Ram R. Bishu

Evaluation of fuzzy linear regression models by comparing membership functions

Fuzzy linear regression models can provide an estimated fuzzy number that has a fuzzy membership function. If a point that has the highest membership value from the estimated fuzzy number is not within the support of the observed fuzzy membership function, a decision-maker can have high risk from the estimate. In this study a modification of fuzzy linear regression analysis based on a criterion of minimizing the difference of the fuzzy membership values between the observed and estimated fuzzy numbers is proposed. Two numerical examples are used to evaluate the fuzzy regression models.

The development and evaluation of an ergonomic glove.

The primary intent of this study was to determine if a hand glove could be designed on a criterion of selective protection. Force distribution patterns on the palmar side of hand were obtained from various studies to develop zones of hand that needed protection. A new design for gloves was developed based on the principle of selective protection, where protective material is introduced in varying levels over different parts of the glove, in order to provide protection where it is most needed, and at the same time preserve the desirable dexterity and strength capabilities of the barehand, optimizing the trade-off between protection and performance. Two pairs of prototype gloves incorporating different levels of protection were fabricated and tested using a battery of performance tests and an algometer test for pressure sensitivity. The test battery comprising four dexterity tasks and a maximal voluntary grip strength task was used to assess a number of glove conditions, including the two prototype gloves developed. The results indicate that the performance of the prototype gloves are comparable, and that the performance times for the double glove and the two prototype gloves tested were not significantly different. For the grip strength, the two prototype gloves were better than the double glove. The assembly task performance for the prototype II (laminar glove) was significantly lower than that of the other glove types tested. It appears that gloves of variable thickness can be developed to afford adequate protection at zones of most need. Glove manufacturers are recommended to use an ergonomic approach in the design of gloves. Such an approach, besides protecting the safety objective of gloves, could enhance productivity considerably.

The need for worker training in advanced manufacturing technology (AMT) environments: A white paper

The international globalization of the World markets for manufactured goods, particularly consumer goods, has placed an emphasis on nations to improve manufacturing productivity. This need to improve productivity is further prompted by a potential loss of competitive edge in the global marketplace. The market competitiveness and e

Effects of glove, orientation, pressure, load, and handle on submaximal grasp force

ciency of any nation is primarily dependent upon the economy, reliability, quality, quickness, and ease of its manufacturing processes and the resulting quality of outcomes (products). To a major extent, the skills of the workforce determine the e!ectiveness and the e

The effects of extra vehicular activity (EVA) gloves on human performance

ciency of the process of manufacturing and the quality of goods produced. And yet, there is a severe lack of standardized and consistent worker training programs for skills needed by workers in modern manufacturing organizations. This review paper shows that there is a dire need to train workers in manufacturing organizations and thereby improve the overall e!ectiveness and e

Glove attributes: Can they predict performance?

ciency of such organizations. Relevance to industry As technology changes, so do the skills workers need. In order to compete successfully in the global market, manufacturing organizations must aim at training workers in skills necessary to produce quality goods. ( 1999 Elsevier Science B.V. All rights reserved.

An Analysis of Grasp Force Degradation with Commercially Available Gloves

Abstract While the use of gloves often aid in the safety of completing tasks, and in some cases can even increase performance, as occurs with torquing tasks, there is most often a trade off between increased safety and performance capability when donning gloves. This is especially true in the microgravity EVA environment. The objectives of the present program of research were to examine grasp force at maximal and submaximal exertions, and to address the possibility of a relationship tactility and grasp force. A series of studies were conducted to examine grasp force at the hand/handle interface under a variety of performance conditions. Experiment 1 was conducted to examine the effect of glove type, pressure differential, and lifted load on grasp force at submaximal exertions. Experiment 2 also examined the effect of glove type and lifted load on submaximal grasp force. In addition, handle size and handle orientation were also examined. Experiment 3 was an examination of the effect of glove type, load lifted, handle size and handle orientation on maximal grasp force. Findings indicated that grasp force was effected by frictional and load tactile feedback. Consistent with published evidence, there was a strong glove effect at maximal exertions. However, the glove effect was marginal at submaximal exertions. This suggests that the neuro-muscular mechanisms utilized during maximal exertions are differentially applied and/or different from those used during submaximal or “just holding” types of exertion. The implications for the designer are discussed. Relevance to industry Across industries, gloves are donned to reduce the likelihood of damage to the human hand. However, there is an inherent trade-off between safety and performance with the use of gloves. This study found glove performance differences between submaximal and maximal exertions. Therefore, to increase task performance and workers safety, engineers must consider exertion levels when choosing the type of glove to use.

Seating comfort and its relationship to spinal profile: A pilot study

Abstract Human strength and capabilities such as dexterity, manipulability, and tactile perception are unique and render the hand as a very versatile, effective, multipurpose tool. This is especially true for unknown microgravity environments such as the EVA environment. Facilitation of these activities, with simultaneous protection from the cruel EVA environment, are the two, often conflicting, objectives of glove design. The objective of this study was to assess the effects of EVA gloves at different pressures on human hand capabilities. A factorial experiment was performed in which three types of EVA gloves were tested at five pressure differentials. The independent variables tested in this experiment were gender, glove type, pressure differential, and glove make. Six subjects participated in an experiment in which a number of dexterity measures such as time to tie a rope, and the time to assemble a nut and bolt, were recorded. Tactility was measured through a two-point discrimination test. The results indicate that (a) With EVA gloves there is a considerable reduction in both strength and dexterity performance; and (b) performance decrements increase with increasing pressure differential. Some interesting gender glove interactions were observed, some of which may have been due to the extent (or lack of) fit of the glove to the hand. The implications for the designer are discussed.

Review and evaluation of techniques for determining fatigue allowances

Abstract A number of human performance capabilities are compromised with gloves. Explanations for the strength reduction with gloved hands have ranged from lack of tactile feedback to improper fit. This paper reports two experiments that attempted to link glove attributes to performance decrements. Fifteen subjects participated in Experiment 1 in which grip and grasp strengths were measured using three different types of gloves. Tenacity, snugness, suppleness, and thickness were measured as glove attributes. Results indicate that tenacity and thickness are important while glove size is not. In experiment 2 six types of gloves were investigated in a gripping task. Fifty-two subjects participated in the experiment. Glove thickness appears to correlate well with percent reduction in grip strength as compared to bare-handed strength. Thicker gloves seem to result in greater strength reduction and greater perceived discomfort. The implications for the designer and practitioner are discussed.

Ergonomic Concerns in Enterprise Resource Planning (ERP) Systems and Its Implementations

Excessive force has been indicated as a causal factor in repetitive motion related occupational diseases such as carpal tunnel syndrome, tendinitis, and tenosynovitis. When gloves are worn, grasp capabilities may be compromised causing more force to be exerted. The objective of this research was to evaluate several brands and styles of gloves. Specifically, this evaluation determined the degradation of maximum grasping force for each of the gloves tested versus a bare-handed grasp. The results of this study indicate how much each glove inhibits grasp and a hierarchy of gloves is formed using the percentage of grasp degradation for each glove when it is compared with a bare-handed grasp.