• 한국과학교육학회지
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• 제25권5호
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• pp.595-602
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• 2005

이 연구의 목적은 과학학습에서 가설 생성력 향상에 미치는 삼원귀추모형(TAM)의 적용 효과를 검증하는 것이다. 이를 위해 TAM의 가설 생성 절차에 따른 가설 생성 활동 10개와 전통적인 방법에 따른 가설생성활동 10개를 개발하여 각각26명의 고등학생으로 구성된 TAM 집단과 27명의 전통 집단에 투입하였다. 가설 생성 활동 10개가 투입되는 과정에서 4개의 활동에서 학생들이 생성한 최종 가설의 설명도를 평가하였다. 또한 가설 생성력의 향상 정도를 검증하기 위해서 과학 지식 생성력 검사 A형과 B형을 사전과 사후에 각각 투입하여 연구 대상 학생들의 가설 생성력을 검사하였다. 연구 결과 TAM 집단이 생성한 가설의 설명도가 전통 집단의 가설보다 통계적으로 의미 있는 수준에서 높았다. 가설 생성력 검사에서는 TAM 집단과 전통 집단의 검사 점수가 사전 검사에서는 통계적으로 유의미한 수준에서 차이가 없었으나 사후에는 TAM집단이 의미 있게 높았다. 따라서 TAM을 적용한 가설 생성 활동은 전통적인 방법보다 가설 생성력 향상에 효과적이라고 할 수 있다.

• 한국과학교육학회지
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• 제24권4호
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• pp.731-747
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• 2004

The scientific inquiry enterprise consists of formulating hypotheses, testing hypotheses, evaluating evidence, and revising hypothesis. Scientific inquiry in the science classrooms requires students' background experience and knowledge with the phenomenon in order to ask appropriate questions, identify and define variables operationally, formulate hypotheses, and design clear and complete experiment. The ability to test hypotheses has been postulated to play a central role in cognitive processes. The purpose of this study was to analyze what the change of the quantity and quality of the hypothesis, the rejecting or accepting of the hypothesis, and the use results in the repetitional hypothesis activity experiments. To examine the problems, this study analyzed 5 classes which were designed and administered to 16 students of the 7th grade. The results of this study showed that students preferred the engineering method to scientific method and the quality of a second hypothesis got low. The quality of the hypothesis came to be higher through a repetitional hypothesis and the number of hypothesis was reduced. The results of the experiments did not play central roles in revising hypotheses and accepting or rejecting hypothesis.

• Journal of the Korean Data and Information Science Society
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• 제25권2호
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• pp.385-392
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• 2014

랜덤워크 가설은 금융시장의 예측 어려움을 이론적으로 설명하는 가설이다. 현재까지 다양한 랜덤워크 검정방법들이 개발되어 왔으나 낮은 검정력과 유의수준 왜곡 등의 문제를 보이는 것으로 알려져 있다. 본 논문에서는 이러한 문제점들을 개선하기 위해 부호검정에 기초한 랜덤워크 검정방법을 제안하였다. 랜덤워크와 관련하여 흔히 사용되고 있는 Dickey와 Fuller (1979) 검정과 모의실험을 통해 성능을 비교하였다.

• Journal of the Korean Data and Information Science Society
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• 제21권2호
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• pp.371-377
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• 2010

In this study, we propose two informal hypothesis tests which may be useful in determining the number of trees in a random forest for use in classification. The first test declares that a case is 'easy' if the hypothesis of the equality of probabilities of two most popular classes is rejected. The second test declares that a case is 'hard' if the hypothesis that the relative difference or the margin of victory between the probabilities of two most popular classes is greater than or equal to some small number, say 0.05, is rejected. We propose to continue generating trees until all (or all but a small fraction) of the training cases are declared easy or hard. The advantage of combining the second test along with the first test is that the number of trees required to stop becomes much smaller than the first test only, where all (or all but a small fraction) of the training cases should be declared easy.

• Communications for Statistical Applications and Methods
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• 제5권2호
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• pp.411-416
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• 1998

A simple nonparametric test of complete or total independence is suggested for continuous multivariate distributions. This procedure first discretizes the original variables based on their order statistics, and then tests the hypothesis of complete independence for the resulting contingency table. Under the hypothesis of independence, the chi-squared test statistic has an asymptotic chi-squared distribution. We present a simulation study to illustrate the accuracy in finite samples of the limiting distribution of the test statistic. We compare our method to another nonparametric test of complete independence via a simulation study. Finally, we apply our method to the residuals from a real data set.

• ETRI Journal
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• 제18권3호
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• pp.207-213
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• 1996

This paper proposes a new nonparametric test for testing the null hypothesis that the MRL is constant against the alternative hypothesis that the MRL is decreasing (increasing) for ramdomly censored data. The proposed test statistic is a L-statistic, and we use L-statistic theory to establish its asymptotic normality of the test statistic. We discuss the efficiency loss due to censoring and also calculate the asymptotic relative efficiencies of our test statistic with respect to the Chen, Hollander and Langberg's test for several alternatives.

• 한국과학교육학회지
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• 제19권1호
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• pp.117-127
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• 1999

최근의 보고에 따르면 우리 나라 학생들은 학년이 높아질수록 과학적 수준은 반대로 떨어지는 경향을 보이고 있지만 고등학교 이후 집단의 과학적 추론능력에 대한 연구는 체계적으로 이루어지지 않고 있다. 특히 가설검정능력과 관련된 과학적 추론은 가장 고등한 인지기능의 하나로 여겨지고 있고, 또 창의적이고 비판적인 사고에 매우 중요하다고 보고되어 왔다. 따라서 본 연구는 우리나라 대학생들의 과학적 추론 능력을 조사하고, 이를 미국 대학생들의 과학적 추론 능력과 비교하여 분석하였다. 아울러 본 연구는 가설 검정능력이 과학적 추론능력의 다른 하위요소에 비해 고등한 추론기능이라는 가설도 검정하였다. 고등학교 이후의 과학적 추론에 대한 경향을 조사하기 위하여 본 연구는 한국의 대학생 774명과 미국의 대학생 568명에게 과학적 추론 검사를 실시하여서 비교 분석하였고, 이 자료를 토대로 가설검정능력이 과학적 추론의 다른 하위요소에 비해 고등한 추론이라는 가설도 검정하였다. 본 연구에 사용된 과학적 추론 검사는 보존논리, 비례논리, 변인통제, 확률논리, 상관논리, 그리고 가설검정기능에 관련된 127개의 과제로 구성되어 있다. 본 연구의 결과는 한국 대학생들이 비례 및 확률논리를 평가하는 과제에 대해서는 미국 학생들보다 월등하게 높은 접수를 기록하였고, 보존이나 변인통제, 그리고 상관논리를 평가하는 과제에 대해서는 반대의 경향을 나타내었다. 또한 가설검정 능력을 평가하는 문항에서는 양국 모두 다른 과학적 추론 과제에 비해서 뚜렷하게 낮은 점수를 보여주었다. 본 연구는 이들 결과에 대해서 본 연구의 목적과 관련해서 논의하였고 이의 교육적 적용에 대해서도 논의하였다.

• 대한간호학회지
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• 제27권1호
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• pp.109-119
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• 1997

This study has been attempted to set up the strategies of the nursing which can promote the activity performance for early rehabilitation for the patients by examining the effect of the structured patient education on the early rehabilitation knowledge and activity performance of the C.V.A patients. The study method has been done by investigating the experiment group and control group in advance through the question papers and interview and observation on 65 patients who had been hospitalized at oriental medicine hospital of K Medical Center from July 1st 1995 to the end of Sep, 1995. The analysis of the collected material had been done for the homogeneity test in which general characters of experiment group and control group had been tested by X²and the homogeneity test of ADL by t-test. To test the hypothesis the t-test had been given for the difference of the early rehabilitation knowledge and activity performance between the two groups and the correlation between early rehabilitation knowledge and activity performance had been tested by Pearson's Correlation Coefficient. The result of the test of the hypothesis is as the below. 1 The 1st hypothesis “The experiment group which had received the structured education should be higher in the early rehabilitation knowledge than the control group” was supported(t=4.45. p=.000). 2. The 2nd hypothesis “The experiment group which received the structured education should be higher in the early rehabilitation activity performance than the control group”was supported(t=2.11, p=.036). 3. The 3rd hypothesis “The higher the early rehabilitation knowledge of the patient the higher the activity performance degree” was rejected (r=.1546, p=.219). In conclusion, the patients who received the structured education showed the increase in the degree of early rehabilitation knowledge and activity performance, so it has been judged that education has been prerequisite in increasing the knowledge and activity performance of early rehabilitation.

• Communications for Statistical Applications and Methods
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• 제4권3호
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• pp.787-793
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• 1997

It is well known that the assumption of independence is ofter not valid for real data. This phenomenon has been observed empirically by many prominent scientists. In this article the sensitivity of dependence on Bayes test of a sharp null hypothesis is considered. The robustness is considered with respect to the significant level and the prior probability on the null hypothesis.

• 지역사회간호학회지
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• 제12권3호
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• pp.773-784
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• 2001

The study was conducted to test the effectiveness of thermotherapy for high school girls who suffered from disruption in school activities through dysmenorrhea, and to study the extent of its availability in school infirmaries as one of the nursing methods. The test for the study was designed to make a contrast between half of the subjects (20) who did not receive the thermotherapy, and the rest (20) who did during the period from February 15th to April 14th, 2001. Measurements were taken of the subjects who complained of painful menstruation by a set of variables. The variables that were established and complemented by Hur, Mung-heang (1985) consist of 29 items that assess the dysmenorrhea and vitality through the symptoms of primary menstruation visually. Spsswin was used to analyze the data. The Cronbach-${\alpha}$ method was used for statistic confidence, and the test effect of both the subjects and the contrary ones was analyzed by way of T-test. The conclusions are as follow. (1) The hypothesis 1 states that the subjects with themotherapy have a lower degree of dysmenorrhea rather than the contrary ones without it. By the above assessment, there was a quantitative difference between the subjects at 39.40, and the contrary ones at 22.0. After the themotherapy, the degree of dysmenorrhea in the subjects was low indicating that there is a still 5% chance of statistic meaningful difference (t= 2.651. P= .012). As a result, the first hypothesis was accepted. (2) The hypothesis 2 states that the subjects with themotherapy have a different primary menstruation than those without. Data indicate that there was a difference of -5.95 and -4.80. The subjects showed low degrees. Since it was statistically insignificant (t=-1.398, P=.170), the second hypothesis was rejected. (3) The hypothesis 3 states that the subjects with themotherapy have a different vitality. The vitality was measured in three aspects. (1) pulse rate (/min) The hypothesis 3' states that the subjects with themotherapy have the different pulse rate from those without. Data indicate that there was no statistically meaningful difference between the two groups (t=.237, P=. 814). Therefore, the third 1st hypothesis was rejected. (2) Respiration rate The hypothesis 3' states that the subjects with themotherapy have a different respiration rate between pre-thermotherapy and post-thermotherapy. in contrast with the ones without it. The data show that there was no statistically meaningful difference (t=.133. P=.895). A little respiration rate difference was shown between pre-and post-. Likewise. the third 2nd hypothesis was rejected. (3) Blood pressure In the 3rd sub-hypothesis that there would be a difference between experimental and controlled groups was also rejected. because there was no statistically significant difference between the contracting blood pressure and the relaxing blood pressure. In terms of vitality. the pulse rate, respiration rate and blood pressure have no statistical meaning but the first two ones show the decreasing in the rate. In short, though exclusive studies focused on thermo therapy have not been conducted and the comparison can not be made, this study shows not only that the thermotherapy is very effective to dysmenorrhea, but also that it can be available in school infirmaries as one of the nursing methods.