Detailed Design Requirements Research Articles

Separate emission/reception transducers for 3D ultrafast ultrasound imaging

Recent advancements in ultrafast 3D ultrasound imaging have revolutionized the field of echography, enabling its extension to novel applications such as cerebral dynamics, cardiac electrophysiology and the quantitative imaging of intrinsic mechanical properties of tumors. To facilitate these advancements, two primary transducer strategies are employed in 3D imaging. The first involves dense 2D probes equipped with a large number of elements, typically exceeding 1024. The second strategy uses row-column addressing, which simplifies the electronic control of the probe elements. Despite their effectiveness, these methods entail complexities in design and fabrication. Addressing these challenges, our study introduces an innovative transducer configuration that distinctly separates emission and reception functionalities. This separation not only simplifies the overall transducer design but also significantly reduces the system's complexity. A sparse array of PVDF transducers, which have been laser micro-machined to ensure acoustic transparency, is used at the reception. For the emission aspect, we employ a specialized acoustic concentrator to emulate point-like emission. The paper presents the detailed design requirements, assembly process, and the operational principles of this novel transducer. Furthermore, an experimental validation is conducted using a CIRS 040GSE phantom model. This validation is crucial to demonstrate the practical applicability and reliability of our transducer in real-world medical imaging scenarios.

The Width-Thickness Ratio Limits of Thin-Walled Steel Elements with Complex Edge Stiffeners

Complex edge stiffeners are widely used because of their superior performance over simple edge stiffeners in limiting flange buckling and improving local stability. However, most of the studies on complex edge stiffeners are qualitative. In this paper, the criterion to judge the stiffening adequacy based on the buckling half-wavelength and buckling coefficient is proposed. It is considered as the criterion that the edge stiffeners’ stiffness is not less than the minimum stiffening stiffness or the half-wavelength of buckling is not more than the width of the flange. The criterion is followed for the minimum limits of the edge stiffener width−thickness ratios; whether the flange buckling occurs before the edge stiffener buckling and the economic implications are the criteria that should be followed for the maximum limits of the edge stiffener width−thickness ratios. Using the finite strip method, the feasibility of the criteria was verified by comparing them with the rules of simple edge stiffeners. The detailed design requirements for the width−thickness ratio limits of thin-walled steel elements with complex edge stiffeners were first given from an extensive parametric analysis. Based on the optimization algorithm, the suggestions and optimum sizes of complex edge stiffeners for thin-walled steel elements are provided, considering the sections’ economy and performance. It is considered that a ratio of 1:1 between the primary and the secondary edge stiffeners’ widths is the best configuration for elements with complex edge stiffeners.

Bootstrap Aggregated Case-Based Reasoning Method for Conceptual Cost Estimation

Conceptual cost estimation is an important step in project feasibility decisions when there is not enough information on detailed design and project requirements. Methods that enable quick and reasonably accurate conceptual cost estimates are crucial for achieving successful decisions in the early stages of construction projects. For this reason, numerous machine learning methods proposed in the literature that use different learning mechanisms. In recent years, the case-based reasoning (CBR) method has received particular attention in the literature for conceptual cost estimation of construction projects that use similarity-based learning principles. Despite the fact that CBR provides a powerful and practical alternative for conceptual cost estimation, one of the main criticisms about CBR is its low prediction performance when there is not a sufficient number of cases. This paper presents a bootstrap aggregated CBR method for achieving advancement in CBR research, particularly for conceptual cost estimation of construction projects when a limited number of training cases are available. The proposed learning method is designed so that CBR can learn from a diverse set of training data even when there are not a sufficient number of cases. The performance of the proposed bootstrap aggregated CBR method is evaluated using three data sets. The results revealed that the prediction performance of the new bootstrap aggregated CBR method is better than the prediction performance of the existing CBR method. Since the majority of conceptual cost estimates are made with a limited number of cases, the proposed method provides a contribution to CBR research and practice by improving the existing methods for conceptual cost estimating.

Design and Verification of Calorimeter for CFETR Neutral Beam Injection System Prototype with Negative Ion Source

Currently, a neutral beam injection (NBI) system prototype with a 200-keV negative ion source, called the negative neutral beam injection (NNBI) system, is under construction for the China Fusion Engineering Test Reactor Project. In the NNBI system, the calorimeter is an extremely important high-heat-flux component, and its panels have to withstand a heat flux density of up to dozens of MW/m2 under some extreme conditions; thus, its efficient heat transfer enhancement design and the corresponding supporting structural design are most important, especially under the condition of a 3600-s long pulse. According to the detailed design requirements of the NNBI system, an overall design scheme of the calorimeter based on the heat transfer enhancement structure of the swirl tube (SW for short) is proposed in this paper. By using the gas-liquid two-phase flow boiling model and the supporting structure’s finite element model, the heat transfer performance of the heat exchange module, the mass flow distribution and pressure drop of the entire cooling circuit of the component, and the strength of the support structure are evaluated to verify the feasibility of the design scheme. Finally, based on the proposed design scheme, the detailed design of the temperature monitor system, which has high reliability and economy, is completed. This research provides important theoretical and engineering support for the structural development of the calorimeter for the NNBI verification prototype and will also provide references for the design and development of other internal components of large-scale fusion devices.

A helium mini-cryostat for the nanoprobe beamline ID16B at ESRF: characteristics and performance.

A helium mini-cryostat has been developed for the hard X-ray nanoprobe ID16B of the European Synchrotron to collect X-ray excited optical luminescence and X-ray fluorescence at low temperature (<10 K). The mini-cryostat has been specifically designed to fit within the strong space restrictions and high-demanding mechanical constraints imposed by the beamline to provide vibration-free operation and maximal thermal stability. This paper reports the detailed design, architecture and technical requirements of the mini-cryostat, and presents the first experimental data measured using the cryogenic equipment. The resulting cryo-system features ultimate thermal stability, fast cool-down and ultra-low vibrations. The simultaneous X-ray fluorescence and X-ray excited optical luminescence data acquired from bulk GaN and core/shell InGaN/GaN multi-quantum wells validated the excellent performance of the cryostat with ultimate resolution, stability and sensitivity.

A brief analysis of the power cable planning and design of the utility tunnel

The urban utility tunnel plays an important role in improving the utilization efficiency of urban underground space. With the vigorous promotion of the construction of urban utility tunnel, the scale of power cable into urban utility tunnel is also increasing rapidly. There are some problems in the planning and design process of utility tunnel, such as the lack of technical specifications or the inconsistency of existing standards and norms. Thus, some detailed design requirements of the overall design, section design and ancillary system design of the power pipeline are proposed in this paper, especially the details of the power cables entering into the utility tunnel are discussed in detail, providing a reference for other engineering. It would be helpful for the electric power cables entering into the utility tunnel in the future.

Influence of the Brace Configurations on the Seismic Performance of Steel Concentrically Braced Frames

Concentrically braced frame is an effective and prevalent seismic force resisting system which is commonly used in low-rise buildings. This type of structural system utilizes steel braces to provide the stiffness and strength needed to dissipate earthquake energy. Several bracing configurations have been proposed in different building codes worldwide. These codes provide detailed design requirements for the structural members and connections, but no guidance is provided in selecting the best bracing configuration for the design. In this study, the impact of the bracing configuration on the seismic response of a five-story prototype office building located in Vancouver, Canada, is systematically examined. Five different bracing configurations were designed according to the National Building Code of Canada and CSA S16 standard. Detailed structural responses, initial costs, and life cycle costs of the prototype building with five different bracing configurations were systematically compared. The results show that the different bracing configurations play an important role in sizing the structural members, which impacts the initial material usage and the overall life cycle cost of the building.

Techno-economic comparison of solar power tower system/photovoltaic system/wind turbine/diesel generator in supplying electrical energy to small loads

ABSTRACTThis study presents a techno-economic comparison of four alternatives (experimental prototype of concentrating solar power tower system, photovoltaic (PV) system, collapsible vertical axis wind turbine and diesel generator) to supply electrical energy for a small compound of buildings. Among the services needed in the compound are the provision of an adequate drinking water, health centre for immunization purposes, and learning centre. The result of this study shows that the amount of electrical energy needed to meet the basic power requirements is 7.3 kWh/day. Detailed analysis and design requirements of the four alternatives are presented. Dynamic indicators (life cycle cost, annualized life cycle cost and cost of energy production) were applied to evaluate the economic-effectiveness of these energy supply systems. The cost of energy was $1.06/kWh, $1.18/kWh, $1.19/kWh and $2.98/kWh for the PV system, solar power tower system, diesel generator system and wind turbine system, respectively. Providing electricity to the compound buildings using solar power tower and PV systems is very beneficial and competitive among the other types of energy sources.

Study of Rapid Calibration Method of Angel of Attack Sensor and Error Impact on Flight Control System

The current calibration methods of combat aircraft’s attarck angle sensors are too complex and have some insufficiencies. According to the detailed design requirements of flight control system，a method combined with linear fitting and neural network identification is proposed, which can calibrate the measure data of the attarck angle sensors qucikly and accurately. The method proposed avoids the disadvantages of traditional interplation method， improves the computating efficiency, and ensures the the flight control system’s fault-tolerant ability. A simulation on flight control system with this calibration method was carrid out, which validated the precision and dependability of the method. The method can also deal strong nonlinear data quickly.

Selection of kinematic structure for portable machine tool

Selection of kinematic structure for portable machine tool The article presents the problem of selecting kinematic structures for the proposed portable machine tool. Developed methodology of selection has been based on the detailed design requirements and elimination conditions formulated thanks to them. The paper describes the program developed to assist the process of selecting the kinematic structures for the portable machine tool and the results achieved.

Switching Transient Analysis and Specifications for Practical Hybrid High-Resistance Grounded Generator Applications—An IEEE/IAS Working Group Report #2

This paper reports on the continuing efforts of an IAS Working Group to investigate industry concerns with excessive stator fault-point burning damage in conjunction with various industrial generator grounding and ground fault protection practices. Previous working group efforts were reported in a series of papers discussing typical voltage bus connected industrial generator applications. These papers proposed a new method of grounding, called hybrid grounding, that offered the ability to limit damage while still providing the required level of ground fault current under all operating conditions. This new Working Group paper reports on the detailed design requirements for hybrid grounding. The paper reports the results of switching transient studies that formed the bases for recommended overvoltage protection. It also provides guidance in selection of equipment and fault protection required for hybrid grounding. The experience gained with several hybrid grounding applications is also reported.

분리형 부재 옹벽 설계 프로그램 개발

본 연구에서는 지압형 보강재를 갖는 분리형 부재 옹벽의 설계에 있어 검토해야 할 세부 검토항목을 살펴보고 설계 프로그램을 개발하였다. 분리형 부재 옹벽의 설계시 세부 설계내용은 외적 안정성 검토, 내적 안정성 검토 그리고 국부적 안정성 검토의 세 가지로 대별할 수 있다. 설계 프로그램에 반영된 외적 안정성 검토는 통상적인 옹벽에 대한 검토와 큰 차이는 없다. 내적 안정성 검토에서 고려해야 할 보강재의 인장파괴에 대한 검토와 인발에 대한 검토 세부 사항을 살펴보았고 국부적 안정성 검토에서 고려해야 할 보강재와 전면부재 사이의 연결강도에 대한 검토와 전면부재의 접촉면 사이의 전단강도에 관련한 벌징(bulging)에 대한 검토 세부 사항을 살펴보고 이를 개발된 프로그램에 구현하였다. 또한, 설계 예를 제시하여 입력자료와 검토결과를 나타냄으로써 개발된 프로그램의 이해를 증진시키고자 하였다. In this study, detailed design requirements for segmental retaining wall (SRW) which were concerned with external stability, internal stability, and local stability were investigated and a computer program for designing the SRW was developed as well. There are little differences in the estimation of the external stability between the algorithm of the developed program and the conventional method for the design of the SRW. Methods for accounting tension failure and pullout of the reinforcement were incorporated in the developed program, which were essentials in the internal stability. Methods for accounting the connection strength between a reinforcement and a facing block and for accounting the bulging concerned with the shear strength of the interface between two blocks were also incorporated in the developed program, which are essentials in the local stability. Design example run by the developed program is presented in order to enhance the knowledge of the developed program.

Conceptual study for TBM-related activities in ITER Hot Cell Facility before TBM shipment back to owner

The post-irradiation examination (PIE) of the test blanket module (TBM) is an important part of the testing programme. To avoid the expense and difficulty of shipping large radioactive components from ITER site to Parties, the main functions of the TBM pre-PIE HCF (Hot Cell Facilities) will most probably to be performed, by remote handling, optical and other easy non-destructive examinations, extract specimen cassettes, cut the TBM into smaller, more manageable pieces, and prepare these pieces for shipment. This study presented the TBM-related activities in the ITER HCF including the operation sequences, operation tools, space allocations. The detailed equipments design and engineering requirements are needed. A detailed TBM cutting strategy capable of meeting pre-PIE and transfer requirements needs to be elaborated.

A New Method for Optimum Allocation of Design Requirements in Aircraft Conceptual Design

A new method, Collaborative Allocation (CA), is proposed to solve the large-scale optimum allocation problem in aircraft conceptual design. According to the characteristics of optimum allocation in aircraft conceptual design. The principle and mathematical model of CA are established. The optimum allocation problem is decomposed into one main optimization problem and several sub-optimization problems. A group of design requirements for subsystems are provided by the main system respectively, and the subsystems execute their own optimizations or further provide the detailed design requirements to the bottom components of aircraft, such as spars, ribs and skins, etc. The subsystems minimize the discrepancy between their own local variables and the corresponding allocated values, and then return the optimization results to main optimization. The main optimization is performed to reallocate the design requirements for improving the integration performance and progressing toward the compatibilities among subsystems. CA provides the general optimum allocation architecture and is easy to be carried out. Furthermore, the concurrent computation can also be realized. Two examples of optimum reliability allocation are used to describe the implementation procedure of CA for two-level allocation and three-level allocation respectively, and to validate preliminarily its correctness and effectiveness. It is shown that the developed method can be successfully used in optimum allocation of design requirements. Then taking weight requirement allocation as example, the mathematical model and solution procedure for collaborative allocation of design requirements in aircraft conceptual design are briefly depicted.

Feasibility of Computer Visualization in Highway Development: A Fuzzy Logic-Based Approach

: Building transportation infrastructure requires careful planning and design with due consideration to land and environmental impacts. Imprecise assessments of detailed design requirements, and land and environmental impacts lead to frequent scope changes of transportation infrastructure improvement projects. Computer visualization (CV) and geographic information systems (GIS) can greatly assist in understanding the detailed design requirements as well as land and environmental impacts. However, the application of CV is quite limited in transportation primarily because of the limited knowledge of its benefits over cost. This study investigates the feasibility of CV in modeling highway improvement sections. Two potential benefits are realized through the proposed modeling: (1) better representation of future improvements resulting in enhanced public and political support and (2) early identification of adverse environmental and land impacts as well as detail design requirements resulting in fewer scope changes. A fuzzy logic-based general approach is proposed to calculate the expected benefits of CV. A computer code called the Projection Option Processor (POP) is developed in Microstation's BASIC language to automate repetitive tasks in the visualization procedure. Two real highway projects from Maryland are visualized and the benefits and costs of the visualization are estimated using the proposed fuzzy logic-based approach. The results indicate that using POP is cost-effective resulting in higher benefit-cost ratios (B/C). Increasing the number of views, alternatives, and reevaluations for visualization may increase the total visualization cost significantly.

The passive ALWR approach to assuring containment integrity

Design requirements for the advanced light water reactor (ALWR) have been developed so as to provide high assurance of containment integrity even in the event of a severe accident. The containment integrity requirements are in the form of two design criteria, and associated methodology, which address containment severe accident performance and offsite dose and are specified in the ALWR utility requirements document (URD), a set of detailed design requirements for next generation plants in the US. The containment performance criterion, which is the main focus of this paper, specifies that plant design characteristics and features shall be provided to preclude core damage sequences which could bypass containment and to withstand core damage sequence loads. This containment performance capability, along with the associated dose mitigation capability, provides a technical basis for emergency planning change since there would not be the same need for rapid offsite emergency response that is called for under the existing US emergency planning basis.

Nearly decoupled robust MIMO control of an unstable plant

The design of a nearly decoupled, robust control system with an unstable plant is considered. The main aim is to present an effective design methodology that is applicable to a non-minimum phase and/or unstable multivariable uncertain plant. The controller resulting from the present design technique for nearly decoupled multivariable control has no right half-plane poles/zeros other than those specified by the designer, even when the given plant is of non-minimum phase and/or unstable. Unlike the prevailing techniques, the present approach can handle detailed and tight design requirements specified on the Bode array of the closed-loop system. Furthermore, a non-conservative robustness criterion presented in a previous paper is integrated into the design methodology such that the resultant design is robust in the presence of plant uncertainties.