• Title/Summary/Keyword: divergence point

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Three Cases with the Multiple Occurrences of Freezing Rain in One Day in Korea (12 January 2006; 11 January 2008; and 22 February 2009)

  • Park, Chang-Kyun;Byun, Hi-Ryong
    • Atmosphere
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    • v.25 no.1
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    • pp.31-49
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    • 2015
  • From the hourly data of 75 Korean weather stations over a 12-year period (2001~2012), this study has chosen three cases (January 12, 2006; January 11, 2008; and February 22, 2009) of multiple freezing rains and investigated the atmospheric circulations that seemed to cause the events. As a result, the receding high pressure type (2006), prevailing high pressure type (2008), and warm front type (2009) are confirmed as synoptic patterns. In all three cases, freezing rain was found in regions with a strong ascending current near the end point of a low-level jet that carried the warm humid air from low latitudes. The strong ascending current resulted from lower-level convergence and upper-level divergence. In 2006 and 2009, the melting process was confirmed. In 2008, the supercooled warm rain process (SWRP) was confirmed. In contrast to existing SWRP theory, it was found that the cool air produced at the middle atmosphere and near the earth's surface led to the formation of freezing rain. The sources of this cool air were supposed to be the evaporative latent heat and the cold advection coming from the northeast. On the other hand, a special case was detected, in which the freezing rain occurred when both the soil surface temperature and surface air temperature were above $0^{\circ}C$. The thickness distributions related to freezing rain in Korea were found to be similar to those in North America. A P-type nomogram was considered for freezing rain forecasting; however, it was not relevant enough to Korea, and few modifications were needed.

An Adaptive Control of Symmetry Contribution Based Generalized Symmetry Transform (적응적 대칭기여도 제어 기반 일반화 대칭변환)

  • Jeon, Joon-Hyung;Lee, Seung-Hee;Park, Kil-Houm
    • Journal of Korea Multimedia Society
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    • v.17 no.2
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    • pp.208-217
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    • 2014
  • This paper propose an adaptive control of symmetry contribution based generalized symmetry transform. which can be controlled symmetry contribution according to the intensity orientation of two pixels. In the proposed method, we define the C-D(convergent and divergent)plane which represents convergence and divergence region of gradient pairs. and used the gaussian phase wight function, with respect to the distance from the gradient pair to an extreme point, in calculating the symmetry contribution. The proposed method can be detect the object more efficiently by adaptive controlling the cut-off frequency of the gaussian phase wight function. To evaluate a performance of the proposed method, we compare the proposed method and conventional GST method in various images including IR image. we prove that the proposed method have better performance in object detection.

A Pre-Resource Reservation Mechanism using NSIS protocol (NSIS 프로토콜을 이용한 사전자원예약 방안)

  • Kim, Sun-Young;Byun, Hae-Sun;Lee, Mee-Jeong
    • Journal of KIISE:Information Networking
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    • v.35 no.6
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    • pp.538-548
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    • 2008
  • In the Internet Engineering Task Force(IETF), Next Step in Signaling(NSIS) working group, proposed a mechanism to discover the Crossover Node(CRN), when the route is changed by Mobile Node(MN) handover. The CRN is divergence or convergence node on old and new path for reserving resources. Trough the CRN discovery mechanism, it possible to reduce a signaling delay and avoid the redundant reservation on the common path between old and new path. However, the QoS(Quality of Service) can be guaranteed continuously while the MN is performing handover, it is needed to pre-reserve the resource on the new path before completion of the handover. When the nodes on the new path try to make a pre-resource reservation before the handover, it is difficult to pre-reserve the resource with the existing CRN discovery mechanism. Therefore, we proposed a Passive CRN(PCRN) discovery scheme and pre-resource reservation mechanism. The PCRN which means an initial common point between the current reserved and the new paths, where the handover can take place.

Integrating Study of Kidney on Left & Life Gate on Right(左腎右命門) and Moving Energy between two kidneys(腎間動氣) (좌신우명문(左腎右命門)과 신간동기(腎間動氣)의 통합적 이해를 위한 연구)

  • Kim, Jin-Ho
    • Journal of Korean Medical classics
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    • v.26 no.4
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    • pp.253-266
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    • 2013
  • Objective : There was no attempt to understand Moving Energy between two kidneys(腎間動氣) and Kidney on Left & Life Gate on Right(左腎右命門) by integration progress. So I have faced to study based on two parts with concerning as clues. One is 'Life Right (左 右)' and the other is 'Between(間)'. Methods : Revealing the source of the origin, Nanjingbenyi(難經本義) is given on the basis. Take a close look at publications related to Nanjing(難經) which is about Kidney on Left & Life Gate on Right and Moving Energy between two kidneys. Take a close look at Kidney, the Life Gate and Moving Energy between two kidneys. Look see the three-dimensional uplift movement of Gi(氣). Results : In Neijing(內經) and Nanjing, the basic point of view for Kidney is the same. That is explained in line with attributes of convergence(收斂). 'Life Gate(命門)' is a term to express the divergence feature(發散機能) of kidney. Moving Energy between two kidneys is used to mean the mainspring of human body activity. The Gi in human body loses altitude turning left(左旋而下降) and gains height turning right(右旋而上升). Conclusion : Watching on functional aspect, there are two names for kidney. One is 'Kidney(腎)' which collects the losing altitude turning left and the other is 'Life Gate' which rises turning right. Moreover, the fundamental power that effectuate the uplift movement is Moving Energy between two kidneys. This kind model is a way that can be understood syntagmatically the Kidney on Left & Life Gate on Right and the Moving Energy between two kidneys without any gainsaying the original of Nanjing.

Three-dimensional Electromagnetic Modeling in Frequency Domain (주파수영역 전자법의 3차원 모델링)

  • Jang, Hannuree;Kim, Hee Joon
    • Geophysics and Geophysical Exploration
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    • v.17 no.3
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    • pp.163-170
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    • 2014
  • Development of a modeling technique for accurately interpreting electromagnetic (EM) data is increasingly required. We introduce finite difference (FD) and finite-element (FE) methods for three-dimensional (3D) frequency-domain EM modeling. In the controlled-source EM methods, formulating the governing equations into a secondary electric field enables us to avoid a singularity problem at the source point. The secondary electric field is discretized using the FD or FE methods for the model region. We represent iterative and direct methods to solve the system of equations resulting from the FD or FE schemes. By applying the static divergence correction in the iterative method, the rate of convergence is dramatically improved, and it is particularly useful to compute a model including surface topography in the FD method. Finally, as an example of an airborne EM survey, we present 3D modeling using the FD method.

A Case Study of Fluid Simulation in the Film 'Sector 7' (사례연구: 영화 '7광구'의 유체 시뮬레이션)

  • Kim, Sun-Tae;Lee, Jeong-Hyun;Kim, Dae-yeong;Park, Yeong-Su;Jang, Seong-Ho;Hong, Jeong-Mo
    • Journal of the Korea Computer Graphics Society
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    • v.18 no.3
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    • pp.17-27
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    • 2012
  • In this paper, we describe a case study of the film 'Sector 7' which was produced by technologies applied fluid simulation. For the CG scenes in the movie which include highly detailed fluid motions, we used smoothed particle hydrodynamics(SPH) technique to express subtle movements of seawater from a crashed huge tank, and used hybrid simulation method of particles and levelsets to describe bursting water from a submarine's broken canopy. We also used detonation shock dynamics(DSD) technique for detailed flame simulations to produce a burning monster, the film"s main character. At this point, the divergence-free vortex particle method was applied to conserve the incompressible property of fluids. In addition, we used an upsampling method to achieve more efficient video production. Consequently, we could produce the high-quality visual effects by using the domestic technologies.

An Experimental Study on Performance of Second Throat Exhaust Diffusers of Different Configuration (2차목 초음속 디퓨저의 형상 변화에 따른 성능에 관한 실험적 연구)

  • Jeon, Jun Su;Kim, Wan Chan;Yeoun, Hae In;Kim, Min Sang;Ko, Young Sung;Han, Young Min
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.38 no.4
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    • pp.279-288
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    • 2014
  • Second throat supersonic exhaust diffusers (STEDs) were designed to simulate high-altitude conditions according to the normal-shock model. Experimental studies were performed on the STEDs to investigate how performance characteristics varied with the length and diameter of the STED using high-pressure nitrogen gas. The variation in performance due to length indicated that the performance of the STED could be very slightly improved by adjusting the diffuser inlet length ($L_d$), and it could be significantly improved by optimizing the second throat length ratio ($L_{st}/D_{st}$) and the divergence length ($L_s$). The starting and vacuum chamber pressures exhibited the highest level of performance near ($A_d/A_{st}$) of the design point.

Morphologic and Genetic Identification of Diphyllobothrium nihonkaiense in Korea

  • Jeon, Hyeong-Kyu;Kim, Kyu-Heon;Huh, Sun;Chai, Jong-Yil;Min, Duk-Young;Rim, Han-Jong;Eom, Kee-Seon S.
    • Parasites, Hosts and Diseases
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    • v.47 no.4
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    • pp.369-375
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    • 2009
  • Diphyllobothrium nihonkaiense was first described by Yamane in 1986 but the taxonomical features have been obscure due to lack of critical morphologic criteria in its larval and adult stages. In Korea, this tapeworm had long been known as Diphyllobothrium latum. In this study, we observed 62 specimens collected from Korean residents and analyzed them by morphological features and nucleotide sequences of mitochondrial cox1 gene as well as the ITS1 region. Adult tapeworms were examined after carmine or trichrome stain. Longitudinal sections of the gravid proglottids showed an obtuse angle of about 150 degree between the cirrus sac and seminal vesicle. This angle is known as a major differential point compared with that of D. latum. Nucleotide sequence differences between D. latum and the specimens from Koreans represented 17.3% in mitochondrial DNA cox1 gene. Sequence divergence of ITS1 among 4 Korean isolates was 0.3% and similarity was 99.7% with D. nihonkaiense and D. klebanovskii. All of the Korean specimens analyzed in this study were identified as being D. nihonkaiense (n = 62). We propose its Korean name as "Dong-hae-gin-chon-chung" which means 'long tapeworm of the East Sea' for this newly analyzed diphyllobothriid tapeworm in Korea.

Method Decoder for Low-Cost RFID Tags

  • Juels, Ari
    • 한국정보컨버전스학회:학술대회논문집
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    • 2008.06a
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    • pp.47-52
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    • 2008
  • A radio-frequency identification(RFID) tag is a small, inexpensive microchip that emits an identifier in response to a query from a nearby reader. The price of these tags promises to drop to the range of $0.05 per unit in the next several years, offering a viable and powerful replacement for barcodes. The challenge in providing security for low-cost RFID tags is that they are computationally weak devices, unable to perform even basic symmetric-key cryptographic operations. Security researchers often therefore assume that good privacy protection in RFID tags is unattainable. In this paper, we explore a notion of minimalist cryptography suitable for RFID tags. We consider the type of security obtainable in RFID devices with a small amount of rewritable memory, but very limited computing capability. Our aim is to show that standard cryptography is not necessary as a starting point for improving security of very weak RFID devices. Our contribution is threefold: 1. We propose a new formal security model for authentication and privacy in RFID tags. This model takes into account the natural computational limitations and the likely attack scenarios for RFID tags in real-world settings. It represents a useful divergence from standard cryptographic security modeling, and thus a new view of practical formalization of minimal security requirements for low-cost RFID-tag security. 2. We describe protocol that provably achieves the properties of authentication and privacy in RFID tags in our proposed model, and in a good practical sense. Our proposed protocol involves no computationally intensive cryptographic operations, and relatively little storage. 3. Of particular practical interest, we describe some reduced-functionality variants of our protocol. We show, for instance, how static pseudonyms may considerably enhance security against eavesdropping in low-cost RFID tags. Our most basic static-pseudonym proposals require virtually no increase in existing RFID tag resources.

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Coleridge's "Christabel" as l'écriture féminine (코울리지의 「크리스터벨」 -'여성적 글쓰기')

  • Sun, Heejung
    • Journal of English Language & Literature
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    • v.56 no.2
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    • pp.329-356
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    • 2010
  • Coleridge's fame as a poet rests on the achievement of the mystery poems, "The Anceint Mariner," "Kubla Khan," and "Christabel." Coleridge's achievement in "Christabel" goes far beyond what previous critics have imagined. Coleridge is one of a handful of great writers who are included as representatives of androgyny. Throughout his life, Coleridge was accustomed to point out feminine qualities within himself. "Christabel" exemplifies the kind of writing contemporary feminist theories call l'écriture féminine. L'écriture féminine is not necessarily the creation of women but may rather be the works of those who refuse to identify with the father and the laws of paternal discourse. "Christabel" becomes Coleridge's most daring symbolic story. "Christabel" appears in its full significance as a vehicle for some profound insights into the dynamics of relationships between men and women, fathers and daughters. Through her deformity, Geraldine is actually the casualty of her father's hatred of women, and is the embodiment of all its anti-virtual aspects. The poem shows no bitterness against women, only compassion and remorse. Coleridge is sympathetically presenting Christabel's suffering as a woman at the hands of an overmastering man. Also, "Christabel" demonstrates woman power as well. In fact, the one person whose tales have any real effect within this narrative is the ambiguous Geraldine. Geraldine excels at story-telling, at making words act for her. Perhaps, despite the appearance of the surface, in which men hold all the cards, it is in fact women, or the feminine, so necessary to procreation and creativity, who hold sway here. This apparent dominion of the feminine derives at least partly from Coleridge's use of the conventions of that feminine genre, the Gothic romance. L'écriture féminine is a concept defined by its divergence from a dominant cultural norm. One may speculate that the fragmentary state of "Christabel" and "Kubla Khan" is in fact congruent with this mode of writing. If these poems imply a theoretical écriture féminine, they are by definition "incomplete," for completeness is a standard of patriarchal language and culture. More perplexing even than the other "mystery poems," "Christabel" is the true fragment of the three.