• 대한산업공학회지
• /
• 제41권3호
• /
• pp.225-232
• /
• 2015

The smart watch is the most popular wearable computing device because it takes a form of wristwatch. Many smart watches have adopted the touch screen interface due to the limited size of display. This paper focuses on touch key size and spacing that affect the usability about the touch key of smart watch. The experiments were made for four touch key sizes (width${\times}$height; $5{\times}5$, $5{\times}7$, $7{\times}5$, $7{\times}7mm$) and nine touch key spacing (vertical${\times}$horizontal; $0{\times}0$, $0{\times}1$, $0{\times}3$, $1{\times}0$, $1{\times}1$, $1{\times}3$, $3{\times}0$, $3{\times}1$, $3{\times}3mm$). The completion time, error rate, control discomfort and identification discomfort were measured. The touch key size $7{\times}7$, $7{\times}5$ and the touch key spacing $3{\times}3$, $1{\times}3$ provided the best results in terms of the completion time and the control discomfort, while the square touch key ($7{\times}7$, $5{\times}5$) provided the best performance for the error rate measure. The result of this study can help ergonomically design the touch interface of the smart watch.

• 대한산업공학회지
• /
• 제38권2호
• /
• pp.80-88
• /
• 2012

This paper focuses on small touch key size and spacing that affect the usability of the smart phones. The experiments examined thirty-six different touch key designs, combinations of four touch key sizes (width (mm) ${\times}$height (mm); $4{\times}4$, $4{\times}7$, $7{\times}4$, and $7{\times}7$), and nine spacings (horizontal (mm)${\times}$vertical (mm); $0{\times}0$, $0{\times}1$, $0{\times}3$, $1{\times}0$, $1{\times}1$, $1{\times}3$, $3{\times}0$, $3{\times}1$, and $3{\times}3$). Forty participants volunteered in the experiment. The completion time, error rate, identification discomfort, and control discomfort were measured. The results revealed that the touch key sizes of $7{\times}7$ and $7{\times}4$ provide the best performance in terms of the error rate measure, while the touch key size of $7{\times}7$ provides the best results for other measures. In addition, touch key spacings of $1{\times}1$, $1{\times}3$ and $3{\times}1$ are regarded as the best for all the measures. The results of this study suggest a practical approach for the small touch key design for the smart phones.

• 대한산업공학회지
• /
• 제37권1호
• /
• pp.30-40
• /
• 2011

In recent years, driver information systems (DIS's) became popular and the use of DIS's increased significantly. A majority of DIS's provides touch-screen interfaces because of intuitiveness of the interaction and the flexibility of interface design. In many cases, touch-screen interfaces are mainly manipulated by fingers. In this case, investigating the effect of touch-key sizes on usability is known to be one of the most important research issues, and lots of studies address the effect of touch-key size for mobile devices or kiosks. However, there is few study on DIS's. The importance of touch-key size study for DIS's should be emphasized because it is closely related to safety issues besides usability issues. In this study, we investigated the effect of touch-key sizes of DIS's while simulated driving (0, 50, and 100km/h) considering driving safety (lateral deviation, velocity deviation, total glance time, mean glance time, total time between glances, mean number of glances) and usability of DIS's (task completion time, error rate, subjective preference, NASA TLX) simultaneously. As a result, both of driving safety and usability of DIS's increased as driving speed decreased and touch-key size increased. However, there were no significant differences when touch-key size is larger than a certain level (in this study : 17.5mm).

• 산업공학
• /
• 제20권4호
• /
• pp.539-546
• /
• 2007

This study has been conducted on touch screen interface design for mobile devices. It was intended to measure user’s satisfaction on one-handed thumb input mobile devices. Recent studies proposed the optimal touch button size, but it is inappropriate for mobile devices. Therefore, this study was focused on four touch key factors-width, height, the horizontal and vertical distance between touch keys-as independent variables. The ANOVA results showed that the user satisfaction of four touch key factors was significantly affected by the thumb input. It also apparent that the interactions between four factors were significant. As a result, the horizontal and vertical distance as well as the width and height affected the satisfaction of users. In addition, this study suggested satisfaction models which represent the top 30%, 50%, 70% of user satisfaction measurement. The results of this study could be used to design touch keys that are able to enhance the usability on touch screen based mobile devices.

• 대한산업공학회지
• /
• 제40권3호
• /
• pp.267-274
• /
• 2014

The purpose of this study is to identify a relationship between the time taken and the characteristics of touch key for touch-screen-based in-vehicle information system (IVIS) and to suggest a new Fitts' law formula that is added a driving speed parameter. Many studies already have shown that Fitts' law is well fitted in various devices for primary tasks, but there is no study of Fitts' law for secondary task in dual-task situation. Fitts' law may not be applied to the secondary task as it is, because the secondary task performance can be affected by the amount of attention for the primary task. To verify this, we carried out an experiment that showed whether pointing task to touch-screen-based IVIS during driving is affected by driving speeds or not. In the experiment, 30 people were volunteered for participants and the participants carried out driving task and pointing task on the screen of IVIS simultaneously. We measured the time to point a touch key on IVIS for every condition (3 driving speeds${\times}5$ touch key sizes${\times}7$ distances between steering wheel and touch key). As a result, there was an effect of driving speed on the pointing time. As we extended the index of difficulty of the conventional Fitts' law formula by incorporating driving speed, we established an extended Fitts' law formula for pointing on IVIS, which showed better accordance with dual task situation. This study can be evidence that secondary task performance is affected by degree of concentration on primary task, and the extended Fitts' law formula can be useful to design interfaces of IVIS.

• 조명전기설비학회논문지
• /
• 제23권4호
• /
• pp.39-46
• /
• 2009

본 논문에서는 저항과 클록 주파수 변동에 의한 문제를 효과적으로 감소시킬 수 있는 풀 디지털 정전용량 방식의 터치키를 제안한다. 제안된 방식은 측정하고자 하는 정전용량 두 개와 두 정전용량 사이의 저항으로 구성되어 있으며, 각 정전용량과 저항의 지연을 각각 측정한 후 두 지연의 비를 구한다. 양자화 오차를 무시할 경우 두 지연의 비는 측정하고자 하는 두 정전용량의 비로 표시되어 저항 값과 클럭 주파수와 무관하다. 실험결과에서도 제안된 방법이 저항과 클록주파수에 의한 변동을 효과적으로 줄일 수 있음을 보였으며, 제안된 방법의 정전용량 해상도가 1.04[pF]여서 터치키로 사용될 수 있음을 보였다.

• 대한인간공학회지
• /
• 제29권4호
• /
• pp.605-610
• /
• 2010

In order to design a touch interface for the elderly, human performance of input tasks on the touch screen was investigated by the laboratory experiment. Input times and input errors were measured in the experimental conditions that were changed according to age, key size, interkey space and input tool(finger or stylus pen). In the most of all experimental conditions, the task performance of the elderly was lower than that of the young. However, there were significantly different performance patterns between both groups. As the difficulty of task was getting higher, the task performance of the elderly was sharply decreased; pressing small key button by finger sharply increased input time and error rate, compared to that of the young. Therefore, the square key size suitable to the elderly may be over $8.0{\times}8.0mm$. While the interkey space did not influence to the input task performance of the young, the task performance of the elderly was influenced. The elderly showed big difference of task performance according to input tool. However, the young were less influenced by input tool.

• 구강회복응용과학지
• /
• 제33권4호
• /
• pp.269-277
• /
• 2017

목적: 치과의사의 사용 만족도 비교를 통해 두 가지 피에조 엔진의 성능을 비교평가 하고자 한다. 연구 재료 및 방법: 본 연구에서는 두 가지의 피에조 엔진을 평가하였다:TRAUS XUS10 (Saeshin), PIEZOSURGERY touch (Mectron). 20명의 치과의사가 11개 평가항목에 답하였고, 평가결과는 Likert의 5점 척도를 적용하여 수치화하였다. 핸드피스 소음평가는 10초 동안 5회 측정하여 최고소음을 비교하였다. 핸드피스 발열평가는 세 부위에서 3분동안의 발열량을 측정하였다. 결과: 평가항목 중 '주수펌프 모터의 소음'에서 TRAUS XUS10이 PIEZOSURGERY touch보다 유의하게 만족도가 높았다. 반면, '기능key의 만족도'와 '핸드피스 발열정도'는 PIEZOSURGERY touch가 더 우수했다. 소음 최대값은 TRAUS XUS10이 56.6 dB, PIEZOSURGERY touch는 56.0 dB였다. 두 기기 모두 3분 작동 후 $41^{\circ}C$ 미만의 열을 발생시킴으로써 안전기준을 만족하였다. 결론: TRAUS XUS10는 '기능 key' 및 '핸드피스 발열정도'에서 약간의 개선을 한다면 그 외 대부분의 평가항목에서는 PIEZOSURGERY touch과 견줄만한 성능을 보인다.

• 품질경영학회지
• /
• 제45권4호
• /
• pp.717-738
• /
• 2017

Purpose: This study focused on procedure and methodology for finding the critical design factors in the early stage of product development process. Methods: Firstly, three key criteria, function, affection and usability were defined as the determining factors on customer satisfaction. Secondly, evaluation matrix in terms of each key criteria was proposed for extraction of the critical design factors. Lastly, method of integrating the importance among three key criteria was suggested using structured equation model. Results: As a results of integrating the importance, design factors such as touch sensitiveness and touch method were rated as low in terms of affection. However, these factors were obtained for high ratings with respect to functionality and usability. Thus, touch-related design factors were more facilitated for enhancing customer satisfaction. Conclusion: It is expected that the process suggested in this research could be a considerably useful to maximize customer satisfaction in the early stage of product development process.

• 한국정보과학회논문지:컴퓨팅의 실제 및 레터
• /
• 제15권11호
• /
• pp.866-870
• /
• 2009

최근 터치스크린을 탑재한 휴대폰의 출시가 늘어나면서 기존의 모바일 게임 콘텐츠를 터치스크린 콘텐츠로 변환하여 재사용하고자 하는 요구가 증가하고 있다. 하지만, 기존에 개발된 콘텐츠는 터치스크린 인터페이스를 갖고 있지 않기 때문에 터치스크린 콘텐츠로 자동 변환하는 것은 매우 어려운 문제이다. 본 논문에서는 터치스크린 인터페이스가 없는 모바일 게임 콘텐츠에 대하여 키보드 인터페이스 정보를 이용하여 자동으로 터치스크린 인터페이스를 생성하는 방법을 제안한다. 이 방법은 콘텐츠에서 사용되는 키 이벤트의 종류를 분석하여 최적의 스크린 키보드 레이아웃을 구성하고, 터치스크린 이벤트에 대해 자동으로 대응되는 키 이벤트를 발생시켜 키보드 이벤트 핸들러가 실행되는 터치 스크린 인터페이스를 생성한다. 끝으로, 실험을 통해 콘텐츠에 최적화된 터치스크린 인터페이스가 생성됨을 확인한다.