Guest editorial: Systems modelling across geography's interface     

Richard Thomas  Yee Leung 《GeoJournal》2004,59(3):167-167

  相似文献   

An Analysis of Thermal Stress of Climate in Hong Kong     

Yuk Yee Yan 《Singapore journal of tropical geography》1997,18(2):210-217

The universal scale of apparent temperature (AT) and clo, a unit measuring the amount of clothing insulation required to maintain comfort, were used to examine the weather stress in Hong Kong. Hourly AT and clo values were computed using hourly air temperature, wind speed, vapour pressure and cloud cover data from 1980 to 1994. Results of both AT and clo reflected highly corresponding changes of thermal stress. It is found that the most stressful time in winter and summer occurred in the early morning and afternoon, and cool weather and tropical ensembles were required to surmount the extreme weather stress respectively. A greater percent of time with severe heat stress than those with extreme cold stress was discovered. These results also indicated that clo is a more informative weather stress index than AT since it provides both the thermal stress and clothing requirements to sustain comfort.  相似文献   

IMPACT OF CLIMATE ON SUMMER RESIDENTIAL ELECTRICITY CONSUMPTION IN HONG KONG     

Yuk Yee Yan Department of Geography Hong Kong Baptist University Kowloon Tong  Hong Kong 《地理学报(英文版)》1997,(4)

Ｉ.ＩｎｔｒｏｄｕｃｔｉｏｎＣｌｉｍａｔｅｈａｓｌｏｎｇｂｅｅｎｋｎｏｗｎｔｏｈａｖｅａｐｒｏｍｉｎｅｎｔｉｎｆｌｕｅｎｃｅｏｎｒｅｓｉｄｅｎｔｉａｌｅｎｅｒｇｙｃｏｎｓｕｍｐｔｉｏｎ,ｐａｒｔｉｃｕｌａｒｌｙｔｈｅｕｓｅｏｆｅｌｅｃｔｒｉｃｉｔｙｉｎｓｐａｃｅｈｅａｔｉｎｇａｎｄｃｏｏｌｉｎｇ.ＩｎＨｏｎｇＫｏｎｇ,ｔｈｅｒｅｗａｓａｎｉｎｃｒｅａｓｅｏｆ207ｐｅｒｃｅｎｔｉｎｒｅｓｉｄｅｎｔｉａｌｅｌｅｃｔｒｉｃｉｔｙｃｏｎｓｕｍｐｔｉｏｎ,ｆｒｏｍ8414ｔｅｒａｊｏｕｌｅ(ＴＪ)ｉｎ1980ｔｏ25827Ｔ…  相似文献   

Seasonal changes in imposex and tissue burden of butyltin compounds in Thais clavigera populations along the coastal area of Mirs Bay, China   总被引：1，自引：0，他引：1  

Chan KM  Leung KM  Cheung KC  Wong MH  Qiu JW 《Marine pollution bulletin》2008,57(6-12):645-651

We assessed the current status of tributyltin (TBT) contamination of Thais clavigera (Gastropoda) along the coastal area of Mirs Bay, China for the first time. The snail samples were collected from 10 different sites in the summer (June) and winter (December) of 2006, respectively. They were analyzed for imposex status, i.e. relative penis size index (RPSI) and vas deferens sequence index (VDSI), followed by quantification of butyltins in their tissues. Most of the collected females suffered from imposex, but the level of butyltin contamination varied with the distance from Yantian Port, which is currently the fourth busiest container port in the world. The tissue concentration of TBT varied with season. For a particular site, the winter samples in general contained much higher concentration of TBT than the summer samples. RPSI, VDSI and organotin concentrations were higher in T. clavigera collected from sites closer to the Port, such as the Seafood Street and Kat O. Both RPSI and VDSI were positively correlated with the tissue burden of tributyltin. VDSI exhibited little seasonal variability, whereas RPSI showed marked seasonal variability, with lower values in the summer samples. The current results will serve as an important reference for long-term monitoring of butyltin contamination in this area.  相似文献   

A Stochastic Time Series Model for Threshold Crossing Statistics of Concentration Fluctuations in non-Intermittent Plumes     

Shuming Du  David J. Wilson  Eugene Yee 《Boundary-Layer Meteorology》1999,92(2):229-241

A numerical stochastic model is developed for the upcrossing rate across a specified threshold concentration. The model assumes that the concentration time series at a given spatial point within a dispersing plume can be approximated as a first-order Markovian process designed to be consistent with a given time-invariant concentration probability density function (pdf). The model requires only the specification of a concentration pdf with a given mean and variance and a concentration fluctuation integral time scale. Predicted upcrossing rates are compared with atmospheric plume concentration data obtained from a point source near the ground. For this data set, a log-normal pdf is found to give better estimates of the threshold crossing rate than a gamma pdf.  相似文献   

改革开放以来广东省空间极化研究   总被引：50，自引：7，他引：43  

甄峰  顾朝林  沈建法  黄钧尧  朱剑如 《地理科学》2000,20(5):403-410

改革开放２０年来广东省的空间结构演化表明：传统的核心－边缘模式已发生了很大的变化,区域出现多极化且次级核心区形成。广州华南中心城市的地位已经被香港所取代,韶关、湛江、汕头、潮阳等老中心城市地位不断下降,深圳、珠海、东莞、中山、顺德、南海和番禺等新兴城市正发展成为新区域增长中心。珠江三角洲经济发展开始向外围地区扩展,出现了反极化的趋势。全省空间差异扩大,形成了多层次的空间极化格局。  相似文献   

Observed characteristics of flow,water mass,and turbulent mixing in the Preparis Channel     

Ruijie Ye  Feng Zhou  Xiao Ma  Dingyong Zeng  Feilong Lin  Hongliang Li  Chenggang Liu  Soe Moe Lwin  Hlaing Swe Win  Soe Pyae Aung 《海洋学报(英文版)》2023,42(2):83-93

Preparis Channel is the very important exchange path of energy and materials between the northern Bay of Bengal and Andaman Sea(AS). A set of hydrographic measurements, a microstructure profiler, and a deep mooring were used to determine the characteristics of water masses, turbulent mixing, and flows in the Preparis Channel. The unprecedented short-term mooring data reveal that a deep current in the deep narrow passage(below 400 m) of the Preparis Channel flows toward the Bay of Bengal(BoB) wit...  相似文献   

An adaptive compromise programming method for multi-objective path optimization     

Rongrong Li  Yee Leung  Hui Lin  Bo Huang 《Journal of Geographical Systems》2013,15(2):211-228

Network routing problems generally involve multiple objectives which may conflict one another. An effective way to solve such problems is to generate a set of Pareto-optimal solutions that is small enough to be handled by a decision maker and large enough to give an overview of all possible trade-offs among the conflicting objectives. To accomplish this, the present paper proposes an adaptive method based on compromise programming to assist decision makers in identifying Pareto-optimal paths, particularly for non-convex problems. This method can provide an unbiased approximation of the Pareto-optimal alternatives by adaptively changing the origin and direction of search in the objective space via the dynamic updating of the largest unexplored region till an appropriately structured Pareto front is captured. To demonstrate the efficacy of the proposed methodology, a case study is carried out for the transportation of dangerous goods in the road network of Hong Kong with the support of geographic information system. The experimental results confirm the effectiveness of the approach.  相似文献   

An intelligent expert system shell for knowledge-based Geographical Information Systems: 1. The tools     

Yee Leung  Kwong Sak Leung 《International journal of geographical information science》2013,27(3):189-199

Abstract

An intelligent expert system shell for the development of knowledge-based geographical information systems (GIS) is examined in this two-part article. Basic concepts and the overall architecture of the shell are discussed in the present part. Fuzzy logic and expert systems technology are demonstrated to be appropriate methods for approximating human reasoning and enhancing the level of intelligence in GIS. The shell can be employed as an effective and efficient tool for developing knowledge-based GIS.  相似文献   

A rough set approach to the discovery of classification rules in spatial data     

Yee Leung  Tung Fung  Ju‐Sheng Mi  Wei‐Zhi Wu 《International journal of geographical information science》2013,27(9):1033-1058

This paper proposes a novel rough set approach to discover classification rules in real‐valued spatial data in general and remotely sensed data in particular. A knowledge induction process is formulated to select optimal decision rules with a minimal set of features necessary and sufficient for a remote sensing classification task. The approach first converts a real‐valued or integer‐valued decision system into an interval‐valued information system. A knowledge induction procedure is then formulated to discover all classification rules hidden in the information system. Two real‐life applications are made to verify and substantiate the conceptual arguments. It demonstrates that the proposed approach can effectively discover in remotely sensed data the optimal spectral bands and optimal rule set for a classification task. It is also capable of unraveling critical spectral band(s) discerning certain classes. The framework paves the road for data mining in mixed spatial databases consisting of qualitative and quantitative data.  相似文献