期刊文献+
共找到14篇文章
< 1 >
每页显示 20 50 100
Access network selection strategy using position prediction in heterogeneous wireless networks
1
作者 Chen GU Mei SONG +1 位作者 Yong ZHANG Junde SONG 《Frontiers of Electrical and Electronic Engineering in China》 CSCD 2010年第1期23-28,共6页
Access network selection(ANS)strategy is one of the most important issues in future heterogeneous networks.The current solutions for this issue are not very efficient because they do not consider the motion scenarios ... Access network selection(ANS)strategy is one of the most important issues in future heterogeneous networks.The current solutions for this issue are not very efficient because they do not consider the motion scenarios and cannot predict the next location for mobile node.In this paper,an effective ANS strategy based on global positioning system(GPS)is proposed.Making use of information such as position coordinates and moving velocity acquired by GPS,the ANS proposed can predict the next point of attachment for mobile node(MN),assist existing ANS strategy to make more reasonable decision,and achieve better performance. 展开更多
关键词 position prediction access network selection(ANS) heterogeneous networks global positioning system(GPS)
原文传递
Ship Detection and Recognition Based on Improved YOLOv7 被引量:3
2
作者 Wei Wu Xiulai Li +1 位作者 Zhuhua Hu Xiaozhang Liu 《Computers, Materials & Continua》 SCIE EI 2023年第7期489-498,共10页
In this paper,an advanced YOLOv7 model is proposed to tackle the challenges associated with ship detection and recognition tasks,such as the irregular shapes and varying sizes of ships.The improved model replaces the ... In this paper,an advanced YOLOv7 model is proposed to tackle the challenges associated with ship detection and recognition tasks,such as the irregular shapes and varying sizes of ships.The improved model replaces the fixed anchor boxes utilized in conventional YOLOv7 models with a set of more suitable anchor boxes specifically designed based on the size distribution of ships in the dataset.This paper also introduces a novel multi-scale feature fusion module,which comprises Path Aggregation Network(PAN)modules,enabling the efficient capture of ship features across different scales.Furthermore,data preprocessing is enhanced through the application of data augmentation techniques,including random rotation,scaling,and cropping,which serve to bolster data diversity and robustness.The distribution of positive and negative samples in the dataset is balanced using random sampling,ensuring a more accurate representation of real-world scenarios.Comprehensive experimental results demonstrate that the proposed method significantly outperforms existing state-of-the-art approaches in terms of both detection accuracy and robustness,highlighting the potential of the improved YOLOv7 model for practical applications in the maritime domain. 展开更多
关键词 Ship position prediction target detection YOLOv7 data augmentation techniques
下载PDF
Diagnosis of Helicobacter pylori Infection in Low Out-Outcome Country: Rapid Urease Test, Serological Test, versus Direct Microbiological Examination with Gram Stain
3
作者 Winnie Tatiana Bekolo Nga Guy Roger Nsenga Djapa +9 位作者 Kelly Ilinga Meme Mamende Antonin Wilson Ndjitoyap Ndam David Sepo Sepo Agnès Malongue Firmin Ankouane Andoulo Oudou Njoya Henry Luma Namme Elie Claude Ndjitoyap Ndam Carole Else Eboumbou Servais Albert Fiacre Eloumou Bagnaka 《Open Journal of Gastroenterology》 2023年第6期199-208,共10页
Introduction: Helicobacter pylori is a gram-negative bacillus responsible for numerous gastroduodenal pathologies, and this infection is a public health problem. The prevalence of infection with this bacterium remains... Introduction: Helicobacter pylori is a gram-negative bacillus responsible for numerous gastroduodenal pathologies, and this infection is a public health problem. The prevalence of infection with this bacterium remains high in countries with limited resources. Diagnosis relies mainly on numerous invasive and noninvasive methods. The aim of this work was to evaluate the different indirect diagnostic methods using bacterial cultures. Methods: We conducted a cross-sectional and analytical study from January to May 2022 in the gastroenterology departments of Douala General Hospital and Douala Military Hospital. All patients aged 18 years and older who were in the gastroenterology consultation and agreed to participate were included in our study. Sociodemographic, clinical, and paraclinical data were collected. Urease, liquid urea, and culture tests were performed from the specimens obtained by fibroscopy. Serological tests were performed on the blood sample. Results: 101 patients were included, 58 were female and 43 were male, for a sex ratio of 1.3. The mean age was 44.2 ± 16 years. The prevalence of infection was 90.5%, 44.1%, 40.6% and 21.8% for serology, direct microbiological examination, RUT (rapid urea test) and culture, respectively. Comparison of the different tests showed sensitivity and specificity of 67.1% and 64%, respectively, for RUT, 100% and 73.7%, respectively, for direct microbiological examination, and 100% and 14.8%, respectively, for serology. The positive and negative predictive values were 39.5% and 100% for serology, 39% and 85% for RUT, and 55.6% and 100% for direct microbiological examination, respectively. Conclusion: The prevalence of Helicobacter pylori infection depends on the type of test used. Direct examination is more reliable than RUT and serology. 展开更多
关键词 Helicobacter pylori Diagnostic Tests Sensitivity SPECIFICITY Positive and Negative Predictive Value
下载PDF
Attention-based LSTM predictive model for the attitude and position of shield machine in tunneling 被引量:1
4
作者 Qing Kang Elton J.Chen +2 位作者 Zhong-Chao Li Han-Bin Luo Yong Liu 《Underground Space》 SCIE EI CSCD 2023年第6期335-350,共16页
Shield machine may deviate from its design axis during excavation due to the uncertainty of geological environment and the complexity of operation.This study therefore introduced a framework to predict the attitude an... Shield machine may deviate from its design axis during excavation due to the uncertainty of geological environment and the complexity of operation.This study therefore introduced a framework to predict the attitude and position of shield machine by combining long short-term memory(LSTM)model with attention mechanism.The data obtained from the Wuhan Rail Transit Line 6 project were utilized to verify the feasibility of the proposed method.By adding the attention mechanism into the LSTM model,the proposed model can focus more on parameters with higher weights.Sensitivity analysis based on Pearson correlation coefficient was conducted to improve the prediction efficiency and reduce the irrelevant input parameters.Compared with LSTM model,LSTM-attention model has higher accuracy.The mean value of coefficient of determination(R^(2))increases from 0.625 to 0.736,and the mean value of root mean square error(RMSE)decreases from 3.31 to 2.24.The proposed LSTM-attention model can provide an effective prediction for attitude and position of shield machine in practical tunneling engineering. 展开更多
关键词 LSTM Shield machine Attitude and position prediction Attention mechanism Tunnel excavation
原文传递
Accuracy of optimized Sirius ray-tracing method in intraocular lens power calculation 被引量:1
5
作者 Li-Qing Wei Ying-Hui Fu +4 位作者 Wei-Hua Pan Li Nie Yu Chen Gui-Fang Liu Zhen-Bin Qian 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2022年第2期228-232,共5页
AIM:To evaluate the accuracy and predictability of ray tracing-assisted intraocular lens(IOL) calculation function in Sirius internal software and further improve the accuracy by optimizing the calculation of predicte... AIM:To evaluate the accuracy and predictability of ray tracing-assisted intraocular lens(IOL) calculation function in Sirius internal software and further improve the accuracy by optimizing the calculation of predicted lens position(PLP).METHODS:This retrospective study recruited 52 eyes of 49 patients.All of the cases with cataract had undergone phacoemulsification combined with IOL implantation.SRK-T,Haigis formula,and Sirius ray-tracing method were all used for each eye’s IOL calculation.The mean absolute value of prediction error(prediction error=predicted refraction-postoperative refraction) was defined as mean absolute prediction error(MAPE) and was determined for each method.Calculation of PLP was optimized by effective lens position(ELP).Optimized PLP was entered to Sirius internal software again to verify whether the method was improved.RESULTS:Compared with SRK-T and Haigis formulas,less accuracy was shown in Sirius ray-tracing method(P=0.001).The ELP of the IOL moved forward compared to PLP(P<0.001).The MAPE of the ELP-inputted Sirius ray-tracing method was reduced.ELP and PLP were well correlated.Taking ELP as y and PLP given by Sirius soft as x,a linear regression formula y=0.1637 x+3.1741 was concluded(R^(2)=0.1066,P=0.018).It was shown that the optimized Sirius ray-tracing method(optimized PLP entered),compared with SRK-T and Haigis formulas,worked with the same accuracy(P=0.038).CONCLUSION:The original Sirius ray tracing method is not satisfactory enough.However,in normal eyes,the optimized Sirius ray-tracing method in IOL calculation was as accurate as SRK-T and Haigis formulas. 展开更多
关键词 Sirius RAY-TRACING IOL-MASTER CATARACT refractive error predicted IOL position
下载PDF
Evaluation of the immunochromatographic strip test for the rapid diagnosis of antenatal syphilis in women in Eldoret,Kenya
6
作者 Lydia B. Nyamwamu Michael M. Gicheru +3 位作者 Rekha R. Sharma lbert Kimutai Willy K.Tonui Peter Kamau Ngure 《Journal of Nanjing Medical University》 2009年第5期317-321,共5页
Objective: This study compared the performance of the immunochromatographic strip (ICS) to the Venereal Disease Research Laboratory (VDRL) test and Treponema pallidum haemagglutination assay (TPHA) at a primary... Objective: This study compared the performance of the immunochromatographic strip (ICS) to the Venereal Disease Research Laboratory (VDRL) test and Treponema pallidum haemagglutination assay (TPHA) at a primary health care setting. Methods: The study group was comprised of 150 females randomly drawn from a population of pregnant women attending their first antenatal visit or follow-up visits at West Maternity Hospital in Eldoret Kenya, but without a previous syphilis test during that pregnancy. On-site VDRL, ICS and TPHA tests were performed and immediate treatment provided where appropriate. The performance of the three tests was compared, Results: The sero-prevalence of syphilis as determined by the VDRL test was 3%. There was no significant difference between the ICS and the VDRL test (P 〉 0.05). The sensitivity and specificity of the ICS test were 80% and 98.6% respectively, while the negative predictive value (NPV) and positive predictive value (PPV) were both 100%. On the other hand, the sensitivity and specificity of the VDRL test were 66.7% and 99.3%, while the NPV and PPV were 80% and 98.6% respectively. The Treponema pallidum haemagglutination assay was used as a reference test and had sensitivity, specificity, NPV and PPV of 100%. Conclusion: The diagnostic accuracy of the ICS compared favorably with theVDRL gold standard. The use of the ICS in Kenya can improve the diagnosis of syphilis in health facilities both with and without laboratories and allow community health care workers to make a rapid diagnosis of the disease, and consequently make immediate therapeutic decisions. 展开更多
关键词 SYPHILIS Immunochromatographic strip test Venereal Disease Research Laboratory Treponema Pa//idum haemagglutinationAssay SPECIFICITY Sensitivity Positive Predictive Value Negative Predictive Value antenatal syphilis
下载PDF
Predictive power of statistical significance
7
作者 Thomas F Heston Jackson M King 《World Journal of Methodology》 2017年第4期112-116,共5页
A statistically significant research finding should not be defined as a P-value of 0.05 or less, because this definition does not take into account study power. Statistical significance was originally defined by Fishe... A statistically significant research finding should not be defined as a P-value of 0.05 or less, because this definition does not take into account study power. Statistical significance was originally defined by Fisher RA as a P-value of 0.05 or less. According to Fisher, any finding that is likely to occur by random variation no more than 1 in 20 times is considered significant. Neyman J and Pearson ES subsequently argued that Fisher's definition was incomplete. They proposed that statistical significance could only be determined by analyzing the chance of incorrectly considering a study finding was significant(a Type Ⅰ?error) or incorrectly considering a study finding was insignificant(a Type Ⅱ error). Their definition of statistical significance is also incomplete because the error rates are considered separately, not together. A better definition of statistical significance is the positive predictive value of a P-value, which is equal to the power divided by the sum of power and the P-value. This definition is more complete and relevant than Fisher's or Neyman-Peason's definitions, because it takes into account both concepts of statistical significance. Using this definition, a statistically significant finding requires a P-value of 0.05 or less when the power is at least 95%, and a P-value of 0.032 or less when the power is 60%. To achieve statistical significance, P-values must be adjusted downward as the study power decreases. 展开更多
关键词 Statistical significance Positive predictive value BIOSTATISTICS Clinical signifcance Powe
下载PDF
Evaluation of Sensitivity and Positive Predictive Values of Cytopathologic Diagnosis of Solid Masses in Dogs
8
作者 Richard M. Kabuusu Tracy Volger +7 位作者 Sachin Kumthekar Keshaw Tiwari Alfred Chikweto Muhammad I. Bhaiyat Claude De Allie Ruth Alexander Carla Richards Ravindra N. Sharma 《Open Journal of Veterinary Medicine》 2016年第6期95-98,共4页
In this retrospective study, a total of 275 solid masses were examined for cytopathologic diagnosis. Twenty four percent (67/275) of these cytologic samples were followed by surgical biopsy and histopathologic diagnos... In this retrospective study, a total of 275 solid masses were examined for cytopathologic diagnosis. Twenty four percent (67/275) of these cytologic samples were followed by surgical biopsy and histopathologic diagnosis, allowing for comparisons. On average, the cutaneous and subcutaneous solid masses were recognized when the dogs were aged between 6 and 9 years old. The origins of the solid masses included connective tissue tumors 37.1% (23/62), epithelial tissue tumors 33.9% (21/62), round cell tumors 19.4% (12/62), masses of inflammatory lesions 4.8% (3/62) and lesions due to other causes 4.8% (3/62). The sensitivity and positive predictive value (PPV) of cytopathology in the diagnosis of solid masses were 93% (62/67) and 97% (62/64), respectively. Generally, neo-plasms were over diagnosed by cytopathology as was indicated by the positive predictive value. Both the sensitivity and the PPV of cytopathology comparative to histopathology in the diagnosis of inflammatory processes were 100% (3/3). The inflammatory lesions were eventually confirmed as necrotizing myositis, necro-suppurative cystitis and endocrine inflammatory dermatopathy based on histopathology. Less than 8% (5/67) of samples were incorrectly diagnosed by cytology. The study showed high accuracy between cytological and histopathological examination of solid masses in dogs, and thus a reliable diagnostic tool in patient care. 展开更多
关键词 CYTOPATHOLOGY HISTOPATHOLOGY DOG Sensitivity Positive Predictive Value Solid Masses
下载PDF
Feasibility of the Routine Clinical Use of a Multiplex Virus Polymerase Chain Reaction Assay Based on Blood Virus Detection in Hematopoietic Stem Cell-Transplanted Patients
9
作者 Hiroko Tsunemine Miho Sasaki +9 位作者 Yuriko Zushi Toshiharu Saitoh Norio Shimizu Yasuhiro Tomaru Yumi Aoyama Ryusuke Yamamoto Tomomi Sakai Nobuyoshi Arima Taiichi Kodaka Takayuki Takahashi 《International Journal of Clinical Medicine》 2022年第2期67-81,共15页
Background: Multiplex virus assays are useful in immunocompromised hosts but still challenging in routine clinical settings in terms of their sensitivity, specificity, reproducibility, and time and cost performances. ... Background: Multiplex virus assays are useful in immunocompromised hosts but still challenging in routine clinical settings in terms of their sensitivity, specificity, reproducibility, and time and cost performances. In recent years, we developed a qualitative multiplex virus PCR assay capable of the simultaneous detection of 13 virus species within 3 h. However, because of the multiple and concomitant nature of this virus assay, it should be validated for qualitative reliability. Materials and Methods: As a preclinical examination, this multiplex PCR was able to detect 1.25 × 10<sup>3</sup> copies/mL of 13 synthesized virus genomes and preserved same virus DNAs by the serial dilution method. Blood samples from 40 patients who underwent hematopoietic stem cell transplantation were then examined by multiplex PCR for 13 virus species, followed by quantitative real-time PCR for all 13 virus species as reference PCR when these patients developed symptoms suggestive of viral infection. Results: In 421 cumulative qualitative-quantitative tests, the multiplex PCR certainly detected 1.0 × 103 copies/mL of 5 viruses (CMV, JCV, BKV, HHV-6, ADV) that were frequently detected and thus reasonably analyzed. The positive and negative predictive values of multiplex PCR were 84.2% - 93.3% and 90.7% - 99.0%, respectively, and sensitivity and specificity were 59.0% - 83.3% and 97.2% - 99.2%, respectively, for these 5 viruses. Conclusion: From these performances, the multiplex PCR assay may be acceptable in a routine clinical laboratory setting. 展开更多
关键词 Multiplex Virus PCR Assay Routine Laboratory Use Positive Predictive Value Negative Predictive Value Sensitivity SPECIFICITY
下载PDF
The evolution characteristics of positive and negative earthquakes before strong quakes in Kanto area and the Hyugo earthquake in Japan
10
作者 王裕仓 宋治平 +2 位作者 细野耕司 陈学中 尹祥础 《Acta Seismologica Sinica(English Edition)》 CSCD 1998年第1期33-40,共8页
This paper studies the evolution charateristics of positive and negative quakes before Hyugo earthquake of M =7.2 and several strong quakes in Kanto area in Japan.The results show that the earthquakes over a certai... This paper studies the evolution charateristics of positive and negative quakes before Hyugo earthquake of M =7.2 and several strong quakes in Kanto area in Japan.The results show that the earthquakes over a certain megnitude are mainly positive ones a certain time before the main shock in or near the focal regions of most strong quakes,and form a concentratingintervals of positive quakes,The main quakes generally locate in or near the areas of positive quake distribution.Negative quakes often occur several months before the main shocks (not excluding positive ones), with the decrease of LURR (Loading/Unloading Response Ratio) values.It possibly shows that earthquake generating process has come to a short term stage.These characteristics may help to predict the time and location of the future earthquakes,and have been applied to the preliminary prediction of the time and the location of the earthquake of M =6.6 on Sep.11,1996 in Kanto area. 展开更多
关键词 Load/Unload Response Ratio (LURR) positive and negative quake earthquake prediction Hyugo earthquake
下载PDF
Economic recovery in Greater China—Surveys in Hong Kong and China's Mainland predict a positive outlook for both economies
11
《China Economist》 2009年第5期123-126,共4页
Two surveys conducted in Hong Kong and China's Mainland reveal predictions of a quick recovery ahead for both economies.The surveys were conducted by CPA Australia,with the Hong Kong survey jointly sponsored by De... Two surveys conducted in Hong Kong and China's Mainland reveal predictions of a quick recovery ahead for both economies.The surveys were conducted by CPA Australia,with the Hong Kong survey jointly sponsored by Deloitte China and CPA Australia’s Hong Kong China division. 展开更多
关键词 over Surveys in Hong Kong and China's Mainland predict a positive outlook for both economies Economic recovery in Greater China
下载PDF
Nested Group Testing Procedure
12
作者 Wenjun Xiong Juan Ding +2 位作者 Wei Zhang Aiyi Liu Qizhai Li 《Communications in Mathematics and Statistics》 SCIE CSCD 2023年第4期663-693,共31页
We investigated the false-negative,true-negative,false-positive,and true-positive predictive values from a general group testing procedure for a heterogeneous population.We show that its false(true)-negative predictiv... We investigated the false-negative,true-negative,false-positive,and true-positive predictive values from a general group testing procedure for a heterogeneous population.We show that its false(true)-negative predictive value of a specimen is larger(smaller),and the false(true)-positive predictive value is smaller(larger)than that from individual testing procedure,where the former is in aversion.Then we propose a nested group testing procedure,and show that it can keep the sterling characteristics and also improve the false-negative predictive values for a specimen,not larger than that from individual testing.These characteristics are studied from both theoretical and numerical points of view.The nested group testing procedure is better than individual testing on both false-positive and false-negative predictive values,while retains the efficiency as a basic characteristic of a group testing procedure.Applications to Dorfman’s,Halving and Sterrett procedures are discussed.Results from extensive simulation studies and an application to malaria infection in microscopy-negative Malawian women exemplify the findings. 展开更多
关键词 Group testing Negative predictive value Positive predictive value RETEST
原文传递
Error-space estimate method for generalized synergic target tracking
13
作者 Ming CEN Chengyu FU +1 位作者 Ke CHEN Xingfa LIU 《Frontiers of Electrical and Electronic Engineering in China》 CSCD 2009年第1期88-92,共5页
To improve the tracking accuracy and stability of an optic-electronic target tracking system,the concept of generalized synergic target and an algorithm named error-space estimate method is presented.In this algorithm... To improve the tracking accuracy and stability of an optic-electronic target tracking system,the concept of generalized synergic target and an algorithm named error-space estimate method is presented.In this algorithm,the motion of target is described by guide data and guide errors,and then the maneuver of the target is separated into guide data and guide errors to reduce the maneuver level.Then state estimate is implemented in target state-space and error-space respectively,and the prediction data of target position are acquired by synthesizing the filtering data from target state-space according to kinematic model and the prediction data from errorspace according to guide error model.Differing from typical multi-model method,the kinematic and guide error models work concurrently rather than switch between models.Experiment results show that the performance of the algorithm is better than Kalman filter and strong tracking filter at the same maneuver level. 展开更多
关键词 target tracking generalized synergic target position prediction error-space estimate
原文传递
Screening for colorectal cancer in Tianhe,Guangzhou:results of combining fecal immunochemical tests and risk factors for selecting patients requiring colonoscopy
14
作者 Yi Liao Senmao Li +5 位作者 Chunyu Chen Xuan He Feng Lin Jianping Wang Zuli Yang Ping Lan 《Gastroenterology Report》 SCIE EI 2018年第2期132-136,I0003,共6页
Objective:To explore the performance of a protocol combining fecal immunochemical test(FIT)and a high-risk factor questionnaire(HRFQ)for selecting patients requiring colonoscopy as part of a population-based colorecta... Objective:To explore the performance of a protocol combining fecal immunochemical test(FIT)and a high-risk factor questionnaire(HRFQ)for selecting patients requiring colonoscopy as part of a population-based colorectal cancer(CRC)screening program in China.Methods:From 2015 to 2016,we conducted a CRC screening program for all residents aged 45 years or older in Tianhe District,Guangzhou City,China.Participants underwent an FIT and received an HRFQ as part of primary screening.Those with positive FIT and/or HRFQ results were considered to be at high risk and were recommended to undergo colonoscopy.Results:A total of 10074 subjects were recruited and enrolled in the screening program.In the enrolled population,17.5%had positive FIT results and 19.4%had positive HRFQ results.Of those recommended to undergo diagnostic colonoscopy,773 did so.The screening method’s overall positive predictive value(PPV)was 4.9%for non-adenomatous polyps,11.4%for low-risk adenomas(LRAs),15.9%for high-risk adenomas(HRAs)and 1.6%for CRC.The PPVs of positive FIT results for nonadenomatous polyps,LRAs,HRAs and CRC were 5.2%,15.9%,22.5%and 2.5%,respectively.The PPVs of positive HRFQ results for non-adenomatous polyps,LRA,HRA and CRC were 4.1%,10.2%,14.3%and 1.4%,respectively.The PPVs associated with combined positive FIT and HRFQ results for non-adenomatous polyps,LRAs,HRAs and CRC were 4.5%,16.4%,23.7%and 2.8%,respectively.Conclusion:Our results suggest that this two-step CRC screening strategy,involving a combination of FIT and HRFQ followed by colonoscopy,is useful to identify early-stage CRC.The high detection rates and PPVs for CRC and adenomas encourage this strategy’s use in ongoing screening programs. 展开更多
关键词 colorectal cancer SCREENING fecal immunochemical test high-risk factors COLONOSCOPY positive predictive value
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部