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Why ecosystem characteristics predicted from remotely sensed data are unbiased and biased at the same time-and how this affects applications

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Forest Ecosystems 2024年第1期11卷 24-31页

作者： Goran Ståhl Terje Gobakken Svetlana Saarela henrik j.Persson Magnus Ekstrom Sean P.Healey Zhiqiang Yang johan Holmgren Eva Lindberg Kenneth Nystrom Emanuele Papucci Patrik Ulvdal Hans OleØrka Erik Næsset Zhengyang Hou Håkan Olsson Ronald E.McRoberts Department of Forest Resource Management Swedish University of Agricultural Sciences90183UmeåSweden Faculty of Environmental Sciences and Natural Resource Management Norwegian University of Life SciencesÅsNorway USDA Forest Service Rocky Mountain Research StationOgdenUTUSA The Key Laboratory for Silviculture and Conservation of Ministry of Education Beijing Forestry UniversityBeijing100083China Department of Forest Resources University of MinnesotaSt.PaulMNUSA

Remotely sensed data are frequently used for predicting and mapping ecosystem characteristics,and spatially explicit wall-to-wall information is sometimes proposed as the best possible source of information for ***,wall-to-wall information typically relies on model-based prediction,and several features of model-based prediction should be understood before extensively relying on this type of *** such feature is that model-based predictors can be considered both unbiased and biased at the same time,which has important implications in several areas of *** this discussion paper,we first describe the conventional model-unbiasedness paradigm that underpins most prediction techniques using remotely sensed(or other)auxiliary *** this point of view,model-based predictors are typically ***,we show that for specific domains,identified based on their true values,the same model-based predictors can be considered biased,and sometimes severely *** suggest distinguishing between conventional model-bias,defined in the statistical literature as the difference between the expected value of a predictor and the expected value of the quantity being predicted,and design-bias of model-based estimators,defined as the difference between the expected value of a model-based estimator and the true value of the quantity being *** show that model-based estimators(or predictors)are typically design-biased,and that there is a trend in the design-bias from overestimating small true values to underestimating large true ***,we give examples of applications where this is important to acknowledge and to potentially make adjustments to correct for the design-bias *** argue that relying entirely on conventional model-unbiasedness may lead to mistakes in several areas of application that use predictions from remotely sensed data.

关键词： Bias Model-based inference Design-based inference

A Primal-Dual SGD Algorithm for Distributed Nonconvex Optimization

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IEEE/CAA journal of Automatica Sinica 2022年第5期9卷 812-833页

作者： Xinlei Yi Shengjun Zhang Tao Yang Tianyou Chai Karl henrik johansson Division of Decision and Control Systems School of Electrical Engineering and Computer ScienceKTH Royal Institute of Technologyand also affiliated with the Digital FuturesStockholm 10044Sweden Department of Electrical Engineering University of North TexasDentonTX 76203 USA IEEE State Key Laboratory of Synthetical Automation for Process Industries Northeastern UniversityShenyang 110819China

The distributed nonconvex optimization problem of minimizing a global cost function formed by a sum of n local cost functions by using local information exchange is *** problem is an important component of many machine learning techniques with data parallelism,such as deep learning and federated *** propose a distributed primal-dual stochastic gradient descent(SGD)algorithm,suitable for arbitrarily connected communication networks and any smooth(possibly nonconvex)cost *** show that the proposed algorithm achieves the linear speedup convergence rate O(1/(√nT))for general nonconvex cost functions and the linear speedup convergence rate O(1/(nT)) when the global cost function satisfies the Polyak-Lojasiewicz(P-L)condition,where T is the total number of *** also show that the output of the proposed algorithm with constant parameters linearly converges to a neighborhood of a global *** demonstrate through numerical experiments the efficiency of our algorithm in comparison with the baseline centralized SGD and recently proposed distributed SGD algorithms.

关键词： Distributed nonconvex optimization linear speedup Polyak-Lojasiewicz(P-L)condition primal-dual algorithm stochastic gradient descent

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胆道纤维化的发生发展与治疗

中华消化外科杂志 2024年第7期23卷 989-1000页

作者：赵进玉林延延岳平姚佳米宁宁李麻图付文康高龙 Azumi Suzuki Peng F Wong Kiyohito Tanaka Rungsun Rerknimitr henrik H junger Tan T Cheung Emmanuel Melloul Nicolas Demartines joseph W Leung 袁金秋 Hans j Schlitt 孟文勃兰州大学第一临床医学院兰州730030 兰州大学第一医院普通外科兰州730030 浜松医学中心消化科日本浜松432-8002 詹姆斯库克大学医院血管外科英国米德尔斯堡TS43BW 京都第二红十字医院消化科日本京都602-8031 朱拉隆功国王纪念医院胃肠内镜卓越中心泰国曼谷10330 雷根斯堡大学医学中心外科德国雷根斯堡93053 香港大学外科学系中国香港999077 洛桑大学医院内脏外科瑞士洛桑CH-1015 加州大学戴维斯分校医学中心和萨克拉门托退伍军人医学中心胃肠肝病科美国萨克拉门托95817 中山大学附属第七医院临床研究中心深圳518107

胆道纤维化(BF)是病理性胆道损伤修复的结果,主要表现为胆管壁的增厚硬化和管腔的进行性狭窄,最终可能导致胆道梗阻、胆汁性肝硬化、肝衰竭、肝胆恶性肿瘤等严重不良结局。目前的研究将BF描述为某些胆管病的病理特征,对其病因、病理生... 详细信息

胆道纤维化(BF)是病理性胆道损伤修复的结果,主要表现为胆管壁的增厚硬化和管腔的进行性狭窄,最终可能导致胆道梗阻、胆汁性肝硬化、肝衰竭、肝胆恶性肿瘤等严重不良结局。目前的研究将BF描述为某些胆管病的病理特征,对其病因、病理生理、分子机制和治疗缺乏系统总结。BF是胆道系统普遍存在但容易被忽略的疾病状态,可能通过病理性胆道损伤后的异常修复机制促进肝胆疾病的发生和进展,笔者结合国内外最新研究进展,综述BF的概念、临床表现、病因、发病机制和治疗策略,为临床医师提供参考。

关键词：胆道疾病纤维化胆管反应病因信号通路治疗

Nuclear Phytochrome B Regulates Leaf Flattening through Phytochrome Interacting Factors

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Molecular Plant 2014年第11期7卷 1693-1696页

作者： henrik johansson jon Hughes Department of Plant Physiology Justus Liebig University D35390 Giessen Germany

Dear Editor, Plants are equipped with an array of photorecep- tors to measure UV-B, blue, red, and far-red light in order to monitor their light environment. However, although both synergistic and antagonistic interactions have been described between blue and red light signals （Casal, 2000）, little is known about how different light signals are inte- grated into modulate plant growth and development.

关键词： ARABIDOPSIS PHOTOTROPIN AUXIN PIF4 LIGHT

Modelling erosion of a single rock block using a coupled CFD-DEM approach

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journal of Rock Mechanics and Geotechnical Engineering 2023年第9期15卷 2375-2387页

作者： Penghua Teng Fredrik johansson j.Gunnar I.Hellström Division of Fluid and Experimental Mechanics Department of Engineering Sciences and MathematicsLuleåUniversity of TechnologyLuleåSE-97187Sweden Division of Soil and Rock Mechanics KTH Royal Institute of TechnologyStockholmSE-10044Sweden

Rock block removal is the prevalent physical mechanism for rock erosion and could affect the stability of dam foundations and *** this,understanding of block removal is still inadequate because of the complex interactions among block characteristics,hydraulic forces,and erosive processes acting on the ***,based on a previously conducted physical experiment of erosion of a single rock block,the removal processes of two different protruding blocks are represented by a coupled computational fluid dynamics-discrete element model(CFD-DEM)approach under varied flow ***,the blocks could be rotated with respect to the flow direction to consider the effect of the discontinuity orientation on the block removal *** results visualize the entire block removal *** simulations reproduce the effects of the discontinuity orientation on the critical flow velocity inducing block incipient motion and the trajectory of the block motion observed in the physical *** numerical results present a similar tendency of the critical velocities at different discontinuity orientations but have slightly lower *** trajectory of the block in the simulations fits well with the experimental *** relationship between the dimensionless critical shear stress and discontinuity orientation observed from the simulations shows that the effect of block protrusion becomes more dominant on the block incipient motion with the increase of relative protrusion *** our knowledge,this present study is the first attempt to use the coupled finite volume method(FVM)-DEM approach for modelling the interaction behavior between the block and the flowing water so that the block removal process can be reproduced and analyzed.

关键词： Rock erosion Block removal Incipient motion Coupled CFD-DEM Critical shear stress

Distributed non-cooperative robust MPC based on reduced-order models

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Control Theory and Technology 2016年第1期14卷 11-20页

作者： Yushen LONG Shuai LIU Lihua XIE Karl henrik johansson School of Electrical and Electronic Engineering Nanyang Technological University 639798 Singapore ACCESS Linnaeus Center School of Electrical Engineering Royal Institute of Technology SE-100 44 Stockholm Sweden

In this paper, a non-cooperative distributed MPC algorithm based on reduced order model is proposed to stabilize large-scale systems. The large-scale system consists of a group of interconnected subsystems. Each subsystem can be partitioned into two parts： measurable part, whose states can be directly measured by sensors, and the unmeasurable part. In the online computation phase, only the measurable dynamics of the corresponding subsystem and neighbour-to-neighbour communication are necessary for the local controller design. Satisfaction of the state constraints and the practical stability are guaranteed while the complexity of the optimization problem is reduced. Numerical examples are given to show the effectiveness of this algorithm.

关键词： Model predictive control distributed control building energy efficiency

Finite-time consensus protocols for multi-dimensional multi-agent systems

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Control Theory and Technology 2020年第4期18卷 419-430页

作者： jieqiang Wei Bart Besselink junfeng Wu henrik Sandberg Karl H.johansson Ericsson Global AI Accelerator Torshamnsgatan 21StockholmSweden Bernoulli Institute for Mathematics Computer Science and Artificial IntelligenceUniversity of GroningenP.O.Box 4079700 GroningenAKThe Netherlands College of Control Science and Engineering Zhejiang University310027 HangzhouChina Division of Decision and Control Systems KTH Royal Institute of Technology10044 StockholmSweden

A fnite.-time consensus protocol is proposed for multi -dimensional multi- agent systems, using direction peserving signumcontrols. Flipp solutions and nonsmooh analysis tehniques are adopted to handle discontinuities. Suficient and ncessaryconditions are provided to guarantee infinte time convergence and boundedness of the solutions. It turns out that the numberof agents which have cotinuous contol law plays an ssenan role in fnite-tine conerence In adidio it is shown thatthe unit bals itoduced bylp, norms. where p ∈[1,∞] , are inariat for the closed lop.

关键词： Multi-agent systems Network consensus Finite time convergence Nonsmooth analysis

Immune checkpoint therapy for pancreatic cancer

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World journal of Gastroenterology 2016年第43期22卷 9457-9476页

作者： henrik johansson Roland Andersson Monika Bauden Sarah Hammes Stefan Holdenrieder Daniel Ansari Department of Surgery Clinical Sciences Lund Lund University and Sk?ne University Hospital Institute of Laboratory Medicine German Heart Center at the Technical University Munich

Novel treatment modalities are necessary for pancreatic cancer. Immunotherapy with immune checkpoint inhibition has shown effect in other solid tumors, and could have a place in pancreatic cancer treatment. Most available clinical studies on immune checkpoint inhibitors for pancreatic cancer are not yet completed and are still recruiting patients. Among the completed trials, there have been findings of a preliminary nature such as delayed disease progression and enhanced overall survival after treatment with immune checkpoint inhibitors in mono- or combination therapy. However, due to small sample sizes, major results are not yet identifiable. The present article provides a clinical overview of immune checkpoint inhibition in pancreatic cancer. Pub Med, Clinical *** and American Society of Clinical Oncology's meeting abstracts were systematically searched for relevant clinical studies. Four articles, five abstracts and 25 clinical trials were identified and analyzed in detail.

关键词：胰腺的癌症有免疫力的检查点禁止者临床的试用

A novel method for geometric quality assurance of rock joint replicas in direct shear testing-Part 2:Validation and mechanical replicability

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journal of Rock Mechanics and Geotechnical Engineering 2023年第9期15卷 2209-2223页

作者： j.Larsson F.johansson D.Mas Ivars E.johnson M.Flansbjer N.W.Portal Division of Material and Production Department of Chemistry and Applied MechanicsResearch Institutes of Sweden(RISE)Brinellgatan 4Borås50115Sweden Division of Soil and Rock Mechanics Department of Civil and Architectural EngineeringRoyal Institute of Technology(KTH)Brinellvägen 23Stockholm10044Sweden Swedish Nuclear Fuel and Waste Management Co.(SKB) SolnaSweden

Each rock joint is unique by nature which means that utilization of replicas in direct shear tests is required in experimental parameter ***,a method to acquire knowledge about the ability of the replicas to imitate the shear mechanical behavior of the rock joint and their dispersion in direct shear testing is *** this study,a novel method is presented for geometric quality assurance of *** aim is to facilitate generation of high-quality direct shear testing data as a prerequisite for reliable subsequent analyses of the *** Part 1 of this study,two quality assurance parameters,smf and V_(Hp100),are derived and their usefulness for evaluation of geometric deviations,*** reproducibility,is *** Part 2,the parameters are validated by showing a correlation between the parameters and the shear mechanical behavior,which qualifies the parameters for usage in the quality assurance *** results from direct shear tests presenting comparisons between replicas and the rock joint show that replicas fulfilling proposed threshold values of σ_(mf)joint in all aspects apart from having a slightly lower peak shear *** wear in these replicas,which have similar morphology as the rock joint,is in the same areas as in the rock *** wear is slightly larger in the rock joint and therefore the discrepancy in peak shear strength derives from differences in material properties,possibly from differences in *** is shown by application of the suggested method that the quality assured replicas manufactured following the process employed in this study phenomenologically capture the shear strength characteristics,which makes them useful in parameter studies.

关键词： Three-dimensional(3D)scanning Contact area measurements Direct shear testing Geometric quality assurance Mechanical replicability Replicas Rock joint