• 한국멀티미디어학회논문지
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• 제19권10호
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• pp.1782-1791
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• 2016

Various color spaces such as RGB, HSV, log-chromaticity have been used in the field of person re-identification. However, not enough studies have been done to find suitable color space for the re-identification. This paper reviews color invariance of color spaces by diagonal model and explores the suitability of each color space in the application of person re-identification. It also proposes a method for person re-identification based on a histogram refinement technique and some fusion strategies of color spaces. Two public datasets (ALOI and ImageLab) were used for the suitability test on color space and the ImageLab dataset was used for evaluating the feasibility of the proposed method for person re-identification. Experimental results show that RGB and HSV are more suitable for the re-identification problem than other color spaces such as normalized RGB and log-chromaticity. The cumulative recognition rates up to the third rank under RGB and HSV were 79.3% and 83.6% respectively. Furthermore, the fusion strategy using max score showed performance improvement of 16% or more. These results show that the proposed method is more effective than some other methods that use single color space in person re-identification.

• 응용통계연구
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• 제11권1호
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• pp.113-127
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• 1998

생존자료의 분석에 있어 두 집단간의 생존분포의 비교는 자주 관심의 대상이 되고 있다. 중도절단(censoring)이 존재하는 생존자료에 있어 두 생존분포의 동일성을 검정하는 방법으로 log-rank 통계량과 Gehan의 일반화된 Wilcoxon 통계량에 근거한 검정법이 주로 사용되어 왔다. 그러나 이 두 가지 검정통계량이 어떤 상황에서나 적절한 것은 아니고, 두 생존분포의 여러가지 형태와 중도절단의 정도에 따라 통계량의 검정력은 크게 달라진다. 따라서 본 논문에서는 두 생존분포의 비교를 위해 제안된 몇 가지 검정통계량들을 여러가지 상황에서 모의실험을 통하여 비교하고, 그 결과를 토대호 주어진 상황에서 적절한 통계량을 선택하는데 대한 유용한 정보를 제공하였다.

• Genomics & Informatics
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• 제13권3호
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• pp.86-89
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• 2015

Because there are clear molecular differences entailing different treatment effectiveness between Korean and non-Korean cancer patients, identifying distinct molecular characteristics of Korean cancers is profoundly important. Here, we report a web-based data repository, namely Korean Cancer Genome Database (KCGD), for searching gene signatures associated with Korean cancer patients. Currently, a total of 1,403 cancer genomics data were collected, processed and stored in our repository, an ever-growing database. We incorporated most widely used statistical survival analysis methods including the Cox proportional hazard model, log-rank test and Kaplan-Meier plot to provide instant significance estimation for searched molecules. As an initial repository with the aim of Korean-specific marker detection, KCGD would be a promising web application for users without bioinformatics expertise to identify significant factors associated with cancer in Korean.

• Asian Pacific Journal of Cancer Prevention
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• 제13권10호
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• pp.5033-5036
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• 2012

Objective: To study the relationship between expression of $p57^{KIP2}$ and prognosis and other clinicopathological parameters in invasive breast cancers. Methods: We assessed the expression of $p57^{KIP2}$ in 89 cases of invasive breast cancer and 20 cases of normal breast tissue by immunohistochemical methods and analyzed the results with SPSS software (ver. 16.0). Result: The positive expression rates of $p57^{KIP2}$ protein in the invasive breast cancers and surrounding normal tissue were 30.3% (27/89) and 65% (13/20), respectively. Cases with no $p57^{KIP2}$ expression exhibited a significantly higher post-operative distant metastasis rate than those with $p57^{KIP2}$ expression (37.9% vs. 14.8%; P = 0.01). DFS analysis showed that $p57^{KIP2}$-/C-erbB-2+ tumors also exhibited a significantly higher post-operative distant metastasis rate than the other groups (66.7% vs. 29.2%; P = 0.007), as did $p57^{KIP2}$-/p53+ tumors (64.3% vs. 22.7%; P = 0.001). Survival analysis revealed that $p57^{KIP2}$ was associated with breast cancer-specific survival overall (P = 0.045, log-rank test). Subgroup analysis demonstrated that individuals with $p57^{KIP2}$-/C-erbB-2+tumors experienced significantly worse post-operative survival than those with $p57^{KIP2}$-/C-erbB-2- or other tumors (P = 0.006, log-rank test). $p57^{KIP2}$-/p53+ tumors were associated with significantly worse post-operative survival than $p57^{KIP2}$-/p53- or other tumors (P = 0.001, log-rank test). Cox regression analysis showed that $p57^{KIP2}$ was a non-independent prognostic factor for breast cancer (P = 0.303). Conclusions: $p57^{KIP2}$ is expressed at low levels in invasive breast cancer and is associated with better overall survival rate and disease-free survival in breast cancer patients, but it was a non-independent prognostic factor for breast cancer. Thus, the connection between $p57^{KIP2}$/p53 and $p57^{KIP2}$/C-erbB-2 may provide biomarkers for breast cancer.

• Journal of Chest Surgery
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• 제40권2호
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• pp.109-113
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• 2007

배경: 비소세포폐암에 흔히 발생하는 악성 흉수는 환자의 예후에 나쁜 인자로 작용하여, 원격전이가 발생한 환자들과 비슷한 생존기간을 보인다. 비소세포폐암에 발생하는 악성 흉수의 진단과 치료에 대한 연구는 많이 이루어졌으나, 환자의 예후에 영향을 미치는 인자에 대한 연구는 많지 않다. 저자들은 악성 흉수가 발생한 비소세포폐암 환자들의 예후에 영향을 미치는 예후 인자들을 알아보고자 연구를 시행하였다. 대상 및 방법: 2002년 1월부터 2003년 12월까지 악성 흉수를 동반한 비소세포폐암으로 치료를 받은 환자 33명을 대상으로 하였다. 환자의 예후에 영향을 미칠 가능성이 있는 환자의 특성(성별, 연령), 폐암 조직형 및 병기, 흉수 천자액 검사(pH, CEA, LDH, glucose, albumin), 흉수 발견 후 치료 방법을 인자로 설정하여 조사하였다. 각 인자의 생존기간을 Kaplan-Meier법으로 구한 후, log-rank test를 통한 단변량분석으로 인자 각 군의 생존기간 차이를 비교하였고, 환자의 예후에 영향을 미치는 독립적 예후 인자를 찾기 위해 다변량분석으로 Cox Regression을 실시하였다. 결과: 대상환자 33명의 폐암 조직형은 선암이 23명으로 가장 많았다. 폐암과 악성 흉수가 동시에 진단된 경우를 제외하면 폐암 진단 후 악성 흉수가 진단되기까지의 중앙값 기간은 7.3개월($25^{th}{\sim}75^{th}:\;3.9{\sim}11.8$)이었다. 환자의 중앙값 생존기간은 3.6개월(95% Confidence Interval: $1.14{\sim}5.99$)이었다. 단변량분석에선 폐암 조직형이 유의성은 떨어지나 생존기간에 차이를 보였다(선암 4.067 vs. 비선암 1.867 개월, p=0.067). 교란변수의 영향을 제거한 다변량분석에서 통계적 유의성은 없으나 비선암이 선암보다 사망위험도가 높아지는 경향을 보였다(R.R 2.754, 95% Cl $0.988{\sim}7.672$, p=0.053). 결론: 본 연구에서 저자들은 악성흉수가 발생한 비소세포폐암 환자들의 예후에 영향을 미치는 예후 인자를 확인할 수 없었다. 그러나 조직형에 따라 암사망 위험도에 차이를 보이는 경향이 관찰되어 향후 이에 대한 연구가 필요할 것이다.

• Asian Pacific Journal of Cancer Prevention
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• 제16권10호
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• pp.4421-4427
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• 2015

Objectives: To investigate the prognosis significance of preoperative serum alpha-fetoprotein (AFP) and the correlation with clinicopathological factors of hepatocellular carcinoma (HCC) patients who underwent hepatectomy. Materials and Methods: Clinicopathological data of retrospective analysis were collected for 251 HCC patients undergoing hepatectomy in this study. According to preoperative AFP level, patients were categorized into AFP-negative (0-20ng/mL) and AFP-positive (>20 ng/mL) groups for Kaplan-Meier analysis and Cox proportional hazard regression modeling. Results: The results demonstrated that increased AFP was associated with longer prothrombin time (PTs), liver capsule invasion, low grade differentiation, and late Barcelona Clinic Liver Center (BCLC) stage. Moreover, the female patients had a greater prevalence of increased preoperative AFP than male patients [284.8 (3.975-3167.5) vs (3.653-140.65); Z-2.895, p=0.004]. The 1-, 3-, and 5-year recurrence-free survival (RFS) rates were 78.1, 57.5, and 40.6 % in the AFP-negative group and 61.8, 37.7, and 31.4 %, respectively, in the AFP-positive group (log-rank test 8.312, p=0.004). The 1-, 3-, and 5-year overall survival (OS) rates were 94.4, 83.8, and 62.3% in the AFP-negative group and 87.2, 60.0, and 36.7%, respectively, in the AFP-positive group. The difference was statistically significant (log-rank test, 16.884, p=0.000). Cox proportional-hazards model identified preoperative AFP to be an independent prognostic predictor of overall survival. Conclusions: Preoperative serum AFP is an independent predictor of prognosis among HCC patients following surgical resection. Female patients have a higher preoperative AFP than their male counterparts.

• Journal of Korean Neurosurgical Society
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• 제54권5호
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• pp.399-404
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• 2013

Objective : The authors conducted a retrospective cohort study to determine prognostic factors and treatment outcomes of brain metastases (BM) from breast cancer (BC) after Gamma Knife radiosurgery (GKS). Methods : Pathologic and clinical features, and outcomes were analyzed in a cohort of 62 patients with BM from BC treated by GKS. The Kaplan- Meier method, the log-rank test, and Cox's proportional hazards model were used to assess prognostic factors. Results : Median survival after GKS was 73.0 weeks (95% confidence interval, 46.0-100.1). HER2+ [hazard ratio (HR) 0.441; p=0.045], Karnofsky performance scale (KPS) ${\geq}70$ (RR 0.416; p=0.050) and systemic chemotherapy after GKS (RR 0.282; p=0.001) were found to be a favorable prognostic factor of overall survival. Actuarial local control (LC) rate were $89.5{\pm}4.5%$ and $70.5{\pm}6.9%$ at 6 and 12 months after GKS, respectively. No prognostic factors were found to affect LC rate. Uni- and multivariate analysis revealed that the distant control (DC) rate was higher in patients with; a small number (${\leq}3$) of metastasis (HR 0.300; p=0.045), no known extracranial metastasis (p=0.013, log-rank test), or the HER2+ subtype (HR 0.267; p=0.027). Additional whole brain radiation therapy and metastasis volume were not found to be significantly associated with LC, DC, or overall survival. Conclusion : The treatment outcomes of patients with newly diagnosed BM from BC treated with GKS could be affected primarily by intrinsic subtype, KPS, and systemic chemotherapy. Therapeutic strategy and prognosis scoring system should be individualized based on considerations of intrinsic subtype in addition to traditionally known parameters related to stereotactic radiosurgery.

• Journal of Chest Surgery
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• 제40권10호
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• pp.680-684
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• 2007

배경: IB기 비소세포폐암의 가장 효과적인 치료는 완전 절제이나, 수술 후 재발이 생기면 생존율이 떨어진다. 최근 IB기 비소세포폐암의 완전 절제 후 시행하는 보조 요법에 대해 관심이 높아지고 있다. 적절한 보조 요법을 사용하기 위해서는 재발의 위험 인자를 아는 것이 중요하다. 대상 및 방법: 114명을 대상으로 연구하였으며, 환자의 성별, 나이, 수술 방법, 조직학적 유형, 분화의 정도, 종양의 크기, 장측 흉막 침범 유무 등과 재발과의 관계를 분석하였다. 생존율과 무재발률은 Kaplan-Meier 방법으로 구하였으며, log rank test로 단변량 분석을, Cox's proportional hazard model을 이용하여 다변량 분석을 하였다. p값이 0.05 미만인 경우에 통계학적으로 유의하다고 판정하였다. 결과: 3년 생존율 및 무재발률은 각각 87.0%, 79.4%였다. 단변량 분석에서 분화도가 통계학적으로 의미가 있었으며, 다변량 분석에서도 저분화의 경우가 예후가 좋지 않았다. 결론: 완전 절제된 IB기 비소세포폐암 환자에서 저분화도가 재발과 연관된 인자이므로 수술 후 보조 요법이 필요할 것으로 기대된다.

• Journal of Chest Surgery
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• 제29권5호
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• pp.517-523
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• 1996

원자력병원에서는 1988년 5월부터 1994년 6월까지 373명의 비소세포 폐암 환자를 개흥하였으며, 이 중 병 리 학적 병기 lIIB로 판명된 48명의 겨록을 분석하였다. 74 병소는 대 혈관(26례), 심장(5례), 동측폐 전이 (4ET ), 식도(4El ), 기관 분기를(3례), 종격동(2례), 기관(1례), 및 척추 체부(1례) 등의 침범과 늑막 파종(늑막 전이, 15례)이었다. 수술은 48명중 25명에서 확대 폐절제및 림프절 절제를 시행하였으나, 23 례 에서는 시험 개흥술만 시행하였으며, 가장 흔한 절제 불가능의 원인은 늑막 파종이 었다. 절제 군의 수 술 유병률과 사망률은 각각 32 % (8125), 16 % (4125)이었고, 시험 개흥술 군에서는 각각 4% (1123), 0% (0123)이었다 수술 후 대부분의 환자에서 (37148) 항암 치료 또는 방사선 치료 등의 보조요법을 병 행하였 다. 수숲 후 1년 및 3년 생존률은 수술 사망을 포함하여 절제 군에서는 각각 57.2%, 23.8 % (중앙값, 15개 횡)이 었으며, 시험 개흥군에서는 각각 48.4%, 0 % (중앙값, 7개 월)이 었다(Log-Rank test, p = 0.17). 이상의 결과로,74환자의 일부에서 확대 폐절제의 역할이 인정 된다고 할 수 있으나 수술의 위험성 이 높으므 \ulcorner환자의 선택에 신중을 기해야 하며, 불필요한 개흥을 피하기 위해서는 늑막 파종과 종격동 구조물의 침습을수술전에 발견하기 위한보다 정교한 진단 및 병기 결정 과정이 요구된다.

• Journal of Gastric Cancer
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• 제19권3호
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• pp.329-343
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• 2019

Purpose: Gastric cancer with lymph node metastasis (LNM) more than 15 (N3b) was defined as stage IV until the 6th AJCC system. However, it has been reclassified as a localized disease (stage IIb or III) since the 7th system. The aim of this study is to demonstrate that the survival of N3b is comparable to cytology-only positive (CY1-only) stage IV and to propose a new TNM system interpreting N3b as an eligibility criterion for receiving more intensive chemotherapy regimens. Materials and Methods: 1,430 patients who underwent gastric cancer surgery at Seoul National University Hospital from 2007 to 2012 were retrospectively analyzed. The 5-year survival rate (5YSR) and 3-year recurrence-free survival (RFS) were evaluated according to the 7th and 8th systems, as well as a new categorization based on N-classification; N0-2 (LNM<7), N3a (LNM 7-15), or N3b (LNM>15). Results: The survival of N3b is comparable to that of CY1-only stage IV (log rank test, P=0.671) and is distinct from that of grossly stage IV (log rank test, P<0.001). The survival of the remaining stage IIIc (T4bN3a) was comparable to those of N3b and CY1-only stage IV. Most N3b patients had significantly shorter 3-year RFS and mean RFS than those with IIb-IIIc, as if N3b itself was a higher TNM stage. Conclusions: In terms of survival, T4bN3a, N3b, and CY1-only stage IV were unified as stage IVa, while grossly stage IV was defined as stage IVb. N3b can be regarded as an eligibility criterion for undergoing more intensive chemotherapy regimens.