• The Journal of the Acoustical Society of Korea
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• v.22 no.6
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• pp.425-433
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• 2003

Acoustic Echo Canceller (AEC) is a signal processing system for removing unwanted echo signals in teleconference and hands-free communication. Least mean square (LMS) algorithm is one of the adaptive echo cancellation algorithms and it has been most attractive because of its simplicity and robustness. However, the convergence properties of the LMS algorithm degrade with highly correlated input signals such as speech. For this reason, transform-domain adaptive filtering algorithm was introduced to decorrelate the colored input samples by using the orthogonal transform matrix such as DCT, DFT and then LMS adaptive filtering process is applied. In this paper, we propose a MLT domain adaptive echo canceller base on the MLT (Modulated lapped Transform) orthogonal transform matrix. The proposed algorithm achieves high decorrelation efficiency and fast convergence speed via modulated lapped transform of size 2NXN instead of NXN unitary transform such as DCT, DFT, Hadamad and it is applied to the acoustical echo cancellation system. Form the computer simulation with both synthesis and real speech, the proposed MLT domain adaptive echo canceller shows approximately twice faster convergence speed and 20∼30 ㏈ ERLE improvements over the DCT frequency domain acoustic echo cancellation system.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.2
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• pp.10-14
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• 2014

Krylov-Schur iteration method has been applied to the 2-Dim. waveguides of the varied geometrical structure. The eigen-equations for them have been constructed from FEM based on the tangential edge vectors of triangular elements. The eigen-values and their modes have been determined from the diagonal components of the Schur matrices and its transforming matrices. The eigen-pairs as the results have been revealed visually in the schematic representations.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.10C
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• pp.1484-1489
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• 2004

Given a video frame in terms of its 8${\times}$8 block-DCT coefncients, we wish to obtain a downsized or upsized version of this Dame also in terms of 8${\times}$8 block DCT coefficients. The DCT being a linear unitary transform is distributive over matrix multiplication. This fact has been used for downsampling video frames in the DCT domains in Dugad's, Mukherjee's, and Park's methods. The downsampling and upsampling schemes combined together preserve all the low-frequency DCT coefficients of the original image. This implies tremendous savings for coding the difference between the original frame (unsampled image) and its prediction (the upsampled image).This is desirable for many applications based on scalable encoding of video. In this paper, we extend the earlier works to various DCT sizes, when we downsample and then upsample of an image by a factor of two. Through experiment, we could improve the PSM values whenever we increase the DCT block size. However, because the complexity will be also increase, we can say there is a tradeoff. The experiment result would provide important data for developing fast algorithms of compressed-domain image/video resizing.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.7
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• pp.142-148
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• 2014

Krylov-Schur iteration method has been applied to the 3-Dim. resonant cavity of a cylindrical form. The vector Helmholtz equation has been analysed for the resonant field strength in homogeneous media by FEM. An eigen-equation has been constructed from element equations basing on tangential edges of the tetrahedra element. This equation made up of two square matrices associated with the curl-curl form of the Helmholtz operator. By performing Krylov-Schur iteration loops on them, Eigen-values and their modes have been determined from the diagonal components of the Schur matrices and its transforming matrices. Eigen-pairs as a result have been revealed visually in the schematic representations. The spectra have been compared with each other to identify the effect of boundary conditions.

• Journal of Korean Public Health Nursing
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• v.11 no.2
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• pp.141-151
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• 1997

As concerns about dementia patients increase gradually in society, the nursing of them becomes more and more important. For intervening in dementia patients effectively, the most fundamental thing is to understand their characteristics and to increase the ability of assessing them. The assessment data supply us with the foundations of Nursing diagnosis and nursing plan. The reaseons why the assessment data are especially important to dementia patients are as follows; First, dementia patients have great differences among them in intellectual, physical ability. And their condition varies from time to time. Second, the intervention without planning results in the deficiency of consistence, and it rather embarrasses and makes dementia patients uneasy. Third, nursing of dementia patients requires participation of multi-disciplinary team because of characteristics of that disease. The development of an unitary assessment tool is essential for all members of the team to have close relations between them and care for dementia patients. Fully understanding the importance of assessment data, this study investigate the content to be included in the assessment before developing assessment tools to be used in community. It points out that the assessment should include the informations about patients, their family, and main care-giver. And it sets up items that can supply with detailed information on each person. In the future it is necessary to transform the contents of this study to more concrete items and develope the assessment tools for dementia patients. And recording paper for follow up should be supplemented to check any changes in family caring for dementia patients and describe the changes in detail. To make assessment tools is one of the fundamental works in controlling dementia patients. Therefore the official assessment tools should be provided as soon as possible. This study aimed at presenting the guiding principles for developing that assessment tools.

• Journal of Korean Academy of Nursing
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• v.22 no.3
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• pp.337-351
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• 1992

Nursing as it is practiced and taught, historically has been viewed as natural science. There are new movements to create a paradigm of nursing in the human sciences. A natural science methodologies elicit quantitative data from observable phenomena and reveal causal relationships. Human science methodology is the study of Unitary Man's participative experience in a situation, the simultaneity paradigm. In a theory of nursing rooted in human science assumptions about man and health are synthesized, and the practice of nursing is continuously expanded through research. To find independent nursing interventions especially cognitive nursing intervention models it has been necessary to consult a multitude of journals and text sources for references, and no one nursing textbook can be used in help patients achieve nursing goals. The goals of nursing in the simultaneity paradigm focus on the quality of life from the person's perspective. Cognitive interventions based on the person's perspective were selected from those that colleagues deemed appropriate to nursing and those that were identified in the nursing literature. They were supportive nursing care, reminiscence, meditation, relaxation and imagery. Nurses have been reluctant to make diagnoses, implement actions, and assume responsibility for this actions and this is of concern but can be understood because nurses have had little exposure to action and lack an intervention armamentarium from with which to choose actions to achieve nursing goals. Efforts in nursing education and nursing service are required to remedy this problem. Nurses must be convinced of the challenge and excitement associated with autonomous functioning. It is a characteristic of the true professional. Traditionally, nursing has prescribed one method for handling a situation. Fundamental nursing texts usually only present one way to handle a situation, because alternative interventions to achieve a client goal may be available. Considerably more research is necessary before these can be prescribed. However, unless a first step is taken, progress will not be made. The quality of health care or nursing care is enhanced when nurses transform dilemas into commited action. This is apparent from widespread experiences of nurses.