Artificial neural networks and naturally ventilated buildings

The author found that the results obtained were reliable and indicates that neural networks can be used as a predictor for investigating window opening configurations to study the effects on interior air motion. Further study is needed in the development of the database to cover wider architectural parameters and the implementation of new types of network is also needed, as well as the need to consider variation spatial coefficients more fully.     

基于离散单元法的混凝土细观力学模型研究进展

介绍了离散单元法用于混凝土细观结构数值模拟的优越性及其基本原理;总结了目前基于离散单元法的刚体-弹簧元模型、扩展的离散单元法、颗粒-界面元模型、梁-颗粒模型等常用模型的原理、研究现状、成果,以及各自的优缺点;对数值模型建立中应考虑的关键问题,如破坏准则、本构关系以及材料参数的确定方法等作了归纳分析.指出目前离散单元法用于混凝土数值模拟的研究主要以二维模型、简单受力状态、定性分析为主,而在复杂受力状态、定量分析、随机性分析以及相应实用软件的开发等方面仍有待进一步研究.     

A framework for the future of urban underground engineering

A special and holistic approach is needed that captures aggregate attributes and emergent behaviors of the complex system of infrastructure systems in a region. Effective management of the impacts of future population growth, urbanization, and risks arising from continued evolution of our natural, physical and human/societal systems will require a systematic exploration and characterization of the urban subsurface, including much improved understanding and assessment of geologic risks. With recent cost escalations for underground construction projects, incentives are needed for the underground construction industry to develop and implement innovations in methods and technology, and smart integrated planning is needed to reduce costs both during construction and with life-cycle engineered design and operation of our subsurface facilities.The needed framework requires investigation of potential metrics that reflect the performance of aggregate functions of an urban environment so that we can holistically study system performance response under “normal” and “stressed” operation. Such a metric can support a cross-disciplinary exploration of urban resilience, and build knowledge as we develop and test theory and models that explore resilience of complex socio-technical systems. Econometrics with spatial and temporal granularity will help to understand the integrated functionality of our cities and to establish appropriate policies that will drive continuous improvement in the quality of urban life while providing natural, human, and physical urban environmental resilience. The underground in urban regions can become an important component of managing the increasing complexity of our physical systems, and can also make more significant contributions to improving the robustness and resilience of our future cities.     

利用表面自由能法对添加消石灰的WMA水稳定性的研究

温拌沥青混合料在摊铺行业应用越来越多。尽管温拌沥青有许多优点,水稳定性是温拌沥青混合料潜在的不利因素之一,所以有必要在这一领域进行更多的研究,以提高温拌沥青性能。在研究中,熟石灰作为改善沥青混合料的水稳定性的抗剥落剂,用表面自由能法对集料和沥青之间的粘结性进行了分析。该实验采用了石灰岩和花岗岩两种类型的集料,并用asphamin作为温拌剂,熟石灰作为抗剥落剂。结果表明,熟石灰增加了沥青对集料的浸润性,提高了沥青和集料之间的附着力。添加消石灰的样品,沥青-集料与水-集料的表面自由能相差不大。这说明如果发生剥落则需要更多的能量,也就是消石灰提高了温拌沥青混合料的抗水损害性能。     

Organization for Urban Planning: Some Barriers to Integration

Some writers contend that metropolitan decentralization is a new phenomenon; others insist that it is a pattern of long standing. Although fraught with problems of measurement, a historical-statistical investigation throws some new light on the question. The results offer some solace to both camps; although decentralization appeared a century ago, it did not become a widespread pattern until after World War II. What is needed now is a return to the theoretical insights of earlier writers and research geared to the study of the metropolitan community as the spatial expression of a complex social system.     

Energy, economic and environmental (3E) analysis of a micro gas turbine employed for on-site combined heat and power production

This paper studies the optimization of micro turbine application to meet the electrical, heating and cooling loads of a building by energy, economics and environmental analysis. In this study following three cases are considered: 1: A simple micro gas turbine to meet the electrical power of the building. 2: A simple micro gas turbine to meet the electrical power of the building as well as the power required by heat pump and mechanical refrigerator needed for heating, cooling and domestic hot water (DHW) systems. 3: A CHP micro gas turbine to meet the electrical power of the building as well as part of the power required by heat pump and mechanical refrigerator needed for heating, cooling and DHW systems. The remaining part of the power for heat pump and mechanical refrigerator is provided by the exhaust gases.The research shows that the initial investment is a considerable portion of electricity cost. For an annual interest rate of 10% this portion ranges from 31 to 40% depending on system design configurations, and the lower interest rates results in the smaller portions. It is also concluded that the number of turbine units and electricity cost are highly depended on electricity consumption management.     

Effort and effectiveness considerations in computational design evaluation: a case study

Computational building evaluation tools have the potential to provide an effective means to support informed design decision making. Computational modeling, however, comes with a cost. Thereby, the most important cost factor is not software acquisition, but the time needed for learning and using the software. The extent of required time and effort is believed to be one of the main hindrances toward the pervasive use of computational building performance assessment tools by designers: Currently, modeling applications are mostly used, if at all, in the later stages of design and by specialists, rather than architects. However, few studies have explicitly dealt with the ascertainment and quantification of the actual effort needed to understand, master, and apply computational building evaluation tools. Thus, little factual information is available as to the cost and burden of computational building evaluation and its effectiveness in building design support. In this context, the present paper describes a case study, whose motivation was to estimate the time and effort needed by novice designers to computationally evaluate the performance of building designs. A group of senior architecture students participated in the study, learning and using a software application to assess the energy performance of six project submissions for a school building design competition. The outcome of this study (time investment ranges for various components of the modeling activity) was evaluated and further extrapolated to estimate the effort needed for a more comprehensive computational assessment of the environmental performance of these designs.     

Modelling the thermal performance of buildings

The mathematical model developed by Shaviv and Shaviv for predicting the thermal performance of full scale buildings is used to improve the design of a particular house. The climatological data needed for the calculations are described as well as other technical data.A case study is brought as a numerical example in which a particular design with architectural constraints is improved step by step so as to obtain thermal comfort in summer with minimal energy consumption.     

Standardized tests fail to assess the effects of antibiotics on environmental bacteria

Pharmaceuticals are designed and used because of their specific biological effects. Over the past decade, compounds from various classes of pharmaceuticals have been detected in the environment. Concern has grown about the adverse effects pharmaceuticals in the environment might potentially have on human and ecological health. A sound risk assessment is therefore urgently needed for pharmaceuticals. Standardized tests for assessing the effects of chemicals on environmental organisms are widely used for this purpose. However it is questionable whether classical standardized tests give reliable data needed for environmental risk assessment. In this study we investigated the suitability of the respiration inhibition test OECD 209 for the assessment of the effects of antibiotics, disinfectants and cytotoxics on sewage sludge bacteria. We found that inhibition concentrations can strongly depend on the test period and the type of compound. We conclude that tests to assess the effects of pharmaceuticals on environmental organisms such as bacteria have to be evaluated before their results can be used in environmental risk assessment.     

Construction Techniques of Wooden Dwelling Column Frame in Tibetan Regions of Yunnan Province,China

Column frame of folk dwellings with slope roof in Tibetan regions of Yunnan Province was studied. Through field investigation and surveying, column frame timber, main components and construction techniques were introduced. The research showed that column frame of slope-roof dwelling in Tibetan regions of Yunnan is a regional construction technique using timber as the major materials, tenon-and-mortise work as the major connection, characterized by excellent structural expandability, and shock resistance, but it has no quantitative technical support. Scientific and systemic study is needed to improve safeness and livability of local dwellings.     

Residents' Experiences in Condominiums: A Case Study of Australian Apartment Living

This research examines issues facing resident owners purchasing and living in condominiums in a major Australian tourist destination. The authors argue that the trend towards urban consolidation presents challenges for purchasers who buy ‘off the plan’ with the intention of self-occupation of apartments. Using a qualitative approach involving in-depth interviews of residents, the study identifies four main areas of concern for resident owners. Issues such as residential use, zoning, dispute resolution and the role of the caretaker are discussed. The study concludes that action is needed in order to reform body corporate legislation and to encourage local authorities to discharge responsibilities not just for planning but also for land use.     

Automated sensor-driven mapping of reinforcement bars

Non-destructive mapping of reinforcement in concrete elements of old buildings may be needed when changes or extensive maintenance is required. It is always needed when reliable design drawings are not available. The mapping will indicate the location of reinforcement bars and their diameters and depths of cover. The objective of the study presented here was to develop a reliable method for automated mapping of reinforcement bars. The methodology included a review of sensing devices, selection of a reliable sensing device for detecting reinforcement bars in concrete, and development of algorithmic procedure for manual and automated mapping of the reinforcement, based on the features of this tool. The sensor selected for this study was an electromagnetic covermeter. The automatic mapping mode proceeds in two major phases: (i) point determination of a bar; and (ii) straight and bent bar mapping algorithm. The algorithm was tested on a set of rebar configurations by simulation and by full-scale experiments. The results of manual mapping showed that the tolerance of the location measurement does not exceed 5 mm. The automated mapping procedure appears to be robust and reliable, and its mapping tolerance does not exceed 10 mm. Running times of automatic mapping are half as long as those of manual mapping. The efficiency of the automated mapping is expected to be higher for mapping of large surfaces.     

Comparison of sensor systems designed using multizone,zonal, and CFD data for protection of indoor environments

Sensors that detect chemical and biological warfare agents can offer early warning of dangerous contaminants. However, current sensor system design is mostly by intuition and experience rather than by systematic design. To develop a sensor system design methodology, the proper selection of an indoor airflow model is needed. Various indoor airflow models exist in the literature, from complex computational fluid dynamics (CFD) to simpler approaches such as multizone and zonal models. Airflow models provide the contaminant concentration data, to which an optimization method can be applied to design sensor systems. The authors utilized a subzonal modeling approach when using a multizone model and were the first to utilize a zonal model for systematic sensor system design. The objective of the study was to examine whether or not data from a simpler airflow model could be used to design sensor systems capable of performing just as well as those designed using data from more complex CFD models. Three test environments, a small office, a large hall, and an office suite were examined. Results showed that when a unique sensor system design was not needed, sensor systems designed using data from simpler airflow models could perform just as well as those designed using CFD data. Further, only for the small office did the common engineering sensor system design practice of placing a sensor at the exhaust result in sensor system performance that was equivalent to one designed using CFD data.     

“风格”的来源——150年中国近现代建筑探索的收获

建筑以人为本,风格当随时代,这两个基本原则揭示了建筑界的一个普遍＂常识＂,即＂风格＂是果,不是因。历时150年的中国近现代建筑＂新风格＂探索历程说明：中西成熟的建筑＂风格＂不是中国现代建筑＂新风格＂的来源;当代中国建筑应该放弃无果的＂风格＂借鉴,思考如何做到以人为本和风格紧随时代,专心研究当代中国人及社会对建筑所提出的真正要求如此,中国当代建筑的＂新风格＂就会自然而然地生长出来。     

隧道病害分级的现状及问题

随着我国隧道建设的快速发展，隧道病害问题日益突出。为了对隧道检测结果进行综合分析以便科学地评价隧道病害状况和提出切中要害的整治方案，就需要对隧道病害程度进行恰当的分级。本文对国内外隧道病害分级现状进行了综述，对衬砌裂缝、渗漏水、衬砌剥落、衬砌材质劣化、衬砌变形、冻害、鼓出、翻浆冒泥等病害的分级方法进行了详细的分析，最后提出了在隧道病害分级中还需要进一步研究的问题。     

A Comparison between Industry’s and Academia’s Perceptions of a Career in Construction Education

It is well documented that real-world experience is essential in teaching the applied sciences. However, it has also been shown that faculty positions are being filled with candidates with strong research agendas but less industry experience. The aim of this study is to understand what industry’s perception of a career in academia is like and compare it to the perceptions of those actually in the profession. This is viewed as a needed first step in attracting more industry practitioners into construction education. The study surveys practitioners and faculty on how satisfying a career in CM academia is at meeting 16 factors identified as important to overall job satisfaction. The responses of both groups were compared to evaluate where industry’s perceptions did not align with those of faculty. The study also compared the workplace attributes that industry indicated they valued most and what faculty indicated a career in education provided. The study found that a terminal degree, interest in research and publishing, interest in teaching, and salary were the greatest barriers for industry practitioners to enter CM academia. The comparison of work place priority and barriers to entry was used to provide potential strategies to encourage more industry practitioners into CM education.     

后工业时代中国产业类历史建筑遗产保护性再利用

产业类历史建筑及地段的保护性改造再利用是我国当今城市发展建设面临的一个迫切需要解决的重要科学问题。文章通过对国内外该领域近年的发展前沿动向和实践的回顾,探讨了产业类历史建筑及地段的保护性改造再利用的必要性和科学意义,分析列举了在中国实施保护和改造再利用研究的基本内容,指出经由对产业类历史建筑及地段实践层面上的实证研究,提出具有现实技术针对性的改造设计方法、评估原则和技术规范要点为中国当前之必须。     

浅谈工程建设项目各阶段投资管理与控制

对工程建设项目前期调研、设计、施工、竣工验收各阶段的投资管理与控制进行了阐述,指出在项目前期要充分调研,确定合适的建设规模及建设标准,同时要推行限额设计,在施工中严格设计变更,还需建立严格审计制度,从而把工程投资控制在概算范围内。     

Capital efficiency, its measurements and its role in regulatory reviews of utility industries: Lessons from developed and developing countries

Designing regulatory regimes that incentivise the delivery of agreed capex at as low a cost as possible has proven relatively straight-forward when it is possible to establish credible forecasts of the necessary capex and its associated cost. Greater problems arise when there is uncertainty about what capex is needed, when it may be needed and how much it will cost. Yet it is still possible to establish incentive based systems for regulating capex with some or all the characteristics that create uncertainty. This paper explores some of the issues related to incentive based regulation of capex and how flexible approaches can be developed to handle the uncertainty inherent in certain types of capex. Examples of incentive based systems are also provided.     

空间经济绩效导向下的城市用地布局优化研究

空间绩效是衡量城市用地布局合理与否的重要内容。本文基于我国城镇化质量提升的转型发展背景,提出空间经济绩效导向下的城市用地布局优化研究思路,即在定量研究分析城市空间经济绩效的基础上,通过经济绩效和绩效空间的耦合分析,判读出城市绩效样本空间(高效空间生成元)和改进需求空间的分布情况,并以此作为构建新的城市空间经济绩效网络的依据,最后在地方制度环境和社会环境的约束下提出城市用地布局的优化方案。研究将这一理念和方法运用于宁夏固原市的案例研究中,结果表明:该方法能够较好地实现研究定量化和空间可视化,并为城市用地的优化布局提供方法支撑。