• Communications for Statistical Applications and Methods
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• 제18권6호
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• pp.859-869
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• 2011

영화의 흥행 결정 요인에 대한 학문적 연구와 함께 상업적 시각에서 개별 영화의 흥행 예측에 대한 관심이 증대되고 있다. 본 연구는 2010년 한국에서 개봉된 영화를 대상으로 영화 흥행에 영향을 미치는 요인들과 영화 흥행 성과간의 관계를 분석하였다. 제작 전 투자 의사결정단계에서 영화 장르, 관람등급, 감독, 배우가 통계적으로 유의한 결과를 보였으며, 배급편성의 의사결정단계에서는 배우효과, 스크린수, 배급사파워, 소셜미디어가 통계적으로 유의한 결과를 나타내고 있다. 선택확률개념을 이용한 다항로짓모형을 통해 영화 흥행작의 성과에 영향을 미치는 요인을 검증하였으며, 인공신경망, 판별분석과 비교하여 다항로짓모형의 흥행영화 예측력을 입증하였다.

• 응용통계연구
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• 제30권5호
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• pp.701-717
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• 2017

급속한 고령화로 인하여 미래의 인구와 인구구조에 관해 사회와 정부의 관심이 증가하고 있으며 우리나라의 사망률은 감소하고 있으나 감소폭은 변동적이다. 본 연구에서는 이를 고려할 수 있는 모형을 살펴보고자 LC 모형, LM 모형, BMS 모형 그리고 비모수평활 기법이 적용된 FDM과 Coherent FDM을 비교 분석하여 연령별 사망률과 기대수명 예측의 정확성 측면에서 남녀 사망률 개선 추이를 예측하는데 적합한 모형을 살펴보았다. 또한 우리나라 사망률 예측에 비모수 기법의 활용 가능성을 검토하였다. 분석 결과 최근 자료의 추세를 잘 반영하는 비모수기법을 활용한 인구통계모델인 FDM과 Coherent FDM의 예측력이 우수함을 알 수 있었다. 결과적으로 FDM과 Coherent FDM은 적합이 뛰어나고, 미래에 변화가 크지 않다면 예측력 또한 우수하다 볼 수 있을 것이다.

• 한국구조물진단유지관리공학회 논문집
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• 제22권5호
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• pp.39-46
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• 2018

최근 한반도는 동계올림픽 단일팀 참가, 남북정상회담 이후 남북 경제협력 방안이 본격적으로 논의될 것으로 보이고, 도로, 철도 등 남북 주요 인프라에 대한 관심이 커지고 있다. 그리고 대부분의 북한 시설물은 고령화, 노후화 및 유지관리 불량 등 시설물의 안전성과 기능성에 대한 문제점이 제기되고 있다. 이에 본 연구에서는 북한 인프라 개선 및 개발에 대한 새로운 전략을 마련하기 위하여 성능관점의 북한 유지관리 수준을 분석하고 남북 상호 인프라 유지관리 수준을 비교하였다. 본 연구결과, 북한의 도로, 철도 등 국가기반시설과 전력 및 통신, 상하수도 등 생활기반시설의 유지관리가 매우 취약한 것으로 조사되었고, 이에 대한 보수 보강 등 개선이 시급한 것으로 나타났다. 이에 본 연구는 안전과 성능에 대한 평가를 통해 남북 유지관리 수준의 격차를 줄이고, 향후 통합 한반도 안전 및 유지관리 체계를 구축하는데 기초자료로 활용하고자 한다.

• Coupled systems mechanics
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• 제4권1호
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• pp.37-65
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• 2015

Modeling and simulation of mechanical response of infrastructure object, solids and structures, relies on the use of computational models to foretell the state of a physical system under conditions for which such computational model has not been validated. Verification and Validation (V&V) procedures are the primary means of assessing accuracy, building confidence and credibility in modeling and computational simulations of behavior of those infrastructure objects. Validation is the process of determining a degree to which a model is an accurate representation of the real world from the perspective of the intended uses of the model. It is mainly a physics issue and provides evidence that the correct model is solved (Oberkampf et al. 2002). Our primary interest is in modeling and simulating behavior of porous particulate media that is fully saturated with pore fluid, including cyclic mobility and liquefaction. Fully saturated soils undergoing dynamic shaking fall in this category. Verification modeling and simulation of fully saturated porous soils is addressed in more detail by (Tasiopoulou et al. 2014), and in this paper we address validation. A set of centrifuge experiments is used for this purpose. Discussion is provided assessing the effects of scaling laws on centrifuge experiments and their influence on the validation. Available validation test are reviewed in view of first and second order phenomena and their importance to validation. For example, dynamics behavior of the system, following the dynamic time, and dissipation of the pore fluid pressures, following diffusion time, are not happening in the same time scale and those discrepancies are discussed. Laboratory tests, performed on soil that is used in centrifuge experiments, were used to calibrate material models that are then used in a validation process. Number of physical and numerical examples are used for validation and to illustrate presented discussion. In particular, it is shown that for the most part, numerical prediction of behavior, using laboratory test data to calibrate soil material model, prior to centrifuge experiments, can be validated using scaled tests. There are, of course, discrepancies, sources of which are analyzed and discussed.

• 대기
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• 제24권2호
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• pp.131-140
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• 2014

The "Barents Oscillation (BO)", first designated by Paul Skeie (2000), is an anomalous recurring atmospheric circulation pattern of high relevance for the climate of the Nordic Seas and Siberia, which is defined as the second Emperical Orthogonal Function (EOF) of monthly winter sea level pressure (SLP) anomalies, where the leading EOF is the Arctic Oscillation (AO). BO, however, did not attracted much interest. In recent two decades, variability of BO tends to increase. In this study, we analyzed the spatio-temporal structures of Atmospheric internal modes such as Arctic Oscillation (AO) and Barents Oscillation (BO) and examined how these are related with Arctic warming in recent decade. We identified various aspects of BO, not dealt in Skeie (2000), such as upper-level circulation and surface characteristics for extended period including recent decade and examined link with other surface variables such as sea-ice and sea surface temperature. From the results, it was shown that the BO showed more regionally confined spatial pattern compared to AO and has intensified during recent decade. The regional dipolelar structure centered at Barents sea and Siberia was revealed in both sea-level pressure and 500 hPa geopotential height. Also, BO showed a stronger link (correlation) with sea-ice and sea surface temperature especially over Barents-Kara seas suggesting it is playing an important role for recent Arctic amplification. BO also showed high correlation with Ural Blocking Index (UBI), which measures seasonal activity of Ural blocking. Since Ural blocking is known as a major component of Eurasian winter monsoon and can be linked to extreme weathers, we suggest deeper understanding of BO can provide a missing link between recent Arctic amplification and increase in extreme weathers in midlatitude in recent decades.

• Imaging Science in Dentistry
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• 제42권4호
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• pp.231-235
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• 2012

Purpose: This study was performed to evaluate the trabecular pattern on panoramic radiographs to predict age-related osteoporosis in postmenopausal women. Materials and Methods: Thirty-one postmenopausal osteoporotic women and 25 postmenopausal healthy women between the ages of 50 and 88 were enrolled in this study. The bone mineral density (BMD) of the lumbar vertebrae and femur were calculated using dual-energy X-ray absorptiometry (DXA), and panoramic radiographs were obtained. Fractal dimension (FD) was measured using the box counting method from 560 regions of interest ($51{\times}51$ pixels) in 6 sites on the panoramic radiographs. The relationships between age and BMD and between FD and BMD were assessed, and the intraobserver agreement was determined. Results: There was a significant difference in the FD values between the osteoporotic and normal groups (p<0.05). There was a significant difference in the FD values at three sites in the jaws (p<0.05). Age was significantly correlated with the BMD measurements, with an odds ratio of 1.25. However, the FD values were not significantly correlated with the BMD measurements, with an odds ratio of 0.000. The intraobserver agreement showed relatively higher correlation coefficients at the upper premolar, lower premolar, and lower anterior regions than the other sites. Conclusion: Age was an important risk factor for predicting the presence of osteoporosis in postmenopausal women. The lower premolar region was the most appropriate site for evaluating the FD value on panoramic radiographs. However, further investigation might be needed to predict osteoporosis using an FD value on panoramic radiographs.

• 한국사회복지학
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• 제38권
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• pp.180-205
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• 1999

이 연구의 목적은 장애아모의 스트레스에 대한 대처전략과 적응 간의 관계를 정립하는 것이었다. 특히 장애아모의 적응에 영향을 미친다고 알려진 장애아모와 장애자녀의 개인 및 환경적 특성의 영향력을 통제한 상태에서 대처전략의 적응에의 순수한 독립적 영향력을 분석하는 데에 연구의 초점을 두었다. 서울, 창원, 대구의 장애인복지관에 등록된 장애아동의 어머니 92명을 대상으로 한 설문조사 분석결과, 대처전략과 장애아모의 적응간의 유의미한 관계가 입증되었다. Stepwise multiple regression 분석을 통해 밝혀진 장애아모의 적응 예측에 기여한 대처전략은 직면전략, 책임수용 전략 그리고 긍정적 재평가전략이었다. 직면과 책임수용전략은 장애아모의 적응에 부정적인 영향을 미친 반면, 긍정적 재평가전략은 장애아모의 적응에 긍정적인 영향을 미쳤다. 이들 직면, 책임수용, 긍정적 재평가전략의 적응에의 효과는 다른 예측변수의 영향력을 보수적인 방법으로 통제한 상태에서도 통계학적으로 유의미한 것으로 나타났다. 연구결과를 바탕으로 장애아모를 위한 사회사업개입방안이 논의되었다.

• Smart Structures and Systems
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• 제25권6호
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• pp.751-764
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• 2020

Real-time monitoring of stiffness and strength in cement based system has received significant attention in past few decades owing to the development of advanced techniques. Also, use of environment friendly supplementary cementitious materials (SCM) in cement, though gaining huge interest, severely affect the strength gain especially in early ages. Continuous monitoring of strength- and stiffness- gain using an efficient technique will systematically facilitate to choose the suitable time of removal of formwork for structures made with SCM incorporated concrete. This paper presents a technique for monitoring the strength and stiffness evolution in hydrating fly ash blended cement systems using electro-mechanical impedance (EMI) based technique. It is important to observe that the slower pozzolanic reactivity of fly ash blended cement systems could be effectively tracked using the evolution of equivalent local stiffness of the hydrating medium. Strength prediction models are proposed for estimating the strength and stiffness of the fly ash cement system, where curing age (in terms of hours/days) and the percentage replacement of cement by fly ash are the parameters. Evaluation of strength as obtained from EMI characteristics is validated with the results from destructive compression test and also compared with the same obtained from commonly used ultrasonic wave velocity (UPV). Statistical error indices indicate that the EMI technique is capable of predicting the strength of fly ash blended cement system more accurate than that from UPV. Further, the correlations between stiffness- and strength- gain over the time of hydration are also established. From the study, it is found that EMI based method can be effectively used for monitoring of strength gain in the fly ash incorporated cement system during hardening.

• 디지털융복합연구
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• 제18권7호
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• pp.223-228
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• 2020

주가는 사람들의 심리를 반영하고 있으며, 주식시장 전체에 영향을 미치는 요인으로는 경제성장률, 경제지료, 이자율, 무역수지, 환율, 통화량 등이 있다. 국내 주식시장은 전날 미국 및 주변 국가들의 주가지수에 영향을 많이 받고 있으며 대표적인 주가지수가 다우지수, 나스닥, S&P500이다. 최근 주가뉴스를 이용한 주가분석 연구가 활발히 진행되고 있으며, 인공지능 기반한 분석을 통하여 과거 시계열 데이터를 기반으로 미래를 예측하는 연구가 진행 중에 있다. 하지만, 주식시장은 예측시스템에 의해서 단기간 적중이 되더라도, 시장은 더 이상의 단기 전략대로 움직여지지 않고, 새롭게 변할 수밖에 없다. 따라서, 본 모델을 삼성전자 주식데이터와 뉴스 정보를 텍스트 마이닝으로 모니터링하여 분석한 결과를 나타내어 예측이 가능한 모델을 제시하였으며, 향후 종목별 예측을 통하여 실제 예측이 정확한지 확인하여 발전시켜 나갈 예정임.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2013년도 추계학술대회 논문집
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• pp.291-291
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• 2013

The interior vehicle noise due to the exterior aerodynamic field is an important topic in the acoustic design of a car. The air flow detached from the A-pillar and impacting the side windows are of particular interest as they are located close to the driver / passenger and provides a lower insulation index than the trimmed car body parts. HMC is interested in the numerical prediction of this aerodynamic noise generated by the car windows with the final objective of improving the products design and reducing this noise. The methodology proposed in this paper relies on two steps: the first step involves the computation of the exterior flow and turbulence induced non-linear acoustic field using the CAA(Computational aeroacoustics) solver CAA++. The second step consists in the computation of the vibro-acoustic transmission through the side window using the finite element vibro-acoustic solver Actran. The internal air cavity including trim component are included in the simulation. In order to validate the numerical process, an experimental set-up has been created based on a generic car shape. The car body includes the windshield and two side windows. The body is made of aluminum and trimmed with porous layers. First, this paper describes the method including the CAA and the vibro-acoustic models, from the boundary conditions to the different components involved, like the windows, the trims and the car cavity is detailed. In a second step, the experimental set-up is described. In the last part, the vibration of the windshield and windows, the total wind noise level results and the relative contributions of the different windows are then presented and compared to measurements. The influence of the flow yaw angle (different wind orientation) is also assessed.