• 설비공학논문집
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• 제25권7호
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• pp.398-405
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• 2013

Small and medium-size buildings employ a multi-distributed individual air-conditioning system that utilizes package air conditioners instead of centralized cooling systems, which can allow easier building management and maintenance, along with a diversification of facility use. Inverter driven system heat pumps have been developed to achieve not only an easy distribution control, allowing free combination of indoor units with different models and different capacities, but also wide applications to intelligent air conditioning. However, the control algorithms of the system heat pump are limited in the open literature, due to complicated operating conditions. In this paper, an inverter-driven system heat pump having two indoor units with electronic expansion valves (EEV) was simulated in the cooling mode. An integral optimum regulating controller employing the state space control method was also simulated, and applied to the system-heat pump system, to obtain efficient control of the MIMO (multi input multi output) system. The simulation model for the controller yielded satisfactory prediction results. The new control model can be successfully utilized as a basic tool in controller design.

• 한국정보통신학회논문지
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• 제9권5호
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• pp.1142-1148
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• 2005

본 논문에서는 클라이언트들의 작업부하를 분산하기 위한 측정 알고리즘을 제안하였다. 이 알고리즘은 작업들이 재배치되는 것을 허용할 때, 송신자가 수신자에게 요청한 처리량만큼 적절하게 전송하여야 한다. 이 양은 송신자와 수신자의 협상 과정에서 동적으로 결정된다. 전송하여야 할 작업량을 결정할 때 전송 노드는 수신하는 다른 노드들의 처리 속도를 포함하여 송신 노드와 수신 노드의 현재 부하상태, 재배치하기에 적절한 작업의 처리 요구량 등의 요소들을 고려하여야 한다. 이러한 분석에 근거하여 이기종 분산 웹서버 시스템에 적합한 새로운 알고리즘을 제안하고, 기존 알고리즘과의 성능을 비교하였다. 시뮬레이션을 통하여 본 논문에서 제안한 알고리즘이 CPU 이용율과 응답시간에서 성능의 개선을 보였다.

• 대한전기학회논문지:전력기술부문A
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• 제55권9호
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• pp.376-383
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• 2006

In this paper, autonomous information exchange methodology is studied between IEDs using SOAP protocol based on XML and PtP communication to archive the safety and reliability of large-scale system operation. The SOAP protocol has the advantages in the independency Problem for operating systems, using language, platforms and the security problem because it is XML-based RPC protocol. Inference-based solution of the IED is designed as rule-based solution so that the IED internal status, the system status or the faulted zone can be inferred autonomously using the internal data as well as information data obtained from free information exchange among other IEDS, Also, it is designed so that the inference results and the operation information are transmitted to the above SCADA system, and determined autonomously whether the commands from the SCADA are executed or not. Finally, The inference-based solution of IED and information exchange system among IEDS is implemented using MS Visual C++ MFC, MS SOAP and MS XML. Availability and accuracy of the proposed methodology and the design is verified from diversity simulation reviews for typical distribution substation.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권7호
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• pp.3150-3170
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• 2016

In Intelligent Transportation Systems (ITS), logistics distribution and mobile e-commerce, the real-time, accurate and reliable vehicle trajectory prediction has significant application value. Vehicle trajectory prediction can not only provide accurate location-based services, but also can monitor and predict traffic situation in advance, and then further recommend the optimal route for users. In this paper, firstly, we mine the double layers of hidden states of vehicle historical trajectories, and then determine the parameters of HMM (hidden Markov model) by historical data. Secondly, we adopt Viterbi algorithm to seek the double layers hidden states sequences corresponding to the just driven trajectory. Finally, we propose a new algorithm (DHMTP) for vehicle trajectory prediction based on the hidden Markov model of double layers hidden states, and predict the nearest neighbor unit of location information of the next k stages. The experimental results demonstrate that the prediction accuracy of the proposed algorithm is increased by 18.3% compared with TPMO algorithm and increased by 23.1% compared with Naive algorithm in aspect of predicting the next k phases' trajectories, especially when traffic flow is greater, such as this time from weekday morning to evening. Moreover, the time performance of DHMTP algorithm is also clearly improved compared with TPMO algorithm.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권8호
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• pp.2948-2963
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• 2015

In the field of computer vision, visual surveillance systems have recently become an important research topic. Growth in this area is being driven by both the increase in the availability of inexpensive computing devices and image sensors as well as the general inefficiency of manual surveillance and monitoring. In particular, the ultimate goal for many visual surveillance systems is to provide automatic activity recognition for events at a given site. A higher level of understanding of these activities requires certain lower-level computer vision tasks to be performed. So in this paper, we propose an intelligent activity recognition model that uses a structure learning method and a classification method. The structure learning method is provided as a K2-learning algorithm that generates Bayesian networks of causal relationships between sensors for a given activity. The statistical characteristics of the sensor values and the topological characteristics of the generated graphs are learned for each activity, and then a neural network is designed to classify the current activity according to the features extracted from the multiple sensor values that have been collected. Finally, the proposed method is implemented and tested by using PETS2013 benchmark data.

• 대한디지털의료영상학회논문지
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• 제6권1호
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• pp.51-64
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• 2003

This thesis describes the effective interfacing methods of PACS Modality based on the system installation andoperating experiences. PACS(Picture Archiving and Communication Systems) is a system for medical image archiving and communication using large storage device and high-speed network. The standard communication protocol of PACS is DICOM(Digital Imaging and Communication in Medicine) based on TCP/IP and point-to-point protocol. However, there are many Non-DICOM Modalities and DICOM Modalities having problems. First, we had interfaced almost modalities. Fuji CR, GE CT, MRI, Angio, Fluoro, Phillips Angio, Shimadzu Fluoro. Ultrasound PACS, with the main PACS in the Seoul S Hospital as large scale hospital. And we manipulated the intelligent image distribution and the CT. MRI Interfaces never experienced beforein the Anyang J Hospital and the Chungju C Hospital as mid or small scale hospital. Technically, we developed both the DICOM Interface and the Non-DICOM Interface. At the last, the DICOM Worklist and the DICOM Print Interface were implemented in the Seoul B Hospital, the Bucheon SJ Hospital and the Seoul K Hospital independently with PACS. The Oracle, Sybase and MS-SQL are used as database, and UNIX, Macintosh, MS Windows as operating systems. And the Visual C++ and UNIX C are the main programming tools. We have used UTP, coaxial and fiber optic cable under 10/100 mbps LAN for networking.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권11호
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• pp.5574-5591
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• 2017

Inspired by the idea of Artificial Immune System, many researches of wireless sensor network (WSN) intrusion detection is based on the artificial intelligent system (AIS). However, a large number of generated detectors, black hole, overlap problem of NSA have impeded further used in WSN. In order to improve the anomaly detection performance for WSN, detector generation mechanism need to be improved. Therefore, in this paper, a Differential Evolution Constraint Multi-objective Optimization Problem based Negative Selection Algorithm (DE-CMOP based NSA) is proposed to optimize the distribution and effectiveness of the detector. By combining the constraint handling and multi-objective optimization technique, the algorithm is able to generate the detector set with maximized coverage of non-self space and minimized overlap among detectors. By employing differential evolution, the algorithm can reduce the black hole effectively. The experiment results show that our proposed scheme provides improved NSA algorithm in-terms, the detectors generated by the DE-CMOP based NSA more uniform with less overlap and minimum black hole, thus effectively improves the intrusion detection performance. At the same time, the new algorithm reduces the number of detectors which reduces the complexity of detection phase. Thus, this makes it suitable for intrusion detection in WSN.

• Smart Structures and Systems
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• 제9권5호
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• pp.427-439
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• 2012

The present paper deals with the analytical solution of a functionally graded piezoelectric (FGP) cylinder in the magnetic field under mechanical, thermal and electrical loads. All mechanical, thermal and electrical properties except Poisson ratio can be varied continuously and gradually along the thickness direction of the cylinder based on a power function. The cylinder is assumed to be axisymmetric. Steady state heat transfer equation is solved by considering the appropriate boundary conditions. Using Maxwell electro dynamic equation and assumed magnetic field along the axis of the cylinder, Lorentz's force due to magnetic field is evaluated for non homogenous state. This force can be employed as a body force in the equilibrium equation. Equilibrium and Maxwell equations are two fundamental equations for analysis of the problem. Comprehensive solution of Maxwell equation is considered in the present paper for general states of non homogeneity. Solution of governing equations may be obtained using solution of the characteristic equation of the system. Achieved results indicate that with increasing the non homogenous index, different mechanical and electrical components present different behaviors along the thickness direction. FGP can control the distribution of the mechanical and electrical components in various structures with good precision. For intelligent properties of functionally graded piezoelectric materials, these materials can be used as an actuator, sensor or a component of piezo motor in electromechanical systems.

• Smart Structures and Systems
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• 제5권3호
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• pp.241-260
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• 2009

Shape control of flexible structures using piezoelectric materials has attracted much attention due to its wide applications in controllable systems such as space and aeronautical engineering. The major work in the field is to find a best control voltage or an optimal placement of the piezoelectric actuators in order to actuate the structure shape as close as possible to the desired one. The current research focus on the investigation of static shape control of intelligent shells using spatially distributed piezoelectric curve beam actuators. The finite element formulation of the piezoelectric model is briefly described. The piezoelectric curve beam element is then integrated into a collocated host shell element by using nodal displacement constraint equations. The linear least square method (LLSM) is employed to get the optimum voltage distributions in the control system so that the desired structure shape can be well matched. Furthermore, to find the optimal placement of the piezoelectric curve beam actuators, a genetic algorithm (GA) is introduced in the computation model as well as the consideration of the different objective functions. Numerical results are given to demonstrate the validity of the theoretical model and numerical algorithm developed.

• 대한디지털의료영상학회논문지
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• 제5권1호
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• pp.46-63
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• 2002

This thesis describes the effective interfacing methods of PACS Modality based on the system installation and operating experiences. PACS(Picture Archiving and Communication Systems) is a system for medical image archiving and communication using large storage device and high-speed network. The standard communication protocol of PACS is DICOM(Digital Imaging and Communication in Medicine) based on TCP/IP and point-to-point protocol. However, there are many Non-DICOM Modalities and DICOM Modalities having problems. First, we had interfaced almost modalities, Fuji CR, GE CT, MRI, Angio, Fluoro, Phillips Angio, Shimadzu Fluoro, Ultrasound PACS, with the main PACS in the Seoul S Hospital as large scale hospital. And we manipulated the intelligent image distribution and the CT, MRI Interfaces never experienced before in the Anyang J Hospital and the Chungju C Hospital as mid or small scale hospital. Technically, we developed both the DICOM Interface and the Non-DICOM Interface. At the last, the DICOM Worklist and the DICOM Print Interface were implemented in the Seoul B Hospital, the Bucheon SJ Hospital and the Seoul K Hospital independently with PACS. The Oracle, Sybase and MS-SQL are used as database, and UNIX, Macintosh, MS Windows as operating systems. And the Visual C++ and UNIX C are the main programming tools. We have used UTP, coaxial and fiber optic Gable under 10/100 mbps LAN for networking.