LMI Approach to Robust H_∞/H_2 Controller Design with Regional Poles Constraint of a Pump-Motor System

The time domain guideposts requirements of a pump-motor system is transfered into a series of constraints which express the robust performance upper bound and regional poles limits of the closed loop system. Then the servo system control problem is transferred into the problem of robust performance optimizing under regional poles constrains described by linear matrix inequality （LMI）. These LMIs are easy to solve through the Matlab LMI-toolbox. Simulations indicate that the controller has excellent dynamic, static and disturbance rejection performance, and the control system is robust and has perfect H2 performance to the bounded external torque disturbance.

Research on Combined Hot Extrusion Forming Process of Alternator Poles

Based on the structure analysis of alternator poles, two closed die forging steps in one heat forming process of alternator poles were put forward, as well as the forming die system. Firstly, a thicker bottom base of alternator poles was per-formed by radial forging, then the middle boss and pole claw were forming on the bottom base by backward extrusion. A 3-D coupled thermo-mechanical finite element model was created. The billet deformation, metal flow and forming load were obtained. The results showed that a filling well forging without overlap defects could be obtained by this process, and that?the forming load at the first step increased slowly, but the load increased sharply at the second step when the middle boss was filling completely by the former process. An improved process was put forward, which changed the flow mode in the second forging step, it can considerably reduce the final forging load.

GFRP Poles for Traffic Signs and Signal Poles: A Case Study in Saudi Arabia

GFRP poles have been widely used as lighting poles but their use as traffic signs and signal poles is still under development. This paper highlights the literature review and case study of using GFRP poles for traffic signs and signal poles in the Eastern Province of Saudi Arabia. The case study details the design of poles, construction, maintenance and their performance. Traffic sign poles were manufactured using filament winding and signal poles using pultrusion process. AASHTO Standard “Specifications for Structural Supports for Highway Signs, Luminaires and Traffic Signals” and ANSI 136.2. were used as materials specification and design for the pole. There is a need to develop dedicated design and construction guidelines to standardize the construction process. Further study about the crash resistance of GFRP poles at different speeds needs to be explored. In addition, the paper presents a high level comparison between the different materials like weight, safety, environmental degradation, strength, service life, durability in an aggressive environment, carbon footprint and economics.

Research on the Casting-forging Precision Forming Process of Alternator Poles

The casting-forging combined technique and the closed die forging without flash-less are both new developed material working methods. The former can not only decrease forming operations of forgings, but also increase the material utilization ratio. Therefore, it is applied to produce more complex forgings. The latter is required for forging precise parts without burrs. The alternator pole is a complex forging, which was usually produced by hot forging, upsetting-extrusion or upsetting-extrusion and bending processes. During these processes, not only the forming force is higher, but the material of burrs accounts for 30 percent or so of total required material. And burrs are difficult to remove in the sequential machining process. In accordance with defects exiting in current manufacturing of alternator poles by upsetting-extruding process, such as more material demand, higher forming force and difficulty of next machining, a casting-forging precision process of alternator poles was developed and investigated in this paper. In the process, the pole was formed by two operations. One is the pre-forming operation by casting. The other is the final forming operation by the closed precision forging process. This can not only shorten processes, decrease material and power demand, but also increase precision of forgings. First, the casting blocker was designed considering the casting process and the forging ratio and the mode of deformation. Then the die structure for closed precision forging was designed, and the closing device for forging dies with spring assemblies in order to provide the necessary closing force was also designed. Finally the forming processes was investigated by test and numerical simulation method to optimum process parameters and die structure design parameters. The result can provide basis for applying the process to manufacture poles in practice.

AN INEQUALITY ON THE ZEROS AND POLES OF VECTOR VALUED MEROMORPHIC FUNCTIONS

The author proves that if f ： C → C^n is a transcendental vector valued mero-morphic function of finite order and assume, This result extends the related results for meromorphic function by Singh and Kulkarni.

Torque Calculation of Five-Phase Synchronous Reluctance Motors With Shifted-Asymmetrical-Salient-Poles Under Saturation Condition

In traditional analytical method(AM),the magnetic saturation is always ignored to simplify the calculation process.However,synchronous reluctance motors(SynRMs)often operate around saturation point to achieve higher torque density.Therefore,a new AM is proposed,in which the saturation of stator iron has been considered.The key of the proposed method includes a saturation factor,and an iterative method is adopted to compute the saturation factor in the SynRM by increasing the air-gap length.Especially,the proposed AM can be applied to a SynRM even with shifted-asymmetrical-salient-poles.In the process of AM,the expression of stator magnetomotive force(MMF)is built firstly.Additionally,the air-gap density including slotting effect and salient-poles is calculated.Then,the rotor MMF under saturation of the stator iron is obtained.Therefore,the precision of the instantaneous torque can be improved significantly.Eventually,by the verification of finite elements method(FEM)and experiments,the torque performance of SynRMs with shifted asymmetrical rotor can be predicted accurately by the proposed AM.

Collecting Traffic Video Data Using Portable Poles: Survey, Proposal, and Analysis

Several initiatives have been launched to help prevention of traffic accidents and near-accidents across the European Union. To aid the overall goal of reducing deaths and injuries related to traffic, one must understand the causation of the traffic accidents in order to prevent them. Rather than deploying a person to physically monitor a location, the task is eased by camera equipment installed in existing infrastructure, e.g. poles, and buildings, etc. In rural areas there is however a very limited infrastructure available which complicates the data acquisition. But even if there is infrastructure available in either the rural area or the urban area, this might not serve as an ideal position to capture video data from. In this work, we survey and provide an overview of available and relevant portable poles setups with respect to capturing data in both urban areas and rural areas. The conclusion of the survey shows a lack of a mobile, lightweight, compact, and easy deployable portable pole. We therefore design and develop a new portable pole meeting these requirements. The new proposed portable pole can be deployed by 2 persons in 2 hours in both rural areas as well as urban areas due to its compactness. The deployment and usage of the new portable pole is a complimentary tool, which may improve the camera capturing angle in case existing infrastructure is insufficient. This ultimately improves the traffic monitoring opportunities. Further, the survey of selected portable poles provides an excellent overview and can aid multiple applications within road traffic.

Reducing Greenhouse Gas Emissions through Improving the Life Span of Wooden Power Electric Poles of Eucalyptus saligna

The present work deals with reducing greenhouse gas emissions through improving the life span of wooden power electric poles of Eucalyptus saligna. Indeed, in Sub-Saharan African countries, Cameroon in particular, most of the power line networks are made of wooden supports and according to the Cameroon energy distribution company, wooden poles represent 32% of the causes of death linked to the state of the network. The company’s 2019 annual report indicates that 40,000 wooden poles were in critical condition and should be replaced. A significant number of mechanical failures affecting these supports have been observed. For example, on the HVA/LV power line “D17 Nko- abang” in Yaoundé in Cameroon, less than three years old, 10 (ten) cases of poles falling and/or breaking, due to their mechanical loading, were observed over a period of fewer than nine months, causing an average service stoppage for more than 11 hours and affecting an average of 3280 customers. These incidents lead to questions about how the supports are dimensioned and what load capacities they are designed to support. The aim of this work is, therefore, to suggest a method of dimensioning wooden poles hence reducing green- house gas emissions due to the deforestation by reducing the number of woo- den poles at risk to be replaced on Cameroon’s electricity distribution network. And more specifically, to reduce the number of mechanical failures affecting the wooden supports observed by analyzing the current wooden supports with their loads and to make proposals for improving the actual dimensioning me- thods. From the study carried out, it appears that 449 out of 845 supports, i.e., 53% needed to be replaced or monitored because they support the nominal forces ranging from 85% to 150% of their admissible limit and proposals have been made to improve their dimensioning.

Surface energy budget diagnosis reveals possible mechanism for the different warming rate among Earth’s three poles in recent decades

With the introduction of the‘‘Third Pole'[1],the Arctic,Antarctic,and Tibetan Plateau(TP)can be collectively referred to as the‘‘three poles of the Earth'.The cryosphere is an important component of the climate system because of its effect on Earth’s surface albedo and its role in reducing the amount of heat exchanged between the atmosphere and ocean or land(2)As the dominant parts of the cryosphere,the Arctic,Antarctic,and TP are pivotal and sensitive areas of global climate change.Global warming will weaken the inherent stability of the cryosphere,such as its ice shelves,glaciers and permafrost[3,4].

Co-varying temperatures at 200 hPa over the Earth’s three poles

The Earth’s three poles,the North Pole,South Pole,and Third Pole(i.e.,the Tibetan Plateau and its surroundings),hold the largest amount of fresh water on Earth as glaciers,sea ice,and snow.They are sensitive to climate change.However,the linkages between climate variations of the three poles,particularly between the South Pole and Third Pole,remain largely unknown.The temperatures at 200 hPa over the three poles are the highest in the summer and are less affected by surface conditions,which could reflect large-scale dynamic linkages.Temperatures at 200 hPa peak the three poles during their respective hemispheric summer and exhibit in-phase variations on interdecadal timescales(10–100 years).The 200 hPa temperatures over the North Pole and South Pole were significantly correlated with the Brewer-Dobson circulation(BDC),which transports stratospheric ozone poleward,heating the air at 200 hPa.Tropopause warming over the Third Pole was found to enhance the poleward BDC,particularly to the South Pole,linking the Third Pole’s climate to the other two poles.Additionally,the Interdecadal Pacific Oscillation(IPO)also exhibits links with the 200 hPa temperatures of the three poles.

Fibrillarin redistributes to the spindle poles and partially colocalizes with NuMA during mitosis

Fibrillann, a major protein in the nucleolus. is known to redistribute during mitosis from the nucleolus to the cytosol, and is related to the dynamics of post-mitotic reassembly of the nucleolus. To better understand the dynamic behavior and the relationship with other cytoplasmic structures, we have now expressed fibrillarin-pDsRedl fusion protein in HeLa cells. The results showed that a part of fibrillarin was associated with mitotic spindle poles in the mitotic cells. Nocodazole-induced microtubule depolymeri-zation resulted in fibrillarin redistribution throughout the cytoplasm, and removal of nocodazole resulted in relocaliza-tion of fibrillarin at the polar region during the mitotic spindles reassembly. In a mitotic cell free system, fibrillarin was found in the center of taxol-induced microtubule asters. Moreover, fibrillarin was found to colocalize with the nuclear mitotic apparatus protein (NuMA) at the poles of mitotic cells. Therefore, it is postulated that the polar redistribution of

Inverse Scattering Transform and Soliton Solutions for the Hirota Equation with N Distinct Arbitrary Order Poles

We employ the Riemann-Hilbert(RH)method to study the Hirota equation with arbitrary order zero poles under zero boundary conditions.Through the spectral analysis,the asymptoticity,symmetry,and analysis of the Jost functions are obtained,which play a key role in constructing the RH problem.Then we successfully established the exact solution of the equation without reflection potential by solving the RH problem.Choosing some appropriate parameters of the resulting solutions,we further derive the soliton solutions with different order poles,including four cases of a fourthorder pole,two second-order poles,a third-order pole and a first-order pole,and four first-order points.Finally,the dynamical behavior of these solutions are analyzed via graphic analysis.

On the location of the secondary instantaneous poles in two-degree-of-freedom spherical mechanisms

As the instant centers in planar mechanisms, the instantaneous poles （or instant poles, in brief） can be used for kinematic analysis in spherical mechanisms. One of the mandatory steps in this analysis is the determination of the location of these poles. This paper presents a theorem showing analytically that the locus of an unknown secondary instant pole in two-degree-of-freedom （2-DOF） spherical mechanisms is a great circle （GC）. The exact location of the pole on its GC is obtained based on the configuration of the mechanism and velocity ratio of the two inputs. Moreover, using the results of the theorem, a geometrical technique is presented to determine the GC of the pole.

A Part From the Poles

The Poland Pavilion becomes a hit at the 2010 World Expo,as the European country displays many cultural similarities to

Global stabilization of linear systems by bounded controls with guaranteed poles

The global stabilization of asymptotically null controllable linear systems by bounded control is considered. A nested type saturation control law is proposed which is a generalization of the existing results reported in the literature. The primary characteristic of this modified control law is that more design parameters, which are the closed-loop eigenvalues when the system is operating in linear form, are introduced and which can be well designed to achieve better system performance. Using this law, the pole locations of the closed-loop systems depending on a linear trans- formation can be placed arbitrarily within certain areas. Numerical example shows that the performance of the closed-loop system under this control law can be significantly improved if the free parameters are properly chosen.

Water Ice on Mars' Poles,but Not a Drop to Drink

选注者言:火星的南极和北极的“干冰”下藏匿着大量的冰。但是,这对于来自地球的要寻找一口水喝的客人来说,并非是一则好消息。本文对此作了详尽的解释。本文的文字表达文采斐然。比如,它讲究对称:fired imaginations andspurred search for intelligent life there;比如,它善于创造:short on dry ice andlong on water ice(英语有“short on/缺少”的说法,却没有long on的习惯表达);比如,它喜用小词:is wayin the future。其中的way,用作副词,意思是:by a greatdistance or to a great degree;far/非常;远远地;非常。另如:way off base/远离基础;way over budget/大大超过预算。

Framework for Measuring the Resilience of Utility Poles of an Electric Power Distribution Network

The utility poles of an electric power distribution system are frequently damaged by wind-related disasters.This study notes that the wooden poles are particularly vulnerable to such disasters and the failures of the poles can cause a network-level failure leading to short-or longterm power outages. To mitigate the problem, this study proposes a framework for measuring the resilience of the wooden utility poles based on the angular deflection of a pole due to the wind force. Given the existing inclination angle of a pole, the angular deflection is measured by finite element analysis using ANSYS~? Workbench^1 to determine the resilience area under various wind speeds. For this, the conditions of load and support for a pole, which are called boundary conditions in ANSYS~?, are generated. The proposed framework also includes an approach to cost–benefit analysis that compares different strategies for corrective action. The results of the case study in which the framework was applied show that the proposed framework can be effectively utilized by electric power distribution companies to increase the resilience of their systems.

Automatic Assessment and Prediction of the Resilience of Utility Poles Using Unmanned Aerial Vehicles and Computer Vision Techniques

The utility poles of electric power distribution lines are very vulnerable to many natural hazards, while power outages due to pole failures can lead to adverse economic and social consequences. Utility companies,therefore, need to monitor the conditions of poles regularly and predict their future conditions accurately and promptly to operate the distribution system continuously and safely.This article presents a novel pole monitoring method that uses state-of-the-art deep learning and computer vision methods to meet the need. The proposed method automatically captures the current pole inclination angles using an unmanned aerial vehicle. The method calculates the bending moment exerted on the poles due to wind and gravitational forces, as well as cable weight, to compare it with the moment of rupture. The method also includes a machine learning-based model that is built by using a support vector machine to predict the resilience conditions of a pole after a wind event in a faster manner. The three modules of the proposed method are effective tools to classify pole conditions and are expected to enable utility companies to increase the resilience of their systems.