Dissertations / Theses on the topic 'Decay of buildings'

Leaky buildings are those that show elevated moisture contents of the framing timber, which can subsequently lead to the establishment of fungal and bacterial decay. Prior to this study, the causative agents of the decay in these leaky buildings were unknown, though it was suspected to be one or more species of decay fungi. Therefore, the overall goal of this multi-disciplinary PhD thesis research was to determine the causative agents of decay in leaky buildings of New Zealand in an effort to develop solutions for both their remediation and future prevention. Use of molecular biology methodology and classical mycological techniques based on morphology enabled identification of decay fungi from framing timber and air samples of leaky New Zealand buildings and provided insight into relative importance based on isolation frequency. In most cases, fungi colonising Pinus radiata D. Don were isolated to produce pure cultures. Mycelia from these cultures on agar media were collected to extract DNA. To identify the fungi to the species level, polymerase chain reaction (PCR) with fungal specific DNA primer pairs were performed followed by DNA sequencing of the internal transcribed spacer (ITS) region. Identification was by BLAST (Basic Local Alignment Search Tool) search on sequences in known GenBanks. In total, 421 samples from leaky buildings were processed, predominately untreated P. radiata decayed framing timber and also fibre cement boards and building paper. From these, sixty-eight fungal identifications were made. The only taxa that were isolated with significant frequency were identified as 4 basidiomycete species, as follows, along with the number of times they were isolated from the 421 samples: • Gloeophyllum sepiarium (Wulf.: Fr.) Karst. 13x • Oligoporus placenta (Fries 1865) Gilb. In Ryv.1985 11x • Antrodia sinuosa (Fr.) Karst. 8x • Gloeophyllum trabeum (Fr.) Murr. 4x Although these species were identified repeatedly, in total they represent less than 10% of the total samples and, therefore, it is concluded that the leaky building decay samples represent high fungal biodiversity. An aerial spore study of internal air, wall cavity air and exterior air of leaky buildings was carried out using a Merck MAS-100 instrument which collects spores directly onto selective media plates. Viable fungal aerial spores were detected at every sampling location tested at the leaky buildings, by the criteria of culturing, with a highest mean of 3714 colony-forming units (CFU) per cubic metre found in the cavities of water-damaged walls. This aerial spore study in conjunction with isolation from decayed wood samples from the same leaky buildings enabled identification of G. sepiarium and A. sinuosa at the same test site. The use of carboxymethylcellulose medium further demonstrated the presence of potential cellulose-degrading fungi within and around the location. Overall, the combination of direct sampling of timber and air sampling proved useful for detection of fungal species variability at a multi-unit building. Four decay fungi isolated from New Zealand leaky buildings and two standard control decay fungi (Coniophora puteana and Serpula lacrymans) were submitted to laboratory wood block testing to determine the effectiveness of currently used wood framing preservatives under laboratory conditions before and after a standard leaching regime. P. radiata blocks were treated with water based boron copper azole and solvent based IPBC propiconazole plus tebuconazole (1:1) preservatives and exposed to the basidiomycetes for 12 weeks. Mass loss for the fungal decay-infected samples was recorded of up to 55% for preservative-treated samples, up to 62% mass loss for leached samples and up to 58% mass loss for un-preservative treated samples. Additionally, well defined dosage responses and approximate toxic thresholds were obtained for all preservatives tested. Results suggested that the minimum IPBC retention specified by Hazard Class 1.2 of NZS3640:2003 (0.025% m/m) is on the low side, and demonstrated after the 2 week leaching regime complete loss of efficacy of boron at 0.4% m/m boric acid equivalent (BAE). This PhD research gave a first overview of fungi occurring in New Zealand leaky buildings, and it demonstrated the following key aspects of wood preservation: 1. The isolated test fungus Antrodia sinuosa was more difficult to control with propiconazole plus tebuconazole at retention 0.007% m/m than the known tolerant fungus Oligoporus placenta; 2. Boron at Hazard Class 1.2 retention of 0.4% m/m BAE was not toxic to Oligoporus placenta; 3. Serpula lacrymans exhibited tolerance to the highest retention of 0.06 %m/m tebuconazole plus propiconazole; and 4. Gloeophyllum species appeared susceptible to all wood preservatives. In order to correlate fungal colonisation and wood decay, colonised wood blocks were studied using light microscopy (LM) and field- emission scanning electron microscopy (FE-SEM). Microscopic observations of P. radiata wood blocks following a standard wood decay test of twelve weeks of fungal colonisation by Serpula lacrymans, Antrodia sinuosa, Oligoporus placenta and Gloeophyllum sepiarium revealed that the two microscopic techniques employed were complementary by allowing features such as pit membranes, chlamydospores or S3/S2 compound middle lamella interface to be photographed in greater detail, allowing for more precise analyses and interpretation of key findings, as follows: 1. Brown rot fungi directly target their apical growth towards degraded pit apetures; 2. Reliance on light microscopy and observed birefringence as a tool to record changes in cell wall crystallinity associated with brown rot decay alone could be misleading; 3. Presence of fine (≤ 1 m) to wide (≥ 3.5 m) bore-hole and hyphal size ranges, and nearly unchanged cell wall thickness of all wood/test fungal combinations, confirmed active decay at moderate to late stages; 4. Some ray parenchyma cells for Antrodia sinuosa, Oligoporus placenta and Gloeophyllum sepiarium colonised blocks were intact throughout late stages of decay, outlining that they were not preferentially degraded early in the brown rot decay process, and 5. Presence of bore-holes, clamp and medallion clamp formation and resting spores (chlamydospores and arthrospores) are fungal specific, can aid in their differentiation and identification, and should be recorded during wood decay studies, as especially resting spores are an important factor when planning remediation strategies. In summary, this PhD thesis research provided the first comprehensive investigation into the biodiversity of fungi from leaky New Zealand buildings, identified the dominant species and presented details about their micromorphology and their decay patterns. It also demonstrated substantial differences in efficacy of preservative formulations currently (December 2008) approved for framing treatments in New Zealand and possible deficiencies where framing may be subjected to severe leaching. This study also provided the first comparative analyses of viable fungal aerial spores between leaky wall cavities and the surrounding air environment. Subsequently, this research added to the knowledge of the decay fungal species diversity in and around New Zealand leaky buildings, outlined their capabilities to degrade treated and un-treated P. radiata framing timber and illustrated the efficacy of New Zealand approved wood preservatives for their potential as remedial treatment and future prevention.

Urban decay is among the most urgent problems in Hong Kong today. There are more than 3,000 blocks of building are considered sub-standard and 110,000 families are living in these homes. Despite the Government's immense effort in undertaking its own renewal projects for many years, Hong Kong Housing Society (HKHS) was the earlier urban renewal agent whom was invited by the Government to undertake redevelopment in the urban areas. In light of the rapid ageing of Hong Kong' building stock during the last two decades, HKHS has further assisted the Government with its own resources and expertise by implementing a 10-year maintenance incentive named "Building Management and Maintenance Scheme" (BMMS) since 2005. The BMMS aims at encouraging property owners to improve safety and hygiene of their living environment, it is administrated by HKHS with the provision of professional advice and financial assistance for publicizing proper building management and timely maintenance. HKHS has exerted all its strength to promote the BMMS for seven years, the research is to gauge the effectiveness of HKHS for the achievement and shortcomings in the aspect of offering building maintenance incentives, particular in the launch of BMMS. The evaluation will focus on the three aspects, including the scheme performance, scheme design process and implementation process. An opinion survey was conducted in June 2012 for the data collection purpose and survey results correlates with the goals and objectives of the study are comprehensively discussed in Analysis I & II. The findings show the effectiveness of HKHS in offering building maintenance incentives much depends on what stage does the scheme undergo, whilst the BMMS in general is operated effectively to address the problem of urban decay, with the exception of running it at the outset of the scheme design stage. In the course of time, the recommendations pursuant to the weakness of the BMMS and the highlights in survey findings are drawn up at the end of the study, in order to make the building maintenance incentives more effectively in solving the urban decay problem.
published_or_final_version
Housing Management
Master
Master of Housing Management

Measurements of the external pressure coefficients around open and sealed 1:20 scale models of a low-rise, naturally ventilated building with a gable roof for livestock housing were made in the NRCC wind tunnel. In addition, the internal pressure coefficients were recorded within the open models. All structural configuration changes of the building had an effect on: the external pressure coefficient distributions, calculated and measured internal pressure coefficients, air inlet and outlet zones, magnitude of the local airflows through individual openings, and on the calculated ventilation rate coefficients. As well, there were considerable differences between results for the sealed and open models especially at the ridge level. Generally, the comparisons between the ventilation rate coefficients of the open and sealed model suggest that the larger the total sidewall, end wall and ridge opening areas were, the greater the discrepancies were between open and sealed models' predictions. (Abstract shortened by UMI.)

Rising damp is an almost inevitable and hazardous phenomenon for historic buildings. This phenomenon, which already exists in buildings (to a lesser or greater extent), accelerates when faced with disasters that dramatically increase the water content within the building. While researchers are developing new monitoring methods to examine the effects of rising damp on structures effectively, organizations are designing new risk management plans to minimize the impact of disasters to which cultural heritages are exposed. The case study presented in this thesis includes studies carried out in the Byzantine church of Santa Croce in Ravenna, Italy, which was exposed to rising moisture from flooding due to soil submersion. By analyzing the samples collected from the church, the extent of the decay was determined. Moreover, a new method ensured that the monitoring of moisture in the church was reliable. The data obtained can be used to support the multi-disciplinary studies carried out in the church of Santa Croce, which was selected as part of the EU Horizon 2020 SHELTER project.

The role of bacteria in the decay of building stone from ancient monuments was examined using the framework of Koch's postulates. This involved a stepwise approach to investigate the occurrence, nature and decay potential of bacteria on stone. Prior to investigating the occurrence of bacteria on stonework it was necessary to develop a standardised procedure of high precision for the recovery and enumeration of these bacteria. A number of different methods to remove bacteria from stone were studied including physical agitation, chemical desorption and surfactant treatment. Finally a method was adopted in which stone samples were powdered, homogenised in a dilute solution of surfactant (Tween 80) and counted on an automatic plating system. A range of growth media were used to examine three different bacterial types, namely, sulphur-oxidising, nitrifying and heterotrophic. To investigate the occurrence and distri but10n of bacteria on both sound and decayed stone extensive bacteriological surveys were conducted on stonework at two monuments, Portchester Castle and Tintern Abbey. All types of bacteria were widely distributed on both sandstone and limestone at the monuments. At each monument, significantly more sulphur-oxidising and heterotrophic bacteria were associated with severely decayed stone than undecayed stone. Electron microscopy confirmed that large populations of bacteria could be found predominantly 5-10mm below the surface of decayed stone. Approximately 200 bacteria were isolated into pure culture during the field surveys of the two monuments. All isolates were screened for decay potential using a liquid culture system involving static growth of bacteria in the presence of 1cm stone discs. From the 200 isolates, about 30 were capable of causing substantial weight loss in sandstone discs under heterotrophic conditions. Five isolates were able to cause a large weight loss using only mineral nutrients. Some isolates caused a significant weight gain in the stone discs under these conditions. Statistical analysis of the data from this decay screen indicated that weight loss of stone could be directly correlated to a decrease in pH of the medium and a release of calcium and silicate from the stone. Futher decay studies carried out on selected isolates suggested that under heterotrophic conditions the bacteria secreted quantities of organic acids in to the medium which could attack the stone. However, in the presence of an inorganic nutrient source, the generation of mineral acids may be involved. Under both conditions different stones had varying resistance to bacterial decay and this appeared to be dependent upon the level of calcite in the stone. Specific antibody techniques such as BLISA and FAT were examined and proved very useful in demonstrating the presence of certain principal decay species on samples of decayed stone.

Delays are a common feature of construction projects and frequently lead to disputes between the parties. In resolving these disputes it is essential to have a robust methodology for analysing delays. It is argued that current understanding of available delay analysis methodologies is inadequate and hindered by taxonomic confusion. There is a need for guidance on available delay analysis methodologies and an explanation of how these are implemented, and, as a result, models have been proposed that aid practitioners in the selection of a defendable and most appropriate delay analysis method under the specific circumstances of a project. This suggests an element of choice over the method to be selected: for example, the Society of Construction Law recommended the Time Impact Analysis methodology for undertaking a retrospective delay analysis. The question is whether this or any such methodology is necessarily appropriate. There is general confusion over the selection of delay analysis methodologies. Here, it is proposed that this confusion can be reduced and delay analysis improved by an analysis of the latest research on the status of delay analysis in the UK, an analysis of common law guidance on methodology, an assessment of professional and research literature on delay analysis and research into what is being currently undertaken by experts in the field of delay analysis. This has been done using a mixed methods approach that included: (i) analysis of a questionnaire survey by the CIOB to understand the current state of time management in the UK construction industry; (ii) analysis of the industry guidance on delay analysis methodologies; (iii) a comprehensive review of related English Case Law; and (iv) an analysis of 27 case studies comprising programming expert reports that were presented as evidence in arbitrations. These multiple sources enabled the researcher to ascertain, in the case of each delay analysis methodology: (a) the dominant method actually used in disputes; (b) the details of its application; (c) the reasons for its selection; and (d) its level of accuracy and subsequent acceptability. The research demonstrates that when time claims are accompanied by cost claims there is a dichotomy in the choice of appropriate methodology. There is a clear preference for prospective analysis of time issues, but a retrospective approach for claims that involve finance. At the same time, when a claim contains both elements, the courts appear to prefer a single approach, namely, the retrospective approach. This has resulted in the recommended method of undertaking delay analysis by the Society of Construction Law being not supported by English common law and ultimately to an increase in confusion within the Industry. Given the courts’ fundamental opposition to a method that better accords with forensic logic, it is expedient to recommend a ‘best of the rest’ method for delay analysis rather than adopt a formulaic approach to selecting the appropriate delay analysis methodology. Case study reviews have shown the Windows Analysis methodology is widely used and this is also widely accepted as the most accurate and appropriate methodology, although less well known than other less appropriate delay analysis methodologies. Apart from its theoretical significance, the research should improve construction practitioners’ understanding of delay analysis, and provide clarity on the evidence required to support a claim for an extension of time. It has the potential to reduce disputes over selection criteria and promote harmony between the construction and the legal professions over the appropriate method of resolving delay claims.

The present study firstly aimed to identify children with delayed reading who were missing the component skills of decoding fluency and who also displayed antisocial behaviour in the classroom. It also aimed to replicate with them an intervention designed by Church, Nixon, Zintl and Williams (2005). The study finally aimed to explore the question of whether children who have both a reading delay and a disruptive behaviour disorder require a reinforcement scheme to maintain their engagement in learning activities. Six participants worked with same-age peer tutors on specially-designed practice activities for approximately 20 minutes a day, four times a week, for 8-18 sessions. Improvement in decoding fluency and prose reading fluency was tracked for each child throughout the intervention. Results showed that the six participants gained, on average, sixteen months on their age-equivalent score for reading rate. Decoding fluency scores increased from a pre-test average of 16 correct graphemes per minute to 32 correct graphemes per minute at the post-test measure. Reading accuracy improved by an average of five months and reading comprehension by an average of six months. The gains in reading rate are most likely due to the practice opportunities afforded by the testing procedures as decoding fluency scores did not improve enough to have had a direct impact on the learners’ prose reading ability. Implications for remedial reading interventions with children with behaviour problems are discussed.

This is a methodology of ‘Building Pathology’ explained through theoretically and practically by applying it on a case study. The stages are developed from the references of the previous books knowledge, combined by following codes of Normal 1/88 and latest methods of rehabilitation and protection. The stages are followed with an order from Initial investigation of visual survey, continuing with diagnostic analysis based on the intrinsic causes due to the conditions of site and architectural errors, Extrinsic natural causes due to climatic, temperature, weather along with some anthropic condition caused by human actions. The results from the diagnostics are further classified according to class based on type of damage as structural and nonstructural. Another class based on nature of degradation mechanism as physical, chemical and biological. Final class based on Type of alteration as reversible and irreversible. The classified alterations are represented using the codes of Normal 1/88 which indicates the Hatching in AutoCAD with the exact dimensions of the case study taken. By using the AutoCAD file with exact dimensions and hatchings calculation of individual alterations is possible. By the Detailed analysis and esteemed calculations of alterations type of renovation can be suggested in an order as cleaning followed by repairs and strengthening finally protection measurements can be ensured. As from the suggested renovation and market price of material along with the present labor, technicians daily charge the final cost estimation can be calculated.

The construction industry suffers from many practical problems and challenges; most being related to construction management. One of the most common recurring problems in construction projects is delay. Delay is a primary factor that can have an effect on project duration, scheduled delivery date, as well as the overhead cost of the project. This study investigated the problem of delays in construction projects. The research focused on the combination of Building Information Modeling (BIM) and Last Planner System (LPS) together to measure the execution time of construction projects. The aim of this study was to determine whether using BIM and LPS together affect construction process delay differently than using BIM or LPS alone. The methodology of this study relied on data collection through administration of survey questionnaires to key players and participants at construction companies. Interviews were conducted with construction experts from four construction companies that used BIM and LPS individually in their system as case studies to verify and validate the findings. The outcomes of this survey will be helpful to construction practitioners to reduce delay in construction operations and to shorten projects duration.

Although patterns of African American and white women breast cancer incidence and mortality in St. Louis, Missouri is consistent with those seen elsewhere in the United States, rates vary greatly across zip codes within the city of St. Louis. North St. Louis, whose neighborhoods are primarily African American, exhibits rates of breast cancer mortality that are among the highest in the city and higher than the state as a whole. Based on information that up to 50% of women in North St. Louis with a suspicious diagnosis of breast cancer never enter treatment, we conducted three 2-hour group model building sessions with 34 community stakeholders (e.g., breast cancer survivors or family members or caregivers and community support members such as navigators) to identify the reasons why African American women do not begin or delay breast cancer treatment. Participant sessions produced a very rich and dynamic causal loop diagram of the system producing disparities in breast cancer mortality in St. Louis. The diagram includes 8 major subsystems, causal links between system factors, and feedback loops, all of which shed light on treatment delays/initiation. Our work suggests that numerous intersecting factors contribute to not seeking treatment, which in turn may contribute to African American and white disparities in mortality.

This thesis examined the delay causes of Malaysian public sector projects. Using a systematic approach, the researcher identified the main delay factors and categorised them into pathogens. The pathogens were matched with beneficial Supply Chain Management (SCM) tools and developed into a holistic SCM framework to facilitate improvements in Malaysian public sector projects. The researcher concluded that SCM is the potential saviour for the delay dilemma and that it is necessary for the Malaysian government to initiate the revolutionary practice.

The preservation of cultural heritage is, today, more than ever, a practice of remembering. Of researching the contact with the past, sometimes in very concrete forms. One of the major expressions of this linking activity is represented by the architecture, where memory becomes a visible, tangible and useful. Preserving the memory is preserving the link between our sense of civilization. Preserving, restructuring, consolidating are also productive practices, very complex ones if related with the new building productions. The practice of Restoration is very delicate and specific. This thesis aims to afford the thematic of those specificity, analyzing one case study: the Restoration of the church of Santa Maria del Torrione, in Ravenna. A little baroque church that, besides its dimensions, has the importance of a cathedral in therms of restoring the link between the objects and the city life of Ravenna.

Este trabalho de investigação destina‐se a conhecer a arquitetura em terra da Serra de Monchique, recolher informações que possam constituir as bases de um plano para a conservação futura deste património construído, assim como indicar métodos de conservação. São abordados aspetos arquitetónicos, como as tipologias e os métodos de construção mais especificamente a caracterização do solo, definição da capacidade resistente da taipa e métodos de estabilização da mesma. A investigação incide ainda sobre o comportamento da arquitetura de terra face aos sismos e aos incêndios, neste campo foram aprofundados conhecimentos já desenvolvidos no estudo do “lnventário dos danos resultantes dos incêndios ocorridos de 8 a 16 de Agosto 2003 e de 11 a 18 de Setembro de 2004” e da informação regional existente sobre os danos do terramoto de 1755, do “Inquérito aos prejuízos causados pelo sismo de 28‐2‐69 em habitações no Algarve”. /ABSTRACT ‐ The aim of the research is the knowledge of rammed earth architecture in Serra of Monchique and gather information for a future conservation plan of such buildings, as well as describing conservation methods for their rehabilitation. Architectural aspects, as typologies and building techniques are treated as do engineering ones such as soil characterization, definition of the resistant capacity of rammed earth and methods earth stabilization. The “survey of the resulting damages from the fires between 8 and 12 August 2003 and 11 to 18 September 2004" the information on the damages caused by the 1755 earthquake and from the “lnquiry of the damages caused by earthquake of 28‐2‐69 on households in the Algarve” as well as the most recent investigation on the subject were used to describe the behavior of rammed earth in situation of earthquakes.

Diploma thesis deals with the issue of terrrorism in relation to soft targets and subsequent assessment of the selected soft target in terms of possible terrorist attack. The objective is primary school Sirotkova in Brno. The assessment criteria was evacuation of the school as a whole and its individual parts. A risk analysis was performed for the object to determine real threats in which there were clasified the probability and extent of impacts of potential attacks. The most likely scenarios of the attack were identified, based on this analysis. These scenarios were subsequently implemented into an advanced numerical 3D model, where the evacuation was simulated within these scenarios. In the framework of the school assessment, the work focused on comparing three different approaches to the evacuation process. The evacuation process was compared according to parameters of experimental data obtained from the practise of evacuation of primary school with evacuation processes set acording to the parameters of fire standards CSN and international SFPE fire safety standards. The results of the individual simulations were processed with a statistically determined probability percentile. The outcome of the assessment was to determine the probable evacuation time of the school and its individual parts. Based on these results, there was performed a proposal to optimize the evacuation process of the school, which made the process more efective and shortened the evacuation time to minimalize the impact of a potential terrorist attack.

The main aim of the thesis was focused on hygrothermal simulation of critical details of two prefabricated wooden buildings - especially connections of the perimeter wall to monolithic foundations, respectively with waterproofing layer. The composition of the external walls of these selected buildings has quite different compositions and thus different potentials of drying integrated moisture from the components. Practical measurement of moisture weight-content was applied to the wooden bottom plate, which is in direct contact with the concrete slab structures. The influence of different design solutions on hygrothermal characteristics of the wooden plate was examined with regards to the risk of mould growth, analysis of mass loss due to the decay fungi and with the aim to estimate the durability of the studied details of prefabricated wooden houses. The subsequent research focused on the differences in physical and mechanical properties of natural spruce wood (Untreated, (-), A) and impregnated spruce (Treated, (+), B) using supercritical CO2 and its possible impact on wood protection for mould growth. Samples of identical Untreated and Treated spruce were collected in the laboratory and subjected to thermal and hygrothermal experiments. The comparison of the resulting values of the individual experiments is presented. Required values needed for numerical calculations were obtained from these experiments. In conclusion, the summary of founded comparison is presented. The mould growth analysis and its influence on the durability of wooden structures offer a view of the behaviour of the structures. Relevant findings and recommendations for the future praxis are mentioned.

Purpose of engaged task is elaborate a functional mechanism to emergency brake for escalators company Otis. To this purpose is gradually reached up in several phases. In primary phase was taken view on similar products from competitive company and do not get in conflict with patent right, in second phase was needed delimitate working space for brake and exact specification of straining. In next steps the proposal and test phase is blending together. In this moment emergency brake has own shape and first tests are showing the functions, but as well necessity modification of same elements on brake and on escalator.

博士
國立中興大學
土木工程學系所
97
An optimal H∞ control algorithm was employed to design active tendon control system in reducing structural seismic responses in this dissertation. For H∞ control systems, it is widely understood that selection of control parameters αand γ control force execution time delay are two major issues to assure control performance and system stability. Thus, when examining the applicability of active control, these two factors have to be taken into consideration. Furthermore, the neglect of both torsion-coupling (TC) and soil-structure interaction (SSI) effects in real buildings may greatly degrade the performance of active control systems in practice. To consider above both issues, this dissertation consists of two parts. The first part proposes a design procedure on selection of optimal control parameters of time-delayed control systems. The second part deals with the soil-structure interaction effect on vibration control effectiveness of active tendon systems for irregular buildings. In the first part of this dissertation, the strategy to select both control parameters, α and γ, of H∞ control algorithm is investigated extensively to achieve optimal control performance. Analytical results show that decrease in γ or increase in α yields better control performance, but requires larger control forces. The selection range ofα and γ for a controlled system becoming overdamped or unstable is obtained. To assure system stability and better performance than LQR control, analytical expressions of the upper and lower bounds of α and γ are derived. Therefore, the seismic responses can be effectively reduced with an appropriate selection of α and γ. In addition, control force execution time delay cannot be avoided in real application of active control. Small delay time can degrade the control performance and may even cause system instability. Explicit formulae to calculate the maximum allowable delay time and critical control parameters of α and γ are also derived for the design of stable time-delayed control systems. The desired control performance can thus be guaranteed even with time delay. The second part of this dissertation analyzes the soil-structure interaction effect on vibration control effectiveness of active tendon systems for an irregular building, which is modeled as a torsionally-coupled structure, subjected to earthquake excitations. An active tendon system using H∞ direct output feedback control algorithm is applied to reduce the seismic responses of TC building structures. The pre-calculated frequency-independent and time-invariant feedback gain matrix based on a fixed-base model is obtained. Numerical simulation results show that the required numbers of sensors, controllers and their installation locations depend highly on the degree of floor eccentricity. For a large two-way eccentric building, a one-way active tendon system placed in one of two frames farthest away from the center of resistance (C.R.) can reduce both translational and torsional responses. The SSI effect is governed by the slenderness ratio of superstructure and by the stiffness ratio of soil to superstructure. When the SSI effect is significant, the proposed control system can still reduce the structural responses with less effectiveness than that of assumed fixed base model. Therefore, the TC and SSI effects should be considered in the design of active control devices, especially for high-rise buildings located on soft site.

碩士
淡江大學
資訊工程學系資訊網路與多媒體碩士班
104
In recent years, Taiwan''s college students often graduate delay phenomenon, in addition to personal factors deliberately delaying graduates, college students can check for completing credits, the school only provides summer course, and no other remedial or preventive measures. Once the students do not pay attention to their own course credit, the slightest negligence will easily lead to delay graduation. This study allows students to learn what courses to be filled as soon as possible to make up the missing credits, reducing delays graduation through early warning notification. In addition, the department supervisor and administrative units can also be through this mechanism, to understand students'' learning situation, early detection may delay graduation to help students successfully complete their education.

碩士
國立臺灣科技大學
營建工程系
106
In order to achieve a balance between quality and cost to create a sustainable building space, the construction project is required to pay more attention to the management of construction period, quality and safety at various stages. In view of the current ways to process the construction delays in domestic public construction projects, it is often treated by trement measurements such as the change of design, extension of schedule or compensation of management fee, or by means of the charge of delay penaty to the contractors. However, no matter what kind of treatment measurements is used, it cannot change the fact that these measuremtns result the influence on the delay of engineering project. Therefore, this study explores the influence factors that cause the construction delay at the tendering stage in order to prompt the planning and design unit to review the completion degree of the bidding documents and propose more suitable content. Therefore, it is expected to improve the performance process of construction project by controlling the beginning source to allivate the unnecessary change of design or construction disputes .

碩士
國立高雄應用科技大學
高階經營管理研究所碩士在職專班
106
Government agencies always aim at performing on schedule, of good quality, on budget controlling, and accident free when they execute public construction projects. In order to complete the project by meeting planned schedule and make a reasonable profit, contractors should do their best to crash the activities by taking costs and business reputation in consideration. Therefore, the government agencies and the contractors are in the same boat where both should collaborate to achieve mutual benefits. The government agencies have been building the petrochemical plants by applying the Engineering, Procurement and Construction (EPC) procedure and the most advantageous tender model to improve the efficiency and quality for a long time. However, there are still cases of not meeting project schedule and unable to complete on time. Due to the fact that the government agencies and the contractors have individual standpoints, if dispute happened, the government agencies would enforce a delay penalty or relinquish the contract. Many contractors think that they are treated unfairly by the incurred dispute mediation as well as arbitration and litigation. This study will not judge who is right or wrong but rather utilizing a case study of petrochemical plant building EPC project to demonstrate critical factors causing schedule delay. Through reviewing of related literature, interviews with specialists, and Delphi questionnaires, this study develops a framework of seven aspects and 28 factors for evaluating schedule delay factors. Analytic Hierarchy Process (AHP) was then implemented to compute the relative weights of the associated aspects and factors to identify the critical factors. The results show that the top three important aspects of schedule delay of petrochemical plant building EPC project are the environment, supervise and construction management. The most critical factor of schedule delay is that the construction permits were rejected. It is suggested that the results of this study could be provided to petrochemical EPC project as a reference and help create a win-win situation for the government agencies and the contractors.

Submitted in fulfillment of the academic requirements for the degree of Master of Technology in Construction Management, Durban University of Technology, Durban, South Africa, 2015.
On-time completion and conformity with assigned cost of every project are the most important factors in the success of project plans. Cost overruns and time overrun (delays) have been critical problems of many projects around the world in general and in South Africa in particular. The main objectives of this research are to assess the dominant causes of cost and time overruns, identifying possible and practical measures that can minimize overruns in office building construction projects around eThekwini Municipal area of Kwazulu-Natal. These objectives are achieved through the implementation of the research methodologies that are mainly literature review and questionnaire survey conducted to identify and evaluate the significant factors contributing to delay and cost overruns within the projects of interest. A review of literature identified eighty-five variables for delay, grouped in nine major categories and nine variables for cost overruns ranked in their order of importance in three sets based on the responses from the professionals working for the client, consultants and contractors. The agreement among the sets of rankings for delay and cost overruns has also been tested using statistical methods. The result indicates that there is strong agreement on ranking the importance of the individual variables of delay and cost overruns between parties. From each of the three sets of rankings, the twenty most important variables of delay and the three most important variables of cost overrun are identified as critical. Based on overall results, the top five most important causes are contractor’s cash flow problems, delay in progress payments by the client, poor site supervision and management by contractor, inefficient quality control by the contractor during construction leading to rework due to errors, and contractor’s difficulties in financing the project. Out of the 20 most important delay causing variables, three are found to be common between all parties. These are delay in progress payments by the client, delay in delivery and late ordering of material, and insufficient skill of labour. Furthermore, the study reveals that all stakeholders of construction parties are deeply involved in contributing to the causes of the problems. Thus, in order to eliminate or minimize cost and time extension of office construction projects in the eThekwini Municipal area, a joint effort based on teamwork is essential through effective project planning, controlling and monitoring which boils down to putting in place best practice construction project management.

Obstacles can occur on a project causing nonconformance in terms of time and cost. A Power Plant in Indonesia is being constructed and the project was still underway, when a delay was anticipated. In this case, the construction progress was only 13.1% on day-92, while it should have been completed around 26.4% to finish within 184 days. This thesis purpose is to identify and analyze the delay causes, by applying Critical Path Method (CPM) and Project Evaluation Review Technique (PERT) methods. Data concerning project activities and three estimation times were collected from internal reports and semistructured interviews, as follows: optimistic, most likely, and pessimistic durations. A project schedule and the critical path were computed by using Microsoft-Excel and Microsoft-Project software to operationalize PERT/CPM methods. These results were analyzed using of s-curve, network diagram and probability calculation, to anticipate the due date achievement level. The delay causes were collected by subsequent interview and treated by the Fishbone Analysis, which enabled the following categorization of failures: labor, machine, material, environment and method. These provided support for managers to take action. Finally, a discussion concerning the traditional methods of Project Management, i.e., Design-Bid-Build, suggests that Building Information Modelling (BIM) could generate better synchronization among stakeholders, by eliminating the major source of delays. Also, the Life Cycle Assessment was found necessary to decrease carbon dioxide emissions, so the building could achieve more sustainable performances. Moreover, integrating BIM, Building Energy Modelling and LC Energy Analysis was suggested to improve project sustainability.
Num projecto, há obstáculos que podem causar não-conformidades, no tempo e custo. No caso em apreço, antecipou-se um atraso numa Central Hidroelétrica em construção. No dia 92, o avanço da construção era de apenas 13,1%, enquanto deveria ter sido concluído 26.4%, para ser possível terminar o projecto em 184 dias. O objetivo desta dissertação é identificar e analisar as causas de atraso, aplicando o Critical Path Method (CPM) e a Progam Evaluation and Review Technique (PERT). Os dados relativos às atividades do projeto e às estimativas de tempos otimista, mais-provável e pessimista foram recolhidos em relatórios e entrevistas semi-estruturadas. O cronograma e caminho crítico foram calculados através do Microsoft-Excel e Microsoft-Project que operacionalizam os métodos PERT/CPM. Para antecipar o cumprimento da data de entrega prevista, esses resultados foram analisados através da s-curva, diagrama de rede e cálculo de probabilidades. As causas de atraso foram recolhidas por consequentes entrevistas e tratadas pela Análise-de-Espinha-de-Peixe, o que permitiu a categorização das falhas em mão de obra, máquina, material, ambiente e método. Finalmente, uma discussão sobre os métodos tradicionais de gestão de projetos, ou seja, DesignBid-Build sugere que o Building Information Modelling (BIM) poderia gerar melhor sincronização entre as partes interessadas, para eliminar a principal fonte de atrasos. Além disso, a Avaliação do Ciclo de Vida foi considerada necessária para diminuir as emissões de CO2, para que o edifício pudesse atingir um desempenho sustentável. Também foi sugerida a integração entre BIM, Building Energy Modeling e LC Energy Analysis para melhorar a sustentabilidade do projeto.