• 제목/요약/키워드: RAM2-RAM4

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SBC(Odroid-xu4) 성능에 따른 Hector slam 최적화 (Optimization of Hector Slam according to SBC Performance)

  • 이승진;김상훈
    • 한국정보처리학회:학술대회논문집
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    • 한국정보처리학회 2018년도 춘계학술발표대회
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    • pp.250-252
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    • 2018
  • 본 논문은 4차 산업 혁명 핵심 기술인 자율주행에 대하여 기술하였으며 그 중 Hector Slam을 사용 하였다. Hector slam 같은 경우 RAM이 4G 이상 되어야 제대로 동작하지만 SBC(Odroid xu4) 같은 경우 RAM의 크기가 2G이므로 최적화할 필요성이 있다. SBC(Odroid xu4)에서도 사용 가능하도록 Hector slam 구현 최적화를 하였으며, 향후에 Aruco Marker를 이용하여 위치를 좀 더 섬세히 보정 해볼 것이며 또한 Aruco Marker의 ID를 통해 사물 인식을 하여 사람에게 사물에 대한 정보를 알려줌으로써 사람과 협업을 할 수 있는 로봇이 될 것이다.

상온에서 RF 스퍼터링 방법으로 증착한 Hafnium Oxide 박막의 저항 변화 특성 (Resistive Switching Characteristics of Hafnium Oxide Thin Films Sputtered at Room Temperature)

  • 한용;조경아;윤정권;김상식
    • 한국전기전자재료학회논문지
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    • 제24권9호
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    • pp.710-712
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    • 2011
  • In this study, we fabricate resistive switching random access memory (ReRAM) devices constructed with a Al/$HfO_2$/ITO structure on glass substrates and investigate their memory characteristics. The hafnium oxide thin film used as a resistive switching layer is sputtered at room temperature in a sputtering system with a cooling unit. The Al/$HfO_2$/ITO device exhibits bipolar resistive switching characteristics, and the ratio of the high resistance (HRS) to low resistance states (LRS) is more than 60. In addition, the resistance ratio maintains even after $10^4$ seconds.

DAB 시스템에서 낮은 복잡도와 효율적인 구조를 갖는 FEC 설계 (FEC design with low complexity and efficient structure for DAB system)

  • 김주병;임영진;이문호;이광재
    • 한국통신학회논문지
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    • 제26권8A호
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    • pp.1348-1357
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    • 2001
  • 본 논문에서는 DAB 시스템에서 사용하는 FEC(Forward Error Correction) 블록을 하드웨어 크기를 고려하여 효율적인 구조를 갖도록 설계하였다. DAB 시스템의 FEC 블록은 크게 스크램블러(에너지분산), 리드-솔로몬 코더, 길쌈 인터리버로 구성된다. RS 디코더 블록 중 키 방정식을 계산해 내는 블록과 길쌈 인터리버가 차지하는 하드웨어 비중은 굉장히 크다. 본 논문에서는 스크램블러 부분에서 데이터의 시작을 알려주는 신호의 효율적인 검출기법을 제안하고, 리드-솔로몬 디코더 블록의 수정 유클리드 알고리즘을 효율적인 하드웨어로 구현하기 위한 새로운 구조와 길쌈 인터리버에서 최적의 메모리 구조를 효과적인 구조를 제안한다. 제안한 구조에서는 단지 8개의 GF 곱셈기와 4개의 덧셈기만을 가지고 RS 디코더의 수정 유클리드 알고리즘을 구현하였으며, 2 RAM(128)과 4 RAM(256)을 가지고 컨벌루셔널 인터리버를 구현하였다. 제안한 구조로 설계했을 경우 디코더 블록이 Altera-FPGA 칩(FLEX10K)에 모두 들어갈 수 있었다.

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GAUSS 소거법을 이용한 초음파 트랜스듀서의 지향성합성 SIMULATION (Directivity Synthesis Simulation of Ultrasonic Transducer Using Gauss Elimination Method)

  • 이정남;조기량;이진선;이문수
    • 한국전자파학회지:전자파기술
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    • 제6권4호
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    • pp.20-27
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    • 1995
  • 본 논문에서는 직선 배열 응원에 의한 초음파 트랜스듀서의 목적 지향성에 대한 Beam forming을 Gauss 소거법을 이용하여 수치 계산하였다. 하나의 System으로 여러 가지의 조건에 대한 지향성 합성의 실현을 목적으로 하였으며, 목적 지향성으로는 계산에 의해 합성된 선음원에 의한 지향성과 임의로 설정한 Beam 폭의 변화와 방사 방향의 회전에 대한 준이상 Beam을 선택하여 지향성 합성을 시융레이션 하였다. 수치 계산에는 PC(CPU: 80486DX2, RAM 16Mbyte)를 이용하였으며, 수치 계산 결과, 반복법(LMS볍, DFP볍)에 비해 훨씬 빠른 지향성 합성이 가능하고, 또 System 안정도 면에서도 매우 양호함을 확인했다.

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두개의 동일한 탐조등으로 볼록다각형을 비추는 알고리즘 (An Algorithm for Illuminating a Convex Polygon with Two Equal Floodlights)

  • 김성권;신찬수
    • 한국정보과학회논문지:시스템및이론
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    • 제27권4호
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    • pp.416-419
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    • 2000
  • G를 꼭지점들이 일반 위치에 있는 n개의 꼭지점을 갖는 볼록다각형이라 하자. 본 논문에서는 두 개의 탐조등을 G의 경계선에 배치하여 G의 내부를 모두 비추는 알고리즘을 개발하는데, 두 탐조등의 최대각을 최소화하는 것이 목적이다. 확장된 real-RAM상에서 O($n^2$) 시간 알고리즘을 제시한다

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Fabrication of Nd-Substituted Bi4Ti3O12 Thin Films by Metal Organic Chemical Vapor Deposition and Their Ferroelectrical Characterization

  • Kim, Hyoeng-Ki;Kang, Dong-Kyun;Kim, Byong-Ho
    • 한국세라믹학회지
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    • 제42권4호
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    • pp.219-223
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    • 2005
  • A promising capacitor, which has conformable step coverage and good uniformity of thickness and composition, is needed to manufacture high-density non-volatile FeRAM capacitors with a stacked cell structure. In this study, ferroelectric $Bi_{3.61}Nd_{0.39}Ti_3O_{12}$ (BNdT) thin films were prepared on $Pt(111)/TiO_2/SiO_2/Si$ substrates by the liquid delivery system MOCVD method. In these experiments, $Bi(ph)_{3}$, $Nd(TMHD)\_{3}$ and $Ti(O^iPr)_{2}(TMHD)_{2}$ were used as the precursors and were dissolved in n-butyl acetate. The BNdT thin films were deposited at a substrate temperature and reactor pressure of approximately $600^{\circ}C$ and 4.8 Torr, respectively. The microstructure of the layered perovskite phase was observed by XRD and SEM. The remanent polarization value (2Pr) of the BNdT thin film was $31.67\;{\mu}C/cm^{2}$ at an applied voltage of 5 V.

p.R72P, PIN3 Ins16bp Polymorphisms of TP53 and CCR5Δ32 in North Indian Breast Cancer Patients

  • Guleria, Kamlesh;Sharma, Sarika;Manjari, Mridu;Uppal, Manjit Singh;Singh, Neeti Rajan;Sambyal, Vasudha
    • Asian Pacific Journal of Cancer Prevention
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    • 제13권7호
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    • pp.3305-3311
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    • 2012
  • Background: The present study aimed to find the prognostic implications of two polymorphisms in TP53 (p.R72P, PIN3 Ins16bp) and one in CCR5 ($CCR5{\Delta}32$) in sporadic breast cancer patients. Methods: DNA samples of 80 breast cancer patients and 80 age and gender matched unrelated healthy control individuals from Punjab, North West India were analyzed. Results: For p.R72P, the genotype frequency was 13.8% (RR), 58.8% (RP), 27.5% (PP) in patients and 33.9% (RR), 40.0% (RP), 26.5% (PP) in controls. For PIN3 Ins16bp, the genotype frequencies were 53.75% (A1A1), 37.5% (A1A2), 8.75% (A2A2) in patients and 66.3% (A1A1), 31.3% (A1A2), 2.5% (A2A2) in controls. Only 4 (5%) breast cancer patients were heterozygous for $CCR5{\Delta}32$ deletion. Common RR-A1A1-WT/WT genotype was lower while RP-A1A2-WT/WT genotype was higher in patients as compared to controls. RP-A1A1-WT/WT genotype was significantly higher in patients as compared to control individuals (p = 0.008). Conclusion: Though a clear association of any particular genotype with sporadic breast cancer or stage was not apparent, the results of present study were suggestive that sporadic breast cancer patients with RR-A1A1-WT/WT genotype might have a better response to chemotherapy, thus improving their chances of survival.

초폭굉속도 램가속기의 정상발진과 불발과정에 대한 수치해석 (Numerical Study of Normal Start and Unstart Processes In a Superdetonative Speed Ram Accelerator)

  • 문귀원;정인석;최정렬
    • 한국연소학회:학술대회논문집
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    • 한국연소학회 2002년도 제24회 KOSCO SYMPOSIUM 논문집
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    • pp.123-132
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    • 2002
  • A numerical study was conducted to investigate the combustion phenomena of normal start and unstart processes based on ISL's RAMAC 30 experiments with different diluent amounts and fill pressures in a ram accelerator. The initial projectile launching speed was 1.8 km/s which corresponded to the superdetonative speed of the stoichiometric $H_2/O_2$ mixture diluted with 5 $CO_2$ or 4 $CO_2$. Experiments with same condition except for projectile surface material demonstrated that ignition was successful with an aluminum projectile, but no combustion was observed in case of a steel projectile. In this study, it was found that neither shock nor viscous heating was sufficient to ignite the mixture at a low speed of 1.8 km/s, as was found in the experiments using a steel projectile. However, we could succeed in igniting the mixtures by imposing a minimal amount of additional heat to the combustor section and simulate the normal start and unstart processes found in the experiments with an aluminum projectile. For the numerical simulation of supersonic combustion, multi-species Navier-Stokes equations coupled with a Baldwin-Lomax turbulence model and detailed chemistry reaction equations of $H_2/O_2/CO_2$ suitable for high-pressure gaseous combustion were considered. The governing equations were discretized by a high order accurate upwind scheme and solved in a fully coupled manner with a fully implicit, time accurate integration method. The numerical results matched almost exactly to the experimental results. As a result, it was found that the normal start and unstart processes depended on the strength of gas mixture, development of shock-induced combustion wave stabilized by the first separation bubble, and its size and location.

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Effects of Butylated Hydroxytoluene on Freezability of Ram Spermatozoa

  • Farshad, A.;Khalili, B.;Jafaroghli, M.
    • Asian-Australasian Journal of Animal Sciences
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    • 제23권10호
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    • pp.1276-1281
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    • 2010
  • The present study was conducted to investigate the effects of butylated hydroxytoluene (BHT) supplementation on diluted, cooled and frozen-thawed ram spermatozoa. After primary evaluation of collected ejaculates, only semen samples with motility of more than 70% and sperm concentration higher than $3{\times}10^3$ sperm/ml were used for cryopreservation. The selected semen samples were then pooled and diluted 1:4 with Tris Citrate Fructose Yolk (TCFY) extender supplemented with different concentrations of BHT (0.5, 10, 2.0 and 3.0 mM). As the control, semen was diluted and frozen in the diluent without BHT. Motility, progressive motility, viability, membranes and acrosome integrity were evaluated after dilution (part 1), cooling (part 2) and freezing and thawing (part 3). The results of the first part of the experiment showed that there were no significant difference between treatments in the motility, progressive motility, viability, membranes and acrosome integrity of spermatozoa, but the results with 2.0 mM BHT were slightly better than obtained with other levels of BHT and control extender. Significantly better results (p<0.05) were observed in the second part of the experiment for cooled spermatozoa characteristics, when extender was supplemented with 2.0 and 3.0 mM BHT. Furthermore, the results obtained in the third part of the experiment indicated that, after freezing and thawing, all evaluated semen characteristics were improved significantly (p<0.05) by increasing BHT levels, with the best results obtained for extender containing 2 mM BHT. Comparison of these results with those of control diluent, the effects of supplementation were significantly (p<0.01) better. However, the higher concentration of BHT (3.0 mM) reduced the motility, acrosomal integrity, viability and hypo-osmotic swelling response of spermatozoa compared to extender containing 2.0 mM BHT. In conclusion, the results obtained in this study showed that the semen quality of rams was improved when BHT was added to extender used before the freezing process.