Real-time prediction of rock mass classification based on TBM operation big data and stacking technique of ensemble learning

Real-time prediction of the rock mass class in front of the tunnel face is essential for the adaptive adjustment of tunnel boring machines(TBMs).During the TBM tunnelling process,a large number of operation data are generated,reflecting the interaction between the TBM system and surrounding rock,and these data can be used to evaluate the rock mass quality.This study proposed a stacking ensemble classifier for the real-time prediction of the rock mass classification using TBM operation data.Based on the Songhua River water conveyance project,a total of 7538 TBM tunnelling cycles and the corresponding rock mass classes are obtained after data preprocessing.Then,through the tree-based feature selection method,10 key TBM operation parameters are selected,and the mean values of the 10 selected features in the stable phase after removing outliers are calculated as the inputs of classifiers.The preprocessed data are randomly divided into the training set(90%)and test set(10%)using simple random sampling.Besides stacking ensemble classifier,seven individual classifiers are established as the comparison.These classifiers include support vector machine(SVM),k-nearest neighbors(KNN),random forest(RF),gradient boosting decision tree(GBDT),decision tree(DT),logistic regression(LR)and multilayer perceptron(MLP),where the hyper-parameters of each classifier are optimised using the grid search method.The prediction results show that the stacking ensemble classifier has a better performance than individual classifiers,and it shows a more powerful learning and generalisation ability for small and imbalanced samples.Additionally,a relative balance training set is obtained by the synthetic minority oversampling technique(SMOTE),and the influence of sample imbalance on the prediction performance is discussed.     

Evolution of research on water leakage control strategies: where are we now?

ABSTRACT

This study provides an overview of the 21st century research trends for water leakage control strategies that focus on pressure management, active leakage control, pipe rehabilitation, asset management and District Metered Area (DMA) design. The biggest contribution comes from the research team in Italy, whilst the most active researcher is based in Greece. Research in this field has gained momentum from 2008 although a couple of studies have been conducted since 2000. Control strategies are receiving attention not only from academia but also from industrial players who are looking for technological advances by collaborating with academic institutions in research and development. The main strategy to reduce water leakage is the pressure management of water distribution systems using optimal settings of a pressure reducing valve installation. Despite available technologies, the commitment from the government, the water operators and the local consumers are the most important criterion for the effective implementation of water-leakage control strategies.     

A probabilistic framework for multi-hazard risk mitigation for electric power transmission systems subjected to seismic and hurricane hazards

Abstract

Many areas of the world are prone to multiple hazards that can be concurrent/non-concurrent and dependent/independent. Infrastructure systems located in such areas will likely be subjected to more than one hazard in their lifetime. The damage due to such hazards on electric power systems is well documented. Over the years, strategies to mitigate single hazards have been proposed for electric power systems. However, accurate long-term decisions on investment in risk mitigation strategies require the consideration of multiple hazards that can impact a system over its lifespan. Therefore, there is a need to investigate the cost-effectiveness of mitigation strategies in reducing risks to infrastructure systems that are vulnerable to multiple hazards given the constraints on resources. This requires a comprehensive multi-hazard risk assessment approach. This paper presents a framework for investigating the effectiveness of multi-hazard risk mitigation strategies for electric power systems subjected to seismic and hurricane wind hazards. The framework includes probabilistically weighted deterministic hazard analysis model, component vulnerability models, topologically based system performance model, component importance measure appropriate for networked systems, and life cycle cost analysis. A notional electric power network assumed to be located in Charleston, SC, and New York, NY, is used to demonstrate the proposed framework.     

Impact of operating rules on planning capacity expansion of urban water supply systems

ABSTRACT

Water utilities often rely on industrial water supply (e.g. desalination) to complement natural resources. These climate-independent sources of supply allow operators to respond quickly to varying operating conditions, but require them to choose operating strategies, or rules. How does such operational flexibility impact the performance of water supply systems? How might it affect long-term plans for capacity expansion? Possibly significantly, as demonstrated by the analysis of a water supply system based on Singapore. First, we simulate the dynamics of the system under multiple rainfall and operating scenarios to understand the extent to which the operators’ behavior affect system performance. Results show that different operating rules can have comparable impact on the variability in system performance as hydrological conditions. Then, we show that small changes in the operating rules can lead to substantial changes in the capacity expansions, such as the size of a new desalination plant.     

Exogenous pressures and probabilistic assessment of risk and vulnerability of urban water systems in Ghana

ABSTRACT

Risk and vulnerability assessment of urban water systems can be extended to include several components. This work formulates a probable quantitative assessment of risk and vulnerability of urban water system based on climatic conditions and urban population growth. Climate change scenarios and population projections are used to estimate susceptibility to water supply systems’ risk and vulnerability. Quantile regression was used to establish the exponent correlation between the climate variables and population; and evaluate their consequential influences on urban water supply systems. We complemented the analysis with a probabilistic model to assess the robustness of urban water system that depends wholly on the climate for freshwater source. The study established that Climatic conditions, though uncertain, point to freshwater deficiency in the future. Moreover, population trends project a higher urban population thereby increasingly lowering water per capita and subsequently leading to doubtful urban water system’s resilience to the exogenous pressures.     

Water resources carrying capacity evaluation of a dense city group: a comprehensive water resources carrying capacity evaluation model of Wuhan urban agglomeration

ABSTRACT

In this paper, the current situation and the carrying capacity of water resources in Wuhan urban agglomeration are analyzed. A comprehensive evaluation model is established to quantify the distribution of water resources and carrying capacity of cities in Wuhan urban agglomeration. The entropy method and synergistic theoretical model are applied to calculate parameters, and a series of indicators are also used to characterize the water resources carrying capacity in Wuhan urban agglomeration. The results show that water resources are in severe shortage and overloaded in Wuhan. It also tends to be overloaded in Ezhou.The larger protential of WRCC should be recognized in other cities of Wuhan urban agglomeration, such as Xiaogan, Huanggang, Qianjiang and Tianmen. Therefore, the rational planning and utilization of water resources, adjustment of industrial structure and the implementation of strict water-saving regulations are important for the protection of water resources and sustainable economic development of the urban agglomeration.     

Smart technology in the home: time for more clarity

ABSTRACT

The idea of the smart home has been around for decades but smart homes (under most definitions) are extremely rare, although digital technology and automated appliances are commonplace in the more affluent regions of the world. This commentary argues that there are inherent difficulties with expectations for smart homes and with making them viable; and with definitions and roles of ‘users’ in smart systems. It considers what a smart home might be and the problems that smart homes might address, identifying two types of narrative in the smart-energy literature. One centres on the highly automated dwelling with integrated appliances, emphasizing state-of-the-art technology, convenience and, in some sense, efficiency. The second narrative type focuses more on system-level issues such as peak demand, ancillary services and the spread of microgeneration, and on selective applications of information and communication technology (ICT) to address these. Both raise questions about the identity of users, nature of control, boundaries of the home and ecological impact.     

TRNSYS simulation for solar-assisted liquid desiccant evaporative cooling

ABSTRACT

Recently, desiccant cooling systems are well thought of as a competent method for controlling the water content in the air. A solar flat-plate collector has been used as it decreases the dependency on non-renewable resources. Solar-aided liquid desiccant systems have been used to reduce the dependency of air-conditioning systems on non-renewable sources of energy. Manipal’s humid and searing climate provides certain benefits in setting up such a system. The suggested system has reliability and equipment life and also takes complete advantage of the available solar energy for the renewal of the liquid desiccant. TRNSYS simulation is used to predict the efficiency and feasibility of the system. The temperature and energy-load variations were successfully obtained. An effective simulation was developed whereby the solar air conditioning of a room was indicated.     

Analysis of building maintenance requests using a text mining approach: building services evaluation

ABSTRACT

End users’ maintenance requests gathered from computerized maintenance management systems (CMMS) configure a rich source of information to evaluate the occupants’ satisfaction and the building systems. Nevertheless, the non-standardized data gathered from CMMS makes it difficult to carry out analytics. This paper presents a text mining approach to extract information from end users’ maintenance requests and an analysis of 6,830 maintenance requests derived from 46 buildings including offices, academic buildings and laboratories over two and a half years. The research results reveal that the most common maintenance requests during building operation and maintenance are related to problems in electrical and HVAC fixtures. Although the year of construction is not related to the occupants’ maintenance requests, the type of building use and building property do influence them. The implementation of control and preventive strategies based on these results may increase facility managers’ productivity and building systems’ performance.     

City Managers Have Ethics Too? Comparing Planning and City Management Codes of Ethics

Problem, research strategy, and ­findings: Planners and city and county managers regularly work together but often face ethical conundrums. We compare the codes of ethics from their two U.S. professional organizations—the American Institute of Certified Planners (AICP) and the International City/County Management Association (ICMA)—and then apply the AICP Code of Ethics to five published ICMA ethics scenarios to determine how the two professions might respond differently in each. We find common professional values in the codes: equality, creativity, and diligence. The AICP Code, however, emphasizes direct democracy and engaging citizens, while the ICMA Code emphasizes representative democracy and engaging elected officials. Code values and actual behaviors are not always related, but we believe our work shows the source of ethical challenges and power struggles between managers and planners.

Takeaway for practice: Planners can learn from ICMA’s Code to focus on elected officials. Managers can learn from AICP’s Code to focus on citizens. Planners and managers can overcome their professional biases and blind spots by understanding the ethical codes under which the other profession operates. Planners work from the outside in, managers from the inside out; working together, they can improve the communities they serve.     

Towards democratic planning? Negotiating change in St Kilda,Melbourne

Are planners ‘dealmakers’ caught up in selling urban areas to the highest bidder, or are they negotiators concerned to maintain democratic planning and social diversity in areas that are subject to gentrification? This paper explores this question through the example of two sites in St Kilda, Melbourne. The sites highlight planning strategies used at the local government level by planners who are attempting to negotiate change and to maintain the social and cultural diversity of the area. The first example illustrates the processes of ‘democratic planning’ where planners question what is ‘legitimate’ and draw on discourses of local need. The second example illustrates the problems of co‐opting local culture within a process of democratic planning that is based on community consultation. Together, the examples illustrate the need for tighter local government policies, including stricter policies about the use of developer contributions, and a closer and more critical focus on the term ‘community consultation’, if democratic planning is to be achieved.     

Water Distribution System Computer‐Aided Design by Agent Swarm Optimization

Optimal design of water distribution systems (WDSs), including the sizing of components, quality control, reliability, renewal, and rehabilitation strategies, etc., is a complex problem in water engineering that requires robust methods of optimization. Classical methods of optimization are not well suited for analyzing highly dimensional, multimodal, nonlinear problems, especially given inaccurate, noisy, discrete, and complex data. Agent Swarm Optimization (ASO) is a novel paradigm that exploits swarm intelligence and borrows some ideas from multiagent‐based systems. It is aimed at supporting decision‐making processes by solving multiobjective optimization problems. ASO offers robustness through a framework where various population‐based algorithms coexist. The ASO framework is described and used to solve the optimal design of WDS. The approach allows engineers to work in parallel with the computational algorithms to force the recruitment of new searching elements, thus contributing to the solution process with expert‐based proposals.     

Normalizing biproportional methods

Biproportional methods are used to update matrices: the projection of a matrix Z to give it the column and row sums of another matrix is R Z S, where R and S are diagonal and secure the constraints of the problem (R and S have no signification at all because they are not identified). However, normalizing R or S generates important mathematical difficulties: it amounts to put constraints on Lagrange multipliers, non negativity (and so the existence of the solution) is not guaranteed at equilibrium or along the path to equilibrium. Received: June 2001/Accepted: September 2001     

Metabolism-modelling approaches to long-term sustainability assessment of urban water services

There is a discernible need for a holistic, long-term and sustainability approach in decision-making in water and wastewater utilities around the world. Metabolism-based modelling, which can quantify various flows within an urban water system (UWS), has shown its effective usability for a more comprehensive understanding of the impacts of intervention strategies and can be used by any water utility for future planning of UWS. This study presents the main principles of a holistic Sustainability Assessment Framework which can be simulated by using two analytical, conceptual, mass-balance-based models to quantify relevant key performance indicators (KPIs) associated with the metabolic flows of the urban water cycle. These two models are WaterMet² (WM2) and dynamic metabolism model (DMM), developed recently under the aegis of the EU TRUST (Transitions to the Urban Water Services of Tomorrow) project. There are clear differences between the two models which make them useful in different contexts and circumstantial situations. DMM is a mass-balance consistent model which quantifies and presents annually-aggregated performance values for system wide energy consumption, emissions, environmental impacts and costs for the entire UWS though it is also possible to derive corresponding indicators for individual sub-systems (e.g. water distribution and wastewater transport). WM2 is the opposite of this, it is a distributed metabolism model which simulates water related and other resource flows throughout the UWS components with a higher resolution both spatially (e.g. multiple water resources and service reservoirs) and temporally (e.g. daily and monthly), and thereby is useful in contexts where utilities would like to focus on further details of the UWS metabolism with the aim to understand and solve specific problems. Overall, these two complementary metabolism-based approaches enable any water utility to quantitatively explore and understand the influences of different external drivers and intervention strategies on future performance profiles linked to any physical, environmental and economic criteria.     

Planning for Place and Plexus: Metropolitan Land Use and Transport

Problem: Human and natural systems will probably have to adapt to climate change impacts, but this cannot be planned for using the traditional approach based on predictions because of the subject's great complexity, its planning horizon more than 50 years away, and uncertainty about the future climate and how effectively CO₂ emissions will be reduced.

Purpose: This article proposes a more appropriate basis for planning climate change adaptation. Anticipatory governance is a flexible decision framework that uses a wide range of possible futures to prepare for change and to guide current decisions toward maximizing future alternatives or minimizing future threats. Rather than trying to tame or ignore uncertainty, this approach explores uncertainty and its implications for current and future decision making.

Methods: I review and summarize the literature on anticipatory governance and provide three case studies to demonstrate its application to climate change planning.

Results and conclusions: Denver Water, New York City, and the City of Phoenix are all using scenarios to anticipate the range of global climate changes that may impact their communities and to develop adaptation strategies to address these impacts. Each is developing a decision framework for implementing adaptation strategies incrementally based on climate monitoring. An incremental approach minimizes the resources that must be allocated to address these risks and has allowed these cities to plan in spite of the high uncertainty associated with climate change science and social change.

Takeaway for practice: The complexity, uncertainty, and distant planning horizon associated with climate change cannot be managed sufficiently for the traditional predict-and-plan approach to yield good decisions about the significant social and capital investments likely to be required for adaptation. To be successful, social institutions must embrace new methods that explore uncertainty and that provide strategic guidance for current and future decisions.

Research support: None.     

Assessing filter robustness at drinking water treatment plants

This investigation explores the use of five‐parameter logistic curve fitting in quantifying turbidity robustness and risk scoring in clarification and filtrations stages of several surface water treatment works in the Anglian Water region of the United Kingdom. The approach taken reviews different scoring systems and addresses issues of weighting, averages and variability in robustness performance using turbidity robustness indices (TRIs). It also proposes an area‐based risk scoring profile to assess performance [relative area profile for T₉₀ (RAP₉₀)]. The metrics produced are considered to be a logical and rational way to help prioritise where resources for water treatment operation should be deployed.     

A detailed review on solar desalination techniques

ABSTRACT

World is growing very fast as the population and technological development increased every day. Shortage of water becomes a significant obstacle in the development process of many parts of the world due to global warming and salinity of natural potable resource lead us to find out smart techniques of desalination of saline and brackish water. Many research works are successful in establish large desalination plant. But decidedly fewer attempts are made for the arid region where low cost; maintenance free and low operating cost techniques are needed. Fast developing and under developing country are facing problems for providing pure drinking water to all the peoples. In this review, one attempt is made to study different solar desalination techniques and find out the solution by combinations of varying desalination techniques for the small and arid region.     

Using EPA-SWMM to simulate intermittent water distribution systems

ABSTRACT

EPA Storm Water Management Model (EPA-SWMM), developed for the analysis of urban drainage systems, was used in a novel way to simulate the filling phase in intermittent water distribution systems. Firstly, the model was validated against field experimental observations from a filling test in a real water distribution network in Sicily. Then, model results were compared to those obtained by the use of a model based on the theory of the rigid water column, revealing the potential and limitations of the two approaches. The obtained results open new perspectives for the use of EPA-SWMM for the analysis of processes occurring in intermittent water distribution systems.     

Fighting Traffic: The Dawn of the Motor Age in the American City

Problem: Suburban areas have an important role to play in reducing greenhouse gas (GHG) emissions, yet little is known about the magnitude of reductions that can be expected or which strategies are most promising. Local GHG reduction strategies are often capital investments such as new green buildings, ignoring the promise of operational strategies.

Purpose: The research is intended to support local planning efforts for GHG reduction in areas where land uses are separated and transit use is low. It is also intended to contribute to the dialogue on the potential for local actions versus broader state, federal, or international initiatives.

Methods: Using the California State Polytechnic University, Pomona (CPP) campus in eastern Los Angeles County as a case study, this ex ante evaluation estimates the cost effectiveness of eight capital and operating GHG-reduction strategies. It uses locally developed estimation methods in combination with the Clean Air-Cool Planet GHG inventory model.

Results and conclusions: Carbon neutrality in suburban areas is a fantasy unless there are supportive energy, transportation, and carbon sequestration initiatives at the state, national, and international level. We find that local operational strategies, such as online classes and alternative scheduling, green energy purchase, and parking pricing and carpool programs have merit. Greater results are achieved when operational strategies are combined with cost-effective capital investments such as land use mixing (in this case, on-campus housing). Even so, some of the most favored capital approaches, such as a new green building or building commuter rail transit station facilities, rank near the bottom in cost effectiveness.

Takeaway for practice: Given the urgency of reducing GHG emissions, local planners and activity center managers should evaluate both capital and operating strategies and implement the most cost-effective strategies in new and existing development.

Research support: Support for this research was provided by the President's Office, California State Polytechnic University, Pomona.