• 한국정보통신설비학회:학술대회논문집
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• 한국정보통신설비학회 2008년도 정보통신설비 학술대회
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• pp.327-330
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• 2008

This paper shows an implementation of WLAN-based Audio/Video(A/V) system for multimedia home networks. Proposed WLAN-based A/V system can transmit multimedia data of high quality. The entire system consists of a 16-bit RISC controller, a program ROM, a SRAM, timers, an interrupt controller, a DART, GPIOs, an I2C and the OFDM modem supporting for the IEEE 802.11g standard. The simple MAC functions are implemented by firmware on an embedded 16-bit RISC controller. The OFDM modem supports a complete set of data rates up to 54Mbps. Proposed the system is implemented by an Altera FPGA EP1S60F1020C6 device, a 10-bit 2-ch DAC, a 10-bit 2-ch ADC and RF/IF chips.

• 한국농공학회지
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• 제20권2호
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• pp.4695-4707
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• 1978

The objeative of this study is to study how to rapidly convert tidal land into cultivable land. The study of a rapid, reasonable desalinization method is conducted at Namyang tidal land which represents soil texture of tidal lands along the south west costa larea of Korea. Therefore, Researches were made at many Pilots in order to find a way of high efficiency of leaching with simpler facilities and cheaper costs. The results of study are briefly summarized as follaws: 1. Subdrainage efficieny is 35%. This is a Poorly drained area, and needs longer leaching desalinization period. 2. The efficieny of desalinization in P.V.C 16 meters plot is the same as that of mole drainage 2 meters plot. P.V.C 4 meters plot has desalinization effect as much as two times compared to P.V.C 16 meters plot. 3. Because the soil texture is silty-clay, desalinization in non-treated plot of sub-drainage and surface drainage desalinization take three times longer period in comparision with P.V.C 4 meters plot. 4. As to the desalinization rate of soluble salt in the soil, the efficieny of desalinization of the topsoil in P.V.C plots was 50% higher than that of mole drainage plot and about 170% higher than that of non-treated plot. In the deep soil salt accumulation at topsoil was observed in non-treated and mole drainage plots, but efficiency in P.V.C polt is about 40 times as high as that of mole drainage and non-treated plot. 5. As to the results of use gypsum and lime as sub-drainage soil improver, gypsum was 60% more efficieny than lime in the continuously inundated plot and 44% in the intermittently inundated plot. The efficieny of gypsum and lime in the intermittently flooded plot is 35% and 42% higher than that of continuously flooded plot reapeaticee1y.

• 한국도로학회논문집
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• 제15권5호
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• pp.217-226
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• 2013

PURPOSES : Under the capacity conditions with balanced approach flows, roundabouts give less delay than existing signalized intersections; however, flows over 450 vehicles/hour/lane with unbalanced approach flow conditions, roundabouts efficiency drops due to the short time difference between the critical gap and the follow-up headway. The purpose of this study is developing a roundabout Signal Metering operation method by considering approach lanes degree of saturation. METHODS : A four-way-approach with one-lane roundabout is selected to compare the Signal Metering performance for the case of 16 different unbalanced flow conditions. Based on these traffic conditions, the performance is evaluated for 64 different cases of Signal Metering combinations by using SIDRA software. A degree of saturation(V/C ratio) sum for two adjoined approaches is used for the performance index of choosing Metered Approach and Controlling Approach. RESULTS : When the V/C ratio sum is 0.29~0.81 and Metered Approach flow is less than Controlling Approach flow, the average delay saving per vehicle is about 7 seconds; however, after this rage the delay saving decreases gradually until the V/C ratio sum reaches around 1.0. The range of V/C ratio sum 0.93~1.09 provides average delay saving per vehicle about 3 seconds. In case of V/C ratio sum is grater than 1.0 and the flows of Metered Approach is grater than Controlling Approach, the average delay per vehicle increases 3~11 times respectively. CONCLUSIONS : As expected, the Signal Metering provides substantial improvements in delay saving for the case of V/C ratio sum is 0.3~1.0 under the traffic flow conditions of Metered Approach is less than Controlling Approach.

• 한국진공학회지
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• 제1권3호
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• pp.371-375
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• 1992

Low cost, PC controlled electrical property measurement systems were constructed to study thin film characteristics such as ; I-V, C-V, C-t, and low current. In addition, a GPIB card and C language program for data control and analysis were made for this study.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 하계학술대회 논문집
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• pp.58-61
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• 2001

Metal-insulator-semiconductor (MIS) C-V properties with high dielectric AIN thin films showed no hysteresis and good interface properties. The dielectric constant of the AIN film calculated from the capacitance at the accumulation region in the capacitance-voltage(C-V) characteristics was about 8. The C-V characteristics of MFIS capacitor showed a hysteresis loop due to the ferroelectric nature of the LiNbO$_3$ thin films. Typical dielectric constant value of LiNbO$_3$ film of MFIS device was about 23. The memory window width was about 1.2V at the gate voltage of $\pm$5 V ranges. Typical gate leakage current density of the MFIS structure was the order of 10$^{-9}$ A/cm$^2$ at the range of within $\pm$500 kV/cm. The ferroelectric capacitors showed no polarization degradation up to about 10$^{11}$ switching cycles when subjected to symmetric bipolar voltage pulse(peak-to-peak 8V, 50% duty cycle) in the 500kHz.

• 한국터널지하공간학회 논문집
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• 제14권4호
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• pp.375-395
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• 2012

종전 환기설계기준에 따르면 전속도(10~80 km/h)를 대상으로 환기검토를 수행하였다. 이는 원활시 및 지체시 상황을 모두 고려한 환기계획이며 도심터널 등에서는 합리적인 방법이다. 그러나 최근 지방부 고속도로의 터널은 교통량이 낮고, 지체발생빈도가 매우 낮기 때문에 지정체를 모두 고려하여 환기계획을 수행하는 것은 다소 불합리성이 있다. 따라서 적정 환기계획을 위해 원활교통과 지체교통을 구분할 필요가 있으며, 교통류의 지정체에 따른 지정체 판별식을 개발할 필요성이 제기된다. 본 연구에서는 합리적 환기계획을 위해 지정체 여부에 따른 환기검토 제외속도를 결정하고자 하였다. 먼저 국내 고속도로상 지정체 교통량을 조사하고 지정체 원인을 분석하였다. 그리고 '여유속도' ($u-u_m$) 개념을 도입하여 지정체 판별모델을 개발하였으며 대상터널에 대한 그 적용성을 분석하였다. V/C 비율에 따른 환기검토 제외속도 분석결과, 설계속도 100 km/h 일 경우 V/C 가 0.1 이하일 경우는 40 km/h 이하, V/C 가 0.35 이하일 경우는 30 km/h 이하, V/C 가 0.6 이하일 경우는 20 km/h 이하, V/C 가 0.75 이하일 경우는 10 km/h 이하에서 환기검토 제외가 가능하였다.

• 한국항공우주학회지
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• 제41권9호
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• pp.708-713
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• 2013

한국항공우주연구원(KARI)은 고고도 전기추진 장기체공 무인기(EAV-3)를 개발하고 있는 중 이다. 우선 고고도 상승 기술 시연을 위한 축소형 비행체 EAV-2H를 개발하였고 EAV-2H로 초도 비행시험을 수행한 결과 측풍에 대한 방향 안정성 및 조종성의 향상이 요구되므로 Advanced Aircraft Analysis(AAA)를 이용한 수직 꼬리날개와 방향타의 재설계를 진행하였다. 방향 조종성을 개선하기위해 방향타의 크기를 기존의 평균 방향타 시위대 수직 꼬리날개 시위 $C_r/C_v(%)=30$을 $C_r/C_v(%)=60$로 늘려 EAV-2H가 가지는 측풍에 대한 방향 조종성(${\beta}(deg)=25^{\circ}$, $v_1(m/sec)=3.54$)을 개선하였다. 또한, 측풍에 의해 발생하는 측력(side force)의 영향을 최소화하기위해 EAV-2H의 수직미익 크기를 기존 대비 15% 줄여(최소한의 방향 안정성 확보, $Cn_{\beta}=0.0588rad^{-1}$), $C_{y_{\beta}}$는 15% $C_{y_r}$는 22% 감소시킴으로써 측풍이 EAV-2H에 미치는 영향을 최소화 하였다. 설계된 EAV-2H의 꼬리날개의 성능은 비행 시험을 통해 검증하였고 그 결과를 적용하여 고고도 장기체공 전기추진 무인기(EAV-3)의 꼬리날개를 설계하였다.

• Journal of Applied and Pure Mathematics
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• 제4권3_4호
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• pp.85-97
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• 2022

Let a graph G = (V, E) be a (p, q) graph. Define $${\rho}\;=\;\{\array{{\frac{p}{2}}&p\text{ is even}\\{\frac{p-1}{2}}\;&p\text{ is odd,}}$$ and M = {±1, ±2, ⋯ ± 𝜌} called the set of labels. Consider a mapping λ : V → M by assigning different labels in M to the different elements of V when p is even and different labels in M to p - 1 elements of V and repeating a label for the remaining one vertex when p is odd. The labeling as defined above is said to be a pair mean cordial labeling if for each edge uv of G, there exists a labeling $\frac{{\lambda}(u)+{\lambda}(v)}{2}$ if λ(u) + λ(v) is even and $\frac{{\lambda}(u)+{\lambda}(v)+1}{2}$ if λ(u) + λ(v) is odd such that ${\mid}\bar{\mathbb{S}}_{{\lambda}_1}-\bar{\mathbb{S}}_{{\lambda}^c_1}{\mid}{\leq}1$ where $\bar{\mathbb{S}}_{{\lambda}_1}$ and $\bar{\mathbb{S}}_{{\lambda}^c_1}$ respectively denote the number of edges labeled with 1 and the number of edges not labeled with 1. A graph G for which there exists a pair mean cordial labeling is called a pair mean cordial graph. In this paper, we investigate the pair mean cordial labeling of graphs which are obtained from path and cycle.

• Journal of Applied and Pure Mathematics
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• 제5권3_4호
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• pp.237-253
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• 2023

Let a graph G = (V, E) be a (p, q) graph. Define $${\rho}=\{\array{{\frac{p}{2}} & \;\;p\text{ is even} \\ {\frac{p-1}{2}} & \;\;p\text{ is odd,}$$ and M = {±1, ±2, … ± ρ} called the set of labels. Consider a mapping λ : V → M by assigning different labels in M to the different elements of V when p is even and different labels in M to p - 1 elements of V and repeating a label for the remaining one vertex when p is odd. The labeling as defined above is said to be a pair mean cordial labeling if for each edge uv of G, there exists a labeling ${\frac{{\lambda}(u)+{\lambda}(v)}{2}}$ if λ(u) + λ(v) is even and ${\frac{{\lambda}(u)+{\lambda}(v)+1}{2}}$ if λ(u) + λ(v) is odd such that ${\mid}{\bar{{\mathbb{S}}}}_{\lambda}{_1}-{\bar{{\mathbb{S}}}}_{{\lambda}^c_1}{\mid}{\leq}1$ where ${\bar{{\mathbb{S}}}}_{\lambda}{_1}$ and ${\bar{{\mathbb{S}}}}_{{\lambda}^c_1}$ respectively denote the number of edges labeled with 1 and the number of edges not labeled with 1. A graph G for which there exists a pair mean cordial labeling is called a pair mean cordial graph. In this paper, we investigate the pair mean cordial labeling behavior of few graphs including the closed helm graph, web graph, jewel graph, sunflower graph, flower graph, tadpole graph, dumbbell graph, umbrella graph, butterfly graph, jelly fish, triangular book graph, quadrilateral book graph.

• Journal of Applied and Pure Mathematics
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• 제6권1_2호
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• pp.55-69
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• 2024

Let a graph G = (V, E) be a (p, q) graph. Define $${\rho}=\{\array{{\frac{p}{2}} && p\;\text{is even} \\ {\frac{p-1}{2}} && p\;\text{is odd,}}$$ and M = {±1, ±2, … ± 𝜌} called the set of labels. Consider a mapping λ : V → M by assigning different labels in M to the different elements of V when p is even and different labels in M to p - 1 elements of V and repeating a label for the remaining one vertex when p is odd. The labeling as defined above is said to be a pair mean cordial labeling if for each edge uv of G, there exists a labeling $\frac{{\lambda}(u)+{\lambda}(v)}{2}$ if λ(u) + λ(v) is even and $\frac{{\lambda}(u)+{\lambda}(v)+1}{2}$ if λ(u) + λ(v) is odd such that ${\mid}\bar{\mathbb{s}}_{{\lambda}_1}-\bar{\mathbb{s}}_{{\lambda}^c_1}{\mid}\,{\leq}\,1$ where $\bar{\mathbb{s}}_{{\lambda}_1}$ and $\bar{\mathbb{s}}_{{\lambda}^c_1}$ respectively denote the number of edges labeled with 1 and the number of edges not labeled with 1. A graph G with a pair mean cordial labeling is called a pair mean cordial graph. In this paper, we investigate the pair mean cordial labeling behavior of some union of graphs.