• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.12
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• pp.1873-1879
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• 2010

This study was conducted to estimate the heavy metal contents of vegetables available on the markets in Seoul area. Concentrations of mercury (Hg), lead (Pb), cadmium (Cd), arsenic (As), chrome (Cr), nickel (Ni), copper (Cu), and zinc (Zn) were measured in 300 samples using a mercury analyzer and inductively coupled plasma optical emission spectrometer (ICP-OES) after wet digestion. The average values of heavy metals in vegetables were as follows [mean (minimum~maximum), mg/kg]; Hg: 0.0005 (N.D~0.007), Pb: 0.011 (N.D~0.259), Cd: 0.012 (N.D~0.188), As: 0.002 (N.D~0.142), Cr: 0.100 (0.019~0.954), Ni: 0.093 (0.003~1.231), Cu: 1.098 (0.072~36.29), and Zn: 3.48 (0.485~21.31). The heavy metal contents of vegetables available on the markets in Seoul were almost the same as or lower than those reported in other studies. The weekly average intakes of mercury, lead and cadmium from vegetables take 0.44~7.71% of PTWI (Provisional Tolerable Weekly Intakes) that the FAO/WHO Joint Food Additive and Contaminants Committee sets for evaluation of food safety.

• Korean Security Journal
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• no.51
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• pp.103-124
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• 2017

The purpose of this study is to analyze regional clusters and discrimination on size and sector of private security in national 16 areas in 2015. The results of the study using hierarchical cluster analysis and discriminant analysis are as follows. First, we can classify national 16 areas into 3 clusters, such as Large Area(1), Medium Area(2), and Small Area(3) according to the size of private security. The discriminant functions D for each cluster is as follows: (1) Large Area(1) = -383.981 + (.108 ${\times}$ number of security companies) + (.016 ${\times}$ number of guards), (2) Medium Area(2) = -35.570 + (.029 ${\times}$ number of security companies) + (.005 ${\times}$ number of guards), and (3) Small Area(3) = -5.381 + (.012 ${\times}$ number of security companies) + (.002 ${\times}$ number of guards). Second, we can classify national 16 areas into 3 clusters, such as Large Area(1), Medium Area(2), and Small Area(3) according to the sector of private security. The discriminant function D for each cluster is as follows: (1) Large Area(1) = -2224.402 + (-.562 ${\times}$ facilities security) + (1.245 ${\times}$ protection security) + (171.142 ${\times}$ convoy security) + (-2.722 ${\times}$ electronic security) + (2.020 ${\times}$ special security), (2) Medium Area(2) = -4.762 + (.052 ${\times}$ facilities security) + (.063 ${\times}$ protection security) + (-3.819 ${\times}$ convoy security) + (.110 ${\times}$ electronic security) + (-.165 ${\times}$ special security), and (3) Small Area(3) = -125.742 + (-.009 ${\times}$ facilities security) + (.432 ${\times}$ protection security) + (5.748 ${\times}$ convoy security) + (5.530 ${\times}$ electronic security) + (-.901 ${\times}$ special security).

• Nuclear Engineering and Technology
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• v.18 no.3
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• pp.218-227
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• 1986

Studies were conducted to determine the extent of oxidation and same of the mechanical property changes of Zircaloy-4 fuel cladding after it was exposed to hot steam environment. The purpose of these tests was to provide some informations on the embrittlement behavior of CANDU type fuel cladding, which could be experienced under the loss-of-coolant accident conditions. The Zircaloy fuel cladding tubes were exposed in a steam environment at the temperature of 90$0^{\circ}C$, 1,00$0^{\circ}C$. The growth of the ZrO$_2$ layer combined with an oxygen rich $\alpha$-phase layer into the Zircaloy tube material was found as a function of time t and temperature of steam exposure, E=1.1√Dt+0.002 where D is a temperature dependent diffusion coefficient. The tensile strength of the specimens exposed for a short period increased but decreased continuously with further exposure. The circumferential elongation was drastically changed with the exposure time while the hoop strength did't decrease greatly. The X-ray measurement of preferred orientation of the Zircaloy tube material indicated that grains in the as received tube were oriented such that the poles of the basal (0001) planes were predominantly radial, while the poles of the basal plane in the tube materials heattreated at 1,00$0^{\circ}C$ were oriented tangentially. It appears that this reoriented texture may contribute to lessening the decrease of the hoop strength of the heat treated Zircaloy tube material.

• Korean Journal of Ecology and Environment
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• v.45 no.4
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• pp.392-402
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• 2012

In this study, to analyze the stream health using fish assemblage and make effective management, we conducted fish monitoring in the Hoeya River basin and neighboring streams. A total of 33 species classified into 12 families were collected from 29 sites in 2007. Dominant species was Zacco platypus (Relative abundance, RA: 24.8%), and subdominant species was Rhynchocypris oxycephalus (RA: 16.2%). Eight Korean endemic species and 4 exotic species were identified. Moreover, two species (Opsariichthys uncirostris amurensis and Hemiculter eigenmanni) were translocated from other basin. To evaluate stream health of the study sites, Index of Biological Integrity (IBI) was applied, based on fish assemblages. Overall, IBI values were "C (Fair)" or "D (Poor)" condition, according to the grade except two sites which recorded "B (Good)". The correlation between land use pattern of surrounding watershed and IBI was analyzed to verify impact of development on stream health using fish assemblage. As a result, when percentage of the developmental groups increased, IBI values were decreased (Pearson correlation, r=-0.425, p=0.022). In contrast, increment of percent forest and grass land was positively correlated with IBI (r=0.556, p=0.002). The agricultural group and IBI did not significantly correlate with each other (r=-0.231, p=0.333). In this study, we identified a relationship between land use of surrounding watershed and stream health using fish data (i.e. IBI). These results could be provided useful fundamental information to establish management and restoration plan in the Hoeya River basin and other rivers distributed in Korea.

• Korean Journal of Poultry Science
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• v.36 no.2
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• pp.157-163
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• 2009

This work was conducted to investigate the amount and major compositions of excreta from broilers. One hundred fifty 1-d-old male and female Ross broilers were used in this work and ten broilers were selected to measure excreta. Average amount of excreta per broiler was 85.4 g, and average moisture content was 76.9%. N, $P_2O_5$ and $K_2O$ in excreta were 1.19, 0.29 and 0.49%, respectively. pH, $BOD_5$, $COD_{mn}$, and SS were 7.80, 42,134 mg/L, 52,668 mg/L, and 106,669 mg/L, respectively. Pb in poultry excreta was 0.803 mg/kg and highly lowed compared with the standard contents (150 mg/kg). Cd was not founded in excreta. Hg was founded in excreta as 0.002 mg/kg, but it was low compared with the standard level (2 mg/kg).

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.3
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• pp.389-398
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• 2018

This study examined the influence of problem solving ability, communication skill and self-efficacy on clinical competence of nursing students. The research subjects were 184 grade 4 nursing students in D and G city. Data were collected from September 1 to September 10, 2016 and analyzed by independent t-test, one-way ANOVA, Pearson's correlation, and stepwise multiple regression using the IBM SPSS/WIN 20.0 program. The results showed that the problem solving ability was 3.60, communication skill was 3.79, and self-efficacy was 3.45. The clinical competence was positively correlated with problem solving ability, communication skill and self-efficacy. Problem solving ability (${\beta}=0.283$, p<0.001), self-efficacy (${\beta}=0.249$, p<0.001), motivation for nursing (${\beta}=0.182$, p=0.002), communication skills (${\beta}=0.176$, p=0.016), and interpersonal relationships (${\beta}=0.101$, p=0.082) explained 42.8% of the total variance in clinical competence of nursing students. The most significant predictors of clinical competence were problem solving ability, followed by self-efficacy and communication skills. Therefore, it is necessary to develop an empowerment program to improve problem solving ability, self-efficacy and communication skills of nursing students.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.2
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• pp.194-201
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• 2010

We propose a frequency selective surface(FSS) using double split ring resonators(DSRRs) for isolation enhancement between CDMA and RFID. The structure consists of an outer SRR and an inner SRR, and the gaps are formed in the same direction. By properly adjusting the gap and line width, the resonant frequency and skirt characteristics can be adjusted without varying the unit cell size. The proposed structure has a different field distribution from that of an ordinary SRR for magneto-dielectric materials. One layer consists of $9{\times}9$ unit cells and the other layer was separated by 50 mm. To validate the simulation results, we fabricated the patch antenna and the FSSs, and the measured results show a good agreement with the simulated ones. The electrical size of the unit cell is $0.110\;{\lambda}{\times}0.110\;{\lambda}{\times}0.002\;{\lambda}$, and the size of the two layer FSS is $1.058\;{\lambda}{\times}1.058\;{\lambda}{\times}0.153\;{\lambda}$. The two layer FSS maintain gain in CDMA frequency and has 6.9 dB reduced gain in RFID frequency.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.12
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• pp.254-263
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• 2017

This study was conducted to identify the relationship between negative emotion and obesity and provide adequate information to enable effective nursing intervention in elderly. Participants were 216 elderly who had been attending two geriatric welfare facilities in Chungbuk. The data were collected between 14 and 30 August, 2017 with a structured questionnaire and body measurement. The questionnaires were CES-D, RULS, BPS and collected data were analyzed using descriptive statistics, t-tests, ${\chi}^2-test$, Fisher' exact tests, Pearson's correlation, and logistic regression with SPSS/WIN 22.0. The mean BMI of participants was $23.59{\pm}3.48$ and the prevalence of obesity was 31.9%. Significant differences were observed in age (${\chi}^2=8.16$, p=.003), gender (${\chi}^2=9.27$, p=.002), smoking (${\chi}^2=7.78$, p=.004), depression (t=2.54, p=.012) and social isolation (t=2.98, p=.003) between the normal and obesity groups. Depression (OR,1.04; 95% CI, 1.00-1.09) and social isolation (OR, 1.06; 95% CI, 1.02-1.11) was associated with an increased risk obesity. Therefore, it was necessary to measure and quantify the depression and social isolation for weight management among the elderly. Moreover, it is necessary to develop health promotion programs and nursing intervention, including the need for physical, mental, and social relationships.

• Applied Chemistry for Engineering
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• v.18 no.5
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• pp.522-526
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• 2007

Structural features and electrochemical performances of cokes pyrolized from oxidized cokes were examined, and compared with KOH-activated coke. Needle cokes ($d_{002}=3.5{\AA} $), having a graphene layer structure, were changed to a single phase of graphite oxide after oxidation treatment with an acidic solution having an $NaCLO_3$/needle coke composition ratio of above 7.5, and the inter-layer distance of the oxidized coke was expanded to $6.9{\AA} $ with increasing oxygen content. After heating at $200^{\circ}C$, the oxidized coke was pyrolized to the graphene layer structure with inter-layer distance of $3.6{\AA} $. However, the change of the inter-layer distance of the needle coke was not observed in the KOH activation process. On the other hand, an intercalation of electrolyte ions into the pyrolized coke, observed at first charge, occurred at 1.0 V, in which the value was lower than that of KOH-activation coke. The cell capacitor using pyrolized coke exhibited a lower internal resistance of $0.57{\Omega}$ in 1 kHz, and a larger capacitance per weight and volume of 30.3 F/g and 26.9 F/ml at the two-electrode system in the potential range 0~2.5 V than those of the cell capacitor using KOH-activation of coke. This better electrochemical performance may be associated with structure defects in the graphene layer derived from the process of the inter-layer expansion and shrinkage.

• Korean Journal of Ichthyology
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• v.25 no.2
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• pp.53-58
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• 2013

Seven individuals (16.1~29.1 mm in length) which were estimated with fishes of genus Abudefduf were collected in Seogwipo, Jeju Island in the summer of 2011 and 2012. Among them, five individuals (20.8~29.1 mm SL) are similar to Abudefduf notatus, based on morphological characters such as yellow transverse band on the body, one small black spot on the base of the pectoral fin, and yellow caudal fin. On the other hand, two individuals (16.1 mm, 17.0 mm SL) differ from them in several light transverse bands and transparent rays of all fins except for pelvic fin, and anterior transparent head with only one (16.1 mm). According to the results of molecular analyses of 578 base pairs of mtDNA 16S rRNA sequences, these individuals correspond to A. notatus adult, with a high bootstrap value of 95% (genetic distance, d=0.002). Therefore, this study shows that the individuals more than 20.8 mm similar to adult body color but the 16.1 mm individual differs to that of adult. We confirm that this species changes to body color during their early life stages. This result regards as a survival strategy to protect themselves against their predator during their early life stages.