• Journal of Information Processing Systems
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• v.16 no.5
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• pp.1113-1128
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• 2020

Ad hoc networks play an important role in mobile communications, and the performance of nodes has a significant impact on the choice of communication links. To ensure efficient and secure data forwarding and delivery, an intelligent routing protocol (IAODV) based on learning method is constructed. Five attributes of node energy, rate, credit value, computing power and transmission distance are taken as the basis of segmentation. By learning the selected samples and calculating the information gain of each attribute, the decision tree of routing node is constructed, and the rules of routing node selection are determined. IAODV algorithm realizes the adaptive evaluation and classification of network nodes, so as to determine the optimal transmission path from the source node to the destination node. The simulation results verify the feasibility, effectiveness and security of IAODV.

• Journal of Korea Society of Industrial Information Systems
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• v.12 no.1
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• pp.61-71
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• 2007

The main purpose of this study was to develop Automatic Measurement System for monitoring tree's vigor using Ubiquitous Sensor Network This study also focused on presenting an alternative for monitoring automatically tree's vigor due to Shigometer's limits. Application test of the system in comparison with Shigometer showed that the measurement values were not different to choose between the two, and battery lasted about 1,844 days in this system. To test the sensor network the possible transmission distance using the sensor network in maximum was 130m. Investigation and management expenses can be reduced and labor productivity will also be improved in the forest and street trees.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.1
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• pp.171-192
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• 2017

The change of any element in the network is possible to cause performance degradation of the multicast network. So it is necessary to optimize the topology path through the multicast update strategy, which directly affects the performance and user experience of the overlay multicast. In view of the above, a new multicast tree update strategy based on perturbation theory Musp (Multicast Update Strategy based on Perturbation theory) is proposed, which reduces the data transmission interruption caused by the multicast tree update and improves user experiences. According to the multicast tree's elements performance and the topology structure, the Musp strategy defines the multicast metric matrix and based on the matrix perturbation theory it also defines the multicast fluctuation factor. Besides it also demonstrates the calculability of the multicast fluctuation factor presents the steps of the Musp algorithm and calculates the complexity. The experimental results show that compared with other update strategies, as for the sensitivity of the multicast fluctuation factor's energized multicast tree to the network disturbance, the maximum delay of the Musp update strategy is minimal in the case of the local degradation of network performance.

• IEIE Transactions on Smart Processing and Computing
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• v.4 no.2
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• pp.65-70
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• 2015

In this paper, we describe the world's first real-time ray-tracing chip architecture. Ray-tracing technology generates high-quality 3D graphics images better than current rasterization technology by providing four essential light effects: shadow, reflection, refraction and transmission. The real-time ray-tracing chip named RayChip includes a real-time ray-tracing graphics processing unit and an accelerating tree-building unit. An ARM Ltd. central processing unit (CPU) and other peripherals are also included to support all processes of 3D graphics applications. Using the accelerating tree-building unit named RayTree to minimize the CPU load, the chip uses a low-end CPU and decreases both silicon area and power consumption. The evaluation results with RayChip show appropriate performance to support real-time ray tracing in high-definition (HD) resolution, while the rendered images are scaled to full HD resolution. The chip also integrates the Linux operating system and the familiar OpenGL for Embedded Systems application programming interface for easy application development.

• Journal of the Korea Furniture Society
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• v.22 no.4
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• pp.270-277
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• 2011

This study aims to find new solutions to the problem of utilization of materials and techniques represented in the development of modern lighting design. LED is an important component in modern lighting design and pine tree is one of the most popular domestic wood in furniture design in Korea. In this study, design is developed into various types of furniture such as a table, a chest, and a lighting, by researching manufacturing process and examining the use of slicing pine tree. The technique of slicing pine tree is a simple linear arrangement that was traditionally used in wooden furniture in Lee dynasty, with an emphasis on repetitive rhythm. The slicing technology is used to expand the usage of domestic pine tree. The beauty of natural wood is expressed with the transmission of light by applying this technique to the lighting design. It also brings new communication in between artificial lighting and natural wood combining this traditional technique and LED lighting in design. Finally, this study suggests particular value through the convergence of analog and digital by using the traditional wooden technique that keeps natural wood prints and new digital technology by using LED lighting. More discussions and research about this subject are expected continuously through this study.

• Journal of the Korea Society of Computer and Information
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• v.17 no.2
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• pp.207-214
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• 2012

This paper is to improve an identification ratio of tags by analyzing Slotted ALOHA, Dynamic Slotted ALOHA, Binary-tree and Query-tree and shortening the tag identification time in mobile RFID. Also, it enables the stable information transmission of tags by saving backscattering power of tags through shortening of identification time. As a result, this increases the available time of the battery and accessibility to a RFID service. For this, we proposed the energy-efficient tag anti-collision protocol for mobile RFID. The proposed scheme shows advanced result in identification time and collision counts. This scheme may be the first attempt for the mobile anti-collision.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.6B
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• pp.1002-1011
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• 2000

In this paper, we propose a multiresolution progressive image transmission with spatial and bit-rate scalabilities using a $2{\times}2$ DCT. The multiresolition image represented by a $2{\times}2$ DCT is used for the progressive image transmission with spatial and bit-rate scalabilities. Because the proposed progressive image transmission method supports both spatial and bit-rate scalabilities, it can be adaptively applied to the receiver's scalability requests. We compare the proposed progressive transmission with that of the higher-order convolution-based Wavelet method. Comparisons show that the proposed method needs much less computations, but insignificant loss of image quality.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.122-123
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• 2003

Apple stem grooving virus (ASGV) belongs to Capillovirus and infects pome fruits. Transmission mode of ASGV is known by grafting and mechanical inoculation into susceptible hosts, not by any other natural vectors. But we have observed the spread of ASGV in the field without mechanical inoculation or grafting. Transmission seems to be occurred from tree-to-tree and tree-to-susceptible herbaceous plants along but not across ditches in the field. In order to ascertain this possibility, various fungi were isolated and cultured from ASGV-infected plants and 69 isolates were characterized. By means of RNA dot-blot hybridization and PCR analysis, 3 isolates were sorted out for further studies. The isolates were identified to Tataromyces sp. and belonged to Phenicillium by morphological characteristics and molecular markers. As an experimental host, 10 kidney beans (Phaseolus vulgaris) were screened and Kyunggi-5 was selected for virus amplification and symptom development. Kyunggj-5 infected by fungi which seemed to carry ASGV showed the typical disease symptoms and viral coat protein genes were detected from all tested plants. To confirm the Koch's rule, fungi cultured from inoculation origins of kidney bean were grown on PDA media and re-inoculated to hosts. The fungi isolated from inoculation origins induced the typical disease symptoms on hosts. However virus free fungi did not induce any symptom on the experimental hosts. This bioassay showed that these typical symptoms were caused by virus, not fungi.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.10a
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• pp.794-797
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• 2015

As the interest in VANET is increased, a study on the beacon message transmission between vehicles is actively being made. IEEE 802.11p/1609.4 standard is based on a multichannel system consisting of multiple service channels (SCH) and a control channel (CCH). Multiple SCHs are defined for nonsafety data transfer, while the CCH is used to broadcast safety messages called beacons and control messages (i.e., service advertisement messages). However, most messages broadcast in the only one CCH belong to safety application that must be contested in dense vehicular network. This paper suggests safety message transfer algorithm in dense vehicular congestion. The proposed algorithm is that the priority of safety messages is decided by decision tree and messages are stored in proper queues according to their priorities. Then, safety messages with higher priorities are sent in turn by CCH in the assigned time. The proposed algorithm decreases the beacon transmission delay and increase on the probability of a successful beacon reception in an IEEE 802.11p/1609.4-based network.

• Journal of Korea Multimedia Society
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• v.11 no.7
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• pp.986-996
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• 2008

The home network environment based on the power line communication has some unexpected events. The noise source from the home appliances makes the network impedance increased, and the transmission packets distorted. Therefore the packet transmission from the source node may not be delivered to the destination node directly. In this paper we propose a new self-healing mechanism which relays the packet to the directly unreachable destination automatically with the help of intermediate nodes. In order to choose the minimum required intermediate nodes our mechanism makes a spanning tree with both the directly reachable nodes and indirectly reachable nodes via the intermedia nodes. We developed the network simulator in order to compare its performance to the Echelon's repeater selecting mechanism. Though it required more packet relations than Echelon's but the reachable probability to the destination was highly increased about two times.