• 한국유체기계학회 논문집
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• 제13권3호
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• pp.54-58
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• 2010

The pneumatic waste collection system, which is a complete solution for solving the waste collection problems, are constructed in many countries all over the world. However, research data for piping network design are insufficient. In this paper the pressure losses of the straight and curved pipes, pipe junctions are obtained using the numerical method in order to investigate the optimal pipe network design for the waste collection system. As an experimental result, the length of 1.8 meter is the reasonable for the radius of curvature of a curved pipe and the angle of 30 degree is suitable for confluent pipe.

• Advances in Computational Design
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• 제5권3호
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• pp.261-276
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• 2020

The reasonable layout of vacuum cleaner can effectively improve the collection efficiency of iron filings generated in the process of steel production. Therefore, in this study, the CFD-DEM coupling model and two-fluid model are used to calculate the iron filings collection efficiency of vacuum cleaner with different inclination/cross-sectional area, pressure drop and inlet angle. The results are as follows: The CFD-DEM coupling method can truly reflect the motion mode of iron filings in pneumatic conveying. Considering the instability and the decline of the growth rate of iron filings collection efficiency caused by high pressure drop, the layout of 75° inclination is suggested, and the optimal pressure drop is 100Pa. The optimal simulation results based on two-fluid model show that when the inlet angle and pressure drop are in the range of 45°~65° and 70Pa~100Pa, larger mass flow rate of iron filings can be obtained. It is hoped that the simulation results can offer some suggestion to the layout of vacuum cleaner in the rolling mill.

• 디지털산업정보학회논문지
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• 제16권1호
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• pp.33-39
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• 2020

A smart grid is a next-generation power grid that can improve energy efficiency by applying information and communication technology to the general power grid. The smart grid makes it possible to exchange information about electricity production and consumption between electricity providers and consumers in real-time. Advanced metering infrastructure (AMI) is the core technology of the smart grid. The AMI provides two-way communication by installing a modem in an existing digital meter and typically include smart meters, data collection units, and meter data management systems. Because the AMI requires data collection units to control multiple smart meters, it is essential to ensure network availability under heavy network loads. If the load on the work done by the data collection unit is high, it is necessary to allocation new data collection units to ensure availability and improve energy efficiency. In this paper, we discuss the allocation scheme of data collection units for the energy efficiency of the AMI.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회B
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• pp.2794-2797
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• 2008

The pneumatic waste collection system, which is a complete solution for solving the waste collection problems, are constructed in many countries all over the world. However, research data for piping network design are insufficient. In this paper the pressure losses of the straight and curved pipes, pipe junctions are obtained using the numerical method in order to investigate the optimal pipe network design for the waste collection system.

• 대한의생명과학회지
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• 제8권2호
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• pp.63-69
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• 2002

This study was performed to investigate the effectiveness of the aspiration trap method for collection of sputum by comparing with the conventional method which was collecting specimens at canular cap swab. In this study, the author tested by two methods to collect specimens from 46 patients who were cared with tracheostomy and intubation at the intensive care unit of an university hospital in Pusan, and investigated the incidence of the lower respiratory tract infection, the consistency between the two methods, the level of specimen contamination. Major results were as follows: Among the patients, 35 were cared with tracheostomy and 11 were cared with intubation. In clinical diagnosis we were classified the subjects in to two group, 17 of pneumonia group and 29 of non-pneumonia group. A total of 247 strains were isolated. Among them, most three strains were Serratia marcescens (62 strains; 25.1%), Pseudomonas aeruginosa (52 strains; 21.1%), and Acinetobacter baumannii (19 strains; 7.8%). Out of total, 188 (76.1%) strains were Gram negative bacilli. The isolated strains by the aspiration trap method were the average 2.1 strains, but by the canular cap swab method were 1.6 strains. In spite of the high contaminated possibility from the incision site and the oral cavity swab, the low isolated rates of the canular cap may be the dried environment of the canular of cap area. But the contamination rates were 57.2% of the canular cap, 51.5% of the oral swab and 50.5% of the incision site swab, respectively. The consistency of predominant microorganisms according to collection method were 86.7% of aspiration, 78.3% of canular, 74.3% of incision, and 63.6% of oral. In conclusion, the aspiration trap method fur the sputum collection from the patients with intubation of tracheostomy showed the lower contamination rate of the specimens and it was helpful for rapid, accurated interpretation of the lower respiratory tract infection and hospital infection.

• 한국항행학회논문지
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• 제11권3호
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• pp.337-342
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• 2007

본 논문에서는 현재 국내 ETCS(Electrical Toll Collection System)에 적용될 예정에 있는 후불식 지불 방식에 있어서 수행해야할 전자 신용카드(EMV) 처리절차를 제안한다. 현재 국내에서는 한국도로공사의 하이패스, 터치패스 시스템이 비접촉식 ETCS로 운영되고 있으며, 현재의 운영 방식은 일종의 전자화폐 개념의 선불(pre-paid)식이다. 이에 반해 후불(credit)식은 신용카드 기반의 지불을 수행함으로써 미리 지불할 필요가 없다는 장점이 있다. 현재 국내의 ETCS에 후불식의 도입이 준비 중에 있으며, 본 논문에서는 이러한 후불식 지불에서 고려해야 할 EMV 처리 방식을 제안한다.

• 한국유체기계학회 논문집
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• 제10권4호
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• pp.55-60
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• 2007

This paper describes an evaluation method of pressure drop in a circular pipe of waste collection piping system. Accurate pressure drop in a piping system is very important to determine the capacity of turbo blower, which is one of the main elements in the system. Three-dimensional Navier-Stokes analysis is introduced to analyze the pressure drop in the piping system. Organic waste is selected and modeled using the result of site survey performed in an apartment area. Evaluation method of pressure drop used In the present numerical simulation is performed in the shortened pipe line prior to the calculation of the real system. Throughout the numerical simulation, pressure drop in a waste pipe is obtained and compared to the value determined by analytical method. The pressure drop obtained by numerical simulation has a good agreement with that of the analytic method. It is noted that present evaluation method is effective to determine a pressure drop in the piping system. Detailed flow characteristics inside the pipe line are also analyzed and discussed.

• 한국농공학회지
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• 제39권3호
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• pp.128-137
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• 1997

In this study, examined influence of consolidation effect that had affected by location of pump inlet that was set collection well for drainage of pore water discharged by embankment on soft ground through the field test. The results of this study are summarized as follows; 1 Initial consolidation curve value were larger than theoritic value, the cause of these phenomena were thought influence of secondary consolidation and three dimensional strain of soft clay. 2. The settlement value of Hosino method was larger than that of Hyperbolic method, but settlement value of Hyperbolic method was accurate more than that of Hosino method in the prediction of settlement. 3. When pump inlet in collection well came down from GL+O.3m to GL-1.5m, settlement value increased about 10cm and when the ground water level was made insitu after pumping had completed , settlement was expanded about 7~8cm. So it is found that location change of pump inlet bad an influence on settlement remarkably. 4. If location of pump inlet in collection well for large scale estate or wide road site is lowered than original ground level, the settlement will be accelerated effectively, and at this stage automatic pump must be used in pumping.

• 한국ITS학회:학술대회논문집
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• 한국ITS학회 2007년도 제6회 추계학술대회 및 정기총회
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• pp.244-250
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• 2007

• Journal of Oral Medicine and Pain
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• 제47권1호
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• pp.10-26
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• 2022

Purpose: The purpose of this study was to investigate whether various saliva collection methods affect the observed salivary microbiome and whether microbiomes of stimulated and unstimulated saliva and plaque differ in richness and diversity. Methods: Seven sampling methods for unstimulated saliva, stimulated saliva, and plaque samples were applied to six orally and systemically healthy participants. Bacterial 16S ribosomal RNA genes of 10 major oral bacterial species, namely, Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola, Fusobacterium nucleatum, Prevotella intermedia, Prevotella nigrescens, Streptococcus mitis, Streptococcus sobrinus, and Lactobacillus casei, were analyzed by real-time polymerase chain reaction. We comprehensively examined the dependence of the amount of bacterial ribosomal DNA (rDNA), bacterial-community composition, and relative abundance of each species on sample collection methods. Results: There were significant differences in the bacterial rDNA copy number depending on the collection method in three species: F. nucleatum, P. nigrescens, and S. mitis. The species with the highest richness was S. mitis, with the range from 89.31% to 100.00%, followed by F. nucleatum, P. nigrescens, T. denticola, T. forsythia, and P. intermedia, and the sum of the proportions of the remaining five species was less than 1%. The species with the lowest observed richness was P. gingivalis (<0.1%). The Shannon diversity index was the highest in unstimulated saliva collected with a funnel (4.449). The Shannon diversity index was higher in plaque samples (3.623) than in unstimulated (3.171) and stimulated (3.129) saliva and in mouthwash saliva samples (2.061). Conclusions: The oral microbial profile of saliva samples can be affected by sample collection methods, and saliva differs from plaque in the microbiome. An easy and rapid technique for saliva collection is desirable; however, observed microbial-community composition may more accurately reflect the actual microbiome when unstimulated saliva is assayed.