• Title/Summary/Keyword: Mobile AD

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Improvement of OLSR Through MIMC's Decreased Overhead in MANET (모바일 애드 혹 네트워크 환경 하에서 멀티인터페이스 멀티채널의 오버헤드 감소를 통한 OLSR의 성능 개선)

  • Jang, Jae-young;Kim, Jung-ho
    • KIPS Transactions on Computer and Communication Systems
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    • v.5 no.3
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    • pp.55-70
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    • 2016
  • The most critical research issue in MANET environment is on supporting reliable communication between various devices. Various Multi-Hop Routing Protocol studies have proceeded. However, some problems you might have found when you use the existing link state routing technique are that it increases Control Message Overhead and it is unstable when node moves in CR circumstance which has transformation of using channel and MIMC circumstance which uses a number of interfaces. This essay offers a technique which is based on On-Demand Hello and the other technique which used Broadcast Interface of optimization as a solution to decrease Control Message Overhead. Also it proposes Quick Route Restoration technique which is utilized by GPS and MPR Selection technique which consider mobility as a solution of stable communication when node moves. Those offered Routing Protocol and OPNET based simulator result will be expected to be an excellent comparison in related research fields.

A Security method and Performance evaluation of preventing DoS attack against DAD in MANET (MANET 환경에서 중복 주소 탐지에 대한 DoS 공격을 방지하는 보안 기법과 성능 평가)

  • Lim, Jeong-Mi;Park, Chang-Seop
    • Journal of Korea Multimedia Society
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    • v.12 no.8
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    • pp.1099-1108
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    • 2009
  • The study of IP address allocation in MANET can be categories into Stateful and Stateless. The one, special node monitors other nodes' IP address and allocates IF address. And the other, node generates IP address by itself. Nodes in MANET have mobility and restricted resource, so Stateless is more suitable than Stateful. But, in Stateless, node requires DAD process because of unique IP address allocation. And Dos attack can be happened in DAD precess. In this paper, we propose a security method on preventing DoS attack against DAD in MANET using one-way hash function. Since, Computation of one-way hash function is suitable for nodes' restricted resource character in MANET. And we evaluate performance using NS2 and compare with other security method which is CGA using signature.

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A Classification of Medical and Advertising Blogs Using Machine Learning (머신러닝을 이용한 의료 및 광고 블로그 분류)

  • Lee, Gi-Sung;Lee, Jong-Chan
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.11
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    • pp.730-737
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    • 2018
  • With the increasing number of health consumers aiming for a happy quality of life, the O2O medical marketing market is activated by choosing reliable health care facilities and receiving high quality medical services based on the medical information distributed on web's blog. Because unstructured text data used on the Internet, mobile, and social networks directly or indirectly reflects authors' interests, preferences, and expectations in addition to their expertise, it is difficult to guarantee credibility of medical information. In this study, we propose a blog reading system that provides users with a higher quality medical information service by classifying medical information blogs (medical blog, ad blog) using bigdata and MLP processing. We collect and analyze many domestic medical information blogs on the Internet based on the proposed big data and machine learning technology, and develop a personalized health information recommendation system for each disease. It is expected that the user will be able to maintain his / her health condition by continuously checking his / her health problems and taking the most appropriate measures.

Heterogeneous Network Gateway Architecture and Simulation for Tactical MANET (전술 에드혹 환경에서 이종망 게이트웨이 구조 및 시뮬레이션 연구)

  • Roh, Bong Soo;Han, Myoung Hun;Kwon, Dae Hoon;Ham, Jae Hyun;Yun, Seon Hui;Ha, Jae Kyoung;Kim, Ki Il
    • Journal of the Korea Society for Simulation
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    • v.28 no.2
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    • pp.97-105
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    • 2019
  • The tactical mobile ad-hoc network(MANET) consists of distributed autonomous networks between individual ground nodes, which is effective in terms of network survivability and flexibility. However, due to constraints such as limited power, terrain, and mobility, frequent link disconnection and shadow area may occur in communication. On the other hand, the satellite network has the advantage of providing a wide-area wireless link overcoming terrain and mobility, but has limited bandwidth and high-latency characteristic. In the future battlefield, an integrated network architecture for interworking multi-layer networks through a heterogeneous network gateway (HNG) is required to overcome the limitations of the existing individual networks and increase reliability and efficiency of communication. In this paper, we propose a new HNG architecture and detailed algorithm that integrates satellite network and the tactical MANET and enables reliable data transfer based on flow characteristics of traffic. The simulations validated the proposed architecture using Riverbed Modeler, a network-level simulator.

A Study on Intrusion Detection Method using Collaborative Technique (협업 기법을 이용한 침입탐지 탐지 방법에 관한 연구)

  • Yang, Hwan Seok
    • Convergence Security Journal
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    • v.21 no.1
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    • pp.121-127
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    • 2021
  • MANET, which does not have any infrastructure other than wireless nodes, has the advantage of being able to construct a fast network. However, the movement of nodes and wireless media are also the causes of security vulnerabilities of MANET. In particular, the damage caused by the attacking nodes existing on the network is considerably greater than that of other networks. Therefore, it is necessary to detection technique for attacking nodes and techniques to reduce damage caused by attacks. In this paper, we proposed a hierarchical structure technique to increase the efficiency of intrusion detection and collaboration-based intrusion detection technique applying a P2P mesh network configuration technique to reduce damage caused by attacks. There was excluded the network participation of the attacking node in advance through the reliability evaluation of the nodes in the cluster. In addition, when an attack by an attacking node is detected, this paper was applied a method of minimizing the damage of the attacking node by transmitting quickly the attack node information to the global network through the P2P mesh network between cluster heads. The ns-2 simulator was used to evaluate the performance of the proposed technique, and the excellent performance of the proposed technique was confirmed through comparative experiments.

Development of Digital Transceiver Unit for 5G Optical Repeater (5G 광중계기 구동을 위한 디지털 송수신 유닛 설계)

  • Min, Kyoung-Ok;Lee, Seung-Ho
    • Journal of IKEEE
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    • v.25 no.1
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    • pp.156-167
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    • 2021
  • In this paper, we propose a digital transceiver unit design for in-building of 5G optical repeaters that extends the coverage of 5G mobile communication network services and connects to a stable wireless network in a building. The digital transceiver unit for driving the proposed 5G optical repeater is composed of 4 blocks: a signal processing unit, an RF transceiver unit, an optical input/output unit, and a clock generation unit. The signal processing unit plays an important role, such as a combination of a basic operation of the CPRI interface, a 4-channel antenna signal, and response to external control commands. It also transmits and receives high-quality IQ data through the JESD204B interface. CFR and DPD blocks operate to protect the power amplifier. The RF transmitter/receiver converts the RF signal received from the antenna to AD, is transmitted to the signal processing unit through the JESD204B interface, and DA converts the digital signal transmitted from the signal processing unit to the JESD204B interface and transmits the RF signal to the antenna. The optical input/output unit converts an electric signal into an optical signal and transmits it, and converts the optical signal into an electric signal and receives it. The clock generator suppresses jitter of the synchronous clock supplied from the CPRI interface of the optical input/output unit, and supplies a stable synchronous clock to the signal processing unit and the RF transceiver. Before CPRI connection, a local clock is supplied to operate in a CPRI connection ready state. XCZU9CG-2FFVC900I of Xilinx's MPSoC series was used to evaluate the accuracy of the digital transceiver unit for driving the 5G optical repeater proposed in this paper, and Vivado 2018.3 was used as the design tool. The 5G optical repeater digital transceiver unit proposed in this paper converts the 5G RF signal input to the ADC into digital and transmits it to the JIG through CPRI and outputs the downlink data signal received from the JIG through the CPRI to the DAC. And evaluated the performance. The experimental results showed that flatness, Return Loss, Channel Power, ACLR, EVM, Frequency Error, etc. exceeded the target set value.

Improved Cluster Routing Algorithm Using Remaining Electric Energy Based on CBRP (CBRP 기반 잔여전력량을 이용한 개선된 클러스터 라우팅 기법)

  • Park, Hyeran;Kim, Wuwoan;Jang, Sangdong
    • Journal of the Korea Society of Computer and Information
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    • v.18 no.1
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    • pp.63-71
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    • 2013
  • In the Cluster-Based Routing Protocol (CBRP) a cluster header in each cluster should be elected. The cluster headers consume energy much more than other member nodes do because they manage and operate all of mobile nodes in their cluster. The traditional CBRP elects a cluster header without considering the remaining electric energy of each node. So, there exist problems that the cluster header has short average lifetime, and a new cluster header should be elected again frequently. In this paper, we propose the improved protocol which prolongs the lifetime of the cluster header, decreases the problem of re-electing the cluster header and enhances the stability of the path. In order to achieve this, when a cluster header is elected in a cluster, the remaining electric energies of all the nodes are compared with one another, and the node with the highest energy is elected as the cluster header. Also, the node with the second highest energy is elected as the second header. If the elected cluster header is unable to perform the role of the cluster header any more because the remaining energy level goes low, it sends a beacon message to neighbor member nodes, then the second header will serve as the cluster header.

A Secure Mobile Message Authentication Over VANET (VANET 상에서의 이동성을 고려한 안전한 메시지 인증기법)

  • Seo, Hwa-Jeong;Kim, Ho-Won
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.15 no.5
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    • pp.1087-1096
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    • 2011
  • Vehicular Ad Hoc Network(VANET) using wireless network is offering the communications between vehicle and vehicle(V2V) or vehicle and infrastructure(V2I). VANET is being actively researched from industry field and university because of the rapid developments of the industry and vehicular automation. Information, collected from VANET, of velocity, acceleration, condition of road and environments provides various services related with safe drive to the drivers, so security over network is the inevitable factor. For the secure message authentication, a number of authentication proposals have been proposed. Among of them, a scheme, proposed by Jung, applying database search algorithm, Bloom filter, to RAISE scheme, is efficient authentication algorithm in a dense space. However, k-anonymity used for obtaining the accurate vehicular identification in the paper has a weak point. Whenever requesting the righteous identification, all hash value of messages are calculated. For this reason, as the number of car increases, a amount of hash operation increases exponentially. Moreover the paper does not provide a complete key exchange algorithm while the hand-over operation. In this paper, we use a Received Signal Strength Indicator(RSSI) based velocity and distance estimation algorithm to localize the identification and provide the secure and efficient algorithm in which the problem of hand-over algorithm is corrected.

A Study on the Compositions and Applications of Video Solution for Small-sized Theater Performance:Focused on the Musical (소극장 공연에 적합한 영상 솔루션 구성과 활용방안 연구 : 뮤지컬 <트레이스 유(2018)>를 중심으로)

  • Kim, Kyu-Jong
    • The Journal of the Korea Contents Association
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    • v.19 no.8
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    • pp.359-369
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    • 2019
  • This research suggests video solutions and efficient implementations for low-budget performances. This study adopts Millumin as a mapping server, which reflects the character of small theatres with a lower budget that doesn't use more than four projectors in a show. By comparing pros and cons of media servers, the study discovers how to employ an appropriate server as well as to participate in a pre-video production stage, which increases the artistry of directing and reduces unnecessary graphics. Meanwhile, with the participation of an interpretive programmer, this study suggests a way to manage the rehearsal time and to increase the artistry of directing. In addition, this study analyses the relationship between the video's visual motive source in the story's development, crisis, climax, twist and the provided narrative based on "Trace U the musical (2018)", by this analyzation, the relationship between storytelling and the video is fully shown. A visual motive is related to the action of actors, the movement of dancers, the music, the lyrics and the lines. Furthermore, the provided narrative confirms that the existence of an actual relationship with the turning point of the plots, characters' emotion, suggestions of sub-plot and the twists of own story. In conclusion, it implies a video of small theatres can not be separated from the probability of the narrative.sh an efficient ad execution strategy that reflected the characteristics of mobile devices.

A New Item Recommendation Procedure Using Preference Boundary

  • Kim, Hyea-Kyeong;Jang, Moon-Kyoung;Kim, Jae-Kyeong;Cho, Yoon-Ho
    • Asia pacific journal of information systems
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    • v.20 no.1
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    • pp.81-99
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    • 2010
  • Lately, in consumers' markets the number of new items is rapidly increasing at an overwhelming rate while consumers have limited access to information about those new products in making a sensible, well-informed purchase. Therefore, item providers and customers need a system which recommends right items to right customers. Also, whenever new items are released, for instance, the recommender system specializing in new items can help item providers locate and identify potential customers. Currently, new items are being added to an existing system without being specially noted to consumers, making it difficult for consumers to identify and evaluate new products introduced in the markets. Most of previous approaches for recommender systems have to rely on the usage history of customers. For new items, this content-based (CB) approach is simply not available for the system to recommend those new items to potential consumers. Although collaborative filtering (CF) approach is not directly applicable to solve the new item problem, it would be a good idea to use the basic principle of CF which identifies similar customers, i,e. neighbors, and recommend items to those customers who have liked the similar items in the past. This research aims to suggest a hybrid recommendation procedure based on the preference boundary of target customer. We suggest the hybrid recommendation procedure using the preference boundary in the feature space for recommending new items only. The basic principle is that if a new item belongs within the preference boundary of a target customer, then it is evaluated to be preferred by the customer. Customers' preferences and characteristics of items including new items are represented in a feature space, and the scope or boundary of the target customer's preference is extended to those of neighbors'. The new item recommendation procedure consists of three steps. The first step is analyzing the profile of items, which are represented as k-dimensional feature values. The second step is to determine the representative point of the target customer's preference boundary, the centroid, based on a personal information set. To determine the centroid of preference boundary of a target customer, three algorithms are developed in this research: one is using the centroid of a target customer only (TC), the other is using centroid of a (dummy) big target customer that is composed of a target customer and his/her neighbors (BC), and another is using centroids of a target customer and his/her neighbors (NC). The third step is to determine the range of the preference boundary, the radius. The suggested algorithm Is using the average distance (AD) between the centroid and all purchased items. We test whether the CF-based approach to determine the centroid of the preference boundary improves the recommendation quality or not. For this purpose, we develop two hybrid algorithms, BC and NC, which use neighbors when deciding centroid of the preference boundary. To test the validity of hybrid algorithms, BC and NC, we developed CB-algorithm, TC, which uses target customers only. We measured effectiveness scores of suggested algorithms and compared them through a series of experiments with a set of real mobile image transaction data. We spilt the period between 1st June 2004 and 31st July and the period between 1st August and 31st August 2004 as a training set and a test set, respectively. The training set Is used to make the preference boundary, and the test set is used to evaluate the performance of the suggested hybrid recommendation procedure. The main aim of this research Is to compare the hybrid recommendation algorithm with the CB algorithm. To evaluate the performance of each algorithm, we compare the purchased new item list in test period with the recommended item list which is recommended by suggested algorithms. So we employ the evaluation metric to hit the ratio for evaluating our algorithms. The hit ratio is defined as the ratio of the hit set size to the recommended set size. The hit set size means the number of success of recommendations in our experiment, and the test set size means the number of purchased items during the test period. Experimental test result shows the hit ratio of BC and NC is bigger than that of TC. This means using neighbors Is more effective to recommend new items. That is hybrid algorithm using CF is more effective when recommending to consumers new items than the algorithm using only CB. The reason of the smaller hit ratio of BC than that of NC is that BC is defined as a dummy or virtual customer who purchased all items of target customers' and neighbors'. That is centroid of BC often shifts from that of TC, so it tends to reflect skewed characters of target customer. So the recommendation algorithm using NC shows the best hit ratio, because NC has sufficient information about target customers and their neighbors without damaging the information about the target customers.