Process Control Program Research Articles

A Vision for Global CT Radiation Dose Optimization

The topic of CT radiation dose management is receiving renewed attention since the recent approval by CMS for new CT dose measures. Widespread variation in CT dose persists in practices across the world, suggesting that current dose optimization techniques are lacking. The author outlines a proposed strategy for facilitating global CT radiation dose optimization. CT radiation dose optimization can be defined as the routine use of CT scan parameters that consistently produce images just above the minimum threshold of acceptable image quality for a given clinical indication, accounting for relevant patient characteristics, using the most dose-efficient techniques available on the scanner. To accomplish this, an image quality–based target dose must be established for every protocol; for nonhead CT applications, these target dose values must be expressed as a function of patient size. As variation in outcomes is reduced, the dose targets can be decreased to more closely approximate the minimum image quality threshold. Maintaining CT radiation dose optimization requires a process control program, including measurement, evaluation, feedback, and control. This is best accomplished by local teams made up of radiologists, medical physicists, and technologists, supported with protected time and needed tools, including analytics and protocol management applications. Other stakeholders critical to facilitating CT radiation dose management include researchers, funding agencies, industry, regulators, accreditors, payers, and the ACR. Analogous coordinated approaches have transformed quality in other industries and can be the mechanism for achieving the universal goal of CT radiation dose optimization.

Thermal field control in heated concrete mixture

Direct electric preheating of concrete mixture (DEPC), which significantly improves the energy efficiency of thermal curing stage, is mostly used in winter concreting and is promising for application in precast concrete production. However, to date, DEPC is not fully utilized. One of its limitations is the temperature difference in the heated volume. The paper proposes methods and means of achieving the uniform temperature field distribution in the heated concrete mixture. The proposed method includes the replacement of plate electrodes by a group of independently controlled electrodes of a smaller size, that makes the system flexible and capable of controlling the electric and, consequently, thermal field. The paper describes the equipment, principles of constructing the algorithm for the heating process control program.

Derivation of operating conditions for the Jordan cement solidification process and evaluation of disposability of the cement waste form produced in the process

The purpose of this study is to develop a process control program for the cement solidification process of the Jordan Research and Training Reactor (JRTR). The optimal operating conditions of the cement solidification process were found to be a concentrate/cement ratio of 0.65 (water/cement ratio of 0.45) and a salt content of 20 wt%. The compressive strength of the cement solidified material was 17.8–23.8 MPa, which is much higher than the 3.44 MPa specified in the waste acceptance criteria (WAC) for a disposal facility in South Korea, as developed by the Korea radioactive waste agency. In addition, through evaluation of the leaching stability for Cs, Sr, and Co, the leaching index of the samples was confirmed to be >10, 10.8, and 8.05 for Co, Sr, and Cs, respectively; all of these values exceed the WAC leaching index standard of 6.

Expert Elicitation To Estimate the Feed Safety Impact of Criteria Included in the Canadian Food Inspection Agency Risk Assessment Model for Feed Mills

The Canadian Food Inspection Agency is developing an Establishment-based Risk Assessment (ERA) model for commercial and on-farm mills involved in the manufacture, storage, packaging, labeling, or distribution of livestock feed (ERA-Feed Mill model). This model will help inform the allocation of inspection resources on the basis of feed safety risk, including animal health and food safety risk. In a previous study, 34 risk factors, grouped into inherent, mitigation, and compliance clusters, along with assessment criteria were selected. The objective of this current study was to estimate the relative risk (RR) of the 203 assessment criteria on the basis of the impact on feed safety to design an ERA-Feed Mill model algorithm. Furthermore, the intent of this study was to assess the maximum increase or decrease of risk obtained when multiple criteria belonging to a same cluster were identified in a specific feed mill. To do so, a two-round face-to-face expert elicitation was conducted with 28 Canadian feed experts. Results showed no significant association between respondent profiles (years of experience and work sector) and estimated RR. Uniformity of answers between experts improved between rounds. Criteria having the highest increase in risk (median RR ≥ 4) included the presence of materials prohibited to be fed to ruminants in a facility that produces ruminant feed, the presence of multiple livestock species on-site, and historical noncompliances related to the inspection of the feed mill's process control and end-product control programs. Risk mitigation criteria having the highest impact on decreasing the risk were the implementation of feed safety certifications, the use of dedicated manufacturing lines (prohibited materials or medications), and having a hazard sampling plan in place for finished feed. The median RR assigned to each criterion and cluster will be used to build an algorithm of the Canadian Food Inspection Agency's ERA-Feed Mill model.

Response of the ArcCHECK® device at 6MV and 15MV for VMAT and IMRT quality control.

To study the response of the ArcCHECK® device as VMAT and IMRT verification system. Various tests analyzing the linearity, the repeatability and the angular dependence of the device response, its dependence with the pulse repetition rate and the leakage losses were performed. The long-term response in dose measurements and the uniformity of the detectors conforming the system were controlled using a statistical process control program. The Elekta Infinity™ 6 and 15MV photon beams were used. The device showed excellent repeatability and linearity. The differences between the responses obtained for any pair of angular incidences were less than 2%. The absorbed dose increased by 3% when the pulse repetition rate varied from 50 to 600MU/min. Results are in overall agreement with those found in previous works for the ArcCHECK®, in which a reduced number of the device diodes were analyzed, and for the MapCheck®, an older 2D device that used the same diodes. Charge losses were found to be negligible except for some of the diodes of the device. The statistical process control program is a very useful tool to control the correct functioning of the device in the long term. The results of the analysis carried out indicate that the working and stability conditions of the ArcCHECK® device are adequate for its purpose. The dependence with the pulse repetition rate should be considered when VMAT or similar treatments are evaluated. A control program for the statistical monitoring of the device would be desirable and useful.

Imaging Quality Control in the Era of Artificial Intelligence

The advent of artificial intelligence (AI) promises to have a transformational impact on quality in medicine, including in radiology. However, experience has shown that quality tools alone are often not sufficient to bring about consistent excellent performance. Specifically, rather than assuming outcome targets are consistently met, in quality control, managers assume that wide variation is likely present unless proven otherwise with objective performance data. In this article, we discuss what we consider to be the eight essential elements required to achieve comprehensive process control, necessary to deliver consistent quality in radiology: a process control framework, performance measures, performance standards and targets, monitoring applications, prediction models, optimization models, feedback mechanisms, and accountability mechanisms. We consider these elements to be universally applicable, including in the application of AI-based models. We also discuss how the lack of specific elements of a quality control program can hinder widespread quality control efforts. We illustrate the concept using the example of a CT radiation dose optimization and process control program previously developed by one of the authors and provide several examples of how AI-based tools might be used for quality control in radiology.

Improvement on plant thermal efficiency in MLNG Satu via MLNG Molecule Allocation Program (M-MAP)

It has always been an aspiration for a Liquefied Natural Gas (LNG) plant to be able to monetize natural gas to its design plant capacity and best plant efficiency. Being able to achieve design capacity means project investment is paid off, whereas operating at the best efficiency means operating cost is optimum. Malaysia LNG Sdn Bhd (MLNG SATU) is consistently operated at design nameplate capacity post MLNG Rejuvenation and Revamp (MRR) project in 2005. Existing process control and optimization program has been helping the plant to consistently achieve maximum plant capacity within constraints on operational target and equipment performance. MLNG Molecule Allocation Program (M-MAP) was developed in 2016 to improve current program by looking at the plant thermal efficiency aspect, defines as Process Efficiency (PE). Leveraging on good existing plant data acquisition system and effective process control and optimization program in MLNG SATU, M-MAP has successfully expanded from a simple engineering calculation to a program that enables MLNG SATU production to achieve at its best efficiency. Developed in bi-phases, the Phase 1 of M-MAP has improved the overall efficiency of MLNG SATU by 1.3%. The Phase 2 of the M-MAP is currently under implementation; expecting another step in the overall efficiency of MLNG SATU within 0.5%.

Research of Building the Monitoring System of Cleaning in Place Applying MCGS

Cleaning In-place (CIP) system is a set of technical systems including cleaning main unit and software technology. The paper is introduced with the technical scheme of real-time process monitoring system using for CIP; designed by the hardware configuration of signal acquisition, signal transformation and data control in monitoring system; used MCGS to realize with the monitoring and controlling configuration design of central computer, real-time database build and peripheral device driver, monitoring parameters scale transforming, data acquisition module design, and cleaning process control program design, then ,the man-machine interface is achieved, real-time process animation is displayed, automatic and real-time monitoring the CIP process, real-time data browsing and preservation, as well as real-time and historical data trend is displayed and report output functions.

Molecular detection and characterization of bovine viral diarrhea virus in Mongolian cattle and yaks.

Bovine viral diarrhea virus (BVDV) is classified into two species, namely, Bovine viral diarrhea virus 1 and Bovine viral diarrhea virus 2, and affects cattle worldwide, resulting in significant economic loss. The prevalence of BVDV-1 and BVDV-2 infections and its genotypes in Mongolian animals has not been studied. In this study, we surveyed BVDV infection in dairy cattle and yaks from Bornuur and Bulgan counties by RT-PCR, and the average infection rate in the sampling sites was 15.8% and 20.0%, respectively. In addition, molecular features of the 5'-UTR region of the BVDV genome in Mongolian cattle and yaks were identified as belonging to the subtypes BVDV-1a and BVDV-2a, respectively. Determining the prevalence, geographical distribution, and molecular diversity of BVDV-1 and BVDV-2 in various host species in Mongolia is important for further studies and process control programs.

A Domain Specific Language for High-level Process Control Programming in Smart Buildings

Web services composition is a recurring idea in the field of smart residential environments (SRE), since it helps to solve complex problems such as energy saving, security control or health care by combining and orchestrating the available basic services. Smart environments are composed of networked devices (sensors and actuators) embedded within web services, which contain well-defined programming interfaces allowing them to share data, capture events and create composed control applications. There is still, however, a lack of domain specific languages (DSL) supporting a high degree of abstraction and transparency and allowing users to define control scenarios in a compact and comprehensible way. To satisfy these needs, the present paper aims to propose a DSL for describing scenarios to control SRE, with considerable gains in transparency, abstraction, expressiveness and simplicity.

Practice and Analysis of Life Measuring Device for Motor Valve

Motor valve leakage is not easy to detect during using, so it must carry out quality inspection before assembly into gas meter. The quality appraisement of valve mainly relies on switch times before leakage, and pressure difference measurement is better method for leakage judgment. The static pressure leak detection method, reference gas chamber and control program of solenoid valve are key technologies in pressure difference measurement and life measurement. The new type device is designed with hardware and software, such as gas path and pipes, sensor, the solenoid valves of dynamic structure static switching unit, controller, gas pressure regulation system, automatic detection and valve switching process control program etc. Based on support of hardware and software, dynamic flow pipe is separated to static segments which are reference gas chamber and measuring air chambers; and the signal of chambers pressure difference and switch times without leakage are the output result. Switching frequency ratio of solenoid valves to motor valve is 1:5 or 1:10; lower ratio can prolong the service life of solenoid valves.

Monaco—A domain-specific language solution for reactive process control programming with hierarchical components

In this paper, we present Monaco – a domain-specific language for developing event-based, reactive process control programs – and its visual interactive programming environment. The main purpose of the language is to bring process control programming closer to domain experts. Important design goals have therefore been to keep the language concise and to allow programs to be written that reflect the perceptions of domain experts. Monaco is similar to Statecharts in its expressive power, but adopts an imperative notation. Moreover, Monaco uses a state-of-the-art component approach with interfaces and polymorphic implementations, and enforces strict hierarchical component architectures that support hierarchical abstraction of control functionality. We present the main design goals, the essential programming elements, the visual interactive programming environment, results from industrial case studies, and a formal definition of the semantics of the reactive behavior of Monaco programs in the form of labeled transition systems.

Application of CAD/CAE/CAM Technology in Plastics Injection Mould Design and Manufacture

The process of injection mould design and manufacture was introduced by taking the cover as an example. Firstly, the 3D model of the part and the injection mould structure were designed based on SolidWorks software. Secondly, the injection molding progress was analyzed and simulated based on Moldflow software. Finally, the toolpaths of cavity and core were designed based on MasterCAM software, and its manufacture process and numerical control programming was simulated. The period of product development was shortened effectively and the quality of design and manufacture was improved by CAD/CAE/CAM integrated technology.

Process-control program for a series of automated polishing–lapping optical machines with computer control

A specialized control program has been developed, intended for carrying out sessions in which the surfaces of optical items are shaped on automatic polishing–lapping machines with numerical program control based on the Aerotech A3200 controller. The program makes it possible to monitor various aspects of process sessions, to correctly respond to emergencies, and to resume execution after they are overcome.

Development of support tool for control design of nuclear power plant using hierarchical control chart (HCC)

Control design of complex systems, such as nuclear power plants (NPP), is multidimensional problem that requires concurrent engineering environment. This paper presents the idea of integrating process and control models and associated knowledge using hierarchical control chart (HCC), which supports control activities throughout the analysis, design, and operation phases. Automated solution for implementing HCC is developed and presented using a selected case study of steam generator control design of nuclear power plant. Integrated knowledge architecture is presented to support different views during the control design stage: process design, control analysis, control design, control programming, operation, and troubleshooting. The proposed solution will provide better ways to structure and share control knowledge, which will reduce overall risks in the engineering process.

Computer-control of surface science experiments with LabVIEW

LabVIEW TM 2009-based remote and process control program for an ultra-high vacuum system and a variety of surface science experiments is presented. The apparatus consists of five individual recipients for sample preparation, surface analysis, scanning tunneling microscopy and a central chamber connecting them by means of gate-valves. All processes like electron-beam heating, ion sputtering, gas exposure, thermal and electron-beam evaporation, analysis techniques, sample manipulation can run under full automatic control; transfers are supported. A variety of useful auxiliary functions are implemented to control bake-out processes, titanium sublimation pumps, pressure regulation of leak valves but also data acquiring, automatic reporting through ftp and emails, as well as external communication and control via a TCP/IP connection with a portable PC. Important features of the software include a time- control module to operate up to five channels (repetitive heating, sputtering, gas exposure, evaporation and manipulation to evaporation positions) as well as full process control. Such tools allows us to set up automatically processed experiments that include e.g. the preparation of single-crystal surfaces, their AES (Auger electron spectroscopy) and LEED (low energy electron diffraction) analysis as well as the evaporation and various treatments of thin films.

Efficient Biogas Production through Process Simulation

An interactive simulator of the process of anaerobic digestion was developed. It is based on four interacting submodels describing the biological, physicochemical, reactor, and plant subsystems of the overall process. The simulator was adapted to simulate a 10 L lab-scale reactor processing three different well-defined substrates as well as varying mixtures of these compounds. Because of its structured configuration, the simulator can be adapted to other types of biogas plants with respect to plant setup, reactor volume, and substrate composition. The biological and physicochemical submodels were implemented in the programming language FORTRAN; the reactor and plant submodels were implemented in an industrial process control and simulation program. The combined submodels result in an interactive process simulator that was equipped with various control loops, automations, data acquisition systems, and graphical user interfaces. The simulator can be used for the design, test, and optimization of automation ...

On‐line Statistical Process Monitoring and Fault Diagnosis in Batch Baker's Yeast Fermentation

AbstractThis study involves real‐time monitoring and fault diagnosis in batch baker's yeast fermentation. A specific Real Time Statistical Process Analysis and Control (RT‐SPAC) program was developed to monitor instantaneous reaction conditions. The air flow rate fed to the reactor, temperature, pH, and dissolved oxygen concentration in a laboratory‐size fermenter were monitored and recorded by means of on‐line sensors. Under control of the RT‐SPAC program, 22 batch baker's yeast fermentation operations were carried out. In the first 20 operations, an ordinary process was followed under previously defined nominal operating conditions. Historical data collected from these batches were then used for on‐line Dynamic Principal Component Analysis (DPCA) in the course of the following two batches. The last two batches were implemented such that some deliberate faults (in temperature and pH) were introduced during the operation. The results indicated that the software was capable of capturing the process faults, and furthermore the possible causes of these faults were identified by contribution plots.

Profile Charts for Monitoring Lumber Manufacturing Using Laser Range Sensor Data

Real-time technologies using noncontact laser range sensors (LRS) have recently been introduced to improve statistical process control (SPC) programs in automated lumber mills by greatly increasing the volume of data available for SPC. However, present SPC procedures based on sampling theory developed for manual data collection do not fully utilize data from these systems. A new system of control charts is introduced here that simultaneously monitors multiple lumber surfaces and specifically targets three common sawing defects (taper, snipe/flare, and snake). Nontraditional control charts are suggested based on the decomposition of LRS measurements into trend, waviness, and roughness. The proposed charts can be used to monitor the slope parameter of a multiple linear regression model and the peak-to-peak waviness of observations from each board. Applying these methods should lead to process improvements in sawmills by better detecting common sawing problems and identifying the causes.

Confidence intervals in repeatability and reproducibility using the Bootstrap method

The repeatability and reproducibility (R&R) study--also called a gauge capability study--has been employed as part of the statistical process control program in many organizations. The objective of the study is to determine whether a measurement procedure or instrument is adequate for monitoring the performance of a process. The classical control chart method can be easily performed and calculations can be done with a spreadsheet or statistical computer software. However, this approach only provides the point estimates on the variance components of the measurement error study. In many situations, confidence intervals are more useful than point estimates, because an interval estimate enables an engineer to see both how small and how large an effect may be. In this paper, the Bootstrap method is used for obtaining the confidence intervals of the gauge variability when the control chart method is use for finding the point estimates. One real-life example is used to show the application of this control chart with the Bootstrapping method and comparisons are made with three experimental design procedures in terms of point estimates and confidence intervals for repeatability, reproducibility and total gauge variability.