• Title/Summary/Keyword: Ns-2

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Efficient Power Management Mechanism considering Network Characteristic in 802.11 (802.11에서 네트워크 특성을 고려한 전력 감소 기법)

  • Nam, Jae-Hyun
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2010.10a
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    • pp.475-477
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    • 2010
  • In the power saving mechanism specified in IEEE 802.11, all node use the sam ATIM window size. Since the ATIM window size critically affects throughput and energy consumption, a fixed ATIM window does not perform well in all situations. This paper proposes the efficient power management mechanism considering network characteristic in 802.11. To reflect the network characteristic, the paper uses th (m,k)-firm deadline technique. Simulation result shows that proposed mechanism outperforms the IEEE 802.11 power saving mechanism in terms of the amount of power consumed.

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The Method of Nearest Surrounder Query Processing in Three-Dimensional Space (3차원 지리 공간 환경에서의 근접주변 객체 질의 처리 기법)

  • Gromyko, Diana;Jang, Hong-Jun;Choi, Woo-Sung;Hyun, Kyeong-Seok;Chung, Jaehwa;Jung, Soon-Young
    • Proceedings of the Korea Information Processing Society Conference
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    • 2015.10a
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    • pp.1211-1214
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    • 2015
  • 최근 모바일 기기의 발달과 기기의 보급으로 인하여, 사용자의 이동성에 따른 위치 정보에 관한 질의 요구가 증가되고 있다. 이러한 사회적 특성에 맞추어 현재 위치를 중심으로 주변 객체를 찾는 최근접주변 객체 질의에 대한 연구가 활발히 진행되고 있다. 기존 최근접 주변객체 질의는 2차원 공간에서 질의 점 주변에 보이는 모든 객체를 검색하며 보이지 않는 객체는 제외시킨다. 하지만 3차원 공간 환경일 경우 객체들의 높이를 감안해야 하기 때문에 기존 기법들로는 3차원 근접주변 객체를 검색하기에는 적합하지 않다. 본 논문에서는 이런 문제점을 해결하는 새로운 3차원 최근접 주변객체 질의 (3dimensional Nearest Surrounder Query: 3dNS)를 제안한다. 객체들 간의 Z_angle 수직각도를 사용함으로써 3차원 공간 환경에서 객체 검색을 가능하게 하며 질의 처리의 정확성을 높일 수 있다.

A New Framework of 6lowpan node for Neighboring Communication with Healthcare Monitoring Applications

  • Singh, Dhananjay;Lee, Hoon-Jae;Chung, Wan-Young
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2009.05a
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    • pp.281-286
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    • 2009
  • The proposed technique uses cyclic frame structure, where three periods such as beacon period (BP), mesh contention access period (MCAP) and slotted period (SP) are in a data frame. This paper studies on a mechanism to allow communication nodes (6lowpan) in a PAN with different logical channel for global healthcare applications monitoring technology. The proposed super framework structure system has installed 6lowpan sensor nodes to communicate with each other. The basic idea is to time share logical channels to perform 6lowpan sensor node. The concept of 6lowpan sensor node and various biomedical sensors fixed on the patient BAN (Body Area Network) for monitoring health condition. In PAN (hospital area), has fixed gateways that received biomedical data from 6lowpan (patient). Each 6lowpan sensor node (patient) has IP-addresses that would be directly connected to the internet. With the help of IP-address service provider can recognize or analyze patient data from all over the globe by the internet service provider, with specific equipments i.e. cell phone, PDA, note book. The NS-2.33 result shows the performance of data transmission delay and data delivery ratio in the case of hop count in a PAN (Personal Area Networks).

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Streamflow sensitivity to land cover changes: Akaki River, Ethiopia

  • Mitiku, Dereje Birhanu;Kim, Hyeon Jun;Jang, Cheol Hee;Park, Sanghyun;Choi, Shin Woo
    • Proceedings of the Korea Water Resources Association Conference
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    • 2016.05a
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    • pp.49-49
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    • 2016
  • The impact of land cover changes on streamflow of the Akaki catchment will be assessed using Soil and Water Assessment Tool (SWAT) model. The study will analyze the historical land cover changes (1993 to 2016) that have taken place in the catchment and its effect on the streamflow of the study area. Arc GIS will be used to analysis the satellite images obtained from the United States Geological Survey (USGS). To investigate the impact of land cover change on streamflow the model set up will be done using readily available spatial and temporal data, and calibrated against measured discharge. Two third of the data will be used for model calibration (1993?2000) and the remaining one-third for model validation (2001?2004). Model performance will be evaluated by using Nash and Sutcliff efficiency (NS) and coefficient of determination (R2). The calibrated model will be used to assess two land cover change (2002 and 2016) scenarios and its likely impacts of land use changes on the runoff will be quantified. The evaluation of the model response to these changes on streamflow will be presented properly. The study will contribute a lot to understand land use and land cover change on streamflow. This enhances the ability of stakeholder to implement sound policies to minimize undesirable future impacts and management alternatives which have a significant role in future flood control of the study area.

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An Energy Efficient Clustering Algorithm in Mobile Adhoc Network Using Ticket Id Based Clustering Manager

  • Venkatasubramanian, S.;Suhasini, A.;Vennila, C.
    • International Journal of Computer Science & Network Security
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    • v.21 no.7
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    • pp.341-349
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    • 2021
  • Many emerging mobile ad-hoc network application communications are group-oriented. Multicast supports group-oriented applications efficiently, particularly in a mobile environment that has a limited bandwidth and limited power. Energy effectiveness along with safety are 2 key problem in MANET design. Within this paper, MANET is presented with a stable, energy-efficient clustering technique. In this proposed work advanced clustering in the networks with ticket ID cluster manager (TID-CMGR) has formed in MANET. The proposed routing scheme makes secure networking the shortest route possible. In this article, we propose a Cluster manager approach based on TICKET-ID to address energy consumption issues and reduce CH workload. TID-CMGR includes two mechanism including ticket ID controller, ticketing pool, route planning and other components. The CA (cluster agent) shall control and supervise the functions of nodes and inform to TID-CMGR. The CH conducts and transfers packets to the network nodes. As the CH energy level is depleted, CA elects the corresponding node with elevated energy values, and all new and old operations are simultaneously stored by CA at this time. A simulation trial for 20 to 100 nodes was performed to show the proposed scheme performance. The suggested approach is used to do experimental work using the NS- simulator. TIDCMGR is compared with TID BRM and PSO to calculate the utility of the work proposed. The assessment shows that the proposed TICKET-ID scheme achieves 90 percent more than other current systems.

Performance of 3D printed plastic scintillators for gamma-ray detection

  • Kim, Dong-geon;Lee, Sangmin;Park, Junesic;Son, Jaebum;Kim, Tae Hoon;Kim, Yong Hyun;Pak, Kihong;Kim, Yong Kyun
    • Nuclear Engineering and Technology
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    • v.52 no.12
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    • pp.2910-2917
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    • 2020
  • Digital light processing three-dimensional (3D) printing technique is a powerful tool to rapidly manufacture plastic scintillators of almost any shape or geometric features. In our previous study, the main properties of light output and transmission were analyzed. However, a more detailed study of the other properties is required to develop 3D printed plastic scintillators with expectable and reproducible properties. The 3D printed plastic scintillator displayed an average decay time constants of 15.6 ns, intrinsic energy resolution of 13.2%, and intrinsic detection efficiency of 6.81% for 477 keV Compton electrons from the 137Cs γ-ray source. The 3D printed plastic scintillator showed a similar decay time and intrinsic detection efficiency as that of a commercial plastic scintillator BC408. Furthermore, the presented estimates for the properties showed good agreement with the analyzed data.

The Option of Motion Preservation in Cervical Spondylosis: Cervical Disc Arthroplasty Update

  • Chang, Chih-Chang;Huang, Wen-Cheng;Wu, Jau-Ching;Mummaneni, Praveen V.
    • Neurospine
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    • v.15 no.4
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    • pp.296-305
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    • 2018
  • Cervical disc arthroplasty (CDA), or total disc replacement, has emerged as an option in the past two decades for the management of 1- and 2-level cervical disc herniation and spondylosis causing radiculopathy, myelopathy, or both. Multiple prospective randomized controlled trials have demonstrated CDA to be as safe and effective as anterior cervical discectomy and fusion, which has been the standard of care for decades. Moreover, CDA successfully preserved segmental mobility in the majority of surgical levels for 5-10 years. Although CDA has been suggested to have long-term efficacy for the reduction of adjacent segment disease in some studies, more data are needed on this topic. Surgery for CDA is more demanding for decompression, because indirect decompression by placement of a tall bone graft is not possible in CDA. The artificial discs should be properly sized, centered, and installed to allow movement of the vertebrae, and are commonly 6 mm high or less in most patients. The key to successful CDA surgery includes strict patient selection, generous decompression of the neural elements, accurate sizing of the device, and appropriately centered implant placement.

The Effects of Backhole Attack on Lattice Structure MANET (격자구조 MANET에서 블랙홀 공격의 영향)

  • Kim, Young-Dong
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2014.05a
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    • pp.578-581
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    • 2014
  • Blackhole attack, a kinds of attacks to routing function, can cause critical effects to network transmission function, Especially, on MANET(Mobile Ad-hoc Network) which it is not easy to prepare functions to respond malicious intrusion, transmission functions of entire networks could be degraded. In this paper, effects of blackhole attack to network transmission performance is analyzed on lattice structured MANET. Specially, performance is measured for various location of blackhole attack on lattice MANET, and compared with the performance of random structured MANET. This paper is done with computer simulation, VoIP(Voice over Internet Protocol) traffic is used in simulation. The results of this paper can be used for data to deal with blackhole attack.

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Network Coding-based Maximum Lifetime Algorithm for Sliding Window in WSNs

  • Sun, Baolin;Gui, Chao;Song, Ying;Chen, Hua
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.13 no.3
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    • pp.1298-1310
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    • 2019
  • Network coding (NC) is a promising technology that can improve available bandwidth and packet throughput in wireless sensor networks (WSNs). Sliding window is an improved technology of NC, which is a supplement of TCP/IP technology and can improve data throughput and network lifetime on WSNs. This paper proposes a network coding-based maximum lifetime algorithm for sliding window in WSNs (NC-MLSW) which improves the throughput and network lifetime in WSN. The packets on the source node are sent on the WSNs. The intermediate node encodes the received original packet and forwards the newly encoded packet to the next node. Finally, the destination node decodes the received encoded data packet and recovers the original packet. The performance of the NC-MLSW algorithm is studied using NS2 simulation software and the network packet throughput, network lifetime and data packet loss rate were evaluated. The simulations experiment results show that the NC-MLSW algorithm can obviously improve the network packet throughput and network lifetime.

Reducing Cybersecurity Risks in Cloud Computing Using A Distributed Key Mechanism

  • Altowaijri, Saleh M.
    • International Journal of Computer Science & Network Security
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    • v.21 no.9
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    • pp.1-10
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    • 2021
  • The Internet of things (IoT) is the main advancement in data processing and communication technologies. In IoT, intelligent devices play an exciting role in wireless communication. Although, sensor nodes are low-cost devices for communication and data gathering. However, sensor nodes are more vulnerable to different security threats because these nodes have continuous access to the internet. Therefore, the multiparty security credential-based key generation mechanism provides effective security against several attacks. The key generation-based methods are implemented at sensor nodes, edge nodes, and also at server nodes for secure communication. The main challenging issue in a collaborative key generation scheme is the extensive multiplication. When the number of parties increased the multiplications are more complex. Thus, the computational cost of batch key and multiparty key-based schemes is high. This paper presents a Secure Multipart Key Distribution scheme (SMKD) that provides secure communication among the nodes by generating a multiparty secure key for communication. In this paper, we provide node authentication and session key generation mechanism among mobile nodes, head nodes, and trusted servers. We analyzed the achievements of the SMKD scheme against SPPDA, PPDAS, and PFDA schemes. Thus, the simulation environment is established by employing an NS 2. Simulation results prove that the performance of SMKD is better in terms of communication cost, computational cost, and energy consumption.