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Netro-非视距(Non Line Of Sight)固定无线架构的灵活性
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《无线电工程》 2002年第11期60-61,共2页
成功地部署一个固定宽带无线(FBW)网络取决于两个关键因素:射频网络规划的灵活性和视距(LOS)/非视距(NLOS)情况。因为在视距(LOS)情况下要求在发射机和接收器之间没有阻挡,运营商在规划和部署一个视距(LOS)的固定宽带无线(FBW)网络... 成功地部署一个固定宽带无线(FBW)网络取决于两个关键因素:射频网络规划的灵活性和视距(LOS)/非视距(NLOS)情况。因为在视距(LOS)情况下要求在发射机和接收器之间没有阻挡,运营商在规划和部署一个视距(LOS)的固定宽带无线(FBW)网络时,需面对许多技术和业务上的困难;事实上第…… 展开更多
关键词 非视距 Netro non line Of sight NLOS 频率复用 自适应调制 蜂窝
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Locating the position of objects in non-line-of-sight based on time delay estimation
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作者 王雪峰 王元庆 +1 位作者 苏金善 杨兴雨 《Chinese Physics B》 SCIE EI CAS CSCD 2016年第8期163-169,共7页
Non-line-of-sight imaging detection is to detect hidden objects by indirect light and intermediary surface(diffuser).It has very important significance in indirect access to an object or dangerous object detection, ... Non-line-of-sight imaging detection is to detect hidden objects by indirect light and intermediary surface(diffuser).It has very important significance in indirect access to an object or dangerous object detection, such as medical treatment and rescue. An approach to locating the positions of hidden objects is proposed based on time delay estimation. The time delays between the received signals and the source signal can be obtained by correlation analysis, and then the positions of hidden objects will be located. Compared with earlier systems and methods, the proposed approach has some modifications and provides significant improvements, such as quick data acquisition, simple system structure and low cost, and can locate the positions of hidden objects as well: this technology lays a good foundation for developing a practical system that can be used in real applications. 展开更多
关键词 non-line-OF-sight time delay estimation CROSS-CORRELATION hidden object location
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Characterization of Blue-Green Light Non-Line-of-Sight Transmission in Seawater
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作者 Xizheng Ke Gang Li 《Optics and Photonics Journal》 CAS 2022年第11期234-252,共19页
The blue-green light in the 450 nm to 550 nm band is usually used in underwater wireless optical communication (UWOC). The blue-green light transmission in seawater is scattered by the seawater effect and can achieve ... The blue-green light in the 450 nm to 550 nm band is usually used in underwater wireless optical communication (UWOC). The blue-green light transmission in seawater is scattered by the seawater effect and can achieve communication in non-line-of-sight (NLOS) transmission mode. Compared to line-of-sight (LOS) transmission, NLOS transmission does not require alignment and can be adapted to various underwater environments. The scattering coefficients of seawater at different depths are different, which makes the scattering of light in different depths of seawater different. In this paper, the received optical power and bit error rate (BER) of the photodetector (PD) were calculated when the scattering coefficients of blue-green light in seawater vary from large to small with increasing depth for NLOS transmission. The results show that blue-green light in different depths of seawater in the same way NLOS communication at the same distance, the received optical power and BER at the receiver are different, and the received optical power of green light is greater than that of blue light. Increasing the forward scattering coverage of the laser will suppress the received optical power of the PD, so when performing NLOS communication, appropriate trade-offs should be made between the forward scattering coverage of the laser and the received optical power. 展开更多
关键词 Underwater Wireless Optical Communication non-line-of-sight Transmission Scattering Coefficient Received Optical Power Bit Error Rate
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A new method to determine the gravity field of small bodies from line-of-sight acceleration data 被引量:1
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作者 Nian-Chuan Jian Jian-Guo Yan +2 位作者 Jin-Song Ping Jean-Pierre Barriot J.Alexis P.Rodriguez 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2019年第3期155-164,共10页
We present a new method to derive line-of-sight acceleration observables from spacecraft radio tracking data. The observables can be used to estimate the mass and gravity of a natural satellite as a spacecraft flyby. ... We present a new method to derive line-of-sight acceleration observables from spacecraft radio tracking data. The observables can be used to estimate the mass and gravity of a natural satellite as a spacecraft flyby. The corresponding observation model adapts to one-way and two/three-way tracking modes. As a test case for method validation and application, we estimated the mass and degree two gravity field for the Martian moon Phobos using simulated tracking data when the spacecraft Mars Express flew by Phobos on 2013 December 29. We have a few real tracking data during flyby and they will be used to confirm raw data simulation. The main purpose of this paper is to demonstrate the method of line-of-sight acceleration reduction from raw tracking data and the feasibility to estimate mass and gravity of a natural satellite using this type of observable. This novel method is potentially applicable to planet and asteroid gravity field studies combined with Doppler tracking data. 展开更多
关键词 line of sight acceleration-Doppler-celestial MECHANICS
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Comparison of visual effects of FS-LASIK for myopia centered on the coaxially sighted corneal light reflex or the line of sight 被引量:1
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作者 Jing Zhang Shi-Sheng Zhang +1 位作者 Qin Yu Jing-Cai Lian 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2017年第4期624-631,共8页
AIM:To compare visual quality after femtosecond laser in situ keratomileusis(FS-LASIK),between the coaxially sighted corneal light reflex(CSCLR) group and conventional ablation line of sight(LOS) group.METHODS... AIM:To compare visual quality after femtosecond laser in situ keratomileusis(FS-LASIK),between the coaxially sighted corneal light reflex(CSCLR) group and conventional ablation line of sight(LOS) group.METHODS:In total,243 eyes(122 patients) were treated with centration on the CSCLR(visual axis) and 238 eyes(119 patients) treated with centration on the pupil center(LOS).Postoperative outcomes [uncorrected visual acuity(UCVA),best spectacle-corrected visual acuity(BSCVA)],safety index,efficacy index,refractive outcome,ablation center distance from the visual axis,corneal high-order aberrations,subjective discomfort glare and shadowing incidence rate,and contrast sensitivity at 1,3,and 6mo were measured and compared.RESULTS:The mean age was 27.77±7.1y in the CSCLR group and 26.03±7.70 y in the LOS group.Preoperatively,the manifest refraction spherical equivalent(MRSE) was-6.68±2.60 D in the CSCLR group and-6.65±2.68 D in the LOS group.The postoperative UCVA,BSCVA,MRSE(-0.03±0.263 D in the CSCLR group,-0.05±0.265 D in the LOS group),efficacy index(1.04,1.03),and safety index(1.09,1.08) were not significantly different between the groups(all P〉0.05).In total,3% lost one line and more of BSCVA in the CSCLR group,as 9% in the LOS group postoperatively(P〈0.05).The ablation center deviation was 0.20±0.15 mm from the visual axis(Pentacam system default setting;range,0-0.75 mm) in the CSCLR group,and 0.43±0.22 mm(range,0-1.32 mm) in the LOS group(P〈0.0001).Statistically significant greater augmentationof total corneal higher-order aberrations(0.15±0.10 μm and 0.20±0.12 μm respectively,P=0.03) and vertical and horizontal coma(P〈0.0001) were noted in the LOS group.Subjective discomfort glare and shadowing incidence rates were 8.59% and 17.5% in the CSCLR and LOS groups,respectively(P〈0.05).The 1-month postoperative contrast sensitivity visual acuity in the CSCLR group was significantly higher than that in the LOS group on contrast(100%,25%,10%) with a dark background,but there was no significant difference between the groups at 3 or 6m.CONCLUSION:Myopic LASIK centered on the CSCLR achieves significantly lower induction of loss of BSCVA,corneal high-order aberrations,and lower risk of subjective discomfort glare and shadowing,and lower decline in early contrast sensitivity by comparison with centration on the LOS,giving advantages in visual quality postoperatively. 展开更多
关键词 laser in situ keratomileusis ablation center line of sight coaxially sighted corneal light reflex
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Efficiency Effect of Obstacle Margin on Line-of-Sight in Wireless Networks 被引量:1
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作者 Murad A.A.Almekhlafi Taiseer Abdalla Elfadil Eisa +5 位作者 Fahd N.Al-Wesabi Abdelzahir Abdelmaboud Manar Ahmed Hamza Abdelwahed Motwakel Ishfaq Yaseen Mohammed Rizwanullah 《Computers, Materials & Continua》 SCIE EI 2022年第7期227-242,共16页
Line-of-sight clarity and assurance are essential because they are considered the golden rule in wireless network planning,allowing the direct propagation path to connect the transmitter and receiver and retain the st... Line-of-sight clarity and assurance are essential because they are considered the golden rule in wireless network planning,allowing the direct propagation path to connect the transmitter and receiver and retain the strength of the signal to be received.Despite the increasing literature on the line of sight with different scenarios,no comprehensive study focuses on the multiplicity of parameters and basic concepts that must be taken into account when studying such a topic as it affects the results and their accuracy.Therefore,this research aims to find limited values that ensure that the signal reaches the future efficiently and enhances the accuracy of these values’results.We have designed MATLAB simulation and programming programs by Visual Basic.NET for a semi-realistic communication system.It includes all the basic parameters of this system,taking into account the environment’s diversity and the characteristics of the obstacle between the transmitting station and the receiving station.Then we verified the correctness of the system’s work.Moreover,we begin by analyzing and studying multiple and branching cases to achieve the goal.We get several values from the results,which are finite values,which are a useful reference for engineers and designers of wireless networks. 展开更多
关键词 line of sight obstacle margin wireless networks communication link radio wave propagation
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Link Budget Design for RF Line-of-Sight via Theoretical Propagation Prediction 被引量:1
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作者 Anwar H. Ibrahim Mohammed F. Alsharekh +2 位作者 Mohammed S. Almanee Abdulrahman S. Al-Turki Muhammed Islam 《International Journal of Communications, Network and System Sciences》 2019年第1期11-17,共7页
Line-of-sight (LOS) link planning condition has been observed to have effects on the atmospheric factor which cause crucial signal loss. The main objective of the planning was to improve a set of a link using point to... Line-of-sight (LOS) link planning condition has been observed to have effects on the atmospheric factor which cause crucial signal loss. The main objective of the planning was to improve a set of a link using point to point condition to assist the performance in emerging its strategy for handling the fixed WLAN service. The purpose of this paper is to provide a quick description of various propagation loss mechanisms on Link Budget Tool (LBT). LBT is customized to create point to point link for local area network (LAN) through radio frequency range operating between 2.400 GHz and 5.800 GHz. This software is able to define the effect of signal loss and expected performances according to the distances between link propagation conditions based on a number of system parameters. 展开更多
关键词 Path Loss (PL) line of sight (LOS) Microwave LINK BUDGET (MLB) LINK Planning (LP)
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Calculation of Probability of Cloud-Free Lines-of-Sightat Given Heights in Foshan, China 被引量:1
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作者 李昀英 孙立潭 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 1999年第2期297-303,共7页
Based on Lund and Shanklin’s work (1972), methods of calculating Probability of Cloud-Free Lines-of-Sight (PCFLOS), Persistence Probability of Cloud-Free Lines-of-Sight (PPCFLOS) and Recurrence Probability of Cloud-f... Based on Lund and Shanklin’s work (1972), methods of calculating Probability of Cloud-Free Lines-of-Sight (PCFLOS), Persistence Probability of Cloud-Free Lines-of-Sight (PPCFLOS) and Recurrence Probability of Cloud-free Lines-of-Sight (RPCFLOS) at given heights are presented. PCFLOS, PPCFLOS and RPCFLOS are calculated in Foshan, China by conventional observation data from 1961 to 1990. The conclusions are: (1) The higher the elevations, the smaller the PCFLOS and the larger the view angles, the larger the PCFLOS. (2) PPCFLOS and RPCFLOS decrease with the increase of elevation and the delay of time. (3) RPCFLOS is always equal to or larger than PPCFLOS at lag times. 展开更多
关键词 Probability of cloud-free lines-of-sight Persistence probability of cloud-free lines-of-sight Recurrence probability of cloud-free lines-of-sight Cloud climate
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GLOBAL CONVERGENCE RESULTS OF A THREE TERM MEMORY GRADIENT METHOD WITH A NON-MONOTONE LINE SEARCH TECHNIQUE 被引量:12
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作者 孙清滢 《Acta Mathematica Scientia》 SCIE CSCD 2005年第1期170-178,共9页
In this paper, a new class of three term memory gradient method with non-monotone line search technique for unconstrained optimization is presented. Global convergence properties of the new methods are discussed. Comb... In this paper, a new class of three term memory gradient method with non-monotone line search technique for unconstrained optimization is presented. Global convergence properties of the new methods are discussed. Combining the quasi-Newton method with the new method, the former is modified to have global convergence property. Numerical results show that the new algorithm is efficient. 展开更多
关键词 non-linear programming three term memory gradient method convergence non-monotone line search technique numerical experiment
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Transient Fault Locating Method Based on Line Voltage and Zero-mode Current in Non-solidly Earthed Network 被引量:48
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作者 ZHANG Linli XU Bingyin +1 位作者 XUE Yongduan GAO Houlei 《中国电机工程学报》 EI CSCD 北大核心 2012年第13期I0015-I0015,198,共1页
为解决配电网小电流接地故障时故障点定位困难的问题,提出一种基于线电压和零模电流暂态分量的故障定位新方法。该方法借助馈线自动化(feeder automation,FA)系统实现,不需要额外增加设备。馈线终端检测线电压和零模电流信号,利... 为解决配电网小电流接地故障时故障点定位困难的问题,提出一种基于线电压和零模电流暂态分量的故障定位新方法。该方法借助馈线自动化(feeder automation,FA)系统实现,不需要额外增加设备。馈线终端检测线电压和零模电流信号,利用暂态线电压的希尔伯特变换与暂态零模电流的乘积计算故障方向参数,FA主站根据故障点前后方向参数极性相反的特征确定故障点所在的线路区段。介绍基于线电压的小电流接地故障检测和接地故障相确定的算法。数字仿真与试验结果表明该方法是正确可行的。 展开更多
关键词 低压配电网络 瞬态故障 定位方法 接地电流 线电压 非直接接地系统 单相接地故障 馈线自动化
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Weekly albumin-bound paclitaxel/cisplatin versus gemcitabine/cisplatin as first-line therapy for patients with advanced non-small-cell lung cancer:A phase II open-label clinical study 被引量:9
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作者 Shanshan Qin Hui Yu +10 位作者 Xianghua Wu Zhiguo Luo Huijie Wang Si Sun Mingzhu Huang Jia Jin Zhonghua Tao Jie Qiao Yu Feng Jialei Wang Jianhua Chang 《Chinese Journal of Cancer Research》 SCIE CAS CSCD 2019年第2期339-348,共10页
Objective: The aim of this trial was to compare both the efficacy and the safety of a weekly nanoparticle albumin-bound paclitaxel(nab-paclitaxel) plus cisplatin vs. gemcitabine plus cisplatin in patients with advance... Objective: The aim of this trial was to compare both the efficacy and the safety of a weekly nanoparticle albumin-bound paclitaxel(nab-paclitaxel) plus cisplatin vs. gemcitabine plus cisplatin in patients with advanced non-small-cell lung cancer(NSCLC).Methods: A total of 84 participants received either 100 mg/m^2 nab-paclitaxel each week on d 1, 8 and 15 of a 28 day cycle, as well as cisplatin 75 mg/m^2 on d 1 every three weeks(nab-TP arm); or gemcitabine 1,000 mg/m^2 on d 1 and 8, plus cisplatin 75 mg/m^2 on d 1 every three weeks(GP arm). The primary end point was progression-free survival(PFS). The secondary end points were overall response rate(ORR) and overall survival(OS).Results: According to our analysis, the median PFS was 4.8 months for the nab-TP arm vs. 5.2 months for the GP arm(P=0.55). Analysis showed the median OS was 14.6 months for participants who were in the nab-TP arm vs. 15.1 months for those in the GP arm(P=0.94). Besides, nab-TP showed OS advantages over GP in patients harboring epidermal growth factor receptor(EGFR) mutation(26.7 vs. 15.3 months, P=0.046) and patients with a performance status of 0(23.5 vs. 14.7 months, P=0.020). It was found that incidences of drug-related grade 3 or 4 toxicities were comparable between the two treatment arms.Conclusions: Therefore, it can be seen that weekly nab-TP treatment has a similar efficacy and tolerability to GP treatment for patients who are undergoing their first-line treatment for NSCLC. It could be that survival differences among platinum doublets in the context of both EGFR mutation and performance status have the potential to be the basis for our further clinical trials. 展开更多
关键词 Albumin-bound paclitaxel CISPLATIN GEMCITABINE FIRST-line therapy ADVANCED non-small-cell lung cancer
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Non-bismuth quadruple therapy for first-line Helicobacter pylori eradication:A randomized study in Japan 被引量:5
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作者 Ayako Yanai Kei Sakamoto +2 位作者 Masao Akanuma Keiji Ogura Shin Maeda 《World Journal of Gastrointestinal Pharmacology and Therapeutics》 CAS 2012年第1期1-6,共6页
AIM:To find the way to improve the eradication rate of first-line therapy in Japanese patients.METHODS:We prospectively compared the effectiveness of 7-d quadruple therapy to standard 7 d triple therapy in Japanese pa... AIM:To find the way to improve the eradication rate of first-line therapy in Japanese patients.METHODS:We prospectively compared the effectiveness of 7-d quadruple therapy to standard 7 d triple therapy in Japanese patients infected with Helicobacter pylori(H.pylori).One hundred and nineteen patients were randomly assigned to receive 7-d non-bismuth quadruple therapy with lansoprazole,amoxicillin,clarithromycin and metronidazole(LACM7) or 7-d triple therapy with lansoprazole,amoxicillin and clarithromycin(LAC7).After three months,H.pylori status was analyzed by 13C-urea breath test.Incidence rates of adverse events were evaluated by use of questionnaires.RESULTS:By intention-to-treat(ITT) analysis,the eradication rate in the LACM7 group was 94.9%,which was significantly higher than the LAC7 group(68.3%,P < 0.001).Per protocol analysis also showed a significantly higher eradication rate in the LACM7 group(98.3%) than the LAC7 group(73.2%,P < 0.001).Nevertheless,the incidence of serious adverse events did not differ between the two groups(RR:1.10,95% CI:0.70-1.73,P = 0.67).CONCLUSION:Seven day non-bismuth quadruple therapy(LACM7) was superior to standard 7-d triple therapy(LAC7) for first-line eradication. 展开更多
关键词 HELICOBACTER PYLORI Eradication FIRST-line treatment non-bismuth quadruple therapy Prospective study
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Riemann Boundary Value Problem of Non-Normal Type on the Infinite Straight Line 被引量:2
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作者 Lixia Cao 《Applied Mathematics》 2013年第8期1226-1230,共5页
Various kinds of Riemann boundary value problems (BVPs) for analytic functions on closed curves or on open arc, doubly periodic Riemann BVPs, doubly quasi-periodic Riemann BVPs, and BVPs for polyanalytic functions hav... Various kinds of Riemann boundary value problems (BVPs) for analytic functions on closed curves or on open arc, doubly periodic Riemann BVPs, doubly quasi-periodic Riemann BVPs, and BVPs for polyanalytic functions have been widely investigated in [1-8]. The main ap- proach is to use the decomposition of polyanalytic functions and their generalization to transform the boundary value problems to their corresponding boundary value problems for analytic functions. Recently, inverse Riemann BVPs for generalized analytic functions or bianalytic functions have been investigated in [9-12]. In this paper, we consider a kind of Riemann BVP of non-normal type on the infinite straight line and discuss the solvable conditions and the general solution for it. 展开更多
关键词 non-Normal Type RIEMANN BOUNDARY VALUE Problem The INFINITE STRAIGHT line
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Line-of-Sight MIMO for Next-Generation Microwave Transmission Systems
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作者 Xianwei Gong Zhifeng Yuan +1 位作者 Jun Xu Liujun Hu 《ZTE Communications》 2012年第4期33-38,共6页
Line-of-sight MIMQ (LoS MIMO) is not applicable in scattering wireless transmission scenarios, but it may be applied in LoS microwave transmission scenarios if antenna spacing (within transmit and/or receive arrays... Line-of-sight MIMQ (LoS MIMO) is not applicable in scattering wireless transmission scenarios, but it may be applied in LoS microwave transmission scenarios if antenna spacing (within transmit and/or receive arrays) is suitable and there is one hop distance. LoS MIMQ can improve channel capacity and performance of a transmission system. In this paper, we discuss factors affecting channel capacity and performance in LoS MIMO. We also discuss the feasibility LoS MIMO applications. 展开更多
关键词 line of sight MIMO MICROWAVE channel capacity
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Disparity-Based Generation of Line-of-Sight DSM for Image-Elevation Co-Registration to Support Building Detection in Off-Nadir VHR Satellite Images 被引量:1
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作者 Alaeldin Suliman Yun Zhang 《Journal of Geographic Information System》 2018年第1期25-56,共32页
The integration of optical images and elevation data is of great importance for 3D-assisted mapping applications. Very high resolution (VHR) satellite images provide ideal geo-data for mapping building information. Si... The integration of optical images and elevation data is of great importance for 3D-assisted mapping applications. Very high resolution (VHR) satellite images provide ideal geo-data for mapping building information. Since buildings are inherently elevated objects, these images need to be co-registered with their elevation data for reliable building detection results. However, accurate co-registration is extremely difficult for off-nadir VHR images acquired over dense urban areas. Therefore, this research proposes a Disparity-Based Elevation Co-Registration (DECR) method for generating a Line-of-Sight Digital Surface Model (LoS-DSM) to efficiently achieve image-elevation data co-registration with pixel-level accuracy. Relative to the traditional photogrammetric approach, the RMSE value of the derived elevations is found to be less than 2 pixels. The applicability of the DECR method is demonstrated through elevation-based building detection (EBD) in a challenging dense urban area. The quality of the detection result is found to be more than 90%. Additionally, the detected objects were geo-referenced successfully to their correct ground locations to allow direct integration with other maps. In comparison to the original LoS-DSM development algorithm, the DECR algorithm is more efficient by reducing the calculation steps, preserving the co-registration accuracy, and minimizing the need for elevation normalization in dense urban areas. 展开更多
关键词 Stereo VHR Satellite Images Off-Nadir Images DISPARITY Maps ELEVATION Data CO-REGISTRATION Building Detection line-OF-sight DSM
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Efficacy of gefitinib as a first-line single agent treatment in patients with advanced non-small cell lung cancer 被引量:1
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作者 Yongmei Yin Yiting Geng Xiaodong Li Xiaoli Hu Xiaofeng Chen Wei Li Yongqian Shu 《Journal of Nanjing Medical University》 2009年第6期392-397,共6页
Objective: To assess the efficacy and toxicity of gefitinib as a single agent treatment in Chinese patients with advanced non-small cell lung cancer (NSCLC). Methods: Forty-five patients with advanced NSCLC were t... Objective: To assess the efficacy and toxicity of gefitinib as a single agent treatment in Chinese patients with advanced non-small cell lung cancer (NSCLC). Methods: Forty-five patients with advanced NSCLC were treated with gefitinib at 250 mg daily until the disease progressed or the patient could not tolerate the toxicity. Results: None of the patients achieved a complete response (CR), while 15 patients achieved a partial remission (PR) and 17 experienced a stable disease (SD). Thirteen patients continued to have a progressive disease (PD). The response rate and the disease control rate were 33.3% and 71.1%, respectively. The symptom remission rate was 72.5%, and the median remission time was 8 days. The median survival time was 15.3 months. The median progression-free survival time was 6.0 months. The most common toxicities included rash (53.3%) and diarrhea (33.3%). Dehydration and pruritus of the skin developed in 26.7% and 22.2% of the patients, respectively. Hepatic toxicity occurred in 6.7% of patients and oral ulceration occurred in 4.4% of patients. Conclusion: Single agent treatment with gefitinib is effective against advanced NSCLC, and is well tolerated in Chinese patients. 展开更多
关键词 GEFITINIB non-small cell lung cancer (NSCLC) first-line treatment
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Intersecting Line of Conical Surface and Smoothly Blending of Two Tubes Whose Axes Are Non-Coplanar 被引量:1
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作者 Genzhu Bai Zhi Wu Xiao Lin 《Journal of Applied Mathematics and Physics》 2017年第9期1887-1991,共105页
We construct two conical surfaces which take non-coplanar lines as generatrix and rational Bezier curve as ridge-line, and prove that the intersecting line of conical surface has similar properties to Bezier curve. Th... We construct two conical surfaces which take non-coplanar lines as generatrix and rational Bezier curve as ridge-line, and prove that the intersecting line of conical surface has similar properties to Bezier curve. Then, the smoothly blending of two cylinders whose axes are non-coplanar is realized by taking intersecting line of conical surface as axes. 展开更多
关键词 BEZIER CURVE Intersecting line of Conical Surface TUBES non-Coplanar TUBES Smoothly BLENDING
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Application of the sun line-of-sight vector in the optimal attitude estimation of deep-space probe
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作者 常晓华 崔祜涛 邵巍 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2011年第2期96-100,共5页
This paper proposed an optimal algorithm using the sun line-of-sight vector to improve the probe attitude estimation accuracy in deep-space mission.Firstly,the elaborate analysis of the attitude estimation error from ... This paper proposed an optimal algorithm using the sun line-of-sight vector to improve the probe attitude estimation accuracy in deep-space mission.Firstly,the elaborate analysis of the attitude estimation error from vector observations was done to demonstrate that the geometric relation between the reference vectors is an important factor which influences the accuracy of attitude estimation.Then,with introduction of the sun line-of-sight vector,the attitude quaternion obtained from the star-sensor was converted into a pair of mutually perpendicular reference vectors perpendicular to the sun vector.The normalized weights were calculated according to the accuracy of the sensors.Furthermore,the optimal attitude estimation in the least squares sense was achieved with the quaternion estimation method.Finally,the results of simulation demonstrated the validity of the proposed optimal algorithm based on the practical data of the Deep Impact mission. 展开更多
关键词 sun line-of-sight vector attitude estimation deep-space probe
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A Non-Monotone Trust Region Method with Non-Monotone Wolfe-Type Line Search Strategy for Unconstrained Optimization
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作者 Changyuan Li Qinghua Zhou Xiao Wu 《Journal of Applied Mathematics and Physics》 2015年第6期707-712,共6页
In this paper, we propose and analyze a non-monotone trust region method with non-monotone line search strategy for unconstrained optimization problems. Unlike the traditional non-monotone trust region method, our alg... In this paper, we propose and analyze a non-monotone trust region method with non-monotone line search strategy for unconstrained optimization problems. Unlike the traditional non-monotone trust region method, our algorithm utilizes non-monotone Wolfe line search to get the next point if a trial step is not adopted. Thus, it can reduce the number of solving sub-problems. Theoretical analysis shows that the new proposed method has a global convergence under some mild conditions. 展开更多
关键词 UNCONSTRAINED Optimization non-Monotone TRUST Region Method non-Monotone line Search Global Convergence
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On-Line Structural Breaks Estimation for Non-stationary Time Series Models
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作者 成孝刚 李勃 陈启美 《China Communications》 SCIE CSCD 2011年第7期95-104,共10页
Non-stationary time series could be divided into piecewise stationary stochastic signal. However, the number and locations of breakpoints, as well as the approximation function of the respective segment signal are unk... Non-stationary time series could be divided into piecewise stationary stochastic signal. However, the number and locations of breakpoints, as well as the approximation function of the respective segment signal are unknown. To solve this problem, a novel on-line structural breaks estimation algorithm based on piecewise autoregressive processes is proposed. In order to find the "best" combination of the number, lengths, and orders of the piecewise autoregressive (AR) processes, the Akaikes Information Criterion (AIC) and Yule-Walker equations are applied to estimate an AR model fit to the data. Numerical results demonstrate that the proposed estimation algorithm is suitable for different data series. Furthermore, the algorithm is used in a clinical study of electroencephalogram (EEG) with satisfactory results, and the ability to deal with real-time data is the most outstanding characteristic of on-line structural breaks estimation algorithm proposed. 展开更多
关键词 non-stationary signal on-line structural breaks estimation ARMA model BREAKPOINT autocorrelation function DICHOTOMY
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