The rational formula from the runhydrograph

The rational formula is possibly the simplest flood estimation technique available using rainfall-runoff relationships. In spite of the many criticisms regarding its over-simplification of the processes of rainfall conversion into runoff, it remains possibly the most widely used method for estimating peak flood flows for urban drainage systems and small

External validation of prognostic models to predict stillbirth using the International Prediction of Pregnancy Complications (IPPIC) Network database: an individual participant data meta-analysis

Objective Stillbirth is a potentially preventable complication of pregnancy. Identifying women at high risk of stillbirth can guide decisions on the need for closer surveillance and timing of delivery in order to prevent fetal death. Prognostic models have been developed to predict the risk of stillbirth, but none has yet been validated externally. In this study, we externally validated published prediction models for stillbirth using individual participant data (IPD) meta-analysis to assess their predictive performance. Methods MEDLINE, EMBASE, DH-DATA and AMED databases were searched from inception to December 2020 to identify studies reporting stillbirth prediction models. Studies that developed or updated prediction models for stillbirth for use at any time during pregnancy were included. IPD from cohorts within the International Prediction of Pregnancy Complications (IPPIC) Network were used to validate externally the identified prediction models whose individual variables were available in the IPD. The risk of bias of the models and cohorts was assessed using the Prediction study Risk Of Bias ASsessment Tool (PROBAST). The discriminative performance of the models was evaluated using the C-statistic, and calibration was assessed using calibration plots, calibration slope and calibration-in-the-large. Performance measures were estimated separately in each cohort, as well as summarized across cohorts using random-effects meta-analysis. Clinical utility was assessed using net benefit. Results Seventeen studies reporting the development of 40 prognostic models for stillbirth were identified. None of the models had been previously validated externally, and the full model equation was reported for only one-fifth (20%, 8/40) of the models. External validation was possible for three of these models, using IPD from 19 cohorts (491 201 pregnant women) within the IPPIC Network database. Based on evaluation of the model development studies, all three models had an overall high risk of bias, according to PROBAST. In the IPD meta-analysis, the models had summary C-statistics ranging from 0.53 to 0.65 and summary calibration slopes ranging from 0.40 to 0.88, with risk predictions that were generally too extreme compared with the observed risks. The models had little to no clinical utility, as assessed by net benefit. However, there remained uncertainty in the performance of some models due to small available sample sizes. Conclusions The three validated stillbirth prediction models showed generally poor and uncertain predictive performance in new data, with limited evidence to support their clinical application. The findings suggest methodological shortcomings in their development, including overfitting. Further research is needed to further validate these and other models, identify stronger prognostic factors and develop more robust prediction models. (c) 2021 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.Peer reviewe

Passenger preferance criteria for selecting rapid transit system for city of Colombo

Traffic congestion is a condition on road networks that occurs as use increases and is characterized by slower speeds, longer trip times, and increased vehicular queuing. As demand approaches the capacity of a road, extreme traffic congestion sets in. Traffic congestion contributes to waste of time and money every second. Many developed/developing countries find solution for the traffic congestion at roads with the help of rapid transit systems. Rapid transit systems can be dividing in to four major categories; Bus rapid transit (BRT) Monorail system Light rapid transit (LRT) Mass rapid transit (MRT) The main objective of this research is to propose a methodology to select most appropriate rapid transit system technology for a given transport corridor with emphasis on passenger preference criterion for selecting rapid transit system for city of Colombo. The study consists of collecting user preference based on a questionnaire survey. Jayawardenapura corridor has been selected as a case study. This corridor is highly congested at peak time and it will be increase at future due to administration city will become Jayawardenapura corridor. Hence it is essential to give proper solution for the increasing traffic in this corridor. In addition to user preferences the questionnaire focuses on the drawbacks in existing systems, user expectations for a new system. These were used to identify the user related issues in existing systems and to find whether a rapid transit can address those issues. According to the survey results of, 48% respondents of indicated that BRT may be the better option for selected corridor. Balance prefer an elevated system as opposed to BRT. It is required to establish criteria based on the not only passenger’s preference, but also constructability, connectivity with other modes, extendibility in future and environmental friendliness. According to the research, passenger most preferred for the BRT system. With the connectivity with other modes monorail systems is better than BRT. Possibility of future expansion of the system, difficulty face with BRT system due restrictions of land acquisition. From the environment point of view, more emissions are expected from BRT system than Monorail system. According to the cost calculation it is lesser cost required to introduce BRT over Monorail or other elevated system

CONCEPTUALIZING GOVERNMENT-TO-GOVERNMENT (G2G) RELATIONS THROUGH THE CASE OF GEOINFORMATION-

Abstract. This research was developed out of the need to find better methods for understanding and describing Government-to-Government (G2G) relations. In this article G2Gs are viewed from inside the G2G relation, i.e. from within the relation on the basis of which two or more government agencies are cooperating in the exchange and sharing of information. A specific focus was given to Geoinformation(Geo)-based G2Gs. Using a number of (Geo)G2G cases in the Netherlands, a framework was constructed to research these G2G relations further. This comprises of two main elements: the (Geo)ICT, which can be described by the information products, processes and agents; and, the inter-organizational cooperation, which be described by motivation, agreements, responsibilities and intended duration. Ultimately, the research questions aim to address the relation between these two types of elements, such that the impact of (Geo)ICT on inter-organizational characteristics and vice versa can be better understood and described. Once these impacts are better described, it is assumed that G2Gs are better described, and thus can also be better evaluated in the future