• KIPS Transactions on Software and Data Engineering
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• v.2 no.11
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• pp.747-756
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• 2013

It is important to reduce unnecessary overhead in sensor network using battery. In addition encryption is important because of necessity of security. Since unavoidable overhead occurs in case of encryption, security and overhead are in trade-off condition. In this paper, we use a concept called trust to reduce the encryption overhead. We reduce overhead by controlling encryption key sizes while maintaining the security level where high and low trust nodes are mixed. We simulated and compared normal encryption and trust value based encryption. As a result, the latter has lower execution time and overhead. If we define a standard of trust levels considering purpose and circumstances of real network, we can use constrained resources efficiently in sensor network.

• Journal of Advanced Navigation Technology
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• v.13 no.2
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• pp.238-243
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• 2009

Now, the production process systems are largely based on automatic system using the wired network. The production process systems using wired network has disadvantage that it is expensive when the installed and replaced equipment. The each equipment happens to repair cost for control and management in production processes. And the replaced equipment has also the additional expense and breaks production process. These problems are solved through wireless communication between the industrial equipments. So, we propose wireless production process system based on IEEE 802.15.4 technology. It solves a complicated space and stops by replaced equipment in the factory. Then we simulated and analyzed IEEE 802.15.4 for Industrial Equipment based on Wireless Network.

• Journal of the Korean Magnetic Resonance Society
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• v.9 no.1
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• pp.38-47
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• 2005

Axin is a scaffold protein of the APC/axin/GSK complex, binding to all of the other signalling components. Axin interacts with Glycogen synthase kinase 3$\beta$ (GSK 3$\beta$) and functions as a negative regulator of Wnt signalling pathways. To determine the solution structure of the GSK3$\beta$ binding regions of the axin, we initiated NMR study of axin fragment comprising residues 3$Val^{388} - Arg^{401}$using circular dichroism (CD) and two-dimensional NMR spectroscopy. The CD spectra of 3$axin^{pep}$ in the presence of 30% TFE displayed a standard 3$\alpha$-helical conformation, exhibiting the bound structure of 3$axin^{pep}$ to GSK3$\bata$. On the basis of experimental restraints including $NOE_s$, and $^3J_{HN\alpha} $ coupling constants, the solution conformation of $axin^{pep}$ was determined with program CNS. The 20 lowest energy structures were selected out of 50 final simulated-annealing structures in both water and TFE environment, respectively. The $RMSD_s$ for the 20 structures in TFE solution were 0.086 nm for backbone atoms and 0.195 nm for all heavy atoms, respectively. The Ramachandran plot indicates that the $\varphi$, $\psi$ angles of the 20 final structures is properly distributed in energetically acceptable regions. $Axin^pep$ in aqueous solutions consists of a stable $\alpha$-helix spanning residues form $Glu^{391}$ to $Val^{391} $, which is an interacting motif with GSK3$\beta$.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.46 no.7
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• pp.13-23
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• 2009

In this paper, the network performance of a turbo coded optical code division multiple access (CDMA) system with cross-layer, which is between physical and network layers, concept is analyzed and simulated. We consider physical and MAC layers in a cross-layer concept. An intensity-modulated/direct-detection (IM/DD) optical system employing pulse position modulation (PPM) is considered. In order to increase the system performance, turbo codes composed of parallel concatenated convolutional codes (PCCCs) is utilized. The network performance is evaluated in terms of bit error probability (BEP). From the simulation results, it is demonstrated that turbo coding offers considerable coding gain with reasonable encoding and decoding complexity. Also, it is confirmed that the performance of such an optical CDMA network can be substantially improved by increasing e interleaver length and e number of iterations in e decoding process. The results of this paper can be applied to implement the indoor optical wireless LANs.

• Journal of the Korean Institute of Intelligent Systems
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• v.16 no.4
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• pp.485-492
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• 2006

This paper deals with implementation of network for distributed control system of a humanoid robot ISHURO(Inha Semyung Humanoid Robot). A humanoid robot needs much degree of freedom structurally and much data for having flexible movement. To realize such a humanoid robot, distributed control method is preferred to the centralized one since it gives a compactness, modularity and flexibility for the controllers. For organizing distributed control system of a humanoid robot, a control processor on a board is needed to individually control the joint motor and communication technology between the processors is required to transmit its information within control time. The processor is DSP-based processor and includes CAN network on a chip. It shares the computational load such as monitoring the sensor information and controlling the actuator between each of modules. In this paper, the communication architecture is suggested and its message protocol are discussed including message structure, time consumption for transmission, and controller structure at the view of distributed control for a humanoid robot. All of the sequence are simulated with Matlab and then verified with real walking experiment by ISHURO.

• BMB Reports
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• v.36 no.6
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• pp.552-557
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• 2003

Oligomers with $\alpha$-aminooxy acids are reported to form very stable turn and helix structures, and they are supposed to be useful peptidomimetics for drug design. A recent report suggested that homochiral oxa-peptides form a strong eight-member-ring structure by a hydrogen bond between adjacent aminooxy-acid residues in a $CDCl_3$ solution. In order to design an $\alpha$-MSH analog with a stable turn conformation, we synthesized four tetramers and one pentamer, based on $\alpha$-MSH sequence, and determined the solution structures of the molecules by two-dimensional NMR spectroscopy and simulated annealing calculations. The solution conformations of the three peptidomimetic molecules (TLV, TDV, and TLL) in DMSO-$d_6$ contain a stable 7-membered-ring structure that is similar to a $\gamma$-turn in normal peptides. Newly-designed tetramer TDF and pentamer PDF have a ball-type rigid structure that is induced by strong hydrogen bonds between adjacent amide protons and carbonyl oxygens. In conclusion, the aminooxy acids, easily prepared from natural or unnatural amino acids, can be employed to prepare peptidomimetic analogues with well-defined turn structures for pharmaceutical interest.

• The Journal of Korea Robotics Society
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• v.13 no.1
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• pp.26-30
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• 2018

Planetary global localization is necessary for long-range rover missions in which communication with command center operator is throttled due to the long distance. There has been number of researches that address this problem by exploiting and matching rover surroundings with global digital elevation maps (DEM). Using conventional methods for matching, however, is challenging due to artifacts in both DEM rendered images, and/or rover 2D images caused by DEM low resolution, rover image illumination variations and small terrain features. In this work, we use train CNN discriminator to match rover 2D image with DEM rendered images using conditional Generative Adversarial Network architecture (cGAN). We then use this discriminator to search an uncertainty bound given by visual odometry (VO) error bound to estimate rover optimal location and orientation. We demonstrate our network capability to learn to translate rover image into DEM simulated image and match them using Devon Island dataset. The experimental results show that our proposed approach achieves ~74% mean average precision.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.5
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• pp.1646-1652
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• 2010

The communication in wireless sensor network is divided into several layers, because of each of them do their role, the wireless communication is possible, the MAC (Medium Access Control) layer of the one of sensor network communications layer is used to the data errors, control flow, and manage resources. Using MAC Protocol, it ensures the communication between sensor node. In this paper, highlighted the energy efficiency of the S-MAC, T-MAC protocol it emphasized the efficiency of energy by lessening the woken time of all nods effectively, transmitting and receiving the control packet on only necessary nods through use of a method that RTS packet is added to SYNC packet and making other nods sleep. On sending SYNC+RTS packet and receiving the packet, nod noticed that it wasn't necessary to be awaked on this period, would be in Sleep mode, demonstrated mathematically that energy is more effective than existing protocol, and simulated with MATLAB.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.4A
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• pp.388-398
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• 2011

In this paper, we introduce an EMSP(Efficient Mobility Support Protocol) for mobile sensor network with mobility-aware. We propose virtual cluster and node split scheme considering movements of mobile nodes. The existing M-LEACH protocol suffers from communication cost spent on JOIN request information during invitation phase. To address this issue, the large boundary of the cluster in LUR-tree can reduce superfluous update cost. In addition to the expansion of the cluster, the proposed approach exploits node split algorithms used in R-tree in order to uniformly form a cluster. The simulated results show that energy-consumption has less up to about 40% than LEACH-C and 8% than M-LEACH protocol. Finally, we show that the proposed scheme outperforms those of other in terms of lifetime of sensor fields and scalability in wireless sensor network.

• The KIPS Transactions:PartC
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• v.10C no.7
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• pp.923-928
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• 2003

This paper proposes a bottleneck link bandwidth measurement algorithm for reducing packet transmission delay within the grid network. There are two methods for measuring bottleneck link bandwidth：Packet Pair algorithm and Paced Probes algorithm. They measure bottleneck link bandwidth using the difference in arrival times of two paced probe packets of the same size traveling from the same source to destination. In addition, they reduce the influences of cross traffic by pacer packet. But there are some problems on these algorithms：it's not possible to know where bottleneck link occurred because they only focus on measuring the smallest link bandwidth along the path without considering bandwidth of every link on the path. So hop-by-hop based bottleneck link bandwidth measurement algorithm can be used for reducing packet transmission delay on grid network. Timestamp option was used on the paced probe packet for the link level measurement of bottleneck bandwidth. And the reducing of packet transmission delay was simulated by the solving a bottleneck link. The algorithm suggested in this paper can contribute to data transmission ensuring FTP and realtime QoS by detecting bandwidth and the location where bottleneck link occurred.