Space zoning concept-based scheduling model for repetitive construction process

Many researchers have studied effective space zoning to reduce the duration of a construction project and interference among work tasks. These studies, however, attempted to plan the construction schedule using the space zoning concept based on network-based scheduling methods. Accordingly, it was difficult to reflect the representative characteristics of space zoning, such as iteration and overlapping. To overcome such limitations of existing methodologies and to achieve schedule reduction of a construction project by maximizing productivity, a Space zoning Concept-based scHEduling ModEl (SCHEME) for repetitive construction processes that adopt simulation techniques was developed in this study. The result of the application of the developed model to actual construction cases shows that the model reflects well the space-zoning characteristics, and in terms of the reduction of the construction duration, the model yielded a superior outcome in nonspace-zoning cases. The model developed in this study is expected to produce an excellent effect on the repetitive construction processes, in terms of construction duration

BIM Application to Select Appropriate Design Alternative with Consideration of LCA and LCCA

Advancements in building materials and technology have led to the rapid development of various design solutions. At the same time, life cycle assessment (LCA) and life cycle cost analysis (LCCA) of such solutions have become a great burden to engineers and project managers. To help conduct LCA and LCCA conveniently, this study (i) analyzed the information needed to conduct LCA and LCCA, (ii) evaluated a way to obtain such information in an easy and accurate manner using a building information modeling tool, and (iii) developed an Excel spreadsheet-based framework that allowed for the simultaneous implementation of LCA and LCCA. The framework developed for LCA and LCCA was applied to a real building case to evaluate three possible alternatives for an external skin system. The framework could easily and accurately determine which skin system had good properties in terms of the LCA and LCCA performance. Therefore, these results are expected to assist in decision making based on the perspectives of economic and environmental performances in the early phases of a project, where various alternatives can be created and evaluated

Critical Review on Economic Effect of Renovation Works for Sustainable Office Building Based on Opinions of Real-Estate Appraisers

Despite increased renovation work for office buildings to improve energy performance, studies on the appraisal of renovated office buildings (ROB) are scarce. Thus, this study analyzed the perceptions of appraisers regarding renovation work and the effect of renovation work on the economic value of office buildings. Following a reliability evaluation, research results were derived using various methodologies, such as descriptive statistics, Chi-square analysis, analytic hierarchical process, and structural equation modeling, based on the survey results of 118 appraisers. The renovation work was found to positively increase an office building’s value, although the existing appraisal methods have low applicability considering the appraisal of ROB. On evaluating the importance of each factor considered in the ROB appraisal process, the factors related to the “location” of ROB were deemed more important than the attributes directly changed as a result of renovation work. Moreover, factors whose attributes were changed (e.g., working environment, green space, lease area, gross area of floors, number of floors, and number of parking spaces) were found to be critical factors affecting ROB value. The results of this study are expected to provide improvement directions for ROB appraisal methods and significantly aid building owners

Critical Review on Economic Effect of Renovation Works for Sustainable Office Building Based on Opinions of Real-Estate Appraisers

Despite increased renovation work for office buildings to improve energy performance, studies on the appraisal of renovated office buildings (ROB) are scarce. Thus, this study analyzed the perceptions of appraisers regarding renovation work and the effect of renovation work on the economic value of office buildings. Following a reliability evaluation, research results were derived using various methodologies, such as descriptive statistics, Chi-square analysis, analytic hierarchical process, and structural equation modeling, based on the survey results of 118 appraisers. The renovation work was found to positively increase an office building’s value, although the existing appraisal methods have low applicability considering the appraisal of ROB. On evaluating the importance of each factor considered in the ROB appraisal process, the factors related to the “location” of ROB were deemed more important than the attributes directly changed as a result of renovation work. Moreover, factors whose attributes were changed (e.g., working environment, green space, lease area, gross area of floors, number of floors, and number of parking spaces) were found to be critical factors affecting ROB value. The results of this study are expected to provide improvement directions for ROB appraisal methods and significantly aid building owners

Effects of Half-Precast Concrete Slab System on Construction Productivity

A half-precast concrete slab system (HPCSS) is reported to exhibit excellent structural performance when compared with traditional slab systems. However, there is a lack of extant research examining the construction issues of an HPCSS. Thus, in this study, we analyze the construction process and productivity of applying an HPCSS by using a simulation method with the data collected from an actual construction case. The results indicate that (i) the construction productivity of HPCSS is 1.7 times that of a traditional slab system, (ii) the cost per productivity unit of HPCSS exceeds that of a traditional slab system, and (iii) critical resources affecting the HPCSS productivity include form crew and rebar crew. The results of this study suggest that it is possible to develop an optimal construction plan of a construction site in which an HPCSS is installed, and that the HPCSS can be actively applied in the future

Economic Analysis of USN-Based Data Acquisition Systems in Tall Building Construction

The successful construction of tall buildings requires effective construction management based on various quantitative data. The recent development of ubiquitous sensor networks (USNs) enables massive amounts of data to be collected in real-time. However, the application of USN-based data acquisition systems to repetitive tasks on typical floors of tall buildings can be inefficient, because this may involve the repetitive reinstallation of sensors and the repositioning of data loggers and routers to enable continuous data transfer. To minimize this cumbersome work, a modified data acquisition method using reusable sensor nodes and mobile devices can be a useful solution. This study analyzes the economic aspects of the USN-based systems for concrete temperature monitoring by using the activity-based costing technique. The case study shows that the modified system can reduce the process cost by about 19%. It can also reduce the resource input time of management by about 55%, freeing up time for other management activities. Moreover, the cost benefits should scale up as projects increasingly require more measurement and monitoring. This study should facilitate the application of USN-based information management systems, particularly for tall building construction

Treatment of a Large Defect Induced by Atrophic Nonunion of Femoral Fracture in a Dog with Autogenous Coccygeal Bone Grafting

An 11-month-old castrated male Pomeranian presented with nonunion following a femoral fracture that occurred after femoral head and neck osteotomy. Radiography and computed tomography revealed severe atrophy of the proximal bone fragment and retardation of the ipsilateral distal fragment and tibia. An autogenous bone graft using coccygeal bone was performed, in which three and a half coccyges were placed in succession and fixed using an orthogonal locking plate. To promote bone healing and facilitate proper weight bearing and ambulation, bone morphogenetic proteins, biphasic calcium phosphate, platelet-rich plasma, passive-range-of-motion exercises, transcutaneous electrical nerve stimulation, neuromuscular electrical stimulation, and low-level laser therapy were applied. During the four-year follow-up, it was observed that the previously engrafted bone healed well and maintained stability over a prolonged period, resulting in the patient being able to walk comfortably with good outcomes. However, some degree of lameness was noted in the dog when running owing to limb shortening and joint contracture

Model for predicting price change patterns in multi-family houses post renovation work in South Korea

Renovation work on deteriorated multi-family houses (MFHs) is often undertaken to improve their physical performance. However, due to uncertainties in economic benefits from renovation, many MFHs frequently withdraw their renovation plans in South Korea. Despite this problem, there has been very little research on countering this issue. With this background, this study aims to develop a model for predicting the price change patterns (MPPCP) of deteriorated MFHs upon renovation in South Korea. An artificial neural network (ANN)-based MPPCP was developed to detect the relationship between project attributes and price change patterns due to renovations. By combining the parameters of the ANN method, 108 candidate models were identified and a final MPPCP was proposed after conducting simulation tests to verify the level of correct for the candidate`s models. The results of model application to actual MFH renovation cases show that the developed model can facilitate a project owner’s decision-making by estimating price change patterns for the deteriorated MFH in the project planning stage itself