• 대한안전경영과학회:학술대회논문집
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• 대한안전경영과학회 2005년도 추계학술대회
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• pp.211-220
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• 2005

• Bulletin of the Korean Chemical Society
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• 제32권11호
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• pp.4086-4088
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• 2011

• 대한기계학회:학술대회논문집
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• 대한기계학회 2005년도 창립60주년 기념 추계 학술대회
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• pp.189.2-189.2
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• 2005

• 대한안전경영과학회:학술대회논문집
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• 대한안전경영과학회 2006년도 추계공동학술대회
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• pp.385-392
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• 2006

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2011년도 춘계학술대회 논문집
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• pp.373-374
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• 2011

• 한국항해항만학회지
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• 제30권10호
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• pp.839-845
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• 2006

선박 접안을 돕기 위해 레이저 접안 장치는 부두에 설치된 레이저 센서로부터 선박까지의 거리를 센티미터 수준의 정확도로 측정하여 제공한다. 그러나, 레이저 접안 장치는 레이저 센서의 정확한 설치 위치를 알아야 하고, 선박이 접안하는 부두의 전 범위를 다룰 수 있도록 설치되어야 하며, 부두의 선적 및 하역 환경, 조수의 변동을 고려해야 하는 문제가 있다. 특히 레이저 센서 거리 측정기는 가격이 비싸고, 거리를 측정할 수 있는 범위가 좁다는 단점이 있다. 레이저 접안 장치가 지닌 이상과 같은 문제를 해결하기 위한 방법으로 제안된 방법이 반송파보정 측위 기법이다. 본 논문에서는 상대 수평측위 정확 희석도 시뮬레이션을 통하여 레이저 접안 장치가 지닌 문제를 해결하기 위해 기존에 제안된 반송파 보정 측위기법이 연속성을 갖는 센티미터 정확도의 측위 서비스가 어려움을 보이고, 이를 해결하기 위한 방법으로 의사위성 보강 측위기법을 제안한다. 본 논문은 의사위성을 반송파 보정 측위성능 향상을 위해 사용하며, 제안한 측위기법이 기존에 반송파 보정 측위기법과 달리 연속성을 갖는 센티미터 정확도의 측위 서비스가 가능함을 보인다. 또한 제안한 측위기법이 선박 자동접안을 위해 요구하는 측위성능을 만족시키는 기법임을 필드시험을 위해 구축한 테스트 베드에서 확인한다.

• Archives of Pharmacal Research
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• 제25권6호
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• pp.807-816
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• 2002

Dihydrofolate reductases (DHFR) of human, Candida albicans and E. coli were docked with their original ligands of X-ray crystal complex using QXP (Quick eXPlore), a docking program. Conditions to reproduce the crystal structures within the root mean square deviation (rmsd) of 2.00 $\AA$ were established. Applying these conditions, binding modes and species-specificities of a novel antibacterial compound, $N^4-(2-acetoxyethoxymethyl)-2-acetylpyridine$ thiosemicarbazone (MTSC), were studied. As the results, the docking program reproduced the crystal structures with average rmsd of six ligands as 0.91 $\AA$ ranging from 0.49 to 1.45 $\AA$. The interactions including the numbers of hydrogen bonds and hydrophobic interactions were the same as the crystal structures and superposition of the crystal and docked structures almost coincided with each other. For AATSC, the results demonstrated that it could bind to either the substrate or coenzyme sites of DHFR in all three species with different degrees of affinity. It confirms the experimentally determined kinetic behavior of uncompetitive inhibition against either the inhibitor or the coenzyme. The docked MTSC overlapped well with the original ligands and major interactions were consistent with the ones in the crystal complexes. The information generated from this work should be useful for future development of antibacterial and antifungal agents.

• Bulletin of the Korean Chemical Society
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• 제29권8호
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• pp.1499-1504
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• 2008

Pyrazine derivatives bind to b-RAF receptor which is important in cancer therapy. The ligand-receptor interactions have been studied by comparative molecular field analysis (CoMFA) and molecular docking methods. Applying conventional ligand-based alignment schemes for the whole set was not successful. However, QM and DFT results suggested that some ligands have electrostatic interaction while others have steric interactions. On the basis of these results, we divided the dataset into two subsets. Electrostatic effect was found to be important in one set while steric effect for the other. Best docking modes were obtained for each subset based on the available crystal structure. These receptor-guided CoMFA models propose an interesting possibility which is difficult to obtain otherwise. i.e., in one binding mode the electrostatic interaction plays a key role for one subset ($q^2$ = 0.46, $r^2$ = 0.98), while in another binding mode steric effect is important with another subset ($q^2$ = 0.43, $r^2$ = 0.74).

• 약학회지
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• 제46권6호
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• pp.416-425
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• 2002

A comparative study to validate the reliability of a fully automated docking program, FlexiDock, was carried out to predict the binding modes of DHFR-inhibitor complex. The inhibitors were extracted from the crystallographically determined DHFR-NADP$^{+}$(H)-inhibitor ternary complexes of human, Escherichia coli and Candida albicans and then docked back into the remaining DHFR-NADP$^{+}$(H) binary complexes using FlexiDock. The resulting conformations and orientations were compared to the original crystal complex structures for reproducibility. Then, folate, the substrate, and known inhibitors such as methotrexate, piritrexim and trimethoprim were docked into the wild-type human DHFR and their binding modes were compared with X-ray crystallographic or other modeling data. The root mean square deviations (RMSDs) for ligands ranged from 1.14 to 1.57$\AA$, and the protein backbone RMSDs from 0.94 to 1.26$\AA$. FlexiDock reproduced the orientations and binding modes of all seven ligands in good agreement with the crystal structures. It proved to be a reliable and efficient program in studying binding modes of DHFR-inhibitor complexes of different species, and the information obtained from this work may provide additional insight into the design of new agents with improved activity.ity.

• 한국해양공학회지
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• 제17권1호
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• pp.1-7
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• 2003

Autonomous underwater vehicles (AUVs) are unmanned, underwater vessels that are used to investigate sea environments in the study of oceanography. Docking systems are required to increase the capability of the AUVs, to recharge the batteries, and to transmit data in real time for specific underwater works, such as repented jobs at sea bed. This paper presents a visual :em control system used to dock an AUV into an underwater station. A camera mounted at the now center of the AUV is used to guide the AUV into dock. To create the visual servo control system, this paper derives an optical flow model of a camera, where the projected motions of the image plane are described with the rotational and translational velocities of the AUV. This paper combines the optical flow equation of the camera with the AUVs equation of motion, and deriver a state equation for the visual servo AUV. Further, this paper proposes a discrete-time MIMO controller, minimizing a cost function. The control inputs of the AUV are automatically generated with the projected target position on the CCD plane of the camera and with the AUVs motion. To demonstrate the effectiveness of the modeling and the control law of the visual servo AUV simulations on docking the AUV to a target station are performed with the 6-dof nonlinear equations of REMUS AUV and a CCD camera.