Area Reduction Method Research Articles

DISTRIBUSI SEDIMEN PADA WADUK JATIBARANG, KOTA SEMARANG

The main issue in the operation of reservoirs is sedimentation. This can lead to silting and affect the reservoir's storage capacity. The distribution of sediments needs to be understood in order to gain an overview of their spread, so that measures can be taken to address sediment-related issues in the Jatibarang Reservoir. The analysis was conducted using sediment data from previous studies, which reported a total sediment volume of 6.64 million m³ over a period of 50 years. Based on topographic data, it was found that the Jatibarang Reservoir is classified as Type III, with a "hill" classification. The analysis results showed that the dimensionless factor F is 0.22, with a relative depth p of 0.53. Based on the sediment distribution analysis of the Jatibarang Reservoir with Empirical Area Reduction Method, it was found that after 50 years of operation, the new zero elevation of the reservoir would be at an elevation of +126.82 m. In comparison with the low water surface elevation at the existing dead storage of the Jatibarang Reservoir, which is at +136 m, it can be concluded that the Jatibarang reservoir can operate according to the planned lifespan and can still function for more than 50 years

A simultaneous area, delay and leakage current reduction method for Linear Feedback Shift Register (LFSR) using pulsed latches and DTMOS transistors

In digital circuits, the shift registers are the significant elements having the ability of storing and transmitting the data in sequential manner.The linear feedback shift register (LFSR) uses large number of flips-flops that consumes maximum amount of power. To overcome this issue, this research work concentrates on the design of LFSR for the area efficient, power reduction, minimization of delay and leakage current. By replacing the d-flip-flop with the bi-enabled pulsed latch to reduce the power consumption and delay of the proposed LFSR design. For the minimization of area, leakage current and delay, the hybrid body bias generator with dynamic threshold MOS (BBG-DTMOS) is used. Moreover, the pulsed clock signal is generated in the digital circuit with the aid of hybrid BBG-DTMOS technique. The proposed LFSR design is implemented in the tanner EDA tool with the available CMOS model libraries. Based on the implementation result, the proposed LFSR area is 1824 μm2and its power consumption is 172μW at a 100 MHz clock frequency withVDD=5V. Furthermore, having the better performance in different corners of the method, reduces the propagation delay and leakage current in the digital circuit. The proposed LFSR design is compared with some of the shift registers such as unidirectional and bidirectional shift registers. The existing clock pulse generator such as conventional, delayed clock pulse, TIMBER logic, PTL-AND logic and multiplexer based clock pulse generator (MCPG) are compared with the proposed BBG-DTMOS technique.

Clinical and microbiological predictors of healing in Buruli ulcer disease

IntroductionWound measurements are relevant in monitoring the rate of healing (RoH) and may predict time to healing. Predicting the time to healing can help improve the management of Buruli ulcer. We examine three methods for the determination of RoH and their use as predictors of time to healing. MethodsLesion measurements of Buruli ulcer patients treated from 2007 to 2022 were obtained with acetate sheet tracings (2D) or Aranz software (3D) fortnightly. RoH was determined using the absolute area, percentage area reduction and linear methods at 4 weeks post onset of antibiotic treatment. Predicted time to healing was compared to the actual healing time. Baseline characteristics were assessed for associations with healing. ResultsAll three methods for calculating the RoH significantly distinguished between fast and slow healers (p < 0.0001). The predicted healing time using the linear method was comparable to the actual healing time for fast healers (p = 0.34). The RoH was influenced by the form of lesion, with plaques [OR 2.19 5 %CI (1.2–3.6), p = 0.009], and oedemas [OR 8.5; 95 %CI (1.9––36.9), p = 0.004] being associated with delayed healing. The proportion of patients with paradoxical reactions 16 % vs 3 %, p < 0.0001), higher baseline bacterial load (75/104;72 % vs 21/47;45 %, p = 0.001) and delayed clearance of viable organisms (71/104;68 % vs 9/47;19 %, p < 0.0001) was higher in the slow healers than the fast healers. ConclusionPredicted healing rates were comparatively lower for slow healers than fast healers. Baseline characteristics associated with healing can be explored for an improved disease management plan to reduce patient and caregiver anxiety.

Shear strength damage model and damage removal FE modeling of stud shear connectors embedded in UHPC

The study conducted a series of push-out tests to study the shear strength of studs as shear connectors in steel-UHPC (ultra high-performance concrete) composite structures. The damage removal modeling was developed and utilized to simulate stud damage caused by welding defects, concrete cracking, and lifting effects. The study investigated the impact of stud damage on the static performance and shear strength of studs. Results indicated that when the root area of the stud was damaged, the shear strength and stiffness of the stud decreased with the damage degree. When the stud root was damaged within 5%h (h is the height of stud shank), it had a significant effect on the shear strength of the stud. Damage outside the 5%h range of the stud root had no significant effect on the shear strength of the stud. And a shear strength damage model was firstly proposed to reveal the damage mechanism of studs. A reduction factor K was proposed to account for the loss in shear strength caused by stud damage. Two methods for calculating K, namely the area reduction method and the equivalent area method, were developed. The calculated values of shear strength considering stud damage were obtained and verified by comparing the calculated values with the test results. The proposed method offers a better prediction of shear strength for damaged studs in UHPC.

Study of dam sediment distribution using experimental area-reduction method Case study: Karun Dam

Dam construction is one of the measures that is inevitable in many cases and must be done to supply drinking water, agricultural uses and electricity generation. There are many challenges to a successful dam project, and the managers of each project must consider the appropriate solutions for them. One of the studies that is done in dam design is sedimentation in dam reservoirs. The experimental area-reduction method is a very common technique that obtains the sediment distribution in depth and longitudinal profile. This technique shows that sediment accumulation is not limited to the bottom reservoirs. Sediment accumulation in a reservoir is usually distributed below the top of the protection reservoir or normal water level. In this study, the distribution of sediment in the reservoir of Karun Dam after a period of 65 years has been done using the experimental area-reduction method. Elevation–volume and elevation–area curves of the dam reservoir are obtained after the useful life of the dam and sediment deposition. The results showed that after 65 years, 106.47·10 6 m 3 of sediment is deposited in the reservoir of the dam and the useful volume of the reservoir is significantly reduced. Also, up to a height of 36.4 m, the dam reservoir is filled with sediment. Therefore, no valve should be placed up to this height.

An investigation into the characterization of the hardening response of sheet metals using tensile and shear tests with surface strain measurement

The adoption of full-field digital image correlation (DIC) strain measurement in recent years has fundamentally transformed conventional analysis procedures for the mechanical characterization of sheet metals. The wealth of local strain data that is now available until fracture has enabled experimentalists to propose new analysis techniques for tensile and shear tests to obtain the hardening response to large strain levels. Although the tests show great potential, significant gaps remain surrounding their applicability. The choice of test geometry and suitability of the analysis across a broad range of sheet metals with diverse hardening and anisotropic behaviour remain open questions. Critically, the assumptions within the tensile and shear methodologies in applying surface strain measurements to large strains while omitting through-thickness gradients have not been verified. The objective of the present study is to perform a critical evaluation of constitutive characterization techniques for sheet metals under quasi-static, ambient conditions. A series of virtual experiments were developed to numerically replicate the testing and analysis procedures followed in lab-scale experiments to extract the hardening response. A simple shear and two standard tensile test geometries were evaluated across a broad range of plasticity characteristics including different hardening rates and anisotropic behaviour. For each case, the input hardening curve in the virtual experiment is treated as the exact solution and compared to the hardening response obtained from each analysis method. The so-called area reduction method (ARM) used for tensile specimens was found to be relatively insensitive to the specimen geometry, yield exponent, and plastic anisotropy but overestimated the flow stress. The performance of the ARM method hinges upon the aspect ratio of the cross-section to avoid shear band formation and requires empirical correlations to improve its predictions at large strains. Despite their simplicity, tensile analysis methods that use small extensometers or local DIC point data are shown to systematically overestimate the hardening behaviour. Simple shear tests can provide accurate estimations of the hardening response, but the choice of geometry is material dependant. The study concludes by considering a strongly anisotropic mild steel to evaluate the tensile and shear characterization strategies with the results of a hydraulic bulge analysis.

Sedimentation Study of Tawa Dam Reservoir

Tawa irrigation project is a major irrigation scheme consisting of a dam on Tawa River and about 2713 km long canal system in districts Hoshangabad and Harda of Madhya Pradesh. The dam on Tawa River in Narmada basin is the second biggest dam of M.P. completed in 1978. The irrigation was started in the command during 1974–1975. In general, sedimentation problem reduces the capacity of a reservoir with time, that causes changes in the area-storage capacity curve. These curves are important for planners, designers and regulators of dams. Many empirical and other methods have been suggested for predicting these curves. In this case study, empirical area reduction method for full-service time of 50 years (2025) and feasible service time of 100 years (2075) with base year 1975 has been applied to determine the accumulated sediment volume, revised area and modified revised capacity of the Tawa dam reservoir. Total accumulated sediment calculated as 212.57 MCM and 482 MCM, results in gross capacity of the reservoir as 2099 MCM and 1830 MCM against original capacity of 2311.54 MCM, respectively, for 50 years of full-service time and 100 years of feasible service time.

Predicting reservoir volume reduction using artificial neural network

One of the modern methods for predicting the behavior of natural phenomena is using artificial neural network (ANN) model that predicts new data through applying experimental data and finding out the rules behind the data. Area-reduction experimental model is a method for distributing sediments in the reservoirs. The main goal of the present study is to evaluate the feasibility and utilization of ANNs in predicting reservoir volume reduction under low data conditions. The present paper focuses on applying the ANN model with a multi-layer perceptron (MLP) in MATLAB software. Prediction of the volume reduction of ANN model is done by using a 10-year period of data (2003–2013) at Baroon dam reservoir in Maku, Iran as a case study. Furthermore, for modeling the distribution of sediments in dam reservoir, area-reduction experimental model is used for a 30-year period (2009–2037). The analysis of data shows that a volume of 1.67 million cubic meters per second (MCM) on annual average is reduced from the total volume of Baroon dam due to the inflow discharge of sediment loads. Also, it is observed that the reservoir of the dam will be inoperable after 30 years because sediments will reach the minimum level of operation in the dam reservoir. It would be concluded that using experimental models such as area-reduction method for modeling sediment distribution in dam reservoirs is a complicated and costly process. Also, having other datasets such as sediment particle shape and density for modeling and generalization is not considered in the area-reduction method, while application of ANN can predict sediment distribution in dam reservoirs and also reservoir volume reduction properly and precisely.

CATCHMENT AREA EROSION STUDY IN ESTIMATION OF RESERVOIR CAPACITY AT THE END OF LIFE EXPECTANCY (CASE STUDY : GONDANG RESERVOIR, KARANGANYAR)

Gondang Reservoir is one of The National Strategic Projects. Located in Karanganyar Regency, Central Java Province, Gondang Reservoir has 2.08 Mm3 flood storage, 5.03 Mm3 effective storage, 2.03 Mm3 dead storage and 30 years lifetime. In the dam management, one of the problems that often occurs is sedimentation. To overcome this problem, we need to know the sedimentation rate and distribution pattern of Gondang Reservoir for optimalizing the reservoir management. To predict the distribution pattern of the reservoir we use Empirical Area Reduction Methods. The findings of the study show that the sediment volume of the reservoir throughout its effective life is 2,79 Mm3, the new zero elevation is +496 m, there is no remaining dead storage and the remaining effective storage is 2.2 Mm3. This indicates that theoretically the reservoir will work well up to its life expectancy. Dam sedimentation management with structural or non structural must be planned especially at effective storage. Dam sedimentation management at effective storage is very important in order to maintain Gondang Reservoir benefits.

PENGARUH SEDIMENTASI TERHADAP KAPASITAS TAMPUNGAN PADA AKHIR UMUR EFEKTIF (T50) WADUK KARIAN

Karian Reservoir is one of The National Strategic Projects. Located in Lebak Regency, Banten Province, Karian Reservoir has 207.48 Mm 3 effective storage, 46.4 Mm 3 dead storage and 50 years lifetime. In the dam management, one of the problems that often occurs is sedimentation. To overcome this problem, we need to know the sedimentation rate and distribution pattern of Karian Reservoir for optimalizing the reservoir management. To predict the distribution pattern of the reservoir we use Empirical Area Reduction Methods. The findings of the study show that the sediment volume of the reservoir throughout its effective life is 86.50 Mm 3 , the new zero elevation is +37.2 m, the remaining dead storage is 7.62 Mm 3 and the remaining effective storage is 167.19 Mm 3 . This indicates that theoretically the reservoir will work well up to its effective life but the dam sedimentation management must be planned because sediment not only deposit on the dead storage but also on effectife storage.

Characterization and application of a constitutive model for two 7000-series aluminum alloys subjected to hot forming

The constitutive behaviour of AA7075 and a developmental 7000-series alloy is characterized under conditions representative of hot forming. The materials were tested in a solutionized condition following a procedure in which tensile specimens were held at the solutionizing temperature after which they were quenched to the desired testing temperature (ranging from 25–400 °C) and immediately tested. Tensile tests were performed along the sheet rolling, transverse and diagonal directions. Three strain rates were considered: 0.01, 0.1 and 0.5 s−1. A novel area reduction method is proposed to measure the instantaneous cross-setcional area using in situ digital image correlation (DIC) and then calculate the true stress and strain over the cross-section. Shear tests were also performed along at 25 and 470 °C and used to calibrate the plane stress anisotropic Yld-2000 yield criterion. In the solutionized condition, both alloys exhibited Portevin–Le–Chatelier bands resulting in a negative rate sensitivity. At elevated temperatures, strong positive rate sensitivity was observed. The constitutive model and yield surface were used to model a series of hot forming, deep draw experiments. The predicted force-displacement and earing responses were in good agreement with the measured data.

Метод уменьшения площади кристалла для систем согласования импедансов в высокоскоростных каналах передач

Метод уменьшения площади кристалла для систем согласования импедансов в высокоскоростных каналах передач

Comparing the Performance of Genetic and Particle Swarm Algorithms in Calibration of Experimental Area Reduction Method Based on Hydrographic Results of Dez Dam Reservoir

Comparing the Performance of Genetic and Particle Swarm Algorithms in Calibration of Experimental Area Reduction Method Based on Hydrographic Results of Dez Dam Reservoir

Effective histopathological image area reduction method for real-time applications

Effective histopathological image area reduction method for real-time applications

Empirical approaches in prediction of reservoir sediment distribution—An experience of 57 reservoirs in the USA and India

An accurate prediction of sediment distribution may minimize economic losses through proper and timely planning of the functional activities of a reservoir. This study assesses different temporal and spatial factors that affect for sediment deposition in a reservoir and its distribution. This study also focuses on evaluation of two popular distribution prediction methodologies, Area Increment and Empirical Area Reduction, based on experience with sediment distribution in 57 reservoirs in the USA and India. A non-iterative processed empirical distribution model (NPEDM) and a linear regression trend model (LRTM) are proposed to predict sediment distribution. Silt contributing area and inflow entering a reservoir are found to be the most significant factors affecting in reservoir sediment deposition. Compared to the Empirical Area Reduction method, the Area Increment method provided better prediction. The reservoir classification approach and empirical design distribution type curves given by Borland and Miller (1960) are found to be rational. Shape factor values for different periods indicate that reservoir shape (type) changes with time. Thus, long term prediction is not desirable in Type-II & III reservoirs using the Empirical Area Reduction method. Newly developed the NPEDM shows reasonably good prediction of sediment distribution. The NPEDM is very easy to apply and can be used in any reservoir of any size. Extrapolation of the trend of sediment distribution obtained from the LRTM indicates an accurate short term prediction in a few reservoirs as causes of temporal and spatial variations of sediment distribution including the factors of uncertainties of sediment deposition are implicit within the methodology.

Geometry-Based Distributed Spatial Skyline Queries in Wireless Sensor Networks

Algorithms for skyline querying based on wireless sensor networks (WSNs) have been widely used in the field of environmental monitoring. Because of the multi-dimensional nature of the problem of monitoring spatial position, traditional skyline query strategies cause enormous computational costs and energy consumption. To ensure the efficient use of sensor energy, a geometry-based distributed spatial query strategy (GDSSky) is proposed in this paper. Firstly, the paper presents a geometry-based region partition strategy. It uses the skyline area reduction method based on the convex hull vertices, to quickly query the spatial skyline data related to a specific query area, and proposes a regional partition strategy based on the triangulation method, to implement distributed queries in each sub-region and reduce the comparison times between nodes. Secondly, a sub-region clustering strategy is designed to group the data inside into clusters for parallel queries that can save time. Finally, the paper presents a distributed query strategy based on the data node tree to traverse all adjacent sensors’ monitoring locations. It conducts spatial skyline queries for spatial skyline data that have been obtained and not found respectively, so as to realize the parallel queries. A large number of simulation results shows that GDSSky can quickly return the places which are nearer to query locations and have larger pollution capacity, and significantly reduce the WSN energy consumption.

Evaluation and modification of some empirical and semi-empirical approaches for prediction of area-storage capacity curves in reservoirs of dams

The storage capacity of reservoirs is gradually reduced due to sediment accumulation that causes changes in the area-storage capacity (ASC) curves. Establishing these curves and predicting their future change is an important issue for planners, designers and operators of dams. Many empirical and semi-empirical approaches have been suggested for establishing and predicting the future changes for these curves. In this study four empirical and semi-empirical methods were evaluated and three of them were modified to be used for the prediction of changes in the ASC curves due to sedimentation, based on the existing sedimentation survey data for 11 reservoirs in the USA. For evaluation, these approaches were reviewed and used to determine sedimentation depth and establishing the ASC curves for the Mosul dam reservoir (MDR), which is the biggest hydraulic structure on the River Tigris in northern Iraq. MDR started operating in 1986 with a storage capacity of 11.11km3 and a water surface area 380km2 at normal operation stage (330m a.s.l.). The results obtained from these methods were evaluated using observed bathymetric survey data that had been collected in 2011 after 25 years of the operation of the dam. The evaluation results showed three methods had presented more accurate results for estimating water depth or sedimentation depth at dam site with percentage error about 1.06–3.30%. Whilst for establishing ASC curves, one method presented good agreement result with survey data. Furthermore, ASC and sedimentation depths at dam site of MDR for periods 50, 75, 100 and 125 years were estimated using the modified approaches and the area reduction method. The results of the modified methods provided reasonable agreement when compared with the area reduction method proposed by the U.S. Bureau of Reclamation and the agreement became better with an increase in time period.

Calibration the area-reduction method in sediment distribution of Ekbatan reservoir dam using genetic algorithms

Dam reservoirs usually play the most important role in the water resources systems and their optimal utilization in economic and social terms is indispensable. Sedimentation in dam’s reservoirs is one of the destructive phenomena which leads to reduction of useful volume of reservoirs and also damages the installations and disturbs their functions. Area reduction method is the most common experimental method to measure the sediment distribution in reservoirs. In this method, reservoirs are geometrically divided into four types. Parameters obtained for each type are based on limited number of chosen reservoirs and consequently the results lead to large scale errors for accuracy of this method. Therefore choosing appropriate parameters can help us to have more acceptable accuracy. In this study, first based on area reduction method a model was made by using MATLAB software and optimized by GA. Error declined by 46.7 %. Then elevation–area–capacity curves for following years were predicted by best coefficients.

An advanced numerical model of elastomeric seismic isolation bearings

SUMMARYThe nuclear accident at Fukushima Daiichi in March 2011 has led the nuclear community to consider seismic isolation for new large light water and small modular reactors to withstand the effects of beyond design basis loadings, including extreme earthquakes. The United States Nuclear Regulatory Commission is sponsoring a research project that will quantify the response of low damping rubber (LDR) and lead rubber (LR) bearings under loadings associated with extreme earthquakes. Under design basis loadings, the response of an elastomeric bearing is not expected to deviate from well‐established numerical models, and bearings are not expected to experience net tension. However, under extended or beyond design basis shaking, elastomer shear strains may exceed 300% in regions of high seismic hazard, bearings may experience net tension, the compression and tension stiffness will be affected by isolator lateral displacement, and the properties of the lead core in LR bearings will degrade in the short‐term because of substantial energy dissipation.New mathematical models of LDR and LR bearings are presented for the analysis of base isolated structures under design and beyond design basis shaking, explicitly considering both the effects of lateral displacement and cyclic vertical and horizontal loading. These mathematical models extend the available formulations in shear and compression. Phenomenological models are presented to describe the behavior of elastomeric isolation bearings in tension, including the cavitation and post‐cavitation behavior. The elastic mechanical properties make use of the two‐spring model. Strength degradation of LR bearing under cyclic shear loading due to heating of lead core is incorporated. The bilinear area reduction method is used to include variation of critical buckling load capacity with lateral displacement. The numerical models are coded in OpenSees, and the results of numerical analysis are compared with test data. The effect of different parameters on the response is investigated through a series of analyses. Copyright © 2014 John Wiley &amp; Sons, Ltd.

KAJIAN DISTRIBUSI SEDIMENTASI WADUK WONOREJO, TULUNGAGUNG-JAWA TIMUR

This study aims to know the distribution of sedimentation of the most suitable method amongthe Emperical Area Reduction Method and Area Increment Method for predicting the the distributionof sediments in the Reservoir Wonorejo. While the purpose of this study was to determine the baseelevation of a new reservoir (new zero elavation) after the existing sediments. With both methodscan be known distribution of sediments in the reservoir for the operating life of 8 years and 11years. After analysis, it can be concluded that Emperical Area Reduction Method is more suitable topredict the distribution of sedimentation in reservoirs Wonorejo. For operasi period of 8 years,sediment has reached an elevation of +122,21 m which is at 2.21 m above the base elevationreservoirs, the amount of sediment that settles in the reservoir is 2,0608. and for the operationof 11 years, sediments deposited reaches two, 2,2371. at an elevation of +123,47 m or 1,47m above the base elevation of the reservoir.Key word : Distribution of Sedimentation