复杂环境下基于改进Informed RRT*的无人机路径规划算法

针对无人机在复杂环境中进行路径规划时,快速搜索随机树(RRT)算法易出现规划时间长、路径冗余、狭窄空间中易陷入局部约束导致规划失败的问题,提出一种改进的Informed RRT*算法.首先,引入人工势场法使采样点按照势场下降的方式向目标点移动,以提高RRT树扩展的目的性和方向性.然后,考虑随机树在扩展过程中全局环境的复杂度,引入自适应步长调整策略以增加随机树在无障碍环境下的扩展速度,并在随机树扩展的过程中加入相关约束条件以确保生成路径的可行性.在找到第一条可达路径后,采用变化的椭圆或椭球采样域限制采样点选取和自适应步长的扩展范围,加快算法收敛到渐进最优的速度.最后,在复杂二维和三维环境下进行传统算法和改进算法的对比实验,仿真分析表明:改进算法可以在很少的迭代次数下找到更优的初始路径,更快地锁定椭圆或椭球采样域,从而给路径优化留出更多时间,算法规划效果更好.

Corrigendum regarding missing informed consents in previously published articles

The publisher would like to draw the reader's attention to the following errors.Informed consents were not included in the published version of the following articles that appeared in previous issues of Grain&Oil Science and Technology.The authors were contacted after publication to request informed consents for the following articles.The appropriate informed consents,provided by the authors,are included below.

ESR-PINNs:Physics-informed neural networks with expansion-shrinkage resampling selection strategies

Neural network methods have been widely used in many fields of scientific research with the rapid increase of computing power.The physics-informed neural networks(PINNs)have received much attention as a major breakthrough in solving partial differential equations using neural networks.In this paper,a resampling technique based on the expansion-shrinkage point(ESP)selection strategy is developed to dynamically modify the distribution of training points in accordance with the performance of the neural networks.In this new approach both training sites with slight changes in residual values and training points with large residuals are taken into account.In order to make the distribution of training points more uniform,the concept of continuity is further introduced and incorporated.This method successfully addresses the issue that the neural network becomes ill or even crashes due to the extensive alteration of training point distribution.The effectiveness of the improved physics-informed neural networks with expansion-shrinkage resampling is demonstrated through a series of numerical experiments.

改进APF-Informed-RRT*融合算法的无人机航迹规划

近几十年,渐近最优快速搜索随机树(RRT*)算法受到广泛关注。为了解决其收敛速度慢、生成路径代价高的问题,提出一种改进APF(Artificial Potential Field)-Informed-RRT*融合算法进行无人机航迹规划。该算法结合Informed采样策略,将随机点约束在椭圆空间内,提高搜索效率。当新算法找到最近节点后,引入改进APF生成高质量的新节点。目标点及随机采样点对生长树的最近节点产生吸引力,障碍物对其产生排斥力,然后将合力方向作为随机树生长方向,解决局部最小值的问题,大大缩短了收敛时间。将该算法与RRT*,Informed-RRT*算法进行比较,结果表明了新算法的优越性和有效性。

Cases studies of application of model-informed drug development in early phase clinical trials

Model-informed drug develop⁃ment(MIDD)is the application of a various math⁃ematical,statistical,and biological models to facilitate drug development,decision making and regulatory review.As a quantitative tool,MIDD approaches allow an integration of information obtained from non-clinical studies and clinical trials in a drug development program.General understandings of the underlying biology,patho⁃physiology,and pharmacology can also be incor⁃porated into the model.MIDD is centered on knowledge and inferences generated from inte⁃grated models of the physicochemical character⁃istics of a molecule,its disposition in the body,and its mechanism of action,and how the drug might affect a disease from both an efficacy and a safety perspective.MIDD approaches have the potential to significantly streamline drug develop⁃ment,by improving clinical trial efficiency,opti⁃mizing dose and regimen and waive unneces⁃sary clinical studies.This presentation will use cases studies to demonstrate how to apply MIDD in early phase of clinical trials.

基于B样条曲线的无人驾驶车辆Informed RRT^(*)算法研究

车联网技术可以大幅度地增加交通流畅性,节省行驶时间。针对基本RRT算法树的拓展具有随机性、路径中存在冗余的节点、规划出的路径拐点多等问题,本文在RRT^(*)的基础上提出了Informed RRT^(*)算法,同时,为了解决Informed RRT^(*)路径优化效率低的问题,加入三次B样条曲线,解决了曲线光滑问题。改进后的算法在保证规划出来的路径质量的同时,大大缩短了采样时间,采样节点数降低约33%。结果对比证明,改进后的RRT算法,算法搜索效率及平滑性得到明显改善。

PSA-based prostate cancer screening： the role of active surveillance and informed and shared decision making

Since the first publication describing the identification of prostate-specific antigen （PSA） in the 1960s, much progress has been made. The PSA test changed from being initially a monitoring tool to being also used as a diagnostic tool. Over time, the test has been heavily debated due to its lack of sensitivity and specificity. However, up to now the PSA test is still the only biomarker for the detection and monitoring of prostate cancer. PSA-based screening for prostate cancer is associated with a high proportion of unnecessary testing and overdiagnosis with subsequent overtreatment. In the early years of screening for prostate cancer, high rates of uptake were very important. However, over time the opinion on PSA-based screening has shifted towards the notion of informed choice. Nowadays, it is thought to be unethical to screen men without them being aware of the pros and cons of PSA testing, as well as the fact that an informed choice is related to better patient outcomes. Now, as the results of three major screening studies have been presented and the downsides of screening are becoming better understood, informed choice is becoming more relevant.

Physics informed machine learning: Seismic wave equation

Similar to many fields of sciences,recent deep learning advances have been applied extensively in geosciences for both small-and large-scale problems.However,the necessity of using large training data and the’black box’nature of learning have limited them in practice and difficult to interpret.Furthermore,including the governing equations and physical facts in such methods is also another challenge,which entails either ignoring the physics or simplifying them using unrealistic data.To address such issues,physics informed machine learning methods have been developed which can integrate the governing physics law into the learning process.In this work,a 1-dimensional(1 D)time-dependent seismic wave equation is considered and solved using two methods,namely Gaussian process(GP)and physics informed neural networks.We show that these meshless methods are trained by smaller amount of data and can predict the solution of the equation with even high accuracy.They are also capable of inverting any parameter involved in the governing equation such as wave velocity in our case.Results show that the GP can predict the solution of the seismic wave equation with a lower level of error,while our developed neural network is more accurate for velocity(P-and S-wave)and density inversion.

Using GIS Data to Build Informed Virtual Geographic Environments (IVGE)

In this paper, we propose a novel approach to automatically building Informed Virtual Geographic Environments (IVGE) using data provided by Geographic Information Systems (GIS). The obtained IVGE provides 2D and 3D geographic information for visualization and simulation purposes. Conventional VGE approaches are generally built upon a grid-based representation, raising the well-known problems of the lack of accuracy of the localized data and the difficulty to merge data with multiple semantics. On the contrary, our approach uses a topological model and provides an exact representation of GIS data, allowing an accurate geometrical exploitation. Moreover, our model can merge semantic information, even if spatially overlapping. In addition, the proposed IVGE contains spatial information which can be enhanced thanks to a geometric abstraction method. We illustrate this model with an application which automatically extracts the required data from standard GIS files and allows a user to navigate and retrieve information from the computed IVGE.

Knowledge,Awareness,and Attitude of Doctors and Patients regarding Informed Consent to Medical Procedures in Papua New Guinea

This study explores how doctors and patients in Papua New Guinea(PNG)perceive informed consent in medical settings.Doctors and patients from National Capital District and Central Province who responded to the survey were the participants of the study.Researchers asked the participants to fill out questionnaires regarding their knowledge about informed consent for each group,namely,the doctors and participants.From those who responded,six randomly selected participants were chosen to join the focus group discussion which aimed to get experiences from the doctors and patients regarding medical procedures.Results show that both doctors and patients lack knowledge of the legalities of informed consent.Based on the experiences of doctors,they do not use consent forms when seeking permission from patients.Patients,on the other hand,do not see consent forms as important and only served as a formality.Customs,culture surrounding PNG were found to have an impact on how patients perceived informed consent.

Dubins-Informed RRT*算法规划的机械臂运动

针对目前机械臂路径规划需要人工提前进行示教编程的问题,本文使用Informed RRT*算法应用于机械臂的自动路径规划中,并且利用Dubins曲线策略处理Informed RRT*的轨迹,解决了RRT类算法生成的轨迹存在不稳定和尖锐的这两大缺点,并且在计算机软件上进行仿真测试,验证Dubins-Informed RRT*算法应用于机械臂的自动路径规划是可行的。

Evidence-based approach to providing informed consent for hip fracture surgery during the COVID-19 era

BACKGROUND Hip fractures are the most common reason for inpatient orthopaedic trauma admission.Urgent surgical intervention for hip fractures has remained a clinical priority throughout the coronavirus disease 2019(COVID-19)pandemic.Despite this,there is a paucity of clinical guidance addressing the informed consent process for hip fracture surgery in COVID-19 positive patients.This is of paramount medicolegal importance in a high-risk patient population.AIM To quantify the additional perioperative risks for COVID-19 positive patients undergoing hip fracture surgery and provide clinicians with an evidence-based framework to establish an informed consent process.METHODS Two hundred and fifty nine consecutive patients undergoing surgical intervention for hip fractures in four hospitals in the United Kingdom were recruited.51 patients were confirmed positive for COVID-19.Predefined outcomes were analyzed over a 30-d postoperative period.COVID-19 positive and COVID-19 negative patients were compared after adjustment for confounding factors.RESULTS COVID-19 positive patients had more intensive care admissions(27%vs 5%,P<0.001),longer inpatient stays(median 23 d vs 9 d,P<0.001)and a higher 30-d mortality(29%vs 10%,P=0.001)than COVID-19 negative patients.Postoperative complications were evident in 74.5%of COVID-19 positive patients.35.3%of COVID-19 positive patients suffered postoperative lower respiratory tract infections with 13.7%developing acute respiratory distress syndrome(ARDS)and 9.8%experiencing symptomatic thromboembolic events.CONCLUSION The COVID-19 pandemic has created uncertainty in the medical community worldwide and poses unique challenges in providing informed consent for surgery.COVID-19 positive patients undergoing hip fracture surgery should be consented for the additional risk of postoperative complications(including lower respiratory tract infection,ARDS,deep vein thrombosis and pulmonary embolism),increased requirement for intensive care admission,longer inpatient stay and higher risk of mortality.Further,clinicians must be transparent about the potential for unknown risks as research into the long-term surgical outcomes of COVID-19 positive patients continues to evolve.

Informed consent in veterinary medicine: legal and medical perspectives in Italy

During the last four decades the doctrine of in- formed consent (IC) has become a legal stan- dard and an essential component of ethical guidelines in medicine, due to its relevance for basic human rights such as autonomy and re- spect of dignity. Over the last few years, this legal formula has gained importance in veteri- nary medicine, thereby influencing the everyday activities of the veterinary practitioners. This paper briefly describes the ethical and legal background of IC in Italy and examines how it relates to the practice of veterinary medicine, considering the change in social sensibility to- wards animals. It also outlines the discussion that should take place between Veterinarian and client before a planned procedure.

A Comparison Study between Informed and Predictive Prefetching Mechanisms for I/O Storage Systems

In this paper, we present a comparative study between informed and predictive prefetching mechanisms that were presented to leverage the performance gap between I/O storage systems and CPU. In particular, we will focus on transparent informed prefetching (TIP) and predictive prefetching using probability graph approach (PG). Our main objective is to show the main features, motivations, and implementation overview of each mechanism. We also conducted a performance evaluation discussion that shows a comparison between both mechanisms performance when using different cache size values.

Discovering Phase Field Models from Image Data with the Pseudo-Spectral Physics Informed Neural Networks

In this paper,we introduce a new deep learning framework for discovering the phase-field models from existing image data.The new framework embraces the approximation power of physics informed neural networks(PINNs)and the computational efficiency of the pseudo-spectral methods,which we named pseudo-spectral PINN or SPINN.Unlike the baseline PINN,the pseudo-spectral PINN has several advantages.First of all,it requires less training data.A minimum of two temporal snapshots with uniform spatial resolution would be adequate.Secondly,it is computationally efficient,as the pseudo-spectral method is used for spatial discretization.Thirdly,it requires less trainable parameters compared with the baseline PINN,which significantly simplifies the training process and potentially assures fewer local minima or saddle points.We illustrate the effectiveness of pseudo-spectral PINN through several numerical examples.The newly proposed pseudo-spectral PINN is rather general,and it can be readily applied to discover other FDE-based models from image data.

Informed Consent under the Ghana Health Service Patients Charter: Practice and Awareness

Background: Every human being of adult years and sound mind has a right to determine what shall be done with his/her own body. Patient autonomy and the practice of informed patient consent are now pivotal in medical practice. Aim: To assess patient’s knowledge of Patients’ Rights Charter and whether patients receive adequate information to enable them make an informed consent to a particular treatment. Methodology: Patients who were undergoing elective surgery from selected surgical departments of Komfo Anokye teaching hospital in Kumasi were randomly selected and assisted to answer structured questionnaire without the knowledge of their doctors. The study period was in June to December (2014). Descriptive analysis was done using SPSS (II) of the results. Results: 84.7% (144) had no idea about the Patients’ Rights Charter of the Ghana Health Service. 75% (128) did not know or had not heard of informed patient consent. Of those who knew of the charter, 85% (37) had ever stayed in a developed country. 60% (102) did not know of their diagnosis. 79% (134) said the doctor only asked them to either sign or thumb print the consent document without giving them treatment options or possible complications. Conclusion: Most of respondents undergoing various surgical procedures at the Komfo Anokye Teaching Hospital were not aware of the existence of the Patients’ Rights Charter of the Ghana Health Service. Again, practitioners did not provide sufficient information to patients for them to make an informed decision about their health.

Impacts of Clinic-based Informed Choice Program on Quality of Individualized Counseling Service in China

Objective To evaluate the impacts of clinic-based informed choice program on quality of individualized service in family planning clinics in ChinaMethods During the program, family planning service staff in intervention clinics , were trained on counseling skills and key points of individualized counseling service. Questionnaire surveys were conducted pre- and post-informed choice program to evaluate the 'impacts of the program.Results Informed choice program had significantly improved the quality of individualized counseling service. The multivariate regression analysis showed that clients of the clinic were more likely to give the better evaluation of the service, the OR of evaluation score of individualized service is 1/712 (95% CI is 1. 146 to 2. 564) in Experiment Group of post-program in contrast with pre-program. The program also could satisfy individual needs of clients and increase the satisfaction degree of the service. Conclusions Informed choice program is helpful for the improvement of the quality of individualized counseling service. It is necessary and imperative to improve the skills of counseling service provided in family planning clinics.

The Landscape of the Legal Aspects of Informed Consent for Medical Treatment in Papua New Guinea

The major challenges militating against the proper practice of informed consent identified in our desk top review are related to cultural issues of the people.Many patients continue to value strongly their kinship ties with the past and believe in the traditional methods of healing sickness.The patients must be given some information about what the doctor proposes to do.The underlying spirit of informed consent is new in PNG,and it strives against the traditional attitudes of doctors that they know it best for the patients and the strong culture in customs and patients’misconceptions that affect their perceptions in making important health care decisions.Majority of the patients have some notion of informed consent,however not many people understand what it is.They still hang onto their traditional customs,beliefs and opinions that affect their health care decisions;they often look to their village elders,family and parents for advice in times of sickness or death in the family but where the law implies consent it is not often obtained.Summarization of current laws,reports of legal cases,and personal experiences were examined.Special requirements must be prescribed when patients are subjected to medical treatment.Documentation of a well-defined process,not only on paper,may not only protect the medical doctor from exposure to liability but increases the patient’s autonomy in decisions concerning health and encourages compliance with treatment;and advances the interests of both patient and doctor.Lack of informed consent can reinforce a claim of medical malpractice,and could well undermine relevant health care policy to protect patient autonomy.

Informed Consent Prior to Elective Gynaecological Surgery in Two Reference Hospitals in Yaoundé, Cameroon: A Mixed Methods Study

Introduction: Informed consent is a process that enshrines respect for patients’ autonomy, their dignity, and their rights to determine what happens to their own bodies. We set out to describe the surgical informed consent process and evaluate its quality in patients undergoing elective gynaecological surgeries in two University Teaching Hospitals in Yaounde, Cameroon. Methods: This was a cross-sectional, prospective study over 9 month period, from October 1st, 2018, to June 30th, 2019 at the Yaounde Gynaeco-Obstetric and Paediatric Hospital (YGOPH) and the Yaounde Central Hospital (YCH). By administering a modified Brezis questionnaire 48 hours after surgery, we obtained data which enabled us to evaluate and score the informed consent process and obtained written reports of patients’ appreciation of key aspects of the informed consent process prior to surgery. We then called each participant 6 months after their surgery date to obtain information on the occurrence or not of post-operative complications. Results: We recruited 72 patients aged 24 to 68 years old (61 at YGOPH, 11 at YCH). The operating gynaecologist sought patient consent in 65.3% (49/72) of cases, while 61.1% (44/72) of the subjects would have loved to have more information on surgical risks;69.4% (50/72) were satisfied with the consent process;and 56.9% (41/72) could recall and repeat the information they received prior to surgery. While 37.5% (27/72) had poor quality (non-valid consent), 40.3% had good quality consent (valid). Consent administered by the gynaecologist (OR = 0.172;95% CI = 0.060 - 0.049) was a strong determinant of valid consent. Also, patients with non-valid consent significantly reported more complications (OR = 4.469;95% CI = 1.412 - 14.147) than those with valid consent. Conclusion: Informed consent prior to elective gynaecological surgeries in our study was poor. The timing of the consent process, as well as the person involved in the process affect the validity of the consent.

Future needs for informed consent in stem cell clinical trials in neurodegenerative diseases

Translation of recent advances in stem cell research into clinical trials for restorative therapies for human disease is accelerating dramatically,with a strong focus upon neurodegenerative disorders such as Parkinson’s disease（PD）,Huntington’s disease（HD）,and amyotrophic lateral sclerosis（ALS）.