• JSTS:Journal of Semiconductor Technology and Science
• /
• 제17권3호
• /
• pp.319-325
• /
• 2017

Through silicon via (TSV) technology is extensively used in 3D IC integrations. The special structure of the TSV is realized by CMP (Chemically Mechanical Polishing) process with a high Cu removal rate and, low dishing, yielding fine topography without defects. In this study, we investigated the electrochemical behavior of copper slurries with various inhibitors in the Cu CMP process for advanced TSV applications. One of the slurries was carried out for the most promising process with a high removal rate (${\sim}18000{\AA}/Min$ @ 3 psi) and low dishing (${\sim}800{\AA}$), providing good microstructure. The effects of pH value and $H_2O_2$ concentration on the slurry corrosion potential and Cu static etching rate (SER) were also examined. The slurry formula with a pH of 6 and 2% $H_2O_2$, hadthe lowest SER (${\sim}75{\AA}/Min$) and was the best for TSV CMP. A novel Cu TSV CMP process was developed with two CMPs and an additional annealing step after some of the bulk Cu had been removed, effectively improving the condition of the TSV Cu surface and preventing the formation of crack defects by variations in wafer stress during TSV process integration.

• Journal of Mechanical Science and Technology
• /
• 제19권10호
• /
• pp.1919-1931
• /
• 2005

Human joint motion can be kinematically described in three planes, typically the frontal, sagittal, and transverse, and related to experimentally measured data. The selection of reference systems is a prerequisite for accurate kinematic analysis and resulting development of the equations of motion. Moreover, the development of analysis techniques for the minimization of errors, due to skin movement or body deformation, during experiments involving human locomotion is a critically important step, without which accurate results in this type of experiment are an impossibility. The traditional kinematic analysis method is the Angular-based method (ABM), which utilizes the Euler angle or the Bryant angle. However, this analysis method tends to increase cumulative errors due to skin movement. Therefore, the objective of this study was to propose a new kinematic analysis method, Position-based method (PBM), which directly applies position displacement data to represent locomotion. The PBM presented here was designed to minimize cumulative errors via considerations of angle changes and translational motion between markers occurring due to skin movements. In order to verify the efficacy and accuracy of the developed PBM, the mean value of joint dislocation at the knee during one gait cycle and the pattern of three dimensional translation motion of the tibiofemoral joint at the knee, in both flexion and extension, were accessed via ABM and via new method, PBM, with a Local Reference system (LRS) and Segmental Reference system (SRS), and then the data were compared between the two techniques. Our results indicate that the proposed PBM resulted in improved accuracy in terms of motion analysis, as compared to ABM, with the LRS and SRS.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2008년도 추계학술대회 논문집 Vol.21
• /
• pp.399-399
• /
• 2008

Synthesis and characterization of ZnO structure such as nanowires, nanorods, nanotube, nanowall, etc. have been studied to multifunctional application such as optical, nanoscale electronic and chemical devices because it has a room-temperature wide band gap of 3.37eV, large exiton binding energy(60meV) and various properties. Various synthesis methods including chemical vapor deposition (CVD), physical vapor deposition, electrochemical deposition, micro-emulsion, and hydrothermal approach have been reported to fabricate various kinds of ZnO nanostructures. But some of these synthesis methods are expensive and difficult of mass production. Wet chemical method has several advantage such as simple process, mass production, low temperature process, and low cost. In the present work, ZnO nanorods are deposited on ITO/glass substrate by simple wet chemical method. The process is perfomed by two steps. One-step is deposition of ZnO seeds and two-step is growth of ZnO nanorods on substrates. In order to form ZnO seeds on substrates, mixture solution of Zn acetate and Methanol was prepared.(one-step) Seed layers were deposited for control of morpholgy of ZnO seed layers by spin coating process because ZnO seeds is deposited uniformly by centrifugal force of spin coating. The seed-deposited samples were pre-annealed for 30min at $180^{\circ}C$ to enhance adhesion and crystallinnity of ZnO seed layer on substrate. Vertically well-aligned ZnO nanorods were grown by the "dipping-and-holding" process of the substrates into the mixture solution consisting of the mixture solution of DI water, Zinc nitrate and hexamethylenetetramine for 4 hours at $90^{\circ}C$.(two-step) It was found that density and morphology of ZnO nanorods were controlled by manipulation of ZnO seeds through rpm of spin coating. The morphology, crystallinity, optical properties of the grown ZnO nanostructures were carried out by field-emission scanning electron microscopy, high-resolution electron microscopy, photoluminescence, respectively. We are convinced that this method is complementing problems of main techniques of existing reports.

• Bulletin of the Korean Chemical Society
• /
• 제30권6호
• /
• pp.1325-1330
• /
• 2009

A general method has been developed for the solid phase synthesis of drug-like 7-aryl-benzo[b][1,4]oxazin-3(4H)- one derivatives 6. The method relies on a novel, microwave irradiation promoted cyclization reaction of the BOMBA resin bound, N-substituted-$\alpha$-(2-chloro-4-bromophenoxy)acetamide 3 that takes place via a Smiles rearrangement. The 7-bromobenzo[1,4]oxazine 4, produced in this process is converted to 7-aryloxazin analogs 5 by utilizing Suzuki coupling with various substituted arylboronic acids. Finally, the target 7-aryl-benzo[b][1,4]oxazin-3(4H)-ones 6 are liberated from the resin by treatment with 5% TFA. The progress of the reactions involved in this preparative route can be monitored by using ATR-FTIR spectroscopy on a single bead. The target compounds, obtained by using this five-step sequence, are produced in high yields and purities.

• 전자공학회논문지S
• /
• 제35S권7호
• /
• pp.72-85
• /
• 1998

In this paper, we propose a new method that sequentially estimates TDOA(Time Delay Of Arrival) and FDOA(Frequency Delay Of Arrival) for extracting the information about the bearing and relative velocity of a target in passive radar or sonar arrays. The objective is to efficiently estimate the TDOA and FDOA between two sensor signal measurements, corrupted by correlated Gaussian noise sources in an unknown way. The proposed method utilizes the one dimensional slice function of the third order cumulants between the two sensor measurements, by which the effect of correlated Gaussian measurement noises can be significantly suppressed for the estimation of TDOA. Because the proposed sequential algoritjhm uses the one dimensional complex ambiguity function based on the TDOA estimate from the first step, the amount of computations needed for accurate estimationof FDOA can be dramatically reduced, especially for the cases where high frequency resolution is required. It is demonstrated that the proposed algorithm outperforms existing TDOA/FDOA estimation algorithms based on the ML(maximum likelihood) criterionandthe complex ambiguity function of the third order cumulant as well, in the MSE(mean squared error) sense and computational burden. Various numerical resutls on the detection probability, MSE and the floatingpoint computational burden are presented via Monte-Carlo simulations for different types of noises, different lengths of data, and different signal-to-noise ratios.

• 한국세라믹학회지
• /
• 제48권5호
• /
• pp.379-383
• /
• 2011

This paper presents the synthesis of one-dimensional spinel $LiMn_2O_4$ nanostructures using a facile and scalable two-step process. $LiMn_2O_4$ nanorods with average diameter of 100 nm and length of 1.5 ${\mu}m$ have been prepared by solid-state lithiation of hydrothermally synthesized ${\beta}$-$MnO_2$ nanorods. $LiMn_2O_4$ nanowires with diameter of 10 nm and length of several micrometers have been fabricated via solid-state lithiation of ${\beta}$-$MnO_2$ nanowires. The precursors have been lithiated with LiOH and reaction temperature and pressure have been controlled. The complete structural transformation to cubic phase and the maintenance of 1-D nanostructure morphology have been evaluated by XRD, SEM, and TEM analysis. The size distribution of the spinel $LiMn_2O_4$ nanorods/wires has been similar to the $MnO_2$ precursors. By control of reaction pressure, cubic 1-D spinel $LiMn_2O_4$ nanostructures have been fabricated from tetragonal $MnO_2$ precursors even below $500^{\circ}C$.

• 한국통신학회논문지
• /
• 제36권5A호
• /
• pp.511-520
• /
• 2011

본 논문은 다중 사용자 amplify-and-forward relay 시스템에서 전송 모드, 즉, 한 홉 혹은 두 홉 전송, 그리고 적절한 사용자를 두 단계로 선택하는 다중 사용자 스케줄링 기법을 소개한다. 제안하는 다중 사용자 스케줄링을 수행하였을 경우 두 가지 전송 모드별 평균 achievable rate의 닫힘 꼴 표현을 유도하고 단말 수가 무한히 증가할 때 평균 achievable rate에 대한 점근적인 결과도 분석한다. 평균 achievable rate 분석에 기반하여 두 단계 스케줄링 알고리즘을 수행하는데, 먼저 전송 모드 선택을 하고, 그 다음 선택된 전송 모드에 대한 순간 signal-to-noise ratio (SNR)을 기지국으로 피드백 함으로써 이를 이용한 부분적인 피드백 정보를 기반으로 사용자 선택을 수행한다. 또한 다중 사용자 diversity gain이 최대로 취득되는 평균 SNR 조건도 분석하고 추가로 특정 조건에서 피드백 양을 더 줄일 수 있는 방안에 대해 조사한다. 제안된 스케줄링 알고리즘은 모든 전송 모드 (즉, 한홉과 두 홉 전송 모드)에 대한 instantaneous SNR을 피드백하여 최적 다중 다용자 스케줄링을 할 경우와 유사한 achievable rate을 보인다. 반면 제안 기법의 피드백 양은 최적 기법에 비해 대략 절반으로 줄어드는 것을 확인한다.

• 대한임상검사과학회지
• /
• 제48권2호
• /
• pp.68-73
• /
• 2016

암모니아는 매우 독성이 있으며, 흥분 독성, 산화 스트레스, 염증을 통해 신경 세포의 손상을 유발한다. 간이 암모니아 대사를 위한 일차 기관이라는 사실에 근거하여 선천성 대사 오류의 원인이 된다. 혈중 암모니아 판정은 측정값의 일부 범위에서 결정하게 되는데 최근 진단분야에서 혈중 암모니아를 가능한 동시다발적으로 측정하게 되었다. 그러나 혈액검체의 수집, 처리, 저장 및 분석은 오류의 모든 잠재적인 요인이다. 신속하고 신뢰할 수 있는 혈중 암모니아 측정의 평가를 위해 DRI-CHEM 100 (Fuji Film Co., Japan) 및 COBAS 8000 (Roche Diagnostic Ltd., Switzerland) 분석기를 이용해 비교평가 분석하였고 높은 상관성을 얻었으며 one-step 방법은 암모니아 분석에 적합하였다. 암모니아의 채혈 후 시간대별 측정에서는 30, 90, 180분에 각각 46.5, 57.4, 79.0 (${\mu}g/dL$)로 상승하는 경향을 보였다. 또한 암모니아의 용량별 측정에서는 7, 10, 13 (${\mu}L$)에 각각 39, 46, 43 (${\mu}g/dL$)으로 나타났으며 $10{\mu}L$에서 유의성을 보였다(p<0.001). 결론적으로 위 평가 분석은 임상적용에서 유용한 정보를 제공 할 수 있을 것이다.

• 한국ITS학회 논문지
• /
• 제17권1호
• /
• pp.100-113
• /
• 2018

네트워크 수요량 향상 방안 중 가장 주목받고 있는 Proximity Service는 주파수 사용의 효율성 증대를 위해 대부분 주파수 재사용 방식을 사용한다. 그 결과 셀 edge에서 셀룰러 사용자의 Proximity Service 사용자의 셀 간 간섭 문제가 발생한다. 본 논문에서는 eNB에 Proximity Function의 기능과 파라미터를 새롭게 정의하고, ProSe 파라미터와 ProSe user equipment에 대한 정보를 X2 인터페이스를 통해 인접 셀과 교환하게 함으로써 셀 간섭 완화 방안을 제안한다. 우선 ProSe 탐색 과정에서 주파수 센싱을 통해 셀 간 간섭 문제를 일으키지 않을 자원을 할당한다. 그리고 ProSe 통신 상황에서는 ProSe application code, ProSe application QoS, ProSe application ID의 validity timer를 기반으로 간섭을 일으키지 않을 적합한 자원을 재 할당함으로써 셀 간 간섭 문제를 해결한다.

• Archives of Pharmacal Research
• /
• 제25권1호
• /
• pp.11-24
• /
• 2002

The antitumor antibiotic (+)-CC-1065 can alkylate N3 of guanine in certain sequences. A previous high-field $^1H$ NMR study on the$(+)-CC-1065d[GCGCAATTG*CGC]_2$ adduct ($^*$ indicates the drug alkylation site) showed that drag modification on N3 of guanine results in protonation of the cross-strand cytosine [Park, H-J.; Hurley, L. H. J. Am. Chem. Soc.1997, 119,629]. In this contribution we describe a further analysis of the NMR data sets together with restrained molecular dynamics. This study provides not only a solution structure of the (+)-CC-1065(N3- guanine) DNA duplex adduct but also new insight into the molecular basis for the sequence- specific interaction between (+)-CC-1065 and N3-guanine in the DNA duplex. On the basis of NOESY data, we propose that the narrow minor groove at the 7T8T step and conformational kinks at the junctions of 16C17A and 18A19T are both related to DNA bending in the drugDNA adduct. Analysis of the one-dimensional $^1H$ NMR (in $H_2O$) data and rMD trajectories strongly suggests that hydrogen bonding linkages between the 8-OH group of the (+)-CC-1065 A-sub-unit and the 9G10C phosphate via a water molecule are present. All the phenomena observed here in the (+)-CC-1065(N3-guanine) adduct at 5'$-AATTG^*$are reminiscent of those obtained from the studies on the (+)-CC-1065(N3-adenine) adduct at $5'-AGTTA^*$, suggesting that (+)-CC-1065 takes advantage of the conformational flexibility of the 5'-TPu step to entrap the bent structure required for the covalent bonding reaction. This study reveals a common molecular basis for (+)-CC-1065 alkylation at both $5'-TTG^*$ and $5'-TTA^*$, which involves a trapping out of sequence-dependent DNA conformational flexibility as well as sequence-dependent general acid and general base catalysis by duplex DNA.