiority of fully-automated whole-liver segmentation compared to manual approaches with improved reproducibility and post-processing duration; automated dual-seed lobar segmentation showed slight tendencies for underestimating the right hepatic lobe

  11. Evidence that gestation duration and lactation duration are coupled traits in primates.

    PubMed

    Dubman, Evgenia; Collard, Mark; Mooers, Arne Ø

    2012-12-23

    Gestation duration and lactation duration are usually treated as independently evolving traits in primates, but the metabolic theory of ecology (MTE) suggests both durations should be determined by metabolic rate. We used phylogenetic generalized least-squares linear regression to test these different perspectives. We found that the allometries of the durations are divergent from each other and different from the scaling exponent predicted by the MTE (0.25). Gestation duration increases much more slowly (0.06 < m < 0.12), and lactation duration much more quickly (0.36 < m < 0.52) with body mass than the MTE predicts. By contrast, we found that the combined duration of gestation and lactation is consistent with the MTE's predictions (0.22 < m < 0.35). These results suggest that gestation duration and lactation duration might best be viewed as distinct but coupled adaptations. When transferring energy to their offspring, primate mothers must meet metabolically dictated physiological requirements while optimizing the timing of the switch from gestation to lactation in relation to some as-yet-unidentified body-size-related factor.

  12. Can segmental mobility be increased by cervical arthroplasty?

    PubMed

    Chang, Hsuan-Kan; Chang, Chih-Chang; Tu, Tsung-Hsi; Wu, Jau-Ching; Huang, Wen-Cheng; Fay, Li-Yu; Chang, Peng-Yuan; Wu, Ching-Lan; Cheng, Henrich

    2017-02-01

    OBJECTIVE Many reports have successfully demonstrated that cervical disc arthroplasty (CDA) can preserve range of motion after 1- or 2-level discectomy. However, few studies have addressed the extent of changes in segmental mobility after CDA or their clinical correlations. METHODS Data from consecutive patients who underwent 1-level CDA were retrospectively reviewed. Indications for surgery were medically intractable degenerative disc disease and spondylosis. Clinical outcomes, including visual analog scale (VAS)-measured neck and arm pain, Neck Disability Index (NDI), and Japanese Orthopaedic Association (JOA) scores, were analyzed. Radiographic outcomes, including C2-7 Cobb angle, the difference between pre- and postoperative C2-7 Cobb angle (ΔC2-7 Cobb angle), sagittal vertical axis (SVA), the difference between pre- and postoperative SVA (ΔSVA), segmental range of motion (ROM), and the difference between pre- and postoperative ROM (ΔROM), were assessed for their association with clinical outcomes. All patients underwent CT scanning, by which the presence and severity of heterotopic ossification (HO) were determined during the follow-up. RESULTS A total of 50 patients (mean age 45.6 ± 9.33 years) underwent a 1-level CDA (Prestige LP disc) and were followed up for a mean duration of 27.7 ± 8.76 months. All clinical outcomes, including VAS, NDI, and JOA scores, improved significantly after surgery. Preoperative and postoperative ROM values were similar (mean 9.5° vs 9.0°, p > 0.05) at each indexed level. The mean changes in segmental mobility (ΔROM) were -0.5° ± 6.13°. Patients with increased segmental mobility after surgery (ΔROM > 0°) had a lower incidence of HO and HO that was less severe (p = 0.048) than those whose ΔROM was < 0°. Segmental mobility (ROM) was significantly lower in patients with higher HO grade (p = 0.012), but it did not affect the clinical outcomes. The preoperative and postoperative C2-7 Cobb angles and SVA remained similar

  13. Colorization based on soft segmentation

    NASA Astrophysics Data System (ADS)

    Koo, Hyung-Il; Cho, Nam-Ik

    2011-01-01

    This paper proposes a new colorization method based on the chrominance blending. The weights for the blending are computed by using the random walker algorithm, which is a soft segmentation technique that provides sharp probability transition on object boundaries. As a result, the proposed method reduces color bleeding and provides improved colorization performances compared to conventional ones.

  14. Increasing Enrollment through Benefit Segmentation.

    ERIC Educational Resources Information Center

    Goodnow, Betty

    1982-01-01

    The applicability of benefit segmentation, a market research technique which groups people according to benefits expected from a program offering, was tested at the College of DuPage. Preferences and demographic characteristics were analyzed and program improvements adopted, increasing enrollment by 20 percent. (Author/SK)

  15. Multiple Segment Factorial Vignette Designs

    ERIC Educational Resources Information Center

    Ganong, Lawrence H.; Coleman, Marilyn

    2006-01-01

    The multiple segment factorial vignette design (MSFV) combines elements of experimental designs and probability sampling with the inductive, exploratory approach of qualitative research. MSFVs allow researchers to investigate topics that may be hard to study because of ethical or logistical concerns. Participants are presented with short stories…

  16. XRA image segmentation using regression

    NASA Astrophysics Data System (ADS)

    Jin, Jesse S.

    1996-04-01

    Segmentation is an important step in image analysis. Thresholding is one of the most important approaches. There are several difficulties in segmentation, such as automatic selecting threshold, dealing with intensity distortion and noise removal. We have developed an adaptive segmentation scheme by applying the Central Limit Theorem in regression. A Gaussian regression is used to separate the distribution of background from foreground in a single peak histogram. The separation will help to automatically determine the threshold. A small 3 by 3 widow is applied and the modal of the local histogram is used to overcome noise. Thresholding is based on local weighting, where regression is used again for parameter estimation. A connectivity test is applied to the final results to remove impulse noise. We have applied the algorithm to x-ray angiogram images to extract brain arteries. The algorithm works well for single peak distribution where there is no valley in the histogram. The regression provides a method to apply knowledge in clustering. Extending regression for multiple-level segmentation needs further investigation.

  17. Increasing Enrollment through Benefit Segmentation.

    ERIC Educational Resources Information Center

    Goodnow, Betty

    1982-01-01

    The applicability of benefit segmentation, a market research technique which groups people according to benefits expected from a program offering, was tested at the College of DuPage. Preferences and demographic characteristics were analyzed and program improvements adopted, increasing enrollment by 20 percent. (Author/SK)

  18. Multiple Segment Factorial Vignette Designs

    ERIC Educational Resources Information Center

    Ganong, Lawrence H.; Coleman, Marilyn

    2006-01-01

    The multiple segment factorial vignette design (MSFV) combines elements of experimental designs and probability sampling with the inductive, exploratory approach of qualitative research. MSFVs allow researchers to investigate topics that may be hard to study because of ethical or logistical concerns. Participants are presented with short stories…

  19. [Labor duration: from normality to dystocia].

    PubMed

    Kayem, G

    2015-04-01

    "Normal" labor has been surprisingly little studied in the past 60 years even though it is a central axis in obstetrics. Standards were proposed 60 years ago by Emmanuel Friedman and adopted by many countries to become then, driven from Dublin school, the conditions allowing the management of labor: rupture of membranes and oxytocin with, in case of failure for dynamic dystocia, cesarean. Recent data have suggested that labor duration had changed since the 1960s. Changes in women's characteristics and in obstetric practice especially with the widespread use of oxytocin and realization of epidural may have an impact on labor duration. Current studies suggest that it may be possible to authorize longer labor duration without significant increase in maternal or neonatal morbidity. However, it is premature to change practices following the latest American recommendations without prior studies.

  20. STS mission duration enhancement study: (orbiter habitability)

    NASA Technical Reports Server (NTRS)

    Carlson, A. D.

    1979-01-01

    Habitability improvements for early flights that could be implemented with minimum impact were investigated. These included: (1) launching the water dispenser in the on-orbit position instead of in a locker; (2) the sleep pallet concept; and (3) suction cup foot restraints. Past studies that used volumetric terms and requirements for crew size versus mission duration were reviewed and common definitions of key habitability terms were established. An accurately dimensioned drawing of the orbiter mid-deck, locating all of the known major elements was developed. Finally, it was established that orbiter duration and crew size can be increased with minimum modification and impact to the crew module. Preliminary concepts of the aft med-deck, external versions of expanded tunnel adapters (ETA), and interior concepts of ETA-3 were developed and comparison charts showing the various factors of volume, weight, duration, size, impact to orbiter, and number of sleep stations were generated.

  1. Fluctuation behaviors of financial return volatility duration

    NASA Astrophysics Data System (ADS)

    Niu, Hongli; Wang, Jun; Lu, Yunfan

    2016-04-01

    It is of significantly crucial to understand the return volatility of financial markets because it helps to quantify the investment risk, optimize the portfolio, and provide a key input of option pricing models. The characteristics of isolated high volatility events above certain threshold in price fluctuations and the distributions of return intervals between these events arouse great interest in financial research. In the present work, we introduce a new concept of daily return volatility duration, which is defined as the shortest passage time when the future volatility intensity is above or below the current volatility intensity (without predefining a threshold). The statistical properties of the daily return volatility durations for seven representative stock indices from the world financial markets are investigated. Some useful and interesting empirical results of these volatility duration series about the probability distributions, memory effects and multifractal properties are obtained. These results also show that the proposed stock volatility series analysis is a meaningful and beneficial trial.

  2. Latent profile approach to duration of stalking.

    PubMed

    Björklund, Katja; Häkkänen-Nyholm, Helinä; Sheridan, Lorraine; Roberts, Karl; Tolvanen, Asko

    2010-07-01

    Stalking behavior and victim-stalker relationship are often the principal known factors in a stalking case. Thus, they are of great importance when trying to identify factors contributing to stalking duration. The present study aims to identify distinct subgroups of stalking victims based on measures of behavioral stalking dimensions. These victim subgroups, stalking dimensions, and victim-stalker relationship are examined in relation to stalking duration. Using a sample of 137 university students, latent profile analysis (LPA) revealed five distinct victim subgroups based on stalker behavior dimensions: surveillance, low-profile, social lurker, wide scope, and baseline stalkers. The subgroups were significantly related to stalking duration and explained a considerable amount of the variance along with the stalking dimensions and victim-stalker relationship. Connections to stalking literature and utility of person-orientated methods in stalking research are discussed.

  3. Sleep duration and endometrial cancer risk.

    PubMed

    Sturgeon, Susan R; Luisi, Nicole; Balasubramanian, Raji; Reeves, Katherine W

    2012-04-01

    Recent data indicate that night shift work is associated with increased endometrial cancer risk, perhaps through a pathway involving lower melatonin production. Melatonin is an antiestrogenic hormone, with production in a circadian pattern that is dependent on presence of dark at night. Sleep duration is positively associated with melatonin production and may be an indicator of melatonin levels in epidemiologic studies. We evaluated associations between self-reported sleep duration and endometrial cancer risk using publicly available prospective data on 48,725 participants in the Women's Health Initiative Observational Study, among whom 452 adjudicated incident cases of endometrial cancer were diagnosed over approximately 7.5 years of follow-up. Sleep duration was self-reported at baseline. Cox proportional hazards regression was used to estimate hazard ratios (HR) and 95% confidence intervals (CI) for endometrial cancer risk with adjustment for potential confounders. Most women reported sleeping ≤ 6 (33.3%) or 7 (38.5%) h each night; fewer reported sleeping 8 (23.4%) or ≥ 9 (4.8%) h each night. In adjusted analyses, there was an indication of reduced risk associated with longer sleep duration, though no statistically significant association was observed. Women who slept ≥ 9 h had a nonsignificant reduced risk of endometrial cancer compared with women who slept ≤ 6 h (HR = 0.87; 95% CI = 0.51-1.46). We found weak evidence of an association between sleep duration and endometrial cancer risk. Self-reported sleep duration may not adequately represent melatonin levels, thus further studies utilizing urinary melatonin levels are necessary to establish the mechanism by which night shift work increases endometrial cancer risk.

  4. Slow Wave Sleep and Long Duration Spaceflight

    NASA Technical Reports Server (NTRS)

    Whitmire, Alexandra; Orr, Martin; Arias, Diana; Rueger, Melanie; Johnston, Smith; Leveton, Lauren

    2012-01-01

    While ground research has clearly shown that preserving adequate quantities of sleep is essential for optimal health and performance, changes in the progression, order and /or duration of specific stages of sleep is also associated with deleterious outcomes. As seen in Figure 1, in healthy individuals, REM and Non-REM sleep alternate cyclically, with stages of Non-REM sleep structured chronologically. In the early parts of the night, for instance, Non-REM stages 3 and 4 (Slow Wave Sleep, or SWS) last longer while REM sleep spans shorter; as night progresses, the length of SWS is reduced as REM sleep lengthens. This process allows for SWS to establish precedence , with increases in SWS seen when recovering from sleep deprivation. SWS is indeed regarded as the most restorative portion of sleep. During SWS, physiological activities such as hormone secretion, muscle recovery, and immune responses are underway, while neurological processes required for long term learning and memory consolidation, also occur. The structure and duration of specific sleep stages may vary independent of total sleep duration, and changes in the structure and duration have been shown to be associated with deleterious outcomes. Individuals with narcolepsy enter sleep through REM as opposed to stage 1 of NREM. Disrupting slow wave sleep for several consecutive nights without reducing total sleep duration or sleep efficiency is associated with decreased pain threshold, increased discomfort, fatigue, and the inflammatory flare response in skin. Depression has been shown to be associated with a reduction of slow wave sleep and increased REM sleep. Given research that shows deleterious outcomes are associated with changes in sleep structure, it is essential to characterize and mitigate not only total sleep duration, but also changes in sleep stages.

  5. Inverse relationship between sleep duration and myopia.

    PubMed

    Jee, Donghyun; Morgan, Ian G; Kim, Eun Chul

    2016-05-01

    To investigate the association between sleep duration and myopia. This population-based, cross-sectional study using a nationwide, systemic, stratified, multistage, clustered sampling method included a total of 3625 subjects aged 12-19 years who participated in the Korean National Health and Nutrition Examination Survey 2008-2012. All participants underwent ophthalmic examination and a standardized interview including average sleep duration (hr/day), education, physical activity and economic status (annual household income). Refractive error was measured by autorefraction without cycloplegia. Myopia and high myopia were defined as ≤-0.50 dioptres (D) and ≤-6.0 D, respectively. Sleep durations were classified into 5 categories: <5, 6, 7, 8 and >9 hr. The overall prevalence of myopia and high myopia were 77.8% and 9.4%, respectively, and the overall sleep duration was 7.1 hr/day. The refractive error increased by 0.10 D per 1 hr increase in sleep after adjusting for potential confounders including sex, age, height, education level, economic status and physical activity. The adjusted odds ratio (OR) for refractive error was 0.90 (95% confidence interval [CI], 0.83-0.97) per 1 hr increase in sleep. The adjusted OR for myopia was decreased in those with >9 hr of sleep (OR, 0.59; 95% CI, 0.38-0.93; p for trend = 0.006) than in those with <5 hr of sleep. However, high myopia was not associated with sleep duration. This study provides the population-based, epidemiologic evidence for an inverse relationship between sleep duration and myopia in a representative population of Korean adolescents. © 2015 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

  6. Metric Learning to Enhance Hyperspectral Image Segmentation

    NASA Technical Reports Server (NTRS)

    Thompson, David R.; Castano, Rebecca; Bue, Brian; Gilmore, Martha S.

    2013-01-01

    Unsupervised hyperspectral image segmentation can reveal spatial trends that show the physical structure of the scene to an analyst. They highlight borders and reveal areas of homogeneity and change. Segmentations are independently helpful for object recognition, and assist with automated production of symbolic maps. Additionally, a good segmentation can dramatically reduce the number of effective spectra in an image, enabling analyses that would otherwise be computationally prohibitive. Specifically, using an over-segmentation of the image instead of individual pixels can reduce noise and potentially improve the results of statistical post-analysis. In this innovation, a metric learning approach is presented to improve the performance of unsupervised hyperspectral image segmentation. The prototype demonstrations attempt a superpixel segmentation in which the image is conservatively over-segmented; that is, the single surface features may be split into multiple segments, but each individual segment, or superpixel, is ensured to have homogenous mineralogy.

  7. Design Considerations for a Highly Segmented Mirror

    NASA Astrophysics Data System (ADS)

    Padin, Stephen

    2003-06-01

    Design issues for a 30-m highly segmented mirror are explored, with emphasis on parametric models of simple, inexpensive segments. A mirror with many small segments offers cost savings through quantity production and permits high-order active and adaptive wave-front corrections. For a 30-m f/1 .5 paraboloidal mirror made of spherical, hexagonal glass segments, with simple warping harnesses and three-point supports, the maximum segment diameter is ~100 mm, and the minimum segment thickness is ~5 mm. Large-amplitude, low-order gravitational deformations in the mirror cell can be compensated if the segments are mounted on a plate floating on astatic supports. Because gravitational deformations in the plate are small, the segment actuators require a stroke of only a few tens of micrometers, and the segment positions can be measured by a wave-front sensor.

  8. Statistical analysis of random duration times

    SciTech Connect

    Engelhardt, M.E.

    1996-04-01

    This report presents basic statistical methods for analyzing data obtained by observing random time durations. It gives nonparametric estimates of the cumulative distribution function, reliability function and cumulative hazard function. These results can be applied with either complete or censored data. Several models which are commonly used with time data are discussed, and methods for model checking and goodness-of-fit tests are discussed. Maximum likelihood estimates and confidence limits are given for the various models considered. Some results for situations where repeated durations such as repairable systems are also discussed.

  9. Slow Wave Sleep and Long Duration Spaceflight

    NASA Technical Reports Server (NTRS)

    Orr, M.; Whitmire, A.; Arias, D.; Leveton, L.

    2011-01-01

    To review the literature on slow wave sleep (SWS) in long duration space flight, and place this within the context of the broader literature on SWS particularly with respect to analogous environments such as the Antarctic. Explore how SWS could be measured within the International Space Station (ISS) context with the aim to utilize the ISS as an analog for future extra-orbital long duration missions. Discuss the potential use of emergent minimally intrusive wireless technologies like ZEO for integrated prelaunch, flight, and return to Earth analysis and optimization of SWS (and general quality of sleep).

  10. Segment Specification for the Payload Segment of the Reusable Reentry Satellite: Rodent Module Version

    NASA Technical Reports Server (NTRS)

    1991-01-01

    The Reusable Reentry Satellite (RRS) System is composed of the payload segment (PS), vehicle segment (VS), and mission support (MS) segments. This specification establishes the performance, design, development, and test requirements for the RRS Rodent Module (RM).

  11. Electro-Optic Segment-Segment Sensors for Radio and Optical Telescopes

    NASA Technical Reports Server (NTRS)

    Abramovici, Alex

    2012-01-01

    A document discusses an electro-optic sensor that consists of a collimator, attached to one segment, and a quad diode, attached to an adjacent segment. Relative segment-segment motion causes the beam from the collimator to move across the quad diode, thus generating a measureable electric signal. This sensor type, which is relatively inexpensive, can be configured as an edge sensor, or as a remote segment-segment motion sensor.

  12. Superimposed segmental manifestation of cherry angiomas.

    PubMed

    Jaeger, Teresa; Andres, Christian; Hein, Rüdiger; Ring, Johannes; Chen, Wenchieh

    2011-01-01

    Cherry angioma is a common, acquired, vascular proliferation, probably of a polygenic mode of inheritance. Segmental manifestation of multiple cherry angiomas associated with the development of non-segmental lesions has not yet been reported. We describe a 62-year-old Caucasian woman with early formation of segmental cherry angiomas after pregnancy, which are superimposed on non-segmental lesions of later onset after menopause. In this pattern, segmental cherry angiomas could be taken as a further example of superimposed segmental manifestation of a polygenic skin disorder. Molecular research would be needed to confirm this hypothesis.

  13. 14 CFR 21.313 - Duration.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Duration. 21.313 Section 21.313 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT CERTIFICATION PROCEDURES FOR PRODUCTS AND PARTS Approval of Materials, Parts, Processes, and Appliances § 21.313...

  14. Influence of acupuncture on duration of labor.

    PubMed

    Zeisler, H; Tempfer, C; Mayerhofer, K; Barrada, M; Husslein, P

    1998-01-01

    The aim of this case control study was to evaluate the thus far controversially discussed influence of acupuncture (AP) on the duration of labor. Fifty-seven women with AP treatment (group A) were included in our study after spontaneous vaginal full-term delivery. The control group included 63 women (group B). Median duration of the first stage of labor was 196 min in group A and 321 min in group B (Wilcoxon 2-sample test, p < 0.0001). Median duration of the second stage of labor was 57 min in group A and 57 min in group B (Wilcoxon 2-sample test, p = 0.82). Thirty women had a premature rupture of the membranes (PROM), in group A 66.7% and in group B 33.3% (chi2 test, p = 0.02). Women without AP (group B) received significantly more often oxytocin during the first stage of labor compared with group A women (85 and 15%, respectively, chi2 test, p = 0.01) as well as during the second stage of labor (72 and 28%, respectively, chi2 test, p = 0.03). Our study suggests that AP treatment is a recommendable form of childbirth preparation due to its positive effect on the duration of labor, namely by shortening the first stage of labor.

  15. Sleep Duration and Breast Cancer Phenotype

    PubMed Central

    Khawaja, Ali; Rao, Santosh; Li, Li; Thompson, Cheryl L.

    2013-01-01

    Emerging evidence suggests that short sleep is associated with an increased risk of cancer; however, little has been done to study the role of sleep on tumor characteristics. In this study, we evaluated the relationship between sleep duration and tumor phenotype in 972 breast cancer patients. Sleep duration was inversely associated with tumor grade (univariate P = 0.032), particularly in postmenopausal women (univariate P = 0.018). This association did not reach statistical significance after adjustments for age, race, body mass index, hormone replacement therapy use, alcohol consumption, smoking, and physical activity in the entire study sample (P = 0.052), but it remained statistically significant (P = 0.049) among post-menopausal patients. We did not observe a statistically significant association between sleep duration and stage at diagnosis, ER, or HER2 receptor status. These results present a modest association between short duration of sleep and higher grade breast cancer in post-menopausal women. Further work needs to be done to validate these findings. PMID:24319459

  16. 14 CFR 21.443 - Duration.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Duration. 21.443 Section 21.443 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT CERTIFICATION PROCEDURES FOR PRODUCTS AND PARTS Designated Alteration Station Authorization Procedures § 21.443...

  17. A Short-Duration Gel Diffusion Experiment.

    ERIC Educational Resources Information Center

    Mulcahy, D. E.

    1980-01-01

    Described is a gel diffusion experiment that permits the completion of duplicate diffusion runs within a three-hour laboratory session. Information included for the short-duration gel diffusion experiment is the diffusion cell, the experiment, data treatment, and the expected results of the experiment. (Author/DS)

  18. Duration and Intensity as Correlates of Fo.

    ERIC Educational Resources Information Center

    Zee, Eric

    1978-01-01

    The speech of two male Taiwanese speakers was analyzed to determine whether fundamental frequency (Fo) is correlated with both duration and intensity; five conclusions are drawn. The results are discussed in terms of theories of pitch production and speed of pitch change. (EJS)

  19. Short-Duration Simulations from Measurements.

    SciTech Connect

    Mitchell, Dean J.; Enghauser, Michael

    2014-08-01

    A method is presented that ascribes proper statistical variability to simulations that are derived from longer-duration measurements. This method is applicable to simulations of either real-value or integer-value data. An example is presented that demonstrates the applicability of this technique to the synthesis of gamma-ray spectra.

  20. Mortality associated with sleep duration and insomnia.

    PubMed

    Kripke, Daniel F; Garfinkel, Lawrence; Wingard, Deborah L; Klauber, Melville R; Marler, Matthew R

    2002-02-01

    Patients often complain about insufficient sleep or chronic insomnia in the belief that they need 8 hours of sleep. Treatment strategies may be guided by what sleep durations predict optimal survival and whether insomnia might signal mortality risks. In 1982, the Cancer Prevention Study II of the American Cancer Society asked participants about their sleep duration and frequency of insomnia. Cox proportional hazards survival models were computed to determine whether sleep duration or frequency of insomnia was associated with excess mortality up to 1988, controlling simultaneously for demographics, habits, health factors, and use of various medications. Participants were more than 1.1 million men and women from 30 to 102 years of age. The best survival was found among those who slept 7 hours per night. Participants who reported sleeping 8 hours or more experienced significantly increased mortality hazard, as did those who slept 6 hours or less. The increased risk exceeded 15% for those reporting more than 8.5 hours sleep or less than 3.5 or 4.5 hours. In contrast, reports of "insomnia" were not associated with excess mortality hazard. As previously described, prescription sleeping pill use was associated with significantly increased mortality after control for reported sleep durations and insomnia. Patients can be reassured that short sleep and insomnia seem associated with little risk distinct from comorbidities. Slight risks associated with 8 or more hours of sleep and sleeping pill use need further study. Causality is unproven.

  1. Iterated rippled noise discrimination at long durations.

    PubMed

    Yost, William A

    2009-09-01

    Iterated rippled noise (IRN) was used to study discrimination of IRN stimuli with a lower number of iterations from IRN stimuli with a higher number of iterations as a function of stimulus duration (100-2000 ms). Such IRN stimuli differ in the strength of the repetition pitch. In some cases, the gain used to generate IRN stimuli was adjusted so that both IRN stimuli in the discrimination task had the same height of the first peak in the autocorrelation function or autocorrelogram. In previous work involving short-duration IRN stimuli (<500 ms), listeners were not able to discriminate between IRN stimuli that had different numbers of iterations but the same height of the first peak in the autocorrelation function. In the current study, IRN discrimination performance improved with increases in duration, even in cases when the height of the first peak in the autocorrelation was the same for the two IRN stimuli. Thus, future studies involving discrimination of IRN stimuli may need to use longer durations (1 s or greater) than those that have been used in the past.

  2. 14 CFR 21.159 - Duration.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Duration. 21.159 Section 21.159 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT CERTIFICATION... Administrator, or the location of the manufacturing facility is changed....

  3. long duration dust storm sequences on Mars

    NASA Astrophysics Data System (ADS)

    Wang, H.

    2012-12-01

    The Mars Global Surveyor (MGS) Mars Observer Camera (MOC) and Mars Reconnaissance Orbiter (MRO) Mars Color Imager (MARCI) Mars daily global maps have revealed new characteristics for long duration dust storm sequences. These dust storm sequences have long histories of more than a week, travel long distances out of their origination region, and influence large areas in different regions of the planet. During the Ls = 180 - 360 season, except for global dust storms which involve multiple remote dust lifting centers and generally expand explosively from the southern hemisphere northward, other long-lived dust storm sequences usually travel southward through the Acidalia-Chryse, Utopia-Isidis or Arcadia-Amazonis channels with subsequent dust lifting along the way. Sometimes, they penetrate remarkably deep to the southern high latitudes, producing fantastic display of dust band. During the rest of the year, long duration dust storm sequences usually originate from the Argyre/Solis, Hellas/Noachis, or Cimmeria/Sirenum area and travel northward toward the southern low latitudes. Each route exhibits its own peculiar characteristics. We will present our results about these long duration dust storm sequences summarized from the complete archive of MGS MOC daily global maps and two years of MRO MARCI daily global maps. The systematic daily nearly global coverage of these maps makes it feasible to reconstruct the history of long duration dust storm sequences with detail.

  4. 14 CFR 21.77 - Duration.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... surrendered, superseded, revoked, or otherwise terminated, provisional type certificates and amendments... effective for twelve months after the date of issue. (d) An amendment to a Class I or Class II provisional type certificate is effective for the duration of the amended certificate. (e) A provisional...

  5. The Course and Duration of Crisis.

    ERIC Educational Resources Information Center

    Lewis, Marc S.; And Others

    1979-01-01

    Psychological tests were administered to a crisis group undergoing surgery for cancer and to a comparison group on the night before surgery and thereafter at three-week intervals. Results indicated significant psychological changes only in the crisis group. Duration of crisis was greater than six weeks but less than seven months. (Author)

  6. Estimating the duration of speciation from phylogenies.

    PubMed

    Etienne, Rampal S; Morlon, Hélène; Lambert, Amaury

    2014-08-01

    Speciation is not instantaneous but takes time. The protracted birth-death diversification model incorporates this fact and predicts the often observed slowdown of lineage accumulation toward the present. The mathematical complexity of the protracted speciation model has barred estimation of its parameters until recently a method to compute the likelihood of phylogenetic branching times under this model was outlined (Lambert et al. ). Here, we implement this method and study using simulated phylogenies of extant species how well we can estimate the model parameters (rate of initiation of speciation, rate of extinction of incipient and good species, and rate of completion of speciation) as well as the duration of speciation, which is a combination of the aforementioned parameters. We illustrate our approach by applying it to a primate phylogeny. The simulations show that phylogenies often do not contain enough information to provide unbiased estimates of the speciation-initiation rate and the extinction rate, but the duration of speciation can be estimated without much bias. The estimate of the duration of speciation for the primate clade is consistent with literature estimates. We conclude that phylogenies combined with the protracted speciation model provide a promising way to estimate the duration of speciation.

  7. 5 CFR 330.1102 - Duration.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 5 Administrative Personnel 1 2011-01-01 2011-01-01 false Duration. 330.1102 Section 330.1102 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS RECRUITMENT, SELECTION, AND PLACEMENT (GENERAL) Federal Employment Priority Consideration Program for Displaced Employees of...

  8. 5 CFR 330.1102 - Duration.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Duration. 330.1102 Section 330.1102 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS RECRUITMENT, SELECTION, AND PLACEMENT (GENERAL) Federal Employment Priority Consideration Program for Displaced Employees of...

  9. Measuring the success of video segmentation algorithms

    NASA Astrophysics Data System (ADS)

    Power, Gregory J.

    2001-12-01

    Appropriate segmentation of video is a key step for applications such as video surveillance, video composing, video compression, storage and retrieval, and automated target recognition. Video segmentation algorithms involve dissecting the video into scenes based on shot boundaries as well as local objects and events based on spatial shape and regional motions. Many algorithmic approaches to video segmentation have been recently reported, but many lack measures to quantify the success of the segmentation especially in comparison to other algorithms. This paper suggests multiple bench-top measures for evaluating video segmentation. The paper suggests that the measures are most useful when 'truth' data about the video is available such as precise frame-by- frame object shape. When precise 'truth' data is unavailable, this paper suggests using hand-segmented 'truth' data to measure the success of the video segmentation. Thereby, the ability of the video segmentation algorithm to achieve the same quality of segmentation as the human is obtained in the form of a variance in multiple measures. The paper introduces a suite of measures, each scaled from zero to one. A score of one on a particular measure is a perfect score for a singular segmentation measure. Measures are introduced to evaluate the ability of a segmentation algorithm to correctly detect shot boundaries, to correctly determine spatial shape and to correctly determine temporal shape. The usefulness of the measures are demonstrated on a simple segmenter designed to detect and segment a ping pong ball from a table tennis image sequence.

  10. Vibration damping for the Segmented Mirror Telescope

    NASA Astrophysics Data System (ADS)

    Maly, Joseph R.; Yingling, Adam J.; Griffin, Steven F.; Agrawal, Brij N.; Cobb, Richard G.; Chambers, Trevor S.

    2012-09-01

    The Segmented Mirror Telescope (SMT) at the Naval Postgraduate School (NPS) in Monterey is a next-generation deployable telescope, featuring a 3-meter 6-segment primary mirror and advanced wavefront sensing and correction capabilities. In its stowed configuration, the SMT primary mirror segments collapse into a small volume; once on location, these segments open to the full 3-meter diameter. The segments must be very accurately aligned after deployment and the segment surfaces are actively controlled using numerous small, embedded actuators. The SMT employs a passive damping system to complement the actuators and mitigate the effects of low-frequency (<40 Hz) vibration modes of the primary mirror segments. Each of the six segments has three or more modes in this bandwidth, and resonant vibration excited by acoustics or small disturbances on the structure can result in phase mismatches between adjacent segments thereby degrading image quality. The damping system consists of two tuned mass dampers (TMDs) for each of the mirror segments. An adjustable TMD with passive magnetic damping was selected to minimize sensitivity to changes in temperature; both frequency and damping characteristics can be tuned for optimal vibration mitigation. Modal testing was performed with a laser vibrometry system to characterize the SMT segments with and without the TMDs. Objectives of this test were to determine operating deflection shapes of the mirror and to quantify segment edge displacements; relative alignment of λ/4 or better was desired. The TMDs attenuated the vibration amplitudes by 80% and reduced adjacent segment phase mismatches to acceptable levels.

  11. Maternal recall of exclusive breast feeding duration

    PubMed Central

    Bland, R; Rollins, N; Solarsh, G; Van den Broeck, J; Coovadia, H

    2003-01-01

    Background: Both the pattern and duration of breast feeding are important determinants of health outcomes. In vertical HIV transmission research, reliable documentation of early breast feeding practices is important in order to correctly attribute postnatal transmission to feeding pattern. Aims: To validate methods of collecting data on the duration of exclusive breast feeding (EBF) in an area of South Africa with a high HIV prevalence rate. Methods: A total of 130 mothers were interviewed weekly, postnatally. At every interview a 48 hour and a seven day recall breast feeding history were taken. A subset of 70 mothers also received two intermediate visits per week during which additional 48 hour, non-overlapping, recall interviews were conducted. Ninety three infants were revisited at 6–9 months of age when mothers' recall of EBF duration from birth was documented. The different methods of recalling EBF status were compared against an a priori "best comparison" in each case. Results: Reported breast feeding practices over the previous 48 hours did not reflect EBF practices since birth (specificity 65–89%; positive predictive value 31–48%). Six month EBF duration recall was equally poor (sensitivity at 2 weeks 79%; specificity 40%). Seven day recall accurately reflected EBF practices compared with thrice weekly recall over the same time period (sensitivity 96%, specificity 94%). Conclusions: 48 hour EBF status does not accurately reflect feeding practices since birth. Long term recall data on EBF are even more inaccurate. We recommend that data on duration of EBF be collected prospectively at intervals of no longer than one week. PMID:12937095

  12. Childhood Sleep Duration and Lifelong Mortality Risk

    PubMed Central

    Duggan, Katherine A.; Reynolds, Chandra A.; Kern, Margaret L.; Friedman, Howard S.

    2014-01-01

    Objective Sleep duration is known to significantly affect health in adults and children, but little is understood about long-term associations. This prospective cohort study is the first to examine whether childhood sleep duration is associated with lifelong mortality risk. Methods Data from childhood were refined and mortality data collected for 1,145 participants from the Terman Life Cycle Study. Participants were born between 1904 and 1915, lived to at least 1940, and had complete age, bedtime, and waketime data at initial data collection (1917–1926). Homogeneity of the cohort sample (intelligent, mostly white) limits generality but provides natural control of common confounds. Through 2009, 1,039 participants had confirmed deaths. Sleep duration was calculated as the difference between each child’s bed and wake times. Age-adjusted sleep (deviation from that predicted by age) was computed. Cox proportional hazards survival models evaluated childhood sleep duration as a predictor of mortality separately by sex, controlling for baseline age. Results For males, a quadratic relation emerged: male children who under-slept or over-slept compared to peers were at increased risk of lifelong all-cause mortality (HR = 1.15, CI = 1.05 – 1.27). Effect sizes were smaller and non-significant in females (HR = 1.02, CI = 0.91 – 1.14). Conclusions Male children with shorter or longer sleep durations than expected for their age were at increased risk of death at any given age in adulthood. The findings suggest that sleep may be a core biobehavioral trait, with implications for new models of sleep and health throughout the entire lifespan. PMID:24588628

  13. Electrocorticogram encoding of upper extremity movement duration.

    PubMed

    Wang, Po T; King, Christine E; McCrimmon, Colin M; Shaw, Susan J; Millett, David E; Liu, Charles Y; Chui, Luis A; Nenadic, Zoran; Do, An H

    2014-01-01

    Electrocorticogram (ECoG) is a promising long-term signal acquisition platform for brain-computer interface (BCI) systems such as upper extremity prostheses. Several studies have demonstrated decoding of arm and finger trajectories from ECoG high-gamma band (80-160 Hz) signals. In this study, we systematically vary the velocity of three elementary movement types (pincer grasp, elbow and shoulder flexion/extension) to test whether the high-gamma band encodes for the entirety of the movements, or merely the movement onset. To this end, linear regression models were created for the durations and amplitudes of high-gamma power bursts and velocity deflections. One subject with 8×8 high-density ECoG grid (4 mm center-to-center electrode spacing) participated in the experiment. The results of the regression models indicated that the power burst durations varied directly with the movement durations (e.g. R(2)=0.71 and slope=1.0 s/s for elbow). The persistence of power bursts for the duration of the movement suggests that the primary motor cortex (M1) is likely active for the entire duration of a movement, instead of providing a marker for the movement onset. On the other hand, the amplitudes were less co-varied. Furthermore, the electrodes of maximum R(2) conformed to somatotopic arrangement of the brain. Also, electrodes responsible for flexion and extension movements could be resolved on the high-density grid. In summary, these findings suggest that M1 may be directly responsible for activating the individual muscle motor units, and future BCI may be able to utilize them for better control of prostheses.

  14. Sleep duration and health in young adults.

    PubMed

    Steptoe, Andrew; Peacey, Victoria; Wardle, Jane

    2006-09-18

    Both long and short sleep durations have been associated with negative health outcomes in middle-aged and older adults. This study assessed the relationship between sleep duration and self-rated health in young adults. Using anonymous questionnaires, data were collected from 17 465 university students aged 17 to 30 years who were taking non-health-related courses at 27 universities in 24 countries. The response rate was greater than 90%. Sleep duration was measured by self-report; the health outcome was self-rated health; and age, sex, socioeconomic background, smoking, alcohol consumption, body mass index, physical activity, depression (Beck Depression Inventory), recent use of health services, and country of origin were included as covariates. Sixty-three percent of respondents slept for 7 to 8 hours; 21% were short sleepers (6%, <6 hours; 15%, 6-7 hours); and 16% were long sleepers (10%, 8-10 hours; 6%, >10 hours). Compared with the reference category (7-8 hours), the adjusted odds ratio of poor health was 1.56 (95% confidence interval [CI], 1.22-1.99) for respondents sleeping 6 to 7 hours and 1.99 (95% CI, 1.31-3.03) for those sleeping less than 6 hours. The same significant pattern was seen when the results were analyzed separately by sex. When respondents from Japan, Korea, and Thailand (characterized by relatively short sleep durations) were excluded, the adjusted odds ratios were 1.33 (95% CI 1.03-1.73) and 1.62 (95% CI, 1.06-2.48) for those sleeping 6 to 7 hours and less than 6 hours, respectively. There were no significant associations between self-rated health and long sleep duration. Our data suggest that short sleep may be more of a concern than long sleep in young adults.

  15. Factorization-based texture segmentation

    SciTech Connect

    Yuan, Jiangye; Wang, Deliang; Cheriyadat, Anil M.

    2015-06-17

    This study introduces a factorization-based approach that efficiently segments textured images. We use local spectral histograms as features, and construct an M × N feature matrix using M-dimensional feature vectors in an N-pixel image. Based on the observation that each feature can be approximated by a linear combination of several representative features, we factor the feature matrix into two matrices-one consisting of the representative features and the other containing the weights of representative features at each pixel used for linear combination. The factorization method is based on singular value decomposition and nonnegative matrix factorization. The method uses local spectral histograms to discriminate region appearances in a computationally efficient way and at the same time accurately localizes region boundaries. Finally, the experiments conducted on public segmentation data sets show the promise of this simple yet powerful approach.

  16. Factorization-based texture segmentation

    DOE PAGES

    Yuan, Jiangye; Wang, Deliang; Cheriyadat, Anil M.

    2015-06-17

    This study introduces a factorization-based approach that efficiently segments textured images. We use local spectral histograms as features, and construct an M × N feature matrix using M-dimensional feature vectors in an N-pixel image. Based on the observation that each feature can be approximated by a linear combination of several representative features, we factor the feature matrix into two matrices-one consisting of the representative features and the other containing the weights of representative features at each pixel used for linear combination. The factorization method is based on singular value decomposition and nonnegative matrix factorization. The method uses local spectral histogramsmore » to discriminate region appearances in a computationally efficient way and at the same time accurately localizes region boundaries. Finally, the experiments conducted on public segmentation data sets show the promise of this simple yet powerful approach.« less

  17. Printed Arabic optical character segmentation

    NASA Astrophysics Data System (ADS)

    Mohammad, Khader; Ayyesh, Muna; Qaroush, Aziz; Tumar, Iyad

    2015-03-01

    A considerable progress in recognition techniques for many non-Arabic characters has been achieved. In contrary, few efforts have been put on the research of Arabic characters. In any Optical Character Recognition (OCR) system the segmentation step is usually the essential stage in which an extensive portion of processing is devoted and a considerable share of recognition errors is attributed. In this research, a novel segmentation approach for machine Arabic printed text with diacritics is proposed. The proposed method reduces computation, errors, gives a clear description for the sub-word and has advantages over using the skeleton approach in which the data and information of the character can be lost. Both of initial evaluation and testing of the proposed method have been developed using MATLAB and shows 98.7% promising results.

  18. Experimental study on the segmental perfusion and preservation of spleen.

    PubMed

    Limin, H; Hongchi, J; Wenjie, D; Haiquan, Q; Jun, X

    1999-12-01

    Spleen transplanlation has developed to be an effective strategy for hemophilia A. But it has not been reported up to date that which kind of established solutions is most suitable for perfusion and preservation of spleen. This study aimed to establish some experiences with the comparison among Hartmann's solution, Collins' solution and WMO-I solution, in order to instruct the clinical spleen transplantation. After the splenic artery and vein were dissociated clearly, three kinds of perfusion solutions began to perfuse the corresponding segments of spleen with a randomized sequence. When the efferent fluids from the splenic vein became clear, the perfused spleen segments were preserved for different durations with the same perfusing solution to calculate the survival rate of splencocyte (SRS) and were examined with light and electron microscopy. Among the three solutions, SRS with WMO-I solution was significantly higher than those of the other two (P<0.001). The perfused spleen with WMO-I solution showed the slightest morphological changes and a significant longer preservation duration than those with the other two (P<0.05 or P<0.01). Among the three solutions, WMO-I solution was most suitable for perfusion and preservation of spleen.

  19. Multiple images segmentation based on saliency map

    NASA Astrophysics Data System (ADS)

    Ning, XiaoLan; Xu, Cheng; Li, SiQi; Li, ShiYing; Li, ZhiQi

    2017-06-01

    Aiming at discovering and segmenting out common objects from multiple images, co-segmentation is a effective method. It is more accurate to make full use of the relationships between images in segmenting than only single image. The first step is to deal with single image with employing hierarchical segmentation to get a Contour Map, saliency detection to obtain the saliency map and object detection to find the possible common part. Then, constructing a digraph with the multiple local regions, and dealing with the digraph. When a digraph is constructed, the corresponding between adjacent two images is influential to the co-segmentation results. This paper develops a method to sort the images to co-segment. Also, we test the method on ICOSEG and MSRC datasets, and compare it with four proposed method. And the results show that it is efficient in co-segmentation with higher precision than many existing and conventional co-segmentation methods.

  20. Rigid shape matching by segmentation averaging.

    PubMed

    Wang, Hongzhi; Oliensis, John

    2010-04-01

    We use segmentations to match images by shape. The new matching technique does not require point-to-point edge correspondence and is robust to small shape variations and spatial shifts. To address the unreliability of segmentations computed bottom-up, we give a closed form approximation to an average over all segmentations. Our method has many extensions, yielding new algorithms for tracking, object detection, segmentation, and edge-preserving smoothing. For segmentation, instead of a maximum a posteriori approach, we compute the "central" segmentation minimizing the average distance to all segmentations of an image. For smoothing, instead of smoothing images based on local structures, we smooth based on the global optimal image structures. Our methods for segmentation, smoothing, and object detection perform competitively, and we also show promising results in shape-based tracking.

  1. Spectral clustering algorithms for ultrasound image segmentation.

    PubMed

    Archip, Neculai; Rohling, Robert; Cooperberg, Peter; Tahmasebpour, Hamid; Warfield, Simon K

    2005-01-01

    Image segmentation algorithms derived from spectral clustering analysis rely on the eigenvectors of the Laplacian of a weighted graph obtained from the image. The NCut criterion was previously used for image segmentation in supervised manner. We derive a new strategy for unsupervised image segmentation. This article describes an initial investigation to determine the suitability of such segmentation techniques for ultrasound images. The extension of the NCut technique to the unsupervised clustering is first described. The novel segmentation algorithm is then performed on simulated ultrasound images. Tests are also performed on abdominal and fetal images with the segmentation results compared to manual segmentation. Comparisons with the classical NCut algorithm are also presented. Finally, segmentation results on other types of medical images are shown.

  2. Segmented Coil Fails In Steps

    NASA Technical Reports Server (NTRS)

    Stedman, Ronald S.

    1990-01-01

    Electromagnetic coil degrades in steps when faults occur, continues to operate at reduced level instead of failing catastrophically. Made in segments connected in series and separated by electrically insulating barriers. Fault does not damage adjacent components or create hazard. Used to control valves in such critical applications as cooling systems of power generators and chemical process equipment, where flammable liquids or gases handled. Also adapts to electrical control of motors.

  3. Segmentation of the Farallon slab

    NASA Astrophysics Data System (ADS)

    Liu, L.; Stegman, D. R.

    2011-12-01

    Recent tomography images reveal a complex 3D mantle structure beneath western United States, with feature morphology varying rapidly with depth. By assimilating plate motion history, paleo-age of sea floor, and paleo-geography of plate boundaries in a 3-D numerical model, we simulate the Farallon-Juan de Fuca subduction during the past 40 Ma. We find that the highly segmented upper mantle structure of western U.S. is a direct result of the Farallon subduction. We show that the tilted 'horseshoe'-shaped fast seismic anomaly beneath Nevada and Utah at 300-600 km depth range is in fact a segment of curled slab subducted since 15 Ma, and the shallower linear slab beneath the Cascades is younger than 5 Ma. The distinct morphology between these two parts of the subduction system indicates the strong influence of the fast trench rollback since 20 Ma, the northward migrating JF-PA-NA triple-junction, and the toroidal flow around slab edges. The observed mantle structures are used to constrain the rheology of the upper mantle through matching the shape, depth, and location of modeled subducted slab segments. The inferred viscosity for the asthenosphere is 5×10^19 Pa s and that for the transition zone is 1.5×10^21 Pa s. The slab is found to be about 2 orders of magnitude stronger than the ambient mantle above 410 km depth, but of similar order of magnitude viscosity in the transition zone.

  4. Segmentation in local hospital markets.

    PubMed

    Dranove, D; White, W D; Wu, L

    1993-01-01

    This study examines evidence of market segmentation on the basis of patients' insurance status, demographic characteristics, and medical condition in selected local markets in California in the years 1983 and 1989. Substantial differences exist in the probability patients may be admitted to particular hospitals based on insurance coverage, particularly Medicaid, and race. Segmentation based on insurance and race is related to hospital characteristics, but not the characteristics of the hospital's community. Medicaid patients are more likely to go to hospitals with lower costs and fewer service offerings. Privately insured patients go to hospitals offering more services, although cost concerns are increasing. Hispanic patients also go to low-cost hospitals, ceteris paribus. Results indicate little evidence of segmentation based on medical condition in either 1983 or 1989, suggesting that "centers of excellence" have yet to play an important role in patient choice of hospital. The authors found that distance matters, and that patients prefer nearby hospitals, moreso for some medical conditions than others, in ways consistent with economic theories of consumer choice.

  5. Turbo segmentation of textured images.

    PubMed

    Lehmann, Frederic

    2011-01-01

    We consider the problem of semi-supervised segmentation of textured images. Existing model-based approaches model the intensity field of textured images as a Gauss-Markov random field to take into account the local spatial dependencies between the pixels. Classical Bayesian segmentation consists of also modeling the label field as a Markov random field to ensure that neighboring pixels correspond to the same texture class with high probability. Well-known relaxation techniques are available which find the optimal label field with respect to the maximum a posteriori or the maximum posterior mode criterion. But, these techniques are usually computationally intensive because they require a large number of iterations to converge. In this paper, we propose a new Bayesian framework by modeling two-dimensional textured images as the concatenation of two one-dimensional hidden Markov autoregressive models for the lines and the columns, respectively. A segmentation algorithm, which is similar to turbo decoding in the context of error-correcting codes, is obtained based on a factor graph approach. The proposed method estimates the unknown parameters using the Expectation-Maximization algorithm.

  6. Vascular changes at the puncture segments of arteriovenous fistula for hemodialysis access.

    PubMed

    Hsiao, Ju-Feng; Chou, Hsin-Hua; Hsu, Lung-An; Wu, Lung-Sheng; Yang, Chih-Wei; Hsu, Tsu-Shiu; Chang, Chi-Jen

    2010-09-01

    Repeated puncture is a mechanical injury to the hemodialysis accesses. We systemically observed the vascular changes at the puncture segments of arteriovenous fistulas. The native arteriovenous fistulas in 104 patients on maintenance hemodialysis using the buttonhole technique for puncture were studied. We used the duplex scan to observe the intimal lesions, the maximal diameters at the arterial and venous puncture segments, and the references. Intimal lesions were found in 42% and 40% of the arterial and venous puncture segments, none of which resulted in significant luminal stenosis. The differences between diameters at the arterial or venous puncture segments and the corresponding references were significant (arterial, 11.07 +/- 4.45 vs 6.85 +/- 2.35 mm, P < .001; venous, 8.82 +/- 4.13 vs 5.54 +/- 2.22 mm, P < .001). All segments, except only three arterial and four venous puncture segments, were larger than the corresponding references. The degree of vascular dilatation, defined as the diameter difference between the puncture segments and the references calibrated by the reference diameter, were 64.1 +/- 49.6% at arterial puncture segments and 59.9 +/- 42.2% at venous segments. Multivariate analysis revealed that the patient age and the puncture duration were strongly correlated with the degree of vascular dilatation at both the arterial (P = .018 and .007, respectively) and venous puncture segments (P = .020 and .011, respectively). Puncture of arteriovenous fistula using a buttonhole technique resulted in a consistent vascular dilatation and moderately high incidence of intimal thickness, but no significant luminal stenosis was found.

  7. Durational patterning at syntactic and discourse boundaries in Mandarin spontaneous speech.

    PubMed

    Fon, Janice; Johnson, Keith; Chen, Sally

    2011-03-01

    This study focused on durational cues (i.e., syllable duration, pause duration, and syllable onset intervals (SOIs)) at discourse boundaries in two dialects of Mandarin,Taiwan and Mainland varieties. Speech was elicited by having 18 participants describe events in The Pear Story film. Recorded data were transcribed, labeled, and segmented into clauses. Discourse boundary indices were used to label discourse disjuncture levels. Results showed that the scope of lengthening included both the final and the penultimate syllables. Pause was a robust but optional indicator for discourse boundaries, and Taiwan Mandarin preferred unfilled over filled ones, while the Mainland variety did not show such strong preferences. Discourse hierarchy corresponded consistently with occurrences of pauses and duration of SOIs, within which pause was the main contributor. Higher discourse levels were more likely to be accompanied by pauses, and were indicated by longer pauses and SOIs. Syllable duration only played a secondary role in indicating discourse disjuncture size when pause was absent.When there was an accompanying pause, Mainland Mandarin relied solely on it to indicate discourse hierarchy, while Taiwan Mandarin used both syllable and pause duration, a dialectal difference that seemed to be rhythm-related. By shortening the degree of lengthening in the boundary syllable and lengthening the following pause at the same time,Taiwan Mandarin increased the absolute and relative duration of pause and maximized its role in indicating discourse hierarchy.The results of this study implied that the use of pause in discourse disjuncture demarcation was more of a language-specific choice while its role in discourse hierarchy encoding is more language-universal.

  8. Video Segmentation Descriptors for Event Recognition

    DTIC Science & Technology

    2014-12-08

    spatial sizes and motion intensities (2. k ). IV. VIDEO SEGMENTATION Various video segmentation techniques have been proposed based on superpixels [26...to cluster STTs according to color and motion through a meanshift [24] over- segmentation . The second pass iteratively fuses the yielded supertubes...video motion descriptor based on a multi-scale video segmentation to provide a multi- layered output as well as connections with the rich interactions

  9. Hand-Assisted Laparoscopic (HAL) Multiple Segmental Colorectal Resections: Are They Feasible and Safe?

    PubMed Central

    Taggarshe, Deepa; Attuwaybi, Bashir O.; Matier, Brian; Visco, Jeffrey J.; Butler, Bryan N.

    2015-01-01

    The objective of this study was to evaluate the short-term outcomes of synchronous hand-assisted laparoscopic (HAL) segmental colorectal resections. The surgical options for synchronous colonic pathology include extensive colonic resection with single anastomosis, multiple synchronous segmental resections with multiple anastomoses, or staged resections. Traditionally, multiple open, synchronous, segmental resections have been performed. There is a lack of data on HAL multiple segmental colorectal resections. A retrospective chart review was compiled on all patients who underwent HAL synchronous segmental colorectal resections by all the colorectal surgeons from our Group during the period of 1999 to 2014. Demographics, operative details, and short-term outcomes are reported. During the period, 9 patients underwent HAL synchronous multiple segmental colorectal resections. There were 5 women and 4 men, with median age of 54 (24–83) years and median BMI of 24 (19.8–38.7) kg/m2. Two patients were on long-term corticosteroid therapy. The median operative time was 210 (120–330) minutes and median operative blood loss was 200 (75–300) mLs. The median duration for return of bowel function was 2 days and the median length of stay was 3.5 days. We had 2 minor wound infections. There were no deaths. Synchronous segmental colorectal resections with anastomoses using the hand-assisted laparoscopic technique are safe. Early conversion to open and use of stomas are advisable in challenging cases. PMID:25875544

  10. Quick Dissection of the Segmental Bronchi

    ERIC Educational Resources Information Center

    Nakajima, Yuji

    2010-01-01

    Knowledge of the three-dimensional anatomy of the bronchopulmonary segments is essential for respiratory medicine. This report describes a quick guide for dissecting the segmental bronchi in formaldehyde-fixed human material. All segmental bronchi are easy to dissect, and thus, this exercise will help medical students to better understand the…

  11. Quick Dissection of the Segmental Bronchi

    ERIC Educational Resources Information Center

    Nakajima, Yuji

    2010-01-01

    Knowledge of the three-dimensional anatomy of the bronchopulmonary segments is essential for respiratory medicine. This report describes a quick guide for dissecting the segmental bronchi in formaldehyde-fixed human material. All segmental bronchi are easy to dissect, and thus, this exercise will help medical students to better understand the…

  12. Market Segmentation from a Behavioral Perspective

    ERIC Educational Resources Information Center

    Wells, Victoria K.; Chang, Shing Wan; Oliveira-Castro, Jorge; Pallister, John

    2010-01-01

    A segmentation approach is presented using both traditional demographic segmentation bases (age, social class/occupation, and working status) and a segmentation by benefits sought. The benefits sought in this case are utilitarian and informational reinforcement, variables developed from the Behavioral Perspective Model (BPM). Using data from 1,847…

  13. Segmenting the mental health care market.

    PubMed

    Stone, T R; Warren, W E; Stevens, R E

    1990-03-01

    The authors report the results of a segmentation study of the mental health care market. A random sample of 387 residents of a western city were interviewed by telephone. Cluster analysis of the data identified six market segments. Each is described according to the mental health care services to which it is most sensitive. Implications for targeting the segments are discussed.

  14. Market Segmentation from a Behavioral Perspective

    ERIC Educational Resources Information Center

    Wells, Victoria K.; Chang, Shing Wan; Oliveira-Castro, Jorge; Pallister, John

    2010-01-01

    A segmentation approach is presented using both traditional demographic segmentation bases (age, social class/occupation, and working status) and a segmentation by benefits sought. The benefits sought in this case are utilitarian and informational reinforcement, variables developed from the Behavioral Perspective Model (BPM). Using data from 1,847…

  15. Inter-element orientation and distance influence the duration of persistent contour integration.

    PubMed

    Strother, Lars; Alferov, Danila

    2014-01-01

    Contour integration is a fundamental form of perceptual organization. We introduce a new method of studying the mechanisms responsible for contour integration. This method capitalizes on the perceptual persistence of contours under conditions of impending camouflage. Observers viewed arrays of randomly arranged line segments upon which circular contours comprised of similar line segments were superimposed via abrupt onset. Crucially, these contours remained visible for up to a few seconds following onset, but eventually disappeared due to the camouflaging effects of surrounding background line segments. Our main finding was that the duration of contour visibility depended on the distance and degree of co-alignment between adjacent contour segments such that relatively dense smooth contours persisted longest. The stimulus-related effects reported here parallel similar results from contour detection studies, and complement previous reported top-down influences on contour persistence (Strother et al., 2011). We propose that persistent contour visibility reflects the sustained activity of recurrent processing loops within and between visual cortical areas involved in contour integration and other important stages of visual object recognition.

  16. Efficiency, effectiveness, and duration of stroke rehabilitation.

    PubMed

    Shah, S; Vanclay, F; Cooper, B

    1990-02-01

    This prospective multicenter study identifies the variables significant in the prediction of rehabilitation efficiency, achievement of rehabilitation potential and duration of rehabilitation stay in 258 persons with a first stroke admitted to comprehensive inpatient rehabilitation in Brisbane, Australia, during 1984. All three dependent variables were poorly predicted, with only 17% of the variance in rehabilitation efficiency, only 30% of the variance in achievement of rehabilitation potential, and only 22% of the variance in duration of rehabilitation stay explained. Unlike other reports, we considered most of the major medical (side of paralysis, stroke etiology, site of the lesion, arterial distribution affected, etc.), rehabilitative (initial Barthel Index score, interval from stroke onset to acute-care hospital admission, interval from hospital admission to rehabilitation commencement, neurologic measures, etc.), and demographic (age, years of education, occupation, ethnicity, etc.) variables. The high proportion of unexplained variance is likely to be due to nonmedical factors influencing the selection of patients for rehabilitation.

  17. Extended duration Orbiter life support definition

    NASA Technical Reports Server (NTRS)

    Kleiner, G. N.; Thompson, C. D.

    1978-01-01

    Extending the baseline seven-day Orbiter mission to 30 days or longer and operating with a solar power module as the primary source for electrical power requires changes to the existing environmental control and life support (ECLS) system. The existing ECLS system imposes penalties on longer missions which limit the Orbiter capabilities and changes are required to enhance overall mission objectives. Some of these penalties are: large quantities of expendables, the need to dump or store large quantities of waste material, the need to schedule fuel cell operation, and a high landing weight penalty. This paper presents the study ground rules and examines the limitations of the present ECLS system against Extended Duration Orbiter mission requirements. Alternate methods of accomplishing ECLS functions for the Extended Duration Orbiter are discussed. The overall impact of integrating these options into the Orbiter are evaluated and significant Orbiter weight and volume savings with the recommended approaches are described.

  18. Power Systems Design for Long Duration Ballooning

    NASA Technical Reports Server (NTRS)

    Stilwell, Bryan; Chuzel, Alain

    2016-01-01

    The Columbia Scientific Balloon Facility has been designing and building high-altitude balloon power systems for over 26 years. With that experience, we have found certain types of PV panels, batteries, and charge controllers that are reliable in stratospheric environments. The ultimate goal is to ensure that power systems will provide power reliably throughout the duration of an LDB flight. The purpose of this presentation is to provide some general guidelines and best practices for power system design.

  19. Localization of Short Duration Periodic Signals

    DTIC Science & Technology

    2013-09-30

    the localization of multiple interfering sperm whales using multi- sensor time difference of arrival”, 130 Journal of the Acoustical Society of...often make short duration periodic signals such as clicks. It is common to locate whales by measuring the time difference for the same click...can occur when the sources are whales in a pod. In this case, a set of hyperbolic solutions will be created for each source and many false

  20. Extended Duration Orbiter - Meeting the challenge

    NASA Technical Reports Server (NTRS)

    Saucier, D. R.

    1992-01-01

    The paper overviews the Extended Duration Orbiter (EDO) program designed to provide an on-orbit stay capability of 16 days using the Orbiter Vehicle OV-102. Special attention is given to the EDO's subsystems and substructures, including the cryogenic pallet, the cryogenic storage tanks, the cryogenic solenoid valves, the regenerable carbon dioxide removal system, and the waste collection system. The EDO program will start with the STS-50 U.S. Microgravity Lab mission planned for June 1992.

  1. Does Sexual Satisfaction Change With Relationship Duration?

    PubMed

    Schmiedeberg, Claudia; Schröder, Jette

    2016-01-01

    Despite a large body of empirical literature on sexual satisfaction, its development over the course of a relationship is still unclear. Only a small number of studies, most of which have relied on cross-sectional data of convenience samples, have explicitly focused on relationship duration, and empirical evidence is mixed. We analyzed how sexual satisfaction changes over the course of a relationship using three waves of the German Family Panel study (pairfam). We concentrated our analyses on young and middle-aged heterosexual individuals in committed relationships (N = 2,814) and applied fixed effects regression models, which have the advantage of estimations based on changes within individuals over time. We found a positive development of sexual satisfaction in the first year of a relationship, followed by a steady decline. This pattern persisted even when controlling for the frequency of intercourse, although the effects were, in part, mediated by intercourse frequency. We explained the non-linear effect of relationship duration on sexual satisfaction with an initial learning effect regarding partner-specific sexual skills, which is then outweighed by a decline in passion at later stages of a relationship. Moreover, we found significant effects for the control variables of health status, intimacy in couple communication, and conflict style, as expected. In contrast to past research, however, cohabitation and marriage were not found to play a role for sexual satisfaction in our data. Further research is required to deepen the understanding of the reasons why sexual satisfaction changes with relationship duration.

  2. Evaluation of Long Duration Flight on Venus

    NASA Technical Reports Server (NTRS)

    Landis, Geoffrey A.; Colozza, Anthony J.

    2006-01-01

    An analysis was performed to evaluate the potential of utilizing either an airship or aircraft as a flight platform for long duration flight within the atmosphere of Venus. In order to achieve long-duration flight, the power system for the vehicle had to be capable of operating for extended periods of time. To accomplish these, two types of power systems were considered, a solar energy-based power system utilizing a photovoltaic array as the main power source and a radioisotope heat source power system utilizing a Stirling engine as the heat conversion device. Both types of vehicles and power systems were analyzed to determine their flight altitude range. This analysis was performed for a station-keeping mission where the vehicle had to maintain a flight over a location on the ground. This requires the vehicle to be capable of flying faster than the wind speed at a particular altitude. An analysis was also performed to evaluate the altitude range and maximum duration for a vehicle that was not required to maintain station over a specified location. The results of the analysis show that each type of flight vehicle and power system was capable of flight within certain portions of Venus s atmosphere. The aircraft, both solar and radioisotope power proved to be the most versatile and provided the greatest range of coverage both for station-keeping and non-station-keeping missions.

  3. Underwater loudness for pure tones: Duration effects

    NASA Astrophysics Data System (ADS)

    Cudahy, Edward A.; Schwaller, Derek; Fothergill, David; Wolgemuth, Keith

    2003-04-01

    The loudness of underwater pure tones was measured by loudness matching for pure tones from 100 to 16,000 Hz. The standard was a one second tone at 1000 Hz. The signal duration was varied from 20 milliseconds to 5 seconds. Subjects were instructed to match the loudness of the comparison tone at one of the test frequencies to the loudness of the standard tone. Loudness was measured at the threshold, the most comfortable loudness, and the maximum tolerable loudness. The intensity of the standard was varied randomly across the test series. The subjects were bareheaded U.S. Navy divers tested at a depth of 3 meters. All subjects had normal in-air hearing. Tones were presented to the right side of the subject from an array of underwater sound projectors. The sound pressure level was calibrated at the location of the subject's head with the subject absent. Loudness increased and threshold decreased as duration increased. The effect was greatest at the lowest and highest frequencies. The shape of the loudness contours across frequency and duration derived from these measurements are different from in-air measurements. [Research supported by ONR.

  4. Red blood cell storage duration and trauma.

    PubMed

    Sparrow, Rosemary L

    2015-04-01

    Numerous retrospective clinical studies suggest that transfusion of longer stored red blood cells (RBCs) is associated with an independent risk of poorer outcomes for certain groups of patients, including trauma, intensive care, and cardiac surgery patients. Large multicenter randomized controlled trials are currently underway to address the concern about RBC storage duration. However, none of these randomized controlled trials focus specifically on trauma patients with hemorrhage. Major trauma, particularly due to road accidents, is the leading cause of critical injury in the younger-than-40-year-old age group. Severe bleeding associated with major trauma induces hemodynamic dysregulation that increases the risk of hypoxia, coagulopathy, and potentially multiorgan failure, which can be fatal. In major trauma, a multitude of stress-associated changes occur to the patient's RBCs, including morphological changes that increase cell rigidity and thereby alter blood flow hemodynamics, particularly in the microvascular vessels, and reduce RBC survival. Initial inflammatory responses induce deleterious cellular interactions, including endothelial activation, RBC adhesion, and erythrophagocytosis that are quickly followed by profound immunosuppressive responses. Stored RBCs exhibit similar biophysical characteristics to those of trauma-stressed RBCs. Whether transfusion of RBCs that exhibit storage lesion changes exacerbates the hemodynamic perturbations already active in the trauma patient is not known. This article reviews findings from several recent nonrandomized studies examining RBC storage duration and clinical outcomes in trauma patients. The rationale for further research on RBC storage duration in the trauma setting is provided. Copyright © 2015 Elsevier Inc. All rights reserved.

  5. Time interval between concussions and symptom duration.

    PubMed

    Eisenberg, Matthew A; Andrea, John; Meehan, William; Mannix, Rebekah

    2013-07-01

    To test the hypothesis that children with a previous history of concussion have a longer duration of symptoms after a repeat concussion than those without such a history. Prospective cohort study of consecutive patients 11 to 22 years old presenting to the emergency department of a children's hospital with an acute concussion. The main outcome measure was time to symptom resolution, assessed by the Rivermead Post-Concussion Symptoms Questionnaire (RPSQ). Patients and providers completed a questionnaire describing mechanism of injury, associated symptoms, past medical history, examination findings, diagnostic studies, and the RPSQ. Patients were then serially administered the RPSQ for 3 months after the concussion or until all symptoms resolved. A total of 280 patients were enrolled over 12 months. Patients with a history of previous concussion had a longer duration of symptoms than those without previous concussion (24 vs 12 days, P = .02). Median symptom duration was even longer for patients with multiple previous concussions (28 days, P = .03) and for those who had sustained a concussion within the previous year (35 days, P = .007) compared with patients without those risk factors. In a multivariate model, previous concussion, absence of loss of consciousness, age ≥13, and initial RPSQ score >18 were significant predictors of prolonged recovery. Children with a history of a previous concussion, particularly recent or multiple concussions, are at increased risk for prolonged symptoms after concussion. These findings have direct implications on the management of patients with concussion who are at high risk for repeat injuries.

  6. Three-dimensional digital line segments.

    PubMed

    Kim, C E

    1983-02-01

    Digital arcs in 3-D digital pictures are defined. The digital image of an arc is also defined. A digital arc is defined to be a digital line segment if it is the digital image of a line segment. It is shown that a digital line segment may be characterized by the chord property holding for its projections onto the coordinate planes. It is also shown that a digital line segment may not be characterized by its own chord property. A linear time algorithm is presented that determines whether or not a digital arc is a digital line segment.

  7. Segmented ceramic liner for induction furnaces

    DOEpatents

    Gorin, A.H.; Holcombe, C.E.

    1994-07-26

    A non-fibrous ceramic liner for induction furnaces is provided by vertically stackable ring-shaped liner segments made of ceramic material in a light-weight cellular form. The liner segments can each be fabricated as a single unit or from a plurality of arcuate segments joined together by an interlocking mechanism. Also, the liner segments can be formed of a single ceramic material or can be constructed of multiple concentric layers with the layers being of different ceramic materials and/or cellular forms. Thermomechanically damaged liner segments are selectively replaceable in the furnace. 5 figs.

  8. Segmented ceramic liner for induction furnaces

    DOEpatents

    Gorin, Andrew H.; Holcombe, Cressie E.

    1994-01-01

    A non-fibrous ceramic liner for induction furnaces is provided by vertically stackable ring-shaped liner segments made of ceramic material in a light-weight cellular form. The liner segments can each be fabricated as a single unit or from a plurality of arcuate segments joined together by an interlocking mechanism. Also, the liner segments can be formed of a single ceramic material or can be constructed of multiple concentric layers with the layers being of different ceramic materials and/or cellular forms. Thermomechanically damaged liner segments are selectively replaceable in the furnace.

  9. Antenatal breastfeeding education for increasing breastfeeding duration

    PubMed Central

    Lumbiganon, Pisake; Martis, Ruth; Laopaiboon, Malinee; Festin, Mario R; Ho, Jacqueline J; Hakimi, Mohammad

    2014-01-01

    Background Breastfeeding (BF) is well recognised as the best food for infants. The impact of antenatal BF education on the duration of BF has not been evaluated. Objectives To evaluate the effectiveness of antenatal BF education for increasing BF initiation and duration. Search methods We searched the Cochrane Pregnancy and Childbirth Group’s Trials Register (21 April 2010), CENTRAL (The Cochrane Library 2010, Issue 2), MEDLINE (1966 to April 2010) and SCOPUS (January 1985 to April 2010). We contacted experts and searched reference lists of retrieved articles. We updated the search of the Pregnancy and Childbirth Group’s Trials Register on 28 September 2011 and added the results to the awaiting classification section of the review. Selection criteria All identified published, unpublished and ongoing randomised controlled trials (RCTs) assessing the effect of formal antenatal BF education or comparing two different methods of formal antenatal BF education, on duration of BF. We excluded RCTs that also included intrapartum or postpartum BF education. Data collection and analysis We assessed all potential studies identified as a result of the search strategy. Two review authors extracted data from each included study using the agreed form and assessed risk of bias. We resolved discrepancies through discussion. Main results We included 17 studies with 7131 women in the review and 14 studies involving 6932 women contributed data to the analyses. We did not do any meta-analysis because there was only one study for each comparison. Five studies compared a single method of BF education with routine care. Peer counselling significantly increased BF initiation. Three studies compared one form of BF education versus another. No intervention was significantly more effective than another intervention in increasing initiation or duration of BF. Seven studies compared multiple methods versus a single method of BF education. Combined BF educational interventions were not

  10. Metric Learning for Hyperspectral Image Segmentation

    NASA Technical Reports Server (NTRS)

    Bue, Brian D.; Thompson, David R.; Gilmore, Martha S.; Castano, Rebecca

    2011-01-01

    We present a metric learning approach to improve the performance of unsupervised hyperspectral image segmentation. Unsupervised spatial segmentation can assist both user visualization and automatic recognition of surface features. Analysts can use spatially-continuous segments to decrease noise levels and/or localize feature boundaries. However, existing segmentation methods use tasks-agnostic measures of similarity. Here we learn task-specific similarity measures from training data, improving segment fidelity to classes of interest. Multiclass Linear Discriminate Analysis produces a linear transform that optimally separates a labeled set of training classes. The defines a distance metric that generalized to a new scenes, enabling graph-based segmentation that emphasizes key spectral features. We describe tests based on data from the Compact Reconnaissance Imaging Spectrometer (CRISM) in which learned metrics improve segment homogeneity with respect to mineralogical classes.

  11. Efficient graph-cut tattoo segmentation

    NASA Astrophysics Data System (ADS)

    Kim, Joonsoo; Parra, Albert; Li, He; Delp, Edward J.

    2015-03-01

    Law enforcement is interested in exploiting tattoos as an information source to identify, track and prevent gang-related crimes. Many tattoo image retrieval systems have been described. In a retrieval system tattoo segmentation is an important step for retrieval accuracy since segmentation removes background information in a tattoo image. Existing segmentation methods do not extract the tattoo very well when the background includes textures and color similar to skin tones. In this paper we describe a tattoo segmentation approach by determining skin pixels in regions near the tattoo. In these regions graph-cut segmentation using a skin color model and a visual saliency map is used to find skin pixels. After segmentation we determine which set of skin pixels are connected with each other that form a closed contour including a tattoo. The regions surrounded by the closed contours are considered tattoo regions. Our method segments tattoos well when the background includes textures and color similar to skin.

  12. Image Segmentation Using Hierarchical Merge Tree.

    PubMed

    Liu, Ting; Seyedhosseini, Mojtaba; Tasdizen, Tolga

    2016-07-18

    This paper investigates one of the most fundamental computer vision problems: image segmentation. We propose a supervised hierarchical approach to object-independent image segmentation. Starting with over-segmenting superpixels, we use a tree structure to represent the hierarchy of region merging, by which we reduce the problem of segmenting image regions to finding a set of label assignment to tree nodes. We formulate the tree structure as a constrained conditional model to associate region merging with likelihoods predicted using an ensemble boundary classifier. Final segmentations can then be inferred by finding globally optimal solutions to the model efficiently. We also present an iterative training and testing algorithm that generates various tree structures and combines them to emphasize accurate boundaries by segmentation accumulation. Experiment results and comparisons with other recent methods on six public data sets demonstrate that our approach achieves state-of-the-art region accuracy and is competitive in image segmentation without semantic priors.

  13. Augmented-reality-based segmentation refinement

    NASA Astrophysics Data System (ADS)

    Bornik, Alexander; Reitinger, Bernhard; Beichel, Reinhard; Sorantin, Erich; Werkgartner, Georg

    2004-05-01

    Planning of surgical liver tumor resections based on image data from X-ray computed tomography requires correct segmentation of the liver, liver vasculature and pathological structures. Automatic liver segmentation methods frequently fail in cases where the anatomy is degenerated by lesions or other present liver diseases. On the other hand performing a manual segmentation is a tedious and time consuming task. Therefore Augmented Reality based segmentation refinement tools are reported, that aid radiologists to efficiently correct incorrect segmentations in true 3D using head-mounted displays and tracked input devices. The developed methods facilitate segmentation refinement by interactively deforming a mesh data structure reconstructed from an initial segmentation. The variety of refinement methods are all accessible through the intuitive, direct 3D user interface of an Augmented Reality system.

  14. Use of Model-Segmentation Criteria in Clustering and Segmentation of Time Series and Digital Images.

    DTIC Science & Technology

    1983-05-05

    DANS LAS REPARTITION? ET LA SEGMENTATION DES SERIES TEMPORELLES ET DES IMAGES NUMtRICALES Cet article traite le d~veloppement et l’utilisation des...multidimensionnelles et du no-bre des classes des segments dans la segmentation des series temporelles et des imaqes numericales. Les criteres comme ceux de Akaike...NATIONAL BURCAU OF STAND)AROS 1963 A USE OF MODEL-SEGMENTATION CRITERIA IN CLUSTERING AND SEGMENTATION OF TIME SERIES AND DIGITAL IMAGES by STANLEY L

  15. 16 CFR 613.1 - Duration of active duty alerts.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Duration of active duty alerts. 613.1 Section 613.1 Commercial Practices FEDERAL TRADE COMMISSION THE FAIR CREDIT REPORTING ACT DURATION OF ACTIVE DUTY ALERTS § 613.1 Duration of active duty alerts. The duration of an active duty alert shall be...

  16. Flow Duration at Selected Stream-Sites in Kentucky

    USGS Publications Warehouse

    Quinones, F.; Kiesler, J.; Macy, J.

    1980-01-01

    Flow duration characteristics were determined for 195 streamflow stations in Kentucky. The data includes flow duration tables for the period of record of the stations based on mean daily discharges. Seasonal flow durations are also presented from monthly analysis of the data. At sites affected by regulation, tables are published showing both the before and after regulation flow duration data. (USGS)

  17. 32 CFR 2001.12 - Duration of classification.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 32 National Defense 6 2013-07-01 2013-07-01 false Duration of classification. 2001.12 Section 2001... Classification § 2001.12 Duration of classification. (a) Determining duration of classification for information originally classified under the Order—(1) Establishing duration of classification. Except for information...

  18. 32 CFR 2001.12 - Duration of classification.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 6 2010-07-01 2010-07-01 false Duration of classification. 2001.12 Section 2001... Classification § 2001.12 Duration of classification. (a) Determining duration of classification for information originally classified under the Order—(1) Establishing duration of classification. Except for information...

  19. 32 CFR 2001.12 - Duration of classification.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 32 National Defense 6 2011-07-01 2011-07-01 false Duration of classification. 2001.12 Section 2001... Classification § 2001.12 Duration of classification. (a) Determining duration of classification for information originally classified under the Order—(1) Establishing duration of classification. Except for information...

  20. Segmentation of the Farallon slab

    NASA Astrophysics Data System (ADS)

    Liu, Lijun; Stegman, Dave R.

    2011-11-01

    Recent tomography images reveal a complex 3D mantle structure beneath western United States, with feature morphology varying rapidly with depth. By assimilating plate motion history, paleo-age of sea floor, and paleo-geography of plate boundaries in a 3-D numerical model, we simulate the Farallon-Juan de Fuca subduction during the past 40 Ma. We find that the highly segmented upper mantle structure of western U.S. is a direct result of the Farallon subduction. We show that the tilted 'horseshoe'-shaped fast seismic anomaly beneath Nevada and Utah at 300-600 km depth range is in fact a segment of curled slab subducted since 15 Ma, and the shallower linear slab beneath the Cascades is younger than 5 Ma. The distinct morphology between these two parts of the subduction system indicates the strong influence of the fast trench rollback since 20 Ma, the northward migrating JF-PA-NA triple-junction, and the toroidal flow around slab edges. The observed mantle structures are used to constrain the rheology of the upper mantle through matching the shape, depth, and location of modeled subducted slab segments. The inferred viscosity for the asthenosphere is 5 × 10 19 Pa s and those for the transition zone and lower mantle are 1.5 × 10 21 Pa s and 2 × 10 22 Pa s, respectively. The slab is found to be about 2 orders of magnitude stronger than the ambient mantle above 410 km depth, but of similar order of magnitude viscosity in the transition zone.

  1. An efficient iris segmentation approach

    NASA Astrophysics Data System (ADS)

    Gomai, Abdu; El-Zaart, A.; Mathkour, H.

    2011-10-01

    Iris recognition system became a reliable system for authentication and verification tasks. It consists of five stages: image acquisition, iris segmentation, iris normalization, feature encoding, and feature matching. Iris segmentation stage is one of the most important stages. It plays an essential role to locate the iris efficiently and accurately. In this paper, we present a new approach for iris segmentation using image processing technique. This approach is composed of four main parts. (1) Eliminating reflections of light on the eye image based on inverting the color of the grayscale image, filling holes in the intensity image, and inverting the color of the intensity image to get the original grayscale image without any reflections. (2) Pupil boundary detection based on dividing an eye image to nine sub-images and finding the minimum value of the mean intensity for each sub-image to get a suitable threshold value of pupil. (3) Enhancing the contrast of outer iris boundary using exponential operator to have sharp variation. (4) Outer iris boundary localization based on applying a gray threshold and morphological operations on the rectangular part of an eye image including the pupil and the outer boundaries of iris to find the small radius of outer iris boundary from the center of pupil. The proposed approach has been tested on CASIA v1.0 iris image database and other collected iris image database. The experimental results show that the approach is able to detect pupil and outer iris boundary with high accuracy results approximately 100% and reduce time consuming.

  2. Heterologous Packaging Signals on Segment 4, but Not Segment 6 or Segment 8, Limit Influenza A Virus Reassortment.

    PubMed

    White, Maria C; Steel, John; Lowen, Anice C

    2017-06-01

    Influenza A virus (IAV) RNA packaging signals serve to direct the incorporation of IAV gene segments into virus particles, and this process is thought to be mediated by segment-segment interactions. These packaging signals are segment and strain specific, and as such, they have the potential to impact reassortment outcomes between different IAV strains. Our study aimed to quantify the impact of packaging signal mismatch on IAV reassortment using the human seasonal influenza A/Panama/2007/99 (H3N2) and pandemic influenza A/Netherlands/602/2009 (H1N1) viruses. Focusing on the three most divergent segments, we constructed pairs of viruses that encoded identical proteins but differed in the packaging signal regions on a single segment. We then evaluated the frequency with which segments carrying homologous versus heterologous packaging signals were incorporated into reassortant progeny viruses. We found that, when segment 4 (HA) of coinfecting parental viruses was modified, there was a significant preference for the segment containing matched packaging signals relative to the background of the virus. This preference was apparent even when the homologous HA constituted a minority of the HA segment population available in the cell for packaging. Conversely, when segment 6 (NA) or segment 8 (NS) carried modified packaging signals, there was no significant preference for homologous packaging signals. These data suggest that movement of NA and NS segments between the human H3N2 and H1N1 lineages is unlikely to be restricted by packaging signal mismatch, while movement of the HA segment would be more constrained. Our results indicate that the importance of packaging signals in IAV reassortment is segment dependent.IMPORTANCE Influenza A viruses (IAVs) can exchange genes through reassortment. This process contributes to both the highly diverse population of IAVs found in nature and the formation of novel epidemic and pandemic IAV strains. Our study sought to determine the

  3. Interferon Induced Focal Segmental Glomerulosclerosis

    PubMed Central

    Bayram Kayar, Nuket; Alpay, Nadir; Hamdard, Jamshid; Emegil, Sebnem; Bag Soydas, Rabia; Baysal, Birol

    2016-01-01

    Behçet's disease is an inflammatory disease of unknown etiology which involves recurring oral and genital aphthous ulcers and ocular lesions as well as articular, vascular, and nervous system involvement. Focal segmental glomerulosclerosis (FSGS) is usually seen in viral infections, immune deficiency syndrome, sickle cell anemia, and hyperfiltration and secondary to interferon therapy. Here, we present a case of FSGS identified with kidney biopsy in a patient who had been diagnosed with Behçet's disease and received interferon-alpha treatment for uveitis and presented with acute renal failure and nephrotic syndrome associated with interferon. PMID:27847659

  4. Automated lung segmentation in digital chest tomosynthesis

    PubMed Central

    Wang, Jiahui; Dobbins, James T.; Li, Qiang

    2012-01-01

    Purpose: The purpose of this study was to develop an automated lung segmentation method for computerized detection of lung nodules in digital chest tomosynthesis. Methods: The authors collected 45 digital tomosynthesis scans and manually segmented reference lung regions in each scan to assess the performance of the method. The authors automated the technique by calculating the edge gradient in an original image for enhancing lung outline and transforming the edge gradient image to polar coordinate space. The authors then employed a dynamic programming technique to delineate outlines of the unobscured lungs in the transformed edge gradient image. The lung outlines were converted back to the original image to provide the final segmentation result. The above lung segmentation algorithm was first applied to the central reconstructed tomosynthesis slice because of the absence of ribs overlapping lung structures. The segmented lung in the central slice was then used to guide lung segmentation in noncentral slices. The authors evaluated the segmentation method by using (1) an overlap rate of lung regions, (2) a mean absolute distance (MAD) of lung borders, (3) a Hausdorff distance of lung borders between the automatically segmented lungs and manually segmented reference lungs, and (4) the fraction of nodules included in the automatically segmented lungs. Results: The segmentation method achieved mean overlap rates of 85.7%, 88.3%, and 87.0% for left lungs, right lungs, and entire lungs, respectively; mean MAD of 4.8, 3.9, and 4.4 mm for left lungs, right lungs, and entire lungs, respectively; and mean Hausdorrf distance of 25.0 mm, 25.5 mm, and 30.1 mm for left lungs, right lungs, and entire lungs, respectively. All of the nodules inside the reference lungs were correctly included in the segmented lungs obtained with the lung segmentation method. Conclusions: The method achieved relatively high accuracy for lung segmentation and will be useful for computer-aided detection

  5. Segmental and coarticulatory timing in Ikalanga prenasalized stops

    NASA Astrophysics Data System (ADS)

    Beddor, Patrice S.; Onsuwan, Chutamanee; Letsholo, Rose

    2002-05-01

    The temporal characteristics of prenasalized stops in Ikalanga, a Bantu language of Botswana, are investigated. Eight speakers were recorded producing Ikalanga words with VNCV (NC=/mb nd rhookn g), VNV (N=/mn rhookn), and VCV (C=/b d g/) sequences. Acoustic measures of 3 speakers' productions showed that oral closure durations (from vowel offset to closure release) were only slightly longer for NC than for N or C (94, 83, and 83 ms, respectively). When analyzed separately, the N and C portions of VNCV were somewhat shorter than their counterparts in VNV and VCV, but nearly all of the shortening occurred in the C portion (in VNCV, N=78 ms and C closure=16 ms). The durations of vowels preceding the medial consonants did not differ across the three consonant types. Thus, for segmental durations, the main difference between Ikalanga VNCV and VNV was the presence of a brief oral occlusion in the former. However, measures of coarticulatory nasalization point to another systematic difference: while both sequences exhibited comparable anticipatory vowel nasalization, VNV (but not VNCV) sequences showed carryover nasalization extending through more than 70% of the post-nasal vowel. Findings will be compared with previous work on Bantu prenasalized stops. [Work supported by NSF.

  6. Diverse cortical codes for scene segmentation in primate auditory cortex.

    PubMed

    Malone, Brian J; Scott, Brian H; Semple, Malcolm N

    2015-04-01

    The temporal coherence of amplitude fluctuations is a critical cue for segmentation of complex auditory scenes. The auditory system must accurately demarcate the onsets and offsets of acoustic signals. We explored how and how well the timing of onsets and offsets of gated tones are encoded by auditory cortical neurons in awake rhesus macaques. Temporal features of this representation were isolated by presenting otherwise identical pure tones of differing durations. Cortical response patterns were diverse, including selective encoding of onset and offset transients, tonic firing, and sustained suppression. Spike train classification methods revealed that many neurons robustly encoded tone duration despite substantial diversity in the encoding process. Excellent discrimination performance was achieved by neurons whose responses were primarily phasic at tone offset and by those that responded robustly while the tone persisted. Although diverse cortical response patterns converged on effective duration discrimination, this diversity significantly constrained the utility of decoding models referenced to a spiking pattern averaged across all responses or averaged within the same response category. Using maximum likelihood-based decoding models, we demonstrated that the spike train recorded in a single trial could support direct estimation of stimulus onset and offset. Comparisons between different decoding models established the substantial contribution of bursts of activity at sound onset and offset to demarcating the temporal boundaries of gated tones. Our results indicate that relatively few neurons suffice to provide temporally precise estimates of such auditory "edges," particularly for models that assume and exploit the heterogeneity of neural responses in awake cortex.

  7. Review of automatic segmentation methods of multiple sclerosis white matter lesions on conventional magnetic resonance imaging.

    PubMed

    García-Lorenzo, Daniel; Francis, Simon; Narayanan, Sridar; Arnold, Douglas L; Collins, D Louis

    2013-01-01

    Magnetic resonance (MR) imaging is often used to characterize and quantify multiple sclerosis (MS) lesions in the brain and spinal cord. The number and volume of lesions have been used to evaluate MS disease burden, to track the progression of the disease and to evaluate the effect of new pharmaceuticals in clinical trials. Accurate identification of MS lesions in MR images is extremely difficult due to variability in lesion location, size and shape in addition to anatomical variability between subjects. Since manual segmentation requires expert knowledge, is time consuming and is subject to intra- and inter-expert variability, many methods have been proposed to automatically segment lesions. The objective of this study was to carry out a systematic review of the literature to evaluate the state of the art in automated multiple sclerosis lesion segmentation. From 1240 hits found initially with PubMed and Google scholar, our selection criteria identified 80 papers that described an automatic lesion segmentation procedure applied to MS. Only 47 of these included quantitative validation with at least one realistic image. In this paper, we describe the complexity of lesion segmentation, classify the automatic MS lesion segmentation methods found, and review the validation methods applied in each of the papers reviewed. Although many segmentation solutions have been proposed, including some with promising results using MRI data obtained on small groups of patients, no single method is widely employed due to performance issues related to the high variability of MS lesion appearance and differences in image acquisition. The challenge remains to provide segmentation techniques that work in all cases regardless of the type of MS, duration of the disease, or MRI protocol, and this within a comprehensive, standardized validation framework. MS lesion segmentation remains an open problem.

  8. Neural mechanisms of auditory discrimination of long-duration tonal patterns: a neural modeling and fMRI study.

    PubMed

    Ulloa, Antonio; Husain, Fatima T; Kemeny, Stefan; Xu, Jiang; Braun, Allen R; Horwitz, Barry

    2008-12-01

    Language perception comprises mechanisms of perception and discrimination of auditory stimuli. An important component of auditory perception and discrimination concerns auditory objects. Many interesting auditory objects in our environment are of relatively long duration; however, the temporal window of integration of auditory cortex neurons processing these objects is very limited. Thus, it is necessary to make active use of short-term memory in order to construct and temporarily store long-duration objects. We sought to understand the mechanisms by which the brain manipulates long-duration tonal patterns, temporarily stores the segments of those patterns, and integrates them into an auditory object. We extended a previously constructed model of auditory recognition of short-duration tonal patterns by expanding the prefrontal cortically-based short-term memory module of the previous model into a memory buffer with multiple short-term memory submodules and by adding a gating module. The gating module distributes the segments of the input pattern to separate locations of the extended prefrontal cortex in an orderly fashion, allowing a subsequent comparison of the stored segments against the segments of a second pattern. In addition to simulating behavioral data and electrical activity of neurons, our model also produces simulations of the blood oxygen level dependent (BOLD) signal as obtained in fMRI studies. The results of these simulations provided us with predictions that we tested in an fMRI experiment with normal volunteers. This fMRI experiment used the same task and similar stimuli to that of the model. We compared simulated data with experimental values. We found that two brain areas, the right precentral gyrus and the left medial frontal gyrus, correlated well with our simulations of the memory gating module. Other fMRI studies of auditory perception and discrimination have also found correlation of fMRI activation of those areas with similar tasks and thus

  9. Caffeine intake reduces sleep duration in adolescents.

    PubMed

    Lodato, Francesca; Araújo, Joana; Barros, Henrique; Lopes, Carla; Agodi, Antonella; Barchitta, Martina; Ramos, Elisabete

    2013-09-01

    In our study, we hypothesized that higher caffeine intake would be associated with lower sleep duration among 13-year-old adolescents. In addition, we aimed to identify food sources of caffeine intake in this sample. Eligible participants were adolescents who were born in 1990 and attended school in Porto, Portugal, in 2003/2004. Self-administered questionnaires were used, and diet was evaluated using a food frequency questionnaire. From the 2160 eligible participants, only 1522 with valid information regarding their diet were included in this study. In our sample, the median intake of caffeine was 23.1 mg/d, with soft drinks being the major source. Ice tea presented the highest median (25th-75th percentiles) contribution (33.1% [14.0-52.1]), followed by cola (21.1% [6.4-37.6]). Regarding cocoa products, chocolate bars presented a median contribution of 5.1% (1.0-14.0), and snacks containing chocolate had a contribution of 3.0% (0.5-7.2). Coffee and tea presented a negligible contribution. Adolescents who reported less sleep duration and those who spent more time watching TV during the weekend had a significantly higher caffeine intake. Overall, boys had higher intakes of caffeine from soft drinks, and private school attendees, those who had parents with more education, who reported less television viewing time and had lower body mass index presented higher intakes of caffeine from chocolate. Considering sleeping more than 9.5 hours as a reference class, for each increase of 10 mg/d in caffeine intake, we found that the odds ratio of sleeping 8.5 hours or less was 1.12 (95% confidence interval, 1.06-1.19). Our results support the hypothesis that caffeine intake was inversely associated with sleep duration in adolescents. © 2013.

  10. Sleep duration and cancer risk in women.

    PubMed

    Hurley, Susan; Goldberg, Debbie; Bernstein, Leslie; Reynolds, Peggy

    2015-07-01

    The objective was to conduct an analysis of sleep duration and risk of selected site-specific and groups of cancer among a large prospective cohort of California women. The study population was comprised of 101,609 adult females participating in the California Teachers Study. All sites of invasive cancer prospectively diagnosed from baseline (1995-1996) through 2011 were identified through linkage to the California Cancer Registry (n = 12,322). Site-specific analyses focused on the following cancers: breast (n = 5,053), colorectal (n = 983), lung (n = 820), melanoma (n = 749), and endometrial (n = 957). Additionally, we evaluated a group of estrogen-mediated cancers consisting of breast, endometrial, and ovarian cancer (n = 6,458). Sleep duration was based on self-report of average time sleeping in the year prior to baseline. Cox proportional hazard models were used to calculate adjusted hazard ratios and 95 % confidence intervals (HRs, 95 % CI). Point estimates for all sites and site-specific cancers generally were near or below one for short sleepers (<6 h/night) and above one for long sleepers (10+ h/night); confidence intervals, however, were wide and included unity. Compared to average sleepers (7-9 h/night), long sleepers had an increased risk of the group of estrogen-mediated cancers (HR 1.22, 95 % CI 0.97-1.54, p (trend) = 0.04). These analyses suggest that longer sleep may be associated with increased risks of estrogen-mediated cancers. Further studies with more refined measures of sleep duration and quality are warranted.

  11. Duration of wet work in hairdressers.

    PubMed

    Kralj, N; Oertel, Ch; Doench, N M; Nuebling, M; Pohrt, U; Hofmann, F

    2011-01-01

    Occupational contact dermatitis caused by wet work is particularly common in hairdressers. Data on the duration of wet work (DWW) in the hairdresser's trade are not well known until now. A questionnaire or self-reported/estimated skin exposure are not suitable to get accurate information about DWW. According to the guidance of the German Federal Ministry for Labour and Social Affairs, employees with DWW > 2 h per day should get a possibility for targeted occupational-medical health examinations. Targeted occupational-medical health examinations are prescribed for employees with daily duration of wet work longer than 4 h. The aim of the study was to quantify the average daily exposition to wet work in hairdressers. In our study, we used the direct observation as a standard method to analyse the work steps and to measure DWW in hairdressers. We developed the instrument for the analyses of activities in hairdresser salons and measurement of DWW in hairdressers during their 8-h shift. At the beginning of the study, 60 observers were intensively instructed and trained in the procedure of analysis. The mean of duration of wet work (DWW) in 106 8-h shifts analysed was 8,234 s (approx. 2 h 17 min). The minimum of DWW was 278 s and the maximum 21,135 s (approx. 6 h); the standard deviation was 3,826 s. In 37% of the analysed 8-h shifts, DWW was shorter than 2 h, in 58% between 2 and 4 h and in 5% longer than 4 h. Eighteen per cent of the DWW was caused by wearing water-resistant protective gloves. We found positive correlations between "DWW" and "DWW > 2 h", with the predictors "number of customers total", "number of long-haired people" and "number of female customers". According to the guidance of the German Federal Ministry for Labour and Social Affairs, hairdressers should get a possibility for targeted occupational-medical health examinations.

  12. SAR Segmentation using Anisotropic Diffusion

    NASA Astrophysics Data System (ADS)

    Intajag, Sathit; Tipsuwanporn, Vittaya; Cheevasuwit, Fusak

    Speckle effects are commonly observed in synthetic aperture radar (SAR) images. The human eye is capable of deriving meaningful information from SAR images; however, an automatic or semi-automatic processing algorithm has difficulty in distinguishing objects in the images because of noise effects present in those images. This paper presents a segmentation method for SAR images, which employs an anisotropic diffusion algorithm. In the proposed scheme, a SAR image is transformed into a logarithmic domain where the diffusion process is used to grow homogeneous regions in the noise environment until the regions reach some criteria for homogeneity; consequently, the segmented image in the logarithm domain is converted to the intensity domain by an exponential function. To grow homogeneous regions the adaptive diffusion method is introduced with a tensor technique in which tensor data are varied with the neighboring pixels. The diffusion algorithm will stop itself by a standard deviation divided by the mean, which is provided according to the homogeneity criteria. Results are shown on both synthetic and satellite SAR images. The evaluation of the proposed method employs the theoretical gain of equivalent numbers of looks (ENL).

  13. Colony image acquisition and segmentation

    NASA Astrophysics Data System (ADS)

    Wang, W. X.

    2007-12-01

    For counting of both colonies and plaques, there is a large number of applications including food, dairy, beverages, hygiene, environmental monitoring, water, toxicology, sterility testing, AMES testing, pharmaceuticals, paints, sterile fluids and fungal contamination. Recently, many researchers and developers have made efforts for this kind of systems. By investigation, some existing systems have some problems. The main problems are image acquisition and image segmentation. In order to acquire colony images with good quality, an illumination box was constructed as: the box includes front lightning and back lightning, which can be selected by users based on properties of colony dishes. With the illumination box, lightning can be uniform; colony dish can be put in the same place every time, which make image processing easy. The developed colony image segmentation algorithm consists of the sub-algorithms: (1) image classification; (2) image processing; and (3) colony delineation. The colony delineation algorithm main contain: the procedures based on grey level similarity, on boundary tracing, on shape information and colony excluding. In addition, a number of algorithms are developed for colony analysis. The system has been tested and satisfactory.

  14. Segmented holographic spectrum splitting concentrator

    NASA Astrophysics Data System (ADS)

    Ayala, Silvana P.; Vorndran, Shelby; Wu, Yuechen; Chrysler, Benjamin; Kostuk, Raymond K.

    2016-09-01

    This paper presents a segmented parabolic concentrator employing holographic spectral filters that provide focusing and spectral bandwidth separation capability to the system. Strips of low band gap silicon photovoltaic (PV) cells are formed into a parabolic surface as shown by Holman et. al. [1]. The surface of the PV segments is covered with holographic elements formed in dichromated gelatin. The holographic elements are designed to transmit longer wavelengths to silicon cells, and to reflect short wavelength light towards a secondary collector where high-bandgap PV cells are mounted. The system can be optimized for different combinations of diffuse and direct solar illumination conditions for particular geographical locations by controlling the concentration ratio and filtering properties of the holographic elements. In addition, the reflectivity of the back contact of the silicon cells is used to increase the optical path length and light trapping. This potentially allows the use of thin film silicon for the low bandgap PV cell material. The optical design combines the focusing properties of the parabolic concentrator and the holographic element to control the concentration ratio and uniformity of the spectral distribution at the high bandgap cell location. The presentation concludes with a comparison of different spectrum splitting holographic filter materials for this application.

  15. WCE video segmentation using textons

    NASA Astrophysics Data System (ADS)

    Gallo, Giovanni; Granata, Eliana

    2010-03-01

    Wireless Capsule Endoscopy (WCE) integrates wireless transmission with image and video technology. It has been used to examine the small intestine non invasively. Medical specialists look for signicative events in the WCE video by direct visual inspection manually labelling, in tiring and up to one hour long sessions, clinical relevant frames. This limits the WCE usage. To automatically discriminate digestive organs such as esophagus, stomach, small intestine and colon is of great advantage. In this paper we propose to use textons for the automatic discrimination of abrupt changes within a video. In particular, we consider, as features, for each frame hue, saturation, value, high-frequency energy content and the responses to a bank of Gabor filters. The experiments have been conducted on ten video segments extracted from WCE videos, in which the signicative events have been previously labelled by experts. Results have shown that the proposed method may eliminate up to 70% of the frames from further investigations. The direct analysis of the doctors may hence be concentrated only on eventful frames. A graphical tool showing sudden changes in the textons frequencies for each frame is also proposed as a visual aid to find clinically relevant segments of the video.

  16. Pathogenesis of Focal Segmental Glomerulosclerosis

    PubMed Central

    Lim, Beom Jin; Yang, Jae Won; Do, Woo Sung; Fogo, Agnes B.

    2016-01-01

    Focal segmental glomerulosclerosis (FSGS) is characterized by focal and segmental obliteration of glomerular capillary tufts with increased matrix. FSGS is classified as collapsing, tip, cellular, perihilar and not otherwise specified variants according to the location and character of the sclerotic lesion. Primary or idiopathic FSGS is considered to be related to podocyte injury, and the pathogenesis of podocyte injury has been actively investigated. Several circulating factors affecting podocyte permeability barrier have been proposed, but not proven to cause FSGS. FSGS may also be caused by genetic alterations. These genes are mainly those regulating slit diaphragm structure, actin cytoskeleton of podocytes, and foot process structure. The mode of inheritance and age of onset are different according to the gene involved. Recently, the role of parietal epithelial cells (PECs) has been highlighted. Podocytes and PECs have common mesenchymal progenitors, therefore, PECs could be a source of podocyte repopulation after podocyte injury. Activated PECs migrate along adhesion to the glomerular tuft and may also contribute to the progression of sclerosis. Markers of activated PECs, including CD44, could be used to distinguish FSGS from minimal change disease. The pathogenesis of FSGS is very complex; however, understanding basic mechanisms of podocyte injury is important not only for basic research, but also for daily diagnostic pathology practice. PMID:27744657

  17. Duration test of an annular colloid thruster.

    NASA Technical Reports Server (NTRS)

    Perel, J.; Mahoney, J. F.; Daley, H. L.

    1972-01-01

    An annular colloid thruster was continuously operated for 1023 hours. Performance was stable with no sparking and negligible drain currents observed. An average thrust of 25.1 micropounds and an average specific impulse of 1160 seconds were obtained at an accelerating voltage of 15 k he thruster exhaust beam was continuously neutralized using electrons and electrostatic vectoring was demonstrated periodically. The only clear trend with time was an increase in specific impulse during the last third of the test period. From these results the thruster lifetime was estimated to be over an order of magnitude greater than the test duration.

  18. Training Concept for Long Duration Space Mission

    NASA Technical Reports Server (NTRS)

    O'Keefe, William

    2008-01-01

    There has been papers about maintenance and psychological training for Long Duration Space Mission (LDSM). There are papers on the technology needed for LDSMs. Few are looking at how groundbased pre-mission training and on-board in-transit training must be melded into one training concept that leverages this technology. Even more importantly, fewer are looking at how we can certify crews pre-mission. This certification must ensure, before the crew launches, that they can handle any problem using on-board assets without a large ground support team.

  19. Duration test of an annular colloid thruster.

    NASA Technical Reports Server (NTRS)

    Perel, J.; Mahoney, J. F.; Daley, H. L.

    1972-01-01

    An annular colloid thruster was continuously operated for 1023 hours. Performance was stable with no sparking and negligible drain currents observed. An average thrust of 25.1 micropounds and an average specific impulse of 1160 seconds were obtained at an accelerating voltage of 15 k he thruster exhaust beam was continuously neutralized using electrons and electrostatic vectoring was demonstrated periodically. The only clear trend with time was an increase in specific impulse during the last third of the test period. From these results the thruster lifetime was estimated to be over an order of magnitude greater than the test duration.

  20. Long Duration Exposure Facility (LDEF) Archive System

    NASA Technical Reports Server (NTRS)

    Wilson, Brenda K.

    1995-01-01

    The Long Duration Exposure Facility (LDEF) Archive System is designed to provide spacecraft designers and space environment researchers single point access to all available resources from LDEF. These include data, micrographs, photographs, technical reports, papers, hardware and test specimens, as well as technical expertise. Further, the LDEF Archive System is planned such that it could be the foundation for a NASA Space Environments and Effects (SEE) Archive System, with the addition of other spaceflight, laboratory and theoretical space environments and effects data and associated materials. This paper describes the current status and plans of the LDEF Archive System.

  1. Long duration human exposure to microgravity

    NASA Technical Reports Server (NTRS)

    Huntoon, C. L.

    1991-01-01

    Looking toward the era of long duration manned spaceflight, questions remain regarding human adaptation to the weightless environment. In particular, bone calcium loss, cardiovascular deconditioning, and effects of radiation require further study. NASA has undertaken a series of experiments to increase the knowledge base of human adaptation to spaceflight. To date, results in the area of cardiovascular deconditioning countermeasures are the furthest advanced. The results from the upcoming SLS-1 mission will enhance knowledge in all areas. With continued research, there is every confidence that astronauts will be able to be kept healthy for long periods of time.

  2. The extended duration orbiter waste collection system

    NASA Technical Reports Server (NTRS)

    Brasseaux, Hubert J., Jr.; Winkler, H. E.; North, Jeffrey D.; Orlando, Samuel P.

    1990-01-01

    A new waste collection system (WCS) is undergoing development for use in the extended duration orbiter (EDO). Requirements for missions up to 18 days and the capability for missions up to 30 days necessitate the development of a new WCS that will have the appropriate capacity. The new system incorporates design features from both Skylab and Space Shuttle Orbiter WCSs. The system for EDO utilizes redundant fans and urine separators. Plans call for the new WCS to be implemented for OV-105 (Endeavor) as well as for EDO. This paper describes the design and development status of the new WCS.

  3. The effect of 308nm excimer laser on segmental vitiligo: a retrospective study of 80 patients with segmental vitiligo.

    PubMed

    Do, Jeong Eun; Shin, Jae Yong; Kim, Do-Young; Hann, Seung-Kyung; Oh, Sang Ho

    2011-06-01

    Segmental vitiligo (SV), which frequently accompanies poliosis, indicating a poor prognosis that is likely resistant to treatments. In this study, we performed a retrospective analysis to evaluate the treatment response to 308 nm excimer laser in SV patients. A retrospective chart and photographic review was performed on 80 SV patients who had been treated with 308nm excimer laser for >3 months. Eighty patients with SV (mean age: 24.0 years ± 15.3, males: 50%) were included in this study. The mean grade of repigmentation was 2.3 after 20.6 months of mean treatment duration; 23.8% of 80 patients showed grade 4, 20% showed grade 3, and 56.2% showed grade 1-2 repigmentation. However, none of them achieved complete repigmentation with excimer laser. The degree of repigmentation was positively correlated with treatment duration (r=0.315, P=0.004) and cumulative ultraviolet (UV) dosage (r=0.366, P=0.001), whereas it was negatively correlated with disease duration (r=-0.265, P=0.017). This study suggests that SV has a better repigmentation response when excimer laser is used at earlier stages of the disease and long-term use and high cumulative UV energy of the excimer laser elicit better responses. Additional treatments like surgical procedures in addition to excimer laser should be considered for complete repigmentation. © 2011 John Wiley & Sons A/S.

  4. FIST: a fast interactive segmentation technique

    NASA Astrophysics Data System (ADS)

    Padfield, Dirk; Bhotika, Rahul; Natanzon, Alexander

    2015-03-01

    Radiologists are required to read thousands of patient images every day, and any tools that can improve their workflow to help them make efficient and accurate measurements is of great value. Such an interactive tool must be intuitive to use, and we have found that users are accustomed to clicking on the contour of the object for segmentation and would like the final segmentation to pass through these points. The tool must also be fast to enable real-time interactive feedback. To meet these needs, we present a segmentation workflow that enables an intuitive method for fast interactive segmentation of 2D and 3D objects. Given simple user clicks on the contour of an object in one 2D view, the algorithm generates foreground and background seeds and computes foreground and background distributions that are used to segment the object in 2D. It then propagates the information to the two orthogonal planes in a 3D volume and segments all three 2D views. The automated segmentation is automatically updated as the user continues to add points around the contour, and the algorithm is re-run using the total set of points. Based on the segmented objects in these three views, the algorithm then computes a 3D segmentation of the object. This process requires only limited user interaction to segment complex shapes and significantly improves the workflow of the user.

  5. Anatomy-aware measurement of segmentation accuracy

    NASA Astrophysics Data System (ADS)

    Tizhoosh, H. R.; Othman, A. A.

    2016-03-01

    Quantifying the accuracy of segmentation and manual delineation of organs, tissue types and tumors in medical images is a necessary measurement that suffers from multiple problems. One major shortcoming of all accuracy measures is that they neglect the anatomical significance or relevance of different zones within a given segment. Hence, existing accuracy metrics measure the overlap of a given segment with a ground-truth without any anatomical discrimination inside the segment. For instance, if we understand the rectal wall or urethral sphincter as anatomical zones, then current accuracy measures ignore their significance when they are applied to assess the quality of the prostate gland segments. In this paper, we propose an anatomy-aware measurement scheme for segmentation accuracy of medical images. The idea is to create a "master gold" based on a consensus shape containing not just the outline of the segment but also the outlines of the internal zones if existent or relevant. To apply this new approach to accuracy measurement, we introduce the anatomy-aware extensions of both Dice coefficient and Jaccard index and investigate their effect using 500 synthetic prostate ultrasound images with 20 different segments for each image. We show that through anatomy-sensitive calculation of segmentation accuracy, namely by considering relevant anatomical zones, not only the measurement of individual users can change but also the ranking of users' segmentation skills may require reordering.

  6. RSRM Segment Train Derailment and Recovery

    NASA Technical Reports Server (NTRS)

    Taylor Jr., Robert H.; McConnaugghey, Paul K.; Beaman, David E.; Moore, Dennis R.; Reed, Harry

    2008-01-01

    On May 2, 2007, a freight train carrying segments of the space shuttle's solid rocket boosters derailed in Myrtlewood, Alabama, after a rail trestle collapsed. The train was carrying Reusable Solid Rocket Motors (RSRM) 98 center and forward segments (STS-120) and RSRM 99 aft segments (STS-122). Initially, it was not known if the segments had been seriously damaged. Four segments dropped approximately 10 feet when the trestle collapsed and one of those four rolled off the track onto its side. The exit cones and the other four segments, not yet on the trestle, remained on solid ground. ATK and NASA immediately dispatched an investigation and recovery team to determine the safety of the situation and eventually the usability of the segments and exit cones for flight. Instrumentation on each segment provided invaluable data to determine the acceleration loads imparted into each loaded segment and exit cone. This paper details the incident, recovery plan and the team work that created a success story that ended with the safe launch of STS120 using the four center segments and the launch of STS122 using the Aft exit cones assemblies.

  7. Hierarchical morphological segmentation for image sequence coding.

    PubMed

    Salembier, P; Pardas, M

    1994-01-01

    This paper deals with a hierarchical morphological segmentation algorithm for image sequence coding. Mathematical morphology is very attractive for this purpose because it efficiently deals with geometrical features such as size, shape, contrast, or connectivity that can be considered as segmentation-oriented features. The algorithm follows a top-down procedure. It first takes into account the global information and produces a coarse segmentation, that is, with a small number of regions. Then, the segmentation quality is improved by introducing regions corresponding to more local information. The algorithm, considering sequences as being functions on a 3-D space, directly segments 3-D regions. A 3-D approach is used to get a segmentation that is stable in time and to directly solve the region correspondence problem. Each segmentation stage relies on four basic steps: simplification, marker extraction, decision, and quality estimation. The simplification removes information from the sequence to make it easier to segment. Morphological filters based on partial reconstruction are proven to be very efficient for this purpose, especially in the case of sequences. The marker extraction identifies the presence of homogeneous 3-D regions. It is based on constrained flat region labeling and morphological contrast extraction. The goal of the decision is to precisely locate the contours of regions detected by the marker extraction. This decision is performed by a modified watershed algorithm. Finally, the quality estimation concentrates on the coding residue, all the information about the 3-D regions that have not been properly segmented and therefore coded. The procedure allows the introduction of the texture and contour coding schemes within the segmentation algorithm. The coding residue is transmitted to the next segmentation stage to improve the segmentation and coding quality. Finally, segmentation and coding examples are presented to show the validity and interest of

  8. Analyses of Magnetic Resonance Imaging of Cerebrospinal Fluid Dynamics Pre and Post Short and Long-Duration Space Flights

    NASA Technical Reports Server (NTRS)

    Alperin, Noam; Barr, Yael; Lee, Sang H.; Mason,Sara; Bagci, Ahmet M.

    2015-01-01

    Preliminary results are based on analyses of data from 17 crewmembers. The initial analysis compares pre to post-flight changes in total cerebral blood flow (CBF) and craniospinal CSF flow volume. Total CBF is obtained by summation of the mean flow rates through the 4 blood vessels supplying the brain (right and left internal carotid and vertebral arteries). Volumetric flow rates were obtained using an automated lumen segmentation technique shown to have 3-4-fold improved reproducibility and accuracy over manual lumen segmentation (6). Two cohorts, 5 short-duration and 8 long-duration crewmembers, who were scanned within 3 to 8 days post landing were included (4 short-duration crewmembers with MRI scans occurring beyond 10 days post flight were excluded). The VIIP Clinical Practice Guideline (CPG) classification is being used initially as a measure for VIIP syndrome severity. Median CPG scores of the short and long-duration cohorts were similar, 2. Mean preflight total CBF for the short and long-duration cohorts were similar, 863+/-144 and 747+/-119 mL/min, respectively. Percentage CBF changes for all short duration crewmembers were 11% or lower, within the range of normal physiological fluctuations in healthy individuals. In contrast, in 4 of the 8 long-duration crewmembers, the change in CBF exceeded the range of normal physiological fluctuation. In 3 of the 4 subjects an increase in CBF was measured. Large pre to post-flight changes in the craniospinal CSF flow volume were found in 6 of the 8 long-duration crewmembers. Box-Whisker plots of the CPG and the percent CBF and CSF flow changes for the two cohorts are shown in Figure 4. Examples of CSF flow waveforms for a short and two long-duration (CPG 0 and 3) are shown in Figure 5. Changes in CBF and CSF flow dynamics larger than normal physiological fluctuations were observed in the long-duration crewmembers. Changes in CSF flow were more pronounced than changes in CBF. Decreased CSF flow dynamics were observed

  9. Psychiatric issues affecting long duration space missions.

    PubMed

    Kanas, N

    1998-12-01

    As we move into the next Millennium, increasing numbers of people will travel into space. Psychological screening methods will be relaxed on near-Earth missions, such as might occur on a space station or a lunar colony. Crewmembers on interplanetary missions such as a trip to Mars will have to deal with psychiatric problems themselves with no possibility of evacuating an affected individual. For these reasons, it is important for support personnel on Earth and crewmembers in space to be knowledgeable about psychiatric difficulties that might occur and their appropriate treatments. Anecdotal reports from long duration manned space missions and studies from space analog environments on Earth were reviewed for information concerning these issues. Psychiatric problems pertinent to the space environment include adjustment and psychosomatic reactions, asthenia, mood and thought disorders, and post-mission personality changes and family problems. Counter-measures to ameliorate these difficulties involve pre-launch selection and training; monitoring, support, and counseling/psychotherapy during the mission; and post-return debriefings with crew members and their families. Psychoactive medications have been useful during space missions, although unclear pharmacokinetic issues related to microgravity need to be taken into account. Although much is known about psychiatric issues related to long duration manned space travel, more empirical work needs to be done during actual space missions.

  10. Correlating beam radiation with sunshine duration

    SciTech Connect

    Hussain, M. )

    1992-01-01

    For seven locations in north and central India, monthly averaged data of daily beam irradiation on a horizontal surface, I, have been correlated with bright sunshine duration, s, using the relation (I/I{sub o}) = b{sub o}(s/S{prime}) where I{sub o} is the monthly mean value of extraterrestrial irradiation over a day, S{prime} is the corresponding duration over which Campbell-Stokes type sunshine recorders remain sensitive. It is found that b{sub o} is a constant that is period and region dependent. Monthly estimates of beam radiation using the relation above show that for the seven stations rms errors are within 3-6%. Tests made for other stations in India also gave good estimates. For the computation of I, global radiation is not required unlike most estimation techniques and therefore the method should find a wide application. It may be observed that b{sub o} values turn out to be roughly equal to exp({minus}md{sub R}T{sub L}) where m is the relative airmass, d{sub R} is the Raleigh optical thickness and T{sub L} is the Linke turbidity factor.

  11. Mathematical Analysis of Space Radiator Segmenting for Increased Reliability and Reduced Mass

    NASA Technical Reports Server (NTRS)

    Juhasz, Albert J.

    2001-01-01

    Spacecraft for long duration deep space missions will need to be designed to survive micrometeoroid bombardment of their surfaces some of which may actually be punctured. To avoid loss of the entire mission the damage due to such punctures must be limited to small, localized areas. This is especially true for power system radiators, which necessarily feature large surface areas to reject heat at relatively low temperature to the space environment by thermal radiation. It may be intuitively obvious that if a space radiator is composed of a large number of independently operating segments, such as heat pipes, a random micrometeoroid puncture will result only in the loss of the punctured segment, and not the entire radiator. Due to the redundancy achieved by independently operating segments, the wall thickness and consequently the weight of such segments can be drastically reduced. Probability theory is used to estimate the magnitude of such weight reductions as the number of segments is increased. An analysis of relevant parameter values required for minimum mass segmented radiators is also included.

  12. Preliminary Analysis of Effect of Random Segment Errors on Coronagraph Performance

    NASA Technical Reports Server (NTRS)

    Stahl, Mark T.; Shaklan, Stuart B.; Stahl, H. Philip

    2015-01-01

    Are we alone in the Universe is probably the most compelling science question of our generation. To answer it requires a large aperture telescope with extreme wavefront stability. To image and characterize Earth-like planets requires the ability to block 10(exp 10) of the host stars light with a 10(exp -11) stability. For an internal coronagraph, this requires correcting wavefront errors and keeping that correction stable to a few picometers rms for the duration of the science observation. This requirement places severe specifications upon the performance of the observatory, telescope and primary mirror. A key task of the AMTD project (initiated in FY12) is to define telescope level specifications traceable to science requirements and flow those specifications to the primary mirror. From a systems perspective, probably the most important question is: What is the telescope wavefront stability specification? Previously, we suggested this specification should be 10 picometers per 10 minutes; considered issues of how this specification relates to architecture, i.e. monolithic or segmented primary mirror; and asked whether it was better to have few or many segmented. This paper reviews the 10 picometers per 10 minutes specification; provides analysis related to the application of this specification to segmented apertures; and suggests that a 3 or 4 ring segmented aperture is more sensitive to segment rigid body motion that an aperture with fewer or more segments.

  13. The segment as the minimal planning unit in speech production: evidence based on absolute response latencies.

    PubMed

    Kawamoto, Alan H; Liu, Qiang; Lee, Ria J; Grebe, Patricia R

    2014-01-01

    A minimal amount of information about a word must be phonologically and phonetically encoded before a person can begin to utter that word. Most researchers assume that the minimum is the complete word or possibly the initial syllable. However, there is some evidence that the initial segment is sufficient based on longer durations when the initial segment is primed. In two experiments in which the initial segment of a monosyllabic word is primed or not primed, we present additional evidence based on very short absolute response times determined on the basis of acoustic and articulatory onset relative to presentation of the complete target. We argue that the previous failures to find very short absolute response times when the initial segment is primed are due in part to the exclusive use of acoustic onset as a measure of response latency, the exclusion of responses with very short acoustic latencies, the manner of articulation of the initial segment (i.e., plosive vs. nonplosive), and individual differences. Theoretical implications of the segment as the minimal planning unit are considered.

  14. Preliminary analysis of effect of random segment errors on coronagraph performance

    NASA Astrophysics Data System (ADS)

    Stahl, Mark T.; Shaklan, Stuart B.; Stahl, H. Philip

    2015-09-01

    "Are we alone in the Universe?" is probably the most compelling science question of our generation. To answer it requires a large aperture telescope with extreme wavefront stability. To image and characterize Earth-like planets requires the ability to block 1010 of the host star's light with a 10-11 stability. For an internal coronagraph, this requires correcting wavefront errors and keeping that correction stable to a few picometers rms for the duration of the science observation. This requirement places severe specifications upon the performance of the observatory, telescope and primary mirror. A key task of the AMTD project (initiated in FY12) is to define telescope level specifications traceable to science requirements and flow those specifications to the primary mirror. From a systems perspective, probably the most important question is: What is the telescope wavefront stability specification? Previously, we suggested this specification should be 10 picometers per 10 minutes; considered issues of how this specification relates to architecture, i.e. monolithic or segmented primary mirror; and asked whether it was better to have few or many segments. This paper reviews the 10 picometers per 10 minutes specification; provides analysis related to the application of this specification to segmented apertures; and suggests that a 3 or 4 ring segmented aperture is more sensitive to segment rigid body motion that an aperture with fewer or more segments.

  15. Hierarchical image segmentation for learning object priors

    SciTech Connect

    Prasad, Lakshman; Yang, Xingwei; Latecki, Longin J; Li, Nan

    2010-11-10

    The proposed segmentation approach naturally combines experience based and image based information. The experience based information is obtained by training a classifier for each object class. For a given test image, the result of each classifier is represented as a probability map. The final segmentation is obtained with a hierarchial image segmentation algorithm that considers both the probability maps and the image features such as color and edge strength. We also utilize image region hierarchy to obtain not only local but also semi-global features as input to the classifiers. Moreover, to get robust probability maps, we take into account the region context information by averaging the probability maps over different levels of the hierarchical segmentation algorithm. The obtained segmentation results are superior to the state-of-the-art supervised image segmentation algorithms.

  16. Event segmentation ability uniquely predicts event memory.

    PubMed

    Sargent, Jesse Q; Zacks, Jeffrey M; Hambrick, David Z; Zacks, Rose T; Kurby, Christopher A; Bailey, Heather R; Eisenberg, Michelle L; Beck, Taylor M

    2013-11-01

    Memory for everyday events plays a central role in tasks of daily living, autobiographical memory, and planning. Event memory depends in part on segmenting ongoing activity into meaningful units. This study examined the relationship between event segmentation and memory in a lifespan sample to answer the following question: Is the ability to segment activity into meaningful events a unique predictor of subsequent memory, or is the relationship between event perception and memory accounted for by general cognitive abilities? Two hundred and eight adults ranging from 20 to 79years old segmented movies of everyday events and attempted to remember the events afterwards. They also completed psychometric ability tests and tests measuring script knowledge for everyday events. Event segmentation and script knowledge both explained unique variance in event memory above and beyond the psychometric measures, and did so as strongly in older as in younger adults. These results suggest that event segmentation is a basic cognitive mechanism, important for memory across the lifespan.

  17. Self-correcting multi-atlas segmentation

    NASA Astrophysics Data System (ADS)

    Gao, Yi; Wilford, Andrew; Guo, Liang

    2016-03-01

    In multi-atlas segmentation, one typically registers several atlases to the new image, and their respective segmented label images are transformed and fused to form the final segmentation. After each registration, the quality of the registration is reflected by the single global value: the final registration cost. Ideally, if the quality of the registration can be evaluated at each point, independent of the registration process, which also provides a direction in which the deformation can further be improved, the overall segmentation performance can be improved. We propose such a self-correcting multi-atlas segmentation method. The method is applied on hippocampus segmentation from brain images and statistically significantly improvement is observed.

  18. Intelligent multi-spectral IR image segmentation

    NASA Astrophysics Data System (ADS)

    Lu, Thomas; Luong, Andrew; Heim, Stephen; Patel, Maharshi; Chen, Kang; Chao, Tien-Hsin; Chow, Edward; Torres, Gilbert

    2017-05-01

    This article presents a neural network based multi-spectral image segmentation method. A neural network is trained on the selected features of both the objects and background in the longwave (LW) Infrared (IR) images. Multiple iterations of training are performed until the accuracy of the segmentation reaches satisfactory level. The segmentation boundary of the LW image is used to segment the midwave (MW) and shortwave (SW) IR images. A second neural network detects the local discontinuities and refines the accuracy of the local boundaries. This article compares the neural network based segmentation method to the Wavelet-threshold and Grab-Cut methods. Test results have shown increased accuracy and robustness of this segmentation scheme for multi-spectral IR images.

  19. Cooling system for three hook ring segment

    DOEpatents

    Campbell, Christian X.; Eng, Darryl; Lee, Ching-Pang; Patat, Harry

    2014-08-26

    A triple hook ring segment including forward, midsection and aft mounting hooks for engagement with respective hangers formed on a ring segment carrier for supporting a ring segment panel, and defining a forward high pressure chamber and an aft low pressure chamber on opposing sides of the midsection mounting hook. An isolation plate is provided on the aft side of the midsection mounting hook to form an isolation chamber between the aft low pressure chamber and the ring segment panel. High pressure air is supplied to the forward chamber and flows to the isolation chamber through crossover passages in the midsection hook. The isolation chamber provides convection cooling air to an aft portion of the ring segment panel and enables a reduction of air pressure in the aft low pressure chamber to reduce leakage flow of cooling air from the ring segment.

  20. Fluidized bed boiler having a segmented grate

    DOEpatents

    Waryasz, Richard E.

    1984-01-01

    A fluidized bed furnace (10) is provided having a perforate grate (9) within a housing which supports a bed of particulate material including some combustibles. The grate is divided into a plurality of segments (E2-E6, SH1-SH5, RH1-RH5), with the airflow to each segment being independently controlled. Some of the segments have evaporating surface imbedded in the particulate material above them, while other segments are below superheater surface or reheater surface. Some of the segments (E1, E7) have no surface above them, and there are ignitor combustors (32, 34) directed to fire into the segments, for fast startup of the furnace without causing damage to any heating surface.

  1. Milling Stability Analysis Based on Chebyshev Segmentation

    NASA Astrophysics Data System (ADS)

    HUANG, Jianwei; LI, He; HAN, Ping; Wen, Bangchun

    2016-09-01

    Chebyshev segmentation method was used to discretize the time period contained in delay differential equation, then the Newton second-order difference quotient method was used to calculate the cutter motion vector at each time endpoint, and the Floquet theory was used to determine the stability of the milling system after getting the transfer matrix of milling system. Using the above methods, a two degree of freedom milling system stability issues were investigated, and system stability lobe diagrams were got. The results showed that the proposed methods have the following advantages. Firstly, with the same calculation accuracy, the points needed to represent the time period are less by the Chebyshev Segmentation than those of the average segmentation, and the computational efficiency of the Chebyshev Segmentation is higher. Secondly, if the time period is divided into the same parts, the stability lobe diagrams got by Chebyshev segmentation method are more accurate than those of the average segmentation.

  2. Discriminative parameter estimation for random walks segmentation.

    PubMed

    Baudin, Pierre-Yves; Goodman, Danny; Kumrnar, Puneet; Azzabou, Noura; Carlier, Pierre G; Paragios, Nikos; Kumar, M Pawan

    2013-01-01

    The Random Walks (RW) algorithm is one of the most efficient and easy-to-use probabilistic segmentation methods. By combining contrast terms with prior terms, it provides accurate segmentations of medical images in a fully automated manner. However, one of the main drawbacks of using the RW algorithm is that its parameters have to be hand-tuned. we propose a novel discriminative learning framework that estimates the parameters using a training dataset. The main challenge we face is that the training samples are not fully supervised. Specifically, they provide a hard segmentation of the images, instead of a probabilistic segmentation. We overcome this challenge by treating the optimal probabilistic segmentation that is compatible with the given hard segmentation as a latent variable. This allows us to employ the latent support vector machine formulation for parameter estimation. We show that our approach significantly outperforms the baseline methods on a challenging dataset consisting of real clinical 3D MRI volumes of skeletal muscles.

  3. Livewire based single still image segmentation

    NASA Astrophysics Data System (ADS)

    Zhang, Jun; Yang, Rong; Liu, Xiaomao; Yue, Hao; Zhu, Hao; Tian, Dandan; Chen, Shu; Li, Yiquan; Tian, Jinwen

    2011-11-01

    In the application of the video contactless measurement, the quality of the image taken from underwater is not very well. It is well known that automatic image segmental method cannot provide acceptable segmentation result with low quality single still image. Snake algorithm can provide better result in this case with the aiding of human. However, sometimes the segmental result of Snake may far from the initial segmental contour drawn by user. Livewire algorithm can keep the location of the seed points that user selected nailed from the beginning to the end. But the contour may have burrs when the image's noise is quite high and the contrast is low. In this paper, we modified the cost function of Livewire algorithm and proposed a new segmentation method that can be used for single still image segmentation with high noise and low contrast.

  4. Stretching Effects: High-intensity & Moderate-duration vs. Low-intensity & Long-duration.

    PubMed

    Freitas, S R; Vaz, J R; Bruno, P M; Andrade, R; Mil-Homens, P

    2016-03-01

    This study examined whether a high-intensity, moderate-duration bout of stretching would produce the same acute effects as a low-intensity, long-duration bout of stretching. 17 volunteers performed 2 knee-flexor stretching protocols: a high-intensity stretch (i. e., 100% of maximum tolerable passive torque) with a moderate duration (243.5 ± 69.5-s); and a low-intensity stretch (50% of tolerable passive torque) with a long duration (900-s). Passive torque at a given sub-maximal angle, peak passive torque, maximal range of motion (ROM), and muscle activity were assessed before and after each stretching protocol (at intervals of 1, 30 and 60 min). The maximal ROM and tolerable passive torque increased for all time points following the high-intensity stretching (p<0.05), but not after the low-intensity protocol (p>0.05). 1 min post-stretching, the passive torque decreased in both protocols, but to a greater extent in the low-intensity protocol. 30 min post-test, torque returned to baseline for the low-intensity protocol and had increased above the baseline for the high-intensity stretches. The following can be concluded: 1) High-intensity stretching increases the maximal ROM and peak passive torque compared to low-intensity stretching; 2) low-intensity, long-duration stretching is the best way to acutely decrease passive torque; and 3) high-intensity, moderate-duration stretching increases passive torque above the baseline 30 min after stretching.

  5. Contour Completion Without Region Segmentation.

    PubMed

    Ming, Yansheng; Li, Hongdong; He, Xuming

    2016-08-01

    Contour completion plays an important role in visual perception, where the goal is to group fragmented low-level edge elements into perceptually coherent and salient contours. Most existing methods for contour completion have focused on pixelwise detection accuracy. In contrast, fewer methods have addressed the global contour closure effect, despite psychological evidences for its importance. This paper proposes a purely contour-based higher order CRF model to achieve contour closure, through local connectedness approximation. This leads to a simplified problem structure, where our higher order inference problem can be transformed into an integer linear program and be solved efficiently. Compared with the methods based on the same bottom-up edge detector, our method achieves a superior contour grouping ability (measured by Rand index), a comparable precision-recall performance, and more visually pleasing results. Our results suggest that contour closure can be effectively achieved in contour domain, in contrast to a popular view that segmentation is essential for this purpose.

  6. Community study suggests segmentation strategies.

    PubMed

    Gagnard, A

    1989-01-01

    Results of a sample survey commissioned by a voluntary health organization in a major metropolitan area describes why individuals give their time and money to charitable organizations and what approaches are likely to result in such donations. Within demographic subgroups, the variables of age and income proved to be important factors with respect to why people gave and what appeals they prefer. The variables of gender and education were found to be of somewhat less importance. Findings were compared with a national Gallup study conducted in 1987. In an era of increasingly specialized marketing for all organizations, the findings offer voluntary and fund-raising organizations a basis for determining appropriate appeals for demographic segments in a community.

  7. Core Recursive Hierarchical Image Segmentation

    NASA Technical Reports Server (NTRS)

    Tilton, James

    2011-01-01

    The Recursive Hierarchical Image Segmentation (RHSEG) software has been repackaged to provide a version of the RHSEG software that is not subject to patent restrictions and that can be released to the general public through NASA GSFC's Open Source release process. Like the Core HSEG Software Package, this Core RHSEG Software Package also includes a visualization program called HSEGViewer along with a utility program HSEGReader. It also includes an additional utility program called HSEGExtract. The unique feature of the Core RHSEG package is that it is a repackaging of the RHSEG technology designed to specifically avoid the inclusion of the certain software technology. Unlike the Core HSEG package, it includes the recursive portions of the technology, but does not include processing window artifact elimination technology.

  8. Segmented cold cathode display panel

    NASA Technical Reports Server (NTRS)

    Payne, Leslie (Inventor)

    1998-01-01

    The present invention is a video display device that utilizes the novel concept of generating an electronically controlled pattern of electron emission at the output of a segmented photocathode. This pattern of electron emission is amplified via a channel plate. The result is that an intense electronic image can be accelerated toward a phosphor thus creating a bright video image. This novel arrangement allows for one to provide a full color flat video display capable of implementation in large formats. In an alternate arrangement, the present invention is provided without the channel plate and a porous conducting surface is provided instead. In this alternate arrangement, the brightness of the image is reduced but the cost of the overall device is significantly lowered because fabrication complexity is significantly decreased.

  9. Performance Measures For Statistical Segmentation

    NASA Astrophysics Data System (ADS)

    Shazeer, Dov J.

    1983-03-01

    Performance measures for statistical segmentation have been developed for a space-and-time critical Bayesian statistical tracker. They are intended to become an integral part of a knowledge-based tracking algorithm, which has been developed by RCA. The performance measures are serving to quantify the usefulness of the processed input, to assist in the identification of each tracking state and give its reliability, and to predict impending changes of state. They have been tested using stochastically generated target-background frames. Performance measure results have correlated well with the parameters which characterize the difference in the target and background distributions. A host of possible performance measures are discussed in relation to their strengths and weaknesses. Experimental results for the measures currently being employed by RCA are given, and areas for future research are indicated.

  10. Prostate segmentation in HIFU therapy

    PubMed Central

    Garnier, Carole; Bellanger, Jean-Jacques; Wu, Ke; Shu, Huazhong; Costet, Nathalie; Mathieu, Romain; De Crevoisier, Renaud; Coatrieux, Jean-Louis

    2011-01-01

    Prostate segmentation in 3-D transrectal ultrasound images is an important step in the definition of the intra-operative planning of high intensity focused ultrasound (HIFU) therapy. This paper presents two main approaches for the semi-automatic methods based on discrete dynamic contour and optimal surface detection. They operate in 3-D and require a minimal user interaction. They are considered both alone or sequentially combined, with and without postregularization, and applied on anisotropic and isotropic volumes. Their performance, using different metrics, has been evaluated on a set of 28 3-D images by comparison with two expert delineations. For the most efficient algorithm, the symmetric average surface distance was found to be 0.77 mm. PMID:21118767

  11. Segment adaptive gradient angle interpolation.

    PubMed

    Zwart, Christine M; Frakes, David H

    2013-08-01

    We introduce a new edge-directed interpolator based on locally defined, straight line approximations of image isophotes. Spatial derivatives of image intensity are used to describe the principal behavior of pixel-intersecting isophotes in terms of their slopes. The slopes are determined by inverting a tridiagonal matrix and are forced to vary linearly from pixel-to-pixel within segments. Image resizing is performed by interpolating along the approximated isophotes. The proposed method can accommodate arbitrary scaling factors, provides state-of-the-art results in terms of PSNR as well as other quantitative visual quality metrics, and has the advantage of reduced computational complexity that is directly proportional to the number of pixels.

  12. Segmenting data sets for RIP.

    PubMed

    de Sanctis, Daniele; Nanao, Max H

    2012-09-01

    Specific radiation damage can be used for the phasing of macromolecular crystal structures. In practice, however, the optimization of the X-ray dose used to `burn' the crystal to induce specific damage can be difficult. Here, a method is presented in which a single large data set that has not been optimized in any way for radiation-damage-induced phasing (RIP) is segmented into multiple sub-data sets, which can then be used for RIP. The efficacy of this method is demonstrated using two model systems and two test systems. A method to improve the success of this type of phasing experiment by varying the composition of the two sub-data sets with respect to their separation by image number, and hence by absorbed dose, as well as their individual completeness is illustrated.

  13. Precision segmented reflector, figure verification sensor

    NASA Technical Reports Server (NTRS)

    Manhart, Paul K.; Macenka, Steve A.

    1989-01-01

    The Precision Segmented Reflector (PSR) program currently under way at the Jet Propulsion Laboratory is a test bed and technology demonstration program designed to develop and study the structural and material technologies required for lightweight, precision segmented reflectors. A Figure Verification Sensor (FVS) which is designed to monitor the active control system of the segments is described, a best fit surface is defined, and an image or wavefront quality of the assembled array of reflecting panels is assessed

  14. A unique case of segmental vasal atresia

    PubMed Central

    Alalayet, Yasen Fayez; Alkasim, F; Shiba, N; Aldhuayan, I; Alhamaidi, S; Alghamdi, G; Aljobair, F; Shoura, J; Alkhlaif, R

    2014-01-01

    We report a case of a 2-year-old boy who presented with an empty left scrotum. Clinical examination revealed a left palpable undescended testis. During orchidopexy, segmental atresia of the vas deferens was found, and microsurgical repair was carried out. Segmental vasal atresia is an extremely rare condition and is infrequently diagnosed, especially in the pediatric age group. This is the first reported case of segmental vasal atresia without an association with cystic fibrosis. PMID:25419520

  15. Segmentation in dermatological hyperspectral images: dedicated methods.

    PubMed

    Koprowski, Robert; Olczyk, Paweł

    2016-08-17

    Segmentation of hyperspectral medical images is one of many image segmentation methods which require profiling. This profiling involves either the adjustment of existing, known image segmentation methods or a proposal of new dedicated methods of hyperspectral image segmentation. Taking into consideration the size of analysed data, the time of analysis is of major importance. Therefore, the authors proposed three new dedicated methods of hyperspectral image segmentation with special reference to the time of analysis. The segmentation methods presented in this paper were tested and profiled to the images acquired from different hyperspectral cameras including SOC710 Hyperspectral Imaging System, Specim sCMOS-50-V10E. Correct functioning of the method was tested for over 10,000 2D images constituting the sequence of over 700 registrations of the areas of the left and right hand and the forearm. As a result, three new methods of hyperspectral image segmentation have been proposed: fast analysis of emissivity curves (SKE), 3D segmentation (S3D) and hierarchical segmentation (SH). They have the following features: are fully automatic; allow for implementation of fast segmentation methods; are profiled to hyperspectral image segmentation; use emissivity curves in the model form, can be applied in any type of objects not necessarily biological ones, are faster (SKE-2.3 ms, S3D-1949 ms, SH-844 ms for the computer with Intel(®) Core i7 4960X CPU 3.6 GHz) and more accurate (SKE-accuracy 79 %, S3D-90 %, SH-92 %) in comparison with typical methods known from the literature. Profiling and/or proposing new methods of hyperspectral image segmentation is an indispensable element of developing software. This ensures speed, repeatability and low sensitivity of the algorithm to changing parameters.

  16. Design Gabor Filters for Texture Segmentation

    DTIC Science & Technology

    1992-10-01

    DESIGNING GABOR FILTERS FOR TEXTURE SEGMENTATION by D. F. Dunn, W. Higgins, A. Maida, J. Wakeley DTIC ELECTE CT 141992 SA D m Technical Report No. TR 92...REPORT TYPE AND DATES COVEREDOctober 1992 4. T•TLE AND SUBTI’TE S. FUNONG NUMBElS Design Gabor Filters for Texture Segmentation 4. AUTHOR(S) D. F. Dunn, W...TERMS IS. NUMBER OF PAGES Gabor filters , texture segmentation , filters 178 16. PRKIC coot 17.

  17. An algorithm for segmenting range imagery

    SciTech Connect

    Roberts, R.S.

    1997-03-01

    This report describes the technical accomplishments of the FY96 Cross Cutting and Advanced Technology (CC&AT) project at Los Alamos National Laboratory. The project focused on developing algorithms for segmenting range images. The image segmentation algorithm developed during the project is described here. In addition to segmenting range images, the algorithm can fuse multiple range images thereby providing true 3D scene models. The algorithm has been incorporated into the Rapid World Modelling System at Sandia National Laboratory.

  18. Segmentation of fat in MRI using a preparatory pair of rectangular RF pulses of opposite direction.

    PubMed

    Yee, Seonghwan

    2016-05-01

    A radiofrequency (RF) pulse-based MRI method is introduced as a novel fat (or water) segmentation method that, unlike the mostly used Dixon's method, does not depend on the echo times. A pair of rectangular RF pulses of opposite direction, when the duration of its rectangular pulse and the off-resonance of its carrier frequency are set to specific values, is proposed as a preparatory RF pulse to be used for the quantitative fat segmentation. The optimal duration of its rectangular pulse and its specific off-resonance were first determined theoretically. Then, such pair of rectangular pulses of opposite direction (PROD pulse) was applied in imaging a few phantoms and volunteers. During the imaging experiments, MRI images were dynamically acquired with the PROD pulse while its carrier frequency was varied in a predefined off-resonance range. By analyzing the dynamically acquired signal changes, the theoretical properties of the PROD pulse were confirmed and the utility of the PROD pulse for the fat segmentation was verified. All MRI scans were performed in a clinical 3T system. The PROD pulse, if the duration of each rectangular pulse was set to 1.66ms and its carrier frequency was set to a specific off-resonance (e.g. ±223.5Hz, or -670.5Hz) in 3T, was effective in optimally modulating MRI signals to be used for the fat-water segmentation. Therefore, the PROD pulse can successfully be used as a preparatory RF pulse in MRI to achieve effective fat (or water) segmentation in MRI.

  19. Military display market segment: helicopters

    NASA Astrophysics Data System (ADS)

    Desjardins, Daniel D.; Hopper, Darrel G.

    2004-09-01

    The military display market is analyzed in terms of one of its segments: helicopter displays. Parameters requiring special consideration, to include luminance ranges, contrast ratio, viewing angles, and chromaticity coordinates, are examined. Performance requirements for rotary-wing displays relative to several premier applications are summarized. Display sizes having aggregate defense applications of 5,000 units or greater and having DoD applications across 10 or more platforms, are tabulated. The issue of size commonality is addressed where distribution of active area sizes across helicopter platforms, individually, in groups of two through nine, and ten or greater, is illustrated. Rotary-wing displays are also analyzed by technology, where total quantities of such displays are broken out into CRT, LCD, AMLCD, EM, LED, Incandescent, Plasma and TFEL percentages. Custom, versus Rugged commercial, versus commercial off-the-shelf designs are contrasted. High and low information content designs are identified. Displays for several high-profile military helicopter programs are discussed, to include both technical specifications and program history. The military display market study is summarized with breakouts for the helicopter market segment. Our defense-wide study as of March 2004 has documented 1,015,494 direct view and virtual image displays distributed across 1,181 display sizes and 503 weapon systems. Helicopter displays account for 67,472 displays (just 6.6% of DoD total) and comprise 83 sizes (7.0% of total DoD) in 76 platforms (15.1% of total DoD). Some 47.6% of these rotary-wing applications involve low information content displays comprising just a few characters in one color; however, as per fixed-wing aircraft, the predominant instantiation involves higher information content units capable of showing changeable graphics, color and video.

  20. Estimating potential diapause duration in Calanus finmarchicus

    NASA Astrophysics Data System (ADS)

    Saumweber, Whitley J.; Durbin, Edward G.

    2006-11-01

    Deep basins in the Gulf of Maine act as refuge for a large population of diapausing Calanus finmarchicus during the summer and fall. This population acts as the primary seed population for Georges Bank in the spring and is thought to be composed primarily of individuals that developed during the previous spring bloom. The factors affecting growth and mortality in the summer-fall population are not well understood, however, and loss terms from advection and starvation may be large. To assess the potential energetic limitation and loss of C. finmarchicus from the Gulf of Maine basins, a new nitrogen-specific respiration model has been developed for the resting stage of the species. Stage C5 C. finmarchicus were collected during July, September, and December 2003 from Wilkinson and Georges Basins. Animals were collected using both MOCNESS tows and zooplankton samplers on the Johnson Sea Link II submersible. Metabolic rates were measured using a Micro-Oxymax gas analyzer and Winkler incubation techniques both at sea and on animals kept in culture on shore. Respiration rates measured in the field were not significantly different from those measured on shore, with a mean of 130 μmol O 2 gN -1 h -1 (14.4 μmol O 2 gC -1 h -1) at 0 °C and a Q10 of 2.77 (2.58 for carbon-specific respiration). Using the nitrogen-specific rates in conjunction with visual estimates of nitrogen weight and lipid stores, we derived a discrete function for predicting potential diapause duration based on an animal's length, oil sac volume, and the in situ temperature. The maximum potential diapause duration for a C5 C. finmarchicus is predicted to range from 280 days at 0 °C to approximately 90 days at 11 °C. The maximum potential diapause duration in the Gulf of Maine is predicted to be between 3.5 and 5.5 months. These results suggest that energetic limitation may play a role in controlling the population dynamics of diapausing C. finmarchicus in the Gulf of Maine. A reassessment of the

  1. Image segmentation using fuzzy LVQ clustering networks

    NASA Technical Reports Server (NTRS)

    Tsao, Eric Chen-Kuo; Bezdek, James C.; Pal, Nikhil R.

    1992-01-01

    In this note we formulate image segmentation as a clustering problem. Feature vectors extracted from a raw image are clustered into subregions, thereby segmenting the image. A fuzzy generalization of a Kohonen learning vector quantization (LVQ) which integrates the Fuzzy c-Means (FCM) model with the learning rate and updating strategies of the LVQ is used for this task. This network, which segments images in an unsupervised manner, is thus related to the FCM optimization problem. Numerical examples on photographic and magnetic resonance images are given to illustrate this approach to image segmentation.

  2. Phasing piston error in segmented telescopes.

    PubMed

    Jiang, Junlun; Zhao, Weirui

    2016-08-22

    To achieve a diffraction-limited imaging, the piston errors between the segments of the segmented primary mirror telescope should be reduced to λ/40 RMS. We propose a method to detect the piston error by analyzing the intensity distribution on the image plane according to the Fourier optics principle, which can capture segments with the piston errors as large as the coherence length of the input light and reduce these to 0.026λ RMS (λ = 633nm). This method is adaptable to any segmented and deployable primary mirror telescope. Experiments have been carried out to validate the feasibility of the method.

  3. Parallel Fuzzy Segmentation of Multiple Objects*

    PubMed Central

    Garduño, Edgar; Herman, Gabor T.

    2009-01-01

    The usefulness of fuzzy segmentation algorithms based on fuzzy connectedness principles has been established in numerous publications. New technologies are capable of producing larger-and-larger datasets and this causes the sequential implementations of fuzzy segmentation algorithms to be time-consuming. We have adapted a sequential fuzzy segmentation algorithm to multi-processor machines. We demonstrate the efficacy of such a distributed fuzzy segmentation algorithm by testing it with large datasets (of the order of 50 million points/voxels/items): a speed-up factor of approximately five over the sequential implementation seems to be the norm. PMID:19444333

  4. Segmenting hospitals for improved management strategy.

    PubMed

    Malhotra, N K

    1989-09-01

    The author presents a conceptual framework for the a priori and clustering-based approaches to segmentation and evaluates them in the context of segmenting institutional health care markets. An empirical study is reported in which the hospital market is segmented on three state-of-being variables. The segmentation approach also takes into account important organizational decision-making variables. The sophisticated Thurstone Case V procedure is employed. Several marketing implications for hospitals, other health care organizations, hospital suppliers, and donor publics are identified.

  5. Adaptive textural segmentation of medical images

    NASA Astrophysics Data System (ADS)

    Kuklinski, Walter S.; Frost, Gordon S.; MacLaughlin, Thomas

    1992-06-01

    A number of important problems in medical imaging can be described as segmentation problems. Previous fractal-based image segmentation algorithms have used either the local fractal dimension alone or the local fractal dimension and the corresponding image intensity as features for subsequent pattern recognition algorithms. An image segmentation algorithm that utilized the local fractal dimension, image intensity, and the correlation coefficient of the local fractal dimension regression analysis computation, to produce a three-dimension feature space that was partitioned to identify specific pixels of dental radiographs as being either bone, teeth, or a boundary between bone and teeth also has been reported. In this work we formulated the segmentation process as a configurational optimization problem and discuss the application of simulated annealing optimization methods to the solution of this specific optimization problem. The configurational optimization method allows information about both, the degree of correspondence between a candidate segment and an assumed textural model, and morphological information about the candidate segment to be used in the segmentation process. To apply this configurational optimization technique with a fractal textural model however, requires the estimation of the fractal dimension of an irregularly shaped candidate segment. The potential utility of a discrete Gerchberg-Papoulis bandlimited extrapolation algorithm to the estimation of the fractal dimension of an irregularly shaped candidate segment is also discussed.

  6. DT-MRI segmentation using graph cuts

    NASA Astrophysics Data System (ADS)

    Weldeselassie, Yonas T.; Hamarneh, Ghassan

    2007-03-01

    An important problem in medical image analysis is the segmentation of anatomical regions of interest. Once regions of interest are segmented, one can extract shape, appearance, and structural features that can be analyzed for disease diagnosis or treatment evaluation. Diffusion tensor magnetic resonance imaging (DT-MRI) is a relatively new medical imaging modality that captures unique water diffusion properties and fiber orientation information of the imaged tissues. In this paper, we extend the interactive multidimensional graph cuts segmentation technique to operate on DT-MRI data by utilizing latest advances in tensor calculus and diffusion tensor dissimilarity metrics. The user interactively selects certain tensors as object ("obj") or background ("bkg") to provide hard constraints for the segmentation. Additional soft constraints incorporate information about both regional tissue diffusion as well as boundaries between tissues of different diffusion properties. Graph cuts are used to find globally optimal segmentation of the underlying 3D DT-MR image among all segmentations satisfying the constraints. We develop a graph structure from the underlying DT-MR image with the tensor voxels corresponding to the graph vertices and with graph edge weights computed using either Log-Euclidean or the J-divergence tensor dissimilarity metric. The topology of our segmentation is unrestricted and both obj and bkg segments may consist of several isolated parts. We test our method on synthetic DT data and apply it to real 2D and 3D MRI, providing segmentations of the corpus callosum in the brain and the ventricles of the heart.

  7. A molecular view of onychophoran segmentation.

    PubMed

    Janssen, Ralf

    2017-02-14

    This paper summarizes our current knowledge on the expression and assumed function of Drosophila and (other) arthropod segmentation gene orthologs in Onychophora, a closely related outgroup to Arthropoda. This includes orthologs of the so-called Drosophila segmentation gene cascade including the Hox genes, as well as other genetic factors and pathways involved in non-drosophilid arthropods. Open questions about and around the topic are addressed, such as the definition of segments in onychophorans, the unclear regulation of conserved expression patterns downstream of non-conserved factors, and the potential role of mesodermal patterning in onychophoran segmentation.

  8. Dynamic Aperture-based Solar Loop Segmentation

    NASA Technical Reports Server (NTRS)

    Lee, Jon Kwan; Newman, Timothy S.; Gary, G. Allen

    2006-01-01

    A new method to automatically segment arc-like loop structures from intensity images of the Sun's corona is introduced. The method constructively segments credible loop structures by exploiting the Gaussian-like shape of loop cross-sectional intensity profiles. The experimental results show that the method reasonably segments most of the well-defined loops in coronal images. The method is only the second published automated solar loop segmentation method. Its advantage over the other published method is that it operates independently of supplemental time specific data.

  9. Segmented amplifier configurations for laser amplifier

    DOEpatents

    Hagen, Wilhelm F.

    1979-01-01

    An amplifier system for high power lasers, the system comprising a compact array of segments which (1) preserves high, large signal gain with improved pumping efficiency and (2) allows the total amplifier length to be shortened by as much as one order of magnitude. The system uses a three dimensional array of segments, with the plane of each segment being oriented at substantially the amplifier medium Brewster angle relative to the incident laser beam and with one or more linear arrays of flashlamps positioned between adjacent rows of amplifier segments, with the plane of the linear array of flashlamps being substantially parallel to the beam propagation direction.

  10. Arbitrary segments of absolute negative mobility

    NASA Astrophysics Data System (ADS)

    Chen, Ruyin; Nie, Linru; Chen, Chongyang; Wang, Chaojie

    2017-01-01

    In previous research work, investigators have reported only one or two segments of absolute negative mobility (ANM) in a periodic potential. In fact, many segments of ANM also occur in the system considered here. We investigate transport of an inertial particle in a gating ratchet periodic potential subjected to a constant bias force. Our numerical results show that its mean velocity can decrease with the bias force increasing, i.e. ANM phenomenon. Furthermore, the ANM can take place arbitrary segments, even up to more than thirty. Intrinsic physical mechanism and conditions for arbitrary segments of ANM to occur are discussed in detail.

  11. Wavelet-based technique for target segmentation

    NASA Astrophysics Data System (ADS)

    Sadjadi, Firooz A.

    1995-07-01

    Segmentation of targets embedded in clutter obtained by IR imaging sensors is one of the challenging problems in automatic target recognition (ATR). In this paper a new texture-based segmentation technique is presented that uses the statistics of 2D wavelet decomposition components of the lcoal sections of the image. A measure of statistical similarity is then used to segment the image and separate the target from the background. This technique is applied on a set of real sequential IR imagery and has shown to produce a high degree of segmentation accuracy across varying ranges.

  12. Segmentation-free ocular detection and recognition

    NASA Astrophysics Data System (ADS)

    Rodriguez, Andres; Panza, Jeffrey; Vijaya Kumar, B. V. K.

    2011-06-01

    Iris recognition is a well-known technique to identify persons. However this technique requires high resolution images in order to automatically segment the iris. In some scenarios obtaining the required resolution may be difficult. In this paper, we investigate the recognition of ocular regions using correlation filters without segmenting the iris region. This method uses the whole eye region and surrounding areas, i.e., the ocular region, for identification. In our experiments we use the recently developed Quadratic Correlation Filter and show that at low resolutions segmentation-free ocular recognition can succeed while iris segmentation fails.

  13. Simultaneous Segmentation and Statistical Label Fusion.

    PubMed

    Asman, Andrew J; Landmana, Bennett A

    2012-02-23

    Labeling or segmentation of structures of interest in medical imaging plays an essential role in both clinical and scientific understanding. Two of the common techniques to obtain these labels are through either fully automated segmentation or through multi-atlas based segmentation and label fusion. Fully automated techniques often result in highly accurate segmentations but lack the robustness to be viable in many cases. On the other hand, label fusion techniques are often extremely robust, but lack the accuracy of automated algorithms for specific classes of problems. Herein, we propose to perform simultaneous automated segmentation and statistical label fusion through the reformulation of a generative model to include a linkage structure that explicitly estimates the complex global relationships between labels and intensities. These relationships are inferred from the atlas labels and intensities and applied to the target using a non-parametric approach. The novelty of this approach lies in the combination of previously exclusive techniques and attempts to combine the accuracy benefits of automated segmentation with the robustness of a multi-atlas based approach. The accuracy benefits of this simultaneous approach are assessed using a multi-label multi- atlas whole-brain segmentation experiment and the segmentation of the highly variable thyroid on computed tomography images. The results demonstrate that this technique has major benefits for certain types of problems and has the potential to provide a paradigm shift in which the lines between statistical label fusion and automated segmentation are dramatically blurred.

  14. Long Duration Exposure Facility: A general overview

    NASA Technical Reports Server (NTRS)

    Oneal, Robert L.; Lightner, E. Burton

    1992-01-01

    The Long Duration Exposure Facility (LDEF) is a large, low-cost, reusable, unmanned, free-flying spacecraft which accommodates technology, science, and applications experiments for long-term exposure to the space environment. The LDEF was designed and built by the NASA Langley Research Center (LaRC) for NASA's Office of Aeronautics and Space Technology. Specifically, the LDEF was designed to transport experiments into space via the Space Shuttle, to free fly in Earth orbit for an extended period, and be retrieved on a later Space Shuttle flight allowing experiments to be returned to Earth for postflight analysis in the laboratory. The LDEF with a full complement of experiments was placed in Earth orbit in April 1984 by Challenger and retrieved from orbit in January 1990 by Columbia. A general overview of the LDEF, its mission, systems, experiments, and operations is presented. Excerpts from various NASA documents are extensively used.

  15. Effects of methamphetamine on duration discrimination.

    PubMed

    Cevik, Münire Ozlem

    2003-08-01

    Experiments 1 and 2 address the controversy regarding the reliability of methamphetamine effects on interval timing. A temporal discrimination procedure was used, in which the rats were reinforced for pressing the left or the right levers after short and long signals, respectively. Methamphetamine (0.5 mg/kg sc) severely disrupted operant performance at 20-100 min after injection, which disabled the measurement of drug effects on temporal perception (Experiment 1). The same dose of methamphetamine shifted the psychometric function to the left at 100-180 min after injection, indicating an increase in subjective durations (Experiment 2). Although these results confirm the role of dopamine in interval timing, that a change in the speed of a neural clock mediates the methamphetamine-induced change in temporal perception is still a working hypothesis.

  16. Use of pacifiers and breastfeeding duration.

    PubMed

    Victora, C G; Tomasi, E; Olinto, M T; Barros, F C

    1993-02-13

    Pacifiers are widely used in many developing countries. Although their use is not recommended for breastfeeding infants, there have been no published reports on the association between pacifier use and risk of early weaning. In a study of 354 infants in Brazil, mothers were asked about pacifier use at age 1 month, duration of breastfeeding, and introduction of other foods. Among 249 children still breastfed at 1 month, the risk that a child would be weaned at any age between 1 and 24 months was higher in pacifier users than in non-users (hazard ratio 3.0, 95% CI 2.0-4.6). The association remained even after adjustment for the child's age, sex, birthweight, socioeconomic status, and age at introduction of bottle-feeding.

  17. Period and pulse duration with "strobe" lights

    NASA Astrophysics Data System (ADS)

    Birriel, Jennifer

    2016-01-01

    Strobe lights have traditionally been discussed in The Physics Teacher in the context of stop action strobe photography. During the Halloween season most department and hardware stores sell inexpensive, compact "strobe" lights (although these can be found online year round). These lights generally sell for under 10 and usually employ LED lights. Most such devices have a rotary switch to adjust the rate at which the LED bulbs flash. This rotary switch is not calibrated—i.e., it has no markings to indicate the rate, but in general the greater the rotation of the switch from the off position, the faster the rate of flashing. We show how these simple devices can be used with a light sensor to study both the frequency of flashing and the duration of the light pulse. We briefly discuss if these devices are truly strobe lights.

  18. Short Duration Base Heating Test Improvements

    NASA Technical Reports Server (NTRS)

    Bender, Robert L.; Dagostino, Mark G.; Engel, Bradley A.; Engel, Carl D.

    1999-01-01

    Significant improvements have been made to a short duration space launch vehicle base heating test technique. This technique was first developed during the 1960's to investigate launch vehicle plume induced convective environments. Recent improvements include the use of coiled nitrogen buffer gas lines upstream of the hydrogen / oxygen propellant charge tubes, fast acting solenoid valves, stand alone gas delivery and data acquisition systems, and an integrated model design code. Technique improvements were successfully demonstrated during a 2.25% scale X-33 base heating test conducted in the NASA/MSFC Nozzle Test Facility in early 1999. Cost savings of approximately an order of magnitude over previous tests were realized due in large part to these improvements.

  19. Feeding the Astronauts During Long Duration Missions

    NASA Technical Reports Server (NTRS)

    Perchonok, Michele

    2010-01-01

    This slide presentation reviews the issues surrounding feeding astronauts during long duration missions. There is a brief history from the food and food packaging available during Project Mercury through the current food requirements. It shows the packaging and the requirements that have been used. The current food system includes thermostabilized and irradiated foods to reduce the potential of harmful microorganisms. There is an explanation of drinks available, rehydratable foods, and natural forms of food, (i.e., commercially available foods that are packaged in individual serving sizes). There is also discussion of the requirements for future missions, and the research gap for requirements for food that will last 5 years, with packaging and nutrients intact.

  20. Drug stability analyzer for long duration spaceflights

    NASA Astrophysics Data System (ADS)

    Shende, Chetan; Smith, Wayne; Brouillette, Carl; Farquharson, Stuart

    2014-06-01

    Crewmembers of current and future long duration spaceflights require drugs to overcome the deleterious effects of weightlessness, sickness and injuries. Unfortunately, recent studies have shown that some of the drugs currently used may degrade more rapidly in space, losing their potency well before their expiration dates. To complicate matters, the degradation products of some drugs can be toxic. Consequently there is a need for an analyzer that can determine if a drug is safe at the time of use, as well as to monitor and understand space-induced degradation, so that drug types, formulations, and packaging can be improved. Towards this goal we have been investigating the ability of Raman spectroscopy to monitor and quantify drug degradation. Here we present preliminary data by measuring acetaminophen, and its degradation product, p-aminophenol, as pure samples, and during forced degradation reactions.

  1. Long Duration Backlighter Experiments at Omega

    SciTech Connect

    Reighard, A; Glendinning, S; Young, P; Hsing, W; Foord, M; Schneider, M; Lu, K; Dittrich, T; Wallace, R; Sorce, C

    2008-05-01

    We have successfully demonstrated a 7.5 ns-duration pinhole-apertured backlighter at the Omega laser facility. Pinhole-apertured point-projection backlighting for 8 ns will be useful for imaging evolving features in experiments at the National Ignition Facility. The backlighter consisted of a 20 {micro}m diameter pinhole in a 75 {micro}m thick Ta substrate separated from a Zn emitter (9 keV) by a 400 {micro}m thick high-density carbon piece. The carbon prevented the shock from the laser-driven surface from reaching the substrate before 8 ns and helped minimize x-ray ablation of the pinhole substrate. Grid wires in x-ray framing camera images of a gold grid have a source-limited resolution significantly smaller than the pinhole diameter due to the high aspect ratio of the pinhole, but do not become much smaller at late times.

  2. Anticholinesterase duration in the Australian veteran population.

    PubMed

    Gadzhanova, Svetla; Roughead, Libby; Mackson, Judith

    2010-05-01

    The aim of the present study was to determine the duration of initial anticholinesterase treatment in veteran patients in Australia. Three anti-dementia medications were investigated (donepezil, rivastigmine and galantamine) and two different setting were compared (community and residential aged care facilities). A retrospective cohort study was performed using the Department of Veterans' Affairs pharmacy claims data. Patients were included in the cohort if they had been dispensed at least one anticholinesterase prescription (index) between 2003 and 2006, were aged 65 years or over at the time of that index dispensing, and had not been dispensed any anticholinesterase medicine in the previous 12 months. Patients were followed until discontinuation (ceased or switched), death or 1 year of follow up. Time to treatment discontinuation was analysed utilizing the Kaplan-Meier method. Cox proportional hazards models were used to compare the risk of treatment discontinuation among the three treatment groups adjusting for the effect of patients' characteristics. Of the new users of anticholinesterases (n = 10088), 47% of those on donepezil, 46% of those on galantamine, and 47% of rivastigmine patients discontinued their initial therapy within 6 months. A total of 32% of patients who ceased therapy reinitiated it during the study period; 28% returned to the same index medication and 4% restarted therapy with a different anticholinesterase. The median treatment duration was: 199 days (95% CI, 182-208) for donepezil patients (n = 6705), 233 days (95% CI, 212-259) for galantamine patients (n = 2898), and 219 days (95% CI, 176-260) for rivastigmine patients (n = 394). Patients in community settings were more likely to discontinue their initial anticholinesterases earlier compared to those living at residential aged care facilities (relative risk, RR=1.21; 95% CI, 1.12, 1.31). Almost half of the Australian veteran patients who initiated anticholinesterases treatment discontinued

  3. Short duration thermal metamorphism in CR chondrites

    NASA Astrophysics Data System (ADS)

    Briani, G.; Quirico, E.; Gounelle, M.; Paulhiac-Pison, M.; Montagnac, G.; Beck, P.; Orthous-Daunay, F.-R.; Bonal, L.; Jacquet, E.; Kearsley, A.; Russell, S. S.

    2013-12-01

    CR chondrites are considered as one of the most primitive classes of meteorites. Most of them experienced a mild aqueous alteration and show no evidence of significant effect of thermal metamorphism. We present here a search for low degree metamorphic effects in CR chondrites. We studied 15 CR chondrites using different metamorphic indicators: (1) structure and Ni content of metal grains; (2) hydration state of matrix; (3) structure and composition of organic matter. The different metamorphic indicators show that two of the analyzed CR chondrites, GRA 06100 and GRO 03116, experienced thermal metamorphism. Indeed, all of the metal grains in GRA 06100 and half of the metal grains in GRO 03116 show Ni-rich phases; the matrix of GRA 06100 is almost completely dehydrated, and the matrix of GRO 03116 is partially dehydrated; Raman spectra of organic matter in these two meteorites are clearly different from those obtained for organic matter in the other CR chondrites, which resemble Raman spectra of organic matter in unmetamorphosed, CM2 meteorites; IR spectra of insoluble organic matter extracted from GRA 06100 and GRO 03116 show lower carbonyl abundance and higher CH2/CH3 ratio with respect to organic matter of unmetamorphosed chondrites. The other CR chondrites analyzed here lack these characteristics and only show a few metal grains with Ni-rich inclusions. Our results also show that the metamorphic effects observed in GRA 06100 and GRO 03116 are different from those observed in type 3 chondrites, which experienced long-duration metamorphism of radiogenic origin. We infer that thermal processing in these two CRs extended over a short duration and was triggered by impacts.

  4. Sleep duration, life satisfaction and disability.

    PubMed

    Pagan, Ricardo

    2017-04-01

    Although sleep is considered an essential part of individuals' lives, there are no previous studies analysing how sleep duration affects the levels of life satisfaction reported by males and females with disabilities. To analyse and compare the impact of hours of sleep on life satisfaction scores reported by people without and with disabilities (stratified by sex) in Germany. Using data taken from the German Socio-Economic Panel for the period 2008-2013, we estimate life satisfaction equations for males and females (running a fixed-effects model) which include a set of variables measuring the number of sleep hours on workdays and weekends. A higher number of sleep hours on workdays increase life satisfaction for all males and females. However, the contribution of each hour of sleep on workdays is greater for males with disabilities in terms of life satisfaction, whereas for females no significant differences by disability status have been found. Although sleep hours on weekends also increase life satisfaction, the magnitude of the coefficients is relatively higher than that found for the corresponding hours of sleep on workdays, but only for the male sample (disabled or not). The participation and commitment of policymakers, governments, trade unions, employers, and health care professionals are key aspects for developing and formulating new guidelines and specific measures that promote a healthy lifestyle and increase sleep duration. Such guidelines and measures are of essence for people with disabilities who are employed (e.g. using brief sleep opportunities during prolonged work periods, which can contribute to reducing fatigue, stress and anxiety). Copyright © 2016 Elsevier Inc. All rights reserved.

  5. Architectural considerations for lunar long duration habitat

    NASA Astrophysics Data System (ADS)

    Bahrami, Payam

    The future of space exploration science and technology is expected to move toward long duration missions. During this long duration missions the most important factor to success will be the habitation system, the place that crew will live and work. The broad range of future space exploration, new advances in technology and increasing demand for space travel and space tourism will create great opportunities for architects to use their special abilities and skills in the realm of space. The lunar habitat is defined as a multidisciplinary task and cannot be considered an independent project from the main module. Therefore, habitability will become the most important aspect of future human exploration. A successful design strategy should integrate architecture, structure and other disciplines and should bring in elements such as psychological and physiological factors, human interfaces, and privacy. The current research provides "Habitat Architectural Design System (HADS)" in order to evaluate lunar habitat concepts based on habitability, functional optimization, and human factors. HADS helps to promote parametric studied and evaluation of habitat concepts. It will provide a guideline dependent upon mission objectives to standardize architectural needs within the engineering applications and scientific demands. The significance of this research is the process of developing lunar habitat concepts using an architectural system to evaluate the quality of each concept via habitability aspects. This process can be employed during the early stage of design development and is flexible enough to be adjusted by different parameters according to the objectives of lunar mission, limitations, and cost. It also emphasizes the importance of architecture involvement in space projects, especially habitats.

  6. Prediction of Daily Flow Duration Curves and Streamflow for Ungauged Catchments Using Regional Flow Duration Curves

    EPA Science Inventory

    This study presents a method to predict flow duration curves (FDCs) and streamflow for ungauged catchments in the Mid-Atlantic Region, USA. We selected 29 catchments from the Appalachian Plateau, Ridge and Valley, and Piedmont physiographic provinces to develop and test the propo...

  7. Prediction of Daily Flow Duration Curves and Streamflow for Ungauged Catchments Using Regional Flow Duration Curves

    EPA Science Inventory

    This study presents a method to predict flow duration curves (FDCs) and streamflow for ungauged catchments in the Mid-Atlantic Region, USA. We selected 29 catchments from the Appalachian Plateau, Ridge and Valley, and Piedmont physiographic provinces to develop and test the propo...

  8. Biphasic transthoracic defibrillation causes fewer ECG ST-segment changes after shock.

    PubMed

    Reddy, R K; Gleva, M J; Gliner, B E; Dolack, G L; Kudenchuk, P J; Poole, J E; Bardy, G H

    1997-08-01

    Electrocardiographic abnormalities are common after transthoracic defibrillation. ECG ST-segment changes are especially problematic after defibrillation and may indicate ischemic or shock-induced cardiac dysfunction after resuscitation. Biphasic defibrillation waveforms, compared with monophasic waveforms, diminish shock-induced cardiac dysfunction in laboratory preparations. This effect has not been validated in human subjects. We therefore evaluated in a prospective, blinded fashion the effect of biphasic and monophasic transthoracic defibrillation on the ECG ST segment in 30 consecutive patients during surgery for the implantation of a cardioverter-defibrillator. In each patient two low-energy truncated biphasic transthoracic defibrillation shocks (115 and 130 J) were compared with a standard clinical 200 J monophasic damped-sine wave shock. The biphasic shocks and the damped-sine wave shock have been demonstrated to have equal defibrillation efficacy of 97%. Fifteen-second ECG signals recorded across transthoracic defibrillation electrodes were digitized before ventricular fibrillation induction and immediately after each defibrillation attempt. The ST segments 80 msec after the J point were analyzed in a blinded fashion by two reviewers. The ST-segment deflection, QRS-interval duration, QT interval, and heart rate after each therapy were compared with baseline values. ECG ST-segment elevation was significantly greater with the 200-J damped-sine waveform than with either biphasic waveform. The ECG ST-segment levels were -.55 +/- .36 at baseline, -.76 +/- .36 mm after internal shock, -.02-.36 mm after 115-J biphasic shock, .21 +/- .38 mm after 130-J biphasic shock, and 2.09 +/- .37 mm after 200-J damped-sine wave shock (P<.0001). QRS-interval duration, QT interval, and heart rate did not change significantly with any waveform. Transthoracic defibrillation with biphasic waveforms results in less postshock ECG evidence of myocardial dysfunction (injury or ischemia

  9. New evidence suggesting segmentation of Cocos Plate

    SciTech Connect

    Lew, L.R.; Sauermann, R.P.; De Boer, J.

    1985-02-01

    Compilation and analysis of geophysical and geological data indicate that the Cocos plate consists of three segments that have individual poles of rotation and independent motion vectors. Contoured heat-flow and gravity maps of the region delineate the boundaries of the segments within the Cocos plate. These segments have different focal-plane solutions along the Middle America Trench and different sedimentary-basin configurations within the Central America-Mexico island arc. Recent studies of seismic data from the region also have suggested that the subducted Cocos plate consists of three segments. The proposed northern and central segments are separated by the northeast-trending Siqueros-Tehuantepec Ridge fracture zone. The proposed central and southern segments are separated by the northeast-trending Costa Rica fracture zone that is located just northwest of the Cocos Ridge and extends from the Galapagos rift to the central valley of Costa Rica. Poles of rotation and relative motion vectors have been calculated with respect to the Caribbean plate for each segment. The northern segment is moving N75/sup 0/E, oblique to the trench; the central segment is moving N50/sup 0/E, perpendicular to the trench; the southern segment is moving north, perpendicular to the trench. The Siqueros-Tehuantepec and Costa Rice fracture zones appear to join with tectonized zones that dissect the Central America-Mexico island arc and extend across the Caribbean plate, suggesting that it too is segmented. Structural and stratigraphic data from the sedimentary basins on the island arc suggest that these fracture zones have existed throughout the Tertiary history of the region.

  10. Automated area segmentation for ocean bottom surveys

    NASA Astrophysics Data System (ADS)

    Hyland, John C.; Smith, Cheryl M.

    2015-05-01

    In practice, environmental information about an ocean bottom area to be searched using SONAR is often known a priori to some coarse level of resolution. The SONAR search sensor then typically has a different performance characterization function for each environmental classification. Large ocean bottom surveys using search SONAR can pose some difficulties when the environmental conditions vary significantly over the search area because search planning tools cannot adequately segment the area into sub-regions of homogeneous search sensor performance. Such segmentation is critically important to unmanned search vehicles; homogenous bottom segmentation will result in more accurate predictions of search performance and area coverage rate. The Naval Surface Warfare Center, Panama City Division (NSWC PCD) has developed an automated area segmentation algorithm that subdivides the mission area under the constraint that the variation of the search sensor's performance within each sub-mission area cannot exceed a specified threshold, thereby creating sub-regions of homogeneous sensor performance. The algorithm also calculates a new, composite sensor performance function for each sub-mission area. The technique accounts for practical constraints such as enforcing a minimum sub-mission area size and requiring sub-mission areas to be rectangular. Segmentation occurs both across the rows and down the columns of the mission area. Ideally, mission planning should consider both segmentation directions and choose the one with the more favorable result. The Automated Area Segmentation Algorithm was tested using two a priori bottom segmentations: rectangular and triangular; and two search sensor configurations: a set of three bi-modal curves and a set of three uni-modal curves. For each of these four scenarios, the Automated Area Segmentation Algorithm automatically partitioned the mission area across rows and down columns to create regions with homogeneous sensor performance. The

  11. Developmental control of segment numbers in vertebrates

    PubMed Central

    Gomez, Céline; Pourquié, Olivier

    2011-01-01

    Segmentation or metamery in vertebrates is best illustrated by the repetition of the vertebrae and ribs, their associated skeletal muscles and blood vessels, and the spinal nerves and ganglia. The segment number varies tremendously among the different vertebrate species, ranging from as few as six vertebrae in some frogs to as many as several hundred in some snakes and fish. In vertebrates, metameric segments or somites form sequentially during body axis formation. This results in the embryonic axis becoming entirely segmented into metameric units from the level of the otic vesicle almost to the very tip of the tail. The total segment number mostly depends on two parameters: (1) the control of the posterior growth of the body axis during somitogenesis—more same-size segments can be formed in a longer axis and (2) segment size—more smaller-size segments can be formed in a same-size body axis. During evolution, independent variations of these parameters could explain the huge diversity in segment numbers observed among vertebrate species. These variations in segment numbers are accompanied by diversity in the regionalization of the vertebral column. For example, amniotes can exhibit up to five different types of vertebrae: cervical, thoracic, lumbar, sacral and caudal, the number of which varies according to the species. This regionalization of the vertebral column is controlled by the Hox family of transcription factors. We propose that during development, dissociation of the Hox- and segmentation-clock-dependent vertebral patterning systems explains the enormous diversity of vertebral formulae observed in vertebrates. PMID:19621429

  12. 20 CFR 625.7 - Disaster Unemployment Assistance: Duration.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 3 2011-04-01 2011-04-01 false Disaster Unemployment Assistance: Duration... DISASTER UNEMPLOYMENT ASSISTANCE § 625.7 Disaster Unemployment Assistance: Duration. DUA shall be payable... unemployment which begin during a Disaster Assistance Period....

  13. 20 CFR 625.7 - Disaster Unemployment Assistance: Duration.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 20 Employees' Benefits 3 2012-04-01 2012-04-01 false Disaster Unemployment Assistance: Duration... DISASTER UNEMPLOYMENT ASSISTANCE § 625.7 Disaster Unemployment Assistance: Duration. DUA shall be payable... unemployment which begin during a Disaster Assistance Period....

  14. 20 CFR 625.7 - Disaster Unemployment Assistance: Duration.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 20 Employees' Benefits 3 2014-04-01 2014-04-01 false Disaster Unemployment Assistance: Duration... DISASTER UNEMPLOYMENT ASSISTANCE § 625.7 Disaster Unemployment Assistance: Duration. DUA shall be payable... unemployment which begin during a Disaster Assistance Period....

  15. 20 CFR 625.7 - Disaster Unemployment Assistance: Duration.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 20 Employees' Benefits 3 2013-04-01 2013-04-01 false Disaster Unemployment Assistance: Duration... DISASTER UNEMPLOYMENT ASSISTANCE § 625.7 Disaster Unemployment Assistance: Duration. DUA shall be payable... unemployment which begin during a Disaster Assistance Period....

  16. 20 CFR 625.7 - Disaster Unemployment Assistance: Duration.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false Disaster Unemployment Assistance: Duration... DISASTER UNEMPLOYMENT ASSISTANCE § 625.7 Disaster Unemployment Assistance: Duration. DUA shall be payable... unemployment which begin during a Disaster Assistance Period. ...

  17. Automatic segmentation of seven retinal layers in SDOCT images congruent with expert manual segmentation.

    PubMed

    Chiu, Stephanie J; Li, Xiao T; Nicholas, Peter; Toth, Cynthia A; Izatt, Joseph A; Farsiu, Sina

    2010-08-30

    Segmentation of anatomical and pathological structures in ophthalmic images is crucial for the diagnosis and study of ocular diseases. However, manual segmentation is often a time-consuming and subjective process. This paper presents an automatic approach for segmenting retinal layers in Spectral Domain Optical Coherence Tomography images using graph theory and dynamic programming. Results show that this method accurately segments eight retinal layer boundaries in normal adult eyes more closely to an expert grader as compared to a second expert grader.

  18. Timing interventions in relation to temporomandibular joint closed lock duration: a systematic review of 'locking duration'.

    PubMed

    Al-Baghdadi, M; Durham, J; Steele, J

    2014-01-01

    Temporomandibular joint (TMJ) 'closed lock' (CL) is a clinical condition causing TMJ pain and limited mouth opening (painful locking) that is mostly attributed to disc displacement without reduction (DDwoR), or less commonly to anchored disc phenomenon (ADP). Both conditions are described clinically as CL that can be 'acute' or 'chronic' depending on the duration of locking. There is, however, no consensus about the duration of locking that defines the acute state and its effect on the success of interventions. This review paper, therefore, aims to provide: (i) a narrative review of the pathophysiological need for early intervention in DDwoR and the clinical implications of acute/chronic CL stages on the management pathway; (ii) a systematic review investigating the effects of locking duration on the success of interventions for CL management. Electronic and manual searches until mid-August 2013 were conducted for English-language studies of any design investigating the effects of non-surgical and surgical interventions for acute or chronic CL (DDwoR or ADP). A total of 626 records were identified, and 113 studies were included. Data extraction and quality assessment were completed for all included studies. Included studies were, however, heterogeneous and mostly of poor-quality leading to contradictory and inconsistent evidence on the effect of the duration of locking on treatment outcomes. Future high-quality trials investigating the effect of CL duration on treatment outcome are needed. At present, early intervention by 'unlock' mandibular manipulation seems to be the most practical and realistic approach that can be attempted first in every CL patient as an initial diagnostic/therapeutic approach.

  19. GeoSegmenter: A statistically learned Chinese word segmenter for the geoscience domain

    NASA Astrophysics Data System (ADS)

    Huang, Lan; Du, Youfu; Chen, Gongyang

    2015-03-01

    Unlike English, the Chinese language has no space between words. Segmenting texts into words, known as the Chinese word segmentation (CWS) problem, thus becomes a fundamental issue for processing Chinese documents and the first step in many text mining applications, including information retrieval, machine translation and knowledge acquisition. However, for the geoscience subject domain, the CWS problem remains unsolved. Although a generic segmenter can be applied to process geoscience documents, they lack the domain specific knowledge and consequently their segmentation accuracy drops dramatically. This motivated us to develop a segmenter specifically for the geoscience subject domain: the GeoSegmenter. We first proposed a generic two-step framework for domain specific CWS. Following this framework, we built GeoSegmenter using conditional random fields, a principled statistical framework for sequence learning. Specifically, GeoSegmenter first identifies general terms by using a generic baseline segmenter. Then it recognises geoscience terms by learning and applying a model that can transform the initial segmentation into the goal segmentation. Empirical experimental results on geoscience documents and benchmark datasets showed that GeoSegmenter could effectively recognise both geoscience terms and general terms.

  20. Blastoderm segmentation in Oncopeltus fasciatus and the evolution of insect segmentation mechanisms.

    PubMed

    Stahi, Reut; Chipman, Ariel D

    2016-10-12

    Segments are formed simultaneously in the blastoderm of the fly Drosophila melanogaster through a hierarchical cascade of interacting transcription factors. Conversely, in many insects and in all non-insect arthropods most segments are formed sequentially from the posterior. We have looked at segmentation in the milkweed bug Oncopeltus fasciatus. Posterior segments are formed sequentially, through what is probably the ancestral arthropod mechanism. Formation of anterior segments bears many similarities to the Drosophila segmentation mode. These segments appear nearly simultaneously in the blastoderm, via a segmentation cascade that involves orthologues of Drosophila gap genes working through a functionally similar mechanism. We suggest that simultaneous blastoderm segmentation evolved at or close to the origin of holometabolous insects, and formed the basis for the evolution of the segmentation mode seen in Drosophila We discuss the changes in segmentation mechanisms throughout insect evolution, and suggest that the appearance of simultaneous segmentation as a novel feature of holometabolous insects may have contributed to the phenomenal success of this group.

  1. Blastoderm segmentation in Oncopeltus fasciatus and the evolution of insect segmentation mechanisms

    PubMed Central

    Stahi, Reut

    2016-01-01

    Segments are formed simultaneously in the blastoderm of the fly Drosophila melanogaster through a hierarchical cascade of interacting transcription factors. Conversely, in many insects and in all non-insect arthropods most segments are formed sequentially from the posterior. We have looked at segmentation in the milkweed bug Oncopeltus fasciatus. Posterior segments are formed sequentially, through what is probably the ancestral arthropod mechanism. Formation of anterior segments bears many similarities to the Drosophila segmentation mode. These segments appear nearly simultaneously in the blastoderm, via a segmentation cascade that involves orthologues of Drosophila gap genes working through a functionally similar mechanism. We suggest that simultaneous blastoderm segmentation evolved at or close to the origin of holometabolous insects, and formed the basis for the evolution of the segmentation mode seen in Drosophila. We discuss the changes in segmentation mechanisms throughout insect evolution, and suggest that the appearance of simultaneous segmentation as a novel feature of holometabolous insects may have contributed to the phenomenal success of this group. PMID:27708151

  2. Spinal manipulation force and duration affect vertebral movement and neuromuscular responses.

    PubMed

    Colloca, Christopher J; Keller, Tony S; Harrison, Deed E; Moore, Robert J; Gunzburg, Robert; Harrison, Donald D

    2006-03-01

    Previous study in human subjects has documented biomechanical and neurophysiological responses to impulsive spinal manipulative thrusts, but very little is known about the neuromechanical effects of varying thrust force-time profiles. Ten adolescent Merino sheep were anesthetized and posteroanterior mechanical thrusts were applied to the L3 spinous process using a computer-controlled, mechanical testing apparatus. Three variable pulse durations (10, 100, 200 ms, force = 80 N) and three variable force amplitudes (20, 40, 60 N, pulse duration = 100 ms) were examined for their effect on lumbar motion response (L3 displacement, L1, L2 acceleration) and normalized multifidus electromyographic response (L3, L4) using a repeated measures analysis of variance. Increasing L3 posteroanterior force amplitude resulted in a fourfold linear increase in L3 posteroanterior vertebral displacement (p < 0.001) and adjacent segment (L1, L2) posteroanterior acceleration response (p < 0.001). L3 displacement was linearly correlated (p < 0.001) to the acceleration response over the 20-80 N force range (100 ms). At constant force, 10 ms thrusts resulted in nearly fivefold lower L3 displacements and significantly increased segmental (L2) acceleration responses compared to the 100 ms (19%, p = 0.005) and 200 ms (16%, p = 0.023) thrusts. Normalized electromyographic responses increased linearly with increasing force amplitude at higher amplitudes and were appreciably affected by mechanical excitation pulse duration. Changes in the biomechanical and neuromuscular response of the ovine lumbar spine were observed in response to changes in the force-time characteristics of the spinal manipulative thrusts and may be an underlying mechanism in related clinical outcomes.

  3. 32 CFR 2001.12 - Duration of classification.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 32 National Defense 6 2014-07-01 2014-07-01 false Duration of classification. 2001.12 Section 2001.12 National Defense Other Regulations Relating to National Defense INFORMATION SECURITY OVERSIGHT... Classification § 2001.12 Duration of classification. (a) Determining duration of classification for...

  4. 32 CFR 2001.12 - Duration of classification.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 32 National Defense 6 2012-07-01 2012-07-01 false Duration of classification. 2001.12 Section 2001.12 National Defense Other Regulations Relating to National Defense INFORMATION SECURITY OVERSIGHT... Classification § 2001.12 Duration of classification. (a) Determining duration of classification for...

  5. 27 CFR 1.43 - Duration of permits.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Duration of permits. 1.43 Section 1.43 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT... Amendment and Duration of Basic Permits § 1.43 Duration of permits. A basic permit shall continue in effect...

  6. 27 CFR 1.43 - Duration of permits.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2014-04-01 2014-04-01 false Duration of permits. 1.43 Section 1.43 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT... Amendment and Duration of Basic Permits § 1.43 Duration of permits. A basic permit shall continue in effect...

  7. 27 CFR 1.43 - Duration of permits.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Duration of permits. 1.43 Section 1.43 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT... Amendment and Duration of Basic Permits § 1.43 Duration of permits. A basic permit shall continue in effect...

  8. 27 CFR 1.43 - Duration of permits.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2012-04-01 2012-04-01 false Duration of permits. 1.43 Section 1.43 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT... Amendment and Duration of Basic Permits § 1.43 Duration of permits. A basic permit shall continue in effect...

  9. 20 CFR 725.210 - Duration of augmented benefits.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 20 Employees' Benefits 4 2014-04-01 2014-04-01 false Duration of augmented benefits. 725.210... Entitlement Conditions and Duration of Entitlement: Miner's Dependents (augmented Benefits) § 725.210 Duration of augmented benefits. Augmented benefits payable on behalf of a spouse or divorced spouse, or...

  10. 20 CFR 725.210 - Duration of augmented benefits.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 20 Employees' Benefits 4 2013-04-01 2013-04-01 false Duration of augmented benefits. 725.210... Entitlement Conditions and Duration of Entitlement: Miner's Dependents (augmented Benefits) § 725.210 Duration of augmented benefits. Augmented benefits payable on behalf of a spouse or divorced spouse, or...

  11. 20 CFR 725.210 - Duration of augmented benefits.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false Duration of augmented benefits. 725.210... Entitlement Conditions and Duration of Entitlement: Miner's Dependents (augmented Benefits) § 725.210 Duration of augmented benefits. Augmented benefits payable on behalf of a spouse or divorced spouse, or...

  12. 20 CFR 725.210 - Duration of augmented benefits.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 20 Employees' Benefits 4 2012-04-01 2012-04-01 false Duration of augmented benefits. 725.210... Entitlement Conditions and Duration of Entitlement: Miner's Dependents (augmented Benefits) § 725.210 Duration of augmented benefits. Augmented benefits payable on behalf of a spouse or divorced spouse, or...

  13. 20 CFR 725.210 - Duration of augmented benefits.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 3 2011-04-01 2011-04-01 false Duration of augmented benefits. 725.210... Entitlement Conditions and Duration of Entitlement: Miner's Dependents (augmented Benefits) § 725.210 Duration of augmented benefits. Augmented benefits payable on behalf of a spouse or divorced spouse, or...

  14. 20 CFR 336.2 - Duration of normal unemployment benefits.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 20 Employees' Benefits 1 2013-04-01 2012-04-01 true Duration of normal unemployment benefits. 336... UNEMPLOYMENT INSURANCE ACT DURATION OF NORMAL AND EXTENDED BENEFITS Normal Benefits § 336.2 Duration of normal unemployment benefits. (a) 130 compensable day limitation. A qualified employee who has satisfied the...

  15. 20 CFR 336.2 - Duration of normal unemployment benefits.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 20 Employees' Benefits 1 2014-04-01 2012-04-01 true Duration of normal unemployment benefits. 336... UNEMPLOYMENT INSURANCE ACT DURATION OF NORMAL AND EXTENDED BENEFITS Normal Benefits § 336.2 Duration of normal unemployment benefits. (a) 130 compensable day limitation. A qualified employee who has satisfied the...

  16. 20 CFR 336.2 - Duration of normal unemployment benefits.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 20 Employees' Benefits 1 2012-04-01 2012-04-01 false Duration of normal unemployment benefits. 336... UNEMPLOYMENT INSURANCE ACT DURATION OF NORMAL AND EXTENDED BENEFITS Normal Benefits § 336.2 Duration of normal unemployment benefits. (a) 130 compensable day limitation. A qualified employee who has satisfied the...

  17. 20 CFR 336.2 - Duration of normal unemployment benefits.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 1 2011-04-01 2011-04-01 false Duration of normal unemployment benefits. 336... UNEMPLOYMENT INSURANCE ACT DURATION OF NORMAL AND EXTENDED BENEFITS Normal Benefits § 336.2 Duration of normal unemployment benefits. (a) 130 compensable day limitation. A qualified employee who has satisfied the...

  18. Time in Language: Event Duration in Language Comprehension

    ERIC Educational Resources Information Center

    Coll-Florit, Marta; Gennari, Silvia P.

    2011-01-01

    This work investigates how we process and represent event duration in on-line language comprehension. Specifically, it examines how events of different duration are processed and what type of knowledge underlies their representations. Studies 1-4 examined verbs and phrases in different contexts. They showed that durative events took longer to…

  19. 5 CFR 1209.11 - Duration of stay; interim compliance.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 5 Administrative Personnel 3 2010-01-01 2010-01-01 false Duration of stay; interim compliance... WHISTLEBLOWING Stay Requests § 1209.11 Duration of stay; interim compliance. (a) Duration of stay. A stay becomes...) Interim compliance. An agency must immediately comply with an order granting a stay request. Although...

  20. 20 CFR 336.2 - Duration of normal unemployment benefits.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 1 2010-04-01 2010-04-01 false Duration of normal unemployment benefits. 336... UNEMPLOYMENT INSURANCE ACT DURATION OF NORMAL AND EXTENDED BENEFITS Normal Benefits § 336.2 Duration of normal unemployment benefits. (a) 130 compensable day limitation. A qualified employee who has satisfied the waiting...

  1. Boundary overlap for medical image segmentation evaluation

    NASA Astrophysics Data System (ADS)

    Yeghiazaryan, Varduhi; Voiculescu, Irina

    2017-03-01

    All medical image segmentation algorithms need to be validated and compared, and yet no evaluation framework is widely accepted within the imaging community. Collections of segmentation results often need to be compared and ranked by their effectiveness. Evaluation measures which are popular in the literature are based on region overlap or boundary distance. None of these are consistent in the way they rank segmentation results: they tend to be sensitive to one or another type of segmentation error (size, location, shape) but no single measure covers all error types. We introduce a new family of measures, with hybrid characteristics. These measures quantify similarity/difference of segmented regions by considering their overlap around the region boundaries. This family is more sensitive than other measures in the literature to combinations of segmentation error types. We compare measure performance on collections of segmentation results sourced from carefully compiled 2D synthetic data, and also on 3D medical image volumes. We show that our new measure: (1) penalises errors successfully, especially those around region boundaries; (2) gives a low similarity score when existing measures disagree, thus avoiding overly inflated scores; and (3) scores segmentation results over a wider range of values. We consider a representative measure from this family and the effect of its only free parameter on error sensitivity, typical value range, and running time.

  2. Infants Segment Continuous Events Using Transitional Probabilities

    ERIC Educational Resources Information Center

    Stahl, Aimee E.; Romberg, Alexa R.; Roseberry, Sarah; Golinkoff, Roberta Michnick; Hirsh-Pasek, Kathryn

    2014-01-01

    Throughout their 1st year, infants adeptly detect statistical structure in their environment. However, little is known about whether statistical learning is a primary mechanism for event segmentation. This study directly tests whether statistical learning alone is sufficient to segment continuous events. Twenty-eight 7- to 9-month-old infants…

  3. 47 CFR 101.1505 - Segmentation plan.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 5 2011-10-01 2011-10-01 false Segmentation plan. 101.1505 Section 101.1505 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES FIXED MICROWAVE SERVICES Service and Technical Rules for the 70/80/90 GHz Bands § 101.1505 Segmentation plan. (a) An...

  4. Unsupervised Retinal Vessel Segmentation Using Combined Filters

    PubMed Central

    Oliveira, Wendeson S.; Teixeira, Joyce Vitor; Ren, Tsang Ing; Cavalcanti, George D. C.; Sijbers, Jan

    2016-01-01

    Image segmentation of retinal blood vessels is a process that can help to predict and diagnose cardiovascular related diseases, such as hypertension and diabetes, which are known to affect the retinal blood vessels’ appearance. This work proposes an unsupervised method for the segmentation of retinal vessels images using a combined matched filter, Frangi’s filter and Gabor Wavelet filter to enhance the images. The combination of these three filters in order to improve the segmentation is the main motivation of this work. We investigate two approaches to perform the filter combination: weighted mean and median ranking. Segmentation methods are tested after the vessel enhancement. Enhanced images with median ranking are segmented using a simple threshold criterion. Two segmentation procedures are applied when considering enhanced retinal images using the weighted mean approach. The first method is based on deformable models and the second uses fuzzy C-means for the image segmentation. The procedure is evaluated using two public image databases, Drive and Stare. The experimental results demonstrate that the proposed methods perform well for vessel segmentation in comparison with state-of-the-art methods. PMID:26919587

  5. Program Structure Combines Segmentation and Dynamic Storage

    NASA Technical Reports Server (NTRS)

    Tiffany, S. H.

    1982-01-01

    Programing techniques incorporate advantages of overlaying into segmented loads while retaining all dynamic load advantages of segmentation, employing those capabilities that best suit mode of operation, whether batch or interactive. User is allowed to load a program automatically in a variable manner, based solely on a single data input to the program, to maintain minimal field lengths for interactive use.

  6. 47 CFR 101.1505 - Segmentation plan.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Segmentation plan. 101.1505 Section 101.1505 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES FIXED MICROWAVE SERVICES Service and Technical Rules for the 70/80/90 GHz Bands § 101.1505 Segmentation plan. (a) An entity...

  7. Automatic evaluation of uterine cervix segmentations

    NASA Astrophysics Data System (ADS)

    Lotenberg, Shelly; Gordon, Shiri; Long, Rodney; Antani, Sameer; Jeronimo, Jose; Greenspan, Hayit

    2007-03-01

    In this work we focus on the generation of reliable ground truth data for a large medical repository of digital cervicographic images (cervigrams) collected by the National Cancer Institute (NCI). This work is part of an ongoing effort conducted by NCI together with the National Library of Medicine (NLM) at the National Institutes of Health (NIH) to develop a web-based database of the digitized cervix images in order to study the evolution of lesions related to cervical cancer. As part of this effort, NCI has gathered twenty experts to manually segment a set of 933 cervigrams into regions of medical and anatomical interest. This process yields a set of images with multi-expert segmentations. The objectives of the current work are: 1) generate multi-expert ground truth and assess the diffculty of segmenting an image, 2) analyze observer variability in the multi-expert data, and 3) utilize the multi-expert ground truth to evaluate automatic segmentation algorithms. The work is based on STAPLE (Simultaneous Truth and Performance Level Estimation), which is a well known method to generate ground truth segmentation maps from multiple experts' observations. We have analyzed both intra- and inter-expert variability within the segmentation data. We propose novel measures of "segmentation complexity" by which we can automatically identify cervigrams that were found difficult to segment by the experts, based on their inter-observer variability. Finally, the results are used to assess our own automated algorithm for cervix boundary detection.

  8. Benefit segmentation of the fitness market.

    PubMed

    Brown, J D

    1992-01-01

    While considerate attention is being paid to the fitness and wellness needs of people by healthcare and related marketing organizations, little research attention has been directed to identifying the market segments for fitness based upon consumers' perceived benefits of fitness. This article describes three distinct segments of fitness consumers comprising an estimated 50 percent of households. Implications for marketing strategies are also presented.

  9. Segmenting Michigan tourists based on distance traveled

    Treesearch

    Xiamei Xu; Tsao-Fang Yuan; Edwin Gomez; Joseph D. Fridgen

    1998-01-01

    The purpose of this study was to segment Michigan travelers into short, medium and long distance traveler groups by distance that they traveled from home to a primary destination in Michigan, and to compare travel behavior, trip characteristics and sociodemographics among these segments. Significant differences were identified in past trip experiences in Michigan,...

  10. Manifold Warp Segmentation of Human Action.

    PubMed

    Liu, Shenglan; Feng, Lin; Liu, Yang; Qiao, Hong; Wu, Jun; Wang, Wei

    2017-03-08

    Human action segmentation is important for human action analysis, which is a highly active research area. Most segmentation methods are based on clustering or numerical descriptors, which are only related to data, and consider no relationship between the data and physical characteristics of human actions. Physical characteristics of human motions are those that can be directly perceived by human beings, such as speed, acceleration, continuity, and so on, which are quite helpful in detecting human motion segment points. We propose a new physical-based descriptor of human action by curvature sequence warp space alignment (CSWSA) approach for sequence segmentation in this paper. Furthermore, time series-warp metric curvature segmentation method is constructed by the proposed descriptor and CSWSA. In our segmentation method, descriptor can express the changes of human actions, and CSWSA is an auxiliary method to give suggestions for segmentation. The experimental results show that our segmentation method is effective in both CMU human motion and video-based data sets.

  11. Segmental lichen planus pigmentosus: An unusual presentation.

    PubMed

    Kumar, Y Hari Kishan; Babu, Anagha Ramesh

    2014-04-01

    Lichen planus pigmentosus (LPP) is a distinct clinical entity commonly encountered in the Indian population. It is considered a variant of lichen planus (LP). A 40-year-old male presented with asymptomatic hyperpigmented macules in a segmental distribution since 10 years that were clinically and histopathologically suggestive of LPP. We propose the terminology "segmental lichen planus pigmentosus" and report this unusual presentation.

  12. Design of ground segments for small satellites

    NASA Technical Reports Server (NTRS)

    Mace, Guy

    1994-01-01

    New concepts must be implemented when designing a Ground Segment (GS) for small satellites to conform to their specific mission characteristics: low cost, one main instrument, spacecraft autonomy, optimized mission return, etc. This paper presents the key cost drivers of such ground segments, the main design features, and the comparison of various design options that can meet the user requirements.

  13. Effects of Syntactic Expectations on Speech Segmentation

    ERIC Educational Resources Information Center

    Mattys, Sven L.; Melhorn, James F.; White, Laurence

    2007-01-01

    Although the effect of acoustic cues on speech segmentation has been extensively investigated, the role of higher order information (e.g., syntax) has received less attention. Here, the authors examined whether syntactic expectations based on subject-verb agreement have an effect on segmentation and whether they do so despite conflicting acoustic…

  14. Effects of Syntactic Expectations on Speech Segmentation

    ERIC Educational Resources Information Center

    Mattys, Sven L.; Melhorn, James F.; White, Laurence

    2007-01-01

    Although the effect of acoustic cues on speech segmentation has been extensively investigated, the role of higher order information (e.g., syntax) has received less attention. Here, the authors examined whether syntactic expectations based on subject-verb agreement have an effect on segmentation and whether they do so despite conflicting acoustic…

  15. Segmenting the senior health care market.

    PubMed

    Pak, S; Pol, L G

    1996-01-01

    This paper addresses the issue of health market segment comparisons for the senior population. The analysis demonstrates how initial self-assessed health comparisons among three racial/ethnic categories can be adjusted to reflect compositional (age and income) differences among the three groups. The adjustments provide additional insight into the nature of these segments.

  16. 47 CFR 101.1505 - Segmentation plan.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 5 2012-10-01 2012-10-01 false Segmentation plan. 101.1505 Section 101.1505 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES FIXED MICROWAVE SERVICES Service and Technical Rules for the 70/80/90 GHz Bands § 101.1505 Segmentation plan. (a) An...

  17. 47 CFR 101.1505 - Segmentation plan.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 5 2013-10-01 2013-10-01 false Segmentation plan. 101.1505 Section 101.1505 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES FIXED MICROWAVE SERVICES Service and Technical Rules for the 70/80/90 GHz Bands § 101.1505 Segmentation plan. (a) An...

  18. Spinal cord grey matter segmentation challenge.

    PubMed

    Prados, Ferran; Ashburner, John; Blaiotta, Claudia; Brosch, Tom; Carballido-Gamio, Julio; Cardoso, Manuel Jorge; Conrad, Benjamin N; Datta, Esha; Dávid, Gergely; Leener, Benjamin De; Dupont, Sara M; Freund, Patrick; Wheeler-Kingshott, Claudia A M Gandini; Grussu, Francesco; Henry, Roland; Landman, Bennett A; Ljungberg, Emil; Lyttle, Bailey; Ourselin, Sebastien; Papinutto, Nico; Saporito, Salvatore; Schlaeger, Regina; Smith, Seth A; Summers, Paul; Tam, Roger; Yiannakas, Marios C; Zhu, Alyssa; Cohen-Adad, Julien

    2017-03-07

    An important image processing step in spinal cord magnetic resonance imaging is the ability to reliably and accurately segment grey and white matter for tissue specific analysis. There are several semi- or fully-automated segmentation methods for cervical cord cross-sectional area measurement with an excellent performance close or equal to the manual segmentation. However, grey matter segmentation is still challenging due to small cross-sectional size and shape, and active research is being conducted by several groups around the world in this field. Therefore a grey matter spinal cord segmentation challenge was organised to test different capabilities of various methods using the same multi-centre and multi-vendor dataset acquired with distinct 3D gradient-echo sequences. This challenge aimed to characterize the state-of-the-art in the field as well as identifying new opportunities for future improvements. Six different spinal cord grey matter segmentation methods developed independently by various research groups across the world and their performance were compared to manual segmentation outcomes, the present gold-standard. All algorithms provided good overall results for detecting the grey matter butterfly, albeit with variable performance in certain quality-of-segmentation metrics. The data have been made publicly available and the challenge web site remains open to new submissions. No modifications were introduced to any of the presented methods as a result of this challenge for the purposes of this publication.

  19. Algorithmic evaluation of lower jawbone segmentations

    NASA Astrophysics Data System (ADS)

    Egger, Jan; Hochegger, Kerstin; Gall, Markus; Chen, Xiaojun; Reinbacher, Knut; Schwenzer-Zimmerer, Katja; Schmalstieg, Dieter; Wallner, Jürgen

    2017-03-01

    The lower jawbone (or mandible), is due to its exposure to complex biomechanical forces the largest and strongest facial bone in humans. In this publication, an algorithmic evaluation of lower jawbone segmentation with a cellular automata algorithm called GrowCut is presented. For an evaluation, the algorithmic segmentation results were compared with slice-by-slice segmentations from two specialized physicians, which is considered to assess the given ground truth. As a result, pure manual slice-by-slice outlining took on average 39 minutes (minimum 35 minutes and maximum 46 minutes). This stands in strong contrast to an algorithmic segmentation which needed only about one minute for an initialization, hence needing just a fraction of the manual contouring time. At the same time, the algorithmic segmentations could achieve an acceptable Dice Similarity Score (DSC) of nearly ninety percent when compared to the ground truth slice-by-slice segmentations generated by the physicians. This stands in direct comparison to somewhat above ninety percent Dice Score between the two manual segmentations of the jawbones. In summary, this contribution shows that an algorithmic GrowCut segmentation can be an alternative to the very time consuming manual slice-by-slice outlining in the clinical practice.

  20. 47 CFR 101.1505 - Segmentation plan.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 5 2014-10-01 2014-10-01 false Segmentation plan. 101.1505 Section 101.1505 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES FIXED MICROWAVE SERVICES Service and Technical Rules for the 70/80/90 GHz Bands § 101.1505 Segmentation plan. (a) An...

  1. Contour-Driven Atlas-Based Segmentation

    PubMed Central

    Wachinger, Christian; Fritscher, Karl; Sharp, Greg; Golland, Polina

    2016-01-01

    We propose new methods for automatic segmentation of images based on an atlas of manually labeled scans and contours in the image. First, we introduce a Bayesian framework for creating initial label maps from manually annotated training images. Within this framework, we model various registration- and patch-based segmentation techniques by changing the deformation field prior. Second, we perform contour-driven regression on the created label maps to refine the segmentation. Image contours and image parcellations give rise to non-stationary kernel functions that model the relationship between image locations. Setting the kernel to the covariance function in a Gaussian process establishes a distribution over label maps supported by image structures. Maximum a posteriori estimation of the distribution over label maps conditioned on the outcome of the atlas-based segmentation yields the refined segmentation. We evaluate the segmentation in two clinical applications: the segmentation of parotid glands in head and neck CT scans and the segmentation of the left atrium in cardiac MR angiography images. PMID:26068202

  2. Infants Segment Continuous Events Using Transitional Probabilities

    ERIC Educational Resources Information Center

    Stahl, Aimee E.; Romberg, Alexa R.; Roseberry, Sarah; Golinkoff, Roberta Michnick; Hirsh-Pasek, Kathryn

    2014-01-01

    Throughout their 1st year, infants adeptly detect statistical structure in their environment. However, little is known about whether statistical learning is a primary mechanism for event segmentation. This study directly tests whether statistical learning alone is sufficient to segment continuous events. Twenty-eight 7- to 9-month-old infants…

  3. Feature-driven model-based segmentation

    NASA Astrophysics Data System (ADS)

    Qazi, Arish A.; Kim, John; Jaffray, David A.; Pekar, Vladimir

    2011-03-01

    The accurate delineation of anatomical structures is required in many medical image analysis applications. One example is radiation therapy planning (RTP), where traditional manual delineation is tedious, labor intensive, and can require hours of clinician's valuable time. Majority of automated segmentation methods in RTP belong to either model-based or atlas-based approaches. One substantial limitation of model-based segmentation is that its accuracy may be restricted by the uncertainties in image content, specifically when segmenting low-contrast anatomical structures, e.g. soft tissue organs in computed tomography images. In this paper, we introduce a non-parametric feature enhancement filter which replaces raw intensity image data by a high level probabilistic map which guides the deformable model to reliably segment low-contrast regions. The method is evaluated by segmenting the submandibular and parotid glands in the head and neck region and comparing the results to manual segmentations in terms of the volume overlap. Quantitative results show that we are in overall good agreement with expert segmentations, achieving volume overlap of up to 80%. Qualitatively, we demonstrate that we are able to segment low-contrast regions, which otherwise are difficult to delineate with deformable models relying on distinct object boundaries from the original image data.

  4. Labor Market Segmentation and Librarian Salaries.

    ERIC Educational Resources Information Center

    Van House, Nancy A.

    1987-01-01

    Segmented labor market theory is used to explain how the structure of the library labor market may determine salary differences by type of library. Evidence that segmentation exists at intraoccupational levels and the possibility that comparing entire occupations may obscure results are also reported. (Author/CLB)

  5. Webpage Segments Classification with Incremental Knowledge Acquisition

    NASA Astrophysics Data System (ADS)

    Guo, Wei; Kim, Yang Sok; Kang, Byeong Ho

    This paper suggests an incremental information extraction method for social network analysis of web publications. For this purpose, we employed an incremental knowledge acquisition method, called MCRDR (Multiple Classification Ripple-Down Rules), to classify web page segments. Our experimental results show that our MCRDR-based web page segments classification system successfully supports easy acquisition and maintenance of information extraction rules.

  6. ESL batteries and multi-segment applications

    NASA Astrophysics Data System (ADS)

    Hay, J. L.; Pearce, J. G.; Turnbull, L.; Owen, J. R.

    1987-06-01

    A simulation model for nickel cadmium battery cells operating in the environment of a low Earth orbit satellite; simulation applications to investigate the performance of the ESA Simulation Language (ESL) segment or multiprocessor emulation features; a double-precision version of ESL; and development of ESL in equation sorting, segmentation, character handling, and file input/output are described.

  7. Unsupervised Retinal Vessel Segmentation Using Combined Filters.

    PubMed

    Oliveira, Wendeson S; Teixeira, Joyce Vitor; Ren, Tsang Ing; Cavalcanti, George D C; Sijbers, Jan

    2016-01-01

    Image segmentation of retinal blood vessels is a process that can help to predict and diagnose cardiovascular related diseases, such as hypertension and diabetes, which are known to affect the retinal blood vessels' appearance. This work proposes an unsupervised method for the segmentation of retinal vessels images using a combined matched filter, Frangi's filter and Gabor Wavelet filter to enhance the images. The combination of these three filters in order to improve the segmentation is the main motivation of this work. We investigate two approaches to perform the filter combination: weighted mean and median ranking. Segmentation methods are tested after the vessel enhancement. Enhanced images with median ranking are segmented using a simple threshold criterion. Two segmentation procedures are applied when considering enhanced retinal images using the weighted mean approach. The first method is based on deformable models and the second uses fuzzy C-means for the image segmentation. The procedure is evaluated using two public image databases, Drive and Stare. The experimental results demonstrate that the proposed methods perform well for vessel segmentation in comparison with state-of-the-art methods.

  8. Protein-segment universe exhibiting transitions at intermediate segment length in conformational subspaces.

    PubMed

    Ikeda, Kazuyoshi; Hirokawa, Takatsugu; Higo, Junichi; Tomii, Kentaro

    2008-08-13

    Many studies have examined rules governing two aspects of protein structures: short segments and proteins' structural domains. Nevertheless, the organization and nature of the conformational space of segments with intermediate length between short segments and domains remain unclear. Conformational spaces of intermediate length segments probably differ from those of short segments. We investigated the identification and characterization of the boundary(s) between peptide-like (short segment) and protein-like (long segment) distributions. We generated ensembles embedded in globular proteins comprising segments 10-50 residues long. We explored the relationships between the conformational distribution of segments and their lengths, and also protein structural classes using principal component analysis based on the intra-segment Calpha-Calpha atomic distances. Our statistical analyses of segment conformations and length revealed critical dual transitions in their conformational distribution with segments derived from all four structural classes. Dual transitions were identified with the intermediate phase between the short segments and domains. Consequently, protein segment universes were categorized. i) Short segments (10-22 residues) showed a distribution with a high frequency of secondary structure clusters. ii) Medium segments (23-26 residues) showed a distribution corresponding to an intermediate state of transitions. iii) Long segments (27-50 residues) showed a distribution converging on one huge cluster containing compact conformations with a smaller radius of gyration. This distribution reflects the protein structures' organization and protein domains' origin. Three major conformational components (radius of gyration, structural symmetry with respect to the N-terminal and C-terminal halves, and single-turn/two-turn structure) well define most of the segment universes. Furthermore, we identified several conformational components that were unique to each

  9. Protein-segment universe exhibiting transitions at intermediate segment length in conformational subspaces

    PubMed Central

    Ikeda, Kazuyoshi; Hirokawa, Takatsugu; Higo, Junichi; Tomii, Kentaro

    2008-01-01

    Background Many studies have examined rules governing two aspects of protein structures: short segments and proteins' structural domains. Nevertheless, the organization and nature of the conformational space of segments with intermediate length between short segments and domains remain unclear. Conformational spaces of intermediate length segments probably differ from those of short segments. We investigated the identification and characterization of the boundary(s) between peptide-like (short segment) and protein-like (long segment) distributions. We generated ensembles embedded in globular proteins comprising segments 10–50 residues long. We explored the relationships between the conformational distribution of segments and their lengths, and also protein structural classes using principal component analysis based on the intra-segment Cα-Cα atomic distances. Results Our statistical analyses of segment conformations and length revealed critical dual transitions in their conformational distribution with segments derived from all four structural classes. Dual transitions were identified with the intermediate phase between the short segments and domains. Consequently, protein segment universes were categorized. i) Short segments (10–22 residues) showed a distribution with a high frequency of secondary structure clusters. ii) Medium segments (23–26 residues) showed a distribution corresponding to an intermediate state of transitions. iii) Long segments (27–50 residues) showed a distribution converging on one huge cluster containing compact conformations with a smaller radius of gyration. This distribution reflects the protein structures' organization and protein domains' origin. Three major conformational components (radius of gyration, structural symmetry with respect to the N-terminal and C-terminal halves, and single-turn/two-turn structure) well define most of the segment universes. Furthermore, we identified several conformational components that were

  10. Gene expression suggests double-segmental and single-segmental patterning mechanisms during posterior segment addition in the beetle Tribolium castaneum.

    PubMed

    Janssen, Ralf

    2014-01-01

    In the model arthropod Drosophila, all segments are patterned simultaneously in the blastoderm. In most other arthropods, however, posterior segments are added sequentially from a posterior segment addition zone. Posterior addition of single segments likely represents the ancestral mode of arthropod segmentation, although in Drosophila, segments are patterned in pairs by the pair-rule genes. It has been shown that in the new model insect, the beetle Tribolium, a segmentation clock operates that apparently patterns all segments in pairs as well. Here, I report on the expression of the segment polarity gene H15/midline in Tribolium. In the anterior embryo, segmental stripes of H15 appear in pairs, but in the posterior of the embryo stripes appear in a single-segmental periodicity. This implies that either two completely different segmentation-mechanisms may act in the germ band of Tribolium, that the segmentation clock changes its periodicity during development, or that the speed in which posterior segments are patterned changes. In any case, the data suggest the presence of another (or modified), yet undiscovered, mechanism of posterior segment addition in one of the best-understood arthropod models. The finding of a hitherto unrecognized segmentation mechanism in Tribolium may have major implications for the understanding of the origin of segmentation mechanisms, including the origin of pair rule patterning. It also calls for (re)-investigation of posterior segment addition in Tribolium and other previously studied arthropod models.

  11. Repair of Electronics for Long Duration Spaceflight

    NASA Technical Reports Server (NTRS)

    Pettegrew, Richard D.; Easton, John; Struk, Peter

    2007-01-01

    To reduce mission risk, long duration spaceflight and exploration activities will require greater degrees of self-sufficiency with regards to repair capability than have ever been employed before in space exploration. The current repair paradigm of replacing Orbital Replacement Units (ORUs) of malfunctioning avionics and electronic hardware will be impractical, since carrying all of the spares that could possibly be needed for a long duration mission would require upmass and volume at unprecedented and unacceptable levels. A strategy of component-level repair for electronics, however, could significantly reduce the mass and volume necessary for spares and enhance mission safety via a generic contingency capability. This approach is already used to varying degrees by the U.S. Navy, where vessels at sea experience some similar constraints such as the need for self sufficiency for moderately long time periods, and restrictions on volume of repair spares and infrastructure. The concept of conducting component-level repairs of electronics in spacecraft requires the development of design guidelines for future avionics (to enable repair), development of diagnostic techniques to allow an astronaut to pinpoint the faulty component aboard a vastly complex vehicle, and development of tools and methodologies for dealing with the physical processes of replacing the component. This physical process includes tasks such as conformal coating removal and replacement, component removal, replacement, and alignment--all in the difficulty of a reduced gravity environment. Further, the gravitational effects on the soldering process must be characterized and accounted for to ensure reliability of the newly repaired components. The Component-Level Electronics-Assembly Repair (CLEAR) project under the NASA Supportability program was established to develop and demonstrate the practicality of this repair approach. CLEAR involves collaborative efforts between NASA s Glenn Research Center

  12. Bench surgical training with lyophilized esophageal segments.

    PubMed

    Sotres-Vega, Avelina; Osorio-Necoechea, María Elba; Salas-Galindo, Gabriela; González-Ramón, Soemi Careli; Guadarrama-Sánchez, Isabel; Villalba-Caloca, Jaime; Santibáñez-Salgado, José Alfredo

    2013-08-01

    To present lyophilized esophageal segments that can be used to learn surgical skills. Four esophagus were harvested from four non-esophagus related research dogs at the moment of euthanasia. Each esophagus was trimmed in 3 cm long segments. They were lyophilized and stored during 30 days. The day programmed for surgical skills practice, they were rehydrated. Sixteen segments have been used. After rehydrating, all the segments kept their normal anatomic shape and structural integrity. One incision was made on every esophageal segment and sutured with running stitches of 3-0 polyglactin 910. There were no complications, such as tissue tears, nor esophageal hardening. The lyophilized esophagus is a high fidelity, practical, reproducible, portable, low-cost bench model. It allows general surgery apprentices to learn how to handle an esophagus, as well as to perfect their surgical and suture abilities before applying them on real patient's esophagus.

  13. Segmenting images analytically in shape space

    NASA Astrophysics Data System (ADS)

    Rathi, Yogesh; Dambreville, Samuel; Niethammer, Marc; Malcolm, James; Levitt, James; Shenton, Martha E.; Tannenbaum, Allen

    2008-03-01

    This paper presents a novel analytic technique to perform shape-driven segmentation. In our approach, shapes are represented using binary maps, and linear PCA is utilized to provide shape priors for segmentation. Intensity based probability distributions are then employed to convert a given test volume into a binary map representation, and a novel energy functional is proposed whose minimum can be analytically computed to obtain the desired segmentation in the shape space. We compare the proposed method with the log-likelihood based energy to elucidate some key differences. Our algorithm is applied to the segmentation of brain caudate nucleus and hippocampus from MRI data, which is of interest in the study of schizophrenia and Alzheimer's disease. Our validation (we compute the Hausdorff distance and the DICE coefficient between the automatic segmentation and ground-truth) shows that the proposed algorithm is very fast, requires no initialization and outperforms the log-likelihood based energy.

  14. Improving image segmentation by learning region affinities

    SciTech Connect

    Prasad, Lakshman; Yang, Xingwei; Latecki, Longin J

    2010-11-03

    We utilize the context information of other regions in hierarchical image segmentation to learn new regions affinities. It is well known that a single choice of quantization of an image space is highly unlikely to be a common optimal quantization level for all categories. Each level of quantization has its own benefits. Therefore, we utilize the hierarchical information among different quantizations as well as spatial proximity of their regions. The proposed affinity learning takes into account higher order relations among image regions, both local and long range relations, making it robust to instabilities and errors of the original, pairwise region affinities. Once the learnt affinities are obtained, we use a standard image segmentation algorithm to get the final segmentation. Moreover, the learnt affinities can be naturally unutilized in interactive segmentation. Experimental results on Berkeley Segmentation Dataset and MSRC Object Recognition Dataset are comparable and in some aspects better than the state-of-art methods.

  15. Monitoring fish distributions along electrofishing segments

    USGS Publications Warehouse

    Miranda, Leandro E.

    2014-01-01

    Electrofishing is widely used to monitor fish species composition and relative abundance in streams and lakes. According to standard protocols, multiple segments are selected in a body of water to monitor population relative abundance as the ratio of total catch to total sampling effort. The standard protocol provides an assessment of fish distribution at a macrohabitat scale among segments, but not within segments. An ancillary protocol was developed for assessing fish distribution at a finer scale within electrofishing segments. The ancillary protocol was used to estimate spacing, dispersion, and association of two species along shore segments in two local reservoirs. The added information provided by the ancillary protocol may be useful for assessing fish distribution relative to fish of the same species, to fish of different species, and to environmental or habitat characteristics.

  16. Contour detection and hierarchical image segmentation.

    PubMed

    Arbeláez, Pablo; Maire, Michael; Fowlkes, Charless; Malik, Jitendra

    2011-05-01

    This paper investigates two fundamental problems in computer vision: contour detection and image segmentation. We present state-of-the-art algorithms for both of these tasks. Our contour detector combines multiple local cues into a globalization framework based on spectral clustering. Our segmentation algorithm consists of generic machinery for transforming the output of any contour detector into a hierarchical region tree. In this manner, we reduce the problem of image segmentation to that of contour detection. Extensive experimental evaluation demonstrates that both our contour detection and segmentation methods significantly outperform competing algorithms. The automatically generated hierarchical segmentations can be interactively refined by user-specified annotations. Computation at multiple image resolutions provides a means of coupling our system to recognition applications.

  17. Wavefront Compensation Segmented Mirror Sensing and Control

    NASA Technical Reports Server (NTRS)

    Redding, David C.; Lou, John Z.; Kissil, Andrew; Bradford, Charles M.; Woody, David; Padin, Stephen

    2012-01-01

    The primary mirror of very large submillimeter-wave telescopes will necessarily be segmented into many separate mirror panels. These panels must be continuously co-phased to keep the telescope wavefront error less than a small fraction of a wavelength, to ten microns RMS (root mean square) or less. This performance must be maintained continuously across the full aperture of the telescope, in all pointing conditions, and in a variable thermal environment. A wavefront compensation segmented mirror sensing and control system, consisting of optical edge sensors, Wavefront Compensation Estimator/Controller Soft ware, and segment position actuators is proposed. Optical edge sensors are placed two per each segment-to-segment edge to continuously measure changes in segment state. Segment position actuators (three per segment) are used to move the panels. A computer control system uses the edge sensor measurements to estimate the state of all of the segments and to predict the wavefront error; segment actuator commands are computed that minimize the wavefront error. Translational or rotational motions of one segment relative to the other cause lateral displacement of the light beam, which is measured by the imaging sensor. For high accuracy, the collimator uses a shaped mask, such as one or more slits, so that the light beam forms a pattern on the sensor that permits sensing accuracy of better than 0.1 micron in two axes: in the z or local surface normal direction, and in the y direction parallel to the mirror surface and perpendicular to the beam direction. Using a co-aligned pair of sensors, with the location of the detector and collimated light source interchanged, four degrees of freedom can be sensed: transverse x and y displacements, as well as two bending angles (pitch and yaw). In this approach, each optical edge sensor head has a collimator and an imager, placing one sensor head on each side of a segment gap, with two parallel light beams crossing the gap. Two sets

  18. A hybrid technique for medical image segmentation.

    PubMed

    Nyma, Alamgir; Kang, Myeongsu; Kwon, Yung-Keun; Kim, Cheol-Hong; Kim, Jong-Myon

    2012-01-01

    Medical image segmentation is an essential and challenging aspect in computer-aided diagnosis and also in pattern recognition research. This paper proposes a hybrid method for magnetic resonance (MR) image segmentation. We first remove impulsive noise inherent in MR images by utilizing a vector median filter. Subsequently, Otsu thresholding is used as an initial coarse segmentation method that finds the homogeneous regions of the input image. Finally, an enhanced suppressed fuzzy c-means is used to partition brain MR images into multiple segments, which employs an optimal suppression factor for the perfect clustering in the given data set. To evaluate the robustness of the proposed approach in noisy environment, we add different types of noise and different amount of noise to T1-weighted brain MR images. Experimental results show that the proposed algorithm outperforms other FCM based algorithms in terms of segmentation accuracy for both noise-free and noise-inserted MR images.

  19. Monitoring fish distributions along electrofishing segments.

    PubMed

    Miranda, L E

    2014-12-01

    Electrofishing is widely used to monitor fish species composition and relative abundance in streams and lakes. According to standard protocols, multiple segments are selected in a body of water to monitor population relative abundance as the ratio of total catch to total sampling effort. The standard protocol provides an assessment of fish distribution at a macrohabitat scale among segments, but not within segments. An ancillary protocol was developed for assessing fish distribution at a finer scale within electrofishing segments. The ancillary protocol was used to estimate spacing, dispersion, and association of two species along shore segments in two local reservoirs. The added information provided by the ancillary protocol may be useful for assessing fish distribution relative to fish of the same species, to fish of different species, and to environmental or habitat characteristics.

  20. An unsupervised strategy for biomedical image segmentation.

    PubMed

    Rodríguez, Roberto; Hernández, Rubén

    2010-01-01

    Many segmentation techniques have been published, and some of them have been widely used in different application problems. Most of these segmentation techniques have been motivated by specific application purposes. Unsupervised methods, which do not assume any prior scene knowledge can be learned to help the segmentation process, and are obviously more challenging than the supervised ones. In this paper, we present an unsupervised strategy for biomedical image segmentation using an algorithm based on recursively applying mean shift filtering, where entropy is used as a stopping criterion. This strategy is proven with many real images, and a comparison is carried out with manual segmentation. With the proposed strategy, errors less than 20% for false positives and 0% for false negatives are obtained.

  1. An unsupervised strategy for biomedical image segmentation

    PubMed Central

    Rodríguez, Roberto; Hernández, Rubén

    2010-01-01

    Many segmentation techniques have been published, and some of them have been widely used in different application problems. Most of these segmentation techniques have been motivated by specific application purposes. Unsupervised methods, which do not assume any prior scene knowledge can be learned to help the segmentation process, and are obviously more challenging than the supervised ones. In this paper, we present an unsupervised strategy for biomedical image segmentation using an algorithm based on recursively applying mean shift filtering, where entropy is used as a stopping criterion. This strategy is proven with many real images, and a comparison is carried out with manual segmentation. With the proposed strategy, errors less than 20% for false positives and 0% for false negatives are obtained. PMID:21918628

  2. Temporally consistent segmentation of point clouds

    NASA Astrophysics Data System (ADS)

    Owens, Jason L.; Osteen, Philip R.; Daniilidis, Kostas

    2014-06-01

    We consider the problem of generating temporally consistent point cloud segmentations from streaming RGB-D data, where every incoming frame extends existing labels to new points or contributes new labels while maintaining the labels for pre-existing segments. Our approach generates an over-segmentation based on voxel cloud connectivity, where a modified k-means algorithm selects supervoxel seeds and associates similar neighboring voxels to form segments. Given the data stream from a potentially mobile sensor, we solve for the camera transformation between consecutive frames using a joint optimization over point correspondences and image appearance. The aligned point cloud may then be integrated into a consistent model coordinate frame. Previously labeled points are used to mask incoming points from the new frame, while new and previous boundary points extend the existing segmentation. We evaluate the algorithm on newly-generated RGB-D datasets.

  3. Active segmentation of 3D axonal images.

    PubMed

    Muralidhar, Gautam S; Gopinath, Ajay; Bovik, Alan C; Ben-Yakar, Adela

    2012-01-01

    We present an active contour framework for segmenting neuronal axons on 3D confocal microscopy data. Our work is motivated by the need to conduct high throughput experiments involving microfluidic devices and femtosecond lasers to study the genetic mechanisms behind nerve regeneration and repair. While most of the applications for active contours have focused on segmenting closed regions in 2D medical and natural images, there haven't been many applications that have focused on segmenting open-ended curvilinear structures in 2D or higher dimensions. The active contour framework we present here ties together a well known 2D active contour model [5] along with the physics of projection imaging geometry to yield a segmented axon in 3D. Qualitative results illustrate the promise of our approach for segmenting neruonal axons on 3D confocal microscopy data.

  4. Aging and the segmentation of narrative film.

    PubMed

    Kurby, Christopher A; Asiala, Lillian K E; Mills, Steven R

    2014-01-01

    The perception of event structure in continuous activity is important for everyday comprehension. Although the segmentation of experience into events is a normal concomitant of perceptual processing, previous research has shown age differences in the ability to perceive structure in naturalistic activity, such as a movie of someone washing a car. However, past research has also shown that older adults have a preserved ability to comprehend events in narrative text, which suggests that narrative may improve the event processing of older adults. This study tested whether there are age differences in event segmentation at the intersection of continuous activity and narrative: narrative film. Younger and older adults watched and segmented a narrative film, The Red Balloon, into coarse and fine events. Changes in situational features, such as changes in characters, goals, and objects predicted segmentation. Analyses revealed little age-difference in segmentation behavior. This suggests the possibility that narrative structure supports event understanding for older adults.

  5. The influence of different segments of the ongoing envelope on sensitivity to interaural time delays.

    PubMed

    Klein-Hennig, Martin; Dietz, Mathias; Hohmann, Volker; Ewert, Stephan D

    2011-06-01

    The auditory system is sensitive to interaural timing disparities in the fine structure and the envelope of sounds, each contributing important cues for lateralization. In this study, psychophysical measurements were conducted with customized envelope waveforms in order to investigate the isolated effect of different segments of a periodic, ongoing envelope on lateralization. One envelope cycle was composed of the four segments attack flank, hold duration, decay flank, and pause duration, which were independently varied to customize the envelope waveform. The envelope waveforms were applied to a 4-kHz sinusoidal carrier, and just noticeable envelope interaural time differences were measured in six normal hearing subjects. The results indicate that attack durations and pause durations prior to the attack are the most important stimulus characteristics for processing envelope timing disparities. The results were compared to predictions of three binaural lateralization models based on the normalized cross correlation coefficient. Two of the models included an additional stage to mimic neural adaptation prior to binaural interaction, involving either a single short time constant (5 ms) or a combination of five time constants up to 500 ms. It was shown that the model with the single short time constant accounted best for the data.

  6. Segmental colitis associated diverticulosis syndrome

    PubMed Central

    Freeman, Hugh J

    2016-01-01

    Segmental colitis associated diverticulosis (SCAD) has become increasingly appreciated as a form of inflammatory disease of the colon. Several features suggest that SCAD is a distinct disorder. SCAD tends to develop almost exclusively in older adults, predominately, but not exclusively, males. The inflammatory process occurs mainly in the sigmoid colon, and usually remains localized to this region of the colon alone. SCAD most often presents with rectal bleeding and subsequent endoscopic visualization reveals a well localized process with non-specific histopathologic inflammatory changes. Granulomas are not seen, and if present, may be helpful in definition of other disorders such as Crohn’s disease of the colon, an entity often confused with SCAD. Bacteriologic and parasitic studies for an infectious agent are negative. Normal rectal mucosa (i.e., “rectal sparing”) is present and can be confirmed with normal rectal biopsies. SCAD often resolves spontaneously without treatment, or completely after a limited course of therapy with only a 5-aminosalicylate. Recurrent episodes may occur, but most often, patients with this disorder have an entirely self-limited clinical course. Occasionally, treatment with other agents, including corticosteroids, or surgical resection has been required. PMID:27688648

  7. Risk Assessment Update: Russian Segment

    NASA Technical Reports Server (NTRS)

    Christiansen, Eric; Lear, Dana; Hyde, James; Bjorkman, Michael; Hoffman, Kevin

    2012-01-01

    BUMPER-II version 1.95j source code was provided to RSC-E- and Khrunichev at January 2012 MMOD TIM in Moscow. MEMCxP and ORDEM 3.0 environments implemented as external data files. NASA provided a sample ORDEM 3.0 g."key" & "daf" environment file set for demonstration and benchmarking BUMPER -II v1.95j installation at the Jan-12 TIM. ORDEM 3.0 has been completed and is currently in beta testing. NASA will provide a preliminary set of ORDEM 3.0 ".key" & ".daf" environment files for the years 2012 through 2028. Bumper output files produced using the new ORDEM 3.0 data files are intended for internal use only, not for requirements verification. Output files will contain these words ORDEM FILE DESCRIPTION = PRELIMINARY VERSION: not for production. The projectile density term in many BUMPER-II ballistic limit equations will need to be updated. Cube demo scripts and output files delivered at the Jan-12 TIM have been updated for the new ORDEM 3.0 data files. Risk assessment results based on ORDEM 3.0 and MEM will be presented for the Russian Segment (RS) of ISS.

  8. Contour Completion without Region Segmentation.

    PubMed

    Ming, Yansheng; Li, Hongdong; He, Xuming

    2016-05-06

    Contour completion plays an important role in visual perception, where the goal is to group fragmented low-level edge elements into perceptually coherent and salient contours. Most existing methods for contour completion have focused on pixelwise detection accuracy. In contrast, fewer methods have addressed the global contour closure effect, despite of psychological evidences for its importance. This paper proposes a purely contour-based higher-order CRF model to achieve contour closure, through local connectedness approximation. This leads to a simplified problem structure, where our higher-order inference problem can be transformed into an integer linear program (ILP) and be solved efficiently. Compared with methods based on the same bottom-up edge detector, our method achieves a superior contour grouping ability (measured by Rand index), a comparable precision-recall performance, and more visually pleasing results. Our results suggest that contour closure can be effectively achieved in contour domain, in contrast to a popular view that segmentation is essential for this purpose.

  9. Bootstrapping white matter segmentation, Eve++

    NASA Astrophysics Data System (ADS)

    Plassard, Andrew; Hinton, Kendra E.; Venkatraman, Vijay; Gonzalez, Christopher; Resnick, Susan M.; Landman, Bennett A.

    2015-03-01

    Multi-atlas labeling has come in wide spread use for whole brain labeling on magnetic resonance imaging. Recent challenges have shown that leading techniques are near (or at) human expert reproducibility for cortical gray matter labels. However, these approaches tend to treat white matter as essentially homogeneous (as white matter exhibits isointense signal on structural MRI). The state-of-the-art for white matter atlas is the single-subject Johns Hopkins Eve atlas. Numerous approaches have attempted to use tractography and/or orientation information to identify homologous white matter structures across subjects. Despite success with large tracts, these approaches have been plagued by difficulties in with subtle differences in course, low signal to noise, and complex structural relationships for smaller tracts. Here, we investigate use of atlas-based labeling to propagate the Eve atlas to unlabeled datasets. We evaluate single atlas labeling and multi-atlas labeling using synthetic atlases derived from the single manually labeled atlas. On 5 representative tracts for 10 subjects, we demonstrate that (1) single atlas labeling generally provides segmentations within 2mm mean surface distance, (2) morphologically constraining DTI labels within structural MRI white matter reduces variability, and (3) multi-atlas labeling did not improve accuracy. These efforts present a preliminary indication that single atlas labels with correction is reasonable, but caution should be applied. To purse multi-atlas labeling and more fully characterize overall performance, more labeled datasets would be necessary.

  10. Membrane Shell Reflector Segment Antenna

    NASA Technical Reports Server (NTRS)

    Fang, Houfei; Im, Eastwood; Lin, John; Moore, James

    2012-01-01

    The mesh reflector is the only type of large, in-space deployable antenna that has successfully flown in space. However, state-of-the-art large deployable mesh antenna systems are RF-frequency-limited by both global shape accuracy and local surface quality. The limitations of mesh reflectors stem from two factors. First, at higher frequencies, the porosity and surface roughness of the mesh results in loss and scattering of the signal. Second, the mesh material does not have any bending stiffness and thus cannot be formed into true parabolic (or other desired) shapes. To advance the deployable reflector technology at high RF frequencies from the current state-of-the-art, significant improvements need to be made in three major aspects: a high-stability and highprecision deployable truss; a continuously curved RF reflecting surface (the function of the surface as well as its first derivative are both continuous); and the RF reflecting surface should be made of a continuous material. To meet these three requirements, the Membrane Shell Reflector Segment (MSRS) antenna was developed.

  11. Segmentation given partial grouping constraints.

    PubMed

    Yu, Stella X; Shi, Jianbo

    2004-02-01

    We consider data clustering problems where partial grouping is known a priori. We formulate such biased grouping problems as a constrained optimization problem, where structural properties of the data define the goodness of a grouping and partial grouping cues define the feasibility of a grouping. We enforce grouping smoothness and fairness on labeled data points so that sparse partial grouping information can be effectively propagated to the unlabeled data. Considering the normalized cuts criterion in particular, our formulation leads to a constrained eigenvalue problem. By generalizing the Rayleigh-Ritz theorem to projected matrices, we find the global optimum in the relaxed continuous domain by eigendecomposition, from which a near-global optimum to the discrete labeling problem can be obtained effectively. We apply our method to real image segmentation problems, where partial grouping priors can often be derived based on a crude spatial attentional map that binds places with common salient features or focuses on expected object locations. We demonstrate not only that it is possible to integrate both image structures and priors in a single grouping process, but also that objects can be segregated from the background without specific object knowledge.

  12. Cruise control for segmented flow.

    PubMed

    Abolhasani, Milad; Singh, Mayank; Kumacheva, Eugenia; Günther, Axel

    2012-11-21

    Capitalizing on the benefits of microscale segmented flows, e.g., enhanced mixing and reduced sample dispersion, so far requires specialist training and accommodating a few experimental inconveniences. For instance, microscale gas-liquid flows in many current setups take at least 10 min to stabilize and iterative manual adjustments are needed to achieve or maintain desired mixing or residence times. Here, we report a cruise control strategy that overcomes these limitations and allows microscale gas-liquid (bubble) and liquid-liquid (droplet) flow conditions to be rapidly "adjusted" and maintained. Using this strategy we consistently establish bubble and droplet flows with dispersed phase (plug) velocities of 5-300 mm s(-1), plug lengths of 0.6-5 mm and continuous phase (slug) lengths of 0.5-3 mm. The mixing times (1-5 s), mass transfer times (33-250 ms) and residence times (3-300 s) can therefore be directly imposed by dynamically controlling the supply of the dispersed and the continuous liquids either from external pumps or from local pressurized reservoirs. In the latter case, no chip-external pumps, liquid-perfused tubes or valves are necessary while unwanted dead volumes are significantly reduced.

  13. XMM Future Operational Ground Segment

    NASA Astrophysics Data System (ADS)

    Finn, T.; Kirsch, M.; Schmidt, F.; Pfeil, N.; Vasconcellos, A.; Martin, J.

    2014-07-01

    XMM-Newton has been operating for 14 years which have been characterised by an extraordinary scientific return leading to it being considered as one of the most important scientific missions operated by ESA. XMM-Newton has outlived its original operating lifetime and this has led to a new array of technical challenges which new software and operating strategies have greatly mitigated and have enabled XMM-Newton to continue to perform optimally. XMM-Newton relies on reaction wheels and thrusters to manoeuvre consuming on -board fuel and limiting XMM-Newtons operating life. As a result a new operating concept for the reaction wheels has been devised and reduces the fuel consumption by approximately 50% potentially allowing XMM-Newton to operate until 2028. This extension leads to a new set of challenges; firstly, a change in the orbital inclination causes XMM-Newtons ground station Kourou to develop a gap in coverage around perigee for a period of 5 years from mid-2014 and secondly, XMM-Newtons second prime ground station, Perth, is to be decommissioned at the end of 2015 due to regulation governing civil spectrum usage. This paper illustrates how these issues are resoled from a ground segment perspective and when implemented will ensure XMM-Newtons continuance into the next decade.

  14. Optical Ground Segment Performance Summary

    NASA Astrophysics Data System (ADS)

    Breidenthal, J.; Xie, H.; Clare, L.

    2016-05-01

    The performance of candidate optical communication systems for deep space that would use a single optical ground station in conjunction with various space terminals is reported here. We considered three potential diameters of ground receive terminals (4, 8, and 12 m) and three potential ground transmit powers (1, 5, and 10 kW). Combinations of ground receive terminals, ground transmit terminals, and spacecraft terminals were assessed for data rate and volume (both uplink and downlink), and for uplink irradiance needed to enable downlink pointing, in the context of a set of 12 design reference missions. Raw physical link performance was assessed assuming clear weather conditions with conservative desert daytime turbulence, using communication link parameters that were optimized according to previously reported methods using the Strategic Optical Link Tool (SOLT). Also, realistic bad weather conditions were considered, assuming a random process that could at any time make transitions between two states: a cloud-free state and a cloudy state that completely interrupts data transmission. We compared the link performance achievable under our assumptions to the anticipated requirements associated with the design reference missions to determine the degree of satisfaction possible with various optical segments. Nine potential operating concepts for an optical communication system were described, and two were evaluated in detail for the Mars 2022 mission opportunity: raw data delivery and automatic repeat request for complete data delivery.

  15. Vessel segmentation in screening mammograms

    NASA Astrophysics Data System (ADS)

    Mordang, J. J.; Karssemeijer, N.

    2015-03-01

    Blood vessels are a major cause of false positives in computer aided detection systems for the detection of breast cancer. Therefore, the purpose of this study is to construct a framework for the segmentation of blood vessels in screening mammograms. The proposed framework is based on supervised learning using a cascade classifier. This cascade classifier consists of several stages where in each stage a GentleBoost classifier is trained on Haar-like features. A total of 30 cases were included in this study. In each image, vessel pixels were annotated by selecting pixels on the centerline of the vessel, control samples were taken by annotating a region without any visible vascular structures. This resulted in a total of 31,000 pixels marked as vascular and over 4 million control pixels. After training, the classifier assigns a vesselness likelihood to the pixels. The proposed framework was compared to three other vessel enhancing methods, i) a vesselness filter, ii) a gaussian derivative filter, and iii) a tubeness filter. The methods were compared in terms of area under the receiver operating characteristics curves, the Az values. The Az value of the cascade approach is 0:85. This is superior to the vesselness, Gaussian, and tubeness methods, with Az values of 0:77, 0:81, and 0:78, respectively. From these results, it can be concluded that our proposed framework is a promising method for the detection of vessels in screening mammograms.

  16. CENTS: Cortical Enhanced Neonatal Tissue Segmentation

    PubMed Central

    Shi, Feng; Shen, Dinggang; Yap, Pew-Thian; Fan, Yong; Cheng, Jie-Zhi; An, Hongyu; Wald, Lawrence L.; Gerig, Guido; Gilmore, John H.; Lin, Weili

    2010-01-01

    The acquisition of high-quality magnetic resonance (MR) images of neonatal brains is largely hampered by their characteristically small head size and insufficient tissue contrast. As a result, subsequent image processing and analysis, especially brain tissue segmentation, are often affected. To overcome this problem, a dedicated phased array neonatal head coil is utilized to improve MR image quality by augmenting signal-to-noise ratio and spatial resolution without lengthening data acquisition time. In addition, a specialized hybrid atlas-based tissue segmentation algorithm is developed for the delineation of fine structures in the acquired neonatal brain MR images. The proposed tissue segmentation method first enhances the sheet-like cortical gray matter (GM) structures in the to-be-segmented neonatal image with a Hessian filter for generation of a cortical GM confidence map. A neonatal population atlas is then generated by averaging the presegmented images of a population, weighted by their cortical GM similarity with respect to the to-be-segmented image. Finally, the neonatal population atlas is combined with the GM confidence map, and the resulting enhanced tissue probability maps for each tissue form a hybrid atlas that is used for atlas-based segmentation. Various experiments are conducted to compare the segmentations of the proposed method with manual segmentation (on both images acquired with a dedicated phased array coil and a conventional volume coil), as well as with the segmentations of two population-atlas-based methods. Results show the proposed method is capable of segmenting the neonatal brain with the best accuracy, and also preserving the most structural details in the cortical regions. PMID:20690143

  17. Colour application on mammography image segmentation

    NASA Astrophysics Data System (ADS)

    Embong, R.; Aziz, N. M. Nik Ab.; Karim, A. H. Abd; Ibrahim, M. R.

    2017-09-01

    The segmentation process is one of the most important steps in image processing and computer vision since it is vital in the initial stage of image analysis. Segmentation of medical images involves complex structures and it requires precise segmentation result which is necessary for clinical diagnosis such as the detection of tumour, oedema, and necrotic tissues. Since mammography images are grayscale, researchers are looking at the effect of colour in the segmentation process of medical images. Colour is known to play a significant role in the perception of object boundaries in non-medical colour images. Processing colour images require handling more data, hence providing a richer description of objects in the scene. Colour images contain ten percent (10%) additional edge information as compared to their grayscale counterparts. Nevertheless, edge detection in colour image is more challenging than grayscale image as colour space is considered as a vector space. In this study, we implemented red, green, yellow, and blue colour maps to grayscale mammography images with the purpose of testing the effect of colours on the segmentation of abnormality regions in the mammography images. We applied the segmentation process using the Fuzzy C-means algorithm and evaluated the percentage of average relative error of area for each colour type. The results showed that all segmentation with the colour map can be done successfully even for blurred and noisy images. Also the size of the area of the abnormality region is reduced when compare to the segmentation area without the colour map. The green colour map segmentation produced the smallest percentage of average relative error (10.009%) while yellow colour map segmentation gave the largest percentage of relative error (11.367%).

  18. Iterative Vessel Segmentation of Fundus Images.

    PubMed

    Roychowdhury, Sohini; Koozekanani, Dara D; Parhi, Keshab K

    2015-07-01

    This paper presents a novel unsupervised iterative blood vessel segmentation algorithm using fundus images. First, a vessel enhanced image is generated by tophat reconstruction of the negative green plane image. An initial estimate of the segmented vasculature is extracted by global thresholding the vessel enhanced image. Next, new vessel pixels are identified iteratively by adaptive thresholding of the residual image generated by masking out the existing segmented vessel estimate from the vessel enhanced image. The new vessel pixels are, then, region grown into the existing vessel, thereby resulting in an iterative enhancement of the segmented vessel structure. As the iterations progress, the number of false edge pixels identified as new vessel pixels increases compared to the number of actual vessel pixels. A key contribution of this paper is a novel stopping criterion that terminates the iterative process leading to higher vessel segmentation accuracy. This iterative algorithm is robust to the rate of new vessel pixel addition since it achieves 93.2-95.35% vessel segmentation accuracy with 0.9577-0.9638 area under ROC curve (AUC) on abnormal retinal images from the STARE dataset. The proposed algorithm is computationally efficient and consistent in vessel segmentation performance for retinal images with variations due to pathology, uneven illumination, pigmentation, and fields of view since it achieves a vessel segmentation accuracy of about 95% in an average time of 2.45, 3.95, and 8 s on images from three public datasets DRIVE, STARE, and CHASE_DB1, respectively. Additionally, the proposed algorithm has more than 90% segmentation accuracy for segmenting peripapillary blood vessels in the images from the DRIVE and CHASE_DB1 datasets.

  19. Risk estimation in partial duration series

    NASA Astrophysics Data System (ADS)

    Rasmussen, Peter Funder; Rosbjerg, Dan

    1989-11-01

    The estimation of design floods is, in practice, often based on small samples of data, which may cause a severe uncertainty. For a particular version of the partial duration series (exponentially distributed exceedances and Poissonian occurrence times) the distribution of the T-year design estimate xˆT is derived along with the distribution of RT; defined as the true risk of exceeding xˆT within a given disposal period. For a fixed flood level the distributions of the return period estimator Tˆ and the estimator of the risk in lifetime Rˆ are also presented. Analytical closed-form expressions for mean value and standard deviation are derived for these variables, except for Tˆ, which does not possess moments. The concept of "expected risk" is introduced, and an analytical expression describing this property is derived. A risk-based design technique, which is essentially different from the traditional procedure, is presented, and its applicability is verified using Monte Carlo simulation.

  20. Immune changes during short-duration missions

    NASA Technical Reports Server (NTRS)

    Taylor, G. R.

    1993-01-01

    Spaceflight materially influences the immune mechanism of humans and animals. Effects resulting from missions of less than 1 month are examined. Effects from longer missions are discussed in the companion paper by Konstantinova et al. Most immunology studies have involved analyses of subjects and samples from subjects obtained after flight, with the data being compared with similar data obtained before flight. These studies have demonstrated that short-duration missions can result in a postflight depression in blast cell transformation, major changes in cytokine function, and alterations in the relative numbers of immune cell populations. In addition to these post- vs. preflight studies, some data have been produced in flight. However, these in vitro analyses have been less than satisfactory because of differences between in-flight and ground-control conditions. Recently, both the U.S. and Russian space programs have started collecting in-flight, in vivo, cell-mediated immunity data. These studies have confirmed that the human cell-mediated immune system is blunted during spaceflight.