• Title/Summary/Keyword: Time-domain Analysis

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Improving the Electronic Program Guide Development Process using PODA Specification Method (FODA 명세 기법을 활용한 전자프로그램가이드 개발 프로세스의 효율성 향상 방안)

  • KO, Kwangil
    • Convergence Security Journal
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    • v.16 no.5
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    • pp.73-79
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    • 2016
  • EPG (Electronic Program Guide), which shows the title, broadcasting time, genre, parental rating of a program, is recognized as one of the most successful data service by viewers and broadcasting stations, who want an improved TV watching experience and a more fruitful profit model, respectively. In the circumstance, the request for the development or renewal of EPG frequently occurs and so the developers are looking for ways to improve the efficiency of the EPG development. This paper addresses the need of the developers by devising an EPG feature model based on FODA (Feature-Oriented Domain Analysis) and the testcases of each feature of the model. By utilizing the EPG feature model and the testcases, the tasks of requirement analysing and testcase designing, which are major tasks of the EPG development process, can be improved.

Analysis of Dynamic Behavior of Flexible Rectangular Liquid Containers by the Coupled Boundary Element-Finite Element Method (경계요소-유한요소 연계법에 의한 구형 수조구조물의 동적거동 특성해석)

  • Koh, Hyun Moo;Park, Jang Ho;Kim, Jaekwan
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.14 no.5
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    • pp.1033-1042
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    • 1994
  • Dynamic behavior of flexible rectangular liquid containers is analyzed by a two-dimensional coupled boundary element-finite element method. The irrotational motion of inviscid and incompressible ideal fluid is modeled by boundary elements and the motion of structure by finite elements. A singularity free integral formulation is employed for the implementation of boundary element method. Coupling is performed by using compatibility and equilibrium conditions along the interface between the fluid and structure. The fluid-structure interaction effects are reflected into the coupled equation of motion as added fluid mass matrix and sloshing stiffness matrix. By solving the eigen-problem for the coupled equation of motion, natural frequencies and mode shapes of coupled system are obtained. The free surface sloshing motion and hydrodynamic pressure developed in a flexible rectangular container due to horizontal and vertical ground motions are computed in time domain.

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FADD Phosphorylation Modulates Blood Glucose Levels by Decreasing the Expression of InsulinDegrading Enzyme

  • Lin, Yan;Liu, Jia;Chen, Jia;Yao, Chun;Yang, Yunwen;Wang, Jie;Zhuang, Hongqin;Hua, Zi-Chun
    • Molecules and Cells
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    • v.43 no.4
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    • pp.373-383
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    • 2020
  • Our previous study revealed a novel role of Fas-associated death domain-containing protein (FADD) in islet development and insulin secretion. Insulin-degrading enzyme (IDE) is a zinc metalloprotease that selectively degrades biologically important substrates associated with type 2 diabetes (T2DM). The current study was designed to investigate the effect of FADD phosphorylation on IDE. We found that the mRNA and protein levels of IDE were significantly downregulated in FADD-D mouse livers compared with control mice. Quantitative real-time polymerase chain reaction analysis showed that FADD regulates the expression of IDE at the transcriptional level without affecting the stability of the mRNA in HepG2 cells. Following treatment with cycloheximide, the IDE protein degradation rate was found to be increased in both FADD-D primary hepatocytes and FADD-knockdown HepG2 cells. Additionally, IDE expression levels were reduced in insulin-stimulated primary hepatocytes from FADD-D mice compared to those from control mice. Moreover, FADD phosphorylation promotes nuclear translocation of FoxO1, thus inhibiting the transcriptional activity of the IDE promoter. Together, these findings imply a novel role of FADD in the reduction of protein stability and expression levels of IDE.

Analysis of Density Wave Oscillation in Boiler Furnace Wall Tubes with Parallel Channel Modeling (평행관 모델링을 통한 보일러 화로벽관 내 밀도파 불안정의 해석)

  • Kim, Jinil;Choi, Sangmin
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.37 no.2
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    • pp.187-196
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    • 2013
  • A numerical model was developed to predict the density wave oscillation (DWO) in the furnace wall tubes of a fossil-fired once-through boiler. The transient flow fields in the tubes were obtained using a 1D finite volume method in the time domain. A header model was also implemented to simulate the parallel tube connection of the wall tubes. The inlet and outlet mass flow variation in one of the parallel tubes was examined after a heat perturbation to find the DWO. After successful verification with experimental results reported in literature, the developed model was applied to the wall tubes of a 700-MW boiler furnace. In contrast to the simulation of Takitani's experiment, in which the unstable power thresholds tended to rise in the reduced bypass channel flow, no remarkable changes were observed in the power thresholds in the parallel channel modeling of the wall tubes of the boiler furnace.

Ductility and ductility reduction factor for MDOF systems

  • Reyes-Salazar, Alfredo
    • Structural Engineering and Mechanics
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    • v.13 no.4
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    • pp.369-385
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    • 2002
  • Ductility capacity is comprehensively studied for steel moment-resisting frames. Local, story and global ductility are being considered. An appropriate measure of global ductility is suggested. A time domain nonlinear seismic response algorithm is used to evaluate several definitions of ductility. It is observed that for one-story structures, resembling a single degree of freedom (SDOF) system, all definitions of global ductility seem to give reasonable values. However, for complex structures it may give unreasonable values. It indicates that using SDOF systems to estimate the ductility capacity may be a very crude approximation. For multi degree of freedom (MDOF) systems some definitions may not be appropriate, even though they are used in the profession. Results also indicate that the structural global ductility of 4, commonly used for moment-resisting steel frames, cannot be justified based on this study. The ductility of MDOF structural systems and the corresponding equivalent SDOF systems is studied. The global ductility values are very different for the two representations. The ductility reduction factor $F_{\mu}$ is also estimated. For a given frame, the values of the $F_{\mu}$ parameter significantly vary from one earthquake to another, even though the maximum deformation in terms of the interstory displacement is roughly the same for all earthquakes. This is because the $F_{\mu}$ values depend on the amount of dissipated energy, which in turn depends on the plastic mechanism, formed in the frames as well as on the loading, unloading and reloading process at plastic hinges. Based on the results of this study, the Newmark and Hall procedure to relate the ductility reduction factor and the ductility parameter cannot be justified. The reason for this is that SDOF systems were used to model real frames in these studies. Higher mode effects were neglected and energy dissipation was not explicitly considered. In addition, it is not possible to observe the formation of a collapse mechanism in the equivalent SDOF systems. Therefore, the ductility parameter and the force reduction factor should be estimated by using the MDOF representation.

Design and Fabrication of the Dipole-Fed Planar Array Antenna at X-Band (X밴드용 다이폴 급전 평면배열 안테나 설계 및 제작)

  • Mun, Seong-Ik;Yang, Du-Yeong
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.39 no.5
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    • pp.251-258
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    • 2002
  • In this paper, the dipole-fed planar array antenna applied Yagi-Uda antenna away theory to microstrip antenna is designed and fabricated at X-band. The design procedure of the dipole-fed planar array antenna with the wide bandwidth is presented to be easily practiced to a wireless communication system. The radiation pattern, return loss and bandwidth of the antenna are improved by the finite differential time domain(FDTD) numerical method. The propriety of analysis of planar dipole antenna is proved from the measured data. From the measured results, the antenna maximum gain is 4.9dBi at center frequency of 10GHz and frequency bandwidth is about 40%. Front-to-back ratio is 16dB, and half-power beam-width of E-plane and H-plane are 117$^{\circ}$and 156$^{\circ}$, respectively. When VSWR of antenna is less than 2, the measured results are agreed well with the theoretical values in the frequency range from 7.4GHz to 11.88GHz.

Design of Crisscrossed Double-Layer Birdcage Coil for Improving B1+ Field Homogeneity for Small-Animal Magnetic Resonance Imaging at 300 MHz

  • Seo, Jeung-Hoon;Han, Sang-Doc;Kim, Kyoung-Nam
    • Journal of Magnetics
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    • v.20 no.3
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    • pp.308-311
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    • 2015
  • We design a crisscrossed double-layer birdcage (DLBC) coil by modifying the coil geometry of a standard single-layer BC (SLBC) coil to enhance the homogeneity of transmitting magnetic flux density ($B_1{^+}$) along the main magnetic field ($B_0$)-direction for small-animal magnetic resonance imaging (MRI) at 300 MHz. The performance assessment of the crisscrossed DLBC coil is conducted by computational analysis with the finite-difference time domain method (FDTD) and compared with SLBC coil in terms of the $B_1$ and the $B_1{^+}$ distribution. As per the computational calculation studies, the mean value in the two-dimensional $B_1{^+}$ map obtained at the mid-axial slice with the proposed DLBC coil is slightly lower than that obtained with the SLBC coil, but the $B_1{^+}$ value of the DLBC coil in the outermost plane (40 mm away from the central plane) shows improvements of 19.3% and 24.8% over the SLBC coil $B_1{^+}$ value when simulating a spherical phantom and realistic mouse body modeling. These simulation results indicate that, the $B_1{^+}$ homogeneity along the z-direction was improved by using DLBC configuration. Our approach enables $B_1{^+}$ homogeneity improvement along the zdirection, and it can also be applied to ultra-high field (UHF) MRI systems.

Phoneme Segmentation in Consideration of Speech feature in Korean Speech Recognition (한국어 음성인식에서 음성의 특성을 고려한 음소 경계 검출)

  • 서영완;송점동;이정현
    • Journal of Internet Computing and Services
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    • v.2 no.1
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    • pp.31-38
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    • 2001
  • Speech database built of phonemes is significant in the studies of speech recognition, speech synthesis and analysis, Phoneme, consist of voiced sounds and unvoiced ones, Though there are many feature differences in voiced and unvoiced sounds, the traditional algorithms for detecting the boundary between phonemes do not reflect on them and determine the boundary between phonemes by comparing parameters of current frame with those of previous frame in time domain, In this paper, we propose the assort algorithm, which is based on a block and reflecting upon the feature differences between voiced and unvoiced sounds for phoneme segmentation, The assort algorithm uses the distance measure based upon MFCC(Mel-Frequency Cepstrum Coefficient) as a comparing spectrum measure, and uses the energy, zero crossing rate, spectral energy ratio, the formant frequency to separate voiced sounds from unvoiced sounds, N, the result of out experiment, the proposed system showed about 79 percents precision subject to the 3 or 4 syllables isolated words, and improved about 8 percents in the precision over the existing phonemes segmentation system.

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A Study on the Measurement of Volumetric Water Content Using WCR in Final Cover Layer of Landfill (Water Content Reflectometer(WCR)을 이용한 매립지반 최종 복토층의 체적 함수비 측정에 관한 연구)

  • Kim Kyung-Chul;Hwang Koou-Ho;Lee Song
    • Journal of the Korean Geotechnical Society
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    • v.21 no.6
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    • pp.147-154
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    • 2005
  • This study deals with the calibration of low-frequency water content reflectometer for measuring the volumetric water content of soils in landfill final cover layer, and the validity of calibrations was evaluated by electrical conductivity and index properties of the soils. Linear calibrations concerning volumetric water content to WCR period provided good agreement with the data. Analysis of the calibration data indicates that the slope of the calibration decreases as the electrical conductivity of the soil increases. Lower slopes correspond to soils with greater clay content, organic content, liquid limit, and plasticity index, which typically have higher electrical conductivity. It could be well explained that WCR can operate in a lower frequency range.

An Assessment of Structure Safety for Basic Insulation Panel of KC-1 LNG Cargo Containment system under Sloshing Load (슬로싱 하중을 받는 한국형 LNG선 화물창(KC-1)의 보냉 판넬에 대한 구조 안전성 평가)

  • Jin, Kyo-Kook;Oh, Byung-Taek;Kim, Young-Kyun;Yoon, Ihn-Soo;Yang, Young-Chul
    • Journal of the Korean Institute of Gas
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    • v.17 no.2
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    • pp.85-89
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    • 2013
  • The purpose of the development of KC-1 LNG cargo containment system is reduction in royalty and increase in competitiveness of shipbuilding industry. An assessment of structure safety for LNG cargo containment system under sloshing load due to ship motion has become an important design element. The ideal way is to implement fully interaction of the fluid domain and the cargo containment system. However the irregular sloshing pressure were idealized in the form of a triangular wave for safety assessment because the fluid- structure interaction analysis is taken the extensive computation time and difficult to ensure the accuracy of the results. In this study, the sloshing load was assumed to be a triangular wave with a maximum pressure of 10 bar during 15/1000 seconds. In the analytic results, the basic insulation panel of KC-1 LNG cargo containment system was assessed to be structurally safe for sloshing load.