By the contingent value method, we studied the non-use value of wetland ecosystem service of Hongxing National Nature Reserve （HNNR） in Heilongjiang Pro- vince, northeast China. The proportion of respondents willing...By the contingent value method, we studied the non-use value of wetland ecosystem service of Hongxing National Nature Reserve （HNNR） in Heilongjiang Pro- vince, northeast China. The proportion of respondents willing to pay （WTP） for protection of HNNR was 63 %. The WTP ratio was affected by geographical area, contact nature, personal preferences, and familiar degree of the respondents. The WTP value was affected by age, education level and career of the respondents. The mainly reasons for people rejecting to pay for protecting HNNR were ＂I am not familiar to HNNR＂ and ＂I had no capacity for additional spending because of low income＂. Weighted average individual WTP value was CNY 59.26 Yuan ind.^-1 year^-1 for all the respondents with WTP. The total non-use ecosystem service value of HNNR was CNY 1430 million Yuan in 2013. The heritage value was highest followed by existence value and option value. From the high ecosystem service value in HNNR, it is very important to construct nature reserve for protecting natural ecosystems and human sustainable use of natural resources.展开更多
In this paper we study inviscid and viscid Burgers equations with initial conditions in the half plane . First we consider the Burgers equations with initial conditions admitting two and three shocks and use the HOPF-...In this paper we study inviscid and viscid Burgers equations with initial conditions in the half plane . First we consider the Burgers equations with initial conditions admitting two and three shocks and use the HOPF-COLE transformation to linearize the problems and explicitly solve them. Next we study the Burgers equation and solve the initial value problem for it. We study the asymptotic behavior of solutions and we show that the exact solution of boundary value problem for viscid Burgers equation as viscosity parameter is sufficiently small approach the shock type solution of boundary value problem for inviscid Burgers equation. We discuss both confluence and interacting shocks. In this article a new approach has been developed to find the exact solutions. The results are formulated in classical mathematics and proved with infinitesimal technique of non standard analysis.展开更多
In this paper a recursive state-space model identification method is proposed for non-uniformly sampled systems in industrial applications. Two cases for measuring all states and only output(s) of such a system are co...In this paper a recursive state-space model identification method is proposed for non-uniformly sampled systems in industrial applications. Two cases for measuring all states and only output(s) of such a system are considered for identification. In the case of state measurement, an identification algorithm based on the singular value decomposition(SVD) is developed to estimate the model parameter matrices by using the least-squares fitting. In the case of output measurement only, another identification algorithm is given by combining the SVD approach with a hierarchical identification strategy. An example is used to demonstrate the effectiveness of the proposed identification method.展开更多
Various kinds of Riemann boundary value problems (BVPs) for analytic functions on closed curves or on open arc, doubly periodic Riemann BVPs, doubly quasi-periodic Riemann BVPs, and BVPs for polyanalytic functions hav...Various kinds of Riemann boundary value problems (BVPs) for analytic functions on closed curves or on open arc, doubly periodic Riemann BVPs, doubly quasi-periodic Riemann BVPs, and BVPs for polyanalytic functions have been widely investigated in [1-8]. The main ap- proach is to use the decomposition of polyanalytic functions and their generalization to transform the boundary value problems to their corresponding boundary value problems for analytic functions. Recently, inverse Riemann BVPs for generalized analytic functions or bianalytic functions have been investigated in [9-12]. In this paper, we consider a kind of Riemann BVP of non-normal type on the infinite straight line and discuss the solvable conditions and the general solution for it.展开更多
To overcome the deficiencies of the existing Verhulst GM(1,1) model, based on the existing grey theory, a non-equal-interval direct optimum Verhulst GM(1,1) model is built which chooses a modified n-th component x(n) ...To overcome the deficiencies of the existing Verhulst GM(1,1) model, based on the existing grey theory, a non-equal-interval direct optimum Verhulst GM(1,1) model is built which chooses a modified n-th component x(n) of X(0) as the starting condition of the grey differential model. It optimizes a modified β value and the background value, and takes two times fitting optimization. The new model extends equal intervals to non-equal-intervals and is suitable for general data modelling and estimating parameters of the direct Verhulst GM(1,1). The new model does not need to pre-process the primitive data, nor accumulate generating operation (AGO) and inverse accumulated generating operation (IAGO). It is not only suitable for equal interval data modelling, but also for non-equal interval data modelling. As the new information is fully used and two times fitting optimization is taken, the fitting accuracy is the highest in all existing models. The example shows that the new model is simple and practical. The new model is worth expanding on and applying in data processing or on-line monitoring for tests, social sciences and other engineering sciences.展开更多
In this article, we consider the non-linear difference equation(f(z + 1)f(z)-1)(f(z)f(z-1)-1) =P(z, f(z))/Q(z, f(z)),where P(z, f(z)) and Q(z, f(z)) are relatively prime polynomials in f(z) with rational coefficients....In this article, we consider the non-linear difference equation(f(z + 1)f(z)-1)(f(z)f(z-1)-1) =P(z, f(z))/Q(z, f(z)),where P(z, f(z)) and Q(z, f(z)) are relatively prime polynomials in f(z) with rational coefficients. For the above equation, the order of growth, the exponents of convergence of zeros and poles of its transcendental meromorphic solution f(z), and the exponents of convergence of poles of difference △f(z) and divided difference △f(z)/f(z)are estimated. Furthermore, we study the forms of rational solutions of the above equation.展开更多
The contingent valuation method （CVM） is one of the main methods for evaluating non-market values of resources. It originated in the United States and was introduced into China during the 1980s and 1990s. However, a...The contingent valuation method （CVM） is one of the main methods for evaluating non-market values of resources. It originated in the United States and was introduced into China during the 1980s and 1990s. However, application of CVM in China is highly controversial based on three primary aspects： （I） the appropriate guidelines for CVM; （2） the elicitation techniques for willingness to pay （WTP）; and （3） reliability and validity testing of CVM. The major objectives of this paper are to i^eview the recem devel- opments pertaining to guidelines, elicitation techniques, and reliability and validity testing for application of CVM, and to summa- rize the limitations of and measures for improving application of CVM in China. The applicability of CVM in China is discussed to enhance the future development of CVM in China.展开更多
Background: It is known that certain laboratory value abnormalities may increase mortality in patient populations with specific risk factors and specific procedures. The purpose of this paper was to investigate the ef...Background: It is known that certain laboratory value abnormalities may increase mortality in patient populations with specific risk factors and specific procedures. The purpose of this paper was to investigate the effect of drawing a non-routine lab (regardless of its result) on 30 day mortality and to investigate the effect of an abnormal non-routine laboratory value on 30 day mortality. Methods: The electronic medical records of adult patients undergoing non-cardiac surgery from 2011-2014 at LAC + USC Medical Center were reviewed retrospectively as approved by our institutional review board. Demographic data, surgical risk assessment, and routine and non-routine laboratory values (TSH, Troponin, Creatine Kinase, Hb A1c) were recorded;patients were grouped according to the single non-routine lab they had drawn. Multivariate logistic regression analysis was used to determine significant risk factors associated with increased 30 day mortality. Results: 11,306 patients met our inclusion criteria. Drawing a non-routine lab was associated with a statistically significant increase in mortality in the Troponin group (OR = 3.05, P < 0.001) but not in the TSH, Creatine Kinase, or Hb A1c groups. An abnormal non-routine lab value was associated with a statistically significantly increase in mortality in the TSH group (OR = 11.07, P = 0.008) but not in the other three groups. Conclusions: Drawing a non-routine lab was associated with a statistically significant increase in mortality in the Troponin group but not in the TSH, Creatine Kinase, or Hb A1c groups. An abnormal TSH value was associated with a statistically significant increase in mortality but not an abnormal Troponin, Creatine Kinase, or Hb A1c. Routine and non-routine laboratory testing may guide perioperative patient care and result in improved post-surgical outcome.展开更多
A projected subgradient method for solving a class of set-valued mixed variational inequalities （SMVIs） is proposed when the mapping is not necessarily Lipschitz. Under some suitable conditions, it can be proven tha...A projected subgradient method for solving a class of set-valued mixed variational inequalities （SMVIs） is proposed when the mapping is not necessarily Lipschitz. Under some suitable conditions, it can be proven that the sequence generated by the method can strongly converge to the unique solution to the problem in the Hilbert spaces.展开更多
This paper is concerned with the sensitivity of set-valued discrete systems. Firstly, this paper obtained the equivalence between <img src="Edit_7024f70b-0568-4ca8-a554-c0d05abc0df0.bmp" alt="" ...This paper is concerned with the sensitivity of set-valued discrete systems. Firstly, this paper obtained the equivalence between <img src="Edit_7024f70b-0568-4ca8-a554-c0d05abc0df0.bmp" alt="" />or <img src="Edit_95636a59-7d5d-4b6c-8bd5-f699dd9208df.bmp" alt="" /> and the product system <img src="Edit_c714caaf-0ed9-46bc-b3e1-b0223474a8f5.bmp" alt="" /> in sensitivity, infinite sensitivity, <em>F</em>-sensitivity, (<em>F</em><sub>1</sub>, <em>F</em><sub>2</sub>)-sensitivity. Then, the relation between (<em>X</em>, <em>f</em><sub>1,∞</sub>) or (<em>Y</em>, <em>g</em><sub>1,∞</sub>) and <img src="Edit_55b4ce47-89f3-4476-a8a8-4d4db5a4e8eb.bmp" alt="" /> in ergodic sensitivity is obtained. Where <img src="Edit_a99604c4-2f72-4e75-a998-8057b8790e03.bmp" alt="" /> is the set-valued dynamical system induced by a non-autonomous discrete dynamical system (<em>X</em>, <em>f</em><sub>1,∞</sub>).展开更多
The significance of U values in buildings’ shell energy performance is well known in the scientific community as well as in the construction sector. In addition, conducting a validation of the energy performance of a...The significance of U values in buildings’ shell energy performance is well known in the scientific community as well as in the construction sector. In addition, conducting a validation of the energy performance of a building often requires the knowledge of real U value figures, since their theoretical peers may deviate considerably from the real ones. The theoretical U value of a shell element may be calculated using complex material and surface related information, while its practical validation is conducted usually by equipment that requires tedious installation and constant contact with the examined element. Aim of this paper is to introduce an easily deployed, plug and play, contact less technology, able to provide a reasonable approximation of the building element U value and its variation with external air speed as well as an accurate estimation of the U value change in case of a shell (wall or window) retrofit.展开更多
Several problems arising in science and engineering are modeled by differential equations that involve conditions that are specified at more than one point. The non-linear two-point boundary value problem (TPBVP) (Br...Several problems arising in science and engineering are modeled by differential equations that involve conditions that are specified at more than one point. The non-linear two-point boundary value problem (TPBVP) (Bratu’s equation, Troesch’s problems) occurs engineering and science, including the modeling of chemical reactions diffusion processes and heat transfer. An analytical expression pertaining to the concentration of substrate is obtained using Homotopy perturbation method for all values of parameters. These approximate analytical results were found to be in good agreement with the simulation results.展开更多
NoSQL系统因其高性能、高可扩展性的优势在大数据管理中得到广泛应用,而key-value(KV)模型则是NoSQL系统中使用最广泛的一种存储模型.KV型本地存储系统对于以机械磁盘为持久化存储的情形,存在许多性能优化技术,但这些优化技术面对当前...NoSQL系统因其高性能、高可扩展性的优势在大数据管理中得到广泛应用,而key-value(KV)模型则是NoSQL系统中使用最广泛的一种存储模型.KV型本地存储系统对于以机械磁盘为持久化存储的情形,存在许多性能优化技术,但这些优化技术面对当前的硬件发展新趋势,如多核处理器、大内存和低延迟闪存、非易失性内存NVM(Non-Volatile Memory)等,难以充分发挥新硬件的优势,如数据索引、并发控制、事务日志管理等技术在多核架构下存在多核扩展性问题,又如数据存储策略不适应闪存SSD(Solid State Drive)的新存储特性而产生了IO利用率低效的问题.针对多核处理器、大内存和闪存、NVM等硬件发展新趋势,文中面向当前的大数据应用背景,综述了KV型本地存储系统在索引技术、并发控制、事务日志管理和数据放置等核心模块上的最新优化技术和系统研究成果.从处理器、内存和持久化存储的角度概括了KV型本地存储系统当前存在的最优技术,总结了当前研究尚未解决的技术挑战,并对KV型本地存储系统在CPU缓存高效性、事务日志扩展性和高可用性等方面的研究进行了展望.展开更多
By using Leray-Schauder nonlinear alternative, Banach contraction theorem and Guo-Krasnosel’skii theorem, we discuss the existence, uniqueness and positivity of solution to the third-order multi-point nonhomogeneous ...By using Leray-Schauder nonlinear alternative, Banach contraction theorem and Guo-Krasnosel’skii theorem, we discuss the existence, uniqueness and positivity of solution to the third-order multi-point nonhomogeneous boundary value problem (BVP1): where for The interesting point lies in the fact that the nonlinear term is allowed to depend on the first order derivative .展开更多
The author investigates the existence of positive and nontrivial solutions for superlinear (n - 1, 1) conjugate boundary value problems by means of topological degree theory and cone theory. The main theorems improve ...The author investigates the existence of positive and nontrivial solutions for superlinear (n - 1, 1) conjugate boundary value problems by means of topological degree theory and cone theory. The main theorems improve some results published recently.展开更多
in this work,we study the quasilinear initial-boundary value problem , where is a system of real smooth vector fields which is defined on an open domain M of R'', and satisfies the Hormanderls condition,.Assu...in this work,we study the quasilinear initial-boundary value problem , where is a system of real smooth vector fields which is defined on an open domain M of R'', and satisfies the Hormanderls condition,.Assume that is non characteristic for the system X,,..',Xm. Under some hypothesis for the boundary of domain and the elliptic structure condition for nonlinear coerfficients Aij, Bj, C,(i, j= 1, ..', m), we have proved that the existence and regularity of solution for aboveinitialboudary value problems.展开更多
The objective of this paper is to institute farmers’ own perceptions of the on-and off-farm benefits of agroforestry systems (AFS). Using use value approach, this paper presents empirical evidence on the use values o...The objective of this paper is to institute farmers’ own perceptions of the on-and off-farm benefits of agroforestry systems (AFS). Using use value approach, this paper presents empirical evidence on the use values of three types of AFS practiced by the refugees and their hosting communities in Eastern Sudan. The total economic value (TEV) was applied as a framework to estimate the ecosystem values of AFS under study. Goods values were estimated using specific market values, while the services values were qualitatively described according to local perceived values of the local communities. Perceived TEV of AFS includes marketable and non-marketable goods and services. The main direct marketable and sustainable high value products include: food, cash crops, firewood, gum, fodder, NTFPs medicine, fodder, and honey. The valuation results reveal that AFS in the project sites have significantly contributed to the livelihoods of the local communities. Overall, the average net direct-use value of marketable products across all sites was estimated at 7,346,000.0 SDG (1,335,636.36 US$) HH/annum. Gum Arabic alone accounted for 38%, followed by sorghum grain and fodder 35%, and cash crops (sesame) 18%. This value would be many time higher if other indirect values (non-marketable) services such as shade, aesthetic and recreation, environmental protection, biodiversity and carbon sequestration are quantified. The goods and services mentioned above provide sustainable income to the farmer directly and viable benefits to the region indirectly. Hence, AFS in the study sites shows the way to reconcile two conflicting goals: short-term food and livelihood needs with long-term environmental conservation and improvement. The study provides evidence that the high local perceived values of AFS in the study sites constitute a central means of livelihood, whereas its contribution to the local economy. The study stresses the need to quantify the monetary values of non-marketed products to consistently account for resource availability and usage to further sound policy decisions. Tenure security, farmer support services and human capital development were major areas identified for policy development.展开更多
[Objective]The study aimed at assessing the whole value of Qilihai Wetland in Tianjin City.[Method]In this study,the whole value of Qilihai Wetland was divided into two parts,namely use value and non-use value.The use...[Objective]The study aimed at assessing the whole value of Qilihai Wetland in Tianjin City.[Method]In this study,the whole value of Qilihai Wetland was divided into two parts,namely use value and non-use value.The use value of Qilihai Wetland was estimated by market value,travel cost,shadow project method and so forth,and the non-use value of Qilihai Wetland was assessed by contingent valuation method.[Result]The total value of Qilihai Wetland reached 1.892 billion yuan,wherein the direct use value,including animal and plant products,tourism,scientific and cultural value,was 0.539 billion yuan,accounting for 28% of total value;the indirect use value,composed of functional values in hydrology,water quality,erosion control,CO2 fixation and habitats,was up to 0.965 billion yuan,making up 51%;the non-use value totaled 0.388 billion yuan,taking up 21%.In addition,the ecological benefit of Qilihai Wetland was the maximum,accounting for 72% of total benefit,followed by economic benefit（21%）,while the social benefit was the minimum（9%）.[Conclusion]The results can provide scientific references for the effective conservation and sustainable utilization of Qilihai Wetland.展开更多
Non-timber forest products provide important socio-economic services to different village and urban communities in West Africa. However, little is known about the links between the different actors and their contribut...Non-timber forest products provide important socio-economic services to different village and urban communities in West Africa. However, little is known about the links between the different actors and their contribution to the local or national economy. This study was conducted in central southern Niger and aimed to 1) identify and map the main actors in the value chain of <em>Ziziphus mauritiana</em> and <em>Balanites aegyptiaca</em> fruits;and 2) analyse the silvicultural and socio-economic aspects of fruit exploitation of these two species. Socio-economic surveys were conducted in four big villages in two main agroecological zones. Fruit exploitation of these two species affected 3044 people, with estimated 39 tonnes of <em>Z. mauritiana and</em> 27 tonnes of <em>B. aegyptiaca</em> fruit collected in 2017. The surveys revealed that the main actors were women (62.05%), constituting the primary core of the actors of the value chain. Exploitation was mainly conducted in forests (68.6%) or on farms (15.4%) with no restrictions to access. Marketing of <em>Z. mauritiana</em> concerned fresh fruit (68.8%) and fruit processed into biscuits (82.14%), and that of <em>B. aegyptiaca</em> involved fruit (38.5%) and oil extracted from seeds (38.7%);the net margin was estimated at 71.71% ± 21.59% for the first species and 50.31% ± 47.99% for the second. The income was mainly used for the needs of farmers’ households. Links have been identified where consumers and processors supply seeds, after extracting the fruit pulp, to nurserymen for the production of plants for the villages or farms. This study reveals an important potential and opportunity for job creation and improved food and nutritional status of the vulnerable strata of rural communities in Niger. Improving the links between the various actors will establish a more sustainable promotion of the fruits of these two species.展开更多
基金supported by the Fundamental Research Funds for the Central Universities(DL13BAX10)the Natural Science Foundation of Heilongjiang Province of China(QC2013C037)the assisted project by Heilongjiang Postdoctoral Funds for Scientific Research Initiation(LBH-Q13006)
文摘By the contingent value method, we studied the non-use value of wetland ecosystem service of Hongxing National Nature Reserve （HNNR） in Heilongjiang Pro- vince, northeast China. The proportion of respondents willing to pay （WTP） for protection of HNNR was 63 %. The WTP ratio was affected by geographical area, contact nature, personal preferences, and familiar degree of the respondents. The WTP value was affected by age, education level and career of the respondents. The mainly reasons for people rejecting to pay for protecting HNNR were ＂I am not familiar to HNNR＂ and ＂I had no capacity for additional spending because of low income＂. Weighted average individual WTP value was CNY 59.26 Yuan ind.^-1 year^-1 for all the respondents with WTP. The total non-use ecosystem service value of HNNR was CNY 1430 million Yuan in 2013. The heritage value was highest followed by existence value and option value. From the high ecosystem service value in HNNR, it is very important to construct nature reserve for protecting natural ecosystems and human sustainable use of natural resources.
文摘In this paper we study inviscid and viscid Burgers equations with initial conditions in the half plane . First we consider the Burgers equations with initial conditions admitting two and three shocks and use the HOPF-COLE transformation to linearize the problems and explicitly solve them. Next we study the Burgers equation and solve the initial value problem for it. We study the asymptotic behavior of solutions and we show that the exact solution of boundary value problem for viscid Burgers equation as viscosity parameter is sufficiently small approach the shock type solution of boundary value problem for inviscid Burgers equation. We discuss both confluence and interacting shocks. In this article a new approach has been developed to find the exact solutions. The results are formulated in classical mathematics and proved with infinitesimal technique of non standard analysis.
基金Supported in part by the National Thousand Talents Program of Chinathe National Natural Science Foundation of China(61473054)the Fundamental Research Funds for the Central Universities of China
文摘In this paper a recursive state-space model identification method is proposed for non-uniformly sampled systems in industrial applications. Two cases for measuring all states and only output(s) of such a system are considered for identification. In the case of state measurement, an identification algorithm based on the singular value decomposition(SVD) is developed to estimate the model parameter matrices by using the least-squares fitting. In the case of output measurement only, another identification algorithm is given by combining the SVD approach with a hierarchical identification strategy. An example is used to demonstrate the effectiveness of the proposed identification method.
文摘Various kinds of Riemann boundary value problems (BVPs) for analytic functions on closed curves or on open arc, doubly periodic Riemann BVPs, doubly quasi-periodic Riemann BVPs, and BVPs for polyanalytic functions have been widely investigated in [1-8]. The main ap- proach is to use the decomposition of polyanalytic functions and their generalization to transform the boundary value problems to their corresponding boundary value problems for analytic functions. Recently, inverse Riemann BVPs for generalized analytic functions or bianalytic functions have been investigated in [9-12]. In this paper, we consider a kind of Riemann BVP of non-normal type on the infinite straight line and discuss the solvable conditions and the general solution for it.
基金The 11th Five-Year Plan for Key Constructing Academic Subject of Hunan Province(No.XJT2006180)Natural Science Foundation of Hunan Province (No.07JJ3093)Hunan Province Foundation Research Program (No.2007FJ3030,2007GK3058)
文摘To overcome the deficiencies of the existing Verhulst GM(1,1) model, based on the existing grey theory, a non-equal-interval direct optimum Verhulst GM(1,1) model is built which chooses a modified n-th component x(n) of X(0) as the starting condition of the grey differential model. It optimizes a modified β value and the background value, and takes two times fitting optimization. The new model extends equal intervals to non-equal-intervals and is suitable for general data modelling and estimating parameters of the direct Verhulst GM(1,1). The new model does not need to pre-process the primitive data, nor accumulate generating operation (AGO) and inverse accumulated generating operation (IAGO). It is not only suitable for equal interval data modelling, but also for non-equal interval data modelling. As the new information is fully used and two times fitting optimization is taken, the fitting accuracy is the highest in all existing models. The example shows that the new model is simple and practical. The new model is worth expanding on and applying in data processing or on-line monitoring for tests, social sciences and other engineering sciences.
基金supported by the National Natural Science Foundation of China(11371225)National Natural Science Foundation of Guangdong Province(2016A030313686)
文摘In this article, we consider the non-linear difference equation(f(z + 1)f(z)-1)(f(z)f(z-1)-1) =P(z, f(z))/Q(z, f(z)),where P(z, f(z)) and Q(z, f(z)) are relatively prime polynomials in f(z) with rational coefficients. For the above equation, the order of growth, the exponents of convergence of zeros and poles of its transcendental meromorphic solution f(z), and the exponents of convergence of poles of difference △f(z) and divided difference △f(z)/f(z)are estimated. Furthermore, we study the forms of rational solutions of the above equation.
基金supported by the One Hundred Talents Program of the Chinese Academy of Sciences, the National Natural Science Foundation of China (No. 40971278)the "Western Light" Project of the Chinese Academy of Sciences, and the Key Project of the Chinese Academy of Sciences (No. KZZD-EW-04-05)
文摘The contingent valuation method （CVM） is one of the main methods for evaluating non-market values of resources. It originated in the United States and was introduced into China during the 1980s and 1990s. However, application of CVM in China is highly controversial based on three primary aspects： （I） the appropriate guidelines for CVM; （2） the elicitation techniques for willingness to pay （WTP）; and （3） reliability and validity testing of CVM. The major objectives of this paper are to i^eview the recem devel- opments pertaining to guidelines, elicitation techniques, and reliability and validity testing for application of CVM, and to summa- rize the limitations of and measures for improving application of CVM in China. The applicability of CVM in China is discussed to enhance the future development of CVM in China.
文摘Background: It is known that certain laboratory value abnormalities may increase mortality in patient populations with specific risk factors and specific procedures. The purpose of this paper was to investigate the effect of drawing a non-routine lab (regardless of its result) on 30 day mortality and to investigate the effect of an abnormal non-routine laboratory value on 30 day mortality. Methods: The electronic medical records of adult patients undergoing non-cardiac surgery from 2011-2014 at LAC + USC Medical Center were reviewed retrospectively as approved by our institutional review board. Demographic data, surgical risk assessment, and routine and non-routine laboratory values (TSH, Troponin, Creatine Kinase, Hb A1c) were recorded;patients were grouped according to the single non-routine lab they had drawn. Multivariate logistic regression analysis was used to determine significant risk factors associated with increased 30 day mortality. Results: 11,306 patients met our inclusion criteria. Drawing a non-routine lab was associated with a statistically significant increase in mortality in the Troponin group (OR = 3.05, P < 0.001) but not in the TSH, Creatine Kinase, or Hb A1c groups. An abnormal non-routine lab value was associated with a statistically significantly increase in mortality in the TSH group (OR = 11.07, P = 0.008) but not in the other three groups. Conclusions: Drawing a non-routine lab was associated with a statistically significant increase in mortality in the Troponin group but not in the TSH, Creatine Kinase, or Hb A1c groups. An abnormal TSH value was associated with a statistically significant increase in mortality but not an abnormal Troponin, Creatine Kinase, or Hb A1c. Routine and non-routine laboratory testing may guide perioperative patient care and result in improved post-surgical outcome.
基金supported by the Key Program of National Natural Science Foundation of China(No.70831005)the National Natural Science Foundation of China(No.10671135)the Fundamental Research Funds for the Central Universities(No.2009SCU11096)
文摘A projected subgradient method for solving a class of set-valued mixed variational inequalities （SMVIs） is proposed when the mapping is not necessarily Lipschitz. Under some suitable conditions, it can be proven that the sequence generated by the method can strongly converge to the unique solution to the problem in the Hilbert spaces.
文摘This paper is concerned with the sensitivity of set-valued discrete systems. Firstly, this paper obtained the equivalence between <img src="Edit_7024f70b-0568-4ca8-a554-c0d05abc0df0.bmp" alt="" />or <img src="Edit_95636a59-7d5d-4b6c-8bd5-f699dd9208df.bmp" alt="" /> and the product system <img src="Edit_c714caaf-0ed9-46bc-b3e1-b0223474a8f5.bmp" alt="" /> in sensitivity, infinite sensitivity, <em>F</em>-sensitivity, (<em>F</em><sub>1</sub>, <em>F</em><sub>2</sub>)-sensitivity. Then, the relation between (<em>X</em>, <em>f</em><sub>1,∞</sub>) or (<em>Y</em>, <em>g</em><sub>1,∞</sub>) and <img src="Edit_55b4ce47-89f3-4476-a8a8-4d4db5a4e8eb.bmp" alt="" /> in ergodic sensitivity is obtained. Where <img src="Edit_a99604c4-2f72-4e75-a998-8057b8790e03.bmp" alt="" /> is the set-valued dynamical system induced by a non-autonomous discrete dynamical system (<em>X</em>, <em>f</em><sub>1,∞</sub>).
文摘The significance of U values in buildings’ shell energy performance is well known in the scientific community as well as in the construction sector. In addition, conducting a validation of the energy performance of a building often requires the knowledge of real U value figures, since their theoretical peers may deviate considerably from the real ones. The theoretical U value of a shell element may be calculated using complex material and surface related information, while its practical validation is conducted usually by equipment that requires tedious installation and constant contact with the examined element. Aim of this paper is to introduce an easily deployed, plug and play, contact less technology, able to provide a reasonable approximation of the building element U value and its variation with external air speed as well as an accurate estimation of the U value change in case of a shell (wall or window) retrofit.
文摘Several problems arising in science and engineering are modeled by differential equations that involve conditions that are specified at more than one point. The non-linear two-point boundary value problem (TPBVP) (Bratu’s equation, Troesch’s problems) occurs engineering and science, including the modeling of chemical reactions diffusion processes and heat transfer. An analytical expression pertaining to the concentration of substrate is obtained using Homotopy perturbation method for all values of parameters. These approximate analytical results were found to be in good agreement with the simulation results.
文摘NoSQL系统因其高性能、高可扩展性的优势在大数据管理中得到广泛应用,而key-value(KV)模型则是NoSQL系统中使用最广泛的一种存储模型.KV型本地存储系统对于以机械磁盘为持久化存储的情形,存在许多性能优化技术,但这些优化技术面对当前的硬件发展新趋势,如多核处理器、大内存和低延迟闪存、非易失性内存NVM(Non-Volatile Memory)等,难以充分发挥新硬件的优势,如数据索引、并发控制、事务日志管理等技术在多核架构下存在多核扩展性问题,又如数据存储策略不适应闪存SSD(Solid State Drive)的新存储特性而产生了IO利用率低效的问题.针对多核处理器、大内存和闪存、NVM等硬件发展新趋势,文中面向当前的大数据应用背景,综述了KV型本地存储系统在索引技术、并发控制、事务日志管理和数据放置等核心模块上的最新优化技术和系统研究成果.从处理器、内存和持久化存储的角度概括了KV型本地存储系统当前存在的最优技术,总结了当前研究尚未解决的技术挑战,并对KV型本地存储系统在CPU缓存高效性、事务日志扩展性和高可用性等方面的研究进行了展望.
文摘By using Leray-Schauder nonlinear alternative, Banach contraction theorem and Guo-Krasnosel’skii theorem, we discuss the existence, uniqueness and positivity of solution to the third-order multi-point nonhomogeneous boundary value problem (BVP1): where for The interesting point lies in the fact that the nonlinear term is allowed to depend on the first order derivative .
基金The author is supported in part by NNSF of China and Monbusho Scholarship of Japan.
文摘The author investigates the existence of positive and nontrivial solutions for superlinear (n - 1, 1) conjugate boundary value problems by means of topological degree theory and cone theory. The main theorems improve some results published recently.
文摘in this work,we study the quasilinear initial-boundary value problem , where is a system of real smooth vector fields which is defined on an open domain M of R'', and satisfies the Hormanderls condition,.Assume that is non characteristic for the system X,,..',Xm. Under some hypothesis for the boundary of domain and the elliptic structure condition for nonlinear coerfficients Aij, Bj, C,(i, j= 1, ..', m), we have proved that the existence and regularity of solution for aboveinitialboudary value problems.
文摘The objective of this paper is to institute farmers’ own perceptions of the on-and off-farm benefits of agroforestry systems (AFS). Using use value approach, this paper presents empirical evidence on the use values of three types of AFS practiced by the refugees and their hosting communities in Eastern Sudan. The total economic value (TEV) was applied as a framework to estimate the ecosystem values of AFS under study. Goods values were estimated using specific market values, while the services values were qualitatively described according to local perceived values of the local communities. Perceived TEV of AFS includes marketable and non-marketable goods and services. The main direct marketable and sustainable high value products include: food, cash crops, firewood, gum, fodder, NTFPs medicine, fodder, and honey. The valuation results reveal that AFS in the project sites have significantly contributed to the livelihoods of the local communities. Overall, the average net direct-use value of marketable products across all sites was estimated at 7,346,000.0 SDG (1,335,636.36 US$) HH/annum. Gum Arabic alone accounted for 38%, followed by sorghum grain and fodder 35%, and cash crops (sesame) 18%. This value would be many time higher if other indirect values (non-marketable) services such as shade, aesthetic and recreation, environmental protection, biodiversity and carbon sequestration are quantified. The goods and services mentioned above provide sustainable income to the farmer directly and viable benefits to the region indirectly. Hence, AFS in the study sites shows the way to reconcile two conflicting goals: short-term food and livelihood needs with long-term environmental conservation and improvement. The study provides evidence that the high local perceived values of AFS in the study sites constitute a central means of livelihood, whereas its contribution to the local economy. The study stresses the need to quantify the monetary values of non-marketed products to consistently account for resource availability and usage to further sound policy decisions. Tenure security, farmer support services and human capital development were major areas identified for policy development.
基金Supported by 973 Program of China (2010CB434806)NCET Program (NCET-10-0954)+3 种基金Natural Science Foundation of Tianjin City,China (10SYSYJC27400 )Humanities and Social Sciences Research Project of Higher Education of Tianjin City,China(20092117)Doctoral Foundation of Tianjin Normal University(52X09019)Key Project of National Natural Science Foundation of Tianjin City,China (11JCZDJC24500)
文摘[Objective]The study aimed at assessing the whole value of Qilihai Wetland in Tianjin City.[Method]In this study,the whole value of Qilihai Wetland was divided into two parts,namely use value and non-use value.The use value of Qilihai Wetland was estimated by market value,travel cost,shadow project method and so forth,and the non-use value of Qilihai Wetland was assessed by contingent valuation method.[Result]The total value of Qilihai Wetland reached 1.892 billion yuan,wherein the direct use value,including animal and plant products,tourism,scientific and cultural value,was 0.539 billion yuan,accounting for 28% of total value;the indirect use value,composed of functional values in hydrology,water quality,erosion control,CO2 fixation and habitats,was up to 0.965 billion yuan,making up 51%;the non-use value totaled 0.388 billion yuan,taking up 21%.In addition,the ecological benefit of Qilihai Wetland was the maximum,accounting for 72% of total benefit,followed by economic benefit（21%）,while the social benefit was the minimum（9%）.[Conclusion]The results can provide scientific references for the effective conservation and sustainable utilization of Qilihai Wetland.
文摘Non-timber forest products provide important socio-economic services to different village and urban communities in West Africa. However, little is known about the links between the different actors and their contribution to the local or national economy. This study was conducted in central southern Niger and aimed to 1) identify and map the main actors in the value chain of <em>Ziziphus mauritiana</em> and <em>Balanites aegyptiaca</em> fruits;and 2) analyse the silvicultural and socio-economic aspects of fruit exploitation of these two species. Socio-economic surveys were conducted in four big villages in two main agroecological zones. Fruit exploitation of these two species affected 3044 people, with estimated 39 tonnes of <em>Z. mauritiana and</em> 27 tonnes of <em>B. aegyptiaca</em> fruit collected in 2017. The surveys revealed that the main actors were women (62.05%), constituting the primary core of the actors of the value chain. Exploitation was mainly conducted in forests (68.6%) or on farms (15.4%) with no restrictions to access. Marketing of <em>Z. mauritiana</em> concerned fresh fruit (68.8%) and fruit processed into biscuits (82.14%), and that of <em>B. aegyptiaca</em> involved fruit (38.5%) and oil extracted from seeds (38.7%);the net margin was estimated at 71.71% ± 21.59% for the first species and 50.31% ± 47.99% for the second. The income was mainly used for the needs of farmers’ households. Links have been identified where consumers and processors supply seeds, after extracting the fruit pulp, to nurserymen for the production of plants for the villages or farms. This study reveals an important potential and opportunity for job creation and improved food and nutritional status of the vulnerable strata of rural communities in Niger. Improving the links between the various actors will establish a more sustainable promotion of the fruits of these two species.
