• Title/Summary/Keyword: 풀이 알고리듬

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High Efficiency GaN HEMT Power Amplifier Using Harmonic Matching Technique (고조파 정합 기법을 이용한 고효율 GaN HEMT 전력 증폭기)

  • Jin, Tae-Hoon;Kwon, Tae-Yeop;Jeong, Jinho
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.25 no.1
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    • pp.53-61
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    • 2014
  • In this paper, we present the design, fabrication and measurement of high efficiency GaN HEMT power amplifier using harmonic matching technique. In order to achieve high efficiency, harmonic load-pull simulation is performed, that is, the optimum load impedances are determined at $2^{nd}$ and $3^{rd}$ harmonic frequencies as well as at the fundamental. Then, the output matching circuit is designed based on harmonic load-pull simulation. The measurement of the fabricated power amplifier shows the linear gain of 20 dB and $P_{1dB}$(1 dB gain compression point) of 33.7 dBm at 1.85 GHz. The maximum power added efficiency(PAE) of 80.9 % is achieved at the output power of 38.6 dBm, which belongs to best efficiency performance among the reported high efficiency power amplifiers. For W-CDMA input signal, the power amplifier shows a PAE of 27.8 % at the average output power of 28.4 dBm, where an ACLR (Adjacent Channel Leakage Ratio) is measured to be -38.8 dBc. Digital predistortion using polynomial fitting was implemented to linearize the power amplifiers, which allowed about 6.2 dB improvement of an ACLR performance.

Inverse Telecine by Using Frequency Analysis (주파수 분석을 통한 인버스 텔레시네 기법)

  • 구형일;조남익;이종원
    • Journal of Broadcast Engineering
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    • v.8 no.3
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    • pp.306-316
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    • 2003
  • When a cinema being composed of 24 frames/sec is converted to NTSC video or TV program, several fields we repeated to have 60 fields/sec, which is called the telecine or 3:2 pull-down. Hence, when encoding the telecine NTSC video into MPEG format, if we convert it into the original 24 frames/sec Progressive cinema, then we can save 20% of bits compared to the case of encoding all the 60 fields. In this Paper, we propose an algorithm for performing the inverse telecine by using the properties of the frames. Specifically, the algorithm exploits the fact that there Is much Inconsistency between the even and odd fields in the case of telecine frame, which results in high magnitude at the Nyquist frequency In the vertical direction. The experiment shows that the proposed algorithm performs very well regardless of the quality of video with a very few computations, whereas the conventional motion based method requires much computational complexity and its performance is degraded when the video is of low (eg. VHS) quality.

The Architecture of Intra-prediction & DCTQ Hardware for H.264 Encoder (H.264 부호화기를 위한 Intra-prediction & DCTQ Hardware 구조)

  • Suh, Ki-Bum
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.47 no.5
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    • pp.1-9
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    • 2010
  • In this paper, the novel architecture of Intra-prediction & DCTQ hardware, which can process for the Full HD image($1980{\times}1088$@30fps) in realtime, is proposed. The cycle optimization method for the overall cycle of prediction, transform, scaling, descaling, and reconstruction is proposed. To reduce the cycle in the $4{\times}4$ prediction, the quantization process is performed during the prediction cycle and pre-selection of 2 modes among the 9 modes is performed to reduce the hardware area. To reduce the hardware of $16{\times}16$ and $8{\times}8$ prediction, the sharing logic between 2 prediction is utilized. The proposed architecture can process the 30frame/sec of full HD image in 108 MHz clock and operate 425 cycle for one macroblock.

Recent Advances in Cognitive Behavioral Therapy for Panic Disorder (공황장애 인지행동치료의 최신 지견)

  • Seo, Ho-Jun;Lee, Kang-Soo;Lee, Sang-Hyuk;Suh, Ho-Suk
    • Anxiety and mood
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    • v.12 no.1
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    • pp.47-55
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    • 2016
  • 30% of patients with panic disorder (PD) show treatment-resistant and chronic waxing and waning course. Therefore, adequate treatment strategies for PD by evidence based pharmacotherapy and combined cognitive behavioral therapy (CBT) are recommended. Regarding how and why CBT for PD works, three hypotheses include the cognitive theory, anxiety control theory, and behavioral theory were discussed. The recent findings that the altered activation in frontal lobe is normalized after CBT, suggest a reduction of an altered top-down fear processing in the neural correlates of CBT in PD. In order to improve accessibility to CBT, brief CBT and internet based CBT for PD were suggested. Despite limitations of sample sizes and study design, most of studies suggest that brief CBT is more effective than control conditions, and even as equally effective as standard CBT. The evidences suggest that internet based CBT may not be significantly different from face-to-face CBT in reducing anxiety. Several advances within the field of third-wave CBT for PD have led to the development of new techniques based on mindfulness, such as mindfulness-based cognitive therapy and acceptance and commitment therapy. Based on Korean algorithm project for panic disorder, especially the psychological education and cognitive reconstruction components were recommended in CBT with PD.

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A study on the digital carrier recovery loop with adaptive loop bandwidth (적응 루프 대역폭을 가진 디지털 반송파 동기 루프에 관한 연구)

  • 한동석
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.22 no.8
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    • pp.1774-1781
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    • 1997
  • In this paper, we propose a full digital frequency and phase locked loop for CATV and HDTV receivers adopting VSB modulation. The CATV and HDTV receivers proposed by the Grand-Alliance in USA are ultilizing analog signal processing technology for carrier recovery. By the way, it is not a good architecture for the development of single chip ASIC operating in digital domain. To solve this problem while improving the performance, we first down convert the received r.f. signal to a near baseband signal for a low-rate AD converter and then we use digital signal processing techniques. The proposed system has the frequency pull-in range of -200 KHz +2.50 KHz. Moreover, it has the ability of adaptive loop bandwidth control according to the amount of frequency offset to improve the acquisition time while reducing the phase noise.

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Development of Intelligent ATP System Using Genetic Algorithm (유전 알고리듬을 적용한 지능형 ATP 시스템 개발)

  • Kim, Tai-Young
    • Journal of Intelligence and Information Systems
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    • v.16 no.4
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    • pp.131-145
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    • 2010
  • The framework for making a coordinated decision for large-scale facilities has become an important issue in supply chain(SC) management research. The competitive business environment requires companies to continuously search for the ways to achieve high efficiency and lower operational costs. In the areas of production/distribution planning, many researchers and practitioners have developedand evaluated the deterministic models to coordinate important and interrelated logistic decisions such as capacity management, inventory allocation, and vehicle routing. They initially have investigated the various process of SC separately and later become more interested in such problems encompassing the whole SC system. The accurate quotation of ATP(Available-To-Promise) plays a very important role in enhancing customer satisfaction and fill rate maximization. The complexity for intelligent manufacturing system, which includes all the linkages among procurement, production, and distribution, makes the accurate quotation of ATP be a quite difficult job. In addition to, many researchers assumed ATP model with integer time. However, in industry practices, integer times are very rare and the model developed using integer times is therefore approximating the real system. Various alternative models for an ATP system with time lags have been developed and evaluated. In most cases, these models have assumed that the time lags are integer multiples of a unit time grid. However, integer time lags are very rare in practices, and therefore models developed using integer time lags only approximate real systems. The differences occurring by this approximation frequently result in significant accuracy degradations. To introduce the ATP model with time lags, we first introduce the dynamic production function. Hackman and Leachman's dynamic production function in initiated research directly related to the topic of this paper. They propose a modeling framework for a system with non-integer time lags and show how to apply the framework to a variety of systems including continues time series, manufacturing resource planning and critical path method. Their formulation requires no additional variables or constraints and is capable of representing real world systems more accurately. Previously, to cope with non-integer time lags, they usually model a concerned system either by rounding lags to the nearest integers or by subdividing the time grid to make the lags become integer multiples of the grid. But each approach has a critical weakness: the first approach underestimates, potentially leading to infeasibilities or overestimates lead times, potentially resulting in excessive work-inprocesses. The second approach drastically inflates the problem size. We consider an optimized ATP system with non-integer time lag in supply chain management. We focus on a worldwide headquarter, distribution centers, and manufacturing facilities are globally networked. We develop a mixed integer programming(MIP) model for ATP process, which has the definition of required data flow. The illustrative ATP module shows the proposed system is largely affected inSCM. The system we are concerned is composed of a multiple production facility with multiple products, multiple distribution centers and multiple customers. For the system, we consider an ATP scheduling and capacity allocationproblem. In this study, we proposed the model for the ATP system in SCM using the dynamic production function considering the non-integer time lags. The model is developed under the framework suitable for the non-integer lags and, therefore, is more accurate than the models we usually encounter. We developed intelligent ATP System for this model using genetic algorithm. We focus on a capacitated production planning and capacity allocation problem, develop a mixed integer programming model, and propose an efficient heuristic procedure using an evolutionary system to solve it efficiently. This method makes it possible for the population to reach the approximate solution easily. Moreover, we designed and utilized a representation scheme that allows the proposed models to represent real variables. The proposed regeneration procedures, which evaluate each infeasible chromosome, makes the solutions converge to the optimum quickly.

Hierrachical manner of motion parameters for sports video mosaicking (스포츠 동영상의 모자익을 위한 이동계수의 계층적 향상)

  • Lee, Jae-Cheol;Lee, Soo-Jong;Ko, Young-Hoon;Noh, Heung-Sik;Lee Wan-Ju
    • The Journal of Information Technology
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    • v.7 no.2
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    • pp.93-104
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    • 2004
  • Sports scene is characterized by large amount of global motion due to pan and zoom of camera motion, and includes many small objects moving independently. Some short period of sports games is thrilling to televiewers, and important to producers. At the same time that kinds of scenes exhibit exceptionally dynamic motions and it is very difficult to analyze the motions with conventional algorithms. In this thesis, several algorithms are proposed for global motion analysis on these dynamic scenes. It is shown that proposed algorithms worked well for motion compensation and panorama synthesis. When cascading the inter frame motions, accumulated errors are unavoidable. In order to minimize these errors, interpolation method of motion vectors is introduced. Affined transform or perspective projection transform is regarded as a square matrix, which can be factorized into small amount of motion vectors. To solve factorization problem, we preposed the adaptation of Newton Raphson method into vector and matrix form, which is also computationally efficient. Combining multi frame motion estimation and the corresponding interpolation in hierarchical manner enhancement algorithm of motion parameters is proposed, which is suitable for motion compensation and panorama synthesis. The proposed algorithms are suitable for special effect rendering for broadcast system, video indexing, tracking in complex scenes, and other fields requiring global motion estimation.

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