• Journal of the Ergonomics Society of Korea
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• v.35 no.6
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• pp.503-517
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• 2016

Objective: The aim of this study was to evaluate the effectiveness of 3 dimensional contoured pillow through analyzing contact pressure and to suggest its design guidelines through analyzing the posture of head and neck area. Background: The quality of sleep is a very important factor closely related with human's health. To improve the quality of sleep, the verification of design factors affecting the posture of the head and neck is needed, and a pillow design that can induce proper posture is required. Method: This study measured the contact pressures of the two reference groups (bead and cotton pillows) as a method to evaluate the design effectiveness of the contoured pillow. This study proposed 3-dimensional design guidelines by drawing anthropometry (head length) affecting cervical curvature angle (CCA) through the measurement of the participants' cervical curvature angles. Results: In the design effectiveness evaluation, the contact pressure of cervical region was higher than that of a reference group (cotton pillow), and contract area increased, and contract pressure decreased in the shape distributing the occipital region's body pressure. This study proposed pillow's cervical supporting height by percentile of a head length [head length (%tile) (cervical supporting height) affecting the posture of the head and neck: 14.6cm (5%tile) (6.2cm), 15.5cm (25%tile) (6.7cm), 16.4cm (50%tile) (7.1cm), and 19.3cm (75%tile) (8.9cm)]. Conclusion: This study confirmed the contoured pillow's design effectiveness maintaining cervical angle comfortable to sleep with the shape supporting the cervical vertebrae and by reducing the contact load of the occipital region. Also, this study proposed pillow design guidelines based on the 3-dimensional contoured pillow design effectiveness, through which the study laid the foundation for pillow design in a systematic method. Application: The results of this study are expected to be utilized as the basis data by which the optimum pillow type and pillow design according to main percentile can be standardized.

• Journal of the Society of Disaster Information
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• v.19 no.2
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• pp.241-253
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• 2023

Purpose: The purpose of this study is to introduce the structure and functions of an application developed for enhancing risk knowledge/perception, called KNOWRISK, and to identify and determine problems and requirements based on the usability evaluation results of the application. Method: The evaluation was conducted using the Mobile App Rating Scale (MARS) with a sample of 43 application users and related experts. Result: The application received a satisfactory evaluation score with an overall average of 4.074 points, and there was no significant difference in evaluation scores between experts and users. The highest score was for ease of use at 4.47, while the lowest score was for cost payment usage at 2.88. Conclusion: The results of this study suggest that efforts to increase risk knowledge and promote safe behavior using a mobile application can be an effective and efficient strategy for preventing industrial accidents and enhancing safety management.

• Journal of the Korean Society of Safety
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• v.35 no.3
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• pp.58-63
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• 2020

At the construction site of the driving site, the pile rebound and penetration measurements are performed manually to determine the end point of the driving operation, thereby causing the measurer to be exposed to a death accident. In this study, in order to eliminate the risk of this work, a non-contact penetration measuring device was developed and usability evaluation was conducted. The penetration measuring device is manufactured based on the ultrasonic sensor, and can be combined with the pile to deliver the data in real time, and the delivered data can be output in real time on the portable PC and the final penetration can be calculated. Usability evaluation on the device was conducted by comparison with manual work. Usability evaluation was largely evaluated on measured values, subjective comfort, and body parts comfort. The result of the measured value tended to overestimate the value measured manually by the measuring device, which is similar to the previous research. In terms of subjective comfort and body part comfort, overall satisfaction was higher than the manual method when using the measuring device. Taken together, these results indicate that it is possible to use the rudder measuring device in place of manual work in the construction site, and it is judged that the worker's comfort is greatly increased by using the measuring machine. The results of this study suggest that the use of non-contact measuring device in the field can be used as basic data to support them.

• Journal of the Ergonomics Society of Korea
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• v.36 no.4
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• pp.267-280
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• 2017

Objective: The aim of this study is to investigate key user experience factors of interactions for Head Mounted Display (HMD) devices in the Virtual Reality Environment (VRE). Background: Virtual reality interaction research has been conducted steadily, while interaction methods and virtual reality devices have improved. Recently, all of the virtual reality devices are head mounted display based ones. Also, HMD-based interaction types include Remote Controller, Head Tracking, and Hand Gesture. However, there is few study on usability evaluation of virtual reality. Especially, the usability of HMD-based virtual reality was not investigated. Therefore, it is necessary to study the usability of HMD-based virtual reality. Method: HMD-based VR devices released recently have only three interaction types, 'Remote Controller', 'Head Tracking', and 'Hand Gesture'. We search 113 types of research to check the user experience factors or evaluation scales by interaction type. Finally, the key user experience factors or relevant evaluation scales are summarized considering the frequency used in the studies. Results: There are various key user experience factors by each interaction type. First, Remote controller's key user experience factors are 'Ease of learning', 'Ease of use', 'Satisfaction', 'Effectiveness', and 'Efficiency'. Also, Head tracking's key user experience factors are 'Sickness', 'Immersion', 'Intuitiveness', 'Stress', 'Fatigue', and 'Ease of learning'. Finally, Hand gesture's key user experience factors are 'Ease of learning', 'Ease of use', 'Feedback', 'Consistent', 'Simple', 'Natural', 'Efficiency', 'Responsiveness', 'Usefulness', 'Intuitiveness', and 'Adaptability'. Conclusion: We identified key user experience factors for each interaction type through literature review. However, we did not consider objective measures because each study adopted different performance factors. Application: The results of this study can be used when evaluating HMD-based interactions in virtual reality in terms of usability.

• The KIPS Transactions:PartD
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• v.11D no.3
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• pp.635-648
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• 2004

Extreme programming is the most representative methodology among agile software development methodologies that is agile in business environment which change fast. As software industry is matured, usability of software quality characteristics is emphasized gradually, but effort to obtain usability in extreme programming is insufficient. In this paper, three things lacked in extreme programming are reinforced. First, roles of user interface expert are defined. Second, usability testing method to extreme programming are introduced. Third, development process and products are proposed. The proposed plan is validated by four methods, which analyze supporting software development life cycle, analyze satisfaction of CMM key process areas, analyze satisfaction of CMM practices, and analyze development of green tea shopping mail. Green tea shopping mall is improved 23％ in the estimated running time, 21％ in the learnability. Also, usability is improved 18％ in the heuristic evaluation and 16％ in the questionnaire method.

• Science of Emotion and Sensibility
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• v.23 no.1
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• pp.69-78
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• 2020

This study compares and analyzes user experiences of intelligent personal assistant services based on the evaluation criteria of human-computer interaction to explore positive elements of user experiences and factors that could be improved. The research was conducted on Apple's Siri, Google's Google Associate, and Samsung's Bixby, which is presently the smartest personal assistant service on the market. The research method was to compare and analyze the concepts and characteristics of the current services through a literature review and by interviewing seven UI/UX design experts for the second 2 weeks using contextual inquiry. The interview reorganized Peter Morville's user experience honeycomb, reducing his seven usability principles down to five, asking questions about usability, convenience, visual attractiveness, reliability, and satisfaction. On the basis of the reconfigured usability principle, the assessment was conducted on the basis of the assessment timing and the system usability scale. This study is meaningful in that it analyzed the user experience of artificial intelligence personal assistant services both quantitatively and qualitatively.

• International Journal of Internet, Broadcasting and Communication
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• v.12 no.4
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• pp.61-70
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• 2020

As mobile device usage time increases thanks to the development of information and communication alongside the increase in the spread of smartphones, mobile shopping has become a common trend. While mobile shopping has the advantage of saving both time and money, it may also result in dissatisfaction with product differences after purchase. For online clothing shopping malls, in particular, if the size does not match after purchase, it is difficult for customers to return or exchange the goods. To address this problem, some mobile apparel shipping malls offer a virtual fitting service and a size comparison function; however, the number of such malls remains low. In this paper, a usability evaluation was performed on a mobile apparel shopping mall that provides a size comparison function. The three apps selected for evaluation have different size input methods, and a slightly different method of providing results after comparing the user's dimensions with the dimensions of the clothes to be purchased. In this paper, the evaluators were asked to select clothes at the shopping mall and perform the task of deciding the size of the clothes to be purchased through their own measurements and comparison while also evaluating the effectiveness, meaning, and satisfaction of the apps. Based on the analysis of the results, this paper aims to produce an improvement plan and help design the size comparison UI (User Interface) in the future.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2000.11a
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• pp.26-31
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• 2000

웹 환경에서 사용자는 다른 어떠한 인터페이스 환경에서보다도 더 적극적이고 자유로운 인터랙션을 하고 있으며 따라서 웹 사이트 개발에 있어서 사용자 인터페이스 환경을 고려하는 것은 매우 중요하다. 본 연구에서는 꾑 인터페이스 환경과 그 특징에 대해 살펴보고 현재 활용되고 있는 사용성 평가 기법들을 정리한 후, 이를 기반으로 웹에서의 사용자들의 다양한 반응과 양상을 효과적으로 시각화하고 분석/평가할 수 있는 도구를 개발하였다. 또한 개발된 시각화 도구를 한 인터넷 허브 사이트의 사용성 평가 과정에 적용해 보고 그 결과에 대해 논의함으로써 웹에서의 사용 감성의 시각화와 평가를 위한 실질적인 방법을 제안하고자 한다.

• Journal of KIISE:Software and Applications
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• v.30 no.1_2
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• pp.117-128
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• 2003

Software usability is a characteristic of the software that is decided based on learnability, effectiveness, and satisfaction when it is evaluated. The usability is a main factor of the software quality. A software has to be continuously improved by taking guidelines that comes from the usability evaluation. Usability factors may vary among the different software products and even for the same factor, the users may have different opinions according to their experience and knowledge. Therefore, a usability evaluation process must be developed with the consideration of many factors like various applications and users. Existing systems such as satisfaction evaluation and performance evaluation only evaluate the result and do not perform cause analysis. And also unified evaluation items and contents do not reflect the characteristics of the products. To address these problems, this paper presents a evaluation model that is based on the mental model of user and the problems, this paper presents a evaluation model that is based on the mental model of user and the emotion of users. This model uses evaluation factors of the user task which are extracted by analyzing usage of the target product. In the mental model approach, the conceptual model of designer and the mental model of the user are compared and the differences are taken as a gap also reported as a part to be improved in the future. In the emotional factor approach, the emotional factors are extracted for the target products and evaluated in terms of the emotional factors. With this proposed method, we can evaluate the software products with customized attributes of the products and deduce the guidelines for the future improvements. We also takes the GUI framework as a sample case and extracts the directions for improvement. As this model analyzes tasks of users and uses evaluation factors for each task, it is capable of not only reflecting the characteristics of the product, but exactly identifying the items that should be modified and improved.

• Journal of Biomedical Engineering Research
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• v.45 no.1
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• pp.10-19
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• 2024

The purpose of this study is to conduct a summative evaluation of the usability of a general-purpose ventilator to determine whether it can be used for its intended purpose in the intended environment by the intended user and to find possible errors in use. The importance of ventilators has increased due to the accelerated aging of the population and the impact of the pandemic. In addition, patients who require ventilators are often in critical condition, so even a small error in use can be fatal. Therefore, it is important to ensure that the ventilator has sufficient stability and can be used satisfactorily without inconvenience to the user. In this study, we conducted a usability test with 17 respiratory nurses with more than 3 years of experience using the ventilator. We analyzed the task success rate, satisfaction, and opinions of the intended users while going through a total of 17 scenarios. Satisfaction was captured through an ASQ questionnaire and subjective opinions were captured through a detailed opinion questionnaire. The results showed a high level of satisfaction with an average score of 6.3 for the use scenarios. Evaluators expressed satisfaction with the overall visibility and versatility of the features, but noted that improvements were needed for calibration tasks with low task success rates. As the calibration method is different from other equipment, it was suggested that specific explanations of the calibration method and the picture that appears when calibrating are needed, and that if relevant training is provided, the equipment can be used without problems. If the usability evaluation is not limited to securing efficiency and satisfaction from the intended users, but also continuously receives feedback from users to prepare for use in emergency environments such as pandemic situations, it will be very helpful to seize opportunities such as emergency authorization in future situations, and ultimately contribute to patient safety by reducing use errors.