• Asian Pacific Journal of Cancer Prevention
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• 제16권18호
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• pp.8567-8571
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• 2016

Background: The Cox model is known as one of the most frequently-used methods for analyzing survival data. However, in some situations parametric methods may provide better estimates. In this study, a Weibull parametric model was employed to assess possible prognostic factors that may affect the survival of patients with breast cancer. Materials and Methods: We studied 438 patients with breast cancer who visited and were treated at the Cancer Research Center in Shahid Beheshti University of Medical Sciences during 1992 to 2012; the patients were followed up until October 2014. Patients or family members were contacted via telephone calls to confirm whether they were still alive. Clinical, pathological, and biological variables as potential prognostic factors were entered in univariate and multivariate analyses. The log-rank test and the Weibull parametric model with a forward approach, respectively, were used for univariate and multivariate analyses. All analyses were performed using STATA version 11. A P-value lower than 0.05 was defined as significant. Results: On univariate analysis, age at diagnosis, level of education, type of surgery, lymph node status, tumor size, stage, histologic grade, estrogen receptor, progesterone receptor, and lymphovascular invasion had a statistically significant effect on survival time. On multivariate analysis, lymph node status, stage, histologic grade, and lymphovascular invasion were statistically significant. The one-year overall survival rate was 98%. Conclusions: Based on these data and using Weibull parametric model with a forward approach, we found out that patients with lymphovascular invasion were at 2.13 times greater risk of death due to breast cancer.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제48권5호
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• pp.284-291
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• 2022

Objectives: This study aimed to analyze the clinicopathological prognostic factors affecting the survival of patients with oral squamous cell carcinoma (OSCC). Materials and Methods: A retrospective study was conducted on patients with OSCC who received treatment at the Oral Oncology Clinic of the National Cancer Center (NCC) from June 2001 to December 2020. The patients' sex, age, primary site, T stage, node metastasis, TNM staging, perineural invasion (PNI), lymphovascular invasion (LVI), differentiation, surgical resection margin, smoking, and drinking habits were investigated to analyze risk factors. For the univariate analysis, a Kaplan-Meier survival analysis and log-rank test were used. Additionally, for the multivariable analysis, a Cox proportional hazard model analysis was used. For both analyses, statistical significance was considered when P<0.05. Results: During the investigation period, 407 patients were received surgical treatment at the NCC. Their overall survival rate (OS) for five years was 70.7%, and the disease-free survival rate (DFS) was 60.6%. The multivariable analysis revealed that node metastasis, PNI, and differentiation were significantly associated with poor OS. For DFS, PNI and differentiation were associated with poor survival rates. Conclusion: In patients with OSCC, cervical node metastasis, PNI, and differentiation should be considered important prognostic factors for postoperative survival.

• Asian Pacific Journal of Cancer Prevention
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• 제15권15호
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• pp.6455-6459
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• 2014

Background: Nasopharyngeal carcinoma (NPC) is the fourth most common cancer in Malaysia. The objective of this study was to determine the five-year survival rate and median survival time of NPC patients in Hospital Universiti Sains Malaysia (USM). Methods: One hundred and thirty four NPC cases confirmed by histopathology in Hospital USM between $1^{st}$ January 1998 and $31^{st}$ December 2007 that fulfilled the inclusion and exclusion criteria were retrospectively reviewed. Survival time of NPC patients were estimated by Kaplan-Meier survival analysis. Log-rank tests were performed to compare survival of cases among presenting symptoms, WHO type, TNM classification and treatment modalities. Results: The overall five-year survival rate of NPC patients was 38.0% (95% confidence interval (CI): 29.1, 46.9). The overall median survival time of NPC patients was 31.30 months (95%CI: 23.76, 38.84). The significant factors that altered the survival rate and time were age (p=0.041), cranial nerve involvement (p=0.012), stage (p=0.002), metastases (p=0.008) and treatment (p<0.001). Conclusion: The median survival of NPC patients is significantly longer for age ${\leq}50$ years, no cranial nerve involvement, and early stage and is dependent on treatment modalities.

• 한국산업보건학회지
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• 제27권3호
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• pp.231-237
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• 2017

Objectives: This study was conducted to determine firefighters' work-related accident rate and investigate the factors affecting their on-site safety. Methods: We developed a web-based self-reported questionnaire designed to inquire into firefighters' work-related accident experience and the factors (4M; Man, Machine, Media, Management) affecting firefighters' on-site safety. We distributed questionnaires to all members of firefighting organizations in South Korea by e-mail and 9,149 were returned, resulting in a response rate of 23.1%. Results: Fifteen point seven percent of the respondents reported work-related injuries within the past one year, and 35.1% answered that current accident investigation reports are not helpful for preventing the same accident from recurring. Among the 4M factors, the one most affecting firefighters' on-site safety in the order of priority is the Man factor, followed by Machine, Media, and Management. However, the results from detailed sub-categorical factors showed some differences. 'Lack of human resources', one of the Management factors, was the most influential (70.3%), followed by 'worn-out equipment' under the Machine factor (67.2%). The viewpoint of elements of the Man factor including 'forgetting instructions' and 'fatigue and illness' were significantly different according to firefighters' rank. The higher the firefighter's rank, the more they answered 'forgetting instructions,' while the opposite was the case for 'fatigue and disease'. Conclusions: The present firefighters' accident investigation report needs to be improved, and the 4M method could prove very useful. In addition, it is necessary to set up a proper firefighters' accident investigation and prevention system.

• Asian Pacific Journal of Cancer Prevention
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• 제15권14호
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• pp.5601-5605
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• 2014

Background: Agrocybe aegerita Lectin (AAL) has been identified to have high affinity for sulfated and ${\alpha}2$-3-linked sialic acid glycoconjugates, especially the sulfated and sialyl TF (Thomsen-Friedenreich) disaccharide. This study was conducted to investigate the clinicopathological and prognostic value of AAL in identifying aberrant glycosylation in colorectal cancer (CRC). Materials and Methods: Glycoconjugate expression in 59 CRC tissues were detected using AAL-histochemistry. Clinicopathological associates of expression were analyzed with chisquare test or Fisher's exact test. Relationships between expression and the various clinicopathological parameters was estimated using Kaplan-Meier analysis and Cox regression models. Results: AAL specific glycoconjugate expression was significantly higher in tumor than corresponding normal tissues (66.1% and 46.1%, respectively, p=0.037), correlating with depth of invasion (p=0.015) and TNM stage (p=0.024). Patients with lower expression levels had a significantly higher survival rate than those with higher expression (p=0.046 by log rank test and p=0.047 by Breslow test for overall survival; p=0.054 by log rank test and P=0.038 by Breslow test for progress free survival). A marginally significant association was found between AAL specific glycoconjugate expression and overall survival by univariate Cox regression analysis (p=0.059). Conclusions: Lower AAL specific glycoconjugate expression is a significant favorable prognostic factor for overall and progress free survival in CRC. This is the first report about the employment of AAL for histochemical analysis of cancer tissues. The binding characteristics of AAL means it has potential to become a powerful tool for the glycan investigation and clinical application.

• 한국콘텐츠학회논문지
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• 제20권12호
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• pp.221-229
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• 2020

본 연구는 개봉일 흥행순위, 특히 개봉일 흥행 1위 여부에 초점을 두고 영화의 최종 흥행 예측 지표를 탐색하고자 한다. 한국 영화시장의 최근 5년간(2013~2017년) 개봉작 총 794편의 자료에 대한 회귀분석을 통해, 개봉일 흥행 1위를 달성한 영화일수록 최종 흥행성과가 더 좋음을 확인하였다. 또한 영화의 질(quality)이 개봉일 흥행 1위 영화의 흥행에 추가적인 영향을 준다고 보기는 어려웠다. 개봉일 흥행 1위 여부 외에 개봉일 대비 일요일 상영횟수 증가 여부도 최종 관객 수에 영향을 가지는 것으로 나타났다. 개봉일 흥행 1위 영화 158편에 대한 추가 분석 결과, 개봉 2주차 관객증가율의 최종 흥행 설명력이 높았다. 영화의 개봉일 흥행과 최종 흥행 간의 상관계수를 연도별로 비교한 결과, 상관계수가 일관된 증가 추세를 보이지는 않았다. 본 연구는 영화 흥행에 대한 새로운 지표들을 발굴하고 해당 지표들의 최종 흥행에 대한 영향이 유의하다는 것을 확인하였다는 점에서 기존 연구와 차별성을 가진다고 볼 수 있다.

• ETRI Journal
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• 제28권2호
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• pp.205-215
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• 2006

Wireless data communication (WDC) services are increasingly penetrating the market. The two main alternative WDC technologies are wireless LAN and mobile Internet. Services based on these technologies display differences in quality attributes such as terminal device, data transmission speed, pricing scheme and so on. How consumers choose between these two alternatives will be determined by their preferences regarding such quality attributes. In turn, their preferences will affect the evolution of WDC services and related technologies. This study employs a conjoint analysis of consumer valuations of quality attributes of wireless LAN and mobile Internet services. Respondents rate hypothetical service alternatives featuring various combinations of quality attributes. By estimating consumer willingness to pay for the attributes of WDC services, the authors predict the evolution of WDC services and related technologies along various quality dimensions, make a comparison with the results of a previous study, and draw policy implications for national-and company-level R&D strategies.

• Journal of Radiation Protection and Research
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• 제15권2호
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• pp.101-112
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• 1990

For the performance assessment of the radioactive waste disposal system (repository), a biosphere model is suggested. This biosphere model is intended to calculate the annual doses to man caused by the contaminated river water for eight pathways and four radionuclides. This model can also be applied to assess the radiological effects of contaminated well water. To account for the uncertainties on the model parameter values, parameter distributions are assigned to these model parameters. Then, Monte Carlo simulation method with Latin Hypercube sampling technique is used. Also, sensitivity analysis is performed by using the Spearman rank correlation coefficients. It is found that these methods are a very useful tool to treat uncertainties and sensitivities on the model parameter values and to analyze the biosphere model. A conversion factor is proposed to calculate the annual dose rate to humans arising from a unit radionuclide concentration in river water. This conversion factor allows for the substitution of the biosphere model in a probabilistic performance assessment computer code by one single variable.

• Journal of Gastric Cancer
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• 제1권4호
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• pp.197-201
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• 2001

Purpose: There are variants of gastric cancer assoclated with predominantly peritoneal spread of with haematogenous metastases. Perioperative intraperitoneal chemotherapy as an adjuvant to surgery is considered as a rational therapeutic modality to prevent peritoneal spread. We evaluated the influence of early postoperative intraperitoneal chemotherapy on the prognosis of resectable advanced gastric cancer. Materials and Methods: From 1990 to 1995, 246 patients with biopsy proven advanced gastric cancer were enrolled in the study. Among them 123 patients received early postoperative intraperitoneal mitomycin C and 5-fluorouracil. The survival rate was calculated using by the Kaplan-Meier method and was compared using the log-rank test according to 13 clinico-pathologic factors. Multivariate analysis was performed with the Coxproportional hazards model. Results: Gastric resection plusearly postoperative intraperitoneal chemotherapy showed an improved survival rate as compared to surgery alone ($54.1\%\;versus\;40.3\%;$ P=0.0325). Depth of tumor invasion, degree of regional lymph vode metastasis, distant metastasis, tumor size, tumor location, extent of gastric resection, and curability of surgery significantly influenced survival. When a multivariate analysis was performed, depth of tumor invasion, lymph node metastasis, early postoperative intraperitoneal chemotherapy, curability of surgery, and extent of gastric resection emerged as the statistically significant and independent prognostic factors. Conlusion: Early postoperative intraperitoneal chemotherapy is one of the independent prognostic indicators of resectable advanced gastric cancer.

• 한국생물정보학회:학술대회논문집
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• 한국생물정보시스템생물학회 2003년도 제2차 연례학술대회 발표논문집
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• pp.101-106
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• 2003

In this paper, we propose using Hotelling's T2 statistic for the detection of a set of a set of differentially expressed (DE) genes in colorectal cancer based on its gene expression level in tumor tissues compared with those in normal tissues and to evaluate its predictivity which let us rank genes for the development of biomarkers for population screening of colorectal cancer. We compared the prediction rate based on the DE genes selected by Hotelling's T2 statistic and univariate t statistic using various prediction methods, a regulized discrimination analysis and a support vector machine. The result shows that the prediction rate based on T2 is better than that of univatiate t. This implies that it may not be sufficient to look at each gene in a separate universe and that evaluating combinations of genes reveals interesting information that will not be discovered otherwise.