• Journal of Biomedical Engineering Research
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• v.10 no.2
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• pp.117-124
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• 1989

The intelligent trajectory control method that controls moving direction and average velocity for a prosthetic arm is proposed by pattern recognition and force estimations using EMG signals. Also, we propose the real time trajectory planning method which generates continuous accelleration paths using 3 stage linear filters to minimize the impact to human body induced by arm motions and to reduce the muscle fatigue. We use combination of MLP and fuzzy filter for pattern recognition to estimate the direction of a muscle and Hogan`s method for the force estimation. EMG signals are acquired by using a amputation simulator and 2 dimensional joystick motion. The simulation results of proposed prosthetic arm control system using the EMf signals show that the arm is effectively followed the desired trajectory depended on estimated force and direction of muscle movements.

• Journal of Microbiology and Biotechnology
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• v.15 no.3
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• pp.551-559
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• 2005

The recent rapid increase in genomic data related to many microorganisms and the development of computational tools to accurately analyze large amounts of data have enabled us to design several kinds of simulation approaches for the complex behaviors of cells. Among these approaches, dFBA (dynamic flux balance analysis), which utilizes FBA, differential equations, and regulatory events, has correctly predicted cellular behaviors under given environmental conditions. However, until now, dFBA has centered on substrate concentration, cell growth, and gene on/off, but a detailed hierarchical structure of a regulatory network has not been taken into account. The use of Boolean rules for regulatory events in dFBA has limited the representation of interactions between specific regulatory proteins and genes and the whole transcriptional regulation mechanism with environmental change. In this paper, we adopted the operon as the basic structure, constructed a hierarchical structure for a regulatory network with defined fundamental symbols, and introduced a weight between symbols in order to solve the above problems. Finally, the total control mechanism of regulatory elements (operons, genes, effectors, etc.) with time was simulated through the linkage of dFBA with regulatory network modeling. The lac operon, trp operon, and tna operon in the central metabolic network of E. coli were chosen as the basic models for control patterns. The suggested modeling method in this study can be adopted as a basic framework to describe other transcriptional regulations, and provide biologists and engineers with useful information on transcriptional regulation mechanisms under extracellular environmental change.

• Journal of Digital Contents Society
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• v.16 no.3
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• pp.417-424
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• 2015

The research of occupational injury for safety and health is a comparatively recent occurrence. As labor activities took place regarding to employee concerns in industrial uprising, human resources health was tried to enhanced as a labor safety subject. Noticing that traditional statistics approach has limitations in learning future forecasting and major factors causing occupational injuries in each industry, Korean Government initiated a quantitative systematic simulation model project to analyze how the annual injury rate has been dropped and stays in a level for recent years. From this motivation and the project, system dynamics models have been developed to explain the mechanisms for reducing annual injury rate, and the mechanisms quantitatively. The main cause effects for the reduction of annual injury rate were due to the government driven investment on safety facilities. In overall viewpoint the gain achievable from these efforts has been reached a saturated level. However, it could reduce the annual injury rate if you chose the industry and size carefully. The model for forecasting, major injury factors, safety budget and allocation are introduced and analyzed, and Analyzing occupational injury related factors can also reduce employee injury and disease related costs, including medical care, quit, and disability assistance costs.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 2006.05a
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• pp.211-217
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• 2006

The learning control develops controllers that learn to improve their performance at executing a given task, based on experience performing this specific task. In a previous work, the authors presented an iterative precision of linear decentralized learning control based on p-integrated learning method for the vertical dynamic multiple systems. This paper develops an indirect decentralized learning control based on adaptive control method. The original motivation of the teaming control field was teaming in robots doing repetitive tasks such as on an assembly line. This paper starts with decentralized discrete time systems, and progresses to the robot application, modeling the robot as a time varying linear system in the neighborhood of the nominal trajectory, and using the usual robot controllers that are decentralized, treating each link as if it is independent of any coupling with other links. Error wave propagation method will show up in the numerical simulation for five-bar linkage as a vertical dynamic robot. The methods of learning system are shown up for the iterative precision of each link at each time step in repetition domain. Those can be helped to apply to the vertical multiple dynamic systems for precision quality assurance in the industrial robots and medical equipments.

• Journal of Biomedical Engineering Research
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• v.18 no.4
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• pp.389-396
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• 1997

Several types of electrical artifact seen on electroencephalogram( EEG) records are described. Those are the EOG and the PVC roller pump noise, and so on. An adaptive digital filtering of the electroencephalogram( EEG) is a successful way of suppressing mains interference, but it affects some of the frequency components of the signal, whore artifacts may not be acceptable in some cafes of automatic EEG processing. Thus we studied the method for cancelling these artifacts. This proposed method does not use the reference channel, and is realized by connecting the linear predictor and the fixed FIR filter for the EOG artifact, and by cascading the linear predictor and the noise canceller for the pump artifact. The simulation results illustrate the performances of the proposed method in terms of the capability of interferences suppression. In the results we obtained about 20 dB noise reduction.

• Journal of Biomedical Engineering Research
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• v.34 no.1
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• pp.24-33
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• 2013

To enhance the speech perception of hearing aid users in noisy environment, most hearing aid devices adopt various beamforming algorithms such as the first-order differential microphone (DM1) and the two-stage directional microphone (DM2) algorithms that maintain sounds from the direction of the interlocutor and reduce the ambient sounds from the other directions. However, these conventional algorithms represent poor directionality ability in low frequency area. Therefore, to enhance the speech perception of hearing aid uses in low frequency range, our group had suggested a fractional delay subtraction and integration (FDSI) algorithm and estimated its theoretical performance using computer simulation in previous article. In this study, we performed a KEMAR test in non-reverberant room that compares the performance of DM1, DM2, broadband beamforming (BBF), and proposed FDSI algorithms using several objective indices such as a signal-to-noise ratio (SNR) improvement, a segmental SNR (seg-SNR) improvement, a perceptual evaluation of speech quality (PESQ), and an Itakura-Saito measure (IS). Experimental results showed that the performance of the FDSI algorithm was -3.26-7.16 dB in SNR improvement, -1.94-5.41 dB in segSNR improvement, 1.49-2.79 in PESQ, and 0.79-3.59 in IS, which demonstrated that the FDSI algorithm showed the highest improvement of SNR and segSNR, and the lowest IS. We believe that the proposed FDSI algorithm has a potential as a beamformer for digital hearing aid devices.

• Journal of the Institute of Convergence Signal Processing
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• v.10 no.3
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• pp.181-185
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• 2009

Recently, much attention to a self-organizing mobile ad-hoc network is escalating along with progressive deployment of wireless networks in our everyday life. Being readily deployable, the MANET (mobile ad hoc network) can find its applications to emergency medical service, customized calling service, group-based communications, and military purposes. In this paper we investigate a time slot exchange problem found in the time slot based MAC, that is designed for IEEE 802.11b interfaces composing a MANET. The paper provides a method to maintain the quality of voice call by providing a new time slot when the channel assigned for that time slot gets noisy with interferences induced from other nodes, which belong to the same and/or other subgroups. In order to assess the performance of the proposed algorithm, a set of simulations using the OPNET modeler has been performed assuming that the IEEE 802.11b interfaces are operating under a modified MAC, which is a time slot based reservation MAC implemented in the PCF part of the superframe. In a real-time voice call service over a MANET of a size 500 ${\times}$ 500 meter squares with the number of nodes up to 100, the simulation results are collected and analyzed with respect to the packet loss rate and packet delay. The results show us that the proposed time slot exchange protocol improves the quality of voice call over that of plain DCF.

• The Journal of Korean Academic Society of Nursing Education
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• v.17 no.2
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• pp.168-177
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• 2011

Purpose: The purpose of this study was to investigate the attitude toward death in Korean nursing students. Method: The sample consisted of 365 baccalaureate nursing students. The questionnaires included questions on sociodemographics and death-related characteristics of the participants, and the Fear of Death and Dying Scale (FODS) to measure the attitude toward death. Result: The mean of the FODS score was 2.63 out of 4, so the participants had a slightly negative attitude toward death. There were statistically significant differences between gender, religion, religion activity, perceived health status, experience of parents' death, experience of friend's death, and overall FODS score. Among the four subscales of overall FODS, the score of the fear of death of self was significantly higher in the participants who experienced clinical practice and who experienced patient's death in the intensive care unit compared to the emergency room. Conclusion: Based on the study results, educational programs to change the attitude toward death are required before clinical practice. Programs need to consider nursing students' gender and religion, and give opportunity to share experiences and feelings about death of family or friend. In addition, using standardized patients and simulators is advised in the need for simulation training.

• The Journal of Korean Academic Society of Nursing Education
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• v.23 no.4
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• pp.409-418
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• 2017

Purpose: Ineffective communication between healthcare professionals leads to medical errors and puts patients at risk of harm. The aim of this study was to examine the effects of interdisciplinary communication training in simulated settings on self-confidence in communication, observed communication behavior, and technical skill performances of nursing students. Methods: A repeated measures design with one group was conducted. Data was collected from 92 nursing students through a self-administered questionnaire and an observed behavior checklist. Data analysis was performed using descriptive statistics, a paired t-test, the Wilcoxon signed rank test, the Friedmann test, a Repeated Measures ANOVA, and the Spearman correlation coefficient. Results: Self-confidence in communication, observed Identification-Situation-Background-Assessment-Recommendation-Read Back communication behavior, and technical skill performances of nursing students were significantly improved. In observed communication behavior, the performance of Assessment and Read Back communication significantly improved. However, communication of Background, Assessment, and Recommendation did not improve to a satisfactory level. Observed communication behavior was not correlated with the overall technical skill performance. Conclusion: These results indicate that interdisciplinary communication training in simulated settings was effective in improving nursing students' confidence and communication skills with physicians. Longitudinal studies with larger samples are recommended in order to verify the effects of interdisciplinary communication training on clinical outcomes as well as communication competence.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.7
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• pp.1589-1598
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• 2014

To support the WBAN, IEEE 802.15 Task Group 6 announced standardized documents on technical requirements of the PHY and MAC. In the IEEE 802.15.6 MAC protocol, CSMA/CA(Carrier Sense Multiple Access with Collision Avoidance) algorithm is performed based on the eight-level priorities according to the type of traffics of the periodic data from medical sensor nodes. Several nodes, which detected the changed bio signals, transmit emergency data at the same time, so latency could be higher than emergency latency and energy consumption will increase. In this thesis, we proposed a CSMA/CA algorithm in WBAN to solve these problems. Simulations are performed using a Castalia based on the OMNeT++ network simulation framework to estimate the performance of the proposed superframe and algorithms. Performance evaluation results show that the packet transmission success rate and energy efficiency are improved by reducing the probability of collision using the proposed MAC protocol.