• Journal of Distribution Science
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• v.16 no.12
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• pp.47-56
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• 2018

Purpose - The potential use of cryptocurrencies in a retail environment proposes a rapid shift from the traditional financial system. Nakamoto(2008) defines Bitcoin as an open source alt-coin based on the blockchain technology. Luther(2016) insists that the new technology will be widely adopted for the digital payment processes. However, the use of Bitcoin is in the real world is still sparse. Despite the growing attention and purported benefits, it is doubtful whether the Bitcoin will be eagerly accepted by ordinary consumers in the mainstream market. To answer this question, this paper develops a causal model that has a dual path to explain the motivation to adopt Bitcoin. According to Glaser, Zimmermann, Haferkorn, Weber, and Siering(2014), Bitcoin is both an asset and a currency at the same time. In summary, the attitude towards Bitcoin may vary depending on whether the fin-tech product is viewed as an asset or as a currency. Based on the arguments, we propose that asset attitude and currency attitude will give influence to consumers' intention to adopt Bitcoin. Research design, data, and methodology - Quantitative data collection is conducted from a Bitcoin SIG(special interest group) working in an internet community. As a result, 192 respondents who know Bitcoin completed the survey. To analyze the causal relations in the research model, PLS-SEM(partial least squares structural equation modeling) method is used. Also, reliability and validity of measures are tested by performing Cronbach's alpha test, Fornell-Larcker test and confirmatory factor test. Results - Our test results show that every hypothesis is supported except the influence of perceived ease of use. In addition, we find that the relationships between constructs are different between the high innovative group and low innovative group. Conclusions - We provide evidence that asset attitude and currency attitude are key antecedents of Bitcoin adoption.

• Journal of Environmental Health Sciences
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• v.43 no.1
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• pp.23-41
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• 2017

Objectives: In this study, we seek to perform a priority selection for test substances for chronic inhalation toxicity studies, including acute and subchronic inhalation toxicity studies, which are to be performed after the construction of a chronic/carcinogenicity inhalation toxicity study facility and enactment of pertinent legislation. Methods: Through this study, qualitative and quantitative priority evaluation of test substances according to acute, subchronic and chronic categories were respectively performed and priorities were suggested by expert group review, redundancy and other methods. Meanwhile, a draft on test substance selection criteria, procedures and methods referring to the National Toxicology Program (NTP) system was proposed. Results: This study selected priorities for candidate substances for chronic inhalation toxicity studies to be conducted from 2016. Conclusions: In the future, by assessing in advance the toxicological effects of chemicals to which workers can be potentially exposed in the workplace via long-term inhalation, expected health disturbances among workers will be reduced and it is anticipated that occupational disease induced by chemicals will be effectively prevented.

• Journal of Digital Convergence
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• v.13 no.10
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• pp.1-7
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• 2015

Many people are interesting software quality. Because of, we depend on software in our life. In terms of, I think, good software is a good quality software. So, when we develop the software, we need trying to improve software quality. In this paper, we analyze software test data. We emphasize that software quality is very important in our life. We use software experimental data, in order to analyze of software quality. On the basis of ISO/IEC 9126-2, we classify the test data and we analyze the difference of error frequency according to functionality, reliability, usability, efficiency, maintainability, portability. We analyze the number of test and used time according software type. We want to search effect variable, going through testing result and measurement convergence, we know the effect variable of functionality and efficiency.

• Restorative Dentistry and Endodontics
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• v.29 no.5
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• pp.413-422
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• 2004

Established microleakage tests have their own disadvantages. In this study, 3D reconstruction method was tried to overcome these disadvantages. Four types of microleakage tests were used and relationships among them were estimated: penetrated dye volume: marginal adaptability: degree of dye penetration and relative penetrated length to cavity wall. Twenty-four Class V cavities were bulk filled with composite (Esthet X) following surface treatments: N group (no treatment): E group (etching only): T group (etching + Prime & Bond NT). 50% silver nitrate was used as a dye solution after thermocycling ($5^{\circ}C{\;}&{\;}55^{\circ}C$, 1.000 times). Teeth were serially ground with a thickness of 0.2 mm. Volume of dye penetration was estimated from a three-dimensionally reconstructed image with a software (3D-DOCTOR). Percentage of margin without gap was estimated from SEM and degree of dye penetration and the relative length of dye penetration to overall cavity wall were also estimated. ANOVA and Scheffe test for dye volume, Kruskal-Wallis and Mann-Whitney test for marginal quality, Spearman's rho test for checking of relationships among methods were used. The results were as follows: 1. Dye penetration could be seen from several directions, furthermore, its volumetric estimation was possible. 2. Reverse relationship was found between dye volume and marginal quality (r = -0.881/ p = 0.004). 3. Very low relationship was seen between dye volume and two-dimensional tests (degree of dye penetration and relative length). However, 2D evaluation methods showed high relationship (p = 0.002-0.054) each other. 4. Three times vertical section could be recommended as a 2D test.

• Journal of the Korean Society for Nondestructive Testing
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• v.20 no.1
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• pp.18-26
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• 2000

Boiler high-temperature pipelines such as main steam pipe, header and steam drum in fossil power plants are degraded by creep damage due to severe operating conditions such as high temperature and high pressure for an extended period time. Conventional measurement techniques(replica method, electric resistance method, and hardness test method) for measuring creep damage have such disadvantages as complex preparation and measurement procedures, too many control parameters. And also these techniques have low practicality and applied only to component surfaces with good accessibility. In this paper, artificial creep degradation test and ultrasonic measurement for their creep degraded specimens(Cr-Mo alloy steels) were carried out for the purpose of evaluation for creep damage. Absolute measuring method of quantitative ultrasonic measurement for material degradation was established, and long term creep degradation tests using life prediction formula were carried out. As a result of ultrasonic tests for crept specimens. we conformed that both the sound velocity decreased and attenuation coefficient linearly increased in proportion to the Increase of creep life fraction($\Phi$c).

• The Journal of Korean Physical Therapy
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• v.14 no.1
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• pp.75-88
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• 2002

The purpose of this study was to investigate the influence of anterior, posterior, and lateral pelvic tilt exercise upon the gait characteristics of patients with hemiplegia including their gait velocity, cadence, stride length, step length of the non affected side, step length of the affected side, foot angle of the non affected side, foot angle of the affected side, base of support, and so on. The subject of this study was 24 men and women patients with hemiplegia. The patients, the subject of this study, were classified into 12 patients of treatment group applying pelvic tilt exercise using visual feedback and 12 patients of control group applying general pelvic tilt exercise, and then analyzed their gait before and after exercise. Temporal distance gait analysis (Boening, 1977) was used to analyze their gait, and ink foot-print was applied as on of measurement methods. To find out meaningful difference between control group and treatment group, this study carried out independent sample t-test for each item by utilizing SPSS/Win 10.0, compared changes in control group's and treatment group's gait characteristics before and after exercise as percentage, and applied paired t-test to conduct before-after test in same group. Statistical significance level was ${\alpha}$ < 0.05. The results of this study were as follows. As a result of independent sample t-test for control group's and treatment group's gait characteristics after exercise, it was not statistically significant so there was no meaningful difference between two groups. However, it was statistically significant in the change rate(%) of gait characteristics, and treatment group's patients with hemiplegia had been highly changed in gait characteristics in comparison with control group. From the above-mentioned results, could find that pelvic tilt exercise using visual feedback for patients with hemiplegia was effective to improve their gait ability and it could increase the ability in comparison with general pelvic tilt exercise. In the future, studies on the effect of pelvic tilt exercise using visual feedback shall be continued based on more quantitative methods.

• The Korean Journal of Applied Statistics
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• v.19 no.2
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• pp.231-240
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• 2006

It is well understood that a paired comparison (paired t test) provides better precision than a group comparison (two-sample t test), when the pairing is effective (the variation within a pair is small). However, when the variation among the pairs is sufficiently small, the group comparison is likely to yield a better result. To get a statistical explanation of this, we examine the two methods through an analogy to one-way and two-way analysis of variance. We introduce a new measure, R statistic, which is the ratio of their confidence interval lengths, as a quantitative criterion for comparing the two methods. The distribution of the Rf statistic is described by t and F distribution functions. Through this characterization, we show that the paired comparison can be better than group comparison when the variation among the pairs is statistically significantly large.

• Journal of The Korean Association of Information Education
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• v.15 no.4
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• pp.635-644
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• 2011

This research analyzed the brainwave activities and brain hemispherity to find out any implications to design the connections between the activities of the brain function and the computerized arithmetic addition in two difficulty levels: easy: 1-5 vs. hard: 6-9. Thus, in developing the brain based math learning for the computer education by implicit association test(IAT) indicated the significant results for the exclusive brain location and the brain hemispherity on the theta, alpha, low alpha, beta brainwaves by QEEG analysis. The results of this study physiologically supported the theoretical background for the computerized math learning skills as well as the math learning material development. It shows the difficulty levels of math information education and the brain activities on cognitive process of the learner continued on the possible investigation of the brain science.

• The Journal of Korean Association of Computer Education
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• v.10 no.4
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• pp.39-49
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• 2007

The purpose of this study is to provide analysis resources to develop high standard questions by analyzing item characteristics and item usability of 'Basic course of Information Technology' in the College Scholastic Ability Test, For the qualitative research, this paper analyzed content validity. For the quantitative research, this paper analyzed item difficulty, item discrimination, item reliability, and distracters. As a result of analyzing tests in 2005 and 2006, questions were equally extracted from educational contents. However, the standard of questions were in need of revision. The development of high quality contents in Vocational Education Section was needed in order to meet to the College Scholastic Ability Test standards. Therefore, it is required to develop various difficulties and acceptable distinguishable questions.

• JSTS:Journal of Semiconductor Technology and Science
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• v.6 no.4
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• pp.299-312
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• 2006

This paper presents the results of a novel test structure for process control monitor for uncooled IR detector technology of microbolometer arrays. The proposed test structure is based on resistive network configuration. The theoretical model for resistance of this network has been developed using 'Compensation' and 'Superposition' network theorems. The theoretical results of proposed resistive network have been verified by wired hardware testing as well as using an actual 16x16 networked bolometer array. The proposed structure uses simple two-level metal process and is easy to integrate with standard CMOS process line. The proposed structure can imitate the performance of actual fabricated version of area array closely and it uses only 32 pins instead of 512 using conventional method for a $16{\times}16$ array. Further, it has been demonstrated that the defective or faulty elements can be identified vividly using extraction matrix, whose values are quite similar(within the error of 0.1%), which verifies the algorithm in small variation case(${\sim}1%$ variation). For example, an element, intentionally damaged electrically, has been shown to have the difference magnitude much higher than rest of the elements(1.45 a.u. as compared to ${\sim}$ 0.25 a.u. of others), confirming that it is defective. Further, for the devices having non-uniformity ${\leq}$ 10%, both the actual non-uniformity and faults are predicted well. Finally, using our analysis, we have been able to grade(pass or fail) 60 actual devices based on quantitative estimation of non-uniformity ranging from ＜ 5% to ＞ 20%. Additionally, we have been able to identify the number of bad elements ranging from 0 to ＞ 15 in above devices.