• 한국통계학회:학술대회논문집
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• 한국통계학회 2005년도 춘계 학술발표회 논문집
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• pp.95-100
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• 2005

In this paper a class of multifactor designs for estimating the slope of second order response surface regression models with correlated errors is considered. General conditions for second order slope rotatability over all directions and also with respect to the maximum directional variance in case of k=2 have been derived assuming errors have a general correlated error structure. And we consider the measures for evaluating slope rotatability with correlated errors similar to in case of uncorrelated error structures.

• Communications for Statistical Applications and Methods
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• 제28권6호
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• pp.595-610
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• 2021

Recently a few articles have derived robust first-order rotatable and D-optimal designs for the lifetime response having distributions gamma, lognormal, Weibull, exponential assuming errors that are correlated with different correlation structures such as autocorrelated, intra-class, inter-class, tri-diagonal, compound symmetry. Practically, a first-order model is an adequate approximation to the true surface in a small region of the explanatory variables. A second-order model is always appropriate for an unknown region, or if there is any curvature in the system. The current article aims to extend the ideas of these articles for second-order models. Invariant (free of the above four distributions) robust (free of correlation parameter values) second-order rotatable designs have been derived for the intra-class and inter-class correlated error structures. Second-order rotatability conditions have been derived herein assuming the response follows non-normal distribution (any one of the above four distributions) and errors have a general correlated error structure. These conditions are further simplified under intra-class and inter-class correlated error structures, and second-order rotatable designs are developed under these two structures for the response having anyone of the above four distributions. It is derived herein that robust second-order rotatable designs depend on the respective error variance covariance structure but they are independent of the correlation parameter values, as well as the considered four response lifetime distributions.

• Journal of Korean Neurosurgical Society
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• 제61권2호
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• pp.201-211
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• 2018

Objective : The purpose of this study was to analyze the variability of clopidogrel responses according to duration of a clopidogrel drug regimen after stent-assisted coil embolization (SAC), and to determine the correlation between the variability of clopidogrel responses and thromboembolic or hemorrhagic complications. Methods : A total of 47 patients who underwent SAC procedures to treat unruptured intracranial aneurysms were enrolled in the study. Preoperatively, patients received more than seven days of aspirin (100 mg) and clopidogrel (75 mg), daily. P2Y12 reaction unit (PRU) was checked with the VerifyNow test one day before the procedure (pre-PRU) and one month after the procedure (post-PRU). PRU variability was calculated as the difference between the initial response and the follow-up response. Patients were sorted into two groups based on their response to treatment : responsive and hypo-responsive. Results : PRU variability was significantly greater in the hypo-responsive group when compared to the responsive group (p=0.019). Pre-PRU and serum platelets counts were significantly correlated with PRU variation (p=0.005 and p=0.004, respectively). Although thromboembolic complication had no significant correlated factors, hemorrhagic complication was correlated with pre-PRU (p=0.033). Conclusion : In conclusion, variability of clopidogrel responses during clopidogrel medication was correlated to serum platelet counts and the initial clopidogrel response. Thromboembolic and hemorrhagic complications did not show correlation with the variability of clopidogrel response, or the clopidogrel response after one month of medication; however, hemorrhagic complication was associated with initial clopidogrel response. Therefore, it is recommended to test patients for an initial clopidogrel response only, as further tests would be insignificant.

• Journal of the Korean Statistical Society
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• 제36권4호
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• pp.557-578
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• 2007

In Response Surface Methodology (RSM), rotatability is a natural and highly desirable property. For second order general correlated regression model, the concept of robust rotatability was introduced by Das (1997). In this paper a new measure of robust rotatability for second order response surface designs with correlated errors is developed and illustrated with an example. A comparison is made between the newly developed measure with the previously suggested measure by Das (1999).

• Asian-Australasian Journal of Animal Sciences
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• 제14권7호
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• pp.899-904
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• 2001

A field trial on selection for increased live weight in Black Bengal (BB) goat was conducted over two generations. Parents of both sexes were selected (mass selection) based on mature body weight criteria set against age. A parallel randomly mated line was maintained to compare the response (R) of selection at birth. 3, 6, 9 and 12 months of age in both generations. Lactation yield (LY), average per day yield (APDY) and lactation length (LL) were evaluated in the selected line in comparison to randombreds as a result of correlated response. Live weights were significantly improved at onward bir:th in first generation and only at birth in second generation. Improvements (%) in live weight at 3, 6. 9 and 12 months in first generation were 17.6, 18.4, 16.6, and 12.0 at birth in second generation. Significant correlated R were found in LY and APDY. Results suggest that there may be a positive relationship between live weight and lactational traits in BB goats of Bangladesh. It was also concluded that such a field scheme can be effectively used for genetic improvement of goats in subsistence farming, at least for short term gain.

• 한국임상보건과학회지
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• 제7권2호
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• pp.1345-1354
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• 2019

Purpose: This study aimed to determine the mediating effects of aggressive stress response on the association between clinical practice stress and clinical practice satisfaction in ophthalmic optics majors and provide basic data that could help form opticians' professionalism and make clinical practice more effective. Methods: This study was conducted in 236 sophomores and juniors in Daegu and North Gyeongsang Province who had finished clinical practice. Hierarchical regression analysis and mediating effect testing were performed to determine the associations among clinical practice stress, clinical practice satisfaction, and aggressive stress response and determine the mediating effects of aggressive stress response on the association between clinical practice stress and clinical practice satisfaction. Results: Clinical practice stress was significantly negatively correlated with clinical practice satisfaction and aggressive stress response (p<0.01), and aggressive stress response was significantly positively correlated with clinical practice satisfaction (p<0.01). The association between clinical practice stress and clinical practice satisfaction was more likely to be explained by the addition of clinical practice stress than by being aggressive stress response controlled, which statistically significantly met the criteria for mediating effects (p<0.001). Conclusions: It is necessary to pay more attention to program development and teaching methods within the department of ophthalmic optics so that ophthalmic optics majors can utilize aggressive stress response to overcome clinical practice stress effectively and improve clinical practice satisfaction.

• The Plant Pathology Journal
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• 제35권6호
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• pp.623-634
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• 2019

Little known the connections between soybeans mitogen-activated protein kinase (MAPK) gene expression and the rhizomicrobiome upon invasion of the root pathogen Fusarium oxysporum. To address this lack of knowledge, we assessed the rhizomicrobiome and root transcriptome sequencing of wild and cultivated soybean during the invasion of F. oxysporum. Results indicated F. oxysporum infection enriched Bradyrhizobium spp. and Glomus spp. and induced the expression of more MAPKs in the wild soybean than cultivated soybean. MAPK gene expression was positively correlated with Pseudomonadaceae but negatively correlated with Sphingomonadaceae and Glomeraceae in both cultivated and wild soybean. Specifically, correlation profiles revealed that Pseudomonadaceae was especially correlated with the induced expression of GmMAKKK13-2 (Glyma.14G195300) and GmMAPK3-2 (Glyma.12G073000) in wild and cultivated soybean during F. oxysporum invasion. Main fungal group Glomeraceae was positively correlated with GmMAPKKK14-1 (Glyma.18G060900) and negatively correlated with GmRaf6-4 (Glyma.02G215300) in the wild soybean response to pathogen infection; while there were positive correlations between Hypocreaceae and GmMAPK3-2 (Glyma.12G073000) and between Glomeraceae and GmRaf49-3 (Glyma.06G055300) in the wild soybean response, these correlations were strongly negative in the response of cultivated soybean to F. oxysporum. Taken together, MAPKs correlated with different rhizomicrobiomes indicating the host plant modulated by the host self-immune systems in response to F. oxysporum.

• Journal of the Korean Statistical Society
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• 제30권4호
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• pp.613-635
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• 2001

This paper proposes a skewed multivariate probit model for analyzing a correlated binary response data with covariates. The proposed model is formulated by introducing an asymmetric link based upon a skewed multivariate normal distribution. The model connected to the asymmetric multivariate link, allows for flexible modeling of the correlation structure among binary responses and straightforward interpretation of the parameters. However, complex likelihood function of the model prevents us from fitting and analyzing the model analytically. Simulation-based Bayesian inference methodologies are provided to overcome the problem. We examine the suggested methods through two data sets in order to demonstrate their performances.

• 대한불안의학회지
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• 제6권1호
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• pp.17-23
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• 2010

Objective : This study compared the psychological stresses of depressed patients' families with those of schizophrenic patients' families. We investigated the influence of depressive patients' clinical features and their families' demographic characteristics on the families' depressive symptoms and stresses. Methods : Participants were 23 family members of depressed patients and 20 family members of schizophrenic patients. We measured the patients' clinical features (duration of illness, number of previous hospitalizations, and satisfaction with medication), and each family member's socioeconomic status and psychological characteristics (depressive mood, anxiety, family stress, and stress response), analyzing the data via independent t-test, chi-square test, and correlation and hierarchical multiple regression analyses. Results : The depressed patients' average clinical global impression (CGI) was significantly higher than that of the schizophrenic patients. The depressed patients' family members showed stress responses significantly higher than those of schizophrenic patients' family members. Furthermore, in depressed patients, frequency of hospitalization was positively correlated with family members' stat anxiety. For both patient types, family stress was positively correlated with the patient's severity of illness and the family's state anxiety, trait anxiety, and stress response ; socioeconomic status was positively correlated with the family's depressive symptoms ; the family's state anxiety positively correlated with the family's trait anxiety and stress response ; and the family's trait anxiety positively correlated with the family's stress response. Socioeconomic status predicted the family's depressive symptoms, and socioeconomic, illness severity and stress response predicted family stress. Conclusion : These findings suggest that both depressed patients' families and schizophrenic patients' families suffer from psychological stress. The study data also have important clinical implications, in that families of depressed patients need psychiatric intervention, as well as the patients themselves. In particular, family intervention should focus on psycho-education and stress coping strategies.

• 대한산업공학회지
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• 제19권2호
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• pp.53-64
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• 1993

Successful completion of a visual task in a predetermined time is very crucial to many operations such as piloting an aircraft. Although existing ergonomic interface models often provide a function of vision tests, it determines only the visibility at any given location. To complement this problem in existing models, the isoresponse time region considering the factors related to visual tasks is presented. Using a multiple regression model, equal response time regions were obtained within which mean response time is expected to be the same and is asymmetrical in shape. Among the factors considered, expectancy significantly decreased response time, and when cued, the effects of field heterogeneity, target uncertainty, density, size contrast and peripheral position on search time were less significant than those in unexpected cases. Response time and error rate, gender and visual acuity were not significantly correlated, and response time and age was positively correlated. These results are expected to be directly applicable to designing various visual tasks in real-life situations.