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Type I Chiari malformation presenting orthostatic syncope who treated with decompressive surgery

  • Shin, Hyun-Seung;Kim, Jeong A;Kim, Dong-Seok;Lee, Joon Soo
    • Clinical and Experimental Pediatrics
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    • v.59 no.sup1
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    • pp.149-151
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    • 2016
  • Chiari malformations are a congenital anomaly of the hindbrain. The most common, Chiari malformation type I (CM-I), is characterized by herniation of the cerebellar tonsils extending at least 3 mm below the plane of the foramen magnum. Consequently, CM-I is associated with hydrocephalus and symptoms involving compression of the cervicomedullary junction by ectopic tonsils. Several studies have reported the clinical symptoms associated with CM-I, including suboccipital headache, weakness in the upper extremities, facial numbness, loss of temperature sensation, ataxia, diplopia, dysarthria, dysphagia, vomiting, vertigo, nystagmus, and tinnitus. Syncope is one of the rarest presentations in patients with CM-I. There are many hypotheses regarding the causes of syncope in patients with CM-I; however, the mechanisms are not clearly understood. Although surgical decompression for CM-I in patients with syncope has yielded good clinical results in some studies, such cases are rarely reported. We report a case of orthostatic syncope in a patient with CM-I who was treated with surgical intervention.

지리정보시스템을 위한 기존지도의 수치화에 관한 소개

  • 이현우
    • Computational Structural Engineering
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    • v.4 no.2
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    • pp.32-35
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    • 1991
  • 컴퓨터가 발명된 초기에는 대부분 수식계산 처리만이 목적이었으나, 현재는 계산처리의 용도는 물론이고, M.I.S.(Management Information System), 자료의 생성.보관.처리.관리, Computer Graphics에 널리 이용되고 있으며 A.T.(Artificial Interligence), N.N.(Neural Network)까지 활용, 발전되어가고 있는 추세이다. 본 글에서는 현재 국내에서 부상하고 있는 G.I.S.(Geographic Information System)의 소개와 G.I.S.에서 필요로 하는 기존지도의 수치화(Digital Mapping)의 방법과정을 설명하고자 한다.

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Implementation and Performance Analysis of Single I/O Space Service for Cluster Computers (클러스터 컴퓨터를 위한 단일 I/O 공간 서비스의 구현 및 성능분석)

  • Kim, Tae-Kyu;Kim, Bang-Hyun;Kim, Jong-Hyun
    • The KIPS Transactions:PartA
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    • v.13A no.6 s.103
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    • pp.517-524
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    • 2006
  • In cluster computers, it is essential to Implement the single I/O space(SIOS) supporting integrated I/O substructure to efficiently process I/O intensive applications. SIOS service provides with global I/O address space to directly access peripherals and hard disks in its own or remote nodes from any node in the cluster computer In this thesis, we propose the implementation method of SIOS in Linux clusters by using only freewares. This method is implemented at device driver level that uses Enhanced Network Block Device(ENBD) and file system level that uses S/W RAID and NFS. The major strengths of this method are easiness of implementation and almost no cost due to using freewares. In addition, since freewares used are open sources, it is possible to apply this method to other platforms with only slight modification. Moreover, experiments show that I/O throughputs are up to 5.5 times higher in write operations and approximately 2.3 times higher in read operations than those of CDD method that uses the device driver developed at kernel level.

Power Loss and Electro-Magnetic Characteristics of Ni-Cu-Zn Ferrites (Ni-Cu-Zn페라이트의 손실과 자성 특성)

  • Otsuki E.;Kim Jeong-Su
    • Proceedings of the Korean Institute of Resources Recycling Conference
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    • 2004.12a
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    • pp.3-11
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    • 2004
  • The power loss analysis was carried out for Ni-Cu-Zn ferrite samples with different content of NiO and ZnO. The power loss, Pcv decreases monotonically wi increasing temperature and attains to a certain value at around $100\~120$ degrees Celsius. The frequency dependence of Pcv can be explained by $Pcv\~f^n$', and n is independent of the frequency, f up to 1MHz. The Pcv decreases with an increase in ZnO/NiO. The Pcv was separated to hysteresis loss, Ph and residual loss, (Pcv-Ph). The temperature characteristics and compositional dependence of Pcv can be attributed to the Ph, while (Pcv-Ph) is not affected by both temperature and ZnO/NiO. By analyzing temperature and composition dependence of Ph and initial permeability, ${\mu}^i$ following equations could be formularized. $${\mu}_i{\mu}o=I_x\;^2/(K_1+bs_ol_s)\;\;\;\;(1)$$ $Wh=13.5(I_s\;^2/{\mu}_i{\mu}_o)\;\;\;\;(2)$$ Were ${\mu}_o$ is permeability of vacuum, $I_s$ saturation magnetization, $K_1$ anisotropy constant, $S_o$ internal heterogeneous stress, $I_s$, magnetostriction constant, b unknown constant. Wh hysteresis loss per one cycle of excitation (Ph: Wh*f). Steinmetz constant of Ni-Cu-Zn ferrites, $m=1.64\~2.2$ is smaller than the one of Mn-Zn ferrites, which suggests the difference of loss mechanism between these materials.

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Security Analysis on GFN with Secret S-box (비밀 S-box를 사용한 GFN에 대한 안전성 분석)

  • Lee, Yongseong;Kang, HyungChul;Hong, Deukjo;Sung, Jaechul;Hong, Seokhie
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.27 no.3
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    • pp.467-476
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    • 2017
  • In this paper, we analyze Generalized Feistel Network(GFN) Type I, Type II, Type III that round function use SP update function, secret S-box and $k{\times}k$ MDS matirx. In this case an attacker has no advantage about S-box. For each type of GFN, we analyze and restore secret S-box in 9, 6, 6 round using the basis of integral cryptanalysis with chosen plaintext attack. Also we restore secret S-box in 16 round of GFN Type I with chosen ciphertext attack. In conclusion, we need $2^{2m}$ data complexity and ${\frac{2^{3m}}{32k}},{\frac{2^{3m}}{24k}},{\frac{2^{3m}}{36k}}$ time complexity to restore m bit secret S-box in GFN Type I, Type II, Type III.

Differentiation of Vibrio spp. including Core Group Species by PCR-RFLP (PCR-RFLP에 의한 Vibrio core group을 포함한 Vibrio 종의 구분)

  • Park, Jin-Sook
    • Journal of Life Science
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    • v.22 no.2
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    • pp.245-250
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    • 2012
  • The 16S rDNA - RFLP types for six Vibrio species (V. fluvialis, V. proteolyticus, V. vulnificus, V. mimicus) including two core group members, V. alginolyticus and V. parahaemolyticu s, and Grimontia (Vibrio) hollisae were determined using PCR-RFLP analysis. Six tetrameric restriction enzymes (Alu I, Cfo I, Dde I, Hae III, Msp I, and Rsa I) were selected for RFLP analysis. V. alginolyticus, V. parahaemolyticus, and V. proteolyticus showed the same RFLP pattern following digestion with four of the six used restriction enzymes: CfoI, DdeI, MspI, and RsaI. Various restriction enzyme combinations generated digests recognizable as distinct RFLP types for each of the assayed Vibrio species. In particular, AluI single digestion produced species specific band patterns that enabled the differentiation between these Vibrio species. Dendrogram based on restriction patterns showed that two Vibrio core group members, V. alginolyticus and V. parahaemolyticus were closely related having a similarity over 90%. Although the observed RFLP pattern for Grimontia hollisae shared several common bands with other Vibrio spp., G. hollisae results were still clearly distinct from Vibrio spp. RFLP types for all restriction enzymes tested. If restriction enzymes are aptly selected, PCR-RFLP analysis is still a rapid and effective tool for differentiating Vibrio species.

Symbol Error Probability of DVB-S2 System with I/Q Unbalances (I/Q 불균형이 고려된 DVB-S2 시스템의 심벌 오류 확률)

  • Im, In-Chul;Won, Seung-Chan;Yoon, Dong-Weon;Park, Sang-Kyu
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.32 no.9C
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    • pp.810-819
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    • 2007
  • The I/Q unbalance which is generated by non-ideal components such as a $90^{\circ}$ phase shifter and I/Q filters is an inevitable physical phenomenon and leads to performance degradation when we implement a coherent two-dimensional (2-D) modulation/demodulation system. This paper provides an exact and general expression for the SEP(symbol error probability) of DVB-S2 system with I/Q phase and amplitude unbalance over AWGN channel. Coordinate rotation and shift techniques used to redefine a received signal are key mathematical tools. In conclusion, the derived result is expressed as a linear combination of the 2-D Gaussian Q-functions.


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