• Nuclear Engineering and Technology
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• v.54 no.6
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• pp.2107-2119
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• 2022

Accurate remaining useful life (RUL) prediction for critical components of nuclear power equipment is an important way to realize aging management of nuclear power equipment. The electric gate valve is one of the most safety-critical and widely distributed mechanical equipment in nuclear power installations. However, the electric gate valve's extended service in nuclear installations causes aging and degradation induced by crack propagation and leakages. Hence, it is necessary to develop a robust RUL prediction method to evaluate its operating state. Although the particle filter(PF) algorithm and its variants can deal with this nonlinear problem effectively, they suffer from severe particle degeneracy and depletion, which leads to its sub-optimal performance. In this study, we combined the whale algorithm with regularized particle filtering(RPF) to rationalize the particle distribution before resampling, so as to solve the problem of particle degradation, and for valve RUL prediction. The valve's crack propagation is studied using the RPF approach, which takes the Paris Law as a condition function. The crack growth is observed and updated using the root-mean-square (RMS) signal collected from the acoustic emission sensor. At the same time, the proposed method is compared with other optimization algorithms, such as particle swarm optimization algorithm, and verified by the realistic valve aging experimental data. The conclusion shows that the proposed method can effectively predict and analyze the typical valve degradation patterns.

• Journal of Digital Convergence
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• v.10 no.9
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• pp.363-368
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• 2012

The Cluster-based routing protocol is consumed the energy consumption efficiently, but there are many isolated nodes while clustering, so these are impeding energy efficiency. Hop-by-hop based routing protocol is suitable large-scaled network or dynamic environment. However, with the periodic flooding signal and rapid energy loss of near sink nodes, the network life time become shorter. In this paper, We propose the hybrid routing protocol that combine the cluster based routing method for energy efficiency of nodes and hop-by-hop method for re-joining the isolated nodes and load balance of nodes in the near cluster using fibonacci sequence. Based on the analysis, it is proved that the hybrid routing protocol provided higher energy efficiency and less the isolated nodes than previous methods.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.44 no.1
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• pp.113-121
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• 2007

Commonly, in the Sensor Network that composed with multiple nodes uses Ad-hoc protocol to communicate each other. Each sensed data packets are collected by base node and processed by Host PC. But the Ad-hoc protocol is too vulnerable to Sinkhole attack, where the intruder attracts surrounding nodes with unfaithful routing information, and then performs selective forwarding or changes the data passing through it. The Sinkhole attack increases overhead over the network and boosts energy consumption speed to decrease network's life time. Since the other attacks can be easily adopted through sinkhole attack, the countermeasure must be considered carefully. In this paper, we proposed the Hop-depth algorithm that detects intruder in Sinkhole attack and colluded nodes. First, the proposed algorithm makes list of suspected nodes and identifies the real intruder in the suspected node list through the Hop-depth count value. And recalculates colluder's path information to find the real intruder. We evaluated the performance of the proposed algorithm using NS2. We compared and analyzed the success ratio of finding real intruder, false positive ratio, false negative ratio, and energy consumption.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.4
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• pp.51-56
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• 2012

Nowadays, For that reason, the tactical training system that were applied to recruit training center and police training, a real-life survivor game place is a drill using conventional training methods that there is no special training system at open terrain and field, there is no training accomplishment in conformity with battlefield situation portrayal. Therefore, this paper developed the tactical training evaluation system and real-time monitoring system that is compensated the defect and controlled sensing, interlock with PC as wireless a way of GUI using PCB mounted MICOM. This system evaluate drill that regulate sensor control module, tactical training system remotely according to what they should do, is installed to fit the occasion as to be reflected or transmission choosingly and is a 24V H/W drive module.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2009.01a
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• pp.709-713
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• 2009

Recently, a lot of research that applies data acquired from devices such as cameras and RFIDs to context aware services is being performed in the field on Life-Log and the sensor network. A variety of analytical techniques has been proposed to recognize various information from the raw data because video and audio data include a larger volume of information than other sensor data. However, manually watching a huge amount of media data again has been necessary to create supervised data for the update of a class or the addition of a new class because these techniques generally use supervised learning. Therefore, the problem was that applications were able to use only recognition function based on fixed supervised data in most cases. Then, we proposed a method of acquiring supervised data from a video sharing site where users give comments on any video scene because those sites are remarkably popular and, therefore, many comments are generated. In the first step of this method, words with a high utility value are extracted by filtering the comment about the video. Second, the set of feature data in the time series is calculated by applying functions, which extract various feature data, to media data. Finally, our learning system calculates the correlation coefficient by using the above-mentioned two kinds of data, and the correlation coefficient is stored in the DB of the system. Various other applications contain a recognition function that is used to generate collective intelligence based on Web comments, by applying this correlation coefficient to new media data. In addition, flexible recognition that adjusts to a new object becomes possible by regularly acquiring and learning both media data and comments from a video sharing site while reducing work by manual operation. As a result, recognition of not only the name of the seen object but also indirect information, e.g. the impression or the action toward the object, was enabled.

• Journal of the Institute of Convergence Signal Processing
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• v.19 no.1
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• pp.14-19
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• 2018

Recently, the smart health care industry has been rising rapidly and interest and efforts for public health have been greatly increased. As a result, the public does not visit medical specialists and medical facilities, but the desire to check their health condition in everyday life is increased. Therefore, many domestic and foreign companies continuously research and develop wearable devices that can measure body activity information anytime and anywhere And the market. Especially, it is used for heart activity measurement device using pulse wave sensor and electrocardiogram sensor. However, in this study, a monitoring system that can detect cardiac activity using cardiac sounds, heart sound measurement rather than pulse wave measurement and electrocardiogram measurement, was performed and its performance was evaluated. Experimental results confirmed the predictability of cardiac heart rate and heart valve disease during daily living.

• Journal of Digital Contents Society
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• v.16 no.1
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• pp.97-104
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• 2015

The conventional 1 Hall sensor-type water gauge has some defects that it can not detect counterflow and low-speed flow of water, and it also generates power consumption during even sleep mode. In this paper, a low-power consumption wireless digital remote water gauge with a counterflow detection capability is proposed. The proposed water gauge detects the direction and amount of water flow by using the three Hall sensors placed at $120^{\circ}$ intervals with 8-year national standard life durability. The water gauge with three Hall sensors works without error regardless of water speed does not generate power dissipation during sleep mode by presented reading algorithm for bew water gauge. The proposed water gauge is designed to send its ID, current time and counting value to repeater or central control center with specified frequency by RF Module.

• The Journal of the Korea institute of electronic communication sciences
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• v.5 no.2
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• pp.221-226
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• 2010

Ubiquitous computing is technology that provides services appropriate for the user. At places where environmental and situational context are relevant in making the determination of what services are appropriate, there are sensor nodes installed, which automatically collect, manage and control environmental information. In this computing environment, in order to meet the requirements of services provided to users, a context awareness system is needed for context awareness processing. In this thesis, using RFID/USN sensors, the context of a user entering and leaving an area was produced, and the user's identification information was received via the RFID reader and antenna. At the same time, to decide whether or not to allow access for the user, a distance sensor node was installed to collect context data. Based on this, a system that provides practical services needed in real life for users was designed and implemented. The context of a user entering an area was produced, which the system recognized and provided appropriate services for the user.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.4C
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• pp.338-346
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• 2012

Wireless sensor network (WSN) technology provides a variety of medical and healthcare solutions to assist detection and communication of body conditions. However, data reliability inside WSN might be influenced to healthcare routing protocol due to limited hardware resources of computer, storage, and communication bandwidth. For this reason, we have conducted various wireless communication experiments between nodes using parameters such as RF strength, battery status, and deployment status to get a optimal performance of mobile healthcare routing protocol. This experiment may also extend the life time of the nodes. Performance analysis is done to obtain some important parameters in terms of distance and reception rate between the nodes. Our experiment results show optimal distance between nodes according to battery status and RF strength, or deployment status and RF strength. The packet reception rate according to deployment status and RF strength of nodes was also checked. Based on this performance evaluation, the optimized sensor node battery and deployment in the developed our mobile healthcare routing protocol were proposed.

• Korean Institute of Interior Design Journal
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• v.21 no.3
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• pp.50-57
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• 2012

In Ubiquitous era. architecture is not the old building adapting ubiquitous technology. In order to take the role as new architectural paradigm in space, environment and technology, it has to develop technology continuously and experimental architecture at the same time. it must have co-evolution of architectural field and others through organic network. by that, the evolution of space will be in the way that combines space which is responded to human emotion and user-centric human-friendly. It will be the new paradigm of Ubiquitous digital space. Digital technology resulted in a change to a society as well as to the life of human and its way of thinking. Due to those changes, new terms or concepts come out and a new meaning is added to the conventional concepts. This aims to examine type of spatial contexts for interaction design experience. This study is performed through Literature research for theory by interactive space and case studies for construction elements to design. The range of case study is limited to interaction space in addition of interactive elements and user interface. And analysis conclusion is show the many type, First, Interactive space has special purpose for make a interaction by intelligent elements.(sensor, program, algorithm, New-technology) Second, Interactive space was cooperation with various professional for space purpose. Third. Interactive space is self-develop by algorithm, program, sensor network and that is harmonize with user. finally. Interaction space is show the temper elements about allness, metastatic, activeness, liquidity, relationship. That was written by ecological theory.