• Journal of Chest Surgery
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• v.11 no.4
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• pp.404-415
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• 1978

The present study was carried out to develop the better measures for safety of open heart surgery under extracorporeal circulation (ECC) with Heart-Lung-Machine by preventing changes in the concentrations of serum electrolytes during and after ECC. For this purpose, the cocentrations of serum electrolytes were measured before, during, and after ECC in 21 patients with congenital and acquired heart diseases who received open heart surger, - under ECC using Heart-Lung-Machine. Also considered was the development of safety measured by which changes in serum electrolyte concentrations were prevented during and after open heart surgery under ECC. The mean values for serum sodium levels were observed to be ; $13.14{\pm}0.47$mEq./L. for the samples obtained before ECC. $139.59{\pm}0.68$mEq./L. for the samples obtained 10 minutes after ECC and $138.0{\pm}0.68$mEq./L. for the samples obt"ined 24 hours after ECC. These results indicate that serum sodium concentrations were \\'ithin normal range during and until 24 hours after ECC. 2) The concentrations of serum chloride were found to be $105.38{\pm}0.70$105.38$\pm$0. 70 mEq./L. for the samples collected before ECC, $105.07{\pm}1.01$mEq./L. for the Simples collected 24 minutes aiter ECC and $101.95{\pm}1.09$mEq./L. for the samples collectect 24 hours afte ECC. As was tile case with serum sodium levels, no significant changes were observed in serum chloride levels during and 24 hours after ECC. 3)With proper provisions of potassium chloride solution during ECC, the concentrations of serum potassium were found to be $4.22{\pm}0.06$mEq./L. for the samples removed before EeC, $4.06{\pm}0.14$mEq./L. for the samples removed 10 minutes after ECC and $4.39{\pm}0.07$ mEq./L. for the samples removed 24 hours after ECC. 4)The concentrations of serum calcium were also maintained within normal during and after ECC; $9.15{\pm}0.14$mg/dl for the serum collected before ECC, $8.36{\pm}0.21$mg/dI for the serum collected 10 minutes after ECC and $8.47{\pm}0.14$mg/dl 21 hours after ECC. The maintenance of serum calcium level within normal throughout ECC was achieved by parenteral administrations of calcium gluconate as frequent as required. 5) As were the cases with serum potassium and calcium, the concentrations of plasma bicarbonate was regulated within normal range during and after ECC, only when sodium bicarbonate solution was admini"tered parenterally as it was required; $23.7{\pm}0.50$mEq./L. for the serum collected before ECC. $22.33{\pm}1.09$mEq.lL. for the serum collected 10 minutes after ECC and $25.3{\pm}0.96$mEq./L. for the serum collected 24 hours after ECC. The above results indicate tha t during and after ECC serum sodium and chloride levels remined unchanged without any provision of normal saline, while serum potassium, calcium, and bicarbonate concentrations were kept within normal limits only when these ealectrolytes were administered through parenteral routes. With these results it can be concluded that serum potassium, calcium, and bicarbonate levels should be determined as often as possible during and after ECC and that in order to maintain serum electrolyte levels within normal these electrolytes in the forms of potassium chloride, calcium gluconate, and sodium bicarbonate shou'd be given parenterally as they were found to be required.

• Journal of Internet Computing and Services
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• v.6 no.3
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• pp.1-16
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• 2005

This paper propose not only MDIT(Mobile Digital Investment Trust) agent design for Trust Investment under Mobile E-commerce environment, but also the symmetric key algorithm 3BC(Bit, Byte and Block Cypher) and the public encryption algorithm F2mECC for solving the problems of memory capacity, CPU processing time, and security that mobile environment has. In Particular, the MDIT Security Agent is the banking security project that introduces the concept of investment trust in mobile e-commerce, This mobile security protocol creates a shared secrete key using F2mECC and then it's value is used for 3BC that is block encryption technique. The security and the processing speed of MDIT agent are enhanced using 3BC and F2mECC.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2019.05a
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• pp.254-256
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• 2019

소수체 GF(p)와 이진체 $GF(2^m)$ 상의 다중 타원곡선을 지원하는 듀얼 필드 ECC (DF-ECC) 프로세서를 설계하였다. DF-ECC 프로세서의 저면적 설와 다양한 타원곡선의 지원이 가능하도록 워드 기반 몽고메리 곱셈 알고리듬을 적용한 유한체 곱셈기를 저면적으로 설계하였으며, 페르마의 소정리(Fermat's little theorem)를 유한체 곱셈기에 적용하여 유한체 나눗셈을 구현하였다. 설계된 DF-ECC 프로세서는 스칼라 곱셈과 점 연산, 그리고 모듈러 연산 기능을 가져 다양한 공개키 암호 프로토콜에 응용이 가능하며, 유한체 및 모듈러 연산에 적용되는 파라미터를 내부 연산으로 생성하여 다양한 표준의 타원곡선을 지원하도록 하였다. 설계된 DF-ECC는 FPGA 구현을 하드웨어 동작을 검증하였으며, 0.18-um CMOS 셀 라이브러리로 합성한 결과 22,262 GEs (gate equivalences)와 11 kbit RAM으로 구현되었으며, 최대 100 MHz의 동작 주파수를 갖는다. 설계된 DF-ECC 프로세서의 연산성능은 B-163 Koblitz 타원곡선의 경우 스칼라 곱셈 연산에 885,044 클록 사이클이 소요되며, B-571 슈도랜덤 타원곡선의 스칼라 곱셈에는 25,040,625 사이클이 소요된다.

• Journal of the Korea Concrete Institute
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• v.15 no.3
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• pp.462-469
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• 2003

This paper presents an experimental study on the potential durability enhancement of infrastructures repaired by a sprayed high ductile fiber-reinforced cementitious composite (ECC). For this study, a PVA-ECC which exhibits sprayable properties in the fresh state and tensile strain-hardening behavior in hardened state was sprayed and tested. The experimental results show that the sprayed ECC exhibits mechanical properties with strain capacity comparable to the cast ECC with the same mix design. During loading, the crack widths of ECC are tightly controlled with an average of 30${\mu}m$. It is also revealed that when sprayed ECC is used as a repair material, ductility represented by deformation capacity at peak load of repaired beams in flexure are obviously increased in comparison to those of commercial prepackaged mortar (PM) repaired beams. In addition to high delamination resistance, the significant enhancement of energy absorption capacity and crack width control in ECC repair system suggest that sprayed ECC can be effective in extending the service life of rehabilitated infrastructures.

• Journal of Chest Surgery
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• v.23 no.5
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• pp.854-863
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• 1990

Since the open heart surgery was performed, various kinds of problem concerning the extracorporeal circulation[EGG] have been known. The author investigated the changes of serum potassium ion before and after ECC among the 102 patients including 63 adults and 39 children who underwent open heart surgery from April 19S6 to February 1990 in Chung-Ang University Hospital. The mean values of potassium ion before and after ECC were analyzed according to the influencing factors such as priming solution, aortic cross clamping time, the underlying disease, the type of oxygenator and the amount of cardioplegic solution. The results were as follows: l. In the aspect of congenital and acquired heart disease groups, the mean values of serum potassium ion[Mean\ulcornerS.D.] before and after ECC revealed a significant change only in the acquired heart disease group[congenital; 3.87$\pm$0.48mEq /L vs. 4.05$\pm$0.73mEq /L, P>0.05, acquired: 4.40 $\pm$0.98mEq /L vs. 4.11$\pm$0.52mEq /L, P<0.05]. Between the two groups, the changes of the mean values of serum potassium ion before and after ECC were significant[P<0.05]. But all values were within normal limits. 2. In the aspect of the aortic cross clamping time[ACCT], in the groups of less or more than 120 minutes, the mean values of serum potassium ion before and after ECC revealed no significant change[less than 120 min; 3.97+-0.64mEq /L vs. 3.99+0.67mEq /L, P>0.05, more than 120 min; 4.34+0.82mEq /L vs. 4.27+0.62mEq /L, P>0.05], and The changes of mean values of serum potassium ion between the two groups were not significant[P>0.05]. 3. In both membrane and bubble oxygenator groups, the mean values of serum potassium ion before and after ECC did not reveal a significant difference respectively [membrane; 4.74 +1.40mEq /L vs. 4.28+0.3lmEq /L, P>0.05, bubble; 4.02 +0.60mEq /L vs. 4.05 L0.68mEq/L, P>0.05], and no differences between the membrane and bubble oxygenator groups[P >0.05]. 4. In the groups of membrane and bubble oxygenator in the cases of ACCT more than 120 minutes, the mean values of serum potassium ion before and after ECC did not reveal a significant difference respectively[membrane; 4.36$\pm$0.85mEq /L vs. 4.37$\pm$0.26mEq /L, P>0.05, bubble; 4.30 $\pm$0.80mEq/L vs. 4.23$\pm$0.67mEq/L, P>0.05], and no differences between the two groups[P>0.05]. 5. In spite of increased amount of cold potassium cardioplegic solution, the mean values of serum potassium ion before ECC were similar to those of serum potassium ion after ECC[less than 20ml /kg

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.42 no.8 s.338
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• pp.15-26
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• 2005

In this paper, we propose an efficient $GF(2^m)$ multi-segment multiplier architecture and study its application to elliptic curve cryptography processors. The multi-segment based ECC datapath has a very small combinational multiplier to compute partial products, most of its internal data buses are word-sized, and it has only a single m bit multiplexer and a single m bit register. Hence, the resource requirements of the proposed ECC datapath can be minimized as the segment number increases and word-size is decreased. Hence, as compared to the ECC processor based on digit-serial multiplication, the proposed ECC datapath is more efficient in resource usage. The resource requirement of ECC Processor implementation depends not only on the number of basic hardware components but also on the complexity of interconnection among them. To show the realistic area efficiency of proposed ECC processors, we implemented both the ECC processors based on the proposed multi-segment multiplication and digit serial multiplication and compared their FPGA resource usages. The experimental results show that the Proposed multi-segment multiplication method allows to implement ECC coprocessors, requiring about half of FPGA resources as compared to digit serial multiplication.

• 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.

• Proceedings of the Korea Information Processing Society Conference
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• 2012.11a
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• pp.1084-1085
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• 2012

본 논문에서는 병원과 외부서비스 간의 의료정보 교환 프로토콜을 설계하고, 설계한 프로토콜에 ECC 알고리즘을 적용하였다. 이를 위하여 관련연구로 CCR, ECC 알고리즘에 대해 분석하고, 의료정보 교환 프로토콜을 정의하였으며, 병원과 외부 서비스 간의 정보를 구분하고, ECC 알고리즘을 적용한 의료정보 교환 프로토콜을 설계하였다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.05a
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• pp.169-170
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• 2018

이진체 상의 타원곡선 B-233을 지원하는 타원곡선 암호 프로세서를 32-비트 워드기반 몽고메리 곱셈기를 이용하여 설계하였다. 스칼라 곱셈을 위해 수정된 몽고메리 래더 (Modified montgomery ladder) 알고리즘을 적용하여 단순 전력분석에 내성을 갖도록 하였으며, Lopez-Dahab 투영 좌표계와 페르마의 소정리(Fermat's little theorem)를 적용하여 하드웨어 자원 소모가 큰 나눗셈과 역원 연산을 제거하여 저면적으로 설계하였다. 설계된 ECC 프로세서는 Xilinx ISim을 이용하여 기능검증을 하였으며, $0.18{\mu}m$ CMOS 셀 라이브러리로 합성한 결과 100 MHz의 동작 주파수에서 9,614 GEs와 4 Kbit RAM으로 구현되었으며, 최대 동작 주파수는 125 MHz로 예측되었다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.3C
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• pp.176-184
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• 2005

In this paper, we implemented an Elliptic Curve Cryptography(ECC) processor for Digital Transmission Contents Protection (DTCP), which is a standard for protecting various digital contents in the network. Unlikely to other applications, DTCP uses ECC algorithm which is defined over GF(p), where p is a 160-bit prime integer. The core arithmetic operation of ECC is a scalar multiplication, and it involves large amount of very long integer modular multiplications and additions. In this paper, the modular multiplier was designed using the well-known Montgomery algorithm which was implemented with CSA(Carry-save Adder) and 4-level CLA(Carry-lookahead Adder). Our new ECC processor has been synthesized using Samsung 0.18 m CMOS standard cell library, and the maximum operation frequency was estimated 98 MHz, with the size about 65,000 gates. The resulting performance was 29.6 kbps, that is, it took 5.4 msec to process a 160-bit data frame. We assure that this performance is enough to be used for digital signature, encryption and decryption, and key exchanges in real time environments.