• Journal of the Korean Society of Clothing and Textiles
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• v.47 no.3
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• pp.577-592
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• 2023

In this study, nanofiber-based textile sensors were developed for motion detection and monitoring. Poly(vinylidene fluoride) (PVDF) nanofibers containing zinc oxide (ZnO) nanoparticles and silver nanowires (AgNW) were fabricated using electrospinning. PVDF was chosen as a piezoelectric polymer, zinc oxide as a piezoelectric ceramic, and AgNW as a metal to improve electric conductivity. The PVDF/ZnO/AgNW nanocomposite fibers were used to develop a textile sensor, which was then incorporated into an elbow band to develop a wearable smart band. Changes in the output voltage and peak-to-peak voltage (V_p-p) generated by the joint's flexion and extension were investigated using a dummy elbow. The β-phase crystallinity of pure PVDF nanofibers was 58% when analyzed using Fourier transform infrared spectroscopy; however, the β-phase crystallinity increased to 70% in PVDF nanofibers containing ZnO and to 78% in PVDF nanocomposite fibers containing both ZnO and AgNW. The textile sensor's output voltage values varied with joint-bending angle; upon increasing the joint angle from 45° to 90° to 150°, the V_p-p value increased from 0.321 V_p-p to 0.542 V_p-p to 0.660 V_p-p respectively. This suggests that the textile sensor can be used to detect and monitor body movements.

• Journal of Advanced Marine Engineering and Technology
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• v.36 no.5
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• pp.645-661
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• 2012

Recently, pirates are infesting on the sea and they have been hijacking the several vessels for example Samho Dream and Samho Jewelry of Korea. One of the items to reduce the risk is to adopt the invader detection system. If the pirates break in to the ship, the detection system can monitor the pirates and then call the security alarm. The crew can gain time to hide to the safe room and the report can be automatically sent to the control room to cope with the situation. For the invader detection, an unmanned observation system was proposed using the image detection algorithm that extracts the invader image from the recording image. To detect the motion area, the difference value was calculated between the current image and the prior image of the invader, and the 'AND' operator was used in calculated image and edge line. The image noise was reduced based on the morphology operation and then the image was transformed into morphological information. Finally, a neural network model was applied to recognize the invader. In the experimental results, it was confirmed that the proposed approach can improve the performance of the recognition in the invader monitoring system.

• Journal of Biomedical Engineering Research
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• v.16 no.3
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• pp.353-358
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• 1995

The impedance pneumography which is widely used in monitoring respiration is simple to use and noninvasive, but it is sensitive to motion artifacts and insensitive to detect obstructive apnea. A 3-channel respiratory inductive plethysmography (RIP) developed in this study detects inductance change of the inductance band induced by cross-sectional area change of thorax or abdomen as one breathes. It was confirmed that RIP was less sensitive to various motion artifacts but more sensitive to detection of obstructive apnea than impedance pneumography.

• Journal of the Optical Society of Korea
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• v.14 no.4
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• pp.451-457
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• 2010

Increasing demands on the safety of public train services have led to the development of various types of security monitoring systems. Most of the surveillance systems are focused on the estimation of crowd level in the platform, thereby yielding too many false alarms. In this paper, we present a novel security monitoring system to detect critically dangerous situations such as when a passenger falls from the station platform, or when a passenger walks on the rail tracks. The method is composed of two stages of detecting dangerous situations. Objects falling over to the dangerous zone are detected by motion tracking. 3D depth information retrieved by the stereo vision is used to confirm fallen events. Experimental results show that virtually no error of either false positive or false negative is found while providing highly reliable detection performance. Since stereo matching is performed on a local image only when potentially dangerous situations are found; real-time operation is feasible without using dedicated hardware.

• Journal of Convergence for Information Technology
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• v.11 no.6
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• pp.219-225
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• 2021

As for the battery package method, a prismatic package method is preferred for stability reasons, but it is rapidly expanding due to the stability verification of a pouch type package. The pouch type using the lamination process has an advantage of high battery energy density because it can reduce space waste, but has a disadvantage of low productivity. Therefore, in this paper, by extracting edge detection algorithm precision, pattern algorithm precision, and motion controller recall rate by improving backlight lighting fixtures to minimize light diffusion, securing standards for stereo camera position relationship displacement monitoring, and securing standards for lens release monitoring. We propose to implement a system that ensures accuracy and reliability in positioning. As a result of the experiment, the proposed system shows an average error range of 0.032mm for edge detection, 0.02mm for pattern algorithm, and 0.014mm for motion controller, thus ensuring the accuracy and reliability of the positioning mechanism.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1998.10a
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• pp.413-414
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• 1998

This paper presents a real-time Spatial Decision Support System(SDSS) for security camera image monitoring. Other SDSSs are not real-time systems, i.e., they show the images that are already transformed into data format such as virtual reality. In our system, the image is broadcasted in real-time since the purpose of the security camera needs to do it in real-time. With these real-time images, other systems do not add up anything more; the screen just shows the images from the camera. However in our system, we created a motion detection system so that the supervisor(Judge) of a sec.urity monitoring system does not have to pay attention to it constantly. In other words, we created a judge advising system for the supervisor of the security monitoring system. Most of small objects do not need the supervisor's attention since they could be birds, cats, dogs, etc. if they show up in the screen image. In this new system the system only report the unusual change to the supervisor by calculating the motion and size of objects in the screen. Thus the supervisor can be liberated from the 24-hour concentration duty; instead he/she can be only alerted when the real security threat such as a big moving object like an human intruder appears. Thus this system can be called a real-time Spatial DSS. The utility of this system is proved mathematically by using the concept of entropy. In other words, big objects like human intruders increase the entropy of the screen images significantly therefore the supervisor must be alerted. Thus by proving its utility of the system theoretically, we can claim that our new real-time SDSS is superior to others which do not use our technique.hnique.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1055-1056
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• 2007

Asymmetric electro-magnetic force caused by the frictional worn bearing, rotor misalignment and unbalanced rotor etc. generates an asymmetrical operation, vibration and electro-magnetic noise. The need for detection of these rotor eccentricities has pushed the development of monitoring methods with increasing sensitivity and noise immunity. This paper is proposed the analysis method of the squirrel-cage induction motor driven by IGBT inverter using finite element method (FEM) and subroutine. The effect of the unbalanced magnetic pull in the inverter-fed induction motor which is in asymmetrical whirling motion is presented. The analysis results of rotor eccentricity could compare with motors which have been made normal air-gap motor and irregular air-gap motor and verify reliability. The simulation and experiment results can be useful for on-line faults detection monitoring system of induction motors.

• Journal of Korea Multimedia Society
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• v.23 no.3
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• pp.395-401
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• 2020

In this paper, a motion-based ROI extraction algorithm from a high resolution fisheye image is proposed for multi-view monitoring systems. Lately fisheye cameras are widely used because of the wide angle-of-view and they basically provide a lens correction functionality as well as various viewing modes. However, since the distortion-free angle of conventional algorithms is quite narrow due to the severe distortion ratio, there are lots of unintentional dead areas and they require much computation time in finding undistorted coordinates. Thus, the proposed algorithm adopts an image decimation and a motion detection methods, that can extract the undistorted ROI image with a standard angle-of-view for the fast and intelligent surveillance system. In addition, a mesh-type ROI is presented to reduce the lens correction time, so that this independent ROI scheme can parallelize and maximize the processor's utilization.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1908-1909
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• 2007

The design of an intelligent toothbrush, capable of monitoring brushing motion, orientation through the grip axis, during toothbrushing is described. Inappropriate Toothbrushing styles, even in adults, sometimes cause dental problems, cavities, gingivitis, etc. This smart system provides user to monitor his or her brushing pattern using accelerometer and magnetic sensors for evaluation of toothbrushing style. Directional information of toothbrush with respect to earth's magnetic field and activity data were measured by a miniaturized low-power micro- controller, MSP430 and transmitted to personal computer by 2.4GHz radio transmitter, nRF2401. A personal computer provides an on-line display of activity and orientation measurements during toothbrushing. The signal trace is then analyzed to extract clinically relevant measurement. This preliminary study showed that the proposed monitoring system was conceived to aid dental care personnel in patient education and instruction in oral hygiene regarding brushing style.

• Journal of Korea Multimedia Society
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• v.21 no.3
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• pp.382-390
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• 2018

A major accident occurring on the bed is falls that occur during at times when the care of nurses or protectors is inadequate, which is fatal to patients or the elderly. In particular, Enuresis or sleepiness caused by sleep apnea increases the risk of falls. Therefore, it is very important to detect falls and sleep apnea of patients without infringing privacy in the bed to patient's safety and accident prevention. In this paper, we reviewed the technologies developed for bed monitoring and implemented a non-intrusive monitoring system. The Occupancy Sensor allows the temperature of the bed and surrounding area to be extracted to enable track of the patient's motion. The Doppler Radar detects the patient's movements at normal times and the respiration state when patients have no movement during sleeping. It is specially designed for real-time monitoring of falling and respiration during sleeping through contactless multi-sensing while solving patient's privacy problems.