• Journal of the Institute of Electronics Engineers of Korea SC
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• v.45 no.1
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• pp.50-56
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• 2008

In this paper, a digital inclinometer to measure the angle and acceleration signals of subject laid on Roll was designed. The designed system consists of a tilt sensor, biaxial accelerometer, single chip microprocessor and Bluetooth module. The designed digital inclinometer was easy to handle and to wear. To evaluate the performance of the system, we measured simultaneously the angle and acceleration signals from the 3 subjects on the Roll using two instruments which are ZEBRIS and designed system. The measured signals were processed by statistical method and then the correlation coefficient of 0.93 was shown. From the results, the designed digital inclinometer is shown to be useful in assessment of body movement.

• Journal of the Korean Institute of Intelligent Systems
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• v.14 no.4
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• pp.411-417
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• 2004

Recently, instruments and systems related on biological technology have been enormously developed. Particularly, many researches for biological cell injection have been carried out. Usually, excessive contact force occurring when the end-effector and a biological cell contact might make a damage on the cell. Unfortunately, the excessive force could easily destroy the membrane and tissue of the cell. In order to overcome the problem, we proposed a new injection system for biological cell manipulation. The proposed injection system can measure the contact force between a pipette and a cell by using a force sensor. Also, we used vision technology to correctly guide the tip of the pipette to the cell. Consequently, the proposed injection system could safely manipulate the biological cells without any damage. This paper presents the introduction of our new injection system and design concepts of the new micro end-effector. Through a series of experiments the proposed injection system shows the possibility of application for precision biological cell manipulation such as DNA operation.

• Journal of Sensor Science and Technology
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• v.5 no.5
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• pp.11-20
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• 1996

In this paper, the characteristics of therapy radiation diode sensors have been studied by using therapy radiation from the MM22 microtron accelerator. The linearity, reproducibility and error ratio were measured for feasibility as a radiation detector. Energy dependence, sensitivity change after a amount of irradiation and output value according to a number of diodes were also measured for same purpose. We have formed pulse shaping of diode signal with nuclear instruments for portal image reconstruction. The percent depth dose ratio according to field size and depth was compared with that of the detector of a ion chamber. Using thirteen silicon diodes, we can directly read diode outputs on a computer monitor after A/D conversion with 16 channels analog to digital conversion board with 12 bit resolution. The possibility for portal image with diodes has been suggested from output comparison between output value with a human phantom and that without a human phantom.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.29 no.2
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• pp.159-166
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• 2019

Objectives: The purpose of this study was to evaluate the personal exposure to $PM_{10}$ by body parts for the development of dust monitoring wearable device for swine farmers. Methods: Tasks were classified by using motion pictures taken by action cameras attached to swine farmers. Concentrations of $PM_{10}$ were measured by attaching direct-reading instruments at the head, neck and waist of worker. Differences of $PM_{10}$ exposure between body parts were analyzed with linear regression. Results: We identified three tasks(vaccination, moving pigs, and manure treatment). $PM_{10}$ concentration during vaccination was the highest among the tasks, and the body part showing the highest concentration of $PM_{10}$ was the waist regardless of task. In all tasks, the closer distance between the body parts, the higher were the R-squared values(vaccination 0.4221, moving pigs 0.6990, and manure treatment 0.2164). Conclusions: We presumed that $PM_{10}$ concentrations were affected by the parts of the body in which they were measured. In order to develop swine farmer's wearable device for monitoring dust concentration in air, the determination of the positions of monitoring sensor to ensure accurate measurement is essential. Considering the results of this study, wearable sensor should be positioned at the waist.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.11 no.1
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• pp.81-89
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• 2017

In this paper, we propose a gait pattern recognition method for intelligent prosthesis that enables walking in various environments of femoral amputees. The proposed gait mode changing method is a single sensor based algorithm which can discriminate gait surface and gait phase using only strain gauges sensor, and it is designed to simplify the algorithm based on multiple sensors of existing intelligent prosthesis and to reduce cost of prosthesis system. For the recognition algorithm, we analyzed characteristics of the ground reaction force generated during gait of normal person and defined gait step segmentation and gait detection condition, A gait analyzer was constructed for the gait experiment in the environment similar to the femoral amputee. The validity of the paper was verified through the defined detection conditions and fabricated instruments. The accuracy of the algorithm based on the single sensor was 95%. Based on the proposed single sensor-based algorithm, it is considered that the intelligent prosthesis system can be made inexpensive, and the user can directly grasp the state of the walking surface and shift the walking mode. It is confirmed that it is possible to change the automatic walking mode to switch the walking mode that is suitable for the walking mode.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.599-602
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• 2011

A propulsion controller for one-time flight vehicles should be designed robustly so that it can complete its missions even in case sensor failures. These vehicles improve their fault tolerance by back-up sensors prepared for the failure of major sensors, which raises the total cost. This paper presents the NARX model which substitutes vehicles' velocity sensors, and detects failure of sensor signals by using model based fault detection. The designed NARX model and fault detection algorithm were optimized and installed in TI's TMS320F2812 so that they were linked to HILS instruments in real-time. The designed propulsion controller made the vehicle to have better fault tolerance with fewer sensors and to complete its missions under a lot of complicated failure situations. The controller's applicability was finally confirmed by tests under the HILS environment.

• The Journal of Korea Robotics Society
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• v.15 no.3
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• pp.293-300
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• 2020

The purpose of our sensor system is to transparentize the large hydraulic manipulators of a six-ton dual arm excavator from the operator camera view. Almost 40% of the camera view is blocked by the manipulators. In other words, the operator loses 40% of visual information which might be useful for many manipulator control scenarios such as clearing debris on a disaster site. The proposed method is based on a 3D reconstruction technology. By overlaying the camera image from front top of the cabin with the point cloud data from RGB-D (red, green, blue and depth) cameras placed at the outer side of each manipulator, the manipulator-free camera image can be obtained. Two additional algorithms are proposed to further enhance the productivity of dual arm excavators. First, a color correction algorithm is proposed to cope with the different color distribution of the RGB and RGB-D sensors used on the system. Also, the edge overlay algorithm is proposed. Although the manipulators often limit the operator's view, the visual feedback of the manipulator's configurations or states may be useful to the operator. Thus, the overlay algorithm is proposed to show the edge of the manipulators on the camera image. The experimental results show that the proposed transparentization algorithm helps the operator get information about the environment and objects around the excavator.

• Journal of the Semiconductor & Display Technology
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• v.15 no.4
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• pp.1-9
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• 2016

The warpage on mobile phone camera packages occurs due to the CTE(Coefficient of Thermal Expansion) mismatch between a thin silicon die and a substrate. The warpage in the optical instruments such as camera module has an effect on the field curvature, which is one of the factors degrading the optical performance and the product yield. In this paper, we studied the effect of die bonding epoxy on the package and optical performance of mobile phone camera packages. We calculated the warpages of camera module packages by using a finite element analysis, and their shapes were in good agreement showing parabolic curvature. We also measured the warpages and through-focus MTF of camera module specimens with experiments. The warpage was improved on an epoxy with low elastic modulus at both finite element analysis and experiment results, and the MTF performance increased accordingly. The results show that die bonding epoxy affects the warpage generated on the image sensor during the packaging process, and this warpage eventually affects the optical performance associated with the field curvature.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.1481-1484
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• 1997

The vehicle driving simulator expects vehicle motion with real-time simulation arise from driver's steering, accelerating, stopping and simulates motion of vehicl with visula, audio and washout algorithm. And it gives a vivid feeling to driver in reality. Vehicle driving simulator with vehicle integration control system is used for analysis of analysis of vehicle controllaility, steering capacity and safety in various pseudo environment alike. basides, it analyzeds vehicle safety factor dirver's reaction and promotes traffic safety without driver's own risks. The main proceduress of development of the vehicle driving simulator are classified by 3 parts. first the motion base system which can be generated by the motion queues, should be developed. Secondly, real-time vehicle software which can afford the vehicle dynamics, might be constructed. The third procedure is the integration of vehicle driing simulator which can be interconnected between visual systems with motion base. In this study, we are to study of the motion base for a vehicle driving simulator design and that of its real time control and using an extra gyro sensor and accelerometers to find a position and an orientatiion of the moving platform except for calculating forward kinematics. To drive the motion base, we use National Instruments corp's Labview software. Furthemore, we use analysis module for the vehicle motionand the washout algorithm module to consummate driving simulator, which can be driven by human in reality, so we are doing experimentally process about various vehicle motion conditon.

• Journal of the Korean Society of Tobacco Science
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• v.35 no.1
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• pp.20-27
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• 2013

An Electronic Nose(E-Nose) and Gas Chromatography/Mass Spectroscopy (GC/MS) are meanwhile conventional technique to analyze volatile materials in many industries (e.g., food, medicine, environment) and have broad acceptance in the analysis of tobacco products. In this study, an experiment where tin oxide gas sensor array responses and GC/MS profiles are used to characterize the volatile compounds of different cigarettes at the same time is performed and the measurements of two instruments are compared for cigarette samples with a known chemical information. E-Nose and GC/MS were employed to differentiate and match flavored cigarettes with commercial tobacco flavoring agents (lavender, vanilla, peppermint, orange, star anise). For verifying reliability of two systems, the analyses were conducted in terms of amount of flavors in each cigarettes using partial least squares (PLS) and with the principal components analysis (PCA). Various chemical sensors and GC/MS data was reduced into two principal factors (PC1, PC2) for being distinguished with visualized regions. Both systems provided adequate results for odor characteristics of cigarettes in this study with each instrument having its own advantages and disadvantages.