• Restorative Dentistry and Endodontics
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• v.32 no.2
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• pp.87-94
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• 2007

This study was done to evaluate transportation of the apical foramen after 0.5 mm overinstrumentation by ProFile, ProTaper and $K^3$ in simulated resin root canal. Sixty simulated resin root canal with a curvature of J and S-shape were divided into two groups. Each group consisted of three subgroups with 10 blocks according to the instruments used: $ProFile^{(R)},\;ProTaper^{TM},\;and\;K^{3TM}$. Simulated resin root canal was prepared by ProFile, ProTaper and $K^3$ with 300 rpm by the crown-down preparation technique. Pre- and post-instrumentation apical foramen images were overlapped and recorded with Image-analyzing microscope 100X (Camcope, Sometech Inc, Korea). The amounts of difference in width and dimension on overlapped images were measured after reference points were determined by Image Analysis program ($Image-Pro^{(R)}$ Express, Media Cybernetic, USA). Data were analyzed using Kruskal-Wallis and Mann-Whitney U-test. The results suggest that ProFile showed significantly less canal transportation and maintained original apical foramen shape better than $K^3$ and ProTaper.

• Journal of Food Hygiene and Safety
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• v.25 no.2
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• pp.143-147
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• 2010

Chronic exposure to Arsenic (As) causes significant human health effects including various cancers. Total As concentrations from 300 polished rice samples cultivated near the mining areas in Korea were analyzed to estimate a probabilistic assessment of human health risk from As-contaminated rice. The mean of total As concentrations in rice was 0.09 mg/kg and lognormal distribution model was set for total As concentrations. Human health risk for As in rice was estimated using gender-specific rice consumption data and average daily dose (ADD). While cancer risk (CR) and hazard quotient (HQ) were calculated using oral cancer slope factor (OCSF) and Reference dose (RfD) suggested by the U.S. EPA. Mean of CR posed by total As was 2.16 (for male) and 1.83 (for female) per 10,000. The HQ for general population from rice cultivated near the mining areas in Korea was below 1 as the $50^{th}$ percentile of general population. However, less than 10% of general population consuming rice cultivated near the mining areas would exceed 1.0. This result is similar with those from each gender-specific group.

• Journal of Life Science
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• v.27 no.2
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• pp.194-201
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• 2017

Rapeseed (Brassica napus L.) is an oil crop classified as Brassicaceae, and it is widely grown worldwide. To develop a drought-resistant rapeseed, the ${\beta}$-glucosidase 1 (AtBG1) gene was introduced into rapeseed because drought- and salt-resistance phenotypes were observed when the AtBG1 gene was overexpressed in arabidopsis. Newly developed genetically modified crop must be proved to be safe. Safety assessments are based on the historical usage and scientific reports of a crop. In this study, we examined the potential acute oral toxicity of AtBG1 protein expressed in genetically modified (GM) rapeseed and calculated the minimum lethal dose at 6 weeks in both male and female ICR mice. AtBG1 protein was fed at a dose of 2,000 mg/kg body weight in five male and five female mice according to the marginal capacity concentration of OECD, 2,000 mg/15 ml/kg. Mortalities, clinical findings, and body weight changes were monitored for 14 days after dosing, and postmortem necropsy was performed on day 14. This study showed that no deaths occurred in the test group, and AtBG1 protein did not result in variations in common symptoms, body weight, and postmortem findings between the two groups. This showed that the minimum lethal dose of AtBG1 protein expressed in transgenic rapeseed exceed 2,000 mg/kg body weight in both sexes.

• Journal of the korean academy of Pediatric Dentistry
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• v.34 no.1
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• pp.99-105
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• 2007

In clinical practice, air bubbles trapped in the pit and fissure may increase early loss of sealing materials for fracture, wear and microleakage. The purpose of this investigation was to examine the bubble behavior of pit and fissure sealant. The 140 replicas made of epoxy resin were used to this experiment. Following conditioning, light-polymerized sealants were applied and then exposed to the light source. After stereoscopic examination of standarized specimen by grinding, bubble behavior was analysed. The results obtained were as follows; 1. Ultraseal $XT^{(R)}$ plus grops irrespective of using time were higher than groups of $Helioseal^{(R)}$ with clinpro tip and metal tip in the frequency of bubble(p<0.05), 2. Ultraseal $XT^{(R)}$ plus old group was more than $Clinpro^{(R)}$, Teethmate $F-l^{(R)}$ and $Helioseal^{(R)}$ with brush tip in the number of bubble under 200 magnified cross section(p<0.05). 3. The widest mean area of bubble was shown in the Teethmate $F-1^{(R)}$. 4. No statistically significant difference of the frequency and the site of bubble between $Clinpro^{(R)}$ and $Helioseal^{(R)}$ groups(p>0.05).

• Journal of the Korea Society of Computer and Information
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• v.17 no.4
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• pp.1-9
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• 2012

As we are turnning into the aged society, accidents by falling down are increasing in the aged people's group. In this paper, we design the system with the 3-Axis acceleration sensor which is composed by a single chip. The body activity signal is measured with the signal detector and RF communicator in this proposed system and the and falling by the entering signal pattern analysis with 3-Axis acceleration sensor. For the RF communication, we are using nRF24L01p and 8bits ATmega uC for the processor. The error of energy expenditure estimation between motor driven treadmill and proposed a body activity module was 7.8% respectively. Human activities and falling is monitored according to analyze and judge the critical value of the Signal Vector. as falled down if they don't turn off the alarm after specific period and the aged person's after falling down activities are their position and more.

• Food Science and Preservation
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• v.24 no.2
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• pp.196-205
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• 2017

This study was conducted to increase the functionality of Korean traditional beverage, Sikhye. The Sikhye were prepared by supplementation up to 20% of Seomaeyaksuk extract (SE) and saccharification for five hours (h). During the saccharification, turbidity of SE-added Sikhye (SES) was the highest at two hours of saccharification and then lowered gradually. L vlaue of SES did not show significant difference feduring saccharification, and both a and b value of Sikhye were increased as saccharification time passed and SE addition ratio was increased. The pH before saccharification was not significantly different by SE addition ratio but it was increased to 5.68-5.73 at 5 h saccharification. Soluble solid, total sugar and reducing sugar contents were enhanced as saccharification time and SE addition ratio were increased. The total phenolic compounds contents and DPPH radical scavenging activity showed a similar trend by saccharification time and SE addition. In sensory test, the evaluations of 5% SES and control were not significant different, but 20% SES group showed significant lower evaluation than other groups because strong color and mugwort flavor. From all of these results, physicochemical characteristics and antioxidant activity of SES was improved by SE addition but sensory characteristics was lower. Acceptable addition ratio of SE in Sikhye is determined to be within 15%.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.11 no.2
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• pp.157-163
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• 2017

The aim of the study is to examine the reliability and validity of UFOV, which is a visual driving evaluation tool that has been proven to be reliable and valid in western countries, for the purpose of adapting the tool in a systematic manner to the South Korean population. Two evaluator assessed 23 healthy and 19 stroke patients with UFOV, Trail Making Test A & B(TMT A & B) and Motor Free Visual Perception Test(MVPT) from 7 October 2014 to 25 November, 2014. The researcher analyzed inter-rater reliability, correlation between raters of UFOV with Intraclass correlation coefficient, test-retest reliablility, UFOV with spearman correlation coefficient, concurrent validity, UFOV, TMT A & B and MVPT with spearman correlation coefficient, and discriminative validity, comparison mean scores of UFOV between groups, healthy and stroke with Mann-Whitney U test. UFOV score of participants with stroke had lower compared to the healthy control group. The inter-rater reliability(p<.001), test-retest reliability(p<.01) and concurrent validity(p<.01) was statistically significant. Also discriminant validity was statistically significant(p<.001). Based on this study, Use of UFOV for drivers at risk is essential to prevent future traffic accidents and support driving rehabilitation.

• Journal of Digital Convergence
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• v.10 no.11
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• pp.47-58
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• 2012

This study selects political and military decision factors of Participatory Government's Wartime Operational Control(OPCON) Transition and analyzes, both quantitatively and qualitatively, the effects and relations between those factors. Previous research utilizing the Analytic Hierarchy Process(AHP) selected their decision factors based on academic data and field experience, requiring more objective analysis of the factors. For this study, we conducted a survey among security subject matter experts(SME) both online and offline. The results show that OPCON transition's decision factors were to 'recover military sovereignty', 'set the conditions for peaceful reunification' and 'improve ROK image through enhancing national power' which differs little from the previous AHP method studies. It also showed that 'recover military sovereignty' and 'set the conditions for peaceful reunification' had no relationship to each other and that the key factor that decided the OPCON Transition was actually 'recover military sovereignty' which represents the interest of the liberal party in ROK. This study finds its meaning by analyzing the decision factors of Participartory Government's OPCON Transition thorugh Delphi and DEMATEL method.

• Journal of Microbiology and Biotechnology
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• v.22 no.3
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• pp.292-300
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• 2012

We report the expression, purification, and characterization of L-asparaginase (AnsA) from Rhizobium etli. The enzyme was purified to homogeneity in a single-step procedure involving affinity chromatography, and the kinetic parameters $K_m$, $V_{max}$, and $k_{cat}$ for L-asparagine were determined. The enzymatic activity in the presence of a number of substrates and metal ions was investigated. The molecular mass of the enzyme was 47 kDa by SDS-PAGE. The enzyme showed a maximal activity at $50^{\circ}C$, but the optimal temperature of activity was $37^{\circ}C$. It also showed maximal and optimal activities at pH 9.0. The values of $K_m$, $V_{max}$, $k_{cat}$, and $k_{cat}/K_m$ were $8.9{\pm}0.967{\times}10^{-3}$ M, $128{\pm}2.8$ U/mg protein, $106{\pm}2s^{-1}$, and $1.2{\pm}0.105{\times}10^4M^{-1}s^{-1}$, respectively. The L-asparaginase activity was reduced in the presence of $Mn^{2+}$, $Zn^{2+}$, $Ca^{2+}$, and $Mg^{2+}$ metal ions for about 52% to 31%. In addition, we found that $NH_4{^+}$, L-Asp, D-Asn, and ${\beta}$-aspartyl-hydroxamate in the reaction buffer reduced the activity of the enzyme, whereas L-Gln did not modify its enzymatic activity. This is the first report on the expression and characterization of the L-asparaginase (AnsA) from R. etli. Phylogenetic analysis of asparaginases reveals an increasing group of known sequences of the Rhizobial-type asparaginase II family.

• Journal of the Korea Convergence Society
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• v.8 no.3
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• pp.245-252
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• 2017

The purpose of this study is to analyze the effects of mergers and acquisitions of domestic IT companies on strategic aspects of internal capacity enhancement. Empirical analysis applied to this study analyzed the business performance in the market through the merger of Daum Communications and Kakao Group. After Daum pursued the merger with Kakao, it showed that the platform business of kakao is expanding to the domain of the existing portal site. The merger was completed, and the total value of the stocks went up to the highest level, but soon its value declined. The merger shows that the growth potential of the enterprise is temporarily declining, which seems to be the internal cost of the merger. Even in the case of profitability, the merger did not show positive results. In the case of stability, the expectation due to the merger was reflected and slightly increased. The following two companies were interested in the kakao when they viewed the merger through a chronological analysis. However, after the merger, the interest of the next kakao was similar. This is seen as a result of the expansion of kakao's diverse platform business rather than the following search sites. From the results of this study, it is suggested that domestic IT companies should approach by analyzing the strategic factors that generate synergy when pursuing M & A to strengthen their resources or capabilities.