• Title/Summary/Keyword: cell radius

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The Effect of Soft Handoff Techniques on Cell Coverage for CDMA Cellular System (소프트 핸드오프가 CDMA 셀룰러 시스템의 셀 영역에 미치는 영향)

  • Oh, Hyon-Kyu;Kim, Hang-Rae;Kim, Nam
    • Proceedings of the IEEK Conference
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    • 2000.11a
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    • pp.125-128
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    • 2000
  • In this paper, the handoff margins are analyzed using the propagation attenuation which is modeled as a product of the fourth power of the distant and a log-normal random variable whose standard deviation is 8 ㏈. The effect of handoff techniques on cell coverage for CDMA system are shown that soft handoff increases cell coverage relative to hard handoff. When the cell radius extends 5-10 % and the outage probability is 10 %, the relative cell coverage area is extended 3.22 ㏈-3.99 ㏈ and 2.55 ㏈-2.85 ㏈ with power control and without power control, respectively.

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Surgical treatment of Giant Cell Tumor in Knee Joint (슬관절 주위 거대세포종의 치료)

  • Bae, Dae-Kyung
    • The Journal of the Korean bone and joint tumor society
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    • v.1 no.1
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    • pp.1-6
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    • 1995
  • Giant cell tumors are primary bone tumors originating from non-osteoblastic connective tissue. The sites of involvement were commonly distal femur, proximal tibia, proximal humerus, distal radius and others (including os calcis, ilium and sacrum). Giant cell tumor located around knee joint has been difficult to treat because of local recurrence following curettage with or without bone graft. Although primary resections reduce recurrence of the lesion, the joint function will be markedly impaired. Marginal excision was very often complicated by a loss of joint integrity since all the giant cell tumors occupy juxtaarticular positions. Techniques involving physical adjuncts(high speed burr and electric cauterization) have been used in the hope of decreasing the rate of local recurrence and avoiding the morbidity of primary resection. A meticulous clinical, radiological and histological evaluation is needed to choose the correct treatment, keeping in mind the possibility of recurrence after each treatment modality.

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Electrical Characteristics and FEM Simulations of Beam Type Load Cell (Beam형(形) Load Cell의 FEM Simulation과 그 전기적특성(電氣的特性))

  • Park, Chan-Won;An, Kwang-Hee;Choi, Gyu-Seok
    • Journal of Industrial Technology
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    • v.12
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    • pp.25-36
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    • 1992
  • In this paper, we simulate and calculate the stress and output voltage of the beam structure load cells by using FEM as varing physical structure parameters and loading positions. It is proved that stress enhance as the increase of the notch pitch and radius of the load cell, but decrease as the increase of the notch thickness and beam width. The results are good matched for basic formulas of the single fixed beam, and are verified our simulation is correct. Also, it is found that the stress characteristics of the load cell is varied according to loading positions with structure parameters, and caculated output voltage of the load cell approximate to those of the real manufactured ones. As a result, this study will offer efficient design and analysis technique for making special and variety capacity of load cells.

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Electrochemical Properties of Conducting Polymer for Supercapacitor (Supercapacitor용 도전성 고분자의 전기화학적 특성)

  • 강광우;김종욱;김명산;구할본;김형곤
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.14 no.4
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    • pp.323-327
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    • 2001
  • The purpose of this study is to research and develop conducting polymer(CP) composite electrode for supercapacitor. The radius of semicircle of CP composite cell with polyaniline(PAn) composite electrode adding 30wt% acetylene black was small. The total resistance of supercapacitor cell mainly depended on internal resistance of he electrode. The discharge capacitance of supercapacitor cell with PAn composite electrode adding 30wt% acetylene black in 1st and 50th cycles was 27F/g and 31F/g at current density of 1mA/$\textrm{cm}^2$, respectively. Supercapacitor cell with PAn composite electrode adding 30wt% acetylene black showed a good cycliability. Supercapacitor cell of CP composite electrode with 1M LiClO$_4$/PC brings out god capacitor performance below 4V.

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Electrochemical Properties of Conducting Polymer for Supercapacitor (Supercapacitor용 도전성 고분자의 전기화학적 특성)

  • 강광우;김종욱;구할본
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2000.11a
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    • pp.332-334
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    • 2000
  • The purpose of this study is to research and develop conducting polymer(CP) composite electrode for supercapacitor. Supercapacitor cell of CP composite electrode with 1M LiClO$_4$/ PC bring out good capacitor performance below 4V. The radius of semicircle of CP composite cell with PAn composite electrode adding 30wt% acetylene black was absolutely small. The total resistance of supercapacitor cell mainly depended on internal resistance of the electrode. The discharge capacitance of supercapacitor cell with PAn composite electrode adding 30wt% acetylene black in 1st and 50th cycles was 27F/g and 31F/g at current density of 1mA/$\textrm{cm}^2$. Supercapacitor cell with PAn composite electrode adding 30wt% acetylene black performed a good cycliability.

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Electrical Properties of Supercapacitor with Polyaniline and Polythiophene (Polyaniline과 Polythiophene을 사용한 supercapaccitor의 전기적 특성)

  • 강광우;김종욱;구할본
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2000.07a
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    • pp.487-490
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    • 2000
  • The purpose of this study is to research and develop conducting polymer(CP) composite electrode for supercapacitor. Electrochemical capacitor(supercapacitor) cell of CP composite electrode with 1M LiClO$_4$PC bring out good capacitor performance below 4V. The radius of semicircle of CP composite cell with PAn composite electrode adding l5wt%SP270(PAnS15) and PT composite electrode adding 50wt%SP270 (PTS50) was absolutely small. The total resistance of supercapacitor cell mainly depended on internal resistance of the electrode. The discharge capacitance of supercapacitor cell with PTS50(+)/PAnS15(-) in 1st and 20th cycles was 38F/g and 28F/g at current density of 1mA/cm$^2$. Supercapacitor cell with PTS50(+)/PAnS15(-) showed good capacitance and stability with cycling.

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Analysis of call blocking probability and queuing modeling using call admission control in the CDMA system with the WLAN (WLAN이 연동된 CDMA 시스템에서 Call Admission Control을 이용한 호 차단확률 분석과 Queuing 모델링)

  • 안치훈;기영민;김동구;류승문
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.41 no.4
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    • pp.17-24
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    • 2004
  • Call blocking probabilities of streaming data service in CDMA system with access point(AP) of WLAN are analyzed for different cell geometry of base station and AP and queuing is modeled. The considered system leads to successful handoffs between the APs of WLAN. Blocking probabilities are enumerated as a function for ratio of base station and AP sizes, their locations and the number of buffer in the queue. Results show that blocking probability is not influenced by base station and AP locations but mainly by ratio of their sizes. For CDMA system of radius 100m, 5 buffers in the queue and 7㏈ noise rise(NR), in order to obtain 1% call blocking probability, a cell with hot spot of radius 20m has more 0.6Erlang than that of radius 60m.

Effect of Partial Substitution of Magnetic Rare Earths for La on the Structure, Electric Transport And Magnetic Properties of Oxygen Deficient Phase LaSr2MnCrO7-δ

  • Singh, Devinder;Sharma, Sushma;Mahajan, Arun;Singh, Suram;Singh, Rajinder
    • Bulletin of the Korean Chemical Society
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    • v.34 no.6
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    • pp.1679-1683
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    • 2013
  • Intergrowth perovskite type complex oxides $La_{0.8}Ln_{0.2}Sr_2MnCrO_{7-{\delta}}$ (Ln=La, Nd, Gd, and Dy) have been synthesized by sol-gel method. Rietveld profile analysis shows that the phases crystallize with tetragonal unit cell in the space group I4/mmm. The unit cell parameters a and c decrease with decreasing effective ionic radius of the lanthanide ion. The magnetic studies suggest that the ferromagnetic interactions are dominant due to $Mn^{3+}$-O-$Mn^{4+}$ and $Mn^{3+}$-O-$Cr^{3+}$ double exchange interactions. Both Weiss constant (${\theta}$) and Curie temperature ($T_C$) increase with decreasing ionic radius of lanthanide ion. It was found that the transport mechanism is dominated by Mott's variable range hopping (VRH) model with an increase of Mott localization energy.

Finite Element Analysis of Nonlinear Behavior of a Column Type Sensing Element for Load Cell According to Design Parameters (기둥형 로드셀 감지부의 설계변수에 따른 비선형 거동해석)

  • Lee, Chun-Yeol;Gang, Dae-Im
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.24 no.6 s.177
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    • pp.1540-1546
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    • 2000
  • Recently, force measurement systems are commonly used in many industrial fields and the precision of the measurement system is getting more important as the industry needs more precise tools and in struments to make high quality products. However, a high precision force measurement system is hard to make unless we know precisely the causes, quality and quantity of measurement errors in advance. In this work, many possible mechanical causes of measurement errors are reviewed including ratio of length to diameter of sensing part, radius of contact area, radius of bearing part, ratio of material properties and change of boundary conditions. Also, the measurement errors are analyzed by nonlinear finite element method and the nonlinear behavior of the errors are investigated. The results can be used to design force measurement systems and expected to be very useful especially for compact type load cells.

Compensation of Relation Formula between Luffing Wire Tension and Overturning Moment in a Crawler Crane Considering the Deflection of Boom (크롤러 크레인에서 붐의 처짐을 고려한 러핑와이어 장력과 전도모멘트 사이의 관계식 보정)

  • Jang, Hyo-Pil;Han, Dong-Seop
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.10 no.4
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    • pp.44-49
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    • 2011
  • The crawler crane, which consists of a lattice boom, a driving system, and movable vehicle, is widely used in a construction site. It needs to be installed an overload limiter to prevent the overturning accident and the fracture of structure. This research is undertaken to provide the relation formula for designing the overload limiter as follows: First the relation formulas between the wire-rope tension and the hoisting load or the overturning ratio according to the luffing angle and length of a lattice boom are established. Secondly the derived formulas are corrected by using the compensated angle considering the deflection of boom through the finite element analysis. The stiffness analysis is carried out for 30-kinds of models as a combination of 6-kinds of luffing angle and 5-kinds of length of boom. Finally the shape design of a stick type load cell, which is the device to measure the wire-rope tension, is performed. 5-kinds of notch radius and 5-kinds of center hole radius are adopted as the design parameter for the strength analysis of the load cell.