• 대한원격탐사학회지
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• 제37권4호
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• pp.815-831
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• 2021

Drought forecasting is crucial to minimize the damage to food security and water resources caused by drought. Satellite-based drought research has been conducted since 1980s, which includes drought monitoring, assessment, and prediction. Unlike numerous studies on drought monitoring and assessment for the past few decades, satellite-based drought forecasting has gained popularity in recent years. For successful drought forecasting, it is necessary to carefully identify the relationships between drought factors and drought conditions by drought type and lead time. This paper aims to provide an overview of recent research trends and challenges for satellite-based drought forecasts focusing on lead times. Based on the recent literature survey during the past decade, the satellite-based drought forecasting studies were divided into three groups by lead time (i.e., short-term, sub-seasonal, and seasonal) and reviewed with the characteristics of the predictors (i.e., drought factors) and predictands (i.e., drought indices). Then, three major challenges-difficulty in model generalization, model resolution and feature selection, and saturation of forecasting skill improvement-were discussed, which led to provide several future research directions of satellite-based drought forecasting.

• 한국의류산업학회지
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• 제18권1호
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• pp.103-112
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• 2016

This research was designed to figure out the perception and attitude of university students toward urban outdoor wear and to provide the guidelines for product quality improvement using Kano model. A total of 270 responses were analyzed by SPSS 20.0 through frequency and factor analysis. Respondents' levels for outdoor activity & outdoor products possession being still low, steady growth in urban outdoor wear market is expected. A total of eight quality factors were identified through factor analysis; suitability, production quality, functionality, ease of care, fabric performance, portability, fashionability, and symbolism. Based on Kano model, quality factors of urban outdoor wear were categorized into three groups: one-dimensional; indifferent; and must-be quality factor. It was found that consumers were satisfied with urban outdoor wear only when it meets the needs for suitability for body types and ease of care, meaning that manufactures should be cautious not to lose these features. Being must-be quality factor, production quality(form stability, quality of subsidiary materials), and fabric performance such as colorfastness should be basically satisfied. The relative importance of each quality feature on satisfaction/dissatisfaction was investigated using CSC(customer satisfaction coefficient). Based on the CSC, every item was classified again. Attractive quality features with large CSC were shown in suitability factor. Must-be quality features with small CSC were mainly shown in functionality and fabric performance factors. These findings imply that manufactures of urban outdoor wear should not only maintain the production quality but also focus on suitability features to differentiate their product with previous products.

• 한국건설관리학회논문집
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• 제22권2호
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• pp.63-71
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• 2021

국내 기업의 해외 건설 수주는 지속적으로 성장하고 양적성장을 이루어왔지만, 2011년 유가하락에 이어 최근 COVID-19의 장기화 등 대외환경의 불확실성이 커지며 해외 건설 시장의 침체가 전망된다. 이에 4차 산업혁명의 발전된 기술을 활용해 그간 축적된 데이터를 연구한다면, 향후 해외 건설사업 관리의 역량 및 경쟁력을 키울 수 있을 것이다. 따라서 이 연구에서는 중동 건설시장에서 공정지연과 주요 분쟁의 원인으로 대두되고 있는 공사변경의 상향된 프로젝트 관리 방안을 제시하고자 하였다. 우선 실제 해외 플랜트 건설사례를 분석하여 6가지 주요 공사변경 원인을 도출하였고, 이에 따라 영향을 받는 요인을 8가지로 분류하였다. 특히 머신러닝 기반의 다양한 Feature Selection 기법을 활용해 중요도를 계량화된 수치를 평가함으로써 공사변경과 영향 요인 사이의 유의미한 관계를 파악 하였다. 이를 통해 프로젝트 관리 측면에서 내부적으로는 공사변경의 명확한 관리 방향 수립이 가능하고, 대외적으로는 협상 기간 단축으로 추가적인 공기 지연을 방지하고 비용지출 관리가 가능할 것이라고 판단된다.

• 한국농촌건축학회논문집
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• 제21권4호
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• pp.9-16
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• 2019

This study aims to identify the rural spatial structure and to establish the planning characteristics based on urban-rural connections strategy of North Korea. For this purpose, they were collected such as documents and drawings including primary data related to rural planning in North Korea, and the rural space were classified into three elements in order to analyze them by the rural planning's point of the view. Unlike generalized capitalist cities, socialist North Korean cities are characterized by the coexistence of urban and rural areas. This distinct feature of the city is also reflected in creating rural space in North Korea. Thus, The urban-rural integration in spatial planning is a key factor in understanding the spatial structure of North Korea. This study firstly examines the characteristics of the county(gun), the administrative and economic unit established in the post-war period, secondly, examines the planning method of town(eup) which can be called the urban center in rural areas, and lastly grasps the planning method of rural village focusing on collectivization and identifies how they are connected to the town for the shake of urban-rural integration. As a result, the characteristics of rural planning in North Korea has revealed that it has a comprehensive rural planning established with the goal of strengthening the self-sufficiency of the rural area by the means of the create of rural spatial hierarchy in the whole country.

• 한국조경학회지
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• 제35권2호통권121호
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• pp.25-36
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• 2007

This case study offers fundamental data for the research and construction of future of water. It also provides an understanding of the design and characteristics of the existing water bodies in urban parks. This study was begun by conducting field research on the completion of the construction of 67 different urban parks located in the downtown areas of the following cities: Gimhae, Yangsan, Changwon, Masan, and Jinju. The field research was conducted from July to October of 2006. Additional research was performed in July of 2007. Construction trends were examined and the design and characteristics of the types of locations, shapes, scales, materials, and added objects for the enhancement of recreational value of the 31 water bodies constructed in 18 urban parks out of the 67 were analyzed. According to the results of the study, the most common design feature was a fountain that shot up. The bodies of water were designed by using a simple technique in accordance with the basic principles of location, shape, size, materials, and added objects for the enhancement of recreational value, with the exception of a few different factors in the research subjects. In conclusion, it can be recommended that further research be conducted in the consideration and various plans of location, shape, size, materials, and added objects for the enhancement of recreational value of future constructions of water bodies in urban parks in order to offer a more pleasant environment to the users.

• Asian Journal of Atmospheric Environment
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• 제5권1호
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• pp.29-40
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• 2011

In this study, the effects of an urban thermal environment on air quality were investigated using hourly surface weather observation data and air quality data over six summers from 2000 to 2005 in two cities on the Korean Peninsula. One, the city of Daegu, is representative of basin topography and the other, the city of Busan, represents a coastal area. It is known that the characteristics of an urban thermal environment are represented as an "urban heat island". Here, we focus on the nighttime urban thermal environment, which is called a "tropical night", during the summer. On tropical nights in Busan, the temperature and cloud cover levels were higher than on non-tropical nights. Wind speed did not appear to make a difference even on a tropical night. However, the frequency of southwestern winds from the sea was higher during tropical nights. The prevailing southwest winds in all areas meant an inflow of air from the sea. So at most of the air quality stations, the ozone concentration during tropical nights was lower than during non-tropical nights. In Daegu, the tropical nights had higher temperatures and cloud covers. Despite these higher temperatures, the ozone concentration during the tropical nights was lower than that on non-tropical nights at most of the air quality stations. This feature was caused by low irradiance, which in turn caused an increased cloud cover. Wind speed was stronger during the tropical nights and dispersed the air pollutants. These meteorological characteristics of the tropical nights reduced ozone concentrations in the Daegu Basin.

• 대한원격탐사학회지
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• 제36권1호
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• pp.15-27
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• 2020

Accurate knowledge of land use/land cover (LULC) features and their relative changes over upon the time are essential for sustainable urban management. Urban sprawl growth has been always also a worldwide concern that needs to carefully monitor particularly in a developing country where unplanned building constriction has been expanding at a high rate. Recently, remotely sensed imageries with a very high spatial/spectral resolution and state of the art machine learning approaches sent the urban classification and growth monitoring to a higher level. In this research, we classified the Quickbird satellite imagery by object-based image analysis of Dempster-Shafer (OBIA-DS) for the years of 2002 and 2015 at Karbala-Iraq. The real LULC changes including, residential sprawl expansion, amongst these years, were identified via change detection procedure. In accordance with extracted features of LULC and detected trend of urban pattern, the future LULC dynamic was simulated by using land transformation model (LTM) in geospatial information system (GIS) platform. Both classification and prediction stages were successfully validated using ground control points (GCPs) through accuracy assessment metric of Kappa coefficient that indicated 0.87 and 0.91 for 2002 and 2015 classification as well as 0.79 for prediction part. Detail results revealed a substantial growth in building over fifteen years that mostly replaced by agriculture and orchard field. The prediction scenario of LULC sprawl development for 2030 revealed a substantial decline in green and agriculture land as well as an extensive increment in build-up area especially at the countryside of the city without following the residential pattern standard. The proposed method helps urban decision-makers to identify the detail temporal-spatial growth pattern of highly populated cities like Karbala. Additionally, the results of this study can be considered as a probable future map in order to design enough future social services and amenities for the local inhabitants.

• Journal of Platform Technology
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• 제11권3호
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• pp.24-31
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• 2023

최근, 도시 교통체계 운항으로 수직이착륙이 가능한 UAM(Urban Air Mobility, UAM)의 관심이 고조되고 있다. 따라서 첨단 기술이 적용된 친환경 미래형 교통수단으로 다양한 스타트업 기업에서 관련 기술들을 개발하고 있다. 하지만, UAM의 운항에서 안전성을 높일 수 있는 방안들에 관한 연구들은 아직 미미한 편이다. 특히, 자율주행이 탑재된 UAM이 도심에서의 착륙을 시도하는 과정에서 발생되는 위험에 대한 안전성을 향상시킬 수 있는 노력이 더욱 절실하다. 이에, 본 연구에서는, 도심에서 자율주행 UAM이 착륙을 시도 할 때, 방해가 되는 위험영역을 회피하여 안전하게 착륙할 수 있도록 하는 방안을 제안한다. 이를 위하여, 먼저, UAM의 센서에 의해 관측되는 위험물들의 위도 및 경도 좌표값을 산출하고, 이를 바탕으로, 3차원 영상에서 왜곡이 고려된 평면 영상의 좌표를 위도와 경도로 변환한 후 산출된 위도와 경도를 이용하여 미리 학습된 특징 서술자와HOG(Histogram of Oriented Gradients, HOG) 특징 서술자와의 비교하여 위험영역을 추출하는 방안을 제안한다. 위험영역을 완벽히 추출할 수는 없었지만 대체적으로 만족할 만한 결과를 얻을 수 있었다. 이에, 제안된 연구 방법이 자율주행 기술이 탑재된 UAM의 이착륙장 선정에 따른 막대한 비용을 줄이고, 도심과 같은 복잡한 환경에서 착륙을 시도할 때 위험성을 감소시키고 안전성을 높이기 위한 기초적인 방안에 기여할 것으로 사료된다.

• 제어로봇시스템학회논문지
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• 제22권10호
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• pp.803-810
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• 2016

This paper presents a study of localization methods based on particle filter using 2D laser sensor measurements and road feature map information, for autonomous vehicles. In order to navigate in an urban environment, an autonomous vehicle should be able to estimate the location of the ego-vehicle with reasonable accuracy. In this study, road features such as curbs and road markings are detected to construct a grid-based feature map using 2D laser range finder measurements. Then, we describe a particle filter-based method for accurate positional estimation of the autonomous vehicle in real-time. Finally, the performance of the proposed method is verified through real road driving experiments, in comparison with accurate DGPS data as a reference.

• Journal of Ubiquitous Convergence Technology
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• 제1권1호
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• pp.9-17
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• 2007

Feature based stereo matching is an effective way to perform 3D building reconstruction. However, in urban scene, the cluttered background and various building structures may interfere with the performance of building reconstruction. In this paper, we propose a novel method to robustly reconstruct buildings on the basis of rectangle regions. Firstly, we propose a multi-scale linear feature detector to obtain the salient line segments on the object contours. Secondly, candidate rectangle regions are extracted from the salient line segments based on their local information. Thirdly, stereo matching is performed with the list of matching line segments, which are boundary edges of the corresponding rectangles from the left and right image. Experimental results demonstrate that the proposed method can achieve better accuracy on the reconstructed result than pixel-level stereo matching.