scholarly journals AUTOMATED MOSAICKING OF GEOSTATIONARY OCEAN COLOR IMAGER BY COMBINATION OF SPATIAL AND FREQUENCY MATCHING

2018 ◽  
Vol XLII-2 ◽  
pp. 495-499
Author(s):  
H. G. Kim ◽  
J. H. Son ◽  
T. Kim
Keyword(s):  
Frequency Domain ◽  
Spatial Domain ◽  
Geometric Distortion ◽  
Future Research ◽  
Geometric Correction ◽  
Frequency Matching ◽  
Image Mosaicking ◽  
Important Processing ◽  
Sensor Modelling

In general, image mosaicking is a useful and important processing for handling images with narrow field of view. It is being used widely for images from commercial cameras as well as from aerial and satellite cameras. For mosaicking images with geometric distortion, geometric correction of each image should be performed before combining images. However, automated mosaicking images with geometric distortion is not a trivial task. The goal of this paper is the development of automated mosaicking techniques applicable to handle GOCI images. In this paper, we try to extract tie-points by using spatial domain and frequency domain matching and perform the mosaicking of GOCI. The method includes five steps. First, we classify GOCI image slots according to the existence of shorelines by spatial domain matching. Second, we perform precise geometric correction on the slots with shorelines. Third, we perform initial sensor modelling for the slots without shorelines and apply geometric correction based on the initial model. Fourth, the relative relationship between the slots without shorelines and the slots with shorelines is estimated through frequency domain matching. Lastly, mosaicking of geometrically corrected all 16 image slots is performed. The proposed method was verified by applying to real GOCI images. The proposed method was able to perform automated mosaicking even for images without shorelines, and its accuracy and processing time were satisfactory. For future research, we will improve frequency matching to generate multiple tie-points and to analyse the applicability of precise sensor modelling directly from frequency matching. It is expected that the proposed method can be applied to the follow-up sensor of the GOCI, GOCI-II, and other ocean satellite images.

scholarly journals Comparison of Various Frequency Matching Schemes for Geometric Correction of Geostationary Ocean Color Imager

Sensors ◽  
2019 ◽  
Vol 19 (24) ◽  
pp. 5564
Author(s):  
Jong-Hwan Son ◽  
Han-Gyeol Kim ◽  
Hee-Jeong Han ◽  
Taejung Kim
Keyword(s):  
Frequency Domain ◽  
Ocean Color ◽  
Phase Correlation ◽  
Range Limits ◽  
Geometric Correction ◽  
Matching Method ◽  
Search Range ◽  
Frequency Matching ◽  
Matching Technique ◽  
Matching Schemes

Current precise geometric correction of Geostationary Ocean Color Imager (GOCI) image slots is performed by shoreline matching. However, it is troublesome to handle slots with few or no shorelines, or slots covered by clouds. Geometric correction by frequency matching has been proposed to handle these slots. In this paper, we further extend previous research on frequency matching by comparing the performance of three frequency domain matching methods: phase correlation, gradient correlation, and orientation correlation. We compared the performance of each matching technique in terms of match success rate and geometric accuracy. We concluded that the three frequency domain matching method with peak search range limits was comparable to geometric correction performance with shoreline matching. The proposed method handles translation only, and assumes that rotation has been corrected. We need to do further work on how to handle rotation by frequency matching.

scholarly journals Geometric Correction for the Geostationary Ocean Color Imager from a Combination of Shoreline Matching and Frequency Matching

Sensors ◽  
2018 ◽  
Vol 18 (11) ◽  
pp. 3599 ◽  
Author(s):  
Han-Gyeol Kim ◽  
Jong-Hwan Son ◽  
Taejung Kim
Keyword(s):  
Ocean Color ◽  
Correction Method ◽  
Relative Orientation ◽  
Geometric Distortion ◽  
Geometric Correction ◽  
Frequency Matching ◽  
Sensor Model ◽  
Color Sensors ◽  
Similar Accuracy ◽  
Sensor Modeling

Geometric correction is fundamental in producing high quality satellite data products. However, the geometric correction for ocean color sensors, e.g., Geostationary Ocean Color Imager (GOCI), is challenging because the traditional method based on ground control points (GCPs) cannot be applied when the shoreline is absent. In this study, we develop a hybrid geometric correction method, which applies shoreline matching and frequency matching on slots with shorelines and without shorelines, respectively. Frequency matching has been proposed to estimate the relative orientation between GOCI slots without a shoreline. In this paper, we extend our earlier research for absolute orientation and geometric correction by combining frequency matching results with shoreline matching ones. The proposed method consists of four parts: Initial sensor modeling of slots without shorelines, precise sensor modeling through shoreline matching, relative orientation modeling by frequency matching, and generation of geometric correction results using a combination of the two matching procedures. Initial sensor modeling uses the sensor model equation for GOCI and metadata in order to remove geometric distortion due to the Earth’s rotation and curvature in the slots without shorelines. Precise sensor modeling is performed with shoreline matching and random sample consensus (RANSAC) in the slots with shorelines. Frequency matching computes position shifts for slots without shorelines with respect to the precisely corrected slots with shorelines. GOCI Level 1B scenes are generated by combining the results from shoreline matching and frequency matching. We analyzed the accuracy of shoreline matching alone against that of the combination of shoreline matching and frequency matching. Both methods yielded a similar accuracy of 1.2 km, which supports the idea that frequency matching can replace traditional shoreline matching for slots without visible shorelines.

A Pilot Study of Mobile Telephone Message Interventions with Suicide Attempters in China

Crisis ◽  
2010 ◽  
Vol 31 (2) ◽  
pp. 109-112 ◽  
Author(s):  
Hui Chen ◽  
Brian L. Mishara ◽  
Xiao Xian Liu
Keyword(s):  
Pilot Study ◽  
Effective Means ◽  
Text Message ◽  
Text Messages ◽  
Mobile Telephone ◽  
Future Research ◽  
Quick Method ◽  
Suicide Attempters ◽  
To Receive

Background: In China, where follow-up with hospitalized attempters is generally lacking, there is a great need for inexpensive and effective means of maintaining contact and decreasing recidivism. Aims: Our objective was to test whether mobile telephone message contacts after discharge would be feasible and acceptable to suicide attempters in China. Methods: Fifteen participants were recruited from suicide attempters seen in the Emergency Department in Wuhan, China, to participate in a pilot study to receive mobile telephone messages after discharge. All participants have access to a mobile telephone, and there is no charge for the user to receive text messages. Results: Most participants (12) considered the text message contacts an acceptable and useful form of help and would like to continue to receive them for a longer period of time. Conclusions: This suggests that, as a low-cost and quick method of intervention in areas where more intensive follow-up is not practical or available, telephone messages contacts are accessible, feasible, and acceptable to suicide attempters. We hope that this will inspire future research on regular and long-term message interventions to prevent recidivism in suicide attempters.

Post Discharge Clinically Overt Venous Thromboembolism in Orthopaedic Surgery Patients with Negative Venography -an Overview Analysis

1996 ◽  
Vol 76 (06) ◽  
pp. 0887-0892 ◽  
Author(s):  
Serena Ricotta ◽  
Alfonso lorio ◽  
Pasquale Parise ◽  
Giuseppe G Nenci ◽  
Giancarlo Agnelli
Keyword(s):  
Venous Thromboembolism ◽  
Orthopaedic Surgery ◽  
Diagnostic Methods ◽  
Future Research ◽  
Post Discharge ◽  
Pharmacological Prophylaxis ◽  
Vein Thrombosis ◽  
Overview Analysis ◽  
Major Orthopaedic Surgery

SummaryA high incidence of post-discharge venous thromboembolism in orthopaedic surgery patients has been recently reported drawing further attention to the unresolved issue of the optimal duration of the pharmacological prophylaxis. We performed an overview analysis in order to evaluate the incidence of late occurring clinically overt venous thromboembolism in major orthopaedic surgery patients discharged from the hospital with a negative venography and without further pharmacological prophylaxis. We selected the studies published from January 1974 to December 1995 on the prophylaxis of venous thromboembolism after major orthopaedic surgery fulfilling the following criteria: 1) adoption of pharmacological prophylaxis, 2) performing of a bilateral venography before discharge, 3) interruption of pharmacological prophylaxis at discharge in patients with negative venography, and 4) post-discharge follow-up of the patients for at least four weeks. Out of 31 identified studies, 13 fulfilled the overview criteria. The total number of evaluated patients was 4120. An adequate venography was obtained in 3469 patients (84.1%). In the 2361 patients with negative venography (68.1%), 30 episodes of symptomatic venous thromboembolism after hospital discharge were reported with a resulting cumulative incidence of 1.27% (95% C.I. 0.82-1.72) and a weighted mean incidence of 1.52% (95% C.I. 1.05-1.95). Six cases of pulmonary embolism were reported. Our overview showed a low incidence of clinically overt venous thromboembolism at follow-up in major orthopaedic surgery patients discharged with negative venography. Extending pharmacological prophylaxis in these patients does not appear to be justified. Venous thrombi leading to hospital re-admission are likely to be present but asymptomatic at the time of discharge. Future research should be directed toward improving the accuracy of non invasive diagnostic methods in order to replace venography in the screening of asymptomatic post-operative deep vein thrombosis.

Clinical Evaluation of the Variables associated with Treatment Acceptability and Their Relation to Compliance

1992 ◽  
Vol 18 (1) ◽  
pp. 67-76 ◽  
Author(s):  
Thomas M. Reimers ◽  
David P. Wacker ◽  
Linda J. Cooper ◽  
Agnes O. Deraad
Keyword(s):  
Behavior Problem ◽  
Behavior Management ◽  
Positive Reinforcement ◽  
Treatment Acceptability ◽  
Clinic Visit ◽  
Future Research ◽  
Parental Ratings ◽  
Problem Severity ◽  
The Relationship

The authors examined the acceptability ratings of positive reinforcement procedures recommended to parents seen in a pediatric behavior management outpatient clinic. Parental ratings of acceptability were obtained in the clinic and 1, 3, and 6 months following their initial clinic visit. Acceptability variables were examined by group (parents who rated the acceptability of treatments as high vs. low) and by severity (parents who rated their children's behavior problem as severe vs. mild). The relationship between these variables and reported compliance was also examined. Results show that the acceptability variables were useful in differentiating between parents who rated treatments to be more acceptable and parents who rated treatments to be less acceptable. Differences were also observed as a function of behavior problem severity. Significant correlations occurred between acceptability variables and compliance at each of the follow-up points. Results are discussed in relation to the clinical significance of these findings and the impetus they might serve for future research.

scholarly journals Cohort profile of Acutelines: a large data/biobank of acute and emergency medicine

BMJ Open ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. e047349
Author(s):  
Ewoud ter Avest ◽  
Barbara C van Munster ◽  
Raymond J van Wijk ◽  
Sanne Tent ◽  
Sanne Ter Horst ◽  
...  
Keyword(s):  
Acute Care ◽  
De Novo ◽  
Medical Center ◽  
Large Data ◽  
Future Research ◽  
Imaging Data ◽  
Novel Studies ◽  
Long Term Follow Up ◽  
Registration Number

PurposeResearch in acute care faces many challenges, including enrolment challenges, legal limitations in data sharing, limited funding and lack of singular ownership of the domain of acute care. To overcome these challenges, the Center of Acute Care of the University Medical Center Groningen in the Netherlands, has established a de novo data, image and biobank named ‘Acutelines’.ParticipantsClinical data, imaging data and biomaterials (ie, blood, urine, faeces, hair) are collected from patients presenting to the emergency department (ED) with a broad range of acute disease presentations. A deferred consent procedure (by proxy) is in place to allow collecting data and biomaterials prior to obtaining written consent. The digital infrastructure used ensures automated capturing of all bed-side monitoring data (ie, vital parameters, electrophysiological waveforms) and securely importing data from other sources, such as the electronic health records of the hospital, ambulance and general practitioner, municipal registration and pharmacy. Data are collected from all included participants during the first 72 hours of their hospitalisation, while follow-up data are collected at 3 months, 1 year, 2 years and 5 years after their ED visit.Findings to dateEnrolment of the first participant occurred on 1 September 2020. During the first month, 653 participants were screened for eligibility, of which 180 were approached as potential participants. In total, 151 (84%) provided consent for participation of which 89 participants fulfilled criteria for collection of biomaterials.Future plansThe main aim of Acutelines is to facilitate research in acute medicine by providing the framework for novel studies and issuing data, images and biomaterials for future research. The protocol will be extended by connecting with central registries to obtain long-term follow-up data, for which we already request permission from the participant.Trial registration numberNCT04615065.

scholarly journals A serial optical frequency-domain imaging study of early and late vascular responses to bioresorbable-polymer sirolimus-eluting stents for the treatment of acute myocardial infarction and stable coronary artery disease patients: results of the MECHANISM-ULTIMASTER study

2021 ◽  
Author(s):  
Tomonori Itoh ◽  
◽  
Hiromasa Otake ◽  
Takumi Kimura ◽  
Yoshiro Tsukiyama ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Coronary Artery Disease ◽  
Coronary Artery ◽  
Frequency Domain ◽  
Stable Coronary Artery Disease ◽  
Imaging Study ◽  
Optical Frequency ◽  
Bioresorbable Polymer ◽  
Artery Disease

AbstractThe purpose of this study was to assess early and late vascular healing in response to bioresorbable-polymer sirolimus-eluting stents (BP-SESs) for the treatment of patients with ST-elevation myocardial infarction (STEMI) and stable coronary artery disease (CAD). A total of 106 patients with STEMI and 101 patients with stable-CAD were enrolled. Optical frequency-domain images were acquired at baseline, at 1- or 3-month follow-up, and at 12-month follow-up. In the STEMI and CAD cohorts, the percentage of uncovered struts (%US) was significantly and remarkably decreased during early two points and at 12-month (the STEMI cohort: 1-month: 18.75 ± 0.78%, 3-month: 10.19 ± 0.77%, 12-month: 1.80 ± 0.72%; p < 0.001, the CAD cohort: 1-month: 9.44 ± 0.78%, 3-month: 7.78 ± 0.78%, 12-month: 1.07 ± 0.73%; p < 0.001 respectively). The average peri-strut low-intensity area (PLIA) score in the STEMI cohort was significantly decreased during follow-up period (1.90 ± 1.14, 1.18 ± 1.25, and 1.01 ± 0.72; p ≤ 0.001), whereas the one in the CAD cohort was not significantly changed (0.89 ± 1.24, 0.67 ± 1.07, and 0.64 ± 0.72; p = 0.59). In comparison with both groups, differences of %US and PLIA score at early two points were almost disappeared or close at 12 months. The strut-coverage and healing processes in the early phase after BP-SES implantation were significantly improved in both cohorts, especially markedly in STEMI patients. At 1 year, qualitatively and quantitatively consistent neointimal coverage was achieved in both pathogenetic groups.

scholarly journals Gait Speed as a Predictor for Diabetes Incidence in People with or at Risk of Knee Osteoarthritis: A Longitudinal Analysis from the Osteoarthritis Initiative

2021 ◽  
Vol 18 (9) ◽  
pp. 4414
Author(s):  
Aqeel M. Alenazi ◽  
Bader A. Alqahtani ◽  
Vishal Vennu ◽  
Mohammed M. Alshehri ◽  
Ahmad D. Alanazi ◽  
...  
Keyword(s):  
At Risk ◽  
Gait Speed ◽  
Area Under The Curve ◽  
Incident Diabetes ◽  
Future Research ◽  
Cutoff Score ◽  
Diabetes Incidence ◽  
Knee Oa ◽  
Osteoarthritis Initiative

Background: This study examined the association between baseline gait speed with incident diabetes mellitus (DM) among people with or at elevated risk for knee OA. Materials and Methods: Participants from the Osteoarthritis Initiative, aged 45 to 79 years, where included. Participants with or at risk of knee OA from baseline to the 96-month visit were included. Participants with self-reported DM at baseline were excluded. DM incidence was followed over the 4-time points. Gait speed was measured at baseline using a 20-m walk test. Generalized estimating equations with logistic regression were utilized for analyses. Receiver operator characteristic curves and area under the curve were used to determine the cutoff score for baseline speed. Results: Of the 4313 participants included in the analyses (58.7% females), 301 participants had a cumulative incidence of DM of 7.0% during follow-up. Decreased gait speed was a significant predictor of incident DM (RR 0.44, p = 0.018). The threshold for baseline gait speed that predicted incident DM was 1.32 m/s with an area under the curve of 0.59 (p < 0.001). Conclusions: Baseline gait speed could be an important screening tool for identifying people at risk of incident diabetes, and the determined cutoff value for gait speed should be examined in future research.

scholarly journals Prevalence of Missing Values and Protest Zeros in Contingent Valuation in Dental Medicine

2021 ◽  
Vol 18 (14) ◽  
pp. 7219
Author(s):  
Pedram Sendi ◽  
Arta Ramadani ◽  
Michael M. Bornstein
Keyword(s):  
Contingent Valuation ◽  
Missing Values ◽  
Web Of Science ◽  
Cochrane Library ◽  
Future Research ◽  
False Information ◽  
Complete Case ◽  
Zero Values ◽  
Elicitation Procedure

Background: The number of contingent valuation (CV) studies in dental medicine using willingness-to-pay (WTP) methodology has substantially increased in recent years. Missing values due to absent information (i.e., missingness) or false information (i.e., protest zeros) are a common problem in WTP studies. The objective of this study is to evaluate the prevalence of missing values in CV studies in dental medicine, to assess how these have been dealt with, and to suggest recommendations for future research. Methods: We systematically searched electronic databases (MEDLINE, Web of Science, Cochrane Library, PROSPERO) on 8 June 2021, and hand-searched references of selected reviews. CV studies in clinical dentistry using WTP for valuing a good or service were included. Results: We included 49 WTP studies in our review. Out of these, 19 (38.8%) reported missing values due to absent information, and 28 (57.1%) reported zero values (i.e., WTP valued at zero). Zero values were further classified into true zeros (i.e., representing the underlying preference of the respondent) or protest zeros (i.e., false information as a protest behavior) in only 9 studies. Most studies used a complete case analysis to address missingness while only one study used multiple imputation. Conclusions: There is uncertainty in the dental literature on how to address missing values and zero values in CV studies. Zero values need to be classified as true zeros versus protest zeros with follow-up questions after the WTP elicitation procedure, and then need to be handled differently. Advanced statistical methods are available to address both missing values due to missingness and due to protest zeros but these are currently underused in dental medicine. Failing to appropriately address missing values in CV studies may lead to biased WTP estimates of dental interventions.

The Mortality Experience of Individuals on the Salford Psychiatric Case Register

1996 ◽  
Vol 168 (6) ◽  
pp. 772-779 ◽  
Author(s):  
D. N. Baxter
Keyword(s):  
Future Research ◽  
Historical Cohort ◽  
Case Register ◽  
Service Effectiveness ◽  
Psychiatric Case Register ◽  
Cohort Design ◽  
Psychiatric Case ◽  
Control Programmes ◽  
Expected Mortality

BackgroundSeveral studies, mainly non-UK based, have reported higher than expected mortality for individuals with mental illness. This investigation in Salford (England) was undertaken to determine local experiences.MethodAn historical cohort design was employed with record linkage to determine status at study end: maximum follow-up was 18 years. All 6952 individuals with schizophrenia, neuroses, affective or personality disorders, enrolled on the psychiatric case register between 1 January 1968 and 31 December 1975 were recruited: there were 199 exclusions. Death was the study end-point.ResultsObserved mortality was 65% higher than expected and elevated throughout the whole of follow-up. Mortality was highest in younger ages, females and subjects born locally. Circulatory disorders, injury and poisoning each caused approximately one-third of the excess deaths.ConclusionsDocumenting mortality risk has important applications for prioritisation, resource allocation, developing control programmes, evaluating service effectiveness, disease forecasting and future research.

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