• 제목/요약/키워드: Synthetic Environments

검색결과 104건 처리시간 0.027초

고해상도 SAR 영상의 활용기술 동향분석 (Investigation of Applications Technology for High Resolution SAR Images)

  • 윤근원;고진우;이용웅
    • 한국군사과학기술학회지
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    • 제13권1호
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    • pp.105-113
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    • 2010
  • SAR(Synthetic Aperture Radar) has characteristics well-suited for the measurement of geophysical parameters during day and night in all weather conditions. Recently, SAR data with high resolution acquired by satellites became available to the public. In such data, many features and phenomena of geometric structure of man-made objects and natural environments become observable. In this paper, we discuss main considerations including geometric distortion and coregistration for efficient utilization of high resolution SAR images. And, various advanced technologies in SAR application fields are introduced.

주민 의식에 나타난 주거환경의 쾌적성에 관한 연구 -공동주택단지의 주거환경의 질을 중심으로- (A Study on the Amenity of the Residential Environments reflected on the Residents : with a focus on the Environmental Quality of the Multi-Family Housing Estates)

  • 이재준;황기원
    • 한국조경학회지
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    • 제25권1호
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    • pp.3-17
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    • 1997
  • The purpose of this study is to suggest an Amenity Meaning of the residential Environment reflected on the Residents. It focuses on the Environmental Quality through interviews and surveys of Multi-Family Housing Estates. The demand of Amenity as Environmental Quality of the Residential Environment will increase significantly in a short period of time. The Amenity Meaning fuses psychological and material elements, Also, these relate synthetic Environmental Qualities with Naturally Friendly Housing Estates. Thus, this paper may be used primarily by researchers, housing developers who may wish to incorporate the environmental quality of housing development.

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철산화물의 합성 및 이를 이용한 비소의 흡착제거 (Synthesis of Iron Oxide and Adsorption of Arsenic on Iron Oxide)

  • 김연정;최식영;김영훈
    • 한국환경과학회지
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    • 제28권1호
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    • pp.99-106
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    • 2019
  • Arsenic is among the heavy metals commonly found in aqueous environments. Iron oxide is known as an efficient adsorbent for the arsenic. A new synthetic method was applied to provide iron oxide giving a large specific surface area. The mixing method affects the formation of iron oxide. Ultrasonic waves assisted the formation of very fine iron oxide in an organic phase. The synthesized iron oxide is amorphous type with a high surface area of more than $181.3m^2/g$. Sorption capacity of the synthesized adsorbent was relatively very high for arsenic and varied depending on the oxidation state of arsenic: a higher capacity was obtained with As(V). Lower solution pH provided a higher sorption capacity for As(V). The competitive effect of co-exist anions such as chloride, nitrate, and sulfate was minimal in sorption capacity of the iron oxide for arsenic.

원격지 공간 가상 휴먼 가이드 영향 분석 (Effects on the Virtual Human Guide of Remote Sites)

  • Chung, Jin-Ho;Jo, Dongsik
    • 한국정보통신학회논문지
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    • 제26권8호
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    • pp.1255-1258
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    • 2022
  • Recently, immersive VR/AR contents have actively increased, and various services related to VR/AR allow users to experience remote places. For example, if failure situations occur frequently in factory of the remote site, mixed reality (MR) with a synthetic virtual human expert in reconstructed remote location can help immediate maintenance task with interaction between the operator and the virtual expert. In this paper, we present a technique for synthesizing the virtual human after capturing a 360-degree panorama of a remote environment, and analyze the effects to apply a method of guiding virtual human by interaction types. According to this paper, it was shown that co-presence level significantly increased when verbal, facial expression, and non-verbal animation of the virtual human was all expressed.

모바일 자율 주행 로봇의 지면 표현을 위한 확장된 적응형 역투영 맵핑 방법 (Extended and Adaptive Inverse Perspective Mapping for Ground Representation of Autonomous Mobile Robot)

  • 박주용;조영근
    • 로봇학회논문지
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    • 제18권1호
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    • pp.59-65
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    • 2023
  • This paper proposes an Extended and Adaptive Inverse Perspective Mapping (EA-IPM) model that can obtain an accurate bird's-eye view (BEV) from the forward-looking monocular camera on the sidewalk with various curves. While Inverse Perspective Mapping (IPM) is a good way to obtain ground information, conventional methods assume a fixed relationship between the camera and the ground. Due to the nature of the driving environment of the mobile robot, there are more walking environments with frequent motion changes than flat roads, which have a fatal effect on IPM results. Therefore, we have developed an extended IPM process to be applicable in IPM on sidewalks by adding a formula for complementary Y-derive processes and roll motions to the existing adaptive IPM model that is robust to pitch motions. To convince the performance of the proposed method, we evaluated our results on both synthetic and real road and sidewalk datasets.

염화물에 노출된 콘크리트 기공 내에 솔방울 추출물의 부식 방청 특성 (Corrosion Inhibition Properties of Conifer Cone (Pinus resinosa) Extract in Chloride Contaminated Concrete Pore Solutions)

  • 카식 수비아;박태준;이한승
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2021년도 봄 학술논문 발표대회
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    • pp.63-64
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    • 2021
  • The corrosion inhibition properties of conifer cone (Pinus resinosa) extract were studied in synthetic concrete pore solutions (SCPS) with and without chloride environments by electrochemical methods. The electrochemical impedance spectroscopy (EIS) revealed that the conifer cone (CC) extract showed promising inhibition behavior by diminishing the corrosion rate of steel rebar both solutions i.e. with and without chloride. The extract of conifer cone hinders the corrosion reaction between steel rebar and aggressive ions. Further, it can be verified that the up to 1000mg.L-1 of CC extract can able to reduce the corrosion rate of steel rebar in chloride contaminated concrete.

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그래프 기반 상태 표현을 활용한 작업 계획 알고리즘 개발 (Task Planning Algorithm with Graph-based State Representation)

  • 변성완;오윤선
    • 로봇학회논문지
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    • 제19권2호
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    • pp.196-202
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    • 2024
  • The ability to understand given environments and plan a sequence of actions leading to goal state is crucial for personal service robots. With recent advancements in deep learning, numerous studies have proposed methods for state representation in planning. However, previous works lack explicit information about relationships between objects when the state observation is converted to a single visual embedding containing all state information. In this paper, we introduce graph-based state representation that incorporates both object and relationship features. To leverage these advantages in addressing the task planning problem, we propose a Graph Neural Network (GNN)-based subgoal prediction model. This model can extract rich information about object and their interconnected relationships from given state graph. Moreover, a search-based algorithm is integrated with pre-trained subgoal prediction model and state transition module to explore diverse states and find proper sequence of subgoals. The proposed method is trained with synthetic task dataset collected in simulation environment, demonstrating a higher success rate with fewer additional searches compared to baseline methods.

Synthetic Approach to 99mTc-labeled SPECT Radiotracers with Multi-nitroimidazoles for Hypoxia

  • Anh Thu Nguyen;Hee-Kwon Kim
    • 핵의학기술
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    • 제28권1호
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    • pp.1-11
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    • 2024
  • Hypoxia, defined as the deficiency of oxygen, is a significant hallmark of cancers presenting in the majority of solid tumors. Detection of tumor hypoxia is essential in cancer diagnosis to prevent cancer progression, metastasis, and resistance to cancer therapies in clinical practices. Single-photon emission computed tomography (SPECT) is one of the methods studied and applied for hypoxia detection with the use of radiolabeled imaging agents in which 99mTc is the common radioisotope used for radiolabeling. Nitroimidazoles are the hypoxia-targeting moieties presenting in numerous 99mTc-radiolabeled imaging agents due to their bio-reducible ability in hypoxic environments. Recently, in addition to 99mTc-labeled radiopharmaceuticals containing one nitroimidazole unit, there has been considerable attention given to 99mTc-radiopharmaceuticals bearing two or more nitroimidazole units. This review summarizes the synthesis of hypoxia-targeting chelators and radiolabeling processes to produce these 99mTc-radiopharmaceuticals for SPECT imaging.

Seawater ballast tank 환경에서 저합금강의 내식성에 미치는 합금원소의 영향 (Effects of Alloying Elements on Corrosion Resistance of Low Alloyed Steels in a Seawater Ballast Tank Environment)

  • 김동우;김희산
    • 대한금속재료학회지
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    • 제48권6호
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    • pp.523-532
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    • 2010
  • Co-application of organic coating and cathodic protection has not provided enough durability to low-alloyed steels inseawater ballast tank (SBT) environments. An attempt has made to study the effect of alloy elements (Al, Cr, Cu, Mo, Ni, Si, W) on general and localized corrosion resistance of steels as basic research to develop new low-allowed steels resistive to corrosion in SBT environments. For this study, we measured the corrosion rate by the weigh loss method after periodic immersion in synthetic seawater at $60^{\circ}C$, evaluated the localized corrosion resistance by an immersion test in concentrated chloride solution with the critical pH depending on the alloy element (Fe, Cr, Al, Ni), determined the permeability of chloride ion across the rust layer by measuring the membrane potential, and finally, we analyzed the rust layer by EPMA mapping and compared the result with the E-pH diagram calculated in the study. The immersion test of up to 55 days in the synthetic seawater showed that chromium, aluminium, and nickel are beneficial but the other elements are detrimental to corrosion resistance. Among the beneficial elements, chromium and aluminium effectively decreased the corrosion rate of the steels during the initial immersion, while nickel effectively decreased the corrosion rate in a longer than 30-day immersion. The low corrosion rate of Cr- or Al-alloyed steel in the initial period was due to the formation of $Cr_2FeO_4$ or $Al_2FeO_4$, respectively -the predicted oxide in the E-pH diagram- which is known as a more protective oxide than $Fe_3O_4$. The increased corrosion rate of Cr-alloyed steels with alonger than 30-day exposure was due to low localized corrosion resistance, which is explained bythe effect of the alloying element on a critical pH. In the meantime, the low corrosion rate of Ni-alloyed steel with a longer than 30-day exposure wasdue to an Ni enriched layer containing $Fe_2NiO_4$, the predicted oxide in the E-pH diagram. Finally, the measurement of the membrane potential depending on the alloying element showed that a lower permeability of chloride ion does not always result in higher corrosion resistance in seawater.

최적화된 비선형 합성필터를 이용한 얼굴인증 시스템 (Face Verification System Using Optimum Nonlinear Composite Filter)

  • 이주민;염석원;홍승현
    • 대한전자공학회논문지SP
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    • 제46권3호
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    • pp.44-51
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    • 2009
  • 본 논문에서는 상관에 기반 한 비선형 합성필터를 이용한 왜곡과 잡음에 강인한 얼굴인식 방법을 연구한다. 상관도 기반 방법은 얼굴 영역의 검출과 인증을 동시에 수행하여 보다 신속한 처리를 할 수 있다는 장점이 있다. 최적화된 비선형 합성필터는 학습영상의 출력 값을 일정하게 유지하면서 입력 영상과 잡음의 필터 출력에너지를 최소화함으로써 얻어진다. 입력 영상의 출력에너지를 최소화하여 허위표적과의 식별력을 부여하고 잡음의 출력에너지를 최소화하여 가산성 잡음에 대한 강인성을 증대한다. 본 논문에서는 비선형 합성필터를 두 개의 학습 영상으로 구성하여 표적의 왜곡과 저해상도 그리고 잡음 환경 하에서 얼굴 인증을 실험하였다. 실험결과는 비선형 합성필터가 SDF(synthetic discriminant function) 필터와 비교하여 ROC(receiver operating characteristics) 커브에서 우수한 성능을 보인다.