• Journal of the Korean Society for Nondestructive Testing
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• v.26 no.4
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• pp.211-219
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• 2006

The UET(ultrasound excited thermography) for the ,eat-time diagnostics of the object employs an infrared camera to image defects of the surface and subsurface which are locally heated using high-frequency putted ultrasonic excitation. The dissipation of high-power ultrasonic energy around the feces of the defects causes an increase In temperature. The defect's image appears as a hot spot (bright IR source) within a dark background field. The UET for nondestructive diagnostic and evaluation is based on the image analysis of the hot spot as a local response to ultrasonic excited heat deposition. In this paper the applicability of VET for fast imaging of defect is described. The ultrasonic energy is injected into the sample through a transducer in the vertical and horizontal directions respectively. The voltage applied to the transducer is measured by digital oscilloscope, and the waveform are compared. Measurements were performed on four kinds of materials: SUS fatigue crack specimen(thickness 14mm), PCB plate(1.8 mm), CFRP plate(3 mm) and Inconel 600 plate (1 mm). A high power ultrasonic energy with pulse durations of 250ms Is injected into the samples in the horizontal and vertical directions respectively The obtained experimental result reveals that the dissipation loss of the ultrasonic energy In the vertical injection is less than that in the horizontal direction. In the cafe or PCB, CFRP, the size of hot spot in the vortical injection if larger than that in horizontal direction. Duration time of the hot spot in the vertical direction is three times as long as that in the horizontal direction. In the case of Inconel 600 plate and SUS sample, the hot spot in the horizontal injection was detected faster than that in the vertical direction

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.18 no.4
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• pp.234-265
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• 2013

Oceanic current maps in the secondary school science and earth science textbooks have played an important role in piquing students's inquisitiveness and interests in the ocean. Such maps can provide students with important opportunities to learn about oceanic currents relevant to abrupt climate change and global energy balance issues. Nevertheless, serious and diverse errors in these secondary school oceanic current maps have been discovered upon comparison with up-to-date scientific knowledge concerning oceanic currents. This study presents the fundamental methods and strategies for constructing such maps error-free, through the unification of the diverse current maps currently in the textbooks. In order to do so, we analyzed the maps found in 27 different textbooks and compared them with other up-to-date maps found in scientific journals, and developed a mapping technique for extracting digitalized quantitative information on warm and cold currents in the East Sea. We devised analysis items for the current visualization in relation to the branching features of the Tsushima Warm Current (TWC) in the Korea Strait. These analysis items include: its nearshore and offshore branches, the northern limit and distance from the coast of the East Korea Warm Current, outflow features of the TWC near the Tsugaru and Soya Straits and their returning currents, and flow patterns of the Liman Cold Current and the North Korea Cold Current. The first draft of the current map was constructed based upon the scientific knowledge and input of oceanographers based on oceanic in-situ measurements, and was corrected with the help of a questionnaire survey to the members of an oceanographic society. In addition, diverse comments have been collected from a special session of the 2013 spring meeting of the Korean Oceanographic Society to assist in the construction of an accurate current map of the East Sea which has been corrected repeatedly through in-depth discussions with oceanographers. Finally, we have obtained constructive comments and evaluations of the interim version of the current map from several well-known ocean current experts and incorporated their input to complete the map's final version. To avoid errors in the production of oceanic current maps in future textbooks, we provide the geolocation information (latitude and longitude) of the currents by digitalizing the map. This study is expected to be the first step towards the completion of an oceanographic current map suitable for secondary school textbooks, and to encourage oceanographers to take more interest in oceanic education.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.18 no.4
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• pp.163-177
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• 2013

An instrumented ferry made two transects per day across two current systems which are the North Korean Cold Current and the East Korean Warm Current over the years 2012-2013 from Gangneung to Ulleungdo in the southwestern East Sea. Seawater properties of these transects were measured with high spatial and temporal resolution for an extended period of time. Here the salinity records from the transects with the oceanographic observation data from East Sea Fisheries Institute of NFRDI, AVISO daily current chart and GOCI Chlorophyll-a image in 2012 and 2013 are used to study the time-series variation of salinity at the surface. The high salinity section with the range of 33.15~34.12 occurred on the transect mainly in the middle of eddy, and western boundary of strong northward current from June to October. We can found low salinity waters in both sides of the high salinity section. It is estimated that the western low salinity waters with the range of 30.58~33.20 accompanied by southward current were derived from the NKCC and the eastern waters with the range of 31.30~33.24 accompanied by northward current were derived from the Tsushima Surface Water. The lowest salinity of NKCC is confirmed in this study as 30.36. It is found that the western waters below 33.00 extended extremely toward the east about 110 km area from Gangneung and toward the south around Jukbyon coastal area as a 5~10 m layer. We can find its volume of low saline waters transport is not neglectable compared with that of Tsushima Current region in the western part of the East Sea. In this study we named it as the North Korean Low Saline Surface Water in summer.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.23 no.2
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• pp.76-90
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• 2018

To determine the distribution of mercury (Hg) in the coastal surface sediments around the Korean peninsula, the baseline concentration of Hg was estimated, the extent of contamination was assessed, and the factors controlling the distribution were discussed. The concentrations of Hg in surface sediments were significantly high in Jinhae-Masan Bay in the South Sea, Ulsan-Onsan Bay and Yeongil Bay in the East Sea, but Hg in other sediments showed a similar distribution to Cs and relatively very low concentration between 0.21 and $39.5{\mu}g/kg$ ($13.6{\pm}7.80{\mu}g/kg$). Compared to the sediment quality guidelines in Korea, 8 % of the surface sediments (n=282) analyzed in this study exceeded the values of the threshold effects level (TEL), and six sediments collected around Onsan Port were higher than the value of the probable effects level (PEL). The contamination levels of Hg were assessed by the enrichment factors using the baseline concentration (2.06Cs+1.75) based on the residual analysis from the linear regression line for Cs, and further, factors controlling the distribution of Hg were discussed by the comparison with geochemical substances depending upon the Hg enrichment level. Hg concentrations were correlated well with Cs concentration in the range of less than 1.69 of EF implying grain size control, while in the range of 1.69 and 4.03 Hg concentrations were correlated well with Fe oxyhyroxide and organic carbon contents, which indicates Hg was enriched by superior sorption capability. On the meanwhile, samples with higher EFs (4.03 to 74.9) showed fairly positive correlations with other metals (Cu, Zn, Pb) rather than geochemical substances. For samples in Youngil Bay and Ulsan-Onsan Bay (n=30), Hg concentrations were correlated only with other metals rather than geochemical substances implying simultaneous supply of metal particles from metal refineries. But samples at Gosung, Sokcho and Uljin coast were correlated well with organic carbon even though they had high EFs. In addition, samples in Jinhae-Masan Bay with high contents of S were enriched by relatively high sulfide formation.

• Horticultural Science & Technology
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• v.34 no.1
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• pp.112-121
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• 2016

Development of genetically-modified (GM) crops enables the introduction of new traits to the plant to confer characteristics such as disease resistance, herbicide resistance and human health-promoting bioactivity. Successful commercialization of newly developed GM crops requires stable inheritance of integrated T-DNA and newly introduced traits through the multiple generations. This study was carried out to confirm the stable inheritance of the integrated T-DNA in $T_1$ and $T_2$ transgenic Chinese cabbage (Brassica rapa ssp. pekinensis) that was genetically modified to increase concentrations of phenylethylisothiocyanate (PEITC), which is a potential anti-carcinogenic phytochemical. For this purpose, the IGA 1-3 ($T_1$ generation) and IGA 1-3-5 ($T_2$ generation) lines were selected by PCR and a IGA 1-3 transgenic plant ($T_1$ generation) was analyzed to confirm the T-DNA insertion site in the Chinese cabbage genome by VA-TAIL PCR. The results of this study showed that the introduced T-DNA in IGA 1 line was stably inherited to the next generations without any variations in terms of the structure of the transgenes, and this line also showed the expected transgene function that resulted in increased concentration of PEITC through the multiple generations. Finally, we confirmed the increased QR activity in IGA 1 $T_1$ and $T_2$ transgenic lines, which indicates an enhanced potential anti-carcinogenic bioactivity and its stable inheritance in IGA1 $T_1$ and $T_2$ transgenic lines.

• Korean Journal of Food Science and Technology
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• v.10 no.3
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• pp.320-330
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• 1978

Riced dehydrated potato granules with a good reconstituton quality was made from Irish Cobber (IC) and Shimabara which are representative varieties in Korea. A part of IC potato granules was packed in small vinyl-bags while the rest, including some BHA (75ppm)-treated granules, was packed in $301{\times}407$ plain tin cans. These granules were stored in a room at room temperature, and their physico-chemical properties and lipid composition were studied. The color of the granules was measured with a Hunter-type Tristimules colorimeter. L, $a_L,$ and $b_L-values$ were respectively 83.8, -1.1 and 18.3. Variety and package-type did not affect the color. In general, it was darker than that of commercial wheat flour, but whiter than that of commercial defatted soy flour. At $100^{\circ}C$, the granules, irrespective of variety and package-type, absorbed water rapidly, and reached the maximum moisture content of $90{\sim}92%$ in 3 min., whereas they absorbed water more slowly at $8{\sim}14^{\circ}C$, and reached the maximum content of $72{\sim}74%$ in 5 minutes. Peroxide, TBA, carbonyl, acid, and iodine values of the granules after 3 months storage were respetively $150{\sim}460\;meq/kg,\;20{\sim}26,\;154{\sim}380$ micromole, $24{\sim}59,\;and\;70{\sim}78$. Except iodine values, all the chemical values were affected by variety and package-type. Ether and $CHCl_3-extracts$ of the granules from IC and Shimabara were subjected to GLC and TLC analyses. In case of IC, the major fatty acids were palmitic, stearic, and oleic (30.0, 18.8, 40.6), while in case of Shimabara they were palmitic, oleic, and linoleic acids (26.7, 39.6, 23.4%). The major lipid classes were, in both cases, triglycerides and phospholipids. Their contents were raspectively 19.1 and 43.1 (IC), and 30.1 and 37.4% (Shimabara).

• Journal of the Institute of Convergence Signal Processing
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• v.16 no.4
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• pp.149-155
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• 2015

Tooth implant is located in oral cavity and affects neck, skull base, and facail image. These magnetic inhomogeneities are usually frequency encoding direction which cause artifacts due to change of signal strength and geometric distortion. First, to evaluate signal to noise ratio (SNR) of magnetic resonance image caused by tooth implant this study uses meat phantom which is similar to human body and is consisted with fat, muscle, and water to measure signal to noise ratio. Second, signal to noise ratio by using custom-made fixed phantom is measured, and then signal to noise ratio size of different tooth implant types is compared and analyzed. The measured signal to noise ratio values of Brushite, HSA, Metal, and RBM for meat phantom were 2.76, 2.22, 1.88, and 1.57 on T1 SE, 1.88, 1.78, 1.65, and 1.79 on T2 FLAIR, 2.28, 2.25, 2.88, and 2.05 on T2 FSE, and 2.74, 1.94, 1.67, and 1.48 on T2 GRE. The measured signal to noise ratio values of Brushite, HSA, Metal, and RBM for fixed water phantom were 1.2, 1.06, 1.12, and 1.22 on DWI, 1.93, 1.87, 1.93, and 2.06 T1 SE, 1.83, 1.76, 1.82, and 1.92 on T2 FLAIR, 1.85, 1.79, 7.86, and 1.97 on T2 FSE, and 1.97, 1.93, 1.99, and 2.06 on T2 GRE. By considering through the results, patients and dentists need to consider some impacts from testing many aspects although their main purpose of having tooth implants is a dental restoration. Moreover, depending on the tooth implant characteristics of individual patients this study results can be used as baseline data when choosing test protocol.

• Restorative Dentistry and Endodontics
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• v.34 no.4
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• pp.350-355
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• 2009

Bond strength depends on characteristics of bonding surface and restorative technique. The majority of studies dealing with dentin bond strength were carried out on flat bonding surface, therefore, difference of bond strength between axial wall and pulpal wall is not clear yet. This study evaluated bonding difference between cavity walls in class I composite resin restoration with different filling techniques. Twenty extracted caries-free human third molars were used. Cavities were prepared in 6 ${\times}$4 ${\times}$3 mm box-type and divided into four groups according to filling technique and bonding surface: Group I; bulk filling - pulpal wall, Group II; bulk filling - axial wall, Group III; incremental filling - pulpal wall, Group IV; incremental filling - axial wall. Cavities were filled with Filtek $Z250^{(R)}$(3M/ESPE., USA) and Clearfill SE $bond^{(R)}$(Kuraray, Japan). After 24 hour-storage in $37^{\circ}C$water, the resin bonded teeth were sectioned bucco-lingualy at the center of cavity. Specimens were vertically sectioned into 1.0 ${\times}$1.0 mm thick serial sticks perpendicular to the bond surface using a low-speed diamond saw (Accutom 50, Struers, Copenhagen, Denmark) under water cooling. The trimmed specimens were then attached to the testing device and in turn, was placed in a universal testing machine (EZ test, Shimadzu Co., Kyoto, Japan) for micro-tensile testing at a cross-head speed of 1 mm/min. The results obtained were statistically analyzed using 2-way ANOVA and t-test at a significance level of 95%. The results were as follows: 1. There was no significant difference between bulk filling and incremental filling. 2. There was no significant difference between pulpal wall and axial wall, either. Within the limit of this study, it was concluded that microtensile bond strength was not affected by the filling technique and the site of cavity walls.

• Journal of Nutrition and Health
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• v.50 no.3
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• pp.246-256
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• 2017

Purpose: This study aimed to investigate the association of total dietary antioxidant capacity (TAC) with oxidative stress and metabolic markers among patients with metabolic syndrome according to gender. Methods: A total of 346 subjects aged 30~59 years with two or more risk factors of metabolic syndrome were recruited from a general hospital near Seoul in South Korea between 2010 and 2012 based on data from the medical checkup. Biochemical indices for oxidative stress and metabolic markers were measured. Food consumption data from 3-day food records were linked with the antioxidant capacity database for commonly consumed Korean foods to estimate individual's TAC. Results: Average dietary TAC of the study subjects was 132.0 mg VCE/d/1,000 kcal in men and 196.4 mg VCE/d/1,000 kcal in women. Levels of ${\gamma}$-glutamyltransferase (GGT), systolic blood pressure, diastolic blood pressure, and blood triglycerides were reduced significantly according to increasing TAC in men, but there was no significant trend in women. Intakes of total flavonoids and carotenoids were significantly negatively correlated with GGT (p < 0.05) and d-ROMs (p < 0.01) in men, whereas those of ${\alpha}$-tocopherol (p < 0.05) and ${\gamma}$-tocopherol (p < 0.05) were positively correlated with biological antioxidant potential (BAP) in women. The odds ratio of high oxidative stress indices and abnormal metabolic markers according to TAC level were not significant in either men or women. Conclusion: The results show that dietary TAC was partially associated with oxidative stress and metabolic markers among patients with metabolic syndrome. Further research is required for elucidating the association between dietary TAC and incidence of metabolic syndrome and chronic diseases within a large population in prospective studies.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.6
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• pp.854-861
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• 2015

This study investigated the association between breakfast frequency (0~2 times, 3~6 times, and 7 times per week) and awareness of general school life (physical activity, relationships with teachers and friends, rule compliance, study attitudes, study records, and overall school life) in high school students (boys 146 and girls 155) in the Yongin region. Awareness of physical activity was higher in girls (77.4%) than in boys (65.1%). Rule compliance showed a significant difference in girls (P<0.01), whereas boys did not show any difference. Percentage of 'effective' awareness of study attitudes was 24.0% and 44.5% in boys and girls, respectively. Awareness of study records in girls showed significant difference (0~2 times 37.5%, 3~6 times 30.4%, and 7 times 52.2%) (P<0.05), whereas boys did not show any difference. Awareness of overall school life showed a significant difference in both boys (P<0.05) and girls (P<0.01). Association between breakfast frequency and general school life in boys was as follows: awareness of overall school life had the highest positive value (+0.185) (P<0.05) and relationships with teachers had the second (+0.168) (P<0.05). Girls also showed the highest positive value (+0.323) (P<0.01) for awareness of overall school life, which occurred in the following order: rule compliance (+0.316) (P<0.01)> awareness of study attitudes (+0.267) (P<0.01)> relationships with friends (+0.215) (P<0.01). In conclusion, high school students showed a high positive association between breakfast frequency and general school life, particularly in girls. Therefore, effective nutrition education programs in connection with national policy and school support are highly required to provide healthy breakfast and school life to high school students.