Prediction of Damping Capacity Demand in Seismic Base Isolators via Machine Learning

Base isolators used in buildings provide both a good acceleration reduction and structural vibration control structures.The base isolators may lose their damping capacity over time due to environmental or dynamic effects.This deterioration of them requires the determination of the maintenance and repair needs and is important for the long-termisolator life.In this study,an artificial intelligence prediction model has been developed to determine the damage and maintenance-repair requirements of isolators as a result of environmental effects and dynamic factors over time.With the developed model,the required damping capacity of the isolator structure was estimated and compared with the previously placed isolator capacity,and the decrease in the damping property was tried to be determined.For this purpose,a data set was created by collecting the behavior of structures with single degrees of freedom(SDOF),different stiffness,damping ratio and natural period isolated from the foundation under far fault earthquakes.The data is divided into 5 different damping classes varying between 10%and 50%.Machine learning model was trained in damping classes with the data on the structure’s response to random seismic vibrations.As a result of the isolator behavior under randomly selected earthquakes,the recorded motion and structural acceleration of the structure against any seismic vibration were examined,and the decrease in the damping capacity was estimated on a class basis.The performance loss of the isolators,which are separated according to their damping properties,has been tried to be determined,and the reductions in the amounts to be taken into account have been determined by class.In the developed prediction model,using various supervised machine learning classification algorithms,the classification algorithm providing the highest precision for the model has been decided.When the results are examined,it has been determined that the damping of the isolator structure with the machine learning method is predicted successfully at a level exceeding 96%,and it is an effective method in deciding whether there is a decrease in the damping capacity.

Capacity Set Optimization of Knowledge-Based Enterprise and Its Organizational IQ

In this paper, the knowledge based enterprise is considered as an organism, which possesses a set of capabilities. The organizational structure model of knowledge based enterprise organism is described in order to possess the essential capacity set. A dynamic capacity set is defined and analyzed based on the definition of the growth and development for knowledge based enterprise organism. The structure of the capacity base, a subset of the capacity set, is optimized for different periods of the organism ...

Seismic performance evaluation of steel frame-steel plate shear walls system based on the capacity spectrum method

This paper presents some methods that the standard acceleration design response spectra derived from the present China code for seismic design of buildings are transformed into the seismic demand spectra, and that the base shear force-roof displacement curve of structure is converted to the capacity spectrum of an equivalent single-degree-of-freedom （SDOF） system. The capacity spectrum method （CSM） is programmed by means of MATLABT.0 computer language. A dual lateral force resisting system of 10-story steel frame-steel plate shear walls （SPSW） is designed according to the corresponding China design codes. The base shear force-roof displacement curve of structure subjected to the monotonic increasing lateral inverse triangular load is obtained by applying the equivalent strip model to stimulate SPSW and by using the finite element analysis software SAP2000 to make Pushover analysis. The seismic performance of this dual system subjected to three different conditions, i.e. the 8-intensity frequently occurred earthquake, fortification earthquake and seldom occurred earthquake, is evaluated by CSM program. The excessive safety of steel frame-SPSW system designed according to the present China design codes is pointed out and a new design method is suggested.

Performance-based methodology for assessing seismic vulnerability and capacity of buildings

This paper presents a performance-based methodology for the assessment of seismic vulnerability and capacity of buildings. The vulnerability assessment methodology is based on the HAZUS methodology and the improved capacity- demand-diagram method. The spectral displacement (Sd) of performance points on a capacity curve is used to estimate the damage level of a building. The relationship between Sd and peak ground acceleration (PGA) is established, and then a new vulnerability function is expressed in terms of PGA. Furthermore, the expected value of the seismic capacity index (SCev) is provided to estimate the seismic capacity of buildings based on the probability distribution of damage levels and the corresponding seismic capacity index. The results indicate that the proposed vulnerability methodology is able to assess seismic damage of a large number of building stock directly and quickly following an earthquake. The SCev provides an effective index to measure the seismic capacity of buildings and illustrate the relationship between the seismic capacity of buildings and seismic action. The estimated result is compared with damage surveys of the cities of Dujiangyan and Jiangyou in the M8.0 Wenchuan earthquake, revealing that the methodology is acceptable for seismic risk assessment and decision making. The primary reasons for discrepancies between the estimated results and the damage surveys are discussed.

Dynamic Oxygen Storage Capacity Measurements on Ceria-Based Material

Dynamic oxygen storage and release capability （OSC） measurement apparatus was designed to evaluate the OSC performance of ceria-based oxygen storage material. The optimum measurement condition was at a frequency of 0.1 Hz with the inlet gas-flow sequence CO （5S）→O2（5S）→CO→O2 and a flow rate of 300 ml·min^-1. Under this condition, similar regular square wave in the inlet and outlet of the reactor was obtained to guarantee the reliability of the dynamic OSC results. The dynamic OSC performance of the CeO2 and Ce0.67Zr0.33O2 mixed oxide prepared using the citric sol-gel method was studied at the optimum measurement condition with focus on both quantitative and qualitative analyses, The results reveal distinctly that Ce0.67Zr0.33O2 had better dynamic OSC performance because of its higher oxygen migration rate than CeO2. Under dynamic conditions, two CO2 production peaks occurred corresponding to the CO pulse and the O2 pulse, respectively, during the entire cycle. The intensity and ratio between the two CO2 productions were highly influenced by temperature and frequency indicating complex surface phenomena during the oxygen storage/release process, As a result, this set-up can be applied to the evaluation of ceria-based material on the OSC performance.

Optimal Configuration Method for the Installed Capacity of the Solar-Thermal Power Stations

Because of the randomness of wind power and photovoltaic(PV)output of new energy bases,the problem of peak regulation capability and voltage stability of ultra-high voltage direct current(UHVDC)transmission lines,we proposed an optimum allocation method of installed capacity of the solar-thermal power station based on chance constrained programming in this work.Firstly,we established the uncertainty model of wind power and PV based on the chance constrained planning theory.Then we used the K-medoids clusteringmethod to cluster the scenarios considering the actual operation scenarios throughout the year.Secondly,we established the optimal configuration model based on the objective function of the strongest transient voltage stability and the lowest overall cost of operation.Finally,by quantitative analysis of actual wind power and photovoltaic new energy base,this work verified the feasibility of the proposed method.As a result of the simulations,we found that using the optimal configuration method of solar-thermal power stations could ensure an accurate allocation of installed capacity.When the installed capacity of the solar-thermal power station is 1×106 kW,the transient voltage recovery index(TVRI)is 0.359,which has a strong voltage support capacity for the system.Based on the results of this work,the optimal configuration of the installed capacity of the solar-thermal power plant can improve peak shaving performance,transient voltage support capability,and new energy consumption while satisfying the Direct Current(DC)outgoing transmission premise.

A Systems Approach to Assessing Sustainability Capacity in Kalobeyei Refugee Settlement in Turkana County, Kenya

Refugee settlements face several challenges in transitioning from a temporary planning approach to more sustainable settlements. This is mainly due to an increase in the number of forcibly displaced people over the last few decades, and the difficulties of sustainably providing social services that meet the required standards. The development of refugee settlements assumed that forcibly displaced people would return to their places or countries of origin. Unfortunately, displacement situations are prolonged indefinitely, forcing these people to spend most of their lives in conditions that are often deplorable and substandard, and therefore unsustainable. In most cases, the establishment of refugee settlements is triggered by an emergency caused by an influx of forcibly displaced people, who need to be accommodated urgently and provided with some form of international assistance and protection. This leaves little or no time for proper planning for long-term development as required. In addition, the current approach to temporary settlement harms the environment and can strain limited resources with ad hoc development models that have exacerbated difficulties. As a result, living conditions in refugee settlements have deteriorated over the last few decades and continue to pose challenges as to how best to design, plan, and sustain settlements over time. To contribute to addressing these challenges, this study proposes a new methodology supported by Model-Based Systems Engineering (MBSE) and a Systems Modeling Language (SysML) to develop a typical sustainable human settlement system model, which has functionally and operationally executed using a Systems Engineering (SE) approach. To assess the sustainability capacity of the proposed system, this work applies a matrix of crossed impact multiplication through a case study by conducting a system capacity interdependence analysis (SCIA) using the MICMAC methodology (Cross-impact matrix multiplication applied to classification) to assess the interdependency that exist between the sub-systems categories to deliver services at the system level. The sustainability analysis results based on capacity variables influence and dependency models shows that development activities in the settlement are unstable and, therefore, unsustainable since there is no apparent difference between the influential and dependent data used for the assessment. These results illustrate that an integrated system could improve human settlements’ sustainability and that capacity building in service delivery is beneficial and necessary.

Community capacity for sustainable community—based dengue prevention and control:study of a sub—district in Southern Thailand

Objective:To assess the level of community capacity for dengue prevention and control and to study household environments and larval indices in southern Thailand.Methods:A crosssectional survey was designed for the study,enrolling two communities with higher dengue incidence rate than the standard over the past five years.Data gathering was conducted by the dengue leader group(DLG),including 15 leaders and 15 non-leaders trained by the research team.The dengue community capacity assessment tool(DCCAT) for leaders(115 items.14 domains) and non-leaders(83 items,11 domains).Participants were selected by the DLG based on their communities’ dengue risk.In the low-dengue incidence(LDI) community,32 leaders and 177 non-leaders were selected;while in the high-dengue incidence(HDI) community,31 leaders and 199 non-leaders were chosen.Results:The leaders from the LDI and the HDI communities demonstrated high levels of dengue community-capacity(360.47±58.82,416.22±57.72). Non-leaders in the LDI community demonstrated a moderate level of dengue community capacity competence(205.90±60.76),while the non-leaders in the HDI community had a high level (254.78±50.34).Conclusions:These initial levels of dengue community capacity serves as a baseline for diagnosing each community.For a community that needed to improve its capacity, the DCCAT is essential tool to conduct a pre-post intervention assessment or a serial assessment. A participatory approach is taken to enable local communities to carry out anti-dengue efforts on their own,rather than have intervention by an outsider.

Effect of electroless plating nickel treatment on electrode properties of Zr-based AB_2 type alloy

An electroless plating nickel treatment was processed to improve the active behaviors and discharge capacities of Zr based AB 2 alloys. The effects of the nickel coating on the surface appearance, the structure of the alloy powders and the electrode characteristics were investigated. It is found that the Ni rich layer formed through electroless plating nickel treatment plays an important role on the initial activation property and the discharge capacity of Zr based alloy. The optimal content of electroless plating nickel is about 15%, and the discharge capacity of the electrode can be increased to 400?mA·h·g -1 after 6 cycles. Although coated nickel is beneficial for quick activation and discharge capacity, excessive electroless plating nickel can result in a decreased discharge capacity.

A 330-500 GHz Zero-Biased Broadband Tripler Based on Terahertz Monolithic Integrated Circuits

A 330-500 GHz zero-biased broadband monolithic integrated tripler is reported. The measured results show that the maximum efficiency and the maximum output power are 2% and 194μW at 348 GHz. The saturation characteristic test shows that the output i dB compression point is about -8.5 dBm at 334 GHz and the maximum efficiency is obtained at the point, which is slightly below the 1 dB compression point. Compared with the conventional hybrid integrated circuit, a major advantage of the monolithic integrated circuit is the significant improvement of reliability and consistency. In this work, a terahertz monolithic frequency multiplier at this band is designed and fabricated.

提升农业科研试验示范基地服务能力的思考--以江苏省农业科学院新洋基地为例

文章以江苏省农业科学院新洋基地为例,介绍了科研示范基地的现状,从规划、经费投入、管理机制、功能发挥、人才等方面指出基地建设发展中存在的问题,并围绕技术创新研发、技术集成示范、技术宣传推广、科普教育培训和科技合作交流等方面提出了提升试验基地服务能力的主要途径,并进一步指出发挥基地功能的主要保障措施。

Piezoresistive Response Extraction for Smart Cement-based Composites/Sensors

A kind of piezoresistive response extraction method for smart cement-based composites/sensors was proposed.Two kinds of typical piezoresistive cement-based composites/sensors were fabricated by respectively adding carbon nanotubes and nickel powders as conductive fillers into cement paste or cement mortar.The variation in measured electrical resistance of such cement-based composites/sensors was explored without loading and under repeated compressive loading and impulsive loading.The experimental results indicate that the measured electrical resistance of piezoresistive cement-based composites/sensors exhibits a two-stage variation trend of fast increase and steady increase with measurement time without loading,and an irreversible increase after loading.This results from polarization caused by ionic conduction in these composites/sensors.After reaching a plateau,the measured electrical resistance can be divided into an electrical resistance part and an electrical capacity part.The piezoresistive responses of electrical resistance part in measured electrical resistance to loading can be extracted by eliminating the linear electrical capacity part in measured electrical resistance.

Zr-Cr-Ni BASED MULTICOMPONENT METAL HYDRIDE ELECTRODES

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Performance-based concept on seismic evaluation of existing bridges

Conventional seismic evaluation of existing bridges explores the ability of a bridge to survive under significant earthquake excitations. This approach has several major drawbacks, such as only a single structural performance of near collapse is considered, and the simplified approach of adopting strength-based concept to indirectly estimate the nonlinear behavior of a structure lacks accuracy. As a result, performance-based concepts that include a wider variety of structural performance states of a given bridge excited by different levels of earthquake intensity is needed by the engineering community. This paper introduces an improved process for the seismic evaluation of existing bridges. The relationship between the overall structural performance and earthquakes with varying levels of peak ground acceleration （PGA） can successfully be linked. A universal perspective on the seismic evaluation of bridges over their entire life-cycle can be easily obtained to investigate multiple performance objectives. The accuracy of the proposed method, based on pushover analysis, is proven in a case study that compares the results from the proposed procedure with additional nonlinear time history analyses.

Dephosphorization Thermodynamics of Crude Steel Using CaO-Based Flux

The experiments were carried out at 1 175-1 450 ℃ to study the phosphorus distribution ratio between molten Ca O-based slags and carbon saturated hot metal. The phosphate capacity of the slags and the activity coefficient of PO2. 5were calculated from the phosphorus distribution ratio. The effect of addition of Ca F2 and / or Ca Cl2 on the thermodynamic properties of slags was discussed. The correlation of optical basicity with phosphate capacity of slags was studied,and the dephosphorization ability of Ca O-based fluxes with various additives was compared with the results from different studies.

Distinctive electrochemical performance of novel Fe-based Li-rich cathode material prepared by molten salt method for lithium-ion batteries

For constructing next-generation lithium-ion batteries with advanced performances,pursuit of highcapacity Li-rich cathodes has caused considerable attention.So far,the low discharge specific capacity and serious capacity fading are strangling the development of Fe-based Li-rich materials.To activate the extra-capacity of Fe-based Li-rich cathode materials,a facile molten salt method is exploited using an alkaline mixture of LiOH–LiNO3–Li2O2 in this work.The prepared Li1.09(Fe0.2Ni0.3Mn0.5)0.91O2 material yields high discharge specific capacity and good cycling stability.The discharge specific capacity shows an upward tendency at 0.1 C.After 60 cycles,a high reversible specific capacity of ~250 m Ah g-1is delivered.The redox of Fe3+/Fe4+and Mn3+/Mn4+are gradually activated during cycling.Notably,the redox reaction of Fe2+/Fe3+can be observed reversibly below 2 V,which is quite different from the material prepared by a traditional co-precipitation method.The stable morphology of fine nanoparticles(100–300 nm)is considered benefiting for the distinctive electrochemical performances of Li1.09(Fe0.2Ni0.3Mn0.5)0.91O2.This study demonstrates that molten salt method is an inexpensive and effective approach to activate the extra capacity of Fe-based Li-rich cathode material for high-performance lithium-ion batteries.

SELECTING CLUSTER MODEL IN Sn - BASED SOLDER ALLOY DESIGN WITH DV - X_α CALCULATION METHOD

Applying calculation method in alloy design should be an important tendency due to its characters of inexpensive cost, high efficiency and prediction. DOS calculations of AuSn, AsSn and SbSn Sn- based alloys have been investigated by employing DV - Xa method, in which different cluster models were adopted to calculate electron structure.It is proved that some regulations must be taken into ac- count in order to carry out alloy design calculation successfully,which are described in this paper in detail.

Preparation and the Pore Structure of Viscose-based Activated Carbon Fibers Treated with Pretreatment Reagents

The viscose rayon was pretreated with four different pre-treatment reagents respectively, and the preparation ofactivated carbon fibers (ACF) was performed undersame carbonizing and activating conditions. The poresize distribution, the specific surface area, and the porestructure parameter of these viscose - based ACF werestudied by using quartz spring balance BET- weightmethod. The experiment result indicates that the poresize distribution and the pore structure parameter ofACF is varied by using different pretreatment reagents.

GRAPHICAL COMPUTING METHOD ON FOUR-BAR LINKAGE(1)——Inflexion Circle,Focal Axis,Ball's Point,Centering-point Curve and Circling-point Curve For Four ISPs,Coupler Curves Based on Ball's Points——

By means of programs GTMPAC based- on generalized triangle method,analysis and synthesis of mechanism design in accordance with absolutely graphicalmethod( absolutely germetrical method) are developed.In this paper,we make aspecial study about centering- point curve and circling- point curve and couplercurves based on Ball’s points.

Effects of carbon nanotubes on hydrogen storage property of Mg-based nanocomposites

Mg-based hydrogen storage nanocomposites added with carbon nanotubes(CNTs) were prepared by mechanical milling under the atmosphere of hydrogen. The results show that because of their own excellent heat conductivity and good hydrogen storage ability, the carbon nanotubes improve the mass transfer and heat transfer properties of the Mg-based nanocomponents, thus enhancing the kinetic property of hydrogen absorption and desorption of the hydrogen storage nanocomposites, and raising the hydrogen storage capacity. Due to the addition of the carbon nanotubes, the milling stress in the process of preparing the Mg-based nanocomposites is reduced, the components can be closely bonded easily, and the additives can play better catalytic roles.