Hybrid Pansharpening Algorithm for High Spatial Resolution Satellite Imagery to Improve Spatial Quality

Jaewan Choi,Junho Yeom,Anjin Chang,Younggi Byun,Yongil Kim IEEE 2013 IEEE geoscience and remote sensing letters Vol.10 No.3

<P>Most pansharpened images from existing algorithms are apt to present a tradeoff relationship between the spectral preservation and the spatial enhancement. In this letter, we developed a hybrid pansharpening algorithm based on primary and secondary high-frequency information injection to efficiently improve the spatial quality of the pansharpened image. The injected high-frequency information in our algorithm is composed of two types of data, i.e., the difference between panchromatic and intensity images, and the Laplacian filtered image of high-frequency information. The extracted high frequencies are injected by the multispectral image using the local adaptive fusion parameter and postprocessing of the fusion parameter. In the experiments using various satellite images, our results show better spatial quality than those of other fusion algorithms while maintaining as much spectral information as possible.</P>

A New Adaptive Component-Substitution-Based Satellite Image Fusion by Using Partial Replacement

Jaewan Choi,Kiyun Yu,Yongil Kim IEEE 2011 IEEE transactions on geoscience and remote sensing Vol.49 No.1

<P>Preservation of spectral information and enhancement of spatial resolution are regarded as important issues in remote sensing satellite image fusion. In previous research, various algorithms have been proposed. Although they have been successful, there are still some margins of spatial and spectral quality that can be improved. In addition, a new method that can be used for various types of sensors is required. In this paper, a new adaptive fusion method based on component substitution is proposed to merge a high-spatial-resolution panchromatic (PAN) image with a multispectral image. This method generates high-/low-resolution synthetic component images by partial replacement and uses statistical ratio-based high-frequency injection. Various remote sensing satellite images, such as IKONOS-2, QuickBird, LANDSAT ETM+, and SPOT-5, were employed in the evaluation. Experiments showed that this approach can resolve spectral distortion problems and successfully conserve the spatial information of a PAN image. Thus, the fused image obtained from the proposed method gave higher fusion quality than the images from some other methods. In addition, the proposed method worked efficiently with the different sensors considered in the evaluation.</P>

Scientific Analysis on the Accessory Ornament of Woolen Tapestry Curtain in Seoul Museum of Craft Art

Choi, Jaewan,Lee, Jangjon,An, Boyeon The Korean Society Of Conservation Science For Cul 2021 보존과학회지 Vol.37 No.4

Woolen tapestry curtains possessed by the Seoul Museum of Craft Art were used to hung on the wall or used for carpets in the winter season in the late Joseon dynasty. Since similar artifacts were only used for the curtain as functional aspects, woolen tapestry curtains were a rare case. In this study, scientific analysis on the accessory ornament of woolen tapestry curtains such as components of metal accessories and frame bar were conducted with the microscope, p-XRF, and SEM. Result of frame bar pigments, organic pigments such as ink stick were likely been used in woolen tapestry curtain 1. In woolen tapestry 2, lead red (Minium) was used in the frame bar. The result of metal parts, copper, and zinc were analyzed by p-XRF. This suggests that metal accessories were crafted using brass. Frame bar of woolen tapestry curtain 2 was made of soft pine (Pinus spp.) analyzed with the scanning electron microscope. Artifacts like woolen tapestry curtains are rare in Korea and scientific analysis databases were scarce, so it is important to construct components analysis data of woolen tapestry curtains. It is expected that additional scientific analysis and interpretation on the artifact's crafting technique can be merged with the analytical data gathered in this study to be utilized on the conservation and restoration of not only woolen curtains but curtain artifacts of the late Joseon dynasty in general.

Brush-Shaped ZnO Heteronanorods Synthesized Using Thermal-Assisted Pulsed Laser Deposition

Choi, Jaewan,Ji, Hyunjin,Tambunan, Octolia Togibasa,Hwang, In-Sung,Woo, Hyung-Sik,Lee, Jong-Heun,Lee, Bo Wha,Liu, Chunli,Rhee, Seuk Joo,Jung, Chang Uk,Kim, Gyu-Tae American Chemical Society 2011 ACS APPLIED MATERIALS & INTERFACES Vol.3 No.12

<P>Brush-shaped ZnO heteronanostructures were synthesized using a newly designed thermal-assisted pulsed laser deposition (T-PLD) system that combines the advantages of pulsed laser deposition (PLD) and a hot furnace system. Branched ZnO nanostructures were successfully grown onto CVD-grown backbone nanowires by T-PLD. Although ZnO growth at 300 °C resulted in core–shell structures, brush-shaped hierarchical nanostructures were formed at 500–600 °C. Materials properties were studied via photoluminescence (PL), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) characterizations. The enhanced photocurrent of a SnO<SUB>2</SUB>–ZnO heterostructures device by irradiation with 365 nm wavelength ultraviolet (UV) light was also investigated by the current–voltage characteristics.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/aamick/2011/aamick.2011.3.issue-12/am201106v/production/images/medium/am-2011-01106v_0008.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/am201106v'>ACS Electronic Supporting Info</A></P>

IPMSM Design for Sensorless Control Considering Magnetic Neutral Point Shift According to Magnetic Saturation

JaeWan Choi,Hyun-Soo Seol,Ju Lee 대한전기학회 2018 Journal of Electrical Engineering & Technology Vol.13 No.2

In this paper, interior permanent magnet synchronous motor (IPMSM) design for sensorless drive, considering magnetic neutral point shift according to magnetic saturation, has been proposed. Sensorless control was divided into a method based on inductance and a method based on back induced voltage. Because induced voltage is very small at zero or low speed, error in rotor initial position estimation may occur. Using the ratio of saliency addresses this problem. When using highfrequency injections at low speed, the rotor’s initial position is estimated at the smallest portion of the inductance. IPMSM has the minimum inductance at the d-axis. However, if magnetic saturation leads to magnetic neutral point variation, following the load current change, there is a change in the minimum point of inductance. In this case, it can lead to failure of initial rotor position estimation. As a result, it is essential that the blocking design has an inductance minimum point shift. As such, in this study, an IPMSM design method, by blocking magnetic neutral point change, has been proposed. After determining the inductance profile based on the finite element analysis (FEA), the results of proposed method were verified.

IPMSM Design for Sensorless Control Considering Magnetic Neutral Point Shift According to Magnetic Saturation

Choi, JaeWan,Seol, Hyun-Soo,Lee, Ju The Korean Institute of Electrical Engineers 2018 Journal of Electrical Engineering & Technology Vol.13 No.2

In this paper, interior permanent magnet synchronous motor (IPMSM) design for sensorless drive, considering magnetic neutral point shift according to magnetic saturation, has been proposed. Sensorless control was divided into a method based on inductance and a method based on back induced voltage. Because induced voltage is very small at zero or low speed, error in rotor initial position estimation may occur. Using the ratio of saliency addresses this problem. When using high-frequency injections at low speed, the rotor's initial position is estimated at the smallest portion of the inductance. IPMSM has the minimum inductance at the d-axis. However, if magnetic saturation leads to magnetic neutral point variation, following the load current change, there is a change in the minimum point of inductance. In this case, it can lead to failure of initial rotor position estimation. As a result, it is essential that the blocking design has an inductance minimum point shift. As such, in this study, an IPMSM design method, by blocking magnetic neutral point change, has been proposed. After determining the inductance profile based on the finite element analysis (FEA), the results of proposed method were verified.

객체 기반의 IR-MAD 기법을 활용한 고해상도 위성영상의 무감독 변화탐지

최재완(Choi, Jaewan) 한국측량학회 2015 한국측량학회지 Vol.33 No.4

전기-기계식 구동기 기반 개별 블레이드 피치 조종 시스템의 제어를 위한 외란 관측기와 시간 지연제어기 설계

최재완(Jaewan Choi),김민유(Minyu Kim),최영훈(Younghoon Choi) 항공우주시스템공학회 2024 항공우주시스템공학회지 Vol.18 No.1

Recently, the concept of Urban Air Mobility (UAM) has expanded to Advanced Air Mobility (AAM). A tilt rotor type of vertical take-off and landing aircraft has been actively studied and developed. A tilt-rotor aircraft can perform a transition flight between vertical and horizontal flights. A blade pitch angle control system can be used for flight stability during transition flight time. In addition, Individual Blade Control (IBC) can reduce noise and vibration generated in transition flight. This paper proposed Disturbance Observer Based Control (DOBC) and Time Delay Control (TDC) for individual blade control of an Electro-Mechanical Actuator (EMA) based blade pitch angle control system. To compare and analyze proposed controllers, numerical simulations were conducted with DOBC and TDC.

애니메이션을 활용한 극장광고 제작 연구

최재완(Choi Jaewan) 한국디지털디자인학회 2010 디지털디자인학연구 Vol.10 No.2

애니메이션의 발전은 오늘날 다양한 분야에서 사용 되고 있으며 특히 영상매체분야에서 큰 비중을 차지하고 있다. 영화 드라마 등 영상분야에서는 애니메이션을 제외하고는 이야기할 수 없을 정도의 중요한 위치와 전문성을 띄고 있다고 할 수 있다. 컴퓨터 기술을 이용해 가상의 세계를 창조하고 이야기를 만들어 내는 것은 애니메이션의 역할일 것이다. 애니메이션은 다양하게 적용 및 활용되어 영역을 넓혀가고 있다 그러나 애니메이션의 제작은 현재 장편에 치중되어 있는 것이 현실이다. 장편 애니메이션의 여러 가지 요소 중의 하나인 High-cost는 소규모 회사나 애니메이터들에게는 위협적인 요소일 것이다. 소규모 애니메이션 회사나 개인이 광고를 진행하기에는 광고 시장의 제작비용 부담감이 크다고 할 수 있다. 제작비용을 최소화시키고 애니메이터들의 다양한 작업을 통해 좋은 시나리오를 발굴해내고 채택된 시나리오는 제작으로 이어져야 애니메이션의 저변 확대가 가능할 것이다. TV광고나 영화는 소규모 애니메이션회사나 개인이 제작하기에는 작업시간과 비용의 부담감이 커서 쉽게 접근하지 못하는 경우가 많다. 이에 차선책으로 극장광고시장을 제시하고 지역에 있는 애니메이터들과 극장광고를 연계함으로써 애니메이션을 활성화시키고자 한다. 극장광고의 수요는 점점 더 증가하고 광고시장의 한 영역으로 각광 받고 있다. 극장광고시장은 제작비용의 부담도 적고 시간적 부담도 적으므로 효과적인 애니메이션 광고 및 나아가 경쟁력 있는 양질의 콘텐츠생산이라는 측면에서 가치가 있다고 본다. 애니메이션을 극장광고로 제작 진행하여 광고시장에 차별성을 둔 예를 제시하여 애니메이션의 다양한 활용성을 제시해보고자 한다. The development of animation is used to various fields and especially forming a great part in visual media field. at the present. In the filed of visual media such as movie drama etc the animation is holding a key post and shows professionality as much as we can talk that field without animation. The role of animation should be to create imaginary world and make a story with computer technology. The animation is used and applied variously so its fields are widened. But in fact the animation is producted focused on the feature-length animation currently. The high-cost one of the several factors of the feature-length animation will be threatening factor for small companies or animators. For handling advertisements small animation companies and individuals will get great burden for production cost of advertising market. The production cost is minimized good scenarios are found by various works of animators and the selected scenario is connected to production so the base of animation will be expanded. TV advertisements or movies cannot be easily approached by small animation companies or individuals because of the great burden for working time and cost. Therefore as the second best plan we intend to vitalize animation by proposing the advertising market of regional theater and connecting screen advertisements with animators in the region. The demand of theater advertisement is gradually increased and comes into the spotlight as one field of advertising market. Small companies or animators can check their animation ability by approaching it easily. I intend to present various uses of animation by the examples producing and proceeding the theater advertisement with animation and giving distinction to theater advertising market.

Graphic User Interface와 칸딘스키 조형의식과의 상관성 연구

최재완(Choi Jaewan),하중규(Ha Joonggyu) 한국디지털디자인학회 2008 디지털디자인학연구 Vol.8 No.1

User Interface는 제품사용을 원활히 지원하는 제품언어로서 사용방법을 집약시킨 것이므로 제품과 사용자의 입장에서는 하드웨어적인 문제가 아니라 소프트웨어적인 요소가 중요하게 대두된다. 따라서 사용상의 운용언어 (Operating Language)는 Text보다는 Graphic이다. 인지와 인식이 쉽고 대중화와 세계화에 있어서 중요 요소라고 할 수 있다. 오늘날 인터페이스의 연구는 IT의 발달에 따라 많은 성과를 가져 왔다. 그러나 인터페이스 그래픽 언어의 조형성 검토는 미미한 수준에 머물러 왔다. 기능성·사용성·심미성의 인터페이스 속성 인자들 중에서 심미성은 조형요소에 근원하고 있다. 본 연구에서는 인터페이스 그래픽의 조형성을 탐색할 목적으로 바우하우스시기에 기하학적 조형을 구사한 칸딘스키를 주목하여 그의 작품에 나타난 조형언어가 인터페이스 조형성과 어떠한 상관관계를 갖는지를 살펴보고 인터페이스 속성 인자인 심미성의 근원을 탐색하였다. 칸딘스키의 기초조형 이념은 현재 Graphic User Interface의 지향점과 유사한 점이 많은 동시에 Graphical symbol의 조형 구성 원리와 유사한 것이 많다. 나아가 칸딘스키의 조형이념의 목표가 제품의 형태구성 원리뿐만 Graphic User Interface의 시각언어 구성에 대한 조형화에도 영향을 주었다고 할 수 있다. User Interface is the Language of product usage in which the user's interaction focusing on not hardware problems but software problems. Therefore operating language of the usage is graphical symbol language better than text. The Operating Language for use is Graphic which is easy to recognize and an important factor in popularization and globalization. However the formation about interface language is not being examined with activity. In this original research paper was studied about Bauhaus age considered as the significant Graphic Formative period searched the interface formation of the basic design education directed by Kandinsky. His basic design education is similar to the Graphical design factor brought out in the graphic user interface. Also it affected not only a product shape but also the graphical symbol design of interface