• Journal of Chest Surgery
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• v.25 no.11
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• pp.1203-1208
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• 1992

Current methods of myocardial protection has been improved with cardioplegia and hypothermia. We compared St. Thomas hospital cardiopleic solution without oxygenation[Group I], with oxygenation[Group II] and with oxygenation with filter[Group III] under isolated working heart model. Heart rate recovery was more significantly improved in Group II than Group I after 15 minutes of recovery time [p<0.05]. Maximal systolic pressure shows no difference as it increases with time. Cardiac ouputs were not diffrent between groups. Recovery time was shorter significantly in group II and group III than group I [p<0.05] Use of filter showed no difference. As a conclusion, oxygenated cardioplegic solutions improves ability to protect the heart against ischemia and it is manifested by improved recovery time and heart rate.

• Journal of Chest Surgery
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• v.22 no.6
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• pp.887-893
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• 1989

Donor availability is a major limiting factor in heart transplantation. Prolonging donor heart preservation would facilitate distant heart procurement. The setup used was the isolated retrograde perfused nonworking rabbit heart model and 4 hours of preservation at 2oC. And the electron microscopic findings of the myocardium were evaluated after reperfusion for 5 minutes. The following three groups [each group, n=4] were prepared: Group I: the heart was arrested with the St. Thomas Hospital solution [STH] and stored in Ringers lactate solution [RLS]; Group II: the heart was arrested with STH and stored in Modified Collins-Sachs solution [MCS]; Group g: the heart was arrested with and stored in MCS. The result was the most severe myocardial injury in the Group III on electron microscopic study.

• Journal of the military operations research society of Korea
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• v.25 no.2
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• pp.31-43
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• 1999

This paper deals with the problem of Customs trying to stop a Smuggler attempting to ship a cargo of perishable contraband(or information) across a strait within the limited period. The papers concerning these fields referred by Thomas, Baston et al, and Garnaev, have treated games dealing with one, two, and three patrol boats against one smuggler ship respectively. In this paper the author proposed a game model dealing with N patrol ships against one smuggler ship with the N boats being identical. The strategies for the gamers where games are conducted between them are shown in tables 3.3-1 and the game values thereof are in table 3.2-3. The author has exhaustively filled up the assumptions and conditions in the paper to justify the above-mentioned results so that they may not loose the generality.

• Journal of Korean Association for Spatial Structures
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• v.15 no.1
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• pp.47-55
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• 2015

This paper shows the simplified equation to predict the ultimate moment capacity and corresponding rod stress in reinforced concrete beam with external post-tensioning rods. Because the stress of external post-tensioning rod depends on the beam deflection, the previous analytical model for post-tensioned beams requires a tedious iteration process. Also, the stress equations in ACI code or other researchers' models are suitable only for internal tendons in concrete beams. In this study, given the lack of analytical approaches to predict the nominal stress of the external unbonded rod, a simple and robust equation has been proposed for externally post-tensioned concrete beams. It is concluded that the proposed equation predicted the stress of external steel rods in post-tensioned concrete beams reasonably well.

• Wind and Structures
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• v.3 no.2
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• pp.73-81
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• 2000

Snowdrifts around buildings can cause serious problems when formed on undesirable places. The formation of snowdrifts is highly connected to the wind pattern around the building, and the wind pattern is again dependent on the building design. The shear stress on the surface and snowdrifting around different buildings are investigated through CFD analysis and compared to measurements. The computations of shear stress shows local minima in the same areas as snowdrifts are formed. The snowdrifting computations utilises a drift-flux model where a fluid with snow properties is allowed to drift through a fluid with air properties. An apparent dynamic viscosity of the snow/air mixture is defined and used as a threshold criterion for snowdrifting. The results from the snowdrifting computations show increased snow density where snowdrifts are expected, and are in agreement with previous large-scale snowdrift measurements. The results show that computational fluid dynamics can be a tool for planning building design in snowdrifting areas.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2004.10a
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• pp.389-392
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• 2004

The column generation process for the set-partitioning model of the vehicle routing problem requires repeated solutions of column generation subproblems which has a combinatorial structure similar to that of the traveling salesman problem. This limits the size of the problem that can be addressed. We introduce a new modeling approach, termed route-splitting, which splits each vehicle route into segments, and results in more tractable subproblems. A lower bounding scheme that yields an updated bound at each iteration of the column generation process is developed. Implementation issues, including a technique of controlling columns in the master problem, are explored. Lower bounds are computed on standard benchmark problems with up to 199 customers.

• Environmental Engineering Research
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• v.24 no.1
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• pp.31-37
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• 2019

In this paper the results of the biosorption of lead(II) and cadmium(II) with sugarcane bagasse in fixed bed columns are presented. Experimental data were fitted to several models describing the rupture curve for single-component and two-component systems. The percentages of removal of lead and cadmium in single-component systems are 91% and 90%, respectively. In lead-cadmium bicomponent systems the percentage of elimination of lead was 90% and cadmium 92%. In single-component systems, Yoon-Nelson and Thomas models successfully reproduce the rupture curves. In two-component system, the Dose-Response model was the best one reproducing the experimental rupture curves in the entire measured range.

• International conference on construction engineering and project management
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• 2005.10a
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• pp.830-835
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• 2005

4D models help construction planners to develop and evaluate construction plans. However, current analyses using 4D models are mainly visual and limit the quantitative comparison of construction alternatives. This paper explores the usefulness of extracting quantitative information from 4D models to support time-space analyses. We use two 4D models of an industry test case to illustrate how to analyze 4D content quantitatively (i.e., work space areas and distances between concurrent activities). This paper shows how these two types of 4D content can be extracted from 4D models to support 4D-based-analysis and novel presentation of construction planning information. We suggest further research to formalize the content of 4D models to enable comparative quantitative analyses of construction planning alternatives. Formalized 4D content will enable the development of reasoning mechanisms that automate 4D-model-based analyses and provide the information content for informative presentations of construction planning information.

• Journal of applied mathematics & informatics
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• v.42 no.3
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• pp.483-497
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• 2024

Isometric array grammar is one of the simplest model to generate picture languages, since both sides of its production rule have the same shape. In this paper, we have introduced isometric fuzzy regular array grammars to generate isometric fuzzy regular array languages and discussed its closure properties. Also, the relation between isometric fuzzy regular array grammar and boustrophedon fuzzy finite automata has been discussed. Moreover, we study the relation between two dimensional fuzzy regular grammars with returning fuzzy finite automata and boustrophedon fuzzy finite automata. Further, the hierarchy results of these three classes of languages have been discussed.

• Journal of Korean Society on Water Environment
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• v.28 no.1
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• pp.38-49
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• 2012

In this study, we analyze statistical characteristics of influent water quality in Daejeon waste water treatment plant and apply a stochastic model for data generation. In the analysis, the influent water quality data from year 2003 to 2008, except for year 2006, are used. Among water quality variables, we find strong correlations between BOD and T-N; T-N and T-P; BOD and T-P; $COD_{Mn}$ and T-P; and BOD and $COD_{Mn}$. We also find that different water quality variables follow different theoretical probability distribution functions, which also depends on whether the seasonal cycle is removed. Finally, we generate the influent water quality data using the multi-season 1st Markov model (Thomas-Fiering model). With model parameters calibrated for the period 2003~2005, the generated data for 2007~2008 are well compared with observed data showing good agreement in general. BOD and T-N are underestimated by the stochastic model. This is mainly due to the statistical difference in observed data itself between two periods of 2003~2005 and 2007~2008. Therefore, we expect the stochastic model can be applied with more confidence in the case that the data follows stationary pattern.