Ratio Scaling Method Research Articles

Estimation of anthropometric hand measurements, from ratio scaling method, for the design of sewn gloves

This paper shows the estimation process of the hand’s anthropometric dimensions, for designing leather sewn gloves. Since there is not detailed information about hands in the anthropometric studies of the Colombian population, it was necessary here to use the ratio scaling method (RS) to estimate, 22 anthropometric dimensions. Subsequently, an anthropometric measurement was performed in a sample of 41 participants (18 female – 23 male), in order to compare the similarity between the measured and the estimated dimensions founding a correlation coefficient between 0.9396 and 0.9995, for male, and between 0.9587 and 0.9988, for female. It was found that the estimated dimensions have the required precision to use this information in the products design that involve a direct contact with human beings, which means that the measures can be obtained with a lower cost and in a faster way than with conventional anthropometric studies.

Calibrated Low-Order Transient Thermal and Flow Models for Robust Test Facility Design

This paper describes an upgrade to high temperature operation of the Engine Component AeroThermal (ECAT) facility, an established engine-parts facility at the University of Oxford. The facility is used for high-TRL research and development, new technology demonstration, and for component validation (typically large civil-engine HP NGVs). In current operation the facility allows Reynolds number, Mach number, and coolant-to-mainstream pressure ratio to be matched to engine conditions. Rich-burn or lean-burn temperature, swirl and turbulence profiles can also be simulated. The upgrade will increase the maximum inlet temperature to 600 K, allowing coolant-to-mainstream temperature ratio to be matched to engine conditions. This will allow direct validation of temperature ratio scaling methods in addition to providing a test bed in which all important non-dimensional parameters for aero-thermal behaviour are exactly matched. To accurately predict the operating conditions of the upgraded facility, a low order transient thermal model was developed in which the air delivery system and working section are modelled as a series of distributed thermal masses. Nusselt number correlations were used to calculate convective heat transfer to and from the fluid in the pipes and working section. The correlation was tuned and validated with experimental results taken from tests conducted in the existing facility. This modelling exercise informed a number of high-level facility design decisions, and provides an accurate estimate of the running conditions of the upgraded facility. We present detailed results from the low-order modelling, and discuss the key design decisions. We also present a discussion of challenges in the mechanical design of the working section, which is complicated by transient thermal stress induced in the working section components during facility start-up. The high-temperature core is unusually high-TRL for a research organisation, and we hope both the development and methodology will be of interest to engine designers and the research community.

Determination of Domestic Kitchen Characteristics for Elderly Turkish Women: A Comprehensive Ergonomics Approach

Objective: The paper aimed to present a layout of the kitchen for elderly Turkish women to assure their safety and comfort while executing their tasks in their kitchen. Background: It is appropriate to regard the domestic kitchen used by an elderly woman as her workplace, requiring application of the ergonomics principles such as environmental conditions, equipment design and workplace layout on the kitchen floor. The purpose is to enable them to perform activities in the kitchen comfortably, safely and without assistance. Ergonomic design takes into account the abilities and limitations due to aging and helps to create the best person-environment fit. Proper design can help all people in all age groups but is particularly important for elderly individuals. Safety, physical and social health must be taken into consideration to increase the quality of elderly Turkish women’s lives. Method: The general layout of the kitchen was designed considering the work triangle, to minimize the walking distance in regard of the work sequence. The required functional anthropometric data for elderly Turkish women were obtained by ratio scaling method using the raw data from previous work. Results: The design of cabinets, worktops, base units, storage areas and their lay-out with kitchen appliances were realized to ensure comfort and safety for the elderly Turkish women. A U-shaped kitchen is found appropriate allowing the elderly woman and her company working together. For the counter, the height of the worktop is found as 860 mm from the floor and a 20 mm thick and 620 mm wide granite block is chosen. Placement of wall cupboards is achieved by considering the vertical grip reach of elderly Turkish women (5%) and the height of each shelf from the floor is determined. Conclusion: The absence of housing standard definitions addressing accessibility of the elderly is an ongoing problem in Turkey. This work presents potential solutions to improve the living standards of the elderly Turkish women.

Compressed dynamic mode decomposition for the analysis of centrifugal compressor volute

The compressed dynamic mode decomposition (compressed DMD) is used to analysis the unsteady characteristics of a centrifugal compressor. Firstly, to extract the unsteady flow structures of the volute under the mild surge condition, dynamic mode decomposition (DMD) method is applied to the flow field snapshots. The results indicate that the characteristic frequencies relating to the blade passing frequencies (BPFs) and corresponding modes are captured. Besides, the perturbation oscillating with the characteristic frequency (233.5 Hz), which is generated by the non-synchronic unsteady flow, is also obtained accurately. The non-synchronic unsteady flow is vividly shown by the reconstruction of the mild surge mode. Ten, the unsteady flow of the volute is also analyzed by the compressed DMD method, which is performed on the much compressed datasets and thus saves the calculation time. The dominant characteristic frequencies and corresponding modes can also be extracted accurately by the compressed DMD method when adopting an appropriate compression ratio. The compression ratio has an important influence on the results of the compressed DMD method. Considering the dominant frequencies and the energy ratio spectrum, a conservative recommendation of the compression ratio is 1% in this case. The energy ratio scaling method performs better than the amplitude scaling method.

Research on Risk Sensitivity of Submerged Floating Tunnel Based on Analytic Hierarchy Process

The hierarchical structure model of risks of floating tunnel is built under the sea area conditions in Qiongzhou Strait in combination with the work characteristics in early stage and the overall construction process of floating tunnel. The judgment matrix introduced into the analytic hierarchy process analyzes the relationships between different hierarchical factors for quantitative analysis of their index weight values by A.L.saaty's ratio scale method. The weight values of various main risk factors of floating tunnel are calculated and sequenced, and the risk control measures are proposed. This paper mainly deals with the quantitative research problems in project risk analysis of floating tunnel to provide a reference for decision makers.

A Comparison of Absolute, Ratio and Allometric Scaling Methods for Normalizing Strength in Elite American Football Players

A Comparison of Absolute, Ratio and Allometric Scaling Methods for Normalizing Strength in Elite American Football Players Division I football players exemplify the greatest range in body mass of any modern team sport. Body mass may differ by over 80 kg between the various positions. Absolute muscular strength is typically greater in larger individuals, but such data does not allow for accurate comparisons. Therefore, in order to compare the performance indices of individual groups allometric rather than ratio scaling has been suggested. The purpose of this study was to compare absolute strength, normalized ratio and allometrically scaled data among players of different size.

The Evaluation of Design for Energy Efficiency of Buildings Based on Analysis Hierarchical Process and Grey Theory

Based on the analysis of building energy efficiency features, considering the construction of energy efficiency factors, this paper AHP establish a comprehensive evaluation of building energy efficiency design model based on grey theory. According to the characteristics of the system and basic principles, after comparative analysis of levels of elements, it will introduce 1-9 ratio scale method to construct a matrix. The matrix determines the largest eigenvalue and eigenvector to get the relative weight of various factors. And use grey correlation as a measure to determine the important factors or the optimal solution. This model mainly combines quantitative analysis, qualitative and quantitative analysis methods to overcome the evaluation‘s the subjectivity and arbitrariness, and achieves a scientific and reasonable evaluation of comprehensive energy efficiency design of the building. Finally, this paper designs and develops building energy efficiency evaluation software.

Anthropometry of the Singaporean and Indonesian populations

This research collected anthropometric data of the Singaporean and Indonesian populations. The data were mainly from university students. In total, 245 male and 132 female subjects from Indonesia and 206 male and 109 female subjects from Singapore were measured. The Singapore data were divided into three sub-groups, comprising Singapore overall, Singapore citizens, and the Chinese ethnic sub-group. The Indonesians data were divided into two sub-groups, comprising Indonesia citizens and Indonesia Chinese. This study used 36 measurement dimensions. The authors made a comparison with previous anthropometric data collected in 1990 of over a thousand Singaporeans. The main contributions of this study are: i) an updated anthropometric database of Singaporeans and Indonesians, ii) a comparison of the two samples obtained, and iii) a projection of dimensional changes over time from comparing past to more recent anthropometric data. Statistical analyses show that Singaporeans (both male and female) tend to have larger dimensions than Indonesians in general. In addition, the data reveal the current sample to be significantly larger on more than 50 percent of the dimensions measured, for both males and females. In providing instances of possible application, the Body Mass Index (BMI) of all sub-groups was calculated. The results show both samples to have normal indexes with BMIs in the range of 18.5–25.0. This paper presents also an empirical estimation of unknown anthropometric characteristics using the Ratio Scaling Method. The purpose is to estimate uncollected anthropometric data based on a given scaling dimension. Overall, the reported anthropometric data and analyses can be used as relevant consideration in product and systems design. Relevance to industry The findings of this study indicate differences between Singaporean and Indonesian anthropometry in the citizen and Chinese sub-groups. The utilization of an updated anthropometric database that incorporates geographical origin and ethnic group is useful. Product designers would be able to cater to a wider range of target users.

A comparison of ratio and allometric scaling methods for normalizing power and strength in elite rugby union players

In this study, we compared the effectiveness of ratio and allometric scaling for normalizing power and strength in elite male rugby union players. Rugby union forwards (n = 18) and backs (n = 20) were assessed for squat jump and bench throw peak power, and box squat and bench press one-repetition maximum strength. The performance data for the forwards and backs were compared using ratio (P/BM) and allometric scaling (P/BMb ), where P represents performance, BM is body mass in kilograms, and b is a power exponent. A proposed allometric exponent (0.67) and exponents (±95% confidence intervals) derived for the box squat (0.33 ± 0.31), bench press (0.45 ± 0.30), bench throw (0.46 ± 0.36), and squat jump (0.64 ± 0.31) exercises were used. In general, the absolute expression of power and strength was superior for the heavier forwards, but after ratio scaling these performance measures then favoured the lighter backs. There were no performance differences between the forwards and backs after allometric scaling using either the proposed or the derived exponents. Thus, allometric scaling may provide a more effective method for normalizing power and strength in elite athletes when body size is a confounding variable.

How to derive priorities in AHP: a comparative study

A heated discussion has arisen over the “best” priorities derivation method. Using a Monte Carlo simulation this article compares and evaluates the solutions of four AHP ratio scaling methods: the right eigenvalue method, the left eigenvalue method, the geometric mean and the mean of normalized values. Matrices with different dimensions and degree of impurities are randomly constructed. We observe a high level of agreement between the different scaling techniques. The number of ranking contradictions increases with the dimension of the matrix and the inconsistencies. However, these contradictions affect only close priorities.

Allometric scaling of left ventricular mass by body dimensions in males and females.

Physiological variables must often be scaled for body size differences to permit meaningful comparisons between subjects or groups. This study aimed to determine the proper relationship between body dimensions and left ventricular mass (LVM) via allometric scaling (AS) in 142 subjects (78 males, 64 females; ages 18-40). A cubic formula was used to estimate LVM from wall thickness and left ventricular internal dimensions derived from M-mode echocardiography. Fat free mass (FFM) was predicted from anthropometry. "Best compromise" allometric equations (y = a.xb) revealed a common body mass (BM) exponent of 0.78 (95% CI, 0.65-0.91). The widely adopted ratio scaling (RS) method assumes that the exponent b = 1. In this sample, use of RS would penalize heavier subjects by overcorrecting for BM. The equivalent mean FFM exponent of 1.07 was not different from unity (95% CI, 0.92-1.22). Hence, RS using BM would appear to penalize those subjects who are heavier owing to excess fat not excess FFM. Gender differences in LVM were 70.44, and 18%, for absolute values per BM 0.78 and per FFM 1.07, respectively, (P < 0.05). This reveals quantitative differences in heart size independent of body dimensions. We conclude that sample specific AS permits meaningful intersubject or intergroup comparisons.

Testing for the rank ordering of the priorities of the alternatives in Saaty's ratio-scale method

Saaty uses ratio scale ( π 1, π 2,…, π t ) for the values of the alternatives { T 1, T 2,…, T t } for a decision problem. Here, π i / π j is the ratio of the priority of T i to that of T j . In this context, a specific rank ordering of the ratio scale is tested.

A Comparison of the Eigenvalue Method and The Geometric Mean Procedure for Ratio Scaling

This article evaluates and compares the performance of two ratio scaling methods, the eigenvalue method proposed by Saaty (1977, 1980) and the geometric mean procedure advocated by Williams and Crawford (1980), given random data. The two methods were ex amined in a series of monte carlo simulations for two response methods (direct estimation and constant sum) and various numbers of stimuli and response scales. The sampling distributions of the measures of consist ency of the two methods were tabulated, rules for de tecting and rejecting inconsistent respondents are out lined, and approximation formulas for other designs are derived. Overall, there was a high level of agree ment and correspondence between the results from the two scaling techniques even when the data were ran dom.

Clinical psychophysics: Applications of ratio scaling and signal detection methods to research on pain, fear, drugs, and medical decision making.

Clinical psychophysics: Applications of ratio scaling and signal detection methods to research on pain, fear, drugs, and medical decision making.

Clinical psychophysics: Applications of ratio scaling and signal detection methods to research on pain, fear, drugs, and medical decision making.

Clinical psychophysics: Applications of ratio scaling and signal detection methods to research on pain, fear, drugs, and medical decision making.

Ratio scaling of TAT need for achievement through application of a paired-comparisons method, with a test of internal consistency.

A method for ratio scaling of projective personality variables was devised and tested in two studies, using the TAT and achievement motivation (n Ach). In Exp. I, 4 judges made direct ratio estimates of relative n Ach in all possible pairs of 8 Ss' TAT protocols (28 pairs). In Exp. II, 3 judges used the same procedure to estimate relative n Ach for all pairs of TAT stories told to the same card, rather than for four-story protocols (112 pairs). Ratio scale values correlated with traditional n Ach scoring between .86 and .91 in Exp. I, and .90 and .95 in II. The protocols represented two criterion groups with different n Ach. Ratio scores from Exp. II, but not from I, differentiated these groups as well as traditional scoring. A model was developed for testing the internal consistency of judges' ratio estimates, based on Comrey's work. It showed over 90% of the ratio estimates' variance accounted for by the linearity assumptions of the ratio scaling model. Advantages and problems in using the ratio scaling method were discussed.

RATIO SCALING OF TAT NEED FOR ACHIEVEMENT THROUGH APPLICATION OF A PAIRED-COMPARISONS METHOD, WITH A TEST OF INTERNAL CONSISTENCY

-A method for ratio scaling of projective personality variables was ' devised and tested i n two studies, using the T A T and achievement motivation ( n Ach). In Exp. I, 4 judges made direct ratio estimates of relative n Ach in all possible pairs of 8 Ss' TAT protocols (28 pairs). In Exp. 11, 3 judges used the same procedure to estimate relative n Ach for all pairs of TAT stories told to the same card, rather than for four-story protocols (112 pairs). Ratio scale values correlated with traditional n Ach scoring between .86 and .91 in Exp. I, and .90 and .95 i n 11. The protocols represented two criterion groups with different 7z Ach. Ratio scores from Exp. 11, but not from I, differentiated these groups as well as traditional scoring. A model was developed for testing the internal consistency of judges' ratio estimates, based on Cornrey's work. It showed over 90% o f the ratio estimates' variance accounted for by the linearity assumptions of the ratio scaling model. Advantages and problems in using the ratio scaling method were discussed.

Dimension analysis of the perception of musical style.

Wedin, L. Dimension analysis of the perception of musical style. Scand. J. Psychol., 1969, 10, 97–108.‐The subjective similarity of ten short excerpts from musical works ranging over the period of 1720–1890 was studied by (I) the direct multidimensional ratio scaling method and (2) by the method of similarity analysis. Factor analysis extracted three or four factors depending on the degree of musical training of the subjects. The differentiation and inter‐pretability of the factors were higher for subjects with more musical training and interest. The factors were labeled ‘Baroque’, ‘Rococo’, ‘Viennese classicism’ and ‘Romanticism’.

Ratio-Estimations of Loudness-Intervals

Two loudness-scales have been published: (a) the sone scale,1 and (b) the lambda scale.2 These two scales, based on different scaling procedures, are quite divers. The sone scale, based on direct estimates of the apparent ratios of loudnesses, is a power function of sound-intensity with an exponent of 0.3. The lambda scale, based on both estimates of equalappearing intervals and the apparent ratios of loudnesses, is much less steep and may be approximated by either a logarithmic function or a power function with an exponent of 0.13. Though the lambda scale, founded on both equisectional and fractionational judgments, is a hybrid scale, the form of the scale based primarily on equisectional data is in general agreement with both discriminability and interval scales.3 The present experiment deals with the adequacy of the sone and the lambda scales to predict ratio-estimations of loudness-intervals. Ordinarily, the apparent magnitude of loudness-ratios is studied by ratio-scaling methods, and the apparent magnitude of loudness-intervals by interval scaling-methods.4 That is, the scalings of ratios and of intervals are coupled to two different scaling tasks: that of making ratio-estimations and that of partitioning a segment into equal intervals. By using a ratio-method to study the apparent magnitude of loudness-intervals, the present experiment unties the property scaled from the method of scaling.

Visual perception of capital letters. Multidimensional ratio scaling and multidimensional similarity.

The quantitative similarity of nine capital letters was studied (1) by the direct multidimensional ratio scaling method and (2) by the method of similarity analysis. Three factors, ‘E’, ‘O’ and T, were found. Factor loadings were nearly identical in both methods. A previously proposed equation did not describe the relation between subjective similarity and angular separation of percept vectors.