• 정보보호학회논문지
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• 제29권5호
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• pp.1007-1017
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• 2019

현재 대부분의 생체인증 시스템은 단일 생체정보를 이용하여 사용자를 인증하고 있는데, 이러한 방식은 노이즈로 인한 문제, 데이터에 대한 민감성 문제, 스푸핑, 인식률의 한계 등 많은 문제점들을 가지고 있다. 이를 해결하기 위한 방법 중 하나로 다중 생체정보를 이용하는 방법이 제시되고 있다. 다중 생체인증 시스템은 각각의 생체정보에 대해서 information fusion을 수행하여 새로운 정보를 생성한 뒤, 그 정보를 활용하여 사용자를 인증하는 방식이다. Information fusion 방법들 중에서 score-level fusion 방법을 보편적으로 많이 사용한다. 하지만 정규화 작업이 필요하다는 문제점을 갖고 있고, 데이터가 같아도 정규화 방법에 따라 인식률이 달라진다는 문제점을 갖고 있다. 이에 대한 대안으로 정규화 작업이 필요 없는 rank-level fusion 방법이 제시되고 있다. 하지만 기존의 rank-level fusion 방법들은 score-level fusion 방법보다 인식률이 낮다. 이러한 문제점을 해결하기 위해 상관계수를 이용하여 score-level fusion 방법보다 인식률이 높은 rank-level fusion 방법을 제안한다. 실험은 홍채정보(CASIA V3)와 얼굴정보(FERET V1)를 이용하여 기존의 존재하는 rank-level fusion 방법들의 인식률과 본 논문에서 제안하는 fusion 방법의 인식률을 비교하였다. 또한 score-level fusion 방법들과도 인식률을 비교하였다. 그 결과로 인식률이 약 0.3%에서 3.3%까지 향상되었다.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제14권4호
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• pp.332-339
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• 2014

Face classification has wide applications in security and surveillance. However, this technique presents various challenges caused by pose, illumination, and expression changes. Face recognition with long-distance images involves additional challenges, owing to focusing problems and motion blurring. Multiple frames under varying spatial or temporal settings can acquire additional information, which can be used to achieve improved classification performance. This study investigates the effectiveness of multi-frame decision-level fusion with photon-counting linear discriminant analysis. Multiple frames generate multiple scores for each class. The fusion process comprises three stages: score normalization, score validation, and score combination. Candidate scores are selected during the score validation process, after the scores are normalized. The score validation process removes bad scores that can degrade the final output. The selected candidate scores are combined using one of the following fusion rules: maximum, averaging, and majority voting. Degraded facial images are employed to demonstrate the robustness of multi-frame decision-level fusion in harsh environments. Out-of-focus and motion blurring point-spread functions are applied to the test images, to simulate long-distance acquisition. Experimental results with three facial data sets indicate the efficiency of the proposed decision-level fusion scheme.

• 한국통신학회논문지
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• 제38A권2호
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• pp.174-182
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• 2013

Most methods for fusion-based finger vein recognition were to fuse different features or matching scores from more than one trait to improve performance. To overcome the shortcomings of "the curse of dimensionality" and additional running time in feature extraction, in this paper, we propose a finger vein recognition technology based on matching score-level fusion of a single trait. To enhance the quality of finger vein image, the contrast-limited adaptive histogram equalization (CLAHE) method is utilized and it improves the local contrast of normalized image after ROI detection. Gabor features are then extracted from eight channels based on a bank of Gabor filters. Instead of using the features for the recognition directly, we analyze the contributions of Gabor feature from each channel and apply a weighted matching score-level fusion rule to get the final matching score, which will be used for the last recognition. Experimental results demonstrate the CLAHE method is effective to enhance the finger vein image quality and the proposed matching score-level fusion shows better recognition performance.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제8권7호
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• pp.2420-2433
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• 2014

Fusing the scores of multibiometrics is a very promising approach to improve the overall system's accuracy and the verification performance. In recent years, there are several approaches towards studying score level fusion of several biometric systems. However, most of them does not consider the genuine and imposter score distributions and result in a higher equal error rate usually. In this paper, a novel score level fusion approach of different biometric systems (dual iris, thermal and visible face traits) based on $Acz{\acute{e}}l$-Alsina triangular norm is proposed. It achieves higher identification performance as well as acquires a closer genuine distance and larger imposter distance. The experimental tests are conducted on a virtual multibiometrics database, which merges the challenging CASIA-Iris-Thousand database with noisy samples and the NVIE face database with visible and thermal face images. The rigorous results suggest that significant performance improvement can be achieved after the implementation of multibiometrics. The comparative experiments also ascertain that the proposed fusion approach outperforms the state-of-art verification performance.

• 대한족부족관절학회지
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• 제15권1호
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• pp.1-6
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• 2011

Purpose: The purpose of this study was to compare the clinical and radiological results of single and double fusions in the transverse tarsal joint. Materials and Methods: Between December 2000 and April 2009, 16 patients (16 feet) who had been treated by fusion of transverse tarsal joint were included in this study. In 8 patients, only talonavicular joint was fused and in the other 8 patients, both talonavicular and calcaneocuboid joints were fused simultaneously. We have measured talo-first metatarsal angle, calcaneal pitch angle, talonavicular coverage angle and presence of adjacent joint arthritis for radiological assessment at both preoperative and last visit. Furthermore, we have evaluated Visual Analogue Scale (VAS), American Orthopaedic Foot and Ankle Society (AOFAS) score and patient's satisfaction. Results: In a single fusion group, VAS was improved from $6.4{\pm}1.4$ to $0.8{\pm}1.0$ (p=0.0011) and AOFAS score was improved from $63.8{\pm}6.2$ to $89.4{\pm}9.8$ (p=0.0012). In a double fusion group, VAS was improved from $8.0{\pm}0.75$ to $2.0{\pm}1.8$ (p=0.0011) and AOFAS score was improved from $60.5{\pm}11.2$ to $89.5{\pm}6.0$ (p=0.0012). In the difference of talo-first metatarsal angle between two groups, a single fused group was more improved than a double fused group (p=0.04). Conclusion: Both single and double fusions are useful and attractive treatment for the transverse tarsal joint arthritis. Furthermore, a single fusion has advantages of less invasiveness and preserving some degree of hindfoot motion and could be an effective alternative to a double fusion if patient meets appropriate criteria through careful preoperative evaluation.

• Journal of Korean Neurosurgical Society
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• 제50권3호
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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.

• Asian Spine Journal
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• 제12권6호
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• pp.1017-1027
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• 2018

Study Design: This retrospective study was conducted including 18 patients who underwent posterior-only stabilization and fusion procedure for pseudoarthrosis in the ankylosed spine from October 2007 to May 2015. Purpose: This study aimed to describe the treatment outcomes in 18 patients with Andersson lesion (AL) who were managed using the posterior-only approach. Literature Review: AL is an unstable, localized, vertebral, or discovertebral lesion of the spine. It is observed in patients with ankylosing spondylitis. The exact etiology of this disorder remains unclear, and the treatment guidelines are not clearly described. Methods: We analyzed 18 patients with AL who were treated with posterior long segment spinal fusion without any anterior interbody grafting or posterior osteotomy. Pre- and postoperative radiography, computed tomography, and recent follow-up images were examined. The pre- and postoperative Visual Analog Scale score and the Oswestry Disability Index score were evaluated for all patients. Whiteclouds' outcome analysis criteria were applied at the follow-up. Moreover, at study completion, patient feedback was collected; all the patients were asked to provide their opinion regarding the surgery and were asked whether they would recommend this procedure to other patients and them self undergo the same procedure again if required. Results: The most common site was the thoracolumbar junction. The symptom duration ranged from 1 month to 10 years preoperatively. Most patients experienced fusion by the end of 1 year, and the fusion mass could be observed as early as 4 months. Pseudoarthrosis void of up to 2.5 cm was noted to be healed in subsequent imaging. In addition, clinically, the patients reported good symptomatic relief. No patient required revision surgery. Whiteclouds' outcome analysis score at the latest follow-up revealed goodto-excellent outcomes in all patients. Conclusions: ALs can be treated using the posterior-only approach with long segment fixation and posterior spinal fusion. This is a safe, simple, and quick procedure that prevents the morbidity of anterior surgery.

• Journal of Korean Neurosurgical Society
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• 제30권12호
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• pp.1369-1374
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• 2001

Objectives : The rates of pseudarthrosis for two- and three level fusion have been reported to be 17-63 and 50% without anterior cervical plating. The purpose of this study is to assess the effects of anterior cervical plating in the treatment of multilevel degenerative cervical disease such mostly the additional risks associated with hardware implants and its benefits, fusion rate and radiographic results, and clinical outcomes. Methods : Forty-seven patients who underwent operations between 1993 and 1997 were retrospectively reviewed. The technique for operation was same for both groups(Smith Robinson with autologous iliac bone graft). Group I consisted of 35 consecutive patients treated with anterior cervical decompression and fusion with anterior cervical plate fixation. Group II consisted of 12 consecutive patients treated without plate fixation. We compared clinical outcomes by Prolo score, radiographic results in the rate of fusion, cervical lordosis by Gore angle, disc height by Farfan method, and surgical complications between two groups. Results : The favorable clinical outcomes(excellent and good) by Prolo score were observed with the use of anterior cervical plate fixation(89% vs 75%). The successful fusion rate of multilevel cervical fusion was as seen with anterior cervical plate fixation(97% vs 75%). The overall graft complication rate in multilevel fusions was decreased, with anterior cervical plate fixation, and the hardware related complications were relatively minimal without serious consequences. Conclusion : Anterior cervical plate fixation in the treatment of multilevel cervical disorders is an effective stabilizing method which provides increased bony fusion rate, decreased graft complications, maintained cervical lordosis, early mobilization of the these patients without serious hardware related complications.

• 보건의료산업학회지
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• 제9권3호
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• pp.233-246
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• 2015

Objectives : This study investigated the general characteristics, child rearing characteristics, and the level of self-differentiation of 120 custodial grandmothers. Methods : Data were collected with a self-administered questionnaire from 120 custodial grandmothers who registered Kinship Network in Busan City. Results : For the self-differentiation measure, the mean score of the sample was $2.52{\pm}0.51$. However, the level of the fusion with emotion $1.89{\pm}0.80$ was extremely low partly due to the influence of collectivist culture of Korean society. The levels of emotional reactivity and fusion with emotion were significantly low which were dependent on depression (F=4.387, p=0.015). Conclusions : The findings of this study show the need to improve the level of self-differentiation by increasing the score of emotional reactivity and fusion with the emotion among the kinship network grandmothers. Therefore, supportive programs for kinship network grandmothers need to develop self-differentiation.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2024년도 춘계학술발표대회
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• pp.741-744
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• 2024

본 연구에서는 음성 전처리 기법인 푸리에 변환의 높은 시간 복잡도로 인해 많은 계산 자원을 요구한다는 단점을 보완하기 위한 FTAE(Fourier Transform Auto Encoder)를 설계하고 구현한다. FTAE는 음성 데이터를 입력으로 받아 Early Fusion 특징맵을 출력하도록 설계된 오토인코더 기반 신경망이다. 학습 결과 FTAE의 최종 Training Loss는 0.1479를 나타냈다. 기존 푸리에 변환 기반 Early Fusion 방법과의 성능 비교 실험 결과 FTAE 방법은 Accuracy 0.905, F1-Score 0.905, 탐지 소요 시간 17초의 성능을 보였다. FTAE 방법은 Early Fusion 방법에 비해 Accuracy와 F1-Score는 0.065 하락했지만, 탐지 소요 시간은 약 72배 빠른 결과를 보여주었다.