• Journal of KIISE:Information Networking
• /
• v.32 no.5
• /
• pp.641-649
• /
• 2005

Metro networks use the existing circuit-switching technology like SONET/SDH. Such circuit-switching based networks are inefficient in tarrying Internet traffic with bursty nature. Therefore, metro networks can become a bottleneck In order to resolve this problem, the IEEE 802.17 working group has proposed the RPR (Resilient Packet Ring) technology. In addition to this, the RPR fairness mechanism has been defined to provide fairness among the stations in the RPR network. However, the current RPR fairness mechanism has the problem of inefficient use of the available bandwidth after when the congestion at a node is resolved. In this paper, we propose an improved bandwidth allocation mechanism in which, after the congestion resolution at a node, the node estimates the number of nodes transmitting data and measures the remaining bandwidth and fairly allocates the available bandwidth to active nodes. To show the performance of our proposed mechanism, we have performed simulation and showed that the proposed mechanism offers higher bandwidth utilization.

• Journal of the Korea Society of Computer and Information
• /
• v.12 no.6
• /
• pp.235-242
• /
• 2007

Network Mobility Basic Support protocol reduces location-update signaling by making network movements transparent to the mobile nodes (MNs) behind the mobile router (MR), but causes some problems such as sub-optimal routing and multiple encapsulations. This paper proposes an Route Optimization Employing HMIP Extension for Mobile Networks (ROHMIP) scheme for nested nubile networks support which introduces HMIP concept with relation information between MNNs behind a MR and the MR in order to localize handoff, to optimize routing and especially reduce handoff signal overhead. With ROHMIP, a mobile network node (MNN) behind a MR performs route optimization with a correspondent node (CN) as the MR sends a binding update message (BU) to mobility anchor point (MAP) via root-MR on behalf of all active MNNs when the mobile network moves. This paper describes the new mechanisms and provides simulation results which indicate that our proposal reduces transmission delay, handoff latency and signaling overhead.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.10 no.11
• /
• pp.1265-1270
• /
• 2015

For the sensor node or collection node operating with a battery in a wireless sensor network, MAC protocols with improved energy efficiency are important performance factors. In this paper, in order to improve the restrictive capability in accordance with the fixed activity period of the duty cycle technology in the MAC protocol for wireless sensor networks, we propose a periodic adaptive wakeup technique based on receive prediction. The proposed technique is through a performance evaluation using the CC2500 RF transceiver and C8051F330 microcontroller based wireless node, to analyze the minimum active period. As a result, it was confirmed that it is possible to improve energy efficiency by adaptively changing the sleep period in accordance with the change of period.

• Asian Journal for Public Opinion Research
• /
• v.6 no.1
• /
• pp.31-38
• /
• 2018

Leading up to the 2019 presidential election in Indonesia, campaigns have emerged through social media, particularly Twitter, using various hashtags, such as #2019GantiPresiden (2019 Change President) and #TetapJokowi (Always Jokowi). This paper tries to understand the presidential candidates' power map in forming opinions and influencing voter behavior by analyzing Twitter from August 6, 2018 to September 15, 2018, just before the beginning of the official campaign period, by searching for the keyword "pemilihan presiden RI Tahun 2019" (RI presidential election in 2019). According to our NodeXL's analysis, there were 1,650 active Twitter users talking about the 2019 presidential election. The 1,650 Twitter users have formed a communication network of 46,750 relationships formed from messages in the form of tweets, comments, and retweets. Our analysis found that those mentioning "pilihan presiden 2019" form large communication networks around four clusters: one for each of the two candidates (Jokowi and Prabowo) and two for opinion leaders who are undecided about the election (Gus Mus and Mas Piyu). GusMus is a religious leader, as an official of the PBNU Rais Syuriah (an Islamic organization) and has a large following both on and off Twitter. "MasPiyu" is an unidentified Twitter user; he only has a large following on Twitter, but does not have support offline.

• The KIPS Transactions:PartC
• /
• v.14C no.1 s.111
• /
• pp.73-80
• /
• 2007

In conventional on-demand mobile ad hoc routing algorithms, an alternate path is sought only after an active path is broken. It incurs a significant cost in terms of money and time in detecting the disconnection and establishing a new route. In this thesis, we propose proactive route selection and maintenance to conventional mobile ad hoc on-demand routing algorithms. The key idea for this research is to only consider a path break to be likely when the signal power of a received packet drops below an optimal threshold value and to generate a forewarning packet. In other words, if a path is lost with high probability, the neighboring node that may easily be cut off notifies the source node by sending a forewarning packet. Then the source node can initiate route discovery early and switched to a reliable path potentially avoiding the disconnection altogether. For the simulational study, network simulator(NS2) is used. The result of simulation shows that the algorithm significantly improves the performance of networks comparing to conventional on-demand routing protocols based on DSR and AODV in terms of packet delivery ratio, packet latency and routing overhead.

• Journal of Society of Preventive Korean Medicine
• /
• v.26 no.3
• /
• pp.29-40
• /
• 2022

Objective : This study assessed the effect of a combination of Korean medicine on a thyroid papillary cancer patient who was diagnosed with local lymph node metastasis after thyroidectomy and lymph node dissection but did not want surgery. Methods : Gami-Palmultang administration and moxibustion(large Bmoxa cautery) were performed for six years. Treatment outcomes were evaluated with Brief Fatigue Inventory (BFI), Numerical Rating Scale (NRS), Insomnia Severity Index (ISI), Functional Assessment of Cancer Therapy-General (FACT-G), blood test/ CT imaging results, and patient's statements. Results : After the treatment, all symptoms have been alleviated, the quality of life has increased, and it has been maintained without further metastasis of tumors for six years. Conclusion : Korean medicine treatment along with active observation can be an alternative to patients who do not want surgical treatment after recurrence of local lymph nodes in thyroid papillary cancer, and can have positive results in improving the quality of life.

• Proceedings of the Korea Information Assurance Society Conference
• /
• 2004.05a
• /
• pp.29-34
• /
• 2004

As the number of internet users grows rapidly, the services which users required becomes various. However, for fulfilling these various user requirements, the existing passive network should be standardized for a long time. To resolve the delay on providing services, active network as a new technology was suggested. Its router or switch with DARPA as center has the program running ability, so user oriented network can be composed. However, active network's architecture can resolve the user required service using mobile code on the network node, but it is more complex, easy-to-attack, various than the passive network. Many researchers have tried to resolve this problem. So, this paper studied the mobile code security service in active network environment to provide user's convenience and accommodation, and introduced ANASP system as an alternative.

• Journal of KIISE:Computing Practices and Letters
• /
• v.13 no.7
• /
• pp.540-544
• /
• 2007

Researches on Sensor Network has become much more active and is currently being applied to many different fields. However since sensor network is limited to only collecting and reporting information regarding a certain event, and requires human intervention with that given information, it is often difficult to react to an event or situation immediately and proactively. To overcome this kind of limitation, Wireless Sensor and Actor Networks (WSANs) with immediate-response Actor Nodes has been proposed which adds greater mobility and activity to exisiting sensor networks. Although WSANs shares many common grounds with sensor networks, it is difficult to apply exisiting security technologies due to the fact that WSAN contains Actor Nodes that are resource-independent and mobile. This research therefore seeks to demonstrate ways to provide security, integrity and authentication services for WSAN's secure operation, by separating networks into hierarchcial structure by each node's abilities and providing different encryption key-based secure protocols for each level of hierarchy: Pair-wise Key, Node Key, and Region Key for sensor levels, and Public Key for actor levels.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.11 no.5
• /
• pp.1633-1639
• /
• 2010

Recently Wireless sensor networks have been used for many purposes and is active for this study. The various methods to reduce energy consumption, which are actively being studied Wireless sensor network to reduce energy consumption, leading to improve transport efficiency, Cluster can be viewed using the research methods. Cluster method researches consists of a sensor node to the cluster and in among those they take out the Cluster head node and Cluster head node is having collects sensing information of circumferential nodes sensing to sink node transmits. Selected as cluster head sensor nodes so a lot of the energy consumption is used as a cluster head sensor nodes is lose a shorter life span have to be replaced by another sensor node. In this paper, to complement the disadvantages of a cluster-mesh method, proposes to manage memory efficiently about filtering method for sensing data. Filtering method to store the same data sensing unlike traditional methods of data filtering system sensing first sent directly by the hashing algorithm to calculate the hash table to store addresses and Sensing to store data on the calculated address in a manner to avoid duplication occurred later, and sensing data is not duplicated by filtering data to be stored in the hash table is a way.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.41 no.9
• /
• pp.31-37
• /
• 2004

We have proposed a design methodology for large active-area single-mode VCSELS, which have higher reliability and output power, and are well-suited for high-speed operation. The key idea underlying the design methodology is to reduce the effective index difference between active and cladding regions by controlling the thickness and position of the oxide layer. The idea is confirmed by the self-consistent effective index method. By placing the oxide layer position properly, we can increase the radius of the oxide aperture for single-mode operation by 3 times.