• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.1
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• pp.158-167
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• 2018

The role of S/W in weapon systems has been developed with various functions and complex structures. As the weapon system S/W is directly related to quick and accurate decision making of users, more accurate evaluation is required during the training. However, situation awareness of weapon system S/W users has only been assessed qualitatively such as by simple test or qualitative judgement. Therefore, this study suggests the 'Cognition Ratio' concept which represents the quantitative of users by combining ACT-R cognitive architecture to SA (Situation Awareness) and Fitts' Law based on the theory of cognitive engineering. The cognition ratio is a ratio of cognition among the whole cognitive behavior process including perception and psychomotor. Moreover, this study provides a systematic assessment process of situation awareness that will be applicable to various weapon system S/W for effective assessment.

• Proceedings of the ESK Conference
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• 1997.10a
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• pp.346-350
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• 1997

Index of performance is dervied from consideration of movement times in routine selection tasks. The discrete movement task employed in this study consisted of moving a cursor from the home position to targets located 6.8, 15.9, 25.0, and 34.0 cm. The target widths were 2.3, 4.5, and 6.8cm. Eight subjects with nomovement disabilities took part in the experiment. Fitts' law is found to be applicable in this experiment.

• Journal of the Ergonomics Society of Korea
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• v.32 no.2
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• pp.179-187
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• 2013

Objective: The purpose of this study is to extract GOMS manual operator, except for an experiment with participants. Background: The GOMS model has advantage of rapid modeling which is suitable for the environment of technology development which has a short life cycle products with a fast pace. The GOMS model was originally designed for desktop environment so that it is not adequate for implementing into the latest HCI environment such as small touch screen device. Therefore, this research proposed GOMS manual operator extraction methodology which is excluded experimental method. And flick Gesture was selected to explain application of proposed methodology to extract new operator. Method: Divide into start to final step of hand gesture needed to extract as an operator through gesture task analysis. Then apply the original GOMS operator to each similar step of gesture and modify the operator for implementation stage based on existing Fitts' law research. Steps that are required to move are modified based on the Fitts' law developed in touch screen device. Finally, new operator can be derived from using these stages and a validation experiment, performed to verify the validity of new operator and methodology by comparing human performance. Results: The average movement times of the participants' performance and the operator which is extracted in case study are not different significantly. Also the average of movement times of each type of view study is not different significantly. Conclusion: In conclusion, the result of the proposed methodology for extracting new operator is similar to the result of the experiment with their participants. Furthermore the GOMS model included the operator by the proposed methodology in this research could be applied successfully to predict the user's performance. Application: Using this methodology could be applied to develop new finger gesture in the touch screen. Also this proposed methodology could be applied to evaluate the usability of certain system rapidly including the new finger gesture performance.

• Journal of the Ergonomics Society of Korea
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• v.25 no.3
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• pp.33-41
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• 2006

This study empirically evaluated performance and preference of Hangul entry methods of five mobile phones through questionnaire and experiments. The questionnaire study revealed that 67% of respondents have been using SMS(short message service) more than six times a day, and that Hangul entry method is the most inconvenient thing when inputting Hangul characters. An experiment was conducted for assessing five Hangul entry methods in view of performance of entry time and errors, and subjective measures of satisfaction and preference. The results showed that Hangul entry method significantly affect objective performances as well as subjective measures at α=0.05 or 0.01. This study, in which real mobile phones were used, presented contrary result in terms of Hangul entry time, compared to the existing studies based on the conceptual models of Fitts' law or Hick-Hyman law.

• Journal of information and communication convergence engineering
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• v.8 no.3
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• pp.328-332
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• 2010

Filipino language is an Austronesian language based on numerous native languages with influences from other major languages such as English and Spanish. The Filipino alphabet is consists of 26 English alphabets, with the addition of two letters, "$\tilde{n}$" and "ng", a total of 28 letters. Filipino language expressions and sentences are still incomparable to English and Spanish even though there are numerous borrowed words from these languages. This study aims to discover the uniqueness in the Filipino language by identifying the frequencies of the letters in common words used and be able to introduce a revolutionary keypad for the Filipinos which is scientifically efficient. To compare the efficiency of the revised and the original keypad, computations using Fitts' Law, Hick-Hyman Law and KSPC were done. Results showed that the new keypad layout was more effective than the original keypad. Introducing a improvised keypad to the Filipinos is one step closer in achieving customized services and features to Filipinos in mobile computing.

• 한국HCI학회:학술대회논문집
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• 2007.02b
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• pp.1-6
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• 2007

최근 다양한 기기와 환경에서 문자 입력에 대한 요구가 높아지고 있다. 이에 따라 효율적인 문자 입력 인터페이스 설계를 위해 문자 입력 인터페이스의 평가가 필요한 실정이다. 기존 연구를 살펴보면 문자 입력 시간을 시각 탐색 시간과 손가락 이동 시간으로 나누고 정보처리 이론인 Hick-Hyman Law와 Fitts’ Law를 통해 예측, 평가 하였다. 하지만 위 두 과정은 연속적(serial)인 과정으로 눈과 손의 coordination(협응)에 대해 관과 하는 한계가 있다. 또한, 기존 문자 입력 시간 예측 모델은 전문가라는 특정 숙련도를 가정하고 만들어졌기 때문에 실제 문자 입력 시간에 비해 과대 측정되어 왔다. 이에 본 연구는 문자 입력 시간 예측 모델에 눈-손 coordination 매개변수를 삽입하고자 눈-손 coordination의 시간을 측정하고 행태를 분석하였다. 또한, 비숙련자와 숙련자의 구분을 통해 시각 탐색 시간과 손 움직임 시간 그리고 눈-손 coordination의 시간 과 행태가 어떻게 변화하는 지 분석하였다. 그 결과 눈-손 coordination 시간은 문자 입력 시간과 밀접한 관계가 있었다, 그리고, 눈-손 coordination 시간은 숙련도에 상관없이 문자 입력 시간의 22%를 차지하였다. 또한, 숙련자와 비숙련자의 문자 입력 시간과 비교해 손과 coordination 시간 비율은 차이가 없었다. 하지만, 눈의 움직임 시간 비율은 큰 차이를 나타내었다. 이 결과는 눈-손 coordination과 숙련도 차이를 기존 문자 입력 예측 모델에 매개변수로써 적용하기 위한 기초 자료가 될 것이다.

• 한국HCI학회:학술대회논문집
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• 2009.02a
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• pp.763-768
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• 2009

사용자 중심의 인터페이스를 설계하기 위해서는 작업 환경에 따른 사용자의 작업 특성 및 이와 관련된 인지 과정에 대한 분석이 선행되어야 한다. 하지만 손가락을 직접 사용하는 새로운 작업 환경인 터치스크린을 적용하는 다수의 기기들은 바뀐 작업 환경에 대한 고려 없이 마우스나 키보드 등의 입력 방식에서의 메뉴 구조를 그대로 따르고 있어 사용자에게 불필요한 움직임 및 인지적 과정을 야기시켜 사용성의 저하를 가져오고 있다. 이에 본 연구에서는 터치스크린에서의 한 손가락 작업 환경의 물리적 특성 및 이에 따른 사용자들의 보다 단순한 인지 과정을 고려한 동적인 메뉴 구조를 제안하였다. 그 결과 사용자들은 동적인 메뉴구조에서 보다 빠른 작업 수행 경향을 보였으며, 인지적 과정에 있어서도 그 시간이 적게 소요되는 경향을 보였다. 본 연구 결과, 터치스크린 환경에서의 작업 특성 및 인지 과정을 고려한 동적인 메뉴 구조는 정적인 메뉴 구조보다 일반적인 사용자 중심의 메뉴 기반 인터페이스를 설계하는데 유용하게 쓰일 것으로 보인다.

• 한국HCI학회:학술대회논문집
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• 2007.02a
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• pp.222-227
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• 2007

본 논문에서는 지체장애인들이 유효한 말초신경신호를 이용하여 컴퓨터를 사용할 수 있는 인터페이스를 개발하였다. 손목의 움직임을 통해 아래팔 4부분으로부터 근전도 (electromyogram, EMG) 신호를 추출하였고, 다층 인식 신경망을 사용하여 사용자의 의도를 추출하였다. 이를 통하여 마우스 커서의 움직임을 제어하고, 마우스 버튼을 클릭하는 동작을 할 수 있으며, 시각 디스플레이 장치에 표시된 핸드폰 자판과 같은 유저 인터페이스를 통해 컴퓨터에 글자를 입력할 수 있게 하였다. 추가적으로 Fitts' law를 사용하여 본 인터페이스의 사용성을 평가하였고, 이를 기존연구와 비교함으로써 본 인터페이스의 효용성을 검증하였다.

• Journal of the Ergonomics Society of Korea
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• v.31 no.6
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• pp.725-731
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• 2012

Objective: The aim of this study is to investigate visual feedback effects and human performance in the foot mouse control. Background: Generally, computer mouse tasks are controlled by visual feedback. In order to understand the characteristics of a foot mouse control, it is important to investigate the patterns of visual feedback involved in foot-mouse control tasks. Human performance of foot mouse control is also an important factor to understand the foot mouse control. Method: Three types of mouse control were determined to investigate visual feedback effects and human performance in the foot mouse control. Visual feedback effects in the foot mouse control were compared with those of a typical hand mouse. The cursor movement speed and mental workload were measured in the three types of tasks and two types of mouses. Results: Mouse control tasks with an element of homing-in to the target were more quickly performed by the hand mouse than the foot mouse. Mental workload was also higher in the foot mouse than the hand mouse. However, in the steering movement, human performance of the foot mouse control was not lower than that of the hand mouse control. Visual feedback in the foot mouse control was less required than in the hand mouse control. Conclusion: The foot mouse was not efficient in the most mouse control tasks, compared to the hand mouse. However, the foot mouse was efficient in the steering movement, moving a cursor within a path with lateral constraints. Application: The results of this study might help to develop the foot mouse.

• Journal of the Ergonomics Society of Korea
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• v.26 no.2
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• pp.149-155
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• 2007

Recently, various devices requiring text input such as mobile phone IPTV, PDA and UMPC are emerging. The frequency of text entry for them is also increasing. This study was focused on the evaluation of Korean text entry interface. Various models to evaluate text entry interfaces have been proposed. Most of models were based on human cognitive process for text input. The cognitive process was divided into two components; visual scanning process and finger movement process. The time spent for visual scanning process was modeled as Hick-Hyman law, while the time for finger movement was determined as Fitts' law. There are three questions on the model-based evaluation of text entry interface. Firstly, are human cognitive processes (visual scanning and finger movement) during the entry of text sequentially occurring as the models. Secondly, is it possible to predict real text input time by previous models. Thirdly, does the human cognitive process for text input vary according to users' text entry speed. There was time gap between the real measured text input time and predicted time. The time gap was larger in the case of participants with high speed to enter text. The reason was found out investigating Eye-Hand Coordination during text input process. Differently from an assumption that visual scan on the keyboard is followed by a finger movement, the experienced group performed both visual scanning and finger movement simultaneously. Arrival Lead Time was investigated to measure the extent of time overlapping between two processes. 'Arrival Lead Time' is the interval between the eye fixation on the target button and the button click. In addition to the arrival lead time, it was revealed that the experienced group uses the less number of fixations during text entry than the novice group. This result will contribute to the improvement of evaluation model for text entry interface.