• East Asian mathematical journal
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• v.39 no.1
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• pp.43-50
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• 2023

This paper is concerned with the existence of positive solutions to the second order differential systems with strongly coupled integral boundary value conditions. The fixed point index theorems are used for the main results.

• Tribology and Lubricants
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• v.31 no.1
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• pp.28-34
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• 2015

This paper addresses the problems of using anti-freeze lubricants for different machines that must function at extremely low temperatures during winter operation in the Republic of Sakha (Yakutia). We discuss the possibility of obtaining anti-freeze base oils from Talakan crude oil, an area with major oil and gas deposits of the Republic of Sakha, and also provide the trade and technological classification of Talakan crude oil. We propose two different schemes for processing Talakan crude oil: the fuel scheme (obtaining light and heavy fractions as a fuel oil) and the base oil scheme (obtaining light fractions and base oils). We investigate the influence of pour point depressants on alkyl-methacrylate base on the low-temperature properties of the fractions obtained from Talakan crude oil and Korean base oils, and establish the optimal concentration of pour point depressants. We compare the properties of these fractions with the low-temperature properties of Korean base oils and find that the commercial oil "Ravenol 0W-40" provides optimistic results. We obtain oil with a pour point of minus $50^{\circ}C$ and a viscosity index greater than 100. The Design of Experiment was used to establish the optimum composition of the pour point depressants and the base oil S-8 to obtain lubricant oil with a kinematic viscosity of 17 cSt, viscosity index of 208, and a pour point of minus $64^{\circ}C$.

• Journal of Environmental Science International
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• v.4 no.1
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• pp.1-12
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• 1995

The assessment for a degree of drought has been carried out based on the soil moisture index in Korea. The soil moisture index(Im) was calculated assuming of constant evapotranspiration until wilting point as Im = w2/wf $.$100. The soil moisture content(W2) at the final of a period is obtained from W2 : Pe + Wl - E, here the effective precipitation amount is Pe, evapotranspiration E, and the soil moisture content at the beginning of a period is Wl. The filed capacity(Wf), as a mean value of fine sandy loams, was reduced to 92 mm/ft when we accept the wilting point and the available soil moisture content of 42 mm/ft, respectively. The drought begins in Korea when the soil moisture index drops to less than 50%. The value coincides the isoline of 11 or more consecutive days without measureable precipitation. The soil moisture index frequently drops in the northern part of Youngnam area and Honam area so that both areas are well known as the areas of drought. Key word : Droughts, Soil Moisture Index.

• Journal of the Korean Academy of Clinical Electrophysiology
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• v.1 no.2
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• pp.49-60
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• 2003

The purpose of this study was to evaluate the effect of Halliwick 10 point program on the balance control. Fourteen undergraduate students participated in the experiment, and classified 7 experiment and 7 control group, randomly. Halliwick 10 point program was applied in the experiment group for 4 weeks. Balance index was measured using KAT 2000. Balance index were measured before, during(2 weeks), and after(4 weeks) the training for 4 weeks. 2-way repeated measures ANOVA was used to further distinguish between the groups. The following results were obtained; 1. The total balance index scores from a KAT were significantly decreased after 4 weeks compared with before the training passing of time. However there was no significant difference between experiment and control group. 2. The left and anterior shifting balance index scores from a KAT were significantly decreased after 4 weeks compared with before the training passing of time. However there was no significant difference between experiment and control group. These results lead us to the conclusion that the balance ability of women twenties increase as the water is higher than that of the ground applied Halliwick 10 point program of the water specific therapy province. Therefore, A further direction of this study will be to provide more evidence for Halliwick 10 point program in the water specific therapy.

• Journal of Environmental Health Sciences
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• v.46 no.5
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• pp.588-598
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• 2020

Objectives: Human indices were developed to determine returning point of residents and damage restoration after the chemical accident Methods: To determine the returning point of residents after the chemical accident, a new concept, the standard man model was introduced as a human index, in which both H-code and its acute effects were main idea. To evaluate the applicability, a hydrogen fluoride leakage accident in Gumi was applied. The returning point were suggested as the conservative remission period of acute effects among relevant hazard effects and compared with actual returning point. The coverage of each age group were considered with reflecting average daily dose expected for actual residents. In addition, a relief-index as a social-scientific approach was reflected as well to apply the damage restoration Results: Actual returning point of residents in Gumi was 88 days; and that of standard man model suggested was 84 days. The expected amount of exposure at aged 12 or under was at least 2.35 times greater than that of this model, 40s, theoretically. However, their population ratio was less than 1%, so 99% of residents could be applied when the standard man model was applied. The relief-index was as an objective and quantitative methodology to apply the qualitative aspect. Conclusions: Although evaluated as a relatively positive result, there was a limitation such as the number of accident applied to the verification of standard man model. The relief index was also considered, but further research should be carried out to find threshold level for the relief.

• Journal of the Korean Institute of Landscape Architecture
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• v.21 no.2
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• pp.120-128
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• 1993

This study suggests one hypothesis: The strength of the catchment forces of urban community parks can be represented as an equilibrium point model, which is derived from a centrality index for. That model was designed by Reilly(1931) and developed by Godlund(1956). An equilibrium point model for the catchments is represented as followed formulae: m=$\frac{CA2}{CA-CB}$ m=$\frac {{{{{L SQRT {{C}_{A}$.$ {C}_{B}} {CA-CB} Here, m is distance from the center of park A to the cetner of park B. r is radius of a circle where the catchment between park A and B is equal pointed traces. CA is index of the centrality of park A from Reilly's Law. CB is an index of the centrality of park B from Reilly's Law. L is an the distance between park A and B. The equilibrium point model is testified in the case of Chong-ju community parks. The testification has been limited to the application to such manifest outdoor recreational facilities as bentches, even though there are statistically and economically problems for a quantitative model to be testified. But the testification could be a rationale for the catchment forces of urban community parks, which was quantitatively represented that the distance between two or there parks should be related with the feasibility of the parks. Therefore, the urban community park should be planned to be located, hiving separately its identity that might be considered with the facility diversification and the locational competitiveness of a park.

• East Asian mathematical journal
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• v.24 no.1
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• pp.97-103
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• 2008

New fixed point theorems for permissible maps between $Fr{\acute{e}}chet$ spaces are presented. The proof relies on index theory developed by Dzedzej and on viewing a $Fr{\acute{e}}chet$ space as the projective limit of a sequence of Banach spaces.

• Journal of Korean society of Dental Hygiene
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• v.9 no.3
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• pp.426-438
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• 2009

The purpose of this study was to examine the relationship of the general characteristics of dental patients to their total O'Leary index and individual plaque indexes in a bid to check the oral hygiene state of citizens and evaluate their plaque management ability. The subjects in this study were 288 patients at dental hospitals and clinics in Busan and South Gyeongsang Province. A survey was conducted from September to November 2008. The findings of the study were as follows: 1. Overall, the O'Leary index of the patients investigated stood at 72 percent. By age and gender, the O'Leary index was highest among those in their 30s(83%) and among the women(75%)(p<.05). As to the influence of toothbrushing frequency, the patients who did it twice or more a day had the highest O'Leary index(75%)(p<.001). By the use of oral hygiene supplies, the patients who used oral hygiene supplies had a higher O'Leary index(76%) than the others who didn't(p<.01). 2. As for plaque index for each tooth, 28 percent of their teeth were given zero point, and 52 percent were given one mark. 13 percent were given two marks, and 6.3 percent were given three marks. Thus, the teeth that were given one mark were largest in number(p<.001). 3. As for plaque index for labial posterior mandibular, 43 percent of their teeth were given one point, and 36 percent were given zero mark. 14 percent were given three mark, and 5 percent were given three marks(p<.01). 4. As for plaque index for buccal posterior maxilla, 57 percent of their teeth were given one point, and 20 percent were given zero mark. 16 percent were given two mark, and 6.3 percent were given three marks(p<.01). 5. As for plaque index for lingual posterior mandibular, 56 percent of their teeth were given one point, and 27.8 percent were given zero mark. 9 percent were given three mark and 6 percent were given three mark(p<.001).

• Proceedings of the Korean Geotechical Society Conference
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• 2008.10a
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• pp.1090-1097
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• 2008

This study conducted the decision method of lateral flow in abutment structures founded on the soft soils and the reliability analysis on the foundation pile for abutment. On the basis of the results, this study proposed the reliability design model. Reliability analysis was conducted by applying second moment method, point estimation method, and expected total cost minimization to lateral movement index, lateral movement decision index, modified lateral movement decision index, and circular failure safety factor for the decision criteria of lateral flow. The reliability index by analysis method had a similar tendency each other. Point estimation method was found as a practical method in the aspect of convenience because it could conduct the analysis only by mean and standard deviation as well as the partial derivative on random variables was not necessary. Optimum reliability index and optimum safety according to increasing in failure factors and load ratio were analyzed and loads and resistance factors of the design criteria of optimum reliability were estimated. It presented rational design model which can consider construction level and stability and economical efficiency overall.

• KIPS Transactions on Software and Data Engineering
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• v.2 no.8
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• pp.527-534
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• 2013

The software is changed according to the changing businesses and the user requirement, it involves increasing complexity and cost. Considering the repetitive changes required for the software, replacement is more efficient than maintenance at some point. In this study, the replacement time was predicted using the service dissatisfaction index and replacement point assessment index by the software group for each task. First, fuzzy inference was used to develop the method and indicator for the user's service level dissatisfaction. Second, the replacement point assessment method was established considering the quality, costs, and new technology of the software. Third, a replacement time prediction technique that used the gap between the user service measurement and replacement point assessment values was proposed. The results of the case study with the business solutions of three organizations, which was conducted to verify the validity of the proposed prediction technique in this study, showed that the service dissatisfaction index decreased by approximately 16% and the replacement point assessment index increased by approximately 9%.