• Title/Summary/Keyword: Time-Domain Analysis

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A Study on the Analysis of the Microstrip Line by Using Inner Source at the FDTD Method (유한차분 시간영역 해석법에 내부전원을 이용한 마이크로스트립 선로 해석에 관한 연구)

  • 윤성현;정수길;손창수
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.9 no.5
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    • pp.567-577
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    • 1998
  • When continuous and discontinuous microstrip is analyzed with FDTD(Finite Difference Time Domain) method, we used Berenger's 3D-PML as absorbing boundary condition, and IST(Inner Source Technique) was used for source excitation instead of front excitation that is existing method. In the case using IST, we have observed that analyzed characteristic is not affected by the reduced computational domain of the side and top face in which evanescent field and radiation field is exist. Also, if we control the position of the inner source, we could effectively reject the influence of the reflective wave by mean of imperfective boundary condition. In this paper, by using IST, we have calculated dispersive characteristic and characteristic impedance of the microstrip. And we have calculated magnitude and phase of the scattering coefficient, and obtained equivalent circuit of the open microstrip end.

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Pilot Subcarrier Based Channel Estimation Scheme in IEEE 802.11p Systems (IEEE 802.11p에서 파일럿 부반송파를 이용한 채널추정 기법)

  • Ren, Yongzhe;Park, Dong Chan;Kim, Suk Chan
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.40 no.5
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    • pp.791-798
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    • 2015
  • It has been grown interests of the convergence technologies about communication systems and vehicular industry. Vehicular communications enable a number of infotainment applications to serve cars under high mobility environments. To achieve this goal, a robust and accurate channel estimation scheme is of great importance. This paper proposes an enhanced Decision-Directed channel estimation scheme called PTAU(Pilot Tone Aided Update) for IEEE 802.11p in vehicular communication environment. Existing approaches which use subsequent data symbols to estimate channel response in time domain will lead to the error propagation. In this paper, we use the pilot subcarriers to get initial channel response, then utilize the correlation characteristics to update channel response in frequency domain. Finally, Analysis and simulation results reveal that the proposed scheme outperforms in bit error rate(BER), significantly improve the performance of the estimation.

Performance Comparison and Analysis of SC-FDMA Systems employing IB-DFE (IB-DFE를 적용한 SC-FDMA 시스템의 성능 비교 분석)

  • Cho, Jae-Deok;Ahn, Sang-Sik
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.34 no.9C
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    • pp.906-914
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    • 2009
  • SC-FDMA is employed in the 3GPP-LTE standard as the uplink transmission scheme. SC-FDMA has advantages that the signal has a low PAPR property and a simple equalizer such as FD-LE can be implemented. But FD-LE has inferior performance to Hybrid-DFE composed of frequency-domain feedforward filter and time-domain feedback filter. Recently, several IB-DFE algorithms have been proposed to overcome the disadvantages of implementation and processing complexity of Hybrid-DFE and to obtain superior performance to FD-LE. In this paper, we apply several IB-DFE algorithms to 3GPP-LTE uplink system and compare their performance by calculating BER. We investigate the effects of channel estimation errors and Doppler shift on performance. Finally, by analyzing computational complexity of IB-DFEs, we present some criteria to choose appropriate algorithm and to decide the number of iterative processes.

Molecular Cloning and Characterization of the Estrogen Receptor from the Slender Bitterling (Acheilognathus yamatsutae)

  • Kim, Jong-Geuk;Kim, Ha-Ryong;Park, Yong-Joo;Chung, Kyu-Hyuck;Oh, Seung-Min
    • Environmental Analysis Health and Toxicology
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    • v.26
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    • pp.5.1-5.11
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    • 2011
  • Objectives: In order to identify the possibility of slender bitterling (SB) (Acheilognathus yamatsutae) being used as a test species for estrogenic endocrine disrupting chemicals (EEDCs), we carried out the cloning and sequence characterization of the estrogen receptor (ER). Methods: The ER from a slender bitterling was obtained by reverse transcriptase-polymerase chain reaction (RT-PCR), 5'- and 3'-rapid amplification of cDNA ends (5'-RACE and 3'-RACE) and T-vector cloning. The expression of ER mRNA was also analyzed in six tissues (brain, liver, kidney, gill, gonad, and intestines) by real-time PCR. Results: We obtained an ER from the slender bitterling. The SB ER cDNA was 2189 base pairs (bp) in length and contained a 1707 bp open reading frame that encoded 568 amino acid residues. The SB ER amino acid sequence clustered in a monophyletic group with the $ER{\alpha}$ of other fish, and was more closely related to zebrafish $ER{\alpha}$(88% identity) than to the $ER{\alpha}$ of other fish. The SB ER cDNA was divided into A/B, C, D, E and F domains. The SB ER has conserved important sequences for ER functions, such as the DNA binding domain (D domain), which are consistent with those of other teleosts. Conclusions: The ER of the slender bitterling could provide basic information in toxicological studies of EEDCs in the slender bitterling.

Influence of the Parasitic Inductor Resistance on Controller Design of Boost Converter for Renewable Energy System including an Energy Storage (에너지 저장장치를 포함하는 신재생에너지원용 부스트 컨버터의 인덕터 기생저항에 따른 제어기 설계 영향 분석)

  • Park, Sun-Jae;Park, Joung-Hu;Jeon, Hee-Jong
    • The Transactions of the Korean Institute of Power Electronics
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    • v.16 no.5
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    • pp.511-520
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    • 2011
  • Nowadays, industry of smart grid is important for practical use of the renewable energy. In this situation, it is important to use the energy storage to make more stable and efficient renewable energy sources. The power conditioning systems consist in a boost converter which makes renewable energy source connected with the grid-connected inverter and the charger/discharger which takes the energy transfer between the boost converter and an energy storage. The effects on the controller design of each converter must be investigated to avoid the instability of the entire system. small-signal modelling of the boost converter and charger/discharger have been done and a controller design example is also presented. In this paper, effects on the controller design of the boost converter and the charger/discharger are investigated according to the existence of the parasitic resistance of the boost converter. In conclusion, the parasitic resistance of the inductor should be considered from the aspect of both the frequency domain analysis and time domain simulation using both MATLAB and PSIM.

Automatic Video Genre Classification Method in MPEG compressed domain (MPEG 부호화 영역에서 Video Genre 자동 분류 방법)

  • Kim, Tae-Hee;Lee, Woong-Hee;Jeong, Dong-Seok
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.27 no.8A
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    • pp.836-845
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    • 2002
  • Video summary is one of the tools which can provide the fast and effective browsing for a lengthy video. Video summary consists of many key-frames that could be defined differently depending on the video genre it belongs to. Consequently, the video summary constructed by the uniform manner might lead into inadequate result. Therefore, identifying the video genre is the important first step in generating the meaningful video summary. We propose a new method that can classify the genre of the video data in MPEC compressed bit-stream domain. Since the proposed method operates directly on the compressed bit-stream without decoding the frame, it has merits such as simple calculation and short processing time. In the proposed method, only the visual information is utilized through the spatial-temporal analysis to classify the video genre. Experiments are done for 6 genres of video: Cartoon, commercial, Music Video, News, Sports, and Talk Show. Experimental result shows more than 90% of accuracy in genre classification for the well -structured video data such as Talk Show and Sports.

Elastic floor response spectra of nonlinear frame structures subjected to forward-directivity pulses of near-fault records

  • Kanee, Ali Reza Taghavee;Kani, Iradj Mahmood Zadeh;Noorzad, Assadollah
    • Earthquakes and Structures
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    • v.5 no.1
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    • pp.49-65
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    • 2013
  • This article presents the statistical characteristics of elastic floor acceleration spectra that represent the peak response demand of non-structural components attached to a nonlinear supporting frame. For this purpose, a set of stiff and flexible general moment resisting frames with periods of 0.3-3.6 sec. are analyzed using forty-nine near-field strong ground motion records. Peak accelerations are derived for each single degree of freedom non-structural component, supported by the above mentioned frames, through a direct-integration time-history analysis. These accelerations are obtained by Floor Acceleration Response Spectrum (FARS) method. They are statistically analyzed in the next step to achieve a better understanding of their height-wise distributions. The factors that affect FARS values are found in the relevant state of the art. Here, they are summarized to evaluate the amplification and/or reduction of FARS values especially when the supporting structures undergo inelastic behavior. The properties of FARS values are studied in three regions: long-period, fundamental-period and short-period. Maximum elastic acceleration response of non-structural component, mounted on inelastic frames, depends on the following factors: inelasticity intensity and modal periods of supporting structure; natural period, damping ratio and location of non-structural component. The FARS values, corresponded to the modal periods of supporting structure, are strongly reduced beyond elastic domain. However, they could be amplified in the transferring period domain between the mentioned modal periods. In the next step, the amplification and/or reduction of FARS values, caused by inelastic behavior of supporting structure, are calculated. A parameter called the response acceleration reduction factor ($R_{acc}$), has been previously used for far-field earthquakes. The feasibility of extending this parameter for near-field motions is focused here, suggested repeatedly in the relevant sources. The nonlinearity of supporting structure is included in ($R_{acc}$) for better estimation of maximum non-structural component absolute acceleration demand, which is ordinarily neglected in the seismic design provisions.

Experimental study on air-water countercurrent flow limitation in a vertical tube based on measurement of film thickness behavior

  • Wan, Jie;Sun, Wan;Deng, Jian;Pan, Liang-ming;Ding, Shu-hua
    • Nuclear Engineering and Technology
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    • v.53 no.6
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    • pp.1821-1833
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    • 2021
  • The gas-liquid counter-current flow limitation (CCFL) is closely related to efficient and safety operation of many equipment in industrial cycle. Air-water countercurrent flow experiments were performed in a tube with diameter of 25 mm to understand the triggering mechanism of CCFL. A parallel electrode probe was utilized to measure film thickness whereby the time domain and frequency domain characteristics of liquid film was obtained. The amplitude of the interface wave is small at low liquid flow rate while it becomes large at high liquid flow rate after being disturbed by the airflow. The spectral characteristic curve shows a peak-shaped distribution. The crest exists between 0 and 10 Hz and the amplitude decreases with the frequency increase. The analysis of visual observation and characteristic of film thickness indicate that two flooding mechanisms were identified at low and high liquid flow rate, respectively. At low liquid flow rate, the interfacial waves upward propagation is responsible for the formation of CCFL onset. While flooding at high liquid flow rate takes place as a direct consequence of the liquid bridging in tube due to the turbulent flow pattern. Moreover, it is believed that there is a transition region between the low and high liquid flow rate.

A Research regarding 'Bong Seon Hwa' II; Coterie magazine of Korean Women living in japan -Focusing on the analysis of minority discourse in the class of women in Japan- (재일여성동인지 『봉선화』 연구 II -재일여성 계층에 나타난 소외담론 분석을 중심으로(2001~2013)-)

  • Choi, Soon-Ae
    • The Journal of Korean-Japanese National Studies
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    • no.32
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    • pp.215-275
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    • 2017
  • In the absence of the alternative public space of women in Japan, the experience of the "Bongseonhwa" was interpreted as the public domain of Japanese society as a public domain, a confession that focused on gender discrimination in the patriarchal system of Japan, Most of the enemy discourse is. These alienated discourses are the product of the efforts of women in Japan who do not want to forget about the traces and memories that can not be incorporated into the big narrative. It can not be denied that the women in the society of Japan have been excessively excluded and alienated by national ideology and patriarchal ideology. The meaning of presenting them through "Bongsinghwa" is the resistance of the minority, and it is the expression way of reconstructing and strengthening the identity of the women, and it is said to be a space of symbolic meaning. It is further clarified that it is based on a narrative that creates a new life area for coexistence with Japanese society, on the other hand, by constantly searching for the linkage with the motherland, held by women in Japan. As a result, between public social phenomena and private living space, confirmed that it conflicts with repetitive internal contradiction of controlling power and confirmed that complicated and detailed material of women living in Japan who undergo double discrimination What has been expressed over a period is considered to be a resistance expression and a will of expression of reconciliation to coexist with Japanese society. I have attempted to analyze the confessed alienated discourse of "Bongsinghwa" by classifying it as . As a result, it is confirmed that the public social phenomenon and the private life space are confronted with the repetitive internal contradictions of the power of domination, and the expression of the complex and detailed material of the discriminated women in Japan over a long period of time is a resistance to symbiosis with Japanese society And the will of the conversation.

Galectin-1 from redlip mullet Liza haematocheilia: identification, immune responses, and functional characterization as pattern recognition receptors (PRRs) in host immune defense system

  • Chaehyeon Lim;Hyukjae Kwon;Jehee Lee
    • Fisheries and Aquatic Sciences
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    • v.25 no.11
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    • pp.559-571
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    • 2022
  • Galectins, a family of ß-galactoside-binding lectins, have emerged as soluble mediators in infected cells and pattern recognition receptors (PRRs) responsible for evoking and regulating innate immunity. The present study aimed to evaluate the role of galectin-1 in the host immune response of redlip mullet (Liza haematocheilia). We established a cDNA database for redlip mullet, and the cDNA sequence of galectin-1 (LhGal-1) was characterized. In silico analysis was performed, and the spatial and temporal expression patterns in gills and blood in response to lipopolysaccharide polyinosinic:polycytidylic acid, and Lactococcus garvieae were estimated via quantitative real-time PCR. Functional assays were conducted using recombinant protein to investigate carbohydrate binding, bacterial binding, and bacterial agglutination activity. LhGal-1 was composed of 135 amino acids. Conserved motifs (H-NPR, -N- and -W-E-R) within the carbohydrate recognition domain were found in LhGal-1. The tissue distribution revealed that the healthy stomach expressed high levels of LhGal-1. The temporal monitoring of LhGal-1 mRNA expression in the gill and blood showed its significant upregulation in response to immune challenges with different stimulants. rLhGal-1 exhibited binding activity in response to carbohydrates and bacteria. Moreover, the agglutination of rLhGal-1 against Escherichia coli was observed. Collectively, our findings suggest that LhGal-1 may function as a PRR in redlip mullet. Furthermore, LhGal-1 can be considered a significant gene to play a protective role in redlip mullet immune system.