• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.31 no.4
• /
• pp.637-659
• /
• 2021

Since the creation of the first Bitcoin blockchain in 2009, the number of cryptocurrency users has steadily increased. However, the number of hacking attacks targeting assets stored in these users' cryptocurrency wallets is also increasing. Therefore, we evaluate the security of the wallets currently on the market to ensure that they are safe. We first conduct threat modeling to identify threats to cryptocurrency wallets and identify the security requirements. Second, based on the derived security requirements, we utilize attack trees and Bayesian network analysis to quantitatively measure the risks inherent in each wallet and compare them. According to the results, the average total risk in software wallets is 1.22 times greater than that in hardware wallets. In the comparison of different hardware wallets, we found that the total risk inherent to the Trezor One wallet, which has a general-purpose MCU, is 1.11 times greater than that of the Ledger Nano S wallet, which has a secure element. However, use of a secure element in a cryptocurrency wallet has been shown to be less effective at reducing risks.

• Geomechanics and Engineering
• /
• v.24 no.2
• /
• pp.179-191
• /
• 2021

In this study, the strength and failure mechanism of red sandstones with combined defects were investigated by uniaxial compression tests on red sandstones with different crack angles using two-dimensional particle flow code numerical software, and their mechanical parameters and failure process were studied and analyzed. The results showed that the mechanical characteristics such as peak strength, peak strain, and elastic modulus of the samples with prefabricated combined defects were significantly inferior than those of the intact samples. With increasing crack angle from 15° to 60°, the weakening area of cracks increased, elastic modulus, peak strength, and peak strain gradually reduced, the total number of cracks increased, and more strain energy was released. In addition, the samples underwent initial brittle failure to plastic failure stage, and the failure form was more significant, leading to peeling phenomenon. However, with increasing crack angle from 75° to 90°, the crack-hole combination shared the stress concentration at the tip of the crack-crack combination, resulted in a gradual increase in elastic modulus, peak strain and peak strength, but a decrease in the number of total cracks, the release of strain energy reduced, the plastic failure state weakened, and the spalling phenomenon slowed down. On this basis, the samples with 30° and 45° crack-crack combination were selected for further experimental investigation. Through comparative analysis between the experimental and simulation results, the failure strength and final failure mode with cracks propagation of samples were found to be relatively similar.

• The Journal of Advanced Prosthodontics
• /
• v.13 no.6
• /
• pp.351-360
• /
• 2021

PURPOSE. The aim of this study was to evaluate the efficiency of occlusal and interproximal adjustments of single implant crowns (SIC), comparing a digital cast-free approach (CF) and a protocol using 3D printed casts (PC). MATERIALS AND METHODS. A titanium implant was inserted at position of lower right first molar in a typodont. The implant position was scanned using an intraoral scanner and SICs were fabricated accordingly. Ten crowns (CF; n = 10) were subject to a digital cast-free workflow without any labside occlusal and interproximal modifications. Ten other identical crowns (PC) were adjusted to 3D printed casts before delivery. All crowns were then adapted to the testing model, simulating chair-side adjustments during clinical placement. Adjustment time, quantity of adjustments, and contact relationship were assessed. Data were analyzed using SPSS software (P < .05). RESULTS. Median and interquartile range (IQR) of clinical adjustment time was 02:44 (IQR 00:45) minutes in group CF and 01:46 (IQR 00:21) minutes in group PC. Laboratory and clinical adjustment time in group PC was 04:25 (IQR 00:59) minutes in total. Mean and standard deviation (±SD) of root mean squared error (RMSE) of quantity of clinical adjustments was 45 ± 7 ㎛ in group CF and 34 ± 6 ㎛ in group PC. RMSE of total adjustments was 61 ± 11 ㎛ in group PC. Quality of occlusal contacts was better in group CF. CONCLUSION. Time effort for clinical adjustments was higher in the cast-free protocol, whereas quantity of modifications was lower, and the occlusal contact relationship was found more favourable.

• Nuclear Engineering and Technology
• /
• v.54 no.5
• /
• pp.1754-1759
• /
• 2022

The activity of gamma-ray emitting nuclides is calculated assuming that each gamma-ray is detected individually; thus, the magnitude of the coincidence summing signal must be considered during activity calculations. Here, the correction factor for the coincidence summing effect was calculated, and the detection efficiencies of two HPGe detectors were compared. The CANBERRA Inc. GC4018 high-purity Ge detector provided an estimate for the peak-to-total ratio using a point source to determine the coincidence summing correction factor. The ORTEC Inc. GEM60 high-purity Ge detector uses EFFTRAN in LVis to obtain the parameters of the detector and source model and the gamma-gamma and gamma-X match estimates, in order to determine the coincidence summing correction factor. Nuclide analyses, radioactivity comparisons, and analyses of reference material samples were performed utilizing certified reference materials to accurately determine the detection efficiencies. For both Co-60 and Y-88, the detection efficiency for a point source increased by an average of at least 12-13%, whereas the detection efficiency determined using LVis increased by an average of at least 13-15%. The calculated radioactivity values of the certified reference material and reference material samples were accurate to within 3% and 6% of the measured values, respectively.

• Journal of Veterinary Science
• /
• v.21 no.4
• /
• pp.67.1-67.11
• /
• 2020

Background: Tibial tuberosity transposition (TTT) causes caudalization of the patellar ligament insertion in canine medial patellar luxation, which can lead to increases in patellofemoral contact pressure. Objectives: The purpose of this study is to confirm the effect of patellofemoral contact mechanics after craniolateral and caudolateral transposition of tibial tuberosity in normal canine hindlimbs. Methods: Craniolateral and caudolateral transposition of tibial tuberosity was performed in 5 specimens, respectively. The pressure was measured in the specimen before TTT, and then in the same specimen after TTT. In this process, data was obtained in 10 specimens. The measurement results were output as visualization data through the manufacturer's software and numerical data through spreadsheet. Based on these 2 data and the anatomical structure of the patellofemoral joint (PFJ) surface, whole measurement area was analysed by dividing into medial, lateral and central area. Results: In craniolateralization of tibial tuberosity, total, medial, central contact pressure was decreased and lateral contact pressure was not statistically changed lateral contact pressure than normal PFJ. In caudolateralization of tibial tuberosity, total, lateral contact pressure was increased and medial contact pressure was not statistically changed than normal PFJ. Although not statistically significant changed, central contact pressure in caudolateralization of tibial tuberosity was increased in all 5 specimens. Conclusions: These results imply that traditional TTT, prone to caudal shift of patellar tendon, can increase retropatellar pressure may lead to various complications and diseases of the stifle joint.

• Animal Bioscience
• /
• v.36 no.1
• /
• pp.53-62
• /
• 2023

Objective: In this study, metabolites that changed in the rumen fluid, urine and feces of dairy cows fed different feed ratios were investigated. Methods: Eight Holstein cows were used in this study. Rumen fluid, urine, and feces were collected from the normal concentrate diet (NCD) (Italian ryegrass 80%: concentrate 20% in the total feed) and high concentrate diet (HCD) groups (20%: 80%) of dairy cows. Metabolite analysis was performed using proton nuclear magnetic resonance (NMR) identification, and statistical analysis was performed using Chenomx NMR software 8.4 and Metaboanalyst 4.0. Results: The two groups of rumen fluid and urine samples were separated, and samples from the same group were aggregated together. On the other hand, the feces samples were not separated and showed similar tendencies between the two groups. In total, 160, 177, and 188 metabolites were identified in the rumen fluid, urine, and feces, respectively. The differential metabolites with low and high concentrations were 15 and 49, 14 and 16, and 2 and 2 in the rumen fluid, urine, and feces samples, in the NCD group. Conclusion: As HCD is related to rumen microbial changes, research on different metabolites such as glucuronate, acetylsalicylate, histidine, and O-Acetylcarnitine, which are related to bacterial degradation and metabolism, will need to be carried out in future studies along with microbial analysis. In urine, the identified metabolites, such as gallate, syringate, and vanillate can provide insight into microbial, metabolic, and feed parameters that cause changes depending on the feed rate. Additionally, it is thought that they can be used as potential biomarkers for further research on subacute ruminal acidosis.

• Journal of Society of Preventive Korean Medicine
• /
• v.26 no.2
• /
• pp.11-24
• /
• 2022

Objectives : This study was designed to investigate the effect of Banhahubak-tang on gastroesophageal reflux disease(GERD) through a systematic review and meta-analysis of randomized controlled trials(RCTs). Methods : RCTs using Banhahubak-tang on GERD was searched in databases such as EMBASE, PubMed, MEDLINE, CENTRAL, CNKI, KISS, RISS, ScienceON, and OASIS. RCTs published up to October 8th, 2021 were included. Meta-analysis was performed by synthesizing outcome data, including Total Effectiveness Rate (TER), Reflux Symptom Index(RSI), Reflux Finding Score(RFS), and Incidence of Adverse Reactions. RevMan 5.4 software was used for data analysis. The Cochrane collaboration bias risk assessment scale was used to evaluate the methodological quality of the included studies. Results : Ten RCTs met the inclusion criteria. The total effective rate was the most commonly used outcome measure. The meta-analysis revealed that the TER in the experimental group was higher than that of the control group(N=2, RR:1.22, 95% CI:1.09 to 1.36, P=0.0004, I²=0%)(N=6, RR:1.22, 95% CI:1.14 to 1.32, P<0.00001, I²=0%)(N=8, RR:1.22, 95% CI: 1.14 to 1.30, P<0.00001, I²=0%). On the other hand, RSI(N=2, MD : -4.29, 95% CI: -4.71 to -3.86, I²=94%), RFS(N=2, MD : -3.28, 95% CI: -3.71 to -2.85, I²=96%), and Incidence of Adverse Reactions(N=5, RR: 0.32, 95% CI: 0.17 to 0.61, I²=0%) in the experimental group were lower than that of the control group. Conclusion : Treatment with Banhahubak-tang was found to be effective on GERD. However the results might be biased because of the poor quality and small sample size of the included RCTs.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.32 no.6
• /
• pp.1183-1192
• /
• 2022

Information and Information processing systems must maintain a certain level of security during the total life cycle of Information. To maintain a certain level of security, security management processes are applied to software, automobile development, and the U.S. federal government information system over a life cycle, but theme of no similar security management process in Korea. This paper proposes a Korean-style security risk management framework to maintain a certain level of security in the total life cycle of information and information processing system in the defense sector. By applied to the defense field, we intend to present the direction of defense security work in the future and induce an shift in security paradigm.

• International Journal of Computer Science & Network Security
• /
• v.22 no.11
• /
• pp.213-221
• /
• 2022

Intelligent Character Recognition System for Account Payable (ICRS AP) Automation represents the process of capturing text from scanned invoices and extracting the key fields from invoices and storing the captured fields into properly structured document format. ICRS plays a very critical role in invoice data streamlining, we are interested in data like Vendor Name, Purchase Order Number, Due Date, Total Amount, Payee Name, etc. As companies attempt to cut costs and upgrade their processes, accounts payable (A/P) is an example of a paper-intensive procedure. Invoice processing is a possible candidate for digitization. Most of the companies dealing with an enormous number of invoices, these manual invoice matching procedures start to show their limitations. Receiving a paper invoice and matching it to a purchase order (PO) and general ledger (GL) code can be difficult for businesses. Lack of automation leads to more serious company issues such as accruals for financial close, excessive labor costs, and a lack of insight into corporate expenditures. The proposed system offers tighter control on their invoice processing to make a better and more appropriate decision. AP automation solutions provide tighter controls, quicker clearances, smart payments, and real-time access to transactional data, allowing financial managers to make better and wiser decisions for the bottom line of their organizations. An Intelligent Character Recognition System for AP Automation is a process of extricating fields like Vendor Name, Purchase Order Number, Due Date, Total Amount, Payee Name, etc. based on their x-axis and y-axis position coordinates.

• The Journal of Internal Korean Medicine
• /
• v.44 no.1
• /
• pp.12-34
• /
• 2023

Objective: This study was conducted to evaluate the effectiveness of the combination therapy of Yukmijihwang-tang and Western medicine on primary glomerulonephritis. Methods: We conducted a search using keywords, such as Yukmijihwang-tang and Liuwei Dihuang, in eight databases (CNKI, CiNii, Pubmed, Embase, Cochrane, Science On, OASIS, RISS). There was no limit to the publication period of the papers. A meta-analysis was conducted and classified according to the outcome measurements, such as the total effective rate (TER), serum creatinine (SCr), and blood urea nitrogen (BUN). Data analysis was performed using the RevMan 5.4.1 software, and Cochrane's risk of bias (ROB) was used to assess the quality of the papers. Results: A total of 12 randomized control trials were selected. The meta-analysis showed that the treatment group combining Yumijihwang-tang and Western medicine was more efficient than the control group using Western medicine alone (RR: 1.29, CI: 1.20 to 1.39 p=<0.00001). The treatment group also reduced the BUN (MD: -2.40, CI: -2.90 to -1.89, p<0.00001) and Scr (MD: -33.34, CI: -40.85 to -25.82, P<0.00001) more than the control group. Conclusion: This study suggests that the combination therapy of Yukmijihwang-tang with Western medicine is effective in treating primary glomerulonephritis. However, these findings should be interpreted cautiously due to the unknown or high risk of bias in the included trials.