• Proceedings of the Korean Society Of Semiconductor Equipment Technology
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• 2002.11a
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• pp.115-116
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• 2002

This study aimed to investigate flow measurement by using a 'bucket and stop-watch' method of flow measurement. Most flow measurement systems measure pressure or other fluid properties to infer flow rate, though time is a variable which can be easily and very accurately measured. The main principle behind the method was to fill up a reservoir until a set pressure had been reached. This reservoir would then be emptied and the cycle would repeat itself. The prototype was designed to control flow rate using the method. It made use of computer control with an analogue digital converter and fast acting solenoid valves which controlled the flow into a reservoir. Reservoirs were available with internal diameter of 1mm up to 5.5mm to cope with a range of flow rate.

• Journal of the Semiconductor & Display Technology
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• v.20 no.4
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• pp.146-150
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• 2021

Plasma information based virtual metrology (PI-VM) that predicts wafer-to-wafer etch rate variation after wet cleaning of plasma facing parts was developed. As input parameters, plasma information (PI) variables such as electron temperature, fluorine density and hydrogen density were extracted from optical emission spectroscopy (OES) data for etch plasma. The PI-VM model was trained by stepwise variable selection method and multi-linear regression method. The expected etch rate by PI-VM showed high correlation coefficient with measured etch rate from SEM image analysis. The PI-VM model revealed that the root cause of etch rate variation after the wet cleaning was desorption of hydrogen from the cleaned parts as hydrogen combined with fluorine and decreased etchant density and etch rate.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.12 no.3
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• pp.72-82
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• 2009

Research was initiated to investigate early establislment characteristics and germination pattern of perennial ryegrass (PR, Lolium perenne L.). Eight varieties of PR were evaluated in the study. An alternative environmental condition for a PR germination test required by International Seed Testing Association (ISTA) was applied in the experiment, consisting of 8-hr light at $25^{\circ}C$ and 16-hr dark at $15^{\circ}C$ (ISTA conditions). Daily and cumulative germination pattern were measured and analyzed daily for 30 days. Significant differences were observed in germination pattern, days to the first germination, days to 50% germination, days to 75% germination, and final germination rate. Germination rates were variable among the varieties, being 66.00 to 93.75% at the end of study. There were considerable variations in early germination characteristics and germination pattern among PR varieties. The first germination in all entries tested was initiated from 3 to 5 DAS (days after seeding) under ISTA conditions, being 2 days in differences among the varieties. It was 4 to 7 DAS in days to the 50% germination, being 1 to 3 days later from the first germination and three days were variable among them. Days to the 75% germination were 5.93 to 10.50 DAS under ISTA conditions, being 4.57 days in variety differences. Pennant II and Brightstar II were the fastest varieties. The slowest ones were Revenge GLX and Brightstar SLT. Considering days to the first germination, days to 75% germination, and germination pattern etc, Pennant II and Brightstar II were regarded as excellent varieties under ISTA conditions. From tills study, information on differences in germination characteristics and pattern would be usefully applied for golf course design and construction, when established with PR.

• The Journal of the Convergence on Culture Technology
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• v.7 no.4
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• pp.607-612
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• 2021

This study estimated the impact of the shock of housing price increase on the total fertility rate and the contribution of each variable to changes in the TFR. This study is differentiated by estimating the contribution rate of each variable to the fertility rate through the Shapley decomposition and the panel VAR's forecast error variance decomposition, which previous studies have not attempted. The main results of this study are as follows. First, the decline in the TFR in Korea has been strongly influenced by the recent decline in the total fertility rate, and this influence is expected to continue in the future. In the case of housing costs, in the past, housing sales prices had a relatively small contribution to changes in the total fertility rate compared to the jeonse prices, but their influence is expected to increase in the long term in the future. It has been demonstrated that private education expenses other than housing sale price and Jeonse price also acted as a major cause of the decline in the total fertility rate.

• Journal of Advanced Navigation Technology
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• v.25 no.5
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• pp.363-369
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• 2021

In this paper, We propose variable cut-off frequency and variable sample rate small-area multi-channel digital filter for telemetry system. Proposed digital filter reduced hardware area by implementing filter banks that can variably use cut-off frequency and sample rate without additional filter banks for an arbitrary cut ratio. In addition, We propose the architecture in which sample rate can variably be selected according to the number of filters that pass through the multiplexer control. By using time division multiplexing (TDM) supported by the finite impulse response (FIR) intellectual property (IP) of Quartus, the proposed digital filter can greatly reduce digital signal processing (DSP) blocks from 80 to 1 compared without TDM. Proposed digital filter calculated order and coefficients using Kaiser window function in Matlab, and implemented using very high speed integrated circuits hardware descryption language (VHDL). After applying to the telemetry system, we confirmed that the proposed digital filter was operating through the experimental results in the test environment.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2002.05a
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• pp.154-158
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• 2002

The mechanical properties of Al 6061 excluded bar were deformed in high temperature with the variable deformation conditions and characterized by the tensile test. Three types of different strain rate were experimentally performed by using hydraulic press, crank press and hammer and two types of the nominal strain 0.5 and 0.8 were achieved. To decide optimum forging process, the relationship among the strain rate, strain and mechanical properties was explained by analyzing the microstructures of the forged and heat heated parts. The strength was deeply related with the strain rate due to the dynamic recrystallization (DRX) in hot forging, and the best forging condition was presented in Al 6061 alloy.

• Agricultural and Biosystems Engineering
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• v.5 no.1
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• pp.1-4
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• 2004

Community-based precision farming is a new concept of agricultural systems, which leads to organize groups of wise farmers and technology platforms in Japan. The wisdom farmers create a rational farming system to manage hierarchical variability: variability in farmers' community as well as variability of within-field and between-field. The technology platform develops and provides three key-technologies: mapping technology, variable-rate technology, and decision support systems available for rural constraints. Advancement of bio-production robots leads precision farming to the next level, where two technological innovations: how to produce and manage information-oriented fields and information-added products, can be attained.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.6
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• pp.792-798
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• 2021

In this paper, an algorithm for determining the coagulant input rate in the drug-injection tank during the process of the water purification plant was derived through big data analysis and prediction based on artificial intelligence. In addition, analysis of big data technology and AI algorithm application methods and existing academic and technical data were reviewed to analyze and review application cases in similar fields. Through this, the goal was to develop an algorithm for determining the coagulant input rate and to present the optimal input rate through autonomous driving simulator and pilot operation of the coagulant input process. Through this study, the coagulant injection rate, which is an output variable, is determined based on various input variables, and it is developed to simulate the relationship pattern between the input variable and the output variable and apply the learned pattern to the decision-making pattern of water plant operating workers.

• Proceedings of the SAREK Conference
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• 2007.06a
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• pp.183-183
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• 2007

• Journal of Information Display
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• v.10 no.1
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• pp.37-44
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• 2009

AiPi technology incorporates an embedded clock and control scheme with a point-to-point bus topology, thereby having the smallest possible number of interface lines between a timing controller and column drivers. A point-to-point architecture boosts the data rate and reduces the number of interface lines, because impedance matching can be easily achieved. An embedded clock and control scheme is implemented by means of multi-level signalling, which results in a simple clock/data recovery circuitry. A 46" AiPi-based 10-bit FHD prototype requires only 20 interface lines, compared to 38 lines for mini-LVDS. The measured maximum data rate per data pair is more than 800 Mbps.