Alternative Management Schemes Research Articles

Triangulation and Delphi method analysis of alternative management scheme for sustainable public-rented flats

Purpose Currently, public-rented flats in Jakarta Province are managed by the Management Unit of Public-Rented Flats (MUPRF), which uses the Regional Revenue and Expenditure Budget (RREB) as the source of its financing. However, several previous studies have suggested that the MUPRF change its institutional scheme, to be more independent and not rely on the RREB as its source of finance. The study aims to identify three variable groups, public-rented flats’ characteristics, alternative institutional and financial schemes and challenges in the change of institutional and financial schemes. Design/methodology/approach This is a qualitative research, where both triangulation and the Delphi method are used to enrich findings. Triangulation is used to collect data from more than one source, and the Delphi method is used to gather opinions from experts and reach a consensus on the variables identified in the triangulation process. Findings Based on the findings there are 11 variables of public-rented flats’ characteristics, three variables of alternative institutional and financial schemes and four variables of challenges in the change of institutional and financial scheme. Research limitations/implications Through the triangulation process, only two sources were used, sources from previous research and regulations. In the Delphi method process, experts were staff from the Department of Community Housing and Settlement of the DKI Jakarta Province. Originality/value This research will be used as the basis on developing a system dynamics on how the MUPRF works as a system to figure out whether it can be changed into the alternative scheme proposed, with all the characteristics and challenges identified.

Stochastic modeling of eastern oyster (Crassostrea virginica) production in a Mexican tropical coastal lagoon using alternative stocking density management schemes

A stochastic model was developed to analyze Crassostrea virginica production when cultivated at three stocking densities, defined as the area occupation (50, 75, and 100%) in Nestier-type trays, using juvenile oysters with an initial size (height) of 29.40 ± 0.18 mm. A 25-week grow-out was first conducted in the Rio Lagartos lagoon, showing that final oyster size was inversely related to density (P < 0.05), ranging from 61.87 mm (100% density) to 68.00 mm (50% density). At the same time, mortality was negligible (lower than 1.0%). The environmental conditions in the lagoon were stable, and the oyster growth rate positively correlated with water temperature and pH. Low pH was associated with slow oyster growth, possibly as an adverse effect of acidic conditions on the oyster shell formation. The model indicated that, for an initial 100,000 oyster population, the maximum production (oyster dozens) is obtained after 20 weeks (8310 at 50% density) and 25 weeks (8250 at 75%, and 6670 at 100% density). There was a 100% probability of oysters reaching a minimum commercial size (MCS) of 60.00 mm when using the 50 and 75% densities and 80.6% when using 100%. The model estimated that, for the maximum density, extending the grow-out up to 32 weeks would allow reaching MCS with 100% probability, although this should be experimentally confirmed. The random variability of oyster production in 50 and 75% densities was minimal, while at 100% density, it was extremely high. A sensitivity analysis indicated that for 50 and 75% densities, the main stochastic elements influencing production, are related to oyster mortality, while at 100% density, they are related to oyster growth.

Design and classification of tradable mobility credit schemes

Design and classification of tradable mobility credit schemes

Economic analysis of public investment in alternative agricultural water management schemes: a case study from northern Ghana

ABSTRACT This study assesses the institutions and economics of public investments in three agricultural water management infrastructure and technologies: rehabilitation of small reservoirs, fuel-powered motorized small pumps and electricity-powered large pumps. We find that all three technologies yield positive returns on investment, but their applicability varies spatially and across community due to differences in capital costs and environmental feasibilities or conditions. Sensitivity analyses indicate the base decision parameters – net present value, benefit–cost ratio and internal rate of return – remain stable despite potential changes in the flow of future benefits or costs. This provides further evidence about the worthiness of investment in irrigation infrastructure and technologies. However, significant under-utilized infrastructural capacities exist that warrant complementary investment in human and institutional capacities. Based on the findings policy recommendations are provided.

Crown Lifting of Low-Density Loblolly Pine (Pinus taeda) Plantations on Nonindustrial Private Forest Lands

AbstractPruning or the physical removal of lower branches, in combination with wider tree spacing, offers an alternative management scheme for small nonindustrial private forest landowners in areas lacking markets for small diameter wood. A 5-year-old loblolly pine (Pinus taeda) plantation was thinned to 495 trees/ha (200 trees/ac). Four crown-lifting treatments of 35%, 40%, 45%, and 50% live crown ratio (LCR) were then implemented. An additional unmanaged plot was established in an unthinned, unpruned area. Two replications were established for all pruning treatments. The target LCR was maintained throughout the study with the additional crown-lifting activities in 2003, 2004, and 2008. At age 8, the average diameter of the unmanaged plot was 13.5 cm (5.3 in), and the diameter of the 50% LCR treatment, which had the greatest diameter growth of all the treatments, was 20.8 cm (8.2 in). The highest mortality rate (22%) was observed in the unmanaged plot, but it was not significantly greater than the other treatments. Low density plantings maintained with pruning could allow small nonindustrial private landowners to obtain a high value sawtimber product while eliminating the need for thinning practices commonly used in traditional pine plantation management.

Aquatic Plant Invasion and Management in Riverine Reservoirs: Proactive Management via a Priori Simulation of Management Alternatives

Negative impacts from aquatic invasive plants in the United States include economic costs, loss of commercial and recreational use, and environmental damage. Simulation models are valuable tools for predicting the invasion potentials of species and for the management of existing infestations. We developed a spatially explicit, agent-based model representing the invasion, growth, and senescence of aquatic weeds as functions of day length, water temperature, water depth, and the response of aquatic weeds to biological control. As a case study to evaluate its potential utility, we parameterized the model to represent two historical invasions (1975–1983 and 2004–2007) of Hydrilla (Hydrilla verticillata (L. fil.) Royle) in Lake Conroe, Texas, USA, and their subsequent biological control using grass carp (Ctenopharyngodon idella). Results of several hypothetical alternative management schemes indicated that grass carp stocking densities needed to control Hydrilla infestation increased exponentially as the lag time between initial invasion and initial stocking increased, whereas stocking densities needed to control infestation decreased as the amount of time allowed to control the infestation increased. Predictions such as those produced by our model aid managers in developing proactive management plans for areas most likely to be invaded.

Site position and tillage treatment effects on nitrous oxide emissions from furrow-irrigated rice on a silt-loam Alfisol in the Mid-south, USA

The development of drought-resistant hybrid rice (Oryza sativa) cultivars has allowed furrow-irrigated rice production systems to become an increasingly popular alternative to traditional flood-irrigation. However, potential environmental implications, such as greenhouse gas emissions, specifically nitrous oxide (N2O), have yet to be evaluated. This study evaluated the effects of site position (i.e., up-, mid-, and down-slope) and tillage treatment [i.e., conventional tillage (CT) and no-tillage (NT)] on N2O fluxes and season-long emissions from a furrow-irrigated rice field on a silt-loam soil (Typic Albaqualfs) in east-central Arkansas. Gas collection from closed-chambers occurred weekly over the 2018 and 2019 rice growing seasons. Nitrous oxide fluxes differed (P < 0.001) among site position-tillage treatment combinations in both growing seasons. In 2018, numeric flux maxima for all site position-tillage treatment combinations occurred at 33 days after planting (DAP). Nitrous oxide emissions in 2018 were greatest (P < 0.1) at the down-slope (3.34 kg N2O ha−1 season−1) compared to both the mid- (2.78 kg N2O ha−1 season−1) and up-slope (2.74 kg N2O ha−1 season−1), which did not differ. For both growing seasons, CT produced greater (P < 0.1) N2O emissions than NT, where mean annual emissions from CT were 3.15 and 2.58 kg N2O ha−1 season−1 for the 2018 and 2019 seasons, respectively. The evaluation of N2O fluxes and emissions from furrow-irrigated rice is essential to understanding the potential environmental impacts of furrow-irrigation as an alternative water management scheme for rice production.

Entrepreneuriat social, action locale et image de marque territoriale sur l’île de Lesvos. Vers un processus de reterritorialisation de la petite exploitation oléicole

Social entrepreneurship is a strategy that integrates economic and social value creation so as to unlock local productive potential and foster social progress through alternative funding strategies or management schemes. In Greece, social entrepreneurship has very newly emerged as concept and practice. Social economy could play an essential role for lagging islands, such as Lesvos Island, to survive in the new era of continuous change and become attractive as places of life and work, managing to achieve sustainability goals. Based on field survey data, the paper deals with the case of the Social Cooperative Enterprise (SCE) “Modousa” in the olive area of Gera gulf. Modousa is a community-led initiative of small olive oil producers created in 2014. The key research question focuses on whether and to what extent SCE Modousa: a) represents a different path for valorization of local productive potential compared to the conventional one of wholesale suppliers and conventional marketing channels, b) fulfills its social role and c) succeeds its sustainability goals and territorial branding.

An evidence-based review of the effectiveness of riparian buffers to maintain stream temperature and stream-associated amphibian populations in the Pacific Northwest of Canada and the United States

Abstract We employed a systematic evidence review to evaluate empirical scientific evidence for the effectiveness of buffering headwater (typically non-fish-bearing) streams to maintain stream temperature and stream-associated amphibian populations in the Pacific Northwest of Canada and the United States. To address our synthesis objective, we identified thirteen temperature, seven amphibian, and two temperature/amphibian primary research studies that met objective inclusion criteria. We evaluated external validity for how study treatments inform or were linked to causal factors influencing temperature response (a) and how the sampled population represented or provided inference to an intended target population or landscape (b). The evidence indicated substantial variability in the temperature response to streamside buffers. The effect size for the mean 7-day maximum temperature metric showed a positive association when comparing no-buffers (clearcut) to treatments with wide buffers (≥30 m). However, this effect varied substantially and overlap existed in effect sizes among no-cut buffers, no-cut plus variable retention buffers, and no-cut patch buffers all ≤20 m wide. Large variability in effect size among treatments obscured any potential trend between effect size for the seasonal (summer) mean daily maximum temperature metric and buffer width. Shade was correlated with temperature response within several studies, but direct comparisons of treatment effectiveness among studies as a function of shade was confounded by different measurement methods. The evidence also indicated that variation in temperature response among studies may be associated with multiple factors (geology, hydrology, topography, latitude, and stream azimuth) that influence thermal sensitivity of streams to shade loss. For amphibians, we found mixed evidence for relationships between population responses and buffers maintained along streams after forest harvest. Specifically, we did not find evidence to support the contention that positive population responses are associated consistently with larger buffers. Also, considerable uncertainty exists about which environmental covariates reliably explain variation in amphibian population responses. Collectively, our results indicate that evidence is weak to address questions most relevant to policy discussions concerning effectiveness of alternative riparian management schemes. Future studies should test effectiveness of alternative treatments with either experimental or purposefully structured observational studies to develop tools and derive guidelines for how to achieve management goals based on site and landscape characteristics.

Vascular plant and ground beetle diversity on wet arable land versus conventional crop fields

While artificial farmland drainage has allowed the development of a highly productive agriculture, the availability of periodically flooded arable land as a niche habitat for a broad range of animal and vascular plant species has diminished. Accordingly, many species depending on temporary wetlands are endangered, already extinct or extirpated in Switzerland and other European countries. Some arable fields with temporary pools can still be observed in Switzerland. However, it is not known how suitable such small temporary ponds are as habitats in the modern, intensively-managed agricultural landscape, where disturbance rates are high, and connecting wetland habitats are scarce. We surveyed 120 fields across 10 hot spot regions for potential waterlogging in Switzerland, investigating the effect of temporary waterlogging on the diversity of arable plant and ground beetle species. Half of the fields were heavily influenced by waterlogging, while the other half represented conventional crop field controls. We found that wet fields exhibited a higher number of vascular plant and carabid species on average compared to control fields. This difference was explained by the presence of more hygrophilic plant and ground beetle species on wet fields. While we did find more hygrophilic species on wet fields, the threatened character species of temporary wetland habitats were mostly absent despite availability in regional species pools. These results suggest that temporary pools still provide the raw environmental characteristics that hygrophilic species require in the agricultural landscape. However, alternative management schemes are required to transform them into habitats that can effectively support high-priority, threatened species of temporary wetlands.

Connectivity Mode Management for User Devices in Heterogeneous D2D Networks

Device-to-Device (D2D) paradigm is one of the key enablers for boosting the energy efficiency (EE) of networks. For the actualization of EE in multi-mode heterogeneous D2D networks, resource allocation should be executed accordingly. In that regard, we study resource allocation management in heterogeneous D2D networks where there is a LEO satellite and a cellular base station (BS) with multi-mode user devices (satellite, BS and D2D connectivity modes) dispersed in the terrestrial cell. We formulate the EE optimization of mode selection constrained by a designated total network service capacity threshold. We also implement a sub-optimal pattern search algorithm (PSA) with the aim of enhancing EE while keeping total system service capacity at an acceptable level and compare it to alternative resource management schemes. Based on our simulation results, PSA achieves the most beneficial EE value in contrast to other schemes while still managing to meet the goodput threshold. Additionally, we discuss the multi-mode nature of our heterogeneous network from EE and goodput perspectives.

An economic valuation model for alternative pressure management schemes in water distribution networks

Abstract Pressure management (PM) is commonly used in water distribution networks (WDNs) to provide a wide range of benefits. This study presents an economic evaluation framework to support the decision-making process relating to alternative PM schemes. The methodology allows for the assessment the principal direct and indirect benefits and costs associated with using pressure-reducing valves (PRVs). The methodology is applied to a district metered area in a WDN in Mashhad, Iran, by changing the existing fixed–outlet (FO-PRV) to time-based (TM-PRV) and flow-based modulation (FM-PRV). The results indicated that FM-PRV is the most beneficial scheme for the studied case. The importance of estimating direct and indirect benefits is highlighted. The presented methodology is essential to persuade water utility decision-makers to recognize the economic feasibility and significant benefits of implementing PM schemes and justify the associated investment.

Managing high quality timber plantations as silvopastoral systems: tree growth, soil water dynamics and nitrate leaching risk

The management of high-quality timber plantations prioritizes obtaining high productions with short rotation cycles, which results in high economic and environmental costs, similar to intensive agricultural systems. The suppression of the herbaceous understorey by ploughing, and the use of fertilizers to boost tree growth potentially pose high environmental risks. Managing these plantations as silvopastoral systems (e.g. by introducing livestock and sowing legume-rich pastures) could reduce environmental risks. However, this management shift can only be effective if it is accompanied by an increased complementarity in the use of soil resources to maintain production. We evaluated rooting systems, tree water status and growth, pasture production, soil moisture and nitrate content in the soil solution in a 13-year-old hybrid walnut (Juglans major × regia) plantation under alternative management schemes. The management aimed at reducing herbaceous understorey cover (grazing, ploughing and mowing) and fertilizer usage (no fertilization, inorganic fertilization and legume sowing). Grazed and mowed plots had higher root surface density than ploughed plots. Ploughed plots also showed lower values of soil water (in summer) and tree leaf water potential than grazed and mowed plots. Tree growth and nitrate content in the soil solution was higher in ploughed than grazed or mowed plots. Fertilized and sown plots had higher understorey biomass and lower soil water (in summer) than unfertilized plots. Tree growth was higher in fertilized than unfertilized plots, with intermediate values in sown plots. Managing high-quality timber plantations under silvopastoral schemes with improved legume-rich forages might be a feasible way to reduce the high ecological maintenance costs of these plantations, without compromising their productivity.

Automatic detonator code recognition via deep neural network

Abstract Detonators are hazardous and must be strictly controlled to strengthen public security since they contain explosive. To deal with the stressful management of detonators by manually recording detonator codes, an expert and intelligent system for detonator code recognition is an alternative management scheme for automatically recording detonator codes. How to achieve accurate and reliable recognition performance is also a challenging problem in such an intelligent system. In this study, we develop an intelligent vision-based system based on deep learning for identifying detonator codes. Specifically, we design a detonator image acquisition subsystem to construct the detonator code image dataset, and an intelligent image processing subsystem named as automatic detonator code recognition network (ADCR-Net). The ADCR-Net is a pipeline cascading a deep localization network and a deep recognition network. The multi-scale concatenation block and the features integration module are proposed for the localization network of the ADCR-Net to improve the features expressions. The multi-level progressive self-attention block is put forward for the recognition network of the ADCR-Net to help with focusing on multi-level activation maps. Also, a multi-label loss function for the recognition network is designed to balance the significance of the classifiers of the intelligent system during training. Experiments on our released dataset demonstrate the effectiveness and efficiency of the proposed expert and intelligent system, which achieves 99.18% accuracy in end-to-end recognition. Our work provides an effective resolution to the expert and intelligent system for automatic detonator code recognition. Also, we provide an alternative framework to deal with the tradeoff between inference time and recognition accuracy in deep learning which is becoming a popular method in many expert and intelligent systems. Furthermore, the released dataset is available for distribution to the related researchers to develop their expert systems in the field of industrial optical character recognition.

A narrow size diameter class model for tree growth and yield simulation in a mahoe (Talipariti elatum (SW.) Fryxell, Malvaceae) plantation in Puerto Rico

Forest management planning requires forest growth models that provide a reliable way to forecast growth, calculate yield, and examine the effects of silviculture. Here we used a size stem frequency approach based on differential equations to developed a growth simulator system to guide the management of mahoe ( Talipariti elatum (SW.) Fryxell) in a small plantation in Puerto Rico. We estimated the optimal harvest age using the Faustmann model, and evaluated alternative harvesting schemes using sensitivity analyses. The growth simulator system predicted that tree volume at first rises quickly, reaches a maximum value, and then decreases because of a lack of natural regeneration in the plantation. Thus, harvesting must be followed by replanting and large and healthy trees must be maintained as seed sources. The optimal harvest age was 43 years for a discount rate of 2.5% and 19 years for 5% interest. Analysis for alternative management schemes based on selective harvesting of the largest tress showed that 5%, 15%, or 30% of the trees ≥54.5 cm dbh could be harvested in cycles of 1, 5 or 10 years respectively, without drastically decreasing the basal area. The sustainability of these management schemes will depend on the costs of management, as well as the responses of mahoe to selective harvesting.

Decision Support Model for Evaluating Alternative Waste Electrical and Electronic Equipment Management Schemes—A Case Study

Waste of electrical and electronic equipment (WEEE) is a constantly increasing component of the total volume of municipal solid waste. E-waste streams are expected to continue escalating in the near future. The underlining paradox lies in the fact that end-of-life electrical and electronic equipment constitute a critical waste stream owing to the contained hazardous and toxic elements, but they also present an important source of valuable raw materials. Therefore, identification of alternative scenarios for integrated WEEE management is imperative. To that end, this research develops a methodological approach that focuses on determining the optimal WEEE management scheme, among available alternatives, applicable to the specific case of Greece. In particular, a binary linear programming model is formulated that maximizes the performance of 9 alternative WEEE management scenarios. The mathematical model considers 12 performance assessment criteria identified across financial, technical, social, and environmental dimensions. Priority levels are assigned to each criterion based on the input of 19 involved experts. A range of “what-if” analyses indicate that mechanical recycling of WEEE, in tandem with exporting of residues, is the most efficient e-waste management strategy in the case of Greece. The research findings indicate that the joint cooperation of all stakeholders, together with political will and effectiveness, is required for the integrated WEEE management at a national level.

An Economic Perspective on the Relationship between Wilderness and Water Resources

Proponents of wilderness often cite the provision of high-quality water as a key benefit provided by designated wilderness areas to society. We critically examine this claim by exploring the relationship between wilderness and water resources from an economic perspective. We demonstrate strong spatial and hydrological links from wilderness areas to downstream users: substantial portions of the United States' total water resources originate in, or flow through, wilderness areas. We then discuss coarse estimates of the total economic value of this water flowing from wilderness that could be based on this and related information, focusing our attention on the limitations of this approach. We then consider preliminary examples of the potential specific effects of alternative management schemes on the localized benefits of water resources. Throughout, we demonstrate theoretical and practical challenges to the more readily available approaches for estimating the value added to water resources by wilderness areas. We argue that rigorous characterization of the economic benefits provided by wilderness through water resources, if desired, will require substantial more development of case studies using these types of alternative approaches. That said, our review of the evidence demonstrates many important connections between the water resources that society depends upon and the public lands that it protects as wilderness.(This paper is reprinted from a 2019 US Department of Agriculture, Forest Service, Southern Research Station publication titled A Perpetual Flow of Nature's Benefits: State-of-the Knowledge Report on the Economic, Social, and Tribal Values of Wilderness in America.)

Life cycle analysis of macauba palm cultivation: A promising crop for biofuel production

Abstract The 450 Scenario, which limits the increase in global average temperature to 2 °C, makes it necessary to take steps towards a low-carbon economy. Since the energy sector is a major contribution to anthropogenic greenhouse gas (GHG) emissions, the production of biofuels can play a key role in strategies aimed at climate change mitigation. In this regard, the oil derived from macauba palm (Acrocomia aculeata), mainly constituted of saturated organic chains, has been claimed to hold promise for the production of liquid fuels. The high potential yield, diversity of co-products and various positive features of this emerging energy crop make it an interesting option both from a social and an environmental point of view. Nonetheless, a full environmental evaluation is still missing. In the study presented herein, the impacts produced in its plantation, cultivation and harvesting phases and the associated cumulative energy demand have been determined using a life cycle analysis methodology, in addition to shedding some light on its GHG intensity relative to the other energy crops it can displace. Excluding land use changes and biogenic CO2 fixed by the crop, it was concluded that to produce one ton of macauba fruit in Brazil, the system would absorb 1810.21 MJ, with GHG emissions of 158.69 kg CO2eq in the 20-year timeframe, and of 140.04 kg CO2eq in the 100-year timeframe (comparable to those of African oil palm). Damage to human health, ecosystem quality, and resources would add up to 16 Pt·t−1 according to Eco-indicator 99 methodology. In order to account for the uncertainty derived from improvement and domestication programs, which should affect current production levels, a sensitivity analysis for different productivities was performed. In all analyses, fertilization was found to be responsible for ca. 90% of the impacts, and hence special attention should be paid to the development of alternative fertilizer management schemes.

Comparative environmental assessment of alternative waste management strategies in developing regions: A case study in Kazakhstan

The management of municipal solid waste in the Republic of Kazakhstan is still in its infancy. This situation poses a potential threat to the environment and public health and, therefore, it is necessary to introduce improved management schemes in the country. In this study, the life cycle assessment methodology was followed to evaluate the potential environmental benefits of implementing alternative management schemes based on low-waste generation and renewable energy production. The current situation of the capital city Astana was considered as the base case. Environmental results showed that air emissions in terms of landfill gases are the major contributor to climate change impacts, while landfill disposal of the non-recovered fraction of recyclable materials was responsible for the highest impacts in the other categories (especially land use). However, the reuse of recycled materials largely offsets the related environmental burdens, along with energy generation. In comparative terms, it was demonstrated that the proposed waste management scenarios are more environmentally friendly than current practices (S0), mainly owing to the credits associated with the valorisation of renewable energy (S2) and recovered materials (S3). Consequently, the evaluation showed that greater efforts should be made to exploit the energy potential of organic fraction, together with higher recycling rates, to move towards lower environmental impacts associated with municipal solid waste management.

Coupling fuzzy multiple attribute decision-making with analytic hierarchy process to evaluate urban ecological security: A case study of Guangzhou, China

Abstract Urban ecosystem is plagued with complexities and uncertainties due to the interconnections among multiple subsystems, as well as human and environment interventions. In this study, a hybrid AHP-FMADM method through coupling fuzzy multiple attribute decision-making (FMADM) with analytic hierarchy process (AHP) is developed to evaluate urban ecological security (UES). AHP-FMADM has advantages in (i) reflecting interactive relationships among multiple attributes in UES, (ii) dealing with uncertainties expressed as imprecise linguistic terms and judgments, and (iii) achieving the ranking of alternatives based on pairwise comparison. Then, AHP-FMADM is applied to assessing the ecological security of Guangzhou from 2005 to 2015, where an urban ecological security evaluation indicator system is constructed based on the pressure–state–response conceptual model. A number of scenarios with different weight assignment modes are examined. Results indicate that the overall ecological security of the study city is gradually improved. Urban environment indicators contributes more to the ecological security level than social and economic indicators. However, although ecological security state and response level increase significantly, the ecological pressure has increased since 2012, which may result in a decline of ecological security. Compared to the traditional fuzzy synthetic analysis (FSA) approach with weighted sum operator, AHP-FMADM cannot only reduce the effect of the attributes with low importance and increase that with high importance, but also help decision makers determine alternative adaptation options and management schemes based on their preferences. These findings reveal that indicators with high importance degree need to be efficiently adjusted for decision makers to maintain ecological security, such as increase water reuse ratio and control the rapid growth of the population.