• Bulletin of the Korean Chemical Society
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• 제26권4호
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• pp.634-640
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• 2005

The reaction of cis-[Cr([14]-decane)(OH$_2)_2]^+$ ([14]-decane = rac-5,5,7,12,12,14-hexamethyl-1,4,8,11-teraazacyclotetradecane) with auxiliary ligands {$L_a$ = citrate(cit)} leads to a new dimeric complex cis-[{Cr([14]-decane)($\mu$-cit)}$_2](ClO_4)_2$. This binuclear complex has been structurally characterized by a combination of elemental analysis, conductivity, IR and Vis spectroscopy, mass spectrometry, and X-ray crystallography. Analysis of the crystal structure of cis-[{Cr([14]-decane)($\mu$-cit)})($_2]^+$ reveals that each chromium has a distorted octahedral coordination environment and citrato ligands are monodentate to the two chromium atoms via the carboxyl groups. For dimeric complex the bridging geometry is as follows: Cr$\ldots$Cr = 7.361 $\AA$; Cr-O(average) = 1.958 (8) $\AA$; Cr-N range = 2.108 (9)-2.147(9) $\AA$; N(1)-Cr-N(3) (equatorial position) = 98.0(4)$^{\circ}$; N(2)-Cr-N(4) (axial position) = 166.4(4)$^{\circ}$; O(1)-Cr-N(2) = 98.1(4)$^{\circ}$; O(3)-Cr-N(4) = 96.6(3)$^{\circ}$; O(1)-Cr-O(3) = 90.4$^{\circ}$. The FAB mass spectrum of the dimeric complex displays peak due to the molecular ions cis-[{Cr([14]-decane)($\mu$-cit)})($_2]^+$ at m/z 1053.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국내학술편); Seoul National University, Seoul; 20-22 Oct. 1993
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• pp.742-748
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• 1993

The dynamics and control of two complex column configurations (sidestream column with stripper; prcfractionater/sidestream column configuration), which are multivariable interacting and nonlinear, have been studied. A new control scheme developed by Hanand Park(1993) to deal with the nonlinear and multivariable nature of distillation processes has been applied to these complex distillation configurations. The control scheme incorporates a nonlinear wave model into a generic model control framework. An observer based on the nonlinear wave model is used to determine the profile positions of distillation column sections. The control scheme enables tight control of the profile position of each column section that leads to fast stabilization of product compositions.

• 한국지능시스템학회논문지
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• 제15권1호
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• pp.75-80
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• 2005

이 논문에서는 지능형 교통시스템에서 자율주행용 자계도로 3차원적으로 해석하여 차량의 위치를 검출하기 위한 시스템에 관하여 다룬다. 특히 자율주행시스템을 구성하는 핵심요소 중 하나인 위치검출시스템의 새로운 방법을 제안한다. 기존의 위치검출시스템은 자계와 차량의 위치 관계를 맵핑하는 원리를 이용한다. 이는 데이터의 저장이 필수적이며 대용량의 메모리를 요구되어 상용화시 고비용의 문제점을 가지고 있다. 이 논문에서는 기존 위치검출시스템이 가지는 문제점을 극복하기 위한 방법으로 신경망을 이용한 위치검출시스템을 제안한다. 그리고 제안한 위치검출시스템을 적용한 자율주행시스템을 설계한다. 설계한 자율주행시스템의 적용 가능성을 파악하기 위하여 자율주행실험을 행하고 이를 분석한다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.1299-1306
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• 2007

The combination of laser beam and electric arc sharing common weld pool has widely been investigated since the late seventies, but it is beginning of the industrial uses. Recently, laser-GMA hybrid welding process showed possibility to overcome the tight gap tolerance with improved productivity. The laser-arc hybrid welding process is inherently complex because it has three kinds of process parameters: arc welding, laser welding and hybrid welding parameters. In this study, the optimum range of the process parameters were determined by high speed image analysis which could unveil the welding phenomena in laser-arc hybrid welding. The laser-arc hybrid welding was applied for position welding from the flat position to the overhead position and the welding characteristics were investigated.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1994년도 Proceedings of the Korea Automatic Control Conference, 9th (KACC) ; Taejeon, Korea; 17-20 Oct. 1994
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• pp.672-675
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• 1994

This paper presents a new algorithm to determine the receiver position in satellite navigation for GPS(Global Positioning System). The algorithm which based on vector analysis is able to obtain simultaneously the receiver position and the direction vector which is from the receiver position to a satellite. In its first calculation stage it, does riot require the complex initial value which is used in the previous works and affects the accuracy of the observed receiver position. Furthermore, the algorithm tells us whether a selected configuration among the visible satellites is good or poor for the accuracy. Comparing the algorithm with the previous method, the effectiveness of the algorithm is verified through the experimental simulations.

• 대한기계학회논문집A
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• 제21권12호
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• pp.1973-1983
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• 1997

Higher order isoparametric elements are usually used in the finite element analysis because they can represent easily the geometric shape of a complex structure ad can improve the solution quality. When these elements are used, the position of internal nodes affects greatly on the solution accuracy. Decreasing of the accuracy related to the position of internal nodes is due to non-conformal mapping often results in an unstable Jacobian value. This paper, in order to remove this difficulty, suggests a modified shape function which can establish conformal mapping between two coordinate systems. Numerical experiments with the proposed shape function show that a stable solution can be obtained without respect to the position of internal nodes, and offer convenience that one can take arbitrarily the position of internal nodes considering only the geometric shape of element boundaries.

• 한국ITS학회 논문지
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• 제2권2호
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• pp.85-95
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• 2003

본 논문은 Snake 모델을 이용하여 동영상에서 주위 환경 변화에 적응 가능한 다중 이동 객체 추적 시스템을 제안하였다. Snake 모델은 배경이 복잡한 영상에 대해선 객체의 윤곽선을 정확히 표현하지 못하므로 영상분할 시 초기 위치에 따라 민감하게 영향을 받는다. 제안된 시스템은 프레임간의 차(difference)영상을 이용하여 배경영상을 획득하고, 픽셀의 인접성을 조사하여 객체를 분할하고 위치 특징 값을 구하며, 분할된 특징 값들을 Snake모델의 초기 위치 값으로 부여함으로써 초기 위치 값에 민감한 Snake 모델을 개선하였다 또한 본 시스템은 복잡한 배경 영상을 단순화하고, Snake를 이루는 각 정점들을 객체의 위치로 놓이게 함으로써 탐색 공간을 줄였다. 30fps로 저장된 AVI파일을 적용함으로써 다중 이동차량 추적 시스템으로의 응용 가능함을 보였다.

• 한국항해항만학회지
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• 제37권3호
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• pp.309-313
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• 2013

본 연구는 복합센서를 활용한 무인지게차의 주행 시스템에 대한 것이다. 무인지게차가 화물 이 적재를 위해 랙에 진입할 시 필요한 주행기술로 무인지게차의 위치 및 방향을 정확하게 파악하기 위해 RFID, IMU센서 및 근접센서로 구성된 복합센서 시스템을 이용하였고, 각 센서의 성능실험을 통해 특성을 파악한다. 이를 직접 설계/제작한 실험용 차량에 부착하여 복합센서 시스템을 적용하는 실험을 수행하고 이를 통해 개발된 시스템의 성능을 검증하였다.

• Molecules and Cells
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• 제27권1호
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• pp.99-103
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• 2009

Ribose-5-phosphate isomerase A (RpiA) plays an important role in interconverting between ribose-5-phosphate (R5P) and ribulose-5-phosphate in the pentose phosphate pathway and the Calvin cycle. We have determined the crystal structures of the open form RpiA from Vibrio vulnificus YJ106 (VvRpiA) in complex with the R5P and the closed form with arabinose-5-phosphate (A5P) in parallel with the apo VvRpiA at $2.0{\AA}$ resolution. VvRpiA is highly similar to Escherichia coli RpiA, and the VvRpiA-R5P complex strongly resembles the E. coli RpiA-A5P complex. Interestingly, unlike the E. coli RpiA-A5P complex, the position of A5P in the VvRpiA-A5P complex reveals a different position than the R5P binding mode. VvRpiA-A5P has a sugar ring inside the binding pocket and a phosphate group outside the binding pocket: By contrast, the sugar ring of A5P interacts with the Asp4, Lys7, Ser30, Asp118, and Lys121 residues; the phosphate group of A5P interacts with two water molecules, W51 and W82.

• Journal of Oral Medicine and Pain
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• 제23권1호
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• pp.45-55
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• 1998

The author assessed the sagittal relationships between glenoid fossa of the temporal bone and mandibular condyle from lateral transcranial views of 74 TMJ with disc displacement and 16 TMJ with normal disc-condyle complex by the magnetic resonance image findings. All the subjects were female and also in their 3rd decades. The disc displacement group was subdivided into anterior disc displacement with reduction (ADWR) group and anterior disc displacement without reduction (ADWOR) group. The anterior, superior, and posterior joint spaces as well as anterior/posterior (A/P) ratio of the space at the closed jaw position and vertical and horizontal components of the condyle position relative to the articular eminence at the open jaw position were measured from all the subjects and the data were compared among groups. The result were as follows : 1. The mean posterior joint space of ADWR group was smaller than ADWOR group, but there were no significant differences in anterior and superior joint spaces between two groups. 2. There showed a tendency of higher A/P ratio in ADWR group which meant the condyle of ADWR was likely to take posteriorly displaced position. 3. There were higher proportion of neutral condylar position in glenoid fossa in normal group, but higher proportion of posterior condylar position in ADWR group. 4. There were no significant differences in the degree of condyle-fossa concentricity among groups.