bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of red blood cell transfusion on global oxygenation in anemic critically ill patients
Authors: Themelin Nicolas , Biston Patrick , Massart Jacqueline , Lelubre Christophe , Piagnerelli Michaël
Published: February 2021

Background

Consensus for transfusion in intensive care unit (ICU) patients recommends a restrictive strategy, based on a hemoglobin (Hb) concentration of 7 g/dL. Red blood cell (RBC) transfusion is used to prevent tissue hypoxia by improving oxygen transport (DO2) and therefore oxygen consumption (VO2). We studied the effects of RBC transfusion on systemic oxygenation parameters reflecting systemic oxygen extraction (EO2 = DO2/VO2): S(c)vO2, lactate level, venous‐to‐arterial carbon dioxide difference (Pv‐aCO2), and cardiac index/EO2 (CI/EO2) and evaluated their usefulness in guiding transfusion decisions in ICU patients.

Study Design and Methods

Prospectively, all adult patients transfused were included except those with active bleeding or without a jugular or subclavian catheter. We measured O2 parameters before and after transfusion. Patients were a priori grouped according to their initial S(c)vO2 (< or ≥70%), treatment with vasopressors, cardiac function, and septic status.

Results

A total of 62 patients received 105 RBC transfusions. For all, mean arterial pressure (77 [69‐88] to 81 [73‐91] mm Hg), Hb concentration (7.4 [7.0‐7.8] to 8.4 [7.7‐8.9] g/dL) and S(c)vO2 (65% [59%‐73%] to 69% [62%‐75%]) increased after transfusion (all P < .001). S(c)vO2 improved after transfusion only when initial S(c)vO2 was less than 70% (62% [56%‐65%] to 66% [61%‐71%]; P < .001). In this group, Pv‐aCO2, lactate concentrations, and CI/EO2 did not change after transfusion. Cardiac function, sepsis, or vasopressor therapy did not affect these results.

Conclusions

Among systemic O2 parameters, only a S(c)vO2 < 70% in anemic ICU patients improves after transfusion. As S(c)vO2 can reflect a DO2/VO2 imbalance, it could be helpful when combined with the Hb concentration to decide whether to transfuse. However, the benefit on outcome should be further studied.
Preliminary study of the stability of dexamethasone when added to commercial veterinary ear cleaners over a 90 day period
Authors: Emery Carolyn B. , Outerbridge Catherine A. , Knych Heather K. , Lam Andrea T.H. , Gomez‐Vazquez Jose P. , White Stephen D.
Published: February 2021

Background

Topical corticosteroids are commonly used in the management of allergic otitis externa to diminish inflammation. A common strategy is to make compounded solutions of dexamethasone in ear cleaner.

Hypothesis/Objectives

The objective of this study was to determine the stability of dexamethasone when added to four commercial ear cleaners (ec): designated ecA, ecB, ecC and ecD.

Methods and Materials

Two concentrations (0.1 and 0.25 mg/mL) of dexamethasone were formulated for each cleaner solution from a 2 mg/mL solution and stored in the original manufacturers’ bottles at two temperatures: room (22 ˚C) and refrigerated (4 ˚C). Samples were evaluated in triplicate, using liquid chromatography‐tandem mass spectrometry at 10 time points over 90 days. The mean and standard deviation were calculated for each time point.

Results

A solution was considered stable if the dexamethasone value remained >90% of the target concentration. All dexamethasone solution values were stable to 90 days, except two solutions for ecA; the 0.25 mg/mL dexamethasone concentration was only stable to 14 (4 ˚C) and 21 days (22 ˚C).

Conclusions and clinical importance

These results provide preliminary evidence in support of pharmaceutical stability data for dexamethasone when included in the above compounded solutions at the noted concentrations and temperatures.
A survey of laboratory biosafety and protective measures in blood transfusion departments during the COVID‐19 pandemic
Authors: Liu Haiting , Liu Leping , Zhang Junhua , Shang Xueling , Chen Sai , Li Xisheng , Gui Rong , Huang Rong
Published: February 2021

Background and objectives

Thousands of healthcare workers (HCWs) have been infected with 2019 novel coronavirus pneumonia (COVID‐19) during the COVID‐19 pandemic. Laboratory personnel in blood transfusion departments may be infected with severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) if laboratory biosafety protection is insufficient. Therefore, we investigated the current situation of laboratory biosafety protection in blood transfusion departments to determine how to improve the safety of laboratory processes.

Materials and methods

An online survey was conducted in blood transfusion departments from 1st to 6th May 2020 in China. A total of 653 individuals completed the questionnaire. The questionnaire was designed with reference to COVID‐19 laboratory biosafety summarized in Annex II. All responses were summarized using only descriptive statistics and expressed as frequencies and ratios [n (%)].

Results

Most participants were concerned about COVID‐19. Some participants had inadequate knowledge of COVID‐19. Two participants stated that there were laboratory personnel infected with SARS‐CoV‐2 in their departments. A total of 31 (4.7%) participants did not receive any safety and security training. In terms of laboratory biosafety protection practices, the major challenges were suboptimal laboratory safety practices and insufficient laboratory conditions.

Conclusion

The major deficiencies were insufficient security and safety training, and a lack of personal protective equipment, automatic cap removal centrifuges and biosafety cabinets. Consequently, we should enhance the security and safety training of laboratory personnel to improve their laboratory biosafety protection practices and ensure that laboratory conditions are sufficient to improve the safety of laboratory processes.
A Three-Dimensional Tube Bundle Model Analysis for Leakage Flow Characteristics of Variable Bristle Diameter Brush Seals With Bristle Pack Stratification
Authors: Ma Dengqian , Li Zhigang , Li Jun
Published: February 2021

The leakage flow characteristics of the variable bristle diameter (VBD) brush seals are numerically investigated using the three-dimensional (3D) tube bundle model with consideration of bristle pack stratification. The discretization of the computational domain applies the multiblock structured mesh, which ensures that there is no need to set interfaces between the fluid domains of the bristle pack and the cavities to eliminate interpolation errors. The bristle pack stratification is achieved by using mesh motion technique from the point of cause-effect. The effects of pressure ratio (Rp=1.5, 2.5, 3.5), axial rows of bristles (Nx=9–21), sealing clearance (c=0, 0.1 mm), bristle pack arrangements, and bristles gapping (gi=0, 0.005, 0.010, 0.015 mm) on the leakage flow characteristics and aerodynamic forces are conducted. The recorded leakage flow of the 3D tube bundle model is multiplied by circumferential loop number (Ncl) to determine total leakage flow rate of the brush seal. The numerical results agreed well with the experimental data, which verifies the reliability of the numerical method. The numerical results indicate that the leakage flow rate increases linearly with the pressure ratio. The increase of Nx has a distinctly different effect on the relative rate of leakage flow for the contacting and clearance brush seals. The use of large diameter bristles weakens the sealing performance of the brush seals, particularly in the rear region. Bristle pack stratification can improve the sealing performance of the brush seals. The large diameter bristles increase the porosity and reduce the flow resistance coefficients. On the contrary, the bristle pack stratification decreases the porosity and rises the flow resistance coefficients in the rear region. The results of this article indicate when designing VBD brush seals, the effects of bristle diameter and bristle density on the sealing performance and pressure loading capacity of the brush seals should be fully considered.
Volumetric Velocimetry Measurements of Purge–Mainstream Interaction in a One-Stage Turbine
Authors: Carvalho Figueiredo A. J. , Schreiner B. D. J. , Mesny A. W. , Pountney O. J. , Scobie J. A. , Li Y. S. , Cleaver D. J. , Sangan C. M.
Published: February 2021

Air-cooled gas turbines employ bleed air from the compressor to cool vulnerable components in the turbine. The cooling flow, commonly known as purge air, is introduced at low radius, before exiting through the rim-seal at the periphery of the turbine discs. The purge flow interacts with the mainstream gas path, creating an unsteady and complex flowfield. Of particular interest to the designer is the effect of purge on the secondary-flow structures within the blade passage, the extent of which directly affects the aerodynamic loss in the stage. This paper presents a combined experimental and computational fluid dynamics (CFD) investigation into the effect of purge flow on the secondary flows in the blade passage of an optically accessible one-stage turbine rig. The experimental campaign was conducted using volumetric velocimetry (VV) measurements to assess the three-dimensional inter-blade velocity field; the complementary CFD campaign was carried out using unsteady Reynolds-averaged Navier–Stokes (URANS) computations. The implementation of VV within a rotating environment is a world first and offers an unparalleled level of experimental detail. The baseline flow-field, in the absence of purge flow, demonstrated a classical secondary flow-field: the rollup of a horseshoe vortex, with subsequent downstream convection of a pressure-side and suction-side leg, the former transitioning in to the passage vortex. The introduction of purge, at 1.7% of the mainstream flowrate, was shown to modify the secondary flow-field by enhancing the passage vortex, in both strength and span-wise migration. The computational predictions were in agreement with the enhancement revealed by the experiments.
Adaptive Kriging Method for Uncertainty Quantification of the Photoelectron Sheath and Dust Levitation on the Lunar Surface
Authors: Wei Xinpeng , Zhao Jianxun , He Xiaoming , Hu Zhen , Du Xiaoping , Han Daoru
Published: February 2021

This paper presents an adaptive Kriging based method to perform uncertainty quantification (UQ) of the photoelectron sheath and dust levitation on the lunar surface. The objective of this study is to identify the upper and lower bounds of the electric potential and that of dust levitation height, given the intervals of model parameters in the one-dimensional (1D) photoelectron sheath model. To improve the calculation efficiency, we employ the widely used adaptive Kriging method (AKM). A task-oriented learning function and a stopping criterion are developed to train the Kriging model and customize the AKM. Experiment analysis shows that the proposed AKM is both accurate and efficient.
Errors Characterization of a RANS Simulation
Authors: Pasinato Hugo D. , Krumrick Ezequiel A.
Published: February 2021

This research uses data from direct numerical simulation (DNS) to characterize the different errors associated with a Reynolds-averaged Navier–Stokes (RANS) simulation. The statistics from DNS (Reynolds stresses, kinetic energy of turbulence, κ, and dissipation of turbulence, ε), are fed into a RANS simulation with the same Reynolds number, geometry, and numerical code used for DNS. Three integral metrics error based on the mean velocity, the moduli of the mean rate-of-strain tensor, and the wall shear stress are used to characterize the errors associated with the RANS technique, with the RANS model, and with the linear eddy viscosity model (LEVM). For developed and perturbed flow, it is found that the mean velocity of the RANS simulations with the DNS statistics is almost the same as the mean velocity from DNS data. This procedure enables the study of the relative importance of the different Reynolds stresses in a particular flow. It is shown that for the bounded perturbed turbulent flows studied here, almost all the necessary effects of turbulence are contained in the Reynolds shear stress.
New Hammerstein Modeling and Analysis for Controlling Melt Pool Width in Powder Bed Fusion Additive Manufacturing
Authors: Wang Dan , Zhao Xinyu , Chen Xu
Published: February 2021

Despite the advantages and emerging applications, broader adoption of powder bed fusion (PBF) additive manufacturing is challenged by insufficient reliability and in-process variations. Finite element modeling and control-oriented modeling have been shown to be effective for predicting and engineering part qualities in PBF. This paper first builds a finite element model (FEM) of the thermal fields to look into the convoluted thermal interactions during the PBF process. Using the FEM data, we identify a novel surrogate system model from the laser power to the melt pool width. Linking a linear model with a memoryless nonlinear submodel, we develop a physics-based Hammerstein model that captures the complex spatiotemporal thermomechanical dynamics. We verify the accuracy of the Hammerstein model using the FEM and prove that the linearized model is only a representation of the Hammerstein model around the equilibrium point. Along the way, we conduct the stability and robustness analyses and formalize the Hammerstein model to facilitate the subsequent control designs.
Fluid Dynamics of a Bistable Diverter Under Ultrasonic Excitation—Part I: Performance Characteristic
Authors: Mair Michael , Bacic Marko
Published: February 2021

This paper investigates an ultrasonically driven bistable fluidic diverter at inlet nozzle Mach numbers of up to Mn = 0.3 and operating pressure ratios of up to Pr = 1.1. Part I examines the switching characteristics with respect to nondimensional parameters of excitation amplitude, frequency, required energy, switching time and inlet total pressure. It is shown that to promote switching at turbulent jet Mach numbers of up to Mn = 0.3 it is necessary to excite a jet preferred mode of St = 0.45 which differs from previously reported laminar jet operation of the similar device. For the reference case the switching time amounts to 1.2 ms suggesting oscillation frequencies of up to 500 Hz. Part II is a combined experimental and numerical study that examines the triggered instability modes in the free shear layer using large eddy simulations (LES) and visualizes the flow field using Particle Image Velocimetry (PIV).
Numerical Modeling of Initial Stress Stiffening Effect on the Dynamic Behavior of Axisymmetric Shells
Authors: Ben-Youssef Yacine , Kerboua Youcef , Lakis Aouni A.
Published: February 2021

This paper presents a numerical model to simulate the initial stress stiffening effect, induced by radial pressure and/or axial load on the dynamic behavior of axisymmetric shells. This effect is particularly important for thin shells since their bending stiffness is very small compared to membrane stiffness. The theoretical formulation is based on a combination of the finite element method and classical shell theory. For a perfect geometrical consistency, two semi-analytical finite elements, conical and cylindrical, are used to model axisymmetric shells. The displacement functions are derived from exact solutions of Sanders' shell equilibrium equations. The results obtained using this approach are remarkably accurate. The potential energy is calculated to estimate the initial stiffening effect using direct membrane forces per unit width and rotations about the orthogonal axes. The final stiffness matrix of each finite element is composed of the regular stiffness matrix and the added stiffness matrix generated by membrane loads. The frequencies of vibration are compared with those obtained in other experimental and theoretical research works and very good agreement is observed.
Stability Region-Based Analysis of Walking and Push Recovery Control
Authors: Peng William Z. , Song Hyunjong , Kim Joo H.
Published: February 2021

To achieve walking and push recovery successfully, a biped robot must be able to determine if it can maintain its current contact configuration or transition into another one without falling. In this study, the ability of a humanoid robot to maintain single support (SS) or double support (DS) contact and to achieve a step are represented by balanced and steppable regions, respectively, as proposed partitions of an augmented center-of-mass-state space. These regions are constructed with an optimization method that incorporates full-order system dynamics, system properties such as kinematic and actuation limits, and contact interactions with the environment in the two-dimensional sagittal plane. The SS balanced, DS balanced, and steppable regions are obtained for both experimental and simulated walking trajectories of the robot with and without the swing foot velocity constraint to evaluate the contribution of the swing leg momentum. A comparative analysis against one-step capturability, the ability of a biped to come to a stop after one step, demonstrates that the computed steppable region significantly exceeds the one-step capturability of an equivalent reduced-order model. The use of balanced regions to characterize the full balance capability criteria of the system and benchmark controllers is demonstrated with three push recovery controllers. The implemented hip–knee–ankle controller resulted in improved stabilization with respect to decreased foot tipping and time required to balance, relative to an existing hip–ankle controller and a gyro balance feedback controller.
A New Extensible Continuum Manipulator Using Flexible Parallel Mechanism and Rigid Motion Transmission
Authors: Liu Yujiong , Ben-Tzvi Pinhas
Published: February 2021

An extensible continuum manipulator (ECM) has specific advantages over its nonextensible counterparts. For instance, in certain applications, such as minimally invasive surgery or pipe inspection, the base motion might be limited or disallowed. The additional extensibility provides the robot with more dexterous manipulation and a larger workspace. Existing continuum robot designs achieve extensibility mainly through artificial muscle/pneumatic, extensible backbone, concentric tube, and base extension, etc. This article proposes a new way to achieve this additional motion degree-of-freedom by taking advantage of the rigid coupling hybrid mechanism concept and a flexible parallel mechanism. More specifically, a rack and pinion set is used to transmit the motion of the i-th subsegment to drive the (i+1)-th subsegment. A six-chain flexible parallel mechanism is used to generate the desired spatial bending and one extension mobility for each subsegment. This way, the new manipulator can achieve tail-like spatial bending and worm-like extension at the same time. Simplified kinematic analyses are conducted to estimate the workspace and the motion nonuniformity. A proof-of-concept prototype was integrated to verify the mechanism’s mobility and to evaluate the kinematic model accuracy. The results show that the proposed mechanism achieved the desired mobilities with a maximum extension ratio of 32.2% and a maximum bending angle of 80 deg.
Design and Virtual Prototyping of Human-Worn Manipulation Devices
Authors: Song Peng , Krovi Venkat , Kumar Vijay , Mahoney Richard
Published: February 2021

This paper presents a novel class of human-worn manipulation aids for people with disabilities, and a paradigm for the cost-effective design and manufacture of such devices. These manipulation aids are passive multi-link articulated devices that are physically connected to and controlled by a human user. This physical connection enables proprioceptive feedback control of the end effector. Performance can be enhanced by task and user customization of such devices prior to manufacture. As illustrative examples, we consider two case studies of the design and prototyping of customized manipulation aids for quadriplegics. We explore the use of the virtual prototyping and interactive simulation tools by the designer to customize the designs, virtually analyze the user-product interactions and progressively refine these designed aids. This process is aided by a unified design environment that integrates such support tools as automated data acquisition and measurement, mechanism synthesis and optimization, creation of customized synthetic models of the human user, and the user-based refinement of the product performance.
Development of a Feature Based Design System Using Virtual Reality
Authors: Summers Joshua D. , Butler Alley C. , Kuo Eddy
Published: February 2021

Virtual reality systems have been developed over the last few years to provide real time, immersive, three dimensional rendering. There have been efforts to utilize virtual reality and other similar approaches for design (Jones, 1996); however, limited information has been placed in the open literature describing the development of systems used specifically for the design of complex products, like naval vessels. As added motivation, features have been widely accepted as a useful paradigm for design purposes, but experience with feature based design in a virtual reality environment has also been limited. With these issues in mind, this paper was written to describe an ongoing research project that focuses on the demonstration of feature based design in a virtual reality environment for submarine design. To support this development, progress to date using the GROTTO, a CAVE like system, at the Naval Research Laboratory is reported. A “spin-off” of the research to web based collaboration is reported, an outline of projected system architecture is provided, and conclusions are drawn regarding the development of the virtual system.
Development of a Haptically Enabled Dis/Re-Assembly Simulation Environment
Authors: McDermott Scott D. , Bras Bert
Published: February 2021

Typical CAD environments constrain the user to one sense, sight, and two dimensions, the table upon which the mouse rests. The introduction of a haptic interface into the CAD environment allows users to incorporate both a third dimension and a second sense, that of touch, into their work. We are currently developing HIDRA (Haptic Integrated Dis/Re-assembly Analysis), an application that integrates haptic feedback into a (dis)assembly simulation environment. In this paper, we present the basic computer architecture of the application, including its interface with commercial CAD systems. We also explain some of application constraints unique to haptic simulation and the methods employed to help meet these constraints. Finally, we identify some available avenues for future work.
Wearable Computers and Augmented Reality in an Industrial Application
Authors: Santos Luiz M. A.
Published: February 2021

In the modern industrial scenario, the technological assets of new working methods and machinery in factory plants grow rapidly. Nevertheless, a reverse situation occurs in terms of availability of trained personnel within the subject area. Moreover, even the most experienced technician is faced with a continual need to update his/her skills. In respect to the training activities, more realism and a greater effectiveness could be achieved if the trainee could learn a new technology directly in the real working place. In this paper, considerations are presented for the use of an innovative hardware and Augmented Reality as platform components for the learning material to this training scenario. Both components are described with emphasis on their suitability to the target activity. The proposed platform encompasses a body-worn and wireless-networked computer, and software with specific features to assist the computer user in his/her task by enriching the content of the application environment. The software component, which addresses the application goals and required adaptations to the platform, is presented.
Algorithm Animation in a Three-Dimensional Shared Space for Distance Education of Information Processing
Authors: Ikei Yasushi , Fukuda Shuichi
Published: February 2021

In this paper, a prototype system of distance education over the Internet using a three-dimensional (3D) virtual shared space is discussed. Inside the shared space, animation of sorting algorithms is presented as part of a teaching tool for an elementary information processing course. The system is used via the Internet where an instructor and a student share 3D + 2D representations of objects’ dynamic behavior. The system features consist of automated generation of animation, 2D annotated 3D presentation within a shared browser window, and interaction support between an instructor and a student. After addressing functional design requirements for the system, the views of 3D animation and of associated source code are shown in addition to their implementations as a client server system. Finally, system evaluation regarding annotation forms, interaction support, and an execution time is discussed.
PC-Based Computer Modeling of Combustion Processes
Authors: Gmurczyk Greg W. , Gupta Ashwani K.
Published: February 2021

Constant and significant progress in both computer hardware and numerical algorithms, in recent years, have made it possible to investigate complex phenomena in engineering systems using computer modeling and simulations. Advanced numerical simulations can be treated as an extension of traditional analytical-theoretical analyses. In such cases, some of the simplifying assumptions can usually be dropped and the nonlinear interactions between various processes can be captured. One of the most complex engineering processes encountered in industry is a combustion process utilized either for power/thrust generation or incineration. However, even nowadays, because of the high level of complexity of the general problem of a combustion process in practical systems, it is not currently possible to simulate directly all the length and time scales of interest.

Simplifying assumptions still need to be made, but they can be less drastic than in analytical approaches. Therefore, another view of numerical simulations is as a tool to simulate idealized systems and conduct numerical experiments. Such numerical experiments can be complementary to laboratory experiments and can also provide more detailed, nonintrusive diagnostics. Therefore, simulations, along with theory and laboratory experiments, can provide a more complete picture and better understanding of a combustion process.

As an example of computer modeling of industrial combustion systems, an enclosed spray flame was considered. Such a flame can frequently be encountered in power generation units, turbine engines, and incinerators. Both the physical and mathematical models were formulated based on data from earlier laboratory studies and results obtained for open air spray flames. The purpose of this study was to use those data as model input to predict the characteristics of a confined flame and provide a means of optimizing the system design with a PC computer.
Combustion Process in Perforated Porous Mat Flow in a Turbine Combustor
Authors: Amano R. S. , Singh S. N.
Published: February 2021

An efficient combustion system is needed in a gas turbine combustor. The objective of this study is to investigate the effects of varying upstream flow parameters on the velocity and temperature profiles on the surface of a selectively perforated porous mat. To achieve this objective a three-dimensional computational model was developed by using higher-order turbulence models. For the computations of reacting flows, the PDF model was employed. This model involves the solution of transport equations for a single conserved scalar (the mixture fraction). Therefore, transport equations for individual equations are not solved. Instead, individual component concentrations for the species are derived from the predicted mixture fraction distribution. Computations obtained through this research show quite reasonable results and presented in this paper.
Burning Rates of Typical Items in Fires
Authors: Kim Hyeong-Jin , Lilley David G.
Published: February 2021

Heat release rates of typical items in fires are needed as a prerequisite for estimating fire growth and temperatures in structural fires. That is, these burning rates are required to be specified by the user as input to single-room and multi-room structural fire computer codes like FPETool, FASTLife and HAZARD. Data are given here that permit burning items to be specified in a useful modeled way, taking a t2-fire for the growth and decay periods, with a constant maximum heat release rate between these two periods.
Decision Making in Finite Element Analysis
Authors: Doraiswamy Srikanth , Krishnamurty Sundar , Grosse Ian R.
Published: February 2021

In the absence of analytical expressions for design performance parameters, designers must often resort to either statistical or computer-based numerical techniques for performance estimation. Computer-based techniques without adequate assumptions are often very expensive and thus are infeasible for a complex design. Statistical response surface methods are cheaper, but they have poor accuracy for complex design configurations. Moreover, an initial set of data points are needed for the response surface methodology, which can only be obtained by computer-based techniques or real world data. Finally, the selection of an appropriate model to evaluate a design should be based on designer’s preferences. This paper addresses these issues through the development of a decision based modeling methodology that effectively unites the numerical and statistical approaches. In this work, concepts from decision analysis are employed to deal with trade-offs between modeling attributes from a maximum expected utility perspective to identify “overall best” finite element models based on performance attributes such as analysis accuracy, computational cost and model resolution. Its utilization in a design setup is illustrated with the aid of a windshield wiper case study for selecting the best overall finite element analysis model.
A Versatile PC-Based Method for the Processing of the Large Matrices
Authors: Oanta Emil M. , Nicolescu Bogdan
Published: February 2021

In the paper we present a general solution for handling the large matrices. This solution is general because of the wide use of the matrix based approach in problems concerning numerical methods, experimental mechanics, computational mechanics, CFD, computer aided design, economical problems, etc.

Some of the major advantages of this solution are:

1. lack of requirements regarding the use of some high-performance computers, the constraints being connected to the size of the hard-disk (at present increasing and being cheaper);

2. Windows operating system may be used but it is not absolutely necessary;

3. it represents an interface between the programming languages;

4. it can easily be used for development of multi-language software applications;

5. applicability in all the domains which use, at the logical level, ‘matrices’ (mathematics, engineering, economics);

6. there are no constraints regarding the use of ‘classic’ solutions techniques;

7. it is easy to implement in software applications already written;

8. data type used as interface may easily be modified in order to be adapted in an optimum way to the current application to be developed.

By the use of this solution we solved a series of computer problems and ‘dedicated’ applications in some areas like: Mathematics, Experimental Mechanics, Computational Mechanics, Physics, etc.
Associative Transformation of Query Words for Case Retrieval System Based on Neural Network
Authors: Nagasawa Shigeru , Fukuzawa Yasushi , Miyata Yasunori , Hasegawa Hiroshi , Sakuta Hiroshi
Published: February 2021

This paper deals with intelligent case retrieval system for finite element analysis (FEA) and with a methodology of case learning for query module. Through the development of case database on the FEA input model and of retrieval engine, the associative transformation between query words and regularized code options have been investigated and derived from case learning with the hierarchical neural network model, for the purpose of pertinent indexing to case files. Using the teaching patterns, produced by empirical filtering, actual query menus based on the option space could be constructed.
Teaching Global and Modular Kinematics With a Hypermedia Support
Authors: Galletti Carlo , Giannotti Elena
Published: February 2021

In this paper, we outline the two alternatives we faced in implementing a hypermedia-based educational software for analyzing planar mechanisms by both global and modular approaches. Our software uses a “spatial” information allocation, which is consistent with the physical nature of the problems involved in mechanism simulation, and which follows the paradigm of object-oriented programming. The hypermedia material developed and furnished to students allows them to explore, to carry out individual experiments, to work out projects, and to draw up reports concerning kinematic analysis of linkages.
A Remote Home Automation System Based on Client/Server Architecture of Internet and VRML With Java
Authors: Cha Joo-Heon , Lee Soon-Geul , Jeoun Hee Yeoun
Published: February 2021

Recent development of computer and communication technology of Internet now enables more sophisticated system. This research presents new type of remote home automation system that can perform efficient bi-directional management of appliances and security/safety systems at home through Internet. Three-dimensional graphic user interfaces based on virtual reality technology were used to make remote users feel reality. User feels like being at his home and also gets present state of control objects at home with usual web-browser. This system has client and server architect to obtain efficient bi-directional management and uses Java and VRML for information handling. In this paper, the internet-based remote control system was proposed and proved validity by being applied to home automation system.
JAVA™-Based Design Calculator for Integral Snap-Fits
Authors: Oh Jung S. , Lewis Dean Q. , Lee Daeyong , Gabriele Gary A.
Published: February 2021

Many different types of snap-fits have been developed to replace conventional fasteners, and research efforts have been made to characterize their performance. It is often tedious to look for design equations for unique types of snap-fits to calculate the insertion and retention forces. If found, these equations tend to be long, complex, and difficult to use. For this reason, a snap-fit calculator has been created to help in designing integral attachment features.

Studies of seven most commonly used snap-fits (annular snap, bayonet-and-finger, cantilever hook, cantilever-hole, compressive hook, L-shaped hook, and U-shaped, hook) were used to provide the equations implemented in this snap-fit calculator, more fasteners than any other snap-fit calculator available. This tool aids in designing snap-fits to meet specific loading requirements by allowing the designer to size the feature to obtain desired estimates for maximum insertion and retention forces.

The software for this design tool was written in JAVA™ language that is independent of operating system platforms and can be distributed at a company site-wide over an intranet or worldwide over the Internet. This makes it easily accessible to a user, and universal upgrades can be achieved by simply updating the software at the server location. Designers will find this tool to be useful in the design process and the most convenient way to estimate the performance of snap-fits. This paper describes the development and operation of the IFP snap-fit calculator including several case studies comparing the calculated results to experimental data.
Online Design and Price Quotations for Complex Product Assemblies: The Case of Overhead Cranes
Authors: Veeramani Raj , Mehendale Tushar
Published: February 2021

Several companies, particularly in the retail industry, have successfully employed E–Commerce for promoting and selling of their standard, catalog products over the Internet. However, the majority of manufacturing companies deal with modified–standard and custom products, not standard, catalog products. In this paper, we describe how even manufacturers of complex product assemblies can take advantage of E–Commerce technologies for online design, configuration and price quotation in real–time, based on customer specified product requirements. We illustrate a prototype system in the context of an overhead crane manufacturer.
A Strategy for Extending the House of Quality to Obtain Preliminary Design Specifications
Authors: Brackin Patricia , Colton Jonathan
Published: February 2021

This paper details a strategy for quantifying the House of Quality to produce preliminary design specifications. Estimation modules replace the traditional symbols in the HoQ. Genetic algorithms are used to produce and rate candidate preliminary design specifications. A test case from the automotive industry is implemented in order to test the effectiveness of the strategy. Results from the test case indicate that the strategy produces preliminary design specifications that are reasonable and consistent.
The Technology of Components in Feature-Based Design and Process Planning
Authors: Liu Xiaodong , Wysk Richard A.
Published: February 2021

In current feature-based design and process planning research, two major problems are application system development mode and product information description. Particularly, with our current development mode, programs from other researchers cannot be reused, each researcher has to redevelop a set of new feature-application code almost built-from-scratch to create features and/or produce process planning.... As a result, though we have developed countless features-application programs, the problem about integrating CAD and CAM application is still largely unsolved. From the viewpoint of the technology of components (that is a new, powerful software development technology), we seem to be wasting large amount of time to do a repetitive and ineffective work that is orders of magnitude greater than we should do.

By solving several key obstacles that obstruct us from developing the small, reusable components in advanced CAD/CAM fields, the paper creatively introduces into advanced CAD/ CAM fields the brand new, powerful component technology that has never been explored in the fields. And the paper gives a concrete example (MFIC) in the machinable feature application fields to demonstrate how to apply the technology in a specific field. The framework in the paper is the first component framework for advanced CAD/CAM applications. Because the technology of components provides developers with more reusability, extensibility, reliability and compatibility, so it has been universally accepted as the future software development technology by the entire software world. We believe the component technology is the future software development technology in advanced CAD/CAM fields too, and the component framework will change the development mode of advanced CAD/CAM applications, just like the interchangeability completely changes the manufacturing mode in mechanical industry.
Determination of Mold Parting Direction Based on Automatic Molding Feature Recognition
Authors: Gu Zhengchao , Zhou Zhenyong , Gao Shuming , Shi Jiaoying
Published: February 2021

Mold parting direction is an important factor to verify the moldability of a molded part. The determination of mold parting direction is the first step to achieve automatic design of an injection mold or a casting die. A method using automatic feature recognition is proposed in this paper to automatically determine parting direction of an injection mold. Parting direction determination of a molded part consists of three steps in our approach. First, all features of a molded part are recognized using a universal hint-based feature recognition algorithm, and all candidate and feasible parting directions of each feature are determined according to the type of the feature. Then, all candidate parting directions of the molded part are automatically generated from all recognized features candidate parting directions. The optimal parting direction is finally chosen based on certain criteria. The case studies on several industrial parts show that the proposed method is effective and efficient in determining the optimal parting direction of injection molded parts.
Case Studies to Understand the Relations Among Function, Form and Manufacturing Process for Integration of Process Planning Into Early Design Stage
Authors: Kim Yong Se , Feng Shaw C.
Published: February 2021

Design and manufacturing integration at the early design stage in product development, that is, the integration of conceptual design and conceptual process planning, may make a big impact. Thus the development of systematic computer-based support for this integration is desirable. To select and evaluate manufacturing processes, some aspects of form information is necessary. Thus when only the functionally critical forms have been determined from major functional requirements, synthesis of the configuration shape in a generic form would enable early assessment of manufacturing, processes. As a stepping stone toward the development of the configuration shape synthesis and process selection, case studies have been conducted using real world industrial parts. In this paper, we present the case studies using a planet carrier and a gear box housing, and discuss the issues in development of the shape synthesis and process selection method to support the design and process planning integration.
The Trebuchet: Accuracy Analysis of a Medieval Siege Engine
Authors: Rhoten Ronald P.
Published: February 2021

Throughout history there have been a variety of accuracy measures applied to the act of throwing, hurling, launching and/or firing of objects. These include string measure, mean radius, extreme spread, closest to center, probability of hit and score.

There are two objectives of the present contribution. The first is expository in nature, to describe the use and relative merits of these measures. Historical data will be examined to estimate the accuracies of such weapons as the trebuchet (a technologically advanced form of a catapult), longbow, smooth bore rifle, “Kentucky” muzzleloading rifle, early breech loading rifle and turn of the century schuetzen rifle. Data related to modern military and sporting firearms will also be discussed.

The second objective is to illustrate the use of such measures by evaluating actual data from firings of a scale model of a trebuchet. The model was designed using computer simulations and optimization techniques developed by others.
Abstract Prototyping of Design Support Tools: Methodology and Preliminary Results
Authors: Opiyo Eliab Z. , Horváth Imre , Vergeest Joris S. M.
Published: February 2021

This paper focuses on the problem of pre-implementation testing of design support tools. Typical research in development of design support tools involves a lot of tests that are customarily carried out on partially or fully implemented prototypes. It often requires longer time for tests to be performed and the approach is generally expensive. Our work has resulted in creation of a novel pre-implementation evaluation technique that has been named abstract prototyping. This technique can be used in evaluation of design support tools and methods at various stages of their development. It ensures elicitation of requirements would warrant development of acceptable tools and methods at minimum costs and at a shorter time. In this paper, we present the abstract prototyping technique. We describe the abstract prototyping methodology and outline the initial work on development of the abstract prototyping tool. We also present a practical example on the application of the abstract prototyping methodology in evaluation of new computer based methods prior to their implementation.
Towards a Better Understanding of Modeling Feasibility Robustness in Engineering Design
Authors: Du Xiaoping , Chen Wei
Published: February 2021

In robust design, it is important not only to achieve robust design objectives but also to maintain the robustness of design feasibility under the effect of variations (or uncertainties). However, the evaluation of feasibility robustness is often a computationally intensive process. Simplified approaches in existing robust design applications may lead to either over-conservative or infeasible design solutions. In this paper, several feasibility-modeling techniques for robust optimization are examined. These methods are classified into two categories: methods that require probability and statistical analyses (i.e., the probabilistic feasibility formulation and the moment matching method) and methods do not require probability and statistical analyses (i.e., the worst case analysis, the corner space evaluation, and the variation pattern method). Using illustrative examples, the effectiveness of each method is compared in terms of its efficiency and accuracy. Constructive recommendations are made to employ different techniques for modeling feasibility robustness under different circumstances. Under the framework of probabilistic robust optimization, we propose to use a most probable point (MPP) based importance sampling method, a method rooted in the field of reliability analysis, for evaluating the feasibility robustness. The advantages of this approach are discussed. Though our discussions are centered on robust design, the principles presented are also applicable for general probabilistic optimization problems. The practical significance of this work also lies in the development of efficient feasibility evaluation methods that can support quality engineering practice, such as the Six Sigma approach that is being widely used in American industry.
Measures of Complexity in Design
Authors: El-Haik Basem , Yang Kai
Published: February 2021

The introduction of axiomatic design approach contributed to the advancement of design practices by directing research toward useful arenas. One of these arenas is concerned with elimination/minimization of vulnerabilities that are established in entity as a result of violation of design axioms. One major vulnerability is complexity which can be addressed in the context of the Information Axiom. In this paper, we identified three components of design complexity: coupling, variability, and correlation. We used information measures as complexity measures and derived mathematical relationships that quantify these components within the context of the axiomatic design approach.
A Virtual Bumper Test Laboratory for FMVR 581
Authors: Mase Tom , Wang J. T. , Mayer Robert , Bonello Kenneth , Pachón Larry
Published: February 2021

A virtual, computer-aided test laboratory was developed to simulate Federal Motor Vehicle Regulation (FMVR) No. 581, governing low speed bumper collisions. Required input for the virtual laboratory is an LS-DYNA keyword file containing bumper geometry (nodes and elements), constraints, and material properties. The virtual test laboratory reads the bumper model file and creates all pendulums and rigid barrier in position for computational efficiency. Several FORTRAN files were written to execute the pendulum and barrier placement. A command shell script was written to run the FORTRAN code and LS-DYNA simulations. An example using a simple front bumper is presented demonstrating use of this virtual laboratory.