• 한국전자거래학회지
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• 제26권1호
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• pp.43-65
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• 2021

정보통신기술의 발달에 따라 IT 인력 채용 방식에도 많은 변화가 생겼다. 채용 담당자들은 이력서나 면접과 같은 전통적인 정보 이외에도 웹에서 구직자 정보를 검색할 수 있다. 오픈소스 소프트웨어 개발(OSSD) 플랫폼은 개발자들이 자연스럽게 IT 역량을 발휘할 수 있는 곳이자, 채용 담당자들이 적합한 후보를 찾을 수 있는 장소가 되었다. 이러한 맥락에서 본 연구는 취업 시 OSSD 플랫폼의 개발자 정보(구직 활동 여부, 개인정보 게시 정도, 학습 활동 정도, 지식공헌 활동 정도)가 취업에 미치는 영향을 분석하였다. 실증분석을 위해 웹 크롤러를 개발하여 대표적인 OSSD 플랫폼인 깃허브의 개발자 4,005명을 대상으로 데이터를 수집했다. 구직 기간이 짧다는 것은 취업의 성공적인 결과를 의미하기 때문에 구직 기간에 영향을 미치는 요인을 살펴보기 위해 생존분석법을 실시하였다. 본 연구의 결과에 따르면, 구직 현황을 명시적으로 게시한 개발자가 그렇지 않은 개발자보다 구직 기간이 짧은 것으로 나타났다. 개인정보 게시 정도, 학습 활동 및 지식공헌 활동 정도 또한 구직기간 단축과 긍정적으로 관련이 있는 것으로 나타났다. 본 연구는 향후 채용 담당자의 성공적인 구인뿐만 아니라 개발자의 효과적인 구직을 위한 OSSD 플랫폼의 전략적인 활용 방안에 시사점을 제시해줄 것이다.

• Asian Pacific Journal of Cancer Prevention
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• 제17권5호
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• pp.2643-2648
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• 2016

Background: High-sensitivity C-reactive protein (hsCRP) levels are lower in Japanese compared with Western subjects. Since it is uncertain whether hsCRP is a potent predictor of mortality at low CRP concentrations, the present study examined associations with all-cause and cause-specific mortality in a large population of Japanese. Materials and Methods: Subjects were 4,737 men and 6,343 women aged 49-76 years participating in the baseline survey of an ongoing cohort study of lifestyle-related diseases between February 2004 and July 2006. Hazard ratios for all-cause and cause-specific mortality associated with hsCRP levels were estimated using Cox proportional hazards regression. Results: A total of 436 all-cause deaths occurred during a median follow-up of 8 years. The main cause of death was cancer. In men, hsCRP levels were positively associated with the risk of all-cause mortality as well as deaths from cancer and cardiovascular disease (CVD). All-cause mortality hazards for the 2nd (0.34-0.84 mg/L) and the 3rd (${\geq}0.85mg/L$) tertiles of hsCRP were 1.27 (95% confidence interval [CI], 0.93-1.73) and 1.75 (1.30-2.37), respectively (p for trend=0.001). In women, increased risk of all-cause and cause-specific mortality associated with elevated hsCRP levels was observed, but the associations were not statistically significant. Conclusions: HsCRP may be an independent predictor of all-cause, cancer and CVD mortality in apparently healthy Japanese men, but not women. The differential effect of hsCRP in predicting mortality risk by sex warrants further investigation.

• Asian Pacific Journal of Cancer Prevention
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• 제15권1호
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• pp.185-190
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• 2014

Influence of loneliness on human survival has been established epidemiologically, but genomic research remains undeveloped. We identified 34 loneliness-associated genes which were statistically significant for high-lonely and low-lonely individuals. With the univariate Cox proportional hazards regression model, we obtained corresponding regression coefficients for loneliness-associated genes fo individual cancer patients. Furthermore, risk scores could be generated with the combination of gene expression level multiplied by corresponding regression coefficients of loneliness-associated genes. We verified that high-risk score cancer patients had shorter mean survival time than their low-risk score counterparts. Then we validated the loneliness-associated gene signature in three independent brain cancer cohorts with Kaplan-Meier survival curves (n=77, 85 and 191), significantly separable by log-rank test with hazard ratios (HR) >1 and p-values <0.0001 (HR=2.94, 3.82, and 1.78). Moreover, we validated the loneliness-associated gene signature in bone cancer (HR=5.10, p-value=4.69e-3), lung cancer (HR=2.86, p-value=4.71e-5), ovarian cancer (HR=1.97, p-value=3.11e-5), and leukemia (HR=2.06, p-value=1.79e-4) cohorts. The last lymphoma cohort proved to have an HR=3.50, p-value=1.15e-7. Loneliness-associated genes had good survival prediction for cancer patients, especially bone cancer patients. Our study provided the first indication that expression of loneliness-associated genes are related to survival time of cancer patients.

• 지질공학
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• 제14권4호
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• pp.429-442
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• 2004

1999년 부산광역시에서 발생한 황령산 산사태는 평면파괴 형태였다 그 후, 황령산 절개사면은 재시공 되었으며 최종 구배는 1:2.0이었다. 수평변위, 간극수압 및 축력을 측정하기위하여 공사중인 2000년 8월부터 2002년 2월까지 파괴사면에 대한 계측이 실시되었다. 계측결과를 종합 고려하면, 강우량에 비례해서 간극수압이 증가되지만 강우 후 지반의 압력수두가 신속히 감소하여, 지표에서 유입된 강우가 사면을 따라 신속히 배출되는 것으로 사료된다. 또한, 경사계 및 하중계 계측자료의 분석결과, 지반의 거동은 거의 없으므로, 사면도 안정된 것으로 사료된다. 특히 본 연구지역과 같이 강우와 관련된 산사태 지역의 경우 자동화 계측을 통해서 간극수압의 신속한 증감을 알 수 있었으며, 추후 이러한 주요 시설 사면에서 자동화 방식에 의한 계측관리가 사면의 안정성을 판단하는데 더욱 효과적일 것으로 사료된다.

• Korean Circulation Journal
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• 제48권12호
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• pp.1148-1156
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• 2018

Background and Objectives: It is controversial that decreased left ventricular function could predict poststroke outcomes. The purpose of this study is to elucidate whether left ventricular ejection fraction (LVEF) can predict cardiovascular events and mortality in acute ischemic stroke (AIS) without atrial fibrillation (AF) and coronary heart disease (CHD). Methods: Transthoracic echocardiography was conducted consecutively in patients with AIS or transient ischemic attack at Soonchunhyang University Hospital between January 2008 and July 2016. The clinical data and echocardiographic LVEF of 1,465 patients were reviewed after excluding AF and CHD. Poststroke disability, major adverse cardiac events (MACE; nonfatal stroke, nonfatal myocardial infarction, and cardiovascular death) and all-cause mortality during 1 year after index stroke were prospectively captured. Cox proportional hazards regressions analysis were applied adjusting traditional risk factors and potential determinants. Results: The mean follow-up time was $259.9{\pm}148.8days$ with a total of 29 non-fatal strokes, 3 myocardial infarctions, 33 cardiovascular deaths, and 53 all-cause mortality. The cumulative incidence of MACE and all-cause mortality were significantly higher in the lowest LVEF (<55) group compared with the others (p=0.022 and 0.009). In prediction models, LVEF (per 10%) had hazards ratios of 0.54 (95% confidence interval [CI], 0.36-0.80, p=0.002) for MACE and 0.61 (95% CI, 0.39-0.97, p=0.037) for all-cause mortality. Conclusions: LVEF could be an independent predictor of cardiovascular events and mortality after AIS in the absence of AF and CHD.

• Earthquakes and Structures
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• 제20권3호
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• pp.353-364
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• 2021

Natural hazards like earthquakes, high winds, and tsunami are a threat all the time for multi-story structures. The environmental forces cannot be clogged but the structures can be prevented from these natural hazards by using protective systems. The structural control can be achieved by using protective systems like the passive, active, semi-active, and hybrid protective systems; but the semi-active protective system has gained importance because of its adaptability to the active systems and reliability of the passive systems. Therefore, a semi-active protective system for the earthquake forces has been adopted in this work. Magneto-Rheological (MR) damper is used in the structure as a semi-active protective system; which is connected to the current driver and proposed controller. The Proportional Integral Derivative (PID) controller and reliable PID controller are two proposed controllers, which will actuate the MR damper and the desired force is generated to mitigate the vibration of the structural response subjected to the earthquake. PID controller and reliable PID controller are designed and tuned using Ziegler-Nichols tuning technique along with the MR damper simulated in Simulink toolbox and MATLAB to obtain the reduced vibration in a three-story benchmark structure. The earthquake is considered to be uncertain; where the proposed control algorithm works well during the presence of earthquake; this paper considers robustness to provide satisfactory resilience against this uncertainty. In this work, two different earthquakes are considered like El-Centro and Northridge earthquakes for simulation with different controllers. In this paper performances of the structure with and without two controllers are compared and results are discussed.

• Journal of Korean Neurosurgical Society
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• 제52권4호
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• pp.334-338
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• 2012

Objective : We compared the survival time between patients with multiple gamma knife radiosurgery (GKRS) and patients with a single GKRS plus whole brain radiation therapy (WBRT), in patients with multiple metachronous brain metastases from lung cancer. Methods : From May 2006 to July 2010, we analyzed 31 patients out of 112 patients who showed multiple metachronous brain metastases. 20 out of 31 patients underwent multiple GKRS (group A) and 11 patients underwent a single GKRS plus WBRT (group B). We compared the survival time between group A and B. Kaplan-Meier method and Cox proportional hazards were used to analyze relationship between survival and 1) the number of lesions in each patient, 2) the average volume of lesions in each patient, 3) the number of repeated GKRS, and 4) the interval of development of new lesions, respectively. Results : Median survival time was 18 months (range 6-50 months) in group A and 6 months (range 3-18 months) in group B. Only the average volume of individual lesion (over 10 cc) was negatively related with survival time according to Kaplan-Meier method. Cox-proportional hazard ratio of each variable was 1.1559 for the number of lesions, 1.0005 for the average volume of lesions, 0.0894 for the numbers of repeated GKRS, and 0.5970 for the interval of development of new lesions. Conclusion : This study showed extended survival time in group A compared with group B. Our result supports that multiple GKRS is of value in extending the survival time in patients with multiple metachronous brain metastases, and that the number of the lesions and the frequency of development of new lesions are not an obstacle in treating patients with GKRS.

• Journal of Preventive Medicine and Public Health
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• 제41권1호
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• pp.23-29
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• 2008

Objectives : We examined the association between alcohol consumption and incidence of colorectal cancer in elderly Koreans. Methods : The cohort members (n=14,304) consisted of 4,834 males and 9,470 females derived from the Korea Elderly Pharmacoepidemiologic Cohort (KEPEC), a population-based dynamic cohort. They were aged 65 years old or older and lived in Busan between 1993-1998; they were beneficiaries of the Korean Medical Insurance Corporation (KMIC). Baseline information was surveyed by a self-administered, mailed questionnaire. This study population was restricted to 14,304 participants who reported alcohol drinking habits on the questionnaire and had not been diagnosed with colorectal cancer at baseline. The adjusted hazard ratios (aHR) of status, type, frequency and daily average amount of alcohol consumption were computed with Cox's proportional hazard model, with the never-drinkers as a reference group and controlling for age and gender. Results : After 4.82 person-years of mean follow-up 112 cases of colorectal cancer occurred. The incidence densities of colorectal cancer were 161 (95% CI=123-200) for never-drinkers, 219 (95% CI=125-339) for ex-drinkers, and 137 (95% CI=84-189) for current-drinkers per 100,000 person-year. The status, type, frequency, and daily average amount of alcohol consumption were not significantly related to the incidence of colorectal cancer after controlling for age and gender. Conclusions : There was no significant association between alcohol consumption and colorectal cancer among elderly people after controlling for age and gender.

• Korean Journal of Radiology
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• 제24권6호
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• pp.590-598
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• 2023

Objective: To investigate whether the levels of inflammation detected by 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) can predict disease relapse in immunoglobulin G4-related disease (IgG4-RD) patients receiving standard induction steroid therapy. Materials and Methods: This prospective study analyzed pretherapy FDG PET/CT images from 48 patients (mean age, 63 ± 12.9 years; 45 males and 3 females) diagnosed with IgG4-RD between September 2008 and February 2018, who subsequently received standard induction steroid therapy as the first-line treatment. Multivariable Cox proportional hazards models were used to identify the potential prognostic factors associated with relapse-free survival (RFS). Results: The median follow-up time for the entire cohort was 1913 days (interquartile range [IQR], 803-2929 days). Relapse occurred in 81.3% (39/48) patients during the follow-up period. The median time to relapse was 210 days (IQR, 140-308 days) after completion of standardized induction steroid therapy. Among the 17 parameters analyzed, Cox proportional hazard analysis identified whole-body total lesion glycolysis (WTLG) > 600 on FDG-PET as an independent risk factor for disease relapse (median RFS, 175 vs. 308 days; adjusted hazard ratio, 2.196 [95% confidence interval: 1.080-4.374]; P = 0.030). Conclusion: WTLG on pretherapy FDG PET/CT was the only significant factor associated with RFS in IgG-RD patients receiving standard steroid induction therapy.

• 지질공학
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• 제17권1호
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• pp.57-64
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• 2007

본 연구는 국내에서 산자태 발생빈도가 매우 높은 편마암 풍화토를 대상으로 산사태 모형실험장치를 이용하여 강우강도 및 사면경사에 따른 간극수압 변화의 관계를 파악하기 위하여 수행되었다. 본 연구에서는 강우강도와 사면경사의 변화에 따른 다양한 실험조건하에서 일정 시간 간격으로 간극수압, 사면붕괴양상 및 변위 등을 각각 측정하였다. 실험결과에 따르면, 강우강도에 따른 간극수압의 관계는 강우강도가 클수록 간극수압 증가시간이 빠르며, 모형 토조의 위치별 간극수압 증가시간도 사면 상부에서 가장 빠른 것으로 측정되었다. 이를 표준사를 이용한 실험결과(채병곤 외, 2006)와 비교해 볼 때, 편마암 풍화토는 강우의 침투속도가 표준사에 비해 느린 것을 알 수 있으며, 이로 인해 사면하부로의 강우이동이 상대적으로 원활하지 않아 사면 상단부에서 간극수압의 증가가 빠른 것으로 해석된다. 한편, 간극수압의 증가는 사면의 경사가 작은 경우 먼저 발생하는 것으로 나타났다. 이러한 현상 역시 편마암 풍화토의 느린 강우 침투속도에 기인하는 것으로 생각된다.