Influence of step complexity and presentation style on step performance of computerized emergency operating procedures

With the development of information technology, computerized emergency operating procedures (EOPs) are taking the place of paper-based ones. However, ergonomics issues of computerized EOPs have not been studied adequately since the industrial practice is quite limited yet. This study examined the influence of step complexity and presentation style of EOPs on step performance. A simulated computerized EOP system was developed in two presentation styles: Style A: one- and two-dimensional flowcharts combination; Style B: two-dimensional flowchart and success logic tree combination. Step complexity was quantified by a complexity measure model based on an entropy concept. Forty subjects participated in the experiment of EOP execution using the simulated system. The results of data analysis on the experiment data indicate that step complexity and presentation style could significantly influence step performance (both step error rate and operation time). Regression models were also developed. The regression analysis results imply that operation time of a step could be well predicted by step complexity while step error rate could only partly predicted by it. The result of a questionnaire investigation implies that step error rate was influenced not only by the operation task itself but also by other human factors. These findings may be useful for the design and assessment of computerized EOPs.     

Development of the step complexity measure for emergency operating procedures using entropy concepts

For a nuclear power plant (NPP), symptom-based emergency operating procedures (EOPs) have been adopted to enhance the safety of NPPs through reduction of operators’ workload under emergency conditions. Symptom-based EOPs, however, could place a workload on operators because they have to not only identify related symptoms, but also understand the context of steps that should be carried out. Therefore, many qualitative checklists are suggested to ensure the appropriateness of steps included in EOPs. However, since these qualitative evaluations have some drawbacks, a quantitative measure that can roughly estimate the complexity of EOP steps is imperative to compensate for them.In this paper, a method to evaluate the complexity of an EOP step is developed based on entropy measures that have been used in software engineering. Based on these, step complexity (SC) measure that can evaluate SC from various viewpoints (such as the amount of information/operators’ actions included in each EOP step, and the logic structure of each EOP step) was developed.To verify the suitableness of the SC measure, estimated SC values are compared with subjective task load scores obtained from the NASA-TLX (task load index) method and step performance time obtained from a full scope simulator. From these comparisons, it was observed that estimated SC values generally agree with the NASA-TLX scores and step performance time data. Thus, it could be concluded that the developed SC measure would be considered for evaluating SC of an EOP step.     

A study on the effect of training interval on the use of computerized emergency operatingprocedures

The increase in complexity and the use of computerized displays in the control systems of nuclear power plants have brought new issues related to the training of operators, especially for emergency situations that are known to be very stressful. This study focuses on how the time interval between training sessions can affect the performance (operation time and error rate) of operators using computerized emergency operating procedures. Three levels of time interval (one week, two weeks, and four weeks) were examined. The results indicate significant influence of time interval on operation performance. In general, frequent training results in shorter operation time but not necessarily lower error rate. Learning and forgetting effects can be seen in the retraining process.     

The step complexity measure for emergency operating procedures — comparing with simulation data

In complex systems, such as nuclear power plants (NPPs) or airplane control systems, human errors play a major role in many accidents. Therefore, to prevent occurrences of accidents or to ensure system safety, extensive effort has been made to identify significant factors that cause human errors. According to related studies, written manuals or operating procedures are revealed as one of the most important factors, and complexity or understandability of a procedure is pointed out as one of the major reasons that make procedure-related human errors.Many qualitative checklists are suggested to evaluate emergency operating procedures (EOPs) of NPPs. However, since qualitative evaluations using checklists have some drawbacks, a quantitative measure that can quantify the complexity of EOPs is imperative to compensate for them.In order to quantify the complexity of EOPs, Park et al. suggested the step complexity (SC) measure to quantify the complexity of a step included in EOPs. In this paper, to ensure the appropriateness of the SC measure, SC scores are compared with averaged step performance time data obtained from emergency training records. The total number of available records is 36, and training scenarios are the loss of coolant accident and the excess steam dump event. The number of scenario is 18 each. From these emergency training records, step performance time data for 39 steps are retrieved, and they are compared with estimated SC scores of them. In addition, several questions that are needed to clarify the appropriateness of the SC measure are also discussed.As a result, it was observed that estimated SC scores and step performance time data have a statistically meaningful correlation. Thus, it can be concluded that the SC measure can quantify the complexity of steps included in EOPs.     

A study on the validity of a task complexity measure for emergency operating procedures of nuclear power plants—Comparing task complexity scores with two sets of operator response time data obtained under a simulated SGTR

The appropriateness of the task complexity (TACOM) measure that can quantify the complexity of procedural tasks was validated in this study. To this end, two sets of task performance time data that have been extracted under the simulated steam generator tube rupture (SGTR) conditions of the reference nuclear power plant (NPP) A and B were compared with the associated TACOM scores. As a result, it was observed that two sets of task performance time data seem to be soundly explained by the associated TACOM scores. Although more additional activities should be conducted to clarify the appropriateness of the TACOM measure, the result of this study provides a crucial clue supporting that the complexity of emergency tasks stipulated in emergency operating procedures (EOPs) can be properly quantified by the TACOM measure.     

Solid carriers for improved solubility of glipizide in osmotically controlled oral drug delivery system

The purpose of this study was to increase the solubility of glipizide (gli) by solid dispersions SDs technique with polyvinylpyrrolidone (PVP) in aqueous media. The gli-PVP solid dispersion systems was prepared by physical mixing or spray drying method, and characterized by differential scanning calorimetry (DSC), X-ray powder diffraction (XRD) analysis, Fourier transformation-infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM). The elementary osmotic pumps (EOPs) were prepared with gli-PVP complex and the effect of the PVP percentages on the enhancing of gli dissolution rate was studied. The influences of various parameters e.g., drug- PVP ratio, level of solubility modifier, coating weight gain and diameter of drug releasing orifice on drug release profiles were also investigated. The solubility and dissolution rates of gli were significantly increased by solid dispersion using spray dried method as well as their physical mixture. The obtained results indicated that gli-PVP solid dispersion system has suitable solubility behavior in EOP tablets.     

The effect of two complexity factors on the performance of emergency tasks—An experimental verification

It is well known that the use of procedures is very important in securing the safety of process systems, since good procedures effectively guide human operators by providing ‘what should be done’ and ‘how to do it’, especially under stressful conditions. At the same time, it has been emphasized that the use of complicated procedures could drastically impair operators’ performance. This means that a systematic approach that can properly evaluate the complexity of procedures is indispensable for minimizing the side effects of complicated procedures. For this reason, Park et al. have developed a task complexity measure called TACOM that can be used to quantify the complexity of tasks stipulated in emergency operating procedures (EOPs) of nuclear power plants (NPPs). The TACOM measure consists of five sub-measures that can cover five important factors making the performance of emergency tasks complicated. However, a verification activity for two kinds of complexity factors—the level of abstraction hierarchy (AH) and engineering decision (ED)—seems to be insufficient. In this study, therefore, an experiment is conducted by using a low-fidelity simulator in order to clarify the appropriateness of these complexity factors. As a result, it seems that subjects’ performance data are affected by the level of AH as well as ED. Therefore it is anticipate that both the level of AH and ED will play an important role in evaluating the complexity of EOPs.     

The step complexity measure for emergency operating procedures: measure verification

In complex systems, such as nuclear power plants (NPPs) or airplane control systems, human errors play a major role in many accidents. Therefore, to prevent an occurrence of accidents or to ensure system safety, extensive effort has been made to identify significant factors that can cause human errors. According to related studies, written manuals or operating procedures are revealed as one of the most important factors, and the understandability is pointed out as one of the major reasons for procedure-related human errors.Many qualitative checklists are suggested to evaluate emergency operating procedures (EOPs) of NPPs. However, since qualitative evaluations using checklists have some drawbacks, a quantitative measure that can quantify the complexity of EOPs is very necessary to compensate for them.In order to quantify the complexity of steps included in EOPs, Park et al. suggested the step complexity (SC) measure. In addition, to ascertain the appropriateness of the SC measure, averaged step performance time data obtained from emergency training records for the loss of coolant accident and the excess steam dump event were compared with estimated SC scores. Although averaged step performance time data show good correlation with estimated SC scores, conclusions for some important issues that have to be clarified to ensure the appropriateness of the SC measure were not properly drawn because of lack of backup data.In this paper, to clarify remaining issues, additional activities to verify the appropriateness of the SC measure are performed using averaged step performance time data obtained from emergency training records. The total number of available records is 36, and training scenarios are the steam generator tube rupture and the loss of all feedwater. The number of scenarios is 18 each. From these emergency training records, averaged step performance time data for 30 steps are retrieved.As the results, the SC measure shows statistically meaningful correlation with averaged step performance time data. In addition, since it is observed that the SC measure seems to have the procedure independent property (i.e. steps that have similar SC scores, whether they are included in different procedures or not, would have similar step performance time), it can be concluded that the SC measure can represent the complexity of steps included in EOPs.     

Solid Carriers for Improved Solubility of Glipizide in Osmotically Controlled Oral Drug Delivery System

The purpose of this study was to increase the solubility of glipizide (gli) by solid dispersions SDs technique with polyvinylpyrrolidone (PVP) in aqueous media. The gli–PVP solid dispersion systems was prepared by physical mixing or spray drying method, and characterized by differential scanning calorimetry (DSC), X-ray powder diffraction (XRD) analysis, Fourier transformation-infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM). The elementary osmotic pumps (EOPs) were prepared with gli–PVP complex and the effect of the PVP percentages on the enhancing of gli dissolution rate was studied. The influences of various parameters e.g., drug- PVP ratio, level of solubility modifier, coating weight gain and diameter of drug releasing orifice on drug release profiles were also investigated. The solubility and dissolution rates of gli were significantly increased by solid dispersion using spray dried method as well as their physical mixture. The obtained results indicated that gli–PVP solid dispersion system has suitable solubility behavior in EOP tablets.     

Development of an Electroosmotic Pump Using Nanosilica Particle Packed Capillary

High-pressure electroosmotic pumps (EOPs) operate on the principle that electroosmotic flow (EOF) can be generated through a packed-bed capillary by applying an electric field through it. In this paper, a novel packed-bed EOP design using nanosilica particles is described. The packed-bed capillary was fabricated using a capillary of 5 cm x 530 mum i.d. close packed with silica particles having an average particle size of 20-30 nm. The flow rates, pressures and pressure/flow rate (P-Q)characteristics, electric properties of the pump and the influence of phosphate buffer concentration on the pump were carefully studied. By increasing the pressure, decreasing the applied voltage, and the electric current, the thermodynamic efficiency was about 1%-2% for inorganic buffers and 3%-5% for organic solvents or their mixture without ions.     

营运驾驶员驾驶风格研究

目的探索了解我国营运驾驶员的驾驶风格特点,以及驾驶风格与交通违规之间的关系。方法在辽宁省沈阳、大连两个城市现场选取170名营运驾驶员完成中文版驾驶风格量表。结果驾驶风格的性别差异显著。男性驾驶风格以冒险型和愤怒型为主,女性驾驶风格以焦虑型为主。驾驶员在感觉寻求、愤怒、分心维度上的得分随着年龄的增长而下降。有交通违规记录的驾驶员在愤怒、冒险、分心和焦虑维度上的得分均高于无违规记录的驾驶员,且差异显著。结论驾驶员的驾驶风格越倾向于冒险型、愤怒型和焦虑型,他们的交通违规次数也越多,应当针对危险驾驶行为采取适当有效的预防和干预措施。     

风险偏好类型与风险判断模式的实验分析

测量了被试的风险偏好类型及其对一系列风险投资项目的风险判断值，从而分析风险偏好类型、任务结构与风险判断模式的特征之间的关系。研究发现有４种风险偏好。不同风险偏好类型、不同的风险判断任务结构会对风险判断模式产生不同的影响。双极值的任务结构与风险偏好的交互作用显著，而单极值的任务结构与风险偏好类型的交互作用不显著。被试的风险偏好类型在很大程度上影响了被试的风险判断模式。另外还讨论了影响风险判断偏差的一些因素以及任务结构对风险敏感度的影响等。     

Human Reliability Analysis in Spaceflight Applications,Part 2: Modified CREAM for Spaceflight

Human reliability analysis is a crucial for manned spaceflight success. Cognitive Reliability Error Analysis Model (CREAM) has been developed and used by the nuclear industry in predicting human error. Previously, the authors have calculated the probability error for an International Space Station ingress procedure using performance shaping factors (PSF). In this paper, the procedural risk under both ideal and common conditions using the new spaceflight specific PSFs is calculated. The risk was found to vary from the risk calculated using standard PSFs and to vary greatly depending on the spacecraft specific conditions. Under ideal conditions, the risk was found to be 1 in 88, but under common conditions, the risk was 1 in 3. Then, the new PSFs were used to analyze the impact of the three styles of training used at NASA under common conditions. Of skill‐based training, task‐based training, and knowledge‐based training, the CREAM analysis using the new PSFs showed that skill‐based training resulted in the most significant improvement in the risk of human error, from 1 in 3 to 1 in 11. Copyright © 2013 John Wiley & Sons, Ltd.     

虚拟现实中多通道信息呈现方式的认知负荷定量研究

目的 针对虚拟现实体验系统中的不同信息呈现方式,对使用者交互效率影响难以确定及量化的问题,进行定量研究。方法 通过搭建虚拟现实场景,以信息呈现通道的类别与数量作为变量,展开跟踪–检测响应双任务实验;通过记录任务行为数据中的跟踪误差和响应时间,以及生理数据中的瞳孔直径大小,分析并讨论在不同通道刺激影响因素下的实验中,任务绩效及眼动生理反应变化规律;同时结合主观负荷评价数据,建立了基于BP神经网络的多通道认知负荷模型,以认知负荷作为交互效率的综合评价指标,量化任务执行效率。结果 信息呈现的通道类别及其数量对任务效率均有显著的影响。结论 信息呈现通道数量与任务绩效及生理反应呈一定程度的正相关;多个任务使用相同通道呈现信息会损害所有任务的绩效,增加认知负荷。模型输出的负荷值与主观认知负荷评估值吻合较好,相对误差为8.2%,验证了其有效性。     

扁平化时代风格的族群演进:2013——2020 年

目的探索扁平化时代下中国移动端界面的风格旅群演进情况，描绘了2013- 2020年间主流界面风格的发展全 貌及其演进机制。方法从扇平化风格三源头的关系辨析出发梳理了扇平化时代到来后20余种主流设计风格的成因、特征、分类、流变和相互关系,并沿着3条演进脉絡展开论证:第一，“伪扇平”时代经历了“选择适应期"“视效丰富期"和“质料表达期”3个阶段，其新生风格主要源于突破“扇平面本体”的设计规则限定;第二,基于扁平化风格要素,衍生出“复古初期特征”及“表达技法仿拟”2个风格组团;第三,新复古主义风格则平行架空于磨平化之上，与肩平化呈现出此消彼长的态势。上述风格发展遵循扁平化与报物化矛盾统一的底层逻辑,并呈现出“物竞天择”“适者生存”的进化论特征。结论风格演进的内因受社会观念与申美异化驱动,外因则与传播媒介发展有关。未来基于碎片化“风格模因”的合成风格流行将是一大趋势,公众将成为新风格的创造主体。     

Styles of learning,designing and computing

People differ in the basic cognitive styles that they bring to any learning task. Their learning can be severely impaired if they are mismatched with teachers who prefer, or teaching programmes which impose, a different learning style. The introduction of specific design strategies can also result in a mismatch between the cognitive style of the designer and that implicit in the strategy. In general, designers prefer a holistic, solution-focused strategy rather than an analytic, problem-focused one. Differences in cognitive style may reflect fundamental neurological differences in the two hemispheres of the brain. The left brain dominates in propositional modes of thought, and the right brain dominates in appositional modes. This creates further problems of mismatch between the predominantly appositional cognitive style of designers and the propositional style of computers.     

Identifying cognitive complexity factors affecting the complexity of procedural steps in emergency operating procedures of a nuclear power plant

In complex systems such as a nuclear and chemical plant, it is well known that the provision of understandable procedures that allow operators to clarify what needs to be done and how to do it is one of the requisites to secure their safety.As a previous study in providing understandable procedures, the step complexity (SC) measure that can quantify the complexity of procedural steps in emergency operating procedures (EOPs) of a nuclear power plant (NPP) was suggested. However, the necessity of additional complexity factors that can consider a cognitive aspect in evaluating the complexity of procedural steps is raised.To this end, the comparisons between operators' performance data measured by the form of a step performance time with their behavior in carrying out the prescribed activities of procedural steps are conducted in this study. As a result, two kinds of complexity factors (the abstraction level of knowledge and the level of engineering decision) that could affect an operator's cognitive burden are identified.Although a well-designed experiment is indispensable for confirming the appropriateness of the additional complexity factors, it is strongly believed that the change of operators' performance data can be more authentically explained if the additional complexity factors are taken into consideration.     

纸基摩擦材料纤维、树脂含量和孔隙率对压缩回弹性能的影响

纸基摩擦材料属多孔材料，其摩擦磨损性能与压缩回弹性能密切相关。研究了纸基摩擦材料纤维的含量及类型、树脂的含量，以及材料的孔隙率对其压缩回弹性能的影响。结果表明，材料配方及孔隙率会显著改变材料的压缩率和回弹率。纤维和树脂含量的增加都会造成纸基摩擦材料压缩率的降低和回弹率的升高。其中，树脂含量对材料压缩率的影响较大，纤维含量对材料回弹率的影响较大。加入混杂纤维的材料比较单纯采用芳纶纤维浆粕的材料具有更低的压缩率和更高的回弹率，其中混杂有纸浆纤维的材料压缩回弹性能最好。纸基材料的孔隙率越大，材料压缩率越大，回弹率越低。     

当代商业广告平面设计风格探析

当代商业广告平面设计风格,从表达方式看可划分为豪放型与婉约型两类.以消费者认知心理学角度为切入点,对这两种风格作用于消费者心理因素方面所产生的异同影响做了详细分析与比较,并给出两种风格的特点及适用范围.     

The effect of task complexity on the human learning function

This experimental study analysed the effects of the complexity (entropy) of a repetitive tusk on the human looming function for the task. The results from 20 subjects revealed that the task entropy had a significant influence on the relationship between the performance (cycle time) and practice (the number of repetitions or cycle number). The model parameters for this relationship were found to be significantly and linearly related to the task entropy, the nominal rate of which varied within the maximum range of 0·9·to 6.1 bits/s