자동차 페달 반복 사용 시 보조 발판이 하지근육 활동과 피로에 미치는 영향

김정룡,서경배,Kim, Jung-Yong,Seo, Kyung-Bae 대한인간공학회 2005 大韓人間工學會誌 Vol.24 No.4

This study examined the effect of ergonomic heel rest that was designed for drivers who have physical handicap in the low leg muscles or have to drive prolonged hours with frequent foot pedaling. An experiment was designed to test the ergonomic heel rest with traditional foot pedal. Forty subjects participated in the experiment. Electromyography(EMG) was used to monitor the muscle activity and fatigue of right leg, and Electro-goniometer was used to measure the ranges of motions of the knee and ankle. A simulator of driver's seat was built for the experiment and the heel rest was installed on it. In order to examine the low muscle activity and range of motion, subjects used the foot pedal for 15 minutes repetitively for each experimental condition. Another 15 minutes test without the heel rest was also performed for comparison. The Root Mean Square(RMS) and Mean Power Frequency(MPF) Shift were used to quantify the level of muscle activity and local muscle fatigue. In results, statistically significant decreases of muscle activity and fatigue were found in all the low leg muscles. The range of motion of the knee and ankle joint also decreased when the heel rest was used. The mechanism of the heel rest effect was discussed in this study. This type of heel rest can be applied to real driving situation after ensuring the safety, or overcoming the psychological discomfort possibly due to unfamiliarity.

다자 중심적 사용성 평가 방법의 구조화 과정

김정룡,이하연,최영철,Kim, Jung-Yong,Lee, Ha-Yeun,Choi, Young-Cheol 대한인간공학회 2005 大韓人間工學會誌 Vol.24 No.2

In order to minimize a biased view of evaluators in usability test, a multiple evaluation method so called Multi-Centered Usability Evaluation Method(MCUEM) was suggested and structured in this study. To use MCUEM, the existing evaluation methods were re-categorized into 'developer and evaluator-centered', 'evaluator-centered', 'user-centered', 'evaluator and user-centered', and the 'developer, evaluator, and user-centered methods. Furthermore, in order to verify the relevance of MCUEM, the usability of mobile phone was tested in this study. In results, it was found that different evaluation methods generated greatly different results, that showed the risk of using a particular usability method due to different perspectives of evaluators. At the same time, it was found that MCUEM could greatly minimize such biases. Therefore, it was concluded that using MCUEM could help the usability engineer design a test protocol with a minimal risk of bias due to different perspective of evaluators.

작업부하 평가를 위한 생체역학적 측정방법

김정룡(Jung Yong Kim),박지수(Ji Soo Park),조영진(Young Jin Cho) 대한인간공학회 2010 大韓人間工學會誌 Vol.29 No.4

It is necessary to quantitatively evaluate the workload of workers in order to improve the level of safety and efficiency as well as to prevent workers from musculoskeletal disorders. The purpose of this study is to introduce biomechanical methods that are largely used to quantitatively evaluate workload. The biomechanical methods use kinematics and kinetics to analyze the movement and force of biomechanical body. Motion analysis, joint angle measurement, ground reaction force, mathematical model, and electromyography (EMG) were introduced as a tool or device for biomechanical evaluation. In this study, the special feature of each method was emphasized and important tips for field measurement were summarized. The information and technique disclosed in this summary can be used to evaluate and design the workplace better by effectively control the workload of field workers.

고속도로 건설현장의 인적오류 예방을 위한 실무자용 도구 개발

김정룡(Jung Yong Kim),윤상영(Sang Young Yoon),조영진(Young Jin Cho) 대한인간공학회 2011 大韓人間工學會誌 Vol.30 No.1

Objective: The aim of this study is to reclassify human errors and to develop hands-on tools to apply the new classification for preventing human error accidents in highway construction site. Background: The main cause of accidents in highway construction was reported as the carelessness of workers. However, such diagnosis could not help us operationally prevent accidents in real workplace. Method: The accidents in highway construction were reanalyzed and the causes of human error were reclassified in order to educate and improve the awareness of human error in highway construction. Field survey and interview with safety managers and workers were conducted to find the causal relationship between the actual accidents and the human errors. Results: The most frequently observed human errors in highway construction were classified into six categories such as mis-perception, distraction, memory fail, slip, cognition error and mis-judgment. In order to provide hands-on tools to increase the awareness of human error in construction field, the human error checklist and card sorting diary were developed. Especially, the card sorting diary was designed to increase the ability in human error inspection of safety manager at construction site. Moreover, posters were developed based on actual accident cases. Conclusion: We suggested that the improved awareness and analytical report on checklist, card sorting diary and posters for construction field could collectively prevent the accident. Application: The classification of human error, hands-on tools and posters can be directly applicable on highway construction site. This analytical and collective approach preventing human error-related accident could be extended to other construction workplaces.

휴대전화 설계를 위한 연령대별 사용자 특성

김정룡(Jung Yong Kim),김성훈(Sung Hoon Kim),조영진(Young Jin Cho) 대한인간공학회 2010 大韓人間工學會誌 Vol.29 No.3

The purpose of this study is to investigate the user characteristics in different age groups by investigating the level of satisfaction and preference of design and function of mobile phone. 160 subjects participated in the experiment. Subjects with different ages were selected and divided into four groups: young age group (20 to less than 45), 1<SUP>st</SUP> middle age group (45 to less than 55), 2<SUP>nd</SUP> middle age group(55 to less than 65), and elderly group(over 65). A questionnaire was developed based on the previous design guideline, and additional questions were made to test newly developed function and design of the mobile phone. In particular, depth interviews were conducted in order to have a proper response from old subjects who have difficulties in completing written questionnaire. In result, it was found that except for price the major criterion to purchase mobile phone was the design, and the function of phone was the next except for elderly group. In the case of elderly group, the screen size is the first. Statistical results indicated that 37.5% of the young age group, 22.5% of 1<SUP>st</SUP> middle age group, 22.5% of 2<SUP>nd</SUP> middle age group and 10.0% of the elderly group preferred the design to function when they purchase mobile phones. Most elderly people were not satisfied with the supplementary function of the mobile phone. The 1<SUP>st</SUP> middle age group did not know exactly how to use the supplementary service although they were willing to use it. Regarding the emotional preference on the type of phone, the sliding type was preferred most. Current results can be used to anticipate the future trend of mobile phone and design a user-friendly product for the aged population.

생체신호 측정을 통한 운전자의 감정적 안정상태 평가

김정룡(Jung Yong Kim),박지수(Ji Soo Park),윤상영(Sang Young Yoon) 대한인간공학회 2011 大韓人間工學會誌 Vol.30 No.1

Objective: The aim of this study is to introduce a methodology to assess driver's emotion stability by using bio-signals. Background: Psychophysiological analysis of driver's behavior has been conducted to improve the driving safety and comfort. However, the variability of bio-signal and individual difference made it difficult to assess the psychophysiological status of drivers that can be expressed as emotional stability of drivers. Method: Two experimental studies were reviewed and summarized. New techniques assessing emotional stability of drivers were explained. Statistical concept and multidimensional space were used to identify the emotionally stable conditions. Conclusion: Psychophysiological approach can provide information of driver's emotional status. The experimental methodology and algorithm used in this study showed the possibility of parameterization of psychophysiological response. Application: Currently measured statistical and geometrical data can be further applied to develop an interactive device monitoring and reacting driver's emotion when driver experiences emotionally unstable or uncomfortable situation.

휴대전화와 MP3에 사용되는 Wheel Navigation Key의 사용성 평가

김정룡(Jung?Yong Kim),정현욱(Hyun?Wook Jung),민승남(Seung Nam Min) 대한인간공학회 2009 大韓人間工學會誌 Vol.28 No.3

The aim of the study is to investigate the usability of wheel navigation key(WNK) recently adopted for the new models of mobile phone and MP3 product. In this study, an experiment was designed to evaluate the functional benefit of WNK by using a performance test. A questionnaire was also used to examine the personal preference. In results, a significant difference was found in performance time between wheel-type and button-type product. In general, the difference was more significant as subject's skill level was higher. In particular, the performance time was significantly shortened with the WNK when a searching task was required, but push button was an effective interface for simple search task among beginners. Therefore, the wheel navigation key can be used to improve the usability of product by reducing the searching time in mobile phone and mp3. For practical application, the user's level of skill needs to be considered to maximize the effect of interface when choosing WNK or push button.

User Experience를 고려한 자동차 전조등 설계 방안

김정룡(Jung Yong Kim),윤상영(Sang Young Yoon),민승남(Seung Nam Min),이호상(Ho Sang Lee) 대한인간공학회 2010 大韓人間工學會誌 Vol.29 No.4

The aim of study is to suggest the design procedure of automobile headlamp by considering driver's experience in regard of the visibility and glare during nighttime driving. The characteristics of driver were investigated in terms of the drivers' cognitive ability and reaction time, headlamp specification and visibility, light source and glare. And, the degree of visual discomfort was categorized and recognized as a tool to represent the subjective user experience. The UX point of view was stated when the existing results were seemingly lacking of it. The visual comfort and safety of elderly drivers were also discussed by reviewing the studies of ageing regarding the visibility and driving responses. Finally, this study suggested how to reduce the negative effect of nighttime driving due to the height of headlamp, angle of lighting, color spectrum, discomfort glare, source of light by using the UX perspective and methodology.

휴대전화 설계를 위한 고령자용 인지능력 측정 프로토콜 개발

김정룡(Jung?Yong Kim),조은주(Eun?Ju Cho),조영진(Young Jin Cho),정민근(Min?Keun Chung) 대한인간공학회 2009 大韓人間工學會誌 Vol.28 No.3

The purpose of this research is to develop a protocol which can quantitatively evaluate cognitive ability that is needed when elderly people use mobile phone. Since previous methods for measuring the cognitive ability of elderly people was mainly for clinical evaluation, they would not be adequate to measure cognitive ability for mobile phone development. Therefore, this study suggests cognitive areas which are necessary to use the mobile phone based on the existing evaluation tools. The cognitive areas consist of language, visuospatial ability, memory, executive function and perception. New questionnaire was developed to evaluate the individual cognitive ability for the elderly. They include 9 questions for button comprehension test, 8 for icon button comprehension test, 10 for vocabulary comprehension test, 8 for menu comprehension test, 3 for icon size test, and 2 for font size test. The protocol can be used in the field although further modification may be necessary for betterment.

게임 중독군의 게임 중 스트레스 반응민감도에 따른 HRV 파라미터 추출

김정룡(Jung Yong Kim),김혜솔(Heasol Kim),김동준(Dong Joon Kim) 대한인간공학회 2020 大韓人間工學會誌 Vol.39 No.5

Objective: The purpose of this study is to extract quantitative parameters that indicate significant differences in ECG (electrocardiogram) between game-addicted group and non-addicted group. Background: Although the concept and side-effects of game addiction are recognized around the world, there is no objective means to define game addiction among health authorities, academic societies, and institutions. Also, studies suggesting objective references have been lacking so far. Considering the limitations of the current diagnosis subjective scale, it is necessary to make a quantitative assessment for the prevention and treatment of game addiction. Method: With the existing diagnostic questionnaire, authors classified subjects into game-addicted groups and non-addicted group, and used ECG parameters representing heart rate variability. The parameters were analyzed by applying various window-sizes based on specific game situations. A t-test was used to compare the two groups. Finally, correlation analysis and factor analysis were performed to extract the best parameters to differentiate the two groups. Results: The large window size over 20 minutes of gameplay time, showed no significant difference between the two groups. When the event data were analyzed, there was no significant difference during a player character killed an opponent player. However, when the player character was killed, there were significant differences in parameters. In particular, these differences were most prominent in a window size of 1min 30 sec after the player character was killed. After that, RMSSD and LF were found to be the most sensitive parameters through correlation analysis and factor analysis. Conclusion: In this study, we measured and analyzed the stress response difference by using ECG parameters between game addicted group and the non-addicted group. As a result, it was observed that the game addiction group was sensitive to stress stimuli in a particular situation. The outcome of to extract this study is the optimal window-size and parameters for developing a quantitative model discriminating the sign of addiction among game users in the future. Application: The parameters extracted in this study can be further tested to develop an algorithm to diagnose the addicted players, and the measuring technique used in this study is textile and non-invasive to be used at device development in the future.