• Journal of Korean Academy of Nursing
• /
• v.45 no.4
• /
• pp.501-512
• /
• 2015

Purpose: The purpose of this study, which was guided by the Resiliency Model of Family Stress, Adjustment, and Adaptation, was twofold: (a) to explore family and parental adaptation and factors influencing family adaptation in Korean families of children with Down syndrome (DS) through a quantitative methodology and (b) to understand the life with a Korean child with DS through a qualitative method. Methods: A mixed-methods design was adopted. A total of 147 parents of children with DS completed a package of questionnaires, and 19 parents participated in the in-depth interviews. Quantitative and qualitative data were analyzed using stepwise multiple regression and content analysis respectively. Results: According to the quantitative data, the overall family adaptation scores indicated average family functioning. Financial status was an important variable in understanding both family and parental adaptation. Family adaptation was best explained by family problem solving and coping communication, condition management ability, and family hardiness. Family strains and family hardiness were the family factors with the most influence on parental adaption. Qualitative data analysis showed that family life with a child with DS encompassed both positive and negative aspects and was expressed with 5 themes, 10 categories, and 16 sub-categories. Conclusion: Results of this study expand our limited knowledge and understanding concerning families of children with DS in Korea and can be used to develop effective interventions to improve the adaptation of family as a unit as well as parental adaptation.

• Journal of Biomedical Engineering Research
• /
• v.28 no.2
• /
• pp.205-211
• /
• 2007

A novel envelope extraction algorithm for speech processor of cochlear implants, called adaptation algorithm, was developed which is based on a adaptation effect of the inner hair cell(IHC)/auditory nerve(AN) synapse. We achieved acoustic simulation and hearing experiments with 12 normal hearing persons to compare this adaptation algorithm with existent standard envelope extraction method. The results shows that speech processing strategy using adaptation algorithm showed significant improvements in speech recognition rate under most channel/noise condition, compared to conventional strategy We verified that the proposed adaptation algorithm may yield better speech perception under considerable amount of noise, compared to the conventional speech processing strategy.

• Proceedings of the KSPS conference
• /
• 2005.04a
• /
• pp.53-56
• /
• 2005

In this paper, we propose a transformation based robust adaptation technique that uses the maximum mutual information(MMI) estimation for the objective function and the linear spectral transformation(LST) for adaptation. LST is an adaptation method that deals with environmental noises in the linear spectral domain, so that a small number of parameters can be used for fast adaptation. The proposed technique is called MMI-LST, and evaluated on TIMIT and FFMTIMIT corpora to show that it is advantageous when only a small amount of adaptation speech is used.

• The Journal of the Acoustical Society of Korea
• /
• v.30 no.6
• /
• pp.315-323
• /
• 2011

This paper proposes two methods of estimating prior distribution to improve the performance of rapid speaker adaptation based on maximum a posteriori linear regression (MAPLR). In general, prior distribution of the transformation matrix used in MAPLR adaptation is estimated from all of the training speakers who are employed to construct the speaker-independent model, and it is applied identically to all new speakers. In this paper, we propose a method in which prior distribution is estimated from a group of reference speakers, selected using adaptation data, so that the acoustic characteristics of the selected reference speakers may be similar to that of the new speaker. Additionally, in MAPLR adaptation with block-diagonal transformation matrix, we propose a method in which the mean matrix and covariance matrix of prior distribution are estimated from two groups of transformation matrices obtained from the same training speakers, respectively. To evaluate the performance of the proposed methods, we examine word accuracy according to the number of adaptation words in the isolated word recognition task. Experimental results show that, for very limited adaptation data, statistically significant performance improvement is obtained in comparison with the conventional MAPLR adaptation.

• International Journal of Aeronautical and Space Sciences
• /
• v.3 no.1
• /
• pp.74-85
• /
• 2002

The numerical experiment has been conducted to investigate the unsteady shock wave reflecting phenomena. The cell-vertex finite-volume, Roe's upwind flux difference splitting method with unstructured grid is implemented to solve unsteady Euler equations. The $4^{th}$-order Runge-Kutta method is applied for time integration. A linear reconstruction of the flux vector using the least-square method is applied to obtain the $2^{nd}$-order accuracy for the spatial derivatives. For a better resolution of the shock wave and slipline, the dynamic grid adaptation technique is adopted. The new concept of grid adaptation technique, which is much simpler than that of conventional techniques, is introduced for the current study. Three error indicators (divergence and curl of velocity, and gradient of density) are used for the grid adaptation procedure. Considering the quality of the solution and the numerical efficiency, the grid adaptation procedure was updated up to $2^{nd}$ level at every 20 time steps. For the convenience of comparison with other experimental and analytical results, the case of interaction between the straight incoming shock wave and a sharp wedge is simulated for various flow conditions. The numerical results show good agreement with other experimental and analytical results, in the shock wave reflecting structure, slipline, and the trajectory of the triple points. Some critical cases show disagreement with the analytical results, but these cases also have been proven to show hysteresis phenomena.

• The Transactions of the Korea Information Processing Society
• /
• v.7 no.12
• /
• pp.3923-3932
• /
• 2000

In mobile network, wireless links may be overloaded due to a high concentratioJl of mobile hosts in a given cell. As a result, the required QOS(Quality of Service) cannot be provided to all flows in that cell. So, there exists adaptive applications which can operate with various bandwidth levels. When a wireless link is overloaded, it can adapt by reducing the bandwidths of flows, is referred to as rate adaptation. In this paper, we analyze the performance of existing rate adaptation methods by simulations. The result of simulation experiments shows that average-fair adaptation scheme has very low network overhead but high bandwidth variance of flows, which causes the worse quality of service. We propose a rate adaptation method refined by combining fair adaptation and average-fair adaptation, and shows the refined method can provide lower bandwidth variance of flows by simulations.

• Journal of the Institute of Electronics Engineers of Korea SP
• /
• v.48 no.4
• /
• pp.129-135
• /
• 2011

The alternate adaptation algorithm (AAA) is proposed to improve the convergence characteristics and steady-state performance of the constant modulus algorithm (CMA). The alternate adaptation algorithm is a new equalization method which adapts an equalizer alternately by the algorithm with excellent blind convergence characteristics or the algorithm with better steady-state error performance. In this paper, it is introduced that the alternate adaptation equalization of the vsCMA (variable step-size CMA) and the decision-directed (DD) algorithm. We, first, designed the vsCMA with variable step-size to improve the steady-state error performance of the CMA, and combined it with the DD by alternate adaptation. As a result, it was mitigated that the sensitivity of performance fluctuation due to switching timing in CMA-DD switching method, and it was improved that the convergence speed and steady-state error performance of the CMA. Through computer simulations, under multipath channel condition, the usefulness of the proposed method was confirmed for 16-QAM.

• The Journal of the Acoustical Society of Korea
• /
• v.28 no.3
• /
• pp.268-272
• /
• 2009

In this paper, we propose a Gaussian Mixture Model (GMM) based incremental robust adaptation with a forgetting factor for the speaker verification. Speaker recognition system uses a speaker model adaptation method with small amounts of data in order to obtain a good performance. However, a conventional adaptation method has vulnerable to the outlier from the irregular utterance variations and the presence noise, which results in inaccurate speaker model. As time goes by, a rate in which new data are adapted to a model is reduced. The proposed algorithm uses an incremental robust adaptation in order to reduce effect of outlier and use forgetting factor in order to maintain adaptive rate of new data on GMM based speaker model. The incremental robust adaptation uses a method which registers small amount of data in a speaker recognition model and adapts a model to new data to be tested. Experimental results from the data set gathered over seven months show that the proposed algorithm is robust against outliers and maintains adaptive rate of new data.

• Asian Oncology Nursing
• /
• v.6 no.2
• /
• pp.162-171
• /
• 2006

Purpose: This study was undertaken to obtain the basic data on the spouses‘ stress and adaptation caring their wives affected by gynecological cancer. In addition, moderating variables for adaptation, family resource and situational definition, were also investigated. Method: This study was descriptive survey research work by questionnaire on the 71 spouses hospitalized in an university hospital located on Gwangju from Sep. 2001 to Oct. 2002. Results: The mean score of stress was 2.27, and the mean score of adaptation was 3.12. The correlation between stress and adaptation was significant (r = -.692, p = .000). The adaptation score of high stress group with high family resource was higher (p = .041) than the group with low family resource. The adaptation score of high stress group with high situational definition was higher (p = .033) than the group with low situational definition. Conclusion: This study showed that the spouses experienced a similar level of stress compared with the level of families with other type of cancer. This study also showed that the stress and adaptation levels were different depending upon the family resource and situational definition. This aspect should be considered for the development of nursing intervention program for the spouse of patients with gynecological cancer.

• Journal of Power Electronics
• /
• v.15 no.5
• /
• pp.1274-1285
• /
• 2015

This paper deals with model reference adaptive system (MRAS) speed estimators based on a secondary flux for linear induction motors (LIMs). The operation of these estimators significantly depends on an adaptation mechanism. Fixed-gain PI controller is the most common adaptation mechanism that may fail to estimate the speed correctly in different conditions, such as variation in machine parameters and noisy environment. Two adaptation mechanisms are proposed to improve LIM drive system performance, particularly at very low speed. The first adaptation mechanism is based on fuzzy theory, and the second is obtained from an LIM mechanical model. Compared with a conventional PI controller, the proposed adaptation mechanisms have low sensitivity to both variations of machine parameters and noise. The optimum parameters of adaptation mechanisms are tuned using an offline method through chaotic optimization algorithm (COA) because no design criterion is given to provide these values. The efficiency of MRAS speed estimator is validated by both numerical simulation and real-time hardware-in-the-loop (HIL) implementations. Results indicate that the proposed adaptation mechanisms improve performance of MRAS speed estimator.