• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.34 no.6
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• pp.487-494
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• 2021

Piezoelectric generators use direct piezoelectric effects that convert mechanical energy into electrical energy. Many studies were attempted to fabricate piezoelectric generators using piezoelectrics such as ZnO, PZT, PVDF. However, these various inorganic/organic piezoelectric materials are not suitable for bio-implantable devices due to problems such as brittleness, toxicity, bio-incompatibility, bio-degradation. Thus, in this paper, piezoelectric generators were prepared using a silk fibroin film which is bio-compatible by dip-coating method. The silk fibroin films are a mixed state of silk I and silk II having stable β-sheet type structures and shows the d₃₃ value of 8~10 pC/N. There was a difference in output voltages according to the thickness. The silk fibroin generators, coated 10 times and 20 times, revealed the power density of 16.07 μW/cm² and 35.31 μW/cm² using pushing tester, respectively. The silk fibroin generators are sensitive to various pressure levels, which may arise from body motions such as finger tapping, foot pressing, wrist shaking, etc. The silk fibroin piezoelectric generators with bio-compatibility shows the applicability as a low-power implantable piezoelectric generator, healthcare monitoring service, and biotherapy devices.

• Electronics and Telecommunications Trends
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• v.36 no.5
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• pp.32-41
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• 2021

As the COVID-19 crisis continues, working environments and lifestyles have been changed unexpectedly, therefore the importance of mental health in the working environments has been highlighted. When the workers' mental health deteriorates, there will be personal losses but also human resources losses caused productivity decrements of the company or the organization. Many researchers have been tried to solve these issues with the help of ICT technologies such as wearable devices. Most wearable healthcare devices have been designed to detect the physiological status of users and collect the physical activities of users, and their applications are gradually expanding. Those devices may be good candidates to prevent loss of human resources from working environments especially under the COVID-19 situation by continuously monitoring mental health status in connection with mobile devices and managing the mental health on their own by combining mental well-being with support solutions. In this paper, the development trend of mental health measurement and mental well-being support technologies is analyzed, and development prospects are examined.

• Journal of IKEEE
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• v.22 no.4
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• pp.978-984
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• 2018

Currently, virtual reality technology is actively applied in the entertainment and game fields, and development of professional programs is gradually increasing due to the rapid development of Internet and web technologies. As the current paradigm for healthcare changes from treatment to prevention, it is more important to take good care of it in advance so it doesn't get sick. This paper allows users to monitor the amount of exercise directly after using VR sports games. By using this system, users can exercise more interestingly and manage their own fitness by receiving an analyzed amount of exercise.

• Journal of the Microelectronics and Packaging Society
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• v.25 no.4
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• pp.25-34
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• 2018

In this paper, we review the latest technical progress and commercialization of stretchable interconnectors, stretchable strain sensors, and stretchable substrates for stretchable electronics. The development of stretchable electronics can pave a way for new applications such as wearable devices, bio-integrated devices, healthcare and monitoring, and soft robotics. The essential components of stretchable electronic devices are stretchable interconnector and stretchable substrate. Stretchable interconnector should have high stretchability and high electrical conductivity as well as stability under severe mechanical deformation. Therefore several nanocomposite-based materials using CNT, graphene, nanowire, and metal flake have been developed. Geometric engineering such as wavy, serpentine, buckled and mesh structure has been well developed. Stretchable substrate should also pose high stretchability and compatibility with stretchable sensing or interconnecting material. We summarize the recent research results of new materials for stretchable interconnector and substrate as well as strain sensors. The Important challenges in development of the stretchable interconnector and substrate are also briefly discussed.

• BioChip Journal
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• v.12 no.4
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• pp.326-331
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• 2018

Contamination by pesticides is an everincreasing problem associated with fields of environmental management and healthcare. Accordingly, appropriate treatments are in demand. Pesticide detection methods have been researched extensively, aimed at making the detection convenient, fast, cost-effective, and easy to use. Among the various detecting strategies, paper-based assay is potent for real-time pesticide sensing due to its unique advantages including disposability, light weight, and low cost. In this study, a paper-based sensor for chlorpyrifos, an organophosphate pesticide, has been developed by layering three sheets of patterned plates. In colorimetric quantification of pesticides, the blue color produced by the interaction between acetylcholinesterase and indoxyl acetate is inhibited by the pesticide molecules present in the sample solutions. With the optimized paper-based sensor, the pesticide is sensitively detected (limit of detection =8.60 ppm) within 5min. Furthermore, the shelf life of the device is enhanced to 14 days after from the fabrication, by treating trehalose solution onto the deposited reagents. We expect the paper-based device to be utilized as a first-screening analytic device for water quality monitoring and food analysis.

• Journal of Information Processing Systems
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• v.18 no.3
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• pp.302-310
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• 2022

Efficient use of limited blood products is becoming very important in terms of socioeconomic status and patient recovery. To predict the appropriateness of patient-specific transfusions for the intensive care unit (ICU) patients who require real-time monitoring, we evaluated a model to predict the possibility of transfusion dynamically by using the Medical Information Mart for Intensive Care III (MIMIC-III), an ICU admission record at Harvard Medical School. In this study, we developed an explainable machine learning to predict the possibility of red blood cell transfusion for major medical diseases in the ICU. Target disease groups that received packed red blood cell transfusions at high frequency were selected and 16,222 patients were finally extracted. The prediction model achieved an area under the ROC curve of 0.9070 and an F1-score of 0.8166 (LightGBM). To explain the performance of the machine learning model, feature importance analysis and a partial dependence plot were used. The results of our study can be used as basic data for recommendations related to the adequacy of blood transfusions and are expected to ultimately contribute to the recovery of patients and prevention of excessive consumption of blood products.

• Journal of Information Technology Services
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• v.21 no.6
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• pp.21-37
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• 2022

Due to the development of technology and medical care following the 4th industrial revolution, the medical paradigm is shifting towards patient-centered medical services. Based on the development of smart home technology, the residential environment is changing into a residential space that cares for and heals the lifestyles and the healthcare of families. As lifestyle changes, the concept of supporting smart home care based on the residential environment is making it possible to build a smart home IoT service design with enhanced accessibility and convenience for medical appointments and well-being lifestyle care. This paper is a study on user-centered health care smart home IoT service design suitable for family members based on the health care, beauty care, exercise care, and customized diet care beyond the conventional concept of health care monitoring. Based on the analysis, this paper proposes a personal care coordinate smart home service design in a human-centered wellness clinic care smart home service design environment. Human-centered wellness clinic smart home IoT service design is meaningful in presenting a vision for research on smart home service design that links hospital-linked and care-linked service industries, which should be considered from the smart home construction planning stage.

• Korean Journal of Veterinary Service
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• v.45 no.2
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• pp.125-131
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• 2022

The purpose of this study was to examine antibody titers to structural protein (SP) of the foot-and-mouth disease (FMD) virus after vaccination in animals of the Seoul zoo. After the initial inoculation of FMD vaccine to the susceptible animals of the zoo, a total of 235 blood samples were collected from 42 species of zoo animals during treatment or necropsy. All samples were tested by using enzyme-linked immunosorbent assay (ELISA). The overall positive rate of SP antibodies against FMD virus was 94.0% (221/235). However, the positive rates varied according to animal species. The results of positive rates in 30 species were 100% but in 12 species were 50-94.7%. We showed that most animals that have received FMD vaccine in Seoul zoo have been reached to the level of herd immunity against FMD virus after the vaccination. To the best of our knowledge, this study would be the first report for monitoring the vaccine-induced SP antibody titers against FMD virus after vaccination in various zoo animal species in Korea.

• Journal of Powder Materials
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• v.30 no.4
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• pp.310-317
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• 2023

Small-film-type ion sensors are garnering considerable interest in the fields of wearable healthcare and home-based monitoring systems. The performance of these sensors primarily relies on electrode capacitance, often employing nanocomposite materials composed of nano- and sub-micrometer particles. Traditional techniques for enhancing capacitance involve the creation of nanoparticles on film electrodes, which require cost-intensive and complex chemical synthesis processes, followed by additional coating optimization. In this study, we introduce a simple one-step electrochemical method for fabricating gold nanoparticles on a carbon nanotube (Au NP-CNT) electrode surface through cyclic voltammetry deposition. Furthermore, we assess the improvement in capacitance by distinguishing between the electrical double-layer capacitance and diffusion-controlled capacitance, thereby clarifying the principles underpinning the material design. The Au NP-CNT electrode maintains its stability and sensitivity for up to 50 d, signifying its potential for advanced ion sensing. Additionally, integration with a mobile wireless data system highlights the versatility of the sensor for health applications.

• Proceedings of the Korea Information Processing Society Conference
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• 2009.11a
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• pp.277-278
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• 2009

차세대 하이테크 스마트 의류는 복합 차원에서의 감성적인 요소를 섬유 패션기술에 IT융합 기술을 이용하여 제공하고 있다. 생체신호를 이용한 감성은 모호하여 정량적이고 객관적인 측정이 어렵고, 그 표현도 제한된 감성 어휘에 의하여 나타나기 때문에 구체적으로 파악하는 것은 어려운 일이다. 이를 위하여 제품의 기능적 측면뿐만 아니라 정서적 감정과 선호도가 반영된 제품의 설계나 디자인 또한 요구되고 있다. 본 논문에서는 생체신호 측정을 위한 웨어러블 기반의 심전도 측정 의복을 제안하였다. 착용자가 평소 자주 입는 티셔츠를 응용하여 답답해하거나 불편하지 않게 제작하고 소매 형태로 신축성있는 소재를 사용한다. 인체의 형태에 따라 의복과 바이오센서의 전극이 안정적으로 밀착될 수 있도록 고탄력 밴드를 이용하여 일자형으로 제작하였다. 심전도 측정 의복을 착용에 의해 수집된 심전도 ECG 파형을 수집하고 심박변화율을 계산하는 시뮬레이션을 개발한다.