• Title/Summary/Keyword: smooth

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Fine Structural Analysis on the Dry Adhesion System of the Jumping Spider Plexippus setipes (Araneae: Salticidae)

  • Moon, Myung-Jin;Park, Jong-Gu
    • Animal cells and systems
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    • v.13 no.2
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    • pp.161-167
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    • 2009
  • The cuticle of spider's exoskeleton is a hydrophobic and non-adhesive material, but the jumping spiders have the distinctive attachment apparatus for adhesion on smooth dry surface without sticky fluids. We have examined the whole tarsal appendages of the jumping spider, Plexippus setipes with using scanning electron microscope to reveal the fine structural characteristics of the dry adhesion system. All eight legs have the scopulae with a pair of claws on the tip of feet. Each scopula is composed of two groups of setae that are capable of dry adhesion on smooth surface, and the hook structure of the claw is advanced to move on the rough surface. The setae toward the bottom of the tarsal segment are densely covered by numerous setules on the underside which broadened from middle to distal portion. It has been revealed by this research that the contact area of the setule is always a triangular shape, and these cuticular surfaces are connected by the elongated stalks from the underlying setae. It is likely that the nano-scale structures including a triangular depression and a longitudinal groove on each setule could functionate when the spider detach its feet from the substrate.

Study on Condensation Heat Transfer Characteristics of Hydrocarbons Natural Refrigerants

  • Oh, Hoo-Kyu;Park, Seung-Jun;Park, Ki-Won;Roh, Geon-Sang;Jeong, Jae-Cheon
    • International Journal of Air-Conditioning and Refrigeration
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    • v.9 no.3
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    • pp.10-17
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    • 2001
  • This study investigated the condensation heat transfer coefficients of R-22, R-290 and R-600a inside horizontal tube. Heat transfer measurements were performed for smooth tube with inside diameter of 10.07 mm and outside diameter of 12.07 mm and inner grooved tube having 75 fins whose height is 0.25 mm. Condensation temperatures and mass velocity were ranged from 308K to 323 K and $51kg/m^2s$ to $250kg/m^2s$, respectively. The test results showed that the local condensation heat transfer coefficients increased as the mass flux increased, and also the effects of mass velocity on heat transfer coefficients of R-290 and R-600a were less than those of R-22. Average condensation heat transfer coefficients of natural refrigerants were superior to that of R-22. The present results had a good agreement with Cavallini-Zecchin's correlation for smooth and inner grooved tubes.

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Sharing a Large Secret Image Using Meaningful Shadows Based on VQ and Inpainting

  • Wang, Zhi-Hui;Chen, Kuo-Nan;Chang, Chin-Chen;Qin, Chuan
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.9 no.12
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    • pp.5170-5188
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    • 2015
  • This paper proposes a novel progressive secret image-hiding scheme based on the inpainting technique, the vector quantization technique (VQ) and the exploiting modification direction (EMD) technique. The proposed scheme first divides the secret image into non-overlapping blocks and categorizes the blocks into two groups: complex and smooth. The blocks in the complex group are compressed by VQ with PCA sorted codebook to obtain the VQ index table. Instead of embedding the original secret image, the proposed method progressively embeds the VQ index table into the cover images by using the EMD technique. After the receiver recovers the complex parts of the secret image by decoding the VQ index table from the shadow images, the smooth parts can be reconstructed by using the inpainting technique based on the content of the complex parts. The experimental results demonstrate that the proposed scheme not only has the advantage of progressive data hiding, which involves more shadow images joining to recover the secret image so as to produce a higher quality steganography image, but also can achieve high hiding capacity with acceptable recovered image quality.

Colletotrichum Disease of Mungbean Sprout by Colletotrichum acutatum

  • Kim, Dong-Kil;Lee, Sun-Chul;Kang, Jin-Ho;Kim, Hee-Kyu
    • The Plant Pathology Journal
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    • v.19 no.4
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    • pp.203-204
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    • 2003
  • Decayed samples of marketed mungbean sprout were collected from Sacheon, Suncheon, and Dangjin cities in Korea. Initial symptom on hypocotyls was dark-brown diamond speck, which developed into enlarged sunken brownish-black spot with irregular margin, followed by softening yellowish decay. Brown speck on cotyledon further developed into irregular lesions. This study isolated the fungus Colletotrichum sp. The fungal colony was pale orange, which turned greenish gray after 1 week at $25^{\circ}C$. Colony of reverse side in a petri dish was pink. Neither conidiomata nor setae were present in the culture. Typical fusiform conidia sized 7.5-15.0$\times$2.5-2.9 $\mu\textrm$were hyaline, aseptate, smooth, and had salmon color in mass. Conidiogenous cells were phialidic, hyaline, smooth, and cylindrical with terminal distinct collarette. Basedon these mycological characteristics, the casual organism was identified as Colletotrichum acutatum. This is first report of Colletotrichum acutatum in Korea.

Inhibition of pain substance-induced contraction of vasoactive intestinal polypeptide (VIP) and Increment of VIP of silver spike point low frequency electrical Stimulation (Vasoactive intestinal polypeptide (VIP)의 통증관련물질-유도근 수축반응의 억제와 은침점 저주파 전기자극의 VIP 증가)

  • Choi, Young-Deog;Kim, Jung-Hwan
    • The Journal of Korean Physical Therapy
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    • v.15 no.4
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    • pp.442-454
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    • 2003
  • The aim of this study was to demonstrate the effects of silver spike point (SSP) low frequency electrical stimulation on plasma vasoactive intestinal polypeptide (VIP) activities measured by radioimmunoassay from volunteer and the effects of VIP on pain substance-induced contraction investigated by isometric tension methode in animal. The current of 3 Hz continue type, but not 100 Hz continue type, of SSP low frequency electrical stimulation significantly increased in plasma VIP from normal volunteer. The pain substance, such as norepinephrine, serotonin, and prostaglandin $F2{\alpha}$, increased vascular smooth muscle contraction, respectively. These responses were inhibited by VIP applied cumulatively (1 nM - $1\;{\mu}M$), but not serotonin-induced contraction. In addition, serotonin, and prostaglandin $F2{\alpha}$ induced uterine smooth muscle contraction from rat. However, these responses were inhibited by VIP ($1\;{\mu}M$), only serotonin-induced contraction. These results suggest that the VIP regulates pain substance in part and that the SSP low frequency electrical stimulation, specifically current of 3 Hz continue type, significantly increases plasma VIP from volunteer.

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Non-adrenergic non-cholinergic relaxation and contraction in circular smooth muscle of bovine reticular groove (소(우(牛)) 식도구 윤상근의 비아드레날린 비콜린성 이완 및 수축)

  • Kang, Tong-mook;Han, Ho-jae;Yang, Il-suk
    • Korean Journal of Veterinary Research
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    • v.35 no.2
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    • pp.279-285
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    • 1995
  • To characterize non-adrenergic non-cholinergic(NANC) nerve mediated contractile responses in circular smooth muscle of bovine reticular groove, we investigated NANC relaxation and contraction induced by electric field stimulation to enteric nerves. In the presence of atropine($1{\mu}M$) and guanethidine($50{\mu}M$), electric field stimulation at frequency of 1 to 16Hz(square pulses, 0.5ms duration, 70V) evoked clear-cut relaxations through stimulations. Transient 'rebound contraction' was occured when the stimulus was switched off. All of the responses (relaxation and rebound contraction) were dose-dependently blocked by Nw-nitro-$_{\small{L}}$-arginine methyl ester(L-NAME), an inhibitor of nitric oxide synthesis, and methylene blue, and inhibitor of soluble guanylate cyclase. Tetraethyl ammonium(TEA), a potassium channel blocker, did not block the NANC relaxations.

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A Study on the Possibility of Introducing Arbitration Program to Consumer Dispute Resolution System (소비자분쟁해결제도에 중재제도 도입가능성에 관한 연구)

  • Park, Sung -Yang
    • Journal of Arbitration Studies
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    • v.19 no.2
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    • pp.73-94
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    • 2009
  • There are significant differences between disputes among enterprises and disputes between consumers and an enterprise. A majority of consumers may suffer from the same damages at the same time with small amount concerned and sometimes low chances for find the real cause. Among these distinctive features, the most significant characteristic in consumer-business disputes can be found in that consumers are in a disadvantageous position compared to businesses. When it comes to consumer policy, the biggest aim lies with turning back the damage a consumer is suffering into normalcy. In this regard, the Consumer Dispute Resolution System is the most essential among consumer policies. In Korea, the Collective Alternative Dispute Resolution (ADR) System was introduced to the Consumer Dispute Resolution System in 2007 in line with revision on the Consumer Basic Law. However, smooth damage redress for consumers is still not taking place. Against this backdrop, this report suggests that 'consumer arbitration' program should be introduced to the Consumer Dispute Resolution System as part of making good and smooth progress for consumer damage redress.

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Growth and characterization of amorphous GaN film using a pulsed-laser ablation (펄스 레이저 어블레이션을 이용한 비정질 GaN박막의 성장 및 특성분석)

  • ;;Naoto Koshizaki
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.14 no.1
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    • pp.33-36
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    • 2004
  • Amorphous GaN film was deposited using a laser ablation of the highly densified GaN target. Through the surface morphological and compositional analysis of films deposited under various laser energies and Ar gas pressures, the film deposited under the pressure of 10 Pa were found to be amorphous GaN with the smooth surface. In particular, the film at 200 mJ/pulse showed the enhanced crystallinity and stoichiometric composition, compared with those of the films at relatively lower laser energy. The strong band-gap emission at 2.8 eV was observed from amorphous GaN film in the room temperature photoluminescence spectra, showing the highest efficiency in the film at 200 mJ/pulse under 10 Pa.

Joint Space Trajectory Planning Considering Physical Limits for Two-wheeled Mobile Robots (물리적 제한을 고려한 두 바퀴 로봇의 관절 공간 궤적 생성 방법)

  • Yang, Gil-Jin;Choi, Byoung-Wook
    • Journal of Institute of Control, Robotics and Systems
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    • v.19 no.6
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    • pp.540-546
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    • 2013
  • This paper presents a trajectory planning algorithm for TMR (Two-wheeled Mobile Robots). The trajectory is developed in joint space and considers the physical limits of a TMR. First, we present a process for generating a smooth curve through a Bezier curve. The trajectory for the center of the TMR following the Bezier curve is developed through a convolution operator taking into consideration its physical limits. The trajectory along the Bezier curve is regenerated using time-dependent parameters which correspond to the distance driven by the velocity of the center of the TMR in a sampling time. The velocity commands in the Cartesian space are converted to actuator commands for two wheels. In case that the actuator commands exceed the maximum velocity, the trajectory is redeveloped with compensated center velocity. We also suggest a smooth trajectory planning algorithm in joint space for the two segmented paths. Finally, the effectiveness of the algorithm is shown through numerical examples and application to a simulator.

Robust Finite-Time Stabilization for an Uncertain Nonlinear System (불확실한 비선형 시스템에 대한 강인 유한 시간 안정화)

  • Seo, Sang-Bo;Shin, Hyung-Bo;Seo, Jin-Heon
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.46 no.2
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    • pp.7-14
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    • 2009
  • In this paper we consider the problem of global finite-time stabilization for a class of uncertain nonlinear systems which include uncertainties. The uncertainties are time-varying disturbances or parameters belong to a known compact set. The proposed design method is based on backstepping and dynamic exponent scaling using an augmented dynamics, from which, a dynamic smooth feedback controller is derived. The finite-time stability of the closed-loop system and boundedness of the controller are preyed by the finite-time Lyapunov stability theory and a new notion 'degree indicator'.