Development of a design space and predictive statistical model for capsule filling of low-fill-weight inhalation products

The objectives of this study were to develop a predictive statistical model for low-fill-weight capsule filling of inhalation products with dosator nozzles via the quality by design (QbD) approach and based on that to create refined models that include quadratic terms for significant parameters. Various controllable process parameters and uncontrolled material attributes of 12 powders were initially screened using a linear model with partial least square (PLS) regression to determine their effect on the critical quality attributes (CQA; fill weight and weight variability). After identifying critical material attributes (CMAs) and critical process parameters (CPPs) that influenced the CQA, model refinement was performed to study if interactions or quadratic terms influence the model. Based on the assessment of the effects of the CPPs and CMAs on fill weight and weight variability for low-fill-weight inhalation products, we developed an excellent linear predictive model for fill weight (R^2?=?0.96, Q^2?=?0.96 for powders with good flow properties and R^2?=?0.94, Q^2?=?0.93 for cohesive powders) and a model that provides a good approximation of the fill weight variability for each powder group. We validated the model, established a design space for the performance of different types of inhalation grade lactose on low-fill weight capsule filling and successfully used the CMAs and CPPs to predict fill weight of powders that were not included in the development set.     

A transformation system for interactive reformulation of design optimization strategies

Automatic design optimization is highly sensitive to problem formulation. The choice of objective function, constraints and design parameters can dramatically impact on the computational cost of optimization and the quality of the resulting design. The best formulation varies from one application to another. A design engineer will usually not know the best formulation in advance. To address this problem, we have developed a system that supports interactive formulation, testing and reformulation of design optimization strategies. Our system includes an executable, data-flow language for representing optimization strategies. The language allows an engineer to define multiple stages of optimization, each using different approximations of the objective and constraints or different abstractions of the design space. We have also developed a set of transformations that reformulate strategies represented in our language. The transformations can approximate objective and constraint functions, abstract or reparameterize search spaces, or divide an optimization process into multiple stages. The system is applicable in principle to any design problem that can be expressed in terms of constrained optimization; however, we expect the system to be most useful when the design artifact is governed by algebraic and ordinary differential equations. We have tested the system on problems of racing yacht design and jet engine nozzle design. We report experimental results demonstrating that our reformulation techniques can significantly improve the performance of automatic design optimization. Our research demonstrates the viability of a reformulation methodology that combines symbolic program transformation with numerical experimentation. It is an important first step in a research program aimed at automating the entire strategy formulation process.     

An explanation and critique of taguchi's contributions to quality engineering

Recently there has been much interest and some controversy concerning the statistical methods employed by Professor Genichi Taguchi of Japan for improving the quality of products and processes. These methods include the use of fractional factorial designs and other orthogonal arrays, parameter design to minimize sensitivity to environmental factors, parameter design for minimizing transmitted variation, signal-to-noise ratios, loss functions, accumulation analysis, minute analysis and the analysis of life test data. This paper explains some of Taguchi's contributions to quality engineering and also provides a critical evaluation of his statistical methods. Our conclusion is that although on the one hand, Professor Taguchi's quality engineering ideas are of great importance and should become part of the working knowledge of every engineer, on the other hand, many of the techniques of statistical design and analysis he employs to put these ideas into practice are often inefficient and unnecessarily complicated and should be replaced or appropriately modified. In this short article only an overview is attempted, but references are appended where these matters are discussed in greater detail.     

An approach based on fuzzy sets for manufacturing system design

The aim of this work is to provide Small and Medium Enterprises (SMEs) with adapted design methods for manufacturing systems. In a total quality strategy, the design activity consists of searching for the means able to satisfy all users' needs from company customers to floor plant workers. That includes usual costs, delays and quality targets but also employees' involvement. Due to the variety of data sources and to the continuous changes of goals, the information is imperfect. The main concerns are uncertainty, inaccuracy and vagueness of both objectives and solutions. The fuzzy set theory provides a quite convenient framework to represent all those imperfections using one mathematical objet. Fuzzy logic is used to aggregate specifications and to deploy solutions. Possibility theory finally allows a graded evaluation of expected performances. The obtained result is graded, providing the engineer with some degrees of freedom for the realization of the manufacturing system. The valuation of the design quality is an undeniable progress towards the continuous improvement of the whole system performance. Finally, such a criterion may also be used for an empirical search for a convenient solution, as for the automatic computation of an optimal result.     

Stochastic analysis of failure of earth structures

Uncertainties in material data are a common inconvenience we face when working in the area of geotechnical engineering. Elements of mathematical statistics then often become a valuable tool for allowing reasonable predictions of the behavior of complex material systems. Such an approach is advocated in this paper through two representative examples. Stochastic analysis of failure of dump slopes (tailings) is addressed first, promoting the entire distribution function as an indispensable source of information to assess the quality of the structural system from the stability perspective. The general concept of probability of failure is then revisited in conjunction with time dependent failure of earth structures impaired by a gradual change in the level of ground water table. A conceptual assessment of the instantaneous failure rate, particularly when combined with in situ measurements, is offered as a valuable tool for the design engineer to foresee sudden and catastrophic failures.     

Life-cycle modeling for adaptive and variant design. Part 1: Methodology

Life-cycle modeling for design (LCMD) is a methodology for assessing the life-cycle impacts for a complex product with many individual components starting from initial design phases when few design specifications have been made. The methodology combines life-cycle assessment (LCA) with probabilistic design methods in a way that forecasts attributes of possible final designs yet reduces information needs. Specifically, LCMD is a methodology for generating arrays of design scenarios that communicate the range of designs being considered by a design team, and estimating missing data for those design scenarios. The main contribution to enhancing standard LCA is the incorporation of methods to estimate physical attributes of individual components for various design options and in four analyses for evaluating the arrays of design scenarios. An automotive case study presented in part 2 of this work demonstrates one application of LCMD.     

影响电压暂降问题的多源属性排序方法

对电压暂降的多源属性进行分析,不仅能为供电工程的规划设计、设备选型、运行维护等环节提供全过程技术支撑,还可以有效评估电能质量事件的风险及其严重程度。该文提出电压暂降的多源属性贡献度排序方法。首先,列举电压暂降的多源属性,将其分为内源属性和外源属性;然后,采用设备兼容度指标,计算多源属性下设备的暂降兼容度,并建立基于层次分析法的三层致因体系,针对多源致因属性的权重进行计算;最后,利用蒙特卡洛法进行仿真,结合实际工程数据,分析多源致因属性下发生电压暂降的严重性程度,评估结果验证该方法可行。     

Development and in vitro evaluation of pH-independent release matrix tablet of weakly acidic drug valsartan using quality by design tools

Abstract

The main objective of this study was the development of pH-independent controlled release valsartan matrix tablet in Quality by design (QbD) framework. The quality target product profile (QTPP), critical quality attributes (CQAs) and critical material attributes (CMAs) were defined by science and risk-based methodologies. Potential risk factors were identified with Fishbone diagram. Following, CMAs were further investigated with a semi-quantitative risk assessment method, which has been revised with mitigated risks after development and optimization studies. According to defined critical material attributes, which one of them was determined to be the dissolution, formulation optimization study was performed by using a statistical design of experiment. Formulation variables have been identified and fixed first with a ‘One factor at a time (OFAT)’ approach. After OFAT studies, a statistical experimental design was conducted with the most critical material attributes. Statistical design space and mathematical prediction equations have been developed for dissolution and hardness, which is important to predict drug dissolution behavior. In conclusion, a pH-independent release has been achieved for weakly acidic drug valsartan with a deeper understanding of drug product quality, with the science and risk-based approaches of QbD tools.     

A subjective and objective integrated multiple attribute decision making method for material selection

The selection of an optimal material for an engineering design from among two or more alternative materials on the basis of two or more attributes is a multiple attribute decision making (MADM) problem. The selection decisions are complex, as material selection is more challenging today. There is a need for simple, systematic, and logical methods or mathematical tools to guide decision makers in considering a number of selection attributes and their interrelations and in making right decisions. This paper proposes a novel MADM method for material selection for a considered design problem. The method considers the objective weights of importance of the attributes as well as the subjective preferences of the decision maker to decide the integrated weights of importance of the attributes. Furthermore, the method uses fuzzy logic to convert the qualitative attributes into the quantitative attributes. Three examples are presented to illustrate the potential of the proposed method.     

基于ISO 9000族标准的质量管理体系有效性评价方案设计

在对现行质量管理体系有效性评价方法利弊分析的基础上,借鉴ISO 9000族标准的质量管理体系有效性方法和管理的系统方法,探讨了质量管理体系有效性评价指标体系设计的4条主要原则;依据质量管理体系有效性的内涵,从其运行结果上提出了应从顾客满意度、员工满意度、投资者满意度、供应商满意度及政府满意度评价5个方面进行质量管理体系有效性评价的观点;建立了包括这5个子目标的具体评价指标体系;并在采用Delphi法进行循环调查的基础上,运用隶属度评价方法,筛选掉了评价值＜0.5的相关指标,确定出了5个子目标对应的3×5个属性指标;然后针对顾客满意度和员工满意度2个子目标的特点,设计了其定性评价模型;针对投资者满意度,供应商满意度及政府满意度3个子目标的特点,设计了其定量评估模型;并依据层次分析原理,提出了质量管理体系整体有效性评价模型;结合某公司实际进行了实证研究,并针对评价结果提出了其质量管理体系整体有效性改进建议.     

Predicting heat pump performance by thermodynamic generalizations of fluid flow and heat transfer data

Thermodynamic generalizations based on reduced pressure proposed in the 1960s are reviewed and updated to reflect the current state of the art. The application of the method is illustrated by analytical and numerical examples and an assessment made of its value in heat exchanger design practice with special emphasis on two-phase forced convection refrigeration cycle applications. It is shown that this thermodynamic approach provides the heat exchanger designer, and to some extent the system engineer with an additional tool which is simple, effective and above all more reliable, particularly in evaporator and condenser design practice, than current conventional semi-empirical correlations.     

Robust product development for multiple quality characteristics using computer experiments and an optimization technique

Conventional parameter or tolerance designs focus on developing exact methods to minimize quality loss or manufacturing cost. The inherent assumption is that the response functions which represent the link between controllable variables and response values of quality characteristics are known before a design is developed. Moreover, parameter and tolerance values are assumed to be independent controllable variables in previous works; namely, they are determined separately in design activities. Currently, advanced computer software, such as computer-aided engineering, can help engineers to handle design problems with unknown response functions, at the stage of product design and process planning. Therefore, in this study, the software ANSYS was employed to obtain simulation data which represent the response values of quality characteristics. These response values will be used to fit a set of response functions for later analysis. However, previous works in computer simulation for design and planning usually lack consideration of the noise impact from an external design system. To approximate a realistic design environment, various levels of controllable variables, in conjunction with artificial noises created from uncontrollable variables, are used to generate simulated data for statistical analysis via Response Surface Methodology (RSM). Then, an optimization technique, such as mathematical programming, is adopted to integrate these response functions into one formulation so that optimal parameter and tolerance values are concurrently determined, with multiple quality characteristics taken into consideration. A bike-frame design was used to demonstrate the presented approach, followed by multiple quality characteristics of interest: material cost, bike-frame weight, structure reliability, and rigidity dependability. The goal is to minimize material cost and bike frame weight and to maximize structure reliability and rigidity dependability. This approach is useful for solving any complex design problems in the early stages, while providing enhanced functionality, quality, economic benefits, and a shorter design cycle.     

A constraint‐based approach for the optimum redesign of a packaging operation

The task of the design engineer is to configure a design such that a predetermined functional requirement is fulfilled, and that it is achieved within a given set of performance criteria. As a design evolves, so these performance criteria change, driven by the ever‐increasing needs of the customer and the inherent competition between manufacturers. It is during this evolutionary process that the engineer demands a CAD system which can represent knowledge about the design and explore solutions regarding the relationship between geometry and behaviour. This is necessary in order to realize the full potential of an existing design, or to examine modifications to an existing design that may achieve the desired performance characteristics. The work described in this paper uses a constraint‐based modelling environment to represent and analyse a high‐speed packaging operation. The goal of the modelling work is to produce an optimal design solution for the given performance requirements, as well as to satisfy the constraints imposed by the existing machine system and packaging process. The construction of the model is described and the identification and representation of the design constraints are discussed. These constraints are then applied to a possible machine modification or redesign and an optimized configuration is developed in the modelling environment. Copyright © 2003 John Wiley & Sons, Ltd.     

Improved approach to quality function deployment based on Pythagorean fuzzy sets and application to assembly robot design evaluation

Quality function deployment (QFD) is an effective method that helps companies analyze customer requirements (CRs). These CRs are then turned into product or service characteristics, which are translated to other attributes. With the QFD method, companies could design or improve the quality of products or services close to CRs. To increase the effectiveness of QFD, we propose an improved method based on Pythagorean fuzzy sets (PFSs). We apply an extended method to obtain the group consensus evaluation matrix. We then use a combined weight determining method to integrate former weights to objective weights derived from the evaluation matrix. To determine the exact score of each PFS in the evaluation matrix, we develop an improved score function. Lastly, we apply the proposed method to a case study on assembly robot design evaluation.     

A formal method for subjective design evaluation with multiple attributes

This paper contributes toward a more formal theory and methodology for design by mathematically modeling the functional relationships between design decisions and the ultimate overall worth of a design. The conventional approach to design evaluation is limited in two respects. First, the direct measurement of attribute performance levels does not reflect the subsequentworth to the designer. Second, ad hoc methods for determining the relative importance or priority of attributes do not accurately quantify beneficial attribute tradeoffs. This information is critical to the iterative redesign process. A formal Methodology for the Evaluation of Design Alternatives (MEDA) is presented which resolves these problems and can be used to evaluate design alternatives in the iterative design/redesign process. Multiattribute utility analysis is employed to compare the overall utility or value of alternative designs as a function of the levels of several performance characteristics of a manufactured system. The evaluation function reflects the designer's preferences for sets of multiple attributes. Sensitivity analysis provides a quantitative basis for modifying a design to increase its utility to the decision-maker. Improvements in one or more areas of performance and tradeoffs between attributes which would increase desirability of a design most are identified. A case study of materials selection and design in the automotive industry is presented which illustrates the steps followed in application of the method.     

基于网络评论情感分析和QFD的产品改进设计

目的 分析产品在线网络评论,准确评估用户的使用反馈和需求信息,用于产品改进设计。方法 用网络爬虫采集购物网站的商品评论数据,引入百度AI开放平台的自然语言处理技术,对清洗后的评论数据进行情感分析,计算每条评论的情感极性,结合Nvivo文本分析和人工筛选,得到准确的用户评价。在质量功能展开(QFD)中,评论分析的结果用于产品的目标质量规划,根据质量屋得出的技术特性相对重要度,选择应重点改进的技术属性。结果 该方法发现了产品需要改进的多个重要设计问题,以无线手持吸尘器为例,对比传统调研方法的分析结果,验证该方法的有效性。结论 对网络评论大数据的AI情感分析结合QFD,能发现产品需要改进的大部分问题,具有重要的参考价值,能为产品改进设计提供新方法。     

Reliability Engineering Practice in the Light Duty Dodge Ram Truck Chassis Program

In this paper, we demonstrate how we set up and executed an integrated reliability engineering process with the engineering team in the Light Duty (LD) Dodge Ram (DR) Truck chassis program. Organizationally, the LD DR chassis team consists of core engineering groups and supporting representatives from other related disciplines. The reliability engineer is a member of the team and he is the reliability advocate and leader. The integrated reliability engineering process was customized and implemented in the LD DR chassis program. Many of the tools developed by the company corporate quality office, such as design failure modes and effect analysis (DFMEA), design verification plan and reporting (DVP&R), and finite element analysis (FEA), were used in supporting the reliability engineering process. An array of technical enablers such as Test Matrix and ReliUp were also developed for supporting the implementation of the reliability engineering process. In the execution, the reliability engineer led the engineering team to set up reliability targets, develop reliability work plans, facilitate up‐front design analysis, review and integrate reliability test planning. The reliability engineer also set up the failure reporting, analysis and corrective action system (FRACAS) and managed reliability growth with the team. From the implementation, we have learned several things: (1) an integrated engineering team is crucial in order to develop a product better, quicker and cheaper; (2) a good team leader is the key to product reliability; (3) a capable reliability engineer is the catalyst to a reliability engineering process; (4) the best culture in which to achieve reliability is the delicate balance between ‘inside‐out’ and ‘outside‐in’; and (5) achieving reliability is far more important than measuring reliability. Copyright © 2004 John Wiley & Sons, Ltd.     

General Image-Quality Equation: GIQE

A regression-based model was developed relating aerial image quality, expressed in terms of the National Imagery Interpretability Rating Scale (NIIRS), to fundamental image attributes. The General Image-Quality Equation (GIQE) treats three main attributes: scale, expressed as the ground-sampled distance; sharpness, measured from the system modulation transfer function; and the signal-to-noise ratio. The GIQE can be applied to any visible sensor and predicts NIIRS ratings with a standard error of 0.3 NIIRS. The image attributes treated by the GIQE are influenced by system design and operation parameters. The GIQE allows system designers and operators to perform trade-offs for the optimization of image quality.     

Incentive compatible resource allocation in concurrent design

This article presents an approach that a manager can use to allocate resources needed to design a system among the members of a concurrent design team. The system being designed is assumed to be composed of a number of subsystems, each designed by a different engineer. These engineers possess private information about the performance of their subsystem as a function of the design resources that they are allocated. This article shows how the manager of such a concurrent design project can induce rational self-interested engineers to reveal truthfully their private subsystem performance functions. This is accomplished through an incentive contract that ties each engineer’s pay to the contribution of their subsystem to the performance of the overall system. The approach builds from a Vickrey–Clarke–Groves mechanism to achieve, as an ex-post Nash equilibrium, truthful reporting of private subsystem performance functions by risk-neutral agents.     

航空摄影胶片冲洗质量控制系统的研究与实现

本文介绍了一套实用的摄影冲洗质量控制系统。在简要介绍系统建立的基本思想、主要技术原理和软硬件组成的基础上,重点阐述了系统研究并解决的主要问题—影像密度数据采集、胶片感光特性参数解算、冲洗工艺确定和影像质量评价。实际应用表明,系统确定的最佳冲洗工艺和影像质量评价结果准确、方法实用,能有效提高航空航天摄影冲洗质量,有着很好的推广应用前景。