• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2003년도 유체기계 연구개발 발표회 논문집
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• pp.469-475
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• 2003

The performance of a centrifugal compressor composed of an impeller, tandem diffuser rows and axial guide vanes has been predicted numerically and compared with available experimental results on its design rotational speed. The pitchwise-averaged mixing plane method was employed for the boundaries between rotor and stator to obtain steady state solutions. The overall characteristics showed differently according to the relative positions of tandem diffuser rows while the characteristics of impeller showed almost identical. The numerical results agree with the measured data in respect of their tendency. It turned out that 0% of relative positions is the worst case in terms of static pressure recovery and efficiency. According to the experimental results, some pressure fluctuations and malfunction of the compressor were observed for 75% case. However, this numerical calculation using mixing plane method did not capture any of those phenomena. Thus, unsteady flow calculation should be performed to investigate the stability of the compressor caused by different diffuser configuration.

• 공학논문집
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• 제1권1호
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• pp.31-40
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• 1997

ATM망의 모델링에서 발생되어지는 D-BMAP/Geo/1/K queue의 departure 프로세스를 k-state MMBP로 특성화하는 근사화방법을 제시하고, 그 근사화방법과 decomposition algorithm을 이용하여 셀손실을 갖는 tandem 구조의 한정용량 대기 네트워크를 분석하였다.

• Bulletin of the Korean Chemical Society
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• 제22권3호
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• pp.293-297
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• 2001

The purpose of this paper is to introduce the simplified linkage position determination method using tandem mass spectrometry combined with molecular modeling study. Using low energy tandem mass spectrometric experiments and molecular modeling, it has been suggested that significant differences in glycosidic bond cleavage may occur due not only to ionic considerations but also may have contributions from steric hindrance of the absorbance of collision energy, leading to a statistically higher bond cleavage for sterically crowded linkages. Permethylated derivatives of the linkage-isomeric trisaccharides give useful fragmentation ratios and productions, including a 3-linkage specific ion. The ratios of fragment ions are related to the ability of each linkage position in the oligosaccharide to absorb collisional energy.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2009년도 춘계학술대회 논문집
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• pp.471-472
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• 2009

• Bulletin of the Korean Chemical Society
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• 제12권2호
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• pp.157-163
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• 1991

The total synthesis of dihydroreynosin (1) and dihydrosantamarine (2) via tandem Cope-Claisen rearrangement has been accomplished starting from (S)-carvone (4).

• 한국생산제조학회지
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• 제25권1호
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• pp.30-35
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• 2016

Tandem arc welding is a guarantor for high efficiency and cost saving since the quantity of wire which is deposited in the welding is approximated 30% greater that in conventional welding. The welding process is now being successfully applied in many industries. However, in the case of tandem arc welding, good quality and high productivity should depend on the welding parameters. Therefore, an intelligent algorithms for the automatic tandem arc welding process has been necessarily required. In this study, a predictive model based on the neural network by using the data acquired during tandem gas metal arc (GMA) welding process has been developed. To verify the reliability of the developed predictive model, a mutual comparison with the surface of the top-bead width obtained from actual experiments has been analyzed.

• 한국전기전자재료학회논문지
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• 제18권4호
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• pp.357-362
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• 2005

The tandem solar cell composed of a dye-sensitized solar cell (DSC) and a thermoelectric generator (TEG) was designed. In such new cell, the characteristics of DSC and TEG were investigated. DSC uses the wavelength range of 380∼750 nm and has the maximum efficiency of below 10 ％. If the solar light transmitted through DSC can be converted to heat energy, TEG can generate electric energy using this heat energy. By this means, it is possible to utilize most of solar energy in the wavelength range of 350∼3000 nm for electric generation and it can be expected to obtain higher solar energy conversion efficiency exceeding the known limit of maximum efficiency. For this purpose we suggest the tandem solar cell constructed with DSC and TEG. In this structure, DSC has a carbon nanotube film as a counter electrode of DSC in order to collect the solar light and convert it to heat energy. We measured the I-V characteristics of DSC and TEG, assembled to the tandem cell. As a result, it was shown that DSC with carbon nanotube and TEG had the efficiency of 9.1 ％ and 6.2 ％, respectively. From this results, it is expected that the tandem solar cell of the new design has the possibility of enhanced conversion efficiency to exceed above 15 ％.

• 대한전자공학회논문지SP
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• 제41권4호
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• pp.121-130
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• 2004

무선망과 VoIP 같은 서로 다른 음성 통신 네트워크간의 통신을 할 경우, 서로 다른 구조를 갖는 두 음성부호화기간의 효율적인 연동이 필요하다. 이런 경우, 가장 간단한 방법으로 두 음성부호화기의 복호화기와 부호화기를 직렬로 연결시키는 tandem방식을 사용할 수 있다. 하지만, tandem방식은 긴 지연시간과 많은 연산량, 그리고 음질저하의 문제점들을 갖는데, 이는 상호부호화 방법을 통해서 해결할 수 있다. 상호부호화 알고리듬은 송신단과 수신단의 음성 부호화기의 구조에 의해 결정되고, 본 논문에서는 연산량은 감소시키고, 음질은 향상시킬 수 있는 LSP 변환, 개선된 고속 피치 검색, 상호부호화기를 위한 새로운 지각가중 필터 알고리듬을 제안한다. 제안된 알고리듬은 AMR과 G.723.1간의 상호부호화기에 적용하였다. 제안된 상호부호화 알고리듬을 사용함으로써 tandem 방식에 비하여 연산량은 약 20%-58% 감소되는 반면, 음질은 향상된다.

• 한국표면공학회지
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• 제48권3호
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• pp.115-120
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• 2015

We studied white tandem organic light-emitting diodes using red and blue fluorescent materials. White 2 units tandem OLEDs were fabricated using $Alq_3$:Rubrene (3 vol.% 5 nm) and SH-1 : BD-2 (3 vol.% 25 nm) as emitting layer (EML). The device with $Alq_3$ : Rubrene (3 vol.% 5 nm) / SH-1 : BD-2 (3 vol.% 25 nm) showed yellowish white emission with a Commission Internationale de l'Eclairage (CIE) coordinates of (0.442, 0.473) at $1,000cd/m^2$, and variation of CIE coordinates was low with ($0.44{\pm}0.002$, $0.472{\pm}0.001$) from 500 to $3,000cd/m^2$. White 3 units tandem OLEDs were fabricated by additory stacking the blue or white layer as EML. CIE coordinates of 3 units tandem OLEDs with stacked blue and white layer was low variation of ($0.293{\pm}0.008$, $0.36{\pm}0.005$) and ($0.412{\pm}0.002$, $0.423{\pm}0.001$) from 500 to $3,000cd/m^2$, respectively. Our findings suggest that stacked OLED was possible to controlling CIE coordinates and producing excellent color stability.

• 한국컴퓨터정보학회논문지
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• 제20권1호
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• pp.237-246
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• 2015

본 논문에서는 컨테이너터미널에서 탠덤 리프트 안벽크레인과 고생산성 컨테이너 이송차량 Alternative ship-to-yard vehicles를 고려한 시뮬레이션을 활용하여 컨테이너터미널의 생산성 향상 모델을 제안한다. 이 방법의 특징은 탠덤 리프트 안벽크레인과 고생산성 컨테이너 이송차량의 데이터를 도출하고, 회귀분석 함으로써 탠덤 리프트 안벽크레인의 생산성 모델을 추정한다. 탠덤 리프트 안벽크레인은 한 사이클 당 20ft 컨테이너 4개, 40ft 컨테이너 2개를 동시에 취급함으로서 기존의 싱글 안벽크레인보다 이론상 약 2배의 컨테이너 생산성을 증가시키는 장비이고 Alternative ship-to-yard vehicles는 기존의 야드 트랙터보다 더 많은 최대 4TEU의 컨테이너를 운반시킬 수 있는 장비이다. 본 논문에서는 신기술 안벽장비인 탠덤 리프트 안벽크레인과 신기술 이송장비인 Alternative ship-to-yard vehicles를 적용한 시뮬레이션을 통하여 생산성에 관한 데이터를 도출하고 통계 기법인 회귀분석을 통하여 컨테이너 터미널의 생산성의 추정모델을 구해보고자 한다.