• International journal of advanced smart convergence
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• 제2권1호
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• pp.6-11
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• 2013

Network Coding (NC) is a new paradigm for network communication. In network coding, intermediate nodes create new packets by algebraically combining ingress packets and send it to its neighbor node by broadcast manner. NC has rapidly emerged as a major research area in information theory due to its wide applicability to communication through real networks. Network coding is expected to improve throughput and channel efficiency in the wireless multi-hop network. Many researches have been carried out to employ network coding to wireless ad-hoc network. In this paper, we proposed a dynamic queue management to improve coding opportunistic to enhance efficiency of NC. In our design, intermediate nodes are buffering incoming packets to encode queue. We expect that the proposed algorithm shall improve encoding rate of network coded packet and also reduce end to end latency. From the simulation, the proposed algorithm achieved better performance in terms of coding gain and packet delivery rate than static queue management scheme.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2005년도 추계학술대회 논문집
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• pp.148-151
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• 2005

This paper is concerned with the thermo-mechanical behavior and temperature dependent strain rate sensitivity of steel sheet for an auto-body. In order to Identify the temperature dependent strain rate sensitivity of SPRC35R and SPRC45E, uniaxial tension tests are performed with the variation of the strain rates from 0.001/sec to 200/sec, and the variation of environmental temperatures from $-40^{\circ}C\;to\;200^{\circ}C$. The thermo-mechanical response at the quasi-static state is obtained with the static tensile test and at the intermediate strain rate is from the high speed tensile test. The experimental results show that the strain rate sensitivity increases at low temperature and it decreases at high temperature. It means that as the strain rate getting increasing, the variation of flow stress is more sensitive on the temperature. The results also indicates that the material properties of SPRC35R is more depend on the changes of strain rates and temperature than those of SPRC45E.

• Journal of Microbiology and Biotechnology
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• 제11권1호
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• pp.1-6
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• 2001

Ten strains of plasmid-harboring Bifidobacterium sp. were isolated from the feces of adults and children, and named as Bifidobacterium sp. GE1-GE8, ST, and SH5. These plasmids were categorized into three homologous groups (pKJ50-homologous, pKJ36-homologous, and non-homologous groups) according to Southern hybridization patterns using the formerly characterized bifidobacterial plasmids, pKJ50 and pKJ36, as probes. nine strains harboring the plasmids were shown to accumulate single-stranded DNA as a replication intermediate, based on the S1 nuclease treatment and Southern hybridization. These results suggest that the strains replicate by a rolling circle mechanism. Minimal inhibitory concentrations (MIC) of the isolated bifidobacteria against several antibiotics were determined. Two strains, GE2 and GE3, showed relatively high MiC values against tetracycline ($793.6{\mu}g/ml$) and erythromycin ($153.6{\mu}g/ml$), respectively. The tetracycline resistance of GE2 disappeared when the resident plasmid of GE2 was cured by ethidium bromide. These results show that pKJ36-homologous and pKJ50-homologous plasmids are prevalent among various Bifidobacterium strains and some Bifidobacterium plasmids appear to code for antibiotic resistance.

• 한국결정성장학회지
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• 제15권5호
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• pp.202-207
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• 2005

Kaolin과 규석 및 $Mg(OH)_2$등의 원료로 만들어진 slip을 casting 할 때 slip의 점도가 slip casting 속도와 소결체의 미세조직에 미치는 영향을 보면 slip-casting속도는 slip의 점도가 낮을 경우 감소하였으며 slip의 점도범위는 $3.0\~17.0\;cP$가 적당하였다. Slip의 점도를 조절하면 표면층, 표면 내부층, 중간층, 내면층의 미세조직을 비교적 균일하게 casting 할 수 있다 소성온도 $1350^{\circ}C$에서 시편의 구성광물은 cordierite 결정만으로 되어있었다.

• Structural Engineering and Mechanics
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• 제24권3호
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• pp.323-337
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• 2006

In this paper, the hysteretic behaviors of channel and C-section cold-formed steel members (CFSMs) under cyclic axial loading were simulated with the finite element method. Geometric and material nonlinearities, Bauschinger effect, strain hardening and strength improvement at corner zones were taken into account. Extensive numerical results indicated that, as the width-to-thickness ratio increases, local buckling occurs prematurely. As a result, the hysteretic behavior of the CFSMs degrades and their energy dissipation capability decreases. Due to the presence of lips, the hysteretic behavior of a C-section steel member is superior to that of its corresponding channel section. The intermediate stiffeners in a C-section steel member postpone the occurrence of local buckling and change its shapes, which can greatly improve its hysteretic behavior and energy dissipation capability. Therefore, the CFSMs with a large width-to-thickness ratio can be improved by adding lips and intermediate stiffeners, and can be used more extensively in residential buildings located in seismic areas.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2005년도 춘계종합학술대회
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• pp.804-807
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• 2005

본 논문에서는 Digital IF(Intermediate Frequency) 기술을 이용한 Up/Down 변환기를 설계하고, 이에 대한 성능을 평가 하였다. Digital IF 기술을 사용하는 이유는 passive 소자로 구성되어진 IF 주파수 영역은 고정되어진 한 주파수 밖에 사용하지 못하지만, Digital IF로 구성되어지면 보드의 외형적인 변경 없이 다양한 통신 주파수 영역에서 유연성 있게 사용이 가능하게 된다. 이러한 구성은 기존의 아날로그 헤테로다인 방식에 비하여 높은 유연성을 가지며, 우수한 성능향상을 보여준다.

• 분석과학
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• 제10권1호
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• pp.18-30
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• 1997

Si / Al비가 130 정도인 Na, TPA-ZSM-5를 저온 상압법으로 합성하였으며, 이들의 결정화 과정을 XRD, XRF, FT-IR, NMR 및 SEM을 이용하여 고찰하였다. 결정의 형성과정은 autoclave법과는 다소 다르게 나타났으나 최종 생성물의 분광학적 특성은 전형적인 ZSM-5 영역에서 나타났다. 또한 반응 도중 생성된 국부결함은 소성에 의해 제거됨을 알 수 있었으며, 저온상압하에서도 반응시간을 48시간 이내로 단축할 수 있음을 알 수 있었다.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2006년도 춘계종합학술대회
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• pp.961-965
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• 2006

본 논문에서는 Digital IF(Intermediate Frequency) 기술을 이용한 Up/Down 변환기를 설계하고, 이에 대한 성능을 평가하였다. Digital IF 기술을 사용하는 이유는 passive 소자로 구성되어진 IF주파수 영역은 고정되어진 한 주파수 밖에 사용하지 못하지만, Digital IF로 구성되어지면 보드의 외형적인 변경 없이 다양한 통신 주파수 영역에서 유연성 있게 사용이 가능하게 된다. 이러한 구성은 기존의 아날로그 헤테로다인 방식에 비하여 높은 유연성을 가지며, 우수한 성능향상을 보여준다.

• 반도체디스플레이기술학회지
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• 제17권4호
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• pp.97-100
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• 2018

$NF_3$ Plasma etching of silicon was conducted by injecting only $NF_3$ gas into reactive ion etching. $NF_3$ Plasma etching was done in intermediate pressure. Silicon etching by $NF_3$ plasma in reactive ion etching was diagnosed through residual gas analyzer and optical emission spectroscopy. In plasma etching, optical emission spectroscopy is generally used to know what kinds of species in plasma. Also, residual gas analyzer is mainly to know the byproducts of etching process. Through experiments, the results of optical emission spectroscopy during silicon etching by $NF_3$ plasma was analyzed with connecting the results of etch rate of silicon and residual gas analyzer. It was confirmed that $NF_3$ plasma etching of silicon in reactive ion etching accords with the characteristic of reactive ion etching.

• 한국환경복원기술학회지
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• 제24권3호
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• pp.19-31
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• 2021

The waste landfill that has been used as a park through a stabilization project to provide green space to local residents. Vegetation restoration is necessary for the landfill park project, but it is difficult to restore vegetation due to various disturbances in the landfill. This study analyzed the successional dynamics and ecological characteristics of Robinia pseudoacacia communities from the slopes of Noeul Park by applying the 7-stage successional hypothesis. As a result of the study, there was almost no intermediate successional stage. There are only the early successional stage which Robinia pseudoacacia has an absolute dominance of 100% in the crown and middle layers, and the degeneration successional stage which formed by the introduction of Morus alba. This result showed that the succession of Robinia pseudoacacia communities were not able to proceed to the climax forest due to various disturbances in the waste landfill. Therefore, it was analyzed that it is necessary to induce the succession through intermediate steps such as Morus alba, since it is difficult to transition from Robinia pseudoacacia community to the native Quercus spp. community.