• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.48 no.1
• /
• pp.1-10
• /
• 2022

Customized cosmetics are continuously mentioned as a trend in the cosmetics industry to respond to the recent rapid changes in the social environment and pursue individuality and diversity. Accordingly, four types of liposome essence corresponding to skin types were prepared by varying the ratio of liposome formulation and essence formulation as a customized cosmetic base that can be easily mixed and applied at the workplace. The volatilization residues of four types of liposome essence were measured and the nanoparticle size, polydispersity index, zeta potential and viscosity according to time for 90 d were measured, and Turbiscan was measured as a method for evaluating the stability of a colloidal dispersion system. In addition, a simple usability evaluation was performed for four types of liposome essence corresponding to the skin type. As a result, the amount of volatile residue in the four types of liposome essence was increased in dry products rather than oily ones, and the particle size showed a tendency to increase with time in the range of 165 to 175 nm, increasing up to 31.5%, and the polydispersity index was 0.23 to 0.26. There was little change with time, and the zeta potential was -74 to -72 mV, showing a slight decrease with time, but there was little change to the extent of a maximum decrease of 14.0%. Viscosity showed a decreasing trend with time in the range of 2,580 ~ 3,290 cps, showing a maximum decrease of 17.5%. In the turbiscan measurement, all of the turbiscan stability index, a measure of stability, were less than 1.0, indicating dispersion stability. In the overall simple usability satisfaction evaluation for skin types (6 points), products for oily skin (5.33 ± 0.75 points) > products for medium dry skin (5.13 ± 0.95 points) > products for dry skin (5.03 ± 0.96 points) > products for oily skin (4.80 ± 1.04 points) points) were evaluated in order. The four types of liposome essence corresponding to skin types with different ratios of liposome formulation and essence formulation were physically stable, and the possibility of application as a customized cosmetic base according to skin type was confirmed.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.48 no.4
• /
• pp.343-355
• /
• 2022

Customized cosmetics are continuously mentioned as cosmetics in response to changes in the social environment and trends that emphasize individuality. Therefore, in this study, four types of nanoemulsion ampoules corresponding to skin types were prepared by different ratios of nanoemulsion formulation and ampoule formulation, and the applicability as a customized cosmetic base was checked. Particle size, polydispersity index, zeta potential, and viscosity according to time for 90 d were measured for four nanoemulsion ampoules with different volatile residues, and turbiscan was measured as a method for evaluating the stability of a colloidal dispersion system. Finally, human usability satisfaction was evaluated. As a result, it was confirmed that four kinds of nanoemulsion ampoules had a higher amount of volatile residue in the dry skin test product than in the oily skin test product. The pH was in the range of 6.41 to 6.88, and the particle size was in the range of 170 to 174 nm, and the change after 90 d was within 1.2% of the maximum, and there was no specificity in particle size stability. It was confirmed that the polydispersity index was almost constant, and showed a particle size distribution close to monodispersity by showing a change within a value smaller than 0.21 in all test products. The zeta potential was initially -63 mV or more for all four types of test products, and although it showed a slight decrease with time, there was little change to the extent of a maximum decrease of 2.5%. Viscosity was initially in the range of 4,100 to 5,100 cps and showed a decreasing trend with time, showing a maximum decrease of 37.7%. In the turbiscan measurement, the turbiscan stability index, a measure of stability, was all below 1.0, indicating dispersion stability. In the usability satisfaction evaluation (6 points) of 4 nanoemulsion ampoules corresponding to skin type, oily skin product (5.42 ± 0.67 points) > neutral oily skin product (5.36 ± 0.67 points) > neutral dry skin product (5.15 ± 0.69 point) > dry skin product (4.75 ± 0.75 points) in the order of evaluation. Four types of nanoemulsion ampoules are physically stable and have confirmed their applicability as a customized cosmetic base according to skin type, and are expected to expand in various ways.

• Journal of agricultural medicine and community health
• /
• v.47 no.3
• /
• pp.166-180
• /
• 2022

Objective: This study evaluated the effects of a non-face-to-face obesity management program, implemented during the pandemic. Methods: The non-face-to-face obesity management program used the Intervention mapping protocol (IMP). The program was put into effect over the course of eight weeks, from September 14 to November 13, 2020 in 48 overweight and obese adults, who applied to participate through the Daegu Citizen Health Support Center. Results: IMP was first a needs assessment was conducted; second, goal setting for behavior change was established; third, evidence-based selection of arbitration method and performance strategy was performed; fourth, program design and validation; fifth, the program was run; and sixth, the results were evaluated. The average weight after participation in the program was reduced by 1.2kg, average WC decreased by 3cm, and average BMI decreased by 0.8kg/m² (p<0.05). The results of the health behavior survey showed a positive improvement in lifestyle factors, including average daily intake calories, fruit intake, and time spent in walking exercise before and after participation in the program. A statistically significant difference was seen (p<0.05). The satisfaction level for program process evaluation was high, at 4.57±0.63 point. Conclusion: The non-face-to-face obesity management program was useful for obesity management for adults in communities, as it enables individual counseling by experts and active participation through self-body measurement and recording without restriction by time and place. However, the program had some restrictions on participation that may relate to the age of the subject, such as skill and comfort in using a mobile app.

• Korean Journal of Mineralogy and Petrology
• /
• v.35 no.3
• /
• pp.345-353
• /
• 2022

This study aimed to fundamentally understand changes of cell parameters of cation-exchanged mordenites using high resolution X-ray powder diffraction for studies that immobilization of various heavy metal cation using synthesis mordenite (Na_6.6Al_6.6Si_41.4O₉₆·20.4H₂O, Na-MOR). As a results of measurement by Thermogravimetric analysis (TGA), it was confirmed that 19.4, 20.4 water molecules per unit cell were present in monovalent-cation substituted MOR (Cs-MOR, Na-MOR), and 21, 23.1, 23.2 water molecules per unit cell were present in divalent-cation substituted MOR (Pb-MOR, Sr-MOR, Cd-MOR). The space group of all the samples were identified as Cmcm belonging to the orthorhombic crystal system. Compared to Na-MOR, starting material, relative peak intensity of (110) and (200) is significantly changed after cation substitution whereas peak position is almost similar. Also, (220) peak that was not found in Na-MOR was clearly observed in Pb-, Cd- and Sr-exchanged MOR. Thus, it was estimated that changes of atomic distribution usually occurred on ab-plane while changes of cell parameters were little. Detailed changes in the cell parameters of cation-exchanged mordenites were derived from whole profile fitting method using the GSAS suite program. Changes in the axial lengths and unit cell volume of cation substitution showed different relationship depending on ionic radius and charge number. In case of monovalent-cation substituted MOR, the length of a-axis increases whereas the length of b- and c-axis decrease by absorbed cation radius. In the case of divalent-cation exchanged MOR, the length of a-axis usually decreases while the length of b- and c-axis increases by cation radius. It was confirmed that unit cell volume of monovalent and divalent cation substituted MORs had an independent tendency by cation radius.

• Journal of Korea Water Resources Association
• /
• v.55 no.8
• /
• pp.623-634
• /
• 2022

Due to river maintenance projects such as the creation of hydrophilic areas around rivers and the Four Rivers Project, the flow characteristics of rivers are continuously changing, and the risk of water quality accidents due to the inflow of various pollutants is increasing. In the event of a water quality accident, it is necessary to minimize the effect on the downstream side by predicting the concentration and arrival time of pollutants in consideration of the flow characteristics of the river. In order to track the behavior of these pollutants, it is necessary to calculate the diffusion coefficient and dispersion coefficient for each section of the river. Among them, the dispersion coefficient is used to analyze the diffusion range of soluble pollutants. Existing experimental research cases for tracking the behavior of pollutants require a lot of manpower and cost, and it is difficult to obtain spatially high-resolution data due to limited equipment operation. Recently, research on tracking contaminants using RGB drones has been conducted, but RGB images also have a limitation in that spectral information is limitedly collected. In this study, to supplement the limitations of existing studies, a hyperspectral sensor was mounted on a remote sensing platform using a drone to collect temporally and spatially higher-resolution data than conventional contact measurement. Using the collected spatio-temporal hyperspectral images, the tracer concentration was calculated and the transverse dispersion coefficient was derived. It is expected that by overcoming the limitations of the drone platform through future research and upgrading the dispersion coefficient calculation technology, it will be possible to detect various pollutants leaking into the water system, and to detect changes in various water quality items and river factors.

• The Journal of the Convergence on Culture Technology
• /
• v.8 no.4
• /
• pp.253-261
• /
• 2022

The purpose of this study is to investigate the relationship between transformative leadership, team cohesion, and team performance of Chinese university taekwondo leaders. Specifically, it is to investigate the effect of transformative leadership on team cohesion and team performance and to verify the mediating effect of team cohesion in the relationship between transformative leadership and team performance. In order to achieve the research purpose, a total of 350 people were sampled after setting taekwondo leaders at Chinese universities as a population. The measurement tool used in this study was a questionnaire consisting of 5 items on demographic characteristics, a total of 19 questions on transformational leadership, 10 questions on team cohesion, and 4 questions on team performance. The validity of the questionnaire was verified through exploratory factor analysis, and the reliability was verified through reliability analysis. The reliability Cronbach's α of the questionnaire was found to be α=0.755-0.799 for transformative leadership, α=0.848, and α=0.740 for team performance. As the data processing method, exploratory factor analysis and reliability analysis, one-way analysis (one-way ANOVA), and multiple regression analysis were used using SPSS WIN. The conclusions derived through the above research methods and procedures are as follows. First, the transformative leadership of Taekwondo leaders at Chinese universities influenced team cohesion. Second, the transformative leadership of Taekwondo leaders at Chinese universities influenced team performance. Third, the team cohesiveness of Taekwondo leaders at Chinese universities influenced team performance. Fourth, the transformative leadership of Taekwondo leaders at Chinese universities not only directly affects team performance, but also indirectly affects team cohesion. Therefore, it is believed that Chinese Taekwondo players will help improve their performance by affecting team cohesion and team performance for the best games through the leader's variable leadership.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.27 no.3
• /
• pp.21-29
• /
• 2023

In this study, the stress characteristics of temporary fixed steel rods were analyzed in the "temporary fixing system using internal prestressing tension", which is mainly applied to the construction of superstructures by FCM. It was difficult to confirm the changes in initial tensile force in this system because the steel rod was internally connected to the pier and the PSC BOX. Therefore, measurement was performed before and after the completion of each segment using an FBG sensor to measure the change in the micro length of the steel rod. The results of the analysis showed that 75% to 90% of the maximum vertical contraction of the steel rod that occurred until the completion of the cantilever segment occurred in the fixing ~ 1segment, and the maximum loss of initial prestressing force was 39%. Such excessive loss of tension force to 1 segment means that tension is needed to improve the precision of construction during the fixation, and re-tension is needed to secure stability for conduction of cantilever segments after the completion of 1segment. In the 2 ~ last segment, the stress of the steel rod decreased gradually, and in the summer, the decrease in stress tended to partially recover due to the increase in the length of the steel rod corresponding to the increase in the vertical volume of PSC BOX. The dominant factor in the stress change in 2~ last segment in this phenomenon is judged to be the change in the length of the steel rod according to the temperature. Unlike the change in length, the relaxation was 1.2-2.7%, which was mostly offset by the opposite stress corresponding to the temperature stress. Therefore, a plan was proposed to improve the internal stress, such as adjusting the fixation time.

• Journal of agriculture & life science
• /
• v.50 no.3
• /
• pp.119-127
• /
• 2016

The current disinfection method of vehicles being applied in South Korea has various shortcomings. So, the epidemic has generated continuously at livestock farms. It is very important to develop an effective disinfection system for reduction of the epidemic. And various basic data is required for this development. Therefore, this study was performed to identify the nozzle type and proper discharge pressure of sprayers. The experiment was conducted from January 10, 2012 until February 28, 2012. All the performance measurement experiments were repeated five times. The subjects of experiment were the A, B and C company's products. The sprayed capacity, angle of spray and the covering area ratio were measured for each product. As a result, the sprayed capacity, angle of spray and the covering area ratio were increased as the discharge pressure of the sprayer was increased. In conclusion, the conical shaped of the nozzle is considered more appropriate than V-shaped, and the proper discharge pressure is expected to be at least 20kg/㎠.

• Exercise Science
• /
• v.21 no.2
• /
• pp.231-242
• /
• 2012

The purpose of this study was to develop the prediction model of VO₂max using submaximal metabolic responses from the Bruce protocol, HR responses at several stages and 1,200 m running record, and to compare and analyse the validity of these prediction models. The subjects were consisted of 255 male(133 male for 1,200 m running). They were participated maximal exercise testing with Bruce protocol, and the metabolic responses were measured in the end of the first(3 minute), second stage(6 minute), and 1,200 m running record. Measurement items were VO₂(㎖/kg/min), VCO₂(㎖/kg/min), VE(L/min), HR(bpm) of 3 and 6 minute, time to HR 150 bpm and 170 bpm, HR difference between Bruce protocol 6 and 3 minute, 1,200 m running record. Analyzing with all variables using enter method, the multiple R of total variable model was 0.642(p<.01), SEE was 4.38 ㎖/kg/min, CV was 10.8 %, but multicolinearity was appeared. The multiple R of 3 minutes model 1 and model 2 were 0.341 and 0.461, SEE was 6.05 and 5.72 ㎖/kg/min, CV was 14.9 and 14.1%, and multicolinearity did not appeared. The multiple R of 6 minutes model 1 and model 2 were 0.350 and 0.456, SEE was 6.03 and 5.74 ㎖/kg/min, CV was 14.9 and 14.2%, and multicolinearity did not appeared. The R of HR 170 and HR 170 model were 0.151 and 0.154, SEE were 6.36~6.37 ㎖/kg/min, CV were 15.7%. The R of 1,200 m running model was 0.444, SEE was 4.82 ㎖/kg/min, CV were 11.9%. In conclusion, with considering usefulness and convenience through the validity of these prediction models, the prediction model of VO₂max recommended 6 and 3 minute model, and the validity of HR model and 1,200 m running model were moderately low.

• Korean Journal of School Psychology
• /
• v.15 no.3
• /
• pp.459-488
• /
• 2018

The self-report assessment has been most commonly used to estimate bullying/victimization (B/V) rates in most domestic and international prevalence studies. However, the presence of many potential biasing factors in such an assessment method, including specific operationalization/measurement strategies and testing conditions, has become an issue due to a considerable variability in reported involvement rates across studies. This study analyzed self-reported B/V involvement rates on Olweus Bullying Questionnaire (OBQ) among 690 Korean middle school students by gender and two different cut-offs (generous vs. strict cut-offs) and examined if the involvement rates were significantly varied by testing conditions such as presentation vs. omission of a precise definition of B/V, anonymous vs. non-anonymous/confidential administration, and the use of global vs. specific questions. Chi-square analyses revealed that boys displayed higher involvement rates on global measures of B/V and on items related to direct forms of B/V, with no significant gender differences on specific measures of relational B/V rates. It was also found that a global rate of bullying and specific rates of verbal B/V were 111% to 157% higher when no definition was provided. However, anonymous vs. non-anonymous administration had no significant impacts on rates of involvement, except for one item; there were also no significant differences in reported degrees of frankness and perceived confidentiality of their responses across two adminstration conditions. Finally, when involvement rates were assessed by using specific vs. global items, they were 68% to 148% higher with binominal correlations in low to moderate ranges. Findings also indicated that global items had a high specificity but a relatively low sensitivity. Implications of these findings were fully discussed for researchers and practitioners in the field of B/V assessment.