• Title/Summary/Keyword: Li Chan

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QoS Provisioning for WDM Burst Switched Ring Networks

  • Peng, Li-Mei;Kim, Young-Chon;Youn, Chan-Hyun
    • Proceedings of the Korea Information Processing Society Conference
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    • 2010.04a
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    • pp.717-720
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    • 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.

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

  • Park, Seong-Soo;Kim, Kyoung-Tae;Kim, Byoung-Chan;Park, Jin;Park, Hee-Chan
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.10 no.1
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    • pp.66-72
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    • 2000
  • The behavior of nucleation and crystallization in the $Li_2O_3-SiO_2$ glass heat-treated at different condition under the conventional and microwave processing was studied by differential thermal analysis (DTA), X-ray diffractometry (XRD), optical microscopy (OM), and electrical conductivity measurement. Nucleation temperature and temperature of maximum nucleation rate in both conventionally and microwave heat-treated samples were 460~$500^{\circ}C$ and $580^{\circ}C$, respectively. It was expected that the probability for bulk crystallization increased in microwave heat-treated sample, compared to conventionally heat-treated one. Degree of crystallization increased with increasing crystallization temperature in both conventionally and microwave heat-treated samples. However, pattern of crystallization growth under microwave processing appeared to be quite different from that under the conventional one due to its internal or volumetric heating. Electrical conductivity of conventionally and microwave heat-treated samples were 1.337~2.299, 0.281~~$0.911{\times}10^{-7}\Omega {\textrm}{cm}^{-1}$, respectively.

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

  • Kim, Eun-Joung;Kang, Yun-Chan;Park, Hee-Dong;Ryu, Seung-Kon
    • Korean Journal of Materials Research
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    • v.12 no.10
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    • pp.771-775
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    • 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.

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

  • Lee, Ho Chan;Jung, Mi Young;Choi, Jung Hwa;Jeong, Min Yeong;Park, Soo Yeon
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.32 no.4
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    • pp.291-297
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    • 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.

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

  • Jeon, Seong-Woo;Hong, Hyun-Jung;Lee, Chong-Soo;Lee, Woo-Kyun;Sung, Hyun-Chan
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.10 no.5
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    • pp.20-30
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    • 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.

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

  • Sun, Ho-Jung;Lee, Jae-Ho;Jeong, Hyun-Young;Seok, Dong-Chan;Jung, Yongho;Park, Gyungse;Shim, Joongpyo
    • Transactions of the Korean hydrogen and new energy society
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    • v.24 no.2
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    • pp.160-171
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    • 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.

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

  • Choi, Woonghee;Kang, Chan Hyoung
    • Journal of Powder Materials
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    • v.23 no.4
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    • pp.287-296
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    • 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 $50^{\circ}C$.

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

  • Moon, Jung-In;Cho, Hong-Chan;Song, Jeong-Hwan
    • Korean Journal of Materials Research
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    • v.22 no.7
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    • pp.346-351
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    • 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 $300^{\circ}C$.

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

  • Chan-hwi, Shin;Gyeong-jo, Min;Gyeong-Gyu, Kim;PuReun, Jeon;Hoon, Park;Sang-Ho, Cho
    • Explosives and Blasting
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    • v.40 no.4
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    • pp.15-26
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    • 2022
  • With the recent increase in old and dangerous buildings, the demand for technology in the field of structure demolition is rapidly increasing. In particular, in the case of structures with severe deformation of damage, there is a risk of deterioration in stability and disaster due to changes in the load distribution characteristics in the structure, so rapid structure demolition technology that can be efficiently dismantled in a short period of time is drawing attention. However, structural deformation such as unauthorized extension or illegal remodeling occurs frequently in many old structures, which is not reflected in structural information such as building drawings, and acts as an obstacle in the demolition design process. In this study, as an effective way to overcome the discrepancy between the structural information of old structures and the actual structure, access to actual structures through 3D modeling was considered. 3D point cloud data inside and outside the building were obtained through LiDAR and drone photography for buildings scheduled to be blasting demolition, and precision matching between the two spatial data groups was performed using an open-source based spatial information construction system. The 3D structure model was completed by importing point cloud data matched with 3D modeling software to create structural drawings for each layer and forming each member along the structure slab, pillar, beam, and ceiling boundary. In addition, the modeling technique proposed in this study was verified by comparing it with the actual measurement value for selected structure member.