The Cochran-Weiss-Shanteau performance index as an indicator of upper limb risk assessment expertise

Ergonomists and many other professionals apply ergonomics principles to musculoskeletal health problems. This study examines whether there are differences when it comes to judgement expertise concerning upper limb disorders (ULDs) between ergonomists and those with less ergonomics training. The Cochran-Weiss-Shanteau (CWS) performance index combines judgement consistency with discrimination into one CWS index. Fifty-eight professionals working in the musculoskeletal health area, from four different professions, judged the likelihood of staff complaining of ULDs in a number of written work scenarios containing ULD risk factors. A student group (n = 148) taking an introductory ergonomics module was used as a reference. The ergonomists scored higher on the CWS index than all of the other groups, performing significantly better than all but the occupational health advisors. Performance improved with increased training level but not with experience. This study suggests that ergonomists are quantifiably different from other ergonomics advisors in their judgement performance in this context. Given the global cost of musculoskeletal disorders, assessing the expertise of those giving ergonomics advice for the management of musculoskeletal health is of great significance. This study presents a method for assessing judgement performance in ULD risk assessment, an important part of musculoskeletal health management.     

Soil wetness as an indicator of stream salinity: a landscape position index approach

Dryland salinity is a major environmental issue in much of Australia’s agricultural lands and is expressed as salt affected land or degraded stream water quality. Maps showing areas at risk of land and stream degradation are needed by regional, state and national management and planning authorities, as well as farmers. Part of the management involves establishing end-of-valley targets for water quality. Developing maps of salinity risk is limited by the availability of appropriate spatial data. Elevation data at appropriate scales are available for all Australia.This paper explores the potential to develop catchment and regional scale soil wetness maps, based only on elevation data, as a surrogate for stream salinity risk. Soil wetness indices were derived through the Fuzzy Landscape Analysis GIS (FLAG) model. While FLAG avoids the direct use of process models it uses process understanding. It does this through an index-based approach that requires a training set of areas of wetness, salinity or other attribute associated with position in the landscape. We test whether only one of the FLAG landscape position indices (UPNESS), that has been shown to characterise depositional zones, is correlated to baseflow stream salinity.UPNESS is the uphill area monotonically above each point in the landscape, and is a specialised form of contributing area, a measure of surface and sub-surface water accumulation. This measure characterises catchments as the ‘connectedness’ of drainage or prevalence of runoff sinks. It distinguishes, for example, between freely drained catchments and those with more extensive depositional zones that allow the accumulation and storage of salt and formation of preferential pathways in the system.FLAG analysis was applied over an area of ~12 000 km² in southeastern Australia where salinity research was being conducted by state agencies. Stream electrical conductivity measurements were obtained to compare with the UPNESS index. The results suggest that the model is useful for targeting further investigations in regional scale salinity management planning and research. FLAG is suggested as a first step for obtaining a highly visual rapid assessment of potential wetness, discharge and salinisation at catchment scales.     

A new measure of index assignment in dynamic channels

In dynamic noisy communication channels, a channel bit error rate (BER) varies with time. When channel distortion measure D_c is a function of bit error rate, an optimal index assignment to minimize D_c is not as uniformly optimal as BER varies. The paper presents a new distortion measure called expected channel distortion (ECD). It is independent of the bit error rate by two proposed beta-type distributions in a multiple-error pattern. Additionally, any index assignment algorithm with ECD measure is mismatch-free. In other words, index assignment algorithms can be against channel mismatch even though BER varies with time in dynamic channels. The voice digitization in North American Telephone Systems (CCITT) is adopted to demonstrate the usefulness of the proposed measure.     

A study of dynamic finite size scaling behavior of the scaling functions—calculation of dynamic critical index of Wolff algorithm

In this work we have studied the dynamic scaling behavior of two scaling functions and we have shown that scaling functions obey the dynamic finite size scaling rules. Dynamic finite size scaling of scaling functions opens possibilities for a wide range of applications. As an application we have calculated the dynamic critical exponent (z) of Wolff's cluster algorithm for 2-, 3- and 4-dimensional Ising models. Configurations with vanishing initial magnetization are chosen in order to avoid complications due to initial magnetization. The observed dynamic finite size scaling behavior during early stages of the Monte Carlo simulation yields z for Wolff's cluster algorithm for 2-, 3- and 4-dimensional Ising models with vanishing values which are consistent with the values obtained from the autocorrelations. Especially, the vanishing dynamic critical exponent we obtained for d=3 implies that the Wolff algorithm is more efficient in eliminating critical slowing down in Monte Carlo simulations than previously reported.     

水文桥测车防倾支杆缺陷及应对策略

为防止桥测车在桥上测验时发生侧翻倾覆事故,对采用单点支撑防倾支杆的桥测车工作时的安全性进行分析,结果表明 EQC-2 型桥测车单点支撑防倾支杆存在一定的安全稳定缺陷。针对单点支撑防倾支杆存在的缺陷,优化设计一种三角形结构防倾支杆,即在单点支撑防倾支杆上加装 1 根斜支杆,使斜支杆的一端与单点支撑防倾支杆的底部相连,另一端与吊臂相连,使斜支杆、单点支撑防倾支杆与吊臂之间形成一个三角形结构,并与采用单点支撑防倾支杆的桥测车在工作时最大挂载量、侧滑和侧翻等方面进行对比分析。结果表明：采用三角形结构防倾支杆的桥测车各项指标均明显优于采用单点支撑防倾支杆的桥测车,对桥测车在今后有关设计方面的改进具有一定的参考意义。     

Measuring social behaviour as an indicator of experience

This paper explores and evaluates two techniques that measure aspects of social behaviour as an indicator of experience. The rationale driving the work is the idea that experience is entwined with social interaction and so, while experience itself is difficult to quantify, we might tap into it by measuring aspects of conversation that are related to it. Two techniques are considered as possible ways of doing this: (i) process measures of social behaviour derived from video analysis and (ii) thin-slice ratings ascribed by naïve judges. Regarding (i), process measures of conversational equality, freedom and number of turns are shown to be reliable, sensitive and linked to unfolding experience. Regarding (ii), a Thin Slice Enjoyment Scale is developed and shown to be a reliable and less time-consuming, but also less sensitive, alternative to the process measures. Both methods are of interest to researchers and practitioners who would wish to assess user experience in a group context. Additionally, analysis of the process measures is of broader relevance to researchers who conduct quantitative analyses of talk.     

Constructing a dynamic stock portfolio decision-making assistance model: using the Taiwan 50 Index constituents as an example

There are several decisions in investment management process. Security selection is the most time-consuming stage. Tatical allocation is in order to take advantage of market opportunities based on short-term prediction (Amenc and Le Sourd in Portfolio theory and performance analysis. Wiley, 2003). Although it is difficult to keep track of the fluctuations of volatile financial markets, the capacity of artificial intelligence to perform spatial search and obtain feasible solutions has led to its recent widespread adoption in the resolution of financial problems. Classifier systems possess a dynamic learning mechanism, they can be used to constantly explore environmental conditions, and immediately provide appropriate decisions via self-aware learning. This study consequently employs a classifier system in conjunction with real number encoding to investigate how to obtain optimal stock portfolio based on investor adjustment cycle. We examine the constituents of the TSEC Taiwan 50 Index taking moving average (MA), stochastic indicators (KD), moving average convergence divergence (MACD), relative strength index (RSI) and Williams %R (WMS %R) as input factors, adopting investor-determined adjustment cycle to allocate capital, and then constructing stock portfolio. We have conducted empirical testing using weekly and monthly adjustment cycle; the results revealed that this study’s decision-making assistance model yields average annual interest rate of 49.35%, which is significantly better than the −6.59% of a random purchase model. This research indicates that a classifier system can effectively monitor market fluctuations and help investors obtain relatively optimal returns. The assistance model proposed in this study thus can provide really helpful decision-making information to investors.     

带时间窗口动态车辆路径规划模型及其求解算法

基于事件触发,把带时间窗口动态车辆路径规划问题（DVRPTW）分解成一系列延迟快照,在快照基础上建立相应的动态数学模型,并提出双缓冲区改进大邻域搜索算法进行求解。利用算法的特点,实现新请求无缝插入。采用Solomon设计的56个100节点范例和Lackner相应的动态测试数据,经不同类型动态实例的实验表明,所建立的模型和给出的算法是有效的。     

Acoustic environment as an indicator of social and physical context

Acoustic environments provide many valuable cues for context-aware computing applications. From the acoustic environment we can infer the types of activity, communication modes and other actors involved in the activity. Environmental or background noise can be classified with a high degree of accuracy using recordings from microphones commonly found in PDAs and other consumer devices. We describe an acoustic environment recognition system incorporating an adaptive learning mechanism and its use in a noise tracker. We show how this information is exploited in a mobile context framework. To illustrate our approach we describe a context-aware multimodal weather forecasting service, which accepts spoken or written queries and presents forecast information in several forms, including email, voice and sign languages.

Automatic detection of accommodation steps as an indicator of knowledge maturing

Jointly working on shared digital artifacts - such as wikis - is a well-tried method of developing knowledge collectively within a group or organization. Our assumption is that such knowledge maturing is an accommodation process that can be measured by taking the writing process itself into account. This paper describes the development of a tool that detects accommodation automatically with the help of machine learning algorithms. We applied a software framework for task detection to the automatic identification of accommodation processes within a wiki. To set up the learning algorithms and test its performance, we conducted an empirical study, in which participants had to contribute to a wiki and, at the same time, identify their own tasks. Two domain experts evaluated the participants’ micro-tasks with regard to accommodation. We then applied an ontology-based task detection approach that identified accommodation with a rate of 79.12%. The potential use of our tool for measuring knowledge maturing online is discussed.     

Effects of the presentation characteristics of dual dynamic information text on comprehension using an LCD monitor

Abstract— This study investigated the effects of the presentation method, presentation rate, type of flickering character presented in a dynamic headline, and spacing between the headline and the display window on reading moving Chinese text in a single‐line display. Eighty‐three subjects aged 14–18 years of age completed 27 experimental treatments consisting of three presentation methods (i.e., leading format, rapid serial visual presentation (RSVP), with full display window, and RSVP with clause), three presentation rates (80, 155, and 230 cpm), and three types of flickering characters (twinkling, rotating, and shrinking) presented in a headline. The spacing between the headline and the display window (0.4 vs. 0.7 vs. 1.0 cm) served as the between‐subjects factor. Results showed that comprehension accuracy was lower for dynamic text presented in the leading format than for that presented in the RSVP format with a full display window or with clause. Comprehension accuracy was also lower in response to a presentation rate of 230 cpm than to a presentation rate of 80 cpm. Analyses indicated that the spacing between the headline and the display window significantly affected comprehension accuracy; the rate of accurate responses was greater with a spacing of 1.0 cm than with a spacing of 0.4 cm. However, the type of flickering characters did not significantly affect comprehension accuracy. Implications of these results for designing dynamically presented Chinese text on a Web site are discussed.     

Resource allocation efficiency as an indicator of boredom,work performance and absence

Boredom has been implicated in a range of unfortunate behaviours from absenteeism to substance abuse. Here resource allocation efficiency is proposed as a proximal indicator of both boredom and work behaviour. Clerical volunteers (N = 89) completed a series of computer-based tasks in which puzzle-solving speed was taken as an indicator of resource allocation efficiency. Individual variability in puzzle-solving speed correlated, as predicted, with accuracy of work (r =-0.35, p< 0.01) and days absence (r = + 0.26, p< 0.05) as recorded in annual staff appraisals. Both these behaviours are considered boredom sensitive. These experiments suggest a direct way of predicting the consistency of key work-related behaviours.     

Decrease of force capabilities as an index of upper limb fatigue

The aim of the study was to assess upper limb fatigue on the basis of the force change index (FCI), which expresses changes in developed force, and to demonstrate that this index differentiates muscle fatigue of the upper limb depending on external load. The study was performed on ten young men in 12 conditions of external load. Ten conditions characterized repetitive work in a two-period cycle, in which both or one of the periods were loaded, and two conditions characterized continuous work with constant load. The participants tried to maintain hand-grip force at an imposed level during a determined time in the standard upper limb posture. Changes in values of recorded force exerted during successive cycles were approximated by a regression function. In most cases there was a strong correlation between the measurement data and the logarithmic regression curve. However, several cases of lower external load showed absence of such correlation. In 75% of the cases, there were statistically significant differences between the values of FCI calculated for individual conditions of external load. That means that FCI not only expresses muscle fatigue quantitatively but also points to the differences in upper limb fatigue resulting from differences in the external load. The study results have shown that the developed index (FCI) can be applied for fatigue assessment and discrimination with a more sophisticated model of a repetitive task than just a simple two-period work and rest model.     

Interval optimization of rotor-bearing systems with dynamic behavior constraints using an interval genetic algorithm

A new interval optimization algorithm is presented in this paper. In engineering, most optimization algorithms focus on exact parameters and optimum objectives. However, exact parameters are not easy to be manufactured to because of manufacturing errors and expensive manufacturing cost. To account for these problems, it is necessary to estimate interval design parameters and allowable objective error. This is the first paper to propose a new interval optimization algorithm within the context of Genetic Algorithms. This new algorithm, the Interval Genetic Algorithm (IGA), can neglect interval analysis and determines the optimum interval parameters. Furthermore, it can also effectively maximize the design scope. The optimizing ability of the IGA is tested through the interval optimization of a two-dimensional function. Then the IGA is applied to rotor-bearing systems. The results show that the IGA is effective in deriving optimal interval design parameters within the allowable error when minimizing shaft weight and/or transmitted force of rotor-bearing systems.     

Solving a multi-floor layout design model of a dynamic cellular manufacturing system by an efficient genetic algorithm

This paper presents a mixed-integer programming model for a multi-floor layout design of cellular manufacturing systems (CMSs) in a dynamic environment. A novel aspect of this model is to concurrently determine the cell formation (CF) and group layout (GL) as the interrelated decisions involved in the design of a CMS in order to achieve an optimal (or near-optimal) design solution for a multi-floor factory in a multi-period planning horizon. Other design aspects are to design a multi-floor layout to form cells in different floors, a multi-rows layout of equal area facilities in each cell, flexible reconfigurations of cells during successive periods, distance-based material handling cost, and machine depot keeping idle machines. This model incorporates with an extensive coverage of important manufacturing features used in the design of CMSs. The objective is to minimize the total costs of intra-cell, inter-cell, and inter-floor material handling, purchasing machines, machine processing, machine overhead, and machine relocation. Two numerical examples are solved by the CPLEX software to verify the performance of the presented model and illustrate the model features. Since this model belongs to NP-hard class, an efficient genetic algorithm (GA) with a matrix-based chromosome structure is proposed to derive near-optimal solutions. To verify its computational efficiency in comparison to the CPLEX software, several test problems with different sizes and settings are implemented. The efficiency of the proposed GA in terms of the objective function value and computational time is proved by the obtained results.     

Feedback control of the level of arousal using skin potential level as an index

Skin potential level (SPL) on the palmar surface reduces its electro-negativity at the early stage of sleep and recovers it on waking up. This phenomenon suggests a close relationship between SPL and arousal change. The relationship and its applicability were studied by two experiments in which a vigilance task was imposed on subjects. In the first experiment the relation between changes in SPL and decrement of arousal level was examined. The results showed that electro-negativity in SPL reduced corresponding to the decrease of arousal level measured by task performance. On treatment of SPL, range correction was effective in reducing the individual difference. In the second experiment the above results were applied to designing a means to control the level of arousal and to finding the possibility of keeping a high level of arousal during the vigilance task. In the experiment a bell sound was released to arouse subjects when their SPL reached a pre-set threshold level. The decrement of arousal level which would cause behavioural errors was avoided by choosing the threshold level within a suitable range. This technique may be applicable to a doze alarm system for motor-vehicle drivers, aeroplane pilots, etc.     

Fractional order fuzzy-PID control of a combined cycle power plant using Particle Swarm Optimization algorithm with an improved dynamic parameters selection

The effectiveness of the Particle Swarm Optimization (PSO) algorithm in solving any optimization problem is highly dependent on the right selection of tuning parameters. A better control parameter improves the flexibility and robustness of the algorithm. In this paper, a new PSO algorithm based on dynamic control parameters selection is presented in order to further enhance the algorithm's rate of convergence and the minimization of the fitness function. The powerful Dynamic PSO (DPSO) uses a new mechanism to dynamically select the best performing combinations of acceleration coefficients, inertia weight, and population size. A fractional order fuzzy-PID (fuzzy-FOPID) controller based on the DPSO algorithm is proposed to perform the optimization task of the controller gains and improve the performance of a single-shaft Combined Cycle Power Plant (CCPP). The proposed controller is used in speed control loop to improve the response during frequency drop or change in loading. The performance of the fuzzy-FOPID based DPSO is compared with those of the conventional PSO, Comprehensive Learning PSO (CLPSO), Heterogeneous CLPSO (HCLPSO), Genetic Algorithm (GA), Differential Evolution (DE), and Artificial Bee Colony (ABC) algorithm. The simulation results show the effectiveness and performance of the proposed method for frequency drop or change in loading.     

Linear temporal characteristics of heart interbeat interval as an index of the pilot's perceived risk

The concept of adaptive automation is the first commendable step towards machine monitoring and support of the human operator behaviour and performance. Despite a large number of studies, the concept is still not sufficiently mature and more experimental studies are required to enable its application in the real world. As a small contribution in this direction, this experimental study made an effort to develop some techniques for online assessment of the pilot's perceived risk of the consequences resulting from their inability to execute a task adequately. Linear dynamical characteristics of 60 pilot's heart interbeat intervals were used for the assessment. Past research has shown that such ‘perceived risk’ influences the pilot's need for an automation aid. The preliminary results of this study suggested that the frequency and power of the heart interbeat interval dominant cycle, together with the characteristics of the energy contained in the power spectrum, can be sensitive indices of the level of perceived risk. The study techniques and preliminary results appear promising for incorporation into the algorithm of an intelligent online monitoring and alerting system on future aerospace vehicles to define the moments when the human supervisory controllers require an automation aid.     

基于氧化石墨烯/金纳米粒子放大电信号的二茂铁标记型溶菌酶适体传感器

设计了一种简单的信号衰减型电化学溶菌酶适体传感器。以氧化石墨烯修饰的玻碳电极为基底（GO/GCE）,通过循环伏安法电沉积金纳米粒子在电极表面,得到AuNPs/GO/GCE。将3’端修饰巯基的单链DNA通过金硫键共价连接于电极上,而在与前者可部分杂交的适体探针链5’端标记上二茂铁甲酸。当目标物溶菌酶与适体探针链发生特异性结合,通过示差脉冲伏安法检测到二茂铁甲酸还原峰电流相应的改变,从而实现对溶菌酶的识别及定量检测。结果表明,该传感器对溶菌酶具有较好的选择性和灵敏度,对于溶菌酶的检测范围为1.08×10-11～1.08×10-8mol/L,检出限达到6.02×10-12mol/L。     

Robust tracking of the heating value in an underground coal gasification process using dynamic integral sliding mode control and a gain-scheduled modified Utkin observer

In this paper, a model-based control and state reconstruction of an underground coal gasification (UCG) process is elaborated. In order to deploy model-based control strategies, a sophisticated model of the UCG process based on partial differential equations is approximated with a nonlinear control-oriented model that adequately preserves the fundamental dynamic characteristics of the process. A robust dynamic integral sliding mode control (DISMC) is designed based on the control-oriented model to track the desired heating value, which is one of the key indicators for evaluating the performance of an UCG process. Unknown states required for the model-based control are reconstructed using a gain-scheduled modified Utkin observer (GSMUO). In order to assess the robustness of the nonlinear control and estimation techniques, the water influx phenomenon is considered as an input disturbance. Moreover, the underlying UCG plant model is subjected to parametric variations as well as measurement noise. In order to guarantee the stability of the overall system, the boundedness of the internal dynamics is also proved. To make a fair comparison, the performance of the proposed controller is compared with an integral sliding mode control (ISMC) and a classical proportional-integral (PI) controller. Simulation results highlight the effectiveness of the proposed control scheme in terms of minimum control energy and improved tracking error. Moreover, the simulation study shows that the combination of DISMC and GSMUO exhibit robustness against an input disturbance, parametric uncertainties and measurement noise.