• Proceedings of the KSME Conference
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• 2000.04b
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• pp.886-891
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• 2000

One of the domestic co-generation plants have undergone excessive vibration problems of turbine attributed to external force for years. The root cause of turbine vibration may be shan alignment problem which sometimes is changed by thermal expansion and external farce, even if turbine technicians perfectly performed it. To evaluate the alignment condition from plant start-up to full load, a strain measurement of turbine and main steam piping subjected to thermal loading is monitored by using strain gages. The strain gages are bonded on both bearing housing adjusting bolts and pipe stoppers which. installed in the x-direction of left-side main steam piping near the turbine inlet in order to monitor closely the effect of turbine under thermal deformation of turbine casing and main steam piping during plant full load. Also in situ load of constant support hangers in main steam piping system is measured by strain gages and its results are used to rebalance the hanger rod load. Consequently, the experimental stress analysis by using strain gages turns out to be very useful tool to diagnose the trouble and failures of not only to stationary components but to rotating machinery in power plants.

• The korean journal of orthodontics
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• v.52 no.3
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• pp.182-200
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• 2022

Objective: This study aims to examine the effectiveness of miniscrew assisted rapid palatal expansion (MARPE) treatment in late adolescents and adult patients using cone-beam computed tomography (CBCT). Methods: Literature search was conducted in five electronic databases (PubMed, Embase, Scopus, Web of Science, and Cochrane Library) based on the PICOS keyword design focusing on MARPE. Out of the 18 CBCT screened outcomes, only nine parameters were sufficient for the quantitative meta-analysis. The parameters were classified into three main groups: 1) skeletal changes, 2) alveolar change, and 3) dental changes. Heterogeneity test, estimation of pooled means, publication bias, sensitivity analysis and risk of bias assessment were also performed. Results: Upon database searching, only 14 full-text articles were qualified from the 364 obtained results. Heterogeneity test indicated the use of the random-effects model. The pooled mean estimate were as follows: 1) Skeletal expansion: zygomatic width, 2.39 mm; nasal width, 2.68 mm; jugular width, 3.12 mm; and midpalatal suture at the posterior nasal spine and anterior nasal spine, 3.34 mm and 4.56 mm, respectively; 2) Alveolar molar width expansion, 4.80 mm; and 3) Dental expansion: inter-canine width, 3.96 mm; inter-premolar width, 4.99 mm and inter-molar width, 5.99 mm. The percentage of expansion demonstrated a skeletal expansion (PNS) of 55.76%, alveolar molar width expansion of 24.37% and dental expansion of 19.87%. Conclusions: In the coronal view, the skeletal and dental expansion created by MARPE was of the pyramidal pattern. MARPE could successfully expand the constricted maxilla in late adolescents and adult patients.

• Proceedings of the Zoological Society Korea Conference
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• 1997.10b
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• pp.114.1-114
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• 1997

No Abstract, See Full Text

• Journal of Information Technology Services
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• v.9 no.1
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• pp.157-172
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• 2010

Recently 'full browsing service' is growing rapidly throughout the world. This service allows mobile phone users to access websites using their mobile phone as they do using a PC. Despite the rapid expansion of the mobile phone market, however, criteria or scales for evaluating the new services are being developed slowly and far behind the current demand trends. Thus, this study proposed a customer satisfaction evaluation model for full browsing services through empirical research. The proposed model is expected to derive and suggest key factors that users consider important in full browsing services and those factors can be used in developing marketing strategies for maintaining existing customers and creating new customers.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.919-922
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• 2008

The objective of this study is to design the full-scale fire test facility of the railroad vehicle with CFD simulation. In the results, the step expansion system should be good enough for the measuring system. Uniform flow is achieved at eight-to-ten diameters of the expanded duct behind the step for moderate expansion ratios($D_{orifice}/D_{duct}$ = 2 being a good choice). To optimization of the fire products collector system with 5 dampers, the additional CFD simulation was also carried out. These results will be help for the railroad fire safety research.

• Clinical and Experimental Reproductive Medicine
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• v.13 no.2
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• pp.195-200
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• 1986

In order to know when the cumulus cells of mouse follicles get ability to expand in vitro, the oocyte cumulus complexes obtained from different growing ages of mice were cultured in the medium containing HCG and their rate of expansion were observed and at the same time their maturation rate was examined. The growth of follicles was also checked by histological method. It was impossible to isolate the oocyte-cumulus complexes from 13 or 15 days old mouse ovaries. The oocyte-cumulus complexes collected from 17 days old mouse were partially induced to expanded by HCG, and from 19 days, most of the complexes were induced to full expansion. The rate of cumulus cell expansion by HCG and the oocyte maturation increased steadly during the growing ages to adult. Thus, the time for follicles to get competence for expansion and maturation seems to be closely related. Antral follicles were appeared from 17 days old mice and Graafian follicles were seen from 21 days old mice. The competence for cumulus expansion increased during follicle growth up to 21 days old mice.

• The korean journal of orthodontics
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• v.51 no.4
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• pp.241-249
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• 2021

Objective: This study aimed to evaluate the volume, amount, and localization of root resorption in the maxillary first premolars using micro-computed tomography (micro-CT) after expansion with four different rapid maxillary expansion (RME) appliances. Methods: In total, 20 patients who required RME and extraction of the maxillary first premolars were recruited for this study. The patients were divided into four groups according to the appliance used: mini-implant-supported hybrid RME appliance, hyrax RME appliance, acrylic-bonded RME appliance, and full-coverage RME appliance. The same activation protocol (one activation daily) was implemented in all groups. For each group, the left and right maxillary first premolars were scanned using micro-CT, and each root were divided into six regions. Resorption craters in the six regions were analyzed using special CTAn software for direct volumetric measurements. Data were statistically analyzed using Kruskal-Wallis one-way analysis of variance and Mann-Whitney U test with Bonferroni adjustment. Results: The hybrid expansion appliance resulted in the lowest volume of root resorption and the smallest number of craters (p < 0.001). In terms of overall root resorption, no significant difference was found among the other groups (p > 0.05). Resorption was greater on the buccal surface than on the lingual surface in all groups except the hybrid appliance group (p < 0.05). Conclusions: The findings of this study suggest that all expansion appliances cause root resorption, with resorption craters generally concentrated on the buccal surface. However, the mini-implant-supported hybrid RME appliance causes lesser root resorption than do other conventional appliances.

• Magazine of the Korean Society of Agricultural Engineers
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• v.35 no.4
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• pp.38-46
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• 1993

This study is to analyze effect of exposure environment and mode of ASR on the engineering properties of synthetic lightweight aggregate concrete, such as dynamic modulus of elasticity and ultrasonic pulse velocity. The results of this study are summarized as foflows ; 1. The expansion rate of each exposure environment in 380$^{\circ}$C and NaCI 4% solution was shown higher than in 20$^{\circ}$C and normal water. The expansion rate of each exposure mode was largely shown in order of fjill immersion, wetting/drying, half immersion. 2. The dynamic modulus of elasticty and ultrasonic pulse velocity of each exposure environment in 38$^{\circ}$C and NaCl 4% solution was shown less than in 20$^{\circ}$C and normal water. The dynamic modulus of elasticity and ultrasonic pulse velocity of each exposure mode was shown smaller in order of full immersion, wetting/drying, half imersion.3. The relation between dynamic modulus of elasticity and ultrasonic pulse velocity was highly significant. The dynamic modulus of elasticity was increased with increase of ultrasonic pulse velocity. The decreasing rate of the dynamic modulus of elasticity was shown 2.1~3.4 times higher than the ultrasonic pulse velocity at each age, exposure environment and mode, respectively. 4. The expansion of each exposure environment and mode was increased with increase of curing age. The dynamic modulus of elasticity and ultrasonic pulse velocity of those concrete was increased with increase of curing age. At the curing age 28 days, the highest properties was showed at each type concrete, it was gradually decreased with increase of curing age. Specially, at the curing age 98 days of full immersion, the rate of expansion of type D was shown 3.95 times higher than the type A. But the dynamic modulus of elasticity and ultrasonic pulse velocity was decreased 17% and 8.3%.

• International Journal of Concrete Structures and Materials
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• v.9 no.4
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• pp.463-473
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• 2015

Three full-scale instrumented test slabs were constructed and tested using a heavy vehicle simulator (HVS) to evaluate the structural behavior of internally cured concrete (ICC) for use in pavements under Florida condition. Three mix designs selected from a previous laboratory testing program include the standard mixture with 0.40 water-cement ratio, the ICC with 0.32 water-cement ratio, and the ICC mixture with 0.40 water-cement ratio. Concrete samples were prepared and laboratory tests were performed to measure strength, elastic modulus, coefficient of thermal expansion and shrinkage properties. The environmental responses were measured using strain gages, thermocouples, and linear variable differential transformers instrumented in full-scale concrete slabs. A 3-D finite element model was developed and calibrated using strain data measured from the full-scale tests using the HVS. The results indicate that the ICC slabs were less susceptible to the change of environmental conditions and appear to have better potential performance based on the critical stress analysis.

• International Journal of Naval Architecture and Ocean Engineering
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• v.6 no.4
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• pp.965-980
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• 2014

This paper presents a new estimation method of full scale propulsive performance for the pulling type podded propeller. In order to estimate the drag of pod housing, a drag velocity ratio, which includes the effects of podded propeller loading and Reynolds number, is presented and evaluated through the comparison of model test and numerical analysis. By separating the thrust of propeller blade and the drag of pod housing, extrapolation method of pod housing drag to full scale is deduced, and correction method of propeller blade thrust and torque to full scale is presented. This study utilized the drag coefficient ratio of the pod housing as a measure for expanding it to full scale, but in order to increase the accuracy of performance evaluation, additional study is necessary on the method for the full scale expansion via separating the drag of pod body, strut and fin which consist the pod housing.