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A New Optimized Localized Technique of CG Return Stroke Lightning Channel in Forest

  • Kabir, Homayun;Kanesan, Jeevan;Reza, Ahmed Wasif;Ramiah, Harikrishnan;Dimyati, Kaharudin
    • Journal of Electrical Engineering and Technology
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    • v.10 no.6
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    • pp.2356-2363
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    • 2015
  • Localization of lightning strike point (LSP) in the forest is modeled to mitigate the forest fire damage. Though forest fire ignited by lightning rarely happens, its damage on the forest is grievousness. Therefore, predicting accurate location of LSP becomes crucial in order to control the forest fire. In this paper, we proposed a new hybrid localization algorithm by combining the received signal strength (RSS) and the received signal strength ratio (RSSR) to improve the accuracy by mitigating the environmental effect of lightning strike location in the forest. The proposed hybrid algorithm employs antenna theory (AT) model of cloud-to-ground (CG) return stroke lightning channel to forecast the location of the lightning strike. The obtained results show that the proposed hybrid algorithm achieves better location accuracy compared to the existing RSS method for predicting the lightning strike location considering additive white Gaussian noise (AWGN) environment.

Synthesis and Characterization of Thermo Sensitive Poly(styrene-co-N-isopropylacrylamide) Microgels (열 감응성 Poly(styrene-co-N-isopropylacrylamide) 마이크로겔의 합성 및 특성)

  • Cho, Suk Hyeong;Kim, Kong Soo;Jung, Tea Uk
    • Applied Chemistry for Engineering
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    • v.16 no.3
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    • pp.397-402
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    • 2005
  • Core-shell Poly(styrene-co-N-isopropylacrylamide) (poly(St-co-NIPAm) was prepared by soap-free emulsion polymerization of styrene (St) and N-isopropylacrylamide (NIPAm) in aqueous solution with potassium persulfate (KPS) as an initiator. The effects of St/NIPAm ratio, concentrations of monomer and crosslinker were studied. Also, Thermo sensitivity of microgels prepared was investigated. Particle size of microgels increased with increasing mol ratio of NIPAm to styrene. Transmittance of the microgel dispersion decreased rapidly when heated above a low critical solution temperature (near $32{\sim}34^{\circ}C$, cloud point). Swelling ratio of the microgel increased with increasing of the concentration of monomer (NIPAm) and decreased proportional to the concentration of crosslinker.

Holographic Polymer-Dispersed Liquid Crystals and Polymeric Photonic Crystals Formed by Holographic Photolithography

  • Kyu Thein;Meng Scott;Duran Hatice;Nanjundiah Kumar;Yandek Gregory R.
    • Macromolecular Research
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    • v.14 no.2
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    • pp.155-165
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    • 2006
  • The present article describes the experimental and theoretical observations on the formation of holographic, polymer-dispersed, liquid crystals and electrically switchable, photonic crystals. A phase diagram of the starting mixture of nematic liquid crystal and photo-reactive triacrylate monomer was established by means of differential scanning calorimetry (DSC) and cloud point measurement. Photolithographic patterns were imprinted on the starting mixture of LC/triacrylate via multi-beam interference. A similar study was extended to a dendrimer/photocurative mixture as well as to a single component system (tetra-acrylate). Theoretical modeling and numerical simulation were carried out based on the combination of Flory-Huggins free energy of mixing and Maier-Saupe free energy of nematic ordering. The combined free energy densities were incorporated into the time-dependent Ginzburg-Landau (Model C) equations coupled with the photopolymerization rate equation to elucidate the spatio-temporal structure growth. The 2-D photonic structures thus simulated were consistent with the experimental observations. Furthermore, 3-D simulation was performed to guide the fabrication of assorted photonic crystals under various beam-geometries. Electro-optical performance such as diffraction efficiency was evaluated during the pattern photopolymerization process and also as a function of driving voltage.

A Study on the Environment Characteristics and Continuous Usage Intention for Improvement of Fintech (핀테크 활성화를 위한 사용환경특성과 지속사용의도)

  • Jung, Dae-Hyun;Chang, Hwal-Sik;Park, Kwang-O
    • The Journal of Information Systems
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    • v.26 no.2
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    • pp.123-142
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    • 2017
  • Purpose The development of the Fintech industry can be on the basis of the development in IT technologies such as Big data, IoT, cloud computing, it can be considered that the financial industry is repeating the evolution into Fintech. But the awareness of the consumers is still very low. Therefore the current dissertation, tries to deduce the suggestions for invigoration measures for Fintech by conducting an empirical study on the factors that influence the intention of reuse of Fintech on the consumer's point of view. Design/methodology/approach This study made a design of the research model by integrating the factors deducted from the Expectation Confirmation Theory. This paper empirically analyzes the impact of Continuous Usage Intention for Improvement of Fintech. The 302 survey responses were used to verify research hypotheses through covariate structural equation model. Findings According to the empirical analysis result, this study confirmed that the ultimate purpose of the Fintech service is to eliminate the social cost's waste element occurring from issue of money by not using or reducing the usage of cash. Since many Fintech users have pointed out security as the priority task, a direction for the related institutions has been proposed. Second, the content of the current dissertation will be the opportunity of broadening the perception of the current consumers that perceive Fintech as only a NFC simple payment service.

The Preference and Purchase Intention of American College Students on Korean Traditional Motifs and Their Relationship with Sensibility (미국대학생의 한국전통문양에 대한 선호도와 구매의도 및 감성이미지와의 관계)

  • 장수경
    • The Research Journal of the Costume Culture
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    • v.12 no.3
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    • pp.369-378
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    • 2004
  • The objectives of this study were to measure the preference and purchase intention on Korean traditional motifs and to investigate the relationship among preference, purchase intention, and sensibility. The subjects consisted of 217 male and 351 female US undergraduate students. The experimental materials used in this study were 48 stimuli and a questionnaire, composed of 7-point semantic differential scales of 17 bi-polar adjectives. The data were analyzed by ANOVA, Duncan's multiple range test, Regression, and t-test. The major findings were as follows; First, interpretation type and application object had significant effects on the preference, while category and interpretation type had significant effects on the purchase intension. The application of Korean traditional motifs for pattern design was preferred to their application for clothing design. Decorative type was found to be more related to the preference and purchase intention than the other interpretation types of realistic, stylized and abstract types. The purchase intention on crain motif was lower than the other categories of lotus and cloud motifs. Second, in overall, the preference on Korean traditional motifs was higher than purchase intention. Third, the preference and purchase intention were affected mainly by 'Quality' image, a component of sensibility, followed by 'Cheerfulness' image, but not affected by 'Simplicity' and 'Modernity' image.

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Aerial Object Detection and Tracking based on Fusion of Vision and Lidar Sensors using Kalman Filter for UAV

  • Park, Cheonman;Lee, Seongbong;Kim, Hyeji;Lee, Dongjin
    • International journal of advanced smart convergence
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    • v.9 no.3
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    • pp.232-238
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    • 2020
  • In this paper, we study on aerial objects detection and position estimation algorithm for the safety of UAV that flight in BVLOS. We use the vision sensor and LiDAR to detect objects. We use YOLOv2 architecture based on CNN to detect objects on a 2D image. Additionally we use a clustering method to detect objects on point cloud data acquired from LiDAR. When a single sensor used, detection rate can be degraded in a specific situation depending on the characteristics of sensor. If the result of the detection algorithm using a single sensor is absent or false, we need to complement the detection accuracy. In order to complement the accuracy of detection algorithm based on a single sensor, we use the Kalman filter. And we fused the results of a single sensor to improve detection accuracy. We estimate the 3D position of the object using the pixel position of the object and distance measured to LiDAR. We verified the performance of proposed fusion algorithm by performing the simulation using the Gazebo simulator.

Development of 3D scanner using structured light module based on variable focus lens

  • Kim, Kyu-Ha;Lee, Sang-Hyun
    • International Journal of Advanced Culture Technology
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    • v.8 no.3
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    • pp.260-268
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    • 2020
  • Currently, it is usually a 3D scanner processing method as a laser method. However, the laser method has a disadvantage of slow scanning speed and poor precision. Although optical scanners are used as a method to compensate for these shortcomings, optical scanners are closely related to the distance and precision of the object, and have the disadvantage of being expensive. In this paper, 3D scanner using variable focus lens-based structured light module with improved measurement precision was designed to be high performance, low price, and usable in industrial fields. To this end, designed a telecentric optical system based on a variable focus lens and connected to the telecentric mechanism of the step motor and lens to adjust the focus of the variable lens. Designed a connection structure with optimized scalability of hardware circuits that configures a stepper motor to form a system with a built-in processor. In addition, by applying an algorithm that can simultaneously acquire high-resolution texture image and depth information and apply image synthesis technology and GPU-based high-speed structured light processing technology, it is also stable for changes to external light. We will designed and implemented for further improving high measurement precision.

3D Spatial Information Acquisition for Construction Operation and Maintenance on a Construction Site (효율적인 건설공사와 유지관리를 위한 건설현장에서의 3차원 공간 정보 획득)

  • Kim, Chang-Wan
    • Proceedings of the Korean Institute Of Construction Engineering and Management
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    • 2004.11a
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    • pp.188-193
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    • 2004
  • 3D spatial-modeling can be used in various safety-enhancement applications and for as-built data acquisition in project-control systems. The objective of the research reported herein was to provide spatial-modeling methods that represent construction sites in an efficient manner and to validate the proposed methods by testing them in an actual construction environment. Algorithms to construct construction-site scenes and to carry out coordinate transformations in order to merge data from different acquisition locations are presented. Field experiments were conducted to establish performance parameters and validation for the proposed methods and models. Initial experimental work has demonstrated the feasibility of this approach.

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Three Dimension Scanner System Using Parallel Camera Model (패러렐 카메라모델을 이용한 3차원 스캐너 시스템)

  • Lee, Hee-Man
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.38 no.2
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    • pp.27-32
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    • 2001
  • In this paper, the three dimension scanner system employing the parallel camera model is discussed. The camera calibration process and the three dimension scanning algorithm are developed. The laser strip line is utilized for assisting stereo matching. An object being scanned rotates on the plate which is activated by a stepping motor, The world coordinate which is. the measured distance from the camera to the object is converted into the model coordinate. The facets created from the point. cloud of the model coordinate is used for rendering the scanned model by using the graphic library such as OpenGL. The unmatched points having no validate matching points are interpolated from the validate matching points of the vicinity epipolar lines.

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FISS and SDO Observation of a Brightening Event Near a Pore

  • Kang, Juhyeong;Chae, Jongchul
    • The Bulletin of The Korean Astronomical Society
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    • v.42 no.2
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    • pp.61.2-61.2
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    • 2017
  • We report a fine scale transient brightening event near a pore boundary with the Fast Imaging Solar Spectrograph (FISS) of the 1.6m Goode Solar Telescope (GST), the Atmospheric Imaging Assembly (AIA) aboard the Solar Dynamics Observatory (SDO), and Helioseismic and Magnetic Imager (HMI) aboard SDO. The event appears in all AIA extreme ultraviolet bands, also in the two FISS lines, $H{\alpha}$ and Ca II $8542{\AA}$, and lasted for a minute. The brightening occurred at a footpoint of a loop. The conjugate brightening occurred at the other foot point outside the FISS field of view. The brightening near the pore exhibit a redshift of 4.3 km s-1 in the $H{\alpha}$ and about 2.3 km s-1 in Ca II line. Differential emission measure derived from 6 AIA EUV passbands and cloud model fitting of the two FISS lines indicate the temperature increase of between 10,000 and 20 MK at the main event. After the brightening, the upward mass motion appears in the AIA images. We discuss the physical implication of this brightening in the context of magnetic reconnection and coronal heating.

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