• The Journal of the Korea Contents Association
• /
• v.21 no.12
• /
• pp.47-56
• /
• 2021

The purpose of this study is to use network analysis to identify trends in university personality-related studies and provide implications for future research directions. For the purpose of this study, 194 papers related to personality of university students published in Korean scholarly journals. First, research began to be published in 2004, slightly increased in 2012, continued an upward curve from 2015, peaked in 2017, and is confirmed to be a downward trend. Second, the main keywords with the centrality analysis were 'society' and 'cultivation'. Third, keywords on the cognitive side and individual dimension of personality in the first period (2004 - 2010), social dimension and emotional side of personality in the second period (2011-2015), and social level and cognitive, emotional, and behavioral aspects of personality in the third period (2016-2020). Fourth, Topic 2 consisted of keywords of ability, life, interpersonal, satisfaction, and adaptation, and Topic 1 consisted of competence, morality, citizens, society, and practice. Fifth, Topic 4 alone in the first period, in the order of Topic 1 and Topic 2 in the second period, and in the order of Topic 2 and Topic 1 in the third period.

• Analytical Science and Technology
• /
• v.21 no.4
• /
• pp.316-325
• /
• 2008

An inductively coupled plasma mass spectrometry (ICP-MS) instrument equipped with flow injection-hydride generation system was used for the determination of trace arsenic in seawater sample. The accuracy in this method was verified by the analysis of certified reference materials (CRM) of seawater (CASS-4, NASS-5). The analytical results agreed with certified value within the range of uncertainty. The expanded uncertainties for CASS-4 and NASS-5 in this experiment were ranged from 6.2% to 6.8% obtained from repeated analyses of the CRMs (n=5). The detection limit of $As^+$ (m/z=74.9216) in this method was confirmed about 0.01 ug/kg. Linearity obtained from calibration curve of arsenic was excellent ($R^2=1$). The detection at $As^+$ (m/z=74.9216) and $AsO^+$ (m/z=90.9165) by using oxygen reaction gas in DRC mode was compared. Sensitivity at $AsO^+$ (m/z=90.9165) was decreased about 25-fold, but the analytical results are the same that at $As^+$ (m/z=74.9216).

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.30 no.1A
• /
• pp.71-80
• /
• 2010

Bridge deck is directly influenced by environment and vehicle load, it is easily damaged so that it requires an appropriate repair and retrofit. Therefore, developing a bridge deck with high durability is necessary in order to minimize the maintenance of bridge deck and use it to its design life. In this study, static test was carried out to evaluate a fatigue capacity of steel-concrete composite deck, which was newly developed by supplementing problems of existing reinforced concrete deck. Based on results from the static test, fatigue load was decided, and fatigue test was conducted under the constant amplitude repeated load. From the fatigue tests, the S-N curve regarding principle structural details of composite deck was made, and characteristics of fatigue behavior was estimated by comparing and evaluating it with fatigue design criteria. In addition, fatigue design guideline was presented. As a result, it is found that each structural details of composite deck proposed by this study, such as upper flange of corrugated steel plate and middle section of it, shear connector and lower flange of corrugated steel plate, is satisfying the fatigue strength.

• Geomechanics and Engineering
• /
• v.37 no.6
• /
• pp.599-614
• /
• 2024

To evaluate the safety status of deteriorated segments in a submarine shield tunnel during its service life, a seepage model was established based on a cross-sea shield tunnel project. This model was used to study the migration patterns of erosive ions within the shield segments. Based on these laws, the degree of deterioration of the segments was determined. Using the derived analytical solution, the internal forces within the segments were calculated. Lastly, by applying the formula for calculating safety factors, the variation trends in the safety factors of segments with different degrees of deterioration were obtained. The findings demonstrate that corrosive seawater presents the evolution characteristics of continuous seepage from the outside to the inside of the tunnel. The nearby seepage field shows locally concentrated characteristics when there is leakage at the joint, which causes the seepage field's depth and scope to significantly increase. The chlorine ion content decreases gradually with the increase of the distance from the outer surface of the tunnel. The penetration of erosion ions in the segment is facilitated by the presence of water pressure. The ion content of the entire ring segment lining structure is related in the following order: vault < haunch < springing. The difference in the segment's rate of increase in chlorine ion content decreases as service time increases. Based on the analytical solution calculation, the segment's safety factor drops more when the joint leaks than when its intact, and the change rate between the two states exhibits a general downward trend. The safety factor shows a similar change rule at different water depths and continuously decreases at the same segment position as the water depth increases. The three phases of "sudden drop-rise-stability" are represented by a "spoon-shaped" change rule on the safety factor's change curve. The issue of the poor applicability of indicators in earlier studies is resolved by the analytical solution, which only requires determining the loss degree of the segment lining's effective bearing thickness to calculate the safety factor of any cross-section of the shield tunnel. The analytical solution's computation results, however, have some safety margins and are cautious. The process of establishing the evaluation model indicates that the secondary lining made of molded concrete can also have its safety status assessed using the analytical solution. It is very important for the safe operation of the tunnel and the safety of people's property and has a wide range of applications.

• Journal of Life Science
• /
• v.15 no.5 s.72
• /
• pp.819-825
• /
• 2005

The Antioxidative accvities of the cell free extracts containing high glutathione by Saccharomyces cerevisiae FF-8 were tested in vitro experimental models : DPPH method for radical scavenging activity, ferric TBA method and ferric thiocyanate method using linoleic acid and tissue microsome for lipid peroxidation inhibitions. The concentration of intercellular glutathione by cultivating S. cerevisiae FF-8 in the YM optimal medium obtained $204\mug/ml$, which was increased by 2.76-fold from $74\mug/ml$ in the YM basal medium. A comparition between the YM basal medium and the YM optimal medium on antioxidative substance produced by S. cerevisiae FF-8 was investigated. In DPPH ($\alpha, \alpha-diphenyl-\beta-picrylhydrazyl$) method, the electron donating activity of the glutathione produced by S. cerevisiae FF-8 cultured in the YM optimal medium was as high as that of BHT ($ 0.05\%w/v $). The antioxidative a.tivity was measured by inhibition against lipid peroxidation of rat tissues' microsomes. The results of anti-oxidant activity of the cell free extracts by S. rerevisiae FF-8 cultured in the YM optimal medium was shown in the following order . $ liver 60.98\% > kidney 56.43\% > heart 52.91\% > brain 52.13\% > testis 45.57\% > spleen 42.95\% $. In antioxidative activities determined by ferric thiocyanate method and TBA methods against lipid peroxidation, the lipid peroxidation in the control mixture increased more rapidly than the typical peroxidation curve of linoleic acid from one day. The antioxidative activity of the cell free extracts by cultivating S. cerevisine FF-8 in the YM optimal medium were higher than that of the YM basal medium. These data indicate that the cell free extracts containing a high intercellular glutathione of S. cerevisiae FF-8 cultured in YM optimal medium showed strong antioxidative capacities by DPPH radical scavenging activity and ferric thiocyanate and TBARS measurements.

• Journal of Life Science
• /
• v.16 no.2 s.75
• /
• pp.339-344
• /
• 2006

The aim of this study was to examine the timing and magnitude of growth spurt in skinfold, body musle and bone related variables aligned on peak height velocity in boys and girls. In the study design, the subjects and the method were used by the cross-sectional investigation. The subjects participated in this study were 7 through 18 years of age belonged to typical primary, junior, senior high school students, and about 250 males and 250 females in each age group. The total subjects were 2,798 males and 2,762 females. All subjects of this study were lived in Pusan metropolitan city, Korea. The growth velocity magnitudes of sum of the four sites sknfold thickness, body musle and bone related variables. Velocity curve chart of physique was the smoothed according to an approximation of splines by the Sigma Plot-2001 graphic program. In this study, age at PHV of girls occurred eariler about 2 years than boys. In sum of four sites skinfold thickness, PV occurred -2 years from PHV in boys, and PV occurred +2 years from PHV in girls, respectively. In humerus breadth, two PV occurred before and after PHV in boys, whereas PV occurred -1 year from PHV in girls, respectively. In femur breadth, PFV and PHV appeared to occure the same time in boys, PV occurred -2 years from PHV in girls, respectively, In arm circumference, PV occurred after PHV in both sexes. In calf circumference, PV occurred +2 years from PHV in boys, PCCV and PHV appeared to occure the same time in girls, respectively. In magnitudes of peak velocity of body height, humerus breadth, femur breadth, arm circumference and calf circumfence, boys obtained higher than girls, on the other hand, girls obtained higher than boys in sum of four sites skinfold variable. we need to longitudinal and scientific investigation by Korean government level in adolescent growth spurt study, because childhood and adolescence achive higher positive physical education effect than the other ages.

• Journal of Dental Rehabilitation and Applied Science
• /
• v.18 no.3
• /
• pp.145-155
• /
• 2002

The results of the present feasibility study are summarized as follows, 1. The three unit bridge of knitted material and UD fibre reinforcement has both the rigidity and the strength against a vertical occlusal load of 75N. 2. Stress concentration at the junctional area between the bridge and the abutments, i.e. between the pontic and the knitted caps was observed. In the case of the bridge with reinforcement straps, it was partly shown that the concentration problem could be improved by simply increasing the fillet size at the area. Further refining in the surface of the junctional area will be needed to ensure a further improvement in the stress distribution. This will require some trade off in the level of the stress and the available space. A parametric study will help to decide the appropriate size of the fillet. 3. Design refinement is a must to improve the stress distribution and realize the most favourable shape in terms of fabrication. The current straight bar with a constant cross section area can be redesigned to a tapered shape. The curve from the dental arch should also be placed on the pontic design. In accordance with design refinement, the resistance of the bridge frame to other load cases should be evaluated. 4. Although not included in the present feasibility study, it is estimated that bridges of the anterior teeth can be made strong enough with the knitted material without further reinforcement using unidirectional materials. In this regard, a feasibility study on design concepts and stress analysis for 3, 4, 5 unit bridge is suggested. 5. Two types of bridge were analysed in terms of fatigue. The safe life design concept, i.e. fatigue design concept, looks reasonable for the bridge where if cracks should form and propagate there is virtually nothing a dentist to do. The bridge must be designed so that no crack will be initiated during the life span. In the case of crowns, however, if constructed with composite resin with knitted materials, it might be possible to repair them, which in general is impossible for crowns of PFM or of metal. Therefore for composite resin crowns, a damage tolerance design concept can be applied and reasonably higher operational stresses can be allowed. In this case, of course, a periodic inspection program should be established in parallel. 6. Parts of future works in terms of structural viewpoint which need to be addressed are summarized as the following: 1) To develop processing technology to accommodate design concepts; 2) More realistic modelling of the bridge and analysis-geometry and loading condition. Thickness variation in the knitted material, taper in the pontic, design for anterior tooth bridge, the effect of combined loads, etc, will need to be included; 3) To develop appropriate design concepts and design goals for the fibre composite FPD aiming at taking the best advantage of knitted materials, including the damage tolerance design concept; 4) To develop testing method and perform test such as static ultimate load test, fatigue test, repair test, etc, as necessary.

• Journal of Life Science
• /
• v.19 no.9
• /
• pp.1218-1225
• /
• 2009

Difractose anhydrides (DFAs) is studied as a sweetener for diabetics because of its structural property. DFAs have four types: DFA I, III, IV (degradation of levan) and V (degradation of inulin). Especially, DFA IV has been shown to enhance the absorption of calcium in experiments using rats. Levan fructotransferase is an enzyme for producing di-d-fructose-2,6':6,2-dianhydride (DFA IV). To identify structural characterization, we purified wild-type and mutants (D63A, D195N and N85S) of levan fructotransferase (LFTase) from Microbacterium sp. AL-210. These proteins were purified to apparent homogeneity by Ni-NTA affinity column, Q-sepharose ion exchange and gel filtration chromatography and detected by SDS-PAGE. They were also analyzed by circular dichroism (CD) measurements, JNET secondary structure prediction, activity measurements at various temperatures, and pH analysis. The optimum pH for the enzyme-catalyzed reaction was pH 7.5 and optimum temperature was observed at $55^{\circ}C$. Along with wild-type LFTase, mutants were analyzed by CD measurement, fluorescence analysis and differential scanning calorimetry (DSC). N85S showed less $\alpha$-helix and more $\beta$ strand than others. Also, N85S showed almost the same curve as wild-type in their steady-state fluorescence spectra, whereas mutant D63A and D195N showed higher intensity than wild-type. The amino acid sequence of wild-type LFTase was compared to the sequences of exo-inulinase from Aspergillus awamori, a plant fructan 1-exohydrolase from Cichorium intybus, and Thermotogo maritime (Tm) invertase and showed a high identity with Exo-inulinase from Aspergillus awamori.

• Korean Journal of Agricultural Science
• /
• v.31 no.1
• /
• pp.53-75
• /
• 2004

This study is aimed at identifying the national economic value of the irrigation facilities by reviewing the existing papers on economic values of the irrigation facilities and presenting current status of dual O & M problems of the irrigation facilities. This study suggested the unified O & M system rather than continuing the existing dual O & M system of irrigation facilities based on the surveyed results of the activities of irrigation fraternities in Chungnam Province. The findings and proposals for the successful unified and mono O & M system of the irrigation facilities are as follows: (1) Total number of irrigation facilities in the nation accounts for 67,582, while the total length of irrigation and drainage canals amounted to about 174,259km. On account of the total length of structural canals was estimated at 31%, much losses of water and much O & M costs have been inevitable for the full irrigation rice culture. In spite of the past heavy investment for irrigation facilities, the ratio of rain-fed and partially irrigated paddy fields accounts for 23% in 2003. Both Korea Agricultural and Rural Infrastructure Corporation (KARICO) and the city and Gun Governments have managed the irrigation facilities separately by irrigation fraternities. The KARICO have commanded 59% of irrigation paddy area with 18% of the total irrigation facilities, while the city and Gun governments covered 41% of irrigation paddy area with 82% of the existing number of irrigation facilities representing small and medium scale. (2) The 1999 demand prices of irrigation water per ton expressed in 2000 constant market price was estimated at 388 won, the supply price was amounted to 184 won per ton. Considering the supply and demand curve of the irrigation water, the existing irrigation facilities could not satisfy the demand of irrigation water. (3) In 1999, total present added value of the irrigation facilities during the economic life accounted for 48 trillion won, while total supply cost was 44.7 trillion won. The marginal benefit and cost ratio of irrigation water was 1.08. (4) The total O & M cost per year amounting to 681.1 billion won have been required to maintain and repair the existing irrigation facilities in Korea. For the successful unified O & M of irrigation facilities covering whole irrigated paddy field in Korea, 950 billion won of O & M costs are required to keep up the marginal benefit of irrigation water as 2,800 billion won per year. The total O & M cost as 950 billion won should be allocated 40%, 380 billion won for O & M costs of irrigation facilities and 60%, 570 billion won for improvement of irrigation facilities. (5) The study investigated and reviewed the present O & M status of the irrigation facilities by small and medium irrigation fraternities. Most of the farmers belong to the irrigation fraternities preferred not only unified O & M but also KARICO take-over of the whole O & M activities of the irrigation facilities. The prevailing O & M cost per 10a expended by the Corporation was amounted to 104,890 won, while that of city and Gun governments was only amounted to 4,600 won per 10a. regarding the small amount of O & M cost expended by city and Gun governments, it is evident that the existing irrigation system have been managed ineffectively and deteriorated the facilities comparing that of KARICO. In conclusion, the Government could not satisfied the demand of irrigation water by suppling water with existing irrigation facilities. Therefore new additional investment and financial support for irrigation water development should be made to convert rain-fed and partially irrigated paddy fields into fully irrigated ones. The operation and maintenance cost should be supported to keep the marginal values of rice production of existing irrigation facilities in the national economy and to modernize the obsolete irrigation facilities. By unifying the existing dual O & M systems, all the farmers belong to the irrigated paddy fields have to be equally benefited and could be increased their farm income and be stabilized their rural lives.

• Pediatric Gastroenterology, Hepatology & Nutrition
• /
• v.4 no.1
• /
• pp.77-82
• /
• 2001

Purpose: The fecal acid steatocrit is an improved steatocrit method for the evaluation of fecal fat. The present study was set up in order to define the normal range of acid steatocrit values during the first 3 months of life. Methods: Fecal acid steatocrit values were determined in 78 healthy full term and in 21 healthy prematurely born infants between May 1998 and April 2000. The acid steatocrit method was performed in these babies during the first 3 months of life. Results: Steatorrhea occurs during the first month and then decreases, as shown by the fall in the acid steatocrit curve from 1st to 3rd month in our subject. Very high acid steatocrit results (above 90%) were found in all full term and premature infants during the first month of age. Acid steatocrit results of human milk-fed infants were significantly lower than those of formula-fed infants (p=0.0018). Conclusion: We conclude that high acid steatocrit results during the first 1 month of age can be due to physiologic steatorrhea. The acid steatocrit micromethod can be used for the evaluation of milk fat absorption in infants and monitoring steatorrhea instead of other more cumbersome methods.