• Journal of the Institute of Electronics Engineers of Korea SD
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• v.43 no.3 s.345
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• pp.40-47
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• 2006

The finite-field multiplication can be applied to the elliptic curve cryptosystems. However, an efficient algorithm and the hardware design are required since the finite-field multiplication takes much time to compute. In this paper, we propose a radix-4 systolic multiplier on $GF(2^m)$ with comparative area and performance. The algorithm of the proposed standard-basis multiplier is mathematically developed to map on low-cost systolic cells, so that the proposed systolic architecture is suitable for VLSI design. Compared to the bit-parallel, bit-serial and systolic multipliers, the proposed multiplier has relatively effective high performance and low cost. We design and synthesis $GF(2^{193})$ finite-field multiplier using Hynix $0.35{\mu}m$ standard cell library and the maximum clock frequency is 400MHz.

• Journal of Plant Biotechnology
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• v.6 no.2
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• pp.91-96
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• 2004

The use of liquid-medium-based procedure relative to the solid media led to a 4.5-fold increase in the number of cotyledon-stage embryos. The most efficient system for multiplication and regeneration of somatic embryos was CP6 procedure with the media MSD40/MSD20/MSM6AC/FNL0S3S3GM. However, the rate of regeneration was lower. About 71％ of the embryos with dicotyledon were continued to develop the roots after desiccation treatment and 92％ of the germinated embryos produced shoots in 10 days. Of the four morphologically different types of embryos, dicotyledonous ones showed a high frequency of conversion, while only a few with fused and horn type cotyledon developed shoots. Mature somatic embryos were desiccated in empty petri dishes for 12-72 h. Embryo survival rate was the highest after 12 h of desiccation, but maximal germination was observed at 24 h. After desiccation, they were placed on MS medium without growth regulators for germination. Germinating embryos were transferred to small pots with vermiculite for plant regeneration. The etiolating the plants during the growth was resolved to add 1％ activated charcoal on hormone-free MS medium.

• Journal of IKEEE
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• v.19 no.3
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• pp.342-348
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• 2015

High speed implementation of digital filters is required in high data rate applications such as hard-wired wide band modem and high resolution video codec. Since the critical path of the digital filter is the MAC (multiplication and accumulation) circuit, the filter coefficient with sparse non-zero bits enables high speed implementation with adders of low hardware cost. Compressive sensing has been reported to be very successful in sparse representation and sparse signal recovery. In this paper a filter design method for digital FIR filters with CSD (canonic signed digit) coefficients using compressive sensing technique is proposed. The sparse non-zero signed bits are selected in the greedy fashion while pruning the mistakenly selected digits. A few design examples show that the proposed method can be utilized for designing sparse CSD coefficient digital FIR filters approximating the desired frequency response.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.39 no.12
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• pp.1062-1070
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• 2002

In this paper, variable radix-two multibit coding algorithm is presented and applied in the implementation of discrete cosine transform(DCT) and inverse discrete cosine transform(IDCT). Variable radix-two multibit coding means the 2k SD (signed digit) representation of overlapped multibit scanning with variable shift method. SD represented by 2k generates partial products, which can be easily implemented with shifters and adders. This algorithm is most powerful for the hardware implementation of DCT/IDCT with constant coefficient matrix multiplication. This paper introduces the suggested algorithm, it's proof and the implementation of DCT/IDCT The implemented IDCT chip with 8 PEs(Processing Elements) and one transpose memory runs at a tate of 400 Mpixels/sec at 54MHz frequency for high speed parallel signal processing, and it's verified in HDTV and MPEG decoder.

• Journal of IKEEE
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• v.22 no.3
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• pp.522-531
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• 2018

A public-key cryptography processor EC-RSA was designed, which integrates a 224-bit prime field elliptic curve cryptography (ECC) defined in the FIPS 186-2 as well as RSA with 2048-bit key length into a single hardware structure. A finite field arithmetic core used in both scalar multiplication for ECC and exponentiation for RSA was designed with 32-bit data-path. A lightweight implementation was achieved by an efficient hardware sharing of the finite field arithmetic core and internal memory for ECC and RSA operations. The EC-RSA processor was verified by FPGA implementation. It occupied 11,779 gate equivalents (GEs) and 14 kbit RAM synthesized with a 180-nm CMOS cell library and the estimated maximum clock frequency was 133 MHz. It takes 867,746 clock cycles for ECC scalar multiplication resulting in the estimated throughput of 34.3 kbps, and takes 26,149,013 clock cycles for RSA decryption resulting in the estimated throughput of 10.4 kbps.

• Korean Journal of Plant Tissue Culture
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• v.26 no.2
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• pp.85-91
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• 1999

In sweet potato cultivars 'Mokpo #29' and 'Sanchunza', shoots from extplants were formed 100% on the MS medium with 0.1 ㎎/L NAA and 2.0 ㎎/L BA after 30 days of culture and roots produced from the base of stem at frequencies of 66.7% ('Mokpo #29') and 69.2% ('Sanchunza'), respectively, The media with 0.5∼4.0 ㎎/L BA were produced the greatest frequency of multiple shoot and the most of shoots developed rapidly into normal plantlets with rooting within 60 days of culture. Whereas the cultivar 'Keumsi' failed to produce normal shoot multiplication on the medium with cytokinins alone because of callusing of adventitious shoots. When single shoots with 1 to 2 nodes were excised from the multiple shoot or shoots covered with callus devoid of root and transferred to MS medium with 4.0 ㎎/L BA or kinetin. Host divided shoots showed the callus induction at the stem base and it was enable to obtain regenerated plantlets with shoot and root normally.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.16 no.2
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• pp.41-47
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• 2016

The times of multiplication for encryption and decryption of cryptosystem is primarily determined by implementation efficiency of the modular exponentiation of $a^b$(mod m). The most frequently used among standard modular exponentiation methods is a standard binary method, of which n-ary($2{\leq}n{\leq}6$) is most popular. The n-ary($1{\leq}n{\leq}6$) is a square-and-multiply method which partitions $b=b_kb_{k-1}{\cdots}b_1b_{0(2)}$ into n fixed bits from right to left and squares n times and multiplies bit values. This paper proposes a variable-length partition algorithm that partitions $b_{k-1}{\cdots}b_1b_{0(2)}$ from left to right. The proposed algorithm has proved to reduce the multiplication frequency of the fixed-length partition n-ary method.

• Journal of IKEEE
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• v.23 no.1
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• pp.58-67
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• 2019

A design of an elliptic curve cryptography (ECC) processor that supports both pseudo-random curves and Koblitz curves over $GF(2^m)$ defined by the NIST standard is described in this paper. A finite field arithmetic circuit based on a word-based Montgomery multiplier was designed to support five key lengths using a datapath of fixed size, as well as to achieve a lightweight hardware implementation. In addition, Lopez-Dahab's coordinate system was adopted to remove the finite field division operation. The ECC processor was implemented in the FPGA verification platform and the hardware operation was verified by Elliptic Curve Diffie-Hellman (ECDH) key exchange protocol operation. The ECC processor that was synthesized with a 180-nm CMOS cell library occupied 10,674 gate equivalents (GEs) and a dual-port RAM of 9 kbits, and the maximum clock frequency was estimated at 154 MHz. The scalar multiplication operation over the 223-bit pseudo-random elliptic curve takes 1,112,221 clock cycles and has a throughput of 32.3 kbps.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.3
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• pp.419-426
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• 2021

A high-performance elliptic curve cryptography processor (HP-ECCP) was designed to support five field sizes of 192, 224, 256, 384 and 521 bits over GF(p) defined in NIST FIPS 186-2, and it provides eight modes of arithmetic operations including ECPSM, ECPA, ECPD, MA, MS, MM, MI and MD. In order to make the HP-ECCP resistant to side-channel attacks, a modified left-to-right binary algorithm was used, in which point addition and point doubling operations are uniformly performed regardless of the Hamming weight of private key used for ECPSM. In addition, Karatsuba-Ofman multiplication algorithm (KOMA), Lazy reduction and Nikhilam division algorithms were adopted for designing high-performance modular multiplier that is the core arithmetic block for elliptic curve point operations. The HP-ECCP synthesized using a 180-nm CMOS cell library occupied 620,846 gate equivalents with a clock frequency of 67 MHz, and it was evaluated that an ECPSM with a field size of 256 bits can be computed 2,200 times per second.

• Journal of Plant Biotechnology
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• v.48 no.1
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• pp.54-61
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• 2021

This work describe an efficient method for the shoot induction and plant regeneration of seedling-derived apical bud explants of Tilia mandshurica Rupr. & Maxim. The highest rate of shoot induction (82.2%) was obtained when apical bud explants from juvenile seedlings (5 months old) were cultured on Murashige and Skoog (MS) medium containing 1.0 mg/L 6-benzylaminopurine (BAP). However, apical bud explants obtained from mature trees (12 years old) did not produce any shoots, even with BAP supplementation. Among the three cytokinins tested for shoot multiplication (BAP, zeatin, and kinetin), BAP was the most effective; the highest number of shoots per explant (2.1) was observed on MS medium supplemented with 1.0 mg/L BAP. In contrast, the longest average shoot length (3.0 cm) was observed after growth on MS medium with 2.0 mg/L zeatin. No multiplication occurred when apical bud explants were cultured with kinetin-supplemented media. During rooting of in vitro-elongated shoots, the highest rooting rate (100%) was observed in half-strength MS medium supplemented with 0.5 ~ 1.0 mg/L indole-3-butyric acid (IBA) or 3.0 mg/L 1-naphthaleneacetic acid (NAA). During the acclimatization process, plantlets that were rooted on the IBA (0.5 mg/L)-supplemented medium had the highest survival rate (100%) and maximum root length (18.5 cm). These findings suggest that a low concentration (0.5 mg/L) of IBA is appropriate for the rooting and acclimatization of T. mandshurica. Plants were successfully transferred to the greenhouse with a 100% survival rate. This protocol will be useful for the large-scale propagation of Tilia species.