• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.9 no.5
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• pp.1-6
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• 2009

MANET(Mobile Ad-hoc NETwork), a network characterized that its moving nodes freely constructs Network topology, has other different characteristics. Because Policy based Network Management in MANET guarantees QoS between nodes, it is essential in applied areas like VANET which targets safety and convenience. In this paper, we use COPS-PR which is appropriate Policy Exchange Protocol for MANET, and implement DiffServ-based QoS in the real networks and experiment its capability.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.10 no.6
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• pp.47-53
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• 2010

The paper presents a method for decision the optimal cycle time during the vehicle traffic control in single intersection with AHP. To solve this uncertainty optimization problem, the optimization index in the form of linear addition and fuzzy measurement is assumed and fuzzy integral is used. Examples of solution for two cases of optimal cycle time in two traffic controller are presented and compared.

• The Journal of the Korea institute of electronic communication sciences
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• v.4 no.3
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• pp.243-246
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• 2009

A cluster-based routing with a hierachical structure for continuous query stream ubiquitous sensor network is proposed in this paper. the proposed method realizes high energy-efficiency by using a head-set instead of head for transmitting node-messages to a base station. By using head-set, the method make network lifetime increased.

• ETRI Journal
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• v.34 no.6
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• pp.922-931
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• 2012

With the increasing demands for mobile wireless sensor networks in recent years, designing an energy-efficient clustering and routing protocol has become very important. This paper provides an analytical model to evaluate the power consumption of a mobile sensor node. Based on this, a clustering algorithm is designed to optimize the energy efficiency during cluster head formation. A genetic algorithm technique is employed to find the near-optimal threshold for residual energy below which a node has to give up its role of being the cluster head. This clustering algorithm along with a hybrid routing concept is applied as the near-optimal energy-efficient routing technique to increase the overall efficiency of the network. Compared to the mobile low energy adaptive clustering hierarchy protocol, the simulation studies reveal that the energy-efficient routing technique produces a longer network lifetime and achieves better energy efficiency.

• Journal of Information Technology Services
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• v.12 no.4
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• pp.145-164
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• 2013

With the rapidly expanding social network service, the distribution of information shows that social networks have evolved into platforms of communication and new information sharing among users. Previous studies are focused on the motivational factors of information sharing through social networking service. However, in this study, we focus on the factors that affect intention to share information in terms of both user's psychological motivation and functional characteristics of social network service. This study shows that factors such as enjoyfulness, image, identity and communication positively affect the attitude and intention of information sharing.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.05a
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• pp.232-234
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• 2012

NMEA2000 international standards was developed for real-time communication among sensors and devices in ships. This paper describes analysis of NMEA2000 network protocols and implementation of a gateway for wireless data services in NMEA2000 networks. For scalability of the network, developed gateway didn't participate in NMEA2000 network but simply relayed data between wireless devices and the network.

• 한국HCI학회:학술대회논문집
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• 2006.02a
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• pp.753-759
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• 2006

햅틱인터페이스 기술을 이용하면 가상물체의 형태를 만져보고 느껴볼 수 있다. 물체마다 다른 수학적 마찰력 모델을 적용하여 실감있는 마찰력 표현도 가능하다. 그러나 각 물체에 해당하는 마찰력 모델을 선정하는 것과 적절한 마찰계수 등을 반복적 실험을 통하여 알아내는 것은 쉽지 않다. 실제 물체의 마찰력이 알려진 마찰력 모델과 다르다면 수학적 모델로 표현할 수 없는 경우도 있다. 본 논문에서는 신경회로망 학습을 이용하여 마찰력 모델의 선택이나 마찰계수 등을 정하는 과정 없이 실제 물체의 마찰력을 표현하는 방법을 제시하고 있다. 상용 햅틱인터페이스 장치인 PHANToM 2 대를 이용하여 마찰력 획득 시스템을 구성하고 고무판, 종이 등의 물체 표면에서의 속도와 물체에 작용하는 힘을 획득하여 가공한 데이터를 입력 및 출력으로 갖는 신경회로망을 통해 학습시킨 후 OpenGL로 구현한 가상물체에 적용하여 보았다. Force/Torque 센서를 사용하지 못한 일부 문제가 있었으나 예상보다 사실적인 마찰력을 표현할 수 있었다.

• ETRI Journal
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• v.42 no.1
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• pp.36-45
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• 2020

A priority-based data communication approach, developed by employing cognitive radio capacity for sensor nodes in a wireless terrestrial sensor network (TSN), has been proposed. Data sensed by a sensor node-an unlicensed user-were prioritized, taking sensed data importance into account. For data of equal priority, a first come first serve algorithm was used. Non-preemptive priority scheduling was adopted, in order not to interrupt any ongoing transmissions. Licensed users used a nonpersistent, slotted, carrier sense multiple access (CSMA) technique, while unlicensed sensor nodes used a nonpersistent CSMA technique for lossless data transmission, in an energy-restricted, TSN environment. Depending on the analytical model, the proposed wireless TSN environment was simulated using Riverbed software, and to analyze sensor network performance, delay, energy, and throughput parameters were examined. Evaluating the proposed approach showed that the average delay for sensed, high priority data was significantly reduced, indicating that maximum throughput had been achieved using wireless sensor nodes with cognitive radio capacity.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.1897-1900
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• 2004

In recent years, a lot of industrial equipments have serial communication channel such as FieldBus (CAN, Profibus, etc.) or Ethernet that provides real time communication between industrial equipments. Theses applications include gantry crane, robot, chip mounter, etc.. In this paper, we discuss the synchronization technique for networked multi-motor systems where controllers (commercial servo amps) are distributed and interconnected by CAN (Controller Area Networks). We first describe the equivalent model for the individual servo-amp and motor using the frequency response. We design the $H{\infty}$ controller for motion synchronization. Finally, the synchronization technique using the equivalent model and the $H{\infty}$ controller is verified by the simulation and the experiment.

• International Journal of Internet, Broadcasting and Communication
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• v.12 no.4
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• pp.33-41
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• 2020

Nowadays, distributed mobility management (DMM) approaches have been widely adopted to address the limitations of centralized architectural methods to support seamless data transmission schemes in wireless sensor networks. This paper deals with the end-to-end (E2E) integration of Network Mobility (NEMO) basic support protocol in distributed wireless sensor network systems in structural health and environmental monitoring of social overhead capital (SOC) public infrastructures such as bridges, national highways, tunnels, and railroads. The proposed scheme takes advantage of the features of both the NEMO basic support protocol and partially distributed network-based DMM framework in providing seamless data transmission and robust mobility support. The E2E seamless data transmission scheme allows mobile users to roam from fixed-point network access locations and mobile platforms (i.e., vehicles such as cars, buses, and trains) without disconnecting its current sessions (i.e., seamless handover).