• Title/Summary/Keyword: invariant

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Estimation of Sejong VLBI IVP Point Using Coordinates of Reflective Targets with Their Measurement Errors (반사타겟 좌표 및 오차정보를 이용한 세종 VLBI IVP 위치계산)

  • Hong, Chang-Ki;Bae, Tae-Suk;Yi, Sangoh
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.38 no.6
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    • pp.717-723
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    • 2020
  • Determination of local tie vectors between the space geodetic techniques such as VLBI (Very Long Baseline Interferometer), SLR (Satellite Laser Ranging), DORIS (Doppler Orbit determination and Radiopositioning Integrated on Satellite), GNSS (Global Navigation Satellite System) is essential for combination of ITRF (International Terrestrial Reference Frame). Therefore, it is required to compute IVP (Invariant Point) position of each space geodetic technique with high accuracy. In this study, we have computed Sejong VLBI IVP position by using updated mathematical model for adjustment computation so that the improvement on efficiency and reliability in computation are obtained. The measurements used for this study are the coordinates of reflective targets on the VLBI antenna and their accuracies are set to 1.5 mm for each component. The results show that the position of VLBI IVP together with its standard deviation is successfully estimated when they are compared with those of the results from previous study. However, it is notable that additional terrestrial surveying should be performed so that realistic measurement errors are incorporated in the adjustment computation process.

Security Verification of Wireless Remote Control System Using CPN (CPN을 이용한 무선원격제어시스템의 안전성 검증)

  • 이문구
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.13 no.5
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    • pp.81-90
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    • 2003
  • Existing web-based system management software solutions show some limitations in time and space. Moreover, they possess such as shortcomings unreliable error message announcements and difficulties with real-time assistance suppers and emergency measures. In order to solve these deficiencies, Wireless Remote Control System was designed and implemented. Wireless Remote Control System is able to manage and monitor remote systems by using mobile communication devices for instantaneous control. The implementation of Wireless Remote Control System leads to these security Problems as well as solutions to aforementioned issues with existing web-based system management software solutions. Therefore, this paper has focused on the security matters related to Wireless Remote Control System. The designed security functions include mobile device user authentication and target system access control. For security verification of these security functions introduced CPN(Coloured Petri Nets) which is capable of expressing every possible state for each stage. And then in this paper was verified its security through PI(Place Invariant) based on CPN(Coloured Petri Nets). The CPN expression and analysis method of the proposed security function can also be a useful method for analyzing other services in the future.

The Assessment of Cross Calibration/Validation Accuracy for KOMPSAT-3 Using Landsat 8 and 6S

  • Jin, Cheonggil;Choi, Chuluong
    • Korean Journal of Remote Sensing
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    • v.37 no.1
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    • pp.123-137
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    • 2021
  • In this study, we performed cross calibration of KOMPSAT-3 AEISS imaging sensor with reference to normalized pixels in the Landsat 8 OLI scenes of homogenous ROI recorded by both sensors between January 2014 and December 2019 at the Libya 4 PICS. Cross calibration is using images from a stable and well-calibrated satellite sensor as references to harmonize measurements from other sensors and/or characterize other sensors. But cross calibration has two problems; RSR and temporal difference. The RSR of KOMPSAT-3 and Landsat 8 are similar at the blue and green bands. But the red and NIR bands have a large difference. So we calculate SBAF of each sensor. We compared the SBAF estimated from the TOA Radiance simulation with KOMPSAT-3 and Landsat 8, the results displayed a difference of about 2.07~2.92% and 0.96~1.21% in the VIS and NIR bands. Before SBAF, Reflectance and Radiance difference was 0.42~23.23%. Case of difference temporal, we simulated by 6S and Landsat 8 for alignment the same acquisition time. The SBAF-corrected cross calibration coefficients using KOMPSAT-3, 6S and simulated Landsat 8 compared to the initial cross calibration without correction demonstrated a percentage difference in the spectral bands of about 0.866~1.192%. KOMPSAT-3 maximum uncertainty was estimated at 3.26~3.89%; errors due to atmospheric condition minimized to less than 1% (via 6S); Maximum deviation of KOMPSAT-3 DN was less than 1%. As the result, the results affirm that SBAF and 6s simulation enhanced cross-calibration accuracy.

Comparison of Rolling Element Loads and Stress-based Fatigue Life Predictions for Ball Bearings (볼 베어링의 전동체 기반 및 응력 기반 접촉 피로수명의 비교)

  • Kwak, Jae Seob;Park, Yong Whan;Kim, Chan Jung;Kim, Tae Wan
    • Tribology and Lubricants
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    • v.36 no.6
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    • pp.371-377
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    • 2020
  • In In this study, we compared the results of a ball bearing life prediction model based on rolling element loads with the results of fatigue life prediction of ball bearings when a stress-based contact fatigue life prediction technique is applied to the ball bearing. We calculate the load acting on each rolling element by the external load of the bearing and apply the result to the Lundberg-Palmgren (LP) theory to calculate ball bearing life based on the rolling element. We also calculate stress-based ball bearing life through contact and fatigue analyses based on contact modeling of the ball and raceway while considering the fatigue test results of AISI 52100 steel. In stress-based life prediction, we use three high-cycle fatigue-determination equations that can predict the fatigue life when multi-axis proportional loads such as rolling-slide contact conditions are applied. These equations are derived from the stress invariant and critical plane methods and the mesoscopic approach. Life expectancy results are compared with those of the LP model. Results of the analysis indicated that the fatigue life was predicted to be lower in the order of the Crossland, Dang Van, and Matake models. Of the three, the Dang Van fatigue model was found to be the closest to the LP life.

Molecular Characterization of the Nitrate Reductase Gene in Chlorella vulgaris PKVL7422 Isolated from Freshwater in Korea (국내 담수에서 분리된 Chlorella vulgaris PKVL7422 질소환원 유전자의 분자적 특성)

  • Abdellaoui, Najib;Kim, Min-Jeong;Choi, Tae-Jin
    • Journal of Life Science
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    • v.32 no.8
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    • pp.659-665
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    • 2022
  • Chlorella vulgaris is an important freshwater alga that is widely used as a food source by humans and animals. Recently, Chlorella has received considerable attention with regard to its potential application in aquaculture and the production of biofuels, nutrients, and therapeutic proteins. Recently, our laboratory acquired a new strain of C. vulgaris, PKVL7422, characterized by fast growth, ease of culture, and cultivability under dark conditions. However, the genes involved in its nitrogen assimilation are unknown. In this work, we identified the nitrate reductase (NR) gene of C. vulgaris PKVL7422 using rapid amplification of cDNA ends and genome walking. The NR gene of C. vulgaris PKVL7422 is approximately 8 kb long and composed of 18 introns and 19 exons, which encode 877 amino acids. An alignment analysis of the NR gene showed that it possesses the five domains and several invariant residues found in plant NRs. These results provide new insight into the molecular organization of the NR gene in algae.

Review of Identification of Medicinal Products (IDMP) Standards for Standardization of Herbal Medicine Information (한약 정보 표준화를 위한 의약품 식별 표준 (IDMP) 분석 및 고찰)

  • Kim, Young-Sik;Kim, Anna;Lee, Seungho
    • The Korea Journal of Herbology
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    • v.37 no.5
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    • pp.37-51
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    • 2022
  • Objectives : The purpose of this study was to apply informations related to herbal medicines to IDMP (Identification of Medicinal Products), an ISO standards related to medicinal products substances, for systematic collection of data through the integration of informations on distribution, manufacturing, and management of herbal medicines. Methods : By analyzing ISO 11238 and ISO/TS 19844, elements that can be used in the information model of herbal medicine were derived from the identification of medicinal products information model on substances. The labeling specified in the safety and quality control regulations for herbal medicines was mapped to the IDMP information model, and ginseng was applied as an example. Results : Herbal medicine corresponded to substance in IDMP. Among the five types of substances specified by IDMP, herbal medicines were expressed as structurally diverse. Scientific name was used as an invariant property of herbal medicine, and the substance level included information about source material and modification, and specifically included information about the scientific name, medicinal part, fraction, and processing. In addition, the specified substance level had information on the constituents, characteristic attributes, manufacturing, and grade of the herbal medicine. Conclusions : It is necessary to establish a code system for identifying herbal medicines. In order to apply the IDMP standards, research on the development of standard terms is required to express the characteristics of herbal medicines. In addition, information for identification of herbal medicines is also required, and information from production to consumption should be systematically accumulated and managed for actual application.

Effect of Pay-as-you-throw Bag Prices on Domestic Waste: Evidence from a Natural Experiment of Busan (종량제봉투 가격이 생활폐기물 배출량에 미치는 영향: 부산광역시 자연실험 사례)

  • Koo, Namkyu
    • Environmental and Resource Economics Review
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    • v.31 no.3
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    • pp.319-342
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    • 2022
  • This study analyzed the effect of pay-as-you-throw bag prices on domestic waste through the natural experiment difference in difference with synthetic control method using cases of price cuts in some districts in Busan in 2019. In order to consider the endogenous problem when estimating demand and price elasticity, the price-invariant district was set as a synthetic control group and the price-cutting district was set as a treatment group. As a result of the analysis, the price elasticity of demand was 0.05~0.11, and the price of the pay-as-you-throw bag had little effect in sales. This seems to be because pay-as-you-throw bag is necessities and account for a very small proportion of household income. This suggests that a policy that can shift the demand curve will be more effective than a price policy to achieve the waste reduction goal because the demand curve is almost vertical.

Background illumination invariant hand posture recognition system using color temperature compensation (색 온도 보정을 통한 배경 및 조도 변화에 강인한 손 모양 인식 방법)

  • Lee, Seong-il;Min, Hyun-Seok;Shin, Ho-Chul;Lim, Eul-Gyoon;Hwang, Dae Hwan;Ro, Yong Man
    • Proceedings of the Korea Information Processing Society Conference
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    • 2009.11a
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    • pp.411-412
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    • 2009
  • 최근 시각 기반 인터페이스를 위하여, 손 동작 인식 기술 개발의 필요성이 증가하고 있다. 이러한 손 동작 인식 기술에서 손 모양 인식은 중요한 부분이며, 이는 손 영역 검출의 결과에 많은 영향을 받는다. 기존의 많은 손 동작 인식 기술들은 사람의 피부색이 갖는 컬러 특징을 이용하여 손 영역을 검출하였다. 그러나, 이러한 컬러 정보는 배경 및 조도 변화에 매우 민감하다. 이러한 문제를 해결하기 위해 본 논문에서는, 색 온도 보정 과정을 손 영역 검출에 적용함으로써 배경 및 조도 변화에 강인한 손 모양 인식 시스템을 제안한다. 제안한 방법이 배경 및 조도 변화에 강인함을 보이기 위해, 조명의 밝기 수준을 조절하며, 다양한 색을 배경으로 찍은 손 영상을 입력으로 손 모양 인식 성능을 실험하였다. 기존의 피부색을 이용한 손 영역 검출과의 비교 실험 결과를 통해, 제안한 방법이 배경 및 조도 변화에 강인한 손 모양 인식 성능을 가짐을 확인하였다.

Analysis of Computer Vision Application for CGRA Mapping : SIFT (재구성형 프로세서 맵핑을 위한 컴퓨터 비전 응용 분석 : SIFT)

  • Heo, Ingoo;Kim, Yongjoo;Lee, Jinyong;Cho, Yeongpil;Paek, Yunheung;Ko, Kwangman
    • Proceedings of the Korea Information Processing Society Conference
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    • 2011.11a
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    • pp.5-8
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    • 2011
  • 최근 영상이나 이미지로부터 사용자가 원하는 정보를 추출해 내고 재구성 하는 영상 인식, 증강 현실 등의 컴퓨터 비전(Computer Vision) 응용들이 각광을 받고 있다. 이러한 컴퓨터 비전 응용들은 그 동안 많은 알고리즘들의 연구를 통해 꾸준히 개선되고 향상되어 왔으나, 많은 계산량을 요구하기 때문에 임베디드 시스템에서는 널리 쓰이기 힘들었다. 하지만 최근 들어, 스마트폰 등의 모바일 기기에서의 계산 처리 능력이 향상 되고, 소비자 수요가 증가하면서, 이러한 컴퓨터 비전 응용은 점점 모바일 기기에서 널리 쓰이게 되고 있다. 하지만, 여전히 이러한 컴퓨터 응용을 수행하기 위한 계산양은 부족하기 때문에, 충분한 연산량을 제공하기 위한 방법론들이 다양하게 제시되고 있다. 본 논문에서는 이러한 컴퓨터 응용을 위한 프로세서 구조로서 재구성형 프로세서(Reconfigurable Architecture)를 제안한다. 컴퓨터 비전 응용 중 사물 인식 분야에서 널리 쓰이는 SIFT(Scale Invariant Feature Transformation)을 분석하고 이를 재구성형 프로세서에 맵핑하여 성능 향상을 꾀하였다. SIFT의 주요 커널들을 재구성형 프로세서 맵핑한 결과 최소 6.5배에서 최대 9.2배의 성능 향상을 이룰 수 있었다.

FE-CBIRS Using Color Distribution for Cut Retrieval in IPTV (IPTV에서 컷 검색을 위한 색 분포정보를 이용한 FE-CBIRS)

  • Koo, Gun-Seo
    • Journal of the Korea Society of Computer and Information
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    • v.14 no.1
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    • pp.91-97
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    • 2009
  • This paper proposes novel FE-CBIRS that finds best position of a cut to be retrieved based on color feature distribution in digital contents of IPTV. Conventional CBIRS have used a method that utilizes both color and shape information together to classify images, as well as a method that utilizes both feature information of the entire region and feature information of a partial region that is extracted by segmentation for searching. Also, in the algorithm, average, standard deviation and skewness values are used in case of color features for each hue, saturation and intensity values respectively. Furthermore, in case of using partial regions, only a few major colors are used and in case of shape features, the invariant moment is mainly used on the extracted partial regions. Due to these reasons, some problems have been issued in CBIRS in processing time and accuracy so far. Therefore, in order to tackle these problems, this paper proposes the FE-CBIRS that makes searching speed faster by classifying and indexing the extracted color information by each class and by using several cuts that are restricted in range as comparative images.