• Journal of Astronomy and Space Sciences
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• v.37 no.3
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• pp.187-197
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• 2020

In order to avoid the high cost and high risk of demonstration mission of rendezvous-docking technology, missions using nanosatellites have recently been increasing. However, there are few successful mission cases due to many limitations of nanosatellites like small size, power limitation, and limited performances of sensor, thruster, and controller. To improve the probability of rendezvous-docking mission success using nanosatellite, a rendezvous-docking phase analysis tool for nanosatellites is developed. The tool serves to analyze the relative position and attitude control of the chaser satellite at the docking phase. In this tool, the Model Predictive Controller (MPC) is implemented as a controller, and Extended Kalman Filter (EKF) is adopted as a filter for noise filtering. To verify the performance and effectiveness of the developed tool for nanosatellites, simulation study was conducted. Consequently, we confirmed that this tool can be used for the analysis of relative position and attitude control for nanosatellites in the rendezvous-docking phase.

• Journal of the Korean Operations Research and Management Science Society
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• v.30 no.3
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• pp.1-15
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• 2005

In our model, a fleet of vehicles start from docking point to collect loads at the terminals assigned to the point Then the docking points are connected to the hub by primary vehicle routes starting at the hub. This vehicle visit all the docking points to collect the loads which have been collected by the secondary vehicles. Our goal Is to minimize the long-run cost of setting up the docking Points and vehicle operation cost by deciding the location of the docking points and the routes optimally. We propose an heuristic algorithm to solve this and tested it though various experiments.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.1
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• pp.111-116
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• 2014

Objective: To study potential targets of Danshensu via dual inverse docking. Method: PharmMapper and idTarget servers were used as tools, and the results were checked with the molecular docking program autodock vina in PyRx 0.8. Result: The disease-related target HRas was rated top, with a pharmacophore model matching well the molecular features of Danshensu. In addition, docking results indicated that the complex was also matched in terms of structure, H-bonds, and hydrophobicity. Conclusion: Dual inverse docking indicates that HRas may be a potential anticancer target of Danshensu. This approach can provide useful information for studying pharmacological effects of agents of interest.

• Bulletin of the Korean Chemical Society
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• v.29 no.8
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• pp.1479-1484
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• 2008

Protein tyrosine phosphatase (PTP) 1B is the superfamily of PTPs and a negative regulator of multiple receptor tyrosine kinases (RTKs). Inhibition of protein tyrosine phosphatase 1B (PTP1B) has been proposed as a strategy for the treatment of type 2 diabetes and obesity. Recently, it has been reported that amentoflavone, a biflavonoid extracted from Selaginella tamariscina, inhibited PTP1B. In the present study, docking model between amentoflavone and PTP1B was determined using automated docking study. Based on this docking model and the interactions between the known inhibitors and PTP1B, we determined multiple pharmacophore maps which consisted of five features, two hydrogen bonding acceptors, two hydrogen bonding donors, and one lipophilic. Using receptor-oriented pharmacophore-based in silico screening, we searched the biflavonoid database including 40 naturally occurring biflavonoids. From these results, it can be proposed that two biflavonoids, sumaflavone and tetrahydroamentoflavone can be potent allosteric inhibitors, and the linkage at 5',8''-position of two flavones and a hydroxyl group at 4'-position are the critical factors for their allosteric inhibition. This study will be helpful to understand the mechanism of allosteric inhibition of PTP1B by biflavonoids and give insights to develop potent inhibitors of PTP1B.

• Bulletin of the Korean Chemical Society
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• v.28 no.2
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• pp.200-206
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• 2007

Pharmacophore models for lymphocyte-specific protein tyrosine kinase (P56 LCK) were developed using CATALYST HypoGen with a training set comprising of 25 different P56 LCK inhibitors. The best quantitative pharmacophore hypothesis comprises of one hydrogen bond acceptor, one hydrogen bond donor, one hydrophobic aliphatic and one ring aromatic features with correlation coefficient of 0.941, root mean square deviation (RMSD) of 0.933 and cost difference (null cost-total cost) of 66.23. The pharmacophore model was validated by two methods and the validated model was further used to search databases for new compounds with good estimated LCK inhibitory activity. These compounds were evaluated for their binding properties at the active site by molecular docking studies using GOLD software. The compounds with good estimated activity and docking scores were evaluated for physiological properties based on Lipinski's rules. Finally 68 compounds satisfied all the properties required to be a successful inhibitor candidate.

• Journal of the Korea Safety Management & Science
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• v.10 no.2
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• pp.187-193
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• 2008

Cross docking is a warehouse management concept in which items delivered to a distribution facility by inbound trucks are immediately sorted out and reorganized based on customer demands and are routed and loaded into outbound trucks for delivery to customers without actually being held in inventory in the distribution facility. In this research, the design of distribution facility for cross docking systems was studied. The objective of this research is to find the minimum number of receiving docks and shipping docks, respectively, in order to meet the daily demand of the distribution center. Two solution approaches are employed in modeling and solving the problem The first approach is mathematical modeling and the second approach is a simulation. The logic developed in the simulation model is expected to apply to the real world situation.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.10
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• pp.4301-4305
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• 2014

Tanshinone IIA is a pharmacologically active ingredient extracted from Danshen, a Chinese traditional medicine. Its molecular mechanisms are still unclear. The present study utilized computational approaches to uncover the potential targets of this compound. In this research, PharmMapper server was used as the inverse docking tool andnd the results were verified by Autodock vina in PyRx 0.8, and by DRAR-CPI, a server for drug repositioning via the chemical-protein interactome. Results showed that the retinoic acid receptor alpha ($RAR{\alpha}$), a target protein in acute promyelocytic leukemia (APL), was in the top rank, with a pharmacophore model matching well the molecular features of Tanshinone IIA. Moreover, molecular docking and drug repurposing results showed that the complex was also matched in terms of structure and chemical-protein interactions. These results indicated that $RAR{\alpha}$ may be a potential target of Tanshinone IIA for APL. The study can provide useful information for further biological and biochemical research on natural compounds.

• Journal of Integrative Natural Science
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• v.5 no.3
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• pp.190-194
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• 2012

Human P-gp is one of the protein responsible for the multidrug resistance (MDR) develpment. MDR is a major cause of the cancer chemotherapy. In this paper, we performed homology modeling, docking study of papayriferic acid into the P-gp nucleotide binding domain (NBD2). For human P-gp, X-ray crystal structure is not known yet. We developed homology model for human NBD2 using HlyB ABC transporter structure (PDB code: 1XEF, resolution 2.5 ${\AA}$). Docking study was performed using Autodock. Docking result was analyzed, which shows that ligand docks into steroid binding site and interacts through hydrophobic and hydrophilic interactions.

• Bulletin of the Korean Chemical Society
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• v.32 no.4
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• pp.1241-1248
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• 2011

Three dimensional quantitative structure-activity relationships (3D-QSARs) between new thiosemicarbazone analogues (1-31) as a substrate molecule and their inhibitory activity against tyrosinase as a receptor were performed and discussed quantitatively using CoMFA (comparative molecular field analysis) and CoMSIA (comparative molecular similarity indices analysis) methods. According to the optimized CoMSIA 2 model obtained from the above procedure, inhibitory activities were mainly dependent upon H-bond acceptor favored field (36.5%) of substrate molecules. The optimized CoMSIA 2 model, with the sensitivity of the perturbation and the prediction, produced by a progressive scrambling analysis was not dependent on chance correlation. From molecular docking studies, it is supposed that the inhibitory activation of the substrate molecules against tyrosinase (PDB code: 1WX2) would not take place via uncompetitive inhibition forming a chelate between copper atoms in the active site of tyrosinase and thiosemicarbazone moieties of the substrate molecules, but via competitive inhibition based on H-bonding.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.316-320
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• 2003

This paper introduces an autonomous underwater vehicle (AUV) model, ASUM, equipped with a visual servo control system to dock into an underwater station with a camera and motion sensors. To make a visual servoing AUV, this paper implemented the visual servo control system designed with an augmented state equation, which was composed of the optical flow model of a camera and the equation of the AUV's motion. The system design and the hardware configuration of ASUM are presented in this paper. ASUM recognizes the target position by processing the captured image for the lights, which are installed around the end of the cone-type entrance of the duct. Unfortunately, experiments are not yet conducted when we write this article. The authors will present the results for the AUV docking test.