Monotonic Digit Filter for Limited-Area Model

Numerical diffusion or filter are used in most numerical models in order to eliminate small-scale (near two-grid intervals in wavelength) waves, However, conventional diffusion or filter schemes introduce the noise, and indeed few people realized, by filters themselves. For instance, most filters are troubled when they are put to use on meteorological fields with sharp gradient or with steep slope and consequently, the recurrence of undesirable numerical high-frequent oscillations (overshooting and undershooting) seems to be inevitable, Particularly when diffusion or filter is implemented in limited-area models, serious side effects on the limited-area boundaries often contaminate the modeling results. The merits and demerits are surveyed for commonly used diffusion or filter operations. A new type of monotonic digit filter is suggested to prevent overshooting and undershooting (due to the computational shock and Gibbs oscillation) nearby the discontinuous or nearly discontinuous locations when the filtering process was carried out, meanwhile the high selective property of damping is retained. Moreover, the new filter is designed on the implicit framework so that it can easily handle the problem of boundary diminishing in limited-area modeling.

Stand basal area modelling for Chinese fir plantations using an artificial neural network model

Artificial neural network models are a popular estimation tool for fitting nonlinear relationships because they require no assumptions about the form of the fitting function,non-Gaussian distributions,multicollinearity,outliers and noise in the data.The problems of backpropagation models using artificial neural networks include determination of the structure of the network and overlearning courses.According to data from 1981 to 2008 from 15 permanent sample plots on Dagangshan Mountain in Jiangxi Province,a back-propagation artificial neural network model(BPANN)and a support vector machine model(SVM)for basal area of Chinese fir(Cunninghamia lanceolata)plantations were constructed using four kinds of prediction factors,including stand age,site index,surviving stem numbers and quadratic mean diameters.Artificial intelligence methods,especially SVM,could be effective in describing stand basal area growth of Chinese fir under different growth conditions with higher simulation precision than traditional regression models.SVM and the Chapman–Richards nonlinear mixed-effects model had less systematic bias than the BPANN.

A modified simulated annealing algorithm and an excessive area model for floorplanning using fixed-outline constraints

Outline-free floorplanning focuses on area and wirelength reductions, which are usually meaningless, since they can hardly satisfy modern design requirements. We concentrate on a more difficult and useful issue, fixed-outline floorplanning. This issue imposes fixed-outline constraints on the outline-free floorplanning, making the physical design more interesting and challenging. The contributions of this paper are primarily twofold. First, a modified simulated annealing(MSA) algorithm is proposed. In the beginning of the evolutionary process, a new attenuation formula is used to decrease the temperature slowly, to enhance MSA's global searching capacity. After a period of time, the traditional attenuation formula is employed to decrease the temperature rapidly, to maintain MSA's local searching capacity. Second, an excessive area model is designed to guide MSA to find feasible solutions readily. This can save much time for refining feasible solutions. Additionally, B*-tree representation is known as a very useful method for characterizing floorplanning. Therefore, it is employed to perform a perturbing operation for MSA. Finally, six groups of benchmark instances with different dead spaces and aspect ratios—circuits n10, n30, n50, n100, n200, and n300—are chosen to demonstrate the efficiency of our proposed method on fixed-outline floorplanning. Compared to several existing methods, the proposed method is more efficient in obtaining desirable objective function values associated with the chip area, wirelength, and fixed-outline constraints.

IAP General Circulation Models: A First Step Towards Developing a Local Area Model for Weather Prediction in Nigeria

In an earlier study, the Atmospheric Models Intercomparison Program (AMIP) simulations of African climate using the nine-layer gridpoint atmospheric general circulation model were found to be closely related to the observed European Centre for Medium Range Weather Forecast (ECMWF) temperature data at 500 and 850 hPa. This paper presents the analysis of the simulation of African climate using the Global Ocean-Atmosphere-Land System Model (IAP/LASG GOALS) and the nine-layer spectral general circulation model rhomboidally truncated at zonal wave number 15 (L9R15) developed at the Institute of Atmospheric Physics (IAP), Chinese Academy of Sciences, Beijing. Both model simulations were not significantly different from the National Center for Environmental Prediction (NCEP) Reanalysis monthly mean data for 1980-1995 in the case of surface air temperature, sea level pressure and precipitation, with the GOALS reproducing the seasonal mean climate over Africa better. The implications of the encouraging results in developing a local area model for Nigeria have been discussed. The great role of topography in the developing of general circulation models for numerical modelling of weather and climate has been stressed.

IMPACT OF HUMIDITY DATA ON THE PREDICTION OF ONSET VORTEX WITH A LIMITED AREA MODEL

A limited area model has been applied to study the impact of satellite-derived relative humidity data on the predic- tion of onset vortex of monsoon 1979.The results show that inclusion of satellite-derived relative humidity data im- proved the prediction of track of the cyclonic circulation and the rainfall rates in the region of the vortex.

BMC LIMITED AREA MODEL GENERAL DESCRIPTION AND OPERATIONAL RESULTS

The limited area 5-level primitive equation model,as the first operational precipitation forecast model in China,has been run at Beijing (National) Meteorological Center (BMC) for more than four years.The opera- tional results show that this model gives continuous services,and the forecast skill is satisfied for the forecast of some weather situations,such as extratropical cyclone,front and the precipitation associated with them. The forecast guides are widely used at the local weather services now.

Time function of surface subsidence based on Harris model in mined-out area

The surface subsidence is a common environmental hazard in mined-out area. Based on careful analysis of the regularity of surface subsidence in mined-out area, we proposed a new time function based on Harris curve model in consideration of the shortage of current surface subsidence time functions. By analyzing the characteristics of the new time function, we found that it could meet the dynamic process, the velocity change process and the acceleration change process during surface subsidence. Then its rationality had been verified through project cases. The results show that the proposed time function model can give a good reflection of the regularity of surface subsidence in mined-out area and can accurately predict surface subsidence. And the prediction data of the model are a little greater than measured data on condition of proper measured data quantity, which is safety in the engineering. This model provides a new method for the analysis of surface subsidence in mined-out area and reference for future prediction, and it is valuable to engineering application.

The “Valley Economy” Model of Regional Development: A Case Study of Mountain Areas in Beijing, Northern China

A case study is presented of a regional development model for valley economies in the mountain areas of Beijing, China. The nature and framework of the valley economy model are described and the development of the model, which is specific to the mountain areas of Beijing, is analyzed. Five different valley economy models applied in the Beijing mountain areas are compared. The major purpose of the valley economy model is to develop the regional economy, including the selection of appropriate industries, the allocation of industrial space, the establishment of supply chains and the integration of various industries. Pilot experiments using the valley economy model have been conducted in seven counties(districts) in Beijing: Pinggu, Huairou, Changping, Mentougou, and Fangshan districts, and Yanqing and Miyun counties. Five models for developing the Beijing mountain areas have been explored, including: creative cultural industries, characteristic industry clusters, the promotion of large tourist areas, natural scenic tourism and folk cultural tourism. Each model has its own unique features and potential to help in the regional development of mountain areas.

A Study on the Counter Measures for Eco-friendly Land Use Model in Mountainous Area——a Case of Qianjiang District of Chongqing Municipality

Accompanying the development of social economy,the land use model of mountainous area,typically eco-weak area,is changing gradually. Here the establishment of eco-friendly land use model in mountainous area,will pioneer the model of sustainable development in that area. Concerning Qianjiang District of Chongqing Municipality,huge change of land use model,mainly embodied in the unceasing increase of construction land and gradual decrease of agricultural use land,has taken place in recent years. To explore the eco-friendly land use model in mountainous area,Qianjiang District was chosen as the study object in the present study. Via analyzing the changes in land use model,we found that related eco-environment restrictive factors mainly regional climatic change,soil texture,hydrological environment as well as soil erosion and land degradation,etc. And based on these results,we further analyzed the effect of land use change on eco-environment and the factors restricting the maintenance of eco-environment and regional development,finally put forward the counter measures for balancing land use and co-environment in mountainous area. The results will be important for the development of social economy and eco-system construction in Qianjiang District.

A review of stand basal area growth models

Growth and yield modeling has a long history in forestry. The methods of measuring the growth of stand basal area have evolved from those developed in the U.S.A. and Germany during the last century. Stand basal area modeling has progressed rapidly since the first widely used model was published by the U.S. Forest Service. Over the years, a variety of models have been developed for predicting the growth and yield of uneven/even-aged stands using stand-level approaches. The modeling methodology has not only moved from an empirical approach to a more ecological process-based approach but also accommodated a variety of techniques such as： 1） simultaneous equation methods, 2） difference models, 3） artificial neural network techniques, 4） linear/nonlinear regression models, and 5） matrix models. Empirical models using statistical methods were developed to reproduce accurately and precisely field observations. In contrast, process models have a shorter history, developed originally as research and education tools with the aim of increasing the understanding of cause and effect relationships. Empirical and process models can be married into hybrid models in which the shortcomings of both component approaches can, to some extent, be overcome. Algebraic difference forms of stand basal area models which consist of stand age, stand density and site quality can fully describe stand growth dynamics. This paper reviews the current literature regarding stand basal area models, discusses the basic types of models and their merits and outlines recent progress in modeling growth and dynamics of stand basal area. Future trends involving algebraic difference forms, good fitting variables and model types into stand basal area modeling strategies are discussed.

STUDY ON THE MODEL FOR PREDICTING SOIL EROSION AND ITS APPLICATION IN ARID AREA

On the basis of analyzing the soil erosion factors in typical arid area basin, this article tries to build a model by using USLE (Universal Soil Loss Equation). The first step is to digitize the topographic map (1∶100?000) and form the DEM (Digital Elevation Model), then use them to obtain necessary data of topographic factors. The second step is to get main elements causing soil erosion through using Main Element Analyzing Program. The third step is to systematically analyze all factors of soil erosion by applying Grey Dynamic Model and Fuzzy Mathematics, and then take GIS software to draw the colored map in the way that different colors present different intensities of soil erosion. At last the regional change of soil erosion amount on the basis of the color map is analyzed.

Simulating deforestation of Nepal by area production model

Based on the growth rates of population, Gross Domestic Products (GDP) and agriculture productivity, the areas of deforestation were predicted in Jutp ani village, Chitwan district, Nepal by Area Production Model (APM). Through the APM simulation in this study, all of forestland will be transferred into agricu ltural land in 2030 at the rate of 24% per year on the current productivity. And if the productivity of subsistence food crop is assumed to increase at the rate of 1%, the productivity of market crop and export crop increase at the rate of 2% annually, deforestation rate will decrease to 17% per year, but only 124 hm2 forest land will be left till 2038. The agriculture productivity is a very impor tant factor for the deforestation, so intensification of agriculture management is more important.

FORECAST EXPERIMENTS ON FUNCTION OF LAND-USE CATEGORIES IN A LIMITED-AREA MODEL

With a mesoscale model (MM5) nested with the global spectral model of NationalMeteorological Center/CMA and especially with the forecast experiments as to rainfall andtemperature of twenty-seven sampling stations in East China for six months (February, March,April in 1997 and June, July, August in 1998), it has been found that the better prediction can beperformed on the condition that the surface physical process of practical land-use categories andphysical parameters is parameterized in particular forecast domain. limited-area model, land-use category, forecast

A Three-dimensional IP-based Telecom Metropolitan Area Network Model

The Metropolitan Area Network (MAN) has faced serious problems after years of rapid development. The model of three-dimensional IP-based MAN, proposed by ZTE, is a next-generation MAN solution, which not only solves the existing problems but also brings new ideas for the development of next-generation MAN.

Performance and Analysis of a Model for Describing Layered Leaf Area Index of Rice

Layered leaf area index （LAIk） is one of the major determinants for rice canopy. The objective of this study is to attain rice LAI k using morphological traits especially leaf traits that affected plant type. A theoretical model based on rice geometrical structure was established to describe LAI k of rice with leaf length （Li）, width （Wi）, angle （Ai）, and space （Si）, and plant pole height （H） at booting and heading stages. In correlation with traditional manual measurement, the model was performed by high R2-values （0.95-0.89, n=24） for four rice hybrids （Liangyoupeijiu, Liangyou E32, Liangyou Y06, and Shanyou 63） with various plant types and four densities （3 750, 2 812, 1 875, and 1 125 plants per 100 m2） of a particular hybrid （Liangyoupeijiu）. The analysis of leaf length, width, angle, and space on LAI k for two hybrids （Liangyoupeijiu and Shanyou 63） showed that leaves length and space exhibited greater effects on the change of rice LAI k . The radiation intensity showed a significantly negative exponential relation to the accumulation of LAI k , which agreed to the coefficient of light extinction （K）. Our results suggest that plant type regulates radiation distribution through changing LAI k . The present model would be helpful to acquire leaf distribution and judge canopy structure of rice field by computer system after a simple and less-invasive measurement of leaf length, width, angle （by photo）, and space at field with non-dilapidation of plants.

A Study on the Factors Influencing the Income Gap between Urban and Rural Areas Based on State-space Model

The increasingly widening income gap between urban and rural areas is affected by many factors. Using the stepwise regression analysis,we find that urbanization level,socio-economic development,education level,financial development scale and financial development efficiency have the greatest impact on the income gap between urban and rural areas. By cointegration test,it is found that there is a long-term equilibrium relationship between these five variables and the income gap between urban and rural areas. We build the state-space model to research the dynamic impact of these factors on the income gap between urban and rural areas. The results show that by improving the level of urbanization,we can effectively narrow the income gap between urban and rural areas,while socio-economic development,the improvement of education level,expansion of financial development scale and financial development efficiency all significantly expand the income gap between urban and rural areas.

The simulation of LUCC based on Logistic-CA-Markov model in Qilian Mountain area, China

The Qilian mountain area was examined for using the Logistic-CA-Markov coupling model combined with GIS spatial analyst technology to research the transformation of LUCC, driving force system and simulate future tendency of variation. Results show that： （1） Woodland area decreased by 12.55%, while grassland, cultivated land, and settlement areas increased by 0.22%, 7.92%, and 0.03%, respectively, from 1986 to 2014. During the period of 1986 to 2000, forest degradation in the middle section of the mountain area decreased by 1,501.69 km2. Vegetation cover area improved, with a net increase of grassland area of 38.12 km2 from 2000 to 2014. （2） For constructing the system driving force, the best simulation scale was 210m×210m. Based on logistic regression analysis, the contribution （weight） of composite driving forces to land use and cover change was obtained, and the weight value was more objectively compared with AHP and MCE method. （3） In the natural scenarios, it is predicted that land use and cover distribution maps of Qilian mountain area in 2028 and 2042, and the Lee-Sallee index test was adopted. Over the next 27 years （2015-2042）, farmland, woodland, grassland, settlement areas show an increasing trend, especially settlements with an obvious change of 0.56%. The area of bare land will decrease by 0.89%. Without environmental degradation, tremendous structural change of LUCC will not occur, and typical characteristic of the vertical zone of the mountain would remain. Farmland and settlement areas will increase, but only in the vicinity of Qilian and Sunan counties.

Study on the Model between the Occurrence Area of Grasshopper and the Characteristic Quantity Indexes of Atmospheric Circulation in Western Aletai

By analyzing the correlation between the occurrence area of grasshopper and 74 characteristic indexes of atmospheric circulation in western Aletai from 1991 to 2008,the atmospheric circulation factors which had the significant relationship with the occurrence area of grasshopper in different counties were screened.The prediction models for the occurrence area of grasshopper in different counties were established by stepwise regression method,and the models obtained were also tested.These models were subsequently utilized to carry out extended prediction on the occurrence area of grasshopper in different counties of western Aletai from 2009 to 2010.Meanwhile,the relationship between the atmospheric circulation factors and the occurrence area of grasshopper were analyzed.The results provided the theoretical basis for the prediction on grasshopper plague.

A hydrocarbon enrichment model and prediction of favorable accumulation areas in complicated superimposed basins in China

The geologic conditions of superimposed basins in China are very complicated. This is mainly shown by multi-phase structural evolution, multiple sets of source-reservoir-cap rock combinations, multiple stages of hydrocarbon generation and expulsion from source rocks, multi-cycle hydrocarbon enrichment and accumulation, and multi-phase reservoir adjustment and reconstruction. The enrichment, accumulation and distribution of hydrocarbon is mainly controlled by the source rock kitchen, paleo- anticline, regional cap rock and intensity of tectonic movement. In this paper, the T-BCMS model has been developed to predict favorable areas of hydrocarbon accumulation in complicated superimposed basins according to time and spatial relationships among five key factors. The five factors include unconformity surface representing tectonic balancing （B）, regional cap rock representing hydrocarbon protection （C）, paleo-anticline representing hydrocarbon migration and accumulation （M）, source rock kitchen representing hydrocarbon generation and expulsion （S） and geological time （T）. There are three necessary conditions to form favorable areas of hydrocarbon accumulation. First, four key factors BCMS should be strictly in the order of BCMS from top to bottom. Second, superimposition of four key factors BCMS in the same area is the most favorable for hydrocarbon accumulation. Third, vertically ordered combination and superimposition in the same area of BCMS should occur at the same geological time. The model has been used to predict the most favorable exploration areas in Ordovician in the Tarim Basin in the main hydrocarbon accumulation periods. The result shows that 95% of the discovered Ordovician hydrocarbon reservoirs are located in the predicted areas, which indicates the feasibility and reliability of the key factor matching T-BCMS model for hydrocarbon accumulation and enrichment.

Kinetics and model of gas generation of source rocks in the deepwater area, Qiongdongnan Basin

In order to investigate the hydrocarbon generation process and gas potentials of source rocks in deepwater area of the Qiongdongnan Basin, kinetic parameters of gas generation （activation energy distribution and frequency factor） of the Yacheng Formation source rocks （coal and neritic mudstones） was determined by thermal simulation experiments in the closed system and the specific KINETICS Software. The results show that the activation energy （Ea） distribution of C1–C5 generation ranges from 50 to 74 kcal/mol with a frequency factor of 2.4×1015 s–1 for the neritic mudstone and the Ea distribution of C1–C5 generation ranges from 49 to 73 kcal/mol with a frequency factor of 8.92×1013 s–1 for the coal. On the basis of these kinetic parameters and combined with the data of sedimentary burial and paleothermal histories, the gas generation model of the Yacheng Formation source rocks closer to geological condition was worked out, indicating its main gas generation stage at Ro （vitrinite reflectance） of 1.25%–2.8%. Meanwhile, the gas generation process of the source rocks of different structural locations （central part, southern slope and south low uplift） in the Lingshui Sag was simulated. Among them, the gas generation of the Yacheng Formation source rocks in the central part and the southern slope of the sag entered the main gas window at 10 and 5 Ma respectively and the peak gas generation in the southern slope occurred at 3 Ma. The very late peak gas generation and the relatively large gas potential indices （GPI：20×10^8–60×10^8 m^3/km^2） would provide favorable conditions for the accumulation of large natural gas reserves in the deepwater area.