Hasil untuk "Hydraulic engineering"

Fernando Ayach, Vitor Lameirão, Raul Leão et al.

Proto-personas are commonly used during early-stage Product Discovery, such as Lean Inception, to guide product definition and stakeholder alignment. However, the manual creation of proto-personas is often time-consuming, cognitively demanding, and prone to bias. In this paper, we propose and empirically investigate a prompt engineering-based approach to generate proto-personas with the support of Generative AI (GenAI). Our goal is to evaluate the approach in terms of efficiency, effectiveness, user acceptance, and the empathy elicited by the generated personas. We conducted a case study with 19 participants embedded in a real Lean Inception, employing a qualitative and quantitative methods design. The results reveal the approach's efficiency by reducing time and effort and improving the quality and reusability of personas in later discovery phases, such as Minimum Viable Product (MVP) scoping and feature refinement. While acceptance was generally high, especially regarding perceived usefulness and ease of use, participants noted limitations related to generalization and domain specificity. Furthermore, although cognitive empathy was strongly supported, affective and behavioral empathy varied significantly across participants. These results contribute novel empirical evidence on how GenAI can be effectively integrated into software Product Discovery practices, while also identifying key challenges to be addressed in future iterations of such hybrid design processes.

Alexandra Mazak-Huemer, Christian Huemer, Michael Vierhauser et al.

With the increasing significance of Research, Technology, and Innovation (RTI) policies in recent years, the demand for detailed information about the performance of these sectors has surged. Many of the current tools are limited in their application purpose. To address these issues, we introduce a requirements engineering process to identify stakeholders and elicitate requirements to derive a system architecture, for a web-based interactive and open-access RTI system monitoring tool. Based on several core modules, we introduce a multi-tier software architecture of how such a tool is generally implemented from the perspective of software engineers. A cornerstone of this architecture is the user-facing dashboard module. We describe in detail the requirements for this module and additionally illustrate these requirements with the real example of the Austrian RTI Monitor.

Jannatul Bushra, Md Habibor Rahman, Mohammed Shafae et al.

Reverse engineering can be used to derive a 3D model of an existing physical part when such a model is not readily available. For parts that will be fabricated with subtractive and formative manufacturing processes, existing reverse engineering techniques can be readily applied, but parts produced with additive manufacturing can present new challenges due to the high level of process-induced distortions and unique part attributes. This paper introduces an integrated 3D scanning and process simulation data-driven framework to minimize distortions of reverse-engineered additively manufactured components. This framework employs iterative finite element simulations to predict geometric distortions to minimize errors between the predicted and measured geometrical deviations of the key dimensional characteristics of the part. The effectiveness of this approach is then demonstrated by reverse engineering two Inconel-718 components manufactured using laser powder bed fusion additive manufacturing. This paper presents a remanufacturing process that combines reverse engineering and additive manufacturing, leveraging geometric feature-based part compensation through process simulation. Our approach can generate both compensated STL and parametric CAD models, eliminating laborious experimentation during reverse engineering. We evaluate the merits of STL-based and CAD-based approaches by quantifying the errors induced at the different steps of the proposed approach and analyzing the influence of varying part geometries. Using the proposed CAD-based method, the average absolute percent error between simulation-predicted distorted dimensions and actual measured dimensions of the manufactured parts was 0.087%, with better accuracy than the STL-based method.

Thi Yen Pham, Toshinari Maeda, Meng Sun et al.

Using a lab-scale activated sludge system equipped with an external selector for suppressing nitrite oxidising organism (NOO), the microbial population dynamics were investigated during about 400 days of the continuous operation. In the varied selector operations and excess sludge withdrawal, the nitrification, partial nitritation, and nitrification loss followed by the recovery of partial nitritation consecutively took place. The DNA analysis with the high-throughput sequencing revealed that only Nitrosomonas spp. retained during the nitritation–nitrification and only Nitrospira spp. could grow in nitrification, respectively. Proteobacteria was the most predominant heterotroph in the main aeration tank, whilst Bacteroidota was abundant in the external selector in association with the reduced microbial diversities. In the external selector, due to the high nitrite and ammonium, the ammonium oxidising organism’s (AOO) inherent enzyme genes (Amo and Hao) per total microbial gene copies were as low as about 50% of that in the main aeration tank. The dynamically calculated AOO and NOO concentrations using the IWA-ASM1-based model could be linearly correlated to both relative abundances in the activated sludge. The correlations suggested that the DNA analysis could be potentially utilised as an alternative tool to estimate the nitrifier biomass of activated sludge instead of performing kinetic modelling.

Yuqing Liu, Zhubin Zheng, Jianzhong Li et al.

Overexploitation of rare Earth mining areas in southern Jiangxi Province has caused severe vegetation degradation. However, the impact of vegetation restoration on ecosystem services (ESs) and their interactions in rare Earth mining areas remains underexplored. This study uses vegetation coverage (FVC) as an indicator to assess vegetation changes in rare Earth mining areas from 1986 to 2020. The integrated assessment of ESs and tradeoffs (InVEST) and the Carnegie-arms-stanford method model were applied to assess soil conservation, carbon storage, water retention, and purification services in the study area from 1990 to 2020, while analyzing the spatiotemporal evolution of ESs. Finally, the eXtreme Gradient Boosting model was used to construct the regional total ecosystem services (RTES) index, analyzing the threshold effect between ESs and FVC. The results reveal that: 1) From 1986 to 2020, vegetation coverage in rare Earth mining areas exhibited a fluctuating upward trend, with significant increases occurring in 40.14% of the study area; 2) ESs declined significantly overall; 3) Increased vegetation coverage improved the regional ecological environment to some extent, though this improvement was constrained by a threshold effect. To optimize RTES, vegetation coverage in the Gannan rare Earth mining areas should range between 0.6 and 0.7. This study offers a theoretical foundation for large-scale ecological management and moderate restoration of rare Earth mining areas, supporting regional sustainable development. It also underscores the need for the public and managers to recognize the impact of vegetation restoration on ecosystem functions in rare Earth mining areas.

Qinke Sun, Johan Reyns, Jiayi Fang et al.

Study region: Shanghai, China Study focus: This paper proposes a comprehensive framework for quantifying storm surge floods in coastal cities by incorporating the influences of both climate change and urbanization. The framework achieves a physically process-based numerical simulation of storm surge-induced flood hazards due to tropical cyclones in coastal cities by coupling the fast flood inundation model (SFINCS) and the land use change model (GeoSOS-FLUS), along with the numerical nested model for storm surges (Delft 3D Flow & Wave). Using a 1000-year tropical cyclone simulated by the STORM model as an example, this study analyzes and maps coastal flood impacts under the moderate climate scenario (SSPs245) and high emission scenario (SSPs585), and also evaluates the impact of land use changes on these scenarios. New hydrological insights for the region: Taking Shanghai, China as an example, the results show that by 2100, urban land use changes will lead to an increase in the extent of 1000-year TC flooding areas by 4.91–34.00 %, underestimating the inundation area of storm surges if future urban land use changes are not considered. Additionally, our predictions indicate the vulnerability of Chongming island and Changxing island to the impacts of climate change, despite the protective role of coastal embankments considered in the tropical cyclone storm surge simulation. The results of this study represent an important contribution to a better understanding of how future urban land use changes will affect storm surge flooding risks in and around Shanghai. The proposed methodology can be applied to coastal areas worldwide that are vulnerable to tropical cyclones, aiding in the formulation of hazard mitigation policies to alleviate flood impacts in these regions.

Madhava Krishna, Bhagesh Gaur, Arsh Verma et al.

The creation of a Software Requirements Specification (SRS) document is important for any software development project. Given the recent prowess of Large Language Models (LLMs) in answering natural language queries and generating sophisticated textual outputs, our study explores their capability to produce accurate, coherent, and structured drafts of these documents to accelerate the software development lifecycle. We assess the performance of GPT-4 and CodeLlama in drafting an SRS for a university club management system and compare it against human benchmarks using eight distinct criteria. Our results suggest that LLMs can match the output quality of an entry-level software engineer to generate an SRS, delivering complete and consistent drafts. We also evaluate the capabilities of LLMs to identify and rectify problems in a given requirements document. Our experiments indicate that GPT-4 is capable of identifying issues and giving constructive feedback for rectifying them, while CodeLlama's results for validation were not as encouraging. We repeated the generation exercise for four distinct use cases to study the time saved by employing LLMs for SRS generation. The experiment demonstrates that LLMs may facilitate a significant reduction in development time for entry-level software engineers. Hence, we conclude that the LLMs can be gainfully used by software engineers to increase productivity by saving time and effort in generating, validating and rectifying software requirements.

Haochen Li, Jonathan Leung, Zhiqi Shen

Large Language Models (LLMs) have shown prominent performance in various downstream tasks and prompt engineering plays a pivotal role in optimizing LLMs' performance. This paper, not only as an overview of current prompt engineering methods, but also aims to highlight the limitation of designing prompts based on an anthropomorphic assumption that expects LLMs to think like humans. From our review of 50 representative studies, we demonstrate that a goal-oriented prompt formulation, which guides LLMs to follow established human logical thinking, significantly improves the performance of LLMs. Furthermore, We introduce a novel taxonomy that categorizes goal-oriented prompting methods into five interconnected stages and we demonstrate the broad applicability of our framework. With four future directions proposed, we hope to further emphasize the power and potential of goal-oriented prompt engineering in all fields.

N. Wagner, A. Scheuermann, M. Schwing et al.

Precise knowledge of the frequency dependent electromagnetic properties of porous media is urgently necessary for successful utilization of high frequency electromagnetic measurement techniques for near and subsurface sensing. Thus, there is a need of systematic investigations by means of dielectric spectroscopy of unsaturated and saturated soils under controlled hydraulic conditions. In this context, two-port rod based transmission lines (R-TMLs) were characterized in the frequency range from 1 MHz to 10 GHz by combined theoretical, numerical, and experimental investigations. To analyze coupled hydraulic and dielectric soil properties a slightly plastic clay soil was investigated. There is evidence that the bound water contribution of the soil is substantially lower than expected.

Mohammad Golshan

Considering the increase in population and the development of urban and rural communities, it is very important to check the quality of urban drinking water. Baharestan watershed supplies most of the drinking water of Astara city with a population of 91,257 people.  In this research, based on laboratory investigations and the Water Safety Plan (WSP), an assessment was conducted on the unintended changes in water quality and the evaluation of the water supply system in this city. For this purpose, after the field visit, the sampling points were determined and samples were taken by depth integration method in three seasons: spring, summer, and autumn. In the sampling points, water quality parameters including sodium, magnesium, calcium, phosphate, nitrate, nitrite, bicarbonate, manganese, iron, chemical oxygen demand, biological oxygen demand, overall digestive form, dissolved oxygen, acidity, electrical conductivity, and total hardness were determined. According to the results, the region's water quality index (IRWQI) was calculated. The results of water quality measurement in the sampling areas showed that the water of this river has no problem in terms of drinking water. The parameter of iron (Fe) with a value of 6.88 mg/liter in the Mashand branch, which has the most sources of pollution, is more than the permissible limit, which indicates the priority of carrying out control and correction measures in this branch. The value of the IRWQI index was equal to 60.33, which indicates the relatively good water condition of the region. Also, the review of WSP results showed that team formation with a score of 65% has the highest score and the average score of this plan in Astara city is 33.64, which means that by completing the WSP plan and preventing pollution from entering the river water, better quality drinking water can be provided to the citizens.

Riccardo Checchin, Michael Ruderman, Roberto Oboe

In this paper, a controller design targeting the remotely operated hydraulic drive system is presented. A two-degrees-of-freedom PID position controller is used, which is designed so that to maximize the integral action under robust constraint. A linearized model of the system plant, affected by the parameters uncertainties such as variable communication time-delay and overall system gain, is formulated and serves for the control design and analysis. The performed control synthesis and evaluation are targeting the remote operation where the wireless communication channel cannot secure a deterministic real-time of the control loop. The provided analysis of uncertainties makes it possible to ensure system stability under proper conditions. The theoretically expected results are confirmed through laboratory experiments on the standard industrial hydraulic components.

Angelika Kaplan, Thomas Kühn, Ralf Reussner

Background: Classifications in meta-research enable researchers to cope with an increasing body of scientific knowledge. They provide a framework for, e.g., distinguishing methods, reports, reproducibility, and evaluation in a knowledge field as well as a common terminology. Both eases sharing, understanding and evolution of knowledge. In software engineering (SE), there are several classifications that describe the nature of SE research. Regarding the consolidation of the large body of classified knowledge in SE research, a generally applicable classification scheme is crucial. Moreover, the commonalities and differences among different classification schemes have rarely been studied. Due to the fact that classifications are documented textual, it is hard to catalog, reuse, and compare them. To the best of our knowledge, there is no research work so far that addresses documentation and systematic investigation of classifications in SE meta-research. Objective: We aim to construct a unified, generally applicable classification scheme for SE meta-research by collecting and documenting existing classification schemes and unifying their classes and categories. Method: Our execution plan is divided into three phases: construction, validation, and evaluation phase. For the construction phase, we perform a literature review to identify, collect, and analyze a set of established SE research classifications. In the validation phase, we analyze individual categories and classes of included papers. We use quantitative metrics from literature to conduct and assess the unification process to build a generally applicable classification scheme for SE research. Lastly, we investigate the applicability of the unified scheme. Therefore, we perform a workshop session followed by user studies w.r.t. investigations about reliability, correctness, and ease of use.

Denghua Yan, Chenhao Li, Xin Zhang et al.

Measurement(s) river • stream • drainage basin • watershed Technology Type(s) computational modeling technique Sample Characteristic - Environment freshwater river Sample Characteristic - Location Earth (Planet)

Nilton Ricardo de Oliveira Silva, Francisco Carlos Lira Pessoa, Diego Lima Crispim et al.

A água doce, recurso natural de extrema importância para vida, é um bem escasso devido à irregularidade da sua distribuição espacial e às dificuldades de acesso da população ao recurso. Diante deste cenário surgiram diversas iniciativas mundiais na busca por indicadores que auxiliem na gestão dos recursos hídricos. Dessa forma, este trabalho objetiva a elaboração de uma matriz de componentes que propicie o desenvolvimento do Índice de Pobreza Hídrica (IPH) para implantação em áreas urbanas. Foi utilizado a metodologia Delphi para validação da matriz e atribuição de pesos aos componentes Capacidade (C), Recursos Hídricos (R), Acesso (A), Uso (U) e Meio Ambiente (MA), e seus respectivos subcomponentes e variáveis, através de questionários junto à especialistas. Os resultados evidenciaram a eficácia e facilidade de aplicação do método Delphi na pesquisa, além disso, este apresenta uma base sólida e pode ser adaptado para distintas localidades, colaborando com a identificação e avaliação dos problemas oriundos ao acesso e uso da água em diferentes regiões urbanas.

Nasir U. Eisty, Jeffrey C. Carver

Background: Research software is software developed by and/or used by researchers, across a wide variety of domains, to perform their research. Because of the complexity of research software, developers cannot conduct exhaustive testing. As a result, researchers have lower confidence in the correctness of the output of the software. Peer code review, a standard software engineering practice, has helped address this problem in other types of software. Aims: Peer code review is less prevalent in research software than it is in other types of software. In addition, the literature does not contain any studies about the use of peer code review in research software. Therefore, through analyzing developers perceptions, the goal of this work is to understand the current practice of peer code review in the development of research software, identify challenges and barriers associated with peer code review in research software, and present approaches to improve the peer code review in research software. Method: We conducted interviews and a community survey of research software developers to collect information about their current peer code review practices, difficulties they face, and how they address those difficulties. Results: We received 84 unique responses from the interviews and surveys. The results show that while research software teams review a large amount of their code, they lack formal process, proper organization, and adequate people to perform the reviews. Conclusions: Use of peer code review is promising for improving the quality of research software and thereby improving the trustworthiness of the underlying research results. In addition, by using peer code review, research software developers produce more readable and understandable code, which will be easier to maintain.

Hardi M. Mohammed, Zrar Kh. Abdul, Tarik A. Rashid et al.

Purpose: The development of metaheuristic algorithms has increased by researchers to use them extensively in the field of business, science, and engineering. One of the common metaheuristic optimization algorithms is called Grey Wolf Optimization (GWO). The algorithm works based on imitation of the wolves' searching and the process of attacking grey wolves. The main purpose of this paper to overcome the GWO problem which is trapping into local optima. Design or Methodology or Approach: In this paper, the K-means clustering algorithm is used to enhance the performance of the original Grey Wolf Optimization by dividing the population into different parts. The proposed algorithm is called K-means clustering Grey Wolf Optimization (KMGWO). Findings: Results illustrate the efficiency of KMGWO is superior to GWO. To evaluate the performance of the KMGWO, KMGWO applied to solve 10 CEC2019 benchmark test functions. Results prove that KMGWO is better compared to GWO. KMGWO is also compared to Cat Swarm Optimization (CSO), Whale Optimization Algorithm-Bat Algorithm (WOA-BAT), and WOA, so, KMGWO achieves the first rank in terms of performance. Statistical results proved that KMGWO achieved a higher significant value compared to the compared algorithms. Also, the KMGWO is used to solve a pressure vessel design problem and it has outperformed results. Originality/value: Results prove that KMGWO is superior to GWO. KMGWO is also compared to cat swarm optimization (CSO), whale optimization algorithm-bat algorithm (WOA-BAT), WOA, and GWO so KMGWO achieved the first rank in terms of performance. Also, the KMGWO is used to solve a classical engineering problem and it is superior

S. Ragettli, X. Tong, G. Zhang et al.

Flood events are difficult to characterize if available observation records are shorter than the recurrence intervals, and the non-stationarity of the climate adds additional uncertainty. In this study, we use a hydrological model coupled with a stochastic weather generator to simulate the summer flood regime in two mountainous catchments located in China and Switzerland. The models are set up with hourly data from only 10–20 years of observations but are successfully validated against 30–40-year long records of flood frequencies and magnitudes. To assess the climate change impacts on flood frequencies, we re-calibrate the weather generator with the climate statistics for 2021–2050 obtained from ensembles of bias-corrected regional climate models. Across all assessed return periods (10–100 years) and two emission scenarios, nearly all model chains indicate an intensification of flood extremes. According to the ensemble averages, the potential flood magnitudes increase by more than 30% in both catchments. The unambiguousness of the results is remarkable and can be explained by three factors rarely combined in previous studies: reduced statistical uncertainty due to a stochastic modelling approach, hourly time steps and the focus on headwater catchments where local topography and convective storms are causing runoff extremes within a confined area.

Malida O. Hecht, Antonio J. Cobarrubia, Kyle M. Sundqvist

Classical microwave circuit theory is incapable of representing some phenomena at the quantum level. To include quantum statistical effects when treating microwave networks, various theoretical treatments can be employed such as quantum input-output network (QION) theory and SLH theory. However, these require a reformulation of classical microwave theory. To make these topics comprehensible to an electrical engineer, we demonstrate some underpinnings of microwave quantum optics in terms of microwave engineering. For instance, we equate traveling-wave phasors in a transmission line ($V_0^+$) directly to bosonic field operators. Furthermore, we extend QION to include a state-space representation and a transfer function for a single port quantum network. This serves as a case study to highlight how microwave methodologies can be applied in open quantum systems. Although the same conclusion could be found from a full SLH theory treatment, our method was derived directly from first principles of QION.

Arthur M. Skopintsev, Egor V. Dontsov, Pavel V. Kovtunenko et al.

This paper presents the coupled model of a hydraulic fracturing and proppant transport. The former is described in terms of enhanced pseudo-3D model that considers height growth across two symmetric stress barriers, while the latter is given by two-dimensional transport model, stemming from the solution of an elliptical equation for fluid pressure and advection equation for the proppant transport. These two sub-modules are solved numerically using implicit time integration in hydraulic part and explicit time stepping in the transport part. In addition to that, interpolation is used to couple the two models with different grids. Results of several numerical simulations are presented for different configurations to demonstrate the interplay between these two modules. In particular, the developed coupled scheme allows us to study phenomena associated with complex fluid flow within the fracture, such as for the case of Saffman-Taylor instability.

Ricardo Diniz Caldas, Arthur Rodrigues, Eric Bernd Gil et al.

Control theoretical techniques have been successfully adopted as methods for self-adaptive systems design to provide formal guarantees about the effectiveness and robustness of adaptation mechanisms. However, the computational effort to obtain guarantees poses severe constraints when it comes to dynamic adaptation. In order to solve these limitations, in this paper, we propose a hybrid approach combining software engineering, control theory, and AI to design for software self-adaptation. Our solution proposes a hierarchical and dynamic system manager with performance tuning. Due to the gap between high-level requirements specification and the internal knob behavior of the managed system, a hierarchically composed components architecture seek the separation of concerns towards a dynamic solution. Therefore, a two-layered adaptive manager was designed to satisfy the software requirements with parameters optimization through regression analysis and evolutionary meta-heuristic. The optimization relies on the collection and processing of performance, effectiveness, and robustness metrics w.r.t control theoretical metrics at the offline and online stages. We evaluate our work with a prototype of the Body Sensor Network (BSN) in the healthcare domain, which is largely used as a demonstrator by the community. The BSN was implemented under the Robot Operating System (ROS) architecture, and concerns about the system dependability are taken as adaptation goals. Our results reinforce the necessity of performing well on such a safety-critical domain and contribute with substantial evidence on how hybrid approaches that combine control and AI-based techniques for engineering self-adaptive systems can provide effective adaptation.