Initial Design Phase Research Articles

Disassembly task evaluation by muscle fatigue estimation in a virtual reality environment

Today, disassembly operations play a very important role during the initial design phase of industrial products considering the role played by these operations throughout the product life cycle. Current simulation platforms do not offer the necessary information and versatility required for a complete disassembly process simulation, including human/operator physiological data management. The paper deals with a new method for disassembly sequence evaluation. It is based on metabolic energy expenditure and muscle fatigue estimation. For this purpose, the analytical model for mechanical energy expenditure is proposed. In this model, the required mechanical work is used as a parameter that allows comparing the relationships among fatigue levels when performing disassembly sequences. Then, the fatigue levels are evaluated by analyzing the recorded electromyography signal on an operator’s arm. The proposed method is validated by a set of experimental disassembly tests performed in a virtual reality environment. The comparison of the analytical and experimental results has shown good correlation between them. The main result of this study is the proposed model for assessing muscle fatigue and its validation by experimental procedure. The proposed method provides the feasibility to integrate human muscle fatigue into disassembly sequence evaluation via mechanical energy expenditure when performing disassembly operation simulations.

Neutron flux monitoring with in-vessel fission chambers to detect an inadvertent control rod withdrawal in a sodium-cooled fast reactor

The neutron flux monitoring system forms an integral part of the safety design of a Generation IV sodium-cooled fast reactor. During the initial design phase of the neutron flux monitoring system, one needs to explore various detector locations and configurations. Diverse possibilities of the detector system installation should be studied for different locations in the reactor vessel in order to detect any perturbations in the core. In this paper, we investigate the possibility of placing fission chambers beyond the lateral neutron shield, ex-core but in-vessel and study the detectability of an inadvertent control rod withdrawal with these fission chambers. A generic core design of a Generation IV 1500 MWth French sodium-cooled fast reactor is used for the study, and calculations are performed with the Monte Carlo code SERPENT2. We propose certain design changes that are needed to be incorporated, w.r.t. the facilitation of neutron transport to this ex-core location.We are able to show that there is a detectable signature in the fission chambers following an inadvertent control rod withdrawal in the core. The equally-spaced azimuthal detectors are able to follow changes in the neutron flux distribution in the core. This study helps us to analyze multiple detector locations and give the general trends for monitoring indications to detect any perturbations in the core.

Redesign for sustainability and assemblability using particle swarm optimization method

Nowadays, the pursuance of sustainability obligates manufacturers to redesign products in order to reduce negative environmental impacts. However, only a few studies have simultaneously considered environmental sustainability and assemblability. To bridge this research gap, this study aimed to develop a redesign method based on modular product architecture. This method manages to support a sustainable product considering its materials, assembly sequence and line balance at initial design phase. This method begins with a current product analysis based on economic and environmental performances (i.e., total cost and CO2 emissions). Additionally, new materials and assembly methods are incorporated into redesigning a more sustainable product without compromising production performance. To ensure assemblability, the line balance of 60% is served as one of the constraints. This study applies the particle swarm optimization algorithm to calculate an optimal module organization along with assembly methods and assembly sequences. An air purifier case study is presented to demonstrate the benefits of the proposed method. As a result, the redesigned product can be more easily maintained during product usage and be recycled at the end of product life.

Adaptive Arch: Active Stress Minimization in a Thin Arch Structure

The concept of adaptive structures is based on the approach that the behaviour of a structure is not established only once during the initial design phase, but the structural response is controlled continuously via the integration of active components. The activation of these components can be used to manipulate the internal stresses, displacements as well as control vibrations. This approach allows the structure to react to variable loads with the goal of optimizing the load-carrying behaviour in real-time. The design of structural elements can thus be carried out for reduced demands, ideally resulting in substantial material savings in comparison with passive structures.The goal of this research is to develop insights and knowledge about the practical implementation of a control system for adaptive structures. Numerical and laboratory tests are done to minimize the maximum stress in an arch of Plexiglas when externally loaded with varying static loads by active rotation of the supports.

The Influence of Configuration on to the Seismic Resistance of a Building

Configuration of a building, achieved by coordinating the demands of an urban project and designer's style, and conditioned by the building's function (interior design) and the choice of a structural system, has an effect on the building behaviour under earthquake. The need for greater freedom in design results in solutions that present a serious influence onto the seismic performances of a building. Consequences that can lead all the way to collapse demand for overall analyses and structural measures to achieve the set reliability degree of a building. Building configuration is defined in the initial design phases, when it is possible to evaluate the regularity of a structure and observe the influence of the proposed design solution onto the structural treatment (structure analysis, dimensioning, and modelling). It implies the design of regular structures (configuration) when it is necessary to provide the most economic design, building, and maximum predictability of the demanded seismic performances. Designing irregular structures, on the other hand, demands for a structural designer to be included from the initial stage of a conceptual design, the ability of an architect to accept necessary structural measures for seismic resistance and their integration into the design in order to reduce the consequences of irregularity and achieve the demanded aesthetic qualities without endangering the building integrity.

Convertible Lump Sum EPS Contracting Model – How to Get the Plant you Need Now and Still Enjoy in 20 Years?

In most instances process plants are designed to meet performance objectives that are clearly defined by a detailed technical specification. The contractors and licensors designing and building such process plants are quite proficient at designing a plant to meet those performance values for an economically attractive cost. However the reality for the owner and operator of the plant is that over the 40+ year lifetime of the plant the inlet feeds, production rate and operationally desired set points for each piece of equipment will change. Often times this can result in a non-optimal plant and performance problems or poor reliability. This fact is particularly severe for plants which undergo significant corrosion or fouling like that commonly seen in sulphuric acid plants. Plants are built to make money for their owners. The primary way to make the most money out of a facility is to have the plant operational at as high of a capacity as possible for the maximum number of days in the operational life of the plant. There are numerous ways that the plant designer and builder can place design allowances, safety factors, built in redundancy, optional operational configurations, bypasses and other tricks to allow the facility to operate well for all desired production rates and all desired feed types. The costs of such options are often quite small if dealt with in the initial design phase. Unfortunately, in nearly all instances this optimal facility is not the facility that is built for the client. The reason why is often the inflexibility in the client/designer contractual relationship prevents open discussions on optimization. The Convertible Lump Sum EPS model can be used to get the optimal plant design for the client's present and future needs as well as providing price surety of a lump sum execution.This paper will detail the aspects of the Convertible Lump Sum EPS model. It will use an example sulphuric acid plant project to show how the client can be involved in the decision making process to get the best plant design for their site with appropriate design factors and options. Instances will be illustrated where plants have been built that do not have the flexibility required to operate effectively as the plant ages and/or the plant slightly changes operational modes. This lack of flexibility often causes damage to the plant and operational downtime or reduced capacity. Cost/Benefit analyses will be done on each of these cases. This paper will show that use of an effective, technically and commercially transparent contracting model with the appropriate partner can allow significant savings in TIC cost as well as for total return on investment.

Biofeedback System for Novice Snowboarding

The purpose of this project was to design a biofeedback system for beginner snowboarders. The aim was to design and build an electronic system, which analysed the load under the feet of the snowboarder and alerted the rider when more load was put on the back boot compared to the front boot. There are several stages involved in such a project including initial design phase, development of sensors, software development and testing of the product. This report details the design and fabrication processes involved in the project from initial design to working prototype. We were able to successfully design a biofeedback system for beginner snowboarders as well as test the system on the snow.

도로분야 BIM 라이브러리를 활용한 실적공사비 산정모델 구축

Currently, a BIM-based quantity takeoff (QTO) system is mainly focused on architectural projects. To perform this, diverse quantity takeoff methods such as an object-based automatic quantity takeoff, manual quantity and base functions of calculation have widely been utilizing. However, since BIM library for road projects includes structural elements associated with alignment, it is necessary to establish cost estimation system interlocked with historical cost using 3D library by each unit length. Accordingly, the aim of this study is to develop cost estimation model with using a historical cost approach so that it can be utilized in construction planning based on the BIM library for road projects. For this, based on the BIM library for road, the standardized quantity is estimated, and a process for calculating historical cost and a verification model with a 5D simulation was developed by mapping a WBS code with each BIM library object. This can be applied during the approximate cost estimation process in a project planning and an initial design phase for road projects. Besides, it is expected that these results will be utilized in constructing an optimal historical cost estimation process for project libraries.

Validation of a Model for Predicting Airtightness of Residential Units

Airtightness plays a significant role in buildings energy efficiency. This paper describes validation of the new model for predicting airtightness values of residential units. This model utilizes a neural network in prediction of airtightness and is obtained based on in situ measurements at 58 units in the local Osijek area (Croatia) carried out during 2013. The model presents new approach to airtightness estimations by using 4 corrective factors associated with building envelope elements and their airtightness properties. The model was validated in local field conditions, but independent validation of the model in this paper was made on 5 residential buildings in the Republic of Serbia in order to determine its applicability on new data set outside local area of Osijek. The proposed model requires reduced amount of data for predicting airtightness values of residential units and therefore is faster and more economical than the actual field measurements. The proposed model could also be used for predicting airtightness values at the initial design phase already, as well as for planning systematic energy refurbishment of residential buildings in order to achieve adequate energy efficiency and appropriate thermal comfort in accordance with EU recommendations in this field.

설계초기단계에 적용 가능한 초고층건축물의 패시브디자인 계획요소에 관한 연구

High-rise buildings may have problems of negative effects on the environment through excessive energy consumption and CO2 emission. Therefore, the purpose of this study is to establish the passive design elements that can be applied in the initial architectural design phase and to analyze them through some specific high-rise building examples that had acquired LEED green building certification. The findings of this study are as follows; The cooling and lighting are major factors for energy consumption for high-rise buildings. The major factors for reducing the energy consumption in the early design stage are Daylight, Solar heat, Curtain wall facade design, and Solar shades in terms of solar radiation, and Renewable Solar energy, Design for wind load, Natural Ventilation, and Renewable wind energy in terms of air flow. It is necessary to select appropriate strategies for the passive design according to divers climate characteristics. From the twelve buildings of green building certification, applications of passive design method are characterized according to the climatic zones, mass orientations, floor plans, forms and facade design elements.

가상 구속모형시험을 이용한 선박 조종성능 평가

For the more accurate prediction on manoeuvring performance of a ship at initial design phase, bare hull manoeuvring coefficients were estimated by RANS(Reynolds Averaged Navier-Stokes) based virtual captive model tests. Hydrodynamic forces and moment acting on the hull during static drift and harmonic oscillatory motions were computed with a commercial RANS code STAR-CCM+. Automatic and consistent mesh generation could be implemented by using macro functions of the code and user dependency could be greatly reduced. Computed forces and moments on KCS and KVLCC 1&2 were compared with the corresponding measurements from PMM(Planar Motion Mechanism) tests. Quite good agreement can be observed between the CFD and EFD results. Manoeuvring coefficients and IMO standard manoeuvres estimated from the computed data also showed reasonable agreement with those from the experimental data. Based on these results, we could confirm that the developed virtual captive manoeuvring model test process could be applied to evaluate manoeuvrability of a ship at the initial hull design phase.

북해설치 FPSO의 플레어 슬래밍 하중에 대응한 선수 설계

This paper is about the bow structure design of the ship-typed and turret moored FPSO which is subjected to the bow-flare slamming load in harsh North Sea environments. Quad 204 FPSO project involves the redevelopment of the existing Schiehallion FPSO which is damaged by impact wave loads. Normally all offshore systems including FPSO are designed to withstand the 100 year storm I.e. the storm that happens once every hundred years at the location where the system is installed. Several incidents have revealed that impact loading is important issue for moored floating production systems. In this paper, the design impact loads are estimated considering the ship owner’s specification, measured data from model tests, requirements of the classification society rules and results of numerical simulation analyses. The impact pressure by numerical analysis is 1.8 times greater than required value by CSR adopted by IACS. Based on the selected design load, plastic design formulae allowing the local material yielding are applied for the initial scantling of the bow structure. To verify the structural integrity, FE analyses are carried out considering the local area subjected to the impact wave loads. Their results such as structural arrangement, design loads and scantlings are shown and discussed. It is found that plastic design formulae in adopting Initial design phase give sufficiently conservative results in terms of structural strength.

A Problem Identification and Brainstorming Method using Visual Media during the Initial Design Phase

A Problem Identification and Brainstorming Method using Visual Media during the Initial Design Phase

IFC-BIM 연계 지식정보기반 마감공사 개산견적 프레임워크

Cost Estimate for alternative in design phase of construction become criterion for profitability and feasibility analysis of projects. Initial design phase performed schematic estimate based on similar data in the past. The quantity take-off according to estimators experience and calculation method are occurred different or missing. IT (Information Technology) technology evolution has been promoting BIM technology in construction. It is changing the paradigm of planning, design, construction and maintenance phase throughout the construction project. A number of studies have been attempted to apply BIM technology in the construction. In this paper, we propose schematic estimation framework linking standard format IFC (Industry Foundation Classes) and estimate related knowledge. As a result, it performs a cost prediction for decision-making in the design phase, and expected to overcome the limitations of previous studies. In addition, it is possible actively coping with changes.

Method and Case Study of Multiobjective Optimization-Based Energy System Design to Minimize the Primary Energy Use and Initial Investment Cost

This study aimed to develop a building energy system design method to minimize the initial investment cost and primary energy use. As for the energy system, various combinations were generated depending on the type and capacity of the device used as well as the number of units, energy consumption, and efficiency of the building. Because the design process of energy systems is a critical step in determining the performance of the building throughout the lifecycle, an effective design method is necessary. The proposed method determines the energy system that can minimize the primary energy use and initial investment cost through a multiobjective optimization by calculating the cooling and heating energy consumptions of the building and initial investment cost of the energy system using the load profile by the design-day, and the information in the design phase of the building. This method can support the decision-making process by providing engineers with an alternative proposal for minimizing the initial investment cost and primary energy use by the Pareto analysis after reviewing the design combinations of various energy systems with limited information in the initial design phase. To verify the effectiveness of the methodology, a case study of the two buildings was performed, and the analysis results were compared to the conventional design alternatives. As shown in the case study results, using a method developed in comparison with the conventional result can provide the efficient alternative selection with 80% of initial investment cost and 86% of primary energy use, respectively. The results confirmed that the proposed methodology can provide various optimum results more effectively compared to the conventional design methods.

A systems approach to defining environmental regulatory institutions

It is unlikely that any new regulatory regime will involve the establishment of a completely new regulatory institution. Instead, regulatory responsibility is more often apportioned to an existing institution, or several institutions within a portfolio that most closely match the subject matter of the regulatory regime in question. This article therefore offers guidance less for those involved in the initial policy design phase, and more for those engaged in implementation and operational policy, as well as those with review and reform agendas. In emphasising these policy and policy-like elements, the article takes as its lead the argument made by the New Zealand Productivity Commission and the New Zealand government that the traditional emphasis of review and reform efforts on regulatory design has acted to the detriment of implementation and better regulatory practice.

Disassembly operations’ efficiency evaluation in a virtual environment

Disassembly operations play a very important role during the initial design phase of industrial products. The available disassembly evaluation methods today seldom make disassembly as the preferred end-of-life solution for the reuse of parts or components in an economically sustainable way for lower value products. In virtual environment (VE), for instance, a human model is often involved in a digital mock-up model for assembly/disassembly (A/D) evaluation. However, it has limited application areas because of the high cost investment. Focusing on the evaluation of disassembly operations in a VE, a method based on five new criteria – visibility of a part, disassembly angles, number of tools’ changes, path orientation changing, and sub-assembly stability – is proposed here. All five criteria are presented by automatically calculated dimensionless coefficients, thus allowing the evaluation of the complexity of disassembly sequences in a VE. For this purpose, a mixed virtual reality disassembly environment based on Python programming language has been developed, using Visualisation Toolkit and Open Dynamics Engine libraries. The results of the analysis and findings demonstrate the feasibility of the proposed approach thus providing significant assistance for the evaluation of disassembly sequences during Product Development Process.

Framework for Energy Neutral Treatment for the 21st Century through Energy Efficient Aeration

Aeration is commonly identified as the most significant energy use in the treatment of wastewater and therefore garners significant focus in reducing energy use in the ultimate aspirational goal of achieving net energy neutrality for water resource recovery. This research establishes the mechanistic link between biofilm DNA concentration and reduced aeration efficiency caused by biofilm fouling. Although the connection between biofilm growth and fouling has been implicit in discussions of diffuser fouling for many years, this research provides directly measured evidence of the connection between biofouling and reduced diffuser efficiency. This was clearly established by studying systematically the evolution of aeration diffusers' efficiency over time, concurrently with the biological study of the biofilm fouling the diffusers in order to understand the major factors contributing to diffuser fouling. While all diffusers foul eventually, some novel materials exhibited fouling resistance. Fouling mitigation techniques, such as chemical cleaning and membrane reverse-flexing were studied. However, during the course of this study the research could not conclude that these techniques were always effective in curbing effects of fouling. By linking bacterial growth with aeration efficiency and calculating the aeration process energy requirements from the latter, the research was able to show quantitatively the causal connection between bacterial fouling and energy wastage during aeration. The methodology applied here can be extended to perform parallel tests during the initial phases of aeration design to yield site-specific data that increase the robustness of design. Fine-pore diffused aeration is the most commonly used aeration system for new activated sludge treatment processes due to its high oxygen transfer efficiency. However, fouling of finepore diffusers has the double-negative effect of greatly diminishing their oxygen transfer efficiency and increasing the back-pressure on the blower, which decreases its operating efficiency. Development of a fundamental understanding of the science of fouling and its impact on fine-pore diffusers facilitates the development of mitigation strategies and guidelines. Overall, application of the findings of this research will result in reduced energy usage at water resource recovery facilities (WRRFs) that will enable them to close the gap between energy use and energy generation to ultimately reach the goal of energy neutrality. This title belongs to WERF Research Report Series ISBN: 9781780406794 (eBook)

Preliminary design and off-design performance analysis of an Organic Rankine Cycle for geothermal sources

Geothermal fluid of 90°C and 10kg/s can be exploited together with oil in Huabei Oilfield of China. Organic Rankine Cycle is regarded as a reasonable method to utilize these geothermal sources. This study conducts a detailed design and off-design performance analysis based on the preliminary design of turbines and heat exchangers. The radial inflow turbine and plate heat exchanger are selected in this paper. Sliding pressure operation is applied in the simulation and three parameters are considered: geothermal fluid mass flow rate, geothermal fluid temperature and condensing pressure. The results indicate that in all considered conditions the designed radial inflow turbine has smooth off-design performance and no choke or supersonic flow are found at the nozzle and rotor exit. The lager geothermal fluid mass flow rate, the higher geothermal fluid temperature and the lower condensing pressure contribute to the increase of cycle efficiency and net power. Performance maps are illustrated to make system meet different load requirements especially when the geothermal fluid temperature and condensing pressure deviate from the design condition. This model can be used to provide basic data for future detailed design, and predict off-design performance in the initial design phase.

Toward a Model Undergraduate Curriculum for the Emerging Business Intelligence and Analytics Discipline

Business intelligence (BI) combined with business analytics (BA) is an increasingly prominent strategic objective for many organizations. As a pedagogical subject, BI/BA is still in its infancy, and, in order for this to mature, we need to develop an undergraduate model BI/BA curriculum. BI/BA as an academic domain is emerging as a hybrid of disciplines, including information systems, statistics, management science, artificial intelligence, computer science, and business practice/theory. Based on IS 2010’s model curriculum constructs (Topi et al., 2010), we explore two curricular options: a BI/BA concentration in a typical IS major and a comprehensive, integrated BI/BA undergraduate major. In support, we present evidence of industry need for BI/BA, review the current state of BI/BA education, and compare anticipated requirements for BI/BA curricula with the IS 2010 model curriculum. For this initial phase of curricular design, we postulate a preliminary set of knowledge areas relevant for BI/BA pedagogy in a multi-disciplinary framework. Then we discuss avenues for integrating these knowledge areas to develop professionally prepared BI/BA specializations at the undergraduate level. We also examine implications for both AACSB and ABET accreditation and describe the next phase of applying the IS 2010 concept structure to BI/BA curriculum development.