Solving resource availability cost problem in project scheduling by pseudo particle swarm optimization

This paper considers a project scheduling problem with the objective of minimizing resource availability costs appealed to finish al activities before the deadline. There are finish-start type precedence relations among the activities which require some kinds of renewable resources. We predigest the process of sol-ving the resource availability cost problem （RACP） by using start time of each activity to code the schedule. Then, a novel heuris-tic algorithm is proposed to make the process of looking for the best solution efficiently. And then pseudo particle swarm optimiza-tion （PPSO） combined with PSO and path relinking procedure is presented to solve the RACP. Final y, comparative computational experiments are designed and the computational results show that the proposed method is very effective to solve RACP.

Predicting Resource Availability in Local Mobile Crowd Computing Using Convolutional GRU

In mobile crowd computing(MCC),people’s smart mobile devices(SMDs)are utilized as computing resources.Considering the ever-growing computing capabilities of today’s SMDs,a collection of them can offer significantly high-performance computing services.In a localMCC,the SMDs are typically connected to a local Wi-Fi network.Organizations and institutions can leverage the SMDs available within the campus to form local MCCs to cater to their computing needs without any financial and operational burden.Though it offers an economical and sustainable computing solution,users’mobility poses a serious issue in the QoS of MCC.To address this,before submitting a job to an SMD,we suggest estimating that particular SMD’s availability in the network until the job is finished.For this,we propose a convolutional GRU-based prediction model to assess how long an SMD is likely to be available in the network from any given point of time.For experimental purposes,we collected real users’mobility data(in-time and outtime)with respect to a Wi-Fi access point.To build the prediction model,we presented a novel feature extraction method to be applied to the time-series data.The experimental results prove that the proposed convolutional GRU model outperforms the conventional GRU model.

Seasonal dynamics of fine root biomass, root length density, specific root length, and soil resource availability in a Larix gmelinii plantation

Fine root turnover is a major pathway for carbon and nutrient cycling in terrestrial ecosystems and is most likely sensitive to many global change factors.Despite the importance of fine root turnover in plant C allocation and nutrient cycling dynamics and the tremendous research efforts in the past,our understanding of it remains limited.This is because the dynamics processes associated with soil resources availability are still poorly understood.Soil moisture,temperature,and available nitrogen are the most important soil characteristics that impact fine root growth and mortality at both the individual root branch and at the ecosystem level.In temperate forest ecosystems,seasonal changes of soil resource availability will alter the pattern of carbon allocation to belowground.Therefore,fine root biomass,root length density(RLD)and specific root length(SRL)vary during the growing season.Studying seasonal changes of fine root biomass,RLD,and SRL associated with soil resource availability will help us understand the mechanistic controls of carbon to fine root longevity and turnover.The objective of this study was to understand whether seasonal variations of fine root biomass,RLD and SRL were associated with soil resource availability,such as moisture,temperature,and nitrogen,and to understand how these soil components impact fine root dynamics in Larix gmelinii plantation.We used a soil coring method to obtain fine root samples(≤2 mm in diameter)every month from May to October in 2002 from a 17-year-old L.gmelinii plantation in Maoershan Experiment Station,Northeast Forestry University,China.Seventy-two soil cores(inside diameter 60 mm;depth intervals:0-10 cm,10-20 cm,20-30 cm)were sampled randomly from three replicates 25 m×30 m plots to estimate fine root biomass(live and dead),and calculate RLD and SRL.Soil moisture,temperature,and nitrogen(ammonia and nitrates)at three depth intervals were also analyzed in these plots.Results showed that the average standing fine root biomass(live and dead)was 189.1 g·m^(-2)·a^(-1),50%(95.4 g·m^(-2)·a^(-1))in the surface soil layer(0-10 cm),33%(61.5 g·m^(-2)·a^(-1)),17%(32.2 g·m^(-2)·a^(-1))in the middle(10-20 cm)and deep layer(20-30cm),respectively.Live and dead fine root biomass was the highest from May to July and in September,but lower in August and October.The live fine root biomass decreased and dead biomass increased during the growing season.Mean RLD(7,411.56 m·m^(-3)·a^(-1))and SRL(10.83 m·g^(-1)·a^(-1))in the surface layer were higher than RLD(1474.68 m·m^(-3)·a^(-1))and SRL(8.56 m·g^(-1)·a^(-1))in the deep soil layer.RLD and SRL in May were the highest(10621.45 m·m^(-3) and 14.83m·g^(-1))compared with those in the other months,and RLD was the lowest in September(2198.20 m·m^(-3))and SRL in October(3.77 m·g^(-1)).Seasonal dynamics of fine root biomass,RLD,and SRL showed a close relationship with changes in soil moisture,temperature,and nitrogen availability.To a lesser extent,the temperature could be determined by regression analysis.Fine roots in the upper soil layer have a function of absorbing moisture and nutrients,while the main function of deeper soil may be moisture uptake rather than nutrient acquisition.Therefore,carbon allocation to roots in the upper soil layer and deeper soil layer was different.Multiple regression analysis showed that variation in soil resource availability could explain 71-73%of the seasonal variation of RLD and SRL and 58%of the variation in fine root biomass.These results suggested a greater metabolic activity of fine roots living in soil with higher resource availability,which resulted in an increased allocation of carbohydrate to these roots,but a lower allocation of carbohydrate to those in soil with lower resource availability.

Resource availability and plant diversity explain patterns of invasion of an exotic grass

Aims in this study,we examine two common invasion biology hypotheses-biotic resistance and fluctuating resource availability-to explain the patterns of invasion of an invasive grass,Microstegium vimineum.Methods We used 13-year-old deer exclosures in great smoky mountains National Park,USA,to examine how chronic disturbance by deer browsing affects available resources,plant diversity,and invasion in an understory plant community.using two replicate 1 m2 plots in each deer browsed and unbrowsed area,we recorded each plant species present,the abundance per species,and the fractional per-cent cover of vegetation by the cover classes:herbaceous,woody,and graminoid.For each sample plot,we also estimated overstory canopy cover,soil moisture,total soil carbon and nitrogen,and soil pH as a measure of abiotic differences between plots.Important Findings We found that plant community composition between chronically browsed and unbrowsed plots differed markedly.Plant diversity was 40%lower in browsed than in unbrowsed plots.at our sites,diver-sity explained 48%and woody plant cover 35%of the variation in M.vimineum abundance.in addition,we found 3.3 times less M.vimineum in the unbrowsed plots due to higher woody plant cover and plant diversity than in the browsed plots.a parsimonious explanation of these results indicate that disturbances such as herbivory may elicit multiple conditions,namely releasing available resources such as open space,light,and decreasing plant diversity,which may facilitate the proliferation of an invasive species.Finally,by testing two different hypotheses,this study addresses more recent calls to incorporate multiple hypotheses into research attempting to explain plant invasion.

Herbivore and native plant diversity synergistically resist alien plant invasion regardless of nutrient conditions

Alien plant invasion success can be inhibited by two key biotic factors:native herbivores and plant diversity.However,few studies have experimentally tested whether these factors interact to synergistically resist invasion success,especially factoring in changing global environments(e.g.nutrient enrichment).Here we tested how the synergy between native herbivores and plant diversity affects alien plant invasion success in various nutrient conditions.For this purpose,we exposed alien plant species in potmesocosms to different levels of native plant diversity(4 vs.8 species),native generalist herbivores,and high and low soil nutrient levels.We found that generalist herbivores preferred alien plants to native plants,inhibiting invasion success in a native community.This inhibition was amplified by highly diverse native communities.Further,the amplified effect between herbivory and native plant diversity was independent of nutrient conditions.Our results suggest that a higher diversity of native communities can strengthen the resistance of native generalist herbivores to alien plant invasions by enhancing herbivory tolerance.The synergistic effect remains in force in nutrient-enriched habitats that are always invaded by alien plant species.Our results shed light on the effective control of plant invasions using multi-trophic means,even in the face of future global changes.

Belowground Bud Bank Is Insensitive to Short-Term Nutrient Addition in the Meadow Steppe of Inner Mongolia

Human activities and industrialization have significantly increased soil nutrients,such as nitrogen(N)and phos-phorus(P),profoundly impacting the composition and structure of plant community,as well as the ecosystem functions,especially in nutrient-limited ecosystems.However,as the key propagule pool of perennial grasslands,how belowground bud bank and its relationship with aboveground vegetation respond to short-term changes in soil nutrients was still unclear.In this study,we conducted a short-term(2021–2022)soil fertilization experiment with N addition(10 g N m^(-2) yr^(-1))and P addition(5 g N m^(-2) yr^(-1))in the meadow steppe of Inner Mongolia,China,to explore the responses of belowground bud bank,aboveground shoot population and their relationships(represented by the ratio of bud to shoot density-meristem limitation index(MLI))for the whole community and three plant functional groups(perennial rhizomatous grasses-PR,perennial bunchgrasses-PB,and perennial forbs-PF)to nutrient addition.The short-term nutrient addition had no significant influences on belowground bud density,aboveground shoot density,and MLI of the whole plant community.Plant functional groups showed different responses to soil fertilization.Specifically,N addition significantly increased the bud density and shoot density of PR,especially in combination with P addition.N addition reduced the shoot density of PF but had no influence on its bud density and MLI.Nutrient addition had significant effects on the three indicators of PB.Our study indicates that the belowground bud bank and its relationship with aboveground vegetation in temperate meadow steppe are insensitive to short-term soil fertilization,but plant functional groups exhibit specific responses in terms of population regeneration,which implies that plant community composition and ecosystem functions will be changed under the ongoing global change.

China First Discovered Massive Available Hot Dry Rock Resources

Hot Dry Rock （HDR） refers to those generally deeply buried impermeable metamorphic or crystallized biotite gneiss, granite and granodiorite rock bodies, with a burial depth greater than 2000 m, containing no water or vapor. HDR is as implied, hot and dry, with temperatures ranging from 150 to 650℃, and it can be utilized as a heat resource. Because this type of heat system does not require porosity, permeability and fluids and is widespread at the drillable depth range of 10 kin, it is thereby an infinite resource type. By contrast, thermal power generation results in copious pollution; wind power is irregular and unstable; solar energy occupies large areas.

What determines the number of dominant species in forests?

In this work, the difference in number of dominant species in a community on global scale and successional trajectories was analyzed based on the published data. We explained the reasons of these differ-ences using a resource availability hypothesis, proposed in this work, that the distribution of available resource determined the pattern of commu-nity dominance. The results showed that on global scale the number of dominant species of community varied across latitudinal forest zone, namely from single-species dominance in boreal and temperate forest to multi-species codominance, even no dominant species in tropical forest. This was consistent with the pattern of resource distribution on global scale. Similarly, in successional trajectories, the number of dominant species gradually radiated from single-species dominance to multi-species codominance, even no dominant species in tropical forest. The changing available resources in trajectories were responsible for this difference. By contrary, a community was often dominated by single species in temperate or boreal forest. This was determined by the low available resource, especially low available water and temperature. In boreal forest, low temperature greatly reduced availability of water and nutrient, which were responsible for the single-species dominance. In addition, the conclusion that high available resources sustained low dominance of community might be deduced, based on the fact that the dominance of community declined with the increasing of species diversity. To sum up, the richer the available resources were, the lower the dominance of community was, and vice versa. The hypothesis that the resource availability controlled the dominance of community could well elucidate the difference of community dominance on global and community scale.

Modelling of Quasi 3-D Groundwater Flow and Studying of Equivalent Drainage Boundary in Beihai Peninsula,Guangxi

This paper describes a quasi 3-D finite element model of the groundwater flow in two -aquifer system which is constructed from a sequence of aquifer flow equations coupled by leakage terms representing flow through the aquitard . It is applied to evaluate the maximum rate of groundwater resources exploited from the coastal aquifer without seawater intrusion . The main task in this model is to determine the drainage boundary of the aquifer extending under the sea . The information of the boundary can be obtained from the fluctuations of the groundwater level caused by sea-tide fluctuations . A new idea, Equivalent Drainage Boundary (EDB), is proposed and the corresponding methods , determining the EDB, are developed with tidal fluctuations data observed in boreholes . The quasi 3-D model and the methods determining EDB have been applied to the aquifer system of Beihai peninsula , Guangxi Autonomous Region of China for calculating the available groundwater resources .

Sustainable Development, Partnership for the Future

The issue of development as an urgent question is facing future challenges and is recognized along side with the efforts made to promote qualitative changes, aiming at the adaptation, activation, organization, and optimum use of efforts, capacities, and available potentials. So much is said about development, its characteristics, and related considerations. However, main features remain to show in this contest. These include objective participation of society, the endeavor towards adapting the features of advanced societies, together with observing social, economical and environmental specifications, and the changes which aim to fulfill essential needs, together with observing issues emanating from social changes.

Average Amount and Stability of Available Agro-Climate Resources in the Main Maize Cropping Regions in China during 1981–2010

The available agro-climate resources that can be absorbed and converted into dry matter could directly affect crop growth and yield under climate change. Knowledge of the average amount and stability of available agro-climate resources for maize in the main cropping regions of China under climate change is essential for farmers and advisors to optimize cropping choices and develop adaptation strategies under limited resources. In this study, the three main maize cropping regions in China—the North China spring maize region（NCS）, the Huanghuaihai summer maize region（HS）, and the Southwest China mountain maize region（SCM）—were selected as study regions. Based on observed solar radiation, temperature, and precipitation data, we analyzed the spatial distributions and temporal trends in the available agro-climate resources for maize during 1981-2010. During this period, significantly prolonged climatological growing seasons for maize [3.3, 2.0, and 4.7 day（10 yr）^-1 in NCS, HS, and SCM] were found in all three regions. However, the spatiotemporal patterns of the available agro-climate resources differed among the three regions. The available heating resources for maize increased significantly in the three regions, and the rates of increase were higher in NCS [95.5℃ day（10 yr）^-1] and SCM [93.5℃ day（10 yr）^-1] than that in HS [57.7℃ day（10 yr）^-1].Meanwhile, decreasing trends in the available water resources were found in NCS [–5.3 mm（10 yr）^-1] and SCM[–5.8 mm（10 yr）^-1], whereas an increasing trend was observed in HS [3.0 mm（10 yr）^-1]. Increasing trends in the available radiation resources were found in NCS [20.9 MJ m^-2（10 yr）^-1] and SCM [25.2 MJ m^-2（10 yr）^-1], whereas a decreasing trend was found in HS [11.6 MJ m^-2（10 yr）^-1]. Compared with 1981–90, the stability of all three resource types decreased during 1991–2000 and 2001–10 in the three regions. More consideration should be placed on the extreme events caused by more intense climate fluctuations. The results can provide guidance in the development of suitable adaptations to climate change in the main maize cropping regions in China.

Responses of soil microbial communities to freeze–thaw cycles in a Chinese temperate forest

Background:Freeze–thaw events are common in boreal and temperate forest ecosystems and are increasingly infuenced by climate warming.Soil microorganisms play an important role in maintaining ecosystem stability,but their responses to freeze–thaw cycles(FTCs)are poorly understood.We conducted a feld freeze–thaw experiment in a natural Korean pine and broadleaf mixed forest in the Changbai Mountain Nature Reserve,China,to determine the dynamic responses of soil microbial communities to FTCs.Results:Bacteria were more sensitive than fungi to FTCs.Fungal biomass,diversity and community composition were not signifcantly afected by freeze–thaw regardless of the stage.Moderate initial freeze–thaw resulted in increased bacterial biomass,diversity,and copiotrophic taxa abundance.Subsequent FTCs reduced the bacterial biomass and diversity.Compared with the initial FTC,subsequent FTCs exerted an opposite efect on the direction of change in the composition and function of the bacterial community.Soil water content,dissolved organic carbon,ammonium nitrogen,and total dissolved phosphorus were important factors determining bacterial community diversity and composition during FTCs.Moreover,the functional potentials of the microbial community involved in C and N cycling were also afected by FTCs.Conclusions:Diferent stages of FTCs have diferent ecological efects on the soil environment and microbial activities.Soil FTCs changed the soil nutrients and water availability and then mainly infuenced bacterial community composition,diversity,and functional potentials,which may disturb C and N states in this temperate forest soil.This study also improves our understanding of microbial communities regulating their ecological functions in response to climate change.

Seasonal changes on two different spatial scales： response of aquatic invertebrates to water body and microhabitat

Knowledge about the spatial and temporal scales of both habitat use and the functional significance of different adaptations is essential for an understanding of the population dynamics of invertebrate assemblages. This fundamental knowledge is not only interesting from an academic point of view, but is sorely lacking and needed in the field of restoration ecology. Many species are threatened due to degradation. Knowing what environmental conditions are needed dtLring the life cycle of these species is important in the design of restoration measures which aim to lift existing bottlenecks for threatened species. To assess the relative importance of water type and microhabitat in structuring the invertebrate assemblage during different seasons, invertebrates were sampled in three water bodies differing in trophic level and acidity. Different parts within a water body （microhabitats） were sampled separately and each water body was sampled in all four seasons. Results show that water body is an important factor structuring the invertebrate assemblage early in the season, whereas microhabitat became more important later in the season. Structural complexity of microhabitats was related to the type of locomotion employed by invertebrates. Seasonal differences could be related to population dynamics （reproduction, mortality）. Moreover, fluctuations in resource availability were expected to differ between the water bodies, with highest fluctuations in the eutrophic water body and with fluctuations becoming less predictable later in the season. This was confirmed by the data： species synchronization to pulses in food availability was strongest in the eutrophic water body. Moreover, synchronization was strongest in summer, while in autumn waters were invaded by dispersive species. Based on these results a synthesis is presented on the functioning of the different waters during the different seasons.

Spatiotemporal variation in the endangered Thymus decussatus in a hyper-arid environment

Aims Arid environments are resource limited,with scarcity of water the key limiting factor,but hyper-arid environments are rarely studied.We test for spatial and temporal variation in ecologically important characteristics to deduce plant adaptations to the extreme climate.Methods The endangered Sinai Thyme(Thymus decussatus)exists as a set of patches on mountaintops within the St Katherine Protectorate,South Sinai,a hyper-arid environment with rare events of good rains(every 10-15 years).Important Findings From spatial and temporal patterns of plant mortality,size,condition and flowering among 10 patches on the Mt Sinai massif,we deduce that the incidence and amount of flowering responds relatively quickly(1-2 years)to rainfall fluctuations,but plant growth respond only very slowly.Small individuals are most at risk of death dur-ing drought,and a high proportion of plants were dead at the end of 8 years of very low or no rainfall.No recruitment of seedlings was observed even in years of good rainfall.Droughts are expected to become increasingly frequent due to climate change;this may have important consequences for Sinai Thyme and also its associ-ated herbivores,such as the Critically Endangered Sinai Baton Blue(Pseudophilotes sinaicus)whose larval stage feeds exclusively upon the flowers of this plant.