• 한국측량학회지
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• 제35권5호
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• pp.357-364
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• 2017

The purpose of the study is to develop and validate landslide susceptibility map of Bhotang village development committee, Nepal using FR (Frequency Ration) and SI (Statistical Index) methods. For the purpose, firstly, a landslide inventory map was constructed based on mainly high resolution satellite images available in Google Earth Pro, and rest fieldwork as verification. Secondly, ten conditioning factors of landslide occurrence, namely: altitude, slope, aspect, mean topographic wetness index, landcover, normalized difference vegetation index, dominant soil, distance to river, distance to lineaments and rainfall, were derived and used for the development of landslide susceptibility map in GIS (Geographic Information System) environment. The landslide inventory of total 116 landslides was divided randomly such that 70% were used for training and remaining 30% for validating result by receiver operating characteristics curve analysis. The area under the curve were found to be greater than 0.7 indicating an acceptable susceptibility maps obtained using FR and SI methods in GIS for hilly region of Nepal.

• 대한조선학회논문집
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• 제51권4호
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• pp.321-327
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• 2014

A wide scope of numerical simulations was performed to predict model-ship resistances by using STAR-CCM+ and OpenFOAM. The numerical results were compared with experimental measurements in towing tank to analyze statistical reliability of the present simulations. Based on the normal distribution of resistance errors in 113 cases of container carriers, tankers and very large crude-oil carriers, the confidence intervals of numerical error were estimated as [-2.64%,+2.32%] and [-1.82%, +1.87%] with 95% confidence in STAR-CCM+ and OpenFOAM, respectively. The resistance errors of liquefied natural gas carriers with single- and twin-skeg were confident in the ranges of [-2.51%,+2.64%] and [-2.29%, +1.46%], respectively. The grid uncertainty of resistance coefficients for KCS was also quantitatively analyzed by using a grid verification procedure. The grid uncertainty of OpenFOAM (5.1%) was larger than 4.4% uncertainty of STAR-CCM+ although OpenFOAM provided statistically more confident results than those of STAR-CCM+. It means that a grid system verified under a specific condition does not automatically lead to statistical reliability in general cases.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2014년도 추계학술대회 논문집
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• pp.347-349
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• 2014

Model verification and validation (V&V) is a current research topic to build computational models with high predictive capability by addressing the general concepts, processes and statistical techniques. The hypothesis test for validity check is one of the model validation techniques and gives a guideline to evaluate the validity of a computational model when limited experimental data only exist due to restricted test resources (e.g., time and budget). The hypothesis test for validity check mainly employ Type I error, the risk of rejecting the valid computational model, for the validity evaluation since quantification of Type II error is not feasible for model validation. However, Type II error, the risk of accepting invalid computational model, should be importantly considered for an engineered products having high risk on predicted results. This paper proposes a technique named as the response-adaptive experimental design to reduce Type II error by adaptively designing experimental conditions for the validation experiment. A tire tread block problem and a numerical example are employed to show the effectiveness of the response-adaptive experimental design for the validity evaluation.

• 무역학회지
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• 제44권3호
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• pp.253-269
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• 2019

This study examines the utilization effect of FTA on the sales and profit of the secondary auto-part suppliers in two aspects: 1) firm-level survey on the utilization of FTA and 2) statistical inference on the FTA effects on their sales and profit. We use the GLS statistical technique, panel and survey data of 130 secondary auto-part suppliers in the Daegu and Kyungpook area in 2007-2016. The evidence shows that the secondary auto-part suppliers struggle to prepare documents for the FTA certificates of origin due to their small firm size, although they utilize the FTA at the relatively high rate of 92 percent. Statistical evidence shows that an increase in the export of the first vender significantly affects the sale of the secondary auto-part vendors, but not their profit. The low profit and high managing cost of utilizing the FTA deteriorate the utilization effect of the FTA of the secondary auto-part vendors, which is a key factor in a global supply chain and for the competitiveness of the automobile industry. Government policies are required for the secondary auto-part suppliers to utilize the FTA more effectively and share the benefits of tariff reduction with first auto-part vendors under FTA transaction.

• 방송공학회논문지
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• 제23권4호
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• pp.526-535
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• 2018

많은 스테가노그래피 알고리즘들이 연구되어왔고 스테가노그래피의 연구로 인해서 스테가노그래피 알고리즘이 적용된 스테고 영상을 검출하기 위한 스테그아날리시스 또한 연구되어왔다. 특히 영상 스테그아날리시스의 경우에 ALE, SPAM, SRMQ와 같은 통계적인 특성에 기반한 수제 특징이 영상으로부터 추출되고 이 특징을 기계학습 알고리즘을 사용하여 스테고 영상의 분류에 사용하였다. 하지만 이러한 연구들은 단지 단일 영상의 크기, 비밀 정보 삽입 비율에 대해서만 고려하였으며 다양한 영상의 크기, 가로세로 비, 비밀 정보의 비율들에 대해서는 고려하지 않았다. 결과적으로 SPAM 특징이 다양한 조건하에서도 범용성있게 사용가능한지에 대한 검증은 이루어지지 않았다. 본 논문에서는 SPAM 기반의 영상 스테그아날리시스를 사용하여 영상의 크기, 가로 세로 비 비밀 정보 삽입 비율의 다양한 조건에 대한 분류율을 분석하여 SPAM 특징이 일관적인 분류 결과를 보여줄 수 있는지 확인해본다.

• 한국수자원학회논문집
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• 제44권7호
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• pp.537-551
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• 2011

본 연구에서는 앞선 연구를 통해 선정된 최적 입력 자료 조합을 이용하여 한강수계의 왕숙천과 금강유역의 갑천에 대한 Takagi-Sugeno 퍼지기법과 신경망을 연계한 뉴로-퍼지 홍수예측 모형을 구축하였다. 구축된 뉴로-퍼지 홍수예측 모형을 한강수계의 왕숙천과 금강유역의 갑천에 적용하여 30분, 60분, 90분, 120분, 150분, 180분의 선행시간에 대해 각각 홍수예측을 수행하였다. 선행시간별 예측수위를 관측수위와 비교한 결과 안정되고 정확도 높은 홍수예측을 하는 것을 확인할 수 있었다. 추가적으로 정량적 평가를 위해 평균제곱근 오차(Root Mean Square Error)와 같은 통계지표를 산정하여 모형의 적용성을 검증하였다. 검증 결과 모든 통계지표에서 큰 오차 없이 성공적으로 홍수예측이 모의됨을 확인할 수 있었다. 본 연구결과는 향후 중소하천에서 충분한 선행시간을 확보한 정확도 높은 홍수정보시스템의 구축에 활용할 수 있을 것으로 판단된다.

• The Journal of Advanced Prosthodontics
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• 제9권5호
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• pp.358-363
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• 2017

PURPOSE. The purpose of this study was to evaluate the reliability of computer-aided replica technique (CART) by calculating its agreement with the replica technique (RT), using statistical agreement analysis. MATERIALS AND METHODS. A prepared metal die and a metal crown were fabricated. The gap between the restoration and abutment was replicated using silicone indicator paste (n = 25). Gap measurements differed in the control (RT) and experimental (CART) groups. In the RT group, the silicone replica was manually sectioned, and the marginal and occlusal gaps were measured using a microscope. In the CART group, the gap was digitized using optical scanning and image superimposition, and the gaps were measured using a software program. The agreement between the measurement techniques was evaluated by using the 95% Bland-Altman limits of agreement and concordance correlation coefficients (CCC). The least acceptable CCC was 0.90. RESULTS. The RT and CART groups showed linear association, with a strong positive correlation in gap measurements, but without significant differences. The 95% limits of agreement between the paired gap measurements were 3.84% and 7.08% of the mean. The lower 95% confidence limits of CCC were 0.9676 and 0.9188 for the marginal and occlusal gap measurements, respectively, and the values were greater than the allowed limit. CONCLUSION. The CART is a reliable digital approach for evaluating the fit accuracy of fixed dental prostheses.

• 공학교육연구
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• 제19권4호
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• pp.14-23
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• 2016

This study is to analyze the team interaction in accordance with the team size. Thereby, it is to reveal the team size for the attainment of the effective team interaction and the specific goals to achieve the purpose of this study are as follows. Firstly, the frequency and percentage of team interaction in accordance with the team size are presented. Secondly, the statistical verification of the team interaction in the social emotional area is conducted. Thirdly, the statistical verification of the team interaction in the task area is conducted. In order to do this study, we explain the purpose of study, confidentiality, and withdrawal right were described and then 32 persons who agreed to participate were selected as the subjects for the study. After that, the autonomous organization of team was induced and a total of 8 teams were organized - 3 teams comprised of 3 members, 3 teams of 4 members, 1 team of 5 members, and 1 team of 6 members. Further, Bales' (1950) Interaction Process Analysis (IPA) was used in order to analyze the team interaction, and Mangold INTERACT was used as a coding program. The results of study are as follows. Firstly, the highest frequency of the team interaction showed up in the case of five or six members and the lowest in the case of 3 members. Secondly, a statistically significant difference in the social emotional (positive) area showed up in accordance with the team size and the team organizations of three or four members were effective. Thirdly, a statistically significant value in the answer area showed up in accordance with the team size and the team organizations of five or six members were effective.

• 한국수학교육학회지시리즈A:수학교육
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• 제56권4호
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• pp.407-434
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• 2017

The purpose of this study is to develop and verify the TPACK measurement tool for middle and high school mathematics teachers in the Korean context. Also, by clarifying the relationship between subordinate factors of Mathematics teachers' TPACK, an attempt was made to provide suggestions on the designs and directions for the in-service and pre-service teacher education and the programs for improving mathematics teachers' TPACK in the future. In order to achieve this goal, TPACK factors of mathematics teachers were extracted by reviewing literature on PCK, MKT, and TPACK. Then, content validity, basic statistical survey, reliability verification, exploratory factor analysis, confirmatory factor analysis, and structural equation model verification were conducted sequentially. At first, preliminary analysis was carried out on 79 mathematics teachers, and 76 items excluding the items with extreme value and reliability were included in the basic statistical analysis. And secondly, an exploratory factor analysis was conducted on 376 mathematics teachers, and this instrument consisted of 7 subordinate factors(CK, PK, TK, PCK, TCK, TPK, TPACK) and 61 items. Also by conducting confirmatory factor analysis and structural equation model test with 254 mathematics teachers, the measurement tool was confirmed the validity and reliability through statistically significant analysis. Then, the importance of integrated knowledge was confirmed by looking at the relationship between the TPACK factors of in-service mathematics teachers. The integrated knowledge(PCK, TCK, TPK) has played a crucial role in the formation of TPACK rather than the knowledge of CK, PK, and TK alone. Finally, the validity of TCK was confirmed through the structural equation modeling of TPACK. TCK not only directly affected TPACK, but also indirectly through TPK. According to these affirmative results, this measurement tool is claimed to be suitable for measuring the factors of Mathematics teachers' TPACK, and also the structural equation model can be regarded as a suitable model for analyzing the structural relationship of mathematics teachers' TPACK.

• 가족자원경영과 정책
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• 제24권2호
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• pp.49-68
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• 2020

This research seeks to examine the relationship between multicultural education experiences and the multicultural acceptability of military officers. The sample included 552 Republic of Korea Army officers and non-commissioned officers(NCOs) who were located in Gangwon-Do and Gyeonggi-Do. For the statistical analysis, SPSS 18.0 was used to perform descriptive statistical analysis, frequency analysis, differential verification, and multiple regression analysis. The major analysis results are as follows: First, The multicultural acceptability of the military officers and NCOs, including sub-factors, was above the mean level; in terms of the ranking per sub-factor, the scores were in the order of diversity, relationship, and universality. The experience frequency of the targets and the evaluation was lowest in the educational experience within the military, and the evaluations were in the order of public media, school, and military. Second, The differential verification, depending on the characteristics of the sociology of the population and the existence of the multicultural educational experience, showed that the duration of education(personal factor), marital status(family factor), existence of a foreign relative(family factor), and existence of experience of managing multicultural personnel as soldiers under command(military-related factor) showed a significant difference in multicultural acceptability. Additionally, the existence of multicultural education through schools and public media lead to a significant difference in multicultural acceptability, but the existence of education within the military did not lead to a significant difference. Third, The analysis of the influencing relationship through multiple regression analysis showed that the higher the evaluation of multicultural education through the military, school, and public media, the higher the multicultural acceptability.Therefore, this research proposes multicultural educational plans that may improve the multicultural acceptability of military officers and NCOs as a way to establish a multicultural composition in the army.