• Title/Summary/Keyword: direct attack

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A Case of Deficiency of the Seventh Component of Complement with Recurrence of Meningococcal Meningitis and Septicemia (C7 결핍증과 연관된 재발성 수막구균 혈증 1례)

  • Lee, Jong-Seung;Yoo, Jung-Min;Yoo, Soo-Jung;Ko, Tae-Sung;Yoo, Han-Wook
    • Pediatric Infection and Vaccine
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    • v.11 no.2
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    • pp.212-215
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    • 2004
  • The complement system is important in the generation of the normal inflammatory response and in host defense against systemic infection. Therefore, inherited or acquired deficiency of complement is associated with an increased frequency of infection. As a major effector of the complement cascade, the membrane attack complex is responsible for direct complement dependent serum bactericidal activity. Especially late complement component deficiency has a markedly increased risk of meningococcal infection and is subject to recurrent infection. We experienced a patient who had recurrent meningococcal meningitis and septicemia. The patient was 13-years old boy and he had a recurrent episode after 20 months. At second admission, we examined complement level and C7 deficiency was confirmed. He was treated without complication. We report a case of deficiency of C7 with recurrent meningococcal meningitis and septicemia.

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Authentication for Single/Multiple Domain using Attribute Certificates (유비쿼터스 컴퓨팅 환경에서 속성 인증서를 이용한 단일/멀티 도메인 인증)

  • Lee Deok-Gyu;Park Hee-Un;Lee In-Yeong
    • Journal of KIISE:Information Networking
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    • v.32 no.3
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    • pp.291-300
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    • 2005
  • The Ubiquitous computer environment is thing which invisible computer that is not shown linked mutually through network so that user may use computer always is been pervasive. Intend computing environment that can use easily as user wants and it is the smart environment that user provides context awareness that is wanting computing environment. This Ubiquitous computing contains much specially weak side in security. Masquerade attack of that crawl that is quoted to user or server among device that is around user by that discrete various computing devices exist everywhere among them become possible. Hereupon, in this paper, proposed method that have following characteristic. Present authentication model through transfer or device. Suggest two method that realize authentication through device in case of moved to method(MD: Multi Domain) and user ownself space(SD: Single Domain) that realize authentication through device in case of moved user's direct path who device differs.

Analysis on National Economic Loss of Cyber Attack: Voice Phishing Case (사이버공격의 국가 경제적 손실분석 - 보이스 피싱을 중심으로)

  • Shin, Jin
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.16 no.11
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    • pp.2341-2346
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    • 2012
  • Voice phishing against the old or weak persons have used the methods which are social engineering in the object and financial structure and function. Until recently Voice phishing from Chaina caused economic devastation and the economic loss by phishing grows with the South Koreans in the whole. Korean government and public organizations involved have been strengthening protection system and a financial security devices. But it is not easy to verify how much effects of security measures are. In this paper I will study the economic loss caused by voice phishing and potential economic effects of security measures and security device reinforcements of the Republic of Korea. Direct costs are reported about 100 million dollars and potential economic effects of voice phinshing secure measures may be around 320 million dollars.

A Study on Cockpit Voice Command System for Fighter Aircraft (전투기용 음성명령 시스템에 대한 연구)

  • Kim, Seongwoo;Seo, Mingi;Oh, Yunghwan;Kim, Bonggyu
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.41 no.12
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    • pp.1011-1017
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    • 2013
  • The human voice is the most natural means of communication. The need for speech recognition technology is increasing gradually to increase the ease of human and machine interface. The function of the avionics equipment is getting various and complicated in consequence of the growth of digital technology development, so that the load of pilots in the fighter aircraft must become increased since they don't concentrate only the attack function, but also operate the complicated avionics equipments. Accordingly, if speech recognition technology is applied to the aircraft cockpit as regards the operating the avionics equipments, pilots can spend their time and effort on the mission of fighter aircraft. In this paper, the cockpit voice command system applicable to the fighter aircraft has been developed and the function and the performance of the system verified.

Studies on the oxygen-Atom-Transfer Reactions of Peroxo Vanadium(Ⅴ) Complexes (Peroxo Vanadium(Ⅴ)화합물들에 의한 산소 원자 전이 반응에 관한 연구)

  • Won, Tae Jin
    • Journal of the Korean Chemical Society
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    • v.45 no.3
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    • pp.213-218
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    • 2001
  • The reaction of peroxo vanadium(V) complexes, $VO(O_2)_2(pic)^{2-}$, $VO(O_2)(nta)^{2-}$, and $VO(O_2)(dipic)^-$ with thiolato-cobalt(III), $(en)_2Co(SCH_2CH_2NH_2)^{2+}$ resulted in an oxygen-atom transfer in aqueous solutions. Rate constants ($M^{-1}S^{-1}$) for these reactions were (35$\pm$1), $(4.8{\pm}0.4){\times}10^{-2}$ , and $(8.6{\pm}0.5){\times}10^{-4}$, respectively. The coordinate peroxide was activated in the oxygen-atom-transfer reaction of $VO(O_2)_2(pic)^{2-}$, but it is not the case for VO(O$_2$) $(nta)^{2-}$ and VO(O$_2$) $(dipic)^-$. In this paper, we proposed that the direct attack of an electrophilic peroxide to a nucleophilic substrate occurs in the oxygen-atom transfer pathway of peroxo vanadium(V) complexes.

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Acetylcholinesterase(AChE)-Catalyzed Hydrolysis of Long-Chain Thiocholine Esters: Shift to a New Chemical Mechanism

  • Jung, Dai-Il;Shin, Young-Ju;Lee, Eun-Seok;Moon, Tae-sung;Yoon, Chang-No;Lee, Bong-Ho
    • Bulletin of the Korean Chemical Society
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    • v.24 no.1
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    • pp.65-69
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    • 2003
  • The kinetic and chemical mechanisms of AChE-catalyzed hydrolysis of short-chain thiocholine esters are relatively well documented. Up to propanoylthiocholine (PrTCh) the chemical mechanism is general acid-base catalysis by the active site catalytic triad. The chemical mechanism for the enzyme-catalyzed butyrylthiocholine(BuTCh) hydrolysis shifts to a parallel mechanism in which general base catalysis by E199 of direct water attack to the carbonyl carbon of the substrate. [Selwood, T., et al. J. Am. Chem. Soc. 1993, 115, 10477- 10482] The long chain thiocholine esters such as hexanoylthiocholine (HexTCh), heptanoylthiocholine (HepTCh), and octanoylthiocholine (OcTCh) are hydrolyzed by electric eel acetylcholinesterase (AChE). The kinetic parameters are determined to show that these compounds have a lower Michaelis constant than BuTCh and the pH-rate profile showed that the mechanism is similar to that of BuTCh hydrolysis. The solvent isotope effect and proton inventory of AChE-catalyzed hydrolysis of HexTCh showed that one proton transfer is involved in the transition state of the acylation stage. The relationship between the dipole moment and the Michaelis constant of the long chain thiocholine esters showed that the dipole moment is the most important factor for the binding of a substrate to the enzyme active site.

Research on Cyber-terrorism preparation scheme (사이버테러 대응방안에 관한 연구)

  • Kim, Yeon Jun;Kim, Sang Jin
    • Convergence Security Journal
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    • v.16 no.3_2
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    • pp.33-42
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    • 2016
  • While evolving information-oriented society provides a lot of benefits to the human life, new types of threats have been increasing. Particularly, cyber terrorism, happen on the network that is composed of a computer system and information communication network, and the mean and scale of damage has reached a serious level. In other words, it is hard to locate cyber terror since it occurs in the virtual space, not in the real world, so identifying "Who is attacking?" (Non-visibility, non-formulas), or "Where the attack takes place?" (trans-nation) are hard. Hackers, individuals or even a small group of people, who carried out the cyber terror are posing new threats that could intimidate national security and the pace and magnitude of threats keep evolving. Scale and capability of North Korea's cyber terrorism are assessed as world-class level. Recently, North Korea is focusing on strengthen their cyber terrorism force. So improving a response system for cyber terror is a key necessity as North Korea's has emerged as a direct threat to South Korean security. Therefore, Korea has to redeem both legal and institutional systems immediately to perform as a unified control tower for preemptive response to cyber terrors arise from North Korea and neighboring countries.

Kinetics and Mechanism of the Hydrolysis of Phenyl N-Benzenesulfonylchloroformimidate Derivatives (Phenyl N-Benzenesulfonylchloroformimidate 誘導體의 加水分解 反應메카니즘과 反應速度論的 硏究)

  • Nack-Do Sung;Ki-Sung Kwon;Tae-Rin Kim
    • Journal of the Korean Chemical Society
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    • v.28 no.5
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    • pp.328-334
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    • 1984
  • A series of phenyl N-benzenesulfonylchloroformimidate derivatives (p-H, p-Cl, p-CH3 & p-OCH3) were prepared and the hydrolysis of these compounds were studied kinetically at various pH by UV spectrophotometry in 1 ; 4 dioxane-water at $25^{\circ}C$. Hammett ${\rho}$ values measured at pH 5.0 (${\rho}$ = -0.45) and pH 10.0 (${\rho}$ = 0.40) indicate that the reaction proceeds via an azocarbonium ion intermediate in the acidic medium, whereas, it involves direct attack by hydroxide ion on the azomethine carbon atom occurs under the basic medium. The formation of stabilized azocarbonium ion species at pH 5.0 is also consistent with the large solvent effect(m = 1.3-1.5 & n = 5.0-5.5). On the basis of these findings, we may concluded that the hydrolysis of phenyl N-benzenesulfonylchloroformimidate derivatives proceeds by $SN_1$ below pH 8.0, however, above pH 10.0, the hydrolysis proceeds through $SN_2$ and in the range of pH 8.0-10.0, these two reactions occur competitively.

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Upregulation of Dendritic Arborization by N-acetyl-D-Glucosamine Kinase Is Not Dependent on Its Kinase Activity

  • Lee, HyunSook;Dutta, Samikshan;Moon, Il Soo
    • Molecules and Cells
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    • v.37 no.4
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    • pp.322-329
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    • 2014
  • N-acetylglucosamine kinase (GlcNAc kinase or NAGK; EC 2.7.1.59) is highly expressed and plays a critical role in the development of dendrites in brain neurons. In this study, the authors conducted structure-function analysis to verify the previously proposed 3D model structure of GlcNAc/ATP-bound NAGK. Three point NAGK mutants with different substrate binding capacities and reaction velocities were produced. Wild-type (WT) NAGK showed strong substrate preference for GlcNAc. Conversion of Cys143, which does not make direct hydrogen bonds with GlcNAc, to Ser (i.e., C143S) had the least affect on the enzymatic activity of NAGK. Conversion of Asn36, which plays a role in domain closure by making a hydrogen bond with GlcNAc, to Ala (i.e., N36A) mildly reduced NAGK enzyme activity. Conversion of Asp107, which makes hydrogen bonds with GlcNAc and would act as a proton acceptor during nucleophilic attack on the ${\gamma}$-phosphate of ATP, to Ala (i.e., D107A), caused a total loss in enzyme activity. The overexpression of EGFP-tagged WT or any of the mutant NAGKs in rat hippocampal neurons (DIV 5-9) increased dendritic architectural complexity. Finally, the overexpression of the small, but not of the large, domain of NAGK resulted in dendrite degeneration. Our data show the effect of structure on the functional aspects of NAGK, and in particular, that the small domain of NAGK, and not its NAGK kinase activity, plays a critical role in the upregulation of dendritogenesis.

Multi-objective shape optimization of tall buildings considering profitability and multidirectional wind-induced accelerations using CFD, surrogates, and the reduced basis approach

  • Montoya, Miguel Cid;Nieto, Felix;Hernandez, Santiago
    • Wind and Structures
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    • v.32 no.4
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    • pp.355-369
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    • 2021
  • Shape optimization of tall buildings is an efficient approach to mitigate wind-induced effects. Several studies have demonstrated the potential of shape modifications to improve the building's aerodynamic properties. On the other hand, it is well-known that the cross-section geometry has a direct impact in the floor area availability and subsequently in the building's profitability. Hence, it is of interest for the designers to find the balance between these two design criteria that may require contradictory design strategies. This study proposes a surrogate-based multi-objective optimization framework to tackle this design problem. Closed-form equations provided by the Eurocode are used to obtain the wind-induced responses for several wind directions, seeking to develop an industry-oriented approach. CFD-based surrogates emulate the aerodynamic response of the building cross-section, using as input parameters the cross-section geometry and the wind angle of attack. The definition of the building's modified plan shapes is done adopting the reduced basis approach, advancing the current strategies currently adopted in aerodynamic optimization of civil engineering structures. The multi-objective optimization problem is solved with both the classical weighted Sum Method and the Weighted Min-Max approach, which enables obtaining the complete Pareto front in both convex and non-convex regions. Two application examples are presented in this study to demonstrate the feasibility of the proposed strategy, which permits the identification of Pareto optima from which the designer can choose the most adequate design balancing profitability and occupant comfort.