• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2019년도 춘계학술대회
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• pp.395-397
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• 2019

조선기술과 항해장비 기술이 발전하고 있지만 여전히 해양사고는 80%이상이 인적과실에서 비롯되고 있다. 인적과실을 저감시켜 해양사고를 절감시키려는 노력은 항해사를 대상으로 면담이나 설문을 시행하는 등 정성적인 연구방식에 많이 의존하고 있어서 객관적인 인적과실의 실체를 규명하는데 제한이 있다. 본 연구에서는 이 같은 단점을 극복하기 위하여 항해사의 항해 업무 수행을 방해하지 않으며 공간적 제한을 극복할 수 있도록 웨어러블 센서를 활용하여 항해사의 동작을 실측하고 상황인지 여부가 항해 수행 동작에 어떤 영향을 미치는지 구분하고자 한다. Full mission ship handling simulator를 활용하여 항해사가 특정한 시나리오를 수행하는 중에 위험성을 가진 장애물을 발견하기 전과 후의 어떤 행동패턴 변화를 보이는지 측정하였다. 구분된 항해 동작 패턴은 항해 위험 상황에서 적절한 조치를 취하고 있는지 여부를 객관적으로 구분하여 인적과실을 절감하는데 활용될 것으로 기대된다.

• 전자통신동향분석
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• 제33권1호
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• pp.123-130
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• 2018

Tactile sensors, which are commonly referred to as pressure and strain sensors, have been extensively investigated to meet the demands for attachable and wearable electronics for monitoring the health status or activity of human users. For this purpose, the introduction of two-dimensional (2D) materials such as graphene and transition metal dichalcogenides (TMDs) with high mechanical strength at the atomic scale is very suitable for tactile sensors applicable for use in human-friendly devices. In this paper, we examine a descriptive summary of a tactile sensor and review state-of- the-art research trends of 2D material-based tactile sensors in terms of the material and architecture. Finally, we propose a roadmap for future studies into advanced tactile sensors based on our ongoing research.

• 한국콘텐츠학회:학술대회논문집
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• 한국콘텐츠학회 2015년도 춘계 종합학술대회 논문집
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• pp.13-14
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• 2015

In the past few decades, many catastrophic natural disasters have occurred not only in Japan and Korea, but also in other countries in the world, forcing people to live in unfamiliar houses for middle or long range evacuation periods. Residents staying in temporary houses exhibit insomnia, resulting in severe fatigue. In order to investigate sleeping state of residents, measuring vital signals has been performed at examination room of a hospital. To avoid the restriction of residents' movement, we propose to use smartphone and/or wearable devices with various high performance sensors like measuring heart beat rate. We clarify the availability and usefulness of those devices as support for analyzing daily sleeping state of residents.

• Asia pacific journal of information systems
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• 제31권1호
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• pp.121-140
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• 2021

The main purpose of this research is to understand the strongest predictors of wearable adoption among athletes with an emphasis on the perceived ethics of biometric data. We performed a word co-occurrence study of biometrics research to determine the ethical constructs of biometric data. A questionnaire incorporating the Unified Theory of Acceptance and Use of Technology (UTAUT), Health Belief Model and Biometric Data Ethics was then designed to develop a neural network model to predict the adoption of wearable sensors among athletes. Our model shows that wearable adoption's strongest predictors are perceived ethics, perceived profit, and perceived threat; which can be categorized as professional stressors. The key theoretical contribution of this paper is to extend the literature on UTAUT by developing a predictive modeling of factors affecting acceptance of wearables by athletes, and highlighting the ethical implications of athlete's adoption of wearables.

• Journal of Electrical Engineering and Technology
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• 제13권5호
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• pp.2059-2066
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• 2018

This study explored the feasibility of utilizing an SWCNT-coated fabric sensor for the development of a wearable motion sensing device. The extent of variation in electric resistance of the sensor material was evaluated by varying the fiber composition of the SWCNT-coated base fabrics, attachment methods, number of layers, and sensor width and length. 32 sensors were fabricated by employing different combinations of these variables. Using a custom-built experimental jig, the amount of voltage change in a fabric sensor as a function of the length was measured as the fabric sensors underwent loading-unloading test with induced strains of 30 %, 40 %, and 50 % at a frequency of 0.5 Hz. First-step analysis revealed the following: characteristics of the strain-voltage curves of the fabric sensors confirmed that 14 out of 32 sensors were evaluated as more suitable for measuring human joint movement, as they yield stable resistance values under tension-release conditions; furthermore, significantly stable resistance values were observed at each level of strain. Secondly, we analyzed the averaged maximum, minimum, and standard deviations at various strain levels. From this analysis, it was determined that the two-layer sensor structure and welding attachment method contributed to the improvement of sensing accuracy.

• Elastomers and Composites
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• 제56권3호
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• pp.117-123
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• 2021

Electronic skin (or E-skin) is an artificial smart skin composed of one or more than two sensors. E-skins detect external stimuli and convert them into electrical signals. Various types of E-skin sensors exist, including mechanical, physical, and chemical, depending on the detection signals involved. For wearable E-skins with superior sensitivity and reliability, developing conductors that possess both good elasticity and sensitivity is essential. Typical electrical conductors used in these sensors show very high sensitivity, but they have drawbacks such as non-linearity, irreversibility, and a narrow sensing range. To address these issues, stretchable and lightweight ionic conductors have been actively used in E-skin applications. This study summarizes the recent progress on various types of ionic conductors and ionic-conductor-based E-skin sensors.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.363.2-363.2
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• 2016

Stretchable strain sensors are becoming essential in diverse future applications, such as human motion detection, soft robotics, and various biomedical devices. One of the well-known approaches for fabricating stretchable strain sensors is to embed conductive nanomaterials such as metal nanowires/nanoparticles, graphene, conducting polymer and carbon nanotubes (CNTs) within an elastomeric substrate. Among various conducting nanomaterials, CNTs have been considered as important and promising candidate materials for stretchable strain sensors owing to their high electrical conductivity and excellent mechanical properties. In the past decades, CNT-based strain sensors with high stretchability or sensitivity have been developed. However, CNT-based strain sensors which show both high stretchability and sensitivity have not been reported. Herein, highly stretchable and sensitive strain sensors were fabricated by integrating single-walled carbon nanotubes (SWNTs) and nylon textiles via vacuum-assisted spray-layer-by-layer process. Our strain sensors had high sensitivity with 100 % tensile strain (gauge factor ~ 100). Cyclic tests confirmed that our strain sensors showed very robust and reliable characteristic. Moreover, our SWNTs-based strain sensors were easily and successfully integrated on human finger and knee to detect bending and walking motion. Our approach presented here might be route to preparing highly stretchable and sensitive strain sensors with providing new opportunity to realize practical wearable devices.

• 한국HCI학회:학술대회논문집
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• 한국HCI학회 2008년도 학술대회 1부
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• pp.240-244
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• 2008

본 논문에서는 근전도 신호 기반의 무선 착용형 컴퓨터 인터페이스를 개발하였다. 밴드 형태의 무선 착용형 단말기는 4 채널 근전도 센서와 붙어있으며, 대역통과 필터 및 차단 필터, 신호증폭기를 이용하여 구별 가능한 근전도 신호를 추출하였다. 얻어진 신호는 무선통신을 통해 컴퓨터로 전송하게 된다. 컴퓨터 인터페이스를 위해 손목 움직임을 사용하였으며, 움직임으로부터 획득된 신호를 다층 인식 신경망을 사용하여 손목 움직임을 인식하게 하였다. 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.

• 감성과학
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• 제22권3호
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• pp.55-64
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• 2019

Stroke is a health problem experienced by many elderly people around the world. Stroke has a devastating effect on quality of life, causing death or disability. Hemiplegia is clearly an early sign of a stroke and can be detected through patterns of body balance and gait. The goal of this study was to determine various feature vectors of foot pressure and gait parameters of patients with stroke through the use of a wearable sensor and to compare the gait parameters with those of healthy elderly people. To monitor the participants at all times, we used a simple measuring device rather than a medical device. We measured gait data of 220 healthy people older than 65 years of age and of 63 elderly patients who had experienced stroke less than 6 months earlier. The center of pressure and the acceleration during standing and gait-related tasks were recorded by a wearable insole sensor worn by the participants. Both the average acceleration and the maximum acceleration were significantly higher in the healthy participants (p < .01) than in the patients with stroke. Thus gait parameters are helpful for determining whether they are patients with stroke or normal elderly people.

• Journal of information and communication convergence engineering
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• 제15권4호
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• pp.244-249
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• 2017

Wearable sensor-based gait analysis has been widely conducted to analyze various aspects of human ambulation abilities under the free-living condition. However, there have been few research efforts on using wearable sensors to analyze human walking on an unstable surface such as on a ship during a sea voyage. Since the motion of a ship on the unstable sea surface imposes significant differences in walking strategies, investigation is suggested to find better performing wearable sensor-based gait analysis algorithms on this unstable environment. This study aimed to compare two representative gait event algorithms including time domain and frequency domain analyses for detecting heel strike on an unstable platform. As results, although two methods did not miss any heel strike, the frequency domain analysis method perform better when comparing heel strike timing. The finding suggests that the frequency analysis is recommended to efficiently detect gait event in the unstable walking environment.