• Title/Summary/Keyword: spatial approach

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Development for Prediction Model of Disaster Risk through Try and Error Method : Storm Surge (시행 착오법을 활용한 재난 위험도 예측모델 개발 : 폭풍해일)

  • Kim, Dong Hyun;Yoo, HyungJu;Jeong, SeokIl;Lee, Seung Oh
    • Journal of Korean Society of Disaster and Security
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    • v.11 no.2
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    • pp.37-43
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    • 2018
  • The storm surge is caused by an typhoons and it is not easy to predict the location, strength, route of the storm. Therefore, research using a scenario for storms occurrence has been conducted. In Korea, hazard maps for various scenarios were produced using the storm surge numerical simulation. Such a method has a disadvantage in that it is difficult to predict when other scenario occurs, and it is difficult to cope with in real time because the simulation time is long. In order to compensate for this, we developed a method to predict the storm surge damage by using research database. The risk grade prediction for the storm surge was performed predominantly in the study area of the East coast. In order to estimate the equation, COMSOL developed by COMSOL AB Corporation was utilized. Using some assumptions and limitations, the form of the basic equation was derived. the constants and coefficients in the equation were estimated by the trial and error method. Compared with the results, the spatial distribution of risk grade was similar except for the upper part of the map. In the case of the upper part of the map, it was shown that the resistance coefficient, k was calculated due to absence of elevation data. The SIND model is a method for real-time disaster prediction model and it is expected that it will be able to respond quickly to disasters caused by abnormal weather.

Urban Street Planting Scenarios Simulation for Micro-scale Urban Heat Island Effect Mitigation in Seoul (미시적 열섬현상 저감을 위한 도시 가로수 식재 시나리오별 분석 - 서울시를 대상으로 -)

  • Kwon, You Jin;Lee, Dong Kun;Ahn, Saekyul
    • Journal of Environmental Impact Assessment
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    • v.28 no.1
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    • pp.23-34
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    • 2019
  • Global warming becomes a serious issue that poses subsidiary issues like a sea level rise or a capricious climate over the world. Because of severe heat-wave of the summer in Korea in 2016, a big attention has been focused on urban heat island since then. Not just about heat-wave itself, many researches have been concentrated on how to adapt in this trendy warming climate and weather in a small scope. A big part of existing studies is mitigating "Urban Heat Island effect" and that is because of huge impervious surface in urban area where highly populated areas do diverse activities. It is a serious problem that this thermal context has a high possibility causing mortality by heat vulnerability. However, there have been many articles of a green infrastructures' cooling impact in summer. This research pays attention to measure cooling effect of a street planting considering urban canyon and type of green infrastructures in neighborhood scale. This quantitative approach was proceeded by ENVI-met simulation with a spatial scope of a commercial block in Seoul, Korea. We found the dense double-row planting is more sensitive to change in temperature than that of the single-row. Among the double-row planting scenarios, shrubs which have narrow space between the plant and the land surface were found to store heat inside during the daytime and prevent emitting heat so as to have a higher temperature at night. The quantifying an amount of vegetated spaces' cooling effect research is expected to contribute to a study of the cost and benefit for the planting scenarios' assessment in the future.

An Approach to Conceal Hangul Secret Message using Modified Pixel Value Decomposition (수정된 화소 값 분해를 사용하여 한글 비밀 메시지를 숨기는 방법)

  • Ji, Seon-su
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.14 no.4
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    • pp.269-274
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    • 2021
  • In secret communication, steganography is the sending and receiving of secret messages without being recognized by a third party. In the spatial domain method bitwise information is inserted into the virtual bit plane of the decomposed pixel values of the image. That is, the bitwise secret message is sequentially inserted into the least significant bit(LSB) of the image, which is a cover medium. In terms of application, the LSB is simple, but has a drawback that can be easily detected by a third party. If the upper bit plane is used to increase security, the image quality may deteriorate. In this paper, I present a method for concealing Hangul secret messages in image steganography based on the lo-th bit plane and the decomposition of modified pixel intensity values. After decomposing the Hangeul message to be hidden into choseong, jungseong and jongseong, then a shuffling process is applied to increase confidentiality and robustness. PSNR was used to confirm the efficiency of the proposed method. It was confirmed that the proposed technique has a smaller effect in terms of image quality than the method applying BCD and Fibonacci when inserting a secret message in the upper bit plane. When compared with the reference value, it was confirmed that the PSNR value of the proposed method was appropriate.

A Study on the Meaning of School Space: Criticism and Alternatives (학교 공간에 관한 의미 탐색: 비판과 대안)

  • Kim, Dal-Hyo
    • Journal of the Korean Institute of Educational Facilities
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    • v.26 no.4
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    • pp.3-10
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    • 2019
  • In school facilities, space is the basic framework. The structure and arrangement of space will provide the form and feel of school facilities. In order to become a high-quality school facility, it is necessary to focus on the educational, human and ecological aspects of the instructor and learner until the space is conceived, designed and completed. However, even when public education was introduced in the past, it did not become a school space considering this aspect. The school space, which focuses on efficiency and labor production, is a school space that reflects the characteristics of a factory-type school, which has been occupied by a large number until recently. Although efforts to improve the quality of school facilities have been attempted in recent years, there is also a need to pursue more active changes. Future-oriented and progressive school spaces include flexibility, connectivity, individualization, diversity(creativity). In other words, space should be flexible so that it can be used faithfully according to the educational situation, not the fixed and limited school space as in the past. In the future, the school space should be open and securely linked to the place where it is essential to complete community relations with the community. In addition, space should be flexible so that the school can meet the needs of each student as much as possible. And the school space should be transformed from the space design of the past fixed pattern to reflect the close relationship between spatial, psychological, physiological, and behavioral areas. When school space needs to shift away from the past and change in a new future-oriented direction, the remaining tasks should be presented with specific characteristics and content of the direction. And the function of the consignment should be handled by related research. Although the text of this study reveals the characteristics of future-oriented school space, more concrete and empirical research results should be presented by subsequent research at home and abroad. It is necessary to reduce trial and error in creating a future-oriented school space where both professors and learners can be satisfied by analyzing the common points and differences between the results of the study. In order to do this, it is necessary to make efforts to approach such research based on the participation of the subjects who teach and learn directly at the school site.

Seismic Performance Evaluation of Concrete Anchors used in Power Plant Equipment by Shaking Table Tests (진동대 실험을 통한 발전기기용 콘크리트 앵커의 성능평가)

  • Lee, Sang-Moon;Jeon, Bub-Gyu;Jung, Woo-Young
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.41 no.1
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    • pp.21-28
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    • 2021
  • The main purpose of this study is to assess the safety of the fixed anchorages subjected to the seismic motion for an operating facilities in the actual power plant. Thus, the experimental study was conducted to investigate the load response in the event of an actual seismic to the anchorages of a nonstructural components. Since there are economic and spatial constraints to study nonstructural components that actually have various forms, alternative test specimens of steel frames with mass were built and the shaking table test was carried out. In order to evaluate the dynamic characteristics and seismic performance, the natural frequency of the target structure was identified through the shaking table test and then the load response characteristics of the anchorage were evaluated by generating an artificial seismic effect like actual seismic. Finally, the structural stiffness was reinforced by fixing the steel frame to the test specimen using bolts, thereby reducing the load transmitted to the anchorage. It will be carried out on the reliability verification of the experiments and areas that have not been carried out due to the site conditions through the analytical approach in the future.

Development of Snow Depth Frequency Analysis Model Based on A Generalized Mixture Distribution with Threshold (최심신적설량 빈도분석을 위한 임계값을 가지는 일반화된 혼합분포모형 개발)

  • Kim, Ho Jun;Kim, Jang-Gyeong;Kwon, Hyun-Han
    • Journal of Korean Society of Disaster and Security
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    • v.13 no.4
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    • pp.25-36
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    • 2020
  • An increasing frequency and intensity of natural disasters have been observed due to climate change. To better prepare for these, the MOIS (ministry of the interior and safety) announced a comprehensive plan for minimizing damages associated with natural disasters, including drought and heavy snowfall. The spatial-temporal pattern of snowfall is greatly influenced by temperature and geographical features. Heavy snowfalls are often observed in Gangwon-do, surrounded by mountains, whereas less snowfall is dominant in the southern part of the country due to relatively high temperatures. Thus, snow depth data often contains zeros that can lead to difficulties in the selection of probability distribution and estimation of the parameters. A generalized mixture distribution approach to a maximum snow depth series over the southern part of Korea (i.e., Changwon, Tongyeoung, Jinju weather stations) are located is proposed to better estimate a threshold (𝛿) classifying discrete and continuous distribution parts. The model parameters, including the threshold in the mixture model, are effectively estimated within a Bayesian modeling framework, and the uncertainty associated with the parameters is also provided. Comparing to the Daegwallyeong weather station, It was found that the proposed model is more effective for the regions in which less snow depth is observed.

Technology Development for Non-Contact Interface of Multi-Region Classifier based on Context-Aware (상황 인식 기반 다중 영역 분류기 비접촉 인터페이스기술 개발)

  • Jin, Songguo;Rhee, Phill-Kyu
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.20 no.6
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    • pp.175-182
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    • 2020
  • The non-contact eye tracking is a nonintrusive human-computer interface providing hands-free communications for people with severe disabilities. Recently. it is expected to do an important role in non-contact systems due to the recent coronavirus COVID-19, etc. This paper proposes a novel approach for an eye mouse using an eye tracking method based on a context-aware based AdaBoost multi-region classifier and ASSL algorithm. The conventional AdaBoost algorithm, however, cannot provide sufficiently reliable performance in face tracking for eye cursor pointing estimation, because it cannot take advantage of the spatial context relations among facial features. Therefore, we propose the eye-region context based AdaBoost multiple classifier for the efficient non-contact gaze tracking and mouse implementation. The proposed method detects, tracks, and aggregates various eye features to evaluate the gaze and adjusts active and semi-supervised learning based on the on-screen cursor. The proposed system has been successfully employed in eye location, and it can also be used to detect and track eye features. This system controls the computer cursor along the user's gaze and it was postprocessing by applying Gaussian modeling to prevent shaking during the real-time tracking using Kalman filter. In this system, target objects were randomly generated and the eye tracking performance was analyzed according to the Fits law in real time. It is expected that the utilization of non-contact interfaces.

Interpretive Approaches to the Characteristics of Neighborhood Environment Using Qualitative GIS of the Elderly's Outdoor Activities - Focused on the Musugol, a Low-Income Elderly Concentrated Area in Seoul - (노인층 옥외활동의 질적 GIS를 활용한 근린환경 특성의 해석 - 서울시 저소득 노인밀집지역 무수골을 대상으로 -)

  • Yun, Ye-Hwa;Sung, Jong-Sang
    • Journal of the Korean Institute of Landscape Architecture
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    • v.50 no.3
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    • pp.1-18
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    • 2022
  • Prior studies have shown positive effects of outdoor activities on the elderly's physical, mental and social health. 'Active aging' and 'age-friendly' neighborhood can be created by modifying the experiences and perceptions of the outdoor environment. This study aims to investigate the outdoor activities of the elderly living in a low-income elderly concentrated area and their perception of the neighborhood environment. We also explored the context of interactions between the facilitators and inhibitors of outdoor activities on the basis of temporal, spatial, and social conditions. We used a mixed method approach by collecting two different types of qualitative GIS data : observation maps of the main places and individual cognitive maps with in-depth interviews. The observational map analysis indicated that the preferred places and activity patterns differ by age, gender, and size of the group. The cognitive map and interviews demonstrated that the elderly's activity goals and perception of the landscape differ by places such as forests, parks, streams, open-spaces, vegetable gardens, and alleys. The elderly's desire for outdoor activities can be better fulfilled when their front doors and alleys are well-connected to an open-sight pleasant space. Familiarity is an important factor for the elderly, therefore it is important to remove the psychological and physical barriers by increasing the legibility and accessibility of places. In addition, social interactions and conflicts can have a significant influence on the elderly's occupation of space in the neighborhood environment.

Training Performance Analysis of Semantic Segmentation Deep Learning Model by Progressive Combining Multi-modal Spatial Information Datasets (다중 공간정보 데이터의 점진적 조합에 의한 의미적 분류 딥러닝 모델 학습 성능 분석)

  • Lee, Dae-Geon;Shin, Young-Ha;Lee, Dong-Cheon
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.40 no.2
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    • pp.91-108
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    • 2022
  • In most cases, optical images have been used as training data of DL (Deep Learning) models for object detection, recognition, identification, classification, semantic segmentation, and instance segmentation. However, properties of 3D objects in the real-world could not be fully explored with 2D images. One of the major sources of the 3D geospatial information is DSM (Digital Surface Model). In this matter, characteristic information derived from DSM would be effective to analyze 3D terrain features. Especially, man-made objects such as buildings having geometrically unique shape could be described by geometric elements that are obtained from 3D geospatial data. The background and motivation of this paper were drawn from concept of the intrinsic image that is involved in high-level visual information processing. This paper aims to extract buildings after classifying terrain features by training DL model with DSM-derived information including slope, aspect, and SRI (Shaded Relief Image). The experiments were carried out using DSM and label dataset provided by ISPRS (International Society for Photogrammetry and Remote Sensing) for CNN-based SegNet model. In particular, experiments focus on combining multi-source information to improve training performance and synergistic effect of the DL model. The results demonstrate that buildings were effectively classified and extracted by the proposed approach.

Research on the Urban Green Space Connection Paths forthe Enhancement of Ecological Function - Focused on Suwon - (녹지축의 생태적 기능 강화를 위한 도시녹지 연결경로 도출 연구 - 수원시 대상 -)

  • Choi, Jaeyeon;Kim, Suryeon;Park, Chan;Song, Wonkyong;Jung, Kyungmin;Kim, Eunyoung
    • Journal of Environmental Impact Assessment
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    • v.31 no.4
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    • pp.201-213
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    • 2022
  • Creation and administration of green space are emphasized to solve the environmental problem and the management of green space in urban area. Urban area with high development pressure faces green space fragmentation, so the planned approach is needed to improve the continuity of green space. However, the current institutional green axis, used to enhance continuity of urban space is merely an abstract concept under the master plan so that is not a consistent framework for urban green continuity providing no detailed information such as position and path. Therefore, in order to consistently manage green space in continuous point of view, it is insufficient not being connected to each individual green space development projects. This study proposes a method for finding the connection path to enhance urban green space continuity. This proposed method consists of two phases. First phase is finding nodes to connect current green space and second is to calculate the least cost path. We calculate connection cost using NDMI (Normalized Difference Moisture Index), impervious ratio and official land cost, applying to Suwon city and potential greening site that was planned in official master plan. According to the results, we confirm a possibility of finding a cost-effective connection path with detailed spatial information instead of unrealistic abstract concepts and discuss worth applying to a legally plan and policy.