• Applied Chemistry for Engineering
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• v.10 no.6
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• pp.913-916
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• 1999

Fluorine modified diisocyanate(FMD) was synthesized from tris(6-isocyanatohexyl)isocyanurate(TIHI) and N-ethyl-N-2-hydroxyethyl-perfluorooctanesulfonamide(HFA). Fluorine modified polyurethane(FMPU) was also synthesized from FMD and poly(tetramethylene) glycol(PTMG). Modified polyurethanes were made by blending FMPU into the polyester type base polyurethane(BPU). Surface and thermal properties of the blended BPU film was measured by contact angle measurement and DSC. As the amounts of FMPU was increased from 0 wt % to 1 wt %, the surface energy was dramatically decreased from 47.82 dyne/cm to 17.64 dyne/cm. But we observed little change of the contact angle with further increase in the amount of the FMPU up to 10 wt %. The data meant that the surface of the blended polyurethanes was hydrophobic due to the surface arrangement of the fluorine containing moiety in FMPU. Phase separation was induced by the incompatibility of FMPU and BPU for the samples having over 5 wt % of FMPU. The thermal analysis data of these samples showed the thermal behavior of the FMPU itself.

• KSBB Journal
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• v.21 no.3
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• pp.224-229
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• 2006

FEMLAB is a powerful interactive environment for modeling, solving all kinds of scientific and engineering problems based on partial differential equations(PDEs). Separation process of chiral compound in HPLC columns was simulated by FEMLAB. To study change of elution profile with isotherm models, non-competitive and competitive Langmuir adsorption isotherm were adopted. Separated material was (R, S)-ibuprofen [(R, S)-2-(4-isobutyl phenyl) propionic acid], an anti-inflammatory agent, which retain the pharmacological activity in the (S)-(+)-enantiomer. Sample concentrations were changed from 0.5 mg/ml to 2.0 mg/ml at a flow rate of 1 ml/min and flow rate varied from 1 ml/min to 3 ml/min at an ibuprofen concentration of 2.0 mg/ml and $20{\mu}l$ of injection volume. Simulated results were well fitted with experimental data.

• The Korea Journal of Herbology
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• v.33 no.4
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• pp.101-108
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• 2018

Objectives : This study aimed to effects antioxidant activity of citrus peel extract (CPE) and effect on its glucose metabolism in L6 rat skeletal muscle cells. Methods : Antioxidative activities were evaluated by using 10 kinds of natural materials, and total polyphenol and flavonoid contents were examined. The L6 muscle cells toxicity of CPE was examined by MTT assay. Expression of glucose-related genes in L6 muscle cells by CPE treatment was analyzed by real-time PCR and western blotting. Results : The $IC_{50}$ values of DPPH and ABTS free radical scavenging activity of CPE were ($15.47{\pm}0.26{\mu}g/m{\ell}$ and $12.07{\pm}1.23{\mu}g/m{\ell}$, respectively), effectively clearing DPPH and ABTS. CPE showed total polyphenol and flavonoid contents ($20.30{\pm}0.38$ and $64.20{\pm}0.52$, respectively). The selected CPE were used in experiments using an effective concentration that is not toxic in L6 muscle cells. We investigated insulin receptor substrate-1 (IRS-1), phosphatidylinositol 3-kinase regulatory (PI3KR), Akt, and glucose transporter 4 (GLUT4). mRNA analysis by realtime PCR showed no significant difference, but CPE-treated cells showed a tendency to increase in concentration-dependent manner. However, analysis of protein expression of Akt and GLUT4 by western blotting showed that CPE treatment significantly increased concentration dependent (p<0.001). Conclusions : As a result, citrus peel extract with high antioxidant activity regulates glucose metabolism in L6 muscle cells. Therefore, CPE can be a potential treatment for the treatment of diabetes.

• Korean Journal of Environmental Biology
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• v.39 no.1
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• pp.119-135
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• 2021

Korea has stepped up efforts to investigate and catalog its flora and fauna to conserve the biodiversity of the Korean Peninsula and secure biological resources since the ratification of the Convention on Biological Diversity (CBD) in 1992 and the Nagoya Protocol on Access to Genetic Resources and the Fair and Equitable Sharing of Benefits (ABS) in 2010. Thus, after its establishment in 2007, the National Institute of Biological Resources (NIBR) of the Ministry of Environment of Korea initiated a project called the Korean Indigenous Species Investigation Project to investigate indigenous species on the Korean Peninsula. For 15 years since its beginning in 2006, this project has been carried out in five phases, Phase 1 from 2006-2008, Phase 2 from 2009-2011, Phase 3 from 2012-2014, Phase 4 from 2015-2017, and Phase 5 from 2018-2020. Before this project, in 2006, the number of indigenous species surveyed was 29,916. The figure was cumulatively aggregated at the end of each phase as 33,253 species for Phase 1 (2008), 38,011 species for Phase 2 (2011), 42,756 species for Phase 3 (2014), 49,027 species for Phase 4 (2017), and 54,428 species for Phase 5(2020). The number of indigenous species surveyed grew rapidly, showing an approximately 1.8-fold increase as the project progressed. These statistics showed an annual average of 2,320 newly recorded species during the project period. Among the recorded species, a total of 5,242 new species were reported in scientific publications, a great scientific achievement. During this project period, newly recorded species on the Korean Peninsula were identified using the recent taxonomic classifications as follows: 4,440 insect species (including 988 new species), 4,333 invertebrate species except for insects (including 1,492 new species), 98 vertebrate species (fish) (including nine new species), 309 plant species (including 176 vascular plant species, 133 bryophyte species, and 39 new species), 1,916 algae species (including 178 new species), 1,716 fungi and lichen species(including 309 new species), and 4,812 prokaryotic species (including 2,226 new species). The number of collected biological specimens in each phase was aggregated as follows: 247,226 for Phase 1 (2008), 207,827 for Phase 2 (2011), 287,133 for Phase 3 (2014), 244,920 for Phase 4(2017), and 144,333 for Phase 5(2020). A total of 1,131,439 specimens were obtained with an annual average of 75,429. More specifically, 281,054 insect specimens, 194,667 invertebrate specimens (except for insects), 40,100 fish specimens, 378,251 plant specimens, 140,490 algae specimens, 61,695 fungi specimens, and 35,182 prokaryotic specimens were collected. The cumulative number of researchers, which were nearly all professional taxonomists and graduate students majoring in taxonomy across the country, involved in this project was around 5,000, with an annual average of 395. The number of researchers/assistant researchers or mainly graduate students participating in Phase 1 was 597/268; 522/191 in Phase 2; 939/292 in Phase 3; 575/852 in Phase 4; and 601/1,097 in Phase 5. During this project period, 3,488 papers were published in major scientific journals. Of these, 2,320 papers were published in domestic journals and 1,168 papers were published in Science Citation Index(SCI) journals. During the project period, a total of 83.3 billion won (annual average of 5.5 billion won) or approximately US $75 million (annual average of US $5 million) was invested in investigating indigenous species and collecting specimens. This project was a large-scale research study led by the Korean government. It is considered to be a successful example of Korea's compressed development as it attracted almost all of the taxonomists in Korea and made remarkable achievements with a massive budget in a short time. The results from this project led to the National List of Species of Korea, where all species were organized by taxonomic classification. Information regarding the National List of Species of Korea is available to experts, students, and the general public (https://species.nibr.go.kr/index.do). The information, including descriptions, DNA sequences, habitats, distributions, ecological aspects, images, and multimedia, has been digitized, making contributions to scientific advancement in research fields such as phylogenetics and evolution. The species information also serves as a basis for projects aimed at species distribution and biological monitoring such as climate-sensitive biological indicator species. Moreover, the species information helps bio-industries search for useful biological resources. The most meaningful achievement of this project can be in providing support for nurturing young taxonomists like graduate students. This project has continued for the past 15 years and is still ongoing. Efforts to address issues, including species misidentification and invalid synonyms, still have to be made to enhance taxonomic research. Research needs to be conducted to investigate another 50,000 species out of the estimated 100,000 indigenous species on the Korean Peninsula.

• Clinical and Experimental Pediatrics
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• v.51 no.1
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• pp.26-32
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• 2008

Purpose : This study was to provide the methods of developing the growth charts and the blood pressure nomogram among Korean children and adolescents. Methods : The growth charts were developed based on the data from the national growth surveys for children and adolescents in 1998 and 2005. The percentile charts were developed through two stages. At the first stage, the selected empirical charts were smoothed through several fitting procedures including parametric and non-parametric methods. At the second stage, a modified LMS (lambda, mu, sigma) statistical procedure was applied to the smoothed percentile charts. The LMS procedure allowed to estimate any percentile and to calculate standard deviation units and z-scores. The charts for weight-for-age, height-for-age, BMI-for-age, weight-for-height and head circumference-for-age were developed by sex. Age and normalized height controlled sex-specific nomograms of systolic and diastolic blood pressure were developed by a fixed effect model of general regression using the data from 2005 national growth survey. Results : The significant systemic differences between the percentiles of growth charts and the empirical data were not found. The final output of the study is available from Korean Center for Disease Control and Prevention homepage, http://www.cdc.go.kr/webcdc/. Blood Pressure nomogram was tabulated by height percentiles and age using the regression coefficients analyzed with regression model. Conclusion : 2007 growth charts and blood pressure nomogram were the first products based on the statistical modeling using the national survey data. The further study on the methodology including data collection, data cleaning and statistical modeling for representative growth charts would be needed.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.39 no.1
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• pp.79-87
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• 2015

This paper proposes a floating-type wave energy conversion system that consists of a mechanical part (yo-yo vibrating system, motion rectifying system, and power transmission system) and electrical part (power generation system). The yo-yo vibrating system, which converts translational input to rotational motion, is modeled as a single degree-of-freedom system. It can amplify the wave input via the resonance phenomenon and enhance the energy conversion efficiency. The electromechanical model is established from impedance matching of the mechanical part to the electrical system. The performance was analyzed at various wave frequencies and damping ratios for a wave input acceleration of 0.14 g. The maximum output occurred at the resonance frequency and optimal load resistance, where the power conversion efficiency and electrical output power reached 48% and 290 W, respectively. Utilizing the resonance phenomenon was found to greatly enhance the performance of the wave energy converter, and there exists a maximum power point at the optimum load resistance.

• The korean journal of orthodontics
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• v.27 no.5 s.64
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• pp.825-837
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• 1997

The purpose of this study was to evaluate the effect of splinting methods on the rearrangement of periodontal fibers after experimental tooth movement. Orthodontic force was applied by placing closed coil spring between upper third incisor and canine in seven dogs, weighing 20 kg or more. After 3 weeks of force application, 0.0215 inch multistrand wire and polyethylene ribbon were bonded to each side, as a flexible and rigid splinting respectively in 6 experimental animals. The remaining one served as a control. Each two animals were sacrificed at 4, 8 and 12 weeks after splinting respectively and prepared histologically for hematoxylin-eosin and Masson's trichrome staining. The results of this study were obtained as follows: 1. After tooth movement, periodontal space was narrowed and periodontal titers were thick on pressure side while elongated fibers were observed on tension side. 2. After 4 weeks of retention, the rearrangement of periodontal fibers was observed in the flexible splinting group, but not in the rigid splinting group. 3. After 8 weeks of retention, the rearrangement of periodontal titers was observed in both groups, but the difference could not be detected between two groups. 4. During the retention period, the rearrangement of periodontal fibers was faster in tension side than in pressure side. These results show that the rearrangement of periodontal fibers is also obtained by rigid splinting after tooth movement. It is suggested that the rigid splinting by polyethylene ribbon can be used as a way of postorthodontic retention.

• Journal of Pharmacopuncture
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• v.11 no.3
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• pp.113-122
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• 2008

Objective: The purpose of this study was to invigorate the use of infrared thermal imaging apparatus as a diagnostic tool in Oriental medicine by providing standard temperature on specific acupoints. Methods: Subjects for the study was recruited through an advertisement in the school homepage(www.sangji.ac.kr) explaining the objectives and methods. 100 volunteers agreeing to terms were selected and measured the full body thermal image. Common acupoints used in the clinical surrounding were chosen and final 63 acupoints were selected for the measurement. Male/female and right/left readings were obtained for the analysis. Results: Following results were obtained from analyzing the body temperature of 50 male subjects and 50 female subjects 1. Subjects participating in the study ranged from 19 years of age to 44 years. Median male age at $26.86{\pm}6.02$ and female age at $22.88{\pm}2.74$, respectively. 2. For all acupoints, no significant differences were witnessed between the gender and right, left side of the body. 3. 10 acupoints from the facial region(18 bilateral), 8 acupoints from the chest/abdomen region(10 bilateral), 6 acupoints from the back region(11 bilateral), 17 acupoints from the upper extremity(34 bilateral), and 22 acupoints from the lower extremity(44 bilateral) were chosen. 4. In the facial region, BL2 showed the highest temperature and GV26 showed the lowest. 5. In the chest/abdomen region, CV22 showed the highest temperature and CV6 showed the lowest. 6. In the back region, GV14 showed the highest temperature and BL23 showed the lowest. 7. In the upper extremity region, jianqian(extra point) showed the highest temperature and baxie(extra point) showed the lowest. 8. In the lower extremity region, KI1 and bafeng(extra point) shoed the highest temperature and BL40 showed the lowest. Conclusions: Based on the standard body temperature measured on specific acupoints throughout the body, we hope these findings can trigger further studies on applications of infrared thermal imaging and clinical usage in the field of oriental medicine.

• Journal of Navigation and Port Research
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• v.43 no.6
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• pp.403-412
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• 2019

The characteristics of the manoeuvring motion of a ship are dependent on the ship type, as well as draft or speed in the same ship. In recent years, the number of extra-large vessels has increased significantly, which can cause enormous material and environmental damage in the event of a marine accident. Thus, the importance of ship maneuvering is increasing. The IMO has forced the officers to be trained in simulators through the STCW 95 amendment. However, FMSS is costly and difficult to access and the PC-based simulator has the disadvantage that only one person can engage in simulation. The purpose of this study was to solve the shortcomings of the FMSS and PC-based simulators by enabling multiple people to use their PCs to simulate based on a network. The simulator is implemented through the analysis and numerical calculation of the Nomoto model, Radar function mounting, data transfer protocol design, and GUI building. To verify the simulator, the simulation results were compared and analyzed with the test results of T.S. HANBADA according to the criteria of the Korean Register of Shipping(KR) and IMO standards for ship maneuverability. As a result, It showed a relative error of 0%~ 32.1% with an average of 13.7%, and it satisfied the IMO criteria for ship maneuverability.

• Journal of Korean Home Economics Education Association
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• v.22 no.2
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• pp.1-13
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• 2010

This study was planned to provide basic information to help teachers guide lookism-prone students in their home and school life, and to guide them in the unit relating to clothing in school curriculums. To carry out this experiment questionnaires were administered to 481 students in their first and second year in middle and high schools in Gwangju city. The questionnaires are composed of 3 themes; 'general matters', 'attitudes about and recognition of appearance management' and 'school adaptation'. The collected data was analyzed with Component analysis(Varimax rotation) and Cronbach's ${\alpha}$, T-test, one-way ANOVA, Duncan-test, Pearson's correlation analysis and multiple regression analysis using the SPSS WIN 14.0(Kr). The results of this study were as follows; 1. The more they managed their behavior relating to appearance and cleanliness, the better they felt their friendships. 2. The less they concentrated management relating to appearance, the better they felt about their relationships with their teachers. 3. The less they concentrated management relating to appearance but the more they managed cleanliness the easier they adjusted to school rules. 4. The less they pursued a trendy appearance but the more they managed cleanliness, the better they studied.