• International Journal of Reliability and Applications
• /
• 제3권3호
• /
• pp.133-145
• /
• 2002

The traditional methods of evaluating the performance of a network by enumerating all possible states may quickly become computationally prohibitive, since the number of states grows exponentially as the number of components increases. In such cases, enumerating only the most probable states would provide a good approximation. In this paper, we propose a method which efficiently generates upper and lower bounds for coherent performance measures utilizing the most probable states. Compared with Yang and Kubat's method, our procedure significantly reduces the complexity and memory requirement per iteration for computing the bounds and thereby, achieves the given degree of accuracy or the coverage within a shorter time.

• 한국미생물·생명공학회지
• /
• 제24권3호
• /
• pp.364-370
• /
• 1996

Sediments collected from the Jungnang-cheon and its tributaries were used to enumerate anaerobic bacteria by most probable number (MPN) methods. A simple method was developed to detect ferrous ion in the culture fluid in order to count the number of iron ion reducers, and sulfate-reducing bacteria (SRB) and methanogens were detected by the presence of FeS precipitate in the culture or methane in the head space, respectively. The numbers of iron reducer was in the range of 10$^{7}$ - 10$^{8}$ /g in the sediment of the stream containing higher organic content than the tributaries. The sediments of tributaries were analyzed to contain iron reducers less than 10$^{7}$ cells/g. With one exception the numbers of SRB and methanogens were less than 10$^{3}$ cells/g in the sediment. From these results it is concluded that organics in the sediment support the growth of iron reducers, which out-compete SRB and methanogens.

• 한국수산과학회지
• /
• 제47권5호
• /
• pp.556-561
• /
• 2014

We applied a combination of most probable number-polymerase chain reaction (MPN-PCR) methods using a PCR procedure targeting the H-NS (VP1133) gene to detect Vibrio parahaemolyticus presence and density in seawater as well as within short-necked clam Ruditapes philippinarum tissues collected from Gomso Bay, Korea. In 30 seawater samples, V. parahaemolyticus levels ranged from less than 1.8 to $1.1{\times}10^3MPN/100mL$, and samples from August showed higher than those from other months. Furthermore, the levels of V. parahaemolyticus in six short-necked clam samples ranged from $7.8{\times}10^2$ to $2.1{\times}10^3MPN/100g$, approximately 2.5 times higher than in seawater samples from the corresponding month. Our results provide data on V. parahaemolyticus contamination in seawater and short-necked clam tissues, and help to improve quantitative methods of assessing V. parahaemolytcius levels.

• ETRI Journal
• /
• 제31권5호
• /
• pp.610-612
• /
• 2009

We present intra-mixture prediction (IMP) mode for intra prediction and an enhanced estimation method for most probable mode (MPM). IMP mode supports more flexibility in intra prediction by mixing $4{\times}4$ blocks and $8{\times}8$ blocks in one macroblock, while the enhanced MPM estimation extends the number of referenced neighboring blocks and efficiently uses their prediction modes depending on their positions. Simulation results show that the combination of both proposed methods provides a bit reduction in the Bj${\phi}$ntegaard delta bitrate by an average of 2.56% compared to H.264/AVC.

• 한국신뢰성학회:학술대회논문집
• /
• 한국신뢰성학회 2002년도 정기학술대회
• /
• pp.289-296
• /
• 2002

The traditional methods of evaluating the performance of a network by enumerating all possible states may quickly become computationally prohibitive, since the number of states grows exponentially as the number of components increases. In such cases, enumerating only the most probable states would provide a good approximation. In this paper, we propose a method which efficiently generates upper and lower bounds for coherent performance measures utilizing the most probable states. Compared with Yang and Kubat's method, our procedure significantly reduces the complexity and memory requirement per iteration for computing the bounds and thereby, achieves the given degree of accuracy or the coverage within a shorter time.

• 한국미생물·생명공학회지
• /
• 제20권2호
• /
• pp.233-235
• /
• 1992

The number of sulphate-reducing bacteria (SRB) in some of the tributaries to the Han River was determined by the most probable number method using Postgate's Medium E.Higher number of SRB were obtained in the streams to which industrial waste water is discharged than those receiving only domestic waste water.

• 한국수산과학회지
• /
• 제56권4호
• /
• pp.520-525
• /
• 2023

This study aimed to detect Enterococcus spp. strain, a fecal contamination indicator, by PCR assay from short neck clams Venerupis philippinarum in Cheonsu Bay area, Chu Island area and Wonsan Island area, the west coast of Korea, from November 2022 to February 2023 of Enterococcus spp. strain was detected in 19 (79.2%) among 24 samples, and its concentration ranged from <18 to 33,000 MPN (most probable number)/100 g. The 269 isolated Enterococcus spp. strains were identified by PCR assay, and Enterococcus spp. distribution in short neck clams were E. faecium (39.8%), E. faecalis (23.0%), E. hirae (21.9%), E. gallinarum (10.4%), E. casseliflavus (1.5%), E. durans (1.5%) and unidentified strains (1.9%). Thus, E. faecium was the most dominant strain followed by E. faecalis. Overall, these results provide novel insight into the necessity for shellfish sanitation in the sea and could help reduce the fecal contamination risk.

• 대한기계학회논문집A
• /
• 제30권9호
• /
• pp.1116-1123
• /
• 2006

In this study, the effective method for reliability estimation is proposed using tow-staged kriging metamodel and genetic algorithm. Kriging metamodel can be determined by appropriate sampling range and the number of sampling points. The first kriging metamodel is made based on the proposed sampling points. The advanced f'=rst order reliability method is applied to the first kriging metamodel to determine the reliability and most probable failure point(MPFP) approximately. Then, the second kriging metamodel is constructed using additional sampling points near the MPFP. These points are selected using genetic algorithm that have the maximum mean squared error. The Monte-Carlo simulation is applied to the second kriging metamodel to estimate the reliability. The proposed method is applied to numerical examples and the results are almost equal to the reference reliability.

• 생명과학회지
• /
• 제20권10호
• /
• pp.1468-1475
• /
• 2010

유기농법과 관행 농법토양, 청정 갯벌과 오염 갯벌토양 그리고 청정 담수와 오염 담수 토양을 이용하여 계절의 변화에 따라 $^{35}SO_4^{-2}$을 이용한 황산염 환원율, 가스크로마토그래피를 이용한 황화수소 생성량, 최적확수 시험법을 이용한 황산염 환원세균의 분포, 공정시험법을 이용한 수분, 암모니아, 총 질소, 총 유기탄소, 총 탄소, 총 무기인, 총 인, 황산염 농도의 토양 성분조사를 실시하였다. 그 결과 황산염 환원율은 황산염의 농도보다 황산염 환원세균의 군집크기와 질소와 인과 같은 토양 성분과 서로 밀접한 관련이 있는 것으로 확인되었다. 그리고 황화수소 생성량은 10월 토양에서 가장 높게 나타났으나, 담수 토양 보다는 높은 황산염 농도를 함유한 갯벌 토양에서 더 높게 나타났고, 청정 지역보다는 오염 지역 토양에서 높은 값을 나타냈다. 따라서 혐기환경의 황산염 환원율과 황화수소 생성량은 황산염 환원세균의 군집과 토양 내 여러 가지 성분 그리고 온도에 의해 영향 받는 것을 확인하였다.

• 한국환경보건학회지
• /
• 제39권2호
• /
• pp.105-116
• /
• 2013

Background: In Korea, there is low awareness of the respiratory health problems caused by the use of humidifiers, leading to a lack of governmental measures. Objectives: The objectives of this study were to review cases of varying degrees of humidifier lung and fever in connection with the use of humidifiers and to summarize the probable environmental agents causing these cases. Methods: We searched all articles reporting on humidifier lung, humidifier fever, and humidifier diseases caused by the use of a humidifier both at home and in the workplace. Results: We summarized a number of cases of varying degrees of respiratory diseases resulting from inhalation of water mist of humidifiers containing various species of bacteria and fungi and their toxins. Type of respiratory disease connected with humidifier lung includes interstitial pneumonitis, hypersensitivity pneumonitis, fever and several respiratory symptoms. Non-tuberculous mycobacteria (NTM), Actinomycetes, endotoxins and contaminated humidifier water were the most commonly suspected probable environmental agents causing humidifier lung. In Korea, the use of humidifier biocide is suspected as a likely cause of fatal lung injury including death and lung transplantation. Conclusion: Governmental policy should be devised and measures including a national surveillance system should be taken to prevent humidifier lung caused by the use of humidifiers.