• Title/Summary/Keyword: Edge method

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Actual Vegetation and Vegetation Structure at the Coastal Sand Bars in the Nakdong Estuary, South Korea (낙동강 하구 연안사주섬의 현존식생 및 식생구조 연구)

  • Lee, Youl-Kyong;Ahn, Kyung-Hwan
    • Korean Journal of Environment and Ecology
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    • v.26 no.6
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    • pp.911-922
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    • 2012
  • This study aim that definite the relationship between coastal environment and different sand bar communities, as well as to analyze their spatial distribution of barrier island in the Nakdong river estuary. Survey method follow by Braun-Blanquet(1965) and there a total of 118 relev$\acute{e}$'s were undertaken. Definition of the relationships between species and environmental variables with Canonical Correlation Analysis(CCoA) and that to applied these relev$\acute{e}$'s with the RIM(Kim and Kim, 2006) program and that to classification used the SYN-TAX 2000 program(Podani 1979). On the basis of about 118 phytosociological releve's, the vegetation of xeric and hydric type was arranged in twelve plant communities: Xeric type-Pinus thunbergii community,Vitex rotundifolia community, Carex pumila community, Imperata cylindrica var. koenigii community, Miscanthus sacchariflorus community and Calystegia soldanella community, Hydric type-Salix dependens-Calamagrostis epigeios community, Calamagrostis epigeios-Phragmites communis community, Phragmites communis-Ischaemum aristatum community, Phragmites communis community, Scirpus planiculmis community and Suaeda glauca-S. japonica community.These plant communities represents sand dune vegetation and salt marsh vegetation. Widely distributing types in the actual vegetation map were sea club-rush community, reed community in salt marsh, and dry grassland. The edge in the coastal sand bars has zonation that almost distribution by the reed community in salt marsh. But outside of it were distributed sea club-rush community. Dry grassland type distributes higher zone of the center in coastal sand bars. Respectively, the coastal sand dune and salt marsh vegetation types were distributed ocean and inland on the frontier of it.

Flow Visualization of Acoustic Streaming Induced by Ultrasonic Vibration Using Particle Imaging Velocimetry (PIV를 이용한 초음파 진동에 의해 유도된 음향유동의 가시화)

  • 노병국;권기정;이장연;이동렬
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.14 no.6
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    • pp.528-535
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    • 2004
  • Ultrasonic Vibrator is designed to achieve the maximum vibration amplitude at 30 kHz by in-cluding a horn (diameter, 40 mm), mechanical vibration amplifier at the top of the ultrasonic vibrator in the system and making the complete system resonate. In addition, it is experimentally visualized by particle imaging velocimetry (PIV) that the acoustic streaming velocity in the gap is at maximum when the gap between the ultrasonic vibrator and stationary plate agrees with the multiples of half-wavelength of the ultrasonic wave. This fact results from the resonance of the sound wave and the theoretical analysis of that is also accomplished and verified by experiment. It is observed that the magnitude of the acoustic streaming dependent upon the gap between the ultrasonic vibrator and stationary plate possibly changes due to the measurement of the average velocity fields of the acoustic streaming induced by the ultrasonic vibration at resonance and non-resonance. There exists extremely small average velocity at non-resonant gaps while the relatively large average velocity exists at resonant gaps compared with non-resonant gaps. It also reveals that there should be larger axial turbulent intensity at the hub region of the vibrator and at the edge of it in the resonant gap where the air streaming velocity is maximized and the flow phenomena is conspicuous than that at the other region. Because the variation of the acoustic streaming velocity at resonant gap is more distinctive than that at non-resonant gap, shear stress increases more in the resonant gap and is also maximized at the center region of the vibrator except the local position of center (r〓0). At the non-resonant gap there should be low values of vorticity distribution, but in contrast to the non-resonant gap, high and negative values of it exist at the center region of the vibrator with respect to the radial direction and in the vicinity of the middle region with respect to the axial direction. Acoustic streaming is noise-free due to the ultrasonic vibration and maintenance-free because of the absence of moving parts. Moreover, the proposed method by acoustic streaming can be utilized to the nano and micro-electro mechanical systems as a driving mechanism in addition to the augmentation of the streaming velocity.

An Efficient Dead Pixel Detection Algorithm Implementation for CMOS Image Sensor (CMOS 이미지 센서에서의 효율적인 불량화소 검출을 위한 알고리듬 및 하드웨어 설계)

  • An, Jee-Hoon;Shin, Seung-Gi;Lee, Won-Jae;Kim, Jae-Seok
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.44 no.4
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    • pp.55-62
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    • 2007
  • This paper proposes a defective pixel detection algorithm and its hardware structure for CCD/CMOS image sensor. In previous algorithms, the characteristics of image have not been considered. Also, some algorithms need quite a time to detect defective pixels. In order to make up for those disadvantages, the proposed defective pixel detection method detects defective pixels efficiently by considering the edges in the image and verifies them using several frames while checking scene-changes. Whenever scene-change is occurred, potentially defective pixels are checked and confirmed whether it is defective or not. Test results showed that the correct detection rate in a frame was increased 6% and the defective pixel verification time was decreased 60%. The proposed algorithm was implemented with verilog HDL. The edge indicator in color interpolation block was reused. Total logic gate count was 5.4k using 0.25um CMOS standard cell library.

Super Resolution based on Reconstruction Algorithm Using Wavelet basis (웨이브렛 기저를 이용한 초해상도 기반 복원 알고리즘)

  • Baek, Young-Hyun;Byun, Oh-Sung;Moon, Sung-Ryong
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.44 no.1
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    • pp.17-25
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    • 2007
  • In most electronic imaging applications, image with high resolution(HR) are desired. HR means that pixel density within an image is high, and therefore HR image can offer more details that may be critical in various applications. Digital images that are captured by CCD and CMOS cameras usually have a very low resolution, which significantly limits the performance of image recognition systems. Image super-resolution techniques can be applied to overcome the limits of these imaging systems. Super-resolution techniques have been proposed to increase the resolution by combining information from multiple images. To techniques were consisted of the registration algorithm for estimation and shift, the nearest neighbor interpolation using weight of acquired frames and presented frames. In this paper, it is proposed the image interpolation techniques using the wavelet base function. This is applied to embody a correct edge image and natural image when expend part of the still image by applying the wavelet base function coefficient to the conventional Super-Resolution interpolation method. And the proposal algorithm in this paper is confirmed to improve the image applying the nearest neighbor interpolation algorithm, bilinear interpolation algorithm.,bicubic interpolation algorithm through the computer simulation.

Evaluation of Source Identification Method Based on Energy-Weighting Level with Portal Monitoring System Using Plastic Scintillator

  • Lee, Hyun Cheol;Koo, Bon Tack;Choi, Chang Il;Park, Chang Su;Kwon, Jeongwan;Kim, Hong-Suk;Chung, Heejun;Min, Chul Hee
    • Journal of Radiation Protection and Research
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    • v.45 no.3
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    • pp.117-129
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    • 2020
  • Background: Radiation portal monitors (RPMs) involving plastic scintillators installed at the border inspection sites can detect illicit trafficking of radioactive sources in cargo containers within seconds. However, RPMs may generate false alarms because of the naturally occurring radioactive materials. To manage these false alarms, we previously suggested an energy-weighted algorithm that emphasizes the Compton-edge area as an outstanding peak. This study intends to evaluate the identification of radioactive sources using an improved energy-weighted algorithm. Materials and Methods: The algorithm was modified by increasing the energy weighting factor, and different peak combinations of the energy-weighted spectra were tested for source identification. A commercialized RPM system was used to measure the energy-weighted spectra. The RPM comprised two large plastic scintillators with dimensions of 174 × 29 × 7 ㎤ facing each other at a distance of 4.6 m. In addition, the in-house-fabricated signal processing boards were connected to collect the signal converted into a spectrum. Further, the spectra from eight radioactive sources, including special nuclear materials (SNMs), which were set in motion using a linear motion system (LMS) and a cargo truck, were estimated to identify the source identification rate. Results and Discussion: Each energy-weighted spectrum exhibited a specific peak location, although high statistical fluctuation errors could be observed in the spectrum with the increasing source speed. In particular, 137Cs and 60Co in motion were identified completely (100%) at speeds of 5 and 10 km/hr. Further, SNMs, which trigger the RPM alarm, were identified approximately 80% of the time at both the aforementioned speeds. Conclusion: Using the modified energy-weighted algorithm, several characteristics of the energy weighted spectra could be observed when the used sources were in motion and when the geometric efficiency was low. In particular, the discrimination between 60Co and 40K, which triggers false alarms at the primary inspection sites, can be improved using the proposed algorithm.

A Study on the Structural Relationships among Brand Personality, Customer-Brand Relationship Quality, and Repurchase Intention: Focusing on Domestic Pizza Market (브랜드 개성, 소비자-브랜드 관계의 질, 재구매 의도의 구조적 관계 연구 : 국내 피자 시장을 중심으로)

  • Kim, Min-Jung;Seo, Kyung-Hwa;Lee, Soo-Bum
    • Culinary science and hospitality research
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    • v.19 no.2
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    • pp.130-148
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    • 2013
  • Domestic pizza market in Korea is in the age of maturity, and competition in the market is getting intense. Brand personality that can prompt consumer sensibility is evaluated as a proper method to differentiate the image of a corporate rather than products or technology that can be copied easily by competitors. In this study, we examined the structural relationships among brand personality of pizza brands in Korea, customer-brand relationship quality, and repurchase intention with selected measurement based on Aaker's Big 5. Based on questionnaires answered by 291 customers, this study examined validity and reliability by using SPSS 16.0 and AMOS 5.0 for its hypotheses. The result of the study modelling were GFI=0.900, NFI=0.922, CFI=0.965, RMSEA=0.050 at the level of ${\chi}^2$=384.130(df=1.715, p<0.001). First, sincerity, competence, and sophistication of the pizza brand personality had a positive effect on intimacy. Second, sincerity, competence, sophistication, and strength of the pizza brand personality had a positive effect on brand partner quality. Also, intimacy and brand partner quality had a positive effect on repurchase intention. Therefore, in the practical perspective, pizza brand management can utilize the findings of specific pizza brand personality in creating a competitive edge for marketing.

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Expression of Ang-2/Tie-2 and PI3K/AKT in Colorectal Cancer

  • Zhang, Ji-Hong;Wang, Li-Hua;Li, Xiang-Jun;Wang, Ai-Ping;Reng, Li-Qun;Xia, Feng-Guo;Yang, Zhi-Ping;Jiang, Jing;Wang, Xiao-Dan;Wen, Chun-Yang
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.20
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    • pp.8651-8656
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    • 2014
  • Purpose: To study the expression of angiogenin-2 (Ang-2) and its receptor Tie-2 in colorectal cancer and discuss the possible mechanisms behind this process. Materials and Methods: Using the streptavidin-peroxidase (SP) immunohistochemical method, paraffin sections from 100 colorectal cancer samples and 10 samples from tumor-adjacent normal tissue (> 2 cm from the edge of the gross tumor) were tested for protein expression of Ang-2, Tie-2, PI3K, and AKT. Reverse transcription-polymerase chain reaction and Western blots were further used to measure expression of the 4 genes and proteins in 20 freshly-resected colorectal cancer samples and tumor-adjacent normal tissues. Results: In colorectal cancer tissues, the expression of the Ang-2, Tie-2, PI3K, and AKT genes and their proteins was significantly higher than in tumor-adjacent normal tissues. Protein expression in poorly-differentiated adenocarcinoma was higher than that in well and moderately differentiated adenocarcinoma. According to Duke's classification, the protein expression in Stages C and D was significantly higher than that in Stages A and B. In the group with lymphatic metastasis, the protein expression was higher than that without lymphatic metastasis. Conclusions: In colorectal cancer, the expression of the Ang-2, Tie-2, PI3K, and AKT genes and their proteins is markedly higher than those in tumor-adjacent normal tissues. No correlation was observed between protein expression and gender, location, or histologic type. Correlations did exist between protein expression and differentiation level, stage of Duke's classification, and lymphatic metastasis; in colorectal cancer tissues with lower differentiation levels, higher stages of Duke's classification, and lymphatic metastasis, the expression of all 4 proteins was higher. The study of their expression patterns and relationships with aggression and metastasis will provide a valuable experimental foundation for assessing prognosis and targeted therapy of colorectal cancer.

Study of the Experience Process in Action Learning for Fostering Essential competency of University Students -Grounded Theory Approach- (대학생의 핵심역량 육성을 위한 Action Learning에서의 경험과정 연구 -근거이론 접근-)

  • Kim, Young-Hee;Choi, Bo-Young
    • The Journal of the Korea Contents Association
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    • v.13 no.11
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    • pp.477-491
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    • 2013
  • In order to live up to public expectations, universities dedicate their best efforts to cultivating all Essential Competencies for outstanding individuals, especially reorganizing and improving their general education curricula and methods of teaching and learning, in light of the fact that a cutting-edge technology in a specific field does not bear a long span in the modern society. Through a Grounded Theory approach, the aim of this research is to study undergraduates' Experience Process of Action Learning designed to foster their Essential Competencies. With broadly selected 15 students from the courses for Essential Competencies, the method of theoretical sampling was employed so as to secure the diversity of the subjects' characteristics and backgrounds. After in-depth interviews, the data from the subjects were analyzed on the basis of Grounded theory approach of Strauss and Corbin. The conclusions of this analysis are as follows; Firstly, a learning coach should play a different role depending on the levels of Action Learning. Secondly, some time for introspection should be taken for the effective operation of Action Learning. Thirdly, learners ought to solve the problems faced during the learning process on their own. Fourthly, the aims of courses for Essential Competencies are also needed to be focused.

A Study on the Ship Channel Design Method using Variable Bumper Area Model (I) (가변범퍼영역모델을 이용한 항로설계기법(I))

  • Jeong Dae-Deug;Lee Joong-Woo
    • Journal of Navigation and Port Research
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    • v.29 no.1 s.97
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    • pp.9-15
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    • 2005
  • To design ship channel is one of important factors for planning and developing a port. In most case, the core factors for designing ship channel are the layout and width of channel provided the net underkeel clearance is secured to be safe enough to pass. In this study, Variable Bumper Area(VBA) model is applied to design and assess ship channel. This model reflects ship's particular, ship domain theory, ship speed and mariner's ship handling skill and experience, especially external forces which cause leeway, set and drift and the change of ship maneuvering characteristics. A real time, full mission shiphandling simulator is used to analyze ship dynamic data according to mariner's ship control, external forces, ete. This model defines Domain degree and Domain-index for assessing the efficiency and safety of the channel. The proposed model is applied to Ulsan new port plan which has a channel width of 1.5 times the length of the largest vessel, a radius of 5 times the length of the largest vessel in a curve of 57 degree centerline angle and SBM facility adjacent to the lateral edge of channel. The result of this study shows that the width of the channel and radius of channel curve are suitable for the target ship but the difficulty of ship handling is caused by the large course change and SBM located in the vicinity of channel.

Peripheral Dose Distributions of Clinical Photon Beams (광자선에 의한 민조사면 경계영역의 선량분포)

  • 김진기;김정수;권형철
    • Progress in Medical Physics
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    • v.12 no.1
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    • pp.71-77
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    • 2001
  • The region, near the edge of a radiation beam, where the dose changes rapidly according to the distance from the beam axis is known as the penumbra. There is a sharp dose gradient zone even in megavoltage photon beams due to source size, collimator, lead alloy block, other accessories, and internal scatter ray. We investigate dosimetric characteristics on penumbra regions of a standard collimator and compare to those of theoritical model for the optimal use of the system in radiotherapy. Peripheral dose distribution of 6 W Photon beams represents penumbral forming function as the depth. Also we have discussed that the peripheral dose distribution of clinical photon beams, differences between calculation dose use of emperical penumbral forming function and measurements in penumbral region. Predictions by emperical penumbral forming functions are compared with measurements in 3-dimensional water phantom and it is shown that the method is capable of reproduceing the measured peripheral dose values usually to within the statistical uncertainties of the data. The semiconductor detector and ion chamber were positioned at a dmax depth, 5cm depth, 10cm depth, and its specific ratio was determined using a scanning data. The effective penumbra, the distance from 80% to 20% isodose lines were analyzed as a function of the distance. The extent of penumbra will also expand with depth increase. Difference of measurement value and model functions value according to character of the detector show small error in dose distribution of the peripheral dose.

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