• Tunnel and Underground Space
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• v.11 no.2
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• pp.146-155
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• 2001

An inverse calculation method to obtain sectional forces, axial force and flexural moment of a tunnel concrete lining was developed by utilizing convergence measurements acquired at the maintenance stage. To monitor the behavior of the lining, DOCS system was applied to a subway tunnel section. The method was proved to be effective, yielding the same results as measured forces of buried instruments. Many effects such as vibration of sensors, vibration due to test train operation, the variation of temperature and high voltage were checked and a new management scheme for tunnel maintenance was proposed.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2009.05a
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• pp.255-256
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• 2009

The anti suck back centering (ASBC) for preventing backflow of oil for oil rotary pump was designed in the power failure. To evaluate the evacuation characteristics, we manufactured the mini vacuum system, personal computer, AD converter (National instrument, NI-6009), and automatic controller with touch panel for a basis. In this study, we measured the evacuation characteristics of ABSC and analyzed the flow field of viscous flow regime using a commercial software, CFD-ACE+. Also, the leakage of the advaced ASBC for leveling was measured.

• Journal of Biosystems Engineering
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• v.17 no.4
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• pp.354-362
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• 1992

This study was intended to examine feasibility of sizing and color grading of Fuji apple with black/white image processing system, to develop a device with which the whole surface of an apple could be captured by one camera, and to develop an algorithm for a high speed sorting. The results are summarized as follows : 1. The black/white image processing system used in this study showed a maximum error of 1.3% in area measurement with a reference figure while the focusing point of camera and location of the reference figure were changed within a certain range. 2. As the result of evaluating four automatic image segmentation algorithms with apple images, Histogram Clustering Method was the best in terms of computation time and accuracy. 3. The fast algorithm for analyzing size and coloration of apple was developed. 4. The whole surface of an apple could be captured in an image frame with two mirrors installed on the both sides of the sample. The total area of the image representing the whole surface showed a correlation of 0.995 with the weight of apple. 5. The gray level when a particular band pass filter was mounted on the camera showed high correlation with 'L' and 'a' values of Hunt color scale and could represent the coloration of apple.

• Proceedings of the KOSOMBE Conference
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• v.1997 no.11
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• pp.126-130
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• 1997

In the development of the totally implantable artificial heart (TAH), the information of the preload condition is important to ind appropriate condition or the automatic control of the heart. Our TAH configuration consists of two artificial ventricles, and brushless DC motor within actuator. The pressure between ventricles could indicate the preload condition during the TAH operation. If we can measure accurately inspite of the noise induced from TAH and environmental condition. We suggested integrating a feedback loop to remove an unexpected DC drift. NPI 19-series Nova sensor was used which could measure pressure in gas and liquid. This method and sensor enabled us to develop the pressure transducer compact so (that) the systems can be implanted with TAH into patient. This system has been verified in vitro and in vivo test. This results showed that the output waveform of this system was stable irrespective of animal condition.

• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.9
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• pp.1728-1735
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• 1992

Holographic interferometry technique has been used for the measurement of whole-field deformation with high sensitivity. However there are some difficulties in quantitatively analyzing the holographic fringes. Recently, quantitative and automatic fringe analysis by using phase shifting method in interferometry has been studied in many fields. In this paper, a real time holographic interferometry system and a phase shifting method combined with digital image processing technique are employed to record and quantitatively analyze holographic fringe patterns. To evaluate our system and analyze errors, comparison of measured deformation with theoretical deformation of cantilever beam was carried out. The accuracy of 4.5% in our system was verified We have tried to apply this method to quantitatively measure the deformation of turbine blade under the bending force.

• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.5
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• pp.957-968
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• 2021

To improve the data on reliability of the onshore fish farm water quality monitoring system and operate the system efficiently, the water quality data of the onshore seawater fish farms which are progressing test operation, and the marine environmental information network(Wando tidal station) were compared and analyzed. Furthermore, data validation, data range filters, and data displacement checks were applied to analyze the data in a way that eliminates the data errors in water quality monitoring systems and increases the reliability of measurement data.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.4
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• pp.100-105
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• 2016

The use of 3D scanners has increased gradually according to increasing 3D printer applications. The precision inspection of car parts or electronic components is an important issue not only in the field of mass production, but also in small-scale production. Recently, 3D scanner equipment efficiency and recognition technology has been improved continuously. On the other hand, the spraying time to prepare 3D scanning is time-consuming and has environmental problems. Therefore, an automatic spray system has been in demand by the manufacturing industry. Automatic spray equipment was newly developed for the preparation of a 3D scanner. In this research, the automatic spray system guarantees uniform spray operation. To determine the optimal spray parameters, various spraying methods, solutions and conditions were tested and compared with the experiments. The preparation time for 3D scanning was reduced to 1/10 compared to the manual spraying time, and indicates the optimal spraying conditions through a comparison of various spray coating conditions.

• Journal of Animal Environmental Science
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• v.12 no.1
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• pp.21-28
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• 2006

This study was carried out to measure and analyze the characteristics of noise and vibration, and to analyze their effects on the productivity of layers, mechanical troubles, and abnormal wear-out failure of facilities and equipment of the layer house. The measurements of noise and vibration were taken at 13 layer farms nationwide for the operations of feed supplier system, feed distribution system, automatic egg collection system, ventilation system, blot conveyer for layer feces, and fur the case of with and without their operation by a sound level meter and a vibration measuring system in the layer house equipped with upright multi-tier cages. Measurement results showed that normal times were noise(N) 82 dB and vibration(V) 0.2072 cm/s, feed supplier system were 90 dB(N) and 2.8560 cm/s(V), feed distribution system were 90 dB(N) and 2.0222 cm/s(V), automatic egg collection system were 87 dB(N) and 0.1865 cm/s(V), ventilation system 88 dB(N) and 2.5364 cm/s(V), belt conveyer fur layer feces were 88 dB(N) and 0.2387 cm/s(V), and then maximum values of noise and vibration were 90 dB and 2.8560 cm/s, respectively, when feeding systems(feed supplying system and feed distribution system) were operated. Based on these results, an experiment is being conducted to find out the effect of noise and vibration on the productivity of layers in the layer house equipped with upright multi-tier cages.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.3
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• pp.374-383
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• 2010

Microwave radar can penetrate cloud cover regardless of weather conditions and can be used day and night. Especially a ground-based polarimetric scatterometer has advantages of monitoring crop conditions continuously with full polarization and different frequencies. Kim et al. (2009) have measured backscattering coefficients of paddy rice using L-, C-, X-band scatterometer system with full polarization and various angles during the rice growth period and have revealed the necessity of near-continuous automatic measurement to eliminate the difficulties, inaccuracy and sparseness of data acquisitions arising from manual operation of the system. In this study, we constructed an X-band automatic scatterometer system, analyzed scattering characteristics of paddy rice from X-band scatterometer data and estimated rice growth parameter using backscattering coefficients in X-band. The system was installed inside a shelter in an experimental paddy field at the National Academy of Agricultural Science (NAAS) before rice transplanting. The scatterometer system consists of X-band antennas, HP8720D vector network analyzer, RF cables and personal computer that controls frequency, polarization and data storage. This system using automatically measures fully-polarimetric backscattering coefficients of rice crop every 10 minutes. The backscattering coefficients were calculated from the measured data at a fixed incidence angle of $45^{\circ}$ and with full polarization (HH, VV, HV, VH) by applying the radar equation and compared with rice growth data such as plant height, stem number, fresh dry weight and Leaf Area Index (LAI) that were collected at the same time of each rice growth parameter. We examined the temporal behaviour of the backscattering coefficients of the rice crop at X-band during rice growth period. The HH-, VV-polarization backscattering coefficients steadily increased toward panicle initiation stage, thereafter decreased and again increased in early-September. We analyzed the relationships between backscattering coefficients in X-band and plant parameters and predicted the rice growth parameters using backscattering coefficients. It was confirmed that X-band is sensitive to grain maturity at near harvesting season.

• Journal of Advanced Navigation Technology
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• v.25 no.1
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• pp.68-77
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• 2021

In this paper, a GPS/MEMS IMU integrated navigation receiver module capable of operating in a high dynamic environment is designed and fabricated, and the results is confirmed. The designed module is composed of RF receiver unit, inertial measurement unit, signal processing unit, correlator, and navigation S/W. The RF receiver performs the functions of low noise amplification, frequency conversion, filtering, and automatic gain control. The inertial measurement unit collects measurement data from a MEMS class IMU applied with a 3-axis gyroscope, accelerometer, and geomagnetic sensor. In addition, it provides an interface to transmit to the navigation S/W. The signal processing unit and the correlator is implemented with FPGA logic to perform filtering and corrrelation value calculation. Navigation S/W is implemented using the internal CPU of the FPGA. The size of the manufactured module is 95.0×85.0×.12.5mm, the weight is 110g, and the navigation accuracy performance within the specification is confirmed in an environment of 1200m/s and acceleration of 10g.