• Journal of Bio-Environment Control
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• v.30 no.1
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• pp.27-36
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• 2021

A capacitive water sensor was developed to measure the capacitance over a wide part of a substrate using an insulated electrode plate (30 cm × 10 cm) with copper and Teflon attached on either side of the substrate. This study aimed to convert the capacitance output obtained from the condenser-type capacitance sensor into the substrate water content. The quantification experiment was performed by measuring the changes in substrate water weight and capacitance while providing a nutrient solution and by subsequently comparing these values. The substrate water weight and capacitance were measured every 20 to 30 seconds using the sensor and load cell with a software developed specifically for this study. Using a curve-fitting program, the substrate water content was estimated from the output of the capacitance using the water weight and capacitance of the substrate as variables. When the amount of water supplied was increased, the capacitance tended to increase. Coefficient of variation (CV) in capacitance according to the water weight in substrate was greater with the 1.0 kg of water weight, compared with other weights. Thus, the fitting was performed with higher than 1.0 kg, from 1.7 to 6.0 kg of water weight. The correlation coefficient between the capacitance and water weight in substrate was 0.9696. The calibration equation estimated water content from the capacitance, and it was compared with the substrate water weight measured by the load cell.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.14 no.4
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• pp.52-61
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• 2015

PCE(Passenger Car Equivalents) is used to analysis of road capacity and LOS(Level of Service). In this study calculates PCE by number of lane and 12 vehicle type by MOLIT(Minister of Land, Infra Structure and Transport) using individual vehicle data. The results of the calculation, PCEs are increased when high vehicle classification level, many number of lanes and weekend. Heavy vehicle factors are smaller than KHCM on 4, 6 lane. Also, In this study estimates of PCE variation model by heavy vehicle percentage. Impact of Heavy vehicles on PCEs is the most sensitive on 2 lane. The results of the study, heavy vehicles low impact on PCE on multi-lane and business trips are a little in weekend.

• Journal of the Institute of Convergence Signal Processing
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• v.10 no.1
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• pp.49-59
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• 2009

In this paper a watermarking algorithm is proposed to optimize the capacity of the digital watermark insertion in an experimental threshold using the characteristics of human visual system(HVS), adaptive scale factors, and weight functions based on discrete wavelet transform. After the original image is decomposed by a 3-level discrete wavelet transform, the watermarks for capacity optimization are inserted into all subbands except the baseband, by applying the important coefficients from the experimental threshold in the wavelet region. The adaptive scale factors and weight functions based on HVS are considered for the capacity optimization of the digital watermark insertion in order to enhance the robustness and invisibility. The watermarks are consisted of gaussian random sequences and detected by correlation. The experimental results showed that this algorithm can preserve a fine image quality against various attacks such as the JPEG lossy compression, noise addition, cropping, blurring, sharpening, linear and non-linear filtering, etc.

• Journal of Energy Engineering
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• v.2 no.1
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• pp.95-103
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• 1993

A conceptual thermoelectric heat pump(cooling mode) of small capacity is designed. Its performance is investigated through parametric analysis. COP and cooling capacity decease as the ambient temperature increases with ${\mu}$, J, T$\sub$wi/, fixed. To design a system of fixed capacity comes to calculate ${\mu}$ and J when T$\sub$wi/, and T$\sub$a/ are given. As v is fixed by semi-conductor manufacturers, optimum combination of n and I should be searched for ν. Optimum current could be calculated using ${\mu}$-J curve and optimum value of ${\mu}$. COR$\sub$R/ increases as water flow rate increases and T$\sub$a/ decreases. The effect of heat transfer coefficient at hot(heat releasing) side is more significant than that at cold(heat absorbing) side.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.38 no.1
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• pp.23-29
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• 2001

The effects of Ti-silicide process on the electrical properties of an analog polysilicon capacitor were investigated. To improve the linearity with the applied voltage both electrodes, which are polysilicon in our device, should have almost same material properties. The doping concentrations of both electrodes need to be high and to have the similar levels. Voltage Coefficient of Capacitance (VCC) is one of the properties to represent the linearity of analog capacitor, and it is related with the material and the structure of capacitor. In this study, it was possible to obtain the lower VCC by siliciding the polysilicon areas of capacitor. This is due to the parasitic capacitance at the interfaces between silicide and polysilicons, resulting the decrease of unit capacitance. However, we assumed the creation of positive oxide charge near the lower polysilicon electrode during the silicide process.

• Journal of Korean Society of Transportation
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• v.18 no.4
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• pp.41-50
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• 2000

신호교차로에서 맨 우측차로의 대부분이 우회전 공용차로로 사용되는데 도로용량편람에서 우회전이 불가능한 보행자 횡단시간 비율$(f_c)$은 공용차로의 용량을 결정하는 우회전보정계수$(f_{RT})$의 산정시 중요한 요소가 된다. 그러나 이에 대한 국내의 연구는 미미하여 연구의 필요성이 있다고 생각된다. 본 연구는 유입부의 직진신호시간을 위주로 교차방향 횡단보도 내의 보행자수와 우회전차량의 통과여부를 촬영하여 분석하는 방법으로 진행되었으며, 우회전 차량이 교차도로의 보행자 횡단시간에 보행자와의 상충으로 우회전하지 못하는 시간 비율을 산정함에 있어서 횡단보도의 보행자수에 따라 우회전 차량의 통과율을 구하고 이로부터 횡단보도 보행신호시간동안에 우회전이 불가능한 시간비율을 산정했다. 연구결과는 우회전이 불가능한 시간비율이 시간당 보행자수(양방향)가 500인/시~1,500인/시로 변할 때 0.78에서 0.94사이의 값을 가지며 한국도로용량편람에서 제시한 값 0.3에서 0.9보다는 대체로 큰 것으로 나타났다. 따라서 한국용량편람에서 얻은 우회전차로의 용량은 과대 평가되는 경향이 있다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.4D
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• pp.305-311
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• 2012

With the rapid deployment of hipass$^{(R)}$, the congestion is inevitable due to the operation of the hipass lane system. Recently, SMART Highway project have developed a multi-lane mainline tolling system, called SMART Tolling system. To analyze the effectiveness of the system in terms of capacity, this study tries to estimate the capacity and its improvement of multi-lane tolling system based on current hipass$^{(R)}$ data. The methodology uses the saturation time headway. This follows three steps; 1) estimate the saturation time headway, using hipass$^{(R)}$ data, and capacity. 2) estimate two factors (the first one is dividing the one side lane width and lateral clearance factor ($f_w$) into two side one, the second one is dividing the capacity of hipass lane operating a circuit breaker into the capacity of hipass lane not operating, the last one is increasing factor of lane width). 3) calculate the capacity of multi-lane mainline tolling system. The results of method produced 2172~2187 veh/hour as smart tolling capacities, respectively. Those are higher about 370 veh/hour than the values from existing literature reviews. Additionally, saturation time headways were identified as lower by 0.5 seconds/veh than existing headways based on hi-pass$^{(R)}$ based one, which naturally implies the improvement in capacity. Some limitations and future research agenda have also been discussed.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.20 no.8
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• pp.761-769
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• 2009

In this paper, we report on the channel capacity and diversity gain of the vehicle on-glass antenna for FM radio reception. The correlation coefficient and channel capacity were obtained using the simulated 3D radiation pattern of each antenna and the Rayleigh channel model for urban environment. To examine the channel capacity we used two antennas which are a simple straight antenna and L-type antenna. Then we observed the available channel capacity by varying the position of feeds and the shape of the L-type antenna. The sample antenna, which has a maximum feed distance with different polarizations, was built and the receiving performance was measured in the weak FM field area. From the results we confirmed that the distance between the feeds should be placed as far as possible for the high channel capacity. If the distance between the feeds are greater than a certain threshold value than the polarizations of the two antennas are getting more important for determining the channel capacity.

• Journal of Korean Society of Transportation
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• v.16 no.1
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• pp.129-150
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• 1998

신호교차로에서의 효율적인 교통운영을 위해서는 비보호좌회전의 활성화가 필요하며 이를 위해서는 비보호좌회전이 허용되는 신호교차로에서의 교통운영의 정확한 분석이 가능해야한다. 본연구에서는 국내신호교차로에서의 운전자의 행태에 기초하여 USHCM의 비보호 좌회전 분석에서 요구되는 $g_f$, $g_q$, $P_L$, 의 현실적인 값을 산정하기 위한 모형이 제안되었으며 이에 기초하여 비보호좌회전 보정계수 및 용량분석 기법을 제시하였다. 본 연구의 결과는 다음과 같다. 첫째, 공용차로를 가진 비보호좌회전 신호교차로에서 주기당 좌회전교통량(LTC)이 5대까지의 범위에서 G(녹색신호시간)와 LTC를 변수로 한 $g_f$모형이 개발되었다. 둘째, $v_{olc}$와 $qr_o$를 변수로 한 $g_q$모형이 개발되었으며 제안된 모형에 의한 $g_q$값이 진주 및 광주에서의 현장관측치와 거의 일치함을 볼 수 있었다. 셋째, 1994 USHCM의 $P_L$모형이 LTC가 증가할수록 $P_L$값이 감소하는 비현실적인 모형의 구조를 가지므로 현실적인 모형의 구축을 위해 국내 현장자료에 기초하여 LTC를 변수로하여 $P_L$산정을 위한 단순화된 모형이 개발되었다. 넷째, 대향교통류를 통해 좌회전할 수 있는 유효녹색시간의 부분의 $g_u$를 산정하여 비보호좌회전 포화교통류율($S_{LT}$)에 주기 대 $g_u$의 비를 곱한 비보호좌회전 용량산정식이 제안되었다.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.49 no.2
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• pp.17-22
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• 2012

This paper deals with a precoder design method when the system has imperfect channel information. When MIMO relay system knows the correlation coefficient between perfect channel and imperfect channel information and the variance of the difference between perfect channel and correlated imperfect channel, source and relay precoders are designed to maximize the upper bound of the channel capacity. Also, we investigate channel capacities of the system using proposed precoder and compare with the optimal value according to the correlation and the variance of error channel by simulations.