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Conservative and Finite Volume Methods for the Convection-Dominated pricing problem

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Advances in Applied Mathematics and Mechanics 2013年第6期5卷 759-790页

作者： German I.ramırez-Espinoza Matthias Ehrhardt EON Global Commodities Holzstraße 640221 DusseldorfGermany Lehrstuhl fur Angewandte Mathematik und Numerische Analysis Fachbereich C-Mathematik und NaturwissenschaftenBergische Universitat WuppertalGaußstr.2042119WuppertalGermany

This work presents a comparison study of different numerical methods to solve Black-Scholes-type partial differential equations(pDE)in the convectiondominated case,i.e.,for European options,if the ratio of the risk-free interest rate and the squared volatility-known in fluid dynamics as p´eclet number-is *** Asian options,additional similar problems arise when the"spatial"variable,the stock price,is close to *** we focus on three methods:the exponentially fitted scheme,a modification of Wang’s finite volume method specially designed for the Black-Scholes equation,and the Kurganov-Tadmor scheme for a general convection-diffusion equation,that is applied for the first time to option pricing *** emphasis is put in the Kurganov-Tadmor because its flexibility allows the simulation of a great variety of types of options and it exhibits quadratic *** the reduction technique proposed by Wilmott,a put-call parity is presented based on the similarity reduction and the put-call parity expression for Asian ***,we present experiments and comparisons with different(non)linear Black-Scholes pDEs.

关键词： Black-Scholes equation convection-dominated case exponential fitting methods fitted finite volume method Kurganov-Tadmor scheme minmod limiter

Damage modeling of ballistic penetration and impact behavior of concrete panel under low and high velocities

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Defence Technology（防务技术） 2021年第1期17卷 202-211页

作者： Chahmi Oucif J.S.Kalyana rama K.Shankar ram Farid Abed Institute of Structural Mechanics(ISM) Bauhaus-Universitat WeimarMarienstraße 15D-99423WeimarGermany Department of Civil Engineering BITS Pilani-Hyderabad CampusHyderabad500072India Department of Civil Engineering Vignana Bharathi Institute of TechnologyHyderabad501301India Department of Civil Engineering University of CaliforniaBerkeleyBerkeleyCAUnited States Department of Civil Engineering American University of SharjahP.O.Box 26666United Arab Emirates

This work presents a numerical simulation of ballistic penetration and high velocity impact behavior of plain and reinforced concrete *** paper is divided into two *** first part consists of numerical modeling of reinforced concrete panel penetrated with a spherical projectile using concrete damage plasticity(CDp)model,while the second part focuses on the comparison of CDp model and Johnson-Holmquist-2(JH-2)damage model and their ability to describe the behavior of concrete panel under impact *** first and second concrete panels have dimensions of 1500 mm1500 mm150 mm and 675 mm675 mm200 mm,respectively,and are meshed using 8-node hexahedron solid *** impact object used in the first part is a spherical projectile of 150 mm diameter,while in the second part steel projectile of a length of 152 mm is modeled as rigid *** and scabbing characteristics are studied in the first *** the second part,the comparison results are presented as damage contours,kinetic energy of projectile and internal energy of the *** results revealed a severe fracture of the panel and high kinetic energy of the projectile using CDp model comparing to the JH-2 *** addition,the internal energy of concrete using CDp model was found to be less comparing to the JH-2 model.

关键词： Johnson-Holmquist-2 Concrete damage plasticity Concrete panel Damage Impact loads

Importance of charge self-consistency in first-principles description of strongly correlated systems

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npj Computational Materials 2021年第1期7卷 1949-1956页

作者： Swagata acharya Dimitar pashov Alexander N.Rudenk Malte Rösner Mark van Schilfgaarde Mikhail I.Katsnelson Institute for Molecules and Materials Radboud UniversityNijmegen 6525 AJThe Netherlands Theory and Simulation of Condensed Matter King's College LondonThe StrandLondon WC2R2LSUK National Renewable Energy Laboratory Golden80401 ColoradoUSA

First-principles approaches have been successful in solving many-body Hamiltonians for real materials to an extent when correlations are weak or *** the electronic correlations become stronger often embedding methods based on first-principles approaches are used to better treat the correlations by solving a suitably chosen many-body Hamiltonian with a higher level *** success of such embedding theories,often referred to as second-principles,is commonly measured by the quality of self-energy E which is either a function of energy or momentum or ***,E should,in principle,also modify the electronic eigenfunctions and thus change the real space charge *** such practices are not prevalent,some works that use embedding techniques do take into account these *** such cases,choice of partitioning,of the parameters defining the correlated Hamiltonian,of double-counting corrections,and the adequacy of low-level Hamiltonian hosting the correlated subspace hinder a systematic and unambiguous understanding of such ***,for a large variety of correlated systems,strong correlations are largely confined to the charge *** an adequate non local low-order theory is important,and the high-order local correlations embedding contributes become *** we study the impact of charge self-consistency within two example cases,TiSez and CrBrs,and show how real space charge re-distribution due to correlation effects taken *** within a first-principles Green's function-based many-body perturbative approach is key in driving qualitative changes to the final electronic structure of these materials.

关键词： theory charge principles

plant diversity of the Kangchenjunga Landscape, Eastern Himalayas

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plant Diversity 2019年第3期41卷 153-165页

作者： pratikshya Kandel Nakul Chettri ram p.Chaudhary Hemant Kumar Badola Kailash S.Gaira Sonam Wangchuk Namgay Bidha Yadav Uprety Eklabya Sharma International Centre for Integrated Mountain Development Kathmandu Nepal Research Centre for Applied Science and Technology (RECAST) Kathmandu Nepal G B pant National Institute of Himalayan Environment and Sustainable Development (GBpNIHESD) Sikkim India Nature Conservation Division Department of Forest and Park Services Thimphu Bhutan

The Kangchenjunga Landscape (KL) in the Eastern Himalayas is a transboundary complex shared by Bhutan, India, and Nepal. It forms a part of the ‘Himalayan Biodiversity Hotspot’ and is one of the biologically richest landscapes in the Eastern Himalayas. In this paper, we use secondary information to review and consolidate the knowledge on the flora of the KL. We reviewed 215 journal articles, analysed the history of publications on the flora of the KL, their publication pattern in terms of temporal and spatial distribution and key research areas. Our review shows that the landscape has a long history of botanical research that dates back to the 1840s and progressed remarkably after the 1980s. Most of the studies have been carried out in India, followed by Nepal and Bhutan. The majority of these have been vegetation surveys, followed by research on ethnobotanical aspects and Non-Timber Forest products (NTFps). This paper describes the forest types and characteristic species of the KL and details the species richness, diversity and dominant families of seed plants. A total of 5198 species of seed plants belonging to 1548 genera and 216 families have been recorded from the landscape, including 3860 dicots, 1315 monocots and 23 gymnosperms. Among families, Orchidaceae is the most diversely represented family in terms of species richness. This paper also draws attention to the threatened and endemic flora of the KL, including 44 species that are threatened at national and global level and 182 species that are endemic. Finally, the paper reviews the major challenges facing the KL, the conservation efforts and practices that are currently in place and recommends systematic and comprehensive floral surveys, particularly long-term data collection and monitoring and transboundary collaboration, to address the existing knowledge gaps on floral diversity of the KL.

关键词： Floral diversity Transboundary landscape Nepal India Bhutan Biodiversity

Importance of Quercus *** diversity and biomass of vascular epiphytes in a managed pine-oak forest in Southern Mexico

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Forest Ecosystems 2022年第3期9卷 366-377页

作者： Nayely Martínez-Meléndez Neptalí ramírez-Marcial José G. García-Franco Manuel Jesús Cach-pérez pablo Martínez-Zurimendi Departamento de Conservacion de la Biodiversidad El Colegio de la Frontera Sur(ECOSUR)San Cristobal de Las Casas29290ChiapasMexico Red de Ecología Functional Instituto de EcologíaA.C.Xalapa91073VeracruzMexico Departamento de Agricultura Sociedad y AmbienteEl Colegio de la Frontera Sur(ECOSUR)Villahermosa86280TabascoMexico

Background:Forestry management modifies the diversity,structure,and functioning of intervened *** extraction reduces tree density and basal area,leading to changes in the communities of vascular *** objective of this study was to evaluate the diversity and biomass of vascular epiphytes in Quercus trees remaining in two pine-oak forest stands that have been subjected to two stages of the Silvicultural Development Method(release cutting,and thinning)in comparison with an unharvested old-secondary forest in southern *** each treatment,richness of epiphytes present on 60 oak trees was recorded and their dry biomass *** calculated the true diversity(Hill numbers)and beta diversity using the Jaccard coefficient of similarity,and generated rank abundance curves per taxonomic epiphyte group(bromeliads,orchids,ferns and others).For each treatment,the relationships between overall diversity and epiphyte biomass to the host trees basal area were analyzed using log linear ***:We recorded a total of 67 species of epiphytes species belonging to 10 families hosted by five species of *** greatest species richness(^(0)D)was recorded in the old-secondary *** common(^(1)D)and dominant(^(2)D)species were recorded in the release cutting than in the other *** diversity and biomass were both slightly related to host tree basal *** of epiphytes was similar(60%)among treatments,although orchids,bromeliads,and other families were more diverse in the old-secondary *** bromeliad species were shared across all treatments,although orchids presented the most exclusive species in the unharvested *** bromeliad Tillandsia seleriana provided the greatest contribution to biomass in all treatments,followed by the orchid Camaridium *** linear models indicated that epiphyte diversity was significantly related to treatment,and epiphyte biomass to basal area of host ***:Alt

关键词： Bromeliads Chiapas Ferns Orchids Richness Sierra Madre Silvicultural development method(SDM)

Genome-Wide DNA Binding of GBF1 IsModulated by Its Heterodimerizing proteinpartners, HY5 and HYH

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Molecular plant 2014年第2期7卷 448-451页

作者： Hathi ram pushp priya Mukesh Jain Sudip Chattopadhyay [a] National Institute of plant Genome Research Aruna Asaf Ali Marg New Delhi 110067 India [b] Department of Biotechnology National Institute of Technology Mahatma Gandhi Avenue Durgapur 713209 India

Dear Editor, In today＇s post-genomic era where direct targets of manytranscription factors have been identified, it is becomingincreasingly evident that transcriptional networks are verycomplex. Heterodimerization of transcription factors is oneof the several methods by which these complex transcrip-tional networks are formed. By heterodimerization, DNA-binding specificity and affinity, transactivation properties,and ultimately cell physiology might be altered （Naar et al.,2001）. The formation of heterodimers has the potential torecognize additional binding sites and increase the rangeof DNA-binding specificity （Foster et al., 1994）. Further, het-erodimerization also allows the production of new proteinconfigurations. For example, the protein STF1 from soybeancan dimerize with GBF proteins and this dimerization bringstogether the acidic region from STF1 and the proline-richregion of the GBF proteins into one binding element （Cheonget al., 1998）. These results highlight the importance and/orconsequences of heterodimerization of transcription factorsat particular locus. However, to understand the complex tran-scriptional networks, it is important to investigate that howheterodimerization affects the whole-genome-wide bind-ing and transcriptional properties of a transcription *** in this study, we have investigated genome-wide DNAbinding of bZIp transcription factor GBF1, and analyzed theimportance of its heterodimerization with HY5 and HYH forits genome-wide binding. We have found that GBF1 bindingsites are enriched within the 1-kb regions upstream to thetranscription start sites of target genes. Moreover, the bind-ings of GBF1 to most of its targets are largely dependent onHY5, while HYH only affects the binding of GBF1 to somespecific sites.

关键词： DIMERIZATION RESEARCH DNA-binding proteins pLANT photomorphogenesis pLANT gene expression pLANT regulators

The role of human papillomavirus in oral squamous cell carcinoma

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plastic and Aesthetic Research 2016年第1期3卷 132-141页

作者： Francisco A.ramírez-pérez Department of Oral and Maxillofacial-Head and Neck Surgery University Hospital Infanta Cristina06080 BadajozSpain

Aim:The causative role of human papillomavirus(HpV)has been established into the aetiology of oral squamous cell carcinoma(OSCC).Some authors believe that HpV can determinate the prognosis and module treatment response from this kind of ***:Articles published in the last 10 years,focusing on the role of HpV in the development,molecular biology,prognosis and treatment of OSCC were ***:Thirty-nine articles from 252 were selected,highlighting 4 meta-analysis,3 prospective and 2 retrospective *** to its role in the development of cervical cancer,HpV is classified into a high risk for malignant lesions subtype and a low-grade malignant lesions *** and prevalence of HpV varies according to the published data:large studies tend to have lower rates of HpV(pV+patients are usually diagnosed at a younger age,mainly those with oropharyngeal *** is a predilection for the oropharynx and Waldeyer ring *** prognosis,OSCC HpV+patients tend to have better outcome and treatment ***:HpV divides OSCC in two types of tumours with different prognostic and therapeutic implications,with increased survival,better treatment response rates and lower risk of death and recurrences.

关键词： papillomavirus infections carcinoma squamous cell mouth

Central neck compartment dissection in papillary thyroid carcinoma: An update

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World Journal of Surgical procedures 2015年第2期5卷 177-186页

作者： César p ramírez-plaza Department of General and Digestive Surgery Hospital Quirón Málaga

papillary thyroid carcinoma(pTC) is the most common thyroid malignancy, accounting for approximatley 90% of thyroid malignancies in areas of the world without deficit of Iodine. It's universally accepted that total thyroidectomy is the minimal surgical treatment for patients with pTC higher than 1 cm. When a quality surgery is performed, the prognosis for pTC is excellent with 10 and 20-year overall survival rates around 90% and 85%, respectively. Lymph node metastases are very frequent in pTC, occurring in 50%-80% of pTC patients, the most of them being located in the central compartment of the neck(CCN) and with a high rate of occult or clinically undetectable disease. A lot of controversy exists regarding how to treat the central nodal compartment disease of pTC. The first problem is the lack of standardization of the terminology and concepts related to the CCN, which are clearly established and defined in this paper according to the most recent consensus documents of endocrine societies. This uniformity will provide a more consistent and clear communicaction between all the specialist involved in the treatment of pTC. CCN can be performed to treat patients with clinically detectable, radiologically suspected of intraoperative visualized nodal disease(this is defined as therapeutic) or when these findings are absent(also called prophylactic). Indicactions, advantages and disadvantages of both therapeutic and prophylactic CCN dissection are widely discussed and clear recommendations provided.

关键词： Thyroid Cancer papillary Central Node Compartment Dissection prophylactic Therapeutic

Evaluation of antioxidants and argpyrimidine in normal and cataractous lenses in north Indian population

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International Journal of Ophthalmology(English edition) 2017年第7期10卷 1094-1100页

作者： Bharani K Mynampati Sujata Ghosh Thungapathra Muthukumarappa Jagat ram Department of Ophthalmology Advanced Eye CenterPost Graduate Institute of Medical Education and Research Department of Experimental Medicine & Biotechnology Post Graduate Institute of Medical Education and Research Department of Biochemistry Post Graduate Institute of Medical Education and Research

AIM： To assess the level of glutathione, thioltransferase, and argpyrimidine in nuclear and cortical cataractous lenses as well as in the clear lenses in the north Indian ***： Human cataractous lenses were collected from the patients who underwent extracapsular cataract extraction surgery; clear lenses were collected from the freshly donated eye bank eyes. Antioxidant molecules such as glutathione and thioltransferase enzyme activity were measured; simultaneously in these lenses a blue fluorophore argpyrimidine, an advanced glycation end（AGE） product level was assessed using high performance liquid chromatography（HpLC）.RESULTS： The protein concentration was found to be present at higher levels in the control lenses compared to cataract lenses. A significant decrease in the glutathione level was observed in the nuclear cataractous lenses compared to cortical cataractous（p=0.004） and clear lenses（p≤0.005）, but no significant change in the level of antioxidant enzyme thioltransferase was observed. Further, argpyrimidine a blue fluorophore（AGE） was found to be significantly higher in the nuclear cataract（p=0.013） compared to cortical cataract ***： Antioxidants such as glutathione significantly decrease in age-related nuclear and cortical cataract and an AGE, argpyrimidine are present at significantly higher levels in nuclear cataract.

关键词： age-related cataract antioxidants argpyrimidine glutathione nuclear cataract cortical cataract thioltransferase