Earticle

본 논문에서는 RISC 프로세서를 이용하여 다양한 센서 정보를 수집하고 효율적인 데이터 전송을 위한 지능형 LED 조명기기 전송제어 시스템 설계를 제안한다. 제안된 방법은 디밍 제어와 점멸을 위해 변환신호를 여러 단계로 구분하도록 처리하여 드라이버로 보내고 변화하는 데이터 패턴을 모니터링 하여 이벤트의 발생을 감지하고 타깃 전달률을 만족시키기 위해 h개의 독립경로를 통해 메시지를 전달한다. 제안한 전송제어 시스템은 큰 에너지 절감 효과를 얻을 수 있고, 안정적이며 효율적인 데이터 전송을 위해 RISC 프로세서의 프로그램을 변경할 수 있게 하였다.

In this paper, we propose intelligent LED lighting device control circuit system is designed in order to collect information on various sensors and efficient data transmit uses RISC processor. In the proposed method, sends to driver for dimming control and blinking to process the end that separated to different levels and detects the occurrence of critical events by monitoring changing data patterns and transmit a message through h-Independent path to satisfy the target-delivery ratio. The proposed transmit control system is large power savings can be obtained and be able to change the program of the RISC processor for data transfer reliable and efficient.

Nodes in mobile networks change position randomly and quickly so modify their attachment point to the network. A most suitable method for handoff in core of the network is MPLS. For MPLS-TE, the most critical issue is LSP configuration. The goal of the routing algorithms in MPLS-TE is resource management and satisfy QoS metrics. The promising new SDN architecture can be a useful help to MPLS-TE due to its good features. This paper introduces a novel and low complexity SDN-MPLS algorithm. The proposed algorithm advances bandwidth-restricted routing as it trade-offs between network load balancing, route length, energy-saving with low complexity in mobile networks.

Wireless sensor networks are susceptible to a variety of network attacks. Due to the limited energy of nodes and selfish nodes in the network, the packet delivery rate is lower. To address these issues, we innovatively propose an energy-harvesting Q-learning secure routing algorithm with authenticated-encryption. The algorithm uses physical unclonable functions and optimized Q-learning to ensure that the transmission path is reliable. Meanwhile, we combine the LSTM-based prediction model to predict the energy value that the nodes replenish. In addition, simulations are performed to compare the performances of the proposed algorithm with other algorithms under different attacks. The proposed algorithm has greater improvements in the packet delivery rate, filtering selfish nodes, and reducing node energy consumption.

이 논문은 IPTV, 원격 교육/건강과 같은 다중 사용자와 인터넷 브로드 캐스팅의 통신을 제공하고 멀티캐스트 라우팅 네트워크의 공유 경로를 구성하는 휴리스틱 알고리즘을 제안 한다. 노드 사이의 최대 지연의 측정, 평균 지연, 지연된 측정은 성능 분석을 위해 도입하였다. 알고리즘 성능의 열거 방법은 최저 지연과 함께 공유된 경로를 찾기 위한 최적된 솔루션을 사용하여 비교하였다. 라우팅 네트워크 하단의 노드들 사이의 지연을 균등하게 분배하고, 다른 알고리즘 보다 지연 추정을 이용한 알고리즘이 우수한 시뮬레이션 결과를 보여준다.

This paper proposes a heuristic algorithm to construct a shared-route in multicast routing networks that provide communications between multi-users such as IPTV, remote educations/health, and internet broadcasting. The measures of maximum delay, average delay, estimated delay between nodes are adopted for performance analysis. The performance of algorithm is compared with the optimal solution in which enumeration method is used to find the shared-route with minimum delay. Under the routing network with the uniformly distributed delay between nodes, the simulation results show that the algorithm using the estimated delay outperforms the other algorithms.

최근 무선 센서 네트워크에서 센서 노드의 에너지 효율성을 향상시켜 네트워크의 수명을 향상시키는 라우팅기법의 연구가 많이 수행되고 있다. 무선 센서 네트워크는 제한된 에너지 및 하드웨어 성능 때문에 배터리, 메모리 및 프로세서 등 모든 자원을 효율적으로 사용해야 하며, 이를 위해 관련 통신 프로토콜도 저-전력 소모를 달성할 수 있도록 설계하고 구현해야 한다. 센서 네트워크에 많이 사용되는 LEACH, HEED등과 같은 클러스터 기반의 라우팅 방식들은 클러스터 헤더들과 해당 멤버 노드들 간의 데이터 전달을 통하여 에너지의 효율성을 얻는다. 이 논문에서는 에너지를 효율적으로 사용할 수 있는 클러스터 라우팅 알고리즘을 제안하고 시뮬레이션을 이용하여 성능 결과를 제시한다.

Recently, a lot of researches have been done to increase the life span of network using the energy efficient sensor node in WSN. In the WSN environment, we must use limited amount of energy and hardware. Ther efore, it is necessary to design energy efficient communication protocol and use limited resources. Cluster b ased routing method such as LEACH and HEED get the energy efficient routing using data communication between cluster head and related member nodes. In this paper, we propose an energy efficient routing algori thm as well as performance result using simulation.

최근 무선 센서 네트워크(WSN : Wireless Sensor Network)에서 센서노드의 에너지 소모를 균등화 하고 효율성을 향상시켜 전제 네트워크의 수명을 최대화하기 위한 다양한 계층적 라우팅 프로토콜들이 제안되고 있다. 특히, 멀티-홉 기법이 향상된 에너지 효율성과 실제 적용 가능한 모델로 많은 각광을 받고 있다. 멀티-홉 기법에서는 센서 노드사이 거리에 따라 전송 에너지를 효율적으로 조절하는 것이 가능하다고 가정한다. 이 논문에서는 대표적인 클러스터 알고리 즘인 LEACH에 대하여 분석하고 이 알고리즘의 단점을 보완하고 에너지를 효율적으로 사용할 수 있는 지역-중앙 클러 스터 라우팅 알고리즘을 제안한다. 제안한 클러스터 라우팅 알고리즘과 LEACH의 성능을 시뮬레이션을 통해 성능을 평가하고 분석하고 NS-2 시뮬레이션을 이용하여 성능 결과를 제시한다.

Recently, lot of researches for the multi-level protocol have been done to balance the sensor node energy consumption of WSN and improve the node efficiency to extend the life of the entire network. Especially in multi-hop protocol, a variety of models have been proposed to improve energy efficiency and apply it to WSN protocol. In this paper, we analyze LEACH algorithm and propose new method based on center of local clustering routing algorithm in wireless sensor networks. We also perform NS-2 simulation to show the performance of our model.

VANET(Vehicular Ad-hoc Network)는 차량 간 네트워크를 구성하는 기술로 전송 노드 기준으로 전송 범위내의 이웃 노드들의 정보를 이용하여 목적지까지의 경로를 설정한다. 지리적 정보를 이용한 기존의 라우팅 프로토콜은 송신 노드 기준으로 중계 노드 및 목적지 노드까지 거리만 고려하기 때문에 통신에 필요한 노드의 밀도가 충분하지 못하면 네트워크 지연 및 단절을 초래할 수 있다. 이러한 문제점을 해결하기 위해 본 논문에서는 도시 기반의 VANET 환경에서 차량 간 안정적인 통신을 위해 구역 기반의 라우팅 알고리즘을 제안한다. 실제 도시 환경을 구역으로 나누고 목적지까지 거리뿐만 아니라 차량 밀도를 고려하여 최적의 통신 환경을 선택함으로써 패킷 손실률을 최소화 하였다. 성능을 평가하기 위해 구현한 결과 기존 연구 결과 보다 우수한 성능 결과를 보였다.

VANET(Vehicular Ad-hoc Network), which is a technology to create a network among vehicles, decides the route to the destination using information of neighbors within the transmission range as transmission nodes. The existing routing protocol which uses geographical information can cause delay and disconnection of the network when the density of nodes is not high enough to communicate because it only considers the distance of the relay nodes or destination nodes from the source nodes. To solve the problem, this dissertation suggests a routing algorithm based on zones for stable communications among vehicles in the environment of VANET. I minimize the packet loss rate by dividing the city environment into zones and taking into account not only the distance of the destination but also the density of vehicles to choose the best communications environment. This results in a better performance than the established research when the performance evaluation is implemented.

운행시간표 기반 대중교통 경로 탐색 알고리즘은 운행계획에 따른 정류장별 출·도착 시각 을 이용하여 최소 이동 시간이 소요되는 단일 경로를 산출한다. 다만, 경로 계산 과정에서 환승 저항, 대안 경로 선택 등의 추가 요소들을 반영하는데 한계가 있다. 본 연구는 환승 저 항 및 다중 경로 탐색이 반영된 개선된 RAPTOR 알고리즘을 제안한다. 환승 저항은 환승 시 점에 적용되며, 교통수단 유형을 구분하여 적용하였다. 본 연구에서는 수도권 대중교통 이용 승객의 실제 이동 경로를 기준으로 개선 전·후의 알고리즘 결과를 분석하였다. 이를 통해 제 시한 알고리즘이 승객의 다양한 경로 선택 기준을 반영한다는 것을 확인하였다.

Schedule-based public transit routing algorithm computes a single route that calculated minimum travel time using the departure and arrival times for each stop according to vehicle operation plan. However, additional factors such as transfer resistance and alternative route choice are not reflected in the path finding process. Therefore, this paper proposes a improved RAPTOR that reflected transfer resistance and multi-path searching. Transfer resistance is applied at the time of transfer and different values can be set according to type of transit mode. In this study, we analyzed the algorithm's before and after results compared with actual route of passengers. It is confirmed that the proposed algorithm reflects the various route selection criteria of passengers.

무선 센서 네트워크에서 에너지 효율성을 높이려는 연구가 많이 진행되어 왔다. 그러나 현재 이루어지고 있는 대부분의 연구는 클러스터 헤드와 싱크 노드들 사이의 직접적인 통신에 바탕을 두고 있다. 앞에서 이루어진 연구들은 노드들 사이의 거리에 따라 에너지를 계산하는 방식에 기초를 두고 있다. 거리에 따라 에너지를 계산하여 알고리즘을 구현하는 것은 어려운 문제가 된다. 이 논문에서는 싱크 노드에서 다른 모든 노드들까지 고정된 전파 파장의 반경을 갖는다단계 라우팅 알고리즘을 제안한다. 이 논문에서는 시뮬레이션을 이용하여 WSN이 에너지를 효율적으로 줄이는 것과WSNdp 활용 방안을 제시한다.

A lot of researches have been done to improve the energy efficiency of Wireless Sensor Networks. But all thecurrent researches are based on the idea of direct communication between cluster head and sink node. Previousresults assume that node can intelligently regulate signal energy according to the distance between nodes. It isdifficult to implement algorithms based on this assumption. We present a multi-level routing algorithm from thesink node to all other nodes which have fixed radio wave radius. We also show the energy saving efficiency andthe implementation in real WSN using the simulation result.

미래의 창의적인 문제해결력을 지닌 인재 양성을 위해, 본 연구는 초등학생들에게 지도하기 어렵고 학생들이 이해하기 힘든 컴퓨터과학원리 중 라우팅알고리즘에 대한 교수․학습방법을 설계해 이를 지도해 보고 이러한 학습내용이 초등학교 학생들이 이해할 수 있는지를 알아보고자 하는데 그 목적이 있다. 사전․사후 동형 검사지를 통해 지적인 영역을 평가하고, 수업 후의 소감문을 통해 정의적인 영역을 평가하였다. 그 결과 네트워크 중 라우팅알고리즘이 초등학생에게 가르쳐질 수 있음을 확인하고 초등학교 컴퓨터교육의 학습요소로서의 가능성을 제시한다.

The purpose of this study is to design and practice teaching and learning method for routing algorithm among computer science principle which is difficult to be taught to elementary school students and understood by students. And we find out whether elementary school students can understand those learning contents. Intellectual area was assessed through equivalent test paper before and after the test and emotional area was assessed through students' impressions after class. The test showed that routing algorithm could be taught to children. Therefore, this study presents the learnability of routing algorithm as a learning element of elementary school computer education.

The large-scale disasters occur to unexpected accidents such as natural disasters(earthquake, typhoon, tsunami, etc.), and human-caused accidents(fire, collapse, terror etc.). Rescue teams perform rescue activities to save many lives in large-scale disaster area. The main purpose of this study is to compose a optimal routing planning for rescue of multiple victims in disaster area. A realistic routing planning with rescue limit time which considers rehabilitation and reconstruction will be suggested in this study. A mathematical programming model and a hybrid genetic algorithm will be suggested to minimize the total spending time. By comparing the result, the suggested algorithm gives a better solution than existing algorithms.

Wireless sensor network (WSN) is a distributed self-organizing network which contains a large number of tiny multi-functional sensor nodes. The network life time is an important issue in WSN because every sensor node has a constraint on electric supply. In this paper, an energy consumption model is described and a GA-based algorithm will be used to optimize the energy consumption by analyzing the working model of sensor nodes. The model will provide an effective reference of working pattern for WSN. This algorithm is evaluated through analysis and simulations.

According to Genetic algorithms principle, the new hybrid evolutionary algorithm (HEA) is proposed in this paper by combining the Immune algorithm, Genetic algorithm and Pareto optimal solutions. The HEA has high convergence precision and improved the diversity of population. Multiple near optimization paths can be developed by the algorithm with multi‐objective restriction, and satisfy to minimize the routing of transportation and the numbers of the vehicles. The HEA has been used to solve the vehicle routing problem, the results of simulation experiment show that the HEA can gain higher global convergence rate and higher speed.

Recently, a multi facility, multi product and multi period industrial problem has been widely investigated in Supply Chain Network(SCN). One of keys issues in the current SCN research area involves minimizing both production and distribution costs. This study deals with finding an optimal solution for minimizing the total cost of production and distribution problems in supply chain network. First, we presented an integrated mathematical model that satisfies the minimum cost in the supply chain. To solve the presented mathematical model, we used a genetic algorithm with an excellent searching ability for complicated solution space. To represent the given model effectively, the matrix based real-number coding schema is used. The difference rate of the objective function value for the termination condition is applied. Computational experimental results show that the real size problems we encountered can be solved within a reasonable time.

Message transmission in opportunistic networks is accomplished via the encounters of mobile nodes while moving around. The distributing of nodes greatly impacts the performance of message delivery ratio due to their sparse encounter opportunities. Nodes with exhaust energy can’t participate in message transfer process. So it is very meaningful to make nodes energetic and balance the energy consumption between nodes. In this paper, a novel dynamic irregular cellular multiple learning automata (DICMLA) model and the corresponding routing algorithm are proposed to optimize the energy consumption of nodes. The proposed routing algorithm utilizes the characteristics of cellular learning automata to reduce the energy consumption of nodes and improve the delivery ratio of message transmission. The simulation results show that the proposed algorithm can obviously balance energy consumption of nodes and thus prolong the lifetime of the network.

본 논문에서는 도시 내부의 통신 인프라가 파괴된 환경에서 DTN(Delay-Tolerant Network) 노드 간 메시지 전송 효율을 향상시키기 위한 라우팅 방법을 제안하였다. 또한 일정 규모의 통신 인프라가 기능을 할 수 없는 상황에서 향상된 노드 간 메시지 전송 과정을 설명하였다. 노드 간 신뢰성 향상을 위한 효과적인 라우팅 방법을 제안하고 DTN 시뮬레이터를 이용하여 평가하였다. 통신 인프라의 파괴로 인한 불확실한 경로 상에서 노드 간 메시지 전송 관계를 고려 하여 도시 지역에서 신뢰성이 개선된 라우팅 알고리즘을 시뮬레이션으로 확인하였다. 노드가 과거에 경험한 모든 접촉 정보를 포함하는 라우팅 알고리즘을 사용하여 통신 인프라가 파괴된 상황의 메시지를 전달 시뮬레이션에서 기존 라우팅 알고리즘 보다 비교적 좋은 결과를 얻을 수 있었다.

In this paper, we propose a routing method to improve the message transmission efficiency between DTN nodes in an environment where communication infrastructure in the city is destroyed. In the situation where a certain size of communication infrastructure can not function, the message transmission process between the nodes is explained. An effective routing method for improving reliability between nodes was proposed and evaluated using DTN simulator. The routing algorithm with improved reliability in urban areas was confirmed by simulation considering the message transmission relationship between nodes on uncertain path due to the destruction of communication infrastructure. We used a routing algorithm that includes all the contact information the node has experienced in the past. In the simulation of delivering messages in a situation where the communication infrastructure was destroyed, relatively better results were obtained than the existing routing algorithm.

The wireless sensor network (WSN), is a type of self-organized distribution system without complex infrastructure requirement. However, WSN’s independence and un-attended usage limit its power supply and life expectancy. These become a critical issue for any WSN implementation. The in-network processing which, intends to minify data volume locally can greatly reduce the energy consumption of data delivery over a long distance to the sink. However, open problems are still remain with in-network processing, such as how to carry out in-network processing, and how to combine routing scheme to the sink (e.g. the long distance delivery). For any WSN application, the following pre-assumption is vital. There exists a physical signal field which bridges physical events to the sensors of WSN, otherwise WSN does not work. In fact, the physical signal field can be depicted by sensory data of all the nodes, and can even be used for local data convergence (e.g. in-network processing). An immediate solution which we propose is that, sensory data of the nodes can be converged to local extremes of the physical signal field along its gradient direction. Furthermore, the physical signal field is integrated with the cost field routing scheme. The cost field routing is in charge of delivering data to the sink. During the in-network processing, the delivery direction is derived by combining linearly the gradient directions of the cost field and physical signal field. Also simulation results show that the proposed schemes are robust, adaptable, and reliable to the variation of physical events.

MRAGA (Multicast Routing Algorithm based on Genetic algorithm) for the Delay-Constrained Minimum-Energy Multicast Routing problem was presented. The genetic operators of this algorithm reduce the transmission delay and energy consumption of multicast trees, thus accelerating the convergence speed of the algorithm. Experiment results show that the multicast tree found by this algorithm not only guarantee the delay constraint, but also has the minimum energy consumption. Furthermore, this algorithm converges quickly.

Recently, shortest path tree construction is essential in network routing. Dijkstra algorithm, one of the static routing algorithms, is widely used. When some links develop new weights, dynamic routing algorithms become more efficient than static routing algorithms. This is because dynamic routing algorithms reduce the redundancy caused by re-computing the affected part of the network in regards to the changed links. However, dynamic routing algorithms are not always efficient in some cases and increase the computation time when making the shortest path tree. In this paper, we present a Hybrid Shortest Path Tree (HSPT) algorithm which reduces the total execution time of shortest path tree computation by using the advantages of both static and dynamic routing algorithms. Comparisons with the other routing algorithms such as Dijkstra, Dynamic Dijkstra and RDSP show that the HSPT algorithm provides a better performance as demonstrated by the decrease in the execution time.

Recent work shows sink mobility can improve the energy efficiency in wireless sensor networks. However, the mobile sink often leads to increasing the energy consumption and routing protocol variation, so support mobile sinks, energy efficient routing protocol is essential. In this light, the Minimum energy consumption relay node is proposed, which plays a import role to broadcasting the estimated sink’s location information to the nodes which take data packets to establish the efficient routing. Meanwhile the periodic broadcast scheme to provide the sink’s location information is broadcast to entire network in order to increase the data packet delivery ratio. The simulation and experiments show that the proposed routing algorithm reduces the energy consumption of the network node, and at the same time keep the network higher data rate.