• 제목/요약/키워드: cloud cover

검색결과 168건 처리시간 0.019초

수평면 전일사량 산출모델이 일사열취득계수 및 창면적비를 고려한 건물 에너지 성능분석에 미치는 영향 (Impact of Horizontal Global Solar Radiation Calculation Modelson Building Energy Performance Analysis Considering Solar Heat Gain Coefficient and Window-to-wall Ratio)

  • 김기한;오기환
    • 한국태양에너지학회 논문집
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    • 제34권1호
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    • pp.39-47
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    • 2014
  • Solar applications analysis and building energy performance depend on the quality of the solar resource data available. Unfortunately, most of the weather stations do not measure solar radiation data in Korea, as a reason many researchers have studied different solar radiation estimation models and suggested to apply them to various locations in Korea. In addition, they also studied the impact of hourly global solar radiation on energy performance of an office building by comparing the simulated building energy consumptions using four different weather files, one using measured, and three estimated solar radiation from different models, which are Cloud-cover Radiation Model (CRM), Zhang and Huang Model (ZHM), and Meteorological Radiation Model (MRM), and concluded that there was some impact on energy performance of the building due to the using different solar radiation models. However, the result cannot be applied to all other buildings since the simulated office building for that study only used limited building characteristics such as using fixed values of solar heat gain coefficient (SHGC) and window-to-wall ratio (WWR), which are significant parameters related to solar radiation that affect to the building energy consumptions. Therefore, there is a need to identify how the building energy consumption will be changed by varying these building parameters. In this study, the impact of one measured and three estimated global solar radiation on energy performance of the office building was conducted taking account of SHGC and WWR. As a result, it was identified that the impact of four different solar radiation data on energy performance of the office building was evident regardless SHGC and WWR changes, and concluded that the most suitable solar models was changed from the CRM/ZHM to the MRM as SHGC and WWR increases.

SYNOP 지상관측자료를 활용한 수치모델 전구 예측성 검증 (Verification of the Global Numerical Weather Prediction Using SYNOP Surface Observation Data)

  • 이은희;최인진;김기병;강전호;이주원;이은정;설경희
    • 대기
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    • 제27권2호
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    • pp.235-249
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    • 2017
  • This paper describes methodology verifying near-surface predictability of numerical weather prediction models against the surface synoptic weather station network (SYNOP) observation. As verification variables, temperature, wind, humidity-related variables, total cloud cover, and surface pressure are included in this tool. Quality controlled SYNOP observation through the pre-processing for data assimilation is used. To consider the difference of topographic height between observation and model grid points, vertical inter/extrapolation is applied for temperature, humidity, and surface pressure verification. This verification algorithm is applied for verifying medium-range forecasts by a global forecasting model developed by Korea Institute of Atmospheric Prediction Systems to measure the near-surface predictability of the model and to evaluate the capability of the developed verification tool. It is found that the verification of near-surface prediction against SYNOP observation shows consistency with verification of upper atmosphere against global radiosonde observation, suggesting reliability of those data and demonstrating importance of verification against in-situ measurement as well. Although verifying modeled total cloud cover with observation might have limitation due to the different definition between the model and observation, it is also capable to diagnose the relative bias of model predictability such as a regional reliability and diurnal evolution of the bias.

정지궤도 기상위성 기반의 지표면 배경온도장 구축 및 지상관측과 지리정보를 활용한 정확도 분석 (Derivation of Geostationary Satellite Based Background Temperature and Its Validation with Ground Observation and Geographic Information)

  • 최대성;김재환;박형민
    • 대한원격탐사학회지
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    • 제31권6호
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    • pp.583-598
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    • 2015
  • 본 연구에서는 천리안위성 기반의 지표면 열적 특성 감시 및 기상현상 탐지에 이용할 수 있는 배경 온도장을 산출하고 지상관측자료 및 지리정보와 비교하여 정확도를 검증하였다. 배경온도장은 밝기온도를 선택하였으며 2012년 자료를 이용하여 월별로 매 시간대에 대해 산출되었다. 밝기온도 자료에서 청천화소와 구름화소를 구별하기 위해 천리안 구름탐지를 사용하였고, 천리안 구름탐지의 입력자료로 사용된 수치모델자료와 공간 균질성 검사 부분에서 구름 오탐지현상을 발견하였다. 과다하게 구름으로 오탐지된 화소는 통계적인 방법에 기반한 구름화소 복원을 통해 해결하였다. 산출된 밝기온도 배경장은 지상관측 기온과 0.95의 상관관계를 보였으며 0.66 K의 편향과 4.88 K의 평균 제곱근 오차를 보였다. 밝기온도 배경장과 고도는 시간대와 계절에 따라 변동성을 보이는 음의 상관관계를 보였다. 녹지와의 상관관계는 기온이 높은 계절 및 주간에 높게 나타났으며, 상관관계의 시간에 따른 변화가 관측되었다. 이러한 이유로 지표면온도 산출 시 시간에 따른 방출률을 별도로 구성해야 할 필요성이 제기되었다.

다중 시나리오에 의한 '클라우드 BIM 기반 협업 설계 지원 시스템'의 사용자 인터페이스 개발 (Multi-Scenario-Based Implementation of User Interface for a Cloud BIM-Based Design Support System)

  • 김진웅;정재환;김성아
    • 한국통신학회논문지
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    • 제42권2호
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    • pp.403-412
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    • 2017
  • BIM 과 ICT 기술이 도입됨에 따라 '클라우드 기반 협업 설계 지원 시스템'에 관한 연구가 활발히 진행되고 있으며 이를 지원하기 위한 새로운 사용자 인터페이스가 필요하게 되었다. 사용자 인터페이스를 개발할 때 실제 사용 시나리오를 기반으로 사용 상황을 예상하고 사용자의 요구사항을 반영할 수 있는 시나리오 기반 디자인 기법을 선택하였다. 하지만 기존의 시나리오 기반 디자인 기법은 귀납적인 방식이기 때문에 이를 통해 사용 시나리오를 작성할 경우에는 모든 사용자의 사용 상황에 대한 대응이 현실적으로 어렵다. 이러한 이유로 귀납적 방식이 아닌 체계적으로 시나리오를 작성하고 수정할 수 있는 새로운 시나리오 작성 기법이 필요하다. 본 연구에서는 기존의 방식을 보완한 다중 시나리오 기반의 디자인 기법을 제안하였고 이를 '클라우드 BIM 기반 협업 설계 지원 시스템'의 사용자 인터페이스 개발 과정에 적용하여 사용성을 검증하였다.

Visual Monitoring System of Multi-Hosts Behavior for Trustworthiness with Mobile Cloud

  • Song, Eun-Ha;Kim, Hyun-Woo;Jeong, Young-Sik
    • Journal of Information Processing Systems
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    • 제8권2호
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    • pp.347-358
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    • 2012
  • Recently, security researches have been processed on the method to cover a broader range of hacking attacks at the low level in the perspective of hardware. This system security applies not only to individuals' computer systems but also to cloud environments. "Cloud" concerns operations on the web. Therefore it is exposed to a lot of risks and the security of its spaces where data is stored is vulnerable. Accordingly, in order to reduce threat factors to security, the TCG proposed a highly reliable platform based on a semiconductor-chip, the TPM. However, there have been no technologies up to date that enables a real-time visual monitoring of the security status of a PC that is operated based on the TPM. And the TPB has provided the function in a visual method to monitor system status and resources only for the system behavior of a single host. Therefore, this paper will propose a m-TMS (Mobile Trusted Monitoring System) that monitors the trusted state of a computing environment in which a TPM chip-based TPB is mounted and the current status of its system resources in a mobile device environment resulting from the development of network service technology. The m-TMS is provided to users so that system resources of CPU, RAM, and process, which are the monitoring objects in a computer system, may be monitored. Moreover, converting and detouring single entities like a PC or target addresses, which are attack pattern methods that pose a threat to the computer system security, are combined. The branch instruction trace function is monitored using a BiT Profiling tool through which processes attacked or those suspected of being attacked may be traced, thereby enabling users to actively respond.

영동지역의 극한 대설에 대한 위성관측으로부터 구름 추적 (Cloud-cell Tracking Analysis using Satellite Image of Extreme Heavy Snowfall in the Yeongdong Region)

  • 조영준;권태영
    • 대한원격탐사학회지
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    • 제30권1호
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    • pp.83-107
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    • 2014
  • 본 연구에서는 겨울철 영동지역에서 2001 ~ 2012(12년) 동안 일신적설 50 cm 이상의 3개 극한 대설사례를 선정하여 위성에서 관측된 구름을 추적하여 공간적 특성을 분석하였다. 그리고 그 특성을 레이더 강수와 비교하였다. 이 연구에서 선정된 영동지역 극한 대설사례는 영동지역(영동 앞바다)에서 발생하여 발달하거나 동한만 부근에서 발생하여 영동지역으로 이동해 들어오는 독립되고 잘 발달된 그리고 크기가 작은 대류형 구름과 관련이 있다. 주강수 시기의 이 구름덩어리의 최저휘도온도는 -$-40{\sim}-50^{\circ}C$로 낮고, 휘도온도 $-35^{\circ}C$ 혹은 $-40^{\circ}C$ 이하의 구름 크기는 약 17,000 ~ 40,000 $km^2$로 중규모 대류복합체($-52^{\circ}C$ 이하 구름크기 50,000 $km^2$)보다 작은 크기이다. 이 때 레이더의 강수면적(0.5 mm/hr 이상)도 약 4,000 ~ 8,000 $km^2$로 작고 독립된 강수 형태를 보인다. 위성의 구름영역과 레이더 강수영역은 영동 앞바다에 비슷하게 위치하였으나 레이더 강수의 중심이 상대적으로 영동 해안에 인접해 위치하였다. 또한 구름이 발달하는 과정에서 구름의 극값과 강수의 극값이 일치하지 않는 경우도 나타났다. 그러나 모든 사례에서 주강수 시기에 구름은 영동 앞바다에 위치하였다. 따라서 구름덩어리의 위치가 극한 대설에 있어 무엇보다 중요한 요소인 것으로 판단된다. 수증기 영상은 건조구역(암역)의 가장자리 북쪽에서 구름덩어리가 발달함을 보여주었다. 따라서 위성관측의 구름영상과 지상 레이더에 의한 강수관측 값과 비교하여 보았을 때, 위에 선정된 극한 대설 사례는 부저기압 혹은 소용돌이의 발달과 관련되어 있는 것으로 생각된다. 영동지역 극한 대설에 대한 초단기 예보에 있어 초기에 동한만 혹은 영동지역에서 작고 발달된 대류형 구름을 탐지하고 추적하는 것이 중요하다.

Automated Water Surface Extraction in Satellite Images Using a Comprehensive Water Database Collection and Water Index Analysis

  • Anisa Nur Utami;Taejung Kim
    • 대한원격탐사학회지
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    • 제39권4호
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    • pp.425-440
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    • 2023
  • Monitoring water surface has become one of the most prominent areas of research in addressing environmental challenges.Accurate and automated detection of watersurface in remote sensing imagesis crucial for disaster prevention, urban planning, and water resource management, particularly for a country where water plays a vital role in human life. However, achieving precise detection poses challenges. Previous studies have explored different approaches,such as analyzing water indexes, like normalized difference water index (NDWI) derived from satellite imagery's visible or infrared bands and using k-means clustering analysis to identify land cover patterns and segment regions based on similar attributes. Nonetheless, challenges persist, notably distinguishing between waterspectralsignatures and cloud shadow or terrain shadow. In thisstudy, our objective is to enhance the precision of water surface detection by constructing a comprehensive water database (DB) using existing digital and land cover maps. This database serves as an initial assumption for automated water index analysis. We utilized 1:5,000 and 1:25,000 digital maps of Korea to extract water surface, specifically rivers, lakes, and reservoirs. Additionally, the 1:50,000 and 1:5,000 land cover maps of Korea aided in the extraction process. Our research demonstrates the effectiveness of utilizing a water DB product as our first approach for efficient water surface extraction from satellite images, complemented by our second and third approachesinvolving NDWI analysis and k-means analysis. The image segmentation and binary mask methods were employed for image analysis during the water extraction process. To evaluate the accuracy of our approach, we conducted two assessments using reference and ground truth data that we made during this research. Visual interpretation involved comparing our results with the global surface water (GSW) mask 60 m resolution, revealing significant improvements in quality and resolution. Additionally, accuracy assessment measures, including an overall accuracy of 90% and kappa values exceeding 0.8, further support the efficacy of our methodology. In conclusion, thisstudy'sresults demonstrate enhanced extraction quality and resolution. Through comprehensive assessment, our approach proves effective in achieving high accuracy in delineating watersurfaces from satellite images.

태양광발전 단기예측모델 개발 (The Development of the Short-Term Predict Model for Solar Power Generation)

  • 김광득
    • 한국태양에너지학회 논문집
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    • 제33권6호
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    • pp.62-69
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    • 2013
  • In this paper, Korea Institute of Energy Research, building integrated renewable energy monitoring system that utilizes solar power generation forecast data forecast model is proposed. Renewable energy integration of real-time monitoring system based on monitoring data were building a database and the database of the weather conditions and to study the correlation structure was tailoring. The weather forecast cloud cover data, generation data, and solar radiation data, a data mining and time series analysis using the method developed models to forecast solar power. The development of solar power in order to forecast model of weather forecast data it is important to secure. To this end, in three hours, including a three-day forecast today Meteorological data were used from the KMA(korea Meteorological Administration) site offers. In order to verify the accuracy of the predicted solar circle for each prediction and the actual environment can be applied to generation and were analyzed.

Comprehensive Survey on Internet of Things, Architecture, Security Aspects, Applications, Related Technologies, Economic Perspective, and Future Directions

  • Gafurov, Khusanbek;Chung, Tai-Myoung
    • Journal of Information Processing Systems
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    • 제15권4호
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    • pp.797-819
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    • 2019
  • Internet of Things (IoT) is the paradigm of network of Internet-connected things as objects that constantly sense the physical world and share the data for further processing. At the core of IoT lies the early technology of radio frequency identification (RFID), which provides accurate location tracking of real-world objects. With its small size and convenience, RFID tags can be attached to everyday items such as books, clothes, furniture and the like as well as to animals, plants, and even humans. This phenomenon is the beginning of new applications and services for the industry and consumer market. IoT is regarded as a fourth industrial revolution because of its massive coverage of services around the world from smart homes to artificial intelligence-enabled smart driving cars, Internet-enabled medical equipment, etc. It is estimated that there will be several dozens of billions of IoT devices ready and operating until 2020 around the world. Despite the growing statistics, however, IoT has security vulnerabilities that must be addressed appropriately to avoid causing damage in the future. As such, we mention some fields of study as a future topic at the end of the survey. Consequently, in this comprehensive survey of IoT, we will cover the architecture of IoT with various layered models, security characteristics, potential applications, and related supporting technologies of IoT such as 5G, MEC, cloud, WSN, etc., including the economic perspective of IoT and its future directions.

Flexible Intelligent Exit Sign Management of Cloud-Connected Buildings

  • Lee, Minwoo;Mariappan, Vinayagam;Lee, Junghoon;Cho, Juphil;Cha, Jaesang
    • International Journal of Advanced Culture Technology
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    • 제5권1호
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    • pp.58-63
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    • 2017
  • Emergencies and disasters can happen any time without any warning, and things can change and escalate very quickly, and often it is swift and decisive actions that make all the difference. It is a responsibility of the building facility management to ensure that a proven evacuation plan in place to cover various worst scenario to handled automatically inside the facility. To mapping out optimal safe escape routes is a straightforward undertaking, but does not necessarily guarantee residents the highest level of protection. The emergency evacuation navigation approach is a state-of-the-art that designed to evacuate human livings during an emergencies based on real-time decisions using live sensory data with pre-defined optimum path finding algorithm. The poor decision on causalities and guidance may apparently end the evacuation process and cannot then be remedied. This paper propose a cloud connected emergency evacuation system model to react dynamically to changes in the environment in emergency for safest emergency evacuation using IoT based emergency exit sign system. In the previous researches shows that the performance of optimal routing algorithms for evacuation purposes are more sensitive to the initial distribution of evacuees, the occupancy levels, and the type and level of emergency situations. The heuristic-based evacuees routing algorithms have a problem with the choice of certain parameters which causes evacuation process in real-time. Therefore, this paper proposes an evacuee routing algorithm that optimizes evacuation by making using high computational power of cloud servers. The proposed algorithm is evaluated via a cloud-based simulator with different "simulated casualties" are then re-routed using a Dijkstra's algorithm to obtain new safe emergency evacuation paths against guiding evacuees with a predetermined routing algorithm for them to emergency exits. The performance of proposed approach can be iterated as long as corrective action is still possible and give safe evacuation paths and dynamically configure the emergency exit signs to react for real-time instantaneous safe evacuation guidance.