• Title/Summary/Keyword: Cross Bar

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Design of ultra short vertical directional couplers with high extinction ratios composed of two sections (매우 짧은 길이와 높은 소멸비를 가지는 두 개의 영역으로 구성된 수직 방향성 결합기의 설계)

  • Cho, Sung-Chan;Seol, Jong-Chol;Kim, Boo-Gyoun
    • Journal of the Korean Institute of Telematics and Electronics D
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    • v.36D no.9
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    • pp.64-70
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    • 1999
  • We show that both cross and bar states with very high extinction ratios larger than 30 dB can be obtained in ultra short (< $100{\mu}m$) two-section vertical directional couplers. Based on the calculations of various possible combinations of the refractive indices of waveguides in each section using the improved coupled mode theory and beam propagation method, the guidelines for the design of ultra short two-section vertical directional couplers are presented to obtain both cross and bar states with high extinction ratios larger than 30 dB at the ends of section 1 and section 2, respectively.

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Vertical Directional Coupler Switches with Switching Operation Induced and Extinction Ratio Enhanced Sections (스위칭 동작 유도 영역과 소멸비 향상 영역으로 구성된 수직 방향성 결합 스위치 설계)

  • Jo, Seong-Chan;Jeong, Byeong-Min;Kim, Bu-Gyun
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.38 no.9
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    • pp.643-651
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    • 2001
  • Fused vertical directional coupler switches (FVCSs) with switching operation induced section (SOIS) and extinction ratio enhanced section (ERES) are proposed. In these FVCSs, switching operation is achieved by changing the refractive indices of both cores in SOIS and improvement of extinction ratios larger than 30dB for both cross and bar states is achieved by controlling the asymmetry of refractive indices between both cores in ERES. In addition, the design guidelines to have high extinction ratios larger than 30dB with large tolerances of the refractive index of cores are presented.

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Design of Ulta-short Fused Vertical Coupler Switches Composed of Two Sections (두 개의 영역으로 구성된 매우 짧은 길이를 가지는 융합된 수직 방향성 결합 스위치 설계)

  • Cho, Sung-Chan;Seol, Jong-Chol;Kim, Boo-Gyoun
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.37 no.10
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    • pp.42-50
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    • 2000
  • We show that both cross and bar states with high extinction ratios larger than 30dB can be achieved at eh same ends of ultra-short fused vertical directional coupler switches with two sections by changing the refractive indices of cores and inner cladding layers less than 1%. Based on the calculation of extinction ratios of cross state and bar state for various refractive index and thickness of inner cladding layer and core using the improved coupled mode theory and beam propagation method, the guidelines for design to achieve large tolerances in refractive indices of core and inner cladding layer in fused vertical directional coupler switches are presented.

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Effect of Cross-bar Length on Luminous Efficacy in AC-PDP with Fence Electrode Stricture

  • Nam, Hyung-Woo;Choi, Yong-Suk;Bae, Hyo-Won;Kim, Yun-Gi;Ok, Jung-Woo;Kim, Dong-Hyun;Lee, Ho-Jun;Lee, Hae-June;Park, Chung-Hoo
    • 한국정보디스플레이학회:학술대회논문집
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    • 2009.10a
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    • pp.721-724
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    • 2009
  • In this paper, we proposed fence electrode structures. The experimental structures change cross-bar length as 145, 105, 65 and $30{\mu}m$ to improve the electro-optical characteristics. The proposed structures improve the addressing time and luminous efficacy compared with the T145 structure which has the cross-bar length of $145{\mu}m$ as the reference. Especially, in the case of the T30 structure with cross-bar length of $30{\mu}m$, it gains lower power consumption by 34%, and higher luminous efficacy by 20% than those of the reference structure.

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Fabulous Horses out of Water in B.Sīlā as Depicted in the Kūshnāma: A Cultural Encounter between East and West Asia

  • LIU, YINGJUN
    • Acta Via Serica
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    • v.4 no.1
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    • pp.87-109
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    • 2019
  • In the Iranian epic $K{\bar{u}}shn{\bar{a}}ma$, there is a rather interesting story that recounts how the inhabitants of $B.s{\bar{i}}l\bar{a}$ cross-breed their domesticated horses with a magical horse living in the sea in order to obtain fine-bred ones. What is even more interesting is that similar accounts are also seen in many of other classical Perso-Arabic works and Chinese sources. The regions that such events took place in mainly spread over Central Asia and western China while in $K{\bar{u}}shn{\bar{a}}ma$, the story happens in $B.s{\bar{i}}l\bar{a}$, a legendary kingdom with its historical prototype being Silla. By sorting out certain records of how ancient people sought fine horses by cross-breeding domesticated horses with wild horses that inhabited mountains and waters within Chinese sources and classical Muslim works, and comparing these accounts with similar plot lines as depicted in $K{\bar{u}}shn{\bar{a}}ma$, this paper attempts to elucidate that the story in $K{\bar{u}}shn{\bar{a}}ma$ is a result of flourishing land and maritime exchanges between East Asia and West Asia during ancient and medieval times, rather than a purely literary fiction. It was not only influenced by the horse culture that thrived over the Eurasian Steppe, but the story is also coincidentally in accordance with the fact that the nomadic zone which lies within the central Eurasian continent extends as far as the Korean Peninsula in northeast Asia.

Process Map for Improving the Dimensional Accuracy in the Multi-Stage Drawing Process of Rectangular Bar with Various Aspect Ratio (다양한 종횡비의 직사각바 다단 인발공정에서 치수정도 향상을 위한 프로세스 맵)

  • Ko, P.S.;Kim, J.H.;Kim, B.M.
    • Transactions of Materials Processing
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    • v.27 no.3
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    • pp.154-159
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    • 2018
  • In the rectangular bar multi-stage drawing process, the cross-section dimensional accuracy of the rectangular bar varies depending on the aspect ratio and process conditions. It is very important to predict the dimensional error of the cross-section occurring in the multi-stage drawing process according to the aspect ratio of the rectangular bar and the half die angle of each pass. In this study, a process map for improving the dimensional accuracy according to the aspect ratio was derived in the drawing process of a rectangular bar. FE-simulation of the multi-stage shape drawing process was carried out with four types of rectangular bar. The results of the FE-simulation were trained to the nonlinear relationship between the shape parameters using an Artificial Neural Network (ANN), and the process maps were derived from them. The optimum half die angles were determined from the process maps on the dimensional accuracy. The validity of the suggested process map for aspect ratios 1.25~2:1 were verified through FE-simulation and experimentation.

Laboratory Performance Evaluation of Alternative Dowel Bar for Jointed Concrete Pavements (콘크리트 포장용 고내구성 대체 다웰바의 실내공용성 평가)

  • Park, Seong Tae;Park, Jun Young;Lee, Jae Hoon;Kim, Hyung Bae
    • International Journal of Highway Engineering
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    • v.15 no.1
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    • pp.23-36
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    • 2013
  • PURPOSES: The problem under this circumstance is that the erosion not only drops strength of the steel dowel bar but also comes with volume expansion of the steel dowel bar which can reduce load transferring efficiency of the steel dowel bar. To avoid this erosion problem, alternative dowers bars are developed. METHODS: In this study, the bearing stresses between the FRP tube dowel bar and concrete slab are calculated and compared with its allowable bearing stress to check its structural stability in the concrete pavement. These comparisons are conducted with several cross-sections of FRP tube dowel bars. Comprehensive laboratory tests including the shear load-deflection test on a full-scale specimen and the full-scale accelerated joint concrete pavement test are conducted and the results were compared with those from the steel dowel bar. RESULTS: In all cross-sections of FRP tube dowel bars, computed bearing stresses between the FRP tube dowel bar and concrete slab are less than their allowable stress levels. The pultrusion FRP-tube dowel bar show better performance on direct shear tests on full-scale specimen and static compression tests at full-scale concrete pavement joints than prepreg and filament-winding FRP-tube dowel bar. CONCLUSIONS: The FRP tube dowel bars as alternative dowel bar are invulnerable to erosion that may be caused by moisture from masonry joint or bottom of the pavement system. Also, the pultrusion FRP-tube dowel bar performed very well on the laboratory evaluation.

Effects of Pre- and Post-workout Energy Bar Supplementation on Blood Lactate and Fitness in Young Adults with CrossFit Training: A randomized crossover study

  • Byung-Gul Lim;Xinxing Li;Wook Song
    • Journal of The Korean Society of Integrative Medicine
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    • v.11 no.4
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    • pp.61-71
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    • 2023
  • Purpose : Energy bars are increasingly popular among active individuals, yet their timing and nutrient combinations' impact on exercise adaptation remains unclear. This study aims to address this knowledge gap by investigating whether the combination of pre- and post-workout supplementation can synergistically enhance fitness and alleviate fatigue in trained CrossFit participants. Investigate if combining pre- and post-workout supplements can enhance fitness and blood lactate management in trained CrossFit participants, potentially improving exercise performance for this group. Methods : In a randomized crossover study, 20 trained CrossFit individuals (11 males, 9 females) completed thrice-weekly 60-minute CrossFit sessions for 3 weeks, with a one-week washout period. Participants were randomly assigned to either a chocolate bar group (CH, 45 g, 225 kcal) or an energy bar group (ES, 48 g, 238 kcal, with protein, caffeine, taurine, and BCAAs). For one week, participants consumed two bars of their assigned supplement five minutes before and after workouts. After a washout period, they switched supplements. Blood lactate levels and a visual analog scale (VAS) were assessed before, immediately after, and 30 minutes post-workout. Fitness tests (hand grip, broad jump, sit-ups) were conducted at baseline and 30 minutes post-final workout. Data were analyzed using two-way repeated measures ANOVA (p<.05), 95 % confidence intervals, and magnitude inferences. Results : Hand grip strength (t=-5.60, p=.000), broad jump (t=-3.43, p=.003) and sit up (t=-3.94, p=.001) were significantly increased in the ES group. Compared to CH group, there was a significant time and group interactions for blood lactate level (F=5.51, p=.008) and VAS(F=31.67, p=.000) in the ES group. Conclusion : Pre- and post-workout energy bar supplementation may have a beneficial effect on blood lactate clearance and fitness in trained CrossFit individual. The combination of proprietary supplements taken may provide benefits for removing the blood lactate during high-intensity functional exercise.

Development of miniature bar-type structural fuses with cold formed bolted connections

  • Guan, Dongzhi;Yang, Sen;Jia, Liang-Jiu;Guo, Zhengxing
    • Steel and Composite Structures
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    • v.34 no.1
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    • pp.53-73
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    • 2020
  • A novel all-steel miniature bar-type structural fuse (MBSF) with cold formed bolted connections is developed in this study, which consists of a central energy dissipation core cut from a smooth round bar, an external confining tube and nuts. Three types of cross sections for the central energy dissipation core, i.e., triple-cut, double-cut and single-cut cross sections, were studied. Totally 18 specimens were axially tested under either symmetric or asymmetric cyclic loading histories, where the parameters such as cut cross sectional area ratio, length of the yielding portion and cross sectional type were investigated. Numerical simulation of 2 representative specimens were also conducted. An analytical model to evaluate the bending failure at the elastic portion was proposed, and a design method to avoid this failure mode was also presented. The experimental results show that the proposed MBSFs exhibit satisfactory hysteretic performance under both the two cyclic loading histories. Average strain values of 8% and 4% are found to be respectively suitable for designing the new MBSFs as the ultimate strain under the symmetric and asymmetric cyclic loadings.

Development of One-Piece Manufacturing Process for Automotive Cowl Cross Bar Using Rotary Swaging (회전 스웨이징을 이용한 자동차용 카울크로스바의 일체화 제조공정 개발)

  • Kim, H.S.;Youn, J.W.
    • Transactions of Materials Processing
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    • v.25 no.5
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    • pp.332-337
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    • 2016
  • The automobile cowl cross bar which is a backbone frame part holding electrical and air conditioning components inside the cockpit module has been designed with more complex geometries recently due to demands of its enhanced functions and reduced weight of frame parts. The traditional manufacturing process using welding between tubes with different diameters shows several problems such as poor mechanical characteristics and appearance, etc. Therefore, in this study, one-piece manufacturing processes which can eliminate the welding process were developed by applying the rotary swaging process. CAE analyses were conducted to examine the feasibility of the process and prototypes were manufactured by using a rotary swaging machine with 4 split rotating dies and 12 head rollers. Bending tests of the manufactured prototypes confirmed that the rotary swaging process gives better mechanical properties comparing with the conventional processes.