• The Korean Journal of Applied Statistics
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• v.20 no.1
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• pp.39-52
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• 2007

Crossover trials of new drugs in the treatment of angina pectoris, which frequently use treadmill exercise test for the assessment of its efficacy, produce censored survival times. In this paper we consider analysis approaches for censored survival times from crossover trials. Previously, a stratified Cox model for paired observation and nonparametric methods have been presented as possible analysis methods. On the other hand, the differences of two survival times would produce interval-censored survival times and we propose a Cox model for interval-censored data as n alternative analysis method. Example data is analyzed in order to compare these different methods.

• Radiation Oncology Journal
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• v.4 no.1
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• pp.45-50
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• 1986

RTOG proposed a multivariate modelling system predicting the response of head and neck cancers to radiation therapy in 1984. The aim of this study was to veri(y whether PPC (Probaility of primary clearance calculated by a multivariate modelling system) had any correlation with the survival in the patients with carcinoma of the nasopharynx following radiation therapy Analysing 81 patients with carcinoma of the nasopharynx treated with radiotherapy between January 1, 1971 and December 31, 1983 at Yonsei University College of Medicine, Yonsei Cancer Center the actuarial 5 year survival rate was $36\%$ and median survival was 39 months. The survivals for Group 1 (27 who had more than $80\%$ of PPC), Group 2 (20 who had between 71 and $80\%$ of PPC), and Group 3 (29 who had less than $71\%$ of PPC) were $66\%$ (median survival months : more than 72), $27\%$ (31), and $4\%$ (12) respectively. There was a definite correlation between PPC and survival among the three groups.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2001.05a
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• pp.381-382
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• 2001

다슬기 (Semisulcospira libertina libertina)는 식용으로 기호도가 높고 유용 수산자원으로서 개발 가치가 높으나 성장이나 자원량에 관한 기초 생물학적인 조사는 충분히 이루어지지 않고 있다. 최근에는 중금속, 농약 등에 오염될 가능성이 있어 자연산 다슬기의 식용 가능성 여부가 불투명한 상태에 이르고 있으며, 자연자원도 급격히 줄어 들고 있는 실정이다. 따라서 다슬기의 종묘생산 및 양식기술 개발에 대한 관심이 고조되고 있으며, 이 종에 대한 번식생물학적인 연구 (Chang et al., 2000)가 진행되고 있으나, 다슬기 종묘의 성장 상황에 대한 기준 자료는 찾아보기 힘들다. (중략)

• Journal of the Korean Data and Information Science Society
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• v.23 no.1
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• pp.1-11
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• 2012

When the microarray experiment developed, main interest was limited to detect differentially expressed genes associated with a phenotype of interest. However, as human diseases are thought to occur through the interactions of multiple genes within a same functional category, the unit of analysis of the microarray experiment expanded to the set of genes. For the phenotype of censored survival time, Gene Set Enrichment Analysis(GSEA), Global test and Wald type test are widely used. In this paper, we modified the Wald type test by adopting normal score transformation of gene expression values and developed a parametric test which requires much less computation than others. The proposed method is compared with other methods using a real data set of ovarian cancer and a simulation data set.

• Journal of Industrial Convergence
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• v.21 no.1
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• pp.111-122
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• 2023

The purpose of this study is to verify the factors affecting survival time by estimating survival rate and survival time using non-financial information of social enterprises using credit guarantee in credit guarantee institutions, and provide information to stakeholders to improve survival rate and employ to contribute to maintaining and expanding the As a research method, survival analysis was performed using a non-parametric analysis method, Kaplan-Meier Analysis. As a sample, 621 companies (577 normal companies, 44 insolvent companies) established between 2009 and 2018 were selected as the target companies. As a result of examining the factors affecting survival time by classifying social enterprise representative information and corporate information, representative credit rating, representative home ownership, credit transaction period, and corporate credit rating were derived as significant variables affecting survival time. In the future, financial institutions will be able to induce corporate soundness by reflecting factors that affect survival when examining loans for social enterprises, contributing to job retention and reduction of social costs. Supporting organizations such as the government and private organizations will be able to use it in various ways, such as policy establishment and education and training for the growth and sustainability of social enterprises. With this study as an opportunity, I hope that research will continue with more interest in the factors influencing social enterprise performance as well as corporate insolvency.

• Korean Journal of Ecology and Environment
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• v.42 no.1
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• pp.134-138
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• 2009

The survival rate of PIT tagged fish was investigated for five Korean Cyprindae fish species, Acheilognathus lanceolatus (n=18, total length : $92.5{\pm}13.1mm$; body weight : $9.6{\pm}4.3g$), Hemibarbus labeo (n=28, TL : $220{\pm}74.4mm$; BW : $91.8{\pm}76.2g$), Zacco koreanus (n=13, TL : $116.5{\pm}23.8mm$; BW : $13.6{\pm}10.6g$), Zacco platypus (n=108, TL : $100.6{\pm}17.8mm$; BW: $8.7{\pm}4.8g$), Opsariichthys uncirostris amurensis (n=6, TL : $161.8{\pm}26.3mm$; BW : $27.5{\pm}18.3g$) with respect to applicability and effectiveness of PIT tagging. The survival rate were daily checked for 30 days. The survival rate was the highest and lowest for Z. koreanus and Z. platypus, respectively. The survival days were greater as fish total length increased. Based on these results, PIT tagging is not effective for Z. platypus, while PIT tagging for fish>150 mm was effect for field research.

• The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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• v.11 no.4
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• pp.16-25
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• 2000

전자전에 투입되는 군장비들의 생존 가능성은 피탐지율과 밀접한 관련이 있다. 이러한 피탐지율을 줄이기 위해서는 레이다 단면적(RCS)의 주요 산란원에 관한 연구와 레이다 단면적 예측 기술에 대한 이해가 선행되어야 한다. 본 논문에서는 레이다 단면적을 예측하는 기술과 레이다 단면적을 측정할 수 있는 단축걸 전계 측정 무반향실(Compact range)에 대해 소개한다.

• Journal of Navigation and Port Research
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• v.47 no.6
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• pp.331-340
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• 2023

Predicting the survival time of a person in water (PIW) in maritime search and rescue (SAR) operations is an important concern. Although there have been many studies on survival models in marine-developed countries, it is difficult to apply them to Koreans in Korea's oceans because they were developed using marine distress data from the United Kingdom, United States, and Canada. Data on the survival time of a P IW were collected through interviews and surveys with a special rescue team from the Korea Coast Guard, SAR cases, press releases, and Korea Meteorological Administration data to address these issues. The maximum survival time (Korean) equation was developed by performing a regression analysis of this data, and the applicability to actual marine distress was reviewed and compared to the overseas survival model. By comprehensively using the maximum survival time (Korean), domestic SAR cases, and overseas survival models, guidelines for survival time and intensive and recommended search time were suggested. The study findings can contribute to decision-making, such as the input for search and rescue units. The findings can also help to determine the end of or reductions in SAR operations and explain policy decisions to the public and families of a PIW.

• Journal of the Korean Applied Science and Technology
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• v.39 no.3
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• pp.462-470
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• 2022

The purpose of this study was to investigate the role of the Nypa fruticans extracts as a cosmetic additive. The tyrosinase inhibitory effects showed 52.0% at 1,000 ㎍/mL concentration. A cell viability test, measured on melanoma cell (B16F10) hot water extract of nypa fruticans showed 84.8% at 100 ㎍/mL concentration. The protein expression inhibitory effects of nypa fruticans extracts were measured by western blot at 25, 50, 100 ㎍/mL concentration and the β-actin. Results showed that the expression inhibition rates of the MITF, TRP-1, TRP-2, tyrosinase protein were decreased by 70.7%, 83.3%, 45.7%, 45.9% at 100 ㎍/mL concentration, respectively. It was concluded that nypa fruticans extracts had the whitening effects and thus could be applied for cosmetics as a natural ingredient.

• The Korean Journal of Malacology
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• v.27 no.3
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• pp.199-204
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• 2011

We studied possibility of the sowing culture at the bottom after intermediate culture as a method for raising the survival of the Purplish Washington clam, Saxidomus purpuratus. The pearl net ($35cm(W){\times}35cm(B){\times}20cm(H)$) for S. prupuratus spat during the period of intermediate culture (hanging culture) from April to October in 2010. The pearl net (100 inds./net) was installed at two stations (Namhae and Pohang) being about 3-4 m in water depth. After hanging culture, S. prupuratus spat sowed in the bottom of the Gangjin Bay. The survivals (%) of intermediate culture of this species at Namhae station and Pohang station were 73% and 74%, respectively. Daily growth rate of mean shell length and mean weight in Namhae station were higher than those in Pohang station. After sowing at the bottom of the Gangjin Bay, its survival (%) showed 73.98% in January 2011. These results suggested the possibility of the intermediate culture as hanging culture for raising survival rate of S. prupuratus.