• Journal of Periodontal and Implant Science
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• v.51 no.5
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• pp.316-328
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• 2021

Purpose: This study aimed to examine the prevalence and abundance of 9 representative periodontal pathogens in the saliva samples of periodontally healthy subjects (PH) and patients with periodontitis who underwent supportive periodontal therapy (SPT). The age-specific distribution of these pathogens in periodontally healthy individuals was also analyzed. Methods: One hundred subjects (aged >35 years) were recruited (50 each in the PH and SPT groups) between August 2016 and April 2019. The prevalence and abundance of periodontal pathogens in the PH group were compared with those in periodontally healthy young subjects (94 subjects; aged <35 years), who were included in our previous study. DNA copy numbers of Aggregatibacter actinomycetemcomitans (Aa), Porphyromonas gingivalis (Pg), Tannerella forsythia (Tf), Treponema denticola (Td), Prevotella intermedia (Pi), Fusobacterium nucleatum (Fn), Campylobacter rectus (Cr), Peptostreptococcus anaerobius (Pa), and Eikenella corrodens (Ec) were analyzed using real-time polymerase chain reaction. Results: The detection frequencies of all pathogens, except Aa, were high in the PH and SPT groups. The ranking order of pathogen DNA copy numbers was similar in both groups. In both groups, Fn had the highest abundance, Aa had the lowest abundance. Additionally, Td was significantly more abundant in men than in women in both groups (P<0.05). Compared with the PH group, the SPT group exhibited significantly lower total bacteria and Fn abundance and higher Pg abundance (P<0.05). The age-specific pathogen distribution analysis revealed a significantly low Aa abundance and high Tf and Cr abundance in the PH group. Conclusions: The clinical parameters and microbial profiles were similar between the SPT and PH groups. However, patients with periodontitis require supportive care to prevent recurrence. As the abundance of some bacteria varied with age, future studies must elucidate the correlation between age-related physiological changes and periodontal bacterial composition.

• Journal of applied mathematics & informatics
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• v.29 no.3_4
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• pp.803-811
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• 2011

We present an algorithmic solution for the stationary distribution of the M/M/c retrial queue in which the retrial times of each customer in orbit are of phase type distribution of order 2. The system is modeled by the level dependent quasi-birth-and-death (LDQBD) process.

• Journal of Environmental Science International
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• v.20 no.3
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• pp.385-394
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• 2011

Organotin compounds (OTs), namely butyltins compounds (BTs) and phenyltin compounds (PhTs), were measured in surface and core sediments collected in Jeju harbor. The horizontal and vertical distribution was examined and the relationship between the concentration of OTs and organic matter content and particle size distribution was also studied. BTs were detected in significant concentrations in sediments inside Jeju harbor. PhTs were detected in very low concentrations, compared to BTs. The main species in BTs and PhTs were dibutyltin (DBT) and monobutyltin (MBT), monophenyltin (MPhT), respectively. In the relationships between the concentrations of total BTs and organic carbon content, the significant correlations ($r^2$=0.4898 in surface sediments, $r^2$=0.53 in one core sediments) and no correlation in another core sediments obtained, which is estimated that the distribution of BTs in sediments were affected by several factors, such as their physicochemical properties including organic carbon content, and a tide, etc. In the relationships between the concentrations of total BTs and particle size (mud, sand, and gravel) in sediments, the concentrations of total BTs were higher in the sediments with higher mud content, indicating that higher BTs were distributed with increasing sediments of fine granules.

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.242.3-243
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• 2003

The compound of 2"-O-benzoylcinnamaldehyde(CB-ph) is a derivative of 2"-hydroxycinnamaldehyde whcih is a methanol extract of cinnamomum cassia blume. It"s a new anti-cancer agent which has been showed to inhibit the growth of various tumor cells in vitro and in vivo. In order to investigate the effective drug concentration and bio-distribution of CB-ph, the plasma protein binding was studied. In this study, the degree of the binding of Cb-ph to various serum proteins, the binding parameters, the binding site of CB-ph in human serum albumin, and the effect of some extensive protein-binding drugs on the protein binding of CB-ph in human serum ablumin were investigated respectively by ultrafilteration and fluorescence spectrometry. (omitted)

• Journal of the Korean earth science society
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• v.39 no.1
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• pp.67-88
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• 2018

The important PH (paleontological heritages) with scientific, educational and esthetic values designated as natural monuments and protected by legislations of South and North Koreas are herein compared for the first time. On the basis of data (Jan. 2017) provided by the Cultural Heritage Administration of (South) Korea, a total of 457 natural monuments was designated. Of these, geological heritages are 80 in number, which includes 24 (30%) PH. Data (Dec. 2005) of North Korea show that a total of 474 natural monuments was designated. Among these, geological and geographical ones are 154 in number, which includes 22 (14%) PH. Differences between PH of South and North Koreas are regarded to be directly related with geological difference in distribution of the fossil-bearing strata between South and North Koreas. PH of Silurian corals, Devonian plants, Jurassic fishes, Cretaceous dinosaur tracks, birds (so called Korean Archaeopteryx) and pterosaurs, and Pleistocene paleoanthropological fossils appear to be scientifically significant. Together with these North Korean PH, scientific, esthetic, conservational, educational, and economical values of important PH including KCDC (Korean Cretaceous Dinosaur Coast), Jigunsan Shale, and Geumgwangdong Shale of South Korea should be evaluated as potential future candidates for international heritages.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1995.09a
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• pp.99-107
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• 1995

The Phase-type(PH) distribution, defined as a distribution of the time until the absorption in a finite continuous-time Markov chain state with one absorbing state, has been widely used for various stochastic modelling. But great computational burdens often make us hesitate to apply PH methods. In this paper, we propose a seemingly efficient approximation method for phase type distributions. We first describe methods to bound the first passage time distribution in continuous-time Markov chains. Next, we adapt these bounding methods to approximate phase-tupe distributions. Numerical computation results are given to verify their efficiency.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.30 no.1
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• pp.33-40
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• 2007

A multi-server queueing system with finite buffer is considered. The input flow is the BMAP (Batch Markovian Arrival Process). The service time has the PH (Phase) type distribution. Customers from the BMAP enter the system according to the discipline of partial admission. Besides ordinary (positive) customers, the Markovian flow (MAP) of negative customers arrives to the system. A negative customer can delete an ordinary customer in service if the state of its PH-service process belongs to some given set. In opposite case the ordinary customer is considered to be protected of the effect of negative customers. The stationary distribution and the main performance measures of the considered queueing system are calculated.

• Communications for Statistical Applications and Methods
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• v.27 no.4
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• pp.469-486
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• 2020

Entropy is an important term in statistical mechanics that was originally defined in the second law of thermodynamics. In this paper, we consider the maximum likelihood estimation (MLE), maximum product spacings estimation (MPSE) and Bayesian estimation of the entropy of an inverse Weibull distribution (InW) under a generalized type I progressive hybrid censoring scheme (GePH). The MLE and MPSE of the entropy cannot be obtained in closed form; therefore, we propose using the Newton-Raphson algorithm to solve it. Further, the Bayesian estimators for the entropy of InW based on squared error loss function (SqL), precautionary loss function (PrL), general entropy loss function (GeL) and linex loss function (LiL) are derived. In addition, we derive the Lindley's approximate method (LiA) of the Bayesian estimates. Monte Carlo simulations are conducted to compare the results among MLE, MPSE, and Bayesian estimators. A real data set based on the GePH is also analyzed for illustrative purposes.

• Animal cells and systems
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• v.5 no.3
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• pp.263-266
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• 2001

Metallothionein (MT) is induced in the regenerating rat liver. We have investigated expression of MT gene by RT PCR as well as specific localization of MT by immunocytochemistry in regenerating rat liver after partial hepatectomy (PH). MT mRNA level started to increase from 1 h and reached the peak at 8 h after PH. The level decreased gradually by 24 h, and became similar to that of control group. In the immunocytochemical study, in all groups treated with primary antibody, immunogold particles indicating the presence of MT were evenly distributed throughout both cytoplasm and nucleus of the rat hepatocytes. Within the nucleus, the gold particles appeared to be intensely localized in the areas of euchromatin and nucleolus. Within the cytoplasm, gold particles did not seem to adhere to mitochondria or Iysosomes, but were freely distributed. However, rough endoplasmic reticulum was the obvious compartment on which the gold particles were localized. Time course of MT immunoreactivity revealed that distribution of gold particles in hepatocytes increased gradually by 24 h, and decreased at 48 h after PH. Briefly, PH resulted in the sharpest increase in the expression of MT mRNA at 8 h and in the immunoreactivity of MT at 24 h, respectively. It is suggested that the increase of MT mRNA expression, the intensity of immunoreactivity and the specific localization of MT may be associated with the compensatory cell proliferation followed by PH.

• Journal of Ocean Engineering and Technology
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• v.6 no.2
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• pp.55-70
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• 1992

트림변화에 의해서 발생하는 선체 구조응답을 고찰, 계산 결과를 요약하였다. 본 고찰로 부터 같은 크기의 선수, 선미 트림상태일지라도 많은 차이를 보였다. 이에는 중량분포의 효과가 특히 크게 작용함을 밝히었다.