• 대한안과학회지
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• 제59권12호
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• pp.1122-1128
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• 2018

목적: 전층각막이식을 시행받은 환자에서 리바운드 안압계의 임상적 유용성을 골드만 안압계 및 비접촉 안압계와 비교하여 알아보고자 하였다. 대상과 방법: 전층각막이식을 시행한 19안, 정상 대상자의 28안을 대상으로 하였다. 전층각막이식을 시행한 안과 정상안 각각에서 리바운드 안압계로 측정한 안압 결과를 골드만 안압계와 비접촉 안압계로 측정한 결과와 Spearmann 상관분석을 시행하고 Wilcoxon signed rank test 검정을 사용하여 비교하였다. 또한 각 그룹에서 리바운드 안압계로 측정한 안압 결과를 급내상관계수를 이용하여 재현성을 평가하였다. 결과: 정상안에서는 리바운드 안압계로 측정한 결과가 골드만 및 비접촉 안압계로 측정한 결과값과 유의한 차이가 없었다(p>0.050). 전층각막이식을 시행한 안에서는 리바운드 안압계로 측정한 안압은 골드만 안압계로 측정한 안압과 유의한 차이를 보이지 않았으나(p=0.872), 비접촉 안압계로 측정한 안압에 비하여 유의하게 낮았다(p=0.011). 하지만 리바운드 안압계로 측정한 안압과 골드만 및 비접촉 안압계로 측정한 안압은 비교적 높은 상관성을 보였다(r=0.770, 0.879). 리바운드 안압계 측정치의 급내상관계수는 전층각막 이식을 시행한 안에서는 0.986, 정상안에서는 0.961로 두 군 모두 높은 재현성을 보였다. 결론: 전층각막이식을 시행한 안에서 리바운드 안압계 측정값은 골드만 및 비접촉 안압계 측정값과 비교적 높은 상관성을 보였으며 정상안과 유사하게 높은 재현성을 보여 이들 환자의 안압 측정에 있어서 유용한 방법 중 하나로 생각해 볼 수 있다.

• 한국멀티미디어학회논문지
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• 제12권11호
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• pp.1692-1700
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• 2009

본 논문에서는 메쉬 법선 벡터들의 방향 분포를 3차원 모델의 특징 기술자로 제안한다. 특징 기술자로써 요구되는 회전 불변을 주성분 분석법(PCA)으로 처리하고 잡음첨가에 강건하도록 메쉬 간략화를 수행한다. 표면적이 작은 면에 대한 정보가 특징 기술자를 구성하는데 더 적게 반영되도록 법선 벡터의 분포를 각 다각형의 면적에 비례하게 표본을 뽑아 법선 벡터에 가중치를 적용하고 보간하여 변별력을 높인다. 모델간의 유사도는 특징 기술자의 거리를 정규화한 확률 밀도 히스토그램의 L1-norm으로 측정한다. 제안한 방법이 기존 방법에 비해 검색 순위 평균(ANMRR)으로 나타낸 검색 성능이 약 17.2%, 정량적 변별 척도로 나타낸 검색 성능이 최소 9.6%에서 최대 17.5%까지 향상되었음을 알 수 있었다.

• 한국생물정보학회:학술대회논문집
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• 한국생물정보시스템생물학회 2004년도 The 3rd Annual Conference for The Korean Society for Bioinformatics Association of Asian Societies for Bioinformatics 2004 Symposium
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• pp.272-278
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• 2004

Recently, Pepe et al. (2003) employed the receiver operating characteristic (ROC) approach to rank candidate genes from a microarray experiment that can be used for the biomarker development with the ultimate purpose of the population screening of a cancer, In the cancer microarray experiment based on n patients the researcher often wants to compare the tumor tissue with the normal tissue within the same individual using a common reference RNA. This design is referred to as a reference design or an indirect design. Ideally, this experiment produces n pairs of microarray data, where each pair consists of two sets of microarray data resulting from reference versus normal tissue and reference versus tumor tissue hybridizations. However, for certain individuals either normal tissue or tumor tissue is not large enough for the experimenter to extract enough RNA for conducting the microarray experiment, hence there are missing values either in the normal or tumor tissue data. Practically, we have $n_1$ pairs of complete observations, $n_2$ 'normal only' and $n_3$ 'tumor only' data for the microarray experiment with n patients, where n=$n_1$+$n_2$+$n_3$. We refer to this data set as a mixed data set, as it contains a mix of fully observed and partially observed pair data. This mixed data set was actually observed in the microarray experiment based on human tissues, where human tissues were obtained during the surgical operations of cancer patients. Pepe et al. (2003) provide the rationale of using ROC approach based on two independent samples for ranking candidate gene instead of using t or Mann -Whitney statistics. We first modify ROC approach of ranking genes to a paired data set and further extend it to a mixed data set by taking a weighted average of two ROC values obtained by the paired data set and two independent data sets.

• Journal of the Korean Data and Information Science Society
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• 제25권6호
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• pp.1499-1506
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• 2014

랜덤워크는 다양한 분야에서 랜덤현상을 기술하는데 이용되고 있으나, 현재까지 개발된 랜덤워크 검정법에는 유의수준 왜곡과 낮은 검정력 등의 문제가 있는 것으로 알려져 있다. 이러한 문제점들을 개선하기 위해 Kim 등 (2014)은 부호검정에 기초한 랜덤워크 검정 (${\rho}=1$)방법을 제안하였다. 본 논문에서는 보다 개선된 랜덤워크 검정법을 제안하고자 부호검정보다 검정력이 우수한 것으로 알려진 윌콕슨 부호순위검정을 이용한 랜덤워크 검정법을 제안하고, 모의실험을 통해 부호검정, 윌콕슨 부호순위검정, 확장 Dickey-Fuller 검정의 성능을 비교하였다. 모의실험 결과 소표본에서 비모수 검정기법들이 ADF 검정보다 우월하다는 사실을 재확인하였다. 새롭게 밝혀진 사실은 부호검정이 윌콕슨 부호순위검정에 비해 높은 검정력을 가지며, 또한 비모수 검정기법들은 ${\rho}$가 양의 부호를 가지는 경우 (0 < ${\rho}$ < 1) 정규분포보다 이중지수분포에서 낮은 검정력을 가지게 되나, ${\rho}$가 음의 부호(-1 < ${\rho}$ < 0)를 갖는 경우에는 정규분포보다 이중지수분포에서 높은 검정력을 보인다는 사실이다.

• Asian Pacific Journal of Cancer Prevention
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• 제14권6호
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• pp.3613-3618
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• 2013

Object: To detect expression of hypoxia inducible factor-$1{\alpha}$ (HIF-$1{\alpha}$) and lysyl oxidase (LOX) in non-small cell lung cancer (NSCLC) and explore their roles in prognosis. Methods: The mRNA levels of HIF-$1{\alpha}$ and LOX were investigated by real-time reverse-transcriptase polymerase chain reaction in 40 cases of tumour and paired normal tissues. In addition, protein expression of HIF-$1{\alpha}$ and LOX was examined by immunohistochemistry in 82 cases of tumour and 45 paired normal tissues. The relationship between HIF-$1{\alpha}$ or LOX and clinicopathologic characteristics, as well as the correlation between HIF-$1{\alpha}$ and LOX, were also examined. Kaplan-Meier survival curves and the log-rank test were used to analyze progression-free survival. Results: HIF-$1{\alpha}$ or LOX mRNA levels in tumor tissues was significantly higher than those in paired normal tissues (p<0.01). Positive HIF-$1{\alpha}$ or LOX protein expression in tumor tissues was noted in 46/82 (56.1%) and 49/82 (59.8%) of the cases, respectively, being significantly higher than those in paired normal tissues (p<0.05). There was significant correlation between the expression of HIF-$1{\alpha}$ or LOX and tumor size, lymph node metastasis and pathological stage (p<0.05). The expression of HIF-$1{\alpha}$ and LOX had a significant inverse impact on survival of patients with NSCLC. Conclusion: HIF-$1{\alpha}$ and LOX may play a pivotal role in the development of NSCLC, and may act in synergy to promote the progression of NSCLC.

• Asian Pacific Journal of Cancer Prevention
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• 제16권5호
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• pp.1839-1843
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• 2015

Background: MicroRNAs are a class of noncoding RNAs which regulate multiple cellular processes during tumor development. The purpose of this report is to investigate the clinicopathological and prognostic significance of miR-218 in human gliomas. Materials and Methods: Quantitative RT-PCR (qRT-PCR) was conducted to detect the expression of miR-218 in primary normal human astrocytes, three glioma cell lines and 98 paired glioma and adjacent normal brain tissues.Associations of miR-218 with clinicopathological variables of glioma patients were statistically analyzed. Finally, a survival analysis was performed using the Kaplan-Meier method and Cox's proportional hazards model. Results: The expression level of miR-218 in primary normal human astrocytes was significantly higher than that in glioma cell lines (p<0.01). Also, the expression level of miR-218 in glioma tissues was significantly downregulated in comparison with that in the adjacent normal brain tissues (p<0.001). Statistical analyses demonstrated that low miR-218 expression was closely associated with advanced WHO grade (p=0.002) and low Karnofsky performance score (p=0.010) of glioma patients. Kaplan-Meier analysis with the log-rank test showed that patients with low-miR-218 expression had poorer disease-free survival and overall survival (p=0.0045 and 0.0124, respectively). Multivariate analysis revealed that miR-218 expression was independently associated with the disease-free survival (p=0.009) and overall survival (p=0.004) of glioma patients. Conclusions: Our results indicate that miR-218 is downregulated in gliomas and that its status might be a potential valuable biomarker for glioma patients.

• Asian Pacific Journal of Cancer Prevention
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• 제13권3호
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• pp.1049-1052
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• 2012

The purpose of this study was to evaluate expression and prognostic value of matrix metalloproteinase-7 (MMP-7) in colorectal cancer (CRC) patients. CRC tissues and corresponding distal normal mucosa tissues of 118 CRC patients were assessed by immunohistochemistry. Correlations between MMP-7 expression, patients' clinic pathological features, and overall survival rate were analyzed. We found that positive expression of MMP-7 in CRC tissues was significantly higher than that in distal normal mucosa (61.0% vs. 39.8%, p =0.001). Poor histological differentiation, advanced clinical stage and lymph node metastasis were significantly correlated with MMP-7 expression in CRC. The overall survival rate was significantly higher in the MMP-7 negative group than the positive group (Log-rank test= 9.957, p= 0.002). MMP-7 appeared as a significant independent prognostic factor through multivariate survival analysis. Collectively, we found MMP-7 expression to be correlated with progression and metastasis of CRC and thus could be used as a predictive marker of prognosis in CRC patients.

• 지역사회간호학회지
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• 제31권1호
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• pp.107-118
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• 2020

Purpose: Nursing students are key personnel to take care of people with dementia in the nursing field in future. The purpose of this study was to identify subjective attitudes toward dementia in nursing students. Methods: Q methodology, which is a research method to study people's subjective points of views, was used. Thirty seven Q-statements (Q-sample) were derived from the Q population (Concourse) and were arranged in rank order by each of 42 participants into a normal distribution grid (from -4 to +4). A QUANL program was used to analyze the collected data. Results: Three types of attitudes toward dementia were identified: 'self-guided dementia management', 'national-guided dementia management' and 'facility-guided dementia management.' Conclusion: The results of this study suggest that nursing strategies to improve understanding of dementia and actively cope with dementia should be considered.

• 말소리와 음성과학
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• 제1권4호
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• pp.187-193
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• 2009

For this study, the external laryngeal lengths of 9 females and 9 males with normal voices were measured together with their ages, heights, and weights, and after they read aloud sentences for 3 minutes, their habitual speaking fundamental frequencies, speaking low pitches, speaking high pitches, and vocal fold closed quotients were measured. The Spearman rank correlation analysis on these data showed a significant negative correlation between the external laryngeal length and the habitual speaking fundamental frequency for both females and males, a significant negative correlation between the external laryngeal length and the speaking high pitch for only males, a significant negative correlation between the external laryngeal length and the speaking low pitch for both females and males, and a significant positive correlation between the external laryngeal length and the vocal fold closed quotient for only males.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2013년도 추계학술대회
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• pp.130-132
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• 2013

This paper presents an improvement for calculating method of astronomical vessel position with circle of equal altitude equation based on using a virtual object in sun and two stars observation. In addition, to enhance the accuracy of ship position achieved from solving linear matrix system, and surmount the disadvantages on rank deficient matrices situation, the authors used singular value decomposition (SVD) in least square method instead of normal equation and QR decomposition, so, the solution of matrix system will be available in all situation. As proposal algorithm, astronomical ship position will give more accuracy than previous methods.