• Communications for Statistical Applications and Methods
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• v.17 no.6
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• pp.829-843
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• 2010

To test for the serial dependence in time series of counts data, Jung and Tremayne (2003) evaluated the size and power of several tests under the class of INARMA models based on binomial thinning operations for Poisson marginal distributions. The overdispersion phenomenon(i.e., a variance greater than the expectation) is common in the real world. Overdispersed count data can be modeled by using alternative thinning operations such as random coefficient thinning, iterated thinning, and quasi-binomial thinning. Such thinning operations can lead to time series models of counts with negative binomial or generalized Poisson marginal distributions. This paper examines whether the test statistics used by Jung and Tremayne (2003) on serial dependence in time series of counts data are affected by overdispersion.

• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.488-488
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• 2015

Intermittent streamflow is common phenomenon in arid and semi-arid regions. To manage water resources of intermittent streamflows, stochactic simulation data is essential; however the seasonally stochastic modeling for intermittent streamflow is a difficult task. In this study, using the periodic Markov chain model, we simulate intermittent monthly streamflow for occurrence and the periodic gamma autoregressive and copula models for amount. The copula models were tested in a previous study for the simulation of yearly streamflow, resulting in successful replication of the key and operational statistics of historical data; however, the copula models have never been tested on a monthly time scale. The intermittent models were applied to the Colorado River system in the present study. A few drawbacks of the PGAR model were identified, such as significant underestimation of minimum values on an aggregated yearly time scale and restrictions of the parameter boundaries. Conversely, the copula models do not present such drawbacks but show feasible reproduction of key and operational statistics. We concluded that the periodic Markov chain based the copula models is a practicable method to simulate intermittent monthly streamflow time series.

• Proceedings of the Safety Management and Science Conference
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• 2008.11a
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• pp.215-227
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• 2008

As well as the development of the measurement of service quality, various kinds of service measurements are also being developed. Especially the mobile telecommunication service being representative to the mobile telecommunication company would be the mostly developed area. Its development can be understood along with the development of the telecommunication companies as well as cellular companies, not only the service alone. It is a differentiated phenomenon in the current research, such as the organic influence between the service quality and product. Of course there are such products placed on sale and enjoyed the common service, but at present there is another case that the product is on the market exclusively with the mobile company in here.

• Archives of Pharmacal Research
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• v.15 no.2
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• pp.126-129
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• 1992

The critical micelle concentrations (CMCs) of aqueous solutions of a nonionic surfactant, polyoxyl 23 lauryl ether in the presence of various concentration of urea and its derivatives were measured. The CMC of the surfactant increase in proportion to the concentration of the additives, and the CMC-raising activities increased with more and longer alkyl grups substituted in urea. The CMC shift values were successfully correlated with the cloud point shift values and the protein-denaturing activities of the additives, respectively. These results suggest that the micelle formation, clouding of the surfactant and the protein denaturation are a closely related phenomenon, and a common mechanism is operating which might be the hydrophobic interaction.

• Structural Engineering and Mechanics
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• v.60 no.6
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• pp.923-937
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• 2016

The common prospect in diminishing mine-blast vibration is decreasing vibration with increasing distance. This paper indicates that, contrary to the general expectancy, vibration waves change their forms when they are travelling through the low velocity layer like coal and so-called guided waves moving the vibration waves to longer distances without decreasing their amplitudes. The reason for this unexpected vibration increase is the formation of guided waves in the coal bed which has low density and low seismic velocity with respect to the neighboring layers. The amplitudes of these guided waves, that are capable of traveling long distances depending on the seam thickness, are several times higher than that of the usual vibration waves. This phenomenon can many complaints from the residential areas very far away from the blasting sites. Thus, this unexpected behavior of the coal beds in the surface coal mines should also be considered in vibration minimization studies. This study developed a model to predict the effects of guided waves on the propagation ways of blast-induced vibrations. Therefore, vibration mitigation studies considering the nearby buildings can be focused on these target places.

• Cross-Cultural Studies
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• v.22
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• pp.377-401
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• 2011

Major news organizations in Korea are often accused of intentionally conspiring to advance conservative agendas under the disguise of unbiased reporting. Critics suspect that headlines are frequently abused for a certain framing effect. The widespread use of direct quotation is cited as one area of the abuse in headlines. The present study is an attempt to determine whether the criticism is based on facts. We conducted two separate surveys. First, the headlines on three major Korean newspapers were compared with those on The New York Times, Washington Post, and The Times. Then, we collected from Korean and English speakers factivity judgements for the sentences containing a direct quotation. The results confirm previous studies that Korean newspapers engage in a heavy use of direct quotation in headlines. Moreover, the results partially confirm the popular perception that the common use of direct quotation is a recent phenomenon in Korea. Finally, the study finds that both groups of speakers consider direct quotations more truthful than factive sentences.

• The Journal of the Korean dental association
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• v.57 no.10
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• pp.588-594
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• 2019

The fusion is an anomalous union of two or more tooth germ at some stage in the development process resulting in a decreased number of teeth in the dental arch. Fusion is common odontogenic anomaly but triplication of primary teeth is a rare phenomenon. We report a case of a 3 - year - old girl who visited our clinic for the pain on maxillary anterior tooth. The patient was diagnosed by the fusion of a the maxillary primary right central and lateral incisor with a supernumerary tooth and caries of dentine. And then, Endodontic treatment and composite resin restoration were performed on the triple teeth. After follow-up of 6 months period, there was no marked complications.

• International Journal of Internet, Broadcasting and Communication
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• v.13 no.4
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• pp.97-102
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• 2021

The development of CG technology throughout the 2000s brought about a significant growth in the animation market. This phenomenon led to an increase in the number of people required by related industries, which led to an increase in the number of related majors in universities. CG application technologies are becoming more common with the advent of YouTube and virtual YouTubers, but high technology is still required for students to get a job. This situation is not easy to include both technological and creative skills in the college animation curriculum. In order to increase students' creativity, we need a lot of production experience, which requires a lot of knowledge and time if we only use tools like Maya and 3D Max. In this paper, We tried to devote more time to storytelling by minimizing the technical process required for production and proceeding with repetitive or difficult processes for content creation using third-party programs. And through the 12-week class, the experimental production process was applied to the process from planning to completion of animation works that students would submit to the advertisement contest.

• Journal of Trauma and Injury
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• v.34 no.2
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• pp.141-145
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• 2021

Splenic injury is a common result of blunt trauma, and bleeding occurs mainly inside the splenic capsule and may leak into the peritoneal space. Herein, we report a case where active bleeding occurred in the splenic artery and only leaked into the extraperitoneal space. This is the first case of this phenomenon in a trauma patient in the English-language literature. Bleeding passed through the peritoneum, leaked into the anterior pararenal space, and continued along the extraperitoneal space to the prevesical space of the pelvis. Therefore, on the initial computed tomography (CT) scan, the bleeding appeared to be in the left paracolic gutter, so we suspected mesenteric bleeding. However, after the CT series was fully reconstructed, we accurately read the scans and confirmed splenic injury with active bleeding. If there had been a suspicion of bowel or mesenteric injury, surgery would have been required, but fortunately surgery could be avoided in this case. The patient was successfully treated with angioembolization.

• Sleep Medicine and Psychophysiology
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• v.27 no.2
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• pp.41-50
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• 2020

Napping is a natural and universal phenomenon. There are some differences depending on the age, but they are common throughout life. As research on naps in sleep medicine has recently increased, negative perceptions about naps are gradually decreasing with development of new and positive perspectives. First, naps relieve fatigue and sleepiness and increase arousal, improving cognitive abilities. Even in the process of memory consolidation, which allows retention of learned memory content, a period of short daytime sleep shows the same results as nocturnal sleep. In addition, evidence of the contribution of sleep to emotional regulation is increasing. The role of the nap has been extended recently to areas associated with immunity and pain. However, naps can disturb sleep at night. There are also concerns that habitual naps in old age are linked to cardiovascular risk and increased mortality. Various aspects and values of naps are being gradually unveiled. However, compared to that of night sleep, research on naps is insufficient, and more research on naps is required.