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Civil utility projects, both open-trench and trenchless, are subject to risk. These risks have both direct and indirect effect on project cost, schedule, quality and safety. It is therefore critical for the project management team to include risk management as an integral part of their project planning and execution. The purpose of this study is to identify the pipe-bursting construction risks and determine their probability of occurrence and cost impact and provide the appropriate responses to mitigate the identified risks.

This is an exploratory design using an industry-wide questionnaire survey to collect data on the probability of occurrence and impact of risks on cost of pipe-bursting projects. A probability-impact model was used to categorize the risks to determine their criticality and the appropriate risk responses.

The model revealed that majority of the analyzed risks have low impact-low probability of occurrence and high impact-low probability of occurrence. Undocumented repairs to host pipe was the only risk identified as having high probability of occurrence and high impact on cost. The risk responses suggest a combination of risk transfer, reduction and acceptance to be appropriately applied to mitigate the risks. A discussion on the good practices indicates that most pipe-bursting operations can be done safely and successfully if site and project conditions are known before bursting and the appropriate measures are taken to address those conditions.

Although the identified risks may apply to other utility construction methods, the focus of this research is limited to risks that occur during the construction phase of a pipe-bursting construction project.

Risk management is very critical to the success of any construction project. Identification and assessment of risks alone will not serve the purpose of risk management unless meaningful ways to mitigate those risks in a structured way are planned. The probability-impact model for the pipe-bursting construction risks with the mitigation strategies will help owners, engineers and contractors plan for and adequately respond to these risks. Additionally, a logical assessment of the risks will aid in effective decision-making regarding the management of the project.

Extensive literature review indicates that there is no existing literature on the probability of occurrence and impact on cost of risks in pipe-bursting projects. This paper presents the results of a wide-ranging analysis on construction risks in pipe-bursting projects. This is the first analysis incorporating the use of the probability-impact model to determine the criticality of various pipe-bursting construction risks.

Parachutes are equipment that is repeatedly used as and when needed. Some of them are used for as many as 60 jumps. The property of the canopy fabric gets deteriorated with use. It is evaluated by destructive tensile and bursting strength. This study aims to focus on the nondestructive evaluation of the canopy fabric's fitness by testing air permeability and relating it with bursting strength. Predictor equations were developed to determine bursting strength from air permeability values.

ANOVA techniques and statistical regression equations were formed.

A series of samples containing five parachutes fabrics was used seven times, and their air permeability and bursting strength were determined to find the extent to the effect of reuse of parachute fabrics on their bursting strength and air permeability determination. It was found that there was a progressive drop in bursting strength and an increase in air permeability. An investigation of the extent of determination in terms of bursting strength and an increase in air permeability following the sense of five different types of parachute fabrics is reported.

The work focuses on the prediction of bursting strength to textile materials only and may not apply to other materials like membranes and sheets. The process of determining air permeability is relatively simpler and faster.

The bursting strength can be predicted for used parachutes, which are otherwise subjected to destructive testing.

The men using the parachutes can be assured of the superior flawless performance of the parachute as equipment and also contribute to the saving of resources due to nondestructive testing, 100% evaluation of all parachutes is possible.

This article describes the nature of the test procedure and discusses the means of introducing it to users of parachutes. It is accepted that the method must undergo field evaluation and possible modification before it can become a routine tool of parachute using organizations.

Many Twitter users post tweets that are related to their particular interests. Users can also collect information by following other users. One approach clarifies user interests by tagging labels based on the users. A user tagging method is important to discover candidate users with similar interests. This paper aims to propose a new user tagging method using the posting time series data of the number of tweets.

Our hypothesis focuses on the relationship between a user’s interests and the posting times of tweets: as users have interests, they will post more tweets at the time when events occur compared with general times. The authors assume that hashtags are labeled tags to users and observe their occurrence counts in each timestamp. The authors extract burst timestamps using Kleinberg’s burst enumeration algorithm and estimate the burst levels. The authors manage the burst levels as term frequency in documents and calculate the score using typical methods such as cosine similarity, Naïve Bayes and term frequency (TF) in a document and inversed document frequency (IDF; TF-IDF).

From the sophisticated experimental evaluations, the authors demonstrate the high efficiency of the tagging method. Naïve Bayes and cosine similarity are particular suitable for the user tagging and tag score calculation tasks, respectively. Some users, whose hashtags were appropriately estimated by our methods, experienced higher the maximum value of the number of tweets than other users.

Many approaches estimate user interest based on the terms in tweets and apply such graph theory as following networks. The authors propose a new estimation method that uses the time series data of the number of tweets. The merits to estimating user interest using the time series data do not depend on language and can decrease the calculation costs compared with the above-mentioned approaches because the number of features is fewer.

The high-pressure accumulator has been widely used in the hydraulic system. Failure pressure prediction is crucial for the safe design and integrity assessment of the accumulators. The purpose of this study is to accurately predict the burst pressure and location for the accumulator shells due to internal pressure.

This study concentrates the non-linear finite element simulation procedure, which allows determination of the burst pressure and crack location using extensive plastic straining criterion. Meanwhile, the full-scale hydraulic burst test and the analytical solution are conducted for comparative analysis.

A good agreement between predicted and measured the burst pressure that was obtained, and the predicted failure point coincided very well with the fracture location of the actual shell very well. Meanwhile, the burst pressure of the shells increases with wall thickness, independent of the length. It can be said that the non-linear finite element method can be employed to predict the failure behavior of a cylindrical shell with sufficient accuracy.

This paper can provide a designer with additional insight into how the pressurized hollow cylinder might fail, and the failure pressure has been predicted accurately with a minimum error below 1%, comparing the numerical results with experimental data.

The purpose of this paper is to compare the bursting strength, bursting distension, air permeability and wale wise wicking rate properties of recycled polyester (r-PET) and virgin polyester (v-PET) raw materials from which single jersey knitted fabric samples are manufactured. Meanwhile, numerical optimization method was used in predetermined parameters to determine the optimum r-PET and v-PET blend ratio and yarn manufacturing technology. In the optimization analysis, the average values of the important yarn and fabric properties inspected were taken as a target according to the 50 percent proportion of r-PET and v-PET fiber for both compact and ring yarn manufacturing technology.

To encourage the use of value-added textile products produced from recycling PET bottle with the focus of social responsibility is a condition that should be evaluated within the scope of waste management. The recycling of PET bottles and finding new opportunities for the uses in different field are crucial for both contributing environmental economy and conserving natural energy resources. The most important alternative ways is to use the r-PET fiber from recycling PET bottle in textile industry. In this study, 19.7 tex r-PET/cotton and v-PET/cotton-blended compact and ring spun yarns were produced at different blending ratios at the same production parameters.

Results showed that blend type, blend ratio and yarn manufacturing technology have statistical significance effect on bursting strength and air permeability. Besides, it was found that blend type has no significance on wale wise wicking rate unlike other parameters. Optimization analysis indicated that single jersey knitted fabric with v-PET/CO 58.62/41.38 percent compact yarn had higher desirability with the value of 0.72.

At the present time, r-PET fiber is blended in small amount (approximately 5–15 percent blend ratio) with both cotton and polyester together. In addition, it is possible using different fiber blend types instead of cotton and polyester according to the usage area. The most important question is to determine the amount of r-PET proportion. In other words, both optimum yarn/fabric quality parameters should be ensured and at the same time life cycle of the apparels should not be short when the optimum r-PET proportion is taken into consideration.

Additive manufacturing has achieved rapid development in recent years. The purpose of this paper is to visualize the intellectual landscapes of additive manufacturing and identify the hotspots and emerging trends of additive manufacturing, which can provide references for scholars, enterprises and governments to promote the development of theory and practice in the additive manufacturing field.

Science mapping is a fast-growing interdisciplinary field originated in information science and technology. Based on this methodology, guided by a computational approach, the paper visualizes the co-occurring keywords network and co-citation references network by CiteSpaceIII software to explore the hotspots and emerging trends of additive manufacturing by the following five indicators: highly cited keywords, burst keywords, clusters, landmark references and burst references.

“Additive manufacturing,” “3D printing,” “3D powder printing,” “consolidation phenomena,” “microstructure,” “rapid prototyping,” etc., are the main hotspots of additive manufacturing. The trends of additive manufacturing generally consist of three stages: the fundamental concepts stage from 1995 to 2000 (“rapid prototyping,” “additive manufacturing,” etc.), the approaches and techniques applications stage from 2001 to 2010 (“stereolithography,” “scaffold,” etc.), and the emerging trends stage from 2011 to the present (“stem cell”, “selective laser,” “ti-6al-4v,” etc.). The research is most abundant in 2010 and 2012. The medical field is an important hotspot of additive manufacturing. Additive manufacturing has been researched in interdiscipline.

The paper maps the perspective of additive manufacturing and explore the hotspots and emerging trends of additive manufacturing.

Office workspace is more than a place but one of the essential resources in business organizations. In recent years, research in office workspace management has become an increasingly important scholarly focus. However, there is a dearth of bibliometric studies to date on the subject. This study aims to explore a scientometric analysis of office workspace field.

The title/abstract/keyword search method was used to extract related papers from 1990 to 2018. A total of 1,670 papers published in Scopus were obtained and subjected to scientometric data analysis techniques via CiteSpace software.

The results revealed the active research institutions and countries, influential authors, important journals, representative references and research hotspots in this field.

While this study focused on office workspace management, the findings hold useful implications for the built environment in general and facility management in particular, being a sector that encompasses multiple disciplines involving building, office assets, people, processes and technology, which enable effective functioning of the built facilities.

This is probably the most comprehensive scientometric analysis of the office workspace field ever conducted. This study adds to the so far limited knowledge in the field and provides insights for future research.

The wide uptake of green building is hindered by factors such as limited market demand and high up-front cost despite substantial policy incentives. Successful business models (BMs) help facilitate the diffusion of sustainable innovation and have attracted increasing attention. However, little attention has been paid to examining the adoption of green building from the perspective of BM. This paper aims to identify the characteristics of BM that companies adopted to deliver green building projects and examine the evolution path of BM for green buildings.

A total of 744 interdisciplinary bibliographic records related to BM and green buildings from the Web of Science Core Collection database have been identified from the Web of Science Core Collection and analyzed through co-author analysis, co-word analysis and co-citation analysis.

BM research mainly focuses on five subjects, namely, environmental science, engineering, business, economics, science and technology. Keywords “strategy”, “capability”, “perspective” and “design” receive the highest centrality index, which suggests that the strategy design and corporate capability are indispensable elements when designing or innovating a company's BM. “BM canvas” and “resource based view” received the burst citations in the recent decade. Twelve research clusters are identified, including performance evaluation, waste management, energy efficiency, BM, project business, professional capital, leadership and product innovation. These topics highlight three evolution direction for green building projects, i.e. life cycle-oriented value proposition, collaborative value delivery and innovative cost and revenue structure.

The findings contribute to a systematic understanding of the underlying mechanisms of BM for green buildings and illuminate the development trend of business strategies for sustainability.

3D printing is believed to be driving the third industrial revolution. However, a scientometric visualizing of 3D printing research and an exploration its hotspots and emerging trends are lacking. This study aims to promote the theory development of 3D printing, help researchers to determine the research direction and provide a reference for enterprises and government to plan the development of 3D printing industry by a comprehensive understanding of the hotspots and trends of 3D printing.

Based on the theory of scientometrics, 2,769 literatures on the 3D printing theme were found in the Web of Science Core Collection’ Science Citation Index Expanded (SCI-EXPANDED) index between 1995-2016. These were analyzed to explore the research hotspots and emerging trends of 3D printing with the software CiteSpaceIII.

Hotspots had appeared first in 1993, grew rapidly from 2005 and peaked in 2013; hotspots in the “medical field” appeared earliest and have remained extremely active; hotspots have evolved from “drug”, “printer”, “rapid prototyping” and “3D printing” in the 1990s, through “laser-induced consolidation”, “scaffolds”, “sintering” and “metal matrix composites” in the 2000s, to the current hotspots of “stereolithography”, “laser additive manufacturing”, “medical images”; “3D bioprinting”, “titanium”, “Cstem cell” and “chemical reaction” were the emerging hotspots in recent years; “Commercial operation” and “fusion with emerging technology such as big data” may create future hotspots.

It is hard to avoid the possibility of missing important research results on 3D printing. The relevant records could be missing if the query phrases for topic search do not appear in records. Besides, to improve the quality of data, this study selected articles and reviews as the research objects, which may also omit some records.

First, this is the first paper visualizing the hotspots and emerging trends of 3D printing using scientometric tools. Second, not only “burst reference” and “burst keywords” but also “cluster” and “landmark article” are selected as the evaluation factors to judge the hotspots and trends of a domain comprehensively. Third, overall perspective of hotspots and trends of 3D printing is put forward for the first time.

The purpose of this paper is to summarize the research of construction conflict from 1991 to 2020 and propose research directions for future scholarly work. During the recent decades, it is widely accepted that construction conflict is inevitable, and conflict management has become an important component of project management. However, few works were done to map the global study in this field, there is limited review that evaluates the current stage of construction conflict research.

This study adopted a holistic literature review approach that incorporates bibliometric search and scientometric analysis. A total of 698 bibliographic records from the Web of Science core collection database were collected for the scientometric analysis. CiteSpace5.7 was adopted for the science mapping purpose in this study.

Through co-authorship analysis, co-word analysis and co-citation analysis, influential scholars and journals are identified. Several research trends are highlighted according to the scientometric analyses of the construction conflict topics. For example, the application of simulation and algorithms to the study of construction conflict management systems.

Construction is a resource-intensive, multi-participant and multi-targeted industry. Conflicts always exist in the whole life cycle of construction projects, it is important for industry practitioners to be updated of the latest movement and progress of the academic research.

This study contributed to the body of knowledge in construction conflict and bridge the research gap in the thorough review of previous research work.