• Title/Summary/Keyword: Data Heterogeneity

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The Influence of Trade and Foreign Direct Investment on Green Total Factor Productivity: Evidence from China and Korea

  • Li, Kan-Yong;Gong, Wen-Chao;Choi, Beak-Ryul
    • Journal of Korea Trade
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    • v.25 no.2
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    • pp.95-110
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    • 2021
  • Purpose - This paper intends to conduct theoretical analysis and empirical test on the action mechanism of South Korea-China trade and South Korea's FDI to China on green total factor productivity, so as to provide a new perspective and ideas for the improvement of China's green total factor productivity and promote the high-quality development of China's economy Design/methodology - This paper uses the data of 30 provinces, autonomous regions and municipalities in China from 2004 to 2017 as the research sample, adopts the GML index method of SBM Directional Distance Function to measure GTFP, and analyzes the influence of South Korea-China trade and FDI from South Korea on China's GTFP. Findings - Trade is conducive to promoting technological progress, which has a significant promotion effect on China's green total factor productivity. While FDI has a significant inhibitory effect on China's green total factor productivity, which verifies the "pollution haven" hypothesis. In addition, such influence has certain regional overall heterogeneity. Trade has a more significant promoting effect on GTFP in eastern coastal areas, while FDI has a more significant inhibitory effect on GTFP in central and western inland areas. The interaction between trade and FDI is conducive to the improvement of green total factor productivity, indicating that the benign mechanism of trade and FDI has been formed. Urbanization, industrial structure, human resource level and investment in science and technology are all conducive to the improvement of GTFP. Originality/value - Through theoretical analysis and empirical test on the action mechanism of South Korea-China trade and South Korea's FDI on green total factor productivity, this paper provides a solid theoretical foundation for the further development of China-South Korea economic and trade cooperation in the future.

Treatment efficacy of gingival recession defects associated with non-carious cervical lesions: a systematic review

  • Oliveira, Livia Maria Lopes de;Souza, Camila Agra;Cunha, Sinara;Siqueira, Rafael;Vajgel, Bruna de Carvalho Farias;Cimoes, Renata
    • Journal of Periodontal and Implant Science
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    • v.52 no.2
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    • pp.91-115
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    • 2022
  • Purpose: This systematic review aimed to compare the efficacy, defined in terms of the mean percentage of root coverage (mRC), of surgical treatment approaches combined with adhesive restorations of non-carious cervical lesions (NCCLs) to that of root coverage alone in patients with a single gingival recession (GR) and NCCL. Methods: A literature search was conducted to identify longitudinal studies reporting the mRC following treatment for the correction of GR defects associated with NCCLs using a combination of surgical and restorative techniques in systemically and periodontally healthy patients. Results: The search resulted in the retrieval of 12,409 records. Seven publications met the inclusion criteria for the qualitative synthesis of data. The mRCs ranged from 69% to 97%. In the medium term, the gingival margin position was more stable when a connective tissue graft (CTG) was used, independently of whether restoration of teeth with NCCLs was performed. Conclusions: The strength of the evidence was limited by methodological heterogeneity in terms of study design as well as the unit and period of analysis, which precluded a metaanalysis. Although no definitive conclusion could be drawn due to the lack of sufficient evidence to estimate the effectiveness of the interventions, CTG-based procedures contributed to gingival margin stability regardless of the performance of restoration to treat NCCLs.

The Impact of Chinese SMEs' Financial Structure on Innovation Efficiency (중국 중소기업 재무구조가 혁신 효율성에 미치는 영향)

  • Wang, Yiqi;Sim, Jae-Yeon
    • Industry Promotion Research
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    • v.7 no.4
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    • pp.97-108
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    • 2022
  • This paper examined the impact of financing structure on the innovation efficiency of SMEs by constructing an econometric model using panel data of SMEs listed on the SME board from 2010 to 2020 as the research sample. The innovation efficiency of SMEs was measured by the Stochastic Frontier Analysis (SFA), the relationship between financing structure and innovation efficiency of SMEs was examined with the help of the Tobit model, and the corresponding heterogeneity analysis was conducted. Finally, the robustness of the model was tested. It was concluded that the effects of debt and equity financing on the quantitative efficiency of innovation were non-linear and mainly showed an inverted "U" shaped relationship. For innovation quality efficiency, bond financing could positively contribute, while equity financing negatively inhibits. Finally, the corresponding advice was given.

Efficacy of Combination Treatment of Herbal Medicine for External Use and Western Medicine for Atopic Dermatitis: A Systematic Review and Meta Analysis (아토피 피부염에서 한약 외용제와 양약 병용 치료의 효과: 체계적 문헌고찰 및 메타분석)

  • Ji Eun Lee;Su Jin Park;Seo Yeon Jun;Kyuseok Kim
    • Journal of Convergence Korean Medicine
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    • v.5 no.1
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    • pp.5-23
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    • 2023
  • Objectives: This study was conducted to evaluate the effect of combination treatment of herbal medicine for external use and western medicine for atopic dermatitis (AD). Methods: We searched randomized controlled trials (RCTs) which assess the effect of combination treatment of herbal and western medicine for AD through 8 electronic databases from the start to December 2022. The data synthesis was conducted by using Review Manager (RevMan, ver.5.4.1) and Cochrane risk-of-bias tool was used to evaluate the risk of bias. Results: 13 RCTs were included. The combination treatment group had significantly higher total efficacy rate(p<0.0001) and lower SCORAD score (p<0.00001) than the western medicine treatment group. The adverse event rate was also significantly lower in the combination treatment than the western medicine treatment group (p<0.0001). But there was no significant difference in recurrence rate (p=0.09). Conclusion: This study demonstrates that the combination treatment of herbal and western medicine could be safe and effective for AD. However, due to limits of included studies such as high heterogeneity between the literature and unclear risk of bias, further studies are warranted.

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Determinants of a Firm's Exit from Exporting: Evidence from Korean Manufacturing Firms (우리나라 제조업 기업의 수출중단 결정요인 분석)

  • Nam, Yunmi;Choi, Moon Jung
    • Economic Analysis
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    • v.26 no.4
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    • pp.98-136
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    • 2020
  • We empirically investigate the determinants of a firm's exit from exporting, using Korean manufacturing firm-level data for the period from 2006 to 2014. Specifically, we estimate the effects of not only firm-level and industry-level characteristics, but also macroeconomic variables on the probability that a firm stops exporting by applying a Complementary Log-Log Model analysis. The results of our estimation suggest that firm-level heterogeneity, such as workforce size, capital intensity, intangible assets and foreign ownership, industry-level variation, such as the labor displacement rate, and macroeconomic variables, such as domestic demand and world demand, significantly affect the possibility of a firm ceasing exports. Also, we show that market interest rates increase the possibility of an export cessation and that the effects of market interest rates are more pronounced on firms with a higher debt ratio. In the primary exporting industries, the probability of a firm ceasing exports decreases as productivity at the firm rises.

Antimicrobial Activity of Propolis Extract and Their Application as a Natural Preservative in Livestock Products: A Meta-Analysis

  • Andre, Andre;Arief, Irma Isnafia;Apriantini, Astari;Jayanegara, Anuraga;Budiman, Cahyo
    • Food Science of Animal Resources
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    • v.42 no.2
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    • pp.280-294
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    • 2022
  • This study aimed to evaluate the effectiveness of propolis extract as a natural preservative for livestock products in term of chemical and microbiological characteristics by meta-analysis. The stages carried out in this study were identification, selection, checking suitability, and the resulting selected articles were used in the meta-analysis. The selection results obtained a total of 22 selected journal articles consisting of 9 articles for analysis of the antimicrobial activity of propolis extract and 13 articles for analysis of the chemical and mirobiological characteristics of livestock products. The articles were obtained from electronic databases, namely Science Direct and Google Scholar. The model used in this study is the random-effect model involving two groups, control and experimental. Heterogeneity and effect size values were carried out in this study using Hedge's obtained through openMEE software. Forest plot tests and data validation on publication bias was obtained using Kendall's test throught JASP 0.14.1 software. The results showed that there is a significant relationship between propolis extract with the results of the antimicrobial activity (p<0.05). In addition, the results of the application of propolis extract on the livestock products for the test microbes and the value of thiobarbituric acid reactive substances (TBARs) showed significant results (p<0.05). Conclusion based on the random-effect model on the effectiveness of antimicrobial activity of propolis extract and their apllication as a natural preservative of the chemical and microbiological characteristics of livestock products is valid by Kendall's test (p>0.05). Propolis in this case effectively used as natural preservatives in livestock products.

A Critical Systematic Review for Inhaled Corticosteroids on Lung Cancer Incidence: Not Yet Concluded Story

  • Suh-Young Lee;Soon Ho Yoon;Hyunsook Hong
    • Tuberculosis and Respiratory Diseases
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    • v.86 no.2
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    • pp.120-132
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    • 2023
  • Background: To systematically review studies on inhaled corticosteroids (ICS) and lung cancer incidence in chronic airway disease patients. Methods: We conducted electronic bibliographic searches on OVID-MEDLINE, EMBASE, and the Cochrane Database before May 2020 to identify relevant studies. Detailed data on the study population, exposure, and outcome domains were reviewed. Results: Of 4,058 screened publications, 13 eligible studies in adults with chronic obstructive pulmonary disease (COPD) or asthma evaluated lung cancer incidence after ICS exposure. Pooled hazard ratio and odds ratio for developing lung cancer in ICS exposure were 0.81 (95% confidence interval, 0.64 to 1.02; I2=95.7%) from 10 studies and 1.02 (95% confidence interval 0.50 to 2.07; I2=94.7%) from three studies. Meta-regression failed to explain the substantial heterogeneity of pooled estimates. COPD and asthma were variously defined without spirometry in 11 studies. Regarding exposure assessment, three and 10 studies regarded ICS exposure as a time-dependent and fixed variable, respectively. Some studies assessed ICS use for the entire study period, whereas others assessed ICS use for 6 months to 2 years within or before study entry. Smoking was adjusted in four studies, and only four studies introduced 1 to 2 latency years in their main or subgroup analysis. Conclusion: Studies published to date on ICS and lung cancer incidence had heterogeneous study populations, exposures, and outcome assessments, limiting the generation of a pooled conclusion. The beneficial effect of ICS on lung cancer incidence has not yet been established, and understanding the heterogeneities will help future researchers to establish robust evidence on ICS and lung cancer incidence.

Movie Choice under Joint Decision: Reassessment of Online WOM Effect

  • Kim, Youngju;Kim, Jaehwan
    • Asia Marketing Journal
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    • v.15 no.1
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    • pp.155-168
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    • 2013
  • This study describes consumers' movie choices in conjunction with other group members and attempts to reassess the effect of the online word of mouth (WOM) source in a joint decision context. The tendency of many people to go to movies in groups has been mentioned in previous literature but there is no modeling research that studies movie choice from the group decision perspective. We found that ignoring the group movie-going perspective can result in a misunderstanding, especially underestimation of genre preference and the impact of the WOM variables. Most of the studies to measure online WOM effects were done at the aggregate level, and the role of online WOM variables(volume vs valence) is mixed in the literature. We postulate that group-level analysis might offer insight to resolve these mixed understanding of WOM effects in the literature. We implemented the study via a random effect model with group-level heterogeneity. Romance, drama, and action were selected as genre variables; valence and volume were selected as online WOM variables. A choice-based conjoint survey was used for data collection and the models was estimated via Bayesian MCMC method. The empirical results show that (i) both genre and online WOM are important variables when consumers choose movies, especially as group, and (ii) the WOM valence effect are amplified more than the volume effect does as individuals are engaged in group decision. This research contributes to the literature in several ways. First, we investigate movie choice from a group movie-going perspective that is more realistic and consistent with the market behavior. Secondly, the study sheds new light on the WOM effect. At group-level, both valence and volume significantly affect movie choices, which adds to the understanding of the role of online WOM in consumers' movie choice.

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Reference values for pulp oxygen saturation as a diagnostic tool in endodontics: a systematic review and meta-analysis

  • Paula Lambert;Sergio Augusto Quevedo Miguens Jr;Caroline Solda;Juliana Tomaz Sganzerla;Leandro Azambuja Reichert;Carlos Estrela;Fernando Branco Barletta
    • Restorative Dentistry and Endodontics
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    • v.45 no.4
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    • pp.48.1-48.11
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    • 2020
  • Objectives: This systematic review aimed to identify mean oxygen saturation values (SpO2) using pulse oximetry in permanent maxillary anterior teeth. Materials and Methods: The MEDLINE, Scientific Electronic Library Online, Cochrane Central Register of Controlled Trials, EMBASE, and Literatura Latino Americana em Ciências da Saúde electronic databases were searched. Combinations and variations of "oximetry" AND "dental pulp test" were used as search terms. Studies reporting means and standard deviations of SpO2 values were included. Two reviewers independently extracted data following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses checklist. Heterogeneity was assessed using the I2 statistic, and all analyses were performed using R software. Study quality was assessed using the Quality Assessment of Diagnostic Accuracy Studies-2 tool and the Newcastle-Ottawa scale. Results: Of the 251 studies identified, 19 met the eligibility criteria and were included (total sample, 4,541 teeth). In the meta-analysis, the mean SpO2 values were 84.94% (95% confidence interval [CI], 84.85%-85.04%) for the central incisors, 89.29% (95% CI, 89.22%-89.35%) for the lateral incisors, and 89.20% (95% CI, 89.05%-89.34%) for the canines. The studies were predominantly low-quality due to the high risk of bias associated with the index test, unclear risk regarding patient selection, and concerns about outcome assessment. Conclusions: Although most studies were low-quality, the oxygen saturation levels in normal pulp could be established (minimum saturation, 77.52%). Despite the risk of bias of the included studies, the reference values reported herein are clinically relevant for assessments of changes in pulp status.

Effect of Herbal Medicine on Transient Synovitis of Hip in Children: A Systemic Review and Meta-analysis (소아 일과성 고관절 활액막염에 대한 한약의 효과: 체계적 문헌 고찰 및 메타분석)

  • Hong Ye Na;Lee Young Hun;Yu Sun Ae
    • The Journal of Pediatrics of Korean Medicine
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    • v.37 no.4
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    • pp.34-52
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    • 2023
  • Objective This study aimed to evaluate the effect of herbal medicines on transient hip synovitis (TSH) in children. Methods We searched 10 Korean, English, Japanese, and Chinese databases for studies published up to September 19, 2023. Randomized controlled trials (RCTs) evaluating the effect of herbal medicines on TSH levels in children were included. The Cochrane risk of bias was used to evaluate the quality of the studies. A meta-analysis was conducted according to outcome measurements, such as total effective rate (TER), visual analog score (VAS), time to pain relief, and hip joint mobility disorder disappearance time, using the Review Manager website. Results Eleven RCTs were included in this study. TER in the treatment group was significantly higher than in the control group. The duration of pain relief was significantly shorter in the treatment group than in the control group. The VAS score of the treatment group was significantly lower than that of the control group, although the statistical heterogeneity was substantial. The hip joint mobility disorder disappeared in the treatment group treated with external therapy, which was significantly shorter than in the control group. Regarding safety, two of the 11 studies reported that there were no adverse events. Conclusions Herbal medicines are effective in the treatment of TSH in children. However, the safety of herbal medicines should be carefully considered due to the lack of data.