• Title/Summary/Keyword: VD

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Analysis of Bearing Capacity Change of Forest Roadbed by Opening Year (개설시기에 따른 임도 노반의 지지력 변화분석)

  • Chen, Hyeong-Uk;Kim, Dong-Hyeon;Lee, Kwan-Hee;Kim, Dong-Geun
    • Journal of Korean Society of Forest Science
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    • v.108 no.3
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    • pp.322-328
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    • 2019
  • The purpose of this study was to provide basic data for maintenance and repair of the forest road surfaces using the light drop weight test (LDWT), density test, and grain size analysis at four sites in Yeongyang-gun Mt. (2011y, 2014y, 2016y, and 2017y). In terms of the density test results, the opening density in 2011 was the highest at $2.0694g/cm^3$, and the opening density in 2017 was the lowest at $1.7443g/cm^3$. The grain size analysis showed that the proportion of large aggregates was highest at the opening in 2017, and the proportion of large aggregates decreased with the delay of opening date. From the LDWT results, $E_{vd}$ (the dynamic deformation coefficient) of the 2011y forest road was $35.7MN/m^2$, 2014y was $30.5MN/m^2$, 2016y was $28.6MN/m^2$, and 2017y was $23.5MN/m^2$. The $E_{vd}$ value for the oldest forests opened with the 2011y forest road was the highest, the average $E_{vd}$ value of the center portion was $21.45MN/m^2$, the average $E_{vd}$ value of the wheel portion of the banking part was $31.31MN/m^2$, and the average $E_{vd}$ value of the wheel portion of the cut part was $36.71MN/m^2$.

Fuzzy-based ABR Traffic Control Algorithm in VS/VD Switch (VS/VD 구조의 퍼지 기반 ABR 트래픽 제어에 관한 연구)

  • Park, Hyun;Jeong, Kwang-Il;Cheong, Myung-Soo;Chung, Kyung-Taek;Chon, Byoung-Sil
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.39 no.8
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    • pp.7-13
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    • 2002
  • In this paper, we propose an traffic control algorithm for efficient link utilization of ATM-ABR service based on fuzzy logic. The proposed algorithm, controls transmission rates of source according to switch buffer size and input cell tate by using the fuzzy rate . For this method we developed a model and algorithm of fuzzy traffic control method and fuzzy traffic controller which based on ER of VS/VD. For the fuzzy traffic controller, we also designed a membership function, fuzzy control rules, and a max-min inferencing method.

An ABR Service Control for Improving Efficiency of PNNI (사설망인터페이스(PNNI)의 효율성 향상을 위한 ABR 서비스 제어)

  • Kim Byun-Gon
    • Science of Emotion and Sensibility
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    • v.7 no.4
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    • pp.67-75
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    • 2004
  • In this paper, we analyze previous flow control algorithm for serving ABR traffic, and then propose the algorithm which calculate fair transmission rate and control efficiently ABR traffic using VS/VD switch which has an effect on PNNI environment with long delay. For getting the transmission rate, the proposed algorithm use FMMRA as ER scheme which calculate exactly the fair share. And, in large delay state, we can obtain fair cell sharing by calculating transmission rates which obtained by transmitted queue length information of VD to VS for serve and drain cell in queue Through the computer simulation, we evaluate the performance of proposed algorithm, According to the results, the proposed algorithm shows good performance.

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Studies on Pharmacokinetic Parameters of Amikacin in Korean Patients (한국인 환자에서의 아미카신의 체내약물동태학적 파라메타에 관한 연구)

  • Yong, Jae-Ick;Kim, Ock-Nam;Moon, Min-Jung;Shin, Wan-Gyoon
    • Journal of Pharmaceutical Investigation
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    • v.20 no.1
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    • pp.19-28
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    • 1990
  • Pharmacokinetic parameters of aminoglycosides are dependent on renal function, sex, age, hematocrit, fever, lean body weight (LBW) and disease states, etc. Therefore, the individual pharmacokinetic parameters such as half life $(t^{1/2})$ and volume of distribution(Vd) are needed to achieve optimal therapy. However these parameters had not been determined in Koreans. The purpose of this study was to evaluate the Vd and $t^{1/2}$ of amikacin in Korean patients who had normal renal function, to compare the mean values of study group with that reported in the literature and to compare the measured $t^{1/2}$ with the expected $t^{1/2}$ based on actual body weight (ABW), LBW and ideal body weight (IBW), respectively. Based on data, the Vd was greater than the literature and $t^{1/2}$ was similar to the literature. The predicted $t^{1/2}$ based on IBW was the closest to actual $t^{1/2}$. And postpartum patients had greater Vd than other group and had lower correlation between actual elimination rate constant and calculated creatinine clearance but higher correlation between actual elimination rate constant and Vd than other group.

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A Study on Efficient Transmission Rate Control of ABR Traffic in PNNI Networks (PNNI 망에서 효율적인 ABR 트래픽 전송률 제어에 관한 연구)

  • Kim Byun-gon
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.9 no.5
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    • pp.973-980
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    • 2005
  • In this paper, we analyze previous flow control algorithm for serving ABR traffic, and then propose the algorithm which calculate fair transmission rate and control efficiently ABR traffic using VS/VD switch which has an effect on PNNI environment with long delay. For getting the transmission rate, the proposed algorithm use FMMRA as ER scheme which calculate exactly the fair share. And, in large delay state, we can obtain fair cell sharing by calculating transmission rates which obtained by transmitted queue length information of VD to VS for serve and drain cell in queue Through the computer simulation, we evaluate the performance of proposed algorithm. According to the results, the proposed algorithm shows good performance.

Air Circulating Oven-drying Characteristics of Hollowed Round-post for Korean Main Conifer Species Part 3: Effects of Water-vapor Dam and Heartwood Coating Treatments

  • Lee, Nam-Ho;Zhao, Xue-Feng;Shin, Ik-Hyun;Lee, Chang-Jin
    • Journal of the Korean Wood Science and Technology
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    • v.42 no.2
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    • pp.101-111
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    • 2014
  • In this study the effect of heartwood-coating (HCO), vapor-dam (VD), bark-remaining (BR) and bark-remaining-coating (BRC) treatments on the air circulating oven-drying characteristics of Japanese larch hollowed round-post was evaluated. The drying times of the hollowed round-posts for control, VD, HCO and BR specimens were 72, 168, 204 and 240 hours, respectively, from the initial MC to about 8% MC, which was recommended as the indoor in-use MC. The temperature in the hole of the VD specimen was lower than that of wood and the difference between air temperature in the hole and wood temperature became large during drying period. The vapor pressure of air in the hole was higher than that of inside wood for all specimens except VD specimen. The surface checks on all specimens were observed in increasing order of BR, BRC, UC, HCO and VD specimens.

Development of VDS for Geosynchronous Satellite and Verification using PILS & HILS (정지궤도위성 실시간 동역학 시뮬레이터 개발 및 연동시험을 통한 검증)

  • Park, Yeong-Ung;Gu, Ja-Chun;Choe, Jae-Dong;Gu, Cheol-Hoe;Park, Bong-Gyu
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.34 no.1
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    • pp.103-109
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    • 2006
  • In this paper, VDS(Vehicle Dynamics Simulator) and ACS(Attitude Control Simulator) are developed and are verified using PILS(Process In-the Loop Simulation) between VDS and ACS. VDS is including the AOCS(Attitude & Orbit Control Subsystem) hardware modeling of geosynchronous satellite and consists of modulation concept. ACS performs the attitude determination using sensor data and generates the attitude control commands. In order to transfer the data between VDS and PCDU(Power Control & Distribution Unit), data acquisition boards were mounted. VDS performance is verified using HILS(Hardware In-the Loop Simulation) between VDS and PCDU.

Drying Condition Affects Total Phenol Contents and Antioxidant Activities of Hizikia fusiformis

  • Lee, Jin-Man;Kang, Bok-Hee;Kim, Yoo-Kyeong
    • Preventive Nutrition and Food Science
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    • v.15 no.3
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    • pp.244-247
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    • 2010
  • This study was performed to evaluate the effect of drying methods on the polyphenol contents and antioxidant activities of Hizikia fusiformis. The seaweed was dried using four different conditions: vacuum drying (VD) at $20^{\circ}C$ and $30^{\circ}C$ and hot-air drying (HD) at $40^{\circ}C$ and $60^{\circ}C$. After drying, the total phenol content, DPPH and nitrite scavenging activities of the water extracts were determined. The total phenol contents were significantly (p<0.05) higher in the vacuum dried samples than the hot-air dried samples. DPPH radical was scavenged 82.67% and 83.45% by VD-20 and VD-30, and 70.44% and 71.23% by HD-40 and HD-60, respectively. At pH 1.2, Hizikia fusiformis scavenged 87.43%, 88.45%, 72.14% and 73.45% of nitrite by the treatment VD-20, VD-30, HD-40 and HD-60, respectively. Interestingly, the nitrite scavenging activity was much more reduced at pH 3.0 than at pH 1.2. Through these experiments, we were able to show that the drying conditions affect the total phenol contents and antioxidant capacities of Hizikia fusiformis.

A Two-Stage Radix-4 Viterbi Decoder for Multiband OFDM UWB Systems

  • Choi, Sung-Woo;Kang, Kyu-Min;Choi, Sang-Sung
    • ETRI Journal
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    • v.30 no.6
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    • pp.850-852
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    • 2008
  • This letter presents a power efficient 64-state Viterbi decoder (VD) employing a two-stage radix-4 add-compare-select architecture. A class of VD architectures is implemented, and their hardware complexity, maximum operating speed, and power consumption are compared. Implementation results show that the proposed VD architecture is suitable for multiband orthogonal frequency-division multiplexing (MB-OFDM) ultra-wideband (UWB) systems, which can support the data rate of 480 Mbps even when implemented using 0.18-${\mu}m$ CMOS technology.

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Trend and Issues of van der Waals 2D Semiconductor Devices (반데르발스 2차원 반도체소자의 응용과 이슈)

  • Im, Seongil
    • Vacuum Magazine
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    • v.5 no.2
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    • pp.18-22
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    • 2018
  • wo dimensional (2D) van der Waals (vdW) nanosheet semiconductors have recently attracted much attention from researchers because of their potentials as active device materials toward future nano-electronics and -optoelectronics. This review mainly focuses on the features and applications of state-of-the-art vdW 2D material devices which use transition metal dichalcogenides, graphene, hexagonal boron nitride (h-BN), and black phosphorous: field effect transistors (FETs), complementary metal oxide semiconductor (CMOS) inverters, Schottky diode, and PN diode. In a closing remark, important remaining issues of 2D vdW devices are also introduced as requests for future electronics and photonics applications.