• Title, Summary, Keyword: Logarithm number system

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A Design of Low-power/Small-area Divider and Square-Root Circuits based on Logarithm Number System (로그수체계 기반의 저전력/저면적 제산기 및 제곱근기 회로 설계)

  • Kim, Chay-Hyeun;Kim, Jong-Hwan;Lee, Yong-Hwan;Shin, Kyung-Wook
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • v.9 no.2
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    • pp.895-898
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    • 2005
  • This paper describes a design of LNS-based divider and square-root circuits which are key arithmetic units in graphic processor and digital signal processor. To achive area-efficient and low-power that is an essential consideration for mobile environment, a fixed-point format of 16.16 is adopted instead of conventional floating-point format. The designed divider and square-root units consist of binary-to-logarithm converter, subtractor, logarithm-to-binary converter. The binary to logarithm converter is designed using combinational logic based on six regions approximation method. As a result, gate count reduction is obtained when compared with conventional lookup approack. The designed units is 3,130 gate count and 1,280 gate count. To minimize average percent error 3.8% and 4.2%. error compensation method is employed.

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A Design of Low-power/Small-area Arithmetic Units for Mobile 3D Graphic Accelerator (휴대형 3D 그래픽 가속기를 위한 저전력/저면적 산술 연산기 회로 설계)

  • Kim Chay-Hyeun;Shin Kyung-Wook
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.10 no.5
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    • pp.857-864
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    • 2006
  • This paper describes a design of low-power/small-area arithmetic circuits which are vector processing unit powering nit, divider unit and square-root unit for mobile 3D graphic accelerator. To achieve area-efficient and low-power implementation that is an essential consideration for mobile environment, the fixed-point f[mat of 16.16 is adopted instead of conventional floating-point format. The vector processing unit is designed using redundant binary(RB) arithmetic. As a result, it can operate 30% faster and obtained gate count reduction of 10%, compared to the conventional methods which consist of four multipliers and three adders. The powering nit, divider unit and square-root nit are based on logarithm number system. The binary-to-logarithm converter is designed using combinational logic based on six-region approximation method. So, the powering mit, divider unit and square-root unit reduce gate count when compared with lookup table implementation.

A New Multiplication Architecture for DSP Applications

  • Son, Nguyen-Minh;Kim, Jong-Soo;Choi, Jae-Ha
    • Journal of the Institute of Convergence Signal Processing
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    • v.12 no.2
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    • pp.139-144
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    • 2011
  • The modern digital logic technology does not yet satisfy the speed requirements of real-time DSP circuits due to synchronized operation of multiplication and accumulation. This operation degrades DSP performance. Therefore, the double-base number system (DBNS) has emerged in DSP system as an alternative methodology because of fast multiplication and hardware simplicity. In this paper, authors propose a novel multiplication architecture. One operand is an output of a flash analog-to-digital converter (ADC) in DBNS format, while the other operand is a coefficient in the IEEE standard floating-point number format. The DBNS digital output from ADC is produced through a new double base number encoder (DBNE). The multiplied output is in the format of the IEEE standard floating-point number (FPNS). The proposed circuits process multiplication and conversion together. Compared to a typical multiplier that uses the FPNS, the proposed multiplier also consumes 45% less gates, and 44% faster than the FPNS multiplier on Spartan-3 FPGA board. The design is verified with FIR filter applications.

A simple model for ground surface settlement induced by braced excavation subjected to a significant groundwater drawdown

  • Zhang, Runhong;Zhang, Wengang;Goh, A.T.C.;Hou, Zhongjie;Wang, Wei
    • Geomechanics and Engineering
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    • v.16 no.6
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    • pp.635-642
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    • 2018
  • Braced excavation systems are commonly required to ensure stability in construction of basements for shopping malls, underground transportation and other habitation facilities. For excavations in deposits of soft clays or residual soils, stiff retaining wall systems such as diaphragm walls are commonly adopted to restrain the ground movements and wall deflections in order to prevent damage to surrounding buildings and utilities. The ground surface settlement behind the excavation is closely associated with the magnitude of basal heave and the wall deflections and is also greatly influenced by the possible groundwater drawdown caused by potential wall leakage, flow from beneath the wall, flow from perched water and along the wall interface or poor panel connections due to the less satisfactory quality. This paper numerically investigates the influences of excavation geometries, the system stiffness, the soil properties and the groundwater drawdown on ground surface settlement and develops a simplified maximum surface settlement Logarithm Regression model for the maximum ground surface settlement estimation. The settlements estimated by this model compare favorably with a number of published and instrumented records.

McEliece Type PKC Based on Algebraic Geometry Code over Hyperelliptic Curve (초타원 곡선위에서 생성된 대수기하 부호를 이용한McEliece유형의 공개키 암호시스템)

  • 강보경;한상근
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.12 no.1
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    • pp.43-54
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    • 2002
  • McEliece introduced a public-key cryptosystem based on Algebraic codes, specially binary classical Goppa which have a good decoding algorithm and vast number of inequivalent codes with given parameters. And the advantage of this system low cost of their encryption and decryption procedures compared with other public-key systems specially RSA, ECC based on DLP(discrete logarithm problem). But in [1], they resent new attack based on probabilistic algorithm to find minimum weight codeword, so for a sufficient security level, much larger parameter size [2048, 1608,81]is required. Then the big size of public key make McEliece PKC more inefficient. So in this paper, we will propose New Type PKC using q-ary Hyperelliptic code so that with smaller parameter(1 over 3) but still work factor as hi인 as McEliece PKC and faster encryption, decryption can be maintained.

Copper Particle Effect on the Breakdown Strength of Insulating Oil at Combined AC and DC Voltage

  • Wang, You-Yuan;Li, Yuan-Long;Wei, Chao;Zhang, Jing;Li, Xi
    • Journal of Electrical Engineering and Technology
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    • v.12 no.2
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    • pp.865-873
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    • 2017
  • Converter transformer is the key equipment of high voltage direct current transmission system. The solid suspending particles originating from the process of installation and operation of converter transformer have significant influence on the insulation performance of transformer oil, especially in presence of DC component in applied voltage. Under high electric field, the particles easily lead to partial discharge and breakdown of insulating oil. This paper investigated copper particle effect on the breakdown voltage of transformer oil at combined AC and DC voltage. A simulation model with single copper particle was established to interpret the particle effect on the breakdown strength of insulating oil. The experimental and simulation results showed that the particles distort the electric field. The breakdown voltage of insulating oil contaminated with copper particle decreases with the increase of particle number, and the breakdown voltage and the logarithm of particle number approximately satisfy the linear relationship. With the increase of the DC component in applied voltage, the breakdown voltage of contaminated insulating oil decreases. The simulation results show that the particle collides with the electrode more frequently with more DC component contained in the applied voltage, which will trigger more discharge and decrease the breakdown voltage of insulating oil.

A new statistical view to modeling of particle residence time distribution in full-scale overflow ball mill operating in closed-circuit

  • Hassanzadeh, Ahmad
    • Geosystem Engineering
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    • v.21 no.4
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    • pp.199-209
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    • 2018
  • In the present study, residence time distribution (RTD) of an industrial ball mill operating in closed-circuit with hydrocyclones was measured. Several probability distribution functions (PDFs) constituting exponential, Weibull, Gamma, logistic, normal, and lognormal were applied to obtained RTD results and evaluated based on Anderson-Darling statistic (AD) and associated p-value indices. In addition, three most common empirical RTD models (i.e., perfect mixer, N-Mixer and Weller) were fitted to the given practical data. Aside from assessment of coefficient determination ($R^2$) for each model, a factor of incorporating the number of model parameters was considered using Bayesian information criterion, low of iterated logarithm criterion and Akaike information criterion. It was revealed that Weibull PDF is fitted reasonably well to the measured experimental data compared with the other PDFs. Despite the relative variance (${\sigma}^2$) of N-Mixer model was slightly less than the corresponded value of Weller model, the goodness of fit criterion ($R^2$) and all four information criteria (IC) showed better results for Weller model. Therefore, one large with two small tanks in series along with a dead time was selected as the best model from the statistical point of view. Finally, it was concluded that the RTD models must be evaluated not only on the basis of goodness of fit but also the number of model parameters should be taken into account.

A Study on the Performance Evaluation of Elliptic Curve Cryptography based on a Real Number Field (실수체 기반 타원곡선 암호의 성능 평가에 관한 연구)

  • Woo, Chan-Il;Goo, Eun-Hee;Lee, Seung-Dae
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.14 no.3
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    • pp.1439-1444
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    • 2013
  • Recently, as the use of the applications like online banking and stock trading is increasing by the rapid development of the network, security of data content is becoming more and more important. Accordingly, public key or symmetric key encryption algorithm is widely used in open networks such as the internet for the protection of data. Generally, public key cryptographic systems is based on two famous number theoretic problems namely factoring or discrete logarithm problem. So, public key cryptographic systems is relatively slow compared to symmetric key cryptography systems. Among public key cryptographic systems, the advantage of ECC compared to RSA is that it offers equal security for a far smaller key. For this reason, ECC is faster than RSA. In this paper, we propose a efficient key generation method for elliptic curve cryptography system based on the real number field.

Design of Intrusion Responsible System For Enterprise Security Management (통합보안 관리를 위한 침입대응 시스템 설계)

  • Lee, Chang-Woo;Sohn, Woo-Yong;Song, Jung-Gil
    • Convergence Security Journal
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    • v.5 no.2
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    • pp.51-56
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    • 2005
  • Service operating management to keep stable and effective environment according as user increase and network environment of the Internet become complex gradually and requirements of offered service and user become various is felt constraint gradually. To solve this problem, invasion confrontation system through proposed this log analysis can be consisted as search of log file that is XML's advantage storing log file by XML form is easy and fast, and can have advantage log files of system analyze unification and manages according to structure anger of data. Also, created log file by Internet Protocol Address sort by do log and by Port number sort do log, invasion type sort log file and comparative analysis created in other invasion feeler system because change sort to various form such as do log by do logarithm, feeler time possible.

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Wet Fine Grinding of Rice Husk Ash using a Stirred Ball Mill (교반 볼밀을 이용한 왕겨재의 습식 미세분쇄에 관한 연구)

  • Park, S.J.;Kim, M.H.;Choi, Y.K.
    • Journal of Biosystems Engineering
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    • v.31 no.1
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    • pp.33-38
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    • 2006
  • This work was conducted to find the operating characteristics of an efficient wet grinding system designed to obtain fine rice husk ash powder. Once the rice husk was combusted and the thermal energy was recovered from the furnace, the ash was fed and pulverized in the grinding system resulting a fine powder to be used as a supplementary adding material to the portland cement. Grinding time (15, 30, 45 min), impeller speed (250, 500, 750 rpm), and mixed ratio (6.7, 8.4, 11.l, 20.9) were three operating factors examined for the performance of a wet-type stirred ball mill grinding system. For the operating conditions employed, mean diameter of fine ash powder, specific energy input, and grinding energy efficiency were in the range of $2.83{\sim}9.58{\mu}m,\;0.5{\sim}6.73kWh/kg,\;and\;0.51{\sim}3.27m^2/Wh$, respectively. With the wet-type stirred ball mill grinding system used in this study, the grinding energy efficiency decreased with the increase in total grinding time, impeller speed, and mixed ratio. The difference in specific surface area of powder linearly increased with logarithm in total number of impeller revolution and the grinding energy efficiency linearly decreased. Grinding time of 45 min, impeller speed of 500 rpm, and mixed ratio of 6.7 were chosen as the best operating condition. At this condition, mean particle diameter of the fine ash, grinding energy efficiency, grinding throughput, and specific energy input were $2.84{\mu}m,\;2.28m^2/Wh,\;0.17kg/h$, and 2.03kWh/kg, respectively. Wet fine grinding which generates no fly dust causing pollution and makes continuous operation easy, is appeared to be a promising solution to the automatization of rice husk ash grinding process.