• KSII Transactions on Internet and Information Systems (TIIS)
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• 제15권9호
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• pp.3458-3481
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• 2021

Existing methods for blind identification of linear block codes without a candidate set are mainly built on the Gauss elimination process. However, the fault tolerance will fall short when the intercepted bit error rate (BER) is too high. To address this issue, we apply the reverse algebra approach and propose a novel "two-step-screening" algorithm by solving the linear error equations on the binary Galois field, or GF(2). In the first step, a recursive matrix partition is implemented to solve the system linear error equations where the coefficient matrix is constructed by the full codewords which come from the intercepted noisy bitstream. This process is repeated to derive all those possible parity-checks. In the second step, a check matrix constructed by the intercepted codewords is applied to find the correct parity-checks out of all possible parity-checks solutions. This novel "two-step-screening" algorithm can be used in different codes like Hamming codes, BCH codes, LDPC codes, and quasi-cyclic LDPC codes. The simulation results have shown that it can highly improve the fault tolerance ability compared to the existing Gauss elimination process-based algorithms.

• Steel and Composite Structures
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• 제21권2호
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• pp.411-427
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• 2016

While the cyclic behaviour of fiber-reinforced polymer (FRP)-confined columns is studied rather extensively, the cyclic response especially the energy dissipation of FRP-confined damaged and undamaged square RC columns is not yet fully understood. In this paper, an experimental and numerical investigation was conducted to study the cyclic behavior of two different types of Carbon FRP (CFRP)-confined square RC columns: strengthened and repaired. The main variables investigated are initial damage, confinement of CFRP, longitudinal steel reinforcement ratio. The experimental results show that lower initial damage, added confinement with CFRP and longitudinal reinforcement enhance the ductility, energy dissipation capacity and strength of the columns, decrease the stiffness and strength degradation rates of all CFRP-confined square RC columns. Two hysteretic constitutive models were developed for confined damaged and undamaged concrete and cast into the non-linear beam-column fiber-based models in the software Open System for Earthquake Engineering Simulation (OpenSees) to analyze the cyclic behavior of CFRP-confined damaged and undamaged columns. The results of the numerical models are in good agreement with the experiments.

• 한국전기전자재료학회논문지
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• 제18권6호
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• pp.560-570
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• 2005

In this paper, a microelectrode away DNA chip was fabricated on glass slide using photolithography technology. Several probe DNAs consisting of mercaptohexyl moiety at their 5' end were immobilized on the gold electrodes by DNA arrayer utilizing the affinity between gold and sulfu. Then target DNAs were hybridized and reacted with Hoechst 33258, which is a DNA minor groove binder and electrochemically active dye. Cyclic voltammetry in 5mA ferricyanide/ferrocyanide solution at 100 mV/s confirmed the immobilization of probe DNA on the gold electrodes. Linear sweep voltammetry or cyclic voltammetry showed a difference between target DNA and control DNA in the anodic peak current values. It was derived from Hoechst 33258 concentrated at the electrode surface through association with formed hybrid. It suggested that this DNA chip could recognize the sequence specific genes. It suggested that multichannel electrochemical DNA microarray is useful to develop a portable device for clinical gene diagnostic system.

• KSBB Journal
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• 제15권5호
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• pp.489-496
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• 2000

고농도 유전자 재조합 대장균을 이용하여 pyruvate dehy-drogenase complex-E2 특이성 인간 모노클론 항체의 Fab 부분을 효율적으로 생산하기 위해 회분식, 이단 연속식, 반 유 가식, two-stage cyclic fed-batch 동 여러 가지 배양 방법이 조사되었다. 먼저 플라스미드 안정성 문제를 극복하기 위해 growth stage와 production stage를 분리하는 two-phase 회분식 배양과 이단 연속식 시스템을 시도하였다 그 결과 two-phase 회분식 배양보다는 이단 연속식 배양에서의 세포농도와 항체 생산성이 우수하였다 또한 이단 연속식 배양에서의 세포 성 장과 항처l 생산성은 용존산소를 제어한 경우가 그렇지 않은 경우보다 월등하게 높았다. 그리고 plasmid 안정성에 있어서 는 실험기간 내에 거의 100%를 유지하여 높은 안정도를 보 여주었다. 유가식 공정에 적합한 공급 배지로 변형된 M9 배 지가 최적배지로 선정되었고 이 배지 중 최적의 CjN 비율을 조사한 결파 2:3으로 결정되었다. 반 유가식 시스템에서 constant feeding 전략을 사용할 경우 최적 공급속도는 $0.6g/\ell/hr$이었다. 또한 pulse에 의해 공급배지를 공급할 경우에는 총 공급 량이 같을 경우 소량으로 자주 공급해 주는 것이 공급배지를 한꺼번에 많은 양을 공급해주는 것 보다 바람직하였다. 여러 가지 feeding 전략을 조사해 본 결과 linear feeding 방법이 가장 효과적이었다. 하지만 linear feeding 방법마저도 고농도 세포배양에 한계가 있었기 때문에 pH-stat 방법을 이용한 two-stage cyclic fed-batch 시스템을 시도하여 $54 g/\ell$의 세포 를 얻을 수 있었다. 따라서 이 방법이 일단 생산성 향상을 위한 세포의 고농도 배양에는 조사한 여러 배양 시스템 중에 가장 효율적인 시스템임올 알 수 있었다 하지만 이 시스템 에서 포도당을 낮은 level로 유지할 수 있었으나, 초산의 과도한 축적으로 항체 생산성의 향상은 예상에 비해 크지 않았다.

• 대한산업공학회지
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• 제24권4호
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• pp.639-647
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• 1998

We consider a multiclass production system processed by a single machine with cyclic order. Each part belongs to one of several classes and arrives at each queue in a Poisson process. The processing discipline at each queue is either exhaustive or gated. We introduce a new approach to analysis of mean waiting times for each queue. We formulate mean waiting times as cost functions on state of the system. The mean waiting times are obtained by solving a set of O($J^2$) linear equations, where J is the number of queues in the system. We also obtain the mean number of parts of each queue in the system at an arbitrary time. Based on this result, we plot the numerical values of the mean waiting times for several parameter settings.

• Journal of Electrochemical Science and Technology
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• 제11권4호
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• pp.379-383
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• 2020

The novel voltammetry using a semi-circular potential wave for quasi-reversible charge transfer system on electrode is theoretically investigated. Compared with conventional voltammetry based on linear sweep such as linear sweep voltammetry (LSV), semi-circular potential sweep voltammetry (SCV) may decrease the charging current outside the center of potential range and increase the faradaic current at the midpoint due to variable scan rate. In this paper, we investigate the system based on macroelectrode where simple 1 dimensional (1 D) diffusion system is valid with various charge transfer rate constant (k₀). In order to observe the amplification at midpoint, voltammetric response with different midpoint ranging from -200 mV to 200 mV are studied. SCVs shows both the shift of peak potential and the amplification of peak current for quasi-reversible electrode reaction while only higher peak current is observed for reversible reaction. Moreover, the higher current at midpoint enable the amplification of current at low overpotential region which may assist the determination of onset potential as a figure-of-merit in electrocatalyst.

• 한국통신학회논문지
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• 제25권5B호
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• pp.859-870
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• 2000

본 논문에서는 OFDM(Orthogonal Frequency Division Multiplexing) 시스템에서 사용되는 보호구간을 하드웨어로 효율적으로 구현할 수 있는 기법을 제안하고, OFDM기반의 25 Mbps 무선 ATM 모뎀에 적용하여 ASIC칩을 설계한다. OFDM 시스템에서는 가장 긴 delay spread 보다 긴 cyclic prefix를 삽입하여 채널의 선형 컨볼루션을 이산 Fourier 영역에서 circular 컨볼루션으로 변형함으로써 부채널간의 직교성을 유지하고, OFDM 블록내의 심볼간 간섭은 방지한다. 그러나 OFDM 시스템에서 이러한 cyclic prefix를 사용하기 위해서는 원래 샘플을 저장하고 각 블록의 시작 위치에 cyclic prefix를 붙이기 위한 추가적인 하드웨어가 송신단에서 요구된다. 본 논문에서는 cyclic suffix를 사용한 새로운 기법을 제안하고, 제안된 기법이 기존의 cyclic prefix 기법에 비하여 매우 적은 하드웨어로 동일한 성능을 갖게 됨을 확인한다. 마지막으로 제안된 기법을 OFDM기반의 25 Mbps 무선 ATM 모뎀의 ASIC칩 설계에 적용하여 그 성능을 확인한다.

• Steel and Composite Structures
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• 제44권2호
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• pp.283-294
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• 2022

In this study, a new seismic retrofit scheme of building structures is developed by combining a steel moment frame and steel slit plates to be installed inside of an existing reinforced concrete frame. This device has the energy dissipation capability of slit dampers with slight loss of stiffness compared to the conventional steel frame reinforcement method. In order to investigate the seismic performance of the retrofit system, it was installed inside of a reinforced concrete frame and tested under cyclic loading. Finite element analysis was carried out for validation of the test results, and it was observed that the analysis and the test results match well. An analytical model was developed to apply the retrofit system to a commercial software to be used for seismic retrofit design of an example structure. The effectiveness of the retrofit scheme was investigated through nonlinear time-history response analysis (NLTHA). The cyclic loading test showed that the steel frame with slit dampers provides significant increase in strength and ductility to the bare structure. According to the analysis results of a case study building, the proposed system turned out to be effective in decreasing the seismic response of the model structure below the given target limit state.

• 한국결정성장학회지
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• 제22권5호
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• pp.213-217
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• 2012

Carbon coils could be synthesized on nickel catalyst layer-deposited silicon oxide substrate using $C_2H_2$ and $H_2$ as source gases under thermal chemical vapor deposition system. By the incorporation of $SF_6$ additive in cyclic modulation manner, the dominant formation of the nanosized carbon coils could be achieved with maintaining the minimized sulfur additive amount. The geometry variation of the as-grown carbon coils, such as linear type, microsized coil type, wavelike nanosized coil type, and nanosized coil type, were investigated according to the different cyclic modulation manner of $SF_6$ flow. $SF_6$ gas incorporation develops the coil-type geometry. Furthermore, the higher flow rate of $SF_6$ gas increased the amount of the nanosized carbon coils. The slightly increased etching ability by $SF_6$ addition seems to be the cause for these results.

• 한국지진공학회논문집
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• 제5권4호
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• pp.97-105
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• 2001

고무제품에 근간을 둔 면진장치는 상당한 저온효과와 약간의 변형도 속도효과를 보여준다. 면진장치의 비탄성거동에 영향을 미치는 이들의 속성은 면진장치의 거동을 정확히 모델링하기 위해 반드시 고려되어져야 하기 때문에, 고무와 납 모두에 영향을 미치는 저온효과와 변형도 속도효과를 고려할 수 있는 해석모델을 제시하였다. 얼린 면진장치를 일정 수직하중에서 수평방향 반복하중을 가한 실험결과들로부터 시스템 식별(SI : system identification)을 적용하여 해석모델에 필요한 고무와 납의 매개변수들을 구하였다. 제안된 해석모델은 면진장치의 거동을 유사하게 표현할 수 있음을 보여준다.