• Journal of applied mathematics & informatics
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• v.29 no.3_4
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• pp.529-546
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• 2011

A deterministic tuberculosis model for theoretically assessing the potential impact of the combined effects of case detection in the presence of treatment is formulated. The qualitative features of its equilibria are analyzed and it is found that the disease-free equilibrium may not be globally asymptotically stable when the reproduction number is less than unity. This disease threshold number is further used to assess the impact of active TB case finding alone and in conjunction with treatment. A critical threshold parameter ${\Theta}$ say for which case detection will have a positive impact is derived. Using the Centre Manifold theory, the model may exhibit the phenomenon of backward bifurcation (coexistence of a locally stable endemic equilibrium with a stable disease-free equilibrium) when the reproduction number is less than unity. It is shown that the possibility of backward bifurcation occurring decreases with increase case detection. Graphical representations suggest that increase in case finding accompanied by treatment of detected TB cases, result in a marked decrease of TB cases (both latent and active TB).

• East Asian mathematical journal
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• v.35 no.1
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• pp.85-90
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• 2019

In this paper, we are interested in the evaluation of special values of the Dedekind zeta function of a totally real number field. In particular, we revisit Siegel method for values of the zeta function of a totally real number field at negative odd integers and explain how this method is applied to the case of non-normal totally real number field. As one of its applications, we give divisibility property for the values in the special case

• Journal of Korean Library and Information Science Society
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• v.24
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• pp.1-44
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• 1996

This study is to analyze correlations between 10 factors related to university libraries and the number of professional staff, nonprofessional staff, and total library staff of university libraries in Korea and United States of America. The results of this study are summarized as follows: 1. In the case of Korea, there are high positive correlations between the number of total library staff and 7 of 10 variables (coefficient : 0.76-0.99) ; between the number of professional staff and 7 of 10 variables, same as the above (coefficient : 0.76-0.99) ; between the number of nonprofessional staff and 4 of 10 variables (coefficient 0.73-0.93). In the case of America, there are high positive correlations between the number of total library staff and 6 of 10 variables (coefficient : 0.74-0.97) ; between the number of professional staff and 5 of 10 variables (coefficient : 0.78-0.87): between the number of nonprofessional staff and 6 of 10 variables (coefficient : 0.73-0., 96). 2. All the. rank orders of correlation coefficients of two countries show little significant difference, by the results of the Spearman's Rank Order Correlation analysis (coefficient : total staff, 0.9152: professional staff, 0.8667 ; nonprofessional staff, 0.9030) 3. In the case of Korea, among the above factors, correlations of the total university expenditure and the library expenditure show a significant difference more than ones of the other factors. On the other hand, in the case of American professional staff, the correlations of the library expenditure, the library materials expenditure and the volumes in library show a significant difference more than ones of the other factors, while in the case of American nonprofessional staff, only the library expenditure shows a significant difference more than the others. 4. In the results of the correlation analysis between the professional staff and nonprofessional staff in Korea, the number of graduate enrollments, volumes in library, library expenditure and total university expenditure show higher positive correlation to the professional staff than the nonprofessional staff. However, in the case of America, the library expenditure and the library materials expenditure show higher positive correlation to the nonprofessional staff than the professional staff, while the university expenditure per student shows higher positive correlation to the professional staff. 5. In the results of the correlation analysis between Korea and America, in the case of the total library staff, the undergraduate enrollments, the total university expenditure and the library expenditure show higher positive correlation to Korea than America, and in the case of the professional staff, the graduate, enrollments, the volumes in library and the above 3 factors also show higher positive correlation to Korea than America. But in the case of the nonprofessional staff, the graduate enrollments, the volumes in library and library materials expenditure show higher correlation to America than Korea, while the total university expenditure shows the o n.0, pposit phenomenon of the above. And the other factors by the type of staff are little significant difference between two countries.

• Proceedings of the KAIS Fall Conference
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• 2003.11a
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• pp.178-184
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• 2003

Case-based reasoning (CBR) often shows significant promise for improving effectiveness of complex and unstructured decision making. Consequently, it has been applied to various problem-solving areas including manufacturing, finance and marketing. However, the design of appropriate case indexing and retrieval mechanisms to improve the performance of CBR is still challenging issue. Most of previous studies to improve the effectiveness for CBR have focused on the similarity function or optimization of case features and their weights. However, according to some of prior researches, finding the optimal k parameter for k-nearest neighbor (k-NN) is also crucial to improve the performance of CBR system. Nonetheless, there have been few attempts which have tried to optimize the number of neighbors, especially using artificial intelligence (AI) techniques. In this study, we introduce a genetic algorithm (GA) to optimize the number of neighbors to combine. This study applies the new model to the real-world case provided by an online shopping mall in Korea. Experimental results show that a GA-optimized k-NN approach outperforms other AI techniques for purchasing behavior forecasting.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.27 no.3
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• pp.1-25
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• 2014

Objective : For activation of study on filed of odontology in Korean medicine academia, we analyzed the trend of articles that published in journals of Korean medicine. Methods : Using search words of odontology, in internet reference sites we collected papers and classified those into three categories like as review article, original article, case report. Observation points of each item are as follows. Inclusive item of papers; publication year, journal, number of authors, disease. Item of review article; subject of paper, Item of original article; number of patients, period of research, remedy. Item of case report; remedy, valuation of criteria, number of cases. Results : The total number of articles searched was 88, consisting of 23 review articles, 46 original articles and 19 case reports. The percentage of 'TMJ diseases' ranked highest(47.7%) in classification by disease. The most reviewed subject was 'Remedy' (16 times). '25 or less' person ranked highest(50%) in the number of patient in original articles. Acupuncture, chuna manual medicine and herbal medicine were mostly applied in case reports. The number of 'one case' reported case reports was highest(52.6%).

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.3 no.1
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• pp.26-33
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• 1991

An experimental study has been performed on the heat transfer by the natural convection from a conducting tube with two axial fins to a surrounding cylinder. In case of vertical fins, the maximum local Nusselt number of conducting tube appears at ${\theta}{\fallingdotseq}145^{\circ}$ and that of outer cylinder appears at ${\theta}=0^{\circ}$, for $l_F=0.3$. In case of horizontal fins, the maximum local Nusselt number of conducting tube appears at ${\theta}=180^{\circ}$ and that of outer cylinder appears at ${\theta}=0^{\circ}$. The local Nusselt number of the upper fin and the downward fin shows negative values for $l_F=1.0$. The local Nusselt number of the lower fin and the downward fin shows higher values than that of the upper fin and the upward fin. The mean Nusselt number of conducting tube in case of vertical fins are increased in order of $l_F=0.6$, 0.3, 1.0 and 0.0, but in case of horizontal fins, in order of $l_F=1.0$, 0.6, 0.3, and 0.0. The mean Nusselt number of outer cylinder in case of vertical fins are increased in order of $l_F=1.0$, 0.0, 0.3 and 0.6, but in case of horizontal fins, in order of $l_F=0.6$, 1.0, 0.3, and 0.0.

• East Asian mathematical journal
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• v.38 no.4
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• pp.379-396
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• 2022

In this paper, we investigate distribution strategies in the Egyptian fraction, and through this, we examine the distribution strategies of (fraction)÷(fraction) and then provide some educational implications. The (natural number)÷(natural number) of the sharing situation has the meaning of 'share' per unit, which can be seen as a situation where the unit ratio is determined. These concepts can also naturally be extended to the case of (fraction)÷(fraction) by some problem posing situations. That is to say, the case of (fraction)÷(fraction) can be deduced the case (natural number)÷(natural number) by the re-statement of the problem.

• The Korean Journal of Emergency Medical Services
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• v.12 no.2
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• pp.37-43
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• 2008

Purpose : It was to improve medical direction system through presenting need of doctor and paramedic in Korean Fire Service. Methods : This study was conducted by applying demand coefficients(4 for doctor, 3 or 4.5 for paramedic) to some data on medical director, paramedic, ambulance from National Emergency Management Agency. Results : Number of medical director & paramedic were 4 & 1,217. Number of necessary doctor for medical direction was 64 or 28(in case of direct medical direction) & 16 or 7(in case of indirect medical direction). Number of necessary paramedic for direct medical direction was 492(in case of 35% ALS ambulance) & 1,062(in case of 50% ALS ambulance). Conclusions : To improve quality & efficiency of medical direction brought up need of amendment of the Emergency Medical Services Act to apply indirect medical control such as standing orders, protocol, case review.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.301-304
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• 2001

The purpose of this study is presume that reasonable construction period of constract and appropriate number of persons for works according to reconstruction. This study is presume reasonable construction period of constract and appropriate number of person of reconsruction with a case study out of apartment R.C construction. The result of this study are as follows: 1. In case of four building of apartment Resonable constrution period: 750days$\sim$800days, the average(1day) number of persons under working: 63.5 persons. 2. In case of four building of apartment Resonable constrution period: 850days$\sim$900days, the average(1day) number of persons under working: 100.6 persons. 3. In case of four building of apartment Resonable constrution period: 1000days$\sim$1050days, the average(1day) number of persons under working: 145.0 persons.

• Bulletin of the Korean Chemical Society
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• v.17 no.4
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• pp.385-390
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• 1996

It has been well known that the Grad thirteen-moment equations have solutions only when the Mach number is less than a limiting value for the stationary plane shock-waves. The limit of Mach number has been re-examined by including successive terms in the series expansion of distribution function. The method employed is the linear analysis of moment equations near up-streaming and down-streaming flows. For the thirteen moment case, it has been confirmed that equations have solutions only when the Mach number is less than 1.6503, which is consistent with the literature value. For the case of twenty moments, the limit of Mach number is decreased to 1.3416.