• Title/Summary/Keyword: Bio-sensors

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Evolutionary Optimization of Neurocontroller for Physically Simulated Compliant-Wing Ornithopter

  • Shim, Yoonsik
    • Journal of the Korea Society of Computer and Information
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    • v.24 no.12
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    • pp.25-33
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    • 2019
  • This paper presents a novel evolutionary framework for optimizing a bio-inspired fully dynamic neurocontroller for the maneuverable flapping flight of a simulated bird-sized ornithopter robot which takes advantage of the morphological computation and mechansensory feedback to improve flight stability. In order to cope with the difficulty of generating robust flapping flight and its maneuver, the wing of robot is modelled as a series of sub-plates joined by passive torsional springs, which implements the simplified version of feathers attached to the forearm skeleton. The neural controller is designed to have a bilaterally symmetric structure which consists of two fully connected neural network modules receiving mirrored sensory inputs from a series of flight navigation sensors as well as feather mechanosensors to let them participate in pattern generation. The synergy of wing compliance and its sensory reflexes gives a possibility that the robot can feel and exploit aerodynamic forces on its wings to potentially contribute to the agility and stability during flight. The evolved robot exhibited target-following flight maneuver using asymmetric wing movements as well as its tail, showing robustness to external aerodynamic disturbances.

An Exploratory Case Study on the Growth Process and Success Factors in the Research Based Spin-off Ventures;i-SENS (연구기반 스핀오프 벤처기업의 성장과정 및 성공요인에 관한 탐색적 사례연구;(주)아이센스)

  • Lee, Byoung-Heon;Kang, Won-Jin;Jeon, Ho-Eel
    • 한국벤처창업학회:학술대회논문집
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    • 2008.04a
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    • pp.143-178
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    • 2008
  • This study is to look into the spin-off ventures which was incorporated based on the technology developed by public research institute, but underwent difficulties confronted during the development stages focused on the growth process and the factors contributed to their success. The case study was conducted with i-Sense Co., Ltd. which is a ventures organized by professors as a form of research based spin-off venture. i-Sense Co., Ltd. is a new-technology based ventures to produce self-tester for blood sugar level which was incorporated by Prof. Cha, Keun-sik and Prof. Nam, Hak-hyun of Department of Chemistry in Kwangwoon University along with the graduate course students of the Research Laboratory of the University. The two professors operated the Chemical Sensor Research Center at the Kwangwoon University where they produced many preliminary research outputs related with bio-sensors. They also executed the service works at the specialized company they established for research development to make research fund. They established i-Sense Co., Ltd. with the aim to carry out the research they want to. But contrary to the initial intention of the founders of the company, i-Sense Co., Ltd. has grown up as manufacturing company which produces and sells the self-tester for blood sugar level and is expected to be listed by Initial Public Offering (IPO) on the KOSDAQ in 2008. This study is to analyze the foundation and the growth process of i-Sense Co., Ltd. as successful research based spin-off ventures, to find out the factors contributed to their success by enabling them to overcome the difficulties experienced during the growth process, and eventually to provide with suggestive meanings in policy and practical point of view that leaded the research based spin-off ventures to success.

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The Usefulness of a Wearable Smart Insole for Gait and Balance Analyses After Surgery for Adult Degenerative Scoliosis: Immediate and Delayed Effects (척추측만증 환자의 수술 효과 평가 수단으로서 웨어러블 스마트 깔창을 이용한 보행분석의 유용성)

  • Seo, Min Seok;Shin, Myung Jun;Kwon, Ae Ran;Park, Tae Sung;Nam, Kyoung Hyup
    • Journal of Convergence for Information Technology
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    • v.10 no.2
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    • pp.184-192
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    • 2020
  • This study presents a gait analysis method (including time series analysis) using a smart insole as an objective and quantitative evaluating method after lumbar scoliosis surgery. The participant is a degenerative lumbar scoliosis patient. She took 3-min-gait-test four times(before and 8, 16, and 204-days after surgery) and 6-min-gait-test once(204-days after surgery) with smart-insoles in her shoes. Each insole has 8-pressure sensors, an accelerometer, and a gyroscope. The measured values were used to compare the characteristics of gait before and after surgery. The analysis showed that all of the patient's gait parameters improved after surgery. And after 6 months, the gait was more stable. However, after long walk, the swing duration of one leg was slightly shorter than that of the other again. It was a preclinical problem that could not be found in the visual examination by the practitioner. With this analysis method we could evaluate the improvement of patient quantitatively and objectively. And we could find a preclinical problem. This analysis method will lead to the studies that define and distinguish gait patterns of certain diseases, helping to determine appropriate treatments.

Implementation of Gait Analysis System Based on Inertial Sensors (관성센서 기반 보행 분석 시스템 구현)

  • Cho, J.S.;Kang, S.I.;Lee, K.H.;Jang, S.H.;Kim, I.Y.;Lee, J.S.
    • Journal of rehabilitation welfare engineering & assistive technology
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    • v.9 no.2
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    • pp.137-144
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    • 2015
  • In this paper, we present an inertial sensor-based gait analysis system to measure and analyze lower-limb movements. We developed an integral AHRS(Attitude Heading Reference System) using a combination of rate gyroscope, accelerometer and magnetometer sensor signals. Several AHRS modules mounted on segments of the patient's body provide the quaternions representing the patient segments's orientation in space. And a method is also proposed for calculating three-dimensional inter-segment joint angle which is an important bio-mechanical measure for a variety of applications related to rehabilitation. To evaluate the performance of our AHRS module, the Vicon motion capture system, which offers millimeter resolution of 3D spatial displacements and orientations, is used as a reference. The evaluation resulted in a RMSE(Root Mean Square Error) of 1.08 and 1.72 degree in yaw and pitch angle. In order to evaluate the performance of our the gait analysis system, we compared the joint angle for the hip, knee and ankle with those provided by Vicon system. The result shows that our system will provide an in-depth insight into the effectiveness, appropriate level of care, and feedback of the rehabilitation process by performing real-time limb or gait analysis during the post-stroke recovery.

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Smart Emotion Management System based on multi-biosignal Analysis using Artificial Intelligence (인공지능을 활용한 다중 생체신호 분석 기반 스마트 감정 관리 시스템)

  • Noh, Ayoung;Kim, Youngjoon;Kim, Hyeong-Su;Kim, Won-Tae
    • Journal of IKEEE
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    • v.21 no.4
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    • pp.397-403
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    • 2017
  • In the modern society, psychological diseases and impulsive crimes due to stress are occurring. In order to reduce the stress, the existing treatment methods consisted of continuous visit counseling to determine the psychological state and prescribe medication or psychotherapy. Although this face-to-face counseling method is effective, it takes much time to determine the state of the patient, and there is a problem of treatment efficiency that is difficult to be continuously managed depending on the individual situation. In this paper, we propose an artificial intelligence emotion management system that emotions of user monitor in real time and induced to a table state. The system measures multiple bio-signals based on the PPG and the GSR sensors, preprocesses the data into appropriate data types, and classifies four typical emotional states such as pleasure, relax, sadness, and horror through the SVM algorithm. We verify that the emotion of the user is guided to a stable state by providing a real-time emotion management service when the classification result is judged to be a negative state such as sadness or fear through experiments.

Analysis of the PTO Torque of a Transplanter by Planting Condition

  • Kim, Wan Soo;Chung, Sun Ok;Choi, Chang Hyun;Cho, Jong Seung;Choi, Dug Soon;Kim, Young Joo;Lee, Sang Dae;Hong, Soon Jung;Kim, Yong Joo;Koo, Seung Mo
    • Journal of Biosystems Engineering
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    • v.41 no.4
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    • pp.313-318
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    • 2016
  • Purpose: This study measured and analyzed the PTO (power take off) torque of a transplanter according to the planting conditions during field operation. Methods: A torque measurement system was constructed with torque sensors to measure the torque of a PTO shaft, a measurement device to acquire sensor signals, and a power controller to provide power for a laptop computer. The field operation was conducted at four planting distances (26, 35, 43, and 80 cm) and two planting depths using the transplanter on a field with similar soil conditions. One-way ANOVA with planting distance and Duncan's multiple range test at a significance level of 0.05 were used to analyze the PTO torque. The torque ratio was calculated based on the minimum torque using the average PTO torque measured under each planting condition. Results: The average torques on the PTO shaft for planting distances of 26, 35, 43, and 80 cm at a low planting depth were 11.05, 9.07, 7.04, and 3.75 Nm, respectively; the same for planting distances of 26, 35, 43, and 80 cm at a middle planting depth were 12.20, 9.86, 7.94, and 4.32 Nm, respectively. When the planting distance decreased by 43, 35, and 26 cm, the torque ratio at a low planting depth increased by 88, 142, and 195%, respectively. When the planting distance decreased by 43, 35, and 26 cm, the torque ratio at the middle planting depth increased by 84, 128, and 182%, respectively. Conclusions: PTO torque fluctuated by planting distance and depth. Moreover, the PTO torque increased for short planting distances. Therefore, farmers should determine the planting conditions of the transplanter by considering the load and durability of the machine. The results of this study provide useful information pertaining to the optimum PTO design of the transplanter considering the field load.

Development of a Photoplethysmographic method using a CMOS image sensor for Smartphone (스마트폰의 CMOS 영상센서를 이용한 광용적맥파 측정방법 개발)

  • Kim, Ho Chul;Jung, Wonsik;Lee, Kwonhee;Nam, Ki Chang
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.6
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    • pp.4021-4030
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    • 2015
  • Pulse wave is the physiological responses through the autonomic nervous system such as ECG. It is relatively convenient because it can measure the signal just by applying a sensor on a finger. So, it can be usefully employed in the field of U-Healthcare. The objects of this study are acquiring the PPG (Photoplethysmography) one of the way of measuring the pulse waves in non-invasive way using the CMOS image sensor on a smartphone camera, developing the portable system judging stressful or not, and confirming the applicability in the field of u-Healthcare. PPG was acquired by using image data from smartphone camera without separate sensors and analyzed. Also, with that image signal data, HRV (Heart Rate Variability) and stress index were offered users by just using smartphone without separate host equipment. In addition, the reliability and accuracy of acquired data were improved by developing additional hardware device. From these experiments, we can confirm that measuring heart rate through the PPG, and the stress index for analysis the stress degree using the image of a smartphone camera are possible. In this study, we used a smartphone camera, not commercialized product or standardized sensor, so it has low resolution than those of using commercialized external sensor. However, despite this disadvantage, it can be usefully employed as the u-Healthcare device because it can obtain the promising data by developing additional external device for improvement reliability of result and optimization algorithm.

Inferring Pedestrian Level of Service for Pathways through Electrodermal Activity Monitoring

  • Lee, Heejung;Hwang, Sungjoo
    • International conference on construction engineering and project management
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    • 2022.06a
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    • pp.1247-1248
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    • 2022
  • Due to rapid urbanization and population growth, it has become crucial to analyze the various volumes and characteristics of pedestrian pathways to understand the capacity and level of service (LOS) for pathways to promote a better walking environment. Different indicators have been developed to measure pedestrian volume. The pedestrian level of service (PLOS), tailored to analyze pedestrian pathways based on the concept of the LOS in transportation in the Highway Capacity Manual, has been widely used. PLOS is a measurement concept used to assess the quality of pedestrian facilities, from grade A (best condition) to grade F (worst condition), based on the flow rate, average speed, occupied space, and other parameters. Since the original PLOS approach has been criticized for producing idealistic results, several modified versions of PLOS have also been developed. One of these modified versions is perceived PLOS, which measures the LOS for pathways by considering pedestrians' awareness levels. However, this method relies on survey-based measurements, making it difficult to continuously deploy the technique to all the pathways. To measure PLOS more quantitatively and continuously, researchers have adopted computer vision technologies to automatically assess pedestrian flows and PLOS from CCTV videos. However, there are drawbacks even with this method because CCTVs cannot be installed everywhere, e.g., in alleyways. Recently, a technique to monitor bio-signals, such as electrodermal activity (EDA), through wearable sensors that can measure physiological responses to external stimuli (e.g., when another pedestrian passes), has gained popularity. It has the potential to continuously measure perceived PLOS. In their previous experiment, the authors of this study found that there were many significant EDA responses in crowded places when other pedestrians acting as external stimuli passed by. Therefore, we hypothesized that the EDA responses would be significantly higher in places where relatively more dynamic objects pass, i.e., in crowded areas with low PLOS levels (e.g., level F). To this end, the authors conducted an experiment to confirm the validity of EDA in inferring the perceived PLOS. The EDA of the subjects was measured and analyzed while watching both the real-world and virtually created videos with different pedestrian volumes in a laboratory environment. The results showed the possibility of inferring the amount of pedestrian volume on the pathways by measuring the physiological reactions of pedestrians. Through further validation, the research outcome is expected to be used for EDA-based continuous measurement of perceived PLOS at the alley level, which will facilitate modifying the existing walking environments, e.g., constructing pathways with appropriate effective width based on pedestrian volume. Future research will examine the validity of the integrated use of EDA and acceleration signals to increase the accuracy of inferring the perceived PLOS by capturing both physiological and behavioral reactions when walking in a crowded area.

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Feasibility Test on Automatic Control of Soil Water Potential Using a Portable Irrigation Controller with an Electrical Resistance-based Watermark Sensor (전기저항식 워터마크센서기반 소형 관수장치의 토양 수분퍼텐셜 자동제어 효용성 평가)

  • Kim, Hak-Jin;Roh, Mi-Young;Lee, Dong-Hoon;Jeon, Sang-Ho;Hur, Seung-Oh;Choi, Jin-Yong;Chung, Sun-Ok;Rhee, Joong-Yong
    • Journal of Bio-Environment Control
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    • v.20 no.2
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    • pp.93-100
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    • 2011
  • Maintenance of adequate soil water potential during the period of crop growth is necessary to support optimum plant growth and yields. A better understanding of soil water movement within and below the rooting zone can facilitate optimal irrigation scheduling aimed at minimizing the adverse effects of water stress on crop growth and development and the leaching of water below the root zone which can have adverse environmental effects. The objective of this study was to evaluate the feasibility of using a portable irrigation controller with an Watermark sensor for the cultivation of drip-irrigated vegetable crops in a greenhouse. The control capability of the irrigation controller for a soil water potential of -20 kPa was evaluated under summer conditions by cultivating 45-day-old tomato plants grown in three differently textured soils (sandy loam, loam, and loamy sands). Water contents through each soil profile were continuously monitored using three Sentek probes, each consisting of three capacitance sensors at 10, 20, and 30 cm depths. Even though a repeatable cycling of soil water potential occurred for the potential treatment, the lower limit of the Watermark (about 0 kPa) obtained in this study presented a limitation of using the Watermark sensor for optimal irrigation of tomato plants where -20 kPa was used as a point for triggering irrigations. This problem might be related to the slow response time and inadequate soil-sensor interface of the Watermark sensor as compared to a porous and ceramic cup-based tensiometer with a sensitive pressure transducer. In addition, the irrigation time of 50 to 60 min at each of the irrigation operation gave a rapid drop of the potential to zero, resulting in over irrigation of tomatoes. There were differences in water content among the three different soil types under the variable rate irrigation, showing a range of water contents of 16 to 24%, 17 to 28%, and 24 to 32% for loamy sand, sandy loam, and loam soils, respectively. The greatest rate increase in water content was observed in the top of 10 cm depth of sandy loam soil within almost 60 min from the start of irrigation.

Growth of Minuartia laricina, Arenaria juncea, and Corydalis speciose in Field with Various Soil Water Contents (토양 수분 함량에 따른 너도개미자리, 벼룩이울타리, 산괴불주머니의 노지 생육)

  • Gil, Min;Kwon, Hyuck Hwan;Kwon, Young Hyun;Jung, Mi Jin;Kim, Sang Yong;Rhie, Yong Ha
    • Journal of Bio-Environment Control
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    • v.29 no.4
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    • pp.344-353
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    • 2020
  • Plants native in Korea have not only ornamental values but also have excellent environmental adaptability, so they can be used as garden plants. Studies on proper volumetric water content (VWC) of substrates have been reported, but many have been conducted in glasshouse conditions where environmental factors were controlled. When considering garden planting, it is necessary to perform the automated irrigation system in outdoor conditions where rainfall occurs at frequent intervals. This research aimed to investigate the VWC suitable for the growth of Minuartia laricina, Arenaria juncea, and Corydalis speciosa in open filed. Sandy soil which consisted of particles of weathered rock was used, and the VWC of 0.15, 0.20, 0.25, and 0.30 ㎥·m-3 was maintained using an automated irrigation system with capacitance soil moisture sensors and a data logger. No significant differences in growth and antioxidant enzymes activity of A. juncea were observed among VWC treatments. However, the survival rate was low at VWC 0.30 ㎥·m-3 treatment, which was the highest soil moisture content. Even considering the efficiency of water use, we recommended that VWC 0.15-0.20 ㎥·m-3 is suitable for the cultivation of A. juncea. Minuartia laricina showed better growth with lower VWC. Because of frequent rainfall in open field, plant volume and survival rate was high even in VWC 0.15 ㎥·m-3 treatment. In C. speciosa, the plant height, number of shoots and lateral shoots, and fresh and dry weight were higher in plants grown in VWC 0.25 ㎥·m-3 as compared with that in the plants grown at 0.15, 0.20, and 0.30 ㎥·m-3. Based on these results, M. laricina needed less water in open filed, and A. juncea and C. speciosa required higher VWC, but excessive water should be avoided.