Digital Vision Based Concrete Compressive Strength Evaluating Model Using Deep Convolutional Neural Network

Compressive strength of concrete is a significant factor to assess building structure health and safety.Therefore,various methods have been developed to evaluate the compressive strength of concrete structures.However,previous methods have several challenges in costly,time-consuming,and unsafety.To address these drawbacks,this paper proposed a digital vision based concrete compressive strength evaluating model using deep convolutional neural network(DCNN).The proposed model presented an alternative approach to evaluating the concrete strength and contributed to improving efficiency and accuracy.The model was developed with 4,000 digital images and 61,996 images extracted from video recordings collected from concrete samples.The experimental results indicated a root mean square error(RMSE)value of 3.56(MPa),demonstrating a strong feasibility that the proposed model can be utilized to predict the concrete strength with digital images of their surfaces and advantages to overcome the previous limitations.This experiment contributed to provide the basis that could be extended to future research with image analysis technique and artificial neural network in the diagnosis of concrete building structures.

Modeling Energy Generation by Grid Connected Photovoltaic Systems in the United States

This article presents the results of an analysis of hourly data obtained from forty-three photovoltaic (PV) systems installed in North America. Energy data collected from these systems were organized according to monthly output in an effort to identify factors which are effective in predicting energy generation. Independent variables such as system capacity, shading, longitude, latitude, seasonal variation, and orientation were considered. Multiple regression analysis was used to quantify the kilowatt-hours that can be expected from a change in the independent variables. Results show that all six independent variables are significant predictors which can be used in a regression model to estimate system output with a high level of confidence. The analysis shows that approximately 83% of the variation in the amount of energy generated monthly by the forty-three solar panels is explained by the independent variables and the derived equation. Results of the study may prove helpful to solar panel system users who may need to consider less than optimum conditions during a PV panel installation and service life.

THE SYSTEMATIC COURSE DEVELOPMENT PROCESS:Building a Course in Sustainable Construction for Students in the U.S.A.

The construction industry actively adopts the concept of sustainability to not only minimize the impact on the environment but also increase social and economic benefits through accepting sustainable design and construction practices.This growing trend in sustainable construction requires both new knowledge and new skills for sustainability,in addition to conventional knowledge,such as scheduling,estimating,contracting,etc.Due to this paradigm change in the construction industry,construction programs in the U.S.A.should offer sustainable construction courses in order to teach sustainable knowledge,technologies and skills to their students before their entrance into industry.The purpose of this study is to develop a sustainable construction course designed for university construction programs using a systematic course development approach divided into three stages including preparation,development,and improvement.The course described in this paper is used to illustrate the systematic development process and can serve as an example for faculty at other universities on how to use such a method.During the preparation stage,a syllabus review is conducted in order to recognize and evaluate current sustainable construction courses offered by construction programs.In addition,in-depth literature review is performed to identify current trends in sustainable construction courses and related research.The development stage consists of:creating the framework for a sustainable construction course,choosing the goals and objectives for this course,choosing the contents of the course,organizing the chosen contents of the course,and planning the course schedule.At the improvement stage,the proposed course is improved,reviewed,and evaluated by experts from both the construction industry and academia through a detailed feedback process.From this systematically developed sustainable construction course,students in construction programs can learn basic knowledge of sustainability and the importance of sustainable design and construction.They will be exposed to different sustainable building rating systems such as Leadership in Energy and Environmental Design(LEED)and Green Globes,collaborative skills among construction participants,and the advantages and pitfalls of sustainable construction.In addition,construction students who become leaders in the industry will change the nature of the construction industry and society to help not only minimize environmental impacts caused by construction activities but also to secure our earth.

GREEN LUXURY:A CASE STUDY OF TWO GREEN HOTELS

The hotel industry is beginning to implement green design and construction practices,saving energy,water,and resources and thus helping to preserve the environment.In addition,green building practices also can provide healthy and comfortable indoor environments to hotel occupants including guests and employees.However,there is the potential for conflict between green building practices and hotel guests’satisfaction and comfort,as the conservation of resources could detract from the quality of a guest’s visitor experience.This study adopted a case study approach to identify and analyze green design and construction practices that create a green and luxurious environment without damaging the hotels’financial position.An in-depth literature review was conducted to identify green design and construction practices,design features of premium hotels,and major design conflicts between the twin goals of green building and a luxurious hotel environment.Two LEED platinum hotels(the Proximity Hotel and the Bardessono Hotel,both in the United States)were selected and data collected on their green design and construction practices,luxurious design features,and operation and maintenance practices from multiple sources,including the owner,designer,contractor,engineer,and LEED consultant.From the perspective of the entire lifecycle of the building,this data was analyzed to identify green design and construction practices that not only provide a green,luxurious environment but also enhance the hotels’financial strength.

THE GREENING OF AFFORDABLE HOUSING THROUGH PUBLIC AND PRIVATE PARTNERSHIPS: DEVELOPMENT OF A MODEL FOR GREEN AFFORDABLE HOUSING

The trend towards affordable, green housing highlights the need for a Green Affordable Housing (GAH) model that produces durable dwellings that are not significantly more expensive to build, cheaper to operate, healthier for their occupants, and more environmentally sound. The model should also reduce the risk of poverty for those with low and moderate incomes, be close to public transportation, and support a neighborhood that is healthy, walkable and connected to the broader community and natural environment. This case study utilized detailed interviews with occupants, town officials, a developer, and a design builder to explore how green building strategies could be applied in real-world communities with the help of a Community Development Block Grant (CDBG) from the U.S. Department of Housing and Urban Development (HUD) and contributions from other funding bodies. Focusing on the Roanoke and Lee Street housing project in Blacksburg, Virginia (VA), this study demonstrated how green building strategies can be integrated into affordable housing with help from public programs and incentives to provide houses that are more durable, no more expensive to build, cheaper to operate, healthier, more environmentally sound and less risky for their occupants. The new framework includes ways to deal with neighborhood issues such as the deterioration of housing stock and infrastructure to support the creation of a vital and healthy neighborhood with improved public services and community spirit, as well as providing an integrated design process framework that enables stakeholders to work together to achieve the goal of building green and affordable housing.

DESIGNING SUSTAINABLE LEARNING ENVIRONMENTS:LOWERING ENERGY CONSUMPTION IN A K-12 FACILITY

The construction industry is embracing sustainable building practices that boost the“triple bottom line”,namely the building’s ecological,social,and financial performance.Since more than 55 million US students spend a significant part of their day in K-12 schools,it is vital that these facilities should provide healthy,comfortable,and productive learning environments.Here we present an in-depth literature review of how educational facilities affect student school performance,comfort,and health,and we examine the role of sustainable design and construction strategies in influencing the physical learning environment in schools.Significant barriers to implementing sustainable strategies are examined,particularly the first cost premium of a sustainable building.A systematic decision strategy is described that incorporates sustainable design strategies,lowering energy consumption and improving indoor environments.A case study describes the process of incorporating sustainable strategies in a K-12 education facility in North Carolina to lower annual energy consumption and greenhouse gas emissions.Ways to reduce the first cost premium and minimize operating costs over the facility’s life while providing healthy and comfortable learning environments for students and teachers are discussed.The case study school also functions as an experimental learning tool for teaching sustainability to K-12 students,having the potential to improve their attitudes and behavior with respect to sustainability.

BUILDING FOR THE FUTURE:UNITED NATIONS APPROACH FOR THEIR BUILDINGS

INTRODUCTION The term“Sustainable Development”was first used in the Brundtland Report from the United Nations World Commission on Environment Development(WCED)in 1987.In this report,sustainable development was defined as“development that meets the needs of the present without compromising the ability of future generations to meet their own needs.”

GREEN CONSTRUCTION:CONTRACTOR EXPERIENCES,EXPECTATIONS,AND PERCEPTIONS

As the benefits of green building continue to change the Architecture/Engineering/Construction industry and the num-ber of green projects rises in the United States due to market changes,more constructionfirms are gaining experience with this new way of building and changing their expectations for new hires from degree-granting construction pro-grams.This paper documents a baseline study of contractor experiences,expectations,and perceptions associated with green building conducted in Fall 2006.The study was based on detailed survey results from 87 different companies re-cruiting from three major university construction programs in the eastern United States(Auburn,Purdue,and Virginia Tech).The survey collected data regarding current experience levels and capabilities of companies with regard to green construction,corporate expectations of new hires in terms of green construction knowledge and skills,and respondent ex-pectations and perceptions about the future of the industry with regard to green projects.Thefindings of this study sup-port the growing importance of green building as a component of the whole construction market and provide a bench-mark against which to measure future changes in the industry over time.