• 제어로봇시스템학회:학술대회논문집
• /
• 2005.06a
• /
• pp.1938-1943
• /
• 2005

Network human-robot interface is an important research topic. In home application, users access the robotic system directly via voice, gestures or through the network. Users explore a system by using the services provided by this system and to some extend users are enable to participate in a service as partners. A service may be provided by a robot, a group of robots or robots and other network connected systems (distributed sensors, information systems, etc). All these services are done in the network environment, where uncertainty such as the unstable network connection, the availability of the partners in a service, exists. Moreover, these services are controlled by several users, accessing at different time by different methods. Our research aimed at solving this problem to provide a high available level, flexible coordination system. In this paper, a multi-agent framework is proposed. This framework is validated by using our new concept of slave agents, a responsive multi-agent environment, a virtual directory facilitator (VDF), and a task allocation system using contract net protocol. Our system uses a mixed model between distributed and centralized model. It uses a centralized agent management system (AMS) to control the overall system. However, the partners and users may be distributed agents connected to the center through agent communication or centralized at the AMS container using the slave agents to represent the physical agents. The system is able to determine the task allocation for a group of robot working as a team to provide a service. A number of experiments have been conducted successfully in our lab environment using Issac robot, a PDA for user agent and a wireless network system, operated under our multi agent framework control. The experiments show that this framework works well and provides some advantages to existing systems.

• Journal of Institute of Control, Robotics and Systems
• /
• v.20 no.8
• /
• pp.875-881
• /
• 2014

The redundancy resolution of the seven DOF (Degree of Freedom) upper limb exoskeleton is key to the synchronous motion between a robot and a human user. According to the seven DOF human arm model, positioning and orientating the wrist can be completed by multiple arm configurations that results in the non-unique solution to the inverse kinematics. This paper presents analysis on the kinematic and dynamic aspect of the human arm movement and its effect on the redundancy resolution of the seven DOF human arm model. The redundancy of the arm is expressed mathematically by defining the swivel angle. The final form of swivel angle can be represented as a linear combination of two different swivel angles achieved by optimizing two cost functions based on kinematic and dynamic criteria. The kinematic criterion is to maximize the projection of the longest principal axis of the manipulability ellipsoid of the human arm on the vector connecting the wrist and the virtual target on the head region. The dynamic criterion is to minimize the mechanical work done in the joint space for each of two consecutive points along the task space trajectory. The contribution of each criterion on the redundancy was verified by the post processing of experimental data collected with a motion capture system. Results indicate that the bimodal redundancy resolution approach improved the accuracy of the predicted swivel angle. Statistical testing of the dynamic constraint contribution shows that under moderate speeds and no load, the dynamic component of the human arm is not dominant, and it is enough to resolve the redundancy without dynamic constraint for the realtime application.

• Convergence Security Journal
• /
• v.6 no.3
• /
• pp.49-58
• /
• 2006

Currently there are many standards of network management. They are : SNMP (Simple Network Management Protocol-for Internet management), CMIP (Common Management Information Protocol-standardized by ITU-T and ISO), RMON (Remote network MONitoring-for distributed management of the LAN segment), and so on. Especially RMON has created the many concerns in order to manage subnetworks of a large network, but it has negative aspects. For instance, routers or hubs with RMON capability are expensive to a network manager because of adding heavy management cost. Moreover it imposes a heavier burden on network manager, because it must use a network management tool which will be additionally needed with RMON device. This paper proposes a model of PC based RMON Agent system. The RMON Agent system monitors the traffic on LAN segment through the use of a Virtual Device Driver (VxD), based on PC. In term of cost this model will replace the expensive RMON device, and eventually enable a network manager to manage LAN segment more efficiently, due to reduced cost.

• Convergence Security Journal
• /
• v.16 no.7
• /
• pp.21-29
• /
• 2016

Our society is currently exposed to environment of various information that is exchanged real time through networks. Especially regarding medical policy, the government rushes to practice remote medical treatment to improve the quality of medical services for citizens. The remote medical practice requires establishment of medical information based on big data for customized treatment regardless of where patients are. This study suggests establishment of regional medical cluster along with defense and protection cooperation models that in case service availability is harmed, and attacks occur, the attacks can be detected, and proper measures can be taken. For this, the study suggested forming networks with nationwide local government hospitals as regional virtual medical cluster bases by the same medical information system. The study also designed a mutual cooperation security model that can real time cope with IP Spoofing attack that can occur in the medical cluster and DDoS attacks accordingly, so that the limit that sole system and sole security policy have can be overcome.

• Journal of International Society for Simulation Surgery
• /
• v.2 no.2
• /
• pp.90-93
• /
• 2015

The fibula free flap has now become the most reliable and frequently used option for mandible reconstruction. Recently, three dimensional images and printing technologies are applied to mandibular reconstruction. We introduce our recent experience of mandibular reconstruction using three dimensionally planned fibula free flap in a patient with gunshot injury. The defect was virtually reconstructed with three-dimensional image. Because bone fragments are dislocated from original position, relocation was necessary. Fragments are virtually relocated to original position using mirror image of unaffected right side of the mandible. A medical rapid prototyping (MRP) model and cutting guide was made with 3D printer. Titanium reconstruction plate was adapted to the MRP model manually. 7 cm-sized fibula bone flap was designed on left lower leg. After dissection, proximal and distal margin of fibula flap was osteotomized by using three dimensional cutting guide. Segmentation was also done as planned. The fibula bone flap was attached to the inner side of the prebent reconstruction plate and fixed with screws. Postoperative evaluation was done by comparison between preoperative planning and surgical outcome. Although dislocated condyle is still not in ideal position, we can see that reconstruction was done as planned.

• The Bulletin of The Korean Astronomical Society
• /
• v.42 no.2
• /
• pp.61.1-61.1
• /
• 2017

As the application of deep-learning methods has been succeeded in various fields, they have a high potential to be applied to space weather forecasting. Convolutional neural network, one of deep learning methods, is specialized in image recognition. In this study, we apply the AlexNet architecture, which is a winner of Imagenet Large Scale Virtual Recognition Challenge (ILSVRC) 2012, to the forecast of daily solar flare occurrence using the MatConvNet software of MATLAB. Our input images are SOHO/MDI, EIT $195{\AA}$, and $304{\AA}$ from January 1996 to December 2010, and output ones are yes or no of flare occurrence. We consider other input images which consist of last two images and their difference image. We select training dataset from Jan 1996 to Dec 2000 and from Jan 2003 to Dec 2008. Testing dataset is chosen from Jan 2001 to Dec 2002 and from Jan 2009 to Dec 2010 in order to consider the solar cycle effect. In training dataset, we randomly select one fifth of training data for validation dataset to avoid the over-fitting problem. Our model successfully forecasts the flare occurrence with about 0.90 probability of detection (POD) for common flares (C-, M-, and X-class). While POD of major flares (M- and X-class) forecasting is 0.96, false alarm rate (FAR) also scores relatively high(0.60). We also present several statistical parameters such as critical success index (CSI) and true skill statistics (TSS). All statistical parameters do not strongly depend on the number of input data sets. Our model can immediately be applied to automatic forecasting service when image data are available.

• Journal of the Institute of Electronics Engineers of Korea CI
• /
• v.47 no.1
• /
• pp.116-122
• /
• 2010

As the importance of HCI(Human-Computer Interface) caused by dramatically developed computer technology is getting high, the requirement for the design of human friendly systems is also getting high. First of all, the personality and Emotional factor should be considered for implementing more human friendly systems. Many studies on Knowledge, Emotion and personality have been made, but the combined methods connecting these three factors is not so many investigated yet. It is known that memorizing process includes not only knowledge but also the emotion and the emotion state has much effects on the process of reasoning and decision making step. Accordingly, for implementing more human friendly efficient sophisticated intelligent system, the system considering these three factors should be modeled and designed. In this paper, knowledge-emotion reaction model was designed. Five types are defined for representing the personality and emotion reaction mechanism calculating emotion vector based on the extracted Thought threads by Type matching selection was proposed. This system is applied to the virtual memory and its emotional reactions are simulated.

• Journal of KIISE
• /
• v.42 no.11
• /
• pp.1361-1371
• /
• 2015

Depending on the increase amongst various cloud services, the technology of the Cloud Service Broker (CSB) to find the most appropriate services to meet the needs of cloud service consumers has emerged. In order to advance for cloud services to be used through the CSB, it is important to ensure the quality level that meets the demands of consumers through a negotiation process based on the Service Level Agreement (SLA). However, quality metrics of cloud services are different from each other based on the measurement scale, which represents the quality level, and the calculation for each type of cloud services. Therefore, it is necessary to analyze the variability of the quality of cloud services and establish a SLA model for ensuring and improving the level of quality. In this paper, we analyze the quality metrics for the specific type of cloud services by applying the cross-cutting concept and propose a Virtual SLA (VSLA) meta-model.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.18 no.1
• /
• pp.10-17
• /
• 2013

In this paper, a new active damping method of LCL filter without capacitor voltage sensors is proposed for 3 phase PWM Inverter. Normally, L filter or LCL filter is used as an output filter of grid connected PWM inverter. An LCL filter has more excellent performance than L filter to reduce harmonic current, so the small inductance value can be used. However, the resonance problem in LCL filter is happen due to the zero impedance by the addition of LC branch. To solve the resonance problem, the various active damping method has been proposed so far. Generally, the virtual resistor active damping methods is required to additional hardware sensors for measurement of capacitor voltage and current. In this paper, the new active damping method is proposed without any capacitor voltage or current sensors. In the proposed method, the resonance component of the capacitor voltage of LCL filter can be observed by a simple MRAS(Model Reference Adaptive System) observer without additional hardware sensors, and this component is suppressed by feedforward compensation. The validity of the proposed method is proven by simulation and experiment on the 3-phase PWM inverter system.

• Journal of Energy Engineering
• /
• v.16 no.3
• /
• pp.93-102
• /
• 2007

This paper presents a scenario evaluation model of the AHP (Analytic Hierarchy Process) to evaluate dismantling scenarios considering quantitative and qualitative considerations. And decommissioning information producing modules which can obtain a dismantling schedule, quantify radioactive waste, visualize a radioactive inventory, estimate a decommissioning cost, and estimate a worker's exposure was developed to assess qualitatively decommissioning information. The digital mock-up (DMU) system was developed to verify dismantling processes and find error of scenarios in virtual space. It combines and manages the decommissioning information producing modules, the decommissioning DB, and the dismantling evaluation module synthetically. By using AHP model and DMU system, the thermal column in KRR-1 was evaluated on plasma arc cutting scenario and nibbler cutting scenario using the developed decommissioning DMU system.