• Title/Summary/Keyword: Cascade architecture

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A design of a floating point unit with 3 stages for a 3D graphics shader engine

  • Lee, Kwang-Yeob
    • Journal of IKEEE
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    • v.11 no.4
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    • pp.358-363
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    • 2007
  • This paper presents a floating point unit(FPU) with 3 stages for a 3D graphics shader engine. It targeted to accelerate 3D graphics in portable device environments. In order to design a balanced architecture for a shader engine, we analyzed shader assembly instructions and estimated the performance of FPU with the method we propose. The proposed unit handles 4-dimensional data through separated two paths that are lead to general operation module and special function module. The proposed FPU is compiled as a form of the cascade FPU with 3 stages to efficiently handle a matrix operation with relatively low hardware overhead. Except some complex instructions that are executed using macro instructions, all instructions complete an operation in a single instruction cycle at 100MHz frequency. A special function module performs all operations in a single clock cycle using the Newton Raphson method with the look-up table.

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A Study on the Effect of Large Coherent Structures to the Skin Friction by POD Analysis (적합직교분해(POD)기법을 사용한 난류 응집구조 거동에 관한 연구)

  • Shin, Seong-Yun;Jung, Kwang-Hyo;Kang, Yong-Duck;Suh, Sung-Bu;Kim, Jin;An, Nam-Hyun
    • Journal of the Society of Naval Architects of Korea
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    • v.54 no.5
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    • pp.406-414
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    • 2017
  • An experimental study in a recirculating water channel was carried out to investigate the effect of large coherent structures to the skin friction on a flat plate. Particle Image Velocimetry (PIV) technique was used to quantify characteristic features of coherent structures growing to the boundary layer. In the PIV measurement, it is difficult to calculate the friction velocity near the wall region due to laser deflection and uncertainty so that Clauser fitting method at the logarithmic region was adopted to compute the friction velocity and compared with the one directly measured by the dynamometer. With changing the free-stream velocity from 0.5 m/s to 1.0 m/s, the activity of coherent structures in the logarithmic region was increased over three times in terms of Reynolds stress. The flow field was separated by Variable Interval Time Averaging (VITA) technique into the weak and the strong structure case depending on the existence large coherent structures in order to validate its effectiveness. The stream-wise velocity fluctuation was scanned through at the boundary thickness whether it had a large deviation from background flow. With coherent structures connected from near-wall to the boundary layer, mean wall shear stress was higher than that of weak structure case. Proper Orthogonal Decomposition (POD) analysis was also applied to compare the energy budget between them at each free-stream velocity.

Open-Loop Pipeline ADC Design Techniques for High Speed & Low Power Consumption (고속 저전력 동작을 위한 개방형 파이프라인 ADC 설계 기법)

  • Kim Shinhoo;Kim Yunjeong;Youn Jaeyoun;Lim Shin-ll;Kang Sung-Mo;Kim Suki
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.30 no.1A
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    • pp.104-112
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    • 2005
  • Some design techniques for high speed and low power pipelined 8-bit ADC are described. To perform high-speed operation with relatively low power consumption, open loop architecture is adopted, while closed loop architecture (with MDAC) is used in conventional pipeline ADC. A distributed track and hold amplifier and a cascading structure are also adopted to increase the sampling rate. To reduce the power consumption and the die area, the number of amplifiers in each stage are optimized and reduced with proposed zero-crossing point generation method. At 500-MHz sampling rate, simulation results show that the power consumption is 210mW including digital logic with 1.8V power supply. And the targeted ADC achieves ENOB of about 8-bit with input frequency up to 200-MHz and input range of 1.2Vpp (Differential). The ADC is designed using a $0.18{\mu}m$ 6-Metal 1-Poly CMOS process and occupies an area of $900{\mu}m{\times}500{\mu}m$

Review on the Improvement Works of Ecological Stream in Rural Areal - A Focused on Sijeon-ri Dogo-myeon Asan City - (농촌지역 하천정비공사 실태와 제언 -아산시 도고면 시전리를 대상으로-)

  • Nam, Yun-Cheol
    • Journal of the Korean Institute of Rural Architecture
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    • v.17 no.2
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    • pp.51-58
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    • 2015
  • 10 years ago, in Sijeon-ri, Dogo-myeon, Asan-si, the existing stream was repaired to develope Mt. Dogo trail and irrigation systems through road expansion pavement construction and small stream repair construction. The trees such as persimmon and willow are eliminated that rowed on both sides of the stream and dredging work to dig the rock and sand have been performed. As a result, wide asphalt road was built, also flood damage worries were reduced. 10 years passed and now, how did local residents think about the stream repaired before and after? Village residents, public officials, and the stream construction engineer were interviewed. Villagers indicated a problems that brook became a place where water peppers were taking over and water was stagnating due to the slow velocity so nothing could live and natural landscape like a wash place and the cascade disappeared, because rock and sand were taken out brought soil into the brook. Public officials and engineers were aware of the problems at the time of the stream. Now that construction is completed after 10 years, Both realistically and budgetary to restoration would be difficult. However, it is necessary to seek for waterfront space which can be restored or replaced by a part of the stream like similarly before. In addition, it is necessary to restore to the progression of a natural stream which connect with stairs(or slope) - small waterfalls - pools - wash place. In this paper, we hope to take a lesson from the Sijeon-ri model and make rural stream construction be prepared with consideration about not only distinct characteristics of specific area but also the opinion of local resident.

A Study on the Actual Conditionis and Improvement Plan of Interior Landscape in the Subway Stations (지하철역내의 실내조경현황과 개선방안에 관한 연구)

  • 방광자;주진희;박혜경;박성은
    • Journal of the Korean Institute of Landscape Architecture
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    • v.26 no.3
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    • pp.258-266
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    • 1998
  • The purpose of this study is to investigate the actual conditions, to find problems, and to present an improvement plan of interior landscape in the subway stationis. Moreoiver, it will presume the possibilties to develop the subway and ways to utilie underground space effectively. The results are summarized as follows A light intensity was recorded 0-100 Lux as the lowest light and 500 Lux below as the highest in 61 subway stations. An average temperature of 12 $^{\circ}C$and an air humidity of 38% were recorded over a 4 month period from January to April, but includes a drastic variaton between -8.5$^{\circ}C$ and 21.5$^{\circ}C$. Soil acidity of pH 7 below and soil moisture of 1-2 wet degree were apeared in subway stations mostly. Plant forms consisted of artificial flower & flower. Plant species were recorded at a total of 54 species and appeared in the order of Araucaria heteropylla, Ophiophogon jaburan, Aspidistra elatior cv. 'Asahi' and Hedera helix. Plant height was, for the most part, below 0.5m. Plant species that was fined of conditions were Palm, Camellia japonica, Araucaria heterophylla as a high plant, dracaena fragrans, dracaena deremensis cv. Wakneckii as a middle plant, and Ophiopogon jaburan, Hedra helix, ytomium falcatum, Aspidistra elatior cv. Asahi as a low plant. It used to water materials such as small pool, small cascade, water cycles and natural materials such as natural rock, small rock, sand, bark and animal materials such as squirrels, birds, goldfish as an object for plants in the subway stations. From these actual conditions, First of all, It must make up physical environments such as light, temperature humidity, soil for plant growth, and is important to chooce suitable indoor plants and draw up systematic management in the subway environments. Also, it change plants frequently and uses variable objects for subway stationi individuatism, Moreover, indoor plants with strong environmental adaptation abities such as shade tolerance, drought tolerance and cold tolerance need to develope variable species possibly. If these improvements occur, utilization and amenity of subway stationis will increase, according to the use of interior landscape.

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Effect of gacS and gacA Mutations on Colony Architecture, Surface Motility, Biofilm Formation and Chemical Toxicity in Pseudomonas sp. KL28

  • Choi, Kyung-Soon;Veeraragouda, Yaligara;Cho, Kyoung-Mi;Lee, Soo-O;Jo, Geuk-Rae;Cho, Kyung-Yun;Lee, Kyoung
    • Journal of Microbiology
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    • v.45 no.6
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    • pp.492-498
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    • 2007
  • GacS and GacA proteins form a two component signal transduction system in bacteria. Here, Tn5 transposon gacS and gacA (Gac) mutants of Pseudomonas sp. KL28, an alkylphenol degrader, were isolated by selecting for smooth colonies of strain KL28. The mutants exhibited reduced ability to migrate on a solid surface. This surface motility does not require the action of flagella unlike the well-studied swarming motility of other Pseudomonas sp. The Gac mutants also showed reduced levels of biofilm and pellicle formation in liquid culture. In addition, compared to the wild type KL28 strain, these mutants were more resistant to high concentrations of m-cresol but were more sensitive to $H_2O_2$, which are characteristics that they share with an rpoS mutant. These results indicate that the Gac regulatory cascade in strain KL28 positively controls wrinkling morphology, biofilm formation, surface translocation and $H_2O_2$ resistance, which are important traits for its capacity to survive in particular niches.

Approximation of Polynomials and Step function for cosine modulated Gaussian Function in Neural Network Architecture (뉴로 네트워크에서 코사인 모듈화 된 가우스함수의 다항식과 계단함수의 근사)

  • Lee, Sang-Wha
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.49 no.2
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    • pp.115-122
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    • 2012
  • We present here a new class of activation functions for neural networks, which herein will be called CosGauss function. This function is a cosine-modulated gaussian function. In contrast to the sigmoidal-, hyperbolic tangent- and gaussian activation functions, more ridges can be obtained by the CosGauss function. It will be proven that this function can be used to aproximate polynomials and step functions. The CosGauss function was tested with a Cascade-Correlation-Network of the multilayer structure on the Tic-Tac-Toe game and iris plants problems, and results are compared with those obtained with other activation functions.

A 256-Radix Crossbar Switch Using Mux-Matrix-Mux Folded-Clos Topology

  • Lee, Sung-Joon;Kim, Jaeha
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.14 no.6
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    • pp.760-767
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    • 2014
  • This paper describes a high-radix crossbar switch design with low latency and power dissipation for Network-on-Chip (NoC) applications. The reduction in latency and power is achieved by employing a folded-clos topology, implementing the switch organized as three stages of low-radix switches connected in cascade. In addition, to facilitate the uniform placement of wires among the sub-switch stages, this paper proposes a Mux-Matrix-Mux structure, which implements the first and third switch stages as multiplexer-based crossbars and the second stage as a matrix-type crossbar. The proposed 256-radix, 8-bit crossbar switch designed in a 65nm CMOS has the simulated power dissipation of 1.92-W and worst-case propagation delay of 0.991-ns while operating at 1.2-V supply and 500-MHz frequency. Compared with the state-of-the-art designs in literature, the proposed crossbar switch achieves the best energy-delay-area efficiency of $0.73-fJ/cycle{\cdot}ns{\cdot}{\lambda}^2$.

Effcient Neural Network Architecture for Fat Target Detection and Recognition (목표물의 고속 탐지 및 인식을 위한 효율적인 신경망 구조)

  • Weon, Yong-Kwan;Baek, Yong-Chang;Lee, Jeong-Su
    • The Transactions of the Korea Information Processing Society
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    • v.4 no.10
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    • pp.2461-2469
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    • 1997
  • Target detection and recognition problems, in which neural networks are widely used, require translation invariant and real-time processing in addition to the requirements that general pattern recognition problems need. This paper presents a novel architecture that meets the requirements and explains effective methodology to train the network. The proposed neural network is an architectural extension of the shared-weight neural network that is composed of the feature extraction stage followed by the pattern recognition stage. Its feature extraction stage performs correlational operation on the input with a weight kernel, and the entire neural network can be considered a nonlinear correlation filter. Therefore, the output of the proposed neural network is correlational plane with peak values at the location of the target. The architecture of this neural network is suitable for implementing with parallel or distributed computers, and this fact allows the application to the problems which require realtime processing. Net training methodology to overcome the problem caused by unbalance of the number of targets and non-targets is also introduced. To verify the performance, the proposed network is applied to detection and recognition problem of a specific automobile driving around in a parking lot. The results show no false alarms and fast processing enough to track a target that moves as fast as about 190 km per hour.

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Design of A Current-mode Bandpass Filter in Receiver for High speed PLC Modem (고속 전력선통신 모뎀용 수신단측 전류모드 대역통과 필터 설계)

  • Bang, Jun-Ho;Lee, Woo-Choun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.13 no.10
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    • pp.4745-4750
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    • 2012
  • In this paper a $6^{th}$ 1MHz~30MHz bandpass filter for Power line communication(PLC) modem receiver is designed using current mode synthesis method which is good to design the low-voltage and low-power filter. The designed bandpass filter is composed of cascade connecting between $3^{rd}$ Butterworth highpass filter and $3^{rd}$ Chebychev lowpass filter. As a core circuit in the current-mode filter, a current-mode integrator is designed with new architecture which can improve gain and unity gain frequency of the integrator. The gain and the unity gain frequency of the designed integrator is each 32.2dB and 247MHz. And the cutoff frequency of the designed $6^{th}$ bandpass filter can be controlled to 50MHz from 200KHz according to controlling voltage and the power consumption is 2.85mW with supply voltage, 1.8V. The designed bandpass filter was verified using a $0.18{\mu}m$ CMOS parameter.