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1.
《Ergonomics》2012,55(8):1083-1094
Abstract

Chinese text segments were sequentially presented to a single location of a computer screen at rates of 300 and 600 characters per min (CPM). These segments were either structured ‘idea units’ or random segments of equal length. The random segments were shown for equal amounts of time (the uniform condition). The display duration for each idea unit was determined either by its physical size (the structured-fixed condition) or according to the mean reading time in self-paced reading task of a pilot study (the structured-observed condition). Reading performance was assessed using multiple choice comprehension questions. Results showed that the two structured conditions were superior to the uniform condition. Also, the good readers performed better in the structured-observed condition than in the structured-fixed condition when the display rate was 600 CPM. When the display rate was 300 CPM, the poor readers showed a similar effect. These results suggest that the structured-observed condition could be superior to other presentation formats for reading sequentially-presented text.  相似文献   

2.
Two experiments are reported which compared proof-reading performance in various VDU display formats. Experiment 1 found that displaying text one paragraph at a time improved the accuracy of performance, relative to a full screen condition, but at the expense of speed. Subjects also preferred using the paragraph format. Display contrast (positive vs negative) had no effect on performance. Experiment 2 supported the findings of Experiment 1, and found increased accuracy when text was further subdivided into sentences, but speed was again reduced. Possible explanations for the format effect are presented, and its practical implications are considered.  相似文献   

3.
文章首先针对DICOM3.0标准,对DICOM医学图象的数据结构进行系统的分析,阐述了文件元信息,数据集和数据元素的格式;然后结合DICOM图象显示的各种方法,创建了DICOM图象显示核心类.并简要描述了部分函数的功能。  相似文献   

4.
目的 随着机载SAR(合成孔径雷达)图像分辨率越来越高,幅宽越来越大,传统雷达显控系统将整幅图像放入内存、抽样显示的现有方法存在内存资源紧张、显示图像的等待时间过长等问题,为解决此类问题,提出一种动态金字塔实时显示技术。方法 机载SAR图像实时显示软件包括动态金字塔构建和显示技术。动态金字塔构建技术包括:当接收到一个瓦片的图像数据时,输出第0层级的金字塔瓦片;分6种情况,生成高层级瓦片,随着接收数据不断增多,逐步补全金字塔文件。动态金字塔显示技术是指在瓦片数据不全的情况下,采用递归算法,读取较低层级瓦片,合成、显示当前显示层级图像的技术。这两种技术分属两个独立线程,以硬盘文件(瓦片)为接口,实时交互,协同工作。结果 机载SAR图像实时显示软件仅仅占用30 MB内存,且与图像大小无关;显示第1块SAR图像瓦片的时延小于1 s,与传统显控系统对比,减少约一帧图像的传输时延;显示整帧图像的时延因存储介质读写文件的速率存在差异较大,固态硬盘的时延比较稳定,显示1 GB图像的时延为12.55 s;机械盘的时延受读写速度的影响,当发送时间间隔大于6 ms时,显示1 GB图像的时延仅比传输时延多1.47 s。结论 机载SAR图像实时显示软件能实时向用户呈现接收中的SAR图像,提高了机载SAR图像的显示时效性,降低了机载雷达显控终端的内存需求,改善了机载雷达显控终端的用户体验。  相似文献   

5.
《Ergonomics》2012,55(3):175-189
It has been suggested that complexity in fault diagnosis tasks is largely a function of problem complexity and little to do with the perceptual complexity of the format in which the system representation is displayed. An experimental study is reported which shows that a left-to-right diagonal display format improves the speed and diagnostic efficiency with which faults are located. The differences in display format which appear to be most beneficial do not affect problem-solving complexity in any obvious way. Differences in display format which could affect problem-solving complexity, such as constraints on direction of signal flow, do not apparently affect fault diagnosis performance. The improvements in performance apparently stem from an increased ability to perceive components of the system relevant to the observed symptoms.  相似文献   

6.
Drawing on the linguistic theory that differentiates between foreground and background content in narratives, this research proposes that consumer product attitude differs significantly between reviews written in the mixed narrative (MN) format and the divided narrative (DN) format. Results of three experiments show that reviewers are more likely to use adversative conjunctions (ACs) in the MN format than in the DN format when composing two-sided reviews. The presence of ACs affects readers’ attitudes by shifting the allocation of attention between positive and negative content in a review. Moreover, this effect is stronger when positive content is presented first.  相似文献   

7.
The time tunnel display design technique combines the benefits of configural displays (salient visual properties corresponding to critical domain semantics) with the benefits of temporal information (i.e., the value of variables and properties over time). In Experiment 1 a baseline configural display and a time tunnel display were evaluated using real-time measures of system control, fault detection, and state estimation in a simulated process control task. The results provided little evidence in support of the time tunnel format. In Experiment 2 access to the temporal context was limited: Participants performed the detection and estimation tasks with static "snapshots" of system states that had been generated in Experiment 1. The overall pattern of results indicates that the time tunnel display was more effective for state estimation tasks than was the baseline configural display and or a trend display. Issues in the design of temporal displays are discussed, including representational formats and the choice of temporal time frames. Issues in the evaluation of temporal displays are also discussed, including the role of temporal information and the critical nature of participants' access to this information. Actual or potential applications of this research include design techniques for improving graphical displays and methodological insights to guide future evaluations.  相似文献   

8.
We report two experiments in which different features of the display of multiple channels of information are varied in their proximity to one another. The display presents three indicators of aircraft stall danger (airspeed, flaps, and bank). On some trials the stall danger is estimated, requiring information integration. On other trials the value of individual indicators is estimated, requiring focused attention. In Experiment 1 the spatial proximity between indicators and their distinctiveness in color were manipulated. Spatial proximity had little effect on either focused attention or integration, whereas a distinct color code improved focused attention and disrupted integration. In Experiment 2 the three indicators were presented as a bar graph or were combined as features of an object display, either with or without color coding of the separate dimension. Relative to the bar graph display, the object display improved information integration but disrupted focused attention. The presence of color borders restored the focused attention accuracy, with a slight cost to response time.  相似文献   

9.
10.
《Ergonomics》2012,55(9):1114-1128
The luminance surrounding a computer display can potentially reduce visibility of the display (disability glare), result in sensations of discomfort (discomfort glare) and result in transient adaptation effects from fixating back and forth between the two luminance levels. The study objective was to measure the effects of surround luminance levels upon these functions in younger and older adults to determine recommended surround luminance levels. The younger age group comprised 20 subjects (mean age 27.9 years, range 23 – 39) and the older group 17 subjects (mean age 55.5 years, range 47 – 63). The central task was presented with luminance of 91 cd/M2, tested surround luminance levels were 1.4, 2.4, 8.9, 25.5, 50, 91, 175, 317, and 600 cd/M2. Disability glare was tested with low contrast (20%) visual acuity charts, transient adaptation was tested with a task that required regular fixation between the two luminance levels, discomfort was measured with a questionnaire after reading stories with different surround luminance levels, and preferred luminance was measured by method of adjustment. The surround luminance significantly affected transient adaptation (p < 0.0001), optimal performance occurred at 50 cd/M2 and above for the young group and at 91 cd/M2 and above for the older group. Neither low contrast acuity (disability glare) nor symptoms when reading were significantly affected by surround luminance. There was wide variation in preferred surround luminance; however, average preferred surround luminance was 86.9 cd/M2 for the young group and 62.2 cd/M2 for the older group, slightly below the central luminance of 91 cd/M2. The effects of the surround luminance within the tested range are not large; however, the data show that the lowest surround luminance levels should be avoided and that surround luminance levels at or slightly below that of the central task are preferred.  相似文献   

11.
The present study examined factors that decreased task complexity so that a technology which temporally, rather than spatially, distributed information (i.e. RAP COM, for rapid communication) would result in performace advantages. This was accomplished by physically integrating the stimulus information into either the display format (i.e. an analog format) or into the response coding scheme (i.e. a colour coding scheme). Performance using the RAP COM display indicated a lower proportion of errors for the analog than for the digital format; however, a longer mean response time for a correct response was found for the analog than for the digital format. Two colour coding response schemes were used: (a)_a continuous scheme that comparised gradual changes between red and blue; (b) a distinctive scheme consisting of the colours cyan, green, yellow, orange, red, mauve, purple and blue. When the continuous colour coding responses scheme was used, performance using the RAP COM display, as compared with the spatial display, was no different after extended practice. The results of these experiments taken together indicate that the RAP COM display type may be a viable technology for some limited ‘real world’ environments.  相似文献   

12.
Sheedy JE  Smith R  Hayes J 《Ergonomics》2005,48(9):1114-1128
The luminance surrounding a computer display can potentially reduce visibility of the display (disability glare), result in sensations of discomfort (discomfort glare) and result in transient adaptation effects from fixating back and forth between the two luminance levels. The study objective was to measure the effects of surround luminance levels upon these functions in younger and older adults to determine recommended surround luminance levels. The younger age group comprised 20 subjects (mean age 27.9 years, range 23 - 39) and the older group 17 subjects (mean age 55.5 years, range 47 - 63). The central task was presented with luminance of 91 cd/M(2), tested surround luminance levels were 1.4, 2.4, 8.9, 25.5, 50, 91, 175, 317, and 600 cd/M(2). Disability glare was tested with low contrast (20%) visual acuity charts, transient adaptation was tested with a task that required regular fixation between the two luminance levels, discomfort was measured with a questionnaire after reading stories with different surround luminance levels, and preferred luminance was measured by method of adjustment. The surround luminance significantly affected transient adaptation (p < 0.0001), optimal performance occurred at 50 cd/M(2) and above for the young group and at 91 cd/M(2) and above for the older group. Neither low contrast acuity (disability glare) nor symptoms when reading were significantly affected by surround luminance. There was wide variation in preferred surround luminance; however, average preferred surround luminance was 86.9 cd/M(2) for the young group and 62.2 cd/M(2) for the older group, slightly below the central luminance of 91 cd/M(2). The effects of the surround luminance within the tested range are not large; however, the data show that the lowest surround luminance levels should be avoided and that surround luminance levels at or slightly below that of the central task are preferred.  相似文献   

13.
The purpose of this study was to investigate not only the effectiveness of dynamic versus static visualizations on learning star motions but also the influence of students' spatial abilities with these two types of visualizations on their learning. We assigned 155 fifth-grade students to either a dynamic or a static condition. We used a science achievement test to measure student learning outcomes by assessing knowledge acquisition. We classified students as having either a low or high spatial ability based on their test scores for primary mental abilities, specifically spatial relations. The results showed that dynamic visualizations were more effective than static visualizations for learning complex concepts involving star motions. Furthermore, learners' spatial abilities had a positive effect on their learning outcomes but did not moderate the effectiveness of dynamic versus static visualizations for learning in this domain. Our findings suggest that when designing instructional materials, the dynamic properties of visualizations should be aligned with the dynamic nature of the subject matter. We conclude that students' spatial abilities are beneficial to learning, especially when they are studying a complex domain that demands spatial changes and moving processes; therefore, our findings support the importance of assessing spatial ability in learning with visualizations.  相似文献   

14.
In-vehicle technologies (IVTs) create additional tasks for the driver. To the extent that these devices degrade driving performance, there will be safety concerns. This study examines the effects of display clutter from overlay, display separation, and modality on driving and IVT task performance. In a fixed-base simulator, 22 drivers drove different routes and responded to infrequent, unexpected road hazards while engaging in a phone number task presented by different displays. Visual displays were located on a head-up (overlaid on the visual horizon or adjacently, just above the vehicle hood) or head-down display (HDD) located near the midconsole. Alternatively, digits were presented auditorily. In general, there were no differences in performance for the adjacent and overlay displays; however, there were costs associated with the HDD and auditory display for some measures. In particular, responses to hazard events were slowed when drivers used the HDD. Overall, the adjacent display best supported performance on all relevant tasks. Potential applications of this research include the design of IVTs with respect to location and modality.  相似文献   

15.
计算机网络犯罪是一种犯罪的新形态,网络犯罪必须在特定的空间内实施,与传统犯罪形式相比,不会留下物质性痕迹、犯罪目的与动机的特殊性、犯罪证据的即时性和不可物化性,及其犯罪具有极高的隐蔽性,这些使得计算机网络犯罪行为不易被发现、识别和侦破。该文结合计算机网络技术应用与犯罪案件的侦查,对计算机网络犯罪的形态、计算机网络犯罪案件的侦查技术和侦查策略进行了详细的阐述。  相似文献   

16.
17.
Internet financial reporting provides investors with several options regarding which type of financial disclosures to view and the format in which to view these. However, research suggests that these options may result in unintended cognitive effects leading to less optimal decision making. Accordingly, this study examines the individual and joint impact of presentation format and information content on nonprofessional investors’ decision making within the Internet financial reporting environment. Alternative presentation formats which vary in their navigational flexibility are studied to isolate the effects attributable to each format. Specifically, hyperlinked financial information is compared to paper-based financial information. The effects of information content differences are also examined by investigating whether an unaudited letter from a company’s management differentially affects hyperlink and paper users’ investment judgments.  相似文献   

18.
Two experiments conducted in a high-fidelity flight simulator examined the effects of guidance symbology, display size, and geometric field of view (GFOV) within a synthetic vision system (SVS). In Experiment 1, 18 pilots flew highlighted and low-lighted tunnel-in-the-sky displays, as well as a less cluttered follow-me aircraft (FMA), through a series of curved approaches over rugged terrain. The results revealed that both tunnels supported better flight path tracking and lower workload levels than did the FMA because of the availability of more preview information. Increasing tunnel intensity had no benefit on tracking and, in fact, degraded traffic awareness because of clutter and attentional tunneling. In Experiment 2, 24 pilots flew a lowlighted tunnel configured according to different display sizes (small or large) and GFOVs (30 degrees or 60 degrees). Measures of flight path tracking and terrain awareness generally favored the 60 degrees GFOV; however, there were no effects of display size. Actual or potential applications of this research include understanding the impact of SVS properties on flight path tracking, traffic and terrain awareness, workload, and the allocation of attention.  相似文献   

19.
The analysis of network effects in technology-based networks continues to be of significant managerial importance in e-commerce and traditional IS operations. Competitive strategy, economics and IS researchers share this interest, and have been exploring technology adoption, development and product launch contexts where understanding the issues is critical. This article examines settings involving countervailing and complementary network effects, which act as drivers of business value at several levels of analysis: the industry or market level, the firm or process level, the individual or product level, and the technology level. It leverages real options analysis for managerial decision-making under uncertainty across these contexts. We also identify a set of real options—compatibility, sponsorship and ownership option—which are unique to these settings, and which provide a template for managerial thinking and analysis when it is possible to delay an investment decision. We employ a hybrid jump-diffusion process to model countervailing and complementary network effects from the perspective of a user or a firm joining a network. We also do this from the perspective of a network developer. Our analysis shows that when countervailing and complementary network effects occur in the same network technology context, they give rise to real option value effects that may be used to control or modify the valuation trajectory of a network technology. The option value of waiting in these contexts jumps when the related business environment experiences shocks. Further, we find that the functional relationship between network value and the option value is not linear, and that taking into account a risk premium may not always result in a risk-neural investment. We also provide a managerial decision-making template through the different kinds of deferral options that we identify for this IT analysis context.
Ajay KumarEmail:
  相似文献   

20.
Recommender systems and other Internet-enabled technologies have changed the surrounding conditions of pre-purchase evaluations on the Internet. In some cases consumers can now sample entire products prior to a purchase – hereby removing all uncertainty about whether a product fits their taste. While previous research has mainly focused on vendor and product quality uncertainty, it is still not clear how declining product fit uncertainty affects consumers. To close this gap, we conducted a laboratory experiment to analyze the effects on consumers’ vendor selection. We find that full elimination of product fit uncertainty is beneficial for vendors, as it increases both the number of purchases and consumer loyalty. Interestingly, if product fit uncertainty is only partially eliminated, consumers do not necessarily show differential behavior for different levels of remaining product fit uncertainty. This has important implications for online vendors that consider the implementation of additional means to reduce product fit uncertainty.  相似文献   

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