• 제목/요약/키워드: Li Chan

검색결과 316건 처리시간 0.031초

QoS Provisioning for WDM Burst Switched Ring Networks

  • Peng, Li-Mei;Kim, Young-Chon;Youn, Chan-Hyun
    • 한국정보처리학회:학술대회논문집
    • /
    • 한국정보처리학회 2010년도 춘계학술발표대회
    • /
    • pp.717-720
    • /
    • 2010
  • This paper considers the Quality of Service (QoS) provisioning mechanisms for the WDM burst switched ring networks. The loss-sensitive service and the delay-sensitive service are discussed. Considering their different requirements, different QoS provisioning schemes are proposed to provision them respectively. The proposed schemes are evaluated through simulation results.

마이크로파와 재래식 열원을 이용한 고체 전지용 Li$_2$O-2SiO$_2$계 전도성 유리의 제조 및 특성에 관한 연구 (The study for fabrication and characteristic of Li$_2$O-2SiO$_2$conduction glass system using conventional and microwave energies)

  • 박성수;김경태;김병찬;박진;박희찬
    • 한국결정성장학회지
    • /
    • 제10권1호
    • /
    • pp.66-72
    • /
    • 2000
  • 재래식 및 마이크로파 가열법으로 열처리된 $Li_2O_3-SiO_2$계 글라스의 핵 생성 및 결정화 거동을 열분석법(DTA), X-선 회절(XRD), 광학 현미경(OM) 및 전기 전도도의 측정으로 비교 조사하였다. 재래식 및 마이크로피로 열처리된 시료들의 조핵 온도와 최대 핵 생성 온도는 동일하게 각각 460~$500^{\circ}C$$580^{\circ}C$이었다. 한편, 재래식에 비하여 마이크로파로 열처리된 시료에서는 부피 핵 생성이 일어나려는 경향이 컸다. 재래식 및 마이크로파로 열처리된 시편들에서 결정의 성장 속도는 결정화 열처리 온도에 비례하여 증가하였지만, 마이크로파 열처리의 경우는 부피 핵 생성 경향 및 물질 확산 효과의 증대에 기인하여 결정 성장을 재래식 보다 빠르게 진행되었다. 재래식 및 마이크로파로 열처리된 시편들의 전기 전도도 값은 각각 1.337~2.299와 0.281~$0.911{\times}10^{-7}\Omega {\textrm}{cm}^{-1}$이었다.

  • PDF

분무열분해 공정에 의해 합성되어진 나노 크기 Gd2O3:Eu형광체 (Nano-sized Gd2O3:Eu Phosphor Prepared by Spray Pyrolysis)

  • 김은정;강윤찬;박희동;유승곤
    • 한국재료학회지
    • /
    • 제12권10호
    • /
    • pp.771-775
    • /
    • 2002
  • $Gd_2$$O_3$:Eu phosphor particles with nano-sized and non-aggregation characteristics were prepared by spray pyrolysis using the spray solution containing polymeric precursor and $Li_2$$CO_3$ flux material. Nano-sized $Gd_2$$O_3$:Eu phosphor particles had higher brightness than the commercial $Y_2$$O_3$:Eu phosphor particles. The $Gd_2$$O_3$:Eu phosphor particles had nano-size and non-aggregation characteristics after heat-treatment at $1000^{\circ}C$ when the addition amount of $Li_2$$CO_3$ flux was 1 wt.% and 3 wt.%. The mean size of particles were 200 nm and 400 nm when the amount of flux was 1 wt.% and 3 wt.%, respectively. The prepared phosphor particles had higher photoluminescence intensity than that of the commercial product regardless of the content of$ Li_2$$CO_3$ flux and had the maximum brightness when the content of flux was 5 wt %. The photoluminescence intensity of the nano-sized $Gd_2$$O_3$:Eu phosphor particles containing 3 wt.% $Li_2$$CO_3$ flux was 125% in comparison with that of the micron-sized $Y_2$$O_3$:Eu commercial product.

곡지혈 매선침 시술이 경피수분 손실량에 미치는 영향 (Pilot Clinical Trial to Evaluate the Efficacy of Needle-Embedding Acupuncture Therapy at Gokji(LI11) on TEWL)

  • 이호찬;정미영;최정화;정민영;박수연
    • 동의생리병리학회지
    • /
    • 제32권4호
    • /
    • pp.291-297
    • /
    • 2018
  • The purpose of pilot clinical trial is to evaluate the efiicacy and safety of Needle-Embedding acupuncture therapy on TEWL(Transepidermal Water Loss) and Skin hydration. A total of 24 human who visited Dongshin Oriental Medical Center from December 1st, 2016 to July 31st, 2017 were included in the pilot clinical trial. Needle-Embedding acupuncture therapy performed at Gokji(LI11). We observed change of TEWL(Transepidermal Water Loss), Skin hydration before and after Needle-Embedding acupuncture therapy. In the primary endpoint, index of TEWL showed a statistically insignificant decline ($8.5{\pm}2.12{\rightarrow}7.8{\pm}1.53g/h/m^2$). Index of skin hydration showed a statistically significant result ($38.2{\pm}6.77{\rightarrow}36.8{\pm}6.64$). To evaluate the safety, Adverse events and Vital sign check were conducted and there were no problem. And when the physical response, self-awareness, skin system, musculoskeletal pain, and other abnormal responses were assessed 60 minutes and 24 hours and 7 days after Needle-Embedding acupuncture therapy at Gokji(LI11) for stability assessment, Adverse events disappeared during a pilot clinical trial. According to the above pilot clinical trial, it is suggested Needle-Embedding acupuncture therapy were effective for Skin moisturizing and safe.

LiDAR를 활용한 국토환경성평가지도 산림부문 신규 평가항목의 도입 가능성 평가 (Introduction of the New Evaluation Criteria in the Forest Sector of Environmental Conservation Value Map Using LiDAR)

  • 전성우;홍현정;이종수;이우균;성현찬
    • 한국환경복원기술학회지
    • /
    • 제10권5호
    • /
    • pp.20-30
    • /
    • 2007
  • Environmental Conservation Value Assessment Map (ECVAM) is the class map to divide the national land into conservation areas and development areas based on legal and ecological assessment criteria. It contributes to enhancements of the efficiency and the scientificity when framing a policy in various fields including the environment. However, it is impossible to understand the multiphase vegetation structure as data on judging the national forest class in ECVAM are restricted to areal information of Ecological Nature Status, Degree of Green Naturality and Forest Map. This point drops the reliability of ECVAM. Therefore we constructed vegetation information using LiDAR (Light Detection And Raging) technology. We generated Biomass Class Maps as final results of this study, to introduce the new forest assessment criterion in ECVAM that alternates or makes up for existing forest assessment criteria. And then, we compared these with Forest Map and Landsat TM NDVI image. As a result, biomass classes are generally higher than stand age classes and DBH classes of Vegetation Map, and lower than NDVI of Landsat TM image because of the difference of time on data construction. However distributions between these classes are mostly similar. Therefore we estimates that it is possible to apply the biomass item to the new forest assessment criterion of ECVAM. The introduction of the biomass in ECVAM makes it useful to detect the vegetation succession, to adjust the class of the changed zone since the production of Vegetation Map and to rectify the class error of Vegetation Map because variations on tree heights, forest area, gaps between trees, vegetation vitality and so on are acquired as interim findings in process of computing biomass.

리튬이차전지에서 대기압 수소플라즈마 처리된 LiNi1/3Co1/3Mn1/3O2 양극 활물질의 특성분석 (Characterization of Atmospheric H2-Plasma-Treated LiNi1/3Co1/3Mn1/3O2 as Cathode Materials in Lithium Rechargeable Batteries)

  • 선호정;이재호;정현영;석동찬;정용호;박경세;심중표
    • 한국수소및신에너지학회논문집
    • /
    • 제24권2호
    • /
    • pp.160-171
    • /
    • 2013
  • $LiNi_{1/3}Co_{1/3}Mn_{1/3}O_2$ powder for cathode materials in lithium rechargeable batteries was treated by atmospheric plasma containing hydrogen to investigate the relationship between charge/discharge performance and physical/chemical changes of materials. Hydrogen plasma at atmosphere pressure was irradiated on the surface of active materials, and the change for their crystal structure, surface morphology, and chemical composition were observed by XRD, SEM-EDS and titration method, respectively. The crystal structure and surface morphology of $H_2$ plasma-treated powders were not changed but their chemical compositions were slightly varied. For charge/discharge test, $H_2$ plasma affected initial capacity and rate capability of active materials but continuous cycling was not subject to plasma treatment. Therefore, it was observed that $H_2$ plasma treatment affected the surface of materials and caused the change of chemical composition.

전구체 공침 온도가 LiNi1/3Co1/3Mn1/3O2 분말의 특성에 미치는 영향 (Effects of Precursor Co-Precipitation Temperature on the Properties of LiNi1/3Co1/3Mn1/3O2 Powders)

  • 최웅희;강찬형
    • 한국분말재료학회지
    • /
    • 제23권4호
    • /
    • pp.287-296
    • /
    • 2016
  • $Ni_{1/3}Co_{1/3}Mn_{1/3}(OH)_2$ powders have been synthesized in a continuously stirred tank reactor via a co-precipitation reaction between aqueous metal sulfates and NaOH using $NH_4OH$ as a chelating agent. The co-precipitation temperature is varied in the range of $30-80^{\circ}C$. Calcination of the prepared precursors with $Li_2CO_3$ for 8 h at $1000^{\circ}C$ in air results in Li $Ni_{1/3}Co_{1/3}Mn_{1/3}O_2$ powders. Two kinds of obtained powders have been characterized by X-ray diffraction (XRD), scanning electron microscopy, particle size analyzer, and tap density measurements. The co-precipitation temperature does not differentiate the XRD patterns of precursors as well as their final powders. Precursor powders are spherical and dense, consisting of numerous acicular or flaky primary particles. The precursors obtained at 70 and $80^{\circ}C$ possess bigger primary particles having more irregular shapes than those at lower temperatures. This is related to the lower tap density measured for the former. The final powders show a similar tendency in terms of primary particle shape and tap density. Electrochemical characterization shows that the initial charge/discharge capacities and cycle life of final powders from the precursors obtained at 70 and $80^{\circ}C$ are inferior to those at $50^{\circ}C$. It is concluded that the optimum co-precipitation temperature is around $50^{\circ}C$.

Sol-Gel법에 의한 Li1+xAlxTi2-x(PO4)3 (x = 0, 0.3, 0.5)의 합성 및 전도특성 (Synthesis and Conductive Properties of Li1+xAlxTi2-x(PO4)3 (x = 0, 0.3, 0.5) by Sol-Gel Method)

  • 문정인;조홍찬;송정환
    • 한국재료학회지
    • /
    • 제22권7호
    • /
    • pp.346-351
    • /
    • 2012
  • $Li_{1+x}Al_xTi_{2-x}(PO_4)_3$(LATP) is a promising solid electrolyte for all-solid-state Li ion batteries. In this study, LATP is prepared through a sol-gel method using relatively the inexpensive reagents $TiCl_4$. The thermal behavior, structural characteristics, fractured surface morphology, ion conductivity, and activation energy of the LATP sintered bodies are investigated by TG-DTA, X-ray diffraction, FE-SEM, and by an impedance method. A gelation powder was calcined at $500^{\circ}C$. A single crystalline phase of the $LiTi_2(PO_4)_3$(LTP) system was obtained at a calcination temperature above $650^{\circ}C$. The obtained powder was pelletized and sintered at $900^{\circ}C$ and $1000^{\circ}C$. The LTP sintered at $900{\sim}1000^{\circ}C$ for 6 h had a relatively low apparent density of 75~80%. The LATP(x = 0.3) pellet sintered at $900^{\circ}C$ for 6 h was denser than those sintered under other conditions and showed the highest ion conductivity of $4.50{\times}10^{-5}$ S/cm at room temperature. However, the ion conductivity of LATP (x = 0.3) sintered at $1000^{\circ}C$ decreased to $1.81{\times}10^{-5}$ S/cm, leading to Li volatilization and abnormal grain growth. For LATP sintered at $900^{\circ}C$ for 6 h, x = 0.3 shows the lowest activation energy of 0.42 eV in the temperature range of room temperature to $300^{\circ}C$.

드론 화상 및 LiDAR 스캐닝의 정합처리 자료를 활용한 노후 구조물 3차원 정밀 모델링에 관한 연구 (A Study on the 3D Precise Modeling of Old Structures Using Merged Point Cloud from Drone Images and LiDAR Scanning Data)

  • 신찬휘;민경조;김경규;전푸른;박훈;조상호
    • 화약ㆍ발파
    • /
    • 제40권4호
    • /
    • pp.15-26
    • /
    • 2022
  • 최근 건축물의 노령화에 따른 건물 전체 기능저하와 화재 및 지반침하와 같은 재난에 따른 건축물의 안정성 저하로 구조물 해체 수요가 급격히 증가하는 추세이다. 특히, 구조물 구성부위의 변형이나 손상의 정도가 심각한 구조물은 부재 내 집중하중이 발생하여 구조물 전체의 안정성이 저하되어 빠른 시일 내에 안전하게 구조물 해체가 가능한 시공기술에 대한 수요가 증가하고 있다. 또한, 노후 구조물에 대한 비인가 증축이나 불법 개조와 같은 구조적 변경으로 시공 당시 건물의 설계도면과 상이한 경우가 빈번하다고 보고되어오고 있다. 본 연구에서는 해체 대상 구조물의 시공 당시 도면과 현 시점 구조와의 차이점을 보완하기 위하여, 실내외 구조 표면에 대한 실측값을 활용하여 3차원 모델을 역설계하는 기법을 제안하였다. 실제 해체 시공 예정인 건축물을 대상으로 구조물 외곽에 대하여 드론 촬영을 실시하고 구조물 내부는 LiDAR 스캐닝을 수행하여 건물외곽과 실내에 대한 점군데이터를 획득한다. 각각 점군데이터는 Smartmapper를 활용하여 정밀하게 정합되며 2차원 도면제작과 3차원 구조해석용 모델 작성에 사용된다. 제안된 역설계 기법을 검증하기 위하여 드론화상자료, LiDAR 스캐너자료, 정합자료로부터 생성된 3차원 모델과 실측된 부재간의 거리를 비교하였다.