• Journal of the Korea Society of Computer and Information
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• v.22 no.1
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• pp.71-76
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• 2017

Recently, there are various researches using inaudible high frequencies like as wireless communication based smart devices, data transmission algorithm, indoor positioning trace technologies. However, when they use high frequencies of inaudible range, they have a problem that the accuracy of data transmission with high frequencies was low because of interference from ambient noise in our real life. To solve this problem, in this paper, we proposed an application based on smart phone and server system for collection of ambient noise and detection of robust high frequency range. The server system could detect the robust high frequency range from statistical analysis of collected noise and the robust high frequency could avoid interference from ambient noise. We tested the proposed application's ability to gather noise and high frequencies for a certain period of time to evaluate performance. According to the testing results, we confirmed that the proposed application and server system could detect a robust high-frequency range via noise analysis in real life. Therefore, the proposed application and server could be a useful technology for future research on inaudible high frequencies.

• Journal of Korean Academy of Nursing
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• v.48 no.5
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• pp.521-533
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• 2018

Purpose: The aims of this study are to provide a theoretical framework for improving the self-care of adults with severe hypertension and to examine the practical suitability of a middle-range theory of self-care for chronic illness by validating the structural model. Methods: Data were collected at a university hospital in D metropolitan city from July 1 to August 14, 2015. A total of 224 Korean adult patients with severe hypertension were recruited. Data were analyzed using SPSS 22.0 and AMOS 22.0. Results: The results show that the fit index of the hypothetical model meets the recommended level; 7 out of 8 hypothetical model paths were statistically significant. Motivation, self-efficacy, support from others, and accessibility to care showed statistical significance and explained 67.3% of the self-care process. The self-care process explained 45.3%, 63.6%, and 26.5% of quality of life, health, and illness stability, respectively. Conclusion: This model can be used as a theoretical framework for improving self-care among adult Korean patients with severe hypertension. Moreover, the practical suitability and validity of the middle-range theory of self-care for chronic illness is secured.

• Steel and Composite Structures
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• v.12 no.4
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• pp.325-350
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• 2012

Concrete filled steel hollow structural sections (CFSs) are an efficient, sustainable, and attractive option for both ambient temperature and fire resistance design of columns in multi-storey buildings and are becoming increasingly common in modern construction practice around the world. Whilst the design of these sections at ambient temperatures is reasonably well understood, and models to predict the strength and failure modes of these elements at ambient temperatures correlate well with observations from tests, this appears not to be true in the case of fire resistant design. This paper reviews available data from furnace tests on CFS columns and assesses the statistical confidence in available fire resistance design models/approaches used in North America and Europe. This is done using a meta-analysis comparing the available experimental data from large-scale standard fire tests performed around the world against fire resistance predictions from design codes. It is shown that available design approaches carry a very large uncertainty of prediction, suggesting that they fail to properly account for fundamental aspects of the underlying thermal response and/or structural mechanics during fire. Current North American fire resistance design approaches for CFS columns are shown to be considerably less conservative, on average, than those used in Europe.

• The Korean Journal of Applied Statistics
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• v.17 no.1
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• pp.89-103
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• 2004

If the given information is exact, though it is the little, we had better use it than not use in analysis. In this article, the problem of independence test in a contingency table is considered when two marginal distributions of a population are given exactly. For that case, a likelihood-ratio chi-squared test statistic and its Pearsonian type chi-squared test statistic are derived. By Monte Carlo Simulations the traditional chi-square tests and the derived tests are compared. And the related some testing problems are synthetically explained on a geometrical viewpoint.

• The Journal of Korean Academy of Prosthodontics
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• v.35 no.3
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• pp.458-469
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• 1997

This study was to compare the tensile bond strength and flexibility of four different soft liners(Coe-Soft, Soft Relining, Soft-Liner, Dura Base Soft) before & after thermocycling. Each soft liner was bonded to denture base resin block, and measured the tensile bond strength and modulus of elasticity using Universal testing machine. The mean value of tensile bond strength and modulus of elasticity for each experimental groups were statistically processed by SPSS(Statistical Package of Social Science). The obtained results were as follows : 1. Dura Base Soft had the highest tensile bond strength and Coe-Soft had the lowest tensile bond strength. 2. Coe-Soft had the lowest modulus of elasticity, and Dura Base Soft had the highest modulus of elasticity. 3. Thermocycling had no effects on the tensile bond strength and modulus of elasticity of all the soft liners. 4. The failure modes of Coe-Soft, Soft Relining, Soft Liner were mainly cohesive failure, and that of Dura Base Soft were mainly adhesive failure.

• Industrial Engineering and Management Systems
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• v.1 no.1
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• pp.87-92
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• 2002

A stochastic process {$A_n$, n = 1, 2, ...} is an arithmetic process (AP) if there exists some real number, d, so that {$A_n$ + (n-1)d, n =1, 2, ...} is a renewal process (RP). AP is a stochastically monotonic process and can be used for modeling a point process, i.e. point events occurring in a haphazard way in time (or space), especially with a trend. For example, the vents may be failures arising from a deteriorating machine; and such a series of failures id distributed haphazardly along a time continuum. In this paper, we discuss estimation procedures for an AP, similar to those for a geometric process (GP) proposed by Lam (1992). Two statistics are suggested for testing whether a given process is an AP. If this is so, we can estimate the parameters d, ${\mu}_{A1}$ and ${\sigma}^{2}_{A1}$ of the AP based on the techniques of simple linear regression, where ${\mu}_{A1}$ and ${\sigma}^2_{A1}$ are the mean and variance of the first random variable $A_1$ respectively. In this paper, the procedures are, for the most part, discussed in reliability terminology. Of course, the methods are valid in any area of application, in which case they should be interpreted accordingly.

• Journal of the Korean Society of Clothing and Textiles
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• v.31 no.4 s.163
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• pp.531-539
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• 2007

The purpose of this article was to determine how the current auto mechanic's coverall restricts movements, to develop prototype coverall, and finally, to improve working efficiency. To investigate the problem and complaint of current coveralls, 35 mechanics were interviewed. Video captured method was used to analyze the representative movement. Based on the previous investigation, the prototype coverall was developed. Pleats and band were inserted on each side of the back, under the armhole, and the back waist area for flexibility. To analyze the mobility of current and prototype coveralls objectively, range-of-motion of selected movements was measured by Leighton flexometer and goniometer. Also, wearer acceptability scale was tested to investigate subjective preference of current and prototype coveralls. As subjects, 10 auto mechanics were participated. Order of testing was randomized. ANOBA and LSD were used for statistical analysis. As a results, prototype coverall was significantly different from current coverall at all test movements. Also, prototype coverall was significantly different from current coverall at 13 scales among 23 subjective scales. The results identified that prototype coverall design improved auto mechanic's body movement and subjective acceptability.

• Restorative Dentistry and Endodontics
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• v.42 no.1
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• pp.34-38
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• 2017

Objectives: The aim of this study was to evaluate the cyclic fatigue resistance of the ProTaper Universal D1 file (Dentsply Maillefer) under continuous and adaptive motion. Materials and Methods: Forty ProTaper Universal D1 files were included in this study. The cyclic fatigue tests were performed using a dynamic cyclic fatigue testing device, which had an artificial stainless steel canal with a $60^{\circ}$ angle of curvature and a 5 mm radius of curvature. The files were randomly divided into two groups (Group 1, Rotary motion; Group 2, Adaptive motion). The time to failure of the files were recorded in seconds. The number of cycles to failure (NCF) was calculated for each group. The data were statistically analyzed using Student's t-test. The statistical significant level was set at p < 0.05. Results: The cyclic fatigue resistance of the adaptive motion group was significantly higher than the rotary motion group (p < 0.05). Conclusion: Within the limitations of the present study, the 'Adaptive motion' significantly increased the resistance of the ProTaper Universal D1 file to cyclic facture.

• The Korean Journal of Applied Statistics
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• v.11 no.2
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• pp.257-268
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• 1998

Many epidemiological studies investigate whether an association exists between a binary risk factor X and a binary response variable Y. They analyse whether an observed association between X and Y persists when the level of another factor Z that might influence the association is controlled. This involves testing conditional independence of X and Y controlling for Z. The Mantel-Haenszel test is most widely used to test conditional independence for sparse tables. But if the association between X and Y varies along the levels of Z, Mantel-Haenszel test has a low power problem. In this study, we propose an alternative test procedure which overcomes the low power problem in that case. We find out the null distribution of the alternative test statistic and compare its performance with the Mantel-Haenszel test by simulation.

• The Korean Journal of Applied Statistics
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• v.29 no.4
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• pp.699-706
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• 2016

Outlier detection methods without performing a test often do not succeed in detecting multiple outliers because they are structurally vulnerable to a masking effect or a swamping effect. This paper considers testing procedures supplemented to a clustering-based method of identifying the group with a minority of the observations as outliers. One of general steps is performing a variety of t-test on individual outlier-candidates. This paper proposes a sequential procedure for searching for outliers by changing cutoff values on a cluster tree and performing a test on a set of outlier-candidates. The proposed method is illustrated and compared to existing methods by an example and Monte Carlo studies.