• Bulletin of the Korean Chemical Society
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• v.23 no.12
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• pp.1773-1777
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• 2002

Reactive oxygen species(ROS) have been investigated to have pivotal roles on amyloidogenecity of $\beta-amyloidpeptide(A\beta)$, the major component of senile plaques in Alzheimer's disease(AD) brain. Addition of radical scavengers is one of the on-going strategies for therapeutic treatment for AD patients. Hsp104 protein including two ATP binding sites from Saccharomyces cerevisiae, as a molecular chaperone, was known to function as a protector of ROS generation when exposed to oxidative stress in our previous study. This observation has led us to investigate Hsp104 protein as a molecular mediator of $A{\beta}$ aggregation in this study. We have developed a new way of expression for Hsp104 protein using GST-fusion tag. As we expected, formation of $A{\beta}$ aggregate was protected by wild type Hsp104 protein, but not by the two ATP-binding site mutant, based on Thioflavin-T fluorescence. Interestingly, Hsp104 protein was observed to keep $A{\beta}$ from forming aggregates independent of ATP binding. On the other hand, disaggregation of $A{\beta}$ aggregates by wild type Hsp104 was totally dependent on the presence of ATP. On the other hand, mutant Hsp104 with two ATP binding sites altered exhibited no inhibition. Another effective antioxidant, hydrazine analogs of curcumin were also effective in $A{\beta}$ fibrilization as protectors against oxidative stress. Based on these observations we conclude that Hsp104 and curcumin derivatives, as protectors of oxidative stress, inhibit $A{\beta}$ aggregation in virto and can be candidates for therapeutic approaches in cure of some neurodegenerative disease.

• The KIPS Transactions:PartD
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• v.17D no.2
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• pp.147-156
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• 2010

Conformance testing for embedded software is to check whether software was correctly implemented according to software specification or not. In conformance testing, test scenarios must be extracted to cover every test cases of software. In a general way, test scenarios simply focus on testing all functions at least one time. But, test scenarios are necessary to consider efficiency of test execution. In this paper, we propose a test scenario extraction method by considering function's execution time and waiting time for user interaction. A test model is a graph model which is generated from state machine diagram and test cases in software specification. The test model is augmented by describing test execution time and user interaction information. Based on the test model, test scenarios are extracted by a modified Dijkstra's algorithm. Our test scenario approach can reduce testing time and improve test automation.

• Journal of Digital Convergence
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• v.11 no.10
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• pp.493-505
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• 2013

We investigated the effect of red ginseng extracts on blood biochemical parameters, bone density and bone inorganic components etc. and data were analyzed by one-way ANOVA and Post-Hoc Test. In the results of our study, the level of albumin and HDL, Ca, P, Mg, and estradiol in blood, and the content of Ca, P, ash in femur were significantly increased in red ginseng treated group than in OVX group, and the level of ALP, AST, ALT, blood glucose, total cholesterol, triglyceride, LDL, creatinine, osteocalcin, and N-terminal telopeptide were significantly decreased in red ginseng treated group than in OVX group (p < 0.01). From these results, we knew that within the normal level, red ginseng extracts improved liver and kidney function, component of glucose and lipid in blood, bone density, bone ash and inorganic components in femur, and index related with bone metabolism.

• Journal of Dental Rehabilitation and Applied Science
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• v.31 no.2
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• pp.96-103
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• 2015

Purpose: The purpose of this study was to spectrophotometrically evaluate the influence of porcelain layer thickness and substructure. Materials and Methods: Four groups of porcelain specimens (metal and ceramic substructure) was prepared for analysis. Color parameters were measured with spectrophotometer and color difference (${\Delta}E*$) were calculated. T-test and one-way ANOVA test were used to find out significant difference and Tukey test was used to identify where the difference ware. Results: Increasing the thickness of porcelain decreased values (P < 0.05). Increasing the thickness of porcelain on ceramic substructure decreased the $a^*$ (P < 0.05) but, the $b^*$ were not statistically different. Total color difference (${\Delta}E*$) were below 1 when the difference of porcelain thickness were 0.5 mm. Conclusion: The thickness of porcelain are the factor effecting on color. This study will help the color are controlled by changing the thickness of porcelain clinically.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.3B
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• pp.220-230
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• 2011

Mobile RFID which integrates mobile network with RFID technique is the technique to get the information of products by transmitting the identifier through mobile network after reading the identifier of RFID tag. It attached on the equipment as the mobile phone. However, mobile RFID has the privacy-related problem among requested secure problems required from the existing RFID. In this paper, the random key created by mobile RFID reader and Tag during the inter-certificating and initialization procedure for mobile RFID users to receive tag information from backend server securely is divided into random sizes and any information on the tag which requires the protection of privacy shouldn't be provided to anyone. In performance analysis, previous protocol used modulo operation in registration and login computation. But the proposed protocol has higher efficiency in saving space and computation volume than MARP scheme and Kim. et. al scheme because our protocol is accomplished by mutual authentication and registering user information through one-way hash function.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.29 no.6
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• pp.1413-1424
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• 2019

Cryptocurrency has limitations to be used as an actual payment method due to the scalability problem of the blockchain consensus protocol, and various off-chain solutions to solve these limitations are being studied. In this paper, we design an efficient off-chain payment channel using one-way hash function and implement the designed payment channel using Ethereum smart contract. In addition, the experiment was conducted to measure and analyze execution time and cost for each method by deploying it in the same environment as the previously implemented plasma MVP. As a result, compared with plasma MVP, the proposed solution was able to reduce the total cumulative time by about 34% and reduce the overall execution cost by about 41%.

• Archives of design research
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• v.12 no.4
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• pp.23-32
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• 1999

The 'Hard Matte' was the method being wide-screen to the directors wanted more vivid and made real films to the audience at the beginning of cinematography. The hard matte have changed as unique device in films as opening and closing credit titles making impressions which being captured strongly to the people at the time the wide-screen has developed. In HDTV has invented in NHK the hard matte is called 'letter box style and on music video channel we can see the style as easily. That kind of hard matte images on music video have effected to commercial films are seen recently. But some of commercial films have problems like only expending horizontal way. The hard matte is one of important ways that could regulate the art contents with art form. Korean film image makers as directors and production designers must know the role and function of hard matter has arranged reasonable in foreign films.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.2
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• pp.445-451
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• 2014

Dual LED lantern, which is composed of two light sources in one lantern, can be utilized as an auxiliary light source when the main light source is in trouble. Nevertheless, there are no way to obtain status information of the system and control the light source if the current domestic standard protocol is applied, since the standards for dual LED lantern are not defined yet. Regarding to this problem, we suggested expanded lantern protocol for management system of dual LED lantern based on current domestic standard. Also, we confirmed the normal operation of dual LED lantern after implementing suggested protocol on the developed management system. Control system suggested and implemented in this study is tested not only its function of controlling and acquiring the operating status of dual LED lantern, but also its capability to utilize as a control system of currently used LED lanterns.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.10
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• pp.6242-6249
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• 2014

The aim of this study was to determine the physical performance and fear of falls in the community dwelling elderly and to investigate how the factors were connected to one another. The data was collected between January 3rd and March 30th, 2014 from 460 elderly people, aged 65 or older, who agreed to participate in this study. The data was sampled among the elders' assistants as a way of responding to the questionnaire after being read. The study scales were composed of the demographic characteristics, physical function and fear of falls. A total of 139 (30.2%) subjects had experienced a fall. The results showed a positive correlation with the chair rise, standing on the leg, pick up a penny from floor, timed up and go test, and fear of falls. Multiple linear regression analysis showed that a predictor of the fear of falls were chair rise and timed up and go test. A combination of physical performance accounted for 16.9% of the fear of fall. Based on the findings of this study, it is useful to more effectively develop fall prevention and intervention programs in a future study.

• Restorative Dentistry and Endodontics
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• v.42 no.1
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• pp.27-33
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• 2017

Objectives: To determine the optimal timing for post space preparation of root canals sealed with epoxy resin-based AH Plus sealer in terms of its polymerization and influence on apical leakage. Materials and Methods: The epoxy polymerization of AH Plus (Dentsply DeTrey) as a function of time after mixing (8, 24, and 72 hours, and 1 week) was evaluated using Fourier transform infrared (FTIR) spectroscopy and microhardness measurements. The change in the glass transition temperature ($T_g$) of the material with time was also investigated using differential scanning calorimetry (DSC). Fifty extracted human single-rooted premolars were filled with gutta-percha and AH Plus, and randomly separated into five groups (n = 10) based on post space preparation timing (immediately after root canal obturation and 8, 24, and 72 hours, and 1 week after root canal obturation). The extent of apical leakage (mm) of the five groups was compared using a dye leakage test. Each dataset was statistically analyzed by one-way analysis of variance and Tukey's post hoc test (${\alpha}=0.05$). Results: Continuous epoxy polymerization of the material with time was observed. Although the $T_g$ values of the material gradually increased with time, the specimens presented no clear $T_g$ value at 1 week after mixing. When the post space was prepared 1 week after root canal obturation, the leakage was significantly higher than in the other groups (p < 0.05), among which there was no significant difference in leakage. Conclusions: Poor apical seal was detected when post space preparation was delayed until 1 week after root canal obturation.