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Fast T_(1)mapping MRI in preclinical and clinical settings using subspace-constrained joint-domain reconstructions
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作者 Lingceng Ma Qingjia Bao +2 位作者 Ricardo P.Martinho Zhong Chen Lucio Frydman 《Magnetic Resonance Letters》 2024年第4期12-24,共13页
This work aims to develop fast T_(1)mapping methods for preclinical and clinical scanners based on subspace-constrained reconstructions.Two sequences are explored for rapid T_(1)characterizations:1)Interleaved spatiot... This work aims to develop fast T_(1)mapping methods for preclinical and clinical scanners based on subspace-constrained reconstructions.Two sequences are explored for rapid T_(1)characterizations:1)Interleaved spatiotemporal encoding incorporating variable repetition times.2)Inversion recovery gradient echo with random sampling of the phaseencoding(PE)dimension.For both sequences,the subspace reconstruction of the signal recovery was applied,to jointly reconstruct the down-sampled images while characterizing the T_(1)relaxation.In vivo scans on human brains and abdomens confirmed the efficiency of the proposed methods,including compatibility with breath-holding.In addition,Scans on animals with abdominal tumors and dynamic contrast-enhanced T_(1)mapping on kidneys support the applicability of the proposed methods also in preclinical settings. 展开更多
关键词 T_(1)mapping Subspace-constrained reconstructions IR GRE SPEN Dynamic contrast enhancement Pancreatic cancer
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The Quality of Life of Gastric Cancer Patients with and without Duodenal Passage Reconstructions after Total Gastrectomy 被引量:4
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作者 Dongsheng Li Huimian Xu 《Chinese Journal of Clinical Oncology》 CSCD 2005年第5期810-814,共5页
OBJECTIVE To evaluate the Quality of Life of the patients who received a total gastrectomy with different kinds of reconstruction methods. METHODS Patients who received a total gastrectomy between May 1999 to May 2003... OBJECTIVE To evaluate the Quality of Life of the patients who received a total gastrectomy with different kinds of reconstruction methods. METHODS Patients who received a total gastrectomy between May 1999 to May 2003 were followed-up via questionnaires. Fifty-nine who were alive more than 2 years with no sigh of recurrence were enrolled in this study. The patients were divided into 2 groups as follows: a group treated with reconstruction with a duodenal passage after total gastrectomy (gastric substitute, GS); and a group receiving reconstruction without duodenal passage after total gastrectomy (Jejenal pouch, JP). Follow-up feedback data of 14 items from the patients were analyzed, comparing the Quality of Life (QOL) between the 2 groups. RESULTS Six months after operation, the most common symptoms of all patients were reflux and loss of body weight, but there was no statistically significant differences in the 14 items related to the special post-operation symptoms between the 2 groups. At 12 months after the operations, there were significant differences between the 2 groups in body weight (P=0.01), eating time (P=0.034〈0.05), and frequency of food intake (P= 0.040〈0.05); At 24 months after the operations, the only difference between the 2 groups was body weight gain (P=0.025〈0.05). The JP group was better than the GS group. CONCLUSION The JP reconstruction pattern is superior to a simple GS in gain of body weight, volume of food intake and frequency of food intake, soon after the operation. 展开更多
关键词 quality of life reconstructions gastrectomy.
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VolGraph-A PC-Based Visualization System for Three-Dimensional Medical Reconstructions
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作者 张加万 孙志刚 孙济洲 《Transactions of Tianjin University》 EI CAS 2003年第3期206-210,共5页
Three-dimensional reconstructions from tomography slices are paid great attention in medical applications nowadays. This paper introduces the design and the implement of VolGraph system: a new, inexpensive, PC-based v... Three-dimensional reconstructions from tomography slices are paid great attention in medical applications nowadays. This paper introduces the design and the implement of VolGraph system: a new, inexpensive, PC-based visualization tool for three-dimensional medical reconstructions, which fully integrates the latest popular visualization algorithms ranging from classical surface rendering algorithm to volume rendering algorithms, such as Ray Casting, Splatting, and Shear-Warp.The input of VolGraph can be medical ima- ges including CT, MRI, etc, and the output can be in common image, VRML/XML or animation formats. Practice proves that the realization of a medical volume visualization system is now feasible on desktop PCs. 展开更多
关键词 VolGraph medical reconstructions SPLATTING Marching Cubes volume rendering
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Dyke Swarms: Keys to Paleogeographic Reconstructions, Preface for IDC7 2016
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作者 PENG Peng Richard ERNST 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2016年第S1期3-5,共3页
Focusing on geological,geochemical and geophysical aspects of dykes and related units,the International Dyke Conference(IDC)series was launched in Toronto,Canada in 1985 by Prof.Henry C.Halls(University of Toronto).It... Focusing on geological,geochemical and geophysical aspects of dykes and related units,the International Dyke Conference(IDC)series was launched in Toronto,Canada in 1985 by Prof.Henry C.Halls(University of Toronto).It has continued approximately every five years with 展开更多
关键词 IDC Dyke Swarms Keys to Paleogeographic reconstructions Preface for IDC7 2016
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Paleomagnetic Data and Dyke Swarms Geometries – Important Tools for Precambrian Paleogeographic Reconstructions
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作者 Sergei A.PISAREVSKY 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2016年第S1期40-,共1页
There are only two quantitative tools for Precambrian paleogeographic reconstructions–paleomagnetic data and dyke swarms geometries.Paleomagnetic data provide information about paleolatitudes and orientation of rigid
关键词 DATA Important Tools for Precambrian Paleogeographic reconstructions Paleomagnetic Data and Dyke Swarms Geometries
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One-and Multi-dimensional CWENOZ Reconstructions for Implementing Boundary Conditions Without Ghost Cells
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作者 M.Semplice E.Travaglia G.Puppo 《Communications on Applied Mathematics and Computation》 2023年第1期143-169,共27页
We address the issue of point value reconstructions from cell averages in the context of third-order finite volume schemes,focusing in particular on the cells close to the boundaries of the domain.In fact,most techniq... We address the issue of point value reconstructions from cell averages in the context of third-order finite volume schemes,focusing in particular on the cells close to the boundaries of the domain.In fact,most techniques in the literature rely on the creation of ghost cells outside the boundary and on some form of extrapolation from the inside that,taking into account the boundary conditions,fills the ghost cells with appropriate values,so that a standard reconstruction can be applied also in the boundary cells.In Naumann et al.(Appl.Math.Comput.325:252–270.https://doi.org/10.1016/j.amc.2017.12.041,2018),motivated by the difficulty of choosing appropriate boundary conditions at the internal nodes of a network,a different technique was explored that avoids the use of ghost cells,but instead employs for the boundary cells a different stencil,biased towards the interior of the domain.In this paper,extending that approach,which does not make use of ghost cells,we propose a more accurate reconstruction for the one-dimensional case and a two-dimensional one for Cartesian grids.In several numerical tests,we compare the novel reconstruction with the standard approach using ghost cells. 展开更多
关键词 High-order finite volume schemes Boundary conditions without ghost cells Hyperbolic systems CWENOZ reconstruction Adaptive order reconstructions
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Paleoglacial and paleoclimate reconstructions during the global Last Glacial Maximum in the Longriba area, eastern Tibetan Plateau 被引量:3
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作者 YANG Wei-lin HAN Ye-song +3 位作者 PENG Xu RAN Ze-ze LIU Qing LIU Geng-nian 《Journal of Mountain Science》 SCIE CSCD 2021年第2期307-322,共16页
Owing to the remoteness of the Longriba area and the lack of dating records,it is extremely challenging to reconstruct the chronology and extent of the paleoglaciers in this area.In this paper,we combined limited obse... Owing to the remoteness of the Longriba area and the lack of dating records,it is extremely challenging to reconstruct the chronology and extent of the paleoglaciers in this area.In this paper,we combined limited observational data with automated modelling for paleoglacial reconstructions.We first identified a broadly distributed paleoglacier from satellite imagery and field investigation based on the sediment-landform assemblage principle and dated it to 23.1±1.4~19.5±1.2 ka by ^(10)Be exposure dating,corresponding to the global Last Glacial Maximum(gLGM).Then,we reconstructed the extent and ice surface of 171 paleoglaciers formed during the similar period based on geomorphological evidence and‘ice surface profile’modelling.The results showed that the paleoglacial coverage was 426.5 km2,with an ice volume of 38.1 km^(3),in the Longriba area.The reconstructed equilibrium line altitudes(ELAs)based on modelled ice surfaces yielded an average of 4245±66 m above sea level(asl),~725±73 m lower than the present ELA(4970±29 m asl).The temperature was~5.51-6.68℃lower,and the precipitation was~30-34%less in Longriba,during the gLGM compared to the present day.This glacial advance was mainly driven by colder climate that was synchronous with Northern Hemisphere cooling events. 展开更多
关键词 Ice surface profile ^(10)Be surface exposure dating Paleoglacial reconstruction Paleoclimate reconstruction Global Last Glacial Maximum Eastern Tibetan Plateau
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Shape reconstructions and morphing kinematics of an eagle during perching manoeuvres 被引量:1
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作者 Di Tang Dawei Liu +3 位作者 Hai Zhu Xipeng Huang Zhongyong Fan Mingxia Lei 《Chinese Physics B》 SCIE EI CAS CSCD 2020年第2期327-336,共10页
The key to high manoeuvre ability in bird flight lies in the combined morphing of wings and tail.The perching of a wild Haliaeetus Albicilla without running or wing flapping is recorded and investigated using a high-s... The key to high manoeuvre ability in bird flight lies in the combined morphing of wings and tail.The perching of a wild Haliaeetus Albicilla without running or wing flapping is recorded and investigated using a high-speed digital video.A shape reconstruction method is proposed to describe wing contours and tail contours during perching.The avian airfoil geometries of the Aquila Chrysaetos are extracted from noncontact surface measurements using a ROMBER 3D laser scanner.The wing planform,chord distribution and twist distribution are fitted in convenient analytical expressions to obtain a 3D wing geometry.A three-jointed arm model is proposed to associate with the 3D wing geometry,while a one-joint arm model is proposed to describe the kinematics of tail.Therefore,a 3D bird model is established.The perching sequences of the wild eagle are recaptured and regenerated with the proposed 3D bird model.A quasi-steady aerodynamic model is applied in the aerodynamic predictions,a four-step Adams-Bashforth method is used to calculate the ordinary differential equations,thus a BFGS based optimization method is established to predict the perching motions. 展开更多
关键词 large BIRD of PREY shape reconstruction MORPHING KINEMATIC PERCHING
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MHD Equilibrium Configuration Reconstructions for HL-2A Tokamak
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作者 何志雄 董家齐 +3 位作者 何宏达 蒋海滨 高喆 张锦华 《Plasma Science and Technology》 SCIE EI CAS CSCD 2011年第4期424-430,共7页
The EFIT (Equilibrium Fitting) code is modified for the equilibrium configuration reconstruction in HL-2A. Signals from Langmuir probe (LP) at the divertor target plates are employed in the reconstruction of diver... The EFIT (Equilibrium Fitting) code is modified for the equilibrium configuration reconstruction in HL-2A. Signals from Langmuir probe (LP) at the divertor target plates are employed in the reconstruction of divertor configurations. The results show that discharge #2895 starts with a limiter configuration and develops gradually into a divertor configuration after t = 230 ms. This transition process is clearly demonstrated by the LP signals for the reconstruction. The profiles of plasma parameters such as safety factor q, pressure and current density as well as the evolution of major shape parameters of plasma, such as the boundary magnetic fluxes, the positions of both x-point and magnetic axis, are calculated from the reconstructed configurations. The possibility to apply the method to the swing of strike point on the target plate is discussed. 展开更多
关键词 equilibrium reconstruction MHD equilibrium LP signals HL-2A tokamak
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Successful treatment of corrosive esophageal strictures after failed esophageal reconstructions with colon and jejunum
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作者 周景海 蒋耀光 +6 位作者 王如文 赵云平 龚太乾 谭群友 马铮 林一丹 邓波 《Journal of Medical Colleges of PLA(China)》 CAS 2006年第3期200-202,共3页
Dense and extensive esophageal strictures after caustic agent ingestion require surgical treatment. Colon, stomach and jejunum can be used to reconstruct esophagus. Here, we report an unusual patient with corrosive es... Dense and extensive esophageal strictures after caustic agent ingestion require surgical treatment. Colon, stomach and jejunum can be used to reconstruct esophagus. Here, we report an unusual patient with corrosive esophageal stricture who had received unsuccessful esophageal replacements twice at other hospitals. Colon interposition had been first performed 6 months after corrosive esophageal burn, but the colon graft necrosis occurred. Esophageal reconstruction had been carried out 10 years later in another hospital. However, the graft necrosis developed again 5 months later. A salvage operation was performed to remove the necrotic transplant in our hospital. Then as much food as possible had been given to expand the stomach through the gastrostomy since the procedure. The patient underwent esophagecto-my and concomitant gastroesophagostomy in the neck 1. 5 years later. Esophageal dilations had been performed to prevent recurrent anastomotic stricture for 1 year. He has eaten a normal diet since being discharged. 展开更多
关键词 corrosive esophageal burn STRICTURE esophageal reconstruction ESOPHAGOGASTROSTOMY
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Long-range precipitation forecasts using paleoclimate reconstructions in the western United States
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作者 Christopher Allen CARRIER Ajay KALRA Sajjad AHMAD 《Journal of Mountain Science》 SCIE CSCD 2016年第4期614-632,共19页
Long-range precipitation forecasts are useful when managing water supplies.Oceanicatmospheric oscillations have been shown to influence precipitation.Due to a longer cycle of some of the oscillations,a short instrumen... Long-range precipitation forecasts are useful when managing water supplies.Oceanicatmospheric oscillations have been shown to influence precipitation.Due to a longer cycle of some of the oscillations,a short instrumental record is a limitation in using them for long-range precipitation forecasts.The influence of oscillations over precipitation is observable within paleoclimate reconstructions;however,there have been no attempts to utilize these reconstructions in precipitation forecasting.A data-driven model,KStar,is used for obtaining long-range precipitation forecasts by extending the period of record through the use of reconstructions of oscillations.KStar is a nearest neighbor algorithm with an entropy-based distance function.Oceanic-atmospheric oscillation reconstructions include the El Nino-Southern Oscillation(ENSO),the Pacific Decadal Oscillation(PDO),the North Atlantic Oscillation(NAO),and the Atlantic Multi-decadal Oscillation(AMO).Precipitation is forecasted for 20 climate divisions in the western United States.A 10-year moving average is applied to aid in the identification of oscillation phases.A lead time approach is used to simulate a one-year forecast,with a 10-fold cross-validation technique to test the models.Reconstructions are used from 1658-1899,while the observed record is used from 1900-2007.The model is evaluated using mean absolute error(MAE),root mean squared error(RMSE),RMSE-observations standard deviation ratio(RSR),Pearson's correlation coefficient(R),NashSutcliffe coefficient of efficiency(NSE),and linear error in probability space(LEPS) skill score(SK).The role of individual and coupled oscillations is evaluated by dropping oscillations in the model.The results indicate 'good' precipitation estimates using the KStar model.This modeling technique is expected to be useful for long-term water resources planning and management. 展开更多
关键词 Precipitation Oscillations Paleoclimate reconstruction Forecast KStar
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Tribal Councils as a Decision-Making Mechanism for Post-disaster Reconstructions: A Case Study of Ulaljuc
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作者 Chaohsing Huang Paiteng Cheng +2 位作者 Hsin-Chieh Kao Tjepelang Ruvaniyaw Yuhsin Chen 《Sociology Study》 2013年第4期261-268,共8页
Since the 1990s, indigenous people in Taiwan have engaged in tribal councils for the purpose of integrating the tribal authority and the modern administrative system. The establishment of tribal councils provides a co... Since the 1990s, indigenous people in Taiwan have engaged in tribal councils for the purpose of integrating the tribal authority and the modern administrative system. The establishment of tribal councils provides a communicative forum for tribal leaders, village, and the association of community development to make decisions of common tribal affairs. When disasters happen, the internal tribal response strategies and external assistance mechanisms might cooperate through either traditional or modern administrative systems. The research focused on how these organizations, while in interim housing, influenced the reconstruction and rehabilitation after disasters. The research's findings suggested that tribal councils, a pre-existing mechanism, seemed to be an appropriate forum for negotiation and decision-making for tribal affairs. 展开更多
关键词 Interim housing tribal council post-disaster reconstruction
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A novel procedure for pollen-based quantitative paleoclimate reconstructions and its application in China 被引量:9
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作者 CHEN JianHui LV FeiYa +10 位作者 HUANG XiaoZhong H.John B.BIRKS Richard J.TELFORD ZHANG ShengRui XU QingHai ZHAO Yan WANG HaiPeng ZHOU AiFeng HUANG Wei LIU JianBao WEI GuoYing 《Science China Earth Sciences》 SCIE EI CAS CSCD 2017年第11期2059-2066,共8页
Traditionally, the evaluation of pollen-based quantitative paleoclimate reconstructions focuses on the ability of calibration sets to infer present climatic conditions and/or the similarity between fossil and modem as... Traditionally, the evaluation of pollen-based quantitative paleoclimate reconstructions focuses on the ability of calibration sets to infer present climatic conditions and/or the similarity between fossil and modem assemblages. Objective criteria for choosing the most appropriate climate parameter(s) to be reconstructed at a specific site are thus lacking. Using a novel approach for testing the statistical significance of a quantitative reconstruction using random environmental data, in combination with the advantageous large environmental gradients, abundant vegetation types and comprehensive modem pollen databases in China, we describe a new procedure for pollen-based quantitative paleoclimatic reconstructions. First, the most significant environmental variable controlling the fossil pollen assemblage changes is identified. Second, a calibration set to infer changes in this targeted variable is built up, by limiting the modem ranges of other environmental variables. Finally, the pollen-based quantitative reconstruction is obtained and its statistical significance assessed. This novel procedure was used to reconstruct the mean annual precipitation (Pann) from Gonghai Lake in the Lvliang Mountains, and Tianchi Lake in the Liupan Mountains, on the eastern and western fringe of the Chinese Loess Plateau, respectively. Both Pann. reconstructions are statistically significant (p〈0.001), and a sound and stable correlation relationship exists in their common period, showing a rapid precipitation decrease since 3300 cal yr BP. Thus, we propose that this procedure has great potential for reducing the uncertainties associated with pollen-based quantitative paleoclimatic reconstructions in China. 展开更多
关键词 POLLEN Quantitative reconstructions Statistical significance Marginal areas of the Asian summer monsoon
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Structural Features and Proto-Type Basin Reconstructions of the Bay of Bengal Basin:A Remnant Ocean Basin Model 被引量:5
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作者 Peng Zhang Lianfu Mei +3 位作者 Ping Xiong Xiaolin Hu Renyuan Li Huaning Qiu 《Journal of Earth Science》 SCIE CAS CSCD 2017年第4期666-682,共17页
Remnant ocean basin is a key to understand the plate suturing and subsequent uplift and erosion of orogen. The Bay of Bengal Basin (BOBB) provides a typical example to analyze the remnant ocean basin structures, evo... Remnant ocean basin is a key to understand the plate suturing and subsequent uplift and erosion of orogen. The Bay of Bengal Basin (BOBB) provides a typical example to analyze the remnant ocean basin structures, evolution, and relationships between depositional filling and uplifting of the Himalayan Orogen. Thirty-nine seismic profiles as well as interval velocities of well BODC3 were used to compile isopach maps of the basin. Among the seismic data, 26 seismic profiles were applied to estab- lish 8 cross sections. The cross sections suggest the basin is asymmetric, bounded to the west by the eastern continental margin of India (ECMI) with graben-horst and to the east by the Sunda conver- gence margin dominated by trench-arc system. The BOBB is characterized by a prominent down flex- ure structures caused by huge amount of Bengal fan turbidite sediments accumulation. Our isopach maps and chronology data collected from adjacent regions reveal the initial development and fast southward growth of the Bengal fan were related to the early and major stage uplift and erosion of the Himalayan Orogen, respectively. The BOBB has experienced a critical transition from an ocean basin to a remnant ocean basin at Late Oligocene. Such basin structures and evolution features indicate the BOBB provides whole records of oblique convergence of the India and Asia plates, and the early and major stage evolution of the Himalayan Orogen. 展开更多
关键词 basin structures prototype-basin reconstructions remnant ocean basin the Bay of Bengal Basin India-Asia collision Bengal fan.
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Navigating medial patellotibial ligament reconstruction:Clinical perspectives and surgical strategies
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作者 Juan Pablo Zicaro Ignacio Garcia-Mansilla 《World Journal of Clinical Cases》 SCIE 2025年第1期6-10,共5页
The surgical approach for patellar instability usually refers to reconstruction of the medial patellofemoral ligament associated with an osteotomy of the tibial tuberosity or a trochleoplasty when required.The medial ... The surgical approach for patellar instability usually refers to reconstruction of the medial patellofemoral ligament associated with an osteotomy of the tibial tuberosity or a trochleoplasty when required.The medial patellotibial ligament and the medial patellomeniscal ligament are secondary stabilizers of the patella.Despite this,both the medial patellotibial and patellofemoral ligaments aid in patellar rotation and tilt when the knee is flexed beyond 45°.The medial patellotibial ligament plays a particularly important role in the final stages of stretching in extension and between 40 degrees to 90 degrees of flexion.The clinical relevance and surgical indications for medial patellotibial ligament reconstruction associated with medial patellofemoral ligament reconstruction are still controversial.This editorial explores the surgical indications and clinical results for medial patellotibial ligament reconstruction to improve readers’understanding of this technique,especially because reported clinical outcomes have remained sparse. 展开更多
关键词 Medial patellotibial ligament Patellar instability RECONSTRUCTION SURGICAL
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A method for the separation and reconstructions of charged hadron and neutral hadron from their overlapped showers in an electromagnetic calorimeter
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作者 梁松 陶军全 +17 位作者 沈玉乔 范嘉伟 肖虹 陈国明 陈和生 卞建国 陈晔 李祖豪 孟祥伟 唐志成 汪先友 王征 徐明 许伟伟 严琪 杨民 张诚 朱世海 《Chinese Physics C》 SCIE CAS CSCD 2013年第9期41-47,共7页
The separation and reconstructions of charged hadron and neutral hadron from their overlapped showers in an electromagnetic calorimeter is very important for the reconstructions of some particles with hadronic decays,... The separation and reconstructions of charged hadron and neutral hadron from their overlapped showers in an electromagnetic calorimeter is very important for the reconstructions of some particles with hadronic decays, for example the tau reconstruction in the searches for the Standard Model and supersymmetric Higgs bosons at the LHC. In this paper, a method combining the shower cluster in an electromagnetic calorimeter and the parametric formula for hadron showers, was developed to separate the overlapped showers between charged hadron and neutral hadron. Taking the hadronic decay containing one charged pion and one neutral pion in the final status of tau for example, satisfied results of the separation of the overlapped showers, the reconstructions of the energy and positions of the hadrons were obtained. An improved result for the tau reconstruction with this decay model can be also achieved after the application of the proposed method. 展开更多
关键词 separation and reconstructions overlapped showers parametric formula
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3D palaeogeographic reconstructions of the Phanerozoic versus sea-level and Sr-ratio variations 被引量:9
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作者 Christian Vérard Cyril Hochard +1 位作者 Peter O.Baumgartner Gérard M.Stampfli 《Journal of Palaeogeography》 SCIE CSCD 2015年第1期64-84,共21页
A full global geodynamical model over 600 million years (Ma) has been de- veloped at the University of Lausanne during the past 20 years. We show herein how the 2D maps were converted into 3D (i.e., full hypsometry... A full global geodynamical model over 600 million years (Ma) has been de- veloped at the University of Lausanne during the past 20 years. We show herein how the 2D maps were converted into 3D (i.e., full hypsometry and bathymetry), using a heuristic-based approach. Although the synthetic topography may be viewed as relatively crude, it has the advantage of being applicable anywhere on the globe and at any geological time. The model allows estimating the sea-level changes throughout the Phanerozoic, with the possibility, for the first time, to flood accordingly continental areas. One of the most striking results is the good correlation with "measured" sea-level changes, implying that long-term variations are predominantly tectonically-driven. Volumes of mountain relief are also estimated through time and compared with strontium isotopic ratio (Sr-ratio), commonly thought to reflect mountain belt erosion. The tectonic impact upon the general Sr-retio trend is shown herein for the first time, although such influence was long been inferred. 展开更多
关键词 PALAEOGEOGRAPHY reconstruction HYPSOMETRY BATHYMETRY SEA-LEVEL Sr-ratio tectonic-climate relationship
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Light field imaging: models-, calibrations, reconstructions, and applications 被引量:8
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作者 Hao ZHU Qing WANG Jingyi YU 《Frontiers of Information Technology & Electronic Engineering》 SCIE EI CSCD 2017年第9期1236-1249,共14页
Light field imaging is an emerging technology in computational photography areas. Based on innovative designs of the imaging model and the optical path, light field cameras not only record the spatial intensity of thr... Light field imaging is an emerging technology in computational photography areas. Based on innovative designs of the imaging model and the optical path, light field cameras not only record the spatial intensity of three- dimensional (3D) objects, but also capture the angular information of the physical world, which provides new ways to address various problems in computer vision, such as 3D reconstruction, saliency detection, and object recognition. In this paper, three key aspects of light field cameras, i.e., model, calibration, and reconstruction, are reviewed extensively. Furthermore, light field based applications on informatics, physics, medicine, and biology are exhibited. Finally, open issues in light field imaging and long-term application prospects in other natural sciences are discussed. 展开更多
关键词 Light field imaging Plenoptic function Imaging model CALIBRATION RECONSTRUCTION
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The Vérard et al.(2015) method for 3D palaeogeographic reconstructions:How solid is its base? 被引量:10
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作者 A.J.(Tom) van Loon 《Journal of Palaeogeography》 SCIE CSCD 2015年第3期244-247,共4页
Verard and co-workers proposed in an earlier issue of this journal a method to reconstruct the 3D palaeogeography "anywhere in the world at any time". The present contribution is a discussion of some of the assumpti... Verard and co-workers proposed in an earlier issue of this journal a method to reconstruct the 3D palaeogeography "anywhere in the world at any time". The present contribution is a discussion of some of the assumptions on which the method of Verard et al. is based. The reason for this discussion is that the method will give, at least seemingly, illogical outcomes for numerous situations. Moreover, some assumptions used by Verard and his team pose theoretical probtems. It is deduced that the method developed by Verard and co-workers may occasionally help, indeed, to obtain a rough picture of the altitude of the sedimentary surface on the continents and of the depth of the sedimentary surface in the oceans in the geological past. The outcomes should, however, be treated with utmost care as severat of the assumptions on which the interpretative 3D method is based have no solid basis, so that even the rough outcomes of the method must be considered questionable. 展开更多
关键词 pataeogeography RECONSTRUCTION 3D model
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Accuracy Assessment of Three-dimensional Surface Reconstructions of In vivo Teeth from Cone-beam Computed Tomography 被引量:7
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作者 Yan-Hui Sang Hong-Cheng Hu +3 位作者 Song-He Lu Yu-Wei Wu Wei-Ran Li Zhi-Hui Tang 《Chinese Medical Journal》 SCIE CAS CSCD 2016年第12期1464-1470,共7页
Background: The accuracy of three-dimensional (3 D) reconstructions from cone-beam computed tomography (CBCT) has been particularly important in dentistry, which will affect the effectiveness of diagnosis, treatm... Background: The accuracy of three-dimensional (3 D) reconstructions from cone-beam computed tomography (CBCT) has been particularly important in dentistry, which will affect the effectiveness of diagnosis, treatment plan, and outcome in clinical practice. The aims of this study were to assess the linear, volumetric, and geometric accuracy of 3 D reconstructions from CBCT and to investigate the influence of voxel size and CBCT system on the reconstructions results. Methods: Fifty teeth from 18 orthodontic patients were assigned to three groups as NewTom VG 0.15 mm group (NewTom VG; voxel size: 0.15 ram; n = 17), NewTom VG 0.30 mm group (NewTom VG; voxel size: 0.30 ram; n - 16), and VATECH DCTPRO 0.30 mm group (VATECH DCTPRO; voxel size: 0.30 ram; n = 17). The 3D reconstruction models of the teeth were segmented from CBCT data manually using Mimics 18.0 (Materialise Dental, Leuven, Belgium), and the extracted teeth were scanned by 3Shape optical scanner (3Shape A/S, Denmark). Linear and volumetric deviations were separately assessed by comparing the length and volume of the 3D reconstruction model with physical measurement by paired t-test Geometric deviations were assessed by the root mean square value of the imposed 3D reconstruction and optical models by one-sample t-test. To assess the influence of voxel size and CBCT system on 3D reconstruction, analysis of variance (ANOVA) was used (α = 0.05). Results: The linear, volumetric, and geometric deviations were -0.03±0.48 mm, -5.4 ±2.8%, and 0.117 ± 0.018 mm for NewTom VG 0.15 mm group; -0.45 ± 0.42 mm, -4.5±3.4%, and 0.116 + 0.014 mm for NewTom VG 0.30 mm group; and 0.93 ± 0.40 ram, 4.8 ± 5.1%, and 0.194 ± 0.117 mm for VATECH DCTPRO 0.30 mm group, respectively. There were statistically significant differences between groups in terms of linear measurement (P 〈 0.001), but no significant difference in terms of volumetric measurement (P 0.774). No statistically significant difference were found on geometric measurement between NewTom VG 0.15 mm and NewTom VG 0.30 mm groups (P - 0.999) while a significant difference was found between VATECH DCTPRO 0.30 mm and NewTom VG 0.30 mm groups (P = 0.006). Conclusions: The 3D reconstruction from CBCT data can achieve a high linear, volumetric, and geometric accuracy. Increasing voxel resolution from 0.30 to 0.15 mm does not result in increased accuracy of 3D tooth reconstruction while different systems can affect the accuracy. 展开更多
关键词 ACCURACY Cone-beam Computed Tomography Reconstruction TOOTH
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