• Title/Summary/Keyword: max

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Security Scheme for Prevent malicious Nodes in WiMAX Environment (WiMAX 환경에서 악의적 노드 예방을 위한 보안 기법)

  • Jeong, Yoon-Su;Kim, Yong-Tae;Park, Gil-Cheol;Lee, Sang-Ho
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.13 no.2
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    • pp.382-389
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    • 2009
  • As the use of mobile device is popularized, the needs of variable services of WiMAX technique and the importance of security is increasing. There is a problem that can be easily attacked from a malicious attack because the action is achieved connectionlessly between neighbor link establishing procedure and TEK exchange procedure in mobile WiMAX even though typical 1 hop network security technique is adapted to WiMAX for satisfying these security requirement. In this paper, security connected mechanism which safely connects neighbor link establishing procedure of WiMAX and TEK exchange procedure additional to the basic function provided by IEEE 802.16e standard to satisfy security requirement of mobile WiMAX is proposed. The proposed mechanism strengthens the function of security about SS and BS by application random number and private value which generated by SS and BS to public key of neighbor link establishing procedure and TEK exchange procedure. Also, we can prevent from inside attack like man-in-the-middle which can occur in the request of TEK through cryptographic connection of neighbor link establishing procedure and TEK exchange procedure.

A Convergence Test of the Full-potential Linearized Augmented Plane Wave (FLAPW) Method: Ferromagnetic Bulk BCC Fe

  • Seo, Seung-Woo;Song, You-Young;Gul, Rahman;Kim, In-Gee;Weinert, M.;Freeman, A.J.
    • Journal of Magnetics
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    • v.14 no.4
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    • pp.137-143
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    • 2009
  • The convergence behavior of the all-electron full-potential linearized augmented plane-wave (FLAPW) method with the explicit orthogonalization (XO) scheme is tested on ferromagnetic bulk body-centered-cubic Fe. Applying a commonly used criterion relating the plane-wave and angular momentum cutoffs, $l_{max}\;=\;R_{MT}K_{max}$, where $R_{MT}$ is the muffin-tin (MT) sphere radius and $K_{max}$ is the plane-wave cutoff for the basis - the total energy is converged and stable for $K_{max}R_{MT}$ = 10. The total energy convergence dependence on the star-function cutoff, $G_{max}$, is minimal and so a $G_{max}$ of 3$K_{max}$ or a large enough $G_{max}$ is a reasonable choice. We demonstrate that the convergence with respect to $l_{max}$ or a fixed large enough $G_{max}\;and\;K_{max}$ are independent, and that $K_{max}$ provides a better measure of the convergence than $R_{MT}K_{max}$. The dependence of the total energy on $R_{MT}$ is shown to be small if the core states are treated equivalently, and that the XO scheme is able to treat systems with significantly smaller $R_{MT}$ than the standard LAPW method. For converged systems, the calculated lattice parameter, bulk modulus, and magnetic moments are in excellent agreement with the experimental values.

Timetabling and Analysis of Train Connection Schedule Using Max-Plus Algebra (Max-Plus 대수를 이용한 환승 스케줄 시간표 작성 및 분석)

  • Park, Bum-Hwan
    • Journal of the Korean Society for Railway
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    • v.12 no.2
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    • pp.267-275
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    • 2009
  • Max-plus algebra is a nonlinear system comprised of two operations, maximization (max) and addition (Plus), which are corresponding to the addition and the multiplication in conventional algebra, respectively. This methodology is applicable to many discrete event systems containing the state transition with the maximization and addition operation. Timetable with connection is one of such systems. We present the method based on max-plus algebra, which can make up timetable considering transfer and analyse its stability and robustness. In this study, it will be shown how to make up the timetable of the urban train and analyse its stability using Max-Plus algebra.

Performance of the BD MAX MDR-TB assay in a clinical setting and its impact on the clinical course of patients with pulmonary tuberculosis: a retrospective before-after study

  • Sung Jun Ko;Kui Hyun Yoon;Sang Hee Lee
    • Journal of Yeungnam Medical Science
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    • v.41 no.2
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    • pp.113-119
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    • 2024
  • Background: Missing isoniazid (INH) resistance during tuberculosis (TB) diagnosis can worsen the outcomes of INH-resistant TB. The BD MAX MDR-TB assay (BD MAX) facilitates the rapid detection of TB and INH and rifampin (RIF) resistance; however, data related to its performance in clinical setting remain limited. Moreover, its effect on treatment outcomes has not yet been studied. Methods: We compared the performance of BD MAX for the detection of INH/RIF resistances to that of the line probe assay (LPA) in patients with pulmonary TB (PTB), using the results of a phenotypic drug sensitivity test as a reference standard. The treatment outcomes of patients who used BD MAX were compared with those of patients who did not. Results: Of the 83 patients included in the study, the BD MAX was used for an initial PTB diagnosis in 39 patients. The sensitivity of BD MAX for detecting PTB was 79.5%. The sensitivity and specificity of BD MAX for INH resistance were both 100%, whereas these were 50.0% and 95.8%, respectively, for RIF resistance. The sensitivity and specificity of BD MAX were comparable to those of LPA. The BD MAX group had a shorter time interval from specimen request to the initiation of anti-TB drugs (2.0 days vs. 5.5 days, p=0.001). Conclusion: BD MAX showed comparable performance to conventional tests for detecting PTB and INH/RIF resistances. The implementation of BD MAX as a diagnostic tool for PTB resulted in a shorter turnaround time for the initiation of PTB treatment.

Implementation of a Smart Antenna Base Station for mobile-WiMAX (Mobile-WiMAX를 위한 스마트 안테나 기지국 구현)

  • Lee, Chang-Hoon;Choi, Seung-Won
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.47 no.1
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    • pp.43-52
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    • 2010
  • In this paper, the mobile-WiMAX (m-WiMAX) using the Smart antenna technique is implemented. Experiments are performed to compare Smart antenna system with conventional single antenna system. To implement the m-WiMAX smart antenna system there are many considerations, key issues of which are symbol time acquisition, beamforming, calibration. In the paper, symbol time acquisition, beamforming, calibration are implemented in WiMAX Smart antenna system and we verified that Smart antenna system is superior to single antenna system. The experimental results show 5.5 dB performance enhancement of implemented Smart antenna system in throughput compared with a single antenna system. The experimental result is almost same as theoretical result of 6 dB.

Design of Triple-Band Microstrip Antenna for WLAN/WiMAX (WLAN/WiMAX용 삼중대역 마이크로스트립 안테나 설계)

  • Oh, Mal-Goen;Kim, Kab-Ki
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.14 no.4
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    • pp.213-217
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    • 2014
  • In this paper, we designed monopole microstrip antenna for WLAN/WiMAX system. The monopole antenna is designed by FR-4 substrate with size is $30mm{\times}40mm$. The proposed antenna is based on a planar monopole design which cover WLAN and WiMAX frequency bands. To obtain the optimized parameters, we used the simulator, CST's Microwave Studio Program and found the parameters that greatly effect antenna characteristics. Using the obtained parameters, the antenna is designed. Thus the proposed antenna satisfied the -10 dB impedance bandwidth requirement while simultaneously covering the WLAN and WiMAX bands. And characteristics of gain and radiation patterns are obtained for WLAN/WiMAX frequency bands.

CLASSIFICATIONS OF (α, β)-FUZZY SUBALGEBRAS OF BCK/BCI-ALGEBRAS

  • Jun, Young Bae;Ahn, Sun Shin;Lee, Kyoung Ja
    • Honam Mathematical Journal
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    • v.36 no.3
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    • pp.623-635
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    • 2014
  • Classications of (${\alpha},{\beta}$)-fuzzy subalgebras of BCK/BCI-algebras are discussed. Relations between (${\in},{\in}{\vee}q$)-fuzzy subalgebras and ($q,{\in}{\vee}q$)-fuzzy subalgebras are established. Given special sets, so called t-q-set and t-${\in}{\vee}q$-set, conditions for the t-q-set and t-${\in}{\vee}q$-set to be subalgebras are considered. The notions of $({\in},q)^{max}$-fuzzy subalgebra, $(q,{\in})^{max}$-fuzzy subalgebra and $(q,{\in}{\vee}q)^{max}$-fuzzy subalgebra are introduced. Conditions for a fuzzy set to be an $({\in},q)^{max}$-fuzzy subalgebra, a $(q,{\in})^{max}$-fuzzy subalgebra and a $(q,{\in}{\vee}q)^{max}$-fuzzy subalgebra are considered.

A Study on the Initial Maximum Value of Heat Flux, $q_{max}$ of Wool Fabrics (Part I) - The correlation between $q_{max}$ and thermal conductivity, thermal transmittance, surface air cavity of wool fabrics - (양모 복지의 초기열류속최대치($q_{max}$)에 관한 연구( I ) -열전도도, 열통과성, 표면기공도와의 상관성을 중심으로-)

  • Choi Suk Chul;Jung Jin Soun;Chun Tae il
    • Journal of the Korean Society of Clothing and Textiles
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    • v.15 no.4 s.40
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    • pp.367-372
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    • 1991
  • In this study, we discussed about the factors effected upon the initial maximum value of heat flux ($q_{max}$). Thermal conductivity, thermal transmittance and surface air cavity of wool fabrics were examind and their correlation to the $q_{max}$ was studied. The factors were examined which had an effect upon the $q_{max}$ of an objective measure of warm/cool feeling. It was simulated by Thermo-Labo apparatures. We selected twenty sorts of pure wool woven fabrics for men's fall -winter cloth (all Wool). The conclusions are as follows; 1. There was not a certain correlation between the $q_{max}$ and the thermal conductivity of wool fabric. 2. When the fabrics touched on the copper plates, the thickness of wool fabric had a negative correlation to the $q_{max}$. The thermal transmittance had a positive correlation. Both of them had a good correlation to the $q_{max}$. 3. As a major factor, the thickness of fabric effected on the $q_{max}$.

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