• Title/Summary/Keyword: AOA

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Research Regarding Filter Composition and Motor control for Yagi-Antenna Remote Tracking System (야기 안테나가 적용된 원격추적시스템을 위한 필터구성 및 모터 제어에 관한 연구)

  • You, Chong-Ho;Song, Beob-Seong;Hwang, In-Gab
    • The Journal of the Korea institute of electronic communication sciences
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    • v.11 no.11
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    • pp.1039-1046
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    • 2016
  • To study a habit and life patten of a wild animal, this paper do a research on the location tracing system of wild animal by yagi-antenna low pass filter, angle tracking technology. Commonly, VHF Radio Telemetry is used for the location tracing system of wild animal. Considering movement, Previous yagi-antenna has 4-element and has advantage of portability but the other advantages are small and preference is weak. To make the advantage of yagi-antenna higher than previous one, Supposed technology adapt to 6-element and make out Narrow space yagi-antenna technology. Also, It supposes that AOA (:Angle of arrival) technology is applied to detecting technology for a close direction from received signal. Based on this study suggest that position tracing technology is so as to figure out a life patten and habit of a wild animal which live in a certain area.

The 3D Numerical Analysis on the Turbulent at 40° Crosswind, for the Predictions of Flight Stability at Take-off and Landing (이·착륙 비행 안정성 예측을 위한 측풍 40° 방향에 대한 3차원 수치해석)

  • Sheen, Dong-Jin;Kim, Do-Hyun;Park, Soo-Bok
    • Journal of Advanced Navigation Technology
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    • v.16 no.2
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    • pp.179-189
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    • 2012
  • The aim of this paper is to research the change in the turbulent flow and the AOA(Angle Of Attack) occurred by $40^{\circ}$ crosswind to the direction of runway through the three-dimensional numerical analysis and to predict the take-off and landing flight stability. As a result, the maximum amplitude of AOA variation on runway reached $2^{\circ}$ within 3 second because of the wake formed by the constructions in the vicinity of the airport, and the overall effects appeared as an irregular aperiodic forms. Additionally, it was observed that the layout and shape of the buildings effected on the strength of turbulence directly, and the rapid flow generated between the buildings changed into stronger wake and eventually expected that the flow raises serious take-off and landing flight instability.

Methylation Status of the O6-Methylguanine-Deoxyribonucleic Acid Methyltransferase Gene Promoter in World Health Organization Grade III Gliomas

  • Yang, Seung-Heon;Kim, Yong-Hwy;Kim, Jin-Wook;Park, Chul-Kee;Park, Sung-Hye;Jung, Hee-Won
    • Journal of Korean Neurosurgical Society
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    • v.46 no.4
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    • pp.385-388
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    • 2009
  • Objective : We analyzed the methylation status of the O6-methylguanine-DNA methyltransferase (MGMT) gene promoter in World Health Organization (WHO) grade III gliomas in association with other molecular markers to evaluate their prevalence. Methods : The samples of a total of 36 newly WHO grade III glioma patients including 19 anaplastic oligodendrogliomas (AO), 7 anaplastic oligoastrocytomas (AOA), and 10 anaplastic astrocytomas (AA) were analyzed. The methylation status of the MGMT gene promoter was confirmed by methylation-specific polymerase chain reaction. The 1p/19q chromosomal deletion status and EGFR amplification were assessed by Fluorescence In-Situ Hybridization. MGMT, EGFR, EGFRvlll, and p53 expression were analyzed by immunohistochemical staining. Results : The MGMT gene promoter was methylated in 32 (88.9%) and unmethylated in 4 (11.2%) Among them, all of the AO and AOA had methylated MGMT gene promoter without exception. Significant associations between MGMT gene promoter hypermethylation and 1p/19q deletion was observed (p=0.003). Other molecular markers failed to show significant associations between MGMT gene promoter statuses. Conclusion : There was extensive epigenetic silencing of MGMT gene in high grade gliomas with oligodendroglial component. Together with frequent 1p/19q co-deletion in oligodendroglial tumors, this may add plausible explanations supporting the relative favorable prognosis in oligodendroglial tumors compared with pure astrocytic tumors.

A Location Estimation Method Using TDOA Scheme in Vessel Environment (선박 환경에서 TDOA 기법에 의한 위치 추정 방법)

  • Kim, Beom-mu;Jeong, Min A;Lee, Seong Ro
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.19 no.8
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    • pp.1934-1942
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    • 2015
  • An estimation problem in the environment which GPS signals do not reach, should be solved by employing an indoor location estimation scheme. Location estimation schemes for indoor environments generally include the AOA, TOA, RSS, Fingerprint, and TDOA. For a ship environment where there exist many spaces enclosed by iron plates, the TDOA scheme is appropriate because location estimation is usually performed at a closed range. In this paper, we address the problem of estimating the location of a terminal under the ship environment. The problem of location estimation by using the TDOA is presented in detail, and then an algorithm for applying the estimation to the ship environment is proposed. Finally, the proposed algorithm of location estimation in a ship by the TDOA scheme is verified through simulations from three viewpoints.

Performance Analysis of MIMO-OFDM System over Nakagami Fading Channel (나카가미 페이딩 채널하에서 MIMO-OFDM 시스템의 성능분석)

  • Kang, Kyung-Sik;Kim, Won-Sub;Park, Chun-Ho
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.15 no.8
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    • pp.1797-1804
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    • 2011
  • In this paper, I analyzed array organization of MIMO channel antenna and effect of operation environment by evaluating average BER from linear Space-Time Block Code orthogonal design and suggests designing condition of MT antenna for improved BER and the fading index m. To analyze system performance, I used M-PSK and M-QAM modulation, and to use analysis equations I used integrated by Nakagami fading variable, non-integrated Nakagami fading variable. We can get the organization of channel array by using mathematical calculation on matrix. STBE BER performance will decrease as AOA spreading decrease and such loss can be compensated from extending antenna spacing, and changing array organization.

Potential Antioxidant Peptides in Rice Wine

  • Rhee, Sook-Jong;Lee, Chung-Yung J.;Kim, Mi-Ryung;Lee, Cherl-Ho
    • Journal of Microbiology and Biotechnology
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    • v.14 no.4
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    • pp.715-721
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    • 2004
  • Many food protein hydrolysates have been shown to have antioxidant activities, and recent research focuses on low molecular peptides produced during hydrolysis of food protein. Korean rice wine contains about 60-70% of protein at dry base and originates from raw materials. It has been suggested that the protein is transformed into low molecular weight peptides, and have antioxidant activity during fermentation. The objectives of this study were to evaluate the antioxidant activity of the pre-purified and purified peptides found in Korean rice wine and to identify the responsible peptides. The wine extract of Samhaeju, a traditional Korean rice wine made by low temperature fermentation, was evaporated at $35^{\circ}C$. The two methods employed in the evaluation of antioxidant activity were the DPPH radical scavenging method and the beta-carotene bleaching test. The pre-purified samples showed 808 AAC (Antioxidant Activity Coefficient) and 56.5% AOA (Antioxidant Activity), which were higher than $\alpha$-tocopherol (572 AAC and 78% AOA). The rice wine extract was separated by reversed-phase HPLC. The protective effect of the four most antioxidant active fractions were tested for t-butyl hydroperoxide induced oxidation of healthy human erythrocytes and the byproduct was determined by malondialdehyde formation. Fraction No.5 showed 35% lower MDA concentration as compared to the control. The peptides were further purified using consecutive chromatographic methods and 4 antioxidant peptides were isolated. The amino acid sequences of the peptides were identified as Ile-His-His, Val- Val-His(Asn), Leu-Val-Pro, and Leu(Val)-Lys-Arg-Pro. The AAC value of the synthetic form of the identified peptides was the highest for Ile-His-His.

A Study on the Removal Method of Radioactive Corrosion Product using its Magnetic Property (방사성 부식생성물의 자기적 성질을 이용한 제거방법에 대한 연구)

  • 송민철;공태영;이건재
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.1 no.1
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    • pp.73-79
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    • 2003
  • In a pressurized water reactor, radioactive corrosion products (CRUD) in primary coolant system are one of the major sources for the occupational radiation exposure of the personnel in a nuclear power plant. Through the recent trend of long term fuel cycle in a nuclear power Plant, radioactive corrosion products deposited in reactor core for a long time are also the cause of Axial Offset Anomaly (AOA) having m effect on reactor power by the hideout of boron. CRUD consist primarily of magnetite, nickel ferrite, cobalt ferrite, and so on. They have the characteristic of strong magnetism. Therefore it is performed the conceptual design to develop the filter which removes the CRUD by magnetic field that is generated by an arrangement of permanent and electric magnets. Contrary to the conventional filter, the proposed filter does not interrupt the fluid flow, so there is little pressure drop and it can be used continuously. It is expected to be applied as one of the technologies for removal of the CRUB.

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Conceptual Design of the Filter using Electromagnet and Permanent Magnets for Removal of Radioactive Corrosion Products (방사성 부식생성물 제거를 위한 전자석 및 영구자석을 이용한 필터의 개념설계)

  • 송민철;공태영;이건재
    • Proceedings of the Korean Radioactive Waste Society Conference
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    • 2003.11a
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    • pp.38-42
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    • 2003
  • In a pressurized water reactor, radioactive corrosion products (CRUD) in primary coolant system are one of the major sources for the occupational radiation exposure of the personnel in a nuclear power plant. Through the recent trend of long term fuel cycle in a nuclear power plant, radioactive corrosion products deposited in reactor core for a long time are also the cause of Axial Offset Anomaly (AOA) having an effect on reactor power by the hideout of boron. CRUD consist primarily of magnetite, nickel ferrite, cobalt ferrite, and so on. They have the characteristic of strong magnetism. Therefore it is peformed the conceptual design to develop the filter which removes the CRUD by magnetic field that is generated by an arrangement of permanent and electric magnets. Contrary to the conventional filter, the proposed filter does not interrupt the fluid flow, so there is little pressure drop and it can be used continuously. It is expected to be applied as one of the technologies for removal of the CRUD.

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Performance Analysis of Beamforming Satellite System Applying Circular Array Antenna (원형 형상 배열 안테나를 적용한 위성 빔형성 시스템 성능 분석)

  • Kim, Tae-Yun;Hwang, Suk-Seung
    • The Journal of the Korea institute of electronic communication sciences
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    • v.14 no.5
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    • pp.845-852
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    • 2019
  • The main goal of Signal Intelligence (SIGNT) based on a satellite is to collect valid and accurate data without the topographical constraints, but, due to the characteristics of the satellite communication, the collected signals are greatly vulnerable to the influence of interference and jamming signals because their power are very low. Therefore, the high performance techniques of estimating the angle of arrivals (AOAs) of the collected signals and suppressing interference signals are required for collecting various signals on the ground employing the satellite. In addition, the high quality of the transmission beam-forming technique is required for accurately transmitting the collected information to a ground control center. In this paper, we present a beam-forming satellite system based on a circular array antenna, considering the above techniques, and evaluate and analysis the performance of the presented beam-forming system through the computer simulation. The circular array antenna structure is expected to effectively employ for the SIGINT system based on a satellite, because it is suitable to be installed in the satellite.

BOTANI: High-fidelity multiphysics model for boron chemistry in CRUD deposits

  • Seo, Seungjin;Park, Byunggi;Kim, Sung Joong;Shin, Ho Cheol;Lee, Seo Jeong;Lee, Minho;Choi, Sungyeol
    • Nuclear Engineering and Technology
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    • v.53 no.5
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    • pp.1676-1685
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    • 2021
  • We develop a new high-fidelity multiphysics model to simulate boron chemistry in the porous Chalk River Unidentified Deposit (CRUD) deposits. Heat transfer, capillary flow, solute transport, and chemical reactions are fully coupled. The evaporation of coolant in the deposits is included in governing equations modified by the volume-averaged assumption of wick boiling. The axial offset anomaly (AOA) of the Seabrook nuclear power plant is simulated. The new model reasonably predicts the distributions of temperature, pressure, velocity, volumetric boiling heat density, and chemical concentrations. In the thicker CRUD regions, 60% of the total heat is removed by evaporative heat transfer, causing boron species accumulation. The new model successfully shows the quantitative effect of coolant evaporation on the local distributions of boron. The total amount of boron in the CRUD layer increases by a factor of 1.21 when an evaporation-driven increase of soluble and precipitated boron concentrations is reflected. In addition, the concentrations of B(OH)3 and LiBO2 are estimated according to various conditions such as different CRUD thickness and porosity. At the end of the cycle in the AOA case, the total mass of boron incorporated in CRUD deposits of a reference single fuel rod is estimated to be about 0.5 mg.