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지표면 재하시 토층구성에 따른 지중응력분포에 관한 연구 (A Study on the Stress Distribution in Soil According to the Composition of the Soil Layer in Case of Surface Loading)

  • 임종석;정상균;하혁
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2005년도 지반공학 공동 학술발표회
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    • pp.510-516
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    • 2005
  • This research aims to verify the stress distribution in soil according to the composition of the soil layer in case of surface loading. For this purpose, loading tests with measurement of stresses in the soil on four kinds of layered model ground in laboratory were performed. Those are (1)homogeneous sand, (2)gravel underlain by sand, (3)sand underlain by clay and (4)gravel underlain by clay. Test results are compared and analysed for the compositions of the soil layers. based on the results obtained, it is found that the larger the difference of the strengths of upper and lower layer is, the smaller the stress in the soil in case of surface loading is.

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C언어 기반 프로그램의 메모리 누수 검출기법 (Memory Leak Detection in C)

  • 배기곤;이숙희;권용래
    • 한국정보과학회:학술대회논문집
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    • 한국정보과학회 2007년도 한국컴퓨터종합학술대회논문집 Vol.34 No.1 (C)
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    • pp.510-515
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    • 2007
  • 더 이상 사용되지 않는 메모리가 계속해서 유지되는 것을 메모리 누수라고 한다. 메모리 누수가 발생하면 메모리 낭비가 누적되기 때문에 시스템의 성능이 저하되고 궁극적으로 시스템 크래시(crash)가 발생 할 수 있다. 본 논문에서는 이러한 메모리 누수를 검출하기 위하여 참조 계수 기법을 이용한다. 참조계수 기법을 이용하면 메모리 누수의 발생 여부뿐만 아니라 메모리 누수 발생시점에 대한 정보까지 제공할 수 있어 디버깅이 용이해진다. 그리고 본 논문에서 제안한 기법을 구현한 도구를 이용하여 사례연구를 수행한다. 사례 연구 분석을 통하여 본 연구에서 제안한 기법이 정확하게 메모리 누수를 검출하고 디버깅에 유용한 정보를 제공할 수 있다는 것을 보인다.

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Efficient CT Image Segmentation Algorithm Using both Spatial and Temporal Information

  • Lee, Sang-Bock;Lee, Jun-Haeng;Lee, Samyol
    • 한국콘텐츠학회:학술대회논문집
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    • 한국콘텐츠학회 2004년도 추계 종합학술대회 논문집
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    • pp.505-510
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    • 2004
  • This paper suggests a new CT-image segmentation algorithm. This algorithm uses morphological filters and the watershed algorithms. The proposed CT-image segmentation algorithm consists of six parts: preprocessing, image simplification, feature extraction, decision making, region merging, and postprocessing. By combining spatial and temporal information, we can get more accurate segmentation results. The simulation results illustrate not only the segmentation results of the conventional scheme but also the results of the proposed scheme; this comparison illustrates the efficacy of the proposed technique. Furthermore, we compare the various medical images of the structuring elements. Indeed, to illustrate the improvement of coding efficiency in postprocessing, we use differential chain coding for the shape coding of results.

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데이터 센터 환경에서의 전력 절감을 위한 OS-based Request 분배 기법 (OS-Based Request Distribution Scheme for Power Saving in Data Center Environment)

  • 김용헌;이진;김정선
    • 한국정보과학회:학술대회논문집
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    • 한국정보과학회 2011년도 한국컴퓨터종합학술대회논문집 Vol.38 No.1(A)
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    • pp.510-513
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    • 2011
  • Green IT의 실현을 위해 컴퓨팅 에너지 소모를 최소화 하고 전력 효율을 높이고자 하는 연구가 활발하게 진행되고 있다. 이러한 연구는 단일 시스템에서 데이터 센터와 같은 다중 시스템 레벨로 점차 확대되고 있는데 데이터 센터에서는 전력 절감을 위해 정책을 수립하는 방법으로 Green IT를 실현하게 된다. 대다수의 전력 절감 정책은 하드웨어 디바이스의 전력 상태를 상황에 맞게 변경시키는 방법을 사용한다. 하지만 디바이스의 빈번한 전력 상태 변경은 추가적인 전력과 컴퓨팅 오버헤드를 발생시키고, 서비스 품질과 직결되는 성능 저하의 문제를 야기할 수 있다. 따라서 본 논문에서는 데이터 센터를 구성하는 각각의 단일 시스템에서 OS를 통해 수집 가능한 정보를 기반으로 요청되는 서비스에 따라 추가적인 오버헤드 없이 처리할 수 있는 시스템을 찾고 작업을 분배하는 기법을 제안한다.

Fenton 산화공정과 Zeolite 흡착공정을 연계한 축산폐수처리에 관한 연구 (A Study on Treatment of Livestock wastewater using Fenton Oxidation and Zeolite Adsorption Process)

  • 조창우;김윤정;정팔진
    • 한국물환경학회지
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    • 제21권5호
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    • pp.505-510
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    • 2005
  • The objective of this study was to remove non-biodegradable matters and ammonia ion in livestock wastewater using Fenton oxidation and Zeolite adsorption process. After coagulation process as 1st treatment, non-biodegradable matters remained after 1st treatment were removed by using OH radical produced in Fenton oxidation process. Zeolite as cation adsoption process was used to remove ammonia ion in 2nd treatment water. As a result of treatment using these processes, NBDCOD removal efficiency was over 90% and ammonia ion was almost removed. Most aromatics or polynuclear aromatics like benzene, phenol and scatol in livestock wastewater wasn't detected after Fenton oxidation process.

FBG 센서가 내장된 스마트 앵커를 이용한 앵커와 그라우트의 하중전이 측정 (Measurement of Load Transfer between Anchor and Grout using Optical FBG Sensors embedded in Smart Anchor)

  • 서동남;김영상;김재민
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2008년도 춘계 학술발표회 초청강연 및 논문집
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    • pp.505-510
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    • 2008
  • FBG Sensor, which is smaller than strain gauge and has better durability and does not have a noise from electromagnetic waves, was adapted to develope a smart anchor. A series of pullout tests were performed to verify the feasibility of smart anchor and find out the load transfer mechanism around the steel wire fixed to rock with grout. Distribution of shear stresses at steel wire-grout interface is assessed from the measured strain distribution by the optical fiber sensors and compared with stress distributions predicted by Farmer's and Aydan's formulas. It was found that present theoretical formulas may underestimate the failure depth and magnitude of shear stresses when the pullout loads increase.

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적외선투과성 $ZrF_4$-유리의 조성과 안정성에 관한 연구 (Composition and Stability Study on the IR Transmitting $ZrF_4$-Based Glasses)

  • 정기호
    • 한국세라믹학회지
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    • 제27권3호
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    • pp.430-436
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    • 1990
  • Glasses of different compositions were synthesized by substituting each component of 56ZrF4-14BaF2-6LaF3-4AlF3-20NaF(ZBLAN) with HfH4, SrF2, GdF3, InF3 and LiF3, each of similar size and chemical property with the component being substituted, respectively. The heating rate used in the DSC runs was 10K/min. All ofthe glasses exhibit glass transition temperatures of 510$\pm$10K, while crystallization temperatures vary between 625 and 720K depending upon different glass compositions. For most glasses crystallization temperatures obtained while cooled are lower than those obtained while heated, but InF3 or SrF2 containing glasses showed opposite trend. HBLAN, ZHBLAN and ZHBLANLi glasses, which were made by substituting HfH4, LiF for ZrF4 and NaF of ZBLAN respectively, showed improvement in the glass stability.

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DCM-A 유도체를 이용한 유기 광전 변환 소자의 특성 (Characteristics of Organic Light Emitting diodes with DCM derivatives)

  • 문수산;이성안;한은미
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2010년도 하계학술대회 논문집
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    • pp.168-168
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    • 2010
  • DCM derivatives were newly synthesized. The OLEDs with a DCM-A as an emitting layer was fabricated and analyzed their opto-electrical properties. The structures of OLEDs were I) ITO/DCM-A/Al, II) ITO/-NPD/DCM-A/LiF/Al, and III) ITO/-NPD/DCM-A/Alq3/LiF/Al. The EL peak of the DCM-A shows the red emission in the range of 700 nm. The structure I) shows that 1050 nW/cm2 at 510 mA/cm2. The structure II) shows that takes the most excellent luminance about 39,000 nW/cm2 at 290 mA/cm2. The EL structure ill shows luminance about 13,000 nW/cm2 at 6 mA/cm2.

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Computationally Efficient Lattice Reduction Aided Detection for MIMO-OFDM Systems under Correlated Fading Channels

  • Liu, Wei;Choi, Kwonhue;Liu, Huaping
    • ETRI Journal
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    • 제34권4호
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    • pp.503-510
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    • 2012
  • We analyze the relationship between channel coherence bandwidth and two complexity-reduced lattice reduction aided detection (LRAD) algorithms for multiple-input multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) systems in correlated fading channels. In both the adaptive LR algorithm and the fixed interval LR algorithm, we exploit the inherent feature of unimodular transformation matrix P that remains the same for the adjacent highly correlated subcarriers. Complexity simulations demonstrate that the adaptive LR algorithm could eliminate up to approximately 90 percent of the multiplications and 95 percent of the divisions of the brute-force LR algorithm with large coherence bandwidth. The results also show that the adaptive algorithm with both optimum and globally suboptimum initial interval settings could significantly reduce the LR complexity, compared with the brute-force LR and fixed interval LR algorithms, while maintaining the system performance.

Analytical Model of Double Gate MOSFET for High Sensitivity Low Power Photosensor

  • Gautam, Rajni;Saxena, Manoj;Gupta, R.S.;Gupta, Mridula
    • JSTS:Journal of Semiconductor Technology and Science
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    • 제13권5호
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    • pp.500-510
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    • 2013
  • In this paper, a high-sensitivity low power photodetector using double gate (DG) MOSFET is proposed for the first time using change in subthreshold current under illumination as the sensitivity parameter. An analytical model for optically controlled double gate (DG) MOSFET under illumination is developed to demonstrate that it can be used as high sensitivity photodetector and simulation results are used to validate the analytical results. Sensitivity of the device is compared with conventional bulk MOSFET and results show that DG MOSFET has higher sensitivity over bulk MOSFET due to much lower dark current obtained in DG MOSFET because of its effective gate control. Impact of the silicon film thickness and gate stack engineering is also studied on sensitivity.