• 유통과학연구
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• 제17권8호
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• pp.67-76
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• 2019

Purpose - This research examined whether entrepreneurial proclivity of retail employees affects job engagement and satisfaction, which are job-related positive aspects; and whether job engagement affects job satisfaction. Research design, data, and methodology - To accomplish this purpose, data were collected for 224 retail employees working in the distribution industry in the Republic of Korea. Reliability, validity, and hypotheses were tested through structural equation modeling, and mediating effects of job engagement between entrepreneurial proclivity and job satisfaction were verified through the bootstrap method by using the process model. Results - The results show that innovativeness and progressiveness in entrepreneurial proclivity positively affected job engagement and job satisfaction, but risk-taking did not affect either job engagement or job satisfaction. Also, this research confirmed that job engagement positively affects job satisfaction. Conclusions - This study contributes to the retail literature by applying the concept of entrepreneurial proclivity in the retail employee context. This study puts forward empirical evidence that identifies the effect of entrepreneurial proclivity as a job resource that influences job engagement and job satisfaction in the JD-R model. Thus, this study surmounts the limitation of prior studies by examining entrepreneurial proclivity from the aspect of retail employees.

• Mycobiology
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• 제47권4호
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• pp.408-414
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• 2019

Crinum asiaticum and Hymenocallis littoralis, commonly known as spider lilies are bulbous perennial and herbaceous plants that widely planted in Malaysia as ornamental. During 2015-2016, symptom of leaf blight was noticed on the hosts from several locations in Penang. The symptom appeared as irregular brown to reddish lesions surrounded by yellow halos. As the disease progressed, the infected leaves became blighted, dried, and fell off with the presence of black microsclerotia and pycnidia on the lesions parts. The present study was conducted to investigate the causal pathogen of leaf blight on C. asiaticum and H. littoralis. Based on morphological characteristics and DNA sequences of internal transcribed spacer (ITS) region and translation elongation factor 1-alpha (TEF1-α) gene, the causal pathogen was identified as Macrophomina phaseolina. Phylogenetic analysis of combined dataset of ITS and TEF1-α grouped the isolates studied with other isolates of M. phaseolina from GenBank. The grouping of the isolates was supported by 96% bootstrap value. Pathogenicity test proved the role of the fungus in causing leaf blight on both hosts.

• Journal of Species Research
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• 제4권1호
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• pp.49-56
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• 2015

Zeuzera is one of the most important wood borer pests in South East Asia. Like of most other genera of moths, the systematic of this genus is still in dispute, especially on the monophyly and the relationship within this genus due to the fact that genus is very varied. This genus was defined based on external characters only such as cross vein Sc-Rs present, humeral plate approximately triangular in shape and anal plate moderately long to moderately short. Therefore, the monophyly of this genus need to be evaluated based on more comprehensive data. To clarify the monophyly of the genus Zeuzera, to reveal the phylogenetic relationships among the Indonesian species, and to establish the genetic characters of Indonesian Zeuzera, we analyzed seven species of Indonesian Zeuzera including three other species distributed around the world based on nucleotide sequence variation across a 580-bp region in the CO I gene. The results showed that the monophyly of Zeuzera was supported by bootstrap tests at the MP and ML tree building methods (>95%). Genus Zeuzera was divided into two groups (A and B) with Z. borneana was excluded from the two groups and occupied at the basal node. Indonesian species was distributed into two different clades. CO I gene alone was able to fully resolve the relationships among species within clade B. However, further investigations were needed by including more species and other genes that the more conserved to test the validity of the phylogenetic hypothesis proposed here.

• The Journal of Asian Finance, Economics and Business
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• 제7권7호
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• pp.269-277
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• 2020

Bao Loc City is the new tourism destination in Lam Dong province, Vietnam, where more and more tourists have been drawn to pay a visit. This study aims to test the correlative impact of tourism service quality factors on satisfaction of the tourists who have visited Bao Loc City. The key theory used in this study is SERVQUAL scale. The survey sample consists of 350 tourists who stayed overnight in Bao Loc City in the last quarter of 2019; 315 valid survey questionnaires could be used for the analysis. The research applied Cronbach's Alpha, exploratory factor analysis (EFA), confirmatory factor analysis (CFA), structural equation modeling (SEM), and bootstrap test. The results show that the satisfaction of the tourists who have visited Bao Loc City has been affected statistically by three factors: (1) Responsiveness; (2) Reliability; and (3) Empathy, which were ranked by descending importance. Surprisingly, the research found that Tangibles and Assurance do not have an impact on tourists' satisfaction towards Bao Loc City. The research formulates some suggestions to the city policy-makers and the tourism businesses management in Bao Loc City in order to enhance tourists' satisfaction through improving the tourism service quality at Bao Loc City.

• Communications for Statistical Applications and Methods
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• 제21권6호
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• pp.487-500
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• 2014

A new method to calculate the transmittable prevalence of an epidemic disease is proposed based on a back-calculation formula. We calculated the probabilities of reactivation and of parasitemia as well as transmittable prevalence (the number of persons with parasitemia in the incubation period) of malaria in South Korea using incidence of 12 years(2001-2012). For this computation, a new probability function of transmittable condition is obtained. The probability of reactivation is estimated by the least squares method for the back-calculated longterm incubation period. The probability of parasitemia is calculated by a convolution of the survival function of the short-term incubation function and the probability of reactivation. Transmittable prevalence is computed by a convolution of the infected numbers and the probabilities of transmission. Confidence intervals are calculated using the parametric bootstrap method. The method proposed is applicable to other epidemic diseases in other countries where incidence and a long incubation period are available. We found the estimated transmittable prevalence in South Korea was concentrated in the summer with 276 cases on a peak at the $31^{st}$ week and with about a 60% reduction in the peak from the naive prevalence. The statistics of transmittable prevalence can be used for malaria prevention programs and to select blood transfusion donors.

• 품질경영학회지
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• 제38권2호
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• pp.261-275
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• 2010

The purpose of this study is to empirically analyze the productivity change of the 10 Single PPM Certification Company in the 3 Industry(Electronics, Motor-Parts, Machines). In this study, Productivity change over the time in Korean small and medium sized firms in the 3 industries by the bootstrapped Malmquist Productivity Index(MPI). The traditional Malmquist Productivity Index(MPI) and Data Envelopment Analysis(DEA) Models have not only bias but also lack statistical confidence intervals. they could lead to wrong evaluations of the efficiency and productivity scores. In this paper, DEA and a MPI are combined with a bootstrap method in order to provide statistical inferences that analyze the performance of the Single PPM Certification Company. The data cover the period between 2004 and 2007. The result of this paper reveals : 1) The Electronics Industry had productivity effect of 17%, but there was not direct effect for other Industries(Motor-Parts, Machines). 2) average productivity Progress of the 7DMU(Electronics), 1DMU(Motor-Parts) and none(Machines).

• 응용통계연구
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• 제29권1호
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• pp.171-180
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• 2016

바젤 위원회는 시장위험의 측정 도구로 Value-at-Risk(VaR)와 expected shortfall(ES)을 사용할 것을 제안하였다. 여러 문헌에서 VaR와 ES의 다양한 추정 방법들이 연구 되었다. 본 연구에서는 준모수적인 방법인 conditional autoregressive value at risk(CAViaR), conditional autoregressive expectile(CARE) 방법들, 그리고 Gaussian 준최대가능도 추정량(QMLE)를 이용한 방법을 사후 검정을 통해서 비교하고자 한다. 각 방법의 타당성을 확인하기 위해서, VaR에 대한 사후 검정은 unconditional coverage(UC)와 conditional coverage(CC) 검정을 사용하고 ES에 대한 검정은 붓스트랩 방법을 사용한다. S&P500 지수와 현대 자동차 주식가격 지수에 대하여 실증 자료 분석이 수행되었다.

• Computers and Concrete
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• 제16권5호
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• pp.741-757
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• 2015

In the last decade, several modeling approaches have been proposed and applied to estimate the high-performance concrete (HPC) slump flow. While HPC is a highly complex material, modeling its behavior is a very difficult issue. Thus, the selection and application of proper modeling methods remain therefore a crucial task. Like many other applications, HPC slump flow prediction suffers from noise which negatively affects the prediction accuracy and increases the variance. In the recent years, ensemble learning methods have introduced to optimize the prediction accuracy and reduce the prediction error. This study investigates the potential usage of bagging (Bag), which is among the most popular ensemble learning methods, in building ensemble models. Four well-known artificial intelligence models (i.e., classification and regression trees CART, support vector machines SVM, multilayer perceptron MLP and radial basis function neural networks RBF) are deployed as base learner. As a result of this study, bagging ensemble models (i.e., Bag-SVM, Bag-RT, Bag-MLP and Bag-RBF) are found superior to their base learners (i.e., SVM, CART, MLP and RBF) and bagging could noticeable optimize prediction accuracy and reduce the prediction error of proposed predictive models.

• Wind and Structures
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• 제25권3호
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• pp.261-282
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• 2017

The probabilistic information of directional extreme wind speeds is important for precisely estimating the design wind loads on structures. A new joint probability distribution model of directional extreme wind speeds is established based on observed wind-speed data using multivariate extreme value theory with the t-Copula function in the present study. At first, the theoretical deficiencies of the Gaussian-Copula and Gumbel-Copula models proposed by previous researchers for the joint probability distribution of directional extreme wind speeds are analysed. Then, the t-Copula model is adopted to solve this deficiency. Next, these three types of Copula models are discussed and evaluated with Spearman's rho, the parametric bootstrap test and the selection criteria based on the empirical Copula. Finally, the extreme wind speeds for a given return period are predicted by the t-Copula model with observed wind-speed records from several areas and the influence of dependence among directional extreme wind speeds on the predicted results is discussed.

• International Journal of Reliability and Applications
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• 제5권4호
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• pp.129-145
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• 2004

We use a novel, forced censoring technique that closer fits the lower tails of strenth distributions to better estimate extremly smaller percentiles for measuring progress in continuous improvement initiatives. These percentiles are of greater interest for companies, government oversight organizations, and consumers concerned with safely and preventing accidents for many products in general, but specifically for medium density fiberboard (MDF). The international industrial standard for MDF for measuring highest quality is internal bond (IB, also called tensile strengh) and its smaller percentiles are crucial, especially the first percentile and lower ones. We induce censoring at a value just above the median to weight lower observations more. Using this approach, we have better fits in the lower tails of the distribution, where these samller percentiles are impacted most. Finally, bootstrap estimates of the small percentiles are used to demonstrate improved intervals by our forced censoring approach and the fitted model. There was evidence from the study to suggest that MDF has potentially different failure modes for early failures. Overall, our approach is parsimonious and is suitable for real time manufacturing settings. The approach works for either strengths distributions or lifetime distributions.