Tool For Design Of Systems Research Articles

Exergy Analysis of Electrochemical Systems for Space Exploration

Human exploration of space, facilitated by electrochemical systems, will require integration of many seemingly disparate systems including but not limited to power systems, in situ resource utilization (ISRU), and environmental control and life support (ECLS). Through combining expressions of the First and Second Laws of Thermodynamics exergy quantifies the useful work that can be obtained from a system, subject to environmental limitations. This approach provides a means of integrating diverse systems and components based on one consistent and physically meaningful property: exergy. Using this property as a basis, diverse systems can be analyzed and integrated effectively based on the exergy destruction and exergy efficiency. Here, the applicability of exergy analysis to systems design and integration is demonstrated through two examples involving electrochemical systems that support human space exploration.First, analysis of the ECLS system aboard the International Space Station (ISS) is conducted to assess its overall performance in terms of exergy destruction rates and exergy efficiency. The ECLS system is divided into constituent subsystems which are further divided into key components. Based on this system decomposition, exergy balances are derived for each component and subsystem. Special focus is given to the Oxygen Generation Assembly (OGA) within the ECLS Atmospheric Revitalization Subsystem. The results of parametric studies of the OGA proton exchange membrane electrolyzer performance are presented with an emphasis on the impacts of operational conditions on exergy efficiency. This electrolyzer is a significant contributor to system exergy destruction and exhibits a low exergetic efficiency. It therefore presents an opportunity for improving overall ECLS system performance.Following the example of ECLS exergy analysis, the application of exergy analysis to the integration of power and ISRU systems for lunar exploration is presented through system level models. Exergy destruction and efficiency are quantified over the lunar diurnal cycle for power and ISRU systems. The power systems analysis focuses on photovoltaic arrays paired with battery and regenerative fuel cell systems. The ISRU system analysis focuses on production of oxygen from lunar regolith through the reduction of ilmenite combined with water electrolysis. Here the application of exergy analysis identifies key opportunities for the use of byproduct heat and the optimal sizing of system components.The studies presented demonstrate the capability of exergy analysis to support the design and integration of electrochemical systems within larger power, ISRU, and ECLS systems supporting space exploration. This approach can enable the full and efficient use of a system’s available work potential based on a consistent, physically meaningful property. Therefore, exergy analysis is shown to be a key tool for the future design and integration of electrochemical systems for space exploration.

Multilayer modelling as a support tool for flood diagnosis and drainage system design

The use of dual-drainage models has increased in recent decades, mostly because of advances in mathematical methods and geographic information system tools. This type of modelling provides precise diagnoses and can be applied to evaluate stormwater infrastructure and diverse drainage alternatives. Minor and major drainage relations in the Dona Eugênia watershed, Brazil, were analysed in this study. Three alternatives simulated the quasi-two-dimensional hydrodynamic model Modcel. The first alternative considered only the terrain surface layer, representing the current situation. In the second alternative, a layer containing a designed storm sewer was introduced. Considering the previous alternatives as a way to diagnose the main minor and major deficiencies, a third alternative was formulated considering previous projects to solve floods in the watershed, incorporating them in the second alternative with functional minor drainage. The results identified the locations of minor drainage gaps, thus helping to direct efforts to the most critical regions, optimise operations and minimise maintenance costs. The results could also be used to evaluate the effects of storm sewer network discharges in major drainage systems, leading to better design of the drainage infrastructure. The major drainage itself can be optimised, once its responsibility in flooding is identified.

APLIKASI MOBILE LEARNING BERBASIS ANDROID UNTUK BELAJAR HURUF HIJAIYAH

Mobile learning is a learning process that utilizes technological developments through electronic devices in the form of smartphones or mobile phones. Currently learning hijaiyah is still widely done by meeting directly with the teaching staff, through Iqra or other print media. With this is considered less effective and ineffective and causes boredom for children. Therefore, an efficient, effective and interactive hijaiyah letter learning medium is needed that is able to increase children's minant power to learn anywhere and anytime. The application will be designed with a system design tool that is UML (Unified Modeling language) that is easy to describe so that it can help in the compounding of the system. The application will be implemented on android-based mobile devices.

Recent Advances on GERT Method Based on Bayesian Networks

Background: Identification of key processes and key paths plays an important role in project management and control. Therefore, in order to reduce the expected time of the project, some analysis methods other than engineering technology must be adopted. The Graphical Evaluation and Review Technique (GERT) is a useful tool in system analysis and design. The GERT can process the relationships in network diagrams, which is a network with feedback function and has been applied in many fields. Methods: In this paper, based on Bayesian network model and GERT network, a new method for analyzing project process has been studied. Firstly, all the variable nodes of the GERT network are determined. Secondly, the variable nodes in the GERT network are divided into tandem nodes, aggregation nodes, distributed nodes, and self-loop nodes in the Bayesian network. Third, the GERT network parsing method is used to calculate the expected time of the partial variable node. Then the network structure of the Bayesian network is constructed by connecting the nodes with the directed edges. Results: Thus, a GERT Bayesian model is established. Based on the posterior probability of Bayesian network, we have determined the key process, improved the key process and shortened the processing time. Conclusion: Finally, this method is used to analyze an ERP project activity flow chart with self-loop structure, identify the key processes and key paths, and determine the time period. Therefore, the validity and reliability of the method in project process management are verified.

Thermal Optimizations and CFD Analysis of Finned Heat Sinks for Natural Convection

It would save a lot of time and efforts if individual heat sinks are thermally optimized prior to using the CFD tools for system analysis and design. The practical example of such process which employs an existing correlation for optimization of finned heat sinks is presented. Several CFD simulations are first performed to compare with the results from the correlations. The good agreement of the U-channel heat transfer coefficient between the correlation and CFD results further validates the accuracy of the correlation. The main focus of the present work is to perform a detailed CFD analysis on the heat sink with the fin optimal spacing of 0.439”. The flow field ultimately determines the heat transfer from the heat sink. Therefore, an effort is made to provide the insight view of the detailed flow fields which has never been done before. The velocity is relatively uniform when the air first enters the finned heat sink from the bottom side (low end). However, due to the entrant flow entering spacing between the fin tips at the face of the heat sink, the velocity of the air flow increases along the length of the heat sink when the air flows upwards. The CFD results indicate that the heat loss per zone decreases along the heat sink length (height). The total natural convection heat loss of this heat sink is 96.61 watts. The heat transfer coefficient of the entire heat sink is 0.7 Btu/hr-ft2 while the heat transfer coefficient from the U-channels alone is 0.61 Btu/hr-ft2. The results indicate that system with the cover in contact with fins perform better thermally than that of the case without the cover. It is also found that there is no effect of the cover/shroud on the heat loss or entrant flow rate as long as the distance between the cover and the heat sink fin tips is greater than 4.36” with the fin height of 2.0”. Based on the limited data in this work, one may conclude that there is no effect of the cover on the heat transfer of a finned heat sink if the distance between the heat sink and the cover is greater than 2.5 times of the fin height.

Perancangan Aplikasi Ujian Online Berbasis Website

The online exam information system is one part of the distance education system through internet technology media. Colleges use Moodle as an online application for new student admissions, in this case Moodle is not integrated with the College's internal system. The concept of an online exam that is not limited by space and time can be a solution to the obstacles that exist in conventional exam methods. The process of collecting data using the method of observation, interviews and literature study. In system development using the Extreme Programming method. System design tools used are Class diagrams, and Use case diagrams. Meanwhile, to create an online exam information system at the university, the author uses the PHP programming language and MySQL database. Based on the results of the study, an online examination information system was obtained at universities. The questions are presented in a multiple choice system. The implementation of this online exam system is made with facilities including exam management, exam management, user data management, and taking exams which will produce value output.

On the needs for combining physiological principles and mathematics to improve crop models

• Basic concepts of crop modelling founders are fading into oblivion since the mid-1990s. • The multi-model ensemble approach does not facilitate the models as a heuristic tool. • A bottom-up approach that assembles all biological elements is not conducive to simulating the crop. • An intermediate approach combining physiology and mathematics is recommended. • Leaf area index and radiation use efficiency are used as showcases. • Outstanding areas for further model development and caveats are outlined. Major crop models were developed before the 1990s and many of their algorithms are (semi-)empirical. In the recent two decades, the number of models has grown rapidly, but the increase in their quality does not match the growth in number. Often, an ensemble of multiple models is required to make a useful prediction. This ensemble approach does not facilitate the improvement of models as a tool to understand crop physiological mechanisms. On the other hand, following a bottom-up approach that tries to assemble all elements along different scales of biological organisation may result in numerically clumsy models that are not necessarily more robust than existing models in simulating phenotypes at the crop scale. We argue that to model complex crop phenotypes in a simple yet accurate manner, crop modellers should be inspired by experiences in some fundamental sciences. For example, physicists used sound theories and solid mathematics in thought experiments, and came up with seemingly simple equations to explain the behaviour of very diverse systems, from sub-atomic particles to the largest clusters of galaxies. We review examples, where biological insights and mathematics are combined to derive simple equations that apply to different processes of crop growth. The essence of this modelling approach is a combination of simplicity , elegance and robustness . Models integrating those equations can predict crop phenotypes as well as generate hypotheses or emerging properties to assist in knowing the unknowns. Thus, crop models should not only provide practical predictions, but should especially be considered as a research tool for data interpretation, system design, and heuristic understanding.

An automated system analysis and design tool for spacecrafts

In this paper, a generic full-system estimation software tool is introduced and applied to a data set of actual flight missions to derive a heuristic for system composition for mass and power ratios of considered sub-systems. The capability of evolutionary algorithms to analyse and effectively design spacecraft (sub-)systems is shown. After deriving top-level estimates for each spacecraft sub-system based on heuristic heritage data, a detailed component-based system analysis follows. Various degrees of freedom exist for a hardware-based sub-system design; these are to be resolved via an evolutionary algorithm to determine an optimal system configuration. A propulsion system implementation for a small satellite test case will serve as a reference example of the implemented algorithm application. The propulsion system includes thruster, power processing unit, tank, propellant and general power supply system masses and power consumptions. Relevant performance parameters such as desired thrust, effective exhaust velocity, utilised propellant, and the propulsion type are considered as degrees of freedom. An evolutionary algorithm is applied to the propulsion system scaling model to demonstrate that such evolutionary algorithms are capable of bypassing complex multidimensional design optimisation problems. An evolutionary algorithm is an algorithm that uses a heuristic to change input parameters and a defined selection criterion (e.g., mass fraction of the system) on an optimisation function to refine solutions successively. With sufficient generations and, thereby, iterations of design points, local optima are determined. Using mitigation methods and a sufficient number of seed points, a global optimal system configurations can be found.

Pareto-optimal front for multi-objective optimization of the suspension of a full-vehicle model in the frequency domain

PurposeThis study aims to propose a complete and powerful methodology that allows the optimization of the passive suspension system of vehicles, which simultaneously takes comfort and safety into account and provides a set of optimal solutions through a Pareto-optimal front, in a low computational time.Design/methodology/approachUnlike papers that consider simple vehicle models (quarter vehicle model or half car model) and/or simplified road profiles (harmonic excitation, for example) and/or perform a single-objective optimization and/or execute the dynamic analysis in the time domain, this paper presents an effective and fast methodology for the multi-objective optimization of the suspension system of a full-car model (including the driver seat) traveling on an irregular road profile, whose dynamic response is determined in the frequency domain, considerably reducing computational time.FindingsThe results showed that there was a reduction of 28% in the driver seat vertical acceleration weighted root mean square (RMS) value of the proposed model, which is directly related to comfort, and, simultaneously, an improvement or constancy concerning safety, with low computational cost. Hence, the proposed methodology can be indicated as a successful tool for the optimal design of the suspension systems, considering, simultaneously, comfort and safety.Originality/valueDespite the extensive literature on optimizing vehicle passive suspension systems, papers combining multi-objective optimization presenting a Pareto-optimal front as a set of optimal results, a full-vehicle model (including the driver seat), an irregular road profile and the determination of the dynamic response in the frequency domain are not found.

Machine Learning Tools Set for Natural Gas Fuel Cell System Design

This study is focusing on leveraging the system design tools set for next-generation solid oxide fuel cell (SOFC) based natural gas fuel cell (NGFC) system. Conventionally, system design and optimization of NGFC systems rely heavily on traditional reduced order model (ROM) techniques and designers’ experience level. For overcoming the technical barriers of system design, multiple multi-physics models and machine learning (ML) tools have been utilized to automate the conceptual design process and enhance the reliability of solutions for the NGFC system. The proposed tools set includes a physics-informed ML tool for automated ROM construction that leverages advances in deep neural networks to significantly reduce ROM prediction error for the NGFC power island compared to traditional approaches. The constructed physics-informed ML ROM can be used in system design and optimization tools set Institute for the Design of Advanced Energy Systems (IDAES) Process Systems Engineering (PSE) framework. The tools set also provides user-friendly graphic user interface built within Jupyter Notebooks, and the whole tools set is open-source public available.

NiFeOx decorated Ge-hematite/perovskite for an efficient water splitting system

To boost the photoelectrochemical water oxidation performance of hematite photoanodes, high temperature annealing has been widely applied to enhance crystallinity, to improve the interface between the hematite-substrate interface, and to introduce tin-dopants from the substrate. However, when using additional dopants, the interaction between the unintentional tin and intentional dopant is poorly understood. Here, using germanium, we investigate how tin diffusion affects overall photoelectrochemical performance in germanium:tin co-doped systems. After revealing that germanium is a better dopant than tin, we develop a facile germanium-doping method which suppresses tin diffusion from the fluorine doped tin oxide substrate, significantly improving hematite performance. The NiFeOx@Ge-PH photoanode shows a photocurrent density of 4.6 mA cm−2 at 1.23 VRHE with a low turn-on voltage. After combining with a perovskite solar cell, our tandem system achieves 4.8% solar-to-hydrogen conversion efficiency (3.9 mA cm−2 in NiFeOx@Ge-PH/perovskite solar water splitting system). Our work provides important insights on a promising diagnostic tool for future co-doping system design.

Machine Learning Tools Set for Natural Gas Fuel Cell System Design

This study is focusing on leveraging the system design tools set for next-generation solid oxide fuel cell (SOFC) based natural gas fuel cell (NGFC) system. Conventionally, system design and optimization of NGFC systems rely heavily on traditional reduced order model (ROM) techniques and designers’ experience level. For overcoming the technical barriers of system design, multiple multi-physics models and machine learning (ML) tools have been utilized to automate the conceptual design process and enhance the reliability of solutions for the NGFC system. The proposed tools set includes a physics-informed ML tool for automated ROM construction that leverages advances in deep neural networks to significantly reduce ROM prediction error for the NGFC power island compared to traditional approaches. The constructed physics-informed ML ROM can be used in system design and optimization tools set Institute for the Design of Advanced Energy Systems (IDAES) Process Systems Engineering (PSE) framework. The tools set also provides user-friendly graphic user interface built within Jupyter Notebooks, and the whole tools set is open-source public available.

Metallurgical and Geometric Properties Controlling of Additively Manufactured Products using Artificial Intelligence

This article has presented a technical concept for producing precisely desired Additive Manufactured (AM) metallic products using Artificial Intelligence (AI). Due to the stochastic nature of the metallic AM process, which causes a greater variance in product properties compared to traditional manufacturing processes, significant inaccuracies in metallurgical properties, as well as geometry, occur. The physics behind these phenomena are related to the melting process, bonding, cooling rate, shrinkage, support condition, part orientation. However, by controlling these phenomena, a wide range of product features can be achieved using the fabricating parameters. A variety of fabricating parameters are involved in the metal AM process, but an appropriate combination of these parameters for a given material is required to obtain an accurate and desired product. Zero defect product can be achieved by controlling these parameters by implementing Knowledge-Based System (KBS). A suitable combination of manufacturing parameters can be determined using mathematical tools with AI, considering the manufacturing time and cost. The knowledge required to integrate AM manufacturing characteristics and constraints into the design and fabricating process is beyond the capabilities of any single engineer. Concurrent Engineering enables the integration of design and manufacturing to enable trades based not only on product performance, but also on other criteria that are not easily evaluated, such as production capability and support. A decision support system or KBS that can guide manufacturing issues during the preliminary design process would be an invaluable tool for system designers. The main objective of this paper is to clearly describe the metal AM manufacturing process problem and show how to develop a KBS for manufacturing process determination.

On methods and tools for rigorous system design

Full a posteriori verification of the correctness of modern software systems is practically infeasible due to the sheer complexity resulting from their intrinsic concurrent nature. An alternative approach consists of ensuring correctness by construction. We discuss the Rigorous System Design (RSD) approach, which relies on a sequence of semantics-preserving transformations to obtain an implementation of the system from a high-level model while preserving all the properties established along the way. In particular, we highlight some of the key requirements for the feasibility of such an approach, namely availability of (1) methods and tools for the design of correct-by-construction high-level models and (2) definition and proof of the validity of suitable domain-specific abstractions. We summarise the results of the extended versions of seven papers selected among those presented at the 1mathrm {st} and the 2mathrm {nd} International Workshops on Methods and Tools for Rigorous System Design (MeTRiD 2018–2019), indicating how they contribute to the advancement of the RSD approach.

Multi-criteria decision analysis of timber–concrete composite floor systems in multi-storey wooden buildings

ABSTRACT This study aims to present a multi-criteria decision analysis (MCDA) for comprehensive performance evaluation of the alternative design of timber–concrete composite (TCC) floor system. Considered objectives are serviceability and sustainability performance with associated criterion as (1) comfort class regarding springiness and vibrations, (2) architectural quality with associated criterion as open spaces, (3) environmental aspect with associated criterion as CO2 emissions and (4) cost aspect with associated criterion as the total costs. Analytical Hierarchy Process (AHP) and Complex Proportional Assessment (COPRAS) as the methods in the multi-criteria analysis have been combined for (1) determining the weighting of criteria based on the survey results, (2) verifying the consistency ratio of decision matrix made by experts and (3) for ranking and selecting the optimal concept design among design candidates. According to the results, the TCC floor with the span length of 7.3 m belonging to comfort class A has got the highest ranking. However, sensitivity analysis indicates that the TCC floor with a 9.0 m span length belonging to comfort class A shall be selected as the optimal concept design. The study contributes by developing a complete concept design tool for TCC floor systems using AHP combined COPRAS methods to handle both beneficial and non-beneficial criteria.

Rapid multi-physics simulation for electro-thermal origami systems

Electro-thermally actuated origami provides a novel method for creating 3-D systems with advanced morphing and functional capabilities. However, it is currently difficult to simulate the multi-physical behavior of such systems because the electro-thermal actuation and large folding deformations are highly interdependent. In this work, we introduce a rapid multi-physics simulation framework for electro-thermally actuated origami systems that can simultaneously capture: thermo-mechancially coupled actuation, inter panel contact, heat transfer, large deformation folding, and other complex loading applied onto the origami. Comparisons with finite element models validate the proposed framework for simulating origami heat transfer with different system geometries, materials, and surrounding environments. Verification of the simulated folding behaviors against physical electro-thermal micro-origami further demonstrates the validity of the proposed model. Simulations of more complex origami patterns and a case study for origami optimization are provided as application examples to show the capability and efficiency of the model. The framework provides a novel simulation tool for analysis, design, control, and optimization of active origami systems, pushing the boundary for feasible shape morphing and functional capability.

Perancangan User InterfaceAplikasi Persediaan dan Distribusi Bubuk Kopi Berbasis Web dengan Model SCM Pada UD. Arman Kota Padang

The purpose of this study was to design a web-based coffee powder supply and distribution application with the SCM method at UD. Arman, where UD. Arman has been facing a problem that is where the processing of inventory data and the distribution of coffee powder products become the problem of the coffee powder that distributors to characters and suppliers are still done manually. So you can know how to inventory at U.D distributors and stores. Arman must wait for confirmation first. With the problems that occur it is necessary to have a special system that can be used to manage inventory and can monitor the product inventory at each distributor and keep the merchant less. the problem faced so far is necessary to find a solution to overcome the problems that occur by designing a web-based application interface and copy book distribution application with the SCM method and building distribution-based supply chain management and supply chain management (SCM) systems at UD Arman using a methodology research using SCLD and system design tools using the UML approach. This system is built using the PHP programming language and MySQL database.Based on the results of the Black box testing, this application already has a function that is in accordance with the results of their respective functions running well. As for the usability method of the SUS method, respondents gave an average score of 72 which means that the test results obtained get a score above the average. Means the value is acceptable (acceptable) by the user. Systems designed to support employee performance and service quality to distributors and stores are included, so leaders are easy to monitor all activities and state of the coffee powder stockKeywords - Design, Supply, Distribution, SCM, UML, Web

PERANCANGAN SISTEM INFORMASI PEMBAYARAN SERVIS ELEKTRONIK TOKO MS COMPUTER MENGGUNAKAN JAVA DAN MYSQL

The problems in the MS Computer Store are the difficulty of officers in data collection of incoming goods, service payment transaction data and the absence of an information system related to customer service data collection. With this problem, an information system is needed to make it easier for officers in the process of data collection which will be stored safely in the database and printing of reports that will be submitted to the Manager of MS Computer. The purpose of this research is to design an electronic service payment application system which is expected to make it easier to process data and transactions properly and quickly. The system is designed using the Research and Development Method because it is more precise. Where in building this system used System Design tools, namely Data Flow Diagrams (DAD), Context, Zero and Detailed and using the Java programming language with Netbeans and MYSQL Database using Xampp. The results of research that has been carried out at the MS Computer Store, with the existence of an electronic service payment application system replacing the old system, the current employee performance becomes more effective and efficient. Admin does not need to input service data or electronic service payments manually, because this application system provides service data entry forms and payment data.

Modeling of contactless bubble–bubble interactions in microchannels with integrated inertial pumps

In this study, the nonlinear effect of contactless bubble–bubble interactions in inertial micropumps is characterized via reduced parameter one-dimensional and three-dimensional computational fluid dynamics (3D CFD) modeling. A one-dimensional pump model is developed to account for contactless bubble-bubble interactions, and the accuracy of the developed one-dimensional model is assessed via the commercial volume of fluid CFD software, FLOW-3D. The FLOW-3D CFD model is validated against experimental bubble dynamics images as well as experimental pump data. Precollapse and postcollapse bubble and flow dynamics for two resistors in a channel have been successfully explained by the modified one-dimensional model. The net pumping effect design space is characterized as a function of resistor placement and firing time delay. The one-dimensional model accurately predicts cumulative flow for simultaneous resistor firing with inner-channel resistor placements (0.2L < x < 0.8L where L is the channel length) as well as delayed resistor firing with inner-channel resistor placements when the time delay is greater than the time required for the vapor bubble to fill the channel cross section. In general, one-dimensional model accuracy suffers at near-reservoir resistor placements and short time delays which we propose is a result of 3D bubble-reservoir interactions and transverse bubble growth interactions, respectively, that are not captured by the one-dimensional model. We find that the one-dimensional model accuracy improves for smaller channel heights. We envision the developed one-dimensional model as a first-order rapid design tool for inertial pump-based microfluidic systems operating in the contactless bubble–bubble interaction nonlinear regime.

Sewage sludge combustion model with reduced chemical kinetics mechanisms

Commonly applied 3D CFD models lack suitable combustion description of fuels with complex composition, such as encountered in wastewater sludge specific applications. This significantly influences their prediction capability, in particular when used in small, confined combustion volumes. To tackle this challenge, it is necessary to introduce detailed chemical kinetic models for specifically tailored fuel surrogates, which ensure physically accurate description of local thermodynamic conditions and heat release rates. However, necessity to increase the level of detail of models needs to be balanced by their computational expenses to preserve their applicability when solving real engineering problems. With an aim to fill this gap, the present study significantly extends the existing surrogate model methods for applications in small-scale systems to include also reduced combustion kinetic mechanisms. The innovative extension applies Simulation Error Minimization Connectivity Method and involves tailoring of kinetic mechanisms to variable thermodynamic conditions and variable surrogate compositions, specific to sewage sludge combustion. Suitability of the proposed approach is confirmed with the 3-D CFD simulations maintaining similar level of accuracy within the design space of reduced mechanisms as well as in off-design conditions, while maintaining sufficient flexibility to adapt to different types and compositions of the sludge. Thereby, reduction of the in-model applied detailed ethanol and propene mechanisms from 47 and 71 species down to 33 and 34 species, respectively, was demonstrated together with linearly dependent decrease in computational time. The proposed model extension and resulting surrogate combustion model thus for the first time offer an efficient tool for affordable and accurate virtual design of small-scale combustion systems using fuels with complex chemical composition.