• The Journal of Asian Finance, Economics and Business
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• v.7 no.10
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• pp.865-874
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• 2020

In Vietnam, the airline service sector plays an important economic role. However, it is a complicated industry that is open to failures. Negative emotions are an essential variable for the airline service industry because they can trigger a variety of coping behaviors that affect consumer loyalty as well as the image and reputation of the airline service providers. However, negative emotions and the accompanying coping behaviors are often investigated partially or as separate issues, thus leading to an incomplete understanding. This study is conducted to fill this gap by proposing and testing the causal relationship between negative emotions (anger, frustration, regret) and coping behaviors (complaint, negative word-of-mouth (WOM), and switching intention) in the context of the airline industry. Eight research hypotheses are tested. Using the partial least squares structural equation modeling (PLS-SEM) on a sample of 587 passengers in Vietnam, the empirical results show that anger and frustration influence complaints, negative WOM, and switching intention, while regret leads to switching intention and negative WOM. Thus, the research has important academic and practical implications. The empirical outcome could be of major importance for airline companies in planning to provide new services and achieve high performance in the long run.

• Communications for Statistical Applications and Methods
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• v.17 no.2
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• pp.263-273
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• 2010

Missing values in time series can be treated as unknown parameters and estimated by maximum likelihood or as random variables and predicted by the conditional expectation of the unknown values given the data. The purpose of this study is to impute missing values which are regarded as the maximum likelihood estimator and random variable in incomplete data and to compare with two methods using ARMA and STAR model. For illustration, the Mumps data reported from the national capital region monthly over the years 2001~2009 are used, and estimate precision of missing values and forecast precision of future data are compared with two methods.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.4
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• pp.939-948
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• 2021

The purpose of the research is to examine whether government regulation on Covid 19 pandemic has had a significant impact in economic sectors, particularly on consumer behavior. Thus there are three hypotheses, 1) viral marketing has an effect on online trust during the Covid-19 Pandemic Era, 2) viral marketing has an effect on impulse buying during the Covid-19 Pandemic Era, and 3) Viral marketing has an effect on impulse buying in the Covid-19 Pandemic Era through online trust. To test the hypotheses, questionnaires were distributed to 150 respondents, however, only 110 were selected due to incomplete data. There are 3 variables, namely viral marketing, online trust, and impulse buying, where online trust is also a mediating variable. Once the assumption test is completed, the researcher employs path analysis to test the hypotheses. The results are 1) there is an effect of viral marketing on online trust in the Covid-19 Pandemic Era, 2) There is no effect of viral marketing on impulse buying in the Covid-19 Pandemic Era, and 3) Viral marketing has an effect on impulse buying in the Covid-19 Pandemic Era through online trust. This means online trust succeed in mediating viral marketing-impulse buying relationship. The findings emphasized that the credibility of online trust enforce consumers in making buying decisions.

• The Korean Journal of Applied Statistics
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• v.35 no.1
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• pp.35-47
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• 2022

The receiver operating characteristic (ROC) curve was developed to quantify the classification ability of marker values (covariates) on the response variable and has been extended to survival data with diverse missing data structure. When survival data is understood as binary data (status of being alive or dead) at each time point, the ROC curve expressed at every time point results in time-dependent ROC curve and time-dependent area under curve (AUC). In particular, a follow-up study brings the change of cohort and incomplete data structures such as censoring and competing risk. In this paper, we review time-dependent ROC estimators under several contexts and perform simulation to check the performance of each estimators. We analyzed a dementia dataset to compare the prognostic power of markers.

• Childhood Kidney Diseases
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• v.28 no.1
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• pp.8-15
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• 2024

With the rapid evolution of diagnostic tools, particularly next-generation sequencing, the identification of genetic diseases, predominantly those with pediatric-onset, has significantly advanced. However, this progress presents challenges that span from selecting appropriate tests to the final interpretation of results. This review examines various genetic testing methodologies, each with specific indications and characteristics, emphasizing the importance of selecting the appropriate genetic test in clinical practice, taking into account factors like detection range, cost, turnaround time, and specificity of the clinical diagnosis. Interpretation of variants has become more challenging, often requiring further validation and significant resource allocation. Laboratories primarily classify variants based on the American College of Medical Genetics and Genomics and the Association for Clinical Genomic Science guidelines, however, this process has limitations. This review underscores the critical role of clinicians in matching patient phenotypes with reported genes/variants and considering additional factors such as variable expressivity, disease pleiotropy, and incomplete penetrance. These considerations should be aligned with specific gene-disease characteristics and segregation results based on an extended pedigree. In conclusion, this review aims to enhance understanding of the complexities of clinical genetic testing, advocating for a multidisciplinary approach to ensure accurate diagnosis and effective management of rare genetic diseases.

• Therapeutic Science for Rehabilitation
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• v.7 no.1
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• pp.63-77
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• 2018

Objective : The purpose of this study was to investigate the effects of task-oriented training with functional electrical stimulation on hand function in incomplete cervical cord injury. Method : The subjects of the study were 3 adults diagnosed as incomplete cervical cord injury. The design of this study was ABA single-subject research design to compare dominant hand function of before and after intervention and detect individual effects. The experiment consisted of 30sessions, in which baseline process A1 and A2 were implemented 5 sessions each for 10sessions. Intervention B was implemented 20 sessions. The dependent variable was converted to the change of hand function every session, and Canadian Occupational Performance Measure (COPM), Jebsen-Taylor Hand Function Test(JTHFT), Wolf Motor Function Test(WMFT) were selected for outcome measurements. Result analysis was suggested through visual analysis using a graph and comparison of pre, post and follow-up intervention measurements. Results : As a result, the quality and quantity of dominant hand function increased during intervention B compared to the baseline A1 for all subjects. Baseline A2 was also maintained without training. Additionally, JTHFT, WMFT and COPM scores demonstrated improvement and maintain. The follow up JTHFT and WMFT showed increased required time on all subjects and decrease or maintain task performance and satisfaction in COPM. Conclusion : The task-oriented training with function electrical stimulation in this study has been positive effects on hand function and task performance and satisfaction.

• Korean Journal of Plant Taxonomy
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• v.45 no.3
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• pp.243-253
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• 2015

Series Chinensis, Genus Iris, endemic to the far regions of East Asia, consists of four species and related varieties. This series is divided into two major groups (I. rossii and I. minutiaurea complex). In this study, the ITS region and matK gene sequences within nuclear ribosomal DNA and plastid DNA were analyzed in order to investigate the phylogenetic relationships among the I. minutiaurea complex (I. minutiaurea, I. odaesanensis, and I. koreana) and the taxonomic identities of a putative hybrid in Mt. Palgong. In the internal transcribed spacer (ITS1, 5.8S, and ITS2) region, a total of 106 cloned genomic sequences from three taxa were obtained to study the intragenomic polymorphisms of the ITS regions. Three taxa revealed high levels of intragenomic polymorphisms, indicative of incomplete nrDNA concerted evolution. This incomplete ITS concerted evolution in the series Chinensis may be linked to the recent species divergence and frequent interspecies hybridization of the series Chinensis. In the matK gene, three taxa were fairly separated by eleven variable sites. In eight individuals collected on Mt. Palgong, putative hybrids between I. odaesanensis and I. minutiaurea were clustered in the I. minutiaurea clade in the NJ (neighbor-joining) tree based on the matK gene. However, in the ITS tree, some of them were clustered in the I. odaesanensis clade and others were clustered in the I. minutiaurea clade. Therefore, the individuals on Mt. Palgong were formed by the hybridization between two taxa (I. odaesanensis and I. minutiaurea) and not through the lineage of I. koreana.

• Journal of Korean Elementary Science Education
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• v.31 no.4
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• pp.541-557
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• 2012

Interest is acknowledged to be a critical motivational variable that influences learning and achievement. The purpose of this study was to investigate the interest of the elementary students when free inquiry activities were performed through a brain-based evolutionary scientific teaching and learning model. For this study, 106 fifth grade students were chosen and performed individually free inquiry activities. The results of this study were as follows: First, after free inquiry activities, as to free inquiry science related attitude, a statistically significant difference was not observed. But they came to have positive feelings about the free inquiry. Especially students marked higher mean score in openness showed consistency in sub-areas of free inquiry science related attitude. Second, students had interests in various fields, especially they had many interests in area of biology. They chose inquiry subjects that seems to be easily accessible from surrounding and as an important criterion of free inquiry they thought the possibility that they could successfully perform it. And students who belong to the high level in the science related attitudes and academic achievement diversified more topics. Third, most of students failed to further their topics. However, the students who specifically and clearly extended their topics suggested appropriate variables in their topics. On the other hand, students who couldn't elaborate their topics were also failed to suggest further topics and their performance of inquiry was more incomplete. In conclusion, the experiences of success in free inquiry make the science attitude of students more positive and help them extend their inquiry. These results have fundamental implications for the authentic science inquiry in the elementary schools and for the further research.

• Archives of Craniofacial Surgery
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• v.16 no.3
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• pp.131-135
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• 2015

Background: Variable methods have been introduced for reduction of the zygomatic fractures. The Dingman elevator is used widely to reduce these fractures but is inappropriate in certain types of fractures which require atypical traction vectors. We introduce and examine an alternate method of reducing zygomatic fractures using wire and hook traction. Methods: A retrospective study was performed for all zygomatic fracture patients admitted between 2008 and 2014. Medially rotated fractures were reduced by using a wire looped through an intermaxillary screw secured on the medial side of the zygoma. Laterally rotated fractures were reduced using a hook introduced through an infrazygomatic skin incision. Results: No accidental bleeding or incomplete reduction was observed in any of the cases. Postoperative imaging demonstrated proper reduction immediately after the operation. Follow-up computed tomography study at 1 month after operation also demonstrated proper reduction and healthy union across the previous site of fracture. Conclusion: The hook and wire method allowed precise application of traction forces across zygomatic fractures. The fractured bone fragment could be pulled in the direction precisely opposite to the vector of impact at the time of trauma. Soft tissue damage due to dissection was minimized. In particular, this method was effective in reducing rotated bone fragments and can be an alternative option to using the zygoma elevator.

• The Korean Journal of Zoology
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• v.28 no.4
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• pp.257-278
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• 1985

The effect of aromatic amino acids such as phenylalaine, tryptophan and tyrosine on somitogenesis at the early stage of chick embryo has been investigated morphologically using light and electron microscopy. Micrographs of aromatic amino acid injected chick embryo showed that an incomplete somite segmentation occurred and some decremental effect on the nervous system were observed. Somites were poorly developed and their size were variable. Electron micrograph of somatic cells from aromatic amino acid injected chick embryo showed that chromatins were coagulated, some of mitochondria were damaged, and nucleus were transformed considerably in some cases. The protein and nucleic acid levels and some enzyme activities of 15-day chick embryo which received the injection of 1mg of aromatic amino acid in 0.05 ml of saline 24 hours after the incubation were analyzed. Protein, DNA and RNA levels of the test group were not lowered significantly but the activities of enzymes for basic metabolism, such as lactate dehydrogenase, succinate dehydrogenase, malate dehydrogenase and glucose 6-phosphate dehydrogenase were considerably lowered as compared with those of control. From the present expeerimental results, it was tentatively suggested that the administration of amino acid might slow down the yolk granule degradation probably by feed back mechanism resulting in the disturbance of amino acid balance in the cell, which might give rise to impair normal metabolic pattern leading to abnormal somitogenesis to chick embryo at very early stage of development.