• 제목/요약/키워드: LPP

검색결과 88건 처리시간 0.019초

야지환경의 비포장도로용 지역경로계획 (Local Path Plan for Unpaved Road in Rough Environment)

  • 이영일;최덕선;박용운
    • 한국군사과학기술학회지
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    • 제16권6호
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    • pp.726-732
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    • 2013
  • It is required for UGV(Unmanned Ground Vehicle) to have a LPP(Local Path Plan) component which generate a local path via the center of road by analyzing binary map to travel autonomously unpaved road in rough environment. In this paper, we present the method of boundary estimation for unpaved road and a local path planning method based on RANGER algorithm using the estimated boundary. In specially, the paper presents an approach to estimate road boundary and the selection method of candidate path to minimize the problem of zigzag driving based on Bayesian probability reasoning. Field test is conducted with scenarios in rough environment in which bush, tree and unpaved road are included and the performance of proposed method is validated.

Influence of the Ceramide(III) and Cholesterol on the Structure of a Non-hydrous Phospholipid-based Lamellar Liquid Crystal : Structural and Thermal Transition Behaviors

  • Jeong, Tae-Hwa;Oh, Seong-Geun
    • Bulletin of the Korean Chemical Society
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    • 제28권6호
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    • pp.1021-1030
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    • 2007
  • The effects of the creamide III (CER3) and cholesterol (CHOL) on the structure of a non-hydrous distearoyl phosphatidylcholine (DSPC)-based lamellar liquid crystal (LC) hydrated by only propylene glycol (PG) without water were investigated by differential scanning calorimetry (DSC), X-ray diffractions (XRDs), and polarized microscope (PM). As soon as CER3 was incorporated into the lamellar phase, the characteristic LPP was appeared as well as the characteristic SPP, and the formation of separated CER3 crystalline phase was observed depending upon the increase of CER3 content by XRDs. Also, by DSC, it was shown that the increase of CER3 made the monotectic thermal transition be changed to the eutectic thermal transition which indicates the formation of separated CER3 crystalline phases and the main transition temperatures (Tc1) to be gradually decreased and the enthalpy change (ΔH) to be linearly increased. Incorporating CHOL, the formation of LPP and SPP showed almost similar behaviors to CER3, but incorporating small amounts of CHOL showed the characteristic peaks of CHOL which meant the existence of crystalline CHOL phase due to the immiscibility of CHOL with DSPC swollen by PG differently from CER3, and increasing CHOL made the intensity of the 1st order diffraction for LPP weakened as well as the intensities of the characteristic diffractions for DSPC. Also, in the results of DSC, it showed more complex thermal behaviors having several Tc than CER3 due to its bulky chemical structure. In the present study, the inducement of CER3 and CHOL as other lipids present in human stratum corneum (SC) into a non-hydrous lamellar phase is discussed in terms of the influence on their structural and thermal transition.

이동 차량의 계층적 통합 경로 계획의 경로 부조화 문제 해결을 위한 임시 경유점 수정법 (Temporal Waypoint Revision Method to Solve Path Mismatch Problem of Hierarchical Integrated Path Planning for Mobile Vehicle)

  • 이준우;석준홍;하정수;이주장;이호주
    • 제어로봇시스템학회논문지
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    • 제18권7호
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    • pp.664-668
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    • 2012
  • Hierarchical IPP (Integrated Path Planning) combining the GPP (Global Path Planner) and the LPP (Local Path Planner) is interesting the researches who study about the mobile vehicle in recent years. However, in this study, there is the path mismatch problem caused by the difference in the map information available to both path planners. If ever a part of the path that was found by the GPP is available to mobile vehicle, the part may be unavailable when the mobile vehicle generates the local path with its built-in sensors while the vehicle moves. This paper proposed the TWR (Temporal Waypoint Reviser) to solve the path mismatch problem of the hierarchical IPP. The results of simulation provide the performance of the IPP with the TWR by comparing with other path planners.

단파장 영역에서 운항 자세가 KCS의 선체 저항에 미치는 영향 (Effects of Trim Conditions on Ship Resistance of KCS in Short Waves)

  • 김연주;이상봉
    • 대한조선학회논문집
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    • 제54권3호
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    • pp.258-266
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    • 2017
  • Numerical simulations of turbulent two phase flows around KCS have been performed to investigate effects of trim conditions on ship resistance of KCS in short waves by utilizing waves2foam. The wave lengths of LPP/2 and LPP/4 with 1m and 2m wave heights were imposed at inlet boundary. The resistance reduction at 2m trim by head and the increase of resistance at trims by stern were observed regardless of wave lengths and wave heights. The hull pressure on fore-and-aft rather than wave patterns around bulbous bows was mainly responsible for the total resistance coefficients of KCS in short waves. A phase diagram of contribution of hull pressure to the total resistance coefficients disclosed that the phase of representing the maximum resistance in time history played an important role in the effect of trim conditions on ship resistance of KCS in short waves.

Re-evaluation of green tide-forming species in the Yellow Sea

  • Kang, Eun Ju;Kim, Ju-Hyoung;Kim, Keunyong;Choi, Han-Gu;Kim, Kwang Young
    • ALGAE
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    • 제29권4호
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    • pp.267-277
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    • 2014
  • Green tides occur every year in the Yellow Sea (YS), and numerous investigations are proceeding on various aspects of the phenomenon. We have identified bloom-forming species collected from diverse locations in the YS using morphological traits and the chloroplast gene for the large subunit of ribulose-1,5-bisphosphate carboxylase (rbcL). Morphological and rbcL sequence data analyses characterized the blooming species on both sides of the YS as belonging to the Ulva linza-procera-prolifera (LPP) complex clade or U. prolifera of earlier reports. However, U. procera within the LPP complex must be regarded as synonym of U. linza. Moreover, U. prolifera in free-floating samples collected from the Qingdao coast in 2009 was clearly in a distinct clade from that of the blooming species. Therefore, U. linza is the main green tide alga in the YS and has the procera-morphology. The green drift mats in the southeastern part of the YS (southwest sea of Korea) consisted predominantly of U. linza and rarely of U. compressa or U. prolifera.

Synechococcus sp.의 광합성이 Cyanophage 증식에 미치는 영향 (Influence of the Photosynthesis of Synechococcus sp. on the Development of its Cyanophage)

  • 김민;최영길
    • 미생물학회지
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    • 제32권1호
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    • pp.65-69
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    • 1994
  • Synechococcus sp.의 cyanophage는 early, late viral function 모두 빛을 필요로 하는 것으로 나타났으며 증식 초기 2시간 동안 암처리한 경우 200%의 burst size를 나타내었다. Dark 상태에서의 Synechococcus sp.의 cyanophage증식은 대조군에 비해 11%의 burst size를 나타내었다. 광합성 억제제인 DCMU를 $10^{-6}$M로 처리했을 때 virus yield가 2%로 감소했으며 $10^{-4}$M의 CCCP는 cyanophage의 증식을 거의 중지시켰다. 또한 이러한 숙주세포의 광합성 의존도는 LPP-1, N-1과 AS-1보다는 크나 SM-1보다는 작은 것으로 나타났다.

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실린더 압력을 이용한 SI엔진의 페루프 점화시기 제어에 관한 연구 (SI Engine Closed-loop Spark Advance Control Using Cylinder Pressure)

  • 박승범;윤팔주;선우명호
    • 대한기계학회논문집A
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    • 제24권9호
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    • pp.2361-2370
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    • 2000
  • The introduction of inexpensive cylinder pressure sensors provides new opportunities for precise engine control. This paper presents a control strategy of spark advance based upon cylinder pressure of spark ignition engines. A location of peak pressure(LPP) is the major parameter for controlling the spark timing, and also the UP is estimated, using a multi-layer feedforward neural network, which needs only five pressure sensor output voltage samples at -40˚, -20˚, 0˚, 20˚, 40˚ after top dead center. The neural network plays an important role in mitigating the A/D conversion load of an electronic engine controller by increasing the sampling interval from 10 crank angle(CA) to 20˚ CA. A proposed control algorithm does not need a sensor calibration and pegging(bias calculation) procedure because the neural network estimates the UP from the raw sensor output voltage. The estimated LPP can be regarded as a good index for combustion phasing, and can also be used as an MBT control parameter. The feasibility of this methodology is closely examined through steady and transient engine operations to control individual cylinder spark advance. The experimental results have revealed a favorable agreement of individual cylinder optimal combustion phasing.

선수 규칙파 중 KCS의 부가저항 및 운동성능 수치해석 (Numerical Simulations of Added Resistance and Motions of KCS in Regular Head Waves)

  • 서성욱;박선호
    • 대한조선학회논문집
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    • 제54권2호
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    • pp.132-142
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    • 2017
  • As the International Maritime Organization (IMO) recently introduced the Energy Efficiency Design Index (EEDI) for new ships building and the Energy Efficiency Operational Indicator (EEOI) for ship operation, thus an accurate estimation of added resistance of ships advancing in waves has become necessary. In the present study, OpenFOAM, computational fluid dynamics libraries of which source codes are opened to the public, was used to calculate the added resistance and motions of the KCS. Unstructured grid using a hanging-node and cut-cell method was used to generate dense grid around a wave and KCS. A dynamic deformation mesh method was used to consider the motions of the KCS. Five wavelengths from a short wavelength (${\lambda}/LPP=0.65$) to a long wavelength (${\lambda}/LPP=1.95$) were considered. The added resistance and the heave & pitch motions calculated for various waves were compared with the results of model experiments.