• Asian Pacific Journal of Cancer Prevention
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• v.15 no.17
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• pp.7065-7068
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• 2014

To investigate the anti-proliferative mechanism of mangiferin in a human nasopharyngeal carcinoma cell line, CNE2 cells were incubated with different concentrations of mangiferin (12.5, 25, 50, 100, 150 and $200{\mu}M$) or with PBS as a control for 72 hours. Analyses were made of the cell cycle and apoptosis with measurement of mRNA and protein levels of two apoptosis-related genes, Bcl-2 and Bax. Flow cytometry assays showed mangiferin could inhibit CNE2 cell proliferation via G2/M arrest and induction of early apoptosis. Real time PCR and Western blotting showed the mRNA and protein level of Bcl-2 to be down-regulated, while those of Bax were upregulated, when CNE2 cells were treated with mangiferin. This investigation indicated anti-proliferation effects of mangiferin through induction of cell apoptosis regulated by Bcl-2 and Bax expression.

• Journal of Institute of Control, Robotics and Systems
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• v.6 no.4
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• pp.327-332
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• 2000

In this paper, a new multi-fingered robot hand using ultrasonic motors and its control system are developed. The developed robot hand has four fingers and fifteen articulated joints. The distal joint of each finger is directly driven by ultrasonic motor and all joints except the distal joint has low transmission gear mechanism with the motor. The developed robot hand has several advantages in size compared to a hand using conventional DC motors, and in performance compared to a hand using tendons to drive joints. A VME-bus based hand control system and ultrasonic motor driver are also developed. The performance of the hand is confirmed by using the developed control system in real-time.

• Journal of Institute of Control, Robotics and Systems
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• v.13 no.9
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• pp.883-895
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• 2007

In this work, we present the development of a patrol robot which is intended to navigate outdoor rough terrain. Proposed mechanism consists of six legs for overcoming an obstacle, and six wheels for traveling. Also, in order to absorb vibration in rough terrain effectively, the slide-spring system and tubed type tire are adopted to each leg and each wheel. The control system of robot consists of several imbedded boards for management of lots of diverse devices such as sensors designed for rough terrain, motor controllers, camera, micro controller and so on. And the base system of the robot is designed to operate in real time and to surveille in the vicinity of the robot, and the robot system is controlled by wireless LAN connected to GUI-based remote control system, while CAN communication connects the control board and the device controllers for sensors and motor controllers. For operating this robot system efficiently, we propose the control algorithms for autonomous navigation using GPS, stabilization maintenance by posture control, obstacle-avoidance by impedance control, and obstacle-overcoming with interference-avoidance between wheels. The performance of the robot and the proposed algorithms are tested and proved by a set of experiments in outdoor rough terrain.

• The Journal of Internal Korean Medicine
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• v.31 no.1
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• pp.25-39
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• 2010

Background : At high glucose levels in $\beta$-cells, cell viability and insulin secretion are decreased by glucotoxicity. Sopyung-tang(SPT) had an effect on blood glucose level decrease and antioxidant enzyme activities in streptozotocin-induced diabetic rats. Objectives : This study performed a series of experiment to verify the effects of SPT extract on the cell viability, antioxidant enzyme activities, insulin secretion and insulin mRNA expression at hyperglycemic states of RIN-m5F. Methods : After treatment at various concentrations of SPT added to the RIN-m5F cells, cell viability by MTT assay, free radical-scavenging activity, SOD activity and insulin secretion were measured. Additionally, insulin-related gene expression was measured using real-time RT-PCR. Results : Compared to the control group, SPT extract showed considerable effects on RIN-m5F cell viability, DPPH radical-scavenging activity, superoxide dismutase (SOD) activity, insulin secretion and insulin-related gene expression. Conclusions : This study showed that SPT extract has an effect on $\beta$-cell cell viability, insulin secretion and insulin-related gene expression. Thus, SPT extract may be used for treatment of diabetes and its complications. Further mechanism studies of SPT seem to be necessary on the glucotoxicity and oxidative stress.

• Composites Research
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• v.13 no.6
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• pp.55-62
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• 2000

The strength test was done for the Carbon/Carbon rotor disk which is the critical part of a carbon/carbon brake system in an operating time. The loading fixture was designed for the static strength test of a single carbon/carbon brake disk using finite element analysis. To simulate the real dynamic system in a static condition, the friction surface of the rotor disk was fixed and static load was applied to the rotor slot in the circumferential direction. The described failure mechanism of the brake disk can be described as matrix cracking occurred first at the contact surface of the rotor slot, subsequent delamination from the cracked contact surface, and the final fracture at the notch of the rotor.

• Journal of Computing Science and Engineering
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• v.2 no.4
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• pp.412-427
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• 2008

We propose ID-exchange protocol for Connectionless Location-Awareness Service (CLAS) to locate mobile nodes in indoor sensor network. When adapting location-awareness service to sensor network, the target system must be designed in accordance with various metrics which reflect the system requirement. We especially consider sustainability of the existing service which has been provided for its original purpose, such as environmental monitoring. The detailed meaning of sustainability here is that, even if location-awareness service is newly added to the existing service, the system must be assured to retain a stable network condition, and to deal with newly caused traffic properly. The CLAS ID-exchange protocol is especially designed for fixture and mobile nodes communication to achieve these properties. The protocol operates on 802.15.4 MAC layer to make mobile node work independently of the procedure to build routing table of fixture node, so a stable routing condition can be achieved even if there are many mobile nodes. Moreover, the dedicated frequency channel is assigned only for this protocol, so that traffic caused by location-awareness service can be distributed to another channel. A real system adapting the protocol was implemented to monitor fire and authorities' positions. We verified the overhead and elapsed time for location-awareness. The result shows the proposed protocol has a high performance in detecting speed, traffic distribution, and stability of overall network.

• Journal of KIISE:Computing Practices and Letters
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• v.14 no.5
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• pp.457-461
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• 2008

Previous studies on overlay ad hoc multi-casting are mainly divided into two categories: hierarchical structure-based multicast schemes and non-hierarchical structure-based multicast schemes. They do not reflect their real-time location information for routing updates. This can be a cause of low performance on energy consumption, throughput, and latency. For improving the problems, we propose an implicit cluster based overlay ad hoc multicast scheme with analysis of related work, and then we evaluate performance through computer simulation.

• BMB Reports
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• v.49 no.9
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• pp.502-507
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• 2016

To examine the effect of TBMS1on breast cancer metastasis, and investigate the potential mechanism by which Tubeimoside-1 (TBMS1) inhibits the CXCR4 expression in breast cancer cells. The expression of CXCR4 in breast cancer cell lines was determined by immunoblotting and real-time PCR. The effect of TBMS1 on NF-κB binding activity was evaluated by EMSA assay and ChIP analysis. Cell proliferation and invasion were analyzed by MTT assay and transwell invasion assay, respectively. The effect of TBMS1 on breast cancer metastasis was further evaluated in a metastasis model of nude mice. TBMS1 suppressed the expression of CXCR4 through inhibition of NF-κB binding activity. TBMS1 inhibited CXCL12-induced invasion in breast cancer cells, while ectopic expression of CXCR4 abolished the inhibitive activity of TBMS1. TBMS1 suppressed breast cancer metastasis in the metastatic model of nude mice. TBMS1 suppressed the CXCR4-mediated metastasis of breast cancer by inhibiting NF-κB binding activity.

• Journal of Internet of Things and Convergence
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• v.2 no.1
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• pp.1-6
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• 2016

The IOT environment, people connected to the network, object, everything such as space (Things) generates data in real time. The information between the object collecting, sharing, are utilized. Currently health care, research in various fields such as smart home has been promoted. Also appeared concepts emphasized all things(IOE) Internet connection between the geographic space and the Internet. Human, while important connections between the objects, such as objects, studies of efficient and secure authentication technologies have been developed. In this paper, we propose a RADIUS (Remote Authentication Dial In User Service) protocol for improved mutual authentication between each object in the IOT environment.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.49 no.10
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• pp.582-590
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• 2000

A fast optimal path planning algorithm using the analog Cellular Nonlinear Circuits(CNC) is proposed. The analog circuits based optimal path planning is very useful since most of the optimal path planning problems require real time computation. There has already been a previous study to implement the dynamic programming with analog circuits. However, it could not be applied for the practically large size of problems since the algorithm employs the mechanism of reducing its input current/voltage by the amount of cost, which causes outputs of distant cells to become zero. In this study, a subgoal-based dynamic programming algorithm to compute the optimal path is proposed. In the algorithm, the optimal paths are computed regardless of the distance between the starting and the goal points. It finds subgoals starting from the starting point when the output of the starting cell is raised from its initial value. The subgoal is set as the next initial position to find the next subgoal until the final goal is reached. The global optimality of the proposed algorithm is discussed and two different kinds of simulations have been done for the proposed algorithm.