Adaptive H_(∞)Filtering Algorithm for Train Positioning Based on Prior Combination Constraints

To solve the problem of data fusion for prior information such as track information and train status in train positioning,an adaptive H∞filtering algorithm with combination constraint is proposed,which fuses prior information with other sensor information in the form of constraints.Firstly,the train precise track constraint method of the train is proposed,and the plane position constraint and train motion state constraints are analysed.A model for combining prior information with constraints is established.Then an adaptive H∞filter with combination constraints is derived based on the adaptive adjustment method of the robustness factor.Finally,the positioning effect of the proposed algorithm is simulated and analysed under the conditions of a straight track and a curved track.The results show that the positioning accuracy of the algorithm with constrained filtering is significantly better than that of the algorithm without constrained filtering and that the algorithm with constrained filtering can achieve better performance when combined with track and condition information,which can significantly reduce the train positioning error.The effectiveness of the proposed algorithm is verified.

A Novel Filtering-Based Detection Method for Small Targets in Infrared Images

Infrared small target detection technology plays a pivotal role in critical military applications,including early warning systems and precision guidance for missiles and other defense mechanisms.Nevertheless,existing traditional methods face several significant challenges,including low background suppression ability,low detection rates,and high false alarm rates when identifying infrared small targets in complex environments.This paper proposes a novel infrared small target detection method based on a transformed Gaussian filter kernel and clustering approach.The method provides improved background suppression and detection accuracy compared to traditional techniques while maintaining simplicity and lower computational costs.In the first step,the infrared image is filtered by a new filter kernel and the results of filtering are normalized.In the second step,an adaptive thresholding method is utilized to determine the pixels in small targets.In the final step,a fuzzy C-mean clustering algorithm is employed to group pixels in the same target,thus yielding the detection results.The results obtained from various real infrared image datasets demonstrate the superiority of the proposed method over traditional approaches.Compared with the traditional method of state of the arts detection method,the detection accuracy of the four sequences is increased by 2.06%,0.95%,1.03%,and 1.01%,respectively,and the false alarm rate is reduced,thus providing a more effective and robust solution.

WSN Mobile Target Tracking Based on Improved Snake-Extended Kalman Filtering Algorithm

A wireless sensor network mobile target tracking algorithm(ISO-EKF)based on improved snake optimization algorithm(ISO)is proposed to address the difficulty of estimating initial values when using extended Kalman filtering to solve the state of nonlinear mobile target tracking.First,the steps of extended Kalman filtering(EKF)are introduced.Second,the ISO is used to adjust the parameters of the EKF in real time to adapt to the current motion state of the mobile target.Finally,the effectiveness of the algorithm is demonstrated through filtering and tracking using the constant velocity circular motion model(CM).Under the specified conditions,the position and velocity mean square error curves are compared among the snake optimizer(SO)-EKF algorithm,EKF algorithm,and the proposed algorithm.The comparison shows that the proposed algorithm reduces the root mean square error of position by 52%and 41%compared to the SOEKF algorithm and EKF algorithm,respectively.

Multiple model PHD filter for tracking sharply maneuvering targets using recursive RANSAC based adaptive birth estimation

An algorithm to track multiple sharply maneuvering targets without prior knowledge about new target birth is proposed. These targets are capable of achieving sharp maneuvers within a short period of time, such as drones and agile missiles.The probability hypothesis density (PHD) filter, which propagates only the first-order statistical moment of the full target posterior, has been shown to be a computationally efficient solution to multitarget tracking problems. However, the standard PHD filter operates on the single dynamic model and requires prior information about target birth distribution, which leads to many limitations in terms of practical applications. In this paper,we introduce a nonzero mean, white noise turn rate dynamic model and generalize jump Markov systems to multitarget case to accommodate sharply maneuvering dynamics. Moreover, to adaptively estimate newborn targets’information, a measurement-driven method based on the recursive random sampling consensus (RANSAC) algorithm is proposed. Simulation results demonstrate that the proposed method achieves significant improvement in tracking multiple sharply maneuvering targets with adaptive birth estimation.

Research on High Speed Communication Method of ELF-EM While Drilling Based on Adaptive Combined Filtering Algorithm

In terms of the electromagnetic wave measurement while drilling,the extremely low frequency electromagnetic(ELF-EM)signal below 20Hz is usually chosen as the downhole data carrier.To improve the transmission rate of ELF-EM signal and the signal to noise ratio(SNR)at the receiving end,the DQPSK modulation was proposed as the modulation method for the communication of electromagnetic wave system.Different from the traditional IQ orthogonal modulation and coherent demodulation methods,the proposed phase selection modulation and correlation algorithm demodulation are easier to implement and more practical.With regard to the communication synchronization,a fast algorithm,which based on the normalized cross-relation number,was used for waveform matching,and the maximum point of the correlation coefficient was used as the starting point of communication synchronization.The communication simulation results show that the proposed DQPSK modulation signal based on the adaptive combined filtering algorithm has better terminal error rate and transmission rate than the traditional modulation method.Under the same carrier frequency and code width,the transmission rate of DQPSK modulation is 4 to 5 times and 2 times that of PPM modulation and 2DPSK modulation respectively.The communication modulation and demodulation modes as well as the decoding algorithm with combined adaptive filter proposed in this paper can effectively solve practical engineering problems.

Target recognition based on modified combination rule

Evidence theory is widely used in the field of target recognition. The invalidation problem of this theory when dealing with highly conflict evidences is a research hotspot. Several alternatives of the combination rule are analyzed and compared. A new combination approach is proposed. Calculate the reliabilities of evidence sources using existing evidences. Construct reliabilities judge matrixes and get the weights of each evidence source. Weight average all inputted evidences. Combine processed evidences with D-S combination rule repeatedly to identify a target. The application in multi-sensor target reeognition as well as the comparison with typical alternatives all validated that this approach can dispose highly conflict evidences efficiently and get reasonable reeognition results rapidly.

Redox-sensitive micelles for targeted intracellular delivery and combination chemotherapy of paclitaxel and all-trans-retinoid acid

The application of paclitaxel(PTX) in clinic has been restricted due to its poor solubility.Several traditional nano-medicines have been developed to improve this defect,while they are still lack of tumor targeting ability and rapid drug release. In this work,an amphiphilic polymeric micelle of hyaluronic acid(HA) – all-trans-retinoid acid(ATRA) with a disulfide bond,was developed successfully for the co-delivery of PTX and ATRA. The combination chemotherapy of PTX and ATRA can strengthen the anti-tumor activity. Along with selfassembling to micelles in water,the delivery system displayed satisfying drug loading capacities for both PTX(32.62% ± 1.39%) and ATRA,due to directly using ATRA as the hydrophobic group. Rapid drug release properties of the PTX-loaded redox-sensitive micelles(HA-SS-ATRA) in vitro were confirmed under reducing condition containing GSH. Besides,HA-CD44 mediated endocytosis promoted the uptake of HA-SS-ATRA micelles by B16 F10 cells. Due to these properties,cytotoxicity assay verified that PTX-loaded HA-SS-ATRA micelles showed concentration-dependent cytotoxicity and displayed obvious combination therapy of PTX and ATRA. Importantly,HA-SS-ATRA micelles could remarkably prolong plasma circulation time after intravenously administration. Therefore,redox-sensitive HASS-ATRA micelles could be utilized and explored as a promising drug delivery system for cancer combination chemotherapy.

Discussion on gemcitabine combined with targeted drugs in the treatment of pancreatic cancer

Pancreatic cancer is a malignant tumor with poor prognosis.The treatment of pancreatic cancer depends on the tumor stage and type,and includes local treatment(surgery,radiotherapy and ablation intervention)and systemic therapy(chemotherapy,targeted therapy and immunotherapy).We read with great interest the review“Effective combinations of anti-cancer and targeted drugs for pancreatic cancer treatment”published on World J Gastroenterol and intended to share some of our perspectives in pancreatic cancer treatment.This review presents the therapeutic effects of the combination of gemcitabine and targeted drugs,which gives us a deeper insight into the combination treatments for pancreatic cancer.

Identification of a LMNA (c.646C>T) variant by whole-exome sequencing in combination with a dilated cardiomyopathy (DCM) related gene filter in a family with familiar DCM

Dilated cardiomyopathy（DCM）is characterized by the dilated heart chambers and reduced systolic function in the absence of specific aetiology[1].Approximately one third of DCM cases are hereditary.In recent years,DCM concomitant with arrhythmias and sudden death resulting from gene mutation has been widely

One patient with metastastic colorectal cancer successfully treated by combination of targeted agents after failure of chemotherpay

Either cetuximab or bevacizumab can improve the survival of patients with metastastic colorectal cancer (mCRC) if administered combided with cytotoxic agents. However, the effect of two or more target agents in combination is uncertain in these patients. Here, we reported a patient with mCRC successfully treated by a combination of target agents after the failure of chemotherapy. The patient received palliative resection of primary tumor followed by 9 cycles of postoperative XELOX regimen, cytokine-induced killer cell (CIK)-based biotherapy, traditional Chinese medicine, particle implantation in the lung metastatic lesions. The tumor progressed 20 months after the standard treatments. Then, the regimen cetuximab, bevacizumab and cefitinib was applied. During the treatment with targeted agents, grade IV acne-like rash and relatively severe parionychia of the toes occurred. Both of them recovered smoothly. The PET-CT reexamination at 40 days after the target treatment showed that the metabolism of mediastinal lymph nodes basically recovered to a normal level. The combination of multiple targeted agents obtained a progression-free survival(PFS) of 11 months and the patient with a good quality of life during this period.

A Small Target Detection Method for Sea Surface Based on Guided Filtering and Local Mean Gray Difference

The traditional small target detection algorithm often results in a high false alarm rate on the sea surface background. To address this issue, a small target detection method based on guided filtering and local average gray level difference was proposed in this paper for the sea surface. Firstly, the method enhanced the details of the small targets by employing guided filtering to suppress the background clutter and noise in the sea surface image. Subsequently, the local average gray level difference of each point in the image was calculated to further distinguish the targets from other interference points. Finally, the threshold segmentation method was utilized to obtain the actual small targets on the sea surface. After conducting experiments on various sea surface scenes, the LSCRG, BSF, and ROC curve were computed for the proposed method and five other algorithms. Comparative analysis with BS, Top-hat, TDLMS, Max-median, and LCM demonstrates the superiority of the proposed method for infrared small target detection on the sea surface.

MULTI-TARGET VISUAL TRACKING AND OCCLUSION DETECTION BY COMBINING BHATTACHARYYA COEFFICIENT AND KALMAN FILTER INNOVATION

This paper introduces an approach for visual tracking of multi-target with occlusion occurrence. Based on the author's previous work in which the Overlap Coefficient (OC) is used to detect the occlusion, in this paper a method of combining Bhattacharyya Coefficient (BC) and Kalman filter innovation term is proposed as the criteria for jointly detecting the occlusion occurrence. Fragmentation of target is introduced in order to closely monitor the occlusion development. In the course of occlusion, the Kalman predictor is applied to determine the location of the occluded target, and the criterion for checking the re-appearance of the occluded target is also presented. The proposed approach is put to test on a standard video sequence, suggesting the satisfactory performance in multi-target tracking.

Effective combinations of anti-cancer and targeted drugs for pancreatic cancer treatment

Pancreatic cancer is highly aggressive and lethal.Due to the lack of effective methods for detecting the disease at an early stage,pancreatic cancer is frequently diagnosed late.Gemcitabine has been the standard chemotherapy drug for patients with pancreatic cancer for over 20 years,but its anti-tumor effect is limited.Therefore,FOLFIRINOX(leucovorin,fluorouracil,irinotecan,oxaliplatin)as well as combination therapies using gemcitabine and conventional agents,such as cisplatin and capecitabine,has also been administered;however,these have not resulted in complete remission.Therefore,there is a need to develop novel and effective therapies for pancreatic cancer.Recently,some studies have reported that combinations of gemcitabine and targeted drugs have had significant antitumor effects on pancreatic cancer cells.As gemcitabine induced DNA damage response,the proteins related to DNA damage response can be suitable additional targets for novel gemcitabine-based combination therapy.Furthermore,KRAS/RAF/MEK/ERK signaling triggered by oncogenic mutated KRAS and autophagy are frequently activated in pancreatic cancer.Therefore,these characteristics of pancreatic cancer are potential targets for developing effective novel therapies.In this minireview,combinations of gemcitabine and targeted drugs to these characteristics,combinations of targeted drugs,combinations of natural products and anti-cancer agents,including gemcitabine,and combinations among natural products are discussed.

The Clinical Study of Multigene Combination Test to Guide Chemotherapy Combined with Targeted Therapy in Patients with Advanced Gastrointestinal Tumors

Objective:To study the clinical effects of multigene combination test to guide chemotherapy combined with targeted therapy in patients with advanced gastrointestinal tumors.Methods:The samples were selected from 60 patients with advanced gastrointestinal tumors admitted to our hospital from March 2019 to July 2020,and were divided into a study group and a control group using a random number table model;patients in the control group did not undergo genetic testing and FOLLOX4+PD-1 chemotherapy,while patients in the study group underwent TYMS,ERCC1,EGFR,and KRAS and VEGF gene expression levels test,and the sensitive treatment plan was determined based on the test results,and the clinical indexes were compared between the two groups.Results:By comparing the total effective rate,survival time,and time to disease progression of chemotherapy in the two groups,the study group has a significant advantage(P<0.05).Conclusion:The combination of chemotherapy and targeted therapy for advanced gastrointestinal tumor patients can improve the efficiency of chemotherapy and prolong the time of disease progression and survival,which is worthy of comprehensive promotion.

Modified unscented Kalman filter using modified filter gain and variance scale factor for highly maneuvering target tracking

To improve the low tracking precision caused by lagged filter gain or imprecise state noise when the target highly maneuvers, a modified unscented Kalman filter algorithm based on the improved filter gain and adaptive scale factor of state noise is presented. In every filter process, the estimated scale factor is used to update the state noise covariance Qk, and the improved filter gain is obtained in the filter process of unscented Kalman filter （UKF） via predicted variance Pk｜k-1, which is similar to the standard Kalman filter. Simulation results show that the proposed algorithm provides better accuracy and ability to adapt to the highly maneuvering target compared with the standard UKF.

Bayesian target tracking based on particle filter

For being able to deal with the nonlinear or non-Gaussian problems, particle filters have been studied by many researchers. Based on particle filter, the extended Kalman filter （EKF） proposal function is applied to Bayesian target tracking. Markov chain Monte Carlo （MCMC） method, the resampling step, ere novel techniques are also introduced into Bayesian target tracking. And the simulation results confirm the improved particle filter with these techniques outperforms the basic one.

Combined proportional navigation law for interception of high-speed targets

A new proportional navigation(PN) guidance law,called combined proportional navigation(CPN),is proposed.The guidance law is designed to intercept high-speed targets,which is a common case for ballistic targets.The range of target-to-interceptor speed ratio during target interception is derived when guidance laws are applied in high-speed targets interception,and the effectiveness of negative navigation ratio in the PN-based guidance law is proven analytically in some lemmas.Based on the lemmas,the lateral acceleration command of CPN is defined,and the solution to the appearance of singularity in time-varying navigation ratio is given.The simulation results show that CPN can determine headon engagement(as PN) or tail-chase engagement(as RPN) through initial path angle compared with PN and retro proportional navigation(RPN),and can adjust the value of navigation ratio for head-on engagement or tail-chase engagement.Therefore,the capture region of CPN is larger than that of other guidance laws using PN-based methods.

Tracking method based on separation and combination of the measurements for radar and IR fusion system

A new distributed fusion method of radar/infrared （IR） tracking system based on separation and combination of the measurements is proposed by analyzing the influence of rate measurement. The rate information separated from the radar measurements together with measurements of IR form a pseudo vector of IR, and the corresponding filter is designed. The results indicate that the method not only makes a great improvement to the local tracker＇s performance, but also improves the global tracking precision efficiently.

Constrained auxiliary particle filtering for bearings-only maneuvering target tracking

To track the nonlinear,non-Gaussian bearings-only maneuvering target accurately online,the constrained auxiliary particle filtering(CAPF)algorithm is presented.To restrict the samples into the feasible area,the soft measurement constraints are implemented into the update routine via the1 regularization.Meanwhile,to enhance the sampling diversity and efficiency,the target kinetic features and the latest observations are involved into the evolution.To take advantage of the past and the current measurement information simultaneously,the sub-optimal importance distribution is constructed as a Gaussian mixture consisting of the original and modified priors with the fuzzy weighted factors.As a result,the corresponding weights are more evenly distributed,and the posterior distribution of interest is approximated well with a heavier tailor.Simulation results demonstrate the validity and superiority of the CAPF algorithm in terms of efficiency and robustness.

Target tracking in glint noise using a MCMC particle filter

In radar target tracking application, the observation noise is usually non-Gaussian, which is also referred as glint noise. The performances of conventional trackers degra de severely in the presence of glint noise. An improved particle filter, Markov chain Monte Carlo particle filter (MCMC-PF), is applied to cope with radar target tracking when the measurements are perturbed by glint noise. Tracking performance of the filter is demonstrated in the present of glint noise by computer simulation.