A Bogus Typhoon Scheme and Its Application to a Movable Nested Mesh Model

A bogus typhoon scheme,designed for the initialization of a typhoon track prediction model,is developed in thispaper.This scheme includes both effects of axisymmetric wind and asymmetric wind.Experimental forecasts using atwo-way interactive movable nested mesh model show that the forecast skill of typhoon tracks has clearly improvedafter introducing the bogus typhoon into the initial fields.

A Regional Spectral Nested Multilevel Primitive Equation Model

By means of vertical normal modes a regional nested multilevel primitive equation model can be reduced to several sets of shallow water equations characterized by various equivalent depths. Therefore, time integration of the model in spectral form can be performed in the manner similar to those used in the spectral nested shallow water equation model case.

A Regional Spectral Nested Shallow Water Equation Model

A method to expand meteorological elements in terms of finite double Fourier series in a limited-region and a spectral nested shallow water equation model based upon the method with conformal map projection in rectangular coordinates, have been proposed, and computational stability and efficiency of time integration have been discussed.

Ensemble Cloud Model Application in Simulating the Catastrophic Heavy Rainfall Event

An attempt has been made in the present research to simulate a deadly flash-flood event over the City of Skopje,Macedonia on 6 August 2016.A cloud model ensemble forecast method is developed to simulate a super-cell storm’s initiation and evolutionary features.Sounding data are generated using an ensemble approach,that utilizes a triple-nested WRF model.A three-dimensional(3-D)convective cloud model(CCM)with a very fine horizontal grid resolution of 250-m is initialized,using the initial representative sounding data,derived from the WRF 1-km forecast outputs.CCM is configured and run with an open lateral boundary conditions LBC,allowing explicit simulation of convective scale processes.This preliminary study showed that the ensemble approach has some advantages in the generation of the initial data and the model initialization.The applied method minimizes the uncertainties and provides a more qualitative-quantitative assessment of super-cell storm initiation,cell structure,evolutionary properties,and intensity.A high-resolution 3-D run is capable to resolve detailed aspects of convection,including high-intensity convective precipitation.The results are significant not only from the aspect of the cloud model’s ability to provide a qualitative-quantitative assessment of intense precipitation but also for a deeper understanding of the essence of storm development,its vortex dynamics,and the meaning of micro-physical processes for the production and release of large amounts of precipitation that were the cause of the catastrophic flood in an urban area.After a series of experiments and verification,such a system could be a reliable tool in weather services for very short-range forecasting(now-casting)and early warning of weather disasters.

Recognizing Expression Variant and Occluded Face Images Based on Nested HMM and Fuzzy Rule Based Approach

The face recognition with expression and occlusion variation becomes the greatest challenge in biometric applications to recognize people. The proposed work concentrates on recognizing occlusion and seven kinds of expression variations such as neutral, surprise, happy, sad, fear, disgust and angry. During enrollment process, principle component analysis (PCA) detects facial regions on the input image. The detected facial region is converted into fuzzy domain data to make decision during recognition process. The Haar wavelet transform extracts features from the detected facial regions. The Nested Hidden markov model is employed to train these features and each feature of face image is considered as states in a Markov chain to perform learning among the features. The maximum likelihood for the input image was estimated by using Baum Welch algorithm and these features were kept on database. During recognition process, the expression and occlusion varied face image is taken as the test image and maximum likelihood for test image is found by following same procedure done in enrollment process. The matching score between maximum likelihood of input image and test image is computed and it is utilized by fuzzy rule based method to decide whether the test image belongs to authorized or unauthorized. The proposed work was tested among several expression varied and occluded face images of JAFFE and AR datasets respectively.

Overview on high-resolution ocean modeling in JAMSTEC

In view of the importance of ocean component for representing climate change,efforts are underway to implement a high-resolution nesting model system in Model for Interdisciplinary Research on Climate(MIROC) for the North Pacific using the same ocean model as used in the coupled model MIROC5. By comparing double(10 km for the northwestern Pacific,50 km for the rest of the Pacific) and triple(double nesting plus 2 km resolution near Japan) nesting,it turns out that relative vorticity is drastically enhanced near Japan with 2 km resolution. It is hoped that such an elaborated nesting system will reveal detailed processes for the ocean heat uptake by,e.g.,intermediate water and mode water formation for which the"perturbed region"near Japan is the key region.

南亚热带河流底栖硅藻β多样性及其对空间距离与环境梯度的响应——基于广义非相似性模拟的分析

β多样性指不同生境间群落物种组成的差异,其空间格局及影响因素是生物多样性维持研究的重要内容。以典型的南亚热带中小型河流—广州流溪河为对象,在对底栖硅藻进行季节调查的基础上,采用Baselga对β多样性的分解框架,基于Sørensen相异性系数将底栖硅藻的β多样性分解为周转和嵌套两个组分,运用广义非相似性模拟(Generalized Dissimilarity Modelling,GDM)分析了空间与环境因子对β多样性及其组分的影响。结果表明:底栖硅藻β多样性、物种周转和嵌套组分无明显季节差异,物种周转是流溪河底栖硅藻β多样性的主要组分(>75%);环境与空间过程共同影响流溪河底栖硅藻β多样性和物种周转组分格局,但环境选择是主要的驱动因子;与枯水期相比,丰水期的空间因素对β多样性和物种周转组分的影响程度降低。作为一种非线性距离回归方法,GDM能较好地识别底栖硅藻β多样性及其组分对环境梯度和空间距离的响应。

Influence of land use characteristics and trip attributes on commuting mode choice: a case of Nanjing

The effects of socio-demographics, land use characteristics and trip attributes on the commute mode choice are studied with a nested logit （NL） model. Based on the random utility maximum theory, the NL model is formulated. The analysis is carried out in the main area of Nanjing. Direct and cross elasticities are calculated to analyze the effects of travel time and travel cost on the selection of travel mode choice. The results reveal that the non-motorized travel modes are more attractive in the areas with higher housing and employment accessibility and car owners are found to be more likely to commute to work by car. The bus and subway choice probabilities are more sensitive to changes in travel times than to changes in travel costs. In conclusion, a comprehensive public transit system and effective integration of land use and transportation policies help to relieve the traffic congestion levels caused by the increasing urban sprawl.

Numerical simulation of the structure and variation of upwelling off the east coast of Hainan Island using QuikSCAT winds

The spatial structure and variation of the upwelling in the waters east and northeast of Hainan Island, China during 2000-2007 were investigated using a nested high-resolution Princeton Ocean Model (POM) forced by QuikSCAT winds. The model produced good simulations of the summer upwelling and the seasonal and annual variability. Strong upwelling occurs from mid-July to mid-August with a peak east of Hainan Island associated with the southwesterly monsoon in the South China Sea. Sensitivity experiments indicated that when the local wind stress controls the variability of the upwelling, the large-scale circulation significantly enhances the upwelling northeast of Hainan Island by inducing a local upwelling and transporting cold water northeast-ward along the island's east coast. The joint effects of the local wind stress and large-scale circulation result in stronger upwelling northeast of Hainan Island. This implies that the annual variation of the upwelling northeast of Hainan Island is controlled not only by the local alongshore wind stress but also by the large-scale circulation. This result will help us investigate the decadal variation of the upwelling in this region in the future.

Computational Techniques of 2D Tidal Flow in Estuaries and Bays

Some problems in the numerical calculation of tidal flow in estuaries and bays, such as distribution bed roughness, relationship between model moving boundary and water volume balance, remedy of certain shortage under open boundary conditions, smooth transfer of the controlling message for the inner boundaries of nested model, can not be solved usually by means of the fundamental equations and computing mode adopted in the numerical model, but can be done by the measures which not only satisfy the physical features but also are convenient for operation. Based on the calculated samples of some areas of Modaomen, Lingdingyang and Huangmaohai of the Pearl River Estuary, and Shuidong Bay (a typical barrier- lagoon tidal channel) in Guangdong Province, method and process of calculation for the above mentioned problems are briefly presented in this paper.

A Generalized Comfort Function of Subway Systems Based on a Nested Logit Model

With rapid urbanization,subway systems are widely acknowledged as one of the best solutions to urban transportation problems.The operators or managers of subway systems should pay more attention to passenger＇s perceptions of service quality to maintain its competitive position.Taking the traffic state,efficiency,and environmental impact into consideration,the concept of generalized comfort is proposed in this paper.Based on a nested logit model,the selection probability for each factor in a generalized comfort function can be estimated using a nested structure.A certain factor is considered to be more significant in a generalized comfort function than others,when the corresponding probability of this factor is higher in value.Using stated preference and revealed preference data about passenger travel behavior obtained from the Beijing subway,the parameters of generalized comfort function are estimated by maximum likelihood techniques.

Probabilistic Approach of Coastal Defense Against Typhoon Attacks for Nuclear Power Plant

With the global warming and sea level rising, it is widely recognized that there is an increasing tendency of typhoon occurrence frequency and intensity. The defenses code against typhoon attacks for nuclear power plant should be calibrated because of the increasing threat of typhoon disaster and severe consequences. This paper discusses the probabilistic approach of definitions about ＂probable maximum typhoon＂ and ＂probable maximum storm surge＂ in nuclear safety regulations of China and has made some design code calibrations by use of a newly proposed Double Layer Nested Mtdti-objective Probability Model （DLNMPM）.

Towards an Ecological Understanding of Translation Etemality in the Context of Iran

This study attempted to investigate the similarities and differences regarding the conceptions of translation eternality among a small group of Iranian people of different social positions and different ages. Sixty-two participants were selected based on the maximum variation sampling. To gather data, semi-structured interview was utilized. The participants were asked a list of 11 questions collected from the existing literature on the similar topics. Then, the interviews were transcribed for analyzing the data. Besides, Erikson＇s （1959） theory of development was used to classify participants of different ages in four groups of teenager, young, middle age, and old. The high frequency factors were found and analyzed with the use of Bronfenbrenner＇s （1979） nested ecological model. Moreover, the participants were classified in 11 groups based on their social positions and their conceptions were analyzed with the same method. Broadly speaking, 17 central tendencies in the interviews were obtained： People mainly focused on subjects of the books, translation fluency, author＇s competence in writing, and translator＇s competence, translations which have common grounds with social events of Iran, advertisement, existence of movie or cartoon adaptation of the book, translator＇s awareness of the content of the book, existence of cultural similarities between the source and target culture, popularity of the translator, author, and the original book, conversational language in translation, translation fidelity, being both translator and author, and effect of censorship on translation. Besides, old participants seemed to have more precise view on translation eternality and teenager＇s concerns were mostly about the appearance-related issues.

Passenger Choice Behavior between Direct and Transit Flights——A Case Study on Passengers Using Hub Airports in the Northeast Asian Region

This study analyzes air passenger route choice behavior for long-haul inter-continental travel. It employs the SP （state preference） technique and logit modeling to investigate the impact of route development via neighboring countries in the region. With the Japanese government pursuing an increase in international routes at Haneda International Airport, and the Chinese government planning to construct Beijing Capital Second International Airport by 2019, the competition among airports to serve as hubs in Northeast Asia will increase significantly. Korean passengers will have a greater number of route choices when traveling to North America or Europe, utilizing not only direct flights from Incheon International Airport but also flights via Tokyo or Beijing area airports including Haneda International Airport, Narita International Airport, Beijing Capital International Airport and Beijing Capital Second International Airport. Accordingly, passengers will choose among the alternatives by considering fares and flight times. As such, it is essential for airports to offer flights with competitive prices for transit passengers to become successful competitive airports in the region. Therefore, it will become more important for market decision makers to strive toward more attractive ticket prices and better route network quality.

Feature selection for energy system modeling: Identification of relevant time series information

Heuristic or clustering based time series aggregation methods are often used to reduce temporal complexity of energy system models by selecting representative days.However,these methods potentially neglect relevant information of time series(e.g.,distribution parameters).To identify relevant time series parameters,feature selection algorithms can be applied.The present research contributes by(a)developing a new feature selection approach based on clustering,nested modeling and regression(CNR)which is designed for applications requiring high selectivity and using different data sets,(b)comparing and evaluating CNR with feature selection methods available from the literature(e.g.,LASSO)and(c)identifying relevant information of the time series applied in energy system models,in particular those of demand,photovoltaic and wind.Results show that CNR achieves on average up to 101%lower mean absolute errors when methods are directly compared.Thus,CNR better identifies relevant information when the number of selected features is restricted.The disadvantage of CNR,however,is its high computational effort.A potential remedy to counter this is the combination with another method(e.g.,as pre-feature selection).In terms of relevant information,energy systems including photovoltaic are mainly characterized by the correlation between demand and photovoltaic time series as well as the range and the 35%quantile of demand.When energy systems include wind power,the minimum and mean of wind as well as the correlation between demand and wind time series are relevant characteristics.The implications of these findings are discussed.

Implementation of a new network equilibrium model of travel choices

This paper develops a new combined network equilibrium model by using more behaviorally sound mathematical forms to represent the four travel choices（i.e., trip frequency,destination, mode, and route） in a conventional travel demand forecasting process. Trip frequency choice relates to the traveler decision on “making a trip” or “not making a trip”so it is given by a binary logit model. Destination choice is formulated as a parameterized dogit model of which the captivity parameters（expressed as functions of independent variables） allow individual travelers to be captive to specific destinations. Mode choice is given by a two-level nested logit model to avoid IIA restriction. Trip assignment is based on Wardrop＇s “user-optimized” principle. All model forms describing travel choices are in response to the level of services incurred by the transportation system. Through the introduction of inclusive values, the traveler decisions concerning trip frequency, destination, mode, and route choices are inherently interrelated and jointly determined.To obtain solutions of the new combined model, it was reformulated as an equivalent convex programming problem with linear constraints, a great advantage from the computational aspects. The model was applied empirically to a transportation network in New Jersey. The application results show that the new model is consistently better than the commonly used logit combined model in reproducing the observed trip flows from origin zones, origin to destination（O-D） trip flows, O-D trip flows by mode, and trip flows on the network links.

嵌套分布格局研究进展:分析方法、影响机制及保护应用

基于物种分布或群落组成的嵌套格局(嵌套分布格局)是岛屿生物地理学和群落生态学的重要前沿研究领域和核心问题之一。嵌套分布格局最初起源于岛屿物种组成的研究,是指物种较贫乏岛屿中的物种是物种较丰富岛屿中的物种的一个适当子集的分布模式。深入了解嵌套分布格局及其影响机制对生物多样性保护具有重要意义,并可用于指导管理工作。近40年来,嵌套分布格局备受生态学家和保护生物学家的关注,并且在分析方法、影响机制、生物多样性保护应用等方面都取得了一系列重要进展。本文通过对文献的系统检索和归纳总结,从4个方面对嵌套分布格局的最新研究进展进行了综述:(1)发展历史及其研究现状;(2)分析方法,包括各个嵌套指数和零模型的优点与局限;(3)影响机制及其检验方法;(4)在生物多样性保护与管理中的应用。最后,我们对该领域进行了归纳总结并对以后的发展方向提出了针对性建议,包括选择最适合的嵌套指数和零模型进行嵌套分析、同时对多种嵌套理论假说进行验证、开展更多关于功能嵌套和谱系嵌套的研究、推动嵌套分布格局与其他相关领域的融合。本文对于深入了解嵌套分布格局的前沿进展,以及推动国内该领域的快速发展将有重要意义。

生物多样性热点地区内的群落预测:堆叠物种分布模型与森林清查数据对比

鉴于当前气候变化和人类活动的影响,生物多样性的空间预测对其保护和修复至关重要。本文将不同堆叠物种分布模型(stacked species distribution models,S-SDMs)的预测结果与森林清查数据进行了比较,以评估这些S-SDMs模型能否捕获生物多样性热点地区物种丰富度的新特性和地理分布及局部群落的组成。我们选取大西洋沿岸森林151处地点的1499个树种进行SDM模型构建,并利用4种模型堆叠方法重建植物群落。这43种方法分别为二进制SDM模型(bS-SDM)、由最小凸多边形裁剪得到的二进制SDM模型(bS-SDM-CROP)、受物种丰富度观测结果约束的堆叠SDM模型(cS-SDM)以及物种出现点的最小凸多边形(MCP)。我们从物种丰富度、组成、群落预测指标以及β多样性组分(物种嵌套和物种周转)等方面将各堆叠方法与局部群落进行对比。研究结果表明,所有S-SDM模型均捕获到了一般分布格局,其中bS-SDM-CROP模型最为简约。各堆叠模型预测得到的物种组成与局部群落的实际情况存在一定的差异,其中bS-SDM、bS-SDM-CROP和MCP模型呈现出嵌套格局,而物种周转在cS-SDM模型中最为显著。这些S-SDM模型在性能、遗漏率和记账错率方面的表现各不相同,对一些脆弱、濒危和极度濒危物种给出了错误预测。尽管与森林清查数据有差别,但这些S-SDM模型均捕获了与局部群落数据的部分差异,可以表征物种的潜在分布区。本研究的结论有助于S-SDM模型在粗尺度生物多样性整合与保护规划中的应用,但在生物高度多样性地区局部尺度上可能会得出错误的预测结果。

Utilize cloud computing to support dust storm forecasting

The simulations and potential forecasting of dust storms are of significant interest to public health and environment sciences.Dust storms have interannual variabilities and are typical disruptive events.The computing platform for a dust storm forecasting operational system should support a disruptive fashion by scaling up to enable high-resolution forecasting and massive public access when dust storms come and scaling down when no dust storm events occur to save energy and costs.With the capability of providing a large,elastic,and virtualized pool of computational resources,cloud computing becomes a new and advantageous computing paradigm to resolve scientific problems traditionally requiring a large-scale and high-performance cluster.This paper examines the viability for cloud computing to support dust storm forecasting.Through a holistic study by systematically comparing cloud computing using Amazon EC2 to traditional high performance computing(HPC)cluster,we find that cloud computing is emerging as a credible solution for(1)supporting dust storm forecasting in spinning off a large group of computing resources in a few minutes to satisfy the disruptive computing requirements of dust storm forecasting,(2)performing high-resolution dust storm forecasting when required,(3)supporting concurrent computing requirements,(4)supporting real dust storm event forecasting for a large geographic domain by using recent dust storm event in Phoniex,05 July 2011 as example,and(5)reducing cost by maintaining low computing support when there is no dust storm events while invoking a large amount of computing resource to perform high-resolution forecasting and responding to large amount of concurrent public accesses.

The effect of the infection within the individual host on its propagation in the population

We consider nested or multiscale models to study the effect of the temporal evolution of the disease within the host in the population dynamics of the disease,for one and two infectious agents.We assumed a coupling between the within-host infection rate and the between-host transmission rate.The age of infection within each individual in a population affects the probability of transmission of the disease to a susceptible host and this will affect the temporal evolution of the disease in the host population.To analyze the infection within the host,we consider bacterial-like and viral-like infections.In the model for two infectious agents,we found that,when strain 2 has a basic reproduction number R02 greater than the basic reproduction number R01 of strain 1,strain 2 replaces strain 1 in the population.However,if R02>R01 but the values are closer,the replacement does not occur immediately and both strains can coexist for a long time.We applied the model to a scenario in which patients infected with the hepatitis C virus(HCV)are cleared of HCV when super-infected with the hepatitis A virus(HAV).We compared the time for the replacement of HCV by HAV in the population considering instantaneous and noninstantaneous replacement within the individuals.The model developed can be generalized for more than two infectious agents.