A novel decision support tool for assessing the suitability of design-build method for civil construction projects in Malaysia

Project delivery method is a crucial decision that determines the quality of construction projects. The two main project delivery methods used in construction projects are designbuild (DB) and design-bid-build (DBB), which are comparable in terms of project quality, decision strategies, and risk factors. Although the DB method is prominent among practitioners, experts, and scholars; only a handful of studies have assessed a decision support tool (DST) to determine the suitability of a DB procurement method in civil construction projects. The decision-making process in civil construction projects heavily relies on the suitability of DB methods, which is also dictated by many factors and drivers. The decision support for any civil project depends on client, consultant, and contractor – the main players who ascertain project success. Past studies revealed that poor information sharing, low performance of decision models, and diverse project characteristics as the most common barriers that fail the DSTs in civil construction projects. Multiple projects are being undertaken across many countries and in diverse domains, such as building, highway, and underground civil projects. Referring to the study findings, a Decision Support Tool for Design-Build (DST-DB) was developed in this study to assess the suitability of a DB method in assisting civil construction project experts, contractors, and practitioners to adopt or reject DB for their construction projects, while concurrently preventing project setbacks. The main critical success factors (CSFs) and the DB drivers were identified and compiled from an extensive and in-depth literature review, while crucial inputs were captured from a panel of industry experts. A questionnaire was developed to gather insights from academicians, experts, and workers; while the DST-DB tool was developed to assess the suitability of the DB method by validating the identified factors and drivers. A total of 111 participants were involved in this study and the quasi-experiment method was conducted to compare the performances of practitioners, experts, and academicians specifically from clients, consultants, and contractors working in prestigious firms across Malaysia. The practitioners selected two commonly applied construction project methods; DST-DB and conventional decision-making methods. The decision-making performances retrieved from the two methods were ranked based on a set of conditions using an actual project to exhibit the practical value of the findings. All data were analyzed using multivariate analysis techniques, such as normalized value (NV), standard deviation (SD), and one-way analysis of variance (ANOVA). The results showed that the key performance measures of DST-DB (i.e., usability, likelihood, precision, confidence, and satisfaction) were higher than those recorded for conventional decision-making process in the civil construction projects undertaken in Malaysia. The pre- and post-surveys revealed that the DST-DB effectively improved the decision-making performance based on the key selection factors used in most countries (i.e., effective client briefing, maximizing resources, and sharing of expertise). Essentially, this study is one of the first decision support studies executed for DB construction projects that captured direct assessment and view from three main stakeholders of civil construction project practitioners (project clients, consultants, and contractors). The study outcomes may serve as a reference for assessing the project delivery method for civil construction projects, a resource for academic scholars working in construction projects domain, and a guide for construction practitioners to enhance their decision-making process. This study paints a comprehensive picture for a DB construction project to embark upon and accomplish future decision-making process

Iterative Equalization Using Improved Block DFE for Synchronous CDMA Systems

Iterative equalization using optimal multiuser detector and trellis-based channel decoder in coded CDMA systems improves the bit error rate (BER) performance dramatically. However, given large number of users employed in the system over multipath channels causing significant multiple-access interference (MAI) and intersymbol interference (ISI), the optimal multiuser detector is thus prohibitively complex. Therefore, the sub-optimal detectors such as low-complexity linear and non-linear equalizers have to be considered. In this paper, a novel low-complexity block decision feedback equalizer (DFE) is proposed for the synchronous CDMA system. Based on the conventional block DFE, the new method is developed by computing the reliable extrinsic log-likelihood ratio (LLR) using two consecutive received samples rather than one received sample in the literature. At each iteration, the estimated symbols by the equalizer is then saved as a priori information for next iteration. Simulation results demonstrate that the proposed low-complexity block DFE algorithm offers very good performance gain over the conventional block DFE

Lymphangiomatous macroglossia associated with extensive cervicomediastinal cystic hygromas

AbstractChildren with lymphangiomatous macroglossia often have difficulty eating and talking, and their airways may be compromised because of bleeding and infection, especially when extensive cervicomediastinal cystic hygromas are present. We report a case of lymphangiomatous macroglossia associated with extensive cystic hygromas in the cervicomediastinal region. The 3-year-old girl was treated with anterior wedge reduction of the tongue, needle aspiration of the cervicomediastinal cystic hygromas, and systemic steroids and antibiotics. The extensive cystic cervicomediastinal hygromas spontaneously regressed, and further surgery was not needed until 4 years later. Surprisingly, subtotal or partial lymphatic malformation removal improved the complicated lymphatic malformation

Temperature measurement and control system for transtibial prostheses: functional evaluation.

The accumulation of heat inside the prosthetic socket increases skin temperature and fosters perspiration, which consequently leads to high tissue stress, friction blister, discomfort, unpleasant odor, and decreased prosthesis suspension and use. In the present study, the prototype of a temperature measurement and control (TM&C) system was designed, fabricated, and functionally evaluated in a phantom model of the transtibial prosthetic socket. The TM&C system was comprised of 12 thermistors divided equally into two groups that arranged internal and external to a prosthetic silicone liner. Its control system was programmed to select the required heating or cooling function of a thermal pump to provide thermal equilibrium based on the amount of temperature difference from a defined set temperature, or the amount of difference between the mean temperature recorded by inside and outside thermistors. A thin layer of aluminum was used for thermal conduction between the thermal pump and different sites around the silicone liner. The results showed functionality of the TM&C system for thermoregulation inside the prosthetic socket. However, enhancing the structure of this TM&C system, increasing its thermal power, and decreasing its weight and cost are main priorities before further development.The Hong Kong Polytechnic University supported all expenses of functional evaluation. Moreover, The ST&G Corporation, South Korea, has donated silicone liners for functional evaluation. The authors received no more support for conduction of this stud

Exploring the role of gut microbiota in advancing personalized medicine

Ongoing extensive research in the field of gut microbiota (GM) has highlighted the crucial role of gut-dwelling microbes in human health. These microbes possess 100 times more genes than the human genome and offer significant biochemical advantages to the host in nutrient and drug absorption, metabolism, and excretion. It is increasingly clear that GM modulates the efficacy and toxicity of drugs, especially those taken orally. In addition, intra-individual variability of GM has been shown to contribute to drug response biases for certain therapeutics. For instance, the efficacy of cyclophosphamide depends on the presence of Enterococcus hirae and Barnesiella intestinihominis in the host intestine. Conversely, the presence of inappropriate or unwanted gut bacteria can inactivate a drug. For example, dehydroxylase of Enterococcus faecalis and Eggerthella lenta A2 can metabolize L-dopa before it converts into the active form (dopamine) and crosses the blood–brain barrier to treat Parkinson’s disease patients. Moreover, GM is emerging as a new player in personalized medicine, and various methods are being developed to treat diseases by remodeling patients’ GM composition, such as prebiotic and probiotic interventions, microbiota transplants, and the introduction of synthetic GM. This review aims to highlight how the host’s GM can improve drug efficacy and discuss how an unwanted bug can cause the inactivation of medicine

Application of decision support tool in design-build projects: A quasi-experiment with novice decision makers

Purpose: Design-Build (DB) is known as the alternative for Design-Bid-Build in the Malaysian construction industry. For DB projects, it is critical to adopt effective decision support tool to ensure the execution of a systematic decision-making technique. This study aimed to examine the impact of a decision support tool for novice decision makers to reject or adopt DB for their construction projects. Design/methodology/approach: Literature review and qualitative input from experts identified several key-selection factors pertaining to critical success factors and design-build drivers. This resulted in the development of Decision Support Tool for Design-Build (DST-DB). A quasi-experiment, which involved 382 novice decision makers in the construction industry, was conducted to test the DST-DB quantitatively. The participants were required to compare two construction projects using DST-DB and traditional decision-making methods. Multivariate analysis was performed to analyse all collected data. Findings: The quasi-experiment data suggests that DST-DB enables significantly higher usability, likelihood, precision, confidence and satisfaction rate when compared to the traditional decision-making process. The pre- and post-surveys indicated that the DST-DB is effective in improving decision-making performance through selection factors of client-briefing, maximised resources and sharing expertise. The participants also agreed that DST-DB is easy to use and helps them to gain better understanding of the decision-making process for construction projects. Originality/value: This research contributes to the existing body of knowledge through the impact of DST on the decisions of novices. The novice decision makers found that DST-DB is practically adaptable and comparatively effective for decision-making process than traditional decision-making methods. This contributes to the practical application of construction companies to provide DST-DB training to the fresh graduate employees to enhance their competencies in the decision-making process

A multi band study of the optically dark GRB 051028

Observations were made of the optical afterglow of GRB 051028 with the Lulin observatory's 1.0 m telescope and the WIDGET robotic telescope system. R band photometric data points were obtained on 2005 October 28 (UT), or 0.095-0.180 days after the burst. There is a possible plateau in the optical light curve around 0.1 days after the burst; the light curve resembles optically bright afterglows (e.g. GRB 041006, GRB 050319, GRB060605) in shape of the light curve but not in brightness. The brightness of the GRB 051028 afterglow is 3 magnitudes fainter than that of one of the dark events, GRB 020124. Optically dark GRBs have been attributed to dust extinction within the host galaxy or high redshift. However, the spectrum analysis of the X-rays implies that there is no significant absorption by the host galaxy. Furthermore, according to the model theoretical calculation of the Ly$\alpha$ absorption to find the limit of GRB 051028's redshift, the expected $R$ band absorption is not high enough to explain the darkness of the afterglow. While the present results disfavor either the high-redshift hypothesis or the high extinction scenario for optically dark bursts, they are consistent with the possibility that the brightness of the optical afterglow, intrinsically dark.Comment: 5page, 5 figures, 1 table, accepted for publication in PASJ Letter. PASJ styl