bluuebunny/crossref_metadata_2025 huggingface dataset:
Flat-gain L-band amplifier containing AlPO4 units in aluminophosphosilicate erbium-doped fibers
Authors: Zhai Ziwei , Halder Arindam , Sahu Jayanta K.
Published: October 2023

We present a flat-gain single-stage L-band erbium-doped fiber amplifier (EDFA) with a gain ripple of ±0.7 dB from 1580 to 1615 nm, by using aluminophosphosilicate erbium-doped fiber (APS-EDF) with an estimated AlPO4 composition of 13.3 mol%. A series of APS-EDFs were fabricated with increasing AlPO4 and Er concentrations, while maintaining a low background loss of 0.031 ± 0.005 dB/m and preventing Er ion clustering. The spectroscopic study shows a slightly narrowing Er cross section and flattened emission cross-section spectrum in the L-band with more AlPO4, thus favoring the L-band amplification with an improved gain flatness. Also, the gain coefficient, gain saturation, and temperature-dependent gain characteristics were reported. A better temperature tolerance was observed with increasing AlPO4.
Stimuli-responsive grating with a tunable period and a diffraction order
Authors: Tian Li-Lan , Yu Le , Zeng Yu-Meng , Li Yao , Guo Zhou , Li Lei , Zhang Yuxian , Chu Fan
Published: October 2023

The next-generation diffraction grating not only requires a nonmechanical control and a remote control to generate a diffraction pattern but also requires a tunable period. Here, we propose a stimuli-responsive liquid crystal (LC) phase grating with a tunable period and a diffraction order. The stimuli-responsive LC diffraction grating is composed of periodically arranged electrodes on a double-sided glass substrate. By adjusting the driving scheme, the pitch and diffraction order of the LC grating can be switched between three different modes. The experimental results show that the LC grating has a lower driving voltage (∼5 V). In addition, the tunable LC grating can achieve more diffraction orders, which can be applied to a holographic display to achieve a wide-viewing angle and an enlarged size.
Mouse visual cortex as a limited resource system that self-learns an ecologically-general representation
Authors: Nayebi Aran , Kong Nathan C. L. , Zhuang Chengxu , Gardner Justin L. , Norcia Anthony M. , Yamins Daniel L. K.
Published: October 2023

Studies of the mouse visual system have revealed a variety of visual brain areas that are thought to support a multitude of behavioral capacities, ranging from stimulus-reward associations, to goal-directed navigation, and object-centric discriminations. However, an overall understanding of the mouse’s visual cortex, and how it supports a range of behaviors, remains unknown. Here, we take a computational approach to help address these questions, providing a high-fidelity quantitative model of mouse visual cortex and identifying key structural and functional principles underlying that model’s success. Structurally, we find that a comparatively shallow network structure with a low-resolution input is optimal for modeling mouse visual cortex. Our main finding is functional—that models trained with task-agnostic, self-supervised objective functions based on the concept of contrastive embeddings are much better matches to mouse cortex, than models trained on supervised objectives or alternative self-supervised methods. This result is very much unlike in primates where prior work showed that the two were roughly equivalent, naturally leading us to ask the question of why these self-supervised objectives are better matches than supervised ones in mouse. To this end, we show that the self-supervised, contrastive objective builds a general-purpose visual representation that enables the system to achieve better transfer on out-of-distribution visual scene understanding and reward-based navigation tasks. Our results suggest that mouse visual cortex is a low-resolution, shallow network that makes best use of the mouse’s limited resources to create a light-weight, general-purpose visual system—in contrast to the deep, high-resolution, and more categorization-dominated visual system of primates.
Predicting regional somatic mutation rates using DNA motifs
Authors: Liu Cong , Wang Zengmiao , Wang Jun , Liu Chengyu , Wang Mengchi , Ngo Vu , Wang Wei
Published: October 2023

How the locus-specificity of epigenetic modifications is regulated remains an unanswered question. A contributing mechanism is that epigenetic enzymes are recruited to specific loci by DNA binding factors recognizing particular sequence motifs (referred to as epi-motifs). Using these motifs to predict biological outputs depending on local epigenetic state such as somatic mutation rates would confirm their functionality. Here, we used DNA motifs including known TF motifs and epi-motifs as a surrogate of epigenetic signals to predict somatic mutation rates in 13 cancers at an average 23kbp resolution. We implemented an interpretable neural network model, called contextual regression, to successfully learn the universal relationship between mutations and DNA motifs, and uncovered motifs that are most impactful on the regional mutation rates such as TP53 and epi-motifs associated with H3K9me3. Furthermore, we identified genomic regions with significantly higher mutation rates than the expected values in each individual tumor and demonstrated that such cancer-related regions can accurately predict cancer types. Interestingly, we found that the same mutation signatures often have different contributions to cancer-related and cancer-independent regions, and we also identified the motifs with the most contribution to each mutation signature.
Genome-wide single-molecule analysis of long-read DNA methylation reveals heterogeneous patterns at heterochromatin that reflect nucleosome organisation
Authors: Kerr Lyndsay , Kafetzopoulos Ioannis , Grima Ramon , Sproul Duncan
Published: October 2023

High-throughput sequencing technology is central to our current understanding of the human methylome. The vast majority of studies use chemical conversion to analyse bulk-level patterns of DNA methylation across the genome from a population of cells. While this technology has been used to probe single-molecule methylation patterns, such analyses are limited to short reads of a few hundred basepairs. DNA methylation can also be directly detected using Nanopore sequencing which can generate reads measuring megabases in length. However, thus far these analyses have largely focused on bulk-level assessment of DNA methylation. Here, we analyse DNA methylation in single Nanopore reads from human lymphoblastoid cells, to show that bulk-level metrics underestimate large-scale heterogeneity in the methylome. We use the correlation in methylation state between neighbouring sites to quantify single-molecule heterogeneity and find that heterogeneity varies significantly across the human genome, with some regions having heterogeneous methylation patterns at the single-molecule level and others possessing more homogeneous methylation patterns. By comparing the genomic distribution of the correlation to epigenomic annotations, we find that the greatest heterogeneity in single-molecule patterns is observed within heterochromatic partially methylated domains (PMDs). In contrast, reads originating from euchromatic regions and gene bodies have more ordered DNA methylation patterns. By analysing the patterns of single molecules in more detail, we show the existence of a nucleosome-scale periodicity in DNA methylation that accounts for some of the heterogeneity we uncover in long single-molecule DNA methylation patterns. We find that this periodic structure is partially masked in bulk data and correlates with DNA accessibility as measured by nanoNOMe-seq, suggesting that it could be generated by nucleosomes. Our findings demonstrate the power of single-molecule analysis of long-read data to understand the structure of the human methylome.
Causal relationship between body mass index, type 2 diabetes and bone mineral density: Mendelian randomization
Authors: Ma Weiwei , Zhou Xiaohong , Huang Xin , Xiong Yong
Published: October 2023

Objective

To reveal the relationship between Body Mass Index(BMI), type 2 diabetes, and bone mineral density(BMD) using a mendelian randomization (MR) approach.

Methods

GWAS data on BMI, type 2 diabetes, and BMD were selected from the IEU GWAS database at the University of Bristol.Univariable, multivariable, and mediated MR analyses were used to explore the relationship between BMI, type 2 diabetes, and BMD. beta(β) values were given, and three methods, including inverse variance weighting, MR-Egger regression, and weighted median, were used in this analysis.

Results

Univariable mendelian randomization (UVMR) results showed that BMI and type 2 diabetes were positively associated with BMD. However, the association between BMI and BMD was insignificant in the multivariable Mendelian randomization (MVMR) analysis, while that between type 2 diabetes and BMD remained significant. Mediated MR analysis indicated that type 2 diabetes mediated the regulation of BMD by BMI.

Conclusion

This study provides evidence supporting a positive causal association between BMI, type 2 diabetes, and BMD. Type 2 diabetes acts as a mediator in the regulation of BMD by BMI, indicating that both BMI and type 2 diabetes exert a protective influence on BMD.
A topological classifier to characterize brain states: When shape matters more than variance
Authors: Ferrà Aina , Cecchini Gloria , Nobbe Fisas Fritz-Pere , Casacuberta Carles , Cos Ignasi
Published: October 2023

Despite the remarkable accuracies attained by machine learning classifiers to separate complex datasets in a supervised fashion, most of their operation falls short to provide an informed intuition about the structure of data, and, what is more important, about the phenomena being characterized by the given datasets. By contrast, topological data analysis (TDA) is devoted to study the shape of data clouds by means of persistence descriptors and provides a quantitative characterization of specific topological features of the dataset under scrutiny. Here we introduce a novel TDA-based classifier that works on the principle of assessing quantifiable changes on topological metrics caused by the addition of new input to a subset of data. We used this classifier with a high-dimensional electro-encephalographic (EEG) dataset recorded from eleven participants during a previous decision-making experiment in which three motivational states were induced through a manipulation of social pressure. We calculated silhouettes from persistence diagrams associated with each motivated state with a ready-made band-pass filtered version of these signals, and classified unlabeled signals according to their impact on each reference silhouette. Our results show that in addition to providing accuracies within the range of those of a nearest neighbour classifier, the TDA classifier provides formal intuition of the structure of the dataset as well as an estimate of its intrinsic dimension. Towards this end, we incorporated variance-based dimensionality reduction methods to our dataset and found that in most cases the accuracy of our TDA classifier remains essentially invariant beyond a certain dimension.
Policy Framework of Green Taxation on Motor Vehicles: A Comparative Perspective
Authors: Singh Kanwal DP , Gahlot Sheetal
Published: October 2023

Green economics is structured to reward more innovative, environmentally sustainable, and low-carbon resource use while imposing taxes on the emission of pollutants that adversely impact the environment and public health. The concept of green taxation is still being tested in many nation-states. Pollution is worst in India, and the country is ranking low on several environmental performance indices. Vehicle exhausts are one of the key pollutants. In 2021, the Indian government released draft guidelines for imposing Green Tax on older motor vehicles. India submitted its first Nationally Determined Contribution Report to the United Nations Framework Convention on Climate Change in 2022. India prioritized green taxonomies, low-carbon transportation systems, and Bharat Stage-VI emission standards and offered incentives and tax breaks to encourage the production and use of higher ethanol-compatible vehicles. There is still a lack of awareness among the masses, as well as academic discussions and literature on the subject. Against this backdrop, the researchers intend to explore the legal and economic actions undertaken by the Indian Government to intercept vehicular air pollution. An effort will also be made to draw a comparative study with the fiscal policy measures and other steps taken by the Italian government to tax polluting vehicles.

Keywords: Green Taxation, Vehicular Pollution, Economic Incentives, Environmental Protection, Sustainable Development
Integration of Environmental Sustainability Issues In Design Education Curriculum
Authors: Kafaridou Marianna , Kazamia Kika Ioannou
Published: October 2023

An early acquirement of knowledge on sustainability can bring a change in how young people act. The focus of this paper is first to evaluate the current knowledge of first year design students on environmental sustainability and second to assess if students consider environmental issues in the approach and resolution of a design project. The research elaborates through a questionnaire given to students of the graphic and digital design program and interior design program which result in a quantitative and qualitative understanding of the focus of the research. Sustainability - based on environmental, social, and economic pillars - is a big concern in the design discipline. Moreover, environmentally sustainable issues are of great importance in design education curricula as most of the design briefs that students receive require the inclusion of sustainability issues. According to the results, this research will attempt to propose the design and implementation of an introductory course for first year students of both programs. The educational benefits of an early introduced course on sustainability are essential for developing the designer’s perception of the design scheme today.

Keywords: sustainability, design, education, environment, course.
Effect of Climate Change in Years 2006-2019 on Crop Yields in Poland
Authors: Gront Elżbieta Wójcik- , Gozdowski Dariusz
Published: October 2023

In recent years, especially since 2005, a substantial increase in temperature has been observed worldwide, including in Poland. Crop production is very important for livestock feeding and food production. In this study, the effect of climate change from 2014 to 2022 on selected crops, especially winter rye yield, was evaluated. The data for the analyses were obtained from the FAOSTAT database and post-registration cultivar trials. The effect of climate change was evaluated for cereals, potatoes, and sugar beets. The trends of crop yields were evaluated using analysis of regression. The results of the study proved a positive correlation between precipitation and crop yield and a negative correlation between temperature and crop yield. The most significant effect of weather conditions was observed in the April-June period.

Keywords: climate change, rye yield, forecast.
The Role of Professional Competencies in Developing a Culture of Safety in the Workplace
Authors: Abikenova Sholpan K. , Oshakbayeva Zhuldyz O. , Bekmagambetov Alimzhan B. , Sarybayeva Inara E.
Published: October 2023

The paper considers the concept of occupational competencies as an integral part of building a culture of occupational safety in the organization. The paper provides examples of competencies that employees need to effectively perform their job safety responsibilities. It also discusses professional education and training issues related to the development of occupational safety competencies. It is believed that the development of occupational health and safety competencies not only influences the design of appropriate and safe working conditions, but also reduces the risk of occupational accidents and diseases. There are two types of occupational competencies: general and vocational. General occupational competencies are required for effective occupational activities to ensure safe work, regardless of the sector. The sectoral nature of occupational health and safety is reflected in the availability of specific occupational competencies.

 The article discusses various methods and approaches for building a new national model for professional skills development. The model is based on the introduction of a risk-based approach in Kazakhstan. Occupational risk assessment is considered as the basis for designing training programs and acquiring the occupational competencies needed for comprehensive protection against risks. The development of a culture of occupational safety and professional competencies is a key factor in the sustainable development of the company and the improvement of the quality of life of its employees.

Keywords: safe work, risk-oriented approach, professional competencies, industrial accident, training programs.
SMEs’ Drivers and Barriers to Decarbonisation in the East of England
Authors: Khosravi Fatemeh , Jelliman Sam , Uchendu Chidinma
Published: October 2023

Most businesses in the UK have under 250 employees and thus count as SMEs. SMEs account for a significant proportion of greenhouse gas emissions and so there is a need for urgent action to be taken by SMEs in the journey to achieve net zero. This is currently recognised by SMEs as they are increasingly taking up decarbonisation actions, but their efforts are impeded by several barriers. Our research sought to provide insights into the barriers SMEs face when decarbonising business operations through an online survey and interview. Although our research confirms that financial constraints has been identified as the principal barrier to decarbonisation from SMEs perspectives, more than half of SMEs confirmed they lack the knowledge (34%, n=33) and skill (21%, n=20) was the main reason for not measing their carbon emission and starting their journey towards decarbonisation.

Keywords: SMEs, Barriers, decarbonisation journey, Net Zero.
Testing Pair-Wise Convergence of Western Balkan and European union Countries
Authors: Duro Enton , Kokaveshi Ergita , Muço Klodian
Published: October 2023

The present research performs the GDP per capita convergence analyses of Western Balkan (WB) countries to European Union (EU) countries. There are few testing convergence methods based on theoretical insights on the neoclassical model, however pairwise convergence method doesn’t seem usually applied in the case of WB and EU countries.  The test of convergence hypothesis in this research is based on the GDP per capita’s data, constant 2017 international $ in PPP terms, made available by the World Bank.  The pairwise convergence test suggested here can be considered as an extension of Webber and While (2003, 2004, 2009) methodology. The outcomes have been compared to Bernard, Durlauf (1995) and Pesaran (2006) methodology of the pairwise convergence, by adapting ADF time series tests of the stationarity. In conclusion, despite to the controversy of one pair case, the comparative process of both methods seems to be aligned. However, further investigation needs to be performed to confirm the effectiveness and efficiency of this suggestion.

Keywords: GDP per capita, pairwise convergence, Western Ballkan countries, methodology
Assessment of the Regions' Investment Attractiveness for Post-War Recovery: The Case of Ukraine
Authors: Osadcha Natalia , Zatyshniak Valentyna
Published: October 2023

The paper analyzes the directions for Ukrainian economic recovery after the war. The successes stories of the countries, that restored their economies after the war, were explored. As a result, the best practices of Israel seem most suitable for Ukraine.

Also, present research determines the priority areas for raising the investment attractiveness of the Ukrainian regions and tests the practical application of the results of their investment appeal evaluation, primarily on the basis of our own approach for their marketing, advancement and disclosure the capability. The paper's uniqueness lies in its emphasis on the proposed marketing territorial investments, in accordance with the results of a comprehensive monitoring of the region-specific investment climate in Ukraine.

A number of indicators effects on the regions' investment attractiveness. Comparing the regions among themselves, according to its figures, gives a new leader every time. The proposed Rasch mathematical model allows obtaining an integral assessment of the regions' investment attractiveness with the appropriate ranking. Such estimates can be used both by investors at the initial stages of choosing a region for investment and by representatives of local authorities to assess the investment attractiveness of the territory for a certain period. The future recalculation of these data will be based on the situation at the front and changes in the economic structure of each region. After the war, the casualties of each region must be assessed and an international audit conducted.

 Key words: Ukraine, post-war recovery, investment attractiveness, Rasch model, assessment.

Jel Classification: E 22
Education for Sustainability: Innovative Teaching on Photosynthesis of Aquatic Plants in Ecological Context
Authors: Ryplova Renata , Pokorny Jan , Baxa Marek
Published: October 2023

Eutrophication due to high load of nutrients from the catchment is significant worldwide problem  causing impairment of water ecosystems and water quality. The reason is tight connection of eutrophication with photosynthetic biomass production of blue green algae resulting in extreme changes of oxygen level, anoxia at the bottom and release of toxic substances in water. Acceleration and extension of eutrophication due to human activities together with insufficient human understanding of the ecological role of photosynthesis of aquatic plants leads to inappropriate water and landscape management resulting in further loss of clear water. To save enough clear water supplies for future generation it is necessary to improve human understanding of these processes starting already from school education. This contribution brings results of a survey aimed on the impact of developed innovative teaching activity  on photosynthetic biomass production of aquatic plants in ecological context and using digital technologies which was implemented into the education at Czech upper secondary schools. Significant improvement of student understanding of ecological function of photosynthetic biomass production in water and increase of attractiveness of plant education for students were proved. The contribution of innovative teaching on photosynthetic biomass production in ecological context for sustainable education is discussed.

Keywords: Plant blindness, Aquatic plants, Eutrophication, Sustainable Education, Water.
Gastric Alimetry Expands Patient Phenotyping in Gastroduodenal Disorders Compared with Gastric Emptying Scintigraphy
Authors: Wang William Jiaen , Foong Daphne , Calder Stefan , Schamberg Gabriel , Varghese Chris , Tack Jan , Xu William , Daker Charlotte , Carson Daniel , Waite Stephen , Hayes Thomas , Du Peng , Abell Thomas L. , Parkman Henry P. , Huang I-Hsuan , Fernandes Vivian , Andrews Christopher N. , Gharibans Armen A. , Ho Vincent , O'Grady Greg
Published: October 2023

INTRODUCTION:

Gastric emptying testing (GET) assesses gastric motility, however, is nonspecific and insensitive for neuromuscular disorders. Gastric Alimetry (GA) is a new medical device combining noninvasive gastric electrophysiological mapping and validated symptom profiling. This study assessed patient-specific phenotyping using GA compared with GET.

METHODS:

Patients with chronic gastroduodenal symptoms underwent simultaneous GET and GA, comprising a 30-minute baseline, 99mTC-labelled egg meal, and 4-hour postprandial recording. Results were referenced to normative ranges. Symptoms were profiled in the validated GA App and phenotyped using rule-based criteria based on their relationships to the meal and gastric activity: (i) sensorimotor, (ii) continuous, and (iii) other.

RESULTS:

Seventy-five patients were assessed, 77% female. Motility abnormality detection rates were as follows: GET 22.7% (14 delayed, 3 rapid), GA spectral analysis 33.3% (14 low rhythm stability/low amplitude, 5 high amplitude, and 6 abnormal frequency), and combined yield 42.7%. In patients with normal spectral analysis, GA symptom phenotypes included sensorimotor 17% (where symptoms strongly paired with gastric amplitude, median r = 0.61), continuous 30%, and other 53%. GA phenotypes showed superior correlations with Gastroparesis Cardinal Symptom Index, Patient Assessment of Upper Gastrointestinal Symptom Severity Index, and anxiety scales, whereas Rome IV Criteria did not correlate with psychometric scores (P > 0.05). Delayed emptying was not predictive of specific GA phenotypes.

DISCUSSION:

GA improves patient phenotyping in chronic gastroduodenal disorders in the presence and absence of motility abnormalities with increased correlation with symptoms and psychometrics compared with gastric emptying status and Rome IV criteria. These findings have implications for the diagnostic profiling and personalized management of gastroduodenal disorders.
Colorectal Cancer Screening Receipt Does Not Differ by 10-Year Mortality Risk Among Older Adults
Authors: Liu Po-Hong , Singal Amit G. , Murphy Caitlin C.
Published: October 2023

BACKGROUND:

Health status and life expectancy are important considerations for assessing potential benefits and harms of colorectal cancer (CRC) screening programs, particularly among older adults.

METHODS:

We examined receipt of past-year CRC screening according to predicted 10-year mortality risk among 25,888 community-dwelling adults aged 65–84 years who were not up-to-date with screening in the nationwide National Health Interview Survey. Ten-year mortality risk was estimated using a validated index; from the lowest to highest quintiles of the index, risk was 12%, 24%, 39%, 58%, and 79%, respectively. We also examined the proportion of screening performed among adults with life expectancy <10 years.

RESULTS:

The prevalence of past-year CRC screening was 39.5%, 40.6%, 38.7%, 36.4%, and 35.4%, from the lowest to highest quintile of 10-year mortality risk. Odds of CRC screening did not differ between adults in the lowest vs highest quintile (adjusted odds ratio 1.05, 95% confidence interval: 0.93–1.20). One-quarter (27.9%) of past-year CRC screening occurred in adults with life expectancy <10 years, and more than half (50.7%) of adults aged 75–84 years had 10-year mortality risk ≥50% at the time of screening. In an exploratory analysis, invasive but not noninvasive screening increased as 10-year mortality risk increased (P< 0.05) among adults aged 70–79 years.

DISCUSSION:

Past-year CRC screening does not differ by predicted 10-year mortality risk. An age-based approach to CRC screening results in underscreening of older, healthier adults and overscreening of younger adults with chronic conditions. Personalized screening with incorporation of individual life expectancy may increase the value of CRC screening programs.
STUDY ON DEFLECTION CONTROL OF COMPOSITE SLABS STRENGTHENED WITH BONDED STEEL PLATES
Authors: Bruwer Carl Pieter
Published: October 2023

This paper demonstrates how long-term deflection of reinforced concrete slabs can be controlled by creating composite slabs. Three similar reinforced concrete slabs, 1,000 mm wide x 150 mm thick, reinforced with five high-strength (fy – 450 MPa) 12 mm diameter bars, spanning 4,500 mm, were constructed for this research study. The compressive strength of the concrete (fcu) was 25 MPa, with an elastic modulus of 33.6 GPa. One control slab, without bonded plates, formed the baseline for the deflection and was compared with the performance of two composite slabs strengthened with steel plates, one with a 110 mm x 6 mm plate (Comp1) and the other with 2 x two 110 mm x 6 mm plates (Comp 2). The bonding surfaces were prepared by scabbling the concrete to expose the well-bonded large aggregate, and the steel plates were dry grit blasted to a white metal finish to obtain a 100-140 µm blast profile. The steel plates were bonded to the concrete surfaces by means of Pro-Struct 618LV primer and Pro-Struct 617NS epoxy. All the slabs were loaded with a UDL of 1.0 kN/m. The experimental deflection results showed deflections of 20.18mm for the control slab, 16.67 mm for SP1and 16.31mm for SP2. The percentage difference between the theoretically calculated and experimentally measured deflections was 20.54% for the control slab, and-34.85% and-37.58% for SP1 and SP2, respectively.
WASTE GLASS AS AN ALKALINE ACTIVATOR AND FLY ASH AS PRECURSOR IN GEOPOLYMER CONCRETE
Authors: Solanki Pranshoo , Jin Guang
Published: October 2023

In this study, an alkaline activator was synthesized by dissolving waste glass in NaOH solution to explore the feasibility of using waste glass as a potential alkaline activator in the preparation of geopolymer concrete (GeoPC) with fly as precursor. A total of three types of glasses with different sizes were used. The exact concentration of Na2O and SiO2 in the activator was measured using inductively coupled plasma – optical emission spectrometry (ICP-OES). A total of 38 GeoPC mixtures were prepared using three glass types and at different Na2O and SiO2 concentration. The compressive strength of GeoPC was measured by testing specimens after 24 hours of heat curing (80±2°C) followed by 24 hours of ambient curing at room temperature (23±2°C). The compressive strength was found to depend on alumina and calcium content of glass type and moduli (SiO2/Na2O) ratio of activator. The higher liquid to solid ratio resulted in lowering of compressive strength.
A BAYESIAN DATA UPDATING MODEL FOR MANAGING BUILDING ENVELOPE INSPECTIONS
Authors: Jang Bora , Mohammadi Jamshid
Published: October 2023

Building envelope management includes all activities, e.g., periodic inspections, condition assessment and maintenance, needed to preserve the integrity of the building exterior. In building envelope management, appropriate decision-making focuses on finding an optimum inspection interval and repair strategy. A Bayesian updating with rating method is presented for conducting planning and decision-making for building envelop inspections using data from previous inspections. The model applies to a zone (strip) of the envelope and uses the previous inspection records to predict the future condition. An artificial neural network (ANN) is used to improve the prediction for the envelope condition. The ANN uses historical data of an envelope condition to determine a correction factor, for the predicted condition, to account for the effect of factors that promote damage. The Bayesian updating will improve the capabilities of the model in predicting the future conditions as more data becomes available. Used along with a cost optimization and reserve analysis, the model will result in a more sustainable and cost-effective building envelope management process.
ENERGY DECARBONIZATION STRATEGIES IN RETROFITTED SINGLE-FAMILY HOMES
Authors: Niemczak Peter , Stefańska Anna , Koda Eugeniusz
Published: October 2023

Legislative work on minimizing greenhouse gas emissions becomes one of the issues of the sustainable approach in the architectural and construction sector. An example of such work is Chicago’s 2022 Climate Action Plan, where nearly 70% of Chicago’s greenhouse gas emissions come from urban environments. While energy consumption in new construction is declining due to tightening building codes, insufficient regulations do not limit emissions in existing buildings, especially single-family housing. The study evaluates building structures and focuses on three decarbonization strategies for retrofitted single-family homes. It interrogates and compares building electrification, envelope retrofitting and the use of renewable energy. Therefore, this study may be helpful in further prioritization of the energetic modernization of existing buildings. The case study is founded on the single-family houses built in Chicago before 1980. The paper presents possible interventions of available retrofit methods regarding grid emission factors and considers the CO2 cycle in the building’s lifetime.
THE SUITABILITY OF EXISTING CONSTRUCTION CONTRACTS FORMS FOR BIM CONSTRUCTION PROJECTS
Authors: Stellmacher Dominik , Kaufhold Matthias , Meins-Becker Anica , Helmus Manfred
Published: October 2023

Numerous major construction projects suffer from cost and schedule overruns. In addition, the potential for conflict between project participants, for example due to changes in performance, additional services or ambiguities in the contract, has increased substantially in recent years, while at the same time the ability to resolve conflicts quickly has declined significantly. In the context of digitization, Building Information Modeling (BIM) represents a way of implementing projects more efficiently and satisfactorily for all parties involved. With the method, "risks can be significantly minimized, construction times considerably shortened and costs noticeably reduced". In order to make the most of the advantages of the BIM method, the choice of a suitable form of construction contract is of decisive importance. Within the research conducted at the University of Wuppertal, characteristic features of conventional and alternative forms of construction contracts as well as management concepts were examined and the respective advantages and disadvantages were compared with regard to the criteria identified. In addition, the construction contract forms and management concepts were also examined and evaluated for compatibility with the BIM method. The result of this investigation shows a scoring model. It includes both the nationally established construction contract forms of individual award with unit price contract as well as alternative forms such as the Framework Alliance Contract-1 with the concept of value engineering. The result of the study should encourage clients to consider alternative forms of construction contracts in order to be able to design construction projects more efficiently.
DEVELOPMENT OF A NORMATIVELY STANDARDIZED CONTENT STRUCTURE FOR THE HARMONIZATION OF BIM USE CASES
Authors: Feller Daiki John , Kaufhold Matthias , Kelm Agnes , Meins-Becker Anica
Published: October 2023

The demand for a formalized content structure to communicate and perform services in the context of Building Information Modeling is becoming increasingly indispensable for the understanding of BIM use cases in the German and international construction industry. Different market participants have already provided their own proposals, but no solution has yet been consistently successful established. To address this demand, the authors of the paper at hand have initiated a research project to develop the needed standardized content structure. Various nationally and internationally engaged experts from research and industry have been involved to develop this universally applicable structure within the framework of the German standardization institutions DIN and VDI, taking into account the perspectives of all involved stakeholder in BIM projects and existing standards. The structure therefore aims not to only describe a BIM use case on a general level but to be an aid for understanding and executing the service described including needed information and possibilities for quality assurance. This paper underlines the fundamental need of such a standard using the example of the (beforehand) current state of industry in the German speaking countries and presents the final results of this efforts to provide a standardized and applicable structure for BIM use cases. An outlook on further currently developed standardization approaches is additionally given
INVESTIGATION OF HYDRODYNAMICS AND SCOUR AROUND BRIDGE PIERS UNDER THE COMBINED WAVE AND CURRENT EFFECTS
Authors: Eldho Thekkilakkattu Iype , Misuriya Gaurav
Published: October 2023

Bridges piers and other marine structures in coastal regions are affected by water currents and waves. These structures may collapse due to scour induced by water currents or waves, leading to huge economic and life losses. The problem worsens when surface waves are superimposed on current. The superposition of the wave further modifies the flow field around the bridge pier. A thorough understanding of turbulent flow under these circumstances will be crucial for the cost-effective and ideal design of the pier. This study experimentally investigates the effect of the superposition of surface wave on the flow hydrodynamics and the local scour around a circular pier over a gravel bed. It also presents the comparison of turbulence characteristics under only current condition and combination of wave and current. Laboratory experiments were performed in a 15 m long rectangular flume. A surface wave with frequency of 0.5 Hz was superimposed in the direction of current. The instantaneous velocity data for evaluating turbulent kinetic energy was recorded using particle image velocimetry (PIV). The analysis of the result showed that the superposition of surface wave significantly increased the turbulence strength which leads to approximately 30% increase in the local scour depth. This study will be helpful in optimal design of bridge piers and other coastal structures by improving the relationship for the scour prediction in coastal area and provide a data set for the numerical simulation of the problem as well.
FRAMEWORK FOR IDENTIFYING INFLUENCING FACTORS FOR FORMWORK SELECTION FOR RESIDENTIAL BUILDING CONSTRUCTION
Authors: Bhardwaz Vishal , Kumar Uddeshya , Lad Vishal H , Patel Kashyapkumar Arvindbhai , Patel Dilipkumar Arvindkumar
Published: October 2023

Formwork systems (FWS) are essential to any reinforced concrete (RC) construction activity. They are the temporary structures that can bear the load from the concrete and also shape the fresh concrete till it hardens. FWS accounts for around 40% to 60% of concrete's cost and 10% of overall construction's cost of the project. Further, FWS operations consume 50% to 70% of the time in RC construction. The selection of a FWS for a particular type of buildings depends on several factors. However, selecting a FWS is a complex process that takes years of knowledge in this way. In the Indian construction sector, FWS decisions primarily rely on formwork specialists' intuitive and subjective opinions. Therefore, the present research proposes a framework to identifying the influencing factors for formwork selection for residential buildings construction using the Delphi technique. Firstly, the study identifies nine factors and their thirty-four sub-factors influencing the formwork selection based on literature review. The factors are finalized after conducting two rounds of the Delphi technique by creating a questionnaire and gathering data from eleven qualified professionals. Eventually eight main factors (Characteristics, Cost Productivity, Building Design, Productivity, Safety, Quality, Formwork aspects, and Degree of repetition) along with their thirty-one sub-factors are shortlisted. To check the reliability, Cronbach's alpha value is calculated for each factor. The proposed framework can be extended for estimating the weightage of influencing shortlisted factors for the selection of FWS of residential projects in the Indian construction sector.
COMPARISON OF ALTERNATIVE CONTRACTING METHODS OVER 10 YEARS IN A LARGE STATE TRANSPORTATION AGENCY
Authors: Shah Dev , Minchin Edward , Asutosh Ashish T.
Published: October 2023

The construction industry is currently under pressure due to the increase in population and deterioration of infrastructure in the last twenty-five years. The Florida Department of Transportation’s (FDOT)’s response to this pressure has led to using Alternative Contracting Methods (ACMs) as replacements of the traditional contracting method, Design-Bid-Build (DBB), which has been serving the public for over a century. ACMs such as design-build (D-B), lump sum contracting, incentive/disincentive (I/D), cost-plus-time (A+B), and no excuse bonus (NEB) have proven to increase project quality, expedite schedule and decrease costs. The performance of ACMs by FDOT on highway construction projects was evaluated by two reports conducted in 2007 (Ellis et al. 2007) and 2016 (Minchin et al. 2016). Based on these two reports, the research analyzed the change in the performance and number of projects applied in ACMs between 2007 and 2016. This research compared the number of projects, costs, and time of the above-mentioned studies to assess the change and the reason behind it encountered in this comparison. The results of this research show that all ACMs evaluated in the 2016 report were performing better than they performed nine years prior, in 2007, in terms of time and cost. Potential obstacles to applying ACMs and lessons learned were identified in the research, as well as recommendations that would help FDOT to improve the application of ACMs in transportation projects.
CALCULATION METHOD OF LATERAL STIFFNESS OF PVC CAVITY PARTITION WALL WITH DIFFERENT CONNECTION FORMS
Authors: zhang biao , hou hetao , yang fuhang , wang yibo
Published: October 2023

To explore the difference in seismic performance of walls with different connections, this paper designs a pseudo-static test of three groups of steel frames infilled with walls and a group of empty steel frame as a control. The test phenomena and the datum are used to evaluate the performance of structures. The results show that: (I) the initial stiffness and the peak load of the cast-in-place wall are large. The main failure modes are cracking at the joint between the wall and the frame, crushing at the corner, and internal splitting as well as curving outwards under large displacement. (II) The wall with L-shaped connectors dissipates energy by bolt slip and the yield deformation of connectors, which has the lowest contribution to the frame in stiffness and strength. The main failure is the cracking of cement mortar at the joint. (III) The connection mode of U-shaped and L-shaped connectors is relatively safe and reliable, which could make the steel frame and wall panel work better together under the action of earthquake. It could be recommended to use according to the bearing capacity requirements; Walls connected by reinforcement are not recommended because of brittleness failure, poor ductility, ordinary bearing capacity and energy dissipation capacity. Based on the principle of equivalent tension and compression bar, a simplified formula for calculating the lateral stiffness of polyvinyl chloride (PVC) cavity wall panel embedded in fabricated steel frame is proposed, and the accuracy of the calculation results is verified.
INTEGRATED SAFETY MANAGEMENT SYSTEM: EMPOWERING WORKERS TO IMPROVE HEALTH AND SAFETY IN CONSTRUCTION
Authors: Amakrhil Qais , Brogmus George
Published: October 2023

This paper presents a systematic approach to incorporate worker input and self-assessments into the safety management system in construction, enhancing safety and wellbeing. Traditional safety management systems primarily have focused on compliance and reaction to safety hazards. The proposed approach integrates the concept of a “safe employee” and the “I-SAFE ME model” (a self-assessment tool and measures introduced in this paper), emphasizing workers' proactive participation and accountability in safety planning and compliance, into a broader integrated safety management system (ISMS). The I-SAFE ME model allows workers to self-assess factors impacting their safety, health, assigned tasks suitability, and readiness for work. This shift will improve workplace safety, worker satisfaction, wellbeing, and project delivery outcomes, encouraging a culture of shared responsibility and teamwork. The proposed approach extends the concept of safety beyond hazard identification and control to include broader health and wellbeing aspects, often overlooked in traditional safety management practices, by encompassing various project elements regarding construction workers. The expected outcome is to fill the existing construction safety policies and procedures gap and support adherence to OSHA regulations and standards.
IMPACTS OF GOVERNANCE CONSTRAINTS ON ODA PROJECT QUALITY: EXPLORATORY STUDY
Authors: Dang Chau Ngoc , Nguyen Long D.
Published: October 2023

Effective project implementation is critical to the success of transportation projects and significantly contributes to the productivity and economic growth. Unfortunately, many transportation projects in developing countries have not yet met their expected outcomes. This study aims to explore the governance constraints in the construction phase and their impacts on the quality of the transportation projects funded by the official development assistance (ODA). Based on 340 survey questionnaires collected from both national and provincial project management units (PMUs) in Vietnam, the mean score method was first used to rank the governance constraints in construction. The results showed that site clearance and handover, capital shortage and parties’ incompetence and irresponsibility were assessed to be the most significant governance constraints by both managers and other members involved in ODA-funded transportation projects. Following the results of one-sample t test, a significant difference between ODA-funded and government-funded projects was also found on five constraints: site clearance and handover, capital shortage, delayed payments to contractors, donor involvement, and cost escalation. In addition, the results of regression analysis indicated that project quality could be significantly affected by such constraints as site clearance and handover, changes in scope of work, review/approval of change orders, cost escalation, and imported long-lead items. These results together could provide international sponsors and practitioners with some useful insights to better implement ODA-funded transportation projects in Vietnam and other developing countries.
RULE-BASED DELAY ANALYSIS SELECTION SYSTEM
Authors: Yang Juneseok , Arditi David , Lee Dong-Eun
Published: October 2023

Since the selection of a delay analysis method depends on the delay analyst's subjective judgment, there is a risk of making problematic decisions due to the delay analyst's ignorance, lack of experience, carelessness, or intention. Each one of these methods may yield different analysis results. Therefore, it is necessary to develop an objective decision-making system based solely on the project environment. The existing delay analysis methods are classified into four types, according to the basic principles used in the analysis. Seven conditions that affect the selection of a delay analysis method (i.e., type of schedule, type of information, timing of analysis, expectations from the delay analysis, acceptance by courts of law, capabilities of delay analysis team, and budget constraint) were identified in a literature review. A delay analysis selection system (DASS) was developed using if-then rules constructed by considering which conditions should exist in a given project environment for successfully performing a specific type of delay analysis and getting realistic results. This system was computerized and validated by implementing it in several but different scenarios considered in this study. The contributions of this study include (1) an objective selection decision can be made based on only the project environment, without relying on the analyst's subjective preference, and (2) unnecessary and expensive legal disputes caused by delay-related issues between construction owners and construction companies can be minimized.