Comparison of concepts in easy-to-use methods for MSD risk assessment

This article presents a comparative analysis of easy-to-use methods for assessing musculoskeletal load and the risk for developing musculoskeletal disorders. In all such methods, assessment of load consists in defining input data, the procedure and the system of assessment. This article shows what assessment steps the methods have in common; it also shows how those methods differ in each step. In addition, the methods are grouped according to their characteristic features. The conclusion is that the concepts of assessing risk in different methods can be used to develop solutions leading to a comprehensive method appropriate for all work tasks and all parts of the body. However, studies are necessary to verify the accepted premises and to introduce some standardization that would make consolidation possible.     

Comparison between five risk assessment methods of patient handling

Several methods currently exist to assess risks resulting from manual handling of patients, based on various perspectives and analyzing different working conditions in the health-care sector. For that reason, a comparison of the main tools properties is discussed in the current study, establishing their strengths and weaknesses in order to provide guidance for the selection of a potential ideal method to use. The comparison is done based on ten items selected from MAPO, DINO, PTAI, Care Thermometer and Dortmund Approach methods, by qualifying each one with different scores, according to a predetermined criterion. For this purpose, a previous fieldwork was performed in various hospital wards and operating rooms of a public health service hospital, comparing the results of partial and total scores. It was observed that, although the five methods compared are similar in nature, the methodology of each them is different and, therefore, the results obtained are unequal. On one hand, it was found that MAPO, PTAI and Care Thermometer methods provide a more balanced approach on the different variables that, in a preventive level, influence the patient handling. On the other hand, it was evidenced that DINO and Dortmund Approach methods focus almost exclusively on the technical work of the caregiver and on the detailed postural analysis that determines the lumbar load, respectively. As a conclusion, we believe that it is necessary to advance with the improvement of these tools, and in this sense we propose the basic lines of a method that integrates those factors that were top rated.     

Comparative analysis of three methods of risk assessment for repetitive movements of the upper limbs: OCRA index,ACGIH(TLV), and strain index

PurposeLiterature proposes different methods for risk assessment due to repeated movements of upper limbs. The results are sometimes different even if methods are applied in the same work conditions. This study, based only on hand/wrist work involving ulnar deviation, compares three methods among those most used for distal upper extremity (DUE) work-related musculoskeletal disorders (WMSDs): OCRA Index (O.I.), Strain Index (S.I.) and ACGIH(TLV).Design/methodology/approachThe work analyzes the algorithms of the methods in terms of number of parameters considered in the formulas, range of variability for each one, and their interaction in determining the final results. Starting to calculate maximum frequency that each method allows in no-risk conditions (varying force and duty cycle), specific scenarios were also created varying one parameter at a time among those determining risk (i.e. force, posture, recovery time …) for a better comprehension of the different algorithms proposed and the provided final results.FindingsThe results are generally different: in the 21 scenarios analyzed, all the methods indicate the same level of risk in only 6 cases when using the formula for the calculation of the hand activity level (HAL) in ACGIH(TLV), and in only 3 cases when using the table. Force bears a higher relative weight for ACGIH(TLV) compared to the others methods: the number of exertions per second allowed in the no-risk zone decreases markedly as the applied force increases. The S.I. was noted to generally be the most precautionary among those examined regarding the frequencies of movements allowed in the no-risk range. The use of categorical multiplier instead of linear, made the results mainly different in the intermediate risk conditions.Originality/valueThe differences in results are due not only to the different number of parameters considered by methods but also to the different risk limit values inside each algorithm. A greater amount of epidemiological data would be desirable in order to better define the conditions to be considered harmful for a worker performing repeated movements of the upper limbs.     

Updating reference values and predictive models of the OCRA method in the risk assessment of work-related musculoskeletal disorders of the upper limbs

A database has been established combining existing data for 23 groups of workers with different level of exposure to repetitive movements of the upper limbs. For all groups, data were available regarding an exposure index (OCcupational Repetitive Actions - OCRA index) and clinically determined UL-WMSDs outcomes (PA = Prevalence of workers affected by one or more UL-WMSDs; PC = Prevalence of single diagnosed cases of an UL-WMSDs). Using these data, new critical values of the OCRA index have been estimated for discriminating different exposure levels (green, yellow, red areas) and new forecasting models of expected PA and PC in exposed populations based on OCRA exposure indexes. The new critical values of the OCRA index were estimated by an original approach in which data for the effect variable (PA) in a reference population not exposed to the relevant risks are combined with the regression function between OCRA and PA. The best simple regression functions between OCRA exposure indexes and health outcomes variables (PA; PC) were researched to obtain forecasting models of effects starting from exposure. Discussion of the results obtained considers their intrinsic limitations, as they are based on prevalence studies, as well as providing recommendations and cautions in the use of the proposed classification system and forecasting models when the OCRA method is applied.     

Risk assessment of cheese processing tasks using the Strain Index and OCRA Checklist

The purpose of this study was to conduct and compare two ergonomic risk assessment methods often used in occupational health research and practice: the Strain Index (SI) and Occupational Repetitive Actions (OCRA) Checklist. Seven raters used the SI and OCRA Checklist to assess task-level physical exposures to the upper extremity of workers performing 21 cheese-manufacturing tasks. Of the total task exposures assessed with both methods, nearly half (49.1%) were classified as hazardous using the OCRA Checklist while 60.2% were classified as hazardous using the SI. Although the underlying injury risk characterization constructs of the SI and OCRA Checklist differ, the results indicated that the SI and OCRA Checklist often classified job tasks into similar risk categories. The differences in risk classifications determined by the SI and OCRA Checklist for job tasks were likely related to the definition of variables measured by these assessment methods as well as the complexity of tasks evaluated. By design, the SI is specific to the distal upper extremity while the OCRA Checklist accounts for the entire upper extremity including the shoulder. When conducting risk assessments of industrial work tasks, the choice of analysis tools should be based on the purpose of the assessment and the complexity of task functions. Both the SI and OCRA Checklist yield risk assessment ratings that are similar for cheese processing tasks.     

无线网络安全风险评估方式的应用研究

通过无线网络连接可以减少有线连接方式中一些不必要的程序和环节,提高了连接网络的效率,但在对无线网络的风险进行评估时,不能利用传统的有线评估方式,导致评估的准确率大大降低,影响了其稳定性和安全性。所以,为了提高无线网络连接的安全性能,就需要对无线网络连接方式的特征进行研究,并根据存在的问题,制定合理有效的应对措施,来有效的对无线网络安全风险进行评估。     

A note on procedures used for accuracy assessment in land cover maps derived from AVHRR data

We present results from analyses conducted to evaluate the performance of advanced supervised classification algorithms (decision trees and neural nets) applied to AVHRR data to map regional land cover in Central America. Our results indicate that the sampling procedure used to stratify ground data into train and test sub-populations can substantially bias accuracy assessment results. In particular, we found spatial autocorrelation in test data to inflate estimates of classification accuracy by up to 50 points. Results from evaluations performed using independent train and test data suggest that the feature space provided by AVHRR NDVI data is poorly suited for most land cover mapping problems, with the exception of those involving highly generalized classes.     

Occupational risk and prolonged standing work in apparel sales assistants

BackgroundThe prolonged standing posture during work affects the risk of developing musculoskeletal disorders of the lower limbs, especially in lack of alternative sitting. While different ergonomic tools are available to assess and manage the postural risk of the back and the upper limbs, there is a dearth of methods relative to the lower limbs.ObjectivesThe aim of this study is to assess the postural risk of sales assistants working in a prolonged standing posture, focusing on critical issues for the lower limbs.Methodsand criteria: 70 sales assistants employed among 9 apparel stores in northern Italy participated in the study. An observational approach was adopted, together with the application of standard ergonomic tools (Rula, Reba, Strain Index, Ocra) to assess the postural risk. Estimates of energy expenditure and movement's patterns were obtained through continuous monitoring with the Sense Wear Armband. Discomfort of the lower limbs was subjectively rated on the Borg's Cr-10 scale at the end of the work shift. The leg circumference was measured on each worker at intervals along the work shift.ResultsThe work of sales assistants in the apparel retail sector is characterized by the prolonged standing posture which accounts for more than 80% of the work shift duration; alternation with walking phases occurs according to assigned tasks and work organization.Activities of the upper limbs and occasional adopted awkward postures are observed, with the postural indexes varying between medium-high level of risk. The average distance walked during the work shift is 3,4 km. The musculoskeletal discomfort of the lower limbs reaches a medium-high intensity (CR 4–5) in 75% of the workers at the end of the work shift. Small but significant variations in the leg circumference were detected between beginning-end of the work shift (increase) and between beginning-end of the break interval (decrease).ConclusionOur data suggest that an indefinite level of risk of developing discomfort and musculoskeletal disorders of the lower limbs is real in sales assistants who work in a prolonged standing posture. The lack of specific assessment tool and of preventive measures could aggravate the exposure level.     

Comparison of statistically-based methods for automated weighting of experimental data in CALPHAD-type assessment

The selection and weighting of experimental and simulated datasets is a necessary step in the development of thermodynamic property models in the calculation of phase diagrams (CALPHAD) approach. Currently, this step requires painstaking and complicated evaluation of the reliability of datasets and thermodynamic consistency between them. In this work, we present two novel and independently developed statistical approaches to aid in this process by addressing outliers and performing automated dataset weighting. The first method, presented here for the first time, applies classical statistical techniques and commonly available optimization algorithms. The second method employs Bayesian statistics via numerical sampling techniques. We compare the strengths and weaknesses of the two approaches through an assessment of the specific heat of aluminum and hafnium metal versus temperature for several experimental datasets. We then compare the weightings of each dataset versus a number of metrics employed by experts to evaluate the reliability of datasets.     

Comparison of ergonomic risk assessment outputs from OWAS and REBA in forestry timber harvesting

Globally, work-related (musculoskeletal disorders (MSDs) are one of the most important health problems encountered by ergonomists. Forest work, especially logging harvesting, is traditionally recognized as one of the most difficult types of physical work and has distinct characteristics. Harvesting works in forestry are composed of the following work stages: logging, skidding, and loading. This study aimed to examine risk factors of MSDs associated with different work postures during harvesting under variable external conditions by comparing work stages using the Ovako Working posture Assessment System (OWAS) and Rapid Entire Body Assessment (REBA). A statistically significant difference was observed between the two methods. While the difference in risk to the musculoskeletal system was statistically significant in different work stages using REBA, logging and skidding were assigned to the same risk level using OWAS. Easy-to-use ergonomic hand tools should be developed that are suitable for working conditions and help reduce MSD risk in forestry workers.     

网络安全风险评估方法分析与比较

本文首先对目前较有代表性的几种网络安全风险评估方法进行简介,然后逐一分析各自优、缺点,最后对各评估方法进行综合对比,指出网络安全风险评估的发展方向,为研究网络安全风险评估提供参考。     

Comparison of four line-based positional assessment methods by means of synthetic data

Positional accuracy of spatial data can be assessed by means of line-based methods. In this work we develop an analysis of the following four methods: Hausdorff Distance, Mean Distance, Single Buffer Overlay and Double Buffer Overlay, using a set of 12 synthetic cases. The synthetic cases incorporate specific shape features for bias, random errors and outliers which correspond to simplified versions of real world possibilities. The use of synthetic cases helps us to understand the basic behavioral differences between the methods. Numerical results for the positional accuracy estimations are different between methods and cases due to the different concepts of distance involved and the specific configurations of each case. When the method results in a function, patterns related to different types of errors can be detected in this function. The length-inclusion level of each method is revealed as the base criterion for comparison. The Single Buffer Overlay Method offers the more general solution because it includes the others’ results.     

肢体协调运动康复机器人的机构设计与实验

针对临床上缺少一种肢体协调运动康复训练设备的现状,研制了一款适用于偏瘫患者个性化训练的上下肢协调运动康复机器人.首先,在探究正常步态上下肢协调运动规律的基础上,选择以肩、膝关节角度协调变化规律作为机器人的设计目标;然后,基于五杆变胞机构设计了康复训练机构及主/辅传动链,并对训练机构进行了运动学分析;最后,在样机上进行了实验,结果表明该机器人能够满足设计目标.     

Data quality assessment of maintenance reporting procedures

Today’s largest and fastest growing companies’ assets are no longer physical, but rather digital (software, algorithms...). This is all the more true in the manufacturing, and particularly in the maintenance sector where quality of enterprise maintenance services are closely linked to the quality of maintenance data reporting procedures. If quality of the reported data is too low, it can results in wrong decision-making and loss of money. Furthermore, various maintenance experts are involved and directly concerned about the quality of enterprises’ daily maintenance data reporting (e.g., maintenance planners, plant managers...), each one having specific needs and responsibilities. To address this Multi-Criteria Decision Making (MCDM) problem, and since data quality is hardly considered in existing expert maintenance systems, this paper develops a maintenance reporting quality assessment (MRQA) dashboard that enables any company stakeholder to easily – and in real-time – assess/rank company branch offices in terms of maintenance reporting quality. From a theoretical standpoint, AHP is used to integrate various data quality dimensions as well as expert preferences. A use case describes how the proposed MRQA dashboard is being used by a Finnish multinational equipment manufacturer to assess and enhance reporting practices in a specific or a group of branch offices.     

Comparison of firefighters and non-firefighters and the test methods used regarding the effects of personal protective equipment on individual mobility

The aims of this study were 1) to evaluate the current pilot test method and ascertain reliable measurements for a standard test method of mobility with personal protective equipment (PPE), such as physical performance and balance ability tests; 2) to compare two participant groups (firefighters versus non-firefighters) and to investigate whether non-firefighters are appropriate as a standard participant group in the field of PPE or not. Totally, 18 participants (nine professional firefighters and nine untrained males) performed the current pilot test method consisting of a balance test, completed prior to and after a performance test. Significant differences were found between PPE conditions and CON (the control clothing ensemble: T-shirt, shorts, and running shoes) for the functional balance test, physical performance test, heart rate, and subjective evaluations in firefighters group. Therefore, the present pilot test method is valid as a standard test method for assessing mobility while wearing PPE. Moreover, the present result shows that firefighters are more reliable than non-firefighters in testing of PPE with current test methods.     

A comparison of methods currently used in inclusive design

Inclusive design has unique challenges because it aims to improve usability for a wide range of users. This typically includes people with lower levels of ability, as well as mainstream users. This paper examines the effectiveness of two methods that are used in inclusive design: user trials and exclusion calculations (an inclusive design inspection method). A study examined three autoinjectors using both methods (n = 30 for the user trials). The usability issues identified by each method are compared and the effectiveness of the methods is discussed. The study found that each method identified different kinds of issues, all of which are important for inclusive design. We therefore conclude that a combination of methods should be used in inclusive design rather than relying on a single method. Recommendations are also given for how the individual methods can be used more effectively in this context.     

内网安全风险评估模型

针对内网安全评估问题构建了内网安全风险评估的系统模型。该模型采用的是基于模糊综合评价的评估方法,并在此基础上重点讨论了基于聚类分析的风险分类方法,其摒弃了传统标准分类的主观方法,对大量客观实验数据进行聚类分析,使风险的分类更具客观性。同时,在评估过程中利用信息熵原理确定各风险因素的权重系数,避免直接赋值的主观性,从而使风险评估的整个过程更加客观,评估结果更加准确。     

Evaluation procedures to be used during the development of CAD systems

This paper describes the different types of CAD system that are available and enters into discussion as to how to choose between one system and another. The paper then follows the path of modification, ie taking an existing system and changing it slightly to meet specific needs. One of the most important parts of this process is the methodology for evaluating existing CAD systems to determine if they could be modified to embrace the particular application. This procedure is described here. The paper concludes with an example in which an engineering company has attempted to speed design and drawing time by using a modified existing drawing package.     

Risk profiles and distributed risk assessment

Risk assessment is concerned with discovering threat paths between potential attackers and critical assets, and is generally carried out during a system's design and then at fixed intervals during its operational life. However, the currency of such analysis is rapidly eroded by system changes; in dynamic systems these include the need to support ad-hoc collaboration, and dynamic connectivity between the system's components. This paper resolves these problems by showing how risks can be assessed incrementally as a system changes, using risk profiles, which characterize the risk to a system from subverted components. We formally define risk profiles, and show that their calculation can be fully distributed; each component is able to compute its own profile from neighbouring information. We further show that profiles converge to the same risks as systematic threat path enumeration, that changes in risk are efficiently propagated throughout a distributed system, and that the distributed computation provides a criterion for when the security consequences of a policy change are local to a component, or will propagate into the wider system. Risk profiles have the potential to supplement conventional risk assessments with useful new metrics, maintain accurate continuous assessment of risks in dynamic distributed systems, link a risk assessment to the wider environment of the system, and evaluate defence-in-depth strategies.