Multi-factor analysis of initial poor graft function after orthotopic liver transplantation

BACKGROUND: In the early period of orthotopic liver transplantation (OLT), initial poor graft function (IPGF) is one of the complications which leads to primary graft non-function (PGNF) in serious cases. This study set out to establish the clinical risk factors resulting in IPGF after OLT. METHODS: Eighty cases of OLT were analyzed. The IPGF group consisted of patients with alanine aminotransferase (ALT) and/or aspartate aminotransferase (AST) above 1500 IU/L within 72 hours after OLT, while those in the non-IPGF group had values below 1500 IU/L. Recipient-associated factors before OLT analyzed were age, sex, primary liver disease and Child-Pugh classification; factors analyzed within the peri-operative period were non-heart beating time (NHBT), cold ischemia time (CIT), rewarming ischemic time (RWIT), liver biopsy at the end of cold ischemia; and factors analyzed within 72 hours after OLT were ALT and/or AST values. A logistic regression model was applied to filter the possible factors resulting in IPGF. RESULTS: Donor NHBT, CIT and RWIT were significantly longer in the IPGF group than in the non-IPGF group; in the logistic regression model, NHBT was the risk factor leading to IPGF (P < 0.05), while CIT and RWIT were possible risk factors. In one case in the IPGF group, PGNF appeared with moderate hepatic steatosis. CONCLUSIONS: Longer NHBT is an important risk factor leading to IPGF, while serious steatosis in the donor liver, CIT and RWIT are potential risk factors.

The multi-factor recombination and processes superimposition model for hydrocarbon accumulation:application to the Silurian in the Tarim Basin

The multi-factor recombination and processes superimposition model for hydrocarbon accumulation is put forward in view of the hydrocarbon geological characteristics of multiple episodes of structural evolution, multiple sets of source-reservoir-seal assemblage, multiple cycles of hydrocarbon accumulation and multiple episodes of readjustment and reconstruction in the complex superimposed basins in China. It is a system including theories and methods that can help to predict favorable exploration regions. According to this model, the basic discipline for hydrocarbon generation, evolution and distribution in the superimposed basins can be summarized in multi-factor recombination, processes superimposition, multiple stages of oil filling and latest stage preservation. With the Silurian of the Tarim basin as an example, based on the reconstruction of the evolution history of the four factors （paleo-anticline, source rock, regional cap rock and kinematic equilibrium belt） controlling hydrocarbon accumulation, this model was adopted to predict favorable hydrocarbon accumulation areas and favorable exploration regions following structural destruction in three stages of oil filling, to provide guidance for further exploration ofoil and gas in the Silurian of the Tarim basin.

Cellular Automata-based Chloride Ion Diffusion Simulation of Concrete Bridges under Multi-factor Coupling Actions

In order to accurately simulate the diffusion of chloride ion in the existing concrete bridge and acquire the precise chloride ion concentration at given time, a cellular automata （CA）-based model is proposed. The process of chloride ion diffusion is analyzed by the CA-based method and a nonlinear solution of the Fick＇s second law is obtained. Considering the impact of various factors such as stress states, temporal and spatial variability of diffusion parameters and water-cement ratio on the process of chloride ion diffusion, the model of chloride ion diffusion under multi-factor coupling actions is presented. A chloride ion penetrating experiment reported in the literature is used to prove the effectiveness and reasonability of the present method, and a T-type beam is taken as an illustrative example to analyze the process of chloride ion diffusion in practical application. The results indicate that CA-based method can simulate the diffusion of chloride ion in the concrete structures with acceptable precision.

Investment in deepwater oil and gas exploration projects:a multi-factor analysis with a real options model

Deepwater oil and gas projects embody high risks from geology and engineering aspects, which exert substantial influence on project valuation. But the uncer- tainties may be converted to additional value to the projects in the case of flexible management. Given the flexibility of project management, this paper extends the classical real options model to a multi-factor model which contains oil price, geology, and engineering uncertainties. It then gives an application example of the new model to evaluate deepwater oil and gas projects with a numerical analytical method. Compared with other methods and models, this multi-factor real options model contains more project information. It reflects the potential value deriving not only from oil price variation but also from geology and engi- neering uncertainties, which provides more accurate and reliable valuation information for decision makers.

Multi-factor sensitivity analysis of shallow unsaturated clay slope stability

An unsaturated clay slope, with various sloping angles and a thickness of 14 m, consists of backfill, slope soil and residual soil. Slide interfaces were determined by geophysical approaches and the original slope was reconstructed. Sub-slope masses were classified based on the varieties of sloping angle. A force recursive principle was proposed to calculate the stability coefficient of the sub-slope masses. The influencing factors such as sloping angle, water content, hydrostatic pressure, seismic force as well as train load were analyzed. The range and correlation of the above-mentioned factors were discussed and coupled wave equations were established to reflect the relationships between unit weight, cohesion, internal frictional angle, and water content, as well as between internal frictional angle and cohesion. The sensitivity analysis of slope stability was carried out and susceptive factors were determined when the factors were taken as independent and dependent variables respectively. The results show that sloping angle, water content and earthquake are the principal susceptive factors influencing slope stability. The impact of hydrostatic pressure on slope stability is similar to the seismic force in quantity. Train load plays a small role in slope stability and its influencing only reaches the roadbed and its neighboring slope segment. If the factors are taken as independent variables, the influencing extent of water content and cohesion on slope stability can be weakened and train load can be magnified.

A branch-and-bound algorithm for discrete multi-factor portfolio optimization model

In this paper, a new branch-and-bound algorithm based on the Lagrangian dual relaxation and continuous relaxation is proposed for discrete multi-factor portfolio selection model with roundlot restriction in financial optimization. This discrete portfolio model is of integer quadratic programming problems. The separable structure of the model is investigated by using Lagrangian relaxation and dual search. Computational results show that the algorithm is capable of solving real-world portfolio problems with data from US stock market and randomly generated test problems with up to 120 securities.

Multi-factor high-order intuitionistic fuzzy timeseries forecasting model

Fuzzy sets theory cannot describe the neutrality degreeof data, which has largely limited the objectivity of fuzzy time seriesin uncertain data forecasting. With this regard, a multi-factor highorderintuitionistic fuzzy time series forecasting model is built. Inthe new model, a fuzzy clustering algorithm is used to get unequalintervals, and a more objective technique for ascertaining membershipand non-membership functions of the intuitionistic fuzzy setis proposed. On these bases, forecast rules based on multidimensionalintuitionistic fuzzy modus ponens inference are established.Finally, contrast experiments on the daily mean temperature ofBeijing are carried out, which show that the novel model has aclear advantage of improving the forecast accuracy.

Dividing the Expropriated Areas Based on Multi-Factor Comprehensive Evaluation—A Case Study of Gongcheng Yao Autonomous County

In recent years, with the rapid development of urbanization in China, land acquisition work is particularly important. The division of expropriated area is the primary factor to be considered when evaluating the comprehensive land price of expropriated area. Reasonable division can help to improve the scientific and applicability of the comprehensive land price of the region. How to maximize the protection of farmers’ rights and interests by the division of land requisition is an urgent problem to be solved. Taking Gongcheng Yao Autonomous County as an example, this study adopted the multi-factor comprehensive evaluation method to evaluate the division of land requisition in this area, and carried out the corresponding spatial analysis and data processing based on GIS technology. Gongcheng Yao Autonomous County was divided into levy areas, and the Delphi method was used to screen the impact factors and determine the weight of the levy areas. Reasonable division of land requisition area can provide references for land requisition area, make it more scientific and reasonable, and protect the rights and interests of farmers.

The prevalence of azoospermia factor microdeletion on the Y chromosome of Chinese infertile men detected by multi-analyte suspension array technology

Aim： To develop a high-throughput multiplex, fast and simple assay to scan azoospermia factor （AZF） region microdeletions on the Y chromosome and establish the prevalence of Y chromosomal microdeletions in Chinese infertile males with azoospermia or oligozoospermia. Methods： In total, 178 infertile patients with azoospermia （nonobstructed）, 134 infertile patients with oligozoospermia as well as 40 fertile man controls were included in the present study. The samples were screened for AZF microdeletion using optimized multi-analyte suspension array （MASA） technology. Results： Of the 312 patients, 36 （11.5%） were found to have deletions in the AZF region. The rnicrodeletion frequency was 14% （25/178） in the azoospermia group and 8.2% （11/134） in the oligospermia group. Among 36 patients with microdeletions, 19 had deletions in the AZFc region, seven had deletions in AZFa and six had deletions in AZFb. In addition, four patients had both AZFb and AZFc deletions. No deletion in the AZF region was found in the 40 fertile controls. Conclusion： There is a high prevalence of Y chromosomal microdeletions in Chinese infertile males with azoospermia or oligozoospermia. The MASA technology, which has been established in the present study, provides a sensitive and high-throughput method for detecting the deletion of the Y chromosome. And the results suggest that genetic screening should be advised to infertile men before starting assisted reproductive treatments.

Enhancing Multi-Factor Authentication in Modern Computing

Most network service providers like MTN Nigeria, currently use two-factor authentication for their 4G wireless networks. This exposes the network subscribers to identify theft and users data to security threats like snooping, sniffing, spoofing and phishing. There is need to curb these problems with the use of an enhanced multi-factor authentication approach. The objective of this work is to create a multi-factor authentication software for a 4G wireless network. Multi-factor authentication involves user’s knowledge factor, user’s possession factor and user’s inherence factor;that is who the user is to be presented before system access can be granted. The research methodologies used for this work include Structured System Analysis and Design Methodology, SSADM and Prototyping. The result of this work will be a Multi-factor authentications software. This software was designed with programming languages like ASP. NET, C# and Microsoft SQL Server for the database.

Multi-factor Analysis Model for Improving Profit Management Using Excel in Shellfish Farming Projects

By using a farm's data in Yantai City and the theory of Cost-Volume-Profit analysis and the financial management methods,this paper construct a multi-factor analysis model for improving profit management using Excel 2007 in Shellfish farming projects and describes the procedures to construct a multi-factor analysis model.The model can quickly calculate the profit,improve the level of profit management,find out the breakeven point and enhance the decision-making efficiency of businesses etc.It is also a thought of the application to offer suggestions for government decisions and economic decisions for corporations as a simple analysis tool.While effort has been exerted to construct a four-variable model,some equally important variables may not be discussed sufficiently due to limitation of the paper's space and the authors'knowledge.All variables can be listed in EXCEL 2007 and can be associated in a logical way to manage the profit of shellfish farming projects more efficiently and more practically.

Effect of Multi-parameter Environmental Factors on Cucumber Leaf Surface Wetness

In this study, artificial leaf resistance was used to simulate leaf wetness. Specific to the solar greenhouse environment in Tianjin, microclimate monitoring equipment was installed for the collection of temperature group and humidity group data, as well as solar radiation and leaf wetness in the greenhouse. In order to reduce the complexity of multivariate factor prediction and ensure the richness of selected data types, correlation analysis was made to the 2 groups of data, screening 5 000 groups of data, including the humidity group data RH, RH_(20), RH_(40), temperature group data T, T_(20), T_(40), and solar radiation W. The data were then analyzed by principal component analysis, screening out 4 groups of principal components to show the leaf wetness index.

Productivity Testing Design Method of Multi-Factor Control for Unconsolidated Sandstone Gas Reservoir

Reservoir safety, testing-string safety, and flow control are key factors that should be considered in deep-water unconsolidated sandstone gas well testing work system. Combined with the feature of testing reservoir, pipe string type and sea area, the required minimum testing flow rate during cleaning up process, as well as minimum test flow rate without hydrate generation, pipe string erosion critical production, the maximum testing flow rate without destroying sand formation and the minimum output of meeting the demand of development was analyzed;based on the above critical test flow rates, testing working system is designed. Field application showed that the designed work system effectively provided good guidance for field test operations;no sand production or hydrate generation happened during the test process;the test parameter evaluated the reservoir accurately;the safe and efficient test operation was achieved.

Factors affecting the performance of a multi-tone carrier source based re-circulating frequency shifter

Generation of single-sideband （SSB） multi-carrier source based on a recirculating frequency shifter （RFS） is anal- ysed theoretically and realized experimentally. The effects of affecting factors originating from the deviation from the right operation bias voltage and unbalanced amplitude, and the phase of the radio frequency （RF） drive signals on the performance of the multi-tone source are discussed in detail. Based on the theoretical analysis, high-quality 50-tone out- put is successfully realized. Experiments under some implementation imperfections are also carried out. The imperfect and low-quality output results are in good agreement with theoretical analysis.

Research on the Voltage Interaction of Multi-Infeed HVDC System and Interaction Factor

In multi-infeed HVDC system, the interactions and influences between DC systems AC systems are complex as the electrical distances among DC converter stations which are relatively short. Multi-infeed interaction factor (MIIF) can effectively reflect the interaction among DC systems. The paper theoretically analyzes the impact factors of MIIF like the electrical distances between two DC converter stations and the equivalent impedance of the receiving end AC system. By applying the Kirchhoff’s current law on the inverter AC bus, the paper deduces the analytical expressions for MIIF. From the expression, it is clear how the equivalent impedance of AC system and coupling impedance can affect MIIF. PSCAD simulations validate the effectiveness and the correctness of the proposed expression and some useful conclusions are drawn.

An Evaluation of the Critical Success Factors in Sustainable Food Supply Chains in Developing Countries

Food is one of the biggest industries in developed and underdeveloped countries. Supply chain sustainability is essential in established and emerging economies because of the rising acceptance of cost-based outsourcing and the growing technological, social, and environmental concerns. The food business faces serious sustainability and growth challenges in developing countries. A comprehensive analysis of the critical success factors (CSFs) influencing the performance outcome and the sustainable supply chain management (SSCM) process. A theoretical framework is established to explain how they are used to examine the organizational aspect of the food supply chain life cycle analysis. This study examined the CSFs and revealed the relationships between them using a methodology that included a review of literature, interpretative structural modeling (ISM), and cross-impact matrix multiplication applied in classification (MICMAC) tool analysis of soil liquefaction factors. The findings of this research demonstrate that the quality and safety of food are important factors and have a direct effect on other factors. To make sustainable food supply chain management more adequate, legislators, managers, and experts need to pay attention to this factor. In this work. It also shows that companies aiming to create a sustainable business model must make sustainability a fundamental tenet of their organization. Practitioners and managers may devise effective long-term plans for establishing a sustainable food supply chain utilizing the recommended methodology.

基于Multi-Agent系统的土地利用情景模拟

以常州市新北区为研究区,运用多智能体空间建模方法,利用Eclipse和Swarm平台,对研究区不同情景下2006—2020年的土地利用情况进行了模拟,为区域规划决策和土地利用调控提供辅助技术支持。研究结果表明:经济社会快速发展情景中城镇化速度较快,城乡用地转换明显,农村居民点整治力度较大;经济社会中速发展情景中城镇用地空间扩张和人口增长都减缓速度,耕地资源的流失得到一定程度的控制;经济社会慢速发展情景中城乡用地变化速度明显放缓,耕地资源流失得到有效控制。多智能体模型突出考虑了土地利用过程中相关主体行为对土地利用变化的影响,并在建模过程中融合了土地利用情景分析,模型构建适用性强,可以较好地模拟不同情景下的土地利用变化情况。

Factor-GARCH模型研究与理论探讨

结合国外研究现状,对解决多维GARCH模型的方法———Factor-GARCH模型进行了系统的讨论.将投资组合的收益率Rt表述为潜在公共因子的函数形式,并对函数形式中的一些变量和假定给出了理论和现实的解释;将投资组合的协方差Ht的结构进一步细化,将其表述为可观测变量的线性函数.并指出了今后的研究方向.

Durability of Concrete under Multi-damage Action

Several different experiments,including freezing-thawing,freezing-thawing+drying-wetting,and drying-wetting,in salt solution and in water respectively,were designed to determine the durability of concrete.The durability damage features of concrete in the above experiments were studied.It is demonstrated that the damage extent of concrete under freezing-thawing and freezing-thawing+drying-wetting in salt solution is larger than that in water.Thus,freezing-thawing and freezing-thawing+drying-wetting in salt solution are stricter and more effective methods to evaluate the durability of concrete in salt-existing environment in cold regions.The damage extent of concrete under freezing-thawing+drying-wetting shows an ultra-superposition effect.The order of concrete durability deterioration degree in these experiments is determined.It shows that effects of multi-damage factors are greater than those of single-damage factor.

ANALYSIS OF PSYCHOLOGIC HEALTH STATE AND INFLUENCING FACTORS IN COLLEGE AND SECONDARY SCHOOL STUDENTS IN SHAANXI PROVINCE

Objective The psychologic health level of college and secondaryschool students and the relevant factors were investigated to scientific basis and guidance for school mental health work.Methods Standard 1251 cases were drawn from 1‰ of students in colleges and middle schools of Shaanxi province.Taking 14 psychic health level indexes in SCL 90 as dependent variable and 109 indexes of psychic health back ground as in dependent variable, multi factor analyses have been made.Results 22.6% of students had relatively serious psychological problems.The score of SCL 90 in females was a little bit higher than that in males.The scores of students at both universities and senior middle schools were higher than that in junior middle schools students.The score of SCL 90 of students who came from the countryside was higher than that of city students.The score of the whole students was higher than that of the normal.The students with psychic problems showed obsession,interpersonal sensitivity,depression,anxiety,paranoia and hostility.Factor analysis showed that influencing factors included history of positive individual risking behavior,physical conditions,grade,address,family influences,menses and sexual prombles,bad relation with others,poor self assessment.Conclusion The psychologic health level of the students investigated is lower than that of the whole society.The factors,which hamper psychic health of students, are biological,psychological and social in nature.