• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.17 no.3
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• pp.353-359
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• 2004

In this study. porcelain insulator samples which have a different alumina composition were manufactured in order to test electrical and mechanical properties and make an analysis of the propagation phenomena of micro cracks on porcelain body. From XRD quantitative analysis the crystalline phases were different with alumina composition, sample C and D which have about l7wt％ Corundum phase without the Cristobalite phase shows better electrical and mechanical properties than sample A and B which have the Cristobalite phase. In dielectrics test on porcelain samples with below l7wt％ alumina composition, it was found that the amount of glass phase(SiO$_2$) have an main effect to decrease the dielectric loss(tan$\delta$), and the dielectric breakdown voltage of aluminous porcelain insulators was largely affected by its relative density. As a micro tracks analysis, HRB were measured, then the intensity of HRB increased with the amount of alumina composition. On the other hand, the propagation behaviors of cracks was fairly influenced by the distribution of pores.

• Journal of Welding and Joining
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• v.22 no.6
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• pp.57-63
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• 2004

Fracture toughness is an important parameter in designing offshore structures to ensure resistance to fracture at various temperatures. In this study, a series of experiments is carried out to obtain fracture toughness values (CTOD) of API 2W Gr.50B, welded using FCAW(Flux Cored Arc Weld). In particular, a comparison of absorbed impact energy and CTOD values are made with respect to two different welding groove shapes; double-V-groove and double-bevel-groove. Charpy impact tests are performed for specimens sampled near the root gap, and CTOD tests are carried out for three point bending specimens having the notch at weld zone. While Charpy impact test result is determined to be a good qualitative measure of fracture toughness, no quantitative correspondence between impact absorbed energy and CTOD values was found. Based on the experiment, it is observed that double-V-groove welds give lower transition temperature than those of double-bevel-groove.

• Journal of Korean Academy of Nursing
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• v.45 no.5
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• pp.641-649
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• 2015

Purpose: The purpose of this study was to introduce the main concepts of statistical testing and effect size and to provide researchers in nursing science with guidance on how to calculate the effect size for the statistical analysis methods mainly used in nursing. Methods: For t-test, analysis of variance, correlation analysis, regression analysis which are used frequently in nursing research, the generally accepted definitions of the effect size were explained. Results: Some formulae for calculating the effect size are described with several examples in nursing research. Furthermore, the authors present the required minimum sample size for each example utilizing G*Power 3 software that is the most widely used program for calculating sample size. Conclusion: It is noted that statistical significance testing and effect size measurement serve different purposes, and the reliance on only one side may be misleading. Some practical guidelines are recommended for combining statistical significance testing and effect size measure in order to make more balanced decisions in quantitative analyses.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.03a
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• pp.1224-1239
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• 2008

The earth retaining walls using stabilizing piles can be applied to shallow excavation works without any stiffener. But, It demends a variety of installed composite stiffener on the earth retaining walls when it is installed as deep excavation works. Because, it causes an excessive displacement of walls. This research tried to overcome the problems created by the above issues and intended to apply the composite stiffener. The model test, focused on the effect of installed composite stiffener, measured the bending stress with stabilizing piles and walls, the settlement of earth surface, the displacement of walls for a step excavation and an increase in strip load. With the test results and soil deformation analysis, the reinforcement effect(relating to control displacement and earth presure) was analyzed in a qualitative and quantitative manner. It is expected to overcome a deep excavation works.

• Aerospace Engineering and Technology
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• v.11 no.2
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• pp.171-181
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• 2012

As a sub-system of an air traffic control system, SDP(Surveillance Data Processor) provides with the system tracks of aircraft using the surveillance sensor data from various air traffic surveillance sensors, such as radars. Therefore, the high accuracy of tracking results is a crucial requirement for safe flights, and verification of the required system performance of SDP is an essential step in development. Moreover, the quantitative evaluation of target tracking accuracy is important for newly developed SDP, since there are several tracking methods for Multi-Sensor Multi-Target Tracking, such as MRT(Multi Radar Tracking), inevitably required as the main function of SDP. In this study, definition of required system performances, establishment of test environment, and test results for MRT performance evaluation of SDP, which is being developed in KARI(Korea Airspace Research Institute) are presented.

• Journal of the Korean Home Economics Association
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• v.18 no.2
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• pp.49-55
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• 1980

As the society has been capitalized, the importance of money has appeared widely. And there are many problems caused from the lack of money is supposed rather a qualitative problem happened by mismanagement of money than a quantitative. The purposes of this study are to suggest the desirable direction in money management education to adolescents and to provide some basic data to resolve the juvenile delin-quency caused from lack of money. With this purposes this study dealt with the money management behavior of adolescents with reference to self-concept, which was considered one of the influential factors to the money management behavior. Questionnaires composed with the Self-concept test (developed by Dr. chung) and the Money management test (developed by Dr. Troelstrup) were distributed to 300 high school students. 180 of them was taken as data. mean score and F-ratio were applied as statistical methods. As result, significant difference in money management behavior between the groups divided by self-concept scores were found. The higher the self-concept score is, the more desirable the money management behavior is. Here we cannclude as follow; As the money management behavior of adolescents differs with reference to the self-concept, it is possible to help the adolescents 세 develop the money management by inspiring the self-concept. And money management training as a consumer education is needed by all means at home, because it has an important effect upon the identity establishment, the major developmental task in adolescence.

• KIEAE Journal
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• v.7 no.4
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• pp.113-118
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• 2007

From the construction material the cement and the concrete which will reach to 90% are used to construction. But the cement occurrence (from the whole industry 4.4% of carbon dioxide exhaust quantity) makes the carbon dioxide of manufacture hour and anti- the recognition which is an environment industry. The cement absorbs the carbon dioxide during life period of the life time. It calls carbonation. In this study in order to evaluate the carbon dioxide absorption of the cement test produced the mortar specimens which it follows in the W/C. And carbonatable material of mortar specimens (calcium hydroxide) the quantitly it measured, reference study it led and absorption of carbon dioxide quantity it produced. Finally two result comparisons leads and it is a fundamental study which does the test evaluation possibility and a propriety investigation of carbon dioxide absorption quantity in objective.

• Speech Sciences
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• v.12 no.2
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• pp.89-99
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• 2005

The purpose of the present study were (1) to assess differences in tongue performances and speech intelligibility between normal and dysarthric speakers; and (2) to analyze the possible interrelationships between tongue strength, range of motion, and speech intelligibility in dysarthric patients. In order to measure maximum strength of anterior and lateral tongue strength, a force transducer has been designed. And a ruler was used for guaging range of motion. 'Word intelligibility test' was administered to each group. The results were analyzed by a quantitative statistical method(t test, Pearson product- moment correlation, and one-way ANOVA). The results were as follows; (1) dysarthric speakers showed significantly poorer performance than the normal in the tongue strength, range of motion, and speech intelligibility tasks; (2) the correlation between speech intelligibility and instrumental tongue performance was high in the dysarthric group; and (3) instrumental assessment was coincide with perceptual judgement of dysarthric tongue performance. The present investigation demonstrated that tongue weakness is causally related to articulation deficits in dysarthric. The clinical use of the force transducer would help a speech pathologist to quantify the degree of tongue weakness.

• Journal of the Korean Geotechnical Society
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• v.16 no.1
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• pp.5-17
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• 2000

The physical and mechanical properties of the sedimentary rocks deposited in Taegu and Kyongbuk region have been measured in the laboratory and at the field. Four kinds of rocks such as the shale, the mudstone, the siltstone and the sandstone were the object of this study. In sedimentary rock joint, bedding made it impossible to extract cores for uniaxial compressive test. Some correlations between the uniaxial compressive strength and the other characteristic values such as Point load index, Schmidt hammer rebound, Brazilian strength, P-wave velocity and Absorption ratio are made. The chemical and mineral compositions are also investigated by the XRF and XRD analysis. In addition, the weathering grade of rocks are classified by the quantitative indices of Point load index, Schmidt hammer rebound and Absorption ratio.

• Journal of Genetic Medicine
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• v.12 no.2
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• pp.72-78
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• 2015

Recently, noninvasive prenatal test (NIPT) has been adopted as a primary screening tool for fetal chromosomal aneuploidy. The principle of NIPT lies in isolating the fetal fraction of cell-free DNA in maternal plasma and analyzing it with bioinformatic tools to measure the amount of gene from the target chromosome, such as chromosomes 21, 18, and 13. NIPT will contribute to decreasing the need for unnecessary invasive procedures, including amniocentesis and chorionic villi sampling, for confirming fetal aneuploidy because of its higher positive predictive value than that of the conventional prenatal screening method. However, its greater cost than that of the current antenatal screening protocol may be an obstacle to the adoption of this innovative technique in clinical practice. Digital polymerase chain reaction (dPCR) is a novel approach for detecting and quantifying nucleic acid. dPCR provides real-time diagnostic advantages with higher sensitivity, accuracy, and absolute quantification than conventional quantitative PCR. Since the groundbreaking discovery that fetal cell-free nucleic acid exists in maternal plasma was reported, dPCR has been used for the quantification of fetal DNA and for screening for fetal aneuploidy. It has been suggested that dPCR will decrease the cost by targeting specific sequences in the target chromosome, and dPCR-based noninvasive testing will facilitate progress toward the implementation of a noninvasive approach for screening for trisomy 21, 18, and 13. In this review, we highlight the principle of dPCR and discuss its future implications in clinical practice.