• Title/Summary/Keyword: Perspective projection

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Ortho-rectification of Satellite-based Linear Pushbroom-type CCD Camera Images (선형 CCD카메라 영상의 정사투영 알고리즘 개발)

  • 곽성희;이영란;신동석
    • Korean Journal of Remote Sensing
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    • v.15 no.1
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    • pp.31-38
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    • 1999
  • In this paper, we introduce an algorithm for the ortho-rectification of high resolution pushbroom-type satellite images. The generation of ortho-images in the ultimate level of the satellite image preprocessing which also includes systematic geocoding and precision geocoding. It is also essential for the mapping of satellite images because topotraphic maps are based on the orthographic projection. The newly developed ortho-image generation algorithm introduced in this paper is on the line of the algorithms previously developed (Shin and Lee, 1997; Shin e 1998). Various experimental results are shown in this paper. The results show that the algorithm completely eliminates the disparities in the perspectively viewed images which were caused by the terrain height. The absolute accuracy of the developed algorithm depends on the accuracy of the camera model and the digital elevation model used.

Issues on Particular Market Situation to Calculate Dumping Margin of Korean Steel Products by the USA

  • Wang, Jingjing;Choi, Chang Hwan
    • Journal of Korea Trade
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    • v.25 no.1
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    • pp.89-111
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    • 2021
  • Purpose - The U.S. Trade Preference Expansion Act (TPEA) of 2015 enables the US Department of Commerce (DOC) to inflate dumping margin when the particular market situation (PMS) exists in the exporter's home market. DOC applied PMS provisions to the steel products from Korea. This paper analyzes whether DOC's calculation by using the regression analysis is consistent with WTO rules. Design/methodology - This paper analyzes the PMS application in law and regression analysis that extends the data period from 10 years to 18 years using the same economic model with DOC, and changes the country group according to the quantities of steelmaking capacity. Findings - Results show that DOC's argument conflating the sales-based with cost-based PMS designed to inflate dumping margins might not be consistent with WTO Antidumping Agreement Article 2.2 and 2.2.1.1 in which costs shall normally be calculated on the basis of records kept by the exporter, providing generally accepted accounting principles and reasonably reflection of the costs and PMS that exists in the Korean steel product markets. Even if it will be consistent, DOC's calculated margin by the regression analysis using a 10-year data is a big gap (5 times) compared with an 18-year data projection and different countries' data through the same methodology, which is a huge gap of regression coefficient. It means that dumping margin would be very wide range from 7.8% to 38.54% and unstable to calculate. Inflating dumping margin by DOC using regression analysis would not only be inconsistent with WTO rules, but also projection result is unreliable. Originality/value - Literature papers have mainly analyzed WTO law itself. This paper however, would be the first attempt to analyze the DOC's new way of dumping margin calculation in both manners of law and an empirical methodology perspective at the same time.

Segmentation and Visualization of Human Anatomy using Medical Imagery (의료영상을 이용한 인체장기의 분할 및 시각화)

  • Lee, Joon-Ku;Kim, Yang-Mo;Kim, Do-Yeon
    • The Journal of the Korea institute of electronic communication sciences
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    • v.8 no.1
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    • pp.191-197
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    • 2013
  • Conventional CT and MRI scans produce cross-section slices of body that are viewed sequentially by radiologists who must imagine or extrapolate from these views what the 3 dimensional anatomy should be. By using sophisticated algorithm and high performance computing, these cross-sections may be rendered as direct 3D representations of human anatomy. The 2D medical image analysis forced to use time-consuming, subjective, error-prone manual techniques, such as slice tracing and region painting, for extracting regions of interest. To overcome the drawbacks of 2D medical image analysis, combining with medical image processing, 3D visualization is essential for extracting anatomical structures and making measurements. We used the gray-level thresholding, region growing, contour following, deformable model to segment human organ and used the feature vectors from texture analysis to detect harmful cancer. We used the perspective projection and marching cube algorithm to render the surface from volumetric MR and CT image data. The 3D visualization of human anatomy and segmented human organ provides valuable benefits for radiation treatment planning, surgical planning, surgery simulation, image guided surgery and interventional imaging applications.

Comparison Among Sensor Modeling Methods in High-Resolution Satellite Imagery (고해상도 위성영상의 센서모형과 방법 비교)

  • Kim, Eui Myoung;Lee, Suk Kun
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.26 no.6D
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    • pp.1025-1032
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    • 2006
  • Sensor modeling of high-resolution satellites is a prerequisite procedure for mapping and GIS applications. Sensor models, describing the geometric relationship between scene and object, are divided into two main categories, which are rigorous and approximate sensor models. A rigorous model is based on the actual geometry of the image formation process, involving internal and external characteristics of the implemented sensor. However, approximate models require neither a comprehensive understanding of imaging geometry nor the internal and external characteristics of the imaging sensor, which has gathered a great interest within photogrammetric communities. This paper described a comparison between rigorous and various approximate sensor models that have been used to determine three-dimensional positions, and proposed the appropriate sensor model in terms of the satellite imagery usage. Through the case study of using IKONOS satellite scenes, rigorous and approximate sensor models have been compared and evaluated for the positional accuracy in terms of acquirable number of ground controls. Bias compensated RFM(Rational Function Model) turned out to be the best among compared approximate sensor models, both modified parallel projection and parallel-perspective model were able to be modelled with a small number of controls. Also affine transformation, one of the approximate sensor models, can be used to determine the planimetric position of high-resolution satellites and perform image registration between scenes.

Historical Transformation of Types of Hand-Drawing and Their Hybridization in Landscape Architectural Design (조경 설계에서 손 드로잉 유형의 역사적 변천과 혼성화)

  • Lee, Myeong-Jun
    • Journal of the Korean Institute of Landscape Architecture
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    • v.45 no.5
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    • pp.71-86
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    • 2017
  • This work explores the historical transformation of manual landscape architectural drawings in terms of hybridization to uncover their inherent creative aspect. Landscape architectural drawing has duel functions; namely, scientific instrumentality and artistic imagination, which are relative, interchangeable, and transformable. These characteristics have been embodied in the forms of particular types of drawing, projections, perspective views, and diagrams, which are not so much clearly distinguishable as rather mutually complementary and hybridized. In particular, the pictorial views of plants in the forms of a perspective view or elevation were frequently hybridized to projection drawings of grounds and architectural structures, which is called planometrics. Particular drawing types have often emerged as suitable and thereby dominant forms, depending on the particular historical styles of landscape design. Sixteenth-century Italian Renaissance gardens and seventeenth-century French formal gardens were generally visualized in the form of projections. Eighteenth-century and early nineteenth-century English landscape gardens were frequently represented in a pictorial perspective view. In nineteenth-century America, different drawing techniques such as competition drawing, photography, and map overlay were specialized depending on their respective functions. Twentieth-century American modernists began to explore the diagram to deploy design strategies. In such transformation, however, the planometric, which considers both the ground plane and plant's frontal identities simultaneously and thereby is suitable to landscape design, was frequently used as a hybridization technique. In the mid-nineteenth century, a top view of plants replaced the planometric, and then, in the twentieth century, plants were no longer represented artistically, instead reduced to the forms of standardized flat symbols. The use of instrumental visualizations thereby gradually increased rather than the use of an imaginative representation for landscape architectural drawings.

Panoramic Image Composition Algorithm through Scaling and Rotation Invariant Features (크기 및 회전 불변 특징점을 이용한 파노라마 영상 합성 알고리즘)

  • Kwon, Ki-Won;Lee, Hae-Yeoun;Oh, Duk-Hwan
    • The KIPS Transactions:PartB
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    • v.17B no.5
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    • pp.333-344
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    • 2010
  • This paper addresses the way to compose paronamic images from images taken the same objects. With the spread of digital camera, the panoramic image has been studied to generate with its interest. In this paper, we propose a panoramic image generation method using scaling and rotation invariant features. First, feature points are extracted from input images and matched with a RANSAC algorithm. Then, after the perspective model is estimated, the input image is registered with this model. Since the SURF feature extraction algorithm is adapted, the proposed method is robust against geometric distortions such as scaling and rotation. Also, the improvement of computational cost is achieved. In the experiment, the SURF feature in the proposed method is compared with features from Harris corner detector or the SIFT algorithm. The proposed method is tested by generating panoramic images using $640{\times}480$ images. Results show that it takes 0.4 second in average for computation and is more efficient than other schemes.

Mathematical Analysis on the Perception of Pavement Markings Using 'Math Field Trip' (수학답사를 통한 도로 노면표시의 인지에 대한 수학적 분석)

  • SUH, Bo Euk
    • Journal of Korean Society of Transportation
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    • v.34 no.3
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    • pp.248-262
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    • 2016
  • The study documents the analysis on characters and symbols shown in the pavement markings in the perspective of mathematics educators. The purpose of this study is to propose a pavement marking method that can enhance readability from the driver's eye position. To this end, this study analyzed the figure of the pavement markings that can be actually recognized by the projective geometry perspective. As a result, it proposed alternatives to the current pavement markings by introducing the concept of the compression ratio. Results of the study are as follows. First, the rule was established to obtain the compression ratio. If the observation of two viewing angles are x and y, then the compression ratio S is ${\sin}y/{\cos}\(\frac{x-y}{2}\)$. Second, we presented two alternatives to the pavement marking method for the displayed information. One is a method for improving the pavement markings in terms of the compression ratio, the other is a method by varying vertical length of the pavement markings while holding its width constant. Based on the outcomes from this study, a mathematical analysis can be further studied for the perception of speed according to the types of pavement marking line.

Public information signage design for driving in perspective of improving contextual visibility (주행 공공 안내표지판의 맥락적 시인성 향상을 위한 표지판 디자인 연구)

  • Lee, SaYa;Cho, IkHyun;Kim, ChaeHee;Lee, JoongSup;Kim, SeungJun;Lee, EunJong
    • Smart Media Journal
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    • v.10 no.4
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    • pp.63-70
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    • 2021
  • Public Signs guiding drivers on the road should help make decisions within a short period of time, so appropriate information should be effectively expressed at the point. Currently, the road marking rules revised by the law show a significant change in the type of information, expression method, and weight of expression compared to existing road signs to be based on road name addresses. This study analyzed whether the revised road signs changed based on the road name were effective in perspective of perception-cognition-understanding-projection and examined whether they provided appropriate information for the actual driving environment. Based on the analyzed information, an experiment was conducted to present an improved design, evaluate the degree of visibility compared to existing road name-oriented signs, and a qualitative investigation was conducted on the suitability of the sign contents. Through this, it is expected that more suitable driving information and measures to increase intuitive visibility can be reviewed.

Republic of Korea Navy's Long-Term Development Plan to Acquire Operational Capabilities at Distant Ocean - Focused on Introduction of Aircraft Carrier and Nuclear-powered Submarine - (원양 작전 능력 확보를 위한 한국 해군의 장기(長期) 발전 방안 - 항공모함 및 원자력 잠수함 도입제안을 중심으로 -)

  • Kim, Jae-Yeop
    • Strategy21
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    • s.34
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    • pp.149-177
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    • 2014
  • Today distant oceans around the world are regarded as a major 'global commons' for international trade and transportation. Korea is not an exception, because Korea hugely depends on sea lines of communication (SLOC) for supplying vital commodities such as food and energy resource. As a result, assuring a free and safe use of distant ocean beyond territory is also an important agenda for Korea's maritime security. However there are a number of challenges for Korea to enjoy a free and safe use of distant ocean; dangers of regional maritime conflict in East Asia, naval arms race of China and Japan, and concerns on possible decline of U.S naval presence and power projection capabilities. These factors provide a reasonable basis for Republic of Korea Navy (ROKN) to pursue capabilities for major naval operations at distant ocean in a long-term perspective toward the year 2030. The introduction of aircraft carrier and nuclear-powered submarine is a key requirement for achieving this goal. ROKN needs to acquire a 'multi-role strategic landing platform' type of light aircraft carrier, which takes a role to escort naval task force by providing air superiority at distant ocean. Additionally nuclear-powered submarine will offer ROKN a formidable power to carry out offensive missions effectively at distant ocean.

Characteristics of the Uses and Exterior Design of Balconies in Urban Housing - Focusing on the Balconies from the Ancient Times to the 19th Century with a Culture-historical Perspective - (도시주거의 발코니에서 나타나는 내부이용 및 외부표현 특성 - 고대부터 19세기 말까지의 동.서양 주거문화사적(文化史的) 고찰을 중심으로 -)

  • Jee, Soo-In
    • Journal of the Korean housing association
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    • v.21 no.2
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    • pp.133-144
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    • 2010
  • The purpose of this study is to analyze the uses and exterior design of the balconies in urban housing from the ancient times to the 19th century. In doing so, the paper seeks to investigate the cultural identity of the balcony in urban housing. The results are as follow. First, in the urban housing the balcony space were made for protection from the heat, light and ventilation; gardening; views toward the streets, city, waterside, inner court, domain for men; breathing french air; watching ceremony, festivals and events; simple houseworks like drying, carpet cleaning and hair coloring; lever installation and fire escape. Second, as part of exterior design the typical projecting characteristic of the balconies was emphasized and they became an impotent decorative element. The monotonous facade changed to a lively design with a rhythmical sense. On the facade the effects of horizontal movement, symmetry or asymmetry from the main entrance, and the center-projection (rialto) were created. In the urban housing the balconies were used for cultural activities which supplement and enlarge the function of the interior space, and moreover the rich effects of the facade contributed to the creation of attractive urban landscape.