• Phonetics and Speech Sciences
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• v.12 no.4
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• pp.73-80
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• 2020

In this study, a method for measuring the jitter component in continuous speech is presented. In the conventional jitter measurement method, pitch variabilities are commonly measured from the sustained vowels. In the case of continuous speech, such as a spoken sentence, distortion occurs with the existing measurement method owing to the influence of prosody information according to the sentence. Therefore, we propose a method to reduce the pitch fluctuations of prosody information in continuous speech. To remove this pitch fluctuation component, a curve representing the fluctuation is obtained via polynomial interpolation for the pitch track in the analysis interval, and the shift is removed according to the curve. Subsequently, the variability of the pitch frequency is obtained by a method of measuring jitter from the trajectory of the pitch from which the shift is removed. To measure the effects of the proposed method, parameter values before and after the operations are compared using samples from the Kay Pentax MEEI database. The statistical analysis of the experimental results showed that jitter components from the continuous speech can be measured effectively by proposed method and the values are comparable to the parameters of sustained vowel from the same speaker.

• The Korean Journal of Applied Statistics
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• v.17 no.2
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• pp.347-357
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• 2004

It is very important to select a split variable in constructing the classification tree. The efficiency of a classification tree algorithm can be evaluated by the variable selection bias and the variable selection power. The C4.5 has largely biased variable selection due to the influence of many distinct values in variable selection and the QUEST has low variable selection power when a continuous predictor variable doesn't deviate from normal distribution. In this thesis, we propose the SRT algorithm which overcomes the drawback of the C4.5 and the QUEST. Simulations were performed to compare the SRT with the C4.5 and the QUEST. As a result, the SRT is characterized with low biased variable selection and robust variable selection power.

• Proceedings of the Acoustical Society of Korea Conference
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• 1998.08a
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• pp.209-213
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• 1998

50개의 담화단독 문장과 연속발성 문장을 대상으로 무장의 첫 어절과 마지막 어절에서의 첫 음절과 마지막 음절의 운율특징을 조사하였다. 이를 체계적으로 살펴 보기 위하여 각 어절에서의 마지막 음절의 음향변수에 대한 첫 음절의 음향변수의 비율을 얻은 뒤 이를 대상으로 하여 평균값과 분포를 구하였다. 지속시간의 경우 두 스타일 간에 주목할 만한 큰 차이점은 없었으나 담화 연속 문장의 문두에서 화자의 조음시간 프로그래밍이 약간 조화롭지 못함을 알 수 있었다. Fo는 마지막 어절 부분의 비율값이 두 스타일간 통계적으로 유의한 차이를 보였으며 운율자질로 기능할 수 있는 가능성을 보였다. 에너지는 Fo와 유사한 분포경향을 보인다. 문미 어절의 마지막 음절이 첫 음절의 약 85% 정도의 힘으로 발성됨을 알 수 있고, 담화 연속 발화의 마지막 어절에서 단독 발화문보다 상대적으로 강하게 조음되었음을 알 수 있었다.

• The Korean Journal of Applied Statistics
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• v.19 no.1
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• pp.149-161
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• 2006

The most important component in decision tree algorithm is the rule for split variable selection. Many earlier algorithms such as CART and C4.5 use greedy search algorithm for variable selection. Recently, many methods were developed to cope with the weakness of greedy search algorithm. Most algorithms have different selection criteria depending on the type of variables: continuous or nominal. However, ordinal type variables are usually treated as continuous ones. This approach did not cause any trouble for the methods using greedy search algorithm. However, it may cause problems for the newer algorithms because they use statistical methods valid for continuous or nominal types only. In this paper, we propose a ordinal variable selection method that uses Cramer-von Mises testing procedure. We performed comparisons among CART, C4.5, QUEST, CRUISE, and the new method. It was shown that the new method has a good variable selection power for ordinal type variables.

• Journal of Korean Society of Disaster and Security
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• v.11 no.2
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• pp.9-15
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• 2018

From natural disasters such as floods, heavy rains, and strong winds and social disasters such as 911 U.S. terrorism and cyber attacks that could have a fatal impact on corporate continuity, it is necessary to introduce and implement a Business Continuity Management System (BCMS) within a firm to maintain continuity of business and to change the organizational structure for an emergency state in order to operate and manage it systematically and efficiently. therefore, this study analyzed and verified the impact of introducing a Business Continuity Management System (BCMS) on the change in the recognition structure of an organization in four categories, including personal recognition, organizational culture, organizational structure, and organizational strategy, in order to analyse the impact and effect of introducing a Business Continuity Management System (BCMS) on the change in the recognition structure of each category. through this study, we believe that the introduction of a Business Continuity Management System (BCMS) within a firm could effectively change the organization's perception of an emergency state and help it maintain its continuity as well as improve its value.

• The Korean Journal of Applied Statistics
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• v.21 no.1
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• pp.35-51
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• 2008

Comparative studies in Phase III clinical trials quite often involve two or more equally important endpoints, and one cannot select primary endpoint from them. O'Brien(1984) proposed for continuous endpoints the OLS and GLS statistics as milti-variate test statistics. Pocock et al. (1987) mentioned the possibility of analyzing a mixture of data types, such as quantitative, binary and survival data types, with the OLS and GLS statistics, but the authors did not explore problems in combining several endpoints of different types. Furthermore, they did not perform a simulation study to assess the efficiencies of the OLS and GLS statistics for endpoints of a mixture of data types. In this paper, we propose the combining methods of correlated P-values for the analysis of multiple endpoints, and compare the efficiencies of this method with those of OLS and GLS statistics for a mixture of data types with a simulation study. Among the several methods of combining P-values that are more advantageous than combining of OLS and GLS statistics, method B maintains nominal significance levels and is more efficient, while method F and G have type I error rates that are larger than the specified significance levels, which might occasionally lead to a wrong conclusion.

• The Korean Journal of Applied Statistics
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• v.29 no.3
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• pp.549-557
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• 2016

Consecutive missing values are likely to occur in long climate data due to system error or defective equipment. Furthermore, it is difficult to impute missing values. However, these complicated problems can be overcame by imputing missing values with reference time series. Reference time series must be composed of similar time series to time series that include missing values. We performed a simulation to compare three missing imputation methods (the adjusted normal ratio method, the regression method and the IDW method) to complete the missing values of time series. A comparison of the three missing imputation methods for the daily mean temperatures at 14 climatological stations indicated that the IDW method was better thanx others at south seaside stations. We also found the regression method was better than others at most stations (except south seaside stations).

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.1
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• pp.466-476
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• 2018

This study was conducted to determine factors affecting professionalism of community health practitioners (CHPs). The participants in this study were 153 community health practitioners working in G province with structured self-report questionnaires from 20 August to 25 September 2017. Data were analyzed by descriptive statistics, t-test, ANONA, Scheffe's test, Pearson's correlation coefficients and stepwise multiple regression using the SPSS 20.0 program. There were statistically significant differences according to income (F=6.951, p<.001), work experience (F=5.245, p=0.002) and motivation for choosing a community health practitioner (F=3.676, p=0.004). The highest related factors were job satisfaction (${\beta}=0.320$, p<0.001), individual disposition (${\beta}=0.291$, p<0.001), income (${\beta}=0.283$, p<0.001) and job continuance (${\beta}=0.176$, p=0.009). These variables explained 49.6% of the total variance in professionalism. These findings suggest that it is necessary to develop a convergence program and policy support at the individual and organizational level to strengthen the professionalism of community health practitioners.

• The Korean Journal of Applied Statistics
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• v.21 no.1
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• pp.19-33
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• 2008

Linear regression method, proposed by Haseman and Elston(1972), for detecting linkage to a quantitative trait of sib pairs is a linkage testing method for a single locus and a single trait. However, multivariate methods for detecting linkage are needed, when information from each of several traits that are affected by the same major gene are available on each individual. Amos et al. (1990) extended the regression method of Haseman and Elston(1972) to incorporate observations of two or more traits by estimating the principal component linear function that results in the strongest correlation between the squared pair differences in the trait measurements and identity by descent at a marker locus. But, it is impossible to control the probability of type I errors with this method at present, since the exact distribution of the statistic that they use is yet unknown. In this paper, we propose a multivariate nonparametric trend test for detecting linkage to multiple traits. We compared with a simulation study the efficiencies of multivariate nonparametric trend test with those of the method developed by Amos et al. (1990) for quantitative traits data. For multivariate nonparametric trend test, the results of the simulation study reveal that the Type I error rates are close to the predetermined significance levels, and have in general high powers.

• Journal of the Korean Geotechnical Society
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• v.27 no.8
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• pp.5-16
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• 2011

The objective of this paper is to assess the potential use of the resilient force of the ground obtained from an accelerometer and to propose a new compaction control process. Several comprehensive field experimental programs were conducted to analyze the correlation of compaction results obtained from an accelerometer and conventional test methods (e.g. the plate load test and field density test). This study focused on comparing the compaction results obtained from an accelerometer with conventional test results statistically. Based on the statistical analysis results, impact and resilient force measured from an accelerometer, mounted on the drum of a roller are very useful factors for continuous compaction control. A new compaction criteria determination process using an accelerometer is also proposed in this study.