• Title/Summary/Keyword: $RRT^*$

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A Study on the Techniques of Path Planning and Measure of Effectiveness for the SEAD Mission of an UAV (무인기의 SEAD 임무 수행을 위한 임무 경로 생성 및 효과도 산출 기법 연구)

  • Woo, Ji Won;Park, Sang Yun;Nam, Gyeong Rae;Go, Jeong Hwan;Kim, Jae Kyung
    • Journal of Advanced Navigation Technology
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    • v.26 no.5
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    • pp.304-311
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    • 2022
  • Although the SEAD(suppression to enemy air defenses) mission is a strategically important task in modern warfare, the high risk of direct exposure to enemy air defense assets forces to use of unmanned aerial vehicles. this paper proposes a path planning algorithm for SEAD mission for an unmanned aerial vehicle and a method for calculating the mission effectiveness on the planned path. Based on the RRT-based path planning algorithm, a low-altitude ingress/egress flight path that can consider the enemy's short-range air defense threat was generated. The Dubins path-based Intercept path planning technique was used to generate a path that is the shortest path while avoiding the enemy's short-range anti-aircraft threat as much as possible. The ingress/intercept/egress paths were connected in order. In addition, mission effectiveness consisting of fuel consumption, the survival probability, the time required to perform the mission, and the target destruction probability was calculated based on the generated path. The proposed techniques were verified through a scenario.

Validation of a Real-Time RT-PCR Method to Quantify Newcastle Disease Virus (NDV) Titer and Comparison with Other Quantifiable Methods

  • Jang, Juno;Hong, Sung-Hwan;Kim, Ik-Hwan
    • Journal of Microbiology and Biotechnology
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    • v.21 no.1
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    • pp.100-108
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    • 2011
  • A method for the rapid detection and quantification of Newcastle disease virus (NDV) produced in an animal cell culture-based production system was developed to enhance the speed of the NDV vaccine manufacturing process. A SYBR Green I-based real-time RT-PCR was designed with a conventional, inexpensive RT-PCR kit targeting the F gene of the NDV LaSota strain. The method developed in this study was validated for specificity, accuracy, precision, linearity, limit of detection (LOD), limit of quantification (LOQ), and robustness. The validation results satisfied the predetermined acceptance criteria. The validated method was used to quantify virus samples produced in an animal cell culture-based production system. The method was able to quantify the NDV samples from mid- or late-production phases, but not effective on samples from the early-production phase. For comparison with other quantifiable methods, immunoblotting, plaque assay, and tissue culture infectious dose 50 ($TCID_{50}$) assay were also performed with the NDV samples. The results demonstrated that the real-time RT-PCR method is suitable for the rapid quantification of virus particles produced in an animal cell-culture-based production system irrespective of viral infectivity.

Effect of Input Soil Properties for Round Robin Test on Ground Response Analysis (지반 응답 해석 Round Robin Test의 입력 지반 물성에 따른 지반 응답 특성 영향 고찰)

  • Kim, Bong-Soo;Lee, Sei-Hyun;Choo, Yun-Wook;Park, Sung-Sik;Kim, Dong-Joon
    • Proceedings of the Korean Geotechical Society Conference
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    • 2007.09a
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    • pp.305-316
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    • 2007
  • Free field ground motion during earthquake is significantly affected by the local soil conditions and it is essential for the seismic design to perform the site specific ground response analysis. So, Round Robin Test (RRT) on ground response analysis was performed for three sites in Korea. A total of 12 teams presented the results of ground response analysis with used input soil properties based on own judgement. In this paper, the results of one dimensional equivalent linear analysis presented by 11 teams were compared to evaluate the effect of input soil properties on ground response analysis. Additionally, 4 influence factors on ground response analysis, that is shear wave velocity of soil layer, nonlinear dynamic deformational characteristics, bedrock depth and bedrock velocity were studied for assumed simple soil conditions.

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HRT-mediated Turnip crinkle virus Resistance in Arabidopsis

  • Park, Jeong-Mee;Daniel F. Klessig
    • The Plant Pathology Journal
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    • v.19 no.1
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    • pp.19-23
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    • 2003
  • Turnip crinkle vims (TCV) inoculation onto resistant Arabidopsis ecotype Dijon(Di-17) leads to a hypersensitive response (HR) on the inoculated leaves. A dominant gene, HRT, which confers an HR to TCV, has been cloned from Di-17 plants by map-based cloning. HRT is a LZ-NBS-LRR class resistance gene and it belongs to a small gene family that includes RPP8, which confers resistance to Peronospora parasitica Emco5. Outside of the LRR region, HRT and RPP8 proteins share 98% amino acid identity while their LRR regions are less conserved (87% identity). HRT-transformed Arabidopsis plants developed an HR but generally remained susceptible to TCV due to a dominant RRT allele, which is not compatible with resistance. However, several transgenic plants that over-expressed HRT much higher than Di-l7 showed micro-HR or no HR when inoculated with TCV and were resistant to infection. Both the HR and resistance are dependent on salicylic acid but independent of NPRI, ethylene, or jasmonic acid. Arabidopsis plants containing both TCV coat protein gene and HRT developed massive necrosis and death in seedlings, indicating that the TCV coat protein is an avirulence factor detected by the HRT.

Unrelated Question Model in Sensitive Multi-Character Surveys

  • Sidhu, Sukhjinder Singh;Bansal, Mohan Lal;Kim, Jong-Min;Singh, Sarjinder
    • Communications for Statistical Applications and Methods
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    • v.16 no.1
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    • pp.169-183
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    • 2009
  • The simplicity and wide application of Greenberg et al. (1971) prompts to propose a set of alternative estimators of population total for multi-character surveys that elicit simultaneous information on many. sensitive study variables. The proposed estimators take into account the already known rough value of the correlation coefficient between Y(the characteristic under study) and p(the measure of size). These estimators are biased, but it is expected that the extent of bias will be smaller, since the proposed estimators are suitable for situations in between those optimum for the usual estimators and the estimators based on multi-characters for no correlation. The relative efficiency of the proposed estimators has been studied under a super population model through empirical study. It has been found through simulation study that a choice of an unrelated variable in the Greenberg et al. (1971) model could be made based on its correlation with the auxiliary variable used at estimation stage in multi-character surveys.

Analysis on the Results of the World Wide Rockwell Hardness Round Robin Test with Conical Indenters (로크웰 경도 국제비교교정 결과 분석)

  • Bahng, G.W.;Tak, N.H.;Polzin, T.
    • Journal of the Korean Society for Heat Treatment
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    • v.14 no.6
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    • pp.336-344
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    • 2001
  • For the establishment of the world wide unified scales of the Rockwell hardness test with conical indenters, round robin test was carried from 1998 to 2000. The pilot laboratory was MPA-NRW and 12 laboratories from 11 countries participated In this RRT. Rockwell hardness of 74 specially prepared blocks was measured for the scales of C, A, D, 45N, 30N, and 15N and the results were compared. It was found that the geometric form of indenter affects on the results very significantly and standardization in the measurement and evaluation of indenter should be established in short time for the reliable hardness measurement. KRISS showed good results in general for all of the ranges except 15N scale which showed relatively large difference compare to the mean value. It was concluded that poor control in loading velocity of the dash pot was the major reason.

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Path Planning Method for an Autonomous Underwater Vehicle With Environmental Movement Congestions (환경이동혼잡조건을 고려한 자율무인잠수정의 이동경로생성 방법)

  • You, Sujeong;Kim, Ji Woong;Ji, Sang Hoon;Woo, Jongsik
    • IEMEK Journal of Embedded Systems and Applications
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    • v.13 no.2
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    • pp.65-71
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    • 2018
  • In order to make the underwater vehicle carry out the mission in a submarine environment, it is needed to plan a safe and efficient route to a given destination and prevent the autonomous submersible from colliding with obstacles while moving along the planned route. The function of collision avoidance makes the travel distance of the autonomous submersible longer. Moreover, it should move slowly near to obstacles against their moving disturbance. As a result, this invokes the degradation of the navigation efficiency in the process of collision avoidance. The side effect of the collision avoidance is not ignorable in the case of high congested environments such as the coast with many obstacles. In this paper, we suggest a path planning method which provides the route with minimum travel time considering collision avoidance in congested environment. For the purpose, we define environmental congestion map related to geometric information and obstacles. And we propose a method to consider the moving cost in the RRT scheme that provides the existing minimum distance path. We verified that the efficiency of our algorithm with simulation experiments.

Path Planning of the Low Altitude Flight Unmanned Aerial Vehicle for the Neutralization of the Enemy Firepower (대화력전 임무수행을 위한 저고도 비행 무인공격기의 경로계획)

  • Yang, Kwang-Jin;Kim, Si-Tai;Jung, Dae-Han
    • Journal of the Korea Institute of Military Science and Technology
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    • v.15 no.4
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    • pp.424-434
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    • 2012
  • This paper presents a path planning algorithm of the unmanned aerial vehicle for the neutralization of the enemy firepower. The long range firepower of the ememy is usually located at the rear side of the mountain which is difficult to bomb. The path planner not only consider the differential constraints of the Unmanned Aerial Vehicle (UAV) but also consider the final approaching angle constraint. This problem is easily solved by incorporating the analytical upper bounded continuous curvature path smoothing algorithm into the Rapidly Exploring Random Tree (RRT) planner. The proposed algorithm can build a feasible path satisfying the kinematic constraints of the UAV on the fly. In addition, the curvatures of the path are continuous over the whole path. Simulation results show that the proposed algorithm can generate a feasible path of the UAV for the bombing mission regardless of the posture of the tunnel.

Route Optimization for Energy-Efficient Path Planning in Smart Factory Autonomous Mobile Robot (스마트 팩토리 모빌리티 에너지 효율을 위한 경로 최적화에 관한 연구)

  • Dong Hui Eom;Dong Wook Cho;Seong Ju Kim;Sang Hyeon Park;Sung Ho Hwang
    • Journal of Drive and Control
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    • v.21 no.1
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    • pp.46-52
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    • 2024
  • The advancement of autonomous driving technology has heightened the importance of Autonomous Mobile Robotics (AMR) within smart factories. Notably, in tasks involving the transportation of heavy objects, the consideration of weight in route optimization and path planning has become crucial. There is ongoing research on local path planning, such as Dijkstra, A*, and RRT*, focusing on minimizing travel time and distance within smart factory warehouses. Additionally, there are ongoing simultaneous studies on route optimization, including TSP algorithms for various path explorations and on minimizing energy consumption in mobile robotics operations. However, previous studies have often overlooked the weight of the objects being transported, emphasizing only minimal travel time or distance. Therefore, this research proposes route planning that accounts for the maximum payload capacity of mobile robotics and offers load-optimized path planning for multi-destination transportation. Considering the load, a genetic algorithm with the objectives of minimizing both travel time and distance, as well as energy consumption is employed. This approach is expected to enhance the efficiency of mobility within smart factories.

Simultaneous Analysis of Stimulants and Narcotic Analgesics by Capillary Column Gas Chromatography with Nitrogen Phosphorus Detector (Capillary Column Gas Chromatography/Nitrogen Phosphorus Detector를 이용한 흥분제 및 마약성 진통제의 동시분석에 관한 연구)

  • Lho, Dong-Seok;Shin, Ho-Sang;Kang, Bo-Kyung;Paek, Heang-Kee;Kim, Seung-Ki;Lee, Jeong-Ae;Kim, Young-Lim;Park, Jong-Sei
    • Journal of the Korean Chemical Society
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    • v.35 no.6
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    • pp.659-666
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    • 1991
  • A systematic analysis of 18 stimulants and narcotic analgesics containing nitrogen atom (s) in human urine by gas chromatography with nitrogen phosphorus detector (GC-NPD), is described. The urinary extract with diethyl ether at pH 8.5 showed good recoveries of the drugs and less interference peaks on GC chromatogram. Retention data were standardized by the calculation of relative retention times using diphenylamine as the internal standard. The relative standard deviations of retention times were less than 0.1% for the within-run analyses. The response factor (RRF) of a drug relative to the internal standard was calculated. RRF decreased with increasing number of nitrogen atoms. This technique can be adapted to various analytical toxicology problems.

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