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Science China Mathematics 2008年第4期51卷 604-619页

作者： christer KISELMAN Uppsala Universitet

We study the class of functions called monodiffric of the second kind by Isaacs. They are discrete analogues of holomorphic functions of one or two complex variables. Discrete analogues of the Cauchy-Riemann operator, of domains of holomorphy in one discrete variable, and of the Hartogs phenomenon in two discrete variables are investigated. Two fundamental solutions to the discrete Cauchy-Riemann equation are studied: one with support in a quadrant, the other with decay at infinity. The first is easy to construct by induction; the second is accessed via its Fourier transform.

关键词： Monodiffric function holomorphic function on a discrete set difference operator Cauchy-Riemann operator domain of holomorphy the Hartogs phenomenon 39A12 47B39 32A99

Functions on discrete sets holomorphic in the sense of Isaacs, or monodiffric functions of the first kind

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Science China Mathematics 2005年第Z1期48卷 86-96页

作者： christer O.Kiselman Department of Mathematics Uppsala University P.O.Box 480SE-751 06 UppsalaSweden

We study discrete analogues of holomorphic functions of one and two variables, especially those that were called monodiffric functions of the first kind by Rufus Isaacs. Discrete analogues of the Cauchy-Riemann operators, domains of holomorphy in one discrete variable, and the Hartogs phenomenon in two discrete variables are investigated.

关键词： monodiffric functions of the first kind, discrete holomorphic functions, functions holomorphic in the sense of Isaacs, discrete Cauchy-Riemann operators, domains of holomorphy, Hartogs' phenomenon.

Domains of holomorphy for Fourier transforms of solutions to discrete convolution equations

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Science China Mathematics 2017年第6期60卷 1005-1018页

作者： KISELMAN christer O. Department of Information Technology Uppsala University Uppsala SE-751 05 Sweden

We study solutions to convolution equations for functions with discrete support in R^n, a special case being functions with support in the integer points. The Fourier transform of a solution can be extended to a holomorphic function in some domains in C^n, and we determine possible domains in terms of the properties of the convolution operator.

关键词： discrete convolution domain of holomorphy Fourier transformation

A metamodel for heritage-based urban recovery

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Built Heritage 2023年第2期7卷 26-49页

作者： christer Gustafsson Matthias Ripp Department of Art History Uppsala University(SE)UppsalaSweden. Department of Archives&Preservation of Historical Monuments City of Regensburg(DE) RegensburgGermany.

Purpose:The purpose of this paper is to discuss the potential transfer of a metamodel for heritage-based urban development(HBUD)in a postcrisis urban recovery ***/methodology/approach:After an introduction to the feld of cultural heritage as a resource for urban development,the research question is elaborated,and the current understanding of urban heritage is *** use of the metamodel in a postcrisis urban recovery setting is described as a potential *** proposed metamodel is introduced along with the grounded theory and design research methodology through which it was *** specifc qualities of metamodels and how they can contribute to the proposed use are *** scenario is then developed further,and specifc ways in which the metamodel could contribute are ***,the metamodel is compared to other methods,such as the historic urban landscape(HUL)approach,and the limitations are ***:The metamodel can potentially be used in a postcrisis urban recovery *** metamodel cannot be used directly,owing to the nature of metamodels;however,it can be transferred to a specifc context and help to structure successful heritage-based urban recovery(HBUR)*** limitations/implications:One limitation is that it can be difcult to understand the diferences between models and *** with a comprehensive understanding of the nature of metamodels can this metamodel be applied,for example,to select appropriate models for *** metamodel can help to ensure that all relevant‘elements’are part of the processes designed for HBUR and emphasise the need for thorough planning,or scoping,of such ***/value:Metamodelling has not previously been used for HBUD or HBUR.

关键词： Urban heritage Recovery Resilience Sustainable development Metamodel Conservation

Remote estimation of the fraction of absorbed photosynthetically active radiation for a maize canopy in Northeast China

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Journal of Plant Ecology 2015年第4期8卷 429-435页

作者： Feng Zhang Guangsheng Zhou christer Nilsson State Key Laboratory of Vegetation and Environmental Change Institute of BotanyChinese Academy of Sciences20 NanxincunXiangshanHaidian DistrictBeijing 100093China Chinese Academy of Meteorological Sciences 46 Zhongguancun South StreetHaidian DistrictBeijing 100081China Landscape Ecology Group Department of Ecology and Environmental ScienceUmeåUniversityUmeåSE-90187Sweden

Aims accurate remote estimation of the fraction of absorbed photosynthetically active radiation(fAPAR)is essential for the light use efficiency(LUE)***,one challenge for the LUE models is lack of knowledge about the relationship between fAPAR and the normalized difference vegetation index(NDVI).Few studies have tested this relationship against field measurements and evaluated the accuracy of the remote estimation *** study aimed to reveal the empirical relationship between NDVI and fAPAR and to improve algorithms for remote estimation of *** to investigate the method of remote estimation of fAPAR seasonal dynamics,the CASA(Carnegie-ames-stanford approach)model and spectral vegetation indices(VIs)were used for in situ measure-ments of spectral reflectance and fAPAR during the growing season of a maize canopy in Northeast *** Findingsthe results showed that the fAPAR increased rapidly with the day of year during the vegetative stage,it remained relatively stable at the stage of reproduction,and finally decreased slowly during the senescence *** addition,fAPAR green[fAPAR_(green)=fAPAR_(green) -fAPAR_(green) LAI_(max))]showed clearer seasonal trends than *** NDVI,red-edge NDVI,wide dynamic range vegetation index,red-edge position(REP)and REP with sentinel-2 bands derived from hyperspectral remote sensing data were all significantly positively related to fAPAR green during the entire growing *** a comparison of the predictive performance of VIs for the whole growing season,REP was the most appropriate spectral index,and can be recommended for monitoring seasonal dynamics of fAPAR in a maize canopy.

关键词： fraction of absorbed photosynthetically active radiation hyperspectral remote sensing maize canopy spectral vegetation indices

Introduction:innovative heritage-based post-crisis urban recovery strategies

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Built Heritage 2023年第2期7卷 1-2页

作者： christer Gustafsson Matthias Ripp Department of Art History Uppsala University(SE)UppsalaSweden Department for cultural heritage RegensburgGermany

Resilience is a concept that has become more and more common during the last *** used in physics and psychology,just recently it has been transferred to the feld of urban planning,urban development and cultural *** purpose of this Special Issue of the international journal Built Heritage is to examine,and discuss,how the concept of resilience can be related to cultural *** understand resilience here in the sense of the SHELTER Resilience defnition which defnes diferent phases before,during and after a disaster or crisis.

关键词： journal disaster heritage

Gap characteristics and their effects on regeneration,dominance and early growth of woody species

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Journal of Plant Ecology 2009年第1期2卷 21-29页

作者： Indra Prasad Sapkota Per christer Oden Swedish University of Agricultural Sciences Southern Swedish Forest Research CentreTropical Silviculture and Seed Science GroupPO Box 49SE-23053 AlnarpSweden

Aims We aim to examine the canopy gap characteristics and evaluate their influence on regeneration,dominance and the early growth of woody species in seasonally dry Shorea robusta forests(Sal forests).Methods Sixty canopy gaps were surveyed in six randomly located transects belts in seasonally dry subtropical Sal forests of central *** transect belt was followed until 10 gap sites were *** equation for the area of an ellipse was used to calculate the size of canopy gap,measuring the longest axis and its perpendicular shorter ***,sizes,ages and causes of tree falls creating canopy gaps along with number and sizes of border trees were identified and *** gap inventories were carried out using square 25-m2 quadrats placed in the middle of each *** individuals>2 m in height within the quadrat were identified at the species level and their diameter at breast height was *** assigned a nested 4-m2 quadrat to the corner of each 25-m2 quadrat,within which all woody individuals>10 cm tall were identified at the species level,and counted them and their regeneration mechanisms were *** height and collar diameter of the tallest individuals were *** statistics was calculated for the variables of interests and Pearson correlation,linear regression,independent-sample t-test and chi-square test were used to relate them and to test for their *** Findings The study found mean gap size of 283 m2 and;50%gaps of 10–15 years *** created by natural single-tree falls were significantly more numerous,and their mean size was significantly smaller than those resulting from artificial causes or multiple-tree *** size correlated with the basal area of felled trees,but it did not correlate with the number of tree *** tree fall basal area was significantly positively correlated to the seed-originated seedling to resprout ratio,it was negatively correlated,along with gap area and th

关键词： canopy gap seedling density seedling growth basal area Sal forests Nepal

Pacing and predictors of performance during cross-country skiing races:A systematic review

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Journal of Sport and Health Science 2018年第4期7卷 381-393页

作者： Thomas Stogg Barbara Pellegrini Hans-christer Holmberg Department of Sport and Exercise Science University of SalzburgHallein/Rif 5400Austria CeRiSM Research Centre＂Sport Mountainand Health＂Rovereto 36068Italy Department of Neuroscience Biomedicine and MovementUniversity of VeronaVerona 37100Italy Swedish Winter Sports Research Centre Mid Sweden UniversityOstersund 83128Sweden School of Sport Sciences UiT Arctic University of NorwayTroms（）9037Norway School of Kinesiology University of British ColumbiaVancouverBC V6T 121Canada Department of Physiology and Pharmacology Karolinska InstitutetStockhol 17177Sweden Corresponding author.E-mail address：thomas.stoeggl@sbg.ac.at

Background： Cross-country skiing （XCS） racing, a popular international winter sport, is complex and challenging from physical, technical, and tactical perspectives. Despite the vast amount of research focusing on this sport, no review has yet addressed the pacing strategies of elite XCS racers or the factors that influence their performance. The aim was to review the scientific literature in an attempt to determine the effects of pacing strategy on the performance of elite XCS racers. Methods： Four electronic databases were searched using relevant subject headings and keywords. Only original research articles published in peerreviewed journals and the English language and addressing performance, biomechanics, physiology, and anthropometry of XCS racers were reviewed. Results： All 27 included articles applied correlative designs to study the effectiveness of different pacing strategies. None of the articles involved the use of an experimental design. Furthermore, potential changes in external conditions （e.g.,weather, ski properties） were not taken into consideration. A comparable number of studies focused on the skating or classical technique. In most cases, positive pacing was observed, with certain indications that higher-level athletes and those with more endurance and strength utilized a more even pacing strategy. The ability to achieve and maintain a long cycle length on all types of terrain was an important determinant of performance in all of the included studies, which was not the case for cycle rate. In general, uphill performance was closely related to overall race performance, with uphill performance being most closely correlated to the success of female skiers and performance on flat terrain being more important for male skiers. Moreover, pacing was coupled to the selection and distribution of technique during a race, with faster skiers employing more double poling and kick double poling, less diagonal stride, and more V2 （double dance） than V1 （single d

关键词： Classic style Competition Cycle characteristics Positive pacing Skating

On the deterring effect of a butterfly＇s eyespot in juvenile and sub-adult chickens

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Current Zoology 2015年第4期61卷 749-757页

作者： Martin OLOFSSON christer WIKLUND Anna FAVATI Department of Zoology Stockholm University SE-106 91 Stockholm Sweden School of Biology Indian Institute of Science Education and Research Thiruvananthapuram Thiruvananthapuram 695016 India

Circular patterns, or eyespots, are common anti-predator features in a variety of animals. Two defensive functions have been documented： large eyespots may intimidate predators, whereas smaller marginal eyespots may divert attacks. However, a given eyespot potentially serves both functions, possibly depending on the predator＇s size and/or experience. Naive predators are potentially more likely to misdirect their attacks towards eyespots; alternatively, their typically smaller size would make them more intimidated by the same eyespots. Here we test how juvenile and sub-adult naive chickens respond to a single eyespot on a butterfly＇s wing. We presented the birds with dead wall brown butterflies, Lasiommata megera, that had their apical eyespot visible or painted over. We assessed the birds＇ responses＇ by （i） scoring their intimidation reaction, （ii） whether they uttered alarm calls and, （iii） if they attacked the butterfly and where they targeted their attacks. Results show that both age categories received higher intimidation scores when offered a butterfly with a visible eyespot. Juveniles were more intimidated by the butterfly than the sub-adults： they received higher intimidation scores and were more prone to utter alarm calls. Moreover, only sub-adults at- tacked and did so by preferentially attacking the butterfly＇s anterior. We demonstrate an intimidating effect of the type of eyespot that has previously been shown only to divert attacks. We suggest that one and the same eyespot may serve two functions relative to different predators; however, further experiments are needed to disentangle the role of predator identity and its link to size, on- togeny and experience [Current Zoology 61 （4）： 749-757, 2015].

关键词： Predator-prey interactions Prey-attack behaviour Butterfly Bird Eyespot Ontogeny