• Title/Summary/Keyword: Target configuration

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A Study on the Improvement of Maintaining Temperature of Aviation Dangerous Goods (항공 운송 위험물의 정온 유지 개선방안)

  • Se-Cheol Shin;Hyung-Hwan An
    • Journal of the Korean Society of Industry Convergence
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    • v.26 no.6_3
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    • pp.1215-1221
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    • 2023
  • According to the study and experiments performed on the Improvement of Maintaining Temperature of Aviation Dangerous Goods, a conclusion was drawn that clear technical guidelines should be established from the design and assembly stage of temperature-controlled packaging, taking into account actual transportation environment. In particular, profiles consisting of only two types of summer and winter are difficult to adjust flexibly in transportation process with severe weather and temperature changes such as spring and fall. To this end, there is a need to establish a compromise profile configuration for summer and winter. It was also found that the condition of the refrigerant, temperature control, and the speed of the packaging operation have a significant impact on maintaining constant temperature. Therefore, all packing operations need to be completed within a short period of time in the environment close to the target temperature. The current packing instructions provided by packaging manufacturers do not provide precise instructions on post-conditioning, but the experiments in this study confirmed that post-conditioning is very important for maintaining the target temperature, so it is necessary to provide precise legal packing technical instructions.

GEOCODING OF SAR IMAGE USING THE ORBIT AND ATTITUDE DETERMINATION OF RADARSAT (RADARSAT 위성의 궤도결정과 자세결정을 이용한 SAR 영상의 자리매김)

  • 소진욱;최규홍;원중선
    • Journal of Astronomy and Space Sciences
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    • v.15 no.1
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    • pp.183-196
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    • 1998
  • The Synthetic Aperture Radar(SAR) image and the Digital Elevation Model(DEM) of an target area are put into use to generate three dimensional image map. An method of image map generation is explained. The orbit and attitude determination of satellite makes it possible to model signal acquisition configuration precisely, which is a key to mapping image coordinates to geographic coordinates of concerned area. An application is made to RADARSAT in the purpose of testing its validity. To determine the orbit, zero Doppler range is used. And to determine the attitude, Doppler centroid frequency, which is the frequency observed when target is put in the center of antenna's view, is used. Conventional geocoding has been performed on the basis of direct method(mapping image coordinates to geographic coordinates), but in this reserch the inverse method(mapping from geographic coordinates to image coordinates) is taken. This paper shows that precise signal acquisition modeling based on the orbit and attitude determination of satellite as a platform leads to a satellite-centered accurate geocoding process. It also shows how to model relative motion between space-borne radar and target. And the relative motion is described in ECIC(earth-centered-initial coordinates) using Doppler equation and signal acquisition geometry.

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Measurement of Spatial Coherence of Active Acoustic Sensor Array Signal (능동 음향센서 배열신호의 공간 상관성 측정)

  • Park, Joung-Soo;Kim, Hyoung-Rok
    • The Journal of the Acoustical Society of Korea
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    • v.31 no.4
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    • pp.205-213
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    • 2012
  • Active acoustic array signal was measured in the East Sea and the South sea and spatial coherence was analyzed. The measurement of ambient noise, target reflection signal, sea surface backscattering signals took place including environmental measurements of sea wind, and vertical temperature profiles. The spatial coherence of ambient noise was lower than that of target reflection signal in the South Sea. The spatial coherence of target reflection signal was above 0.5 over all array length. The spatial coherence of sea surface backscattering signal was higher in high incident angle. The maximum non-dimensional array length was 3.0 ($26^{\circ}$) and 3.5 ($32^{\circ}$) to have spatial coherence above 0.5 in the East Sea. To find a design criteria for array configuration and array performance, more measurements of temporal and spatial coherence will be needed continuously in the future.

A Study on Receiving Beam Pointing Error and MTI(Moving Target Indication) Performance in a Bistatic Radar Using Pulse Chasing (펄스 체이싱을 이용한 바이스태틱 레이더에서 수신 빔 조향 오차와 MTI(Moving Target Indication) 성능에 대한 연구)

  • Yang, Jin-Mo;Lee, Min-Joon;Kim, Whan-Woo
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.21 no.12
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    • pp.1412-1422
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    • 2010
  • A bistatic radar using the pulse chasing can detect a target to track successive transmitted pulses using a receive beam for effectively scanning the cosite search area. When tracking a transmitted pulse with the receive beam, some beam pointing errors within pulse-to-pulse can cause the timing error in received pulse and the variation of the signal strength. In this paper, we have proposed that some errors due to the receive beam pointing error could limit the MTI filter's performance and derived that the relationship between the MTI performance and the geometric factors which are the inherent properties in bistatic configuration. Through the simulation, we have considered the limitations of the improvement performance restricted by the receiving beam pointing error and confirmed the contribution to the performance improvement in maintaining the receiving beam pointing error of under 0.5 degrees.

Effect of System Instability Factors in a Bistatic MTI Radar Using Pulse Chasing Scan Method (펄스 체이싱 스캔 방식을 이용한 바이스태틱 MTI 레이더에서 시스템 불안정 요소들의 영향)

  • Yang, Jin-Mo;Han, Il-Tak;Lee, Yong-Suk;Lee, Min-Joon;Kim, Whan-Woo
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.22 no.3
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    • pp.299-311
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    • 2011
  • In this paper, we have identified the system instability factors in a bistatic radar system using pulse chasing and considered their effects on the bistatic receiver's MTI(Moving Target Indication) improvement performance. The pulse chasing is a scan method that searchs a restricted area on the transmit pulse-to-pulse basis and the MTI filter is a signal processing that separates a target from some kinds of interferences such as clutter using small number of transmit pulses. Ideal MTI processing performance, e.g., clutter attenuation and improvement, has been limited by the property of the clutter itself, however, the MTI performance in a proposed bistatic receiver configuration could be affected by the receiving beam pointing error during pulse chasing scanning. Also, for the bistatic receiver, we have defined other system instability factors, which result from the time synchronization error, COHO's phase error, the frequency/phase synchronization error, and have analyzed their effects on the system performance improvement.

Replacement of Thymidine Phosphorylase RNA with Group I Intron of Tetrahymena thermophila by Targeted Trans-Splicing

  • Park, Young-Hee;Jung, Heung-Su;Kwon, Byung-Su;Lee, Seong-Wook
    • Journal of Microbiology
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    • v.41 no.4
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    • pp.340-344
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    • 2003
  • The group I intron from Tetrahymena thermophila has been demonstrated to employ splicing reactions with its substrate RNA in the trans configuration. Moreover, we have recently shown that the transsplicing group I ribozyme can replace HCV-specific transcripts with a new RNA that exerts anti-viral activity. In this study, we explored the potential use of RNA replacement for cancer treatment by developing trans-splicing group I ribozymes, which could replace tumor-associated RNAs with the RNA sequence attached to the 3' end of the ribozymes. Thymidine phosphorylase (TP) RNA was chosen as a target RNA because it is known as a valid cancer prognostic factor. By performing an RNA mapping strategy that is based on a trans-splicing ribozyme library, we first determined which regions of the TP RNA are accessible to ribozymes, and found that the leader sequences upstream of the AUG start codon appeared to be particularly accessible. Next, we assessed the ribozyme activities by comparing trans-splicing activities of several ribozymes that targeted different regions of the TP RNA. This assessment was performed to verify if the target site predicted to be accessible is truly the most accessible. The ribozyme that could target the most accessible site, identified by mapping studies, was the most active with high fidelity in vitro. Moreover, the specific trans-splicing ribozyme reacted with and altered the TP transcripts by transferring an intended 3' exon tag sequence onto the targeted TP RNA in mammalian cells with high fidelity. These results suggest that the Tetrahymena ribozyme can be utilized to replace TP RNAs in tumors with a new RNA harboring anti-cancer activity, which would revert the malignant phenotype.

Design of the Shortcut based Integrated & Advanced Networking Server(IANS) for QoS path (QoS 경로 설정을 위한 Shortcut 기반 통합 서버 설계)

  • 김기영;이상호
    • Journal of the Korea Society of Computer and Information
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    • v.6 no.4
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    • pp.74-84
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    • 2001
  • In the current Internet, InteServ model based on Resource reSerVation Protocol (RSVP), DiffServ Model based on service differentiation according to per hope behavior(PHB) and traffic engineering policy, and two-tire model of above mentioned two models which are adapted differently as the target network status for providing the end-to-end QoS Path are suggested. But, when we integrated this internet QoS into the ATM based network, differences of the connection setup procedure, name/address translation methods, and QoS provisioning mechanisms for end-to-end path setup procedures are introduced. In this paper, we propose the method of shortcut based QoS path setup procedure to solve these problems, and to guarantee the integration and scalability of Next Generation Internet(NGI) names/address in Integrated IP network into ATM based network. This network should support the engineering differentiated into the multiple service classes, which depend on established by this path is designed suitably into the target router and host step by step. In the near future, this function which provide the QoS guaranteed path based on end-to-end shortcut between the configuration devices are extended into the NGI target network.

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Computational Analysis of the Aerodynamic Performance of a Long-Endurance UAV

  • Jin, Wonjin;Lee, Yung-Gyo
    • International Journal of Aeronautical and Space Sciences
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    • v.15 no.4
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    • pp.374-382
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    • 2014
  • This paper presents the computational aerodynamic analysis of a long-endurance UAV that was developed by the Korea Aerospace Research Institute (KARI), named EAV-2. EAV-2 is a technical demonstrator of aerodynamically efficient design, as well as a hybrid electric-propulsion system for future long-endurance UAVs. We evaluated the aerodynamic characteristics of six low-Reynolds number airfoils, using a panel method code, XFOIL, to select an optimal airfoil for the long-endurance mission of EAV-2. The computational results by a CFD code, FLUENT, suggested that the aerodynamic performance of EAV-2 would be notably improved after adopting SG6043 airfoil, and modifying the fuselage design. This reduced the total drag by 43%, compared to that of a previous KARI model, EAV-1, at the target lift of $C_L=1.0$. Also, we achieved a drag reduction of approximately 14% by means of the low-drag fuselage configuration.

In Flight Simulation for Flight Control Law Evaluation of Fly-by-Wire Aircraft (I)

  • Ko, Joon-Soo;Lee, Ho-Keun
    • 제어로봇시스템학회:학술대회논문집
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    • 2003.10a
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    • pp.2560-2565
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    • 2003
  • The paper presented here covers the work associated with the flight control law design, ground based and in flight simulation and handling qualities assessment of the Fly-by-Wire type Aircraft (FBWA). The control law was designed for the most unstable aircraft configuration flight regime for the target aircraft (FBWA). The ground based simulation including math-model, real-time pilot-in-the-loop and iron bird simulation were used for validation of the control law before the experimental in-flight simulation on the IFS (In.Flight-Simulator) aircraft. The flight tests results showed that Level 1 handling qualities for the most unstable flight regime were achieved.

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Aerodynamic Performance Enhancement and Noise of Cooling Fans for Driving Motor (전동차용 모터 냉각홴의 공력성능 향상 및 소음특성)

  • Kang, Shin-Hyoung;Park, Tae-Choon;Cho, Nam-Hyo
    • The KSFM Journal of Fluid Machinery
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    • v.1 no.1 s.1
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    • pp.32-40
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    • 1998
  • Aerodynamic performance of a cooling fan of driving motor was enhanced modifying the vane-shroud configuration. Performance of a target model was evaluated to obtain baseline data. The aerodynamic performance and sound pressure level were tested and measured with different numbers of vane of increased length. The tested models show high and stable performance and low values of specific noise level. The long vane-shroud structure induces more stable through flow and decreases the tip leakage flow, which contributes to the increases of performance and efficiency. The sound pressure level increases for the modified model, however, specific noise level decreases.

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