• Korean Journal of Food Science and Technology
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• v.3 no.2
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• pp.105-109
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• 1971

Effects of perchloric acid (PCA) and trichloroacetic acid (TCA) on the color generation by orcinol reaction were systematically investigated. When the concentration of PCA on hot acid treatment was varied from 1 through 5 to 10%, and then the concentration of PCA on orcinol reaction was adjusted to 5% of reaction volume, no difference in the color generation was observed between 5 and 10% of PCA, but clearly observed between 1 and 5% PCA. When RNA was treated in 5% hot PCA and then PCA concentrations on orcinol reaction were adjusted to 5% and 10%, respectively, remarkable differences in color generation were observed. When RNA was treated in 10% hot PCA and then PCA concentration on orcinol reaction was adjusted to 5% no difference in color generation between 5% and 10% hot acid treatment was observed. The results show that PCA concentration must be adjusted prior to orcinol reaction.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.9
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• pp.1347-1355
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• 2015

In this study, we compare the recognition performance using PCA and RBFNNs for introducing robust face recognition system to pose variations based on pose estimation. proposed face recognition system uses Honda/UCSD database for comparing recognition performance. Honda/UCSD database consists of 20 people, with 5 poses per person for a total of 500 face images. Extracted image consists of 5 poses using Multiple-Space PCA and each pose is performed by using (2D)²PCA for performing pose classification. Linear polynomial function is used as connection weight of RBFNNs Pattern Classifier and parameter coefficient is set by using Particle Swarm Optimization for model optimization. Proposed (2D)²PCA-based face pose classification performs recognition performance with PCA, (2D)²PCA and RBFNNs.

• The Journal of Korean Academic Society of Nursing Education
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• v.24 no.1
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• pp.5-15
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• 2018

Purpose: The purpose of this study was to investigate the knowledge and practice of patient-controlled analgesia use and management (PCA-UM) among nurses. Methods: Data were collected from 182 nurses employed by four general hospitals having more than 300 beds in Daejeon. The data were collected using self-report questionnaires from November 4 to November 20, 2015. Collected data were analyzed using descriptive statistics, t-test, and ANOVA. Results: The average nurses' knowledge about PCA-UM was 14.8 points out of 20. PCA-UM knowledge was significantly higher for nurses with experience in PCA education (t=3.55, p<.001). Most participants (91.2%) wanted to get PCA training, 86.8% of them provided PCA education to patients after surgery. Approximately 62% of participants regularly evaluated the level of consciousness of patients with PCA. Conclusion: Findings indicate that the knowledge and practice of PCA-UM among nurses were insufficient to provide safe and effective pain management to postoperative patients with PCA. Therefore, it is concluded that it is necessary to develop standardized PCA education programs for nurses to provide safe and effective pain management to postoperative patients with PCA.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.04a
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• pp.920-927
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• 2008

This study deals with modeling of Head-Related Transfer Functions (HRTFs) using Principal Components Analysis (PCA) in the time and frequency domains. Four PCA models based on Head-Related Impulse Responses (HRIRs), complex-valued HRTFs, augmented HRTFs, and log-magnitudes of HRTFs are investigated. The objective of this study is to compare modeling performances of the PCA models in the least-squares sense and to show the theoretical relationship between the PCA models. In terms of the number of principal components needed for modeling, the PCA model based on HRIR or augmented HRTFs showed more efficient modeling performance than the PCA model based on complex-valued HRTFs. The PCA model based on HRIRs in the time domain and that based on augmented HRTFs in the frequency domain are shown to be theoretically equivalent. Modeling performance of the PCA model based on log-magnitudes of HRTFs cannot be compared with that of other PCA models because the PCA model deals with log-scaled magnitude components only, whereas the other PCA models consider both magnitude and phase components in linear scale.

• Korean Journal of Adult Nursing
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• v.14 no.3
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• pp.449-458
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• 2002

Purpose: The purpose of this study was to compare the effectiveness of a structured preoperative PCA education to that of the usual informal teaching provided by hospital staff in alleviating postoperative pain through more effective use of PCA therapy. Method: As an advanced research, the knowledge about the use of PCA therapy and the attitude about the use of the pain medicine were estimated, and then as a later research, the knowledge about the use of PCA therapy, the attitude about the use of the pain medicine, and the score of the pain were estimated. Result: The experimental group those who received structured preoperative PCA education had statistically significant higher knowledge regarding the use of PCA therapy(p=0.026) and more positive attitudes toward using pain medicine(p=0.004). The experimental group those who received structured preoperative PCA education reported better pain control 4(p=0.002), 8(p=0.014) and 24 hours(p=0.018) after the operation. Conclusion: The structured preoperative PCA education increases the knowledge for the use of patient's PCA therapy and changes their attitude toward the use of the pain medicine positively and consequently enable the use of PCA therapy to be more effective and then finally reduced the patient's pain after the operation.

• The Journal of the Korea Contents Association
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• v.4 no.3
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• pp.107-113
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• 2004

This paper improved the performance of the face recognition system using the PCA/LDA hybrid method based on the facial geometric feature and the Wavelet transform. Because the previous PCA/LDA methods have measured the similarity according to the formal dispersion, they could not reflect facial boundaries exactly In order to recover this defect, this paper proposed the method using the distance between eyes and mouth. If the difference of the measured distances on the query and the training images is over the given threshold, then the method reorders the candidate images according to energy feature vectors of eyes, a nose, and a chin. To evaluate the performance of the proposed method the computer simulations have been performed with four hundred facial images in the ORL database. The results showed that our method improves about 4％ recognition rate over the previous PCA/LDA method.

• The Korean Journal of Pain
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• v.9 no.2
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• pp.354-362
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• 1996

Background: We started postoperative pain management service using an intravenous patient-controlled analgesia (IV-PCA, PCA), which is known as convenient and effective analgesic method. In this report, we describe the efficacy and safety of PCA and the experience of developing an acute pain service to treat postoperative pain using a PCA. Methods: Practices of an acute pain service were started at a ward for general surgery after preparation of the standardized protocols for PCA. In each patient, PCA was connected following administration of initial loading doses of analgesics at recovery room after operation. All patients were checked by acute pain service team once or twice daily. The scope of acute pain service was gradually spread to other departments such as orthopedic, thoracic, obstetric and gynecologic departments by requests of patients or surgeons. We managed 1,590 patients during first 22 months. among them, nine hundred seventy two cases were prospectively evaluated for their analgesis efficacy and side effects of PCA. Results: The number of patients was increased day by day. the most common type of operation was gastrectomy (21.6%). Commonly used analgesics were nalbuphine (59%) and morphine (37%). The mean duration of PCA attachment was 3.3 days. The degree of analgesia on operation day was good in 44.8% and tolerable in 52.6% of patients. Only 3.9% of patients complained severe pain during their postoperative periods. One elderly patient experienced respiratory depression (0.06%) owing to accidental misuse of PCA by his relatives. Overall patient's satisfaction was over 93%. Conclusion: According to our experiences, we conclude that PCA is an effective, relatively safe and highly satisfactory method for postoperative pain management. Because of these advantages of PCA, the creation of our acute pain service using a PCA was successful and expanded rapidly.

• The Korean Journal of Applied Statistics
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• v.24 no.5
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• pp.963-977
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• 2011

PCA(Principal Component Analysis) is a well-studied statistical technique and an important tool for handling multivariate data. Although many algorithms exist for PCA, most of them are unsuitable for real time applications or high dimensional problems. Since it is desirable to avoid extensive matrix operations in such cases, alternative solutions are required to calculate the eigenvalues and eigenvectors of the sample covariance matrix. Erdogmus et al. (2004) proposed Recursive PCA(RPCA), which is a fast adaptive on-line solution for PCA, based on the first order perturbation theory. It facilitates the real-time implementation of PCA by recursively approximating updated eigenvalues and eigenvectors. However, the performance of the RPCA method becomes questionable as the size of newly-added data increases. In this paper, we modified the RPCA method by taking advantage of the mathematical relation of eigenvalues and eigenvectors of sample covariance matrix. We compared the performance of the proposed algorithm with that of RPCA, and found that the accuracy of the proposed method remarkably improved.

• Journal of Korean Neurosurgical Society
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• v.50 no.3
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• pp.205-208
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• 2011

Objective : Retrospective analysis to compare the effect and complication of epidural patient-controlled analgesia (epidural PCA) with intravenous patient-controlled analgesia (IV PCA) for the treatment of the post-operative pain after posterior lumbar instrumented fusion. Methods : Sixty patients who underwent posterior lumbar instrumented fusion for degenerative lumbar disease at our institution from September 2007 to January 2008 were enrolled in this study. Out of sixty patients, thirty patients received IV PCA group and thirty patients received epidural PCA group. The pain scale was measured by the visual analogue scale (VAS) score. Results : There were no significant difference between IV PCA group and epidural PCA group on the PCA related complications (p=0.7168). Ten patients in IV PCA group and six patients in epidural PCA group showed PCA related complications. Also, there were no significant differences in reduction of VAS score between two groups on postoperative 2 hours (p=0.9618) and 6 hours (p=0.0744). However, postoperative 12 hours, 24 hours and 48 hours showed the significant differences as mean of reduction of VAS score (p=0.0069, 0.0165, 0.0058 respectively). Conclusion : The epidural PCA is more effective method to control the post-operative pain than IV PCA after 12 hours of spinal fusion operation. However, during the first twelve hours after operation, there were no differences between IV PCA and epidural PCA.

• Journal of the Korea Convergence Society
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• v.9 no.2
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• pp.371-380
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• 2018

The purpose of this study was to investigate the effects of patient controlled analgesia(PCA) convergence education on postoperative pain management in spinal surgery patients. Sixty spinal surgery patients were included. For the experimental group(n=30), PCA education using video, booklet, and a PCA model practice was provided before surgery. The data were collected using questionnaire and were analyzed using descriptive statistics, ${\chi}^2-test$, Fisher's exact test, t-test and repeated measures ANOVA. PCA knowledge-attitude, PCA satisfaction and pain control satisfaction were higher in the experimental group than the control group(p<.001; p=.001; p<.001). Postoperative pain and frequency of additional analgesia use of the experimental group were significantly lower than those of the control group(p<.001; p=.001). This findings showed that the convergence PCA education of audiovisual aids with PCA practice training could be effective pain management intervention in patients undergoing spinal surgery. These apply to development of convergence nursing interventions in clinical practice.