• Journal of Korea Multimedia Society
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• v.21 no.11
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• pp.1263-1270
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• 2018

Dynamic adaptation method is an effective technique to enhance the usability by personalizing the soft keyboard layout using the user's key input information. In this paper, we propose a dynamic adaptation method of a keyboard by automatically extracting typos from key input information and using adjacent-typo information classified through the relationship between typos. This technique does not limit a range of adaptation to the inside of the key but extends the range to the neighbor key so that the adaptation effect can be achieved in a wide range at a high speed, thereby the proposed method improves the usability of the keyboard with a small number of inputs. The proposed method showed 25% increase in usability compared to the existing method through experiment and it was confirmed that usability improves up to 33% when used with the existing method.

• Journal of the Ergonomics Society of Korea
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• v.35 no.6
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• pp.569-580
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• 2016

Objective: This study aims to identify the most effective keyboard layout in the area of performance for securing usability in a smart watch-using environment and to verify the usability of touch keyboard calibrated by hand. Background: It is necessary to understand the environmental characteristics in using the smart watch and to secure the usability of touch keyboard based on this understanding in order to take account of the users who use the touch screen in the extreme input conditions caused by the small screen of a smart watch. Method: 30 participants in this study were required to input characters using the QWERTY keyboard and 3x4 keypad (Naratgul, Chunjiin), which were familiar with them, in order to grasp the keyboard layout suitable in the smart watch- using environment; the performance (error rate, performance time) of this case was measured. In addition, 30 participants in this study were required to input the characters setting the QWERTY keyboard with calibrated touch area and the one with uncalibrated touch area, based on the characteristics of touch behavior, by finger typing the keyboard, with the performance (error rate and performance time) of this case measured. Results: QWERTY keyboard (93.3sec) is found to be 31.2% faster than Naratgul keyboard, a kind of 3x4 keypad, and 43.6% faster than Chunjiin keyboard, in the area of efficiency, in the results of the usability evaluation regarding the keyboard layout. QWERTY keyboard with calibrated touch area (7.5%) is found to be 23.5% improved compared to the QWERTY keyboard with uncalibrated touch area (9.8%) in the area of accuracy (error rate). The results of the usability evaluation regarding the QWERTY keyboard with touch area calibrated by finger typing the keyboard and QWERTY keyboard with calibrated touch area (80.7sec) is found to be 5.7% improved compared to QWERTY keyboard with uncalibrated touch area (85.6sec) in the area of efficiency (performance time). Conclusion: QWERTY keyboard is found to have an effective layout in the area of efficiency in the smart watch-using environment, and its improved usability is verified in the areas of accuracy and efficiency in the QWERTY keyboard with a touch area calibrated by finger typing the keyboard. Application: The results of this study may be used to set up the basic touch keyboard of the smart watch. The input usability is expected to secure the smart watch-using environment, which is an extreme input condition by applying QWERTY keyboard with touch area calibrated by finger typing the keyboard.

• Korea Science and Art Forum
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• v.20
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• pp.409-419
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• 2015

Service Design Platform which has been developing under the sponsorship of the Ministry of Knowledge Economy is aimed at facilitating service design consultancy to carry out service design projects smoothly online. In the development process in order to verify and improve the usability of the platform, heuristic evaluations by usability experts along with usability test done by user participation are required. This study was conducted for the purpose of deriving appropriate evaluation areas and detailed evaluation indices prior to carrying out the heuristic evaluation. For the study, first, the concept of the service design platform was identified and the features of its component were analyzed. Second, based on literature study of standards which are related to usability evaluation indices, usability evaluation areas and indices were analyzed. Third, in order to establish and verify evaluation areas and indices which are appropriate for the evaluation, Delphi survey was conducted and its validity was verified. Through this study, evaluation indices with 4 evaluation areas and 45 detailed items were derived. Derived evaluation indices was made in the form of checklist and will be utilized for heuristic evaluation by usability experts.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.23 no.11
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• pp.1391-1396
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• 2019

With the recent increase in the importance of software, software education is required in elementary schools in Korea. At this point, coding education combining play and education using smart toys is widely used. One of the most widely used smart toys is a block type smart toy. In this study, usability evaluation was performed to improve user's usability for block type smart toy with smartphone application. In order to achieve the purpose of this study, a heuristic technique with experts, one of various usability evaluation techniques, was performed. As a result of the analysis, it was found that the buttons and the switch of the menu were not well distinguished, and the cause of the error was not provided to the user. The results of this study can be the basis for improving the usability of applications for smart toy in the future.

• Journal of the Korean Society of Systems Engineering
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• v.20 no.spc1
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• pp.56-64
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• 2024

This study aims to compare and evaluate the usability of domestic and overseas XR devices. With the recent release of 'Apple Vision Pro', interest in the XR field is increasing rapidly. XR devices are being used in various fields such as defense, medical care, education, and entertainment, but the evaluation system for evaluating usability is still insufficient. Therefore, this study aims to derive improvements in domestic equipment through comparative evaluation of usability for two HMD-type devices and one glasses-type device that are released. In order to conduct the study, 20 participants in their 20s to 30s who were interested in XR devices and had no visual sensory organ-related disabilities were evaluated by wearing VR equipment. As a quantitative evaluation, electromyography through an EMG sensor and the device and body temperature of the device through a thermal imaging camera were measured. As a qualitative evaluation, the safety of wearing, ease of wearing, comfort of wearing, and satisfaction of wearing were evaluated. As a result of comparing the usability of the devices based on the results, it was confirmed that domestic HMD-type device needs improvement in the strap part.

• Physical Therapy Rehabilitation Science
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• v.13 no.2
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• pp.187-195
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• 2024

Objective: Physical activity can promote physical and mental well-being. University students are more sedentary recently due to the increased use of computers and other technology. The aim of this study was to investigate differences between immersive 360-degree virtual cycling (IVC) and virtual cycling with head-mounted display (VCHMD) on aerobic capacity and usability in young adults. Design: A crossover study. Methods: Twenty-five university students (13 male, 12 female) participated in this study and completed 2 separate 30 min cycling sessions, such as IVC and VCHMD. In the IVC, participants rode on a stationary cycle while watching curved TV where recorded video was played. To enhance the sense of realism, auditory stimulation was given to the headset, and the gyroscope sensor was used to track the screen as the head moved. In the VCHMD, participants rode on the stationary cycle with head-mounted display, and other conditions were the same as IVC. Participants were assessed the aerobic capacity which included gas analyzer and portable near-infrared spectroscopy, and usability which included simulator sickness questionnaire and system usability scale. Results: Aerobic capacity was significantly difference in the IVC compared with the VCHMD except for the total hemoglobin of right and left rectus femoris and muslce oxygen saturation of left rectus femoris (p<0.05). Cybersickness was less in the IVC than VCHMD and usability was high in the IVC than VCHMD (p<0.05). Conclusions: The findings suggested that IVC might be beneficial exericse to improve aerobic capacity and has lower cybersickness and higher usability than VCHMD.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.39 no.3
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• pp.64-70
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• 2016

The recent development of modern weapon system by SOS (System of System) has required users to have more exact decision making. It is possible to achieve the control of complex weapon system more efficiently and effectively by increasing usability. Accordingly, many studies on graphical display have been conducted for several years in the field of HCI (Human Computer Interaction) and GUI (Graphic User Interface), starting from its design stage. Therefore, this paper focuses on evaluating the system GUI usability and analyzing several important points based on performance model, which is a tool for the evaluation and the improvement of service quality. Performance Model, the main focus of this study, reflects user expectations (which is defined as user importance in this paper). The study consists of four steps. First, 34 checklists are drawn from the existing studies related to GUI usability evaluation by using a heuristic method, and then the checklists are matched with 11 weapon system design factors. Next, the study evaluates the importance of GUI element and the usability of weapon system "A" with the checklists twice respectively. Third, the performance of user importance ($P_i$) and the performance of usability ($P_u$) are calculated by modifying a numerical formula for normalization in this step. Finally, the study compares the approach it takes and the existing usability evaluation method, demonstrating that there is a significant difference between the two methods as a result. In addition, 4 improvement factors are suggested for weapon system "A" as "Shortcut" and "Description of Abbreviation," and so on. Although it is necessary to conduct more studies for higher reliability and validity of the results, this study is meaningful considering it takes a new point of view.

• Journal of the Ergonomics Society of Korea
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• v.36 no.1
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• pp.37-52
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• 2017

Objective: The present study developed a user-centered 3D virtual liver surgery planning (VLSP) system called Dr. Liver to provide preoperative information for safe and rational surgery. Background: Preoperative 3D VLSP is needed for patients' safety in liver surgery. Existing systems either do not provide functions specialized for liver surgery planning or do not provide functions for cross-check of the accuracy of analysis results. Method: Use scenarios of Dr. Liver were developed through literature review, benchmarking, and interviews with surgeons. User interfaces of Dr. Liver with various user-friendly features (e.g., context-sensitive hotkey menu and 3D view navigation box) was designed. Novel image processing algorithms (e.g., hybrid semi-automatic algorithm for liver extraction and customized region growing algorithm for vessel extraction) were developed for accurate and efficient liver surgery planning. Usability problems of a preliminary version of Dr. Liver were identified by surgeons and system developers and then design changes were made to resolve the identified usability problems. Results: A usability testing showed that the revised version of Dr. Liver achieved a high level of satisfaction ($6.1{\pm}0.8$ out of 7) and an acceptable time efficiency ($26.7{\pm}0.9 min$) in liver surgery planning. Conclusion: Involvement of usability testing in system development process from the beginning is useful to identify potential usability problems to improve for shortening system development period and cost. Application: The development and evaluation process of Dr. Liver in this study can be referred in designing a user-centered system.

• The Journal of Korean Institute for Practical Engineering Education
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• v.3 no.1
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• pp.62-68
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• 2011

Usability heuristics("heuristics") are general principles for usability evaluation during user interface design. This method is commonly used by Human Computer Interaction(HCI) professionals; however, the most widely used set of heuristics which were originally created by Nielsen has not yet been found practical in the current state of Korean technologies. In our prior research, we found that some of Nielsen's heuristics are difficult for some evaluators to understand and insufficient to fully evaluate Korean applications, due to the broad-applicability of these heuristics and differences in cultural context. Therefore, in this study, professionals in computer science and related fields evaluated Nielsen's ten usability heuristics in order to gather logical bases for finding areas for improvement. The results of this study will help creating a new set of heuristics that will better valuate more recently developed applications.

• Journal of the Ergonomics Society of Korea
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• v.33 no.5
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• pp.407-422
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• 2014

Objective: The purpose of the study is to develop quantitative usability evaluation criteria for senior-friendly autonomous transportation robot. Background: The Republic of Korea has become the most rapidly aging society, and is anticipated to enter the post-aged society in 2026. To raise the quality of life of a senior with limited mobility and to reduce the burden of caregivers, many high-tech assistive products with information technologies are developed nowadays. The senior-friendly autonomous transportation robot is one person robot vehicle to move a senior to the destination for hospitals, nursing homes or silver town complex. With built-in navigation system and environmental monitoring censors, it automatically seeks the path to the destination and avoids collision to obstacles and pedestrians on the way. Due to the early stage of the product, few usability studies in this field have been done, mostly on general service robots to assist seniors, power wheelchairs and delivery robots. ISO and KS standards for the service robots are focused on safety. Method: Based on the reference usability index, the early draft of the usability evaluation questionnaires was developed. After small group tests and interviews, the experts modified the initial draft to the Usability Evaluation Criteria for Senior-Friendly Autonomous Transportation Robot (UEC-SFATR). Result: UEC-SFATR consisted of 4 subscales - Safety, Controllability, Efficiency and Satisfaction. All of the 4 subscales of UEC-SFATR were passed the reliability criteria by 4 groups of seniors, divided by gender and familiarity of smart-devices. Conclusion: UEC-SFATR covers wider area of user experiences of the SFATR and is a good measurement tool to help both the users and developers of the robot. Application: This study provides guide to the future product development and product competitiveness evaluation by quantifying user experiences for the SFATR.