PDA를 위한 스크롤 및 정보 제시 방법의 인간공학적 설계

To increase the usability of a new chronic disease self-management system, we conducted a usability study of the system among older adults with chronic diseases (n=33) using a paper prototype based on the think-aloud approach. The metrics used to judge system usability were the task incompletion rate, task completion time, frequency of error, frequency of help, satisfaction, perceived usefulness, and perceived ease of use. We also interviewed the participants to elicit their comments on the system design. The quantitative data were analyzed using descriptive statistics, and the interview data were content analyzed. Overall, the participants were able to carry out the self-management tasks with the current design, but several usability problems were discovered with the system navigation, information search and interpretation, information presentation, and readability. The paper prototype study enabled us to identify these system design weaknesses and to make suitable recommendations for design modifications.

Within the field of mobile health, there is little research conducted on the impacts of mobile health technologies and applications on user comprehension of health content. In this study, we examine the difference between small, medium and large screen mobile phone that affect the user comprehension of health content. We designed an experimental study where 33 users read the contents of a health application on different mobile phone screen sizes. Each participant was timed, tracked for correctness, and gave ratings for both readability and satisfaction on each task. In addition, they were asked some questions about the contents. Results show that there was no significant impact of the screen size on user comprehension of the contents. However, it was found that participants with small screen size took longer to read the health contents.

Background: Increased cell phone use causes individuals to divide their attentional resources between dual tasks in daily life. It is emphasized that this divided attention negatively affects task performance and makes pedestrian cell phone use an increasing safety concern. There is a lack of research on how dual tasks involving cell phone use affect pedestrian movements in laboratory and real-world settings and the time saved by text messaging while walking. Objectıve: The main purpose of this study is to investigate how dual-tasking affects pedestrians by analyzing task completion time and texting performance, as well as investigating potential gender differences. Methods: 119 students were included in the study. Expanded-Timed Up and Go Test was applied as a single task 1. As a single task 2; text messaging was used on a mobile phone. Dual-task was defined as performing both tasks simultaneously. All evaluations were recorded both in the laboratory and outdoor environment. Results: Between all parameters, task completion times showed a significant difference in favor of dual-task in both environments (p ≤ 0.05). There was no significant difference in texting performance when comparing the results of two environments (p ≥ 0.05). Performing texting and walking tasks simultaneously resulted in approximately 43-45% time savings. Conclusıons: However, dual-task increases events such as falling or hitting other pedestrians. We recommend that pedestrians do not endanger their health and the health of other pedestrians to save more or less time.

ABSTRACTBandwidth is still a limiting factor for the Quality of Service (QoS) of mobile communication applications. In particular, for Voice over IP the QoS is not yet as good as for common, well-engineered, public-switched telephone networks. Multisensory communication has been identified as a possibility to moderate this limitation. One of the strengths of mobile video technology lies in its combination of visual and auditory modalities. However, one of the most salient features of mobile video applications is its small screen size. To test the potential of multimodal synergy for mobile devices, we assessed to what extent small screens affect multimodal synergy. This potential was assessed in an experiment with 54 participants, who conducted a standardised video-listening test for three talking-heads videos with a signal-to-noise ratio of –9 dB. The videos were presented on three different screen sizes, whilst keeping the video and auditory signals equal. Compared to a ground truth based on 359 participants, intelligibility was found to be significantly higher when using a large screen than when using a small screen. This indicates that mobile video technology has the potential for a significant multimodal synergy to which screen size is a substantial constraint. To optimally benefit from their multimodal potential, we offer suggestions on how to increase the effective screen size for small screen (e.g. mobile) devices and applications through elaborating the most relevant (visual) features. We conclude that knowledge about human sensory processing can alleviate the identified constraint and maximise the potential QoS of mobile video technology.

The area of multitouch interaction research is at its infancy. The commercial sector has seen an exponential growth in this area with ubiquitous products like Apple i-phone and Microsoft surface table. In spite of their popularity, developers are still finding it difficult to extend this novel interface to engineering applications such as Computer Aided Design (CAD), due to insufficient understanding of the factors affecting the multitouch interface when applied to CAD operations. This problem is magnified when it comes to 3D CAD operations. The aim of this research is to (1) study the key elements of the multitouch interface, (2) identify the factors affecting the performance of a multitouch-enabled 3D modeling environment, and (3) lay a foundation for future research and highlight the direction for researchers and developers to extend the multitouch interface for CAD modeling operations and other engineering applications. We have conducted mouse emulation experiments in order to achieve the goal. We compare the standard mouse device with two finger-based touch interaction techniques (drag state finger touch and track state finger touch) for 3D CAD modeling operations. The mouse device outperformed the finger touch techniques and yielded statistically better performance results in terms of both task completion time and error rates. The paired t-test indicated that both the task completion time and error rates are statistically the same for the two finger touch techniques under investigation. However, the error concentration observed from the experiments revealed that the track state technique is more suited for edge selection tasks as compared to the drag state technique. Regardless, both the finger touch techniques suffered from lack of precise dimension control while executing the tasks. The presence of grid had a significant desirable effect on the error rate.

A pair of commercially available smart glasses, Epson BT-200, was evaluated with different information display modes for assisting machine operators. Two information display modes were selected, displaying animated images only, and displaying animated images with text illustrations. Direction prompts were added in the system. Whether the prompts are helpful or not was also discussed in this study. Task completion time and error rate were collected during the experiment. System Usability Scale (SUS) and NASA-Task Load Index (NASA-TLX) were used to collect subjective information after each experiment. Twenty participants (10 males and 10 females) were recruited. The results showed that the display mode of having smart glasses displaying animated images versus displaying animated images with text illustrations showed no significant difference in task completion time and error rate. But the significant difference was found in the result of SUS scores. Participants preferred the display mode of animate images with text illustrations according to the SUS scores. Moreover, the results indicated that the use of direction prompts had significant influences upon all the measures. Participants completed the tasks faster and had lower error rate by using the smart glasses with direction prompts. And the results of subjective ratings also showed higher SUS score and lower NASA-TLX score were associated with using smart glasses with direction prompts. Thus, the implementation of using smart glasses to guide machine operations should be considered the design of adding direction prompts to increase efficiency and effectiveness of the operations.KeywordsAugmented realityInformation displaySmart glasses

Today's era witnesses the increasing demand of mobile phones and its applications. In Mobile PKI, it is difficult to apply the WAP (Wireless Application Protocol) in mobile environment since wireless internet has lower transmission bandwidth and mobile phone has fundamental limitations like small screen size, low computing power, low memory capacity, etc. To eradicate these problems, development of Mobile-PKI is needed. This paper presents a Mobile Home Agent based Mobile-PKI supporting mobile phones to provide similar security level as the wired PKI. A Mobile Home Agent and Registration Authority have been considered to minimize the work load of mobile phone and CA (Certificate Authority) respectively. Discussion regarding how the proposed Mobile-PKI provides similar security level as the wired PKI and comparisons with existing schemes have been provided.

A user study of auditory versus visual interfaces for use while driving

Predictive capability of cognitive ability and cognitive style for spaceflight emergency operation performance

This study proposes a submenu window as a navigation aid for mobile Internet access on a cellular phone. The submenu window presents child-level menu items along with their upper-level menu. The effectiveness of the submenu window was investigated in an experiment. The factors manipulated in the experiment include the types of submenu window, age of participants, and timing of presenting the submenu. Task completion time, number of button clicks, and subjective preference were measured while the participants were performing target search tasks. The results showed that they preferred the separate submenu window. The best performance was obtained when the submenu immediately followed the selection of its parent menu. In addition, the participants in their 20s found a target menu item with fewer button clicks than did the teenagers. The separate submenu window with no delay was recommended in terms of both performance and subjective preference. The design guidelines for submenu windows on a small-screen device are also provided. The results of this study are expected to be applicable to menu-driven interfaces of many small-screen devices such as digital cameras and personal digital assistants.

This study investigated the effects of the target size and movement distance on user performance and workload in a virtual reality (VR) environment. In a repeated-measures laboratory study, 36 participants (18 male and 18 female) performed the drag-and-drop task as a standard human–computer interaction (HCI) task with different target sizes (1, 1.5, 2, 2.5, and 3 cm) and movement distances (5, 9, 13, 17, and 20 cm). Task completion time (TCT), error rate, and movement time (MT) were measured as performance indices, whereas physical load and effort were assessed as workload indices. The results demonstrated that the target size and movement distance significantly affected all performance measures and workload indices. Large target sizes produced better performance and lower workloads; however, large movement distances decreased performance and increased workload. However, sex had no significant effect on the performance or workload during the drag-and-drop tasks. The best target sizes were 2.5 and 3 cm, and the worst size was 1 cm. The best movement distances were 5 and 9 cm, and the worst distance was 20 cm. The results of this study can provide useful reference information for developing VR technology based on human factors and demonstrate that additional basic research is required to reflect the distinctive features of VR in the future.

In percutaneous coronary intervention (PCI), cardiologists must study two different X-ray image sources: a fluoroscopic image and an angiogram. Manipulating a guidewire while alternately monitoring the two separate images on separate screens requires a deep understanding of the anatomy of coronary vessels and substantial training. We propose 2D/2D spatiotemporal image registration of the two images in a single image in order to provide cardiologists with enhanced visual guidance in PCI. The proposed 2D/2D spatiotemporal registration method uses a cross-correlation of two ECG series in each image to temporally synchronize two separate images and register an angiographic image onto the fluoroscopic image. A guidewire centerline is then extracted from the fluoroscopic image in real time, and the alignment of the centerline with vessel outlines of the chosen angiographic image is optimized using the iterative closest point algorithm for spatial registration. A proof-of-concept evaluation with a phantom coronary vessel model with engineering students showed an error reduction rate greater than 74% on wrong insertion to nontarget branches compared to the non-registration method and more than 47% reduction in the task completion time in performing guidewire manipulation for very difficult tasks. Evaluation with a small number of experienced doctors shows a potentially significant reduction in both task completion time and error rate for difficult tasks. The total registration time with real procedure X-ray (angiographic and fluoroscopic) images takes[Formula: see text]60ms, which is within the fluoroscopic image acquisition rate of 15Hz. By providing cardiologists with better visual guidance in PCI, the proposed spatiotemporal image registration method is shown to be useful in advancing the guidewire to the coronary vessel branches, especially those difficult to insert into.

Effects of design features of train electronic guidance interface on visual search, behavior, and usability

CogTool is a predictive evaluation tool for user interfaces. We wanted to apply CogTool to an evaluation of two mobile phones, but, at the time of writing, CogTool lacks the necessary (modeling baseline) observed human performance data to allow it to make accurate predictions about mobile phone use. To address this problem, we needed to collect performance data from both novice users’ and expert users’ interactions to plug into CogTool. Whilst novice users for a phone are easy to recruit, in order to obtain observed data on expert users’ performance, we had to recruit owners of our two target mobile phone models as participants. Unfortunately, it proved to be hard to find enough owners of each target phone model. Therefore we asked if multiple similar models that had matched interaction sequences could be treated as the same model from the point of view of expert performance characteristics. In this paper, we report an empirical experimental exercise to answer this question. We compared identical target task completion time for experts across two groups of similar models. Because we found significant differences in some of the task completion times within one group of models, we would argue that it is not generally advisable to consider multiple phone models as equivalent for the purpose of obtaining observed data for predictive modeling.KeywordsCognitive ModelCogToolEvaluationHuman Centered DesignHuman InterfaceMobile PhoneSystematizationUsability Test

The ability to use everyday technology has become a key competence for conducting activities of daily living, maintaining an autonomous life, as well as participating in society. However, studying this issue in older adults needs more attention, particularly among those with mild cognitive impairment (MCI). We assessed the performance of N = 80 older adults (M = 73 years) in a range of tasks representing important life domains, i.e., using a blood pressure monitor, a mobile phone, and an eBook reader. Thirty-nine participants had been diagnosed with MCI by experienced geropsychiatrists and 41 healthy controls were matched for age, sex, and education. Standardized observation based on video-recording and coding was combined with cognitive testing and assessment of social-cognitive variables (self-efficacy, perceived obsolescence, attitudes towards technology). Cognitively healthy participants outperformed those with MCI regarding completion time and errors. An interaction effect of device and study group indicated larger differences in completion time for tasks with multilayered interfaces. In hierarchical regression models, aggregated cognitive factors (fluid and memory component) predicted performance and interactions with education level emerged. Obsolescence, addressing a perceived lack of competence to cope with modern society, mediated the effect of cognitive status on performance, both regarding time (partial mediation, adj.R2 = 28%) and errors (full mediation, adj.R2 = 23%). Findings show that social-cognitive factors contribute to differences in performance on everyday technology tasks in addition to cognitive abilities. Training programs may profit from considering respective individual resources or limitations in the cognitive, personality-related or emotional-motivational domain.