• Title/Summary/Keyword: Explaining model

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How Extracellular Reactive Oxygen Species Reach Their Intracellular Targets in Plants

  • Jinsu Lee;Minsoo Han;Yesol Shin;Jung-Min Lee;Geon Heo;Yuree Lee
    • Molecules and Cells
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    • v.46 no.6
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    • pp.329-336
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    • 2023
  • Reactive oxygen species (ROS) serve as secondary messengers that regulate various developmental and signal transduction processes, with ROS primarily generated by NADPH OXIDASEs (referred to as RESPIRATORY BURST OXIDASE HOMOLOGs [RBOHs] in plants). However, the types and locations of ROS produced by RBOHs are different from those expected to mediate intracellular signaling. RBOHs produce O2•- rather than H2O2 which is relatively long-lived and able to diffuse through membranes, and this production occurs outside the cell instead of in the cytoplasm, where signaling cascades occur. A widely accepted model explaining this discrepancy proposes that RBOH-produced extracellular O2•- is converted to H2O2 by superoxide dismutase and then imported by aquaporins to reach its cytoplasmic targets. However, this model does not explain how the specificity of ROS targeting is ensured while minimizing unnecessary damage during the bulk translocation of extracellular ROS (eROS). An increasing number of studies have provided clues about eROS action mechanisms, revealing various mechanisms for eROS perception in the apoplast, crosstalk between eROS and reactive nitrogen species, and the contribution of intracellular organelles to cytoplasmic ROS bursts. In this review, we summarize these recent advances, highlight the mechanisms underlying eROS action, and provide an overview of the routes by which eROS-induced changes reach the intracellular space.

Does Brand Orientation Matter? An Empirical Study of Korean SMEs

  • Park, Sang IL;Kim, Mi Jeong
    • Asia Marketing Journal
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    • v.14 no.4
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    • pp.117-142
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    • 2013
  • Brand orientation is a relatively new paradigm in marketing which was first introduced in the 1990s. Since then, an accumulating body of research has addressed the strategic importance of brand orientation. Although there is a growing body of literature on brand orientation, there have been no empirical studies examining the mediation effect of brand orientation on market orientation-performance relationship to date. Moreover, most studies on brand orientation have been carried out in the context of large enterprises. Hence, the aim of this research is to extend the literature and address market orientation, brand orientation, and firm performance against the backdrop of Korean SMEs. The authors empirically investigate the impact of market/brand orientation on organizational performance and the mediating role of brand orientation. They utilize 178 usable responses to test the four research hypotheses. The hypothesized model predicts that there is a positive association among market orientation, brand orientation, and firm performance. It is also expected that brand orientation mediates the relationship between market orientation and organizational performance. The statistical results based on PLS analysis confirm our prediction among the constructs in the research model. The empirical evidence provides significant theoretical and managerial implications for brand orientation among SMEs. The first theoretical implication is that we provide empirical evidence regarding the important role of brand orientation in explaining the multi-trait perspectives of strategic orientation. The second theoretical implication is that the concept of brand orientation can be empirically validated in the context of SMEs. In terms of managerial implications, managers of SMEs should attempt to build a brand-oriented corporate culture or mindset that places brand values and brand norms as the top priority among their company's tasks. In addition, managers should recognize that brand orientation is critical for SMEs as well as large enterprises. In the last section, the authors address limitations of the study and provide directions for further research.

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The Effect of Customer Experience on Export Performance in Overseas Marketing of SMEs: Moderating Effects of the Personal Contacts and Agility (중소기업의 해외마케팅에서 고객경험이 수출성과에 미치는 영향: 인적접촉과 민첩성의 조절효과)

  • Se-Hwa Ahn
    • Korea Trade Review
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    • v.47 no.5
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    • pp.253-272
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    • 2022
  • As the digital era accelerates, traditional perspectives have limitations in explaining the success or failure of export performance. The purpose of this study is to analyze new factors affecting export performance from the perspective of customer experience, which has emerged as an important factor in securing a competitive advantage and generating organizational performance. After deriving hypotheses based on literature review and discussion, a research model is designed in which three factors of customer experience such as understanding customer's objectives, customer value creation capability, and customer journey management are the antecedents, and export performance is the dependent variable. This model also includes organizational agility and personal contact as the moderating variables. To verify the hypotheses, multiple regression analysis was conducted on the collected data drawn from 198 SME exporters. According to the analysis results, it was found that all three antecedents positively affected export performance. In particular, the organizational agility and personal contact were confirmed to have a moderating effect that creates better export performance by interacting with customer value creation capability. The theoretical significance of this study is to find that effective customer experience management can be a key factor in creating export performance. The results suggest that checking the overall customer journey, exporters should select and intervene to intensively manage key touch points that can have a decisive impact on the quality of customer experience. At the end of the paper, practical implications to be considered in creating export performance through effective customer experience management are presented.

Validation of the Disaster Adaptation and Resilience Scale for Vulnerable Communities in Vietnam's Coastal Regions

  • Thanh Gia Nguyen;Binh Thang Tran;Minh Tu Nguyen;Dinh Duong Le
    • Journal of Preventive Medicine and Public Health
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    • v.57 no.3
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    • pp.279-287
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    • 2024
  • Objectives: This study validated the Vietnamese version of the Disaster Adaptation and Resilience Scale (DARS) for use in vulnerable communities in Vietnam. Methods: This was a cross-sectional study involving 595 adults from 2 identified communities. The original DARS assessment tool was translated, and the validity and reliability of the Vietnamese version of DARS (V-DARS) were assessed. The internal consistency of the overall scale and its subscales was evaluated using Cronbach's alpha and McDonald's omega reliability coefficients. Confirmatory factor analysis (CFA) was employed to evaluate its construct validity, building upon the factor structure identified in exploratory factor analysis (EFA). Construct validity was assessed based on convergent and discriminant validity. Results: Following the established criteria for EFA, 8 items were removed, resulting in a refined V-DARS structure comprising 35 items distributed across 5 distinct factors. Both alpha and omega reliability coefficients indicated strong internal consistency for the overall scale (α=0.963, ω=0.963) and for each of the 5 sub-scales (all>0.80). The CFA model also retained the 5-factor structure with 35 items. The model fit indices showed acceptable values (RMSEA: 0.072; CFI: 0.912; TLI: 0.904; chi-square test: <0.01). Additionally, the convergent and discriminant validity of the V-DARS were deemed appropriate and satisfactory for explaining the measurement structure. Conclusions: Our findings suggest that the V-DARS is a valid and reliable scale for use within vulnerable communities in Vietnam to assess adaptive responses to natural disasters. It may also be considered for use in other populations.

A Critical Review on Behavioral Economics with a Focus on Prospect Theory and EBA Model (프로스펙트 이론과 속성별 제거모형을 중심으로 한 행동경제학에 대한 비판적 고찰)

  • Won, Jee-Sung
    • Journal of Distribution Science
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    • v.11 no.5
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    • pp.63-76
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    • 2013
  • Purpose - For the past several decades, behavioral economics or behavioral decision theory has undergone rapid development. This study provides a critical review of the development of behavioral economics with a focus on what are deemed to be core theories in the field. Starting from the utility function proposed by Daniel Bernoulli in the 18th century, the development history of utility functions until the emergence of the prospect theory is thoroughly reviewed. Some of the experimental results violating the traditionally assumed utility function and supporting the prospect theory value function are summarized. The most representative principles of rational choice are transitivity, independence from irrelevant alternatives (IIA), and regularity. The development of behavioral economics has been triggered by finding counter-examples to these principles. Some of the choice behaviors discussed in this study as counter-examples to the traditional theories of rational choice are the St. Petersburg paradox; the Allais paradox; gambling behavior; and the various context effects including the similarity effect, attraction effect, and the compromise effect. The Elimination-by-Aspects (EBA) model, which was proposed as an explanation for the similarity effect, is discussed in detail as well. Based on the literature review and further analysis, this study summarizes the relationship between the context effects, prospect theory, and EBA model. Research design, data, and methodology - This study provides an extensive literature review on several important theories in the field of behavioral decision theory and adds some critical comments to the theories and the relationships among them. This study first reviews the development of utility functions. Daniel Bernoulli introduced the concept of utility function to solve the St. Petersburg paradox. In the mid-20th century, Herbert Simon proposed the "satisficing" heuristic and presented a value function with a shape different from traditional utility functions. This study highlights the strengths and weaknesses of several utility functions proposed until the emergence of the prospect theory value function. Results - This study posits that prospect theory and EBA model are the two most important theories in the field of behavioral decision theory. They can explain various choice behaviors that traditional utility maximization analysis has been unable to. The application of these models to various fields is further increasing nowadays. This study explains how prospect theory and the EBA model can be used to explain the context effects. Conclusions - The traditional economic theory relies on a single variable called "utility" in explaining consumer choice. However, this study argues that, in investigating consumer choice, several other variables should also be considered. These are the similarity among alternatives, an alternative's prototypicality within the category, the dominance relationship between alternatives, and the reference point in evaluating alternatives. Due to the development of behavioral economics, we are now closer to a more complete understanding of consumer choice behavior than in the past when we had only a single tool called utility.

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Classification Tree Analysis to Assess Contributing Factors Influencing Biosecurity Level on Farrow-to-Finish Pig Farms in Korea (분류 트리 기법을 이용한 국내 일괄사육 양돈장의 차단방역 수준에 영향을 미치는 기여 요인 평가)

  • Kim, Kyu-Wook;Pak, Son-Il
    • Journal of Veterinary Clinics
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    • v.33 no.2
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    • pp.107-112
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    • 2016
  • The objective of this study was to determine potential contributing factors associated with biosecurity level of farrow-to-finish pig farms and to develop a classification tree model to explore how these factors related to each other based on prediction model. To this end, the author analyzed data (n = 193) extracted from a cross-sectional study of 344 farrow-to-finish farms which was conducted between March and September 2014 aimed to explore swine disease status at farm level. Standardized questionnaires with information about basic demographical data and management practices were collected in each farm by on-site visit of trained veterinarians. For the classification of the data sets regarding biosecurity level as a dependent variable and predictor variables, Chi-squared Automatic Interaction Detection (CHAID) algorithm was applied for modeling classification tree. The statistics of misclassification risk was used to evaluate the fitness of the model in terms of prediction results. Categorical multivariate input data (40 variables) was used to construct a classification tree, and the target variable was biosecurity level dichotomized into low versus high. In general, the level of biosecurity was lower in the majority of farms studied, mainly due to the limited implementation of on-farm basic biosecurity measures aimed at controlling the potential introduction and transmission of swine diseases. The CHAID model illustrated the relative importance of significant predictors in explaining the level of biosecurity; maintenance of medical records of treatment and vaccination, use of dedicated clothing to enter the farm, installing fence surrounding the farm perimeter, and periodic monitoring of the herd using written biosecurity plan in place. The misclassification risk estimate of the prediction model was 0.145 with the standard error of 0.025, indicating that 85.5% of the cases could be classified correctly by using the decision rule based on the current tree. Although CHAID approach could provide detailed information and insight about interactions among factors associated with biosecurity level, further evaluation of potential bias intervened in the course of data collection should be included in future studies. In addition, there is still need to validate findings through the external dataset with larger sample size to improve the external validity of the current model.

A Structural Equation Model on Quality of Life in Hemodialysis Patients (혈액투석환자의 삶의 질 구조모형)

  • Kang, Seung-Ja;Seo, Nam-Sook
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.7
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    • pp.589-598
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    • 2019
  • This study was conducted to build a structural equation model explaining factors that affect hemodialysis patients' quality of life to test the goodness of fit of the model and identify directly and indirectly significant paths. To accomplish this, 230 patients receiving hemodialysis registered at study hospitals in G Metropolitan City and M City were randomly selected, and 201 were used in the final analysis. Data were collected using a self reporting questionnaire from February 1 to March 31, 2014. SPSS WIN 18.0 was used for descriptive statistics and correlation analysis of the general characteristics and for reliability analysis of the research tools. In addition, AMOS 18.0 was used for confirmatory factor analysis of latent variables, to determine the goodness of fit of the hypothetic model, and hypotheses testing. The results of this study were as follows: the fit of the modified model was 41.32, GFI = .96, AGFI = .92, RMR = .04, NFI = .96, CFI = .91 and TLI = .95. Twelve out of the 22 research hypotheses that were improved and improved were statistically significant. The results indicated that hemodialysis patients' quality of life was influenced directly by self-efficacy, depression, and self-care behavior, and indirectly by sleep disturbance, stress, fatigue, and family support. These variables explained 58.6% of the variation in quality of life. Overall, these findings suggest that nursing interventions for hemodialysis patients require strategies for managing patient depression and for increasing self-efficacy and self-care behavior to improve quality of life.

The Classification System for Measuring Marketing Expenditure and Marketing Performance (마케팅지출과 마케팅성과의 측정을 위한 분류체계)

  • Jeon, In-Soo;Jeong, Ae-Ju
    • Asia Marketing Journal
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    • v.11 no.1
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    • pp.39-72
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    • 2009
  • With the growing importance of accountability, it is getting necessary to test the impact of marketing expenditure on marketing performance. Including recent ROM, we can find a few researches about marketing accountability. But there are a few problems about definitions and metric of marketing expenditure and marketing performance. Therefore, by defining and analyzing the impact of marketing expenditure on marketing performance, we are going to set the classification scheme of marketing expenditure and marketing performance. Based on research findings, new definitions and metrics are proposed as follows. First, we suggest the classification scheme of marketing expenditure. Marketing expenditure is defined as expense accounts in the balance sheet for doing marketing tasks. Marketing expenditures includes many accounts, for example, marketing research, advertising, sales promotion, foreign market development, physical distribution, after services. Among these marketing investment, advertising expenses have a positive effect on marketing performance. Second, we suggest the classification scheme of marketing performance. Already, marketing performance has been defined as financial metrics, customer metrics, market metrics, and corporate social responsibility. But, in this study, we find that the process model is not relevant for explaining association between the performance metrics. The process model is a virtuous cycle: "customer metrics→market metrics→financial metrics→firm valuation metrics." But, in this study, it is not supported or a little significant association between these metrics. Based on these results, we suggest the balance model or flower model as the classification scheme of marketing performance.

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The Study of Causal Model on Science Teachers' Adoption of 'Science' Focusing on the Fusion in the 2009 Revised Curriculum (과학교사들의 2009 개정 교육과정 융합형 '과학' 수용에 관한 인과 모델 연구)

  • Ha, Minsu;Shin, Sein;Lee, Jun-Ki;Park, HyunJu;Chung, Duk-Ho;Lim, Jae-Keun
    • Journal of The Korean Association For Science Education
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    • v.34 no.3
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    • pp.235-246
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    • 2014
  • This study aims to explore how in-service science teachers adopt newly developed 'Science' focusing on the fusion of science based on 'the diffusion of innovation' model. For this study, we have explored five variables (i.e., perception of need, perception of support, innovativeness, perceived usefulness, self-efficacy of teaching, and intention to adopt) based on literature review and developed survey items to measure the level of five variables that in-service science teachers perceive. In addition, the path model of six variables explaining how in-service science teachers adopt an innovation was hypothesized by the literature review. A total of 349 in-service science teachers have participated in this survey study. First of all, results have illustrated that the levels of six variables have not significantly associated with in-service science teachers' teaching experiences, participation in professional development programs on 'Science' curriculum, and majors. In addition, the statistically acceptable model fit indices have illustrated that path model has been statistically valid to explain how in-service science teachers adopt newly developed 'Science' focusing on the fusion of science. The results have also illustrated that 'perception of support', 'perceived usefulness', and 'self-efficacy of teaching' exhibited strong mediating effects between other variables. For the successful establishment of newly developed curricula, textbook, or policies in science education in school, the level of teachers' intention to adopt innovations should be enhanced. This study will be useful for the development of new science teacher professional development programs to promote the level of teachers' intention to adopt innovations.

A Study on the Policy Performance of Government 3.0 Innovation Model : Case Study on the Higher-education Loan Policy in Korea (정부3.0 혁신모델에 따른 정책성과 분석 - 고등교육 학자금대출 서비스 정책을 중심으로 -)

  • JIN, Sangki;Yun, Seon Young;Kim, Seang Tae
    • Informatization Policy
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    • v.22 no.4
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    • pp.68-90
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    • 2015
  • This study aims, to review and analyze the trend of the paradigm shift of government innovation focused on the relation between government and citizens. This paper tries to analyze the effects and performance of government innovation through the government 3.0 model, which is highlighted in Korea. This paper chooses higher-education loan programs as the case to study and analyzes results using government innovation theories. Especially, this paper re-organizes Korea's higher-education loan programs with 'Government 3.0 model'. We can expect 'Government 3.0 model'is usefull when explaining the specific policy program innovation loan. Lastly, this paper looks, at improvement points in Korea's higher-education loan programs.