Comparison of the hygrothermal performance of two light-framed timber structure buildings under different operation modes

Light-framed timber structure(LTS)buildings have been highly valued in recent years due to their low-carbon characteristics.However,the applicability of the building envelope is closely related to indoor and outdoor conditions.The hot summer and cold winter(HSCW)climate zone in China has high humidity and great temperature variation throughout the year,resulting in distinct outdoor environments in different seasons.The indoor environment is greatly affected by energy-consumption patterns and window-opening habits,which largely depend upon the regulation operations of occupants.All these interrelated factors lead to extremely complex boundary conditions on each side of the building envelope.Whether the structures of LTS buildings are applicable in this climate zone,therefore,needs to be carefully considered.In this study,two LTS buildings with different envelopes were established in Haining,China,situated in the HSCW climate zone,and selected as the study objects.Different operation modes were adopted to create a variety of indoor environments.Under each condition,the processes of heat and moisture transfer within the building envelopes and the indoor environment were monitored and compared.The comparison indicated that the building envelope with high moisture storage and insulation ability maintained a relatively stable indoor environment,especially when the environment changed abruptly.Conversely,if the outdoor environment was equable(e.g.,relative humidity within the range of 30%–60%)or intermittent energy consumption modes were adopted,the building envelope with a low thermal inertia index and weak moisture-buffering ability performed better because it enabled a faster response of the indoor environment to air conditioning.Moreover,a high risk of moisture accumulation between the thermal insulation layer and other materials with a large water vapour transfer resistance factor was also identified,suggesting a higher requirement for the vapour insulation of the envelopes of LTS buildings.

Effects of spray adjuvants and operation modes on droplet deposition and elm aphid control using an unmanned aerial vehicle

A conventional spraying mode and a fully autonomous fruit tree operation mode using a model DJ T30 unmanned aerial vehicle(UAV)were used to control aphids control on elm trees and to clarify the distribution of droplets in elm trees sprayed by a UAV.The effects of six aviation spray adjuvants on elm canopy droplet deposition and aphid control were evaluated.ImageJ software was used to analyze and measure the droplet density and deposition of water sensitive paper in two modes;this was done to calculate the droplet uniformity,depositional penetration,and droplet penetration,and to verify the aphid control effect.The results showed that the droplet density increased by 79.7%-100.7% in the upper canopy and 0-394.1%in the lower canopy without adjuvants in the fully autonomous fruit tree operation mode.The upper canopy deposits increased by 65.7%-179.3%,and the lower canopy increased by 0-152.8%.When adjuvants were added,the droplet density in the upper canopy increased by 49.7-56.1%using Jiexiaofeng(JXF),and the lower canopy increased by 138.2%-177.8% using JXF,45.8%-141.3%using Beidatong(BDT),45.5%-92.9% using Gongbei(GB),0-93.5% using Maisi(MS),and 0-95.2%using Manniu(MN).The deposits of the upper canopy increased by 888.1-1154.2% using JXF,0-1298.3% using MN,0-343.9%using BDT,0-422.5% using GB,0-580.3% using MS.The lower canopy increased by 746.4%-1426.0%using JXF,226.2%-231.0% using BDT,435.8%-644.0% using GB,255.0%-322.4%using MS,and 249.3%-360.0%using MN.When JXF was added,the droplet uniformity,droplet penetration and depositional penetration were better than when using other adjuvants.The effects of JXF,BDT and GB in controlling aphids was significantly better than other adjuvants(p<0.05).The following control effects were observed;94.1% with JXF,93.1% with BDT,and 93.3% with GB after 3 d of application,and 97.9% with JXF,95.6% with BDT,and 97.1% with GB after 7 d of application.At the same time,the application of the fully autonomous fruit tree operation mode and JXF can effectively improve the density and deposits,which will produce a superposition optimization effect.Our study focuses on the prevention and control of elm aphid infestations based on the operation mode of a UAV and aviation spray adjuvants,which can provide a baseline for the control of diseases and insect pests using UAVs in agriculture and forestry.

Optimal operation modes of photovoltaicbattery energy storage system based power plants considering typical scenarios

Recent advances in battery energy storage technologies enable increasing number of photovoltaic-battery energy storage systems(PV-BESS)to be deployed and connected with current power grids.The reliable and efficient utilization of BESS imposes an obvious technical challenge which needs to be urgently addressed.In this paper,the optimal operation of PV-BESS based power plant is investigated.The operational scenarios are firstly partitioned using a self-organizing map(SOM)clustering based approach.The revenue optimization model is adopted for the PV-BESS power plants to determine the optimal operational modes under typical conditions for a set of considerations,e.g.power generation revenue,assessing rewards/penalties as well as peak shaving/valley filling revenue.The solution is evaluated through a set of case studies,and the numerical result demonstrates the effectiveness of the suggested solution can optimally operate the BESS with the maximal revenue.

Discussi on on IPTV Operations Modes

IPTV is a promising broadband video service to which telecom operators are attaching great importance. However,there are many challenges especially to confirm operations modes. Under the circumstances of industry regulation in China,the telecom operators may adopt a standard IPTV mode,IP+TV mode or pure IP mode according to specific requirements when deploying IPTV services that are personalized and interactive. The development of IPTV faces numerous difficulties such as unclear supervision policy,industry barrier difficult to be removed,vague profit models,and imperfect technology specifications. However,the general development tendency decides a bright future of IPTV.

An Improved Multi-Objective Hybrid Genetic-Simulated Annealing Algorithm for AGV Scheduling under Composite Operation Mode

This paper presents an improved hybrid algorithm and a multi-objective model to tackle the scheduling problem of multiple Automated Guided Vehicles(AGVs)under the composite operation mode.The multi-objective model aims to minimize the maximum completion time,the total distance covered by AGVs,and the distance traveled while empty-loaded.The improved hybrid algorithm combines the improved genetic algorithm(GA)and the simulated annealing algorithm(SA)to strengthen the local search ability of the algorithm and improve the stability of the calculation results.Based on the characteristics of the composite operation mode,the authors introduce the combined coding and parallel decoding mode and calculate the fitness function with the grey entropy parallel analysis method to solve the multi-objective problem.The grey entropy parallel analysis method is a combination of the grey correlation analysis method and the entropy weighting method to solve multi-objective solving problems.A task advance evaluation strategy is proposed in the process of crossover and mutation operator to guide the direction of crossover and mutation.The computational experiments results show that the improved hybrid algorithm is better than the GA and the genetic algorithm with task advance evaluation strategy(AEGA)in terms of convergence speed and solution results,and the effectiveness of the multi-objective solution is proved.All three objectives are optimized and the proposed algorithm has an optimization of 7.6%respectively compared with the GA and 3.4%compared with the AEGA in terms of the objective of maximum completion time.

Experimental investigation of the polarityswitching process with different bipolar ionic liquid thruster operating frequencies

The bipolar ionic liquid thruster employs ionic liquid as a propellant to discharge positively and negatively charged high-energy particles under an alternating current(AC)power source,effectively suppressing electrochemical reaction and ensuring charge neutrality.Determining an optimal AC supply power source frequency is critical for sustained stable thruster operation.This study focuses on the emission characteristics of the ionic liquid thruster under varied AC conditions.The AC power supply was set within the frequency range of 0.5-64 Hz,with eight specific frequency conditions selected for experimentation.The experimental results indicate that the thruster operates steadily within a voltage range of±1470 to±1920 V,with corresponding positive polarity current ranging from 0.41 to 4.91μA and negative polarity current ranging from−0.49 to−4.10μA.During voltage polarity switching,an emission delay occurs,manifested as a prominent peak signal caused by circuit capacitance characteristics and a minor peak signal resulting from liquid droplets.Extended emission test was conducted at 16 Hz,demonstrating approximately 1 h and 50 min of consistent emission before intermittent discharge.These findings underscore the favorable impact of AC conditions within the 8-16 Hz range on the self-neutralization capability of the ionic liquid thruster.

High-speed performance self-powered short wave ultraviolet radiation detectors based onκ(ε)-Ga_(2)O_(3)

High-speed solar-blind short wavelength ultraviolet radiation detectors based onκ(ε)-Ga_(2)O_(3)layers with Pt contacts were demonstrated and their properties were studied in detail.Theκ(ε)-Ga_(2)O_(3)layers were deposited by the halide vapor phase epitaxy on patterned GaN templates with sapphire substrates.The spectral dependencies of the photoelectric properties of struc-tures were analyzed in the wavelength interval 200-370 nm.The maximum photo to dark current ratio,responsivity,detectiv-ity and external quantum efficiency of structures were determined as:180.86 arb.un.,3.57 A/W,1.78×10^(12) Hz^(0.5)∙cm·W^(-1) and 2193.6%,respectively,at a wavelength of 200 nm and an applied voltage of 1 V.The enhancement of the photoresponse was caused by the decrease in the Schottky barrier at the Pt/κ(ε)-Ga_(2)O_(3)interface under ultraviolet exposure.The detectors demon-strated could functionalize in self-powered mode due to built-in electric field at the Pt/κ(ε)-Ga_(2)O_(3)interface.The responsivity and external quantum efficiency of the structures at a wavelength of 254 nm and zero applied voltage were 0.9 mA/W and 0.46%,respectively.The rise and decay times in self-powered mode did not exceed 100 ms.

Design and operation strategies of the system for destroying time-sensitive target based on system effectiveness

To improve the effect of destroying time-sensitive target （TST）, a method of operational effectiveness evaluation is presented and some influential factors are analyzed based on the combat flow of system for destroying TST. Considering the possible operation modes of the system, a waved operation mode and a continuous operation mode are put forward at first. At the same time, some relative formulas are modified. In examples, the influential factors and operation modes are analyzed based on the system effectiveness. From simulation results, some design and operation strategies of the system for destroying time sensitive targets are concluded, which benefit to the improvement of the system effectiveness.

Operation Mode on Pulse Modulation in Atmospheric Radio Frequency Glow Discharges

The discharge operation regime of pulse modulated atmospheric radio frequency （RF） glow discharge in helium is investigated on the duty cycle and frequency of modulation pulses. The characteristics of radio frequency discharge burst in terms of breakdown voltage, alpha（s）- gamma（γ） mode transition voltage and current are demonstrated by the discharge current voltage characteristics. The minimum breakdown voltage of RF discharge burst was obtained at the duty cycle of 20% and frequency of 400 kHz, respectively. The α-γ mode transition of RF discharge burst occurs at higher voltage and current by reducing the duty cycle and elevating the modulation frequency before the RF discharge burst evolving into the ignition phase, in which the RF discharge burst can operate stably in the γ mode. It proposes that the intensity and stability of RF discharge burst can be improved by manipulating the duty cycle and modulation frequency in pulse modulated atmospheric RF glow discharge.

Research on representative brand and operation mode of second-hand clothing in Europe

In order to study the current situation and operation mode of second-hand clothing brand in Europe,this paper makes a field investigation on the second-hand clothing shops in European countries.Through classification of the inspected shops,five representative brands with certain popularity and influence and different operation modes in Europe are selected out from high-grade antique boutiques,non-profit charity organizations,professional retailers and middle-grade consignment shops in the second-hand clothing market.This paper analyzes and discusses the development history of stores,the source of goods,the form of stores,and the operation mode,so as to provide a reference for the development and standardization of the second-hand clothing market in China.

Operational Mode Identification Based on Sliding Time Window Method and Eigensystem Realization Algorithm

The identification result of operational mode is eurychoric while operational mode identification is investigated under ambient excitation,which is influenced by the signal size and the time interval.The operational mode identification method,which is based on the sliding time window method and the eigensystem realization algorithm(ERA),is investigated to improve the identification accuracy and stability.Firstly,the theory of the ERA method is introduced.Secondly,the strategy for decomposition and implementation is put forward,including the sliding time window method and the filtration method of modes.At last,an example is studied,where the model of a cantilever beam is built and the white noise exciting is input.Results show that the operational mode identification method can realize the modes,and has high robustness to the signal to noise ratio and signal size.

OPERATIONAL MODAL ANALYSIS SCHEMES USING CORRELATION TECHNIQUE

For some large-scale engineering structures in operating conditions, modal param- eters estimation must base itself on response-only data. This problem has received a considerable amount of attention in the past few years. It is well known that the cross-correlation function between the measured responses is a sum of complex exponential functions of the same form as the impulse response function of the original system. So this paper presents a time-domain operating modal identifcation global scheme and a frequency-domain scheme from output-only by cou- pling the cross-correlation function with conventional modal parameter estimation. The outlined techniques are applied to an airplane model to estimate modal parameters from response-only data.

Load Shedding Application within a Microgrid to Assure Its Dynamic Performance during Its Transition to the Islanded Mode of Operation

This article presents the simulation results and analysis related to the response of the generators within a microgrid towards an accidental overload condition that will require some load shedding action. A microgrid overload can occur due to various reasons ranging from poor load schedule, inadequate switching of circuits within the microgrid, outage of one or more generators inside the microgrid, illegal load connections by some low voltage consumers, etc. It was observed that among the main factors that determine the survival of the microgrid during its transition from the grid connected mode to the islanded mode of operation are the size and type of the load connected (passive or dynamic load) as well as the length of time during which the unexpected load is connected. Models of a speed and voltage regulators of a diesel generator, and important for coping with the overload conditions are provided in the paper. The novelty of the work lies in the load shedding simulation and analysis of the specific generators studied herein, regarding that in many countries the microgrid technology is seen as an important alternative towards the ever increasing load demand and also to assist the system during periods of blackout.

Docurity: A New Cryptographic Primitive for Collaborative Cloud Systems

Recently,there has been a sudden shift from using traditional office applications to the collaborative cloud-based office suite such as Microsoft Office 365.Such cloud-based systems allow users to work together on the same docu-ment stored in a cloud server at once,by which users can effectively collaborate with each other.However,there are security concerns unsolved in using cloud col-laboration.One of the major concerns is the security of data stored in cloud ser-vers,which comes from the fact that data that multiple users are working together cannot be stored in encrypted form because of the dynamic characteristic of cloud collaboration.In this paper,we propose a novel mode of operation,DL-ECB,for AES by which we can modify,insert,and delete the ciphertext based on changes in plaintext.Therefore,we can use encrypted data in collaborative cloud-based platforms.To demonstrate that the DL-ECB mode can preserve the confidential-ity,integrity,and auditability of data used in collaborative cloud systems from adversaries,we implement and evaluate the prototype of the DL-ECB mode.

Effects of spot size on the operation mode of Ga As photoconductive semiconductor switch employing extrinsic photoconductivity

To guide the illuminating design to improve the on-state performances of gallium arsenide(GaAs)photoconductive semiconductor switch(PCSS),the effect of spot size on the operation mode of GaAsPCSS based on a semi-insulating wafer with a thickness of 1 mm,triggered by a 1064-nm extrinsic laser beam with the rectangular spot,has been investigated experimentally.It is found that the variation of the spot size in length and width can act on the different parts of the output waveform integrating the characteristics of the linear and nonlinear modes,and then significantly boosts the PCSS toward different operation modes.On this basis,a two-channel model containing the active and passive parts is introduced to interpret the relevant influencing mechanisms.Results indicate that the increased spot length can peak the amplitude of static domains in the active part to enhance the development of the nonlinear switching,while the extended spot width can change the distribution of photogenerated carriers on both parts to facilitate the linear switching and weaken the nonlinear switching,which have been proved by comparing the domain evolutions under different spot sizes.

Parameters Analysis and Operational Area Calculations of VSG Applied to Distribution Networks

Virtual synchronous generator(VSG)technology is an effective way to realize coordinated energy supply of active distribution networks and comprehensive energy at present.This paper starts from the two perspectives of grid-connected operational modes and island operational modes.Based on the mathematical model of VSG,referring to existing grid standards,comprehensively considering its active and reactive-power loop stability and dynamic performance,the influencing factors of the related control parameters K,Dq,J,Dp are analyzed.And selection range for K,Dq,J,Dp is proposed,which ensures stability and robustness in grid-connected and island operational modes.In this paper,this method can be used as a reference for control strategy research and practical engineering applications of VSG.Finally,effects of parameter selection on stability and dynamic performance of active and reactive-power loops are analyzed by using the zero-pole map and Bode diagram,and feasibility of the scheme is verified by PSCAD/EMTDC.

Adsorption desalination:Advances in porous adsorbents

With the continuous growth of the world population,the demand for fresh water is ever increasing.Water desalination is a means of producing fresh water from saline water,and one of the proposed solutions in the scientific community for solving the current global freshwater shortage.Adsorption is foreseen as a promising technology for desalination due to its relatively low energy requirements,low environmental impact,low cost and high salt removal efficiency.More importantly,chemicals are not required in adsorption processes.Active carbons,zeolites,carbon nanostructures,graphene and coordination framework materials are amongst the most investigated adsorbents for adsorption desalination,which show different performances regarding adsorption rate,adsorption capacity,stability and recyclability.In this review,the latest adsorbent materials with their features are assessed(using metrics)and commented critically,and the current trend for their development is discussed.The adsorption mode is also reviewed,which can provide guidance for the design of adsorbents from the engineering application point of view.

Application of subsurface wastewater infiltration system to on-site treatment of domestic sewage under high hydraulic loading rate

In order to enhance the hydraulic loading rate （HLR） of a subsurface wastewater infiltration system （SWIS） used in treating domestic sewage, the intermittent operation mode was employed in the SWIS. The results show that the intermittent operation mode contributes to the improvement of the HLR and the pollutant removal rate. When the wetting-drying ratio （RwD） was 1.0, the pollutant removal rate increased by （13.6 ± 0.3）% for NH3-N, （20.7 ± 1.1）% for TN, （18.6± 0.4）% for TP, （12.2 ± 0.5）% for BOD, （10.1 ± 0.3）% for COD, and （36.2 ± 1.2）% for SS, compared with pollutant removal rates under the continuous operation mode. The pollutant removal rate declined with the increase of the HLR. The effluent quality met The Reuse of Urban Recycling Water - Water Quality Standard for Scenic Environment Use （GB/T 18921-2002） even when the HLR was as high as 10 cm/d. Hydraulic conductivity, oxidation reduction potential （ORP）, the quantity of nitrifying bacteria, and the pollutant removal rate of NH3-N increased with the decrease of the RWD. For the pollutant removal rates of TP, BOD, and COD, there were no significant difference （p 〈 0.05） under different RwDS. The suggested RWD was 1.0. Relative contribution of the pretreatment and SWlS to the pollutant removal was examined, and more than 80% removal of NH3-N, TN, TP, COD, and BOD occurred in the SWIS.

Multi-mode process monitoring based on a novel weighted local standardization strategy and support vector data description

There are multiple operating modes in the real industrial process, and the collected data follow the complex multimodal distribution, so most traditional process monitoring methods are no longer applicable because their presumptions are that sampled-data should obey the single Gaussian distribution or non-Gaussian distribution. In order to solve these problems, a novel weighted local standardization(WLS) strategy is proposed to standardize the multimodal data, which can eliminate the multi-mode characteristics of the collected data, and normalize them into unimodal data distribution. After detailed analysis of the raised data preprocessing strategy, a new algorithm using WLS strategy with support vector data description(SVDD) is put forward to apply for multi-mode monitoring process. Unlike the strategy of building multiple local models, the developed method only contains a model without the prior knowledge of multi-mode process. To demonstrate the proposed method's validity, it is applied to a numerical example and a Tennessee Eastman(TE) process. Finally, the simulation results show that the WLS strategy is very effective to standardize multimodal data, and the WLS-SVDD monitoring method has great advantages over the traditional SVDD and PCA combined with a local standardization strategy(LNS-PCA) in multi-mode process monitoring.