• Title/Summary/Keyword: exogenous factors

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A Study on Determinants of Photovoltaic Energy Growth: Panel Data Regression with Autoregressive Disturbance (태양광 보급의 결정요인 연구: 자기상관 패널데이터 분석)

  • Kim, Kwangsu;Choi, Jinsoo;Yoon, Yongbeum;Park, Soojin
    • Current Photovoltaic Research
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    • v.10 no.1
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    • pp.6-15
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    • 2022
  • Climate change is among the most important issues facing mankind in modern society. However, global PV energy expansion has been driven mainly by OECD countries. We investigate the determinants of PV energy growth by panel data of selected OECD countries from 1991 to 2018. We investigate four categories of driving factors: socioeconomic, technological, country specific, and policy factors. The test results support that PV capacity growth is significantly driven by technology development and multidimensional environment policy factors. Socioeconomic factors such as CO2, GDP, and electricity price are statistically significant on the growth of PV energy, too. Whereas, country-specific solar potential factor is the least related. As most of the socioeconomic factors are exogenous, we need to focus more on PV technology development and policy measures.

Analysis of the Structural Relationships among Self-efficacy, Experience, Mobile Learning Quality, and Learner Satisfaction in Universities

  • LEE, Jong-Yeon;PARK, Sanghoon
    • Educational Technology International
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    • v.17 no.2
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    • pp.203-228
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    • 2016
  • This study was designed to determine the factors affecting learner satisfaction and examine the relationships of these factors in mobile learning linked to pre-existing e-learning in universities. In the structural model used, three mobile learning quality factors are the endogenous variables, namely, system quality (SYQ), information quality (INQ) and service quality (SEQ) perceived by students, and learner satisfaction (LS), whereas students' self-efficacy (SE) and experience (EX) in mobile learning are the exogenous variables. The subjects were 900 students who registered for mobile learning courses offered by a private university in Seoul, Korea. The results indicated that SE in mobile learning had positive effects on SYQ, INQ, and SEQ. Furthermore, SE influenced LS when analyzed without quality factors as parameters. Mobile learning EX directly affected INQ, but not SYQ or SEQ. EX likewise had a direct effect on LS when analyzed without quality factors as parameters. Meanwhile, both SYQ and INQ showed a positive effect on LS, but not SEQ. SE and EX affected LS indirectly when SYQ and INQ were used as parameters. This study addresses the importance of increasing SE, EX, SYQ, and INQ to increase LS in mobile learning in universities

Disease-specific pluripotent stem cells

  • Kang, Hoon-Chul
    • Clinical and Experimental Pediatrics
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    • v.53 no.8
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    • pp.786-789
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    • 2010
  • Induced pluripotent stem (iPS) cells are generated by epigenetic reprogramming of somatic cells through the exogenous expression of transcription factors. Recently, the generation of iPS cells from patients with a variety of genetic diseases was found to likely have a major impact on regenerative medicine, because these cells self-renew indefinitely in culture while retaining the capacity to differentiate into any cell type in the body, thereby enabling disease investigation and drug development. This review focuses on the current state of iPS cell technology and discusses the potential applications of these cells for disease modeling; drug discovery; and eventually, cell replacement therapy.

The Literatural Study on the classification of cause and the effect of Acupuncture and Moxibustion treatment for Tinnitus (이명(耳鳴)의 병인별(病因別) 분류(分類)와 침구치료(鍼灸治療)에 관(關)한 문헌적(文獻的) 고찰(考察))

  • Yang, Gi-young;Lee, Byung-ryul
    • Journal of Haehwa Medicine
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    • v.8 no.2
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    • pp.273-287
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    • 2000
  • The Literatural Study on the classification of cause and the effect of Acupuncture and Moxibustion treatment for Tinnitus was studied from the viewpoint of therapeutic acupuncture and moxibustion effect. And the results were as follows: 1. The cause of Tinnitus is divided three parts, The Internal Organs factors, Internal damages, and Exogenous pathogenic factors, in The Nei Jing. 2. The basal meridian of acupuncture and moxibustion treatment were the channels of Shaoyang. 3. The treatment of acupuncture had a rule of Ju Ci.

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Current Insights on Cholangiocarcinoma Research: a Brief Review

  • Mathema, Vivek Bhakta;Na-Bangchang, Kesara
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.4
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    • pp.1307-1313
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    • 2015
  • Colangiocarcinoma (CCA) is a progressively fatal disease which generally occurs due to malignant transformation of hepatic biliary cholangiocytes. The incidence of CCA has been increasing worldwide and there is an urgent requirement for effective diagnosis and treatment strategies against this devastating disease. Different factors including liver-fluke infestation, viral hepatitis, exogenous nitrosamine-mediated DNA damage, and chronic inflammation have been linked to CCA genesis. However, the risk factors and underlying complex mechanisms leading to development of CCA are not sufficiently understood to devise an effective targeted treatment therapy. In this review, we summarize currently known epidemiological and pathological aspects of the disease and briefly describe various potential biomarkers and experimental anticancer phytochemicals related to CCA research. In addition, we also sum up recent findings that link chronic inflammation of hepatic biliary cholangiocytes with CCA. The collective information concisely presented in this article would provide useful insights into the current understanding of this cancer.

Effect of foliar spraying 6-benzylaminopurine on the growth and flowering of Sedirea japonica seedling (6-benzylaminopurine의 엽면살포가 나도풍란 유묘의 생장 및 개화에 미치는 영향 분석)

  • Jiae An;Hyeong-Bin Park;Pyoung-Beom Kim;Hwan-Joon Park;Seongjun Kim;Chang-Woo Lee;Byoung-Doo Lee;Ju-Hyoung Baek;Nam-Young Kim;Jung-Eun Hwang
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.26 no.6
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    • pp.155-164
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    • 2023
  • Sedirea japonica is one of the critically endangered species in South Korea mostly due to artificial harms such as illegal collection and habitat destruction. Therefore, artificial propagation through improving germination rate, increasing growth, and controlling flowering is meaningful for the conservation and reintroduction of S. japonica. It is suggested that cytokinins are one of the multi-factors that contribute to plant growth and floral responses. Especially, exogenous cytokinins have been known to induce or promote shoot growth or earlier flowering in orchids. Therefore, it was investigated how the application of 6-benzylaminopurine (BA) influenced the growth and inflorescence of S. japonica. A foliar spray containing BA at 100, 200, 300, and 400 ppm was applied from 1st July to 30th December 2021. Leaf length, leaf length growth rate, leaf width, and width and length ratio were measured as growth-related factors. Visible inflorescence rate, inflorescence length, the number of flowers per inflorescence, and the distance between the stalks were measured as flowering-related factors. Growth-related factors except for leaf growth rate were not affected by BA treatments, while leaf growth rate was significantly increased by 200 ppm of BA treatment. The visible inflorescence rate increased by 200 ppm of BA treatment, and there seems an optimal concentration and threshold of BA treatment. An iterative experiment with more seedlings and measurement factors would be helpful to figure out the effects of exogenous BA treatment on S. japonica, and it can be applied for mass propagation.

Risk Factors for Sudden Infant Death Syndrome and Sleeping Practices in Korea

  • Ahn, Young Mee;Yang, Kyung-moo;Ha, Hong Il;Cho, Jung Ae
    • Child Health Nursing Research
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    • v.26 no.1
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    • pp.82-89
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    • 2020
  • Sudden infant death syndrome (SIDS) in Korea remains a poorly-understood subject for both professionals and the public. Recent reports have emphasized ethnic differences in SIDS rates, suggesting that making adjustments in child-rearing practices may contribute substantially to SIDS reduction. Two of the three major risk factors for SIDS-vulnerability of the infant and exogenous factors-need to be understood in particular depth due to their broad scope and sociocultural grounding. This paper presents substantial issues regarding preterm birth and male gender on infants' vulnerability to SIDS in Korea. Practices of caring for healthy infants are addressed in the context of sleeping practices, including sleeping position, bedding arrangements, sleeping on the floor, the back-to-sleep position, high indoor temperatures and ondol floor heating, and swaddling. Professional and social awareness about how to reduce SIDS should be raised by promoting a better understanding of risk factors in the context of ethnic and cultural variations in child-rearing practices.

A Study on Estabilshing lndicies of National Park Management with Reference to User Satisfaction (이용자 만족도에 준거한 국립공원 관리의 지표설정에 관한 연구)

  • 박찬용
    • Journal of the Korean Institute of Landscape Architecture
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    • v.23 no.1
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    • pp.39-50
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    • 1995
  • This Study aims at identifying factor and variables which have significant effects on user satisfaction with recreational resources and facilities in Juwang National Park and there-by establishes indicies of planning and / or management of the park. To test the causal models of this research, the data was gathered by self-administered questionnaires from users in Juwang National Park. The analysis of the data was conducted in two phases. The first analysis dealt with exploratory gactor analysis which identified major factors involved in satisfaction with recreational facilities in Juwang National Park. The second analysis tested the fit of causal models of this research to the data using LISREL methodology. The factor analysis identified six significant factors in satisfaction with recreational resources, The six factors are convenient park facilities, natural landacape resources, linear park facilities, mineral springs and Buddhist temples, commercial and sleeping accommodations, rest areas and open space for passive recreational activity. The second phase analysis tested the fit of the causal model for satisfaction with recreation facilities to the data. The phase identified statistically significant causal links among overall satisfaction with the park, and other indigenous factors and exogenous variables. From these causal relationships, implications for future management of Juwang National Park were suggested.

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Evaluating the Multi-Period Management Efficiency of Domestic Online-Shopping Companies (DEA와 Malmquist 생산성지수를 이용한 우리나라 온라인쇼핑업체의 다기간 경영 효율성 분석)

  • Ma, Jin-Hee;Ja, Yoon-Ho;Ahn, Young-Hyo
    • Journal of Distribution Science
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    • v.13 no.4
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    • pp.45-53
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    • 2015
  • Purpose - Online shopping enables consumers to conveniently purchase products irrespective of the time and place. As a result, several online shopping companies have emerged to cater to this growing market and, therefore, the competition among them has become increasingly intense. This paper evaluates the comparative efficiency of online shopping companies for a multi-year period (2009-2013), in order to help online shopping managers identify major drivers for enhancing management efficiency and the subsequent competitiveness. Research design, data, and methodology - The researchers collected the data from 2009 to 2013 from the distribution yearbook. This paper analyzes the marketability (sales figures), profitability (business profits), and management conditions (net profits) of domestic online shopping enterprises by incorporating information on human resources (number of employees) and material resources (total assets and capital). Therefore, the number of employees, total assets, and capital are selected as input variables, and sales figures, business profits, and net profits as the output variables. In this study, Data Envelopment Analysis (DEA) was used to measure the comparative efficiency of domestic online shopping companies. In addition, the Malmquist Productivity Index was used to evaluate the trend of change of Decision Making Units' (DMUs') efficiency for a multi-year period. Results - First, as of 2013, Interpark (2.415) was found to be the most efficient online shopping enterprise, followed by Aladdin Communications (2.117), Hyundai Home shopping (1.867), Home&Shopping (1.176), NS Home shopping (1.170), Commerce Planet (1.126), CJ O Shopping (1.105), Ebay Korea (1.088), and GS Home Shopping (1.051). Second, this study recognizes how the management efficiency has changed for the period 2009-2013. Third, the lesser the capital and employees, the more are the net profits, and the better is the management efficiency of domestic online shopping companies. Lastly, the productivity of such companies is influenced by endogenous factors rather than exogenous factors such as shifts in business environment and technological advances. Conclusions - DHC Korea influenced various distribution channels to reach customers through the Internet. Consequently, this helped in increasing the awareness about its products, in addition to an increase in sales. These achievements can be attributed to the characteristics of online shopping companies. Although it is easy for these companies to suggest goods for one-off purchases, they however have difficulties in retaining customers. Overcoming this challenge can be one of the ways to benchmark a successful case of an efficient company. For example, an online shopping company can attract customers by developing a corresponding mobile application as a convenient way to shop online. Additionally, they can satisfy customers by quick delivery of purchased products, which is possible by building an effective logistics network. Our study indicates that the productivity of an online shopping company was influenced by endogenous factors driven by improvements in managerial practices rather than exogenous factors. Accordingly, online shopping companies should adopt strategies to improve their operational efficiency rather than sales volume-oriented management.

A literatual study on the Ecthyma (렴瘡에 對한 文獻的 考察)

  • Kim, Hee-Taek;Oh, Young-Seon;Rho, Sek-Seon
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.10 no.1
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    • pp.209-246
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    • 1997
  • In the literatual study on the Ecthyma, the results were as follows. 1. The pathogenic factors of Ecthyma is divided three parts. One is exogenous pathogenic factors which including the wind evil, wind heat and toxic material produced by wetness evil. Another is endogenous pathogenic factors which including the declination of kidney-yang, impairment of the liver and kidney, the lower classes of yin-fire, accumulation of wetness-heat in the spleen asthenia, impairment of the liver and kidney, wetness-heat of three yang, asthenic heat-syndrome of three yin. The other is pathogenic factors neither endogenous nor exogenous which including the food and living, uncontrol sexual excess, anxiety and angry, injury of skin, injury of insects and animals. 2. Five viscera which was concerned with Ecthyma are liver, spleen and kidney. 3. Frequent region of Ecthyma are S-36(足三里) and C-7(陰交). External Ecthyma was rose to wetness-heat of three yang channel that cured easily. Internal Ecthyma was rose to asthenic heat-syndrome of three yin channel that cured hardly. 4. In the frequency of prescription, the most numerous prescription is Bojungikgitang(補中益氣湯) and the next are Kyukgigo(隔紙膏) and Yukmijihwanghwan(六味地滉丸). 5. In the frequency of medicine, the most medicine is Calomelas(輕粉) which included Hydrargyrum(水銀) and the next are Olibanum(乳香) and Resina Commiphorae Myrrhae(沒藥) which regulating vital energy and pain control medicine used that in order to destroy insects and remove polson. 6. In classification of the medical action, medicine of clearing away summer-heat and heat evil and activating blood circulation to dissipate blood stasis used to be very busy which in order to remove the disorder of vital energy for virulent heat-evil. 7. In classification of four characters, the most part is warm medicine, the next are cold and cool medicine and there is a few that is hot medicine. 8. In classification of five tastes, the most numerous tastes are bitter and acrid, the next are sweet, salty and sour tastes. 9. In classification of virulence of medicine, the most part is non-toxic, the next are weakly and deadly poison. 10. In classification of channel distribution, the most is the medicine that belongs to liver channel, the next are the lung, spleen, stomach and kidney channel.

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