• Title/Summary/Keyword: IP-Network

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Seamless handover protocol to reduce handover latency (핸드오버 지연 시간을 줄일 수 있는 심리스 핸드오버 프로토콜 제안 및 성능 분석)

  • Jang, Jong-Min;Lee, Yu-Tae;Lee, Soong-Hee;Kim, Dong-Il;Choi, Sam-Gil
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.13 no.2
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    • pp.277-284
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    • 2009
  • With significant development in wireless communication technologies, the needs to handover from one network to another have grown dramatically. Recently IETF developed MIPv6 and FMIPv6 which are used to handover between different access networks. These handover mechanisms have some known weaknesses. MIPv6 can not serve time-critical application because it causes long handover latency and packet loss. By these reasons, MIPv6 does not guarantee session continuity. FMIPv6 uses handover preparation phase to reduce DAD latency. However FMIPv66 still suffers from long handover latency, because it must perform binding update at the end of handover procedure. In this paper we propose new handover mechanism FMIPv6-PBU which eliminates binding update latency. The proposed mechanism has compatability with lagacy FMIPv6. In this paper propose FMIPv6-PBU handover procedure and explain its procedures and evaluate it with MIPv6 and FMIPv6.

Ventx1.1 competes with a transcriptional activator Xcad2 to regulate negatively its own expression

  • Kumar, Shiv;Umair, Zobia;Kumar, Vijay;Lee, Unjoo;Choi, Sun-Cheol;Kim, Jaebong
    • BMB Reports
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    • v.52 no.6
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    • pp.403-408
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    • 2019
  • Dorsoventral patterning of body axis in vertebrate embryo is tightly controlled by a complex regulatory network of transcription factors. Ventx1.1 is known as a transcriptional repressor to inhibit dorsal mesoderm formation and neural differentiation in Xenopus. In an attempt to identify, using chromatin immunoprecipitation (ChIP)-Seq, genome-wide binding pattern of Ventx1.1 in Xenopus gastrulae, we observed that Ventx1.1 associates with its own 5'-flanking sequence. In this study, we present evidence that Ventx1.1 binds a cis-acting Ventx1.1 response element (VRE) in its own promoter, leading to repression of its own transcription. Site-directed mutagenesis of the VRE in the Ventx1.1 promoter significantly abrogated this inhibitory autoregulation of Ventx1.1 transcription. Notably, Ventx1.1 and Xcad2, an activator of Ventx1.1 transcription, competitively co-occupied the VRE in the Ventx1.1 promoter. In support of this, mutation of the VRE down-regulated basal and Xcad2-induced levels of Ventx1.1 promoter activity. In addition, overexpression of Ventx1.1 prevented Xcad2 from binding to the Ventx1.1 promoter, and vice versa. Taken together, these results suggest that Ventx1.1 negatively regulates its own transcription in competition with Xcad2, thereby fine-tuning its own expression levels during dorsoventral patterning of Xenopus early embryo.

Selection of Detection Measures for Malicious Codes using Naive Estimator (단순 추정량을 이용한 악성코드의 탐지척도 선정)

  • Mun, Gil-Jong;Kim, Yong-Min
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.18 no.2
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    • pp.97-105
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    • 2008
  • The various mutations of the malicious codes are fast generated on the network. Also the behaviors of them become intelligent and the damage becomes larger step by step. In this paper, we suggest the method to select the useful measures for the detection of the codes. The method has the advantage of shortening the detection time by using header data without payloads and uses connection data that are composed of TCP/IP packets, and much information of each connection makes use of the measures. A naive estimator is applied to the probability distribution that are calculated by the histogram estimator to select the specific measures among 80 measures for the useful detection. The useful measures are then selected by using relative entropy. This method solves the problem that is to misclassify the measure values. We present the usefulness of the proposed method through the result of the detection experiment using the detection patterns based on the selected measures.

Question Similarity Measurement of Chinese Crop Diseases and Insect Pests Based on Mixed Information Extraction

  • Zhou, Han;Guo, Xuchao;Liu, Chengqi;Tang, Zhan;Lu, Shuhan;Li, Lin
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.15 no.11
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    • pp.3991-4010
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    • 2021
  • The Question Similarity Measurement of Chinese Crop Diseases and Insect Pests (QSM-CCD&IP) aims to judge the user's tendency to ask questions regarding input problems. The measurement is the basis of the Agricultural Knowledge Question and Answering (Q & A) system, information retrieval, and other tasks. However, the corpus and measurement methods available in this field have some deficiencies. In addition, error propagation may occur when the word boundary features and local context information are ignored when the general method embeds sentences. Hence, these factors make the task challenging. To solve the above problems and tackle the Question Similarity Measurement task in this work, a corpus on Chinese crop diseases and insect pests(CCDIP), which contains 13 categories, was established. Then, taking the CCDIP as the research object, this study proposes a Chinese agricultural text similarity matching model, namely, the AgrCQS. This model is based on mixed information extraction. Specifically, the hybrid embedding layer can enrich character information and improve the recognition ability of the model on the word boundary. The multi-scale local information can be extracted by multi-core convolutional neural network based on multi-weight (MM-CNN). The self-attention mechanism can enhance the fusion ability of the model on global information. In this research, the performance of the AgrCQS on the CCDIP is verified, and three benchmark datasets, namely, AFQMC, LCQMC, and BQ, are used. The accuracy rates are 93.92%, 74.42%, 86.35%, and 83.05%, respectively, which are higher than that of baseline systems without using any external knowledge. Additionally, the proposed method module can be extracted separately and applied to other models, thus providing reference for related research.

Study on Automation of Comprehensive IT Asset Management (포괄적 IT 자산관리의 자동화에 관한 연구)

  • Wonseop Hwang;Daihwan Min;Junghwan Kim;Hanjin Lee
    • Journal of Information Technology Services
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    • v.23 no.1
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    • pp.1-10
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    • 2024
  • The IT environment is changing due to the acceleration of digital transformation in enterprises and organizations. This expansion of the digital space makes centralized cybersecurity controls more difficult. For this reason, cyberattacks are increasing in frequency and severity and are becoming more sophisticated, such as ransomware and digital supply chain attacks. Even in large organizations with numerous security personnel and systems, security incidents continue to occur due to unmanaged and unknown threats and vulnerabilities to IT assets. It's time to move beyond the current focus on detecting and responding to security threats to managing the full range of cyber risks. This requires the implementation of asset Inventory for comprehensive management by collecting and integrating all IT assets of the enterprise and organization in a wide range. IT Asset Management(ITAM) systems exist to identify and manage various assets from a financial and administrative perspective. However, the asset information managed in this way is not complete, and there are problems with duplication of data. Also, it is insufficient to update of data-set, including Network Infrastructure, Active Directory, Virtualization Management, and Cloud Platforms. In this study, we, the researcher group propose a new framework for automated 'Comprehensive IT Asset Management(CITAM)' required for security operations by designing a process to automatically collect asset data-set. Such as the Hostname, IP, MAC address, Serial, OS, installed software information, last seen time, those are already distributed and stored in operating IT security systems. CITAM framwork could classify them into unique device units through analysis processes in term of aggregation, normalization, deduplication, validation, and integration.

Design and Performance Evaluation of a New SR-ARQ with an Adaptive Timer and Delayed NAK for Improving Handover Performance in Next-Generation Mobile Communication Networks (차세대 이동 통신망에서 핸드오버 성능 향상을 위한 적응형 타이머와 지연 NAK을 이용한 SR-ARQ 설계 및 성능 평가)

  • Park, Man-Kyu;Choi, Yun-Chul;Lee, Jae-Yong;Kim, Byung-Chul;Kim, Dae-Young;Kim, Jae-Ho
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.46 no.1
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    • pp.48-59
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    • 2009
  • Next generation mobile communication system will have various access networks and provide seamless multimedia data service to mobile nodes. The WiNGS system, one of these access network, has superior RAT(Radio Access Technology) and network connectivity other than previous ones. In this paper, we propose link-layer SR-ARQ between mobile node and WAGW to solve packet re-ordering problem during handover. In the proposed scheme, we apply the adaptive timer at the SR-ARQ sender to reduce unnecessary packet retransmission during handoff and delayed NAK algorithm at the SR-ARQ receiver for delaying NAK response due to temporary out-of-sequenced frames. We evaluate the performance of the proposed scheme by implementing the new SR-ARQ protocol at the link-layer using ns-2 simulator, and show the handover performance is improved greatly by preventing unnecessary retransmission.

Effective Routing Protocol Implementation Framework on Riverbed (OPNET) Modeler and its Example for AntHocNet (Riverbed (OPNET) Modeler의 효과적인 라우팅 프로토콜 추가 프레임워크 및 이를 이용한 AntHocNet 라우팅 구현)

  • Kim, Kwangsoo;Lee, Cheol-Woong;Shin, Seung-hun;Roh, Byeong-hee;Roh, Bongsoo;Han, Myoung-hun
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.41 no.8
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    • pp.974-985
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    • 2016
  • Riverbed Modeler, which is a commercial packet-level discrete event simulator is used to model, design, and simulate complicated communication protocols and large-scale network. Riverbed Modeler got credit for its reliability in field of network simulation. In the MANET simulation environment using Riverbed Modeler, it is very complicated to add a new routing protocol into existing architecture of routing protocols because it is required lots of modifications of protocol recognition. In this paper, we propose Routing Adding Framework which can reduce errors or mistakes during modifying the existing routing support architecture. Routing Adding Framework is provided as a adapter API for protocol recognition. and it is only minimum modifications for protocol identifiers when a new routing protocol is added to the child process of manet_mgr process which manages routing protocols for IP layer. With Routing Adding Framework, we can reduce less than half modification. Then, we shows an example of implementation of a hybrid routing protocol AntHocNet using Routing Adding Framework, and we verify its design and application of the Routing Adding Framework by obtaining simulation result with similar result given by AntHocNet.

Lambda Routing Table based Dynamic Routing Scheme and Its Characteristics on GMPLS Network (GMPLS 네트워크에서 Lambda Routing Table 조회형 동적 라우팅 방식 및 특성)

  • Kwon Ho-jin;Kim Young-bu;Han Chi-moon
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.29 no.11B
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    • pp.938-945
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    • 2004
  • This paper describes the problems of the existing two multi-layer routing policies(policy 1 and policy 2) and suggests new multi-layer routing policy(policy 3) which is established the packet LSP by inquiry on packet LSP lambda routing tables for GMPLS based optical If Network. All policies of multi-layer routing schemes first try to allocate a newly requested electrical path to an existing optical path that directly connects the source and destination nodes. U such a path is not available, all policies employ different procedures. Policy 1 tries to find available existing optical paths with two or more hops that connect the source and destination nodes and policy 2 tries to establish a new one-hop optical path between source and destination nodes. Policy 3 tries to establish a new one-hop optical path by inquiry on information of the packet LSP lambda routing tables between source and destination nodes. The performances of the three multi-routing policies are evaluated by computer simulation. Simulation results show that policy 3 is the excellent of routing time and traffic acceptance capabilities compare to existing two polices if p is large, where p is the number of packet-switching-capable ports p.

A Mobile Multicast Mechanism for End-to-End QoS Delivery (End-to-End QoS를 지원하기 위한 이동 멀티캐스트 기법)

  • Kim Tae-Soo;Lee Kwang-Hui
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.30 no.5B
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    • pp.253-263
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    • 2005
  • This paper proposed a mobile multicast technique to satisfy end-to-end QoS for various user requirements in mobile network environment. In order to provide seamless mobility, fast handoff technique was applied. By using L2 mobile trigger, it was possible to minimize remarkable amount of packet loss by delay occurred during handoff. To provide efficient multicast, concept of hierarchy was introduced to Xcast++, which results in a creation of HXcast++. HXcast++ optimized transfer path of multicast and reduced expensive multicast maintenance costs caused by frequent handoff. Suggestion of GMA (Group Management Agent) mechanism allows joining to group immediately without waiting IGMP Membership query during handoff. GMA mechanism will minimize the delay for group registration process and the resource usage due to delay of withdrawal process. And also use of buffering & forwarding technique minimized packet loss during generation of multicast tree. IntServ/RSVP was used to provide End-to-End QoS in local domain and DiffServ was used in global domain. To minimize reestablishment of RSVP session delay, extended HXcast++ control messages ware designed to require PATH message. HXcast++ proposed in this thesis is defined as multicast technique to provide end-to-end QoS and also to satisfy various user requirements in mobile network environment.

Wired/Wireless LED Lighting Communication Using Reconfigurable Peripheral Unit (재구성형 주변장치유닛을 사용한 유무선 LED 조명 통신)

  • Yoo, Sehoon;Gong, Jungchul;Kim, Kichul
    • Journal of IKEEE
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    • v.17 no.4
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    • pp.407-417
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    • 2013
  • In this paper, a reconfigurable peripheral unit for LED lighting communication is presented. Embedded lighting devices require various communication protocols. Usually, serial communication protocols and lighting control communication protocols such as DALI, DMX512, UART, SPI, IrDA, etc. are used in lighting devices. When the requirements of communication protocols are satisfied with separate IPs, the cost and the power consumption can considerably increase. We propose a reconfigurable communication peripheral unit which uses analysis of signal formats of the protocols. The gate count of the reconfigurable peripheral unit uses only 57% of the gate count of the separate implementation. Also, in this paper, a mapping table based DALI-ZigBee interfacing method for flexible lighting network configurations is proposed. Using this method, various DALI-ZigBee network systems can be easily set up. An LED lighting system platform is implemented to verify the operation of the DALI-ZigBee interfacing method. The reconfigurable peripheral unit and the DALI-ZigBee interfacing method can be efficiently used to implement various wired/wireless lighting communication systems.