• KSII Transactions on Internet and Information Systems (TIIS)
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• 제6권7호
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• pp.1874-1893
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• 2012

An approach to detect abnormal activities based on reputations created individually by each node is vulnerable to a false accusation since intrusion detection in ad-hoc networks is done in a distributed and cooperative manner. Detection of false accusation is considered important because the efficiency or survivability of the network can be degraded severely if normal nodes were excluded from the network by being considered as abnormal ones in the intrusion detection process. In this paper, we propose an improved reputation-based intrusion detection technique to efficiently detect and manage false accusations in ad-hoc networks. Additionally, we execute simulations of the proposed technique to analyze its performance and feasibility to be implemented in a real environment.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권6호
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• pp.2861-2880
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• 2018

Mobile Ad hoc Networks (MANETs) have become a viable platform owing to their potential of providing communication without any pre-existing infrastructure and central administrating authority. Mutual support and co-operation among nodes are prerequisites for performing functions in such networks. The scarcity of resources makes it economical for nodes to conserve their resources and misbehave by avoiding participation in the network. Therefore, a mechanism is required to detect and handle such misbehaving nodes and promote co-operation in the network. Existing techniques for handling misbehaving nodes focus only on their current behaviour without considering the antecedent behaviour of nodes. In real world, a node may dynamically change its behaviour in accordance to its requirements. Hence, an efficient mechanism is required for providing security against such misbehaviour. This paper proposes an Adaptive Security Model which contemplates the present as well as anterior behaviour of nodes for providing security against dynamic node behaviour. The adaptivity of the model is nested in its ability to requite well-behaving nodes and penalize misbehaving ones in conformity with their overall behaviour. Simulation results indicate the efficiency of proposed scheme in securing the network from the menace of dynamic behaviour of nodes.

• Journal of Communications and Networks
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• 제18권6호
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• pp.938-947
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• 2016

A mobile ad hoc network (MANET) is a collection of mobile nodes communicating in an infrastructure-less environment without the aid of a central administrating authority. Such networks entail greater dependency on synergy amongst the nodes to execute fundamental network operations. The scarcity of resources makes it economically logical for nodes to misbehave to preserve their resources which makes secure routing difficult to achieve. To ensure secure routing a mechanism is required to discourage misbehavior and maintain the synergy in the network. The proposed scheme employs a partially distributed dynamic model at each node for enhancing the security of the network. Supplementary information regarding misbehavior in the network is partially distributed among the nodes during route establishment which is used as a cautionary measure to ensure secure routing. The proposed scheme contemplates the real world scenario where a node may exhibit different kinds of misbehavior at different times. Thus, it provides a dynamic decision making procedure to deal with nodes exhibiting varying misbehaviors in accordance to their severity. Simulations conducted to evaluate the performance of the model demonstrate its effectiveness in dealing with misbehaving nodes.

• Journal of applied mathematics & informatics
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• 제41권1호
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• pp.95-105
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• 2023

To make the network energy efficient and to protect the network from malignant user's energy efficient grid based secret key sharing scheme is proposed. The cost function is evaluated to select the optimal nodes for carrying out the data transaction process. The network is split into equal number of grids and each grid is placed with certain number of nodes. The node cost function is estimated for all the nodes present in the network. Once the optimal energy proficient nodes are selected then the data transaction process is carried out in a secured way using malicious nodes filtration process. Therefore, the message is transmitted in a secret sharing method to the end user and this process makes the network more efficient. The proposed work is evaluated in network simulated and the performance of the work are analysed in terms of energy, delay, packet delivery ratio, and false detection ratio. From the result, we observed that the work outperforms the other works and achieves better energy and reduced packet rate.

• Journal of Communications and Networks
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• 제17권1호
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• pp.75-83
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• 2015

In mobile ad-hoc networks (MANETs), nodes are mobile in nature. Collaboration between mobile nodes is more significant in MANETs, which have as their greatest challenges vulnerabilities to various security attacks and an inability to operate securely while preserving its resources and performing secure routing among nodes. Therefore, it is essential to develop an effective secure routing protocol to protect the nodes from anonymous behaviors. Currently, game theory is a tool that analyzes, formulates and solves selfishness issues. It is seldom applied to detect malicious behavior in networks. It deals, instead, with the strategic and rational behavior of each node. In our study,we used the dynamic Bayesian signaling game to analyze the strategy profile for regular and malicious nodes. This game also revealed the best actions of individual strategies for each node. Perfect Bayesian equilibrium (PBE) provides a prominent solution for signaling games to solve incomplete information by combining strategies and payoff of players that constitute equilibrium. Using PBE strategies of nodes are private information of regular and malicious nodes. Regular nodes should be cooperative during routing and update their payoff, while malicious nodes take sophisticated risks by evaluating their risk of being identified to decide when to decline. This approach minimizes the utility of malicious nodes and it motivates better cooperation between nodes by using the reputation system. Regular nodes monitor continuously to evaluate their neighbors using belief updating systems of the Bayes rule.

• 전자공학회논문지
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• 제50권10호
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• pp.50-64
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• 2013

클러스터 구조를 가진 센서 네트워크에서 클러스터 헤드는 그 멤버들로부터 데이터를 모아서 모아진 데이터를 싱크에 보내는 역할을 수행하기에, 오염된 노드들이 클러스터 헤드 선출에 개입하여 선출결과를 조작하거나 변경하지 못하도록 막아야 한다. 오염된 노드들로부터 클러스터 헤드 선출 과정을 보호하기 위해서는 선출과정의 비예측성, 비조작성, 그리고 일치성을 보존해야 한다. 하지만, 기존의 클러스터 헤드 선출 방법들은 지능화된 오염노드들이 상호 협력을 통해 위의 속성들을 교묘하게 손상시키는 것을 막지 못한다. 본 논문에서는 이러한 지능화된 오염노드들을 식별하고 제거함으로써 클러스터 헤드 선출과정을 보호하는 방법을 제안한다. 클러스터 헤드 선출 라운드 마다 각 멤버는 다른 멤버들의 행위에 따라 그들에게 직접적인 신뢰값을 부여한다. 각 멤버는 자신이 부여한 직접신뢰값과 다른 멤버들에 의해 부여된 간접신뢰값을 묶어서 멤버들의 실제 신뢰값들을 추출한다. 이후에 각 멤버는 추출된 다른 멤버들의 실제 신뢰값을 평가하고 낮은 신뢰값을 가진 멤버들은 클러스터 헤드 후보자에서 제거한다. 이를 통해 제안방법은 다른 경쟁방법에 비해 클러스터 헤드 선출 결과의 비조작성과 일치성을 크게 향상 시킨다. 또한, 제안방법은 메시지 손실이 발생하는 환경에서도 다른 방법들에 비해 높은 비조작성과 일치성을 제공한다.

• Journal of Chest Surgery
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• 제55권5호
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• pp.405-412
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• 2022

Background: Malignant pleural mesothelioma (MPM) is an aggressive pleural malignancy, and despite all multimodal treatment modalities, the 5-year overall survival rate of patients with MPM is less than 20%. In the present study, we aimed to analyze the surgical and prognostic outcomes of patients with MPM who received multimodal treatment. Methods: In this retrospective, single-center study, the records of patients who underwent surgery for MPM between January 2010 and December 2020 at our department were reviewed retrospectively. Results: Sixty-four patients were included in the study, of whom 23 (35.9%) were women and 41 (64.1%) were men. Extrapleural pneumonectomy, pleurectomy/decortication, and extended pleurectomy/decortication procedures were performed in 34.4%, 45.3%, and 20.3% of patients, respectively. The median survival of patients was 21 months, and the 5-year survival rate was 20.2%. Advanced tumor stage (hazard ratio [HR], 1.8; p=0.04), right-sided extrapleural pneumonectomy (HR, 3.1; p=0.02), lymph node metastasis (HR, 1.8; p=0.04), and incomplete multimodal therapy (HR, 1.9; p=0.03) were poor prognostic factors. There was no significant survival difference according to surgical type or histopathological subtype. Conclusion: Multimodal therapy can offer an acceptable survival rate in patients with MPM. Despite its poor reputation in the literature, the survival rate after extrapleural pneumonectomy, especially left-sided, was not as poor as might be expected.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제16권4호
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• pp.1224-1248
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• 2022

In various sensor network applications, such as climate observation organizations, sensor nodes need to collect information from time to time and pass it on to the recipient of information through multiple bounces. According to field tests, this information corresponds to most of the energy use of the sensor hub. Decreasing the measurement of information transmission in sensor networks becomes an important issue.Compression sensing (CS) can reduce the amount of information delivered to the network and reduce traffic load. However, the total number of classification of information delivered using pure CS is still enormous. The hybrid technique for utilizing CS was proposed to diminish the quantity of transmissions in sensor networks.Further the energy productivity is a test task for the sensor nodes. However, in previous studies, a clustering approach using hybrid CS for a sensor network and an explanatory model was used to investigate the relationship between beam size and number of transmissions of hybrid CS technology. It uses efficient data integration techniques for large networks, but leads to clone attacks or attacks. Here, a new algorithm called SBEA (Snowball Endurance Algorithm) was proposed and tested with a bow. Thus, you can extend the battery life of your WSN by running effective copy detection. Often, multiple nodes, called observers, are selected to verify the reliability of the nodes within the network. Personal data from the source centre (e.g. personality and geographical data) is provided to the observer at the optional witness stage. The trust and reputation system is used to find the reliability of data aggregation across the cluster head and cluster nodes. It is also possible to obtain a mechanism to perform sleep and standby procedures to improve the life of the sensor node. The sniffers have been implemented to monitor the energy of the sensor nodes periodically in the sink. The proposed algorithm SBEA (Snowball Endurance Algorithm) is a combination of ERCD protocol and a combined mobility and routing algorithm that can identify the cluster head and adjacent cluster head nodes.This algorithm is used to yield the network life time and the performance of the sensor nodes can be increased.

• 한국전통조경학회지
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• 제32권2호
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• pp.55-67
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• 2014

조선시대 경강 동호지역은 역사와 문화적 요소가 풍부하여 역사문화경관의 명승명소가 많았으나 현대 한강은 자연경관에 비해서 문화성과 역사성이 낮은 것으로 인식되고 있다. 본 연구는 한강이 지니고 있는 역사문화적 요소를 한강의 경관에 적용하고자 조선시대 문화공간의 경관 특성을 린치의 시각적 이미지요소에 적용하여 경관특성을 살펴보았다. 연구결과는 다음과 같다. 동호를 시각적 이미지 요소에 적용했을 때 '통로'로서 높게 인식되었고 가장자리를 의미하는 '경계'의 명료성 또한 동호가 높게 인식되었다. 방향 전환점인 '결절점'은 두모포가 인지도에서 우수하게 나타났다. 린치의 시각적 이미지 요소에서 '랜드마크'를 문화공간에 적용했을 때 경강 동호, 압구정, 제천정이 우월한 인지도를 보임으로써 역사문화경관의 지명도와 명성은 시각적 이미지 요소에 비례하는 것으로 파악되었다. 문화공간의 패턴, 구조, 의미가 명료하고 정체성이 확실할수록 '랜드마크'와 '지역'요소가 높게 인식되었다. 공간의 지명도가 높을수록 역사문화경관의 인지도가 높았다. 그러므로 한강의 역사문화경관 복원 시 시각적 인지도를 고려하여 조사하고 사례연구 함으로써 장소의 복원과 함께 역사성과 문화성에 대한 인지도를 높일 수 있을 것으로 사료된다.