• Asian Pacific Journal of Cancer Prevention
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• 제17권1호
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• pp.201-205
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• 2016

Cholangiocarcinoma (CCA) is generally a rare primary liver tumor of the bile duct with extremely poor clinical outcomes due to late diagnosis. Osteopontin (OPN) is the most abundant expressed gene in intrahepatic CCA and its involvement in tumor aggressiveness suggests it could be a useful prognostic biomarker. However, the prognostic significance of OPN expression in CCA is still controversial. We therefore immunohistochemically studied OPN expression in 354 resected CCAs and correlated the results with patient clinicopathological parameters. OPN expression was separately scored according to the percentage of cancer cells or degree of stromal tissue staining and classified as low (score 0-1) and high (score 2-3). OPN expression in CCA cells was found in 177 out of 354 patients (56.5%), whereas stroma was positive in 185 out of 354 patients (52.3%). Univariate analysis with several of the aforementioned parameters revealed that stromal but not cancer cell OPN expression was significantly associated with tumor size, tumor direct invasion into normal liver parenchyma, regional lymph node metastasis and higher staging. The combination of cancer cell and stromal OPN expression demonstrated a positive trend for linkage with lymph node metastasis. Multivariate analysis identified gender, the presence of lymphatic permeation and lymph node metastasis, but not OPN expression, as independent prognostic factors. This study confirms the presence of stromal OPN expression in tumor aggressiveness but not survival in CCA patients.

• Journal of Yeungnam Medical Science
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• 제40권1호
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• pp.65-77
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• 2023

Background: This study aimed to compare clinical outcomes between surveillance and adjuvant therapy (AT) groups after R0 resection for cholangiocarcinoma (CCA). Methods: A total of 154 patients who underwent R0 resection for CCA at the Daegu Catholic University Medical Center between January 2010 and December 2019 were included. Overall survival (OS) and progression-free survival (PFS) were analyzed. Results: The median follow-up duration was 899 days. There were 109 patients in the AT group and 45 patients in the surveillance group. The patients in the AT group were younger (67 years vs. 74 years, p<0.001) and included more males (64.2% vs. 46.7%, p=0.044). The proportion of patients with stage III CCA was larger in the AT group than in the surveillance group (13.8% vs. 2.2%, p=0.005). In addition, AT did not improve OS (5-year OS rate, 69.3% in the AT group vs. 64.2% in the surveillance group, p=0.806) or PFS (5-year PFS rate, 42.6% in the AT group vs. 48.9% in the surveillance group, p=0.113). In multivariate analysis using the Cox proportional hazards model, stage III CCA (hazard ratio [HR], 10.81; 95% confidence interval [CI], 2.92-40.00; p<0.001) was a significant predictor of OS. American Society of Anesthesiologists classification II (HR, 0.50; 95% CI, 0.31-0.81; p=0.005), and American Joint Committee on Cancer stages II (HR, 3.14; 95% CI, 1.25-7.89; p=0.015) and III (HR, 8.08; 95% CI, 2.80-23.32; p<0.001) were independent predictors of PFS. Conclusion: AT after R0 resection for CCA did not improve OS or PFS.

• Asian Pacific Journal of Cancer Prevention
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• 제16권7호
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• pp.3043-3050
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• 2015

The tumor microenvironment (TME) includes numerous non-neoplastic cells such as leukocytes and fibroblasts that surround the neoplasm and influence its growth. Tumor-associated macrophages (TAMs) and cancerassociated fibroblasts (CAFs) are documented as key players in facilitating cancer appearance and progression. Alteration of the macrophage (CD68, CD163) and fibroblast (${\alpha}-SMA$, FSP-1) cells in Opisthorchis viverrini (Ov) -induced cholangiocarcinoma (CCA) was here assessed using liver tissues from an established hamster model and from 43 human cases using immunohistochemistry. We further investigated whether M2-activated TAMs influence CCA cell migration ability by wound healing assay and Western blot analysis. Macrophages and fibroblasts change their phenotypes to M2-TAMs (CD68+, CD163+) and CAFs (${\alpha}-SMA+$, FSP-1+), respectively in the early stages of carcinogenesis. Interestingly, a high density of the M2-TAMs CCA in patients is significantly associated with the presence of extrahepatic metastases (p=0.021). Similarly, CD163+ CCA cells are correlated with metastases (p=0.002), and they may be representative of an epithelial-to-mesenchymal transition (EMT) with increased metastatic activity. We further showed that M2-TAM conditioned medium can induce CCA cell migration as well as increase N-cadherin expression (mesenchymal marker). The present work revealed that significant TME changes occur at an early stage of Ov-induced carcinogenesis and that M2-TAMs are key factors contributing to CCA metastasis, possibly via EMT processes.

• 한국생물정보학회:학술대회논문집
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• 한국생물정보시스템생물학회 2005년도 BIOINFO 2005
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• pp.63-68
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• 2005

Transcription factors regulate gene expression by binding to gene upstream region. Each transcription factor has the specific binding site in promoter region. So the analysis of gene upstream sequence is necessary for understanding regulatory mechanism of genes, under a plausible idea that assumption that DNA sequence motif profiles are closely related to gene expression behaviors of the corresponding genes. Here, we present an effective approach to the analysis of the relation between gene expression profiles and gene upstream sequences on the basis of kernel canonical correlation analysis (kernel CCA). Kernel CCA is a useful method for finding relationships underlying between two different data sets. In the application to a yeast cell cycle data set, it is shown that gene upstream sequence profile is closely related to gene expression patterns in terms of canonical correlation scores. By the further analysis of the contributing values or weights of sequence motifs in the construction of a pair of sequence motif profiles and expression profiles, we show that the proposed method can identify significant DNA sequence motifs involved with some specific gene expression patterns, including some well known motifs and those putative, in the process of the yeast cell cycle.

• Asian Pacific Journal of Cancer Prevention
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• 제16권4호
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• pp.1367-1370
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• 2015

Diagnosis of cholangiocarcinoma (CCA) is difficult when patients do not show jaundice. The aim of this study was to examine the feasibility of using the total serum bile acid (TSBA) level as an aid for the diagnosis of CCA in patients without jaundice. For this purpose, TSBA of the following groups were measured using a Beckman Synchron CX4 clinical chemistry analyzer: 60 cases of CCA with total serum bilirubin ${\leq}2mg/dL$ (low total bilirubin group, LTB); 32 cases of CCA with total serum bilirubin >2 mg/dL (high total bilirubin group, HTB); and 115 healthy controls. Liver function parameters such as serum cholesterol, albumin, alanine aminotransferase (ALT), aspartate aminotransferase (AST) and alkaline phosphatase (ALP) were also examined. The results showed that the TSBA of both LTB and HTB groups of the CCA patients were significantly higher than that of the healthy controls. Also, significant correlation was observed between TSBA and total bilirubin levels in the HTB group of CCA patients. However, no such correlation was seen in the LTB group. The cut-off value of TSBA was determined for the LTB group of CCA patients using the receiver operating characteristic curve analysis, and it was $6.05{\mu}mol/L$ with the sensitivity and specificity of 46.7% and 84.4%, respectively. In addition, the ALP level was correlated well with the TSBA level and ALP in HTB group was significantly higher than that of LTB group. Moreover, the combination of high TSBA and high ALP levels gave higher specificity up to 97.4%. TSBA might be useful for the diagnosis of CCA patients without jaundice.

• 한국환경생태학회지
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• 제20권4호
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• pp.365-373
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• 2006

인간 간섭에 영향을 크게 받는 인공호소가 대부분인 우리나라의 호소 특성과 보다 나은 생태계 관리 방안을 도출하고자 하는 목적에서 2005년 4개 호소의 이화학적 요인과 담수조류 정량분석에 의거한 기초자료를 바탕으로 통계학적 분석을 시도하였다. Canonical Correspondence Analysis(CCA)를 하구호인 남양호, 삽교호, 아산호 및 북한강 중하류 수계에 연쇄적으로 위치한 댐호 중 하나인 청평호에 적용하였다 그 결과, 청평호는 3개 하구호와 구분되는 특징을 보였으며, 청평호를 제외한 CCA결과, 아산호-삽교호-남양호 간에도 차이를 보여주었다. 담수조류 군집 구성은 제한된 자료량 때문인지 해석이 생태학적 해석에 어려움이 따랐다. 따라서, 보다 지속적이고 심화된 담수조류 연구 및 기타요인의 채집 및 분석이 수행될 필요가 있음이 나타났다. 그러나, 제한된 자료량에도 불구하고, 청평호 및 3개 호소의 큰 두 그룹으로 호소 그룹이 특징지워진 것은 CCA 적용이 유효함을 나타낸 것으로 보인다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제6권12호
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• pp.3046-3060
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• 2012

Low power listening (LPL) MAC protocols based on duty-cycling mechanism have been studied extensively to achieve ultra low energy consumption in wireless sensor networks (WSNs). Especially, recent ACK-based LPL schemes such as X-MAC employ strobe preambles and an early ACK, and show fair performances in communications and energy efficiencies. However, the state-of-the-art ACK-based LPL scheme still suffers from collision problems due to the protocol incompleteness. These collision effects are not trivial and make WSNs unstable, aggravate energy consumptions. In this paper, we propose two novel schemes; (i) ${\tau}$-duration CCA to mitigate the collision problem in ACK-based LPL MAC protocols. (ii) Short Preamble Counter (SPC) to conserve more energy by reducing unnecessary overhearing. We demonstrate the performance improvement of our scheme via a mathematical analysis and real-time experiments. Both analysis and experimental results confirm that our proposed scheme saves energy by up to 36% compared to the naive ACK-based LPL MAC protocol thanks to ${\tau}$-duration CCA and SPC.

• 한국환경생태학회지
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• 제6권2호
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• pp.113-126
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• 1993

소백산국립공원 희방계곡의 삼림군집구조분석을 위하여 25개소에 조사구(1개 조사구당 500$m^2$면적)를 설치하고 식생조사를 실시하여 TWINSPAN에 의한 classification 분석과 ordination기법의 일종인 DCA와 CCA를 적용하였다. DCA에 의해 군집은 4개로 분리되었고. 나뉘어진 군집은 소나무군집, 신갈나무-소나무군집, 신갈나무-노각나무-서어나무군집, 신갈나무-당단풍군집이었다. 환경인자와 조사지 및 수종과의 관계를 분석한 CCA에서는 토양환경이 변화되지 않은 2차 천이 초기단계를 나타내었다. 두 기법에 의해 추정된 천이과정에서 교목상층은 해발 800m이하에서 소나무$\longrightarrow$신갈나무, 졸참나무$\longrightarrow$서어나무(노각나무) 순이었고, 교목하층 및 관목층에서는 진달래, 철쭉, 개옻나무$\longrightarrow$쪽동백나무, 생강나무$\longrightarrow$함박꽃나무, 참개암나무 순으로 추정되었다. 환경인자의 ordination분석에서는 천이가 진행될 수록 수분과 유기물의 토양성질들이 양호하여졌다.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2011년도 추계학술대회
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• pp.907-910
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• 2011

제철소에서 생산된 철판의 물류 자동화 시스템을 구축하는데 있어 각 철판에 기록된 정보를 정확하게 파악하여 효과적인 적재 및 운반 시스템을 갖추는 것이 관건이다. 이를 위하여 본 논문에서는 생산 및 운반 정보가 기록된 철판 영상을 분석하여 자동화 시스템을 구축하기 위한 문자 추출 기법을 제안한다. 철판 영상은 가로 방향으로 철판의 정보를 나타내는 문자열을 포함하고 있고, 이러한 문자열이 세로 방향으로 배치되어 있기 때문에 각 문자를 분리하기 위해서는 2차원 기법을 적용하도록 한다. 영상을 획득하는 환경에 따라 문자 분리 성능에 미치는 영향을 최소화하기 위하여 국부 특징을 반영한 효율적인 이진화 기법을 제안하고, 잡음 등에 민감한 특성을 제거하기 위하여 CCA(Connected Component Analysis)를 이용한 문자 여부를 판단하는 방법을 제안한다. 이렇게 분석된 영상에 대해 2차원 투영 기법을 적용하여 철판에 기록된 각 문자를 정확하게 분리하도록 한다. 제안된 문자 추출 기법은 높은 성능을 나타내면서도 저 복잡도를 가지도록 설계하여 제한된 자원을 이용하는 기기에 효과적으로 응용될 수 있다.

• 인터넷정보학회논문지
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• 제6권1호
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• pp.85-93
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• 2005

본 논문은 다량의 고차원 얼굴 표정 모션 데이터를 2차원 공간에 분포시키고, 애니메이터가 이 공간을 항해하면서 원하는 표정들을 실시간 적으로 선택함으로써 얼굴 표정 애니메이션을 생성하는 방법을 기술한다. 본 논문에서는 약 2400여개의 얼굴 표정 프레임을 이용하여 표정공간을 구성하였다. 표정공간의 생성은 임의의 두 표정간의 최단거리의 결정으로 귀결된다. 표정공간은 다양체 공간으로서 이 공간내의 두 점간의 거리는 다음과 같이 근사적으로 표현한다. 임의의 마커간의 거리를 표시하는 거리행렬을 사용하여 각 표정의 상태를 표현하는 표정상태벡터를 정의한 후, 두 표정이 인접해 있으면, 이를 두 표정 간 최단거리(다양체 거리)에 대한 근사치로 간주한다. 그리하여 인접 표정들 간의 인접거리가 결정되면, 이들 인접거리들을 연결하여 임의의 두 표정 상태간의 최단거리를 구하는데, 이를 위해 Floyd 알고리즘을 이용한다. 다차원 공간인 표정공간을 가시화하기 위해서는 CCA 투영기법을 이용하여 2차원 평면에 투영시켰다 얼굴 애니메이션은 사용자 인터베이스를 사용하여 애니메이터들이 2차원 공간을 항해하면서 실시간으로 생성한다.