• International Journal of Computer Science & Network Security
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• v.23 no.6
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• pp.181-192
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• 2023

Blockchain system brought innovation in the area of accounting, credit monitoring and trade secrets. Consensus algorithm that considered the central component of blockchain, significantly influences performance and security of blockchain system. In this paper we presented four consensus protocols specifically as Proof of Work (PoW), Proof of Stake (PoS), Delegated Proof of Stake (DPoS) and Practical Byzantine Fault-Tolerance (PBFT), we also reviewed different security threats that affect the performance of Consensus Protocols and precisely enlist their counter measures. Further we evaluated the performance of these Consensus Protocols in tabular form based on different parameters. At the end we discussed a comprehensive comparison of Consensus protocols in terms of Throughput, Latency and Scalability. We presume that our results can be beneficial to blockchain system and token economists, practitioners and researchers.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2015.07a
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• pp.60-62
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• 2015

Dynamic Positioning System(DPS)은 동력, DP control 장치, DP 컴퓨터, 위치참조시스템(PRS), 센서, thruster 시스템 및 DP 운용자(DPO) 7가지로 구성되어 있다. DP 선박은 이들 구성요소들에 문제가 발생하면 그 기능을 상실할 수 있다. 본 연구에서는 2001~2010년까지 10년 동안 IMCA 보고된 DP 선박 관련사고 612건에 대한 분석을 바탕으로 DPS의 7가지 구성요소와 관련된 사고 원인을 파악하고 이들 중 가장 높은 비율을 차지하는 원인을 정성적, 정량적으로 상세 분석하여 요소별 관계와 주요 작용 요소를 확인하고자 한다. 이를 통해 DP 선박의 LOP사과 관련 분석에 있어 베이지안 네트워크의 활용성을 확인해 보았다. 10년 평균 가장 높은 비율을 차지한 DPS 사고원인 요인은 PRS이었으며 이를 전문가 브레인스토밍을 통해 작성된 flowchart를 바탕으로 베이지안 네트워크를 통해 상세 분석해 본 결과 PRS의 각 요소별 조건부 확률 확인할 수 있었다. DP 선박의 drive off를 발생시키는데 주요한 영향을 미치는 것은 DGPS, microwave radar 및 HPR 이었고 DGPS에 주요한 영향을 미치는 에러 요인은 signal blocked, electric components failure, relative mode error 및 signal weak or fail 이었다.

• The Korean Journal of Physiology and Pharmacology
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• v.21 no.2
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• pp.225-232
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• 2017

We demonstrated the effect of nortriptyline, a tricyclic antidepressant drug and serotonin reuptake inhibitor, on voltage-dependent $K^+$ (Kv) channels in freshly isolated rabbit coronary arterial smooth muscle cells using a whole-cell patch clamp technique. Nortriptyline inhibited Kv currents in a concentration-dependent manner, with an apparent $IC_{50}$ value of $2.86{\pm}0.52{\mu}M$ and a Hill coefficient of $0.77{\pm}0.1$. Although application of nortriptyline did not change the activation curve, nortriptyline shifted the inactivation current toward a more negative potential. Application of train pulses (1 or 2 Hz) did not change the nortriptyline-induced Kv channel inhibition, suggesting that the effects of nortiprtyline were not use-dependent. Preincubation with the Kv1.5 and Kv2.1/2.2 inhibitors, DPO-1 and guangxitoxin did not affect nortriptyline inhibition of Kv channels. From these results, we concluded that nortriptyline inhibited Kv channels in a concentration-dependent and state-independent manner independently of serotonin reuptake.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.1
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• pp.42-50
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• 2008

Twenty-four, lactating dairy cows were randomly assigned according to a Rrandomized complete block design (RCBD) to investigate the effect of sunflower oil supplementation (SFOS) with cassava hay based-diets on feed intake, digestibility of nutrients, rumen fermentation efficiency and milk production. The treatments were as follows: T1 = Control, using commercial concentrate as a supplement (CON); T2 = Concentrate with cassava hay (CHSO-0); T3 = Concentrate with cassava hay and 2.5% sunflower oil (CHSO-2.5); T4 = Concentrate with cassava hay and 5% sunflower oil (CHSO-5). The cows were offered concentrate feed at a ratio of concentrate to milk production of 1:2 and urea-treated rice straw was fed ad libitum. The results revealed that feed intake, digestibility of nutrients and ruminal pH were similar among all treatments, while ruminal NH3-N was lower (p<0.05) with SFOS. Blood urea-N (BUN) and milk urea-N (MUN) were not significantly affected by SFOS. The ruminal concentrations of volatile fatty acids were significantly different among the treatments. Sunflower oil supplementation significantly increased concentrations of unsaturated fatty acids, and ratio of unsaturated to saturated fatty acids in the milk, particularly the conjugated fatty acids, was significantly enhanced. Furthermore, production costs of treatments with sunflower oil supplementation were lower than for the control. Based on this study, SFOS in cassava hay based-diets improves rumen ecology, milk yield and milk quality, especially in terms of conjugated linoleic acids.

• Journal of Mushroom
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• v.20 no.2
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• pp.43-49
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• 2022

Pleurotus ostreatus is a globally cultivated mushroom crop. Cap color is a quality factor in P. ostreatus. However, cap color can spontaneously mutate, degrading the quality of the mushroom on the market. Early detection and removal of mutant strains is the best way to maintain the commercial value of the crop. To detect the cap color mutant Gonji7ho, molecular markers were developed based on insertion/deletions (InDels) derived from the comparison of mitogenomes of Gonji7ho and Gonji7hoM mushrooms. Sequencing, assembly, and comparative analysis of the two mitogenomes revealed genome sizes of 73,212 bp and 72,576 bp with 61 and 57 genes or open reading frames (ORFs) in P. ostreatus Gonji7ho and Gonji7hoM, respectively. Fourteen core protein-encoding genes, two rRNA, and 24 tRNA with some OFRs were predicted. Of the 61 genes or OFRs in the wild type, dpo, rpo, and two orf139 were missing (or remnant) in the mutant strain. Molecular markers were developed based on the sequence variations (InDels) between the two mitogenomes. Six polymorphic molecular markers could detect the mutated mitochondria by PCR. These results provide basic knowledge of the mitogenomes of wild-type and mutant P. ostreatus, and can be applied to discriminate mutated mitochondria.

• Journal of Navigation and Port Research
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• v.39 no.3
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• pp.149-156
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• 2015

The Dynamic Positioning System consists of 7 elements which are namely Power system, Human machine interface, DP Computer, Position Reference System(PRS), Sensors, Thruster system and DP Operator. Incidents like loss of position(LOP) on DP vessel usually occur due to errors in these 7 elements. The purpose of this study is to find out safety operation method of DP vessel through qualitative and quantitative analyze of DP LOP incidents which are submitted to IMCA every year. The 612 DP LOP incidents submitted from 2001 to 2010 were analyzed to find out the main cause of the incidents and its rate among other causes. Consequently, the highest rate of incidents involving DP elements are PRS errors. DP computer, Power system, Human error and thruster system came next. The PRS has been analyzed and a flowchart was drawn through expert brainstorming. Also, the conditional probability has been analyzed through Bayesian Networks based on this flowchart. Consequentially, the main causes of drive off incidents were DGPS, microwave radar and HPR. Also, this study identified the main causes of DGPS errors through Bayesian Networks. These causes are signal blocked, electric components failure, relative mode error, signal weak or fail.