• Title/Summary/Keyword: differential impact

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The Impact of Double-Skin Façades on Indoor Airflow in Naturally Ventilated Tall Office Buildings

  • Yohan, Kim;Mahjoub M. Elnimeiri;Raymond J. Clark
    • International Journal of High-Rise Buildings
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    • v.12 no.2
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    • pp.129-136
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    • 2023
  • Natural ventilation has proven to be an effective passive strategy in improving energy efficiency and providing healthy environments. However, such a strategy has not been commonly adopted to tall office buildings that traditionally rely on single-skin façades (SSFs), due to the high wind pressure that creates excessive air velocities and occupant discomfort at upper floors. Double-skin façades (DSFs) can provide an opportunity to facilitate natural ventilation in tall office buildings, as the fundamental components such as the additional skin and openings create a buffer to regulate the direct impact of wind pressure and the airflow around the buildings. This study investigates the impact of modified multi-story type DSFs on indoor airflow in a 60-story, 780-foot (238 m) naturally ventilated tall office building under isothermal conditions. Thus, the performance of wind effect related components was assessed based on the criteria (e.g., air velocity and airflow distribution), particularly with respect to opening size. Computational fluid dynamics (CFD) was utilized to simulate outdoor airflow around the tall office building, and indoor airflow at multiple heights in case of various DSF opening configurations. The simulation results indicate that the outer skin opening is the more influential parameter than the inner skin opening on the indoor airflow behavior. On the other hand, the variations of inner skin opening size help improve the indoor airflow with respect to the desired air velocity and airflow distribution. Despite some vortexes observed in the indoor spaces, cross ventilation can occur as positive pressure on the windward side and negative pressure on the other sides generate productive pressure differential. The results also demonstrate that DSFs with smaller openings suitably reduce not only the impact of wind pressure, but also the concentration of high air velocity near the windows on the windward side, compared to SSFs. Further insight on indoor airflow behaviors depending on DSF opening configurations leads to a better understanding of the DSF design strategies for effective natural ventilation in tall office buildings.

The Effects of Paternal and Maternal Control on Self-Esteem in School-Age Boys and Girls : The Mediating Role of Autonomy (부와 모의 통제가 남녀 아동의 자아존중감에 미치는 영향 : 자율성의 매개적 역할)

  • Lee, Mi-Jung;Doh, Hyun-Sim;Chee, Yeon-Kyung
    • Korean Journal of Child Studies
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    • v.32 no.5
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    • pp.67-84
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    • 2011
  • This study examined the effects of parental control and children's autonomy on self-esteem, using a sample of 415 school-age children (208 boys and 207 girls) recruited in Seoul. Ordinary Least Square regressions revealed a variety of gender-based differences in the associations among these three variables. Boys with high maternal behavioral control had high levels of self-esteem, whereas girls under low paternal psychological and high behavioral control reported high levels of self-esteem. Boys with high maternal behavioral control and girls with high paternal behavioral control also reported high levels of autonomy. Autonomy was found to exert a positive impact on self-esteem for both boy and girls. Autonomy played a mediating role in the relationships between maternal behavioral control and self-esteem for boys, and between paternal behavioral control and self-esteem for girls. These findings highlight the differential influences of psychological control and behavioral control on autonomy and self-esteem, as well as the relative impact of the opposite sex parent on the development of autonomy and self-esteem in late childhood.

Changes in Physicochemical Properties of Rice Starch Processed by Ultra-Fine Pulverization

  • Han, Myung-Ryun;Chang, Moon-Jeong;Kim, Myung-Hwan
    • Journal of Applied Biological Chemistry
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    • v.50 no.4
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    • pp.234-238
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    • 2007
  • The effects of ultra-fine pulverization on the physicochemical properties of rice starch (RS) were investigated using a high impact planetary mill. After pulverization, RVA characteristics, peak viscosity, break down, and set back values of RS decreased from 274.75 to 9.42 RVU, 214.46 to 6.17 RVU, and 87.80 to 17.00 RVU, respectively. The pasting properties also changed significantly. X-Ray diffractogram revealed RS had four A-type peaks, which disappeared after pulverization. The peak temperature and gelatinization enthalpy of RS using differential scanning calorimetry (DSC) were 13.99 J/g at $75.14^{\circ}C$, whereas the pulverized RS (PRS) had two peaks, 0.13 J/g at $63.88^{\circ}C$ and 1.23 J/g at $101.24^{\circ}C$. DSC measurement showed the retrogradation degree of PRS was lower than that of RS after storage at 4 and $25^{\circ}C$. The enzymatic (${\alpha}$-amylase) digestibilities of RS and PRS were 72.7 and 77.3%, respectively.

Characterizing Collaboration in Social Network-enabled Routing

  • Mohaisen, Manar;Mohaisen, Aziz
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.10 no.4
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    • pp.1643-1660
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    • 2016
  • Connectivity and trust in social networks have been exploited to propose applications on top of these networks, including routing, Sybil defenses, and anonymous communication systems. In these networks, and for such applications, connectivity ensures good performance of applications while trust is assumed to always hold, so as collaboration and good behavior are always guaranteed. In this paper, we study the impact of differential behavior of users on performance in typical social network-enabled routing applications. We classify users into either collaborative or rational (probabilistically collaborative) and study the impact of this classification and the associated behavior of users on the performance of such applications, including random walk-based routing, shortest path based routing, breadth-first-search based routing, and Dijkstra routing. By experimenting with real-world social network traces, we make several interesting observations. First, we show that some of the existing social graphs have high routing costs, demonstrating poor structure that prevents their use in such applications. Second, we study the factors that make probabilistically collaborative nodes important for the performance of the routing protocol within the entire network and demonstrate that the importance of these nodes stems from their topological features rather than their percentage of all the nodes within the network.

A Study on Genetic Algorithm-based Biped Robot System (유전 알고리즘 기반의 이족보행로봇 시스템에 관한 연구)

  • 공정식;한경수;김진걸
    • Journal of the Korean Society for Precision Engineering
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    • v.20 no.8
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    • pp.135-143
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    • 2003
  • This paper presents the impact minimization of a biped robot by using genetic algorithm. In case we want to accomplish the designed plan under the special environments, a robot will be required to have walking capability and patterns with legs, which are in a similar manner as the gaits of insects, dogs and human beings. In order to walk more effectively, studies of mobile robot movement are needed. To generate optimal motion for a biped robot, we employ genetic algorithm. Genetic algorithm is searching for technology that can look for solution from the whole district, and it is possible to search optimal solution from a fitness function that needs not to solve differential equation. In this paper, we generate trajectories of gait and trunk motion by using genetic algorithm. Using genetic algorithm not only on gait trajectory but also on trunk motion trajectory, we can obtain the smoothly stable motion of robot that has the least impact during the walk. All of the suggested motions of biped robot are investigated by simulations and verified through the real implementation.

Nursing Students' Experience of Sexual Harassment During Clinical Practicum: A Phenomenological Approach

  • Kim, Mijong;Kim, Taeim;Tilley, Donna Scott;Kapusta, Ann;Allen, Denise;Cho, Ho Soon Michelle
    • Women's Health Nursing
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    • v.24 no.4
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    • pp.379-391
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    • 2018
  • Purpose: To describe nursing students' experience of sexual harassment during clinical practicum. Methods: An interpretive phenomenological qualitative approach was used to understand contextual experiences of participants. Individual in-depth interviews were conducted to collect data from thirteen nursing students who experienced sexual harassment during clinical practice in general hospitals at D metropolitan city. All interviews were recorded and transcribed into Korean and English. Transcripts were analyzed using the data analysis method described by Diekelmann, Allen, and Tanner. Results: The following 12 themes emerged from the data: 'unprepared to respond', 'lack of education', 'unsure about when behavior crosses the line', 'power differential for nursing students', 'balancing self-preservation with obligations to patients', 'shame', 'feeling responsible for not being able to prevent the harassment', 'impact on patient care', 'fear of what might have happened', 'fear of repercussions', 'long term impact', and 'peer support'. Conclusion: Participants in this study described feeling an obligation to care for their patients. However, they seemed to be unable to balance this while feeling vulnerable to sexual harassment with strong negative feelings. Helping students recognize and effectively deal with sexual harassment is a critical element to assure quality learning for participants and maintain quality of care during clinical practice.

The Impact of Consumption Values on Environmentally Friendly Product Purchase Decision

  • LEE, Juyon
    • The Journal of Economics, Marketing and Management
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    • v.9 no.4
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    • pp.31-43
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    • 2021
  • Purpose: This study investigated how consumption values influence consumers' purchasing decisions regarding environmentally friendly products. Based on the Consumption Values Theory, six dimensions of consumption values were defined: functional value-quality, functional value-price, emotional value, social value, conditional value, and epistemic value. In particular, the current study analyzed the differential impact of the environmentally friendly consumption values between two consumer groups - users and nonusers. By doing so, more effective marketing strategies can be applied to the target groups. Research design, data, and methodology: The online survey was conducted through Macromill Embrain in Korea to collect data from users vs. nonusers of environmentally friendly products. There were 215 usable responses in the users sample and 225 responses in the nonusers sample. Structural equation modeling (SEM) was performed by using AMOS 18.0. Results: The results revealed that four dimensions of consumption values, i.e., functional value-price, emotional value, conditional value, and epistemic value, positively influenced the users, while functional value-price and epistemic value positively influenced purchase intention toward environmentally friendly products among the nonusers. Conclusions: These results have important implications for applying effective marketing strategies for target consumers. Theoretical and practical implications are also discussed.

The impact of cancer cachexia on gut microbiota composition and short-chain fatty acid metabolism in a murine model

  • Seung Min Jeong;Eun-Ju Jin;Shibo Wei;Ju-Hyeon Bae;Yosep Ji;Yunju Jo;Jee-Heon Jeong;Se Jin Im;Dongryeol Ryu
    • BMB Reports
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    • v.56 no.7
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    • pp.404-409
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    • 2023
  • This study investigates the relationship between cancer cachexia and the gut microbiota, focusing on the influence of cancer on microbial composition. Lewis lung cancer cell allografts were used to induce cachexia in mice, and body and muscle weight changes were monitored. Fecal samples were collected for targeted metabolomic analysis for short chain fatty acids and microbiome analysis. The cachexia group exhibited lower alpha diversity and distinct beta diversity in gut microbiota, compared to the control group. Differential abundance analysis revealed higher Bifidobacterium and Romboutsia, but lower Streptococcus abundance in the cachexia group. Additionally, lower proportions of acetate and butyrate were observed in the cachexia group. The study observed that the impact of cancer cachexia on gut microbiota and their generated metabolites was significant, indicating a host-to-gut microbiota axis.

Healthcare Systems and COVID-19 Mortality in Selected OECD Countries: A Panel Quantile Regression Analysis

  • Jalil Safaei;Andisheh Saliminezhad
    • Journal of Preventive Medicine and Public Health
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    • v.56 no.6
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    • pp.515-522
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    • 2023
  • Objectives: The pandemic caused by coronavirus disease 2019 (COVID-19) has exerted an unprecedented impact on the health of populations worldwide. However, the adverse health consequences of the pandemic in terms of infection and mortality rates have varied across countries. In this study, we investigate whether COVID-19 mortality rates across a group of developed nations are associated with characteristics of their healthcare systems, beyond the differential policy responses in those countries. Methods: To achieve the study objective, we distinguished healthcare systems based on the extent of healthcare decommodification. Using available daily data from 2020, 2021, and 2022, we applied quantile regression with non-additive fixed effects to estimate mortality rates across quantiles. Our analysis began prior to vaccine development (in 2020) and continued after the vaccines were introduced (throughout 2021 and part of 2022). Results: The findings indicate that higher testing rates, coupled with more stringent containment and public health measures, had a significant negative impact on the death rate in both pre-vaccination and post-vaccination models. The data from the post-vaccination model demonstrate that higher vaccination rates were associated with significant decreases in fatalities. Additionally, our research indicates that countries with healthcare systems characterized by high and medium levels of decommodification experienced lower mortality rates than those with healthcare systems involving low decommodification. Conclusions: The results of this study indicate that stronger public health infrastructure and more inclusive social protections have mitigated the severity of the pandemic's adverse health impacts, more so than emergency containment measures and social restrictions.

Differential Impacts of Discretionary Accrual Directions on Accounting Conservatism

  • Sangkwon CHA;HyeongTae CHO
    • The Journal of Economics, Marketing and Management
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    • v.12 no.3
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    • pp.13-22
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    • 2024
  • Purpose: While there has been extensive research on discretionary accruals (hereafter, 'DA') and accounting conservatism, interpretations have varied among researchers depending on how discretionary accruals are determined as proxies. This study investigates the relationship between discretionary accruals (DA) and accounting conservatism, focusing on the distinctions between signed DA and absolute DA. Research design, data and methodology: Using financial data from companies listed on the KOSPI and KOSDAQ markets from 2010 to 2020, we employ regression analysis to explore how signed and absolute DA impact accounting conservatism. This approach allows us to parse out the effects of positive versus negative discretionary accruals systematically. Results: Our findings indicate a divergent impact of DA on accounting conservatism. Specifically, in cases of negative DA, an increase in DA corresponds with heightened accounting conservatism. Conversely, when DA is positive, increases in DA do not exhibit a significant relationship with changes in accounting conservatism. These effects suggest that the nature of DA-whether it represents upward or downward earnings adjustments-critically influences its relationship with conservatism. Conclusions: The results elucidate the nuanced role of discretionary accruals in influencing accounting conservatism. The decrease in accounting conservatism associated with absolute increases in DA appears primarily driven by groups with downward earnings adjustments. This suggests that as negative DA diminishes toward zero, accounting conservatism intensifies, whereas positive DA does not have a parallel effect.