A knowledge-based decision support tool to increase the effectiveness of purchased material quality verifications

In response to the worldwide proliferation of fraudulent materials, a prototype knowledge-based decision support tool has been developed to increase the effectiveness of incoming purchased material quality verifications. Traditional quality verification practices, especially those used in government regulated industries, are ineffective against poor quality materials that appear to be authentic. Safety considerations abound as these highly defective materials are used in systems that are critical to public safety. Quality assurance programs in several instances have failed to stop the influx of fraudulent materials. In many cases only physical inspections and tests can guard aginst defective purchased materials. Unfortunately, it is impractical and cost ineffective for most organizations to inspect all purchased materials. This paper describes how knowledge engineering techniques can be applied to assist in solving this problem. By formulating commonly available and diverse industry information, a knowledge based system becomes a tool that allows users to focus quality verification efforts on highly suspect materials.     

Coordinated procurement/inspection and production model under inspection errors

In this study, we investigate integrating the acquisition of input materials, material inspection and production planning, where type I and type II inspection errors are allowed, and the unit acquisition cost is dependent on the average quality level. This study aims to find an optimal purchase lot size (or here, equivalently, the fixed production rate multiplied by the production run time), input quality level and the associated inspection policy that minimize the total cost per item including the order cost, materials purchase cost, setup cost, inventory holding cost, and the quality-related cost. Furthermore, the boundaries, conditions and properties for the optimal production run time are obtained under an optimal inspection policy when the input material quality level is fixed. These findings will facilitate the establishing of an efficient algorithm for an optimal solution. The study demonstrates that a partial inspection approach could dominate over both the commonly used policies of full or no inspection, which is different from a previous report where the optimal inspection policy is either full or no inspection. A numerical example is performed to evaluate the impact of the two types of inspection errors and the process deterioration because of a nonconforming process input on the optimal solution, where a Weibull shift distribution is used to simulate the process failure time. Finally, conclusions are addressed.     

Modeling, simulation and fuzzy control of an anthropomorphic robot arm by using Dymola

Analysis and fuzzy control of an anthropomorphic robot arm on a special trajectory is the subject of this paper. These types of systems are used in cutting operations on materials, joining materials by welding, material handling in remote and dangerous environments, packing of foods, inspection/testing electronic parts or medical products. This robot arm realizes the handling motion on a special trajectory. In this study, the first three links of Mitsubishi RV-2AJ Industrial Robot, are like an anthropomorphic arm, have been modeled and simulated by using Dymola. Kinematic equations have been obtained and mathematical model of this system has been formed by using Lagrange’s Equations. Fuzzy logic controller for the joint angles for the motion trajectory has been designed and the simulation results have been presented at the end of the study.     

Knowledge-based approach to quality control assurance using bar code identification systems

A knowledge-based approach to quality assurance using bar code identification systems can be carried out in three different stages. In the first stage, a complete study of the manufacturing processes, raw materials, and procedures of inspection has to be conducted. Data collection forms are prepared and potential trouble areas located to get more information on the types of problems occurring. In the second stage, inspection procedures are established for in-coming raw material. Acceptance Sampling plans have to be agreed upon to facilitate inspection of raw materials. The procedures are based on Acceptance Sampling Military Standards (MIL-STD 105 E and MIL-STD 414). In the last stage an expert system can be developed and integrated with automatic identification of the in-coming raw material packages for acceptance sampling, and with inprocess goods for establishing and monitoring statistical process control.     

基于Petri网的改进检验过程调度算法

原材料的检验方法在生产计划中起着关键的作用.根据检验过程的特点,提出一种改进的检验过程调度算法.该算法解决了此前多处理器调度算法用于分支检验时仅根据原材料投产时间对材料进行调度所产生的问题.改进的算法增加了原材料检验任务的紧迫度的概念,针对检验时间较长的材料,投产时间紧迫的任务实现了有效调度,进而提高生产效率.同时算法结合高级颜色时间Petri网,模拟一个实际企业管理系统,对改进的检验任务调度算法建模并进行仿真测试.测试结果表明,改进的算法在生产计划的检验过程中,检验成功率和检验员的工作效率较先前算法都有较大提高.     

The effect of intention analysis-based fraud detection systems in repeated supply Chain quality inspection: A context of learning and contract

As a result of the information asymmetry on product quality, there is a risk of unethical suppliers defrauding buyers in a supply chain. Buyers often conduct quality inspection on shipments and frame supply contracts to punish quality fraud. Due to cost concerns, buyers need to estimate the suppliers’ fraud possibilities and choose appropriate testing methods and frequencies. As suppliers’ fraud intentions depend on their cost-benefit analysis, it is possible to analyze suppliers’ fraud intention with appropriate modeling of their profit-seeking behavior. In this research, we are interested in how fraud intention analysis may affect the quality inspection process. It should be noted that quality inspection can be a repeated process, with suppliers and buyers conducting multiple rounds of transactions (including transactions with frauds) and learning about each other during the process. Their supply contracts may also affect suppliers’ profit-seeking attitude. We conduct a laboratory experiment to examine the effect of fraud intention analysis systems on inspection decision making considering the learning and contract effects. We put the experiment in the context of a dairy supply chain as a critical and interesting example application. The experiment shows that if there are no strong punitive terms for fraud in the contract, fraud intention analysis can improve buyers’ decision-making efficiency after controlling the learning effect, in terms of decision time, inspection cost, and correctness of rejecting suppliers’ fraudulent shipments.     

Determining the production lot size with a heuristic inspection policy for controlling the quality of input materials and products

This study simultaneously determines the optimal production lot size and an inspection policy for input materials and products, where an unreliable process produces products with a discrete general shift distribution. This work proposes a heuristic inspection policy for materials and products, by first obtaining the inspection range for the input material without considering product inspection, and by further determining the product inspection range based on the obtained range of the input material inspection. The optimal inspection policy shows that common policies of no or full inspection are never optimal. This study includes the optimal production lot size based on the obtained inspection policy. Numerical examples demonstrate the impacts of input quality level, process reliability and unit nonconforming cost on the optimal solution, which adopts a discrete Weibull shift distribution to model the process failure time. Finally, this study addresses the conclusions.     

加工中心在线检测仿真技术

该文对加工中心在线检测仿真技术进行了研究。详细阐述了虚拟检测环境的建立、检测信息的提取以及虚拟侧头的驱动等问题，并采用面向对象的程序设计思想进行了系统结构设计。该仿真系统采用解释的编译方式，逐行对检测宏程序进行扫描，驱动虚拟侧头进行检测仿真，实现了对检测过程的图形化模拟，可有效地避免检测宏程序的编制错误，提高编程的质量与效率。     

Tool support for fine-grained software inspection

Software inspection is a proven technique to improve quality and reduce costs. Detailed source code inspections are an important part of the formal inspection process, but they require a significant time investment. Research advances in static program analysis can reduce the inspection time required. By calculating answers to standard inspection questions, CodeSurfer frees experts to focus their efforts on more challenging inspection issues. CodeSurfer provides access to and answers queries about the system-dependence graph representation of programs, and can be integrated with other tools.     

GIS矢量数据制图规范性质量评价系统构建与应用

以全国1∶25万土地利用/覆被数据中存在的规范性质量问题为研究对象,利用开源GIS软件构建一个操作简易、评判客观、全面的规范性质量评价系统。这种质量检查系统是基于规则的新型质量评价体系,针对不同的数据质量问题灵活地设计出质量检查规则,并有效集成到系统当中。实验结果表明,系统能灵活、高效地检查出土地利用/覆被数据中的规范性质量问题,并给出客观的评价。     

Lot sizing for a recoverable product with inspection and sorting

This paper studies an inventory system where demand is satisfied by recovered and new purchased items. Used units of a product, returned by (or collected from) customers, are kept in recoverable inventory until the start of a combined process of inspection and recovery. Recovered (remanufactured) items are assumed to be as-good-as new. However, some recovered items do not qualify to be classified as “remanufactured” and are perceived by customers to be of secondary quality. These refurbished items are sold to a secondary market at a reduced price. A simple formula that determines the optimal inventory level of recoverable (used) items is developed to be able to start the inspection and recovery processes and the economic order quantity for procurement. According to the relationships among the parameters, this paper proposes and analyzes models that describe the system of interest, which are considered extensions of the work of Koh, Hwang and Sohn [Computers and Industrial Engineering 43(1–2), 59–73, 2002].     

Human factors audit programs for nonrepetitive tasks

In order to provide aircraft maintenance and inspection personnel with a rapid means of locating the human–system mismatches that can lead to errors, two human factors audits were developed. Both the inspection audit and the maintenance audit are in the form of measurement checklists, usable either on a portable computer or in paper form. Both were tested for reliability and modified until high reliability was achieved. Both were validated against human factors professionals, with both programs identifying more mismatches than the practitioners. The programs are in use at an airline as a complement to existing safety and quality audit systems. © 1998 John Wiley & Sons, Inc.     

浅谈生产数据报表在企业中的应用

公司主要原材料及炭素中间过程质检报表电子化是公司缩短质检周期运营转型项目的一项主要措施,质检相关数据没有及时纳入管控一体化系统中,无法实现对质检相关数据的查看与分析。为了解决这一问题,经过需求调研与分析,开发管控相关报表功能,利用管控信息平台方便快捷地传递原材料、炭素生产过程电子报表。此次开发出了一套能够合理查询质检分析报告的报表,该报表是管控一体化系统的一个小模块,它主要有数据输入和数据查询组成,使用Web Service(应用服务器)作为中间层,用Visual Studio.NET 2003中的C#语言来具体编程实现。     

Statistical Pattern Modeling in Vision-Based Quality Control Systems

Machine vision technology improves productivity and quality management and provides a competitive advantage to industries that employ this technology. In this article, visual inspection and quality control theory are combined to develop a robust inspection system with manufacturing applications. The inspection process might be defined as the one used to determine if a given product fulfills a priori specifications, which are the quality standard. In the case of visual inspection, these specifications include the absence of defects, such as lack (or excess) of material, homogeneous visual aspect, required color, predetermined texture, etc. The characterization of the visual aspect of metallic surfaces is studied using quality control chars, which are a graphical technique used to compare on-line capabilities of a product with respect to these specifications. Original algorithms are proposed for implementation in automated visual inspection applications with on-line execution requirements. The proposed artificial vision method is a hybrid between the two usual methods of pattern comparison and theoretical decision. It incorporates quality control theory to statistically model the pattern for defect-free products. Specifically, individual control charts with 6-sigma limits are set so the inspection error is minimized. Experimental studies with metallic surfaces help demonstrate the efficacy and robustness of the proposed methodology.     

The active grading ensemble framework for learning visual quality inspection from multiple humans

When applying machine learning technology to real-world applications, such as visual quality inspection, several practical issues need to be taken care of. One problem is posed by the reality that usually there are multiple human operators doing the inspection, who will inevitably contradict each other for some of the products to be inspected. In this paper an architecture for learning visual quality inspection is proposed which can be trained by multiple human operators, based on trained ensembles of classifiers. Most of the applicable ensemble techniques have however difficulties learning in these circumstances. In order to effectively train the system a novel ensemble framework is proposed as an enhancement of the grading ensemble technique—called active grading. The active grading algorithms are evaluated on data obtained from a real-world industrial system for visual quality inspection of the printing of labels on CDs, which was labelled independently by four different human operators and their supervisor, and compared to the standard grading algorithm and a range of other ensemble (classifier fusion) techniques.     

Identifying the signs of fraudulent accounts using data mining techniques

In today’s technological society there are various new means to commit fraud due to the advancement of media and communication networks. One typical fraud is the ATM phone scams. The commonality of ATM phone scams is basically to attract victims to use financial institutions or ATMs to transfer their money into fraudulent accounts. Regardless of the types of fraud used, fraudsters can only collect victims’ money through fraudulent accounts. Therefore, it is very important to identify the signs of such fraudulent accounts and to detect fraudulent accounts based on these signs, in order to reduce victims’ losses. This study applied Bayesian Classification and Association Rule to identify the signs of fraudulent accounts and the patterns of fraudulent transactions. Detection rules were developed based on the identified signs and applied to the design of a fraudulent account detection system. Empirical verification supported that this fraudulent account detection system can successfully identify fraudulent accounts in early stages and is able to provide reference for financial institutions.     

An on‐line grid‐gaps inspection system for electron‐gun manufacturing

An on‐line grid gaps inspection system (GGIS) for color‐CRT electron‐gun manufacturing has been developed. The measuring principle is based on the digital‐image‐processing technique and incorporates a design of stepping motor motion control. By utilizing the arrangement of stepping path image processing, the measurements for different types of guns and for different gaps on a gun can be effectively executed with higher resolution, and are easily implemented for the purposes of on‐line inspection and statistical quality control. Experimental results show that the system resolution is about 8.5–10 μm and the on‐line inspection index has been improved to about 120 pieces/hour.     

对轮毂铸件X射线检测图像实时处理的软件系统设计

提出了一套对某系列汽车轮毂铸件通用的X射线实时检测系统的数字图像处理软件的设计。此图像处理软件采用Microsoft Visual C++6.0语言编程,根据面向对象的编程思想,以Windows系统标准的多文档界面为主控界面,以Win32多线程编程技术为核心,来实现图像处理。此软件系统具有检测速度快、成像质量高、便于图像处理、分析和识别等特点,能够达到对轮毂铸件内部结构的实时显示,便于工作人员对工件的检测和缺陷的评定。     

Systematic image quality assessment for sewer inspection

Closed circuit television (CCTV) has been applied in many developing or developed counties for sewer inspection due to its low setup cost and technical requirement. Several automated diagnosis systems of sewer pipe defects had been developed to assist the technicians in interpreting or classifying sewer pipe defects. However, many researchers pointed out that good image quality is the prerequisite for accurate interpretation and diagnosis of CCTV inspection but has not a proper evaluation approach. In this paper, a CCTV image quality index considering both of the luminance distortion and the contrast distortion of a CCTV image compared by reference images is proposed and was applied to assess the image quality of the CCTV images shot for a sewer house-connection project. The experimental result indicates that rather than luminance contrast plays a more important role in the CCTV image quality that can be effectively improved by contrast enhancement. Since CCTV image quality can hardly distinguished by human eyes, the proposed image quality index can provide helpful information to efficiently assist the on-site technicians in precisely shooting better CCTV images for the pipe defection. Additionally, a sensitivity analysis of contrast stretch was implemented to quantify the CCTV image quality improvement. CCTV imaging conditions, such as pipe materials and imager status, are found as the factors affecting the CCTV image quality. In the future, a real-time CCTV image quality assessment will be developed by modifying the CCTV image quality index as an instantaneous reference for imaging adjustment that can be expected to be practicable for the on-site sewer inspection because of the extremely short computation time.     

Automatic optical inspection system for IC molding surface

Success or failure of an IC product hinges on the quality of molding process which protects chips from the harm done by external force and moisture. Defects such as cracks, dilapidations or voids may be embedding on the molding surface while a chip was being molded. Human inspection often neglects a very tiny crack or a low-contrast void. Hence an automatic optical inspection system for the integrated circuit (IC) molding surface cannot be over emphasized. The proposed system is composed of a charged coupled device, a coaxial light, a back light and a motion control unit. Based on the characteristics of statistical textures of the molding surface, a series of digital image processing is carried out, including normalization, shrinking, segmenting and Fourier based image restoration and defect identification. Training of the parameter associated with defect inspection algorithm is also discussed. Results of the experiment suggest that the inspection system works effectively with high accuracy rate of 94.2 %, contributing to the inspection quality of IC molding surface.