• Title/Summary/Keyword: empirical research

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On the development of an empirical proton event forecast model based on the information of flares and CMEs

  • Moon, Yong-Jae;Park, Jin-Hye
    • Bulletin of the Korean Space Science Society
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    • 2010.04a
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    • pp.38.2-38.2
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    • 2010
  • We have examined the occurrence probability of solar proton events (SPEs) and their peak fluxes depending three flare parameters (X-ray peak flux, longitude, and impulsive time). For this we used NOAA SPEs from 1976 to 2006, and their associated X-ray flare data. As a result, we selected 166 proton events that were associated with major flares; 85 events associated with X-class flares and 81 events associated with M-class flares. Especially the occurrence probability strongly depends on these three parameters. In addition, the relationship between X-ray flare peak flux and proton peak flux as well as its correlation coefficient are strongly dependent on longitude and impulsive time. Among NOAA SPEs from 1997 to 2006, most of the events are related to both flares and CMEs but a few fraction of events (5/93) are only related with CMEs. We carefully identified the sources of these events using LASCO CME catalog and SOHO MDI data. Specifically, we examined the directions of CMEs related with the events and the history of active regions. As a result, we were able to determine active regions which are likely to produce SPEs without ambiguity as well as their longitudes at the time of SPEs by considering solar rotation rate. From this study, we found that the longitudes of five active regions are all between $90^{\circ}W$ and $120^{\circ}W$. When the flare peak time is assume to be the CME event time, we confirmed that the dependence of their rise times (proton peak time - flare peak time) on longitude are consistent with the previous empirical formula. These results imply that five events should be also associated with flares which were not observed because they occurred from back-side. Now we are examining the occurrence probability of SPEs depending on CME parameters. Finally, we will discuss the future prospects on the development of an empirical SPE forecast model based on the information of flares and CMEs.

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Current Status and Directions of Professional Identity Formation in Medical Education (전문직 정체성 형성 및 촉진을 위한 의학교육 현황과 고려점)

  • Han, Heeyoung;Suh, Boyung
    • Korean Medical Education Review
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    • v.23 no.2
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    • pp.80-89
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    • 2021
  • Professional identity formation (PIF) is an essential concept in professional education. Many scholars have explored conceptual frameworks of PIF and conducted empirical studies to advance an understanding of the construct in medical education. Despite its importance, it is unclear what educational approaches and assessment practices are actually implemented in medical education settings. Therefore, we conducted a literature review of empirical studies reporting educational practices for medical learners' PIF. We searched the Web of Science database using keywords and chose 37 papers for analysis based on inclusion and exclusion criteria. Thematic analysis was conducted. Most empirical papers (92%) were from North America and Western Europe and used qualitative research methods, including mixed methods (99%). The papers reported the use of reflection activities and elective courses for specific purposes, such as art as an educational activity. Patient and healthcare experiences were also found to be a central theme in medical learners' PIF. Through an iterative analysis of the key themes that emerged from the PIF studies, we derived the following key concepts and implications: (1) the importance of creating informal and incidental learning environments, (2) ordinary yet authentic patient experiences, (3) a climate of psychosocial safety in a learning environment embracing individual learners' background and emotional development, and (4) the reconceptualization of PIF education and assessment. In conclusion, research on PIF should be diversified to include various cultural and social contexts. Theoretical frameworks should also be diversified and developed beyond Kegan's developmental framework to accommodate the nonlinear and dynamic nature of PIF.

The Effects of Managerial Attributes on Cost Stickiness: An Empirical Analysis of Korean Exporters and Implications for Start-ups

  • Ji, Sang-Hyun;Kwon, Il Sook;An, Sang Bong
    • Journal of Korea Trade
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    • v.25 no.2
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    • pp.196-219
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    • 2021
  • Purpose - We attempted to empirically verify the effects of managerial attributes on cost stickiness in exporters. Exporters are often affected not only by external factors such as exchange rate but also by internal factors such as managerial attributes regarding their business activities. Because cost stickiness is the product of a manager's decision-making, it has been considered that managerial attributes have a great influence on the behavior. Therefore, our study was intended to find out whether cost stickiness shows differentiated aspects depending on managerial attributes in exporters. Design/methodology - We considered two managerial attributes: CEO power and managerial overconfidence. First, CEO power was measured as CEO pay slice. In addition, managerial overconfidence was measured based on three methodologies presented by previous studies. To measure cost stickiness, we used multiple methodologies presented by prior research. Findings - The results of our empirical analysis are as follows. First, in export firms, the greater CEO power is, the greater cost stickiness is. This result suggested that export managers with great influence little respond to temporary sales decrease promptly, little reduce related production costs flexibly in preparation for future sales recovery, but leave room to endure costs for idle resources. Second, the greater managerial overconfidence is, the greater cost stickiness is. This result indicated that export managers with great overconfidence on their decision-making often view the prospect for sales recovery positively; therefore, they little respond to temporary sales decrease immediately, little reduce related production costs flexibly for future sales recovery, but leave room to endure costs for idle resources. Third, export managers with great influence in their businesses and great overconfidence in their decision-making tend to show relatively great cost stickiness. The results proposed that the combination of the two factors functions to make cost stickiness greater. Originality/value - Our study is differentiated from extant studies in that we provided empirical evidence of the effects of managerial attributes on their business activities in exporters. Specifically, we verified the effects of managerial attributes on cost stickiness in Korean exporters. The results of our study are expected to contribute to providing useful information for exporters and start-ups.

Estimation of Local Scour at Piers Using Artificial Neural Network (인공신경망을 이용한 피어의 국부세굴 평가)

  • Park, Hyun-Il;Shin, Jong-Hyun
    • Journal of the Korean Geotechnical Society
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    • v.24 no.11
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    • pp.17-24
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    • 2008
  • It is known that scour at bridge piers is one of the leading causes of bridge failure. However, the mechanism of flow around a pier structure is so complicated that it is difficult to establish a general empirical model to provide accurate estimation for scour. Especially, each of the proposed empirical formula yields good results for a particular data set but can't show reliable predictability for various scouring data set. In this study, an alternative approach, that is, artificial neural networks (ANN), is proposed to estimate the local scour depth with numerous field data base. The local scour depth was modeled as a function of seven variables; pier shape, pier width, pier length, skew angle, stream velocity, water depth, $D_{50}$. 426 field data were used for the training and testing of ANN model. The predicted results showed that the neural network could provide a better alternative to the empirical equations.

The Influence of South Korea's OFDI under the Effects of Multinational Enterprises' Investment Motivations and Host Country Institutions

  • Jie Gao;Jianlin Li;Ke Yuan;Wanli Liu
    • Journal of Korea Trade
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    • v.26 no.5
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    • pp.1-22
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    • 2022
  • Purpose - This study aims to analyze the influence of South Korea's outward foreign direct investment (OFDI) under the effect of both multinational enterprises' (MNEs) investment motivation and host country institutions. Some suggestions are put forward with regard to South Korean MNEs participating in and integrating into the fierce and changeable world of international market competition. Design/methodology - The basic hypotheses are that MNEs' investment motivations and the host country's superior institutions both boost South Korea's OFDI in those host countries. South Korea's OFDI is divided into investment choice stage and investment scale stage. A Heckman two-stage selection model is established for empirical analysis, using the panel data of South Korea's OFDI and related variables, from 2002 to 2019. Findings - (1) The influence on the investment scale of South Korea's OFDI is more regular and noteworthy than the influence on investment choice. (2) In the investment scale stage, there are obvious motivations to seek markets, labor force and superior technology, but not natural resources. (3) In the investment scale stage, the South Korea's OFDI is more obviously attracted by the host country's superior political institutions, economic institutions and legal institutions, but not cultural institutions. Originality/value - The choices of variables and uses of model expand the theoretical basis and empirical method of OFDI research. The results of the empirical study also provide some reference for the transnational investment of South Korean MNEs and the investment policy formulation of the South Korean government.

Impact Factors of Entrepreneurial Alertness (기업가적 기민성 영향요인)

  • Kim, Woo-Young;Kim, Hyoung-Gil;Hwangbo, Yun
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.13 no.1
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    • pp.1-10
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    • 2018
  • The importance of entrepreneurship has been emphasized recently from academia and government officials and studies trying to investigate entrepreneurial alertness as core competence of entrepreneurial mindset in the research field of entrepreneurship continue. In domestic academic research, research on entrepreneurial alertness has not yet been conducted in earnest, unlike the active flow of research overseas. This paper aims to investigate what factors influence entrepreneurial alertness in the Korean environment, we conducted an empirical analysis through a questionnaire survey for CEOs of small and medium enterprises in Seoul, Gyeonggi province. In this study, we selected prior knowledge of markets and technology, positive attitude, social network, number of books per month as independent variables on entrepreneurial agility based on Ardichvili's Alertness model, and as control variables respondents' Demographic characteristics, such as gender, age, founding career were selected. According to the results of the empirical analysis, prior knowledge of markets and technology, positive attitudes, number of books per month as independent variables, showed positive influence on entrepreneurial alertness, showing statistical significance. However, the social network picked up measured variables by the number of regular meetings which are quantitative indicators, but found that there is no statistically significant effect on entrepreneurial alertness. Despite several limitations of this research, we investigate what factors influence entrepreneurial alertness through empirical research on entrepreneurial alertness impact factors that have not been explained in the domestic academic research. Although you saw it, it can be said that there is academic contribution.

The Role of Postdoctoral Experience in Research Performance and the Size of Research Network of Young Researchers: An Empirical Study on S&T Doctoral Degree Holders (신진연구자의 연구 성과 및 연구 네트워크 규모에서 포닥 경험의 역할: 이공계 박사학위 취득자를 대상으로)

  • Ko, Yun Mi
    • Journal of Technology Innovation
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    • v.24 no.4
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    • pp.1-26
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    • 2016
  • The period after the PhD has a huge impact on the careers of researcher from a researcher lifecycle perspective. This is a turning point which student receives guidance from professor and become an independent researcher. Furthermore, they learn to develop ideas for independent research, apply for grants and manage a project; they also form expert networks in related filed and publish papers to share their findings. This study focuses on the period between earning doctoral degree and being employed as a stable position in university. This study starts from a research questions that asks which factors of postdoctoral experience affect research output. In this study, the paper performance, especially co-authorship of paper, of postdoctoral researchers was investigated. The cumulative advantage theory and Matthew effect were employed to shed a light on this research question. The empirical work is based on the Survey & Analysis of National R&D program in Korea conducted by Korea Institute of S&T Evaluation and Planning (KISTEP). The correlations between the research output and characteristics of postdoctoral experience were verified. These results are expected to contribute as new empirical evidences on investigating knowledge transfer activities of new PhDs.

A Study on a Effect of Product Design and a Primary factor of Qualify Competitiveness (제품 디자인의 파급효과와 품질경쟁력의 결정요인에 관한 연구)

  • Lim, Chae-Suk;Yoon, Jong-Young
    • Archives of design research
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    • v.18 no.4 s.62
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    • pp.95-104
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    • 2005
  • The purpose of this study is to estimate the determinants of product design and analyze the impacts of product design on quality competitiveness, product reliability, and consumer satisfaction in an attempt to provide a foundation for the theory of design management. For this empirical analysis, this study has derived the relevant measurement variables from a survey on 400 Korean manufacturing firms during the period of $August{\sim}October$ 2003. The empirical findings are summarized as follows: First, the determinants of product design are very significantly (at p<0.001) estimated to be the R&D capability, the level of R&D expenditure, the level of innovative activities(5S, TQM, 6Sigma, QC, etc.). This empirical result can support Pawar and Driva(1999)'s two principles by which the performance of product design and product development can be simultaneously evaluated in the context of CE(concurrent engineering) of NPD(newly product development) activities. Second, the hypothesis on the causality: product design${\rightarrow}$quality competitiveness${\rightarrow}$customer satisfaction${\rightarrow}$customer loyalty is very significantly (at p<0.001) accepted. This implies that product design positively affects consumer satisfaction, not directly but indirectly, by influencing quality competitiveness. This empirical result of this study can also support the studies of for example Flynn et al.(1994), Ahire et at.(1996), Afire and Dreyfus(2000) which conclude that design management is a significant determinant of product quality. The aforementioned empirical results are important in the following sense: the empirical result that quality competitiveness plays a bridging role between product design and consumer satisfaction can reconcile the traditional debate between QFD(quality function development) approach asserted by product developers and conjoint analysis maintained by marketers. The first empirical result is related to QFD approach whereas the second empirical result is related to conjoint analysis. At the same time, the empirical results of this study can support the rationale of design integration(DI) of Ettlie(1997), i.e., the coordination of the timing and substance of product development activities performed by the various disciplines and organizational functions of a product's life cycle. Finally, the policy implication (at the corporate level) from the empirical results is that successful design management(DM) requires not only the support of top management but also the removal of communication barriers, (i.e. the adoption of cross-functional teams) so that concurrent engineering(CE), the simultaneous development of product and process designs can assure product development speed, design quality, and market success.

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Prediction of Human Performance Time to Find Objects on Multi-display Monitors using ACT-R Cognitive Architecture

  • Oh, Hyungseok;Myung, Rohae;Kim, Sang-Hyeob;Jang, Eun-Hye;Park, Byoung-Jun
    • Journal of the Ergonomics Society of Korea
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    • v.32 no.2
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    • pp.159-165
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    • 2013
  • Objective: The aim of this study was to predict human performance time in finding objects on multi-display monitors using ACT-R cognitive architecture. Background: Display monitors are one of the representative interfaces for interaction between people and the system. Nowadays, the use of multi-display monitors is increasing so that it is necessary to research about the interaction between users and the system on multi-display monitors. Method: A cognitive model using ACT-R cognitive architecture was developed for the model-based evaluation on multi-display monitors. To develop the cognitive model, first, an experiment was performed to extract the latency about the where system of ACT-R. Then, a menu selection experiment was performed to develop a human performance model to find objects on multi-display monitors. The validation of the cognitive model was also carried out between the developed ACT-R model and empirical data. Results: As a result, no significant difference on performance time was found between the model and empirical data. Conclusion: The ACT-R cognitive architecture could be extended to model human behavior in the search of objects on multi-display monitors.. Application: This model can help predicting performance time for the model-based usability evaluation in the area of multi-display work environments.

Research on Dyeing Crafts of Chinese Indigo Dyed Designs (중국 남인염포 염색 공예 연구)

  • Lee, Min-Jeong;Sohn, Hee-Soon
    • The Research Journal of the Costume Culture
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    • v.19 no.2
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    • pp.376-388
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    • 2011
  • The purpose of this study is to examine the types and characteristics of Chinese indigo dyed designs performed until today in private houses of Chinese minority races and to examine the modern value of traditional dyeing crafts of minority races by investigating the cases of utilizing modern private Chinese indigo dyed designs. As the research methodology for theoretical study about the history of Chinese traditional pattern dyeing, the origin, types and characteristics of Chinese indigo dyed designs, the preceding research data, photo data, and Internet data were utilized, and for the empirical research on Chinese traditional dyeing techniques and the cases of utilizing today Chinese indigo dyed designs, the on-site survey on Guizhou and Yunnan was conducted during February and March 2008 and the data were collected and analyzed. Based on the results of this research, it was found that Chinese indigo dyed designs represented Chinese traditional pattern dyeing, which was inherited and developed mainly in Chinese minority races and Chinese. It could be seen that according to geographical distribution and characteristics of each race, the types and characteristics of dyeing techniques were formed, which are classified into the batik of the Miao of Guizhou in the Chinese southwestern region, the tie-dyeing of Bai of Yunnan, and Chinese blue calico(resist printing) of Chinese private houses in the Hunan and Huseo regions, and these represent the three typical Chinese dyeing techniques today. Based on the results of empirical research on the utilizing cases, focusing on the traditional living handicrafts of Chinese minority races, traditional cultural articles, and artworks, the modern values such as practical, cultural, and artistic values of Chinese indigo dyed designs could be rediscovered.