Method for determining the position of landslide slip-surface with a typical inclinometric curves

In the actual monitoring of deep hole displacement,the identification of slip surfaces is primarily based on abrupt changes observed in the inclinometric curve.In conventional identification methods,inclinometric curves exhibiting indications of sliding can be categorized into three types:B-type,D-type,and r-type.The position of the slip surface is typically determined by identifying the depth corresponding to the point of maximum displacement mutation.However,this method is sensitive to the interval of measurement points and the observation scale of the coordinate axes and suffers from unclear sliding surfaces and uncertain values.Based on the variation characteristics of these diagonal curves,we classified the landslide into three components:the sliding body,the sliding interval,and the immobile body.Moreover,three different generalization models were established to analyze the relationships between the curve form and the slip surface location based on different physical indicators such as displacement rate,relative displacement,and acceleration.The results show that the displacement rate curves of an r-type slope exhibit a clustering feature in the sliding interval,and by solving for the depth of discrete points within the step phase,it is possible to determine the location of the slip surface.On the other hand,D-type slopes have inflection points in the relative displacement curve located at the slip surface.The acceleration curves of B-type slopes exhibit clustering characteristics during the sliding interval,while the scattered acceleration data demonstrate wandering characteristics.Consequently,the slip surface location can be revealed by solving the depth corresponding to the maximum acceleration with cubic spline interpolation.The approach proposed in this paper was applied to the monitoring data of a landslide in Yunnan Province,China.The results indicate that our approach can accurately identify the slip surface location and enable computability of its position,thereby enhancing applicability and reliability of the deep-hole displacement monitoring data.

Development of River Rating Curves for Simple to Complex Hydraulic Structure Based on Calibrated HEC-RAS Hydraulic Model, in Kwale, Coastal Kenya

Accurate and reliable river flow information is critical to planning and management for sustainable water resources utilization. Most of engineering activities related to hydrologic designs, flood, drought, reservoirs and their operations are heavily dependent on the river flow information derived from river rating curve. The rating curve for a given river section is normally developed from a set of direct stage-discharge measurements for different periods. This involves considerable labour, risk and resources, and presupposes a complex and extensive measuring survey. Extrapolating the rating curve beyond the measured range, as common in many cases, is fraught with errors and uncertainties, due to the complex hydraulic behaviour of the surface water profile in transition from section, channel, downstream and flood plain controls which are often poorly understood with direct measurements. Hydraulic modeling has recently emerged as one of the more promising methods to efficiently develop accurate rating curves for a river section with simple or complex hydraulic structures and conditions. This paper explores the use of a Hydraulic Engineering Center-River Analysis System (HEC-RAS) model to review and develop river rating curves for three hydrometric stations on two rivers in Kwale, coastal Kenya. The HEC-RAS models were set up based on topographical (cross section and longitudinal) survey data for the reaches and engineering drawings for the hydraulic structures commonly used as section controls for flow measurement. The model was calibrated under unsteady state conditions against measured stage-discharge data which were captured using a Velocity Current Meter (Valeport) and an Acoustic Doppler Current Profiler (ADCP) for both low and high flow. The rating curves were extracted from model results and the uncertainty associated with each rating curve analyzed. The results obtained by the HEC-RAS model were satisfactory and deemed acceptable for predicting discharge across the stage range at each river section.

An Improved Unique Fatigue Crack Growth Rate Curve Model and Determination of the Model Shape Exponents

It is essential to precisely predict the crack growth,especially the near-threshold regime crack growth under different stress ratios,for most engineering structures consume their fatigue lives in this regime under random loading.In this paper,an improved unique curve model is proposed based on the unique curve model,and the determination of the shape exponents of this model is provided.The crack growth rate curves of some materials taken from the literature are evaluated using the improved model,and the results indicate that the improved model can accurately predict the crack growth rate in the nearthreshold and Paris regimes.The improved unique curve model can solve the problems about the shape exponents determination and weak ability around the near-threshold regime meet in the unique curve model.In addition,the shape exponents in the improved model at negative stress ratios are discussed,which can directly adopt that in the unique curve model.

Flow Rate Measurement of Gravity Infusion Set and Functional Evaluation of Drop Counter: A Pilot Study

Developing a novel drop counter by introducing the Internet of Things concept has been vigorously conducted in recent years. Understanding the newly introduced drop counter’s flow rate control accuracy and flow rate count feature is essential for improving safety in infusion management. This study aimed to verify if the new drop counters could secure accurate flow rate and drip count by conducting actual flow rate measurements using gravimetry and functional evaluation. A drop counter was attached to each drip chamber of the infusion set, and an IV drip was conducted at the 100 ml/h flow rate. The weight of discharged physiological saline was measured to plot trumpet curves. Next, three different types of drop counters were evaluated to determine if they maintained drip count accuracy according to the changes in their position angles. The flow rate errors in all conditions indicated trumpet-like curves, exhibiting an overall error range within ±10% in all observation windows. Although every drop counter successfully detected and measured dripping, it was challenging in some counters to detect dripping when the drip chamber was tilted. In comparing adult and pediatric IV sets, the adult IV set was found to be less likely to detect dripping in the angled position. No significant differences in results were confirmed between high and low flow rates, suggesting that the drop count function would not be affected by the flow rate in the ranges of typical infusion practices. Doppler sensors have a wide range of measurements and high sensitivity;the dripping was detected successfully even when the drip chamber was tilted, probably due to the advantages of these sensors. In contrast, miscounts occurred in those equipped with infrared sensors, which could not detect light intensity changes in tilted positions. Understanding the tendencies in flow rate errors in infusion can be valuable information for infusion management.

THE CURVED BEAM ELEMENT AND ITS CONVERGENCE RATE

The quasi-conforming element of the curved beam and shallow curved beam is given in this paper. Numerical examples illustrate that the quasi-conforming elements of the curved beam and shallow curved beam which is used to approximate the curved beam have better accuracy than the straight beam clement. The curved beam element constructed by displacement method can not satisfy rigid body motion condition and the very fine grids have to be used in order to satisfy rigid body motion condition approxtmately.In this paper it is proved that the straight beam element and the quasi-conforming element of the curved beam and shallow curved beam, when element size is reduced infinitely, have convergence rate with the same order O(l2) and when regular elements are used. I is the element length.

Analysis Approach to Durability Based on Material Initial Fatigue Quality and S-N Curve

Based on probabilistic fracture mechanics approach, a new concept of material initial fatigue quality （MIFQ） is developed. Then, the relation between S-N curve and crack propagation curve is studied. From the study, a new durability analysis method is presented. In this method, S-N curve is used to determine crack growth rate under constant amplitude loading and evaluate the effects of different factors on durability and then the structural durability is analyzed. The tests and analyses indicate that this method has lower dependence on testing, and higher accuracy, reliability and generality and is convenient for application.

Learning curve for double-balloon enteroscopy: Findings from an analysis of 282 procedures

AIM: To determine the learning curves for antegrade double-balloon enteroscopy (aDBE) and retrograde DBE (rDBE) by analyzing the technical success rates. METHODS: A retrospective analysis in a tertiary referral center. This study reviewed all cases from June 2006 to April 2011 with a target lesion in the small-bowel identified by either capsule endoscopy or computed tomography scan posted for DBE examinations. Main outcome measurements were: (1) Technical success of aDBE def ined by f inding or excluding a target lesion after achieving suff icient length of small bowel intubation; and (2) Technical success for rDBE was def ined by either f inding the target lesion or achieving stable overtube placement in the ileum. RESULTS: Two hundred and eighty two procedures fulf illed the inclusion criteria and were analyzed. These procedures were analyzed by blocks of 30 cases. Therewas no distinct learning curve for aDBE. Technical success rates for rDBE continued to rise over time, although on logistic regression analysis testing for trend, there was no signif icance (P = 0.09). The odds of success increased by a factor of 1.73 (95% CI: 0.93-3.22) for rDBE. For these data, it was estimated that at least 30-35 cases of rDBE under supervision were needed to achieve a good technical success of more than 75%. CONCLUSION: There was no learning curve for aDBE. Technical success continued to increase over time for rDBE, although a learning curve could not be proven statistically. Approximately 30-35 cases of rDBE will be required for stable overtube intubation in ileum.

Rating Curve Estimation of Surface Water Quality Data Using LOADEST

Measurement of the nutrient concentrations in the stream is usually done on weekly, biweekly or monthly basis due to limited resources. There is need to estimate concentration and loads during the period when no data is available. The objectives of this study were to test the performance of a suite of regression models in predicting continuous water quality loading data and to determine systematic biases in the prediction. This study used the LOADEST model which includes several predefined regression models that specify the model form and complexity. Water quality data primarily nitrogen and phosphorus from five monitoring stations in the Neuse River Basin in North Carolina, USA were used in the development and analyses of rating curves. We found that LOADEST performed generally well in predicting loads and observation trends with general tendency/bias towards overestimation. Estimated Total Nitrogen (TN) varied from observation (“true” load) by -1% to 9%, but for the Total Phosphorus (TP) it ranged from -2% to 27%. Statistical evaluation using R2, Nash-Sutcliff Efficiency (NSE) and Partial Load Factor (PLF) showed a strong correlation in prediction.

Determination of ultimate bearing capacity of uplift piles using intact and non-intact load−displacement curve

Based on the field destructive test of six rock-socketed piles with shallow overburden,three prediction models are used to quantitatively analyze and predict the intact load−displacement curve.The predicted values of ultimate uplift capacity were further determined by four methods(displacement controlling method(DCM),reduction coefficient method(RCM),maximum curvature method(MCM),and critical stiffness method(CSM))and compared with the measured value.Through the analysis of the relationship between the change rate of pullout stiffness and displacement,a method used to determine the ultimate uplift capacity via non-intact load−displacement curve was proposed.The results show that the predicted value determined by DCM is more conservative,while the predicted value determined by MCM is larger than the measured value.This suggests that RCM and CSM in engineering applications can be preferentially applied.Moreover,the development law of the change rate of pullout stiffness with displacement agrees well with the attenuation form of power function.The theoretical predicted results of ultimate uplift capacity based on the change rate of pullout stiffness will not be affected by the integrity of the curve.The method is simple and applicable for the piles that are not loaded to failure state,and thus provides new insights into ultimate uplift capacity determination of test piles.

Comparison on Mathematical Models for Description of Flow Curves of Stable Austenitic Steels

The flow curves were measured for the stable austenitic steels 304L and 304LN by means of tensile test at room temperature,which are described by the models σ=K1εn1 + exp(K2 + n2ε), σ=Kεn1+n2lnε and σ=σ0+Kεn (where, K1, K2, n1 andn2; K, n1 and n2; σ0, K and n are constant). The comparison of the maximum deviations and the consideration of thevariation of the work hardening rate with true strain show that the flow curves for the austenitic steels 304L and 304LN canbe described by the model σ=Kεn1+n2 lnε at higher precision.The derivatives of the models σ=K1εn1 + exp(K2 + n2ε) and σ=Kεn1+n2lnε with respect to true strain, exhibit theextreme at low true strain. This inherent character indicates that both models are unsuitable to describe the part of the workhardening rate curve at low true strain.

Rating Curve Modification at Low Discharges Using Physical Model Tests

Hydraulic structure is designed based on hydraulic theories or guidelines. To ensure performance, physical model tests are often used at high discharges. However, high discharge in river is rare. Physical model tests at high discharges will probably lead biased hydrological relationship. To improve hydrological relationship at low discharges, in this study, we considered the diversion rating curve of the Yuanshanzi Diversion Work. The 1/100-scaled physical model tests at low and high discharges (90 - 1620 m3/s) were performed and coupled the diversion discharges of 5 flood events (2009-2010) in field. The official diversion rating curve was built only based on physical model tests at high discharges (837 - 1620 m3/s). The results of physical model tests in this study suggested the official diversion rating curve should be modified considering all tests. The modifications showed the official diversion rating curve was over-estimated. A complete series of physical model tests and considering field situations, in this study, indicated expanded physical model tests and constantly field measurements were therefore necessary for hydraulic structure, which provided information to modify used hydrological relationship to fit real situations.

A Review of Geothermal Type-Curves with Damage Effect: A Case of Practical Apply to a Mexican Geothermal Field

A review of the art state was developed about the inflow relationships and their application for reservoir characterization. The theoretical development of the methodology for determining the damage effect using type-curves of the inflow relationships was shown. We show the process followed for achieve the geothermal type-curve affected with damage for reservoirs with mean salinities of 30000 ppm and temperatures up to 350℃. This type-curve was applied using measurement production data in a Mexican geothermal field. According with the obtained results is shown that the methodology for determining the damage effect using production measurements is a sure alternative for the damage effect calculation. It was used an alternative methodology in order to validate the damage presence and the obtained results were consistent. Last thing shows that both methodologies can be combined as a confident manner.

Computer program of nonlinear, curved regression for ‘probacent’-probability equation in biomedicine

On the basis of experimental observations on animals, applications to clinical data on patients and theoretical statistical reasoning, the author developed a com-puter-assisted general mathematical model of the ‘probacent’-probability equation, Equation (1) and death rate (mortality probability) equation, Equation (2) derivable from Equation (1) that may be applica-ble as a general approximation method to make use-ful predictions of probable outcomes in a variety of biomedical phenomena [1-4]. Equations (1) and (2) contain a constant, γ and c, respectively. In the pre-vious studies, the author used the least maximum- difference principle to determine these constants that were expected to best fit reported data, minimizing the deviation. In this study, the author uses the method of computer-assisted least sum of squares to determine the constants, γ and c in constructing the ‘probacent’-related formulas best fitting the NCHS- reported data on survival probabilities and death rates in the US total adult population for 2001. The results of this study reveal that the method of com-puter-assisted mathematical analysis with the least sum of squares seems to be simple, more accurate, convenient and preferable than the previously used least maximum-difference principle, and better fit-ting the NCHS-reported data on survival probabili-ties and death rates in the US total adult population. The computer program of curved regression for the ‘probacent’-probability and death rate equations may be helpful in research in biomedicine.

Global Convergence of Curve Search Methods for Unconstrained Optimization

In this paper we propose a new family of curve search methods for unconstrained optimization problems, which are based on searching a new iterate along a curve through the current iterate at each iteration, while line search methods are based on finding a new iterate on a line starting from the current iterate at each iteration. The global convergence and linear convergence rate of these curve search methods are investigated under some mild conditions. Numerical results show that some curve search methods are stable and effective in solving some large scale minimization problems.

Verifiable Secret Sharing Scheme Based on the Plane Parametric Curve

Verifiable secret sharing is a special kind of secret sharing. In this paper, A secure and efficient threshold secret sharing scheme is proposed by using the plane parametric curve on the basis of the principle of secret sharing. And the performance of this threshold scheme is analyzed. The results reveal that the threshold scheme has its own advantage of one-parameter representation for a master key, and it is a perfect ideal secret sharing scheme. It can easily detect cheaters by single operation in the participants so that the probability of valid cheating is less than 1/p (where p is a large prime).

Age-Structured Population Projection of Bangladesh by Using a Partial Differential Model with Quadratic Polynomial Curve Fitting

In this paper, the age-specific population of Bangladesh based on a linear first order (hyperbolic) partial differential equation which is known as Von-Foerster Equation is studied. Applying quadratic polynomial curve fitting, the total population and population density of Bangladesh are projected for the years 2001 to 2050 based on the explicit upwind finite difference scheme for the age-structured population model based on given data (source: BBS & ICDDR, B) for initial value in the year 2001. For each age-group, the future birth rates and death rates are estimated by using quadratic polynomial curve fitting of the data for the years 2001 to 2012. Quadratic polynomial curve fitting is also used for the boundary value as the (0 - 4) age-group population based on the population size of the age-group for the years 2001 to 2012.

A NEW APPROACH TO ESTIMATE KINETIC DECOMPOSITION FROM TG-DTG OR DSC CURVE

This paper reports a new approach to estimate kinetic parameters for the thermal decomposition of the solid state from TG-DTG or DSC curve.Reduced equations are derived for the first tlme.The validity of these equations was demonstrated employing data obtained from the dehydration process of calcium oxalate monohydrate.

Testing the Hypothesis of J Curve for Turkish Economy

The purpose of this paper is to find the relationship between balance of foreign trade and real exchange rate in econometrics concept by using time series method. The authors used annual data of foreign trade deficit, real exchange rate, gross domestic product （GDP） of Turkey from 1989 to 2014, and analyzed the long-term relation of them by using ARDL bound testing method. By the result of test method; although there was a long-term relationship between balance of foreign trade, real exchange rate, GDP of Turkey and of the world, the coefficient of real exchange rate was insignificant in terms of statistical methods. Turkey and the world as well as being statistically significant coefficient of GDP, it was concluded that there was significant relationship with the economic aspects.

酸橙夏季光合作用特性研究

[目的]研究酸橙夏季光合作用特性。[方法]采用Li-6400便携式光合作用测定系统测定酸橙不同位置叶片净光合速率、酸橙光合日变化、光响应曲线和CO_(2)响应曲线。[结果]酸橙不同方位和不同部位叶片净光合速率存在一定差异;酸橙夏季净光合速率日变化呈双峰型,存在“午睡”现象,其光合峰值分别出现在10:00和14:30;气孔导度的日变化与净光合速率日变化相似。从光响应曲线看,酸橙光饱和点高,光强为0~2000μmol/(m^(2)·s),净光合速率不断上升,最大为13.44μmol/(m^(2)·s),光补偿点为28.33μmol/(m^(2)·s),表观光量子效率为0.036。从CO_(2)响应曲线看,酸橙CO_(2)饱和点在1500μmol/mol,CO_(2)补偿点为60.65μmol/mol,羧化效率为0.079。相关及回归分析结果表明,夏季酸橙净光合速率与气孔导度、空气相对湿度、胞间CO_(2)浓度、蒸腾速率、水汽压亏缺等生理生态因子关系密切。[结论]酸橙是一种喜阳的C_(3)型植物,且对弱光有较强的适应及利用能力,对CO_(2)具有较强的同化能力,同时在夏季高温低湿环境下,酸橙光合作用受各种生理生态因子影响,此期光合有效辐射不是影响净光合速率的关键因子,空气相对湿度与净光合速率呈显著正相关,因此通过环境选择或增加相对湿度的措施,可缓解酸橙夏季“午睡”现象,提高净光合效率。

基于光纤传感器的视频图像几何失真校正方法

视频图像在传播过程中会出现信息畸变,致使图像几何失真,为此提出基于光纤传感器的视频图像几何失真校正方法。分析视频图像像素节点在光敏区域分布情况,提取亚像素视差信息,通过面阵CCD图像传感器获取畸变视频图像;利用畸变曲线近似模型计算出视频图像畸变率,确定畸变图像坐标,并结合双线性灰度插值算法推导校正参数,实现视频图像的几何失真校正。实验结果表明,所提方法能够有效校正不同种类的视频图像几何畸变,校正后的图像与原图像相似度高超过0.97,图像边缘模糊程度降低,提高了图像的视觉观测效果。