• 제목/요약/키워드: Duplex structure

검색결과 112건 처리시간 0.019초

SSD(Simultaneous Single Band Duplex) 시스템을 위한 효과적인 자기 간섭 제거 방법 (Effective Self-Interference Cancellation for SSD(Simultaneous Single Band Duplex) System)

  • 안창영;유흥균
    • 한국전자파학회논문지
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    • 제25권2호
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    • pp.189-198
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    • 2014
  • 본 논문에서는 동일 대역에서 동시에 전 이중 통신을 하기 위한 프레임 구조를 사용하는 터보 등화기를 결합한 SSD (Simultaneous Single band Duplex) 시스템을 제안한다. 본 논문에서는 자기 간섭 신호를 보다 효율적으로 제거하기 위하여 프레임 구조를 사용한다. 본 논문에서는 송수신 프레임 구조를 사용할 경우의 시스템의 특성을 분석하기 위하여 프레임 구조를 사용하지 않는 시스템과 성능을 비교하였다. 시뮬레이션 결과로 본 논문에서 제안하는 시스템은 프레임 구조를 사용하였을 경우, 프레임 구조를 사용하지 않았을 경우보다 더 좋은 성능을 내며, 프레임 구조를 사용하는 제안하는 시스템은 더 적은 터보 등화기의 전역 반복으로 프레임 구조를 사용하지 않은 시스템과 유사한 성능을 낼 수 있는 것을 확인하였다.

고 망간강 2상 혼합조직의 열적 안정성에 관한 연구 (A Study on the Thermal Stability of Duplex High Mn-Steel Structure)

  • 위명용
    • 열처리공학회지
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    • 제5권1호
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    • pp.13-22
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    • 1992
  • The thermal stability of duplex high Mn-steel structure have been investigated using 15%Mn~1.0~2.4%C steels which are composed of ${\gamma}$-and ${\theta}$-phases in the range of temperature from 900 to $1100^{\circ}C$, and time from 50 to 300h. The results are as follows ; 1) The grain growth in single-phase region proceeds by grain boundary migration and the relation between mean radius $\bar{r}$ and annealing time t is described as follows ; $\bar{r}^2-{\bar{r}_0}^2=k_0{\cdot}t$ 2) The grain growth of duplex, (${\gamma}+{\theta}$), strucrure is slower than that single phase because the chemical composition of ${\gamma}$-and ${\theta}$-phases differs esch others. 3) The grain of (${\gamma}+{\theta}$) duplex structure grow slowly in a mode of Ostwald ripening. Because grain boundaries of ${\gamma}$-phase migrate under a restriction of pinning by ${\theta}$-phases. 4) In the duplex structures. the dispersed structures change to the dual-structures, as the volume fraction of the dispersed second-phase increase. Consequently, the growth-law, which is controlled by boundary-diffusion change to that of the volume diffusion-mechanism.

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수퍼 2상 스테인리스강의 부식 저항성에 관한 연구 (Corrosion Resistance of Super Duplex Stainless Steel)

  • 강흥주;남기우;안석환;강창룡;도재윤;박인덕
    • 한국해양공학회지
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    • 제17권2호
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    • pp.40-46
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    • 2003
  • The corrosion resistance of super duplex stainless steel on both its fibrous and dispersed phase was investigated. These structures consist of various volume fraction and distribution of austenite structure, which were obtained by changing the heat treatment temperature and cycle. The fibrous phase had higher austenite volume fraction than that of the dispersed phase at the same temperature. Corrosion resistance of super duplex stainless steel was evaluated through an immersion test and an impingement test, using 35% HCI and sea water, respectively. Super duplex stainless steel was compared with STS316L and STS304. The corrosion resistance of super duplex stainless steel was superior to ST316L and STS304. The dispersed phase of super duplex stainless steel was more stabilized than the fibrous phase in corrosion. The magnitude of corrosion rate was in order STS304, STS316L, fibrous phase of super duplex stainless steel and dispersed phase of super duplex stainless steel.

듀플렉스 시스템의 구조에 따른 신뢰성 평가에 관한 연구 (A study on the Dependability Evaluation according to the structure of Duplex system)

  • 김현기;강민수;신덕호;권용훈;이기서
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 1998년도 창립기념 춘계학술대회 논문집
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    • pp.194-202
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    • 1998
  • This paper shows two models of the duplex system having a fault tolerant system characteristic used in airplane and railway system. The architecture of these systems is based on Mc68000, and we designed the single system, single duplex system, dual system and dual duplex system to evaluate the system characteristic. We calculate the failure rate of components using MIL-SPEC-2l7F and evaluate the reliability, avaliability, safety and MTTF(Mean Time To Failure) of the designed systems by Markov model. We choose our system depending on the developing system characteristic.

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오스테나이트 분포에 따른 수퍼 2상 스테인리스강의 기계적 특성과 피로균열 진전거동 (Mechanical Characteristics and Fatigue Crack Propagation of Super Duplex Stainless Steel by Distribution of Austenite)

  • 도재윤;이상기;안석환;남기우;강창룡
    • 열처리공학회지
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    • 제14권4호
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    • pp.205-211
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    • 2001
  • The characteristics of super duplex stainless steel were investigated on its fibrous structure and dispersed structure. These structures consist of various volume fractions and distributions of the austenite phase that were obtained by changing the heat treatment temperature and cycle. The fibrous structure had higher austenite volume fraction than dispersed structure on the same temperature. As the austenite volume fraction increased in both structures, tensile strength and elongation increased, but hardness decreased. Fatigue life of fibrous structure parallel to rolling direction was shorter than that of perpendicular to rolling direction. Fatigue life of dispersed structure was longer than parallel fibrous structure, and shorter than perpendicular fibrous structure. Fatigue crack propagation rate of fibrous structure was faster than that of dispersed structure.

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0.2% N을 첨가한 수퍼 2상 스테인리스강의 열처리 조건에 따른 특성 평가 - 제2보: 피로균열진전 거동 (Characteristic Evaluation according to Heat Treatment Conditions of Super Duplex Stainless Steel with Additive 0.2% N - Part 2: Fatigue Crack Propagation Behavior)

  • 안석환;강흥주;서현수;남기우;이건찬
    • 한국해양공학회지
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    • 제23권5호
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    • pp.79-84
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    • 2009
  • Super duplex stainless steel has long life in severe environments by showing the enough strength and corrosion resistance. Therefore, the fracture mechanics approach needs to support the structural strength integrity for the used material. In this study, fatigue crack propagation behavior was investigated to super duplex stainless steel with 0.2% nitrogen. The various volume fraction and distribution of austenite structure for applied specimen in test were obtained by changing the heat treatment temperature and cycle. From test results, fatigue crack propagation rate showed two kinds of tendency between da/dN and ${\Delta}K$ according to distribution of austenite structure and structure anisotropy.

Structure of a DNA Duplex Containing a Site-Specific Dewar Isomer: Structural Influence of the 3'-T.G base pair of the Dewar product.

  • Lee, Joon-Hwa;Choi, Byong-Seok
    • BMB Reports
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    • 제33권3호
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    • pp.268-275
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    • 2000
  • In contrast to the pyrimidine (6-4)pyrimidone photoproduct [(6-4) adduct], its Dewar valence isomer (Dewar product) is low mutagenic and produces a broad range of mutations with a 42 % replicating error frequency. In order to determine the origin of the mutagenic property of the Dewar product, we used experimental NMR restraints and molecular dynamics to determine the solution structure of a Dewar·lesion DNA decamer duplex, which contains a mismatched base pair between the 3'-T residue and an opposed G residue. The 3'-T of the Dewar lesion forms stable hydrogen bonds with the opposite G residue. The helical bending and unwinding angles of the DW/GA duplex, however, are much higher than those of the DW/AA duplex. The stable hydrogen bonding of the G 15 residue does not increase the thermal stability of the overall helix. It also does not restore the distorted backbone conformation of the DNA helix that is caused by the forming of a Dewar lesion. These structural features implicate that no thermal stability, or conformational benefits of G over A opposite the 3'-T of the Dewar lesion, facilitate the preferential incorporation of an A. This is in accordance with the A rule during translesion replication and leads to the low frequent $3'-T{\rightarrow}C$ mutation at this site.

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¹H NMR Study of the Effect of G-T Mismatches on Dynamics and Stability of d(GCGTGCGC)₂ and Its Berenil Complex

  • 허성호;홍석주;이조웅;정채준
    • Bulletin of the Korean Chemical Society
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    • 제17권11호
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    • pp.1045-1052
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    • 1996
  • The effects of G-T mismatches on thermal stability, the base-pair lifetime and the global structure of a d(GCGTGCGC)2 duplex were studied by using 1H NMR, UV and CD spectroscopy. The existence of G-T mismatches was found to cause a noticeable change in the chemical environment of imino protons associated with significant decrease in the base-pair lifetime at the mismatched site as well as in thermal stability of the duplex itself. The melting transition of d(GCGTGCGC)2 was not cooperative at all at 100 mM or lower concentration of NaCl, but became cooperative at 500 mM or higher NaCl concentration. The melting temperature (Tm) of this duplex was 32℃ at 500 mM concentration of NaCl, which is much lower than that of d(GCGCGCGC)2 at the same NaCl concentration. This suggests that the decrease in stability may be ascribed to the decrease in the base-pair lifetime and the deviation from the normal structure due to the G-T mismatches. Adding berenil to d(GCGTGCGC)2 caused no observable change in the global structure but the large decrease in the base-pair lifetime and the stability of the duplex.

음극 인가전위 하에서 type 2205과 type 316L의 수소취성 저항성 (Comparison of hydrogen embrittlement resistance between 2205 duplex stainless steels and type 316L austenitic stainless steels under the cathodic applied potential)

  • 서동일;이재봉
    • Corrosion Science and Technology
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    • 제15권5호
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    • pp.237-244
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    • 2016
  • 2205 duplex stainless steels have been used for the construction of the marine environment, because of their excellent corrosion resistance and high strength. However, the resistance to hydrogen embrittlement (HE) may be less than that of 316L austenitic stainless steel. The reason why 316L stainless steels have better resistance to HE is associated with crystal structure (FCC, face centered cubic) and the higher stacking faults energy than 2205 duplex stainless steels. Furthermore 2205 stainless steels with or without tungsten were also examined in terms of HE. 2205 stainless steels containing tungsten is less resistible to HE. It is because dislocation tangle was formed in 2205 duplex stainless steels. Slow strain-rate tensile test (SSRT) was conducted to measure the resistance to HE under the cathodic applied potential. Hydrogen embrittlement index (HEI) was used to evaluate HE resistance through the quantitative calculation.

이상 스테인레스강의 변형거동에 미치는 질소의 영향 (Effects of Nitrogen on Deformation Behavior of Duplex Stainless Steel)

  • 이형직;장영원
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 2003년도 춘계학술대회논문집
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    • pp.49-52
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    • 2003
  • The effects of nitrogen on the deformation behavior of duplex stainless steel have been studied The variation of strength was correlated with the characteristic microstructures. Analysis based on Hall-Petch relation confirmed that nitrogen enhances phase-boundary strengthening effect. The evolution of dislocation structure, slip traces, and misorientation distribution during deformation were also characterized to elucidate the effect of nitrogen on inelastic deformation mechanism.

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