• Title/Summary/Keyword: Time of flight method

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A Study on Congestion Change of Dual Airways between Korea-China (한·중 항로 복선화 전후 혼잡도 변화 연구)

  • Cho, Jin Ho;Baik, Ho Jong;Chang, Jo Won
    • Journal of the Korean Society for Aviation and Aeronautics
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    • v.28 no.1
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    • pp.7-13
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    • 2020
  • A significant growth in local air traffic volume is leading to airway congestion and flight delays especially for Incheon-China and Incheon-Europe sectors. A key method to increase the airway capacity is to place a supplemental airway parallel to the existing one and in cooperation between the aviation authorities between China and Korea, a dual airway track was implemented on December 6, 2018. Here, we use airline A's flight data to analyze the congestion change effect of the new airway. Results show total delay time to Europe is reduced 51% (13.4 to 6.6 minutes) as the delay distribution for 16-30 minutes, 31 minutes and greater decreased from 23.2% to 8.2% and 8.7% to 1.0% respectively. The delay to China also decreased but the drop is not as significant as flights to Europe. This is caused by the difference in flight distance, traffic volume, and characteristics of flights landing and transiting China. Flights to Europe show a broad distribution in altitude allocation and reduction in aircraft separation demonstrating the effectiveness of a dual airway track.

The Coordinate Conversion for Flight Dynamics Simulation (비행 운동 시뮬레이션을 위한 좌표계 변환)

  • Baek, Joong-Hwan;Hwang, Soo-Chan;Kim, Chil-Yong
    • Journal of Advanced Navigation Technology
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    • v.3 no.2
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    • pp.139-146
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    • 1999
  • A flight simulator is composed of engine, navigation systems and instrument modules. However, two problems exist here. First, the coordinate of each independent module is not same. To solve this problem, we design a method that mutual coordinates are capable of transformation each other. Second, the distance and bearing between two points on the earth are computed in a sphere shape using the spherical trigonometry. However, the computing time is very severe. In this paper, we project the sphere into the planar to reduce the computing time. An experimental result shows that the performance of the proposed method is excellent to both distance and bearing calculations in close region. Also, the computing time is reduced from $4.95{\times}10^{-4}$ seconds to $1.648{\times}10^{-4}$ seconds.

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A Study on Neutron Resonance Energy of Tantalum by 46-MeV Electron Linac TOF Method (46-MeV 전자선형가속기의 TOF 방법을 이용한 탄탈의 중성자 공명 에너지 분석에 관한 연구)

  • Lee, Samyol
    • Journal of the Korean Society of Radiology
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    • v.7 no.3
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    • pp.245-249
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    • 2013
  • Neutron sources from photonuclear reaction with 46-MeV electron linear accelerator at Research Reactor Institute, Kyoto University used for resonance energy measurement of natural tantalum. BGO($Bi_4Ge_3O_{12}$) scintillation detectors used for measurement of the prompt gamma ray from the natural tantalum sample. The BGO spectrometer was composed geometrically as total energy absorption detector. The electric signal from the spectrometer was analyzed for TOF(Time-of-Flight) spectrum which is used identification of neutron capture resonance energy. In this study, the neutron energy region is from 1 to 200 eV, because of strong X-ray effect produced photonuclear reaction in Ta target, the measurement was performed to below 1 keV energy region. The resonance energy was compared with the evaluated values(ENDF/B-VI, Mughabghab). All of the resonances from 4.28 ~ 200 eV were seen in the present measurement except 144.3 eV resonance.

Application of Matrix-assisted Laser Desorption/Ionization Time-of-flight Mass Spectrometry (Matrix-assisted Laser Desorption/Ionization Time-of-flight Mass Spectrometry의 활용)

  • Pil Seung KWON
    • Korean Journal of Clinical Laboratory Science
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    • v.55 no.4
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    • pp.244-252
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    • 2023
  • The timeliness and accuracy of test results are crucial factors for clinicians to decide and promptly administer effective and targeted antimicrobial therapy, especially in life-threatening infections or when vital organs and functions, such as sight, are at risk. Further research is needed to refine and optimize matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS)-based assays to obtain accurate and reliable results in the shortest time possible. MALDI-TOF MS-based bacterial identification focuses primarily on techniques for isolating and purifying pathogens from clinical samples, the expansion of spectral libraries, and the upgrading of software. As technology advances, many MALDI-based microbial identification databases and systems have been licensed and put into clinical use. Nevertheless, it is still necessary to develop MALDI-TOF MS-based antimicrobial-resistance analysis for comprehensive clinical microbiology characterization. The important applications of MALDI-TOF MS in clinical research include specific application categories, common analytes, main methods, limitations, and solutions. In order to utilize clinical microbiology laboratories, it is essential to secure expertise through education and training of clinical laboratory scientists, and database construction and experience must be maximized. In the future, MALDI-TOF mass spectrometry is expected to be applied in various fields through the use of more powerful databases.

Identification of Salmonella spp. from porcine salmonellosis by matrix-assisted laser desorption ionization-time of flight mass spectrometry

  • Yang, Hyoung-Seok;Kim, Jae-Hoon
    • Korean Journal of Veterinary Service
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    • v.41 no.2
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    • pp.105-110
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    • 2018
  • A total of 41 Salmonella (S.) strains were isolated from pigs suffered with severe watery diarrhea and were tried to identify by both matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) and polymerase chain reaction (PCR) analysis. Fibrinous exudate and ulceration in the large intestine were prevalent in gross observation, and variable degrees of enteritis were observed in the histology of large intestines. Subsequent polymerase chain reaction (PCR) analyses demonstrated that 41 strains were identified as S. Typhimurium (39 strains), though 2 stains were failed to identify. Further identification was performed using both direct smear and protein extraction method by MALDI-TOF MS analyses. In terms of extraction methods, 100% (41/41) of isolates were identified to species level of S. spp. Whereas only 43.9% (18/41) were identified to species level using the direct method. These results thus suggest that rapid and accurate diagnosis of porcine salmonellosis can be guaranteed by MALDI-TOF MS combined with protein extraction method.

Analysis on the Mean energy of electrons in $SF_6-Ar$ Mixtures Gas used by MCS-BEq Algorithm ($SF_6-Ar$ 혼합기체(混合氣體)의 MCS-BEq알고리즘에 의한 전자(電子) 평균(平均)에너지 해석(解析))

  • Kim, Sang-Nam;Ha, Sung-Chul
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 2004.05a
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    • pp.281-284
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    • 2004
  • Mean energy of electrons in $SF_6-Ar$ Mixtures Gas used by MCS-BEq algorithm has been analysed over the E/N range $30{\sim}300[Td]$ by a two term Boltzmann equation and by a Monte Carlo Simulation using a set of electron cross sections determined by other authors, experimentally the electron swarm parameters for 0.2[%] and 0.5[%] $SF_6-Ar$, 0.1[%] and 5.0[%], $SF_6-Ar$ mixtures were measured by time-of-flight(TOF) method. The transport Coefficients for electrons in (100[%])$SF_6$. (100[%])Ar, (0.2[%])$SF_6-Ar$ and (0.5[%]) $SF_6-Ar$, (5.0[%]) $SF_6-Ar$, (0.1[%])$SF_6-Ar$ mixtures were measured by time-of-flight method, and the electron energy distribution function and the parameters of the velocity and the diffusion were determined by the variation of the collision cross-sections with energy. The results obtained from Boltzmann equation method and Monte Carlo simulation have been compared with present and previously obtained data and respective set of electron collision cross sections of the molecules.

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Mean energy of electrons in $SF_6$-Ar Mixtures Gas ($SF_6$-Ar 혼합기체(混合氣體)의 전자(電子) 평균(平均)에너지)

  • Kim, Sang-Nam;Seong, Nak-Jin
    • Proceedings of the KIEE Conference
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    • 2003.07e
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    • pp.75-78
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    • 2003
  • Energy distribution function for electrons in $SF_6$-Ar mixtures gas used by MCS-BEq algorithm has been analysed over the E/N range $30\sim300$[Td] by a two term Boltzmann equation and by a Monte Carlo Simulation using a set of electron cross sections determined by other authors, experimentally the electron swarm parameters for 0.2[%] and 0.5[%] $SF_6$-Ar mixtures were measured by time-of-flight(TOF) method. The results show that the deduced electron drift velocities, the electron ionization or attachment coefficients, longitudinal and transverse diffusion coefficients and mean energy agree reasonably well with theoretical for a rang of E/N values. The transport coefficients for electrons in (0.2[%])$SF_6$-Ar and (0.5[%]$SF_6$ - Ar mixtures were measured by time-of-flight method, and the electron energy distribution function and the parameters of the velocity and the diffusion were determined by the variation of the collision cross-sections with energy. The results obtained from Boltzmann equation method and Monte Carlo simulation have been compared with present and previously obtained data and respective set of electron collision cross sections of the molecules.

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Heel Trajectory Analysis Method of Walking using a Wearable Sensor (착용형 센서를 이용한 보행 뒤꿈치 궤적 분석 방법)

  • Hee-Chan Kim;Hyun-Jin Choi
    • The Journal of the Korea institute of electronic communication sciences
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    • v.18 no.4
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    • pp.731-736
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    • 2023
  • Walking is a periodic motion that contains specific phases and is a basic movement method for humans. Through gait analysis, various musculoskeletal health conditions can be identified. In this study, we propose a calf wearable sensor system that can perform gait analysis without space limitations. Using a ToF(: Time-of-Flight) sensor that measures distance and an IMU(: Inertial Measurement Unit) sensor that measures inclination the heel trajectory of walking was derived by proposed method. In case of abnormal gait with risk of fall, gait is evaluated by analyzing the change pattern of the heel trajectory.

Lifetime prediction of bearings in on-board starter generator

  • Zieja, Mariusz;Tomaszewska, Justyna;Woch, Marta;Michalski, Mariusz
    • Advances in aircraft and spacecraft science
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    • v.8 no.4
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    • pp.289-302
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    • 2021
  • Ensuring flight safety for passengers as well as crew is the most important aspect of modern aviation, and in order to achieve this, it is necessary to be able to forecast the durability of individual components. The present contribution illustrates the results of a computational analysis to determine the possibility of analysing the prediction of bearing durability in on-board rotating equipment from the point of view of thermal fatigue.In this study, a method developed at the Air Force Institute of Technology was used for analysis, which allowed to determine the bearing durability from the flight altitude profile. Two aircraft have been chosen for analysis - a military M-28 and a civilian Embraer. As a result of the analysis were obtained: the bearing durability in on-board rotating devices, average operation time between failures, as well as failure rate. In conclusion, the practical applicability of this approach is demonstrated by the fact that even with a limited number of flight parameters, it is possible to estimate bearing durability and increase flight safety by regular inspections.

Realization and Design of Predictor Algorithm and Evaluation of Numerical Method on Nonlinear Load Control Model (비선형 하중제어 모델의 예측기 설계 및 알고리즘 구현을 위한 수치연산 오차 분석과 평가)

  • Wang, Hyun-Min;Woo, Kwang-Joon
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.46 no.6
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    • pp.73-79
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    • 2009
  • For the shake of control for movement object, control theory like neural network, nonlinear model predictive control(NMPC) is realized on digital high speed computer. Predictor of flight control system(FCS) based nonlinear model predictive control has to be satisfied with response for hard real-time to perform applications on each module in the FCS. Simultaneously, It gives a serious consideration accuracy to give full play to FCS's performance. Error of mathematical aspect affects realization of whole algorithm. But factors of bring mathematical error is not considered to calculate final accuracy on parameter of predictor. In this paper, Predictor was made using load control model on the digital computer for design FCS at hard real-time and is shown response time on realization algorithm. And is shown realization algorithm of high effective predictor over the accuracy. The predictor was realized on the load control model using Euler method, Heun method, Runge-Kutta and Taylor method.