• Title/Summary/Keyword: RAO

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A Methodology for Finding the Convergence Research Area by Measuring Convergence Index in Government Research Institutes (융합지수 측정을 통한 출연연 융합연구영역 발굴모형 연구)

  • Coh, Byoung-Youl;Kim, So-Young;Lee, Jae-Min
    • Journal of Korea Technology Innovation Society
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    • v.22 no.3
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    • pp.446-474
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    • 2019
  • In conjunction with securing R&D competitiveness through technology convergence, there is a growing interest in the strategy to derive innovation based on the measurement of convergence. In this paper, we present a data-based model that suggests convergence strategies for the research projects of government research institutes (GRIs) in Korea. The convergence characteristics of the research projects are represented by inherent attributes of technology and behavioral attributes of actors. The measuring process of the proxy variables (Rao-Stirling and Herfindahl-Hirschman Indices) for each attributes are proposed. These two indices are used to construct the convergence diagram, through which the research projects of GRIs are distributed into four areas: AllianceIntra, Alliance-Inter, Competition, Mission-Oriented. Based on the convergence diagram proposed in this study the convergence index is measured to derive 30 convergence research areas of GRIs. As a result, we expect to provide appropriate guidelines for setting the policy direction of the convergence research projects.

A Study on Projection for Apophyseal Joints Diagnosis in X-ray Thoracic Bone Oblique Projection (X-ray 등뼈의 사위 촬영에서 돌기사이관절의 진단을 위한 촬영법 연구)

  • Jun-Heang Lee
    • Journal of the Korean Society of Radiology
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    • v.17 no.3
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    • pp.351-357
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    • 2023
  • This Study Rreceived Subjective Evaluation ROC Evaluation from five projection. of projection. at a University Hospital to Obtain and Diagnose Sharp images of apophyseal joints and Vertral arch of Thoracic vertebrae from thoracic X-ray projection. In the Subjective evaluation, the highest Score was obtained by raising the phantom from Supine to LAO by 70° and scoring 20 points at 5° with the X-ray Tube facing the head. In addition, he scored the highest score of 19 points at 8° with the Prone Phantom standing 60° with RAO and the X-ray Tube facing the head. For Objective Evaluation, the Signal-to-noise ratio, was calculated. ROI was set at 1,564 mm2 to obtain the image signal average value (Mean value) and the Standard deviation (SD value). Objective Evaluation The signal-to-noise ratio, was the highest at 5° toward the head in the LPO 70° position of the phantom in the lying position of the Thoracic spine projection, and the Thoracic Spine was the highest at 8° toward the head of the RAO posture of 5,645.

Terrain-referenced Underwater Navigation using Rao-Blackwellized Particle Filter (라오-블랙웰라이즈드 입자필터를 이용한 지형참조 수중항법)

  • Kim, Taeyun;Kim, Jinwhan;Choi, Hyun-Taek
    • Journal of Institute of Control, Robotics and Systems
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    • v.19 no.8
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    • pp.682-687
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    • 2013
  • Navigation is a crucial capability for all types of manned or unmanned vehicles. However, vehicle navigation in underwater environments still remains a challenging problem since GPS signals for position fixes are not available in the water. Terrain-referenced underwater navigation is an alternative navigation technique that utilizes geometric information of the subsea terrain to correct drift errors due to dead-reckoning or inertial navigation. Terrain-referenced navigation requires the description of an undulating terrain surface as a mathematical function or table, which often leads to a highly nonlinear estimation problem. Recently, PFs (Particle Filters), which do not require any restrictive assumptions about the system dynamics and uncertainty distributions, have been widely used for nonlinear filtering applications. However, PF has considerable computational requirements which used to limit its applicability to problems of relatively low state dimensions. This study proposes the use of a Rao-Blackwellized particle filter that is computationally more efficient than the standard PF for terrain-referenced underwater navigation involving a moderate number of states, and its performance is compared with that of the extended Kalman filter algorithm. The validity and feasibility of the proposed algorithm is demonstrated through numerical simulations.

Strain Improvement of Candida tropicalis for the Production of Xylitol: Biochemical and Physiological Characterization of Wild-type and Mutant Strain CT-OMV5

  • Rao Ravella Sreenivas;Jyothi Cherukuri Pavanna;Prakasham Reddy Shetty;Rao Chaganti Subba;Sarma Ponnupalli Nageshwara;Rao Linga Venkateswar
    • Journal of Microbiology
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    • v.44 no.1
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    • pp.113-120
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    • 2006
  • Candida tropicalis was treated with ultraviolet (UV) rays, and the mutants obtained were screened for xylitol production. One of the mutants, the UV1 produced 0.81g of xylitol per gram of xylose. This was further mutated with N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), and the mutants obtained were screened for xylitol production. One of the mutants (CT-OMV5) produced 0.85g/g of xylitol from xylose. Xylitol production improved to 0.87 g/g of xylose with this strain when the production medium was supplemented with urea. The CT-OMV5 mutant strain differs by 12 tests when compared to the wild-type Candida tropicalis strain. The XR activity was higher in mutant CT-OMV5. The distinct difference between the mutant and wild-type strain is the presence of numerous chlamvdospores in the mutant. In this investigation, we have demonstrated that mutagenesis was successful in generating a superior xylitol-producing strain, CT-OMV5, and uncovered distinctive biochemical and physiological characteristics of the wild-type and mutant strain, CT-OMV5.

Cramér-Rao Lower Bound (CRLB) Analysis for Unmanned Aerial Vehicle (UAV) Tracking with Randomly Distributed Ground Stations Using FDOA Measurements (다수의 지상국(GS)을 이용한 무인 항공기(UAV) 추적 FDOA 기반의 CRLB 성능 분석 연구)

  • Min, Byoung-Yoon;An, Chan-Ho;Hong, Seok-Jun;Jang, Jeen-Sang;Kim, Dong-Ku
    • Journal of Advanced Navigation Technology
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    • v.15 no.2
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    • pp.234-240
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    • 2011
  • In this paper, the performances of Cram$\acute{e}$r-Rao Lower Bound (CRLB) with Frequency Difference of Arrival (FDOA) measurements for Unmanned Aerial Vehicle (UAV) tracking are investigated. We focus on two cases: the influence on CRLB with FDOA measurements collected by time, and random distribution of Ground Stations (GSs). We derived the performance by gauging the size of CRLB through Complementary Cumulative Distribution Function (CCDF). From the simulation results, broader distribution of GSs and FDOA measurements by longer time bring about better performance.

Corrosion Resistance and Thermo-optical Properties of Lithium Polysilicate Spray Coated Anodized AZ31B Magnesium Alloy for Space Applications

  • Ghosh, Rahul;Thota, Hari K.;Rani, R. Uma
    • Corrosion Science and Technology
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    • v.18 no.5
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    • pp.182-189
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    • 2019
  • A thin spray coating of inorganic black lithium polysilicate (IBLP) on black anodized AZ31B magnesium alloy was fabricated for better corrosion resistance and thermo-optical properties for thermal control of spacecraft components. The morphology of the specimens with and without IBLP-based spray coating was characterized by SEM-EDS techniques. Impedance and potentiodynamic measurements on the specimens revealed better corrosion resistance for the specimen with a thin coating of lithium polysilicate. This was primarily due to the presence of lithium polysilicate inside the micro-cracks of the black anodized specimen, restricting the diffusion paths for corrosive media. Environmental tests, namely, humidity, thermal cycling, thermo vacuum performance, were used to evaluate the space-worthiness of the coating. The thermo-optical properties of the coating were measured before and after each environmental test to ascertain its stability. The specimen with an IBLP-based spray coating showed enhanced thermo-optical properties, greater than ~0.90. Hence, the proposed coating demonstrated better handling, better corrosion resistance, and space-worthiness during the pre-launch phase owing to its improved thermo-optical properties.

Optimum design of cantilever retaining walls under seismic loads using a hybrid TLBO algorithm

  • Temur, Rasim
    • Geomechanics and Engineering
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    • v.24 no.3
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    • pp.237-251
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    • 2021
  • The main purpose of this study is to investigate the performance of the proposed hybrid teaching-learning based optimization algorithm on the optimum design of reinforced concrete (RC) cantilever retaining walls. For this purpose, three different design examples are optimized with 100 independent runs considering continuous and discrete variables. In order to determine the algorithm performance, the optimization results were compared with the outcomes of the nine powerful meta-heuristic algorithms applied to this problem, previously: the big bang-big crunch (BB-BC), the biogeography based optimization (BBO), the flower pollination (FPA), the grey wolf optimization (GWO), the harmony search (HS), the particle swarm optimization (PSO), the teaching-learning based optimization (TLBO), the jaya (JA), and Rao-3 algorithms. Moreover, Rao-1 and Rao-2 algorithms are applied to this design problem for the first time. The objective function is defined as minimizing the total material and labor costs including concrete, steel, and formwork per unit length of the cantilever retaining walls subjected to the requirements of the American Concrete Institute (ACI 318-05). Furthermore, the effects of peak ground acceleration value on minimum total cost is investigated using various stem height, surcharge loads, and backfill slope angle. Finally, the most robust results were obtained by HTLBO with 50 populations. Consequently the optimization results show that, depending on the increase in PGA value, the optimum cost of RC cantilever retaining walls increases smoothly with the stem height but increases rapidly with the surcharge loads and backfill slope angle.