Values Of Quality Characteristics Research Articles

Comparison of Quality Characteristics and Instrumental Analysis on Korean Makgeolli

To compare different taste evaluating methods on Makgeolli, quality characteristics and instrumental analysis on 41 commercial Makgeolli (unheated 21, heated 20) produced in different regions of South Korea were investigated. Physicochemical characteristics including pH, total titratable acidity, amino-type nitrogen, reducing sugar, and color of Makgeolli samples were analyzed. Sensory characteristics including appearance (turbidity, color), flavor (aroma), taste (sweet, sour, bitter, thick, cool), and total acceptability were evaluated. Five tastes (umami, sour, salty, bitter, astringent) and three after tastes (umami, bitter, astringent) were evaluated by using Taste Sensing System (TS-5000Z). In correlation between analytical values of physicochemical and sensory characteristics, ‘pH, amino-type nitrogen sourness, refreshing, balances’ was showed high correlation. In addition, analytical items between sensory characteristics and Taste Sensing System showed a strong correlation. Results indicate the analytical values of quality characteristics and Taste Sensing System on Makgeolli were highly correlated.

Robust Design using Desirability Function to the Combined-Array with Multiple Quality Characteristics

Robust design is an approach to reducing performance variation of quality characteristic values in quality engineering. Taguchi has an idea that mean and variation are handled simultaneously to reduce the expected loss in products and processes. In the Taguchi parameter design, the product-array approach using orthogonal arrays is mainly used. However, it often requires an excessive number of experiments. An alternative approach, which is called the combined-array approach, was studied. In these studies, only single quality characteristic (or response) was considered. In this paper we propose how to simultaneously optimize for multiple quality characteristics (or multiresponse) using desirability function when we used the combined-array approach to assign control and noise factors.

Data mining of hospital characteristics in online publication of medical quality information

Information disclosure can reduce information asymmetry between health care providers and patients, thus improving both patient safety and medical quality. The National Bureau of Health Insurance (NBHI) inTaiwancurrently publishes health-related information online in order to enhance service efficiency and enable the public to monitor the country’s medical system. A data mining technique, classification and regression tree (CART), is used in this work to investigate online public quality information to compare the characteristics of hospital. The hospital quality indicators and characteristics data are available on the websites of the NBHI (http://www.nhi.gov.tw/AmountInfoWeb/Index.aspx) and the Department of Health (http://www.doh.gov.tw/). The full classification and regression tree presented in this work, grown using the hospitals’ quality medical indicators and characteristic values, classifies all hospitals into seven groups. The rate of stays longer than 30 days, which is the dependent variable in this study, is most influenced by the number of medical staff. This reflects the fact that the fewer medical staffs that are employed, the smaller the hospital is, and patients who are likely to have longer stays tend to go to the medium or large hospitals. Policy makers should work to decrease or eliminate persistent healthcare disparities among different socioeconomic groups and offer more online healthrelated services to reduce information asymmetry between health care providers and patients.

The effect of inspection error on quality and producer losses: the case of nominal-the-best type quality characteristic and rework

In this study, the effect of inspection error (IE) on quality and producer losses is investigated for a nominal-the-best type quality characteristic determined by a manufacturing process centre with a separate rework unit. The probability distribution and the first two moments of the resulting quality characteristic values are derived and used together with Markov chain models and simulation to study the quality and producer losses and the related statistics for various processes and gage capability levels. The results of this study confirm with strong theoretical and empirical evidence that an effective way of achieving robustness to IE is to improve the process capability. This study provides benchmarks that support understanding and decision making of quality professionals.

Applications of utility concept and desirability function for materials selection

To satisfy the requirements of the manufacturing industries, material selection is considered as an important task. Wrongly chosen material may unnecessarily increase the product cost and lead to early failure of the product. While developing a product, the most suitable material is to be selected based on the requirements of the product and the available material properties. These material properties must match with the product requirements. To aid this material selection decision-making process, several mathematical tools and techniques have already been developed by the past researchers. Some of those techniques are computationally complex and their solution accuracy is often affected by the introduction of additional mathematical parameters. In this paper, two conceptually simple but strong mathematical techniques, i.e. utility concept and desirability function approaches are proposed to solve four material selection problems. These two methods are based on the quality characteristic values of the considered material alternatives for arriving at the satisfactory results. Almost a close match between the rankings of the alternatives obtained by these two methods and those derived by the past researchers confirms the suitability of both these approaches for solving material selection problems.

Morphological Characteristics of Korean Dried Ginseng Products

The purpose of this study was to determine a standard quality characteristic through the evaluation and statistical analysis of the morphological characteristics of dried ginseng (white ginseng) products. Samples of 4-year-old 30 and 50 piece grade curved ginseng and 5-year-old 25 and 15 piece grade straight ginseng products were collected from a market, with 5 to 10 packs of each product being collected annually over a 5-year period (2006-2010). Morphological characteristics, such as weight, length, diameter, and surface color, were measured and statistically analyzed to present a standard quality characteristic value using mean±3SD, a range that excluded outlier. The 4-year-old curved ginseng samples of 50 and 30 piece grade were 4.80 to 6.12 cm and 5.28 to 7.60 cm long, 0.22 to 1.70 cm and 0.21 to 2.07 cm wide, and weighed 5.28 to 7.40 g and 8.62 to 12.26 g, respectively. The 5-year-old straight ginseng samples of 25 and 15 piece grade were 9.66 to 15.47 cm and 10.66 to 16.80 cm long, 1.32 to 1.94 cm and 1.48 to 2.43 cm wide, and weighed 9.18 to 16.40 g and 15.89 to 24.82 g, respectively. The surface color of the different piece grades in the same type of dried ginseng product was similar, whereas the straight ginseng demonstrated a lower level of brightness, but the relative redness and yellowness were of higher levels, than that of curved ginseng.

Water quality indices based on bioassessment: The biotic indices

Water quality indices (WQIs), which translate numerical values of several water quality characteristics of a sample into a single value, play a very important role in the monitoring, comparison and control of water quality. The WQIs of modern and post-modern times have been almost exclusively based on physical and chemical characteristics, and have seldom included 'biological' characteristics other than biochemical oxygen demand (BOD) and faecal coliforms. During the last three decades of the 20th century, indices based on bioassessment have been increasingly used in some developed countries, besides South Africa and Serbia, to complement the conventional WQIs, but the rest of the world continues to base its WQIs predominantly on physical and chemical characteristics. The serious drawbacks of this approach have been elucidated in this paper and, against that background, the state-of-the-art of biotic indices has been summarized. The paper makes a strong case for greater reliance on bioassessment-based WQls, especially by developing countries, to strengthen the diagnostic value of the conventional WQls.

Método para aplicação de gráficos de controle de regressão no monitoramento de processos

Este artigo propõe um método para a aplicação do gráfico de controle de regressão no monitoramento de processos industriais. Visando facilitar a aplicação do gráfico, o método é apresentado em duas fases: análise retrospectiva (Fase I) e monitoramento do processo (Fase II), além de incluir uma modificação do gráfico de controle de regressão múltipla, permitindo o monitoramento direto da característica de qualidade do processo ao invés do monitoramento dos resíduos padronizados do modelo. Também é proposto o gráfico de controle de extrapolação, que verifica se as variáveis de controle extrapolam o conjunto de valores utilizado para estimar o modelo de regressão. O método foi aplicado em um processo de uma indústria de borrachas. O desempenho do gráfico de controle foi avaliado pelo Número Médio de Amostras (NMA) até o sinal através do método de Monte Carlo, mostrando a eficiência do gráfico em detectar algumas modificações nos parâmetros do processo.

Principal component analysis for multiple quality characteristics optimization of metal inert gas welding aluminum foam plate

Principal component analysis (PCA) coupled with Taguchi methods are employed in the study for multiple quality characteristics optimization of metal inert gas (MIG) arc welding aluminum foam plates. The quality characteristics investigated are the micro-hardness and the bending strength of the weldments. Eight control factors selected are the type of filler material, MIG current, welding speed, MIG gas flow rate, workpiece gap, MIG arcing angle, groove angle, and electrode extension length. It is shown by the experimental results that the optimal parameter combination of the MIG welding process is A 2 (filler material: Type No. 5356), B 3 (MIG current: 100 A), C 1 (welding speed: 80 mm/min), D (MIG gas flow rate: 13 L/min), E 2 (workpiece gap: 1.7 mm), F 3 (MIG arcing angle: 50°), G 3 (groove angle: 20°), and H 1 (electrode extension length: 15 mm). Moreover, it is ascertained from the analysis of variance (ANOVA) results that B (MIG current), C (welding speed), and E (workpiece gap) are the most important control factors in the process design, and thus strict control must be applied to the three factors. The experimental results likewise show that the optimal process design could indeed improve the multiple quality characteristic values of the MIG-welded aluminum foam plates.

Alpha Error of Taguchi Method with Different OAs for NTB Type QCH by Simulation

Taguchi method has been widely used for parameter design in many industrial applications. Nevertheless, it has been the subject of discussion and much debate in different platforms. This research proposes an extension to ongoing research by investigating the alpha error of Taguchi method with two-, three-, and four-level orthogonal arrays (OAs) for the nominal-the-best (NTB) type quality characteristic (QCH) type via simulation. With each array, it is assumed that QCH values are normally distributed with the same mean and standard deviation. Consequently, the null hypothesis that all factors are insignificant is true. The alternative hypothesis is that at least one factor is identified as significant. Simulation is conducted for 10 cycles each of 10,000 runs. The results showed that the alpha error is very high, which indicates that insignificant factors are misidentified as significant with high probability. In practice, this may provide misleading conclusions about parameter design. In conclusion, Taguchi’s quality engineering concepts are of great importance. However, his method is found inefficient for parameter design.

Optimizing process parameters of hot-bar soldering process through quality function deployment and Taguchi method

As quality values failed to meet customers’ requirements when the hot-bar soldering process (HBSP) was first introduced in the electronic manufacturing service (EMS) company, it is the intention of this study to combine quality function deployment (QFD) and the Taguchi method to analyze the produced quality characteristics and to optimize the process parameters. The product from HBSP is a gate board that transmits vertical signals in thin film transistor liquid crystal display (TFT-LCD) modules. To produce a gate board through HBSP, a film of flexible printed circuit (FPC) is soldered onto the pad of a printed circuit board (PCB) with the hot-bar (HB) which is heated by a pulse heater. When performing a problem analysis, the strength of the solder joints is considered a response value of quality characteristics for the process of HBSP. The critical factors are then identified via the Taguchi method. The results of this study will indicate whether or not the quality of the gate board can be improved significantly and thereby satisfy customers’ requirements.

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.

Parameter estimation for modelling clogging of granular medium permeated with leachate

A numerical model called BioClog is used to backcalculate biological activity rate constants using measured values of water quality and clog chemical characteristics from well-controlled laboratory column experiments that contained a granular-sized material permeated with synthetic and real leachates. BioClog is a multispecies, reactive chemical transport model capable of predicting clogging of a porous media caused by the accumulation of biofilms, chemical precipitates, and entrained particles. Monod kinetic constants for acetate- and butyrate-degrading bacteria were obtained through inverse modelling of granular-sized material permeated with synthetic leachate. The model predicted the changes in concentrations of volatile fatty acids and dissolved calcium and it predicted the changes in clog composition from a juvenile clog containing biofilm to a mature clog containing biofilm with mineral matter. The kinetic constants were then applied to predict spatial and temporal water quality and clog composition for a granular-sized material permeated with real leachate. The kinetic constants deduced through inverse modelling of the synthetic leachate column experiments provided reasonable predictions of the behaviour of the columns permeated with real leachate.

Statistical principles of quality control

115 In the present work, we regard a statistical model in a broader sense than simply as some formula obtained from empirical data as a result of parametric identification. Since real technologies and real quality are represented by measured quantities, they completely correspond to the definition of probabilistic (statistical) models (spaces). The measured values of quality characteristics, for example, form a set of elementary outcomes corresponding to a system of events (high quality, satisfactory quality, rejection, etc.). From the probabilities of elementary events, the probability for each event of the given system (algebra) is determined. Three elements ‐ the set of elementary events, the algebra, and the probabilities—form a probabilistic model (or probabilistic experiment space), with a finite space of outcomes. Obviously, these precepts may also be applied to technologies.

Characteristics and quality of gum arabic from naturally grown Acacia senegal (Linne) Willd. trees in the Central Rift Valley of Ethiopia

Drylands of Ethiopia, including those in the Rift Valley, host good potential for commercial production of natural gums such as gum arabic. However, little researches have assessed the qualities of these gums for their commercial and industrial promotions. The objectives of this study were to assess the (i) quality of gum arabic collected from naturally grown Acacia senegal trees in the Central Rift Valley of Ethiopia and (ii) evaluate these quality characteristics against reported quality attributes of the same kind of gum from known destinations such as the Sudan and with international specifications. Gum samples were collected from randomly identified 10 trees of A. senegal in the study area and composited into one big sample by putting all in one plastic bag. The characteristics analyzed included: color, odor, moisture content, ash content, viscosity, pH, specific rotation, N and tannin contents, and concentration of several metals using standard laboratory procedures. The results yielded moisture content of 15%, ash content of 3.56%, intrinsic viscosity of 1.19 ml g −1, pH on 25% solution of 4.04, specific rotation of −32.5, nitrogen content of 0.35%, protein content of 2.31% and with no tannin content. Mineral contents of the gum arabic (g/100 g) are Ca 0.7, Mg 0.2, Na 0.01, K 0.95, Fe 0.001, P 0.6 and non-detectable traces of Pb, Co, Cu, Zn, Ni, Cd, Cr and Mn. These values agree well with values of same quality characteristics of gum arabic reported from Sudan and other exporting countries, and also conform well to international standards in all aspects. Indeed, it is possible to utilize the gum arabic resource of the Central Rift Valley of Ethiopia for commercial and/or industrial purposes.

Optimal tolerance design for products with correlated characteristics by considering the present worth of quality loss

The quality loss function proposed by Taguchi provides a quantitative measurement of product quality when product’s quality characteristic value deviates from the ideal target at an arbitrary time. However, product use causes degradation on its quality characteristic, and since such a deviation can be changing over time, so can its quality loss. The quality loss caused by degradation on quality characteristic has not been considered in most research. In this paper, the time value of money for quality loss and product degradation over time is integrated into the total cost model, and a new optimization model for the tolerance design of products with correlated characteristics is established. The discussions focus on the multivariate quality loss function as an extension of the Taguchi loss function, which is used to model quality loss due to product degradation as a continuous cash flow function under continuous compounding. The optimal tolerance design is achieved by minimizing the total cost, which is the sum of manufacturing cost and the present worth of expected quality loss. An illustrative example is presented to demonstrate the effectiveness of the proposed model.

Determining optimal print layout for best reading performance in Chinese

The purpose of this research is to evaluate the effects of Chinese print layout on reading performance. Reading performance is defined in this research as the integration of two quality characteristic values: reader speed of reading and the level of comprehension of printed text materials. The results of the research can be used to determine what print format facilitates optimum reading performance. For this research, previous studies were first used to define the factors affecting reading performance. Based on these studies, it was determined that the factors are text–direction arrangement, block arrangement on the page, font size, line spacing, and the age of the readers. Next, a fractional factorial experiment was conducted utilizing Taguchi Quality Engineering Methods — an L18 (21 × 37) design. Finally, a performance-management matrix was applied to determine and analyze the optimal combination of reading-performance factors and levels. The study found that optimal reading performance was realized with text printed horizontally in two blocks per page, in an 11–point size, with line spacing at an exact height of 1.5 times the font size in Microsoft Word, and read by readers in the 21–to–60–year–old age range. The results of the survey may be useful as reference for those who design print formats for Chineselanguage newspapers, magazines, and professional journals.

Experimental study of Nd:YAG laser beam machining—An overview

Abstract Since last four decades laser beams are being used in various manufacturing processes. CO2 and Nd:YAG lasers are most widely used in machining of engineering materials. In recent years the researchers have explored the number of ways to improve the quality of cutting, drilling and micromachining of different materials (metals, alloys, ceramics and composites) using Nd:YAG lasers. This paper reviews the experimental investigations carried out to study the effect of various factors/process parameters on the performance of Nd:YAG laser beam machining. The importance of different design of experiments (DOE) methodologies used by various investigators for achieving the optimum value of different quality characteristics has also been discussed in paper.

Comparison of Quality Characteristics and Breadmaking Functionality of Hard Red Winter and Hard Red Spring Wheat

ABSTRACTVarious whole‐kernel, milling, flour, dough, and breadmaking quality parameters were compared between hard red winter (HRW) and hard red spring (HRS) wheat. From the 50 quality parameters evaluated, values of only nine quality characteristics were found to be similar for both classes. These were test weight, grain moisture content, kernel size, polyphenol oxidase content, average gluten index, insoluble polymeric protein (%), free nonpolar lipids, loaf volume potential, and mixograph tolerance. Some of the quality characteristics that had significantly higher levels in HRS than in HRW wheat samples included grain protein content, grain hardness, most milling and flour quality measurements, most dough physicochemical properties, and most baking characteristics. When HRW and HRS wheat samples were grouped to be within the same wheat protein content range (11.4–15.8%), the average value of many grain and breadmaking quality characteristics were similar for both wheat classes but significant differences still existed. Values that were higher for HRW wheat flour were color b*, free polar lipids content, falling number, and farinograph tolerance. Values that were higher for HRS wheat flour were geometric mean diameter, quantity of insoluble polymeric proteins and gliadins, mixograph mix time, alveograph configuration ratio, dough weight, crumb grain score, and SDS sedimentation volume. This research showed that the grain and flour quality of HRS wheat generally exceeds that of HRW wheat whether or not samples are grouped to include a similar protein content range.

Summary of the 1996 Portland Cement Concrete Performance-Related Specification Shadow Field Trial: Iowa State Route 23

The results of a “shadow” field trial (actual contractor pay was not affected) conducted to demonstrate a Level 1 prototype performance-related specification (PRS) for jointed plain concrete pavement construction are presented. The Level 1 PRS (the most practical PRS method at this time) is believed to be immediately implementable because it uses currently practiced sampling and testing procedures. The future pavement performance is represented by distress indicators that are predicted on the basis of measured acceptance quality characteristic (AQC) values. Pay factors are determined independently for each AQC from simulated pay factor versus AQC curves and corresponding equations. The overall lot pay factor is determined from a simple mathematical manipulation of the individual AQC pay factors. The specific objectives of the field trial were to verify and confirm the draft specification’s effectiveness, identify potential problem areas, and determine its reasonableness. This paper discusses all aspects of the field trial including the relevant definitions, selection of lots and sublots, sampling and testing plan, calculation of shadow PRS pay adjustments, problems encountered, and a summary of lessons learned.