• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.6A
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• pp.517-523
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• 2002

The closed from of sums and weighted sums of the score functions of the locally optimum rank detectors are obtained in this paper. When we consider the asymptotic performance characteristics of a detector based on rank and sign statistics, the sums and weighted sums of the score functions have to be prepared. The efficacy of a detector can be obtained from the sums and weighted sums of the score functions. Score functions based on rank statistics, as well as those based on magnitude rank and sign statistics, have also been considered, which includes most score functions presented in the literature.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.22 no.3
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• pp.63-68
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• 2022

There are 395,789 people with hearing impairment in Korea, according to the 2021 Disability Statistics Annual Report by the Korea Institute for the Development of Disabled Persons. These people are experiencing a lot of inconvenience through hearing impairment, and many studies related to recognition and translation of Korean sign language are being conducted to solve this problem. In sign language recognition and translation research, collecting sign language data has many difficulties because few people use sign language professionally. In addition, most of the existed data is sign language data taken from the front of the speaker. To solve this problem, in this paper, we designed and developed a storage system that can collect sign language data based on multi-view points in real-time, rather than a single point, and store and manage it with high usability.

• Journal of the Korean Data and Information Science Society
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• v.25 no.6
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• pp.1499-1506
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• 2014

Random walk is used for describing random phenomenon in various areas but tests for random walk developed so far are known to suffer from size distortion and low power. Kim et al. (2014) proposed a sign test for unit root (${\rho}=1$) hypothesis based on slopes. This article proposes a Wilcoxon signed rank test based on slopes for unit root hypothesis, and compares it with the augmented Dickey-Fuller test and the sign test by a simulation study. Our results confirm that the nonparametric tests are better than ADF test for small samples like n = 30. The results also show that the sign test is better than the Wilcoxon signed rank test and that for 0 < ${\rho}$ < 1 (-1 < ${\rho}$ < 0), the nonparametric tests suffer from power loss (improvement) as normal error changes to double exponential error.

• The Journal of Korean Obstetrics and Gynecology
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• v.25 no.1
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• pp.47-55
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• 2012

Purpose: Dysmenorrhea mostly depends on the causative factor, which usually falls under the categories of Deficiency and Excess pattern in traditional Oriental medical theories and diagnosis. Thus, we investigated menstruation symptom and sign related to dysmenorrhea and verified the validity of Deficiency and Excess pattern identification. Methods: We investigated menstruation symptom and sign related to dysmenorrhea in total 14 gynecology-medical books including the book ${\ll}$Exemplar Of Korean Medicine (Dongui Bogam)${\gg}$ and whole body symptom and sign identifying Deficiency and Excess pattern at the same time. A survey based on this investigation was carried out targeting women of childbearing age. Results: Total of 14 gynecology-medical books have mostly narrated pre-menstrual and mid & post-menstrual pelvic pain depending on the time of its manifestation for identifying Deficiency and Excess pattern. Dysmenorrhea in pre-menstrual period belonged to Excess pattern and dysmenorrhea in mid & post-menstrual period belonged to Deficiency pattern. Among a total of 343 women, 196 subjects suffered from dysmenorrhea. The number of dysmenorrhea in pre-menstrual period (Excess pattern) was 116 people and in mid & post-menstrual period (Deficiency pattern) was 80 people. Deficiency and Excess pattern of dysmenorrhea in menstrual period significantly correlated to Deficiency and Excess pattern of whole body symptom and sign in the statistics(P-value < 0.05). Conclusion: The results suggest that pre-menstrual and mid & post-menstrual pelvic pain depending on the time of its manifestation is preferentially utilized as symptom and sign related to dysmenorrhea identifying Deficiency and Excess pattern.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.48 no.6
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• pp.348-355
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• 2022

Objectives: To compare the vital sign stability and cost of two commonly used sedatives, midazolam (MDZ) and dexmedetomidine (DEX). Patients and Methods: This retrospective study targeted patients who underwent mandibular third molar extractions under intravenous sedation using MDZ or DEX. The predictor variable was the type of sedative used. The primary outcome variables were vital signs (heart rate and blood pressure), vital sign outliers, and cost of the sedatives. A vital sign outlier was defined as a 30% or more change in vital signs during sedation; the fewer changes, the higher the vital sign stability. The secondary outcome variables included the observer's assessment of alertness/sedation scale, level of amnesia, patient satisfaction, and bispectral index score. Covariates were sex, age, body mass index, sleeping time, dental anxiety score, and Pederson scale. Descriptive statistics were computed including propensity score matching (PSM). The P-value was set at 0.05. Results: The study enrolled 185 patients, 103 in the MDZ group and 82 in the DEX group. Based on the data after PSM, the two samples had similar baseline covariates. The sedative effect of both agents was satisfactory. Heart rate outliers were more common with MDZ than with DEX (49.3% vs 22.7%, P=0.001). Heart rate was higher with MDZ (P=0.000). The cost was higher for DEX than for MDZ (29.27±0.00 USD vs 0.37±0.04 USD, P=0.000). Conclusion: DEX showed more vital sign stability, while MDZ was more economical. These results could be used as a reference to guide clinicians during sedative selection.

• The Korean Journal of Applied Statistics
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• v.30 no.4
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• pp.503-512
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• 2017

In test with multiple choices, it is necessary to have the position of correct answers of each question spreaded evenly over all the questions in order to minimize the influence of answering tendency of test takers with preference to specific position of multiple choices. The scores of tests with correct answers in specific positions would not reflect exactly the academic aptitude of examinees who do not know correct answers but have the biased answering tendency. In this paper, we have randomness test for the positioning of correct answers at the 2017 College Scholastic Ability Test (CSAT) using Bartels rank test, the Wald-Wolfowitz runs test, the turning point test, the Cox Stuart trend test, the difference sign test and the Mann-Kendall tank test, etc. We also do independence test between the location of correct answer and the allocation of score in each question, for it may result in overestimating the test-taker with specific position preference in marking correct answers.

• Journal of the Korean Data and Information Science Society
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• v.26 no.4
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• pp.791-799
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• 2015

In random walk hypothesis, we assume that current change of financial time series is independent of past values. It is interpreted as an existency of a unit root in ARMA models and many researches have been focused on whether ${\rho}$ < 1 or not. If some financial data are generated from an explosive autoregressive model, the chance of a bubble economy increases. We have to find the symptoms of it in advance. Since some well-known parameter estimators contain the parameter itself and other statistic is constructed under a specific parameter structure assumption, those are difficut to be adopted. In this paper we investigate a test for explosive autoregressive models using slope signs. We found the properties of the slope sign test statistic under both independent error and correlated error conditions, mainly by simulations.

• Communications for Statistical Applications and Methods
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• v.10 no.2
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• pp.535-543
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• 2003

A ranked set sample version of the sign test is proposed for testing hypotheses concerning the quantiles of a population characteristic by Kaur, et. al(2002). In this paper, we proposed the ranked set sample Wilcoxon signed rank test for quantiles under equal allocation. We obtain the asymptotic property and the asymptotic relative efficiencies of the proposed test statistic with respect to Wilcoxon signed rank test of simple random sample for quantiles under equal allocation. We calculate the ARE of test statistics, the proposed test statistic is more efficient than simple random sampling for all quantiles. The relative advantage of ranked set sampling is greatest at the median and tapers off in the tails.

• Journal of the Korean Data and Information Science Society
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• v.15 no.4
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• pp.973-980
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• 2004

Phase I clinical trials are often pharmacologically oriented and usually attempt to find the best dose of drug to employ. However, other purposes like determination of sizes and types of side effects and toxicity and organ system involved are equally important. Estimation of treatment effects or side effects is usually ignored since it is usually based on too small sample, even though Phase II clinical trials would be designed based on the Phase I studies. Statistical methods for constructing the approximate confidence interval for population median in case of small sample are considered and an improved method is proposed. The proposed estimator is compared with current methods through simulation studies.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.46 no.5
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• pp.126-134
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• 2009

This paper describes the vision-based system to track road signs from within a moving vehicle. The proposed system has the standard architecture with particle filter due to its robust tracking performance in complex environment. In the case of tracking road signs in real environment, it has a great difficulty in predicting time series data by reason of an occlusion due to an obstacle and the rapid change of objects on roads. To overcome this problem and improve the tracking performance, this paper proposes the algorithm using an autoregressive model as an state transition model which has affine parameters as states and using robust statistics for determining occlusion due to obstacles. The experiments of this paper show that the proposed method is efficient for real time tracking of road signs and performs well in road signs under occlusion due to obstacles.