• Title/Summary/Keyword: time-varying characteristics

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Transmit Antenna Selection for Dual Polarized Channel Using Singular Value Decision

  • Lee Sang-yub;Mun Cheol;Yook Jong-gwan
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.30 no.9A
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    • pp.788-794
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    • 2005
  • In this paper, we focus on the potential of dual polarized antennas in mobile system. thus, this paper designs exact dual polarized channel with Spatial Channel Model (SCM) and investigates the performance for certain environment. Using proposed the channel model; we know estimates of the channel capacity as a function of cross polarization discrimination (XPD) and spatial fading correlation. It is important that the MIMO channel matrix consists of Kronecker product dividable spatial and polarized channel. Through the channel characteristics, we propose an algorithm for the adaptation of transmit antenna configuration to time varying propagation environments. The optimal active transmit antenna subset is determined with equal power allocated to the active transmit antennas, assuming no feedback information on types of the selected antennas. We first consider a heuristic decision strategy in which the optimal active transmit antenna subset and its system capacity are determined such that the transmission data rate is maximized among all possible types. This paper then proposes singular values decision procedure consisting of Kronecker product with spatial and polarize channel. This method of singular value decision, which the first channel environments is determined using singular values of spatial channel part which is made of environment parameters and distance between antennas. level of correlation. Then we will select antenna which have various polarization type. After spatial channel structure is decided, we contact polarization types which have considerable cases It is note that the proposed algorithms and analysis of dual polarized channel using SCM (Spatial Channel Model) optimize channel capacity and reduce the number of transmit antenna selection compare to heuristic method which has considerable 100 cases.

The influence of p53 mutation status on the anti-cancer effect of cisplatin in oral squamous cell carcinoma cell lines

  • Jo, Deuk-Won;Kim, Young-Kyun;Yun, Pil-Young
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.42 no.6
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    • pp.337-344
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    • 2016
  • Objectives: The purpose of this study was to evaluate the anti-cancer activity of cisplatin by studying its effects on cell viability and identifying the mechanisms underlying the induction of cell cycle arrest and apoptosis on oral squamous cell carcinoma (OSCC) cell lines with varying p53 mutation status. Materials and Methods: Three OSCC cell lines, YD-8 (p53 point mutation), YD-9 (p53 wild type), and YD-38 (p53 deletion) were used. To determine the cytotoxic effect of cisplatin, MTS assay was performed. The cell cycle alteration and apoptosis were analyzed using flow cytometry. Western blot analysis was used to detect the expression of cell cycle alteration- or apoptosis-related proteins as well as p53. Results: Cisplatin showed a time- and dose-dependent anti-proliferative effect in all cell lines. Cisplatin induced G2/M cell accumulation in the three cell lines after treatment with 0.5 and $1.0{\mu}g/mL$ of cisplatin for 48 hours. The proportion of annexin V-FITC-stained cells increased following treatment with cisplatin. The apoptotic proportion was lower in the YD-38 cell line than in the YD-9 or YD-8 cell lines. Also, immunoblotting analysis indicated that p53 and p21 were detected only in YD-8 and YD-9 cell lines after cisplatin treatment. Conclusion: In this study, cisplatin showed anti-cancer effects via G2/M phase arrest and apoptosis, with some difference among OSCC cell lines. The mutation status of p53 might have influenced the difference observed among cell lines. Further studies on p53 mutation status are needed to understand the biological behavior and characteristics of OSCCs and to establish appropriate treatment.

The Study on the Etching Characteristics of (Ba, Sr)TiO$_3$ Film by Inductively Coupled Plasma (유도결합 플라즈마에 의한(Ba, Sr)TiO$_3$ 박막의 식각 특성 연구)

  • 김승범;이영준;염근영;김창일
    • Journal of the Korean Institute of Telematics and Electronics D
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    • v.36D no.4
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    • pp.56-62
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    • 1999
  • In this study, (Ba, Sr)$TiO_3$ thin films were etched with $Cl_2$/Ar gas mixing ratio in an inductively coupled plasma (ICP) by varying the etching parameter such as rf power, dc bias voltage, and chamber pressure. The etch rate was 56 nm/min under $Cl_2$/($Cl_2$+Ar) gas mixing ratio of 0.2, rf power of 600 W, dc bias voltage of 250 V, and chamber pressure of 5 mTorr. At this time, the selectivity of BST to Pt, $SiO_2$ was respectively 0.52, 0.43. The surface reaction of the etched (Ba, Sr)$TiO_3$ thin films was investigated with X-ray photoelectron spectroscopy (XPS). Ba is removed by chemical reaction between Sr and Cl to remove Sr. Ti is removed by chemical reaction such as $TiCl_4$ with ease. The results of secondary ion mass spectrometer (SIMS) analysis compared with the results of XPS analysis and the results were the same.

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Effect of Dietary Structural to Nonstructural Carbohydrate Ratio on Rumen Degradability and Digestibility of Fiber Fractions of Wheat Straw in Sheep

  • Tan, Z.-L.;Lu, D.-X.;Hu, M.;Niu, W.-Y.;Han, C.-Y.;Ren, X.-P.;Na, R.;Lin, S.-L.
    • Asian-Australasian Journal of Animal Sciences
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    • v.15 no.11
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    • pp.1591-1598
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    • 2002
  • The effect of different dietary structural carbohydrate (SC) to nonstructural carbohydrate (NSC) ratios on fiber degradation, digestion, flow, apparent digestibility and rumen fluid characteristics was studied with a design using 18 wethers fitted with permanent rumen and duodenum cannulae. All sheep were divided into six groups randomly, receiving six diets with varying SC to NSC ratios. All diets contained the same proportion of wheat straw and concentrate. The dietary SC to NSC ratios were adjusted by adding cornstarch to the concentrate supplements. The duodenal and fecal flows of dry matter (DM), neutral detergent fiber (NDF), acid detergent fiber (ADF), hemicellulose (HC) and cellulose (CEL) were estimated using chromium-mordanted wheat straw as a flow marker. The degradation parameters of wheat straw DM, NDF, ADF, HC and CEL were determined by incubating the ground wheat straw in nylon bags in the rumen for different periods of time. There was no effect (p>0.05) of the different dietary SC to NSC ratios on rumen pH or $NH_3$-N, but acetate, propionate and butyrate concentrations were significantly affected (p<0.05 or p<0.01) by dietary SC to NSC ratios in the rumen fluid. When the dietary SC to NSC ratio was 2.86, the highest rumen degradability of wheat straw DM, NDF, ADF and CEL was found, but the highest apparent rumen digestibilities of DM, NDF, ADF, HC and CEL occurred at a 2.64 SC to NSC ratio. However, because of compensatory digestion in the hindgut, the apparent digestibilities of DM, NDF, ADF, HC and CEL were highest when the dietary SC to NSC ratio was 2.40. In conclusion, there is a optimal range of dietary SC to NSC ratios (between 2.86 and 2.40) that is beneficial to maximize wheat straw fiber degradation and apparent digestibility.

Development of a Temperature Control Model for a Hot Coil Strip using on-line Retrainable RBF Network (온라인 재학습 가능한 RBF 네트워크를 이용한 열연 권취 온도 제어 모델 개발)

  • Jeong, So-Young;Lee, Min-Ho;Lee, Soo-Young
    • Journal of the Korean Institute of Telematics and Electronics S
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    • v.36S no.8
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    • pp.39-47
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    • 1999
  • This paper describes on-line retrainable RBF network in order to control the coiling temperature for a hot coil strip at Pohang Iron & Steel Company(POSCO). The proposed neural network can be used for improving conventional rule-based lookup table, which generates a heat transmission coefficient. To cope with time-varying characteristics of hot coil process, additional synaptic weights for on-line retraining purposes are introduced to hidden-to-output weights of conventional RBF network. Those weights are locally adjusted to newly incoming test data while preserving old information trained with off-line past data. Hence the effect of catastrophic interference can be greatly alleviated with the proposed network. In addition, rejection scheme is introduced for reliability concerns. From the experimental results applied to the actual process, it is noticed that overall control performance represents about 2.2% increase compared to the conventional one.

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The Effect of Added Dandelion on Antioxidative Activity and Quality Characteristics of Jeolpyon (민들레를 첨가한 절편의 항산화 활성 및 품질특성)

  • Gwag, Jung Soon;Yang, Ming;Park, Inshik
    • The Korean Journal of Food And Nutrition
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    • v.27 no.5
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    • pp.796-804
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    • 2014
  • This study was conducted to investigate the effect of the addition of dandelion on color, texture, and antioxidant activity in Jeolpyon. Jeolpyon was prepared with varying amounts of dandelion ranging up to 20%. They were stored for 3 days at room temperature, and the color and texture were analyzed at different time intervals. L and a values decreased with increasing dandelion concentration while b values increased with increasing dandelion concentration in Jeolpyon. From texture analysis by Rheometer, the hardness and chewiness seem to be affected dramatically by the addition of dandelion in Jeolpyon. During storage, the control Jeolpyon without dandelion displayed greater than two fold increase in hardness, chewiness and brittleness, while the Jeolpyon with added dandelion had only slight increase during storage. The addition of dandelion in Jeolpyon also increased antioxidant activities such as DPPH radical scavenging activity, ABTS radical scavenging activity and reducing power. The antioxidant activities increased linearly with increasing dandelion concentration in Jeolpyon. The increase of antioxidant activities in Jeolpyon with the addition of dandelion may be attributed to the polyphenols in dandelion since the amount of total polyphenols increased with increasing amounts of dandelion in Jeolpyon. In sensory evaluation, the panels of twenties, thirties, and forties gave high scores to Jeolpyon with dandelion containing 10% 15%, and 20%, respectively in overall evaluation.

Design of a Integral Sliding Mode Speed Controller having Chattering Alleviation Characteristics for the Sinusoidal type Brushless DC Motor (채터링 저감특성을 갖는 정현파형 브러시리스 직류전동기 (BLDC Motor)의 적분 슬라이딩 모드 속도제어기 설계)

  • Kim, Sei-Il;Choi, Jung-Keyng;Park, Seung-Yub
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.38 no.2
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    • pp.1-11
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    • 2001
  • In this paper, a chattering alleviation VSS controller for the sinusoidal type BLDC motor is designed. Dead Zone function is proposed to change the chattering occurring in the transient state from high frequency to low frequency and time varying gains arc applied for the control input to eliminate the steady state excessive chattering in the conventional ISM. The proposed Dead Zone function represents the sliding layer composed of two switching surfaces and if a state vector exists in this layer, the chattering don't occur. Simulation and experimental results confirm the useful effects of the above algorithm.

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Stress Distribution of Buried Gas Transportation Pipeline According to Vehicle Load Velocity (지중 가스 수송 강관의 차량 이동 속도에 따른 응력 분포 특성)

  • Won, Jong-Hwa;Kim, Moon-Kyum;Yoo, Han-Kyu; Kim, Mi-Seoung
    • Journal of the Korean Institute of Gas
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    • v.12 no.1
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    • pp.7-12
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    • 2008
  • In order to estimate the integrity and identify the dynamic characteristics of buried gas pipelines subjected to vehicle loads, FE analysis is performed based on the 'Highway and Local Road Design Criteria' and the 'KOGAS Guideline for Pipeline Management'. The FE model describes the current burial condition of Korea properly, and the DB-24 load model is adopted for this research. This study considers a varying velocity in the range of $40{\sim}160\;km/h$ and $P_i=8$ MPa(internal pressure) with depth cover, Z=1.5 m. Maximum stress occurs at v=80 km/h and decreases after v=80 km/h. The maximum induced stress by DB-24 loads is about 10 MPa. Under the design pressure, however, the analysis results show that API 5L Gr. X65 pipelines have sufficient integrity to withstand the vibration of vehicle loads.

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Dynamic Characteristics of Buried Pipeline under Vibration Velocity of Vehicle Loads (도로 하부 통과 배관의 주행 하중 속도에 따른 진동 특성)

  • Won, Jong-Hwa;Sun, Jin-Sun;Yoo, Han-Kyu;Kim, Moon-Kyum
    • Journal of the Korean Institute of Gas
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    • v.12 no.1
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    • pp.13-18
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    • 2008
  • Vibration velocity induced by earthquakes or external vibration sources is one of the integrity assessment indexes, and is also a representative value used to describe the amount of vibration because it is based on a proportional relationship with the damage scale. In this study, the vibration velocity criterion for structures is first examined. Then, based on the velocity criterion, an integrity assessment is performed. Burial condition is set up based on the "Highway and Local Road Design Criteria" with API 5L Gr. X65 pipeline(D=762 mm). The FE model considers DB-24 vehicle load as a time function with a varying velocity in the range of $20{\sim}160\;km/h$. Maximum vibration velocity occurs at v=80 km/h and decreases after v=80 km/h. The maximum vibration velocity of buried pipeline by DB-24 loads is about 0.034 cm/s. The velocity that occurs is in the range of allowable values for each vibration velocity criterion. The wave propagation velocity was identified based on attenuation law and the minimum value appears at vehicle velocity 80 km/h that has maximum vibration velocity.

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Remote Sensing of Surface Films as a Tool for the Study of Oceanic Dynamic Processes

  • Mitnik, Leonid;Dubina, Vyacheslav;Konstantinov, Oleg;Fischenko, Vitaly;Darkin, Denis
    • Ocean and Polar Research
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    • v.31 no.1
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    • pp.111-119
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    • 2009
  • Biogenic surface films, which are often present in coastal areas, may enhance the signatures of hydrodynamic processes in microwave, optical, and infrared imagery. We analyzed ERS-1/2 Synthetic Aperture Radar (SAR) and Envisat Advanced Synthetic Aperture Radar (ASAR) images taken over the Japan/East Sea (JES). We focused on the appearance of the contrast SAR signatures, particularly the dark features of different scales caused by various oceanic and atmospheric phenomena. Spiral eddies of different scales were detected through surface film patterns both near the coast and in the open regions of the JES in warm and cold seasons. During field experiments carried out at the Pacific Oceanological Institute (POI) Marine Station 'Cape Shults' in Peter the Great Bay, the sea surface roughness characteristics were measured during the day and night using a developed polarization spectrophotometer and various digital cameras and systems of floats. The velocity of natural and artificial slicks was estimated using video and ADCP time series of tracers deployed on the sea surface. The slopes of gravity-capillary wave power spectra varied between .4 and .5. Surface currents in the natural and artificial slicks increased with the distance from the coast, varying between 4 and 40 cm/s. The contrast of biogenic and anthropogenic slicks detected on vertical and horizontal polarization images against the background varied over a wide range. SAR images and ancillary satellite and field data were processed and analyzed using specialized GIS for marine coastal areas.