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Multi-vehicle cooperation and nearly fuel-optimal flock guidance in strong background flows

OCEAN ENGINEERING 2017年第Sep.1期141卷 388-404页

作者： Song, Zhuoyuan Lipinski, Doug Mohseni, Kamran Univ Florida Dept Mech & Aerosp Engn Gainesville FL 32611 USA Univ Florida Gainesville FL 32611 USA Univ Florida Inst Networked Autonomous Syst Gainesville FL 32611 USA

A multi-vehicle flocking and guidance control scheme is proposed for small autonomous underwater vehicles in the presence of strong ocean flows that exceed vehicles' actuation capabilities. The flocking problem and flock guidance problem are simultaneously addressed by enduing fluid properties to the vehicle swarm. This control scheme generates cohesive flocking behavior with inherent inter-vehicle collision avoidance and velocity consensus. The vehicle flock is guided along a fuel-optimal trajectory calculated for an individual vehicle based on background flow predictions, allowing us to compute a single optimal trajectory while still achieving robust flocking performance and near optimality for all vehicles. Resultant vehicle trajectories are nearly fuel-optimal when the spatial variation of background flow velocities across the flock is small. Dimensional analysis uncovers two important independent parameters dictating the balance between swarm compressibility and the degree of velocity consensus. The efficiency of the presented method is demonstrated in simulations with two synthetic background flow fields resembling realistic ocean flow patterns, and a flow field reconstructed based on ocean model data. A quantitative comparison with a generic artificial potential based control scheme shows that, owing to the inherent velocity consensus effect, the proposed method results in better flocking behavior endless actuation energy consumption.

关键词： Multi-vehicle control Flocking Underwater vehicle Ocean current guidance

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Terminal Impact Angle Constraint guidance With Dual Sliding Surfaces and Model-Free Target Acceleration Estimator

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IEEE TRANSACTIONS ON CONTROL SYSTEMS TECHNOLOGY 2017年第1期25卷 85-100页

作者： Hou, Zhiwei Liu, Lei Wang, Yongji Huang, Jian Fan, Huijin Huazhong Univ Sci & Technol Natl Key Lab Sci & Technol Multispectral Informat Sch Automat Wuhan 430074 Peoples R China

In this paper, a new guidance law based on the variable structure system theory and an associated model-free target acceleration estimator are proposed. The composite guidance-estimation law is designed to intercept constant-velocity and maneuvering targets by missiles at a desired terminal impact angle. Specifically, the scenario of intercepting the targets with speed-disadvantaged missiles, which has not been studied in detail in the literature available, is considered in this paper. A multiple solution problem for the terminal impact angle and a final line-of-sight angle is clarified in this paper. To solve this problem, the generalized variable structure theory is used and an additional sliding mode surface is introduced in the proposed guidance law, by which missiles can reach a wider range of the final impact angle. In addition, the nonsingular terminal sliding mode control method is applied so that the states of the guidance dynamic system are finite time convergent. In order to intercept maneuvering targets, a Kriging-based model-free finite impulse response filter is employed. Based on this filter, this paper puts forward some improvements, including a data preprocessing method and a parameter offline tuning method by the simulated annealing algorithm. In this way, a model-free target acceleration estimator with strong practicality in engineering is proposed. The stability condition of the proposed composite guidance-estimation law is obtained via the Lyapunov theorem. Finally, simulation results in different initial intercepting scenarios are presented to validate the advantage of the proposed guidance law and target acceleration estimator.

关键词： Finite impulse response (FIR) filter guidance impact angle sliding mode control (SMC) target acceleration estimator

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On Practice of the Effect of Systematic Family Nursing guidance on the Quality of Life of Elderly Patients with Implanted Cardiac Pacemaker

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Yangtze Medicine 2018年第3期2卷 171-177页

作者： Xin Ao Nursing Department of Medical School Yangtze University Jingzhou China

Objective: To inquire into the effect of systematic family nursing guidance on improving the Quality of Life for elderly patients with implanted cardiac pacemaker. Methods: 41 elderly patients in accordance with the corresponding requirements were studied after offering systematic family nursing guidance and surveyed through the questionnaires about the QOL (quality of life) respectively 1 month, 3 months and 6 months after leaving hospital. Results: Compared with that of 1 month and 3 months after the operation, the questionnaire scores for 6 months after the operation were found to have significant improvement, and the differences were statistically significant. Conclusion: Systematic family nursing guidance can effectively improve the QOL for elderly patients with implanted cardiac pacemaker, which makes them spend their old age in comfort and happiness.

关键词： Cardiac Pacemaker Elderly Patients Family Nursing guidance Quality of Life SF-36 Health Survey

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Choosing the target difference and undertaking and reporting the sample size calculation for a randomised controlled trial - the development of the DELTA² guidance

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TRIALS 2018年第1期19卷 542-542页

作者： Sones, William Julious, Steven A. Rothwell, Joanne C. Ramsay, Craig Robert Hampson, Lisa V. Emsley, Richard Walters, Stephen J. Hewitt, Catherine Bland, Martin Fergusson, Dean A. Berlin, Jesse A. Altman, Doug Vale, Luke David Cook, Jonathan Alistair Univ Oxford Nuffield Orthopaed Ctr Botnar Res CtrCtr Stat Med Nuffield Dept Orthopaed Rheumatol & Musculoskelet Windmill Rd Oxford OX3 7LD England Univ Sheffield Med Stat Grp ScHARR Regent Court 30 Regent St Sheffield S1 4DA S Yorkshire England Univ Aberdeen Hlth Serv Res Unit Hlth Sci Bldg Aberdeen AB25 2ZD Scotland Univ Lancaster Dept Math & Stat Lancaster LA1 4YF England Novartis Pharma AG Stat Methodol & Consulting Basel Switzerland Kings Coll London Inst Psychiat Psychol & Neurosci Dept Biostat & Hlth Informat Crespigny PkDenmark Hill London SE5 8AF England Univ York Dept Hlth Sci Seebohm Rowntree Bldg York YO10 5DD N Yorkshire England Ottawa Hosp Clin Epidemiol Program Res Inst 501 Smyth RdBox 201B Ottawa ON K1H 8L6 Canada Johnson & Johnson One J&J Pl New Brunswick NJ 08933 USA Newcastle Univ Inst Hlth & Soc Hlth Econ Grp Newcastle Upon Tyne Tyne & Wear England

BackgroundA key step in the design of a randomised controlled trial is the estimation of the number of participants needed. The most common approach is to specify a target difference in the primary outcome between the randomised groups and then estimate the corresponding sample size. The sample size is chosen to provide reassurance that the trial will have high statistical power to detect the target difference at the planned statistical significance level. Alternative approaches are also available, though most still require specification of a target *** sample size has many implications for the conduct of the study, as well as incurring scientific and ethical aspects. Despite the critical role of the target difference for the primary outcome in the design of a randomised controlled trial (RCT), the manner in which it is determined has received little attention. This article reports the development of the DELTA(2) guidance on the specification and reporting of the target difference for the primary outcome in a sample size calculation for a *** DELTA(2) (Difference ELicitation in TriAls) project has five components comprising systematic literature reviews of recent methodological developments (stage 1) and existing funder guidance (stage 2), a Delphi study (stage 3), a 2-day consensus meeting bringing together researchers, funders and patient representatives (stage 4), and the preparation and dissemination of a guidance document (stage 5).ResultsThe project started in April 2016. The literaturesearch identified 28 articles of methodological developments relevant to a method for specifying a target difference. A Delphi study involving 69 participants, along with a 2-day consensus meeting were *** addition, further engagement sessions were held at two international conferences. The main guidance text was finalised on April 18, 2018, after revision informed by feedback gathered from stages 2 and 3 and from funder ***

关键词： Target difference Clinically important difference Sample size guidance Randomised trial Effect size Delphi

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Analysis and Control of Electromagnetic Coupling Effect of Levitation and guidance Systems for Semi-High-Speed Maglev Train Considering Current Direction

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IEEE TRANSACTIONS ON MAGNETICS 2017年第6期53卷 1-4页

作者： Jeong, Jae-Hoon Ha, Chang-Wan Lim, Jaewon Choi, Jang-Young Chungnam Natl Univ Dept Elect Engn Daejeon 34134 South Korea Korea Inst Machinery & Mat Dept Magnet Levitat & Linear Drive Daejeon 34103 South Korea

A semi-high-speed magnetic levitation (maglev) train with a maximum speed of 200 km/h is being developed in Korea. It utilizes linear induction motors for propulsion and adopts electromagnetic suspension for levitation. For high-speed operation, guidance systems should be adopted to stabilize the train especially on curved tracks. For compatibility of the rail with previously developed urban maglev trains, the installation of the guidance electromagnet has to be restricted to be placed near the levitation electromagnet. Owing to the spatial closeness, mutual magnetic flux by the levitation and guidance electromagnets is produced at an overlapping portion of the rail. For stable control of the two systems, the coupling effects must be analyzed, because the levitation and guidance electromagnets are not operated independently. This paper aims to analyze the coupling effects by considering the magnetic field and a magnetic equivalent circuit. This paper suggests levitation and guidance systems for the semi-high-speed maglev train by considering each electromagnetic characteristic depending on the current direction.

关键词： Current direction guidance levitation magnetic equivalent circuit semi-high-speed maglev

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Scientific Opinion about the guidance of the Chemical Regulation Directorate (UK) on how aged sorption studies for pesticides should be conducted, analysed and used in regulatory assessments

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EFSA JOURNAL 2018年第8期16卷 e05382页

作者： Ockleford, Colin Hernandez-Jerez, Antonio F. Bennekou, Susanne Hougaard Klein, Michael Adriaanse, Thomas Paulien Berny, Philippe Brock, Theodorus Duquesne, Sabine Grilli, Sandro Kuhl, Thomas Laskowski, Ryszard Machera, Kyriaki Pelkonen, Olavi Pieper, Silvia Stemmer, Michael Sundh, Ingvar Teodorovic, Ivana Topping, Chris J. Wolterink, Gerrit Smith, Robert H. Gimsing, Anne Louise Kasteel, Roy Boivin, Arnaud van der Linden, Ton Magrans, Jose Oriol Egsmose, Mark Tiktak, Aaldrik EFSA Panel on Plant Protection Products and their Residues (PPR)

The EFSA Panelon Plant Protection Products and their Residues reviewed the guidance on how aged sorption studies for pesticides should be conducted, analysed and used in regulatory assessment. The inclusion of aged sorption is a higher tier in the groundwater leaching assessment. The Panelbased its review on a test with three substances taken from a data set provided by the European Crop Protection Association. Particular points of attention were the quality of the data provided, the proposed fitting procedure of aged sorption experiments and the proposed method for combining results obtained from aged sorption studies and lower-tier studies on degradation and adsorption. Aged sorption was a relevant process in all cases studied. The test revealed that the guidance could generally be well applied and resulted in robust and plausible results. The Panelconsiders the guidance suitable for use in the groundwater leaching assessment after the recommendations in this Scientific Opinion have been implemented, with the exception of the use of field data to derive aged sorption parameters. The Panelnoted that the draft guidance could only be used by experienced users because there is no software tool that fully supports the work flow in the guidance document. It is therefore recommended that a user-friendly software tool be developed. Aged sorption lowered the predicted concentration in groundwater. However, because aged sorption experiments may be conducted in different soils than lower-tier degradation and adsorption experiments, it cannot be guaranteed that the higher tier predicts lower concentrations than the lower tier, while lower tiers should be more conservative than higher tiers. To mitigate this problem, the Panelrecommends using all available higher- and lower-tier data in the leaching assessment. The Panelfurther recommends that aged sorption parameters for metabolites be derived only from metabolite-dosed studies. The formation fraction can be derived from pare

关键词： plant protection products aged sorption guidance modelling leaching review

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The principles and methods behind EFSA's guidance on Uncertainty Analysis in Scientific Assessment

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EFSA JOURNAL 2018年第1期16卷 e05122页

作者： Benford, Diane Halldorsson, Thorhallur Jeger, Michael John Knutsen, Helle Katrine More, Simon Naegeli, Hanspeter Noteborn, Hubert Ockleford, Colin Ricci, Antonia Rychen, Guido Schlatter, Josef R. Silano, Vittorio Solecki, Roland Turck, Dominique Younes, Maged Craig, Peter Hart, Andrew Von Goetz, Natalie Koutsoumanis, Kostas Mortensen, Alicja Ossendorp, Bernadette Germini, Andrea Martino, Laura Merten, Caroline Mosbach-Schulz, Olaf Smith, Anthony Hardy, Anthony EFSA Scientific Committee

To meet the general requirement for transparency in EFSA's work, all its scientific assessments must consider uncertainty. Assessments must say clearly and unambiguously what sources of uncertainty have been identified and what is their impact on the assessment conclusion. This applies to all EFSA's areas, all types of scientific assessment and all types of uncertainty affecting assessment. This current Opinion describes the principles and methods supporting a concise guidance Document on Uncertainty in EFSA's Scientific Assessment, published separately. These documents do not prescribe specific methods for uncertainty analysis but rather provide a flexible framework within which different methods may be selected, according to the needs of each assessment. Assessors should systematically identify sources of uncertainty, checking each part of their assessment to minimise the risk of overlooking important uncertainties. Uncertainty may be expressed qualitatively or quantitatively. It is neither necessary nor possible to quantify separately every source of uncertainty affecting an assessment. However, assessors should express in quantitative terms the combined effect of as many as possible of identified sources of uncertainty. The guidance describes practical approaches. Uncertainty analysis should be conducted in a flexible, iterative manner, starting at a level appropriate to the assessment and refining the analysis as far as is needed or possible within the time available. The methods and results of the uncertainty analysis should be reported fully and transparently. Every EFSA Paneland Unit applied the draft guidance to at least one assessment in their work area during a trial period of one year. Experience gained in this period resulted in improved guidance. The Scientific Committee considers that uncertainty analysis will be unconditional for EFSA Panels and staff and must be embedded into scientific assessment in all areas of EFSA's work. (c) 2018 European Food

关键词： uncertainty analysis principles scientific assessment guidance

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Update: Efficacy of Military Fluid Intake guidance

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MILITARY MEDICINE 2018年第9-10期183卷 E338-E342页

作者： Luippold, Adam J. Charkoudian, Nisha Kenefick, Robert W. Montain, Scott J. Lee, Jason K. W. Teo, Ya Shi Cheuvront, Samuel N. US Army Thermal Mt Med Div Res Inst Environm Med 10 Gen Greene Ave Natick MA 01760 USA US Army Mil Nutr Div Res Inst Environm Med 10 Gen Greene Ave Natick MA 01760 USA DSO Labs Def Med & Environm Res Inst Human Performance Lab 12 Sci Pk Dr Singapore 118225 Singapore Natl Univ Singapore Yong Loo Lin Sch Med Dept Physiol 2 Med Dr Singapore 117593 Singapore

Background: Fluid intake during military training is prescribed based on the interactions among work rates, environmental conditions, and uniform configurations. The efficacy of this guidance has not been empirically assessed in over a decade. To determine the acceptability of the fluid intake guidance, sweat losses were measured in a variety of conditions with modern uniform/body armor configurations and were then compared to prescribed fluid intakes for each condition (workload, environment, clothing). Methods: Whole body sweat losses of 324 Soldiers and 14 model simulations were measured under a variety of work intensities ((Watts) easy, moderate, hard), work durations (2-25 h), environmental conditions (White-Black flag), and uniform configurations (including Army Combat Uniform and body armor). Whole body sweat losses were then calculated relative to 4 h drinking guidance and in accordance with TB MED 507 recommended work/rest ratios. The differences between the prescribed fluid intake and sweat loss were calculated and expressed as a percent loss or gain of body weight. Values within a threshold of +/- 2% body water flux (BWF) were deemed an acceptable conservative starting point for performance and health concerns. Findings: Values within +/- 2% BWF numbered 309/338;25 of 338 observations exceeded the +2% BWF while 4 of 338 observations exceeded the -2% BWF. When total fluid restriction was simulated, all experienced body weight loss with 151 of 338 observations exceeding the -2% BWF. Discussion: When calculated using actual measured sweating rates from the laboratory and model simulations, current fluid intake guidance appears to predict with 91.4% accuracy the volume of fluid required to maintain a proper euhydrated state (+/- 2%) during 4 h of exercise. Simulations of total fluid restriction support the necessity for fluid intake guidance so that the Warfighter's performance does not degrade. It is recommended that the current military fluid intake guidanc

关键词： Assessment guidance Hydration Military

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A prospective and randomised trial comparing fluoroscopic, total ultrasonographic, and combined guidance for renal access in mini-percutaneous nephrolithotomy

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BJU INTERNATIONAL 2017年第4期119卷 612-618页

作者： Zhu, Wei Li, Jiasheng Yuan, Jian Liu, Yongda Wan, Shaw P. Liu, Guanzhao Chen, Wenzhong Wu, Wenqi Luo, Jintai Zhong, Dongliang Qi, Defeng Lei, Ming Zhong, Wen Zhang, Ze He, Zhaohui Zhao, Zhijian Lu, Suilin Wu, Yuji Zeng, Guohua Guangzhou Med Univ Affiliated Hosp 1 Minimally Invas Surg Ctr Dept Urol Kangda Rd 1 Guangzhou 510230 Guangdong Peoples R China Guangdong Key Lab Urol Guangzhou Guangdong Peoples R China

Objective To compare the safety and efficacy of fluoroscopic guidance (FG), total ultrasonographic guidance (USG), and combined ultrasonographic and fluoroscopic guidance (CG) for percutaneous renal access in mini-percutaneous nephrolithotomy (mini-PCNL). Patients and methods The present study was conducted between July 2014 and May 2015 as a prospective randomised trial at the First Affiliated Hospital of Guangzhou Medical University. In all, 450 consecutive patients with renal stones of > 2 cm were randomised to undergo FG, USG, or CG mini-PCNL (150 patients for each group). The primary endpoints were the stone-free rate (SFR) and blood loss (haemoglobin decrease during the operation and transfusion rate). Secondary endpoints included access failure rate, operating time, and complications. S.T.O.N.E. score was used to document the complexity of the renal stones. The study was registered at http://***/(NCT02266381). Results The three groups had similar baseline characteristics. With S.T.O.N.E. scores of 5-6 or 9-13, the SFRs were comparable between the three groups. For S.T.O.N.E. scores of 7-8, FG and CG achieved significantly better SFRs than USG (one-session SFR 85.1% vs 88.5% vs 66.7%, P = 0.006;overall SFR at 3 months postoperatively 89.4% vs 90.2% vs 69.8%, P = 0.002). Multiple-tracts mini-PCNL was used more frequently in the FG and CG groups than in the USG group (20.7% vs 17.1% vs 9.5%, P = 0.028). The mean total radiation exposure time was significantly greater for FG than for CG (47.5 vs 17.9 s, P < 0.001). The USG had zero radiation exposure. There was no significant difference in the haemoglobin decrease, transfusion rate, access failure rate, operating time, nephrostomy drainage time, and hospital stay among the groups. The overall operative complication rates using the Clavien-Dindo grading system were similar between the groups. Conclusions Mini-PCNL under USG is as safe and effective as FG or CG in the treatment of simple kidney stone

关键词： access guidance percutaneous nephrolithotomy randomised controlled trial urolithiasis #KidneyStones

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Monitoring Thyroid Function in Patients on Levothyroxine. Assessment of Conformity to National guidance and Variability in Practice

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EXPERIMENTAL AND CLINICAL ENDOCRINOLOGY & DIABETES 2017年第9期125卷 625-633页

作者： Scargill, Jonathan J. Livingston, Mark Holland, David Duff, Christopher J. Fryer, Anthony A. Heald, Adrian H. Salford Royal Hosp Dept Clin Biochem Salford Lancs England Walsall Manor Hosp Dept Blood Sci Walsall W Midlands England Keele Univ Benchmarking Serv Sch Pharm Keele Staffs England Univ Hosp North Midlands Dept Clin Biochem Stoke On Trent Staffs England Keele Univ Inst Sci & Technol Med Keele Staffs England Univ Manchester Sch Med Manchester Lancs England Univ Manchester Manchester Acad Hlth Sci Ctr Manchester Lancs England Leighton Hosp Dept Med Crewe CW1 4QJ England

Introduction With demand for endocrine tests steadily increasing year-on-year, we examined thyroid function test (TFT) frequencies in patients on levothyroxine replacement therapy to assess the effect of initial TFT results and request source on TFT re-testing interval. Methods All TFTs performed by the Clinical Biochemistry Departments at the Salford Royal Hospital (2009-2012;288263 requests from 139793 patients) and University Hospital of North Midlands (2011-2014;579156 requests from 193035 patients) were extracted from the laboratory computer systems. Of these, 54894 tests were on 13297 patients confirmed to be on levothyroxine therapy in the test cohort (Salford) and 67298 requests on 11971 patients in the confirmatory cohort (North Midlands). Results In the test cohort, median TFT re-testing interval in the total group was 19.1 weeks (IQR 9.1-37.7 weeks), with clearly defined peaks in TFT re-testing evident at 6 and 12 months and a prominent broad peak at 1-3 months. Median re-test interval was much lower than recommended (52 weeks) for those with normal TFTs at 31.3 weeks (30.6 weeks for the confirmatory cohort). Where thyroid-stimulating hormone (TSH) was elevated and free thyroxine (fT4) was below the reference range, re-test interval was much longer than is recommended (8 weeks) at 13.4-17.6 weeks (7.1-23.4 weeks in the confirmatory cohort), as was the interval when TSH was below and fT4 was above the normal range, at 16.7-25.6 weeks (27.5-31.9 weeks in the confirmatory cohort). Conclusion Our findings show that the majority of TFT requests are requested outside recommended intervals and within-practice variability is high. A new approach to ensuring optimum monitoring frequency is required. Direct requesting from the clinical laboratory may provide one such solution.

关键词： Monitoring thyroid function frequency guidance

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