AIM:To evaluate whether celecoxib,a selective cyclooxygenase 2(COX-2) inhibitor,could reduce the severity of gastric precancerous lesions following Helicobacter pylori(H pylori) eradication.METHODS:H pylori-eradicated...AIM:To evaluate whether celecoxib,a selective cyclooxygenase 2(COX-2) inhibitor,could reduce the severity of gastric precancerous lesions following Helicobacter pylori(H pylori) eradication.METHODS:H pylori-eradicated patients with gastric precancerous lesions randomly received either celecoxib(n=30) or placebo(n=30) for up to 3 mo.COX-2 expression and activity was determined by immunostaining and prostaglandin E2(PGE2) assay,cell proliferation by Ki-67 immunostaining,apoptosis by TUNEL staining and angiogenesis by microvascular density(MVD) assay using CD31 staining.RESULTS:COX-2 protein expression was significantly increased in gastric precancerous lesions(atrophy,intestinal metaplasia and dysplasia,respectively) compared with chronic gastritis,and was concomitant with an increase in cell proliferation and angiogenesis.A significant improvement in precancerous lesions was observed in patients who received celecoxib compared with those who received placebo(P<0.001).Of these three changes,84.6% of sites with dysplasia regressed in patients treated with celecoxib(P=0.002) compared with 60% in the placebo group,suggesting that celecoxib was effective on the regression of dysplasia.COX-2 protein expression(P<0.001) and COX-2 activity(P<0.001) in the gastric tissues were consistently lower in celecoxib-treated patients compared with the placebo-treated subjects.Moreover,it was also shown that celecoxib suppressed cell proliferation(P<0.01),induced cell apoptosis(P<0.01) and inhibited angiogenesis with decreased MVD(P<0.001).However,all of these effects were not seen in placebo-treated subjects.Furthermore,COX-2 inhibition resulted in the up-regulation of PPARγ expression,a protective molecule with anti-neoplastic effects.CONCLUSION:H pylori eradication therapy followed by celecoxib treatment improves gastric precancerous lesions by inhibiting COX-2 activity,inducing apoptosis,and suppressing cell proliferation and angiogenesis.展开更多
During the period of May to October in1999,systematical studies were giv en to the rate of decomposition of Calamagrostis angustifolia litter,the phosphorus content and weight in decomposed residua of litte r,and phos...During the period of May to October in1999,systematical studies were giv en to the rate of decomposition of Calamagrostis angustifolia litter,the phosphorus content and weight in decomposed residua of litte r,and phosphorus content in the corresponding soil in the Sanjiang Plain.At the same time,the simulation models were listed in the paper.The results showed that the rate of we ight lost of decomposition of Calamagrostis angustifolia litter is 29.80%and the maximum of daily rate of weight lost i s 0.25%,which appeared in July.The c hange trend of phosphorus content an d weight in the decomposed residua of l itter is to reduce with the decomposing process,when it comes to the day of157,the decrement amount of the both were respectively 57.69mg /kg and 1.6199mg,which were 72.80%and 76.30%of its previous amount.In addition,th ere is a polynomial minus correlatio nship of phosphorus content between the variation in corresponding soil and the decomp osed residua of litter at the corresp onding period.The study will be help ful to further understand the process and mechanis m of biochemical cycling of nutrient elements in wetland ecosystems,in a ddition,it will also be helpful to the restoration and rebuilding of retrogressive wetlands and reasonable development and utilization of wetlands in the Sanjiang Plain.展开更多
The multi-roller straightening process of section steel is analyzed by the springback theory of small curva- ture plane bending. The theoretical analysis results prove the curvature unification in straightening proces...The multi-roller straightening process of section steel is analyzed by the springback theory of small curva- ture plane bending. The theoretical analysis results prove the curvature unification in straightening process and clear- ly reveal the principle of the multi-roller straightening process. The principle can be described as~ the initial curva- tures are reduced by several times anti-bendingl meanwhile the initial curvature differences are diminished and the residual curvatures are unified~ finally, the member after curvature unification is straightened by the last anti-ben- ding. With the plastic region ratios becoming larger, the initial curvatures are more easily unified in straightening process. Based on the plastic region ratios and the required number of roller systems for unifying the initial curva- tures, the large deformation straightening strategy and the small deformation straightening strategy are redefined. The new definition provides an important theoretical basis for setting reliable reduction rules. Through the theoretical analysis results, a new straightener design philosophy is proposed to improve the straightening quality and further increase the adjustment precision as well as the flexibility of the last roller system. The adjustable end roller emerges as the times required, achieving a good effect in practical application.展开更多
Background: Some patients with pelvic organ prolapse may suffer from incontinence (SUI) named de novo SUI alter pelvic floor reconstruction of de novo SUI. ower urinary tract symptoms (LUTS), especially stress ur...Background: Some patients with pelvic organ prolapse may suffer from incontinence (SUI) named de novo SUI alter pelvic floor reconstruction of de novo SUI. ower urinary tract symptoms (LUTS), especially stress urinary This study aimed to investigate the incidence and risk factors Methods: This is a nested case-control study of 533 patients who underwent pelvic floor reconstruction due to pelvic organ prolapse (POP) at the Department of Gynecology in Peking University People's Hospital from January 2011 to March 2013. According to the inclusion and exclusion criteria, 401 patients were enrolled in the study with the follow-up rate of 74.8% (101 patients lost to follow-up). There were 75 patients with de novo SUI postoperatively. According to the ratio of 1:3, we ensured the number of control group (n = 225). The preoperative urinary dynamics, POP-quantification scores, and LUTS were compared between the two groups by univariate and multivariate logistic regression analyses to investigate the risk factors of de novo SUI. Results: The incidence of de novo SUI was 25% (75/300). Univariate analysis showed that the ratio of lower urinary tract obstruction (LUTO) before surgery in de novo SUI group was significantly higher than the control group (odds ratio [OR] = 2.1, 95% confidence interval [(7] [1.1-4.0], P = 0.022). The interaction test of LUTO and other factors displayed that Aa value was an interaction factor. With the increasing score of Aa, the incidence of de novo SUI become higher (OR = 2.1, 95% CI [1.0-3.7], P = 0.045). After multivariable adjustment, multiple regression analysis showed that LUTO was independently associated with a greater risk of de novo SUI after pelvic floor surgery (OR = 2.3, 95% CI [1.2-4.6], P = 0.013). Conclusions: Preoperative LUTO in patients with POP is a high-risk factor of de novo SUI, and high score of Aa-point is related to the occurrence of de novo SUI, which might be due to the outlet obstruction caused by bladder prolapse.展开更多
Background:After radical hysterectomy for cervical cancer,the most common complication is lower urinary tract symptoms.Post-operatively,bladder capacity can alter bladder function for a prolonged period.This study aim...Background:After radical hysterectomy for cervical cancer,the most common complication is lower urinary tract symptoms.Post-operatively,bladder capacity can alter bladder function for a prolonged period.This study aimed to identify factors affecting bladder storage function.Methods:A multicenter,retrospective cohort study was conducted.Information of patients with stages IA2 to IIB cervical cancer with urodynamic study results were retrospectively collected from nine hospitals between June 2013 and June 2018 according to the inclusion criteria.Demographic,surgical,and oncological data were collected.The univariate and multivariate logistic regression was used to identify clinical factors associated with bladder storage function.Results:Two hundred and three patients with cervical cancer had urodynamic testing post-operatively.Ninety-five(46.8%)patients were diagnosed with stress urinary incontinence(SUI).The incidence of low bladder compliance(LBC)was 23.2%.Twenty-seven(13.3%)patients showed detrusor overactivity(DO).Fifty-seven patients(28.1%)presented with a decreased maximum cystometric capacity(DMCC).The probability of composite bladder storage dysfunction was 68.0%.Multivariate analysis confirmed that laparoscopy represents a protective factor for SUI with an odds ratio of 0.498(P=0.034).Patients who underwent a nerve-sparing procedure were less odds to experience SUI(P=0.014).A significant positive correlation between LBC and DO was observed(P<0.001).A greater length of the resected vagina and chemoradiotherapy were common risk factors for LBC and DO,while radiotherapy exerted a stronger effect than chemotherapy.Additionally,patients who received chemoradiotherapy frequently developed a DMCC.The follow-up time was not correlated with bladder storage function.Conclusion:A nerve-sparing procedure without longer resected vagina is recommended for protecting the bladder storage function.展开更多
Background:Pelvic organ prolapse (POP) is a major health concern that affects women.Surgeons have increasingly used prosthetic meshes to correct POP.However,the most common used is synthetic mesh,and absorbable mes...Background:Pelvic organ prolapse (POP) is a major health concern that affects women.Surgeons have increasingly used prosthetic meshes to correct POP.However,the most common used is synthetic mesh,and absorbable mesh is less reported.This research aimed to evaluate the clinical effectiveness of porcine small intestinal submucosa (SIS).Methods:Consecutive forty POP patients who met the inclusion criteria underwent pelvic reconstruction surgery with SIS between March 2012 and December 2013.The patients&#39; clinical characteristics were recorded preoperatively.Surgical outcomes,measured by objective and subjective success rates,were investigated.We evaluated the quality of life (QOL) using the Pelvic Floor Distress Inventory-20 (PFDI-20) and the Pelvic Floor Impact Questionnaire-7 (PFIQ-7).Sexual QOL was assessed by the Pelvic Organ Prolapse/Urinary Incontinence Sexual Function Questionnaire-12 (P1SQ-12).Results:At postoperative 12 months,the subjective recurrence rate (7.5%) was much lower than the objective recurrence rate (40.0%).Postoperatively,no erosion was identified.One underwent a graft release procedure because of urinary retention,and one had anus sphincter reconstruction surgery due to defecation urgency.Another experienced posterior vaginal wall infection where the mesh was implanted,accompanied by severe vaginal pain.Estrogen cream relieved the pain.One patient with recurrence underwent a secondary surgery with Bard Mesh because of stage 3 anterior vaginal wall prolapse.Scoring system of PFDI-20 was from 59.150 ± 13.143 preoperatively to 8.400 ± 4.749 postoperatively and PFIQ-7 was from 73.350 ± 32.281 to 7.150 ± 3.110,while PISQ-12 was from 15.825 ± 4.050 to 12.725 ± 3.471.Conclusions:QOL and the degree of subjective satisfaction were significantly improved postoperatively.Anterior repair deserves more attention because of the higher recurrence rate.The long-term follow-up of the patient is warranted to draw firm conclusion.展开更多
The planting of the vegetation on the floodplain helps the ecological restoration,which is the main form of the river’s ecological corridor.Therefore,the current research of the river dynamics focuses on the water mo...The planting of the vegetation on the floodplain helps the ecological restoration,which is the main form of the river’s ecological corridor.Therefore,the current research of the river dynamics focuses on the water movement under a compound channel with the vegetated floodplains.Two simulated vegetation species are selected in this paper for the flume simulation experiments of the floodplain vegetation,and the compound channel is divided into three subregions in the transverse direction.The Navier-Stokes equation and the eddy viscosity theory are applied to obtain the transverse distribution of the depth-averaged velocity and the results agree well with the experimental data.This paper proposes a new method based on the analytical solution of the flow velocity distribution to calculate the average flow velocity in each section.Calculation results can effectively simulate the average flow velocity of the measured sections.The description of the pollutant transport processes in a moving stream requires a refined determination of the dispersion coefficients in the compound channel.The process of the pollutant concentrations in each zone and the reasons for their occurrence are elucidated on the basis of the experimental results.Simultaneously,the measured values of the longitudinal dispersion coefficients are obtained by the“routing procedure,”and a two-zone model of the pollutant dispersion is constructed on the basis of the hydrodynamic study.The prediction method for the longitudinal dispersion coefficients is also presented.Applying the predicted and measured section average flow velocities to the two-zone model to predict the longitudinal dispersion coefficient,and the average relative errors are only 4.17%,7.15%,respectively.This result indicates that the two-zone model can effectively predict the longitudinal dispersion coefficients.The calculation methods for the longitudinal dispersion coefficients from—various studies are compared.The results reveal that the predicted values of these calculation methods are all larger than the measured values,indicating that the vegetation has a considerable influence on the dispersion process.This study comprehensively shows the dispersion features of the pollutants and provides a theoretical basis for the planning and the design of the vegetated ecological corridors.展开更多
A method based on 3D videos is proposed for multi-target segmentation and tracking with a moving viewing system. A spatiotemporal energy functional is built up to perform motion segmentation and estimation simultaneou...A method based on 3D videos is proposed for multi-target segmentation and tracking with a moving viewing system. A spatiotemporal energy functional is built up to perform motion segmentation and estimation simultaneously. To overcome the limitation of the local minimum problem with the level set method, a convex relaxation method is applied to the 3D spatiotemporal segmentation model. The relaxed convex model is independent of the initial condition. A primal-dual algorithm is used to improve computational efficiency. Several indoor experiments show the validity of the proposed method.展开更多
基金Support by The National Natural Science Foundation of China, No. 30370637
文摘AIM:To evaluate whether celecoxib,a selective cyclooxygenase 2(COX-2) inhibitor,could reduce the severity of gastric precancerous lesions following Helicobacter pylori(H pylori) eradication.METHODS:H pylori-eradicated patients with gastric precancerous lesions randomly received either celecoxib(n=30) or placebo(n=30) for up to 3 mo.COX-2 expression and activity was determined by immunostaining and prostaglandin E2(PGE2) assay,cell proliferation by Ki-67 immunostaining,apoptosis by TUNEL staining and angiogenesis by microvascular density(MVD) assay using CD31 staining.RESULTS:COX-2 protein expression was significantly increased in gastric precancerous lesions(atrophy,intestinal metaplasia and dysplasia,respectively) compared with chronic gastritis,and was concomitant with an increase in cell proliferation and angiogenesis.A significant improvement in precancerous lesions was observed in patients who received celecoxib compared with those who received placebo(P<0.001).Of these three changes,84.6% of sites with dysplasia regressed in patients treated with celecoxib(P=0.002) compared with 60% in the placebo group,suggesting that celecoxib was effective on the regression of dysplasia.COX-2 protein expression(P<0.001) and COX-2 activity(P<0.001) in the gastric tissues were consistently lower in celecoxib-treated patients compared with the placebo-treated subjects.Moreover,it was also shown that celecoxib suppressed cell proliferation(P<0.01),induced cell apoptosis(P<0.01) and inhibited angiogenesis with decreased MVD(P<0.001).However,all of these effects were not seen in placebo-treated subjects.Furthermore,COX-2 inhibition resulted in the up-regulation of PPARγ expression,a protective molecule with anti-neoplastic effects.CONCLUSION:H pylori eradication therapy followed by celecoxib treatment improves gastric precancerous lesions by inhibiting COX-2 activity,inducing apoptosis,and suppressing cell proliferation and angiogenesis.
文摘During the period of May to October in1999,systematical studies were giv en to the rate of decomposition of Calamagrostis angustifolia litter,the phosphorus content and weight in decomposed residua of litte r,and phosphorus content in the corresponding soil in the Sanjiang Plain.At the same time,the simulation models were listed in the paper.The results showed that the rate of we ight lost of decomposition of Calamagrostis angustifolia litter is 29.80%and the maximum of daily rate of weight lost i s 0.25%,which appeared in July.The c hange trend of phosphorus content an d weight in the decomposed residua of l itter is to reduce with the decomposing process,when it comes to the day of157,the decrement amount of the both were respectively 57.69mg /kg and 1.6199mg,which were 72.80%and 76.30%of its previous amount.In addition,th ere is a polynomial minus correlatio nship of phosphorus content between the variation in corresponding soil and the decomp osed residua of litter at the corresp onding period.The study will be help ful to further understand the process and mechanis m of biochemical cycling of nutrient elements in wetland ecosystems,in a ddition,it will also be helpful to the restoration and rebuilding of retrogressive wetlands and reasonable development and utilization of wetlands in the Sanjiang Plain.
基金Item Sponsored by National Natural Science Foundation of China(51178452)
文摘The multi-roller straightening process of section steel is analyzed by the springback theory of small curva- ture plane bending. The theoretical analysis results prove the curvature unification in straightening process and clear- ly reveal the principle of the multi-roller straightening process. The principle can be described as~ the initial curva- tures are reduced by several times anti-bendingl meanwhile the initial curvature differences are diminished and the residual curvatures are unified~ finally, the member after curvature unification is straightened by the last anti-ben- ding. With the plastic region ratios becoming larger, the initial curvatures are more easily unified in straightening process. Based on the plastic region ratios and the required number of roller systems for unifying the initial curva- tures, the large deformation straightening strategy and the small deformation straightening strategy are redefined. The new definition provides an important theoretical basis for setting reliable reduction rules. Through the theoretical analysis results, a new straightener design philosophy is proposed to improve the straightening quality and further increase the adjustment precision as well as the flexibility of the last roller system. The adjustable end roller emerges as the times required, achieving a good effect in practical application.
文摘Background: Some patients with pelvic organ prolapse may suffer from incontinence (SUI) named de novo SUI alter pelvic floor reconstruction of de novo SUI. ower urinary tract symptoms (LUTS), especially stress urinary This study aimed to investigate the incidence and risk factors Methods: This is a nested case-control study of 533 patients who underwent pelvic floor reconstruction due to pelvic organ prolapse (POP) at the Department of Gynecology in Peking University People's Hospital from January 2011 to March 2013. According to the inclusion and exclusion criteria, 401 patients were enrolled in the study with the follow-up rate of 74.8% (101 patients lost to follow-up). There were 75 patients with de novo SUI postoperatively. According to the ratio of 1:3, we ensured the number of control group (n = 225). The preoperative urinary dynamics, POP-quantification scores, and LUTS were compared between the two groups by univariate and multivariate logistic regression analyses to investigate the risk factors of de novo SUI. Results: The incidence of de novo SUI was 25% (75/300). Univariate analysis showed that the ratio of lower urinary tract obstruction (LUTO) before surgery in de novo SUI group was significantly higher than the control group (odds ratio [OR] = 2.1, 95% confidence interval [(7] [1.1-4.0], P = 0.022). The interaction test of LUTO and other factors displayed that Aa value was an interaction factor. With the increasing score of Aa, the incidence of de novo SUI become higher (OR = 2.1, 95% CI [1.0-3.7], P = 0.045). After multivariable adjustment, multiple regression analysis showed that LUTO was independently associated with a greater risk of de novo SUI after pelvic floor surgery (OR = 2.3, 95% CI [1.2-4.6], P = 0.013). Conclusions: Preoperative LUTO in patients with POP is a high-risk factor of de novo SUI, and high score of Aa-point is related to the occurrence of de novo SUI, which might be due to the outlet obstruction caused by bladder prolapse.
基金the National Key R&D Program of China(2018YFC2002200 and 2018YFC2002204)the Beijing Municipal Science&Technology Commission(No.D151100001915003).
文摘Background:After radical hysterectomy for cervical cancer,the most common complication is lower urinary tract symptoms.Post-operatively,bladder capacity can alter bladder function for a prolonged period.This study aimed to identify factors affecting bladder storage function.Methods:A multicenter,retrospective cohort study was conducted.Information of patients with stages IA2 to IIB cervical cancer with urodynamic study results were retrospectively collected from nine hospitals between June 2013 and June 2018 according to the inclusion criteria.Demographic,surgical,and oncological data were collected.The univariate and multivariate logistic regression was used to identify clinical factors associated with bladder storage function.Results:Two hundred and three patients with cervical cancer had urodynamic testing post-operatively.Ninety-five(46.8%)patients were diagnosed with stress urinary incontinence(SUI).The incidence of low bladder compliance(LBC)was 23.2%.Twenty-seven(13.3%)patients showed detrusor overactivity(DO).Fifty-seven patients(28.1%)presented with a decreased maximum cystometric capacity(DMCC).The probability of composite bladder storage dysfunction was 68.0%.Multivariate analysis confirmed that laparoscopy represents a protective factor for SUI with an odds ratio of 0.498(P=0.034).Patients who underwent a nerve-sparing procedure were less odds to experience SUI(P=0.014).A significant positive correlation between LBC and DO was observed(P<0.001).A greater length of the resected vagina and chemoradiotherapy were common risk factors for LBC and DO,while radiotherapy exerted a stronger effect than chemotherapy.Additionally,patients who received chemoradiotherapy frequently developed a DMCC.The follow-up time was not correlated with bladder storage function.Conclusion:A nerve-sparing procedure without longer resected vagina is recommended for protecting the bladder storage function.
文摘Background:Pelvic organ prolapse (POP) is a major health concern that affects women.Surgeons have increasingly used prosthetic meshes to correct POP.However,the most common used is synthetic mesh,and absorbable mesh is less reported.This research aimed to evaluate the clinical effectiveness of porcine small intestinal submucosa (SIS).Methods:Consecutive forty POP patients who met the inclusion criteria underwent pelvic reconstruction surgery with SIS between March 2012 and December 2013.The patients&#39; clinical characteristics were recorded preoperatively.Surgical outcomes,measured by objective and subjective success rates,were investigated.We evaluated the quality of life (QOL) using the Pelvic Floor Distress Inventory-20 (PFDI-20) and the Pelvic Floor Impact Questionnaire-7 (PFIQ-7).Sexual QOL was assessed by the Pelvic Organ Prolapse/Urinary Incontinence Sexual Function Questionnaire-12 (P1SQ-12).Results:At postoperative 12 months,the subjective recurrence rate (7.5%) was much lower than the objective recurrence rate (40.0%).Postoperatively,no erosion was identified.One underwent a graft release procedure because of urinary retention,and one had anus sphincter reconstruction surgery due to defecation urgency.Another experienced posterior vaginal wall infection where the mesh was implanted,accompanied by severe vaginal pain.Estrogen cream relieved the pain.One patient with recurrence underwent a secondary surgery with Bard Mesh because of stage 3 anterior vaginal wall prolapse.Scoring system of PFDI-20 was from 59.150 ± 13.143 preoperatively to 8.400 ± 4.749 postoperatively and PFIQ-7 was from 73.350 ± 32.281 to 7.150 ± 3.110,while PISQ-12 was from 15.825 ± 4.050 to 12.725 ± 3.471.Conclusions:QOL and the degree of subjective satisfaction were significantly improved postoperatively.Anterior repair deserves more attention because of the higher recurrence rate.The long-term follow-up of the patient is warranted to draw firm conclusion.
基金supported by the Research project of China Three Gorges Corporation(Grant No.202103399)the Talent Program of China Institute of Water Resources and Hydropower Research(Grant No.WE0199A052021)+2 种基金the Basic Scientific Research Expense Project of IWHR(Grant No.WR0145B022021)Project supported by the National Key Research and Development Program of China(Grant No.2019YFD1100205)the National Natural Science Foundation of China(Grant Nos.51809286,52209083,51809288,41501204 and U1802241).
文摘The planting of the vegetation on the floodplain helps the ecological restoration,which is the main form of the river’s ecological corridor.Therefore,the current research of the river dynamics focuses on the water movement under a compound channel with the vegetated floodplains.Two simulated vegetation species are selected in this paper for the flume simulation experiments of the floodplain vegetation,and the compound channel is divided into three subregions in the transverse direction.The Navier-Stokes equation and the eddy viscosity theory are applied to obtain the transverse distribution of the depth-averaged velocity and the results agree well with the experimental data.This paper proposes a new method based on the analytical solution of the flow velocity distribution to calculate the average flow velocity in each section.Calculation results can effectively simulate the average flow velocity of the measured sections.The description of the pollutant transport processes in a moving stream requires a refined determination of the dispersion coefficients in the compound channel.The process of the pollutant concentrations in each zone and the reasons for their occurrence are elucidated on the basis of the experimental results.Simultaneously,the measured values of the longitudinal dispersion coefficients are obtained by the“routing procedure,”and a two-zone model of the pollutant dispersion is constructed on the basis of the hydrodynamic study.The prediction method for the longitudinal dispersion coefficients is also presented.Applying the predicted and measured section average flow velocities to the two-zone model to predict the longitudinal dispersion coefficient,and the average relative errors are only 4.17%,7.15%,respectively.This result indicates that the two-zone model can effectively predict the longitudinal dispersion coefficients.The calculation methods for the longitudinal dispersion coefficients from—various studies are compared.The results reveal that the predicted values of these calculation methods are all larger than the measured values,indicating that the vegetation has a considerable influence on the dispersion process.This study comprehensively shows the dispersion features of the pollutants and provides a theoretical basis for the planning and the design of the vegetated ecological corridors.
基金supported by the National Natural Science Foundation of China (No. 60872069)the National Basic Research Program (973)of China (No. 2012CB316400)
文摘A method based on 3D videos is proposed for multi-target segmentation and tracking with a moving viewing system. A spatiotemporal energy functional is built up to perform motion segmentation and estimation simultaneously. To overcome the limitation of the local minimum problem with the level set method, a convex relaxation method is applied to the 3D spatiotemporal segmentation model. The relaxed convex model is independent of the initial condition. A primal-dual algorithm is used to improve computational efficiency. Several indoor experiments show the validity of the proposed method.