• Title/Summary/Keyword: indirect method

Search Result 1,754, Processing Time 0.029 seconds

Study on Selection of Water Treatment Filtration System to Cope with Climate Change (기후변화 대응을 위한 수처리 여과시스템 선정 방안 연구)

  • Hwang, Yun-Bin;Park, Ki-Hak
    • Journal of Climate Change Research
    • /
    • v.9 no.1
    • /
    • pp.75-80
    • /
    • 2018
  • The problem of water shortages and water related disasters caused by climate change has increased the seriousness of water problems and the importance of water treatment technology capable of securing clean water is expanding. In this study, we analyzed not only the water pollutant generated by the filtration system technology of various water treatment technologies but also the indirect greenhouse gas emissions generation, and analyzed the influence on the environment. The subjects of study are Fabric Filter, Reverse Osmosis System and Pressurized Microfiltration Device which are widely used for water treatment and we analyzed the impact on the environment using the Life Cycle Assessment (LCA) method using the electricity amount necessary for use, the water purification efficiency, the throughput per ton and the cost. The amount of greenhouse gas generated when the Pressurized Microfiltration Device operates for 1 year is $2.15E+04kg\;CO_2-eq$., Fabric Filter is $3.29E+04kg\;CO_2-eq$., and Reverse Osmosis System is $1.68E+05kg\;CO_2-eq$. As a result of analyzing the amount of greenhouse gas generated at the time of purifying 1 ton of the Pressurized Microfiltration Device and the conventional filtration system, the Pressurized Microfiltration Device was $20.5g\;CO_2-eq$., Fabric Filter was $34.7g\;CO_2-eq$., and Reverse Osmosis System was $191.7g\;CO_2-eq$. The amount of greenhouse gas generated was calculated to be 41.0% less than that of the Fabric Filter by the Pressurized Microfiltration Device and 89.3% less than the Reverse Osmosis System. From the viewpoint of climate change, it is necessary to select a filtration system that takes climate change into account, not from the viewpoint of water quality removal efficiency and economic efficiency according to future water treatment applications, and it is necessary to select a water treatment filtration system more researches and improvements will be made for.

The Effects of Poverty on Happiness of Children -Mediating Effects of Social Capital- (빈곤이 아동의 사회적 자본을 통해 행복감에 미치는 영향)

  • Baek, Hye Young;Kang, Hyunah
    • Journal of the Korean Society of Child Welfare
    • /
    • no.54
    • /
    • pp.113-144
    • /
    • 2016
  • The purpose of this study was to investigate whether children's social capital(both within and outside the family) and happiness would vary depending on poverty, as well as the effects of poverty on the happiness of children through their social capital. The 2013 Korea Youth General Survey data were utilized. We analyzed data from 766 children between the ages of 9 and 12, as well as their parents. Data were examined using structural equation modeling analysis. The bootstrapping method was used to test the mediating effects of social capital. The results showed that poor children had lower levels of social capital(both within and outside the family) and happiness than non-poor children. Second, poverty had indirect effects one happiness. In particular, poverty affected children's happiness through their social capital obtained both from within and outside the families. The mediating effects were statistically significant. Based on the results, we suggested policy and practice implications, including various interventions for children in poverty that may improve their social capital, which influences children's happiness.

The Effect of Maternal Positive Parenting Attitudes on School Adjustment among Multi-cultural Adolescents in Korea: Mediating Effect of Ego-resiliency (다문화가정 어머니의 긍정적 양육태도가 청소년의 학교적응에 미치는 영향: 자아탄력성의 매개효과)

  • Mok, So Ri;Suh, Bo Lim;Jeong, Jae Kyeong;Kang, Min Ju
    • Human Ecology Research
    • /
    • v.57 no.3
    • /
    • pp.341-352
    • /
    • 2019
  • This study examined the effect of maternal positive parenting attitudes on school adjustment among multi-cultural adolescents in Korea and investigated if multi-cultural adolescents' ego-resiliency mediates the relationship between maternal positive parenting attitudes and school adjustment. We used panel data from the fifth wave (2015) of the Multicultural Adolescents Panel Study (MAPS) collected by the National Youth Policy Institute. Participants were 1,297 multi-cultural adolescents (639 boys, 658 girls) who are second-year middle school students and have foreign mothers. SPSS 25.0 performed descriptive statistical analysis and correlation analysis. The structural equation model (SEM) was estimated with Mplus 5.12. The results of this study were as follows. First, a higher level of maternal positive parenting attitudes were related to higher level of ego-resiliency and school adjustment for multi-cultural adolescents. Second, maternal positive parenting attitudes had an indirect effect on school adjustment for multi-cultural adolescents via ego-resiliency. The results of this study indicate that maternal positive parenting behaviors would help improve the school adjustment of multi-cultural adolescents by increasing the level of ego-resiliency. In addition, the results of this study suggest that improving ego-resiliency for multi-cultural adolescents can be an effective method to help in school adjustment, as well as education for maternal parenting attitude.

Studies on Amylase Secretion Mechanism by Mouse Pancreatic Fragments. (생쥐 췌장의 아밀라아제 분비기작에 관한 연구)

  • 조응행;최임순
    • The Korean Journal of Zoology
    • /
    • v.30 no.2
    • /
    • pp.193-209
    • /
    • 1987
  • Patterns of amylase secretion in mouse pancreatic fragments were studied over a period of time after the tissue was stimulated by acetyicholine and MNNG. MNNG is known to activate guanylate cyclase and thus increase the cGMP concentration in the pancreatic acinar cell. These amylase secretion patterns were studied to investigate the role of cGMP in reaction cascade during secretion response of the tissues stimulated by acetyicholine. Cellular response of amylase secretion in the pancreas by acetyicholine was divided into two phases. During the first phase, zymogen granules which had existed in the cells were secreted by the action of $Ca^2$+ and calmodulin immediately after secretagogue administration, this being known as the initial response. When the tissue was stimulated by acetylcholine in a $Ca^2$+-deficient medium or one containing trifluoperazine as a calmodulin antagonist, this initial response was reduced. In the second phase, newly formed zymogen granules were secreted as sustained response after protein synthesis was triggered by secretagogue. This response was provoked by an activation of protein kinase C. When either cycloheximide as a protein synthesis inhibitor or dibucaine as a protein kinase C inhibitor were added to the incubation medium, this sustained response was remarkablely depressed in the pancreatic fragments stimulated with acetylcholine. In the pancreatic acinar cell, phosphatidylinositol turnover plays an important role in the secretion response and hexachlorocyclohexane inhibits this phosphatidylinositol turnover. The pancreatic tissue treated with the hexachlorocyclohexane exhibited inhibition on both initial and sustained responses of amylase secretion by acetylcholine. MNNG also accelerated amylase secretion from the tissue gradually along incubation time. The 22 minutes fraction of the pancratic secretion after administration of both acetylcholine and MNNG showed higher amylase activity than the neighboring fractions. Guanylate cyclase potentiated the sustained response. Even if it is experimented with an indirect method, guanylate cyclase was found responsible for activation of the sustained response of a step prior to the action of protein kinase C. As conclusion, it was considered that amylase secretion in mouse pancreatic fragments stimulated by acetylcholine is a three phasic response.

  • PDF

A Comparison of Estimated Groundwater Consumption Using Existing Formulae with Actual Pumped Volumes in the Haean Basin, Korea (양구해안분지에서 기존 농업용수 이용량 산정식에 따른 양수량과 실측 양수량 비교)

  • Ryu, Han-Sun;Jeon, Woo-Hyun;Kwon, Kideok;Lee, Jin-Yong
    • Journal of Soil and Groundwater Environment
    • /
    • v.22 no.4
    • /
    • pp.1-8
    • /
    • 2017
  • Efficient groundwater management requires accurate information about the water volume used. The pumped volume of groundwater can be indirectly estimated using empirical formulae based on electric power consumption. The purpose of this study is to test the accuracy of this indirect method. The Haean basin in Gangwon is located in a rural area, where majority of the groundwater extracted is used for irrigation. The pumped volume of groundwater indirectly estimated from electricity usage using these empirical formulae was compared with the actual pumped volume determined by conducting experiments on April 29 and May 19, 2017. The field survey collected data on electricity usage, pumped volume, and groundwater levels. Based on this measured data, correlations were calculated between electricity usage and pumping volume, as well as groundwater level and pumping rate. The results show that electricity usage and pumped volume measured for both wells (YHE1 and YHE2) are highly correlated (r=0.99, p<0.001). However, for YHE1, notably, the correlation between the groundwater level and pumping rate was not significant, and only some correlations were identified for these variables for the YHE2 test well. The average error with respect to the estimation of the actual pumped volume from the existing formula (1) and formulae (2) and (3) are +399% and -88%, respectively. To reduce these errors, these formulae need to consider other factors affecting the pumped volume.

The Association between Social Support and Health Behaviors for Metabolic Syndrome Prevention among University Students: The Mediating Effect of Perceived Stress (대학생 집단에서 사회적 지지와 대사증후군 예방 건강 행동 간의 상관관계: 지각된 스트레스의 매개효과)

  • Park, Sooyeon;Cho, Suah;Lee, Eugene;Choi, Sungchul;Choo, Jina
    • Research in Community and Public Health Nursing
    • /
    • v.32 no.3
    • /
    • pp.404-414
    • /
    • 2021
  • Purpose: Health behaviors for metabolic syndrome (MetS) prevention should be emphasized from early adulthood. There is little information on psychosocial factors associated with health behaviors for MetS prevention. The aim of this study was to determine whether there would be a mediating effect of perceived stress on the association between social support and health behaviors for MetS prevention among university students. Methods: This cross-sectional and correlation study was conducted with 502 university students in South Korea. Social support, perceived stress, and lifestyle evaluation for metabolic syndrome scales were used. Online questionnaire survey was conducted between November and December 2019. The mediating effect of social support on health behaviors for MetS prevention was analyzed using PROCESS macro program with bootstrapping method to test our hypotheses. Results: Social support directly influenced perceived stress (β=-.35, p<.001) and health behaviors for MetS prevention (β=.14, p=.002). Health behaviors for MetS prevention was indirectly influenced by perceived stress (β=-.25, p<.001). The size of indirect effect of social support on health behaviors for MetS prevention was 0.06. Conclusions: The association of social support and health behaviors for MetS prevention was partially mediated by perceived stress among university students. Therefore, a university-based nursing intervention should comprise social support strategies with stress management to promote health behaviors for MetS prevention.

A Study on the Technological Innovation and Introduction of SCM System of SMEs' Industry Using the Innovation Resistance Model (혁신저항모델을 활용한 중소기업 기술혁신에 따른 SCM시스템 도입 영향 연구)

  • Oh, Yongmin;Boo, Jeman
    • Journal of Korean Society of Industrial and Systems Engineering
    • /
    • v.44 no.3
    • /
    • pp.165-175
    • /
    • 2021
  • As the advent of the Fourth Industrial Revolution and Information Age, companies are in the state of infinite competition due to the rapidly changing technological environment and fierce competition. In this situation companies are making efforts to gain the competitive advantage by introducing information systems. Supply Chain Management (SCM) is considered a method to gain a competitive edge in rapid change. In fact, companies that already have introduced the SCM system are achieving company renovation with positive effects such as increase of sales stock reduction on-time delivery cost reduction and improved efficiency. This study was started to investigate the resistance that occurs in introducing the SCM system for small and medium-sized manufacturing industries that have not yet introduced the SCM system despite the importance of the SCM system, and to check the effect on the intention of the introduction. As the result of this study, the first is that the company has the higher technological innovation, the more positive the effect on Relative advantage Compatibility Perceived risk, Complexity. Second, The compatibility of the SCM system was rejected in innovation resistance, but it is adopted with the highest impact in the introduction intention. In addition, the mediating effect of innovation resistance was also rejected, confirming that if the SCM system is compatible for the company, it doesn't affect the resistance and is the biggest factor to consider in the introduction of the SCM system. Third, the perceived risk of the SCM system doesn't directly affect the intention to introduce, but has an indirect effect when mediation innovation resistance.

Ultrasonic Cavitation Behavior and its Degradation Mechanism of Epoxy Coatings in 3.5 % NaCl at 15 ℃

  • Jang, I.J.;Jeon, J.M.;Kim, K.T.;Yoo, Y.R.;Kim, Y.S.
    • Corrosion Science and Technology
    • /
    • v.20 no.1
    • /
    • pp.26-36
    • /
    • 2021
  • Pipes operating in the seawater environment faces cavitation degradation and corrosion of the metallic component, as well as a negative synergistic effect. Cavitation degradation shows the mechanism by which materials deteriorate by causing rapid change of pressure or high-frequency vibration in the solution, and introducing the formation and explosion of bubbles. In order to rate the cavitation resistance of materials, constant conditions have been used. However, while a dynamic cavitation condition can be generated in a real system, there has been little reported on the effect of ultrasonic amplitude on the cavitation resistance and mechanism of composites. In this work, 3 kinds of epoxy coatings were used, and the cavitation resistance of the epoxy coatings was evaluated in 3.5% NaCl at 15 ℃ using an indirect ultrasonic cavitation method. Eleven kinds of mechanical properties were obtained, namely compressive strength, flexural strength and modulus, tensile strength and elongation, Shore D hardness, water absorptivity, impact test, wear test for coating only and pull-off strength for epoxy coating/carbon steel or epoxy coating/rubber/carbon steel. The cavitation erosion mechanism of epoxy coatings was discussed on the basis of the mechanical properties and the effect of ultrasonic amplitude on the degradation of coatings.

The Mediation Effect of Communication on the Relationship between Solidarity and Conflict for Grandmothers Raising Grandchildren and an Adult Child: A Common Fate Model (손자녀 공동양육 조모와 성인자녀의 결속도가 갈등에 미치는 영향에서 의사소통의 매개효과: 공동운명모형(Common Fate Model) 적용)

  • Choi, Hye Jeong;Kang, Su Kyoung;Chung, Mi Ra
    • Human Ecology Research
    • /
    • v.57 no.1
    • /
    • pp.15-26
    • /
    • 2019
  • This study showed that the association between solidarity and conflict is mediated by the communication of grandmothers and an adult child at the dyadic level. The common fate model (CFM) was designed to model mediation effects at the level of dyads. Participants consisted of 297 grandmother dyads and their adult child who were rearing preschool-aged grandchildren in Seoul and Gyeonggi-do. For analysis at the dyadic level, grandmothers and adults responded to the same questionnaire on the same variables. SPSS 23.0 performed descriptive statistical analysis and correlation analysis. The structural equation model (SEM) was estimated with AMOS 23.0. We tested the mediation model using the maximum likelihood method. Model fit index used the chi-square statistic, the incremental fit index (IFI), the comparative fit index (CFI), the root mean square error of approximation (RMSEA). The statistical significance of the indirect effect was examined using a bootstrapping procedure. The results are as follows. First, in the CFM, the direct effect between solidarity and conflict was significant. Therefore, the higher the solidarity, the lower conflict of grandmothers and an adult child. Second, the association between solidarity and conflict is mediated by communication at the dyadic level. Based on the results of this study, we discussed ways to strengthen the capacity of co-parenting between grandmothers and an adult child.

A Research on Space Identity Developing model by Design Process (디자인프로세스를 활용한 공간 아이덴티티 개발 모델에 관한 연구)

  • LEE, Kyung ah
    • Journal of Digital Convergence
    • /
    • v.16 no.12
    • /
    • pp.563-569
    • /
    • 2018
  • This paper deals with a space identity development model using design process. The main contents of the study are as follows. First, this study has defined the design process concept and studied various design process model. Second, the meaning of space design process was studied and concept definition was made. Third, it developed a conceptual model of space design process for developing space identity. Finally, a conceptual model that can define space identity by applying design process to complex and various types of space is studied and presented. This study applied positivist research methods such as literature review and various theoretical review to study design process and space identity. The research on space design process adopts indirect research method based on previous research data.