• Structural Engineering and Mechanics
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• v.31 no.2
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• pp.137-152
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• 2009

Mechanic behavior of Y-shape thin-walled box girder bridge structure is complex, so one can not exactly hold the mechanical behavior of the Y-shape thin-walled box girder bridge structure through general calculation theory and analytical method. To hold the mechanical behavior better, based on elementary beam theory, by increasing the degree of freedom analytical method, taking account of restrained torsiondistortion angledistortion warp and shearing lag effect at the same time, authors obtain a thin-walled box beam analytical element of 10 degrees of freedom of every node, derive stiffness matrix of the element, and code a finite element procedure. In addition, authors combine the obtained procedure with spatial grillage analytical method, meanwhile, they build a new analytical method that is the spatial thin-walled box girder element grillage analysis method. In order to validate the precision of the obtained analysis method, authors analyze a type Y-shape thin-walled box girder bridge structure according to the elementary beam theory analytical method, the shell theory analytical method and the spatial thin-walled box girder element grillage analysis method respectively. At last, authors test a type Y-shape thin-walled box girder bridge structure. Comparisons of the results of theory analysis with the experimental text show that the spatial thin-walled box girder element grillage analysis method is simple and exact. The research results are helpful for the knowledge of the mechanics property of these Y-shape thin-walled box girder bridge structures.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.24 no.7
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• pp.938-944
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• 2000

Recently, micro fin tube is widely used to heat exchanger for high performance. And, as the alternative refrigerants for R-22, hydrocarbons such as R-290, R-600 and R-600a are very promising because of their low GWP and ODP. Thus, R-290 was used as working fluid in this study. Most design of heat exchanger had been based on heat transfer characteristics of pure refrigerant although refrigerant oil exists in the refrigeration cycles. So, the influence of oil on heat transfer characteristics have to be considered for investigating exact evaporation heat transfer characteristics. But, this is an unresolved problem of refrigeration heat transfer. Therefore the influence of the refrigeration oil to the evaporation heat transfer characteristics of R-290 were conducted in a horizontal micro tin tube. The mineral oil was used as refrigeration oil. The experimental apparatus consisted of a basic refrigeration cycle and a system for oil concentration measurement. Test conditions are as the follows; evaporation temperature $5^{\circ}C$, mass velocity 100 $kg/m^2s$, heat flux 10 $kW/m^2$, oil concentration 0, 1.3, 3.3, 5.7 wt.%, and quality $0.07{\sim}1.0$. When refrigeration oil was entered, oil foaming was observed at the low quality region. And, very small bubbles were observed as quality was increased. Pressure drop and heat transfer coefficient increased as the concentration of refrigeration oil increased to 5 wt.%.. The performance index of heat exchanger was the highest near 3.3 wt.%.

• Journal of Korean Academy of Nursing
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• v.16 no.2
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• pp.13-28
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• 1986

The main purpose of th study was to evaluate he validity of Korean Pain Measurement Tool composed of pain terms. The specific purposes of this study were 1. to examine whether pain intensities of pain terms are congruent with those classified in three previous studies. 2. to evaluate the relative intensity of each term by panel of judges. 3. to explore the difference of ranks of pain terms according to the sex, education, and ages. One hundred and sixty normal individuals were selected by 2$\times$2$\times$4 sampling design. Sex (male, female), education (high school, college), and age (20s, 30s, 40s, 50s) were matched. Each individual was asked to rate the ranks of 3~8 pain terms in each subclass. The data measured by ordinal scale were transformed to the interval scale to compare with the pain intensities gained from the previous study. The pain ranks different from previous results were finally rearranged or cancelled through the consultation of 4 panel of judges and sunmed up to 91 pain terms in the scale. As a result, the ranks of pain terms within each of eleven subclasses among the twenty subclasses completely were congruent with the Previous pain ranks, while the ranks of nine subclasses were different from the previous pain ranks. In addition, there was significant relation between sex and pain ranks in skin punctuate pressure pain and cavity pressure. (sp : $\chi$$^2$=5.18 ø=0.26； cp : $\chi$$^2$=5.83 ø=0.24) In conclusion, seven terms from subclasses of inflammatory repeated pain, traction pressure pain, fatigue-related pain, fear-related pain, dull pain, and pulsation. related pain were cancelled. The ranks of four terms in subclasses of incisive Pressure pain and constrictive pressure pain were tentatively rearranged. Ranks of two terms in the tract pain were left as shown in the third study. As a result, six terms must be studied repeatedly for obtaining exact scores from ratio scale.

• Journal of Digital Convergence
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• v.11 no.10
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• pp.387-394
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• 2013

Data mining is the process of discovering hidden, non-trivial patterns in large amounts of data records in order to be used very effectively for analysis and forecasting. Because hundreds of variables give rise to a high level of redundancy and dimensionality with time complexity, they are more likely to have spurious relationships, and even the weakest relationships will be highly significant by any statistical test. Hence cluster analysis is a main task of data mining and is the task of grouping a set of objects in such a way that objects in the same group are more similar to each other than to those in other groups. In this paper system implementation is of great significance, which defines a new definition based on information-theoretic entropy and analyse the analogue behaviors of objects at hand so as to address the measurement of uncertainties in the classification of categorical data. The sources were taken from a survey aimed to identify of job guidance from students in high school pyeongtaek. we show how variable precision information-entropy based rough set can be used to group student in each section. It is proved that the proposed method has the more exact classification than the conventional in attributes more than 10 and that is more effective in job guidance for students.

• Research in Community and Public Health Nursing
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• v.12 no.3
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• pp.620-626
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• 2001

Purpose: This study was aimed at investigating the recognition and attitude of inpatients for the purpose of facilitating the implementation of the home health care program in relation to the opening of the Home Care Department in P University Hospital in Pusan. Method: Data were collected from the questionnaires returned by 293 patients, who were admitted at P University Hospital. from May 1 to May 15, 2001 and analyzed using descriptive statistics and the Fisher exact test. Results: In regard to the previous information about the home health care program, 55.6% of the inpatients heard about the name through the advertisement in the hospital. the mass communication, and from acquaintances. The percentage of right answers regarding the knowledge of home health care program was 43.9%. In regard to the acceptance of the home health care program, 97.1 % of patients agreed with the implementation of the home care program. The reasons for acceptance were: the maintenance of the continuity of care, the alleviation of the family burden of time. Conclusion: For the stabilization and successful implementation of a home health care system, it should be accompanied not only by advertisement but also education for patients about the home health care program, and a post-evaluative study after the implementation.

• Fire Science and Engineering
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• v.23 no.4
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• pp.120-129
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• 2009

Identification of the exact cause of a building fire is generally difficult, because the source and initially ignited objects are often severely damaged or even lost during the early stages of the fire. We made an experimental attempt to reasonably estimate the burning during the very early stages of a fire, and identify its source and causes. The case we studied was an apartment fire, which occurred in Tokyo, in July 2002. The fire was extinguished just after flashover, and the on-site investigations suggested the fire started from the TV and TV stand, which had been damaged so severely that it was difficult to conclude that the TV was the ultimate cause of the fire, simply from the on-site investigation. We conducted a series of burn tests using a TV and other products identical to those actually used in the apartment. Tests were set-up and procedures were carefully studied to recreate the conditions of the articles that remained, and of the room itself. The tests demonstrated that the conditions in the apartment could be recreated only when the fire started inside the TV and came into close contact with dresser.

• Restorative Dentistry and Endodontics
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• v.45 no.2
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• pp.24.1-24.9
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• 2020

Objectives: It is known that bioactive materials interact with the dentin to undergo biomineralization. The exact role of moisture in this interaction is unknown. Here, we investigate the effects of dentin moisture conditions on the dislocation resistance of two bioactive root canal sealers (MTA Fillapex [Angelus Solucoes Odontologicas] and GuttaFlow BioSeal [Colténe/Whaledent AG]) at 3 weeks and 3 months after obturation. Materials and Methods: Mandibular premolars (n = 120) were prepared and randomly divided into 3 groups based on the dentin condition: group 1, dry dentin; group 2, moist dentin; group 3, wet dentin. Each group was divided into 2 subgroups for root canal filling: MTA Fillapex and GuttaFlow BioSeal. Dislocation resistance was evaluated by measuring the push-out bond strength at 3 weeks and 3 months. Failure modes were examined under a stereomicroscope. Data were statistically analyzed by Kruskal-Wallis test with a significance level of 5%. Results: Moist dentin resulted in higher bond strength values for both materials at both time points. This was significantly higher than wet and dry dentin for both the sealers at the 3 months (p < 0.05), while at 3 weeks it was significant only for GuttaFlow Bioseal. The different moisture conditions demonstrated similar trends in their effects on the dislocation resistance of the 2 root canal sealers. Conclusions: The dentin moisture conditions had a significant impact on its interaction with the bioactive materials tested. Maintaining moist dentin, but not dry or wet dentin, may be advantageous before the filling root canals with bioactive sealers.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.5
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• pp.3602-3609
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• 2015

HPFRCC is characterized by a very low water-to-binder ratio which induce extremely large autogenous shrinkage at early age. The restriction of such autogenous shrinkage through the use of forms and reinforcing bars will increase substantially the risk of excessive residual stresses and shrinkage cracking. The exact understanding of the shrinkage behavior and studies on solutions to reduce shrinkage should be imperatively undertaken for further application of HPFRCC to real structures. Therefore, this paper investigated the mechanical properties of HPFRCC with respect to the eventual introduction of expansive admixture(EA) and shrinkage reducing agent (SRA) in the mixture. Autogenous shrinkage test was conducted considering the coefficient of thermal expansion (CTE) measured at early age so as to examine the effects of EA and SRA on the autogenous shrinkage behavior of HPFRCC.

• Restorative Dentistry and Endodontics
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• v.42 no.1
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• pp.19-26
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• 2017

Objectives: Recently, bioceramic sealers like EndoSequence BC Sealer (BC Sealer) have been introduced and are being used in endodontic practice. However, this sealer has limited research related to its retreatability. Hence, the aim of this study was to evaluate the retreatability of two sealers, BC Sealer as compared with AH Plus using micro-computed tomographic (micro-CT) analysis. Materials and Methods: Fifty-six extracted human maxillary incisors were instrumented and randomly divided into 4 groups of 14 teeth: 1A, gutta-percha, AH Plus retreated with chloroform; 1B, gutta-percha, AH Plus retreated without chloroform; 2A, gutta-percha, EndoSequence BC Sealer retreated with chloroform; 2B, gutta-percha, EndoSequence BC Sealer retreated without chloroform. Micro-CT scans were taken before and after obturation and retreatment and analyzed for the volume of residual material. The specimens were longitudinally sectioned and digitized images were taken with the dental operating microscope. Data was analyzed using an ANOVA and a post-hoc Tukey test. Fisher exact tests were performed to analyze the ability to regain patency. Results: There was significantly less residual root canal filling material in the AH Plus groups retreated with chloroform as compared to the others. The BC Sealer samples retreated with chloroform had better results than those retreated without chloroform. Furthermore, patency could be re-established in only 14% of teeth in the BC Sealer without chloroform group. Conclusion: The results of this study demonstrate that the BC Sealer group had significantly more residual filling material than the AH Plus group regardless of whether or not both sealers were retreated with chloroform.

• Research in Plant Disease
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• v.11 no.1
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• pp.48-55
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• 2005

Cylindrocarpon destructans is a soil-borne plant pathogenic fungus causing root rot on ginseng and trees. Rapid and exact detection of this pathogen was practiced on ginseng seedlings by nested PCR using speciesspecific primer set. The second round of PCR amplification by Dest 1 and Dest 4 primer set formed 400 bp of species-specific fragment of C. destructans from the product of first round of amplification by ITS 1 and ITS 4 primer set. In the PCR sensitivity test based on DNA density, nested PCR detected to the limit of one fg and it meant the nested PCR could detect up to a few spores of C. destructans. Also, nested PCR made it possible to detect the pathogen from ginseng seedlings infected by replantation on artificial infested soil. Our nested PCR results using species-specific primer set could be utilized for diagnosis of root rot disease in ginseng cultivation.