Delay Factors Research Articles

Identifying and assessing the impact of 4M1E factors on construction project delays in Afghanistan using structural equation modeling

AbstractConstruction projects in Afghanistan are often challenged by significant delays, posing severe challenges to their successful completion. This study aims to comprehensively assess the impact of various delay factors using the 4M1E framework Man, Machine, Material, Method, and Environment within the Afghan construction sector. By employing a validated Structural Equation Modeling (SEM) approach, the research investigates both direct and indirect effects of these factors on project delays. The analysis reveals that environmental and material factors are particularly influential, with environmental changes often exacerbating delays across other dimensions. The findings underscore the complex interdependencies among the 4M1E factors, highlighting the need for targeted strategies to manage the delay effectively. Practical recommendations are provided to enhance project management practices, with implications that extend beyond Afghanistan to other developing countries facing similar challenges. This study contributes to the academic discourse on construction delays, offering actionable insights for practitioners, policymakers, and stakeholders in the construction industry.

Predictive factors for arteriovenous fistula maturation: A prospective study.

Arteriovenous fistula (AVF) maturation failure remains common despite preoperative ultrasound mapping. Identifying predictive biomarkers can help anticipate primary failure and reducing invasive procedures. Our study aimed to identify clinical and analytical risk factors for primary AVF failure or delay. A prospective study (October 2022-March 2023) included adult patients scheduled for AVF creation. In all patients, a preoperative ultrasound mapping was conducted and AVF maturation assessed at least 6 weeks post-surgery. Clinical, analytical, and demographic data were collected. Eighty patients were included, 62.5% male, and mean age 66.3 years. For distal anastomosis, preoperative vein (3.8 ± 1.2 vs. 2.8 ± 0.6 mm; p 0.002) and supply artery (2.5 ± 0.4 vs. 2.0 ± 0.3 mm; p 0.001) diameters were significant factors impacting primary failure. Also, for proximal anastomosis, the artery diameter (2.4 ± 0.4 vs. 2.0 ± 0.4 mm; p 0.01) had an impact on AVF maturation. ROC curves established for distal AVF a vein diameter cutoff of 3.25 mm (AUC 77.2%) and artery cut-off of 2.35 mm (AUC 74.6%) and for proximal AVF an artery cutoff of 2.25 mm (AUC 76.5%). Distal AVF creation correlated with higher primary failure risk (p < 0.001). No correlation was found between the primary failure rate and the presence of central venous catheter or serum results. In a sub analysis, we found that patients with central venous catheter had higher levels of inflammatory markers. Our study highlights the importance of preoperative evaluation, ultrasound mapping, and careful AVF site selection. Recognizing vein and artery diameter thresholds for optimal outcomes is crucial. Avoiding central venous catheters in suitable patients can positively impact AVF results.

Analyzing Delay Factors in Iraqi Construction Projects: An ANP Approach with Najaf Governorate as a Case Study

Construction projects in Iraq often experience delays owing to various factors, making it challenging to accurately estimate completion times. This study investigates the factors contributing to these delays, focusing on the Najaf Governorate as a case study. The primary objective of this study was to investigate issues related to the construction project completion duration, particularly considering Iraq's current unprecedented reconstruction and building efforts. The most significant factors influencing the completion duration were identified through statistical analysis of the samples and application of the Analytic Network Process (ANP) method. Data were collected and refined using a questionnaire designed according to a five-point Likert scale and administered in two rounds. The first round involved 28 participants, whereas the second round included 5 participants. The analysis revealed that contractor inefficiency, particularly from a financial perspective, is one of the most critical factors affecting construction progress and causing delays. The practice of accepting the lowest bids emerged as the second most crucial aspect leading to project delays in Iraq. Additionally, the study concluded that insufficient cash flow for the employer and the lack of technical expertise within the contractor company were the third and fourth most influential factors affecting the duration of construction projects, respectively. This study also highlighted that legal gaps in Iraq's legislative framework for construction projects are among the most significant causes of delays. Finally, the practice of subcontracting was identified as a significant contributor to both delays and poor work quality in the construction projects in Iraq.

Diagnostic delay in inflammatory bowel disease: Current situation and problems.

In this article, we comment on the article by Blüthner et al published recently. Inflammatory bowel disease (IBD), including ulcerative colitis and Crohn's disease, is a chronic relapsing and remitting condition primarily as a consequence of intestinal inflammation. It is important about adopting early and effective treatment to control clinical symptoms of IBD patients. Diagnostic delay can lead to adverse clinical outcomes and increase disease burden. Diagnostic delay is multifactorial. There are some factors related to diagnostic delay, such as patient factors and healthcare factors. We focus on the diagnostic tools for IBD, the outcomes and factors of diagnostic delay of IBD.

Complex Attention-Deficit Hyperactivity Disorder in a 4-Year-Old With Repaired Critical Congenital Heart Disease and Autism Spectrum Disorder.

Congenital heart disease (CHD) is a risk factor for developmental delay and for attention-deficit hyperactivity disorder (ADHD). The Cardiac Neurodevelopmental Outcome Collaborative has developed recommendations for ongoing monitoring of this at-risk population to be able to detect developmental, learning, and behavioral concerns, as they become apparent as a child ages. A 4-year-old boy with tetralogy of Fallot with a ventricular septal defect repaired in infancy was followed periodically in the cardiac neurodevelopmental follow-up clinic and diagnosed with autism spectrum disorder as well as additional developmental and medical issues. He received early childhood special education and therapeutic interventions as well as social skills training and applied behavior analysis. At age 4 years, Alex presented with symptoms of hyperactivity, inattention, impulsivity, and immediate safety concerns for elopement. The clinician diagnosed him with ADHD-combined type. He was recommended to start medication in addition to behavioral and developmental supports. Managing medications in a child with CHD and ADHD presents unique challenges, and medication decisions were carefully made in collaboration with the child's cardiologist. After some medication adjustments and ongoing behavioral therapy to address behaviors associated with ADHD and autism spectrum disorder, the child is doing well academically and socially. Attention-deficit hyperactivity disorder medications can be safely prescribed in patients with CHD. However, pharmacotherapy for co-occurring ADHD and CHD needs an additional level of oversight and collaboration between cardiology and prescribing clinicians. Behavioral therapies can be transdiagnostic and address challenges associated with autism and symptoms related to ADHD.

Critical Delay Factors Affecting Construction Project Performance – A Contemporary Perspective

The construction industry plays a crucial role in India's fiscal targets amid a growing emphasis on infrastructure development. Despite extensive project management knowledge, persistent delays afflict 33% of projects, averaging a 47-month setback as of August 2021. This study seeks to pinpoint Critical Delay Factors (CDFs) in contemporary construction projects, drawing from 59 attributes identified through literature and expert input. A questionnaire survey gauged expert opinions on the impact of these attributes. Factor analysis unveiled underlying constructs, revealing seven CDFs, and the Relative Importance Index (RII) ranked factors by significance. Across professional roles and regional distinctions, ANOVA demonstrated consistent CDF evaluations. These findings are anticipated to guide project stakeholders in prioritizing factors for effective delay management, promoting successful project outcomes.

Impact of healthy pregnancy and lifestyle in mothers on developmental delay in their offspring: a strength-based analysis of a longitudinal study among indigenous children in Australia

IntroductionExtensive literature has investigated the prenatal risk factors of developmental delay in children, with evidence highlighting the impact of prenatal health, mental health, and behavioural factors. While a deficit discourse has underscored Indigenous health research and policies, strengths-based approaches provide an opportunity to reframe this discourse, to illustrate and celebrate the strength and resilience of Australian Indigenous families. As such, this study aimed to identify the protective impact of healthy pregnancy and lifestyle in mothers on developmental delay in Indigenous Australian children; and whether it varies by child birthweight adjusted for gestational age. Further, we also tested whether child birthweight for adjusted gestational age mediates the association between a healthy pregnancy and lifestyle in mothers and developmental delay in their Indigenous offspring.MethodsStrength-based analysis was conducted using data from 8 longitudinal waves of LSIC study in Australia. Random-effect models were used to longitudinally measure the impact of maternal healthy pregnancy and lifestyle on developmental delays in their children between 2008 and 2018. A composite score (ranging from 0 to 3, score = 3 refers to most healthy pregnancy) was created for a healthy pregnancy and lifestyle variable using three criteria − (1) a lack of medical conditions, (2) no substance use including smoking/alcohol/illicit drugs, and (3) intake of iron/folic acid during pregnancy. All models were adjusted for potential covariates.ResultsOf the 780 mother-child dyads analysed, 65.4% of mothers reported healthy pregnancy and lifestyle; while 73.5% of children born with a recommended appropriate birthweight adjusted for gestational age, and 91.4% reported no developmental delays. In children born in the recommended range of appropriate birthweight adjusted for gestational age, healthy pregnancy in mothers (most healthy, aOR: 4.76, 95% CI: 1.12–20.18; and 2nd most healthy, aOR: 4.02, 95% CI: 1.09–14.83) was protective against development delay compared to maternal unhealthy pregnancy. Living in remote areas (vs. major city, and regional) was also found to be protective against developmental delay in those who were born within the recommended range of birthweight adjusted for gestational age. Further, the current study found that child birthweight for adjusted gestational age does not have any mediating effect on the association between healthy pregnancy in mothers and developmental delay in their children.ConclusionThis strengths-based study suggests healthy pregnancy in mothers should be advocated to prevent developmental delay in their offspring in the Australian Indigenous population. The findings also found living in remote areas has a protective effect against developmental delay in Indigenous children who born within the recommended range of birthweight adjusted for gestational age. These findings have implications for challenging and reframing the deficit discourse surrounding Indigenous Australian health research and policymaking. Further studies are needed to investigate the positive relationship between Indigenous Australians’ health and social and emotional well-being (SEWB) and their connection to their country and culture.

SDIR Mathematical Approach with Time Delay Factor to Reveal Indonesian Students' Interest in Government Organizations and Internships: A Case in FMIPA UNM

This study is to build a time-delay SDIR model on the case of student interest in Organizations and Government Internship Programs, analyze the model and conduct a model simulation to predict the level of student interest cases in Organizations. This study is a theoretical and applied study. Analysis of the time-delay SDIR model of the case of student interest in Organizations, while the model simulation uses Maple Software. The population of the study was active students of FMIPA UNM, with a sample size of 1029 students obtained using the Sloving technique. The results of this study are a mathematical model of SDIR on the case of student interest in Organizations which is a system of differential equations. The model analysis provides a value of the free equilibrium point of the case of student interest in Organizations and a stable endemic equilibrium point. The results also found that the basic reproduction number value for cases without a solution would produce R0n = 9.912507841, which means that in social cases where one individual can influence 9-10 people in their environment to hesitate to participate in organizational activities or internship programs, but on the other hand if the case is given a solution, it will produce R0s = 0.2737372211, which means that there is no psychological spread, where each individual does not influence other individuals.

Treatment and delay control strategy for a non-linear rift valley fever epidemic model

Rift Valley Fever (RVF) is a viral disease affecting animals and humans, causing symptoms such as fever, liver damage, and bleeding, particularly prevalent in Africa. This study focuses on numerical solutions for a non-linear delayed dynamic epidemiological model of RVF. It extends a control problem incorporating the susceptible, infected, treated, recovered vector to analyze the impact of measures such as mosquito repellent and treatment. The goal is to examine how time delays in implementing control measures affect the dynamics of an epidemic. The model considers delay factors such as mosquito replication, hospitalization, travel restrictions, and isolation due to the lack of proper vaccination. The study explores the model’s aspects, including the reproduction number, equilibrium points, and stability. Local and global implications are examined using techniques such as the Lyapunov function and the Brauer-F lemma. Numerical analysis employs the non-standard finite difference method, establishing the local stability of the equilibrium through the effective reproduction number Rrvf and sensitivity analysis. The research highlights the importance of treatment and delay strategies in reducing RVF transmission, emphasizing the critical need for immunization and preventive measures.

Design of a UWB circularly-polarized planar monopole antenna using characteristic mode analysis

This study presents a circularly-polarized (CP) planar monopole antenna designed for ultra-wideband (UWB) applications using characteristic mode analysis (CMA). Initially, a planar monopole antenna with a crescent moon-shaped radiator and a circular open-loop on an FR-4 substrate was designed to achieve wideband characteristics, however, this antenna only satisfied a 3 dB axial ratio (AR) bandwidth within the 8.78–9.4 GHz range. To enhance the AR bandwidth, a triangular slit, a shark fin-shaped stub, and an L-shaped strip were added to the ground plane, generating orthogonal modes in the desired frequency band using CMA. The overall dimensions of the proposed antenna are 30 × 24 × 1.6 mm2 (0.58 × 0.46 × 0.031 λ₀2). The − 10 dB S11 bandwidth is 5.73–10.78 GHz (61.21%) and the 3 dB AR bandwidth is 6–11.12 GHz (59.81%), achieving overlapped bandwidth from 6 to 10.78 GHz (56.9%). The proposed antenna has a realized gain 2.4–5.4 dBi and an average efficiency of 80% within the target frequency. A time-domain analysis, including group delay and system fidelity factor, is conducted to evaluate performance. The fabricated antenna demonstrates omnidirectional radiation patterns at various frequencies and performs well in both the time and frequency domains.

Joint Wideband Spectrum Sensing and Carrier Frequency Estimation in the Multi-Path Propagation Environment Based on Sub-Nyquist Sampling

We consider the wideband spectrum sensing within a multi-path propagation environment, where a multi-antenna base station (BS) is tasked with identifying the frequency positions of multiple narrowband transmissions distributed across a broad range of frequencies. To tackle this, we propose a sub-Nyquist sampling structure that incorporates a phased array system. Specifically, each antenna is connected to two separate sampling channels, i.e., one for direct sampling and another for delayed sampling, with the latter incorporating a specified time delay factor. The cross-correlation matrices associated with the samples, which are characterized by different time lags, are calculated. These matrices are represented in tensor form, and the factor matrices are extracted through CANDECOMP/PARAFAC (CP) decomposition. By these factor matrices, the carrier frequencies and the power spectra of the far-field signals of interest are estimated. Numerical simulations are conducted to evaluate the performance of the proposed method, and the results reveal the feasibility and effectiveness of the approach, demonstrating its potential for accurate and efficient wideband spectrum sensing in complex multi-path propagation environments.

A cycle slip detection and repair method based on generalized-cross-validation regularization for BDS-3 quad/pent-frequency data

Abstract Multi-frequency (quad/pent-frequency) observations improve the success rate for BeiDou Navigation Satellite System (BDS-3) cycle slip detection and repair. Three factors are comprehensively considered: the combination of observation wavelength, the amplification factor of ionospheric delay, and the insensitivity, to select the optimal combination coefficients for BDS-3 multi-frequency cycle slip detection. Due to the ill-conditioned equation in multi-frequency cycle slip repair, the generalized-cross-validation regularization auxiliary LAMBDA method is proposed. To validate the effectiveness of the proposed detection and repair method under different observation environments, two stations are selected for the test. Using real data, the effectiveness of the selected optimal combination coefficients and the proposed method are tested. The conclusions are as follows: (1) for quad-frequency, one geometry-free and ionosphere-free (GFIF) combination [−1, 2, −4, 3] and three linearly independent geometry free carrier phase (GF) combinations [−1, 1, 0, 0], [−1, 1, 1, −1], and [−1, 2, −1, 0] are employed to detect cycle slips. For pent-frequency, one GFIF combination [−2, 2, 1, −2, 1] and four linearly independent GF combinations [−1, 1, 0, 0, 0], [0, 0, −1, 1, 0], [0, 0, −1, 0, 1], and [0, −1, 1, 1, −1] are adopted for cycle slip detection. (2) The algorithm proposed in this paper has been demonstrated to achieve a quad/pent-frequency cycle slip detection success rate of 99.99% and 100% in the coastal environment, and both 100% for quad/pent-frequency detection success in the urban environment. (3) The success rate of repair were 99.27% and 99.94% for the coastal stations, and 99.83% and 100% for the urban stations, respectively. The proposed algorithm offers a dependable approach for the identification and rectification of multi-frequency cycle slips, while also providing a point of reference for the future advancement of multi-frequency cycle slip repair techniques.

Development of gross motor skills in children under the age of 3 years: a decision tree approach.

The early years of life are critical for gross motor development (GMD). This study utilized decision tree modeling to examine the influences on gross motor development in children under the age of 3 years and to rank the key factors affecting their development. Based on randomized stratified sampling, 9,507 children aged 0-3 years in Shenzhen were included in this study. The Ages and Stages Questionnaires (ASQ) were utilized for the assessment of gross motor development. The chi-square test was used to compare groups, and variables were screened using univariable and multivariable regression analyses. Decision tree modeling was employed to rank the importance of statistically significant variables. The research found a prevalence of gross motor developmental delay of 1.41% among the respondents. The accuracy of the decision tree model is 70.96%. The results demonstrated a strong correlation between seven variables affecting the gross motor development of children, which were ranked based on importance: age, whether to provide supplementary food, average time spent interacting with children, family type, feeding method, mode of delivery, and birth order. The risk of gross motor developmental delay increases with age. Furthermore, supplementary food and interacting with other children are critical factors in improving children's GMD delay. It is therefore imperative to enhance the monitoring of children's gross motor skills through regular developmental assessments that detect potential GMD delays. Moreover, family type, feeding method, mode of delivery, and birth order were also predictive factors of GMD delay.

Performance Evaluation of HTTP, DHCP and DNS Protocols of Data Packets for Vulnerabilities Using the Isolation Forest Algorithm

In the contemporary digital landscape, network security is paramount to safeguard data integrity and prevent unauthorized access as data have been structured in the network through protocols. In term of data structure IPv6 protocol has extended data size due to the robust addresses of 128 bits as compare to 32 bits of IPv4. Due to the improved security data structure of IPv6, the study focuses on identifying vulnerabilities in HTTP, DHCP, and DNS packets using the Isolation Forest algorithm approach, a machine-learning technique designed for anomaly detection. By analyzing packet lengths, size, payload and addressing, the study visualizes normal and anomalous behavior, providing insights into potential security threats in IPv4 network structure. The results highlight the effectiveness of Goodput, Quality of service and risk as essential factors in the network, using Little's theorem analysis and the Isolation Forest in detecting anomalies across these different network protocols, offering valuable implications for network security structures, due to IoT in recent networks. The time response determination in this paper explained details information on the time the treats entered the network, the duration of the vulnerabilities within the network, leading to a certain threshold, and traffic delay factors due to deviation of packet length and other social engineering activities. Sensitive multipurpose security devices are involved; MikroTik routers were configured and installed in the network under evaluation. Which the normal DPI technique was unable to effectively and efficiently addressed. ADPI principles and operations where the needed security measures adopted to detect those vulnerabilities which were eventually addressed and have contributed to recent measures of network security.

The Perspective of Haitian Parents on Heritage Language Maintenance in Children With Speech-Language Disorders

Purpose: This study is part of a larger study that explores the beliefs and attitudes of Haitian parents in the United States regarding heritage language maintenance. The study sought to understand Haitian parents' perspective of heritage language maintenance when the parent has a child with a communication disorder. Method: Semistructured interviews were conducted with seven Haitian parents of children who have or had a speech-language disorder. The interviews were conducted virtually through videoconferencing. A thematic analysis was used to explore the data and determine recurring themes. Results: Participants desired to preserve the heritage language; however, fear of further language delay and sociolinguistic factors influenced their language choice. Furthermore, the results revealed that the lack of Haitian Creole language maintenance led to a communication breakdown with family and parental regret on the missed opportunity to pass on the heritage language. Conclusion: The findings from this study demonstrate a need for continued education with physicians, SLPs, and other related service providers on the issues related to bilingual language development, language maintenance, and counseling families regarding home language practice. Supplemental Material: https://doi.org/10.23641/asha.27190611

Time delayed fractional diabetes mellitus model and consistent numerical algorithm

The diabetes mellitus model (DMM) is explored in this study. Many health issues are caused by this disease. For this reason, the integer order DMM is converted into the time delayed fractional order model by fitting the fractional order Caputo differential operator and delay factor in the model. It is proved that the generalized model has the advantage of a unique solution for every time t. Moreover, every solution of the system is positive and bounded. Two equilibrium states of the fractional model are worked out i.e. disease free equilibrium state and the endemic equilibrium state. The risk factor indicator, R0 is computed for the system. The stability analysis is carried out for the underlying system at both the equilibrium states. The key role of R0 is investigated for the disease dynamics and stability of the system. The hybridized finite difference numerical method is formulated for obtaining the numerical solutions of the delayed fractional DMM. The physical features of the numerical method are examined. Simulated graphs are presented to assess the biological behavior of the numerical method. Lastly, the outcomes of the study are furnished in the conclusion section.

Stability and computational analysis of Influenza-A epidemic model through double time delay

Delay factors demonstration has a significant role in controlling a strain of infectious disease instead of a pharmaceutical strategy. According to the World Health Organization (WHO), 3–5 million cases are reported annually and approximately 290,000 to 650,000 respiratory deaths annually. So, in the present study, we develop a delayed mathematical model based on delay differential equations (DDEs) for the influenza epidemic using a deterministic approach by introducing double delay parameters. The four distinct sub-populations are considered susceptible, exposed, infected, and recovered. For the rigorous analysis, the fundamental properties of the model like positivity, boundedness, existence, and uniqueness, were studied. The influenza-free equilibrium (IFE) and influenza-existing equilibrium (IEE), are the two nonnegative equilibrium points that the model demonstrates. Both locally and globally, the asymptotic stability of the equilibrium points of the model is established and shown under specific situations of reproduction number. Additionally, investigated the model's parameter sensitivity and determined the relative sensitivity of each parameter. Both standard and nonstandard methods—such as Euler, Runge-Kutta, and nonstandard finite difference with a delayed sense—are presented to make computational analysis support a dynamical analysis and the best visualization of results. The stability of the non-standard finite difference scheme is thoroughly analyzed around the steady states of the model. Additionally, the results show that the nonstandard finite difference approximation is an efficient, cost-effective method, independent of time step size, to solve such highly nonlinear and complex real-world problems.

Relationship between self-reported challenges with social determinants of health and delayed time-to-treatment initiation for gynecologic malignancies.

90 Background: Delays in time to treatment initiation (TTI) for gynecologic malignancies have been associated with worse survival. Worsened outcomes and presentation with more advanced disease are more common for gynecologic cancer patients who come from socioeconomically disadvantaged populations and whose healthcare is negatively impacted by their social determinants of health (SDoH). There is a need to characterize the particular social determinants of health that are associated with delays in treatment initiation in patients with gynecologic malignancy, particularly in underserved urban populations. Methods: Retrospective cohort study at an urban community-based academic center. Participants were 257 patients with primary gynecologic malignancy either of the cervix, ovary, uterus, vulva/vagina or NOS diagnosed between January 2017 and August 2022, identified through the Montefiore Medical Center Cancer Registry. The primary exposure was TTI, defined as the duration between histopathological diagnosis and initial treatment. Univariate and multivariate logistic regression analyses were conducted to examine the association between delays in TTI and SDoH. Multivariate Cox proportional hazard regression was used to obtain hazard ratios and 95% confidence intervals associated with TTI. Results: Among 257 patients with gynecologic malignancy (median [IQR] age 63 [56-72] years), 205 patients were treated within 45 days of diagnosis, and 52 were treated at or after 45 days. Predictors of delayed TTI (defined as ≥45 days) included positive SDoH screening in univariate logistic regression (OR = 3.12, 95% CI 1.39-6.98, p = 0.0061) and in multivariate logistic regression (OR = 3.06, 95% CI 2.62-3.57, p&lt;0.001) as well as increased age in multivariate logistic regression (OR = 1.02, 95% CI 1.02-1.03, p&lt;0.001). Multivariate logistic regression showed that protective factors for delayed TTI were Non-Hispanic Black race/ethnicity (OR = 0.87, 95% CI 0.77-0.99, p = 0.0351), non-Hispanic white race/ethnicity (OR = 0.37, 95% CI 0.30-0.46, p&lt;0.001), inpatient stay within 30 days of diagnosis (OR = 0.74, 95% CI 0.62-0.88, p=0.001) and AJCC clinically late stage (OR = 0.57, 95% CI 0.50-0.66, p&lt;0.001). Conclusions: In patients with gynecologic malignancies, greater SDoH burden increases risk for delays in treatment ≥ 45 days from diagnosis. Non-Hispanic race/ethnicity, inpatient stay within 30 days of diagnosis and clinically late-stage diagnoses are protective factors for expedited treatment initiation. Identification of predictive and protective factors for treatment delay will help identify at-risk patients and facilitate earlier intervention in hospitals with underserved populations.

Empirical Study on Delays in Highway Projects: A Comparative Analysis of Small and Large Projects

Delays in National Highway projects, regardless of their geographical location, have exerted a substantial impact on project performance and yielded unfavourable economic consequences. The majority of these projects in India are implemented by Public-Private Partnerships (PPPs), which use a wide range of contract types, including traditional ones such as item rate contracts and bills of quantity, in addition to more modern alternatives such as build operate transfer, engineering procurement and transfer, and recently developed hybrid models. This study examines and compares the reasons of critical delays in national highway projects in Himachal Pradesh with project characteristics. This mixed-methods study gathered comprehensive data from project participants using qualitative analysis and a survey questionnaire. Interviews and document analysis identified delay factors, which were then assessed through a structured questionnaire distributed to a representative sample of project participants. The findings highlight critical delay factors in National Highway projects in Himachal Pradesh and offer insights into the unique challenges faced by large PPP projects and small traditional projects. Despite the small sample size of 134 survey responses, the findings are significant but may have limited applicability to other infrastructure projects due to socio-economic and geographic variations. This suggests a research gap indicating that further analysis is needed to understand the challenges in EPC and PPPs for large hilly road projects, along with a focused study on organizational culture to assess highway project performance. This study contributes empirical data to the literature about the steep National Highway projects in Himachal Pradesh. Policymakers, project specialists, and stakeholders may ascertain the reasons of delays and formulate targeted actions to enhance project efficiency.

Method of generating potential evapotranspiration with high precision and resolution

Potential evapotranspiration (PET) is a key factor in hydrological cycle and energy balance and plays an important role in drought and global climate change response. Existing observational and modeling methods for PET retrieval have their limitations, such as low precision and poor spatial resolution, which becomes the focus of this study. A hybrid PET fusion (HPF) method is proposed by fusing station- and grid-based PET, in which the PET expression is determined by considering the factors of location, temperature, and zenith total delay (ZTD). In addition, an improved Helmert variance component estimation method is introduced to determine the optimal weights of the HPF model. Corresponding data, which include monthly Thornthwaite (TH)-derived PET data with a spatial resolution of 0.25° × 0.25° and Penman–Monteith (PM)-derived PET data at 704 meteorological stations, over the past 60 years from 1959 to 2018 in China are selected. The 10-fold cross-validation method is introduced to evaluate the internal and external accuracies of the proposed HPF method. Statistical result shows that the average root mean square (RMS) of the proposed HPF method is 13.98 mm, with an average RMS improvement rate (IR) of 46.71 % compared with TH-derived PET, when PM-derived PET is regarded as a reference. Moreover, the performance of the HPF-derived standardized precipitation evapotranspiration index (SPEI) is evaluated at different time scales, and the average RMS is 0.3, with an average RMS IR of 26.33 % compared with TH-derived SPEI. Such results verify the good performance of the proposed HPF model and enrich the methods for obtaining PET with high precision and resolution.