• Title/Summary/Keyword: Reference group

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Construction of Network RTK Testbed Using Reference Stations of NGII (국토지리정보원 기준국 사용 Network RTK 테스트베드 구축)

  • Bu-Gyeom Kim;Changdon Kee
    • Journal of Positioning, Navigation, and Timing
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    • v.13 no.1
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    • pp.103-110
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    • 2024
  • In this paper, a test bed for real-time network Real-Time Kinematic (RTK) research was constructed using reference stations of the NGII. A group of candidate station networks was derived, including three stations in Seoul. The group consisted of four stations with a distance of less than 100 km between them. Among several candidates, a network composed of stations with short distances between them and demonstrating good data quality for all reference stations was selected as the test bed. After collecting real-time data in Radio Technical Committee for Maritime services (RTCM) format from the selected stations and conducting a noise analysis on measurements, mm-level carrier phase measurement noise was confirmed. Afterwards, the user set the reference station inside the test bed and analyzed the network RTK positioning performance of the MAC method using the GPS L1 frequency as post-processing. From the result of the analysis it was confirmed that the residual error for all users was within 10 cm after applying the correction. Additionally, after determining integer ambiguities through Least-squares AMBiguity Decorrelation Adjustment (LAMBDA), it was confirmed that the fix rate was 100%, and all ambiguities were resolved as true values.

A Robust Watermarking Technique Using Affine Transform and Cross-Reference Points (어파인 변형과 교차참조점을 이용한 강인한 워터마킹 기법)

  • Lee, Hang-Chan
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.56 no.3
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    • pp.615-622
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    • 2007
  • In general, Harris detector is commonly used for finding salient points in watermarking systems using feature points. Harris detector is a kind of combined comer and edge detector which is based on neighboring image data distribution, therefore it has some limitation to find accurate salient points after watermark embedding or any kinds of digital attacks. In this paper, we have used cross reference points which use not data distribution but geometrical structure of a normalized image in order to avoid pointing error caused by the distortion of image data. After normalization, we find cross reference points and take inverse normalization of these points. Next, we construct a group of triangles using tessellation with inversely normalized cross reference points. The watermarks are affine transformed and transformed-watermarks are embedded into not normalized image but original one. Only locations of watermarks are determined on the normalized image. Therefore, we can reduce data loss of watermark which is caused by inverse normalization. As a result, we can detect watermarks with high correlation after several digital attacks.

Development of nutrient-based nutritional standards for foodservice at shelters during disasters in the Republic of Korea

  • Satoko Abe;Meeyoung Kim;Jihyun Yoon
    • Nutrition Research and Practice
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    • v.17 no.1
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    • pp.135-148
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    • 2023
  • BACKGROUND/OBJECTIVES: In times of disaster, simplified and minimized nutritional standards are necessary for a quick response to provide nutritious relief food. This study aimed to develop nutrient-based nutritional standards for foodservice at shelters during disasters in the Republic of Korea (South Korea). SUBJECTS/METHODS: The standards were developed in 2 phases. First, nutrients to be included in the standards were selected. Initial candidates were selected considering 3 aspects: preceding standards, insufficient intake during disasters, and inadequate intake among South Koreans. Final selection was made by excluding nutrients for 3 reasons: nutrients for which there is no deficiency concern in South Korea, nutrients whose intake data were not available, or nutrients whose values presented by Dietary Reference Intakes for Koreans are difficult to achieve based on the current diet among South Koreans. Second, the reference values of energy and the selected nutrients were calculated. The reference values for the entire population who were 1-year-old and over were calculated by multiplying the estimated energy requirements or the recommended nutrient intake and the proportion of each age and sex group. Respective reference values were also calculated for 4 different age groups (1-5, 6-11, 12-64, and ≥ 65-year-old). RESULTS: The standards for the entire population were 2,000 kcal for energy, 55 g for protein, 650 ㎍ retinol activity equivalents for vitamin A, 95 mg for vitamin C, 1.1 mg for thiamin, 1.3 mg for riboflavin, 14 mg niacin equivalents for niacin, 350 ㎍ dietary folate equivalents for folic acid, 750 mg for calcium, and 11 mg for iron. Four additional standards corresponding to each age group were developed. CONCLUSIONS: The nutritional standards during disasters were developed for South Korea, including energy and 9 nutrients with reference values for the entire population and 4 different age groups. The standards will contribute to maintaining the health of disaster evacuees in South Korea.

Discrete Group Method for Nonlinear Heat Equation

  • Darania, Parviz;Ebadian, Ali
    • Kyungpook Mathematical Journal
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    • v.46 no.3
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    • pp.329-336
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    • 2006
  • In the category of the group theoretic methods using invertible discrete group transformation, we give a useful relation between Emden-Fowler equations and nonlinear heat equation. In this paper, by means of appropriate transformations of discrete group analysis, the nonlinear hate equation transformed into the class of the Emden-Fowler equations. This approach shows that, under the group action, the solution of reference equation can be transformed into the solution of the transformed equation.

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Neural Network Compensation Technique for Standard PD-Like Fuzzy Controlled Nonlinear Systems

  • Song, Deok-Hee;Lee, Geun-Hyeong;Jung, Seul
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.8 no.1
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    • pp.68-74
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    • 2008
  • In this paper, a novel neural fuzzy control method is proposed to control nonlinear systems. A standard PD-like fuzzy controller is designed and used as a main controller for the system. Then a neural network controller is added to the reference trajectories to form a neural-fuzzy control structure and used to compensate for nonlinear effects. Two neural-fuzzy control schemes based on two well-known neural network control schemes, the feedback error learning scheme and the reference compensation technique scheme as well as the standard PD-like fuzzy control are studied. Those schemes are tested to control the angle and the position of the inverted pendulum and their performances are compared.

A Transparent Object Group Reference Management Scheme for Group Communication in CORBA (CORBA에서 그룹 통신 지원을 위한 투명성 있는 객체 그룹 참조 관리에 관한 연구)

  • 조영주;이동만;남덕윤;강경란
    • Proceedings of the Korean Information Science Society Conference
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    • 2002.10e
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    • pp.232-234
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    • 2002
  • 분산 어플리케이션에서 고장에 잘 견디고 높은 가용성을 제공하기 위해 객체 복제를 사용한다. 그리고, 객체 그룹에서 복제된 객체들 간의 일관성을 제공하기 위해 그룹 통신에서 그룹 멤버쉽을 사용한다. 그룹 멤버 쉽 서비스는 사용자가 하나의 객체 참조를 사용하여 객체 그룹에 접근할 수 있도록 하는 기능을 제공한다. FT-CORBA에서는 그룹 멤버쉽 정보를 포함하는 IOGR (Interoperable Object Group Reference)을 제공하지만, 객체 복제가 그룹에 참여하거나 떠날 때마다 IOGR이 그룹의 모든 멤버에게 변경 사항을 전달해야 한다는 부담을 갖는다. 본 연구에서는 동적인 멤버쉽의 변경에서도 투명성 있는 객체 그룹 참조관리를 할 수 있는 기법을 제안하고, 제안된 기법을 OCI 기반의 그룹 통신 지원을 위한 프레임워크를 활용하여 구현하였다.

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International Trend Towards Comparability of Glabal Oceanic Nutrient Data: SCOR Working Group 147 (Towards Comparability of Global Oceanic Nutrient Data, COMPONUT) Activity (전 세계 대양 영양염 자료의 상호 비교성 향상을 위한 국제동향 : SCOR Working Group 147 (Towards Comparability of Global Oceanic Nutrient Data, COMPONUT) 활동에 대하여)

  • Rho, TaeKeun;Kim, Eun-Soo;Kahng, Sung-Hyun;Cho, Sung-Rok
    • Ocean and Polar Research
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    • v.37 no.3
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    • pp.225-233
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    • 2015
  • To understand the fluctuation of global carbon levels caused by the biogeochemical cycle within the ocean interior, it is essential to achieve comparability of global oceanic nutrient data to a fairly high degree. The Scientific Committee on Ocean Research (SCOR) commissioned a working group (WG147) to establish a system for achieving comparability of oceanic nutrient data within 1% among laboratories around the world. The introduction of international activities for improving nutrient comparability will facilitate the use of nutrient reference material of seawater by researchers within Korea, which will help in meeting international standards of nutrient comparability and promote international cooperation.

Development of a Mushroom Powder Certified Reference Material for Element Analysis

  • Betru, Tegegn Gizachew;Yim, Yong-Hyeon;Lee, Kyoung-Seok
    • Mass Spectrometry Letters
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    • v.11 no.4
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    • pp.108-112
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    • 2020
  • A certified reference material (CRM) for the analysis of nutrient elements in an edible mushroom (Ganoderma lyceum) powder has been developed (KRISS CRM 108-10-011). The mass fractions of calcium (Ca), iron (Fe), and zinc (Zn) were measured by isotope dilution inductively coupled plasma mass spectrometry (ID ICP/MS). To dissolve the fungi cell wall of mushroom consisted of chitin fibers, sample preparation method by single reaction chamber type microwave-assisted acid digestion with acid mixtures was optimized. The mean measurement results obtained from 12 sample bottles were used to assign as the certified values for the CRM and the between-bottle homogeneities were evaluated from the relative standard deviations. The certified values were metrologically traceable to the definition of the kilogram in the International System of Units (SI). This CRM is expected to be used for validation of analytical methods or quality control of measurement results in analytical laboratories when they determine the mass fractions of elements in mushroom or other similar samples.

"Many Strange Things Were Hinted": The Meaning of Gams in Herman Melville's Moby-Dick from the Perspective of the Sailors' Formation of Group Identity ("많은 낯선 것들이 힌트로 제공되었다": 피쿼드호 선원들의 조직정체성 형성 관점에서 본 허먼 멜빌의 『모비딕』에 나오는 갬의 의미)

  • Lee, Kwangjin
    • American Studies
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    • v.43 no.2
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    • pp.27-56
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    • 2020
  • This paper attempts to interpret the meaning of nine gams in Herman Melville's Moby-Dick. It approaches the topic from an organizational identity perspective. It is the theory which asserts the importance of the reference group in the formation of group members' organizational identity. This paper views the gams as the reference groups for the sailors of the Pequod and shows what meanings or questions each gam presents to them. It divides the nine gams into three groups according to their functions in the organizational sense. This paper argues that the extremely dangerous quest of the Pequod is not led by the captain only, but the sailors, who are given many chances to make their decisions after having gams, eventually choose to obey and follow their leader. The tragic end is partly what they choose, after all.