• Journal of the Korean Society for Aeronautical & Space Sciences
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• 제44권12호
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• pp.1035-1042
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• 2016

By using commercial flight simulation game engine, X-Plane, we have studied QTG(Qualification Test Guide) generation that can satisfy FTD level 5. Flight model is SR-20 of Cirrus. In list of QTG, There are some items to measure control forces. therefore, we have installed CLS(Control Loading System) to flight control devices in order to make it possible to measure control forces. We made Autopilot function externally to make flight model in trim conditions because X-Plane don't provide internal trim routine function. In addition to develop an algorithm, it can automatically perform the test. To avoid the inconvenience to control as it was to be carried out in same conditions. In case of FTD level 5, it is possible to use alternative data sources not only real flight data. By using these alternative data sources, all test results satisfy a scope given by CFR Part 60.

• Progress in Medical Physics
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• 제9권3호
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• pp.143-154
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• 1998

The image intensifier is the key component which determines the imaging characteristics in a fluoroscopic imaging system. A system performance program for clinical evaluation of two image intensifiers, that is simple, non-invasive and time effective, was described. Tests were grouped into three headings: x-ray generator, image quality, and collimation. For the x-ray generator, the kVp accuracy and the automatic exposure control operation were compared. Low- and high-contrast resolution measurements, and mesh pattern study belong to the image quality tests and those tests were performed for the video monitor and photospot images. For the collimation, usable field diameter and image distortion of image intensifiers were measured and quantified. The procedures and the results are hoped to be used for the clinical evaluation of system performance and/or acceptance tests for image intensifiers.

• Journal of the Korea Society of Computer and Information
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• 제17권12호
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• pp.31-39
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• 2012

In this paper, we propose a microprocessor-based automatic voltage regulator(AVR) to reduce consumers' electric energy consumption and to help controlling peak demanding power. Hybrid Switching Automatic Voltage Regulator (HS-AVR) consist of a toroidal core, several tap control switches, display and command control parts. The coil forms an autotransformer which has a serial main winding and four parallel auxiliary windings. It controls the output voltage by changing the combination of the coils and the switches. Relays are adopted as the link switches of the coils to minimize the loss. To make connecting and disconnecting time accurate, relays of the circuit have parallel TRIACs. A software phase locked loop(PLL) has been used to synchronize the timings of the switches to the voltage waveform. The software PLL informs the input voltage zero-crossing and positive/negative peak timing. The traditional voltage transformers and AVRs have a disadvantage of having a large mandatory capacity to accommodate maximum inrush current to avoid the switch contact damage. But we propose a suitable AVR for every purpose in smart grid with reduced size and increased efficiency.

• Proceedings of the KOR-BRONCHOESO Conference
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• 대한기관식도과학회 1978년도 제12차 학술대회연제 순서 및 초록
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• pp.9.2-9
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• 1978

Monaural and binaural hearing aid performance under quiet and noisy conditions were compared in regard to (1) the degree of hearing impairment, (2) the symmetry of pure tone audiogram, (3) the automatic gain control of the hearing aid. (4) hearing impairement with recruitment and, word discrimination ability. Performance using binaural hearing aids was consistently superior to that using monaural hearing aids. The results were as follows. 1. Speech detection thresholds were enhanced by a mean of 4.25dB when tested with danavox 747 PP stereo type hearing aid and by a mean of 4.12 dB when tested hearing aids connected seperately to the right and left ears. 2. Binaurally tested speech reception thresholds were superior to monaurally tested thresholds by a mean of 3.56dB when tested in quiet and by a mean of 5.56dB when tested in noise. 3. Binaurally tested word discrimination scores were also superior by a mean of 17.09% in quiet and by a mean 19.63% in noise. 4. Both SRT and word discrimination scores were performed best by subjects with moderately-severe impairement. The performance by one mildly impaired subject was the poorest of all performances. The levels of performance order were; moderately-severe loss, severe loss. moderate loss and mild loss. 5. The data obtained using AGC aids when compaired with that of linear amplification show that when AGC aids were worn in both ears. the results were very poor but when one AGC aid was worn in one ear and linear amplification in the other. the results were good. 6. The advantages of binaural hearing aids were obvious even in cases 1) with great diferences in hearing thresholds between right and left ears, 2) when the subject was unable to discriminate words without vision and. 3) when the subject had extreme recruitme t phenomenon.

• Journal of Bio-Environment Control
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• 제20권2호
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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.

• Journal of IKEEE
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• 제27권3호
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• pp.340-344
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• 2023

In this paper, we propose a study on the development of deep learning structure to secure visibility of outdoor LED display board according to weather change. The proposed technique secures the visibility of the outdoor LED display board by automatically adjusting the LED luminance according to the weather change using deep learning using an imaging device. In order to automatically adjust the LED luminance according to weather changes, a deep learning model that can classify the weather is created by learning it using a convolutional network after first going through a preprocessing process for the flattened background part image data. The applied deep learning network reduces the difference between the input value and the output value using the Residual learning function, inducing learning while taking the characteristics of the initial input value. Next, by using a controller that recognizes the weather and adjusts the luminance of the outdoor LED display board according to the weather change, the luminance is changed so that the luminance increases when the surrounding environment becomes bright, so that it can be seen clearly. In addition, when the surrounding environment becomes dark, the visibility is reduced due to scattering of light, so the brightness of the electronic display board is lowered so that it can be seen clearly. By applying the method proposed in this paper, the result of the certified measurement test of the luminance measurement according to the weather change of the LED sign board confirmed that the visibility of the outdoor LED sign board was secured according to the weather change.

• Journal of Energy Engineering
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• 제17권2호
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• pp.67-76
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• 2008

A thermal-hydraulic integral effect test facility, ATLAS (Advanced Thermal-hydraulic Test Loop for Accident Simulation), has been constructed at KAERI (Korea Atomic Energy Research Institute). Recently several integral effect tests for the reflood period of a LBLOCA (Large Break LOss of Coolant Accident) of the APR1400 have been performed with the ATLAS. In the APR1400 a high flow condition is changed to a low flow condition due to an fluidic device during an operation of the SIT. As the self-controlled fluidic device was not installed in the ATLAS, a set of characterization tests was performed to simulate its injection capability from the SIT for the APR1400 simulation. In the ATLAS the required SIT flow rate in the high flow condition was acquired by installing orifices with an optimized flow area to throttle the SIT discharge line and the low flow condition was achieved by changing the opening of the flow control valve in the SIT injection line. The test results showed that the safety injection systems of the ATLAS could simulate the required high and low flow rates of the SIT for the APR1400 simulation efficiently.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• 제35권6호
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• pp.527-534
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• 2017

The purpose of this study is to develop unmanned equipment that can automatically move to the desired point and measure water quality at the correct depth. For this purpose, we constructed a water sampling lift and water sampling container, an unmanned vessel equipped with a VRS-GPS, an acoustic echo sounder, and a water quality sensor. Also, we developed an automatic navigation algorithm and program, an automatic water sampling program, and a water quality map generation program. As a result of the experiment in the detention pond, the unmanned vessel sailed along the planned route with an accuracy of about 93% within the error range of 3m. In addition, the water quality sensor installed in the lift was able to acquire the water quality of the target area in real time and transmit it to the server via wireless Internet, and it was possible to monitor the water quality of each site in real time. Through field experiments, the water sampling lift was able to control the desired length with an accuracy of about 94%. The stretch length accuracy experiment of the water sampling lift was impossible to measure directly in the water, so it was replaced land-based experiment. We also found some unstable problems due to the weight of the water sampling lift and the weight of the air compressor to operate the water container. Except these two problems, we accomplished purpose of this study. An automated water quality measurement method using an unmanned vessel can be used to measure the quality of water in a difficult to access area and to secure the safety of the worker.

• Korean Journal of Plant Resources
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• 제29권5호
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• pp.579-587
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• 2016

The final goal of this research is to develop a miniaturized botanical biofilter using a wick-typed automatic humidifier for stabilizing soil moisture content (SMC) and purifying indoor air pollutants by the biofilter. This new biofilter equipped with wick-typed automatic humidifier was manufactured as more compacted design removing an absorption tower-typed humidifier compared with the previous big-sized biofilter made in 2015. This study was performed to compare changes of SMCs among floors depending on the number of wicks installed on the humidifier within the novel biofilter, and to compare changes of SMCs and plant growth parameters before and after planting Spathiphyllum wallisii ‘Mauna Loa’ on the biofilter. SMCs among floors depending on the number of wicks were similar, and all regression lines of SMCs showed almost horizontal lines because of long-term stability on SMCs. Comparing plant growth parameters of S. wallisii ‘Mauna Loa’ before planting and at 30 days after planting on the biofilter, all growth parameters were not statistically significant. Thus, SMCs of the biofilter were more stabilized using this humidifying apparatus regardless of the number of wicks than the previous biofilter using absorption tower-typed humidifying apparatus.

• Korean Journal of Food Science and Technology
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• 제19권3호
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• pp.200-205
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• 1987

A microcomputer-based on-line monitoring and controlling system was built and applied to the dehycration operation. Drying conditions-drying temperatures and air velocities-were successfully controlled by the control deveices incorporated on/off realy and thyristor, and with the high language program. Drying variables-temperature in drier and weight loss of radish slice were accurately measured and acquisited. The computer-based drying system effectively saved the man power required to measure and record data during the drying period and also made possible to conduct the process undisturbed for long period. The drying rate curves of radish at various drying conditions were obtained from automatic data analyzing program. And also the computer programmed control made possible to investigate the effect of air velocity change during the drying period. The dynamic change of air velocity of from one to another level could be performed and affected markedly the drying rate at first stages of drying, but no significant effect were found in falling rate period.