• 한국수자원학회논문집
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• 제35권6호
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• pp.817-826
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• 2002

많은 학자들은 자료의 특성을 분석함으로써 장래를 예측하고자 끊임없이 노력하여 왔으며, 이는 아마도 확정론적 방법과 추계학적 방법으로 크게 대별할 수 있을 것이다. 그러나 예측을 하기 전에 먼저 자료의 특성을 파악하는 것은 모형 구축과 예측을 실행하는데 있어서 매우 중요하다 할 수 있다. 이러한 견지에서 최근 확정론적 방법으로 알려진 비선형 동역학적인 방법이 여러 분야에서 관심의 대상이 되고 있다. 본 연구에서는 비선형 동역학 시스템을 해석하기 위하여 Poincare에 의해 제안된 기하학적 방법을 이용하여 기존에 알려진 자료들과 실제 수문자료에 대한 특성을 비교 분석하였으며 자료의 특성에 따른 예측가능성을 판정하였다. 즉, Poincare section을 통해 Poincare map을 구축함으로써 자료의 특성을 파악하여 자료의 선형, 비선형성 뿐만 아니라 자료가 어떤 모형에 적합한지를 판단할 수 있었다.

• 융합경영연구
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• 제11권2호
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• pp.33-46
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• 2023

Purpose: The purpose of this study is to analyze the relationship between characteristics of social media sites (SNS) and the intention of Pakistani tourists to visit South Korea while determining the role of usefulness, interestingness, and involvement of tourists. Research design, data and methodology: A research model was developed through the previous research, and the questioner-based survey was conducted on Pakistani tourists visiting Korea. The survey data was collected by following multiple hypotheses: the relationship between SNS tourism information and perception of SNS, the relationship between SNS perception and intention to visit, and adjustment of involvement in the relation between tourism information characteristics, and SNS perception. We used SPSS and AMOS24.0 statistical tools to analyze the hypothesis testing data. Results: Based on the data analysis, the study found that the characteristics of SNS have a positive effect on intention to visit via users' perception like usefulness and interestingness. The involvement has a moderating effect between SNS characteristics and users' perception. In the group with high involvement, the degree of influence of the quality factor of SNS on user perception was greater than in the group with low involvement. Conclusions: This study demonstrated that traveler's involvement has a moderating effect on the relationship between SNS characteristics and visit intention for Pakistani travelers visiting Korea. It shows that practitioners or researchers should establish and operate SNS strategies in consideration of user involvement.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2004년도 춘계학술대회 논문집
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• pp.255-261
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• 2004

본 논문에서는 진해만에서 수질환경에 대한 현장관측조사를 통하여 진해만 수질현황에 대한 해수유동 시뮬레이션을 실시하여 대상해역의 유통특성을 파악하고, 계산된 유통data를 이용하여 해양오염시뮬레이션을 행하였으며 해수유동시뮬레이션 결과를 해양조사원에서 실시한 조석 및 조류관측 자료를 이용하여 시뮬레이션 결과를 검증하였으며, 유통결과를 해양오염 시뮬레이션의 유통 입력 자료로 이용하였다. 해수유통 Data 및 해양관측 Data를 이용하여 수질확산시뮬레이션을 행하여 실측데이터와 비교분석하여 COD농도 분포를 계산하여서 진해만의 수질특성을 파악하고자 하였다.

• 대한원격탐사학회지
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• 제27권3호
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• pp.389-401
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• 2011

Most nations around the world have expressed significant concern in the climate change due to a rapid increase in green-house gases and thus reach an international agreement to control total amount of these gases for the mitigation of global warming. As the most important absorber of carbon dioxide, one of major green-house gases, forest resources should be more tightly managed with a means to measure their total amount, forest biomass, efficiently and accurately. Forest biomass has close relations with forest areas and tree height. Airborne LiDAR data helps extract biophysical properties on forest resources such as tree height more efficiently by providing detailed spatial information about the wide-range ground surface. Many researchers have thus developed various methods to estimate tree height using LiDAR data, which retain different performance and characteristics depending on forest environment and data characteristics. In this study, we attempted to investigate such various techniques to estimate tree height, elaborate their advantages and limitations, and suggest future research directions. We first examined the characteristics of LiDAR data applied to forest studies and then analyzed methods on filtering, a precedent procedure for tree height estimation. Regarding the methods for tree height estimation, we classified them into two categories: individual tree-based and regression-based method and described the representative methods under each category with a summary of their analysis results. Finally, we reviewed techniques regarding data fusion between LiDAR and other remote sensing data for future work.

• International Journal of Internet, Broadcasting and Communication
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• 제13권1호
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• pp.187-193
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• 2021

In this paper, we propose an image watermarking technique that effectively hides confidential data in the LSB of image pixels by utilizing the characteristics of the image. In the proposed technique, the image is precisely divided into boundary surface and normal region other than the boundary surface and performs different processing. The boundary surface existing in the image is created by meeting different regions and contains important information of the image. One bit of confidential data is concealed in the LSB of the pixel at the boundary surface to preserve the characteristics of the boundary surface. In normal region other than the boundary surface, the pixel values are similar, and the change with the adjacent pixel values is smooth. Based on this property, even if the 2 bits of confidential data are hidden in the lower 2 bits of the pixel in the normal region, the difference cannot be visually distinguished. When confidential data is concealed in an image as described above, the amount of confidential data concealed in an image can be increased while maintaining excellent image quality. Concealing confidential data by applying the proposed method increases the amount of confidential data concealed by up to 84.6% compared to the existing method. The proposed technique can be effectively used for commercial image watermarking that hides copyright information.

• 대한토목학회논문집
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• 제26권4D호
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• pp.661-670
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• 2006

건설 공정계획을 수립함에 있어 시뮬레이션의 제한적인 활용은 시뮬레이션 관련 데이터의 수집과 모델 구축의 어려움에 그 원인을 두고 있다. 본 연구에서는 시뮬레이션 관련 데이터 수집과 분석을 통하여 건설 장비 운영 특성 데이터 축적과 데이터 분포 특성 분석 방법론을 제시하였다. 실제 현장에서 측정한 건설 장비 운영 데이터를 확률 통계적 기법을 적용하여 데이터의 분포 특성을 분석하였으며, 이러한 데이터 축적 및 데이터베이스(DB)화는 시뮬레이션 입력 데이터의 지원과 건설 장비 운영 계획에 다시 사용되어 건설 관련 정보의 효율적 활용이 가능하다.

• 품질경영학회지
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• 제25권1호
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• pp.44-55
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• 1997

In order to determine procedures for a, pp.opriate model selection of technological growth curves, numerous time series that were representative of growth behavior were collected according to data characteristics. Three different growth curve models were fitted onto data sets in an attempt to determine which growth curve models achieved the best forecasts for types of growth data. The analysis of the results gives rise to an a, pp.oach for selecting a, pp.opriate growth curve models for a given set of data, prior to fitting the models, based on the characteristics of the goodness of fit test.

• Journal of Information Technology Applications and Management
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• 제14권3호
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• pp.49-77
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• 2007

Role-based access control (RBAC) models are recently receiving considerable attention as a generalized approach to access control. In line with the increase in applications that deal with spatial data. an advanced RBAC model whose entities and constraints depend on the characteristics of spatial data is required. Even if some approaches have been proposed for geographic information systems. most studies focus on the location of users instead of the characteristics of spatial data. In this paper. we extend the traditional RBAC model in order to deal with the characteristics of spatial data and propose new spatial constraints. We use the object-oriented modeling based on open GIS consortium geometric model to formalize spatial objects and spatial relations such as hierarchy relation and topology relation. As a result of the formalization for spatial relations. we present spatial constraints classified according to the characteristics of each relation. We demonstrate our extended-RBAC model called OOGIS-RBAC and spatial constraints through case studies. Finally. we compare our OOGIS-RBAC model and the DAC model in the management of access control to prove the efficiency of our model.

• Earthquakes and Structures
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• 제2권2호
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• pp.189-206
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• 2011

In this study, the subspace stochastic realization theories (SSR model I and SSR model II) have been applied to a real bridge for estimating its dynamic characteristics (natural frequencies, damping constants, and vibration modes) under ambient vibration. A numerical simulation is carried out for an arch-type steel truss bridge using a white noise excitation. The estimates obtained from this simulation are compared with those obtained from the Finite Element (FE) analysis, demonstrating good agreement and clarifying the excellent performance of this method in estimating the structural dynamic characteristics. Subsequently, these methods are applied to the vibration induced by both strong and weak winds as obtained by remote monitoring of the Kabashima bridge (an arch-type steel truss bridge of length 136 m, and situated in Nagasaki city). The results obtained with this experimental data reveal that more accurate estimates are obtained when strong wind vibration data is used. In contrast, the vibration data obtained from weak wind provides accurate estimates at lower frequencies, and inaccurate accuracy for higher modes of vibration that do not get excited by the wind of lower intensity. On the basis of the identified results obtained using both simulated data and monitored data from a real bridge, it is determined that the SSR model II realizes more accurate results than the SSR model I. In general, the approach investigated in this study is found to provide acceptable estimates of the dynamic characteristics of highway bridges as well as for the vibration monitoring of bridges.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 1999년도 Proceedings of International Symposium on Remote Sensing
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• pp.132-134
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• 1999

Rainfall characteristics for designing the optimum millimeter-wave communication systems from two rainfall data set was analyzed. Two rainfall data sets were compared; one-minute rainfall rate data, one-hour synoptic observation data. Each data set has different observation method, sampling frequency. We looked for tendency and quality confluence between two data sets. We showed several results using one-minute rainfall data by millimeter-wave attenuation model. A climatological one-minute rainfall rate data set over Korean Peninsula will be made after data quality control procedure