• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2013년도 추계학술대회
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• pp.123-126
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• 2013

시스템 접근제어는 인프라 운용시 관리자와 사용자에 대한 권한을 명확하게 구분해 주는 용어다. 지금도 빈번하게 일어나고 있는 각종 IT 사고들이 발생하고 있으며 이러한 사고에 대한 사태를 막기 위해 접근제어가 필요하다. 본 연구에서는 해커에가 중요시설 인프라 장비에 침입을 하여도 Copy 명령어등 위험한 명령어에 대해 제한을 걸어 사전에 공격을 차단하며 내부 관리자 실수로 인한 사고 발생도 명령어를 제한을 걸어 사전에 위험을 차단 할 수 있다. 또한 내부 관리자 실수 및 해킹 사건이 발생을 하여도 명령어 로그 및 접근 이력 분석을 통해 사후에도 증거 자료로 활용 할 수 있는 기술에 대해 기술한다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제14권12호
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• pp.4909-4926
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• 2020

Cyberattacks penetrate the server and perform various malicious acts such as stealing confidential information, destroying systems, and exposing personal information. To achieve this, attackers perform various malicious actions by infecting endpoints and accessing the internal network. However, the current countermeasures are only anti-viruses that operate in a signature or pattern manner, allowing initial unknown attacks. Endpoint Detection and Response (EDR) technology is focused on providing visibility, and strong countermeasures are lacking. If you fail to respond to the initial attack, it is difficult to respond additionally because malicious behavior like Advanced Persistent Threat (APT) attack does not occur immediately, but occurs over a long period of time. In this paper, we propose a technique that detects an unknown attack using an event log without prior knowledge, although the initial response failed with anti-virus. The proposed technology uses a combination of AutoEncoder and 1D CNN (1-Dimention Convolutional Neural Network) based on semi-supervised learning. The experiment trained a dataset collected over a month in a real-world commercial endpoint environment, and tested the data collected over the next month. As a result of the experiment, 37 unknown attacks were detected in the event log collected for one month in the actual commercial endpoint environment, and 26 of them were verified as malicious through VirusTotal (VT). In the future, it is expected that the proposed model will be applied to EDR technology to form a secure endpoint environment and reduce time and labor costs to effectively detect unknown attacks.

• Journal of Preventive Medicine and Public Health
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• 제39권2호
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• pp.171-176
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• 2006

Objectives : The objective of this study is to assess the factors influencing biological monitoring of textile coating factory workers exposed to N,N-dimethylformamide(DMF). Methods : We studied 35 workers who were occupationally exposed to DMF from 9 textile coating factories. The study was carried out in two phases; summer and winter. While air concentration of DMF, temperature and humidity were assessed in order to monitor the atmospheric conditions, biological monitoring was done to determine the internal dose by analyzing the N-methylformamide(NMF) collected from urine at the beginning and end of the shift. Questionnaires and medical surveillance were also obtained during the two phases. Results : Median air concentrations of DMF in winter and summer were 1.85 ppm and 2.78 ppm respectively. Also the difference between the urinary NMF concentration at the beginning and end of the shift $({\Delta}NMF)$ was always significant in each season (P < 0.001). The correlations between log DMF in air, log end-of-shift urinary NMF (r=0.555, P < 0.001) and log ${\Delta}NMF$ (r = 0.444, P < 0.001) was statistically significant in summer. The temperature, humidity, a shift system and different styles of clothing worn were significantly different during the two phases. In a multivariate analysis, temperature and the concentration of DMF in the air were the main factors influencing biological monitoring of textile coating factory workers. Conclusions : Concerning more comprehensive prevention measures to reduce exposure for those workers occupationally exposed to DMF, dermal exposure conditions such as temperature and humidity together with the air concentration of DMF should be assessed and biological monitoring is necessary to reduce adverse health effects, especially during the summer.

• Journal of Pharmaceutical Investigation
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• 제35권5호
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• pp.323-328
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• 2005

The purpose of the present study was to evaluate the bioequivalence of two torasemide tablets, Torem tablet (Roche Korea Co., Ltd., Korea, reference drug) and Boryung Torsemide tablet (Boryung Pharmaceutical Co., Ltd., Korea, test drug), according to the guidelines of Korea Food and Drug Administration (KFDA). After adding an internal standard (furosemide) to human serum, serum samples were extracted using 5 mL of ethyl acetate. Compounds were analyzed by reverse-phase HPLC method with UV detection. This method showed linear response over the concentration range of 0.05 ug/mL with correlation coefficient of 0.999. The lower limit of quantitation using 0.5 mL of serum was 0.05 ug/mL which was sensitive enough for pharmacokinetic studies. Twenty-eight healthy male Korean volunteers received each medicine at the torasemide dose of 20 mg in a $2{\times}2$ crossover study. There was a one-week washout period between the doses. Serum concentrations of torasemide were monitored by an HPLC-UV for over a period of 12 hr after the administration. $AUC_{t}$(the area under the serum concentration-time curve from time zero to 12 hr) was calculated by the linear trapezoidal rule method. $C_{max}$ (maximum serum drug concentration) and $T_{max}$ (time to reach $C_{max}$) were compiled from the serum concentration-time data. Analysis of variance was carried out using logarithmically transformed $AUC_{t}$ and $C_{max}$. No significant sequence effect was found for all of the bioavailability parameters indicating that the crossover design was properly performed. The 90% confidence intervals of the $AUC_{t}$ ratio and the $C_{max}$ ratio for Boryung Torsemide/Torem were log 0.97-10g 1.03 and log 0.93log 1.12, respectively. These values were within the acceptable bioequivalence intervals of log 0.80-log 1.25. Thus, the criteria of the KFDA guidelines for the bioequivalence was satisfied, indicating Boryung Torsemide tablet and Torem tablet are bioequivalent.

• Tuberculosis and Respiratory Diseases
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• 제80권2호
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• pp.179-186
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• 2017

Background: Although the World Health Organization (WHO) classification of lung squamous cell carcinoma (SCC) was revised in 2015, its clinical implications for lung SCC subsets remain unclear. We investigated whether the morphologic characteristics of lung SCC, including keratinization, were associated with clinical parameters and clinical outcome of patients. Methods: A total of 81 patients who underwent curative surgical resection of diagnosed lung SCC, were enrolled in this study. Attributes such as keratinization, tumor budding, single cell invasion, and nuclear size within the tumor, as well as immunohistochemistry of Bcl-xL and pS6 expressions, were evaluated. Results: The keratinizing and nonkeratinizing subtypes did not differ with respect to age, sex, TNM stage, and morphologic parameters such as nuclear diameter, tumor budding, and single cell invasion at the tumor edge. Most patients with the keratinizing subtype (98.0%) had a history of smoking, whereas the nonkeratinizing group had a relatively higher proportion of never-smokers relative to the keratinizing group (24.0% vs. 2.0%; p=0.008, chi-square test). Expression of pS6 (a surrogate marker of mammalian target of rapamycin complex 1 [mTORC1] signaling that regulates keratinocyte differentiation), and Bcl-xL (a key anti-apoptotic molecule that may inhibit keratinization), did not correlate significantly with the presence of keratinization. Patients with the keratinizing subtype had a significantly shorter overall survival (85.2 months vs. 135.7 months, p=0.010, log-rank test), and a multivariate analysis showed that keratinization was an independent, poor prognostic factor (hazard ratio, 2.389; 95% confidence interval, 1.090-5.233; p=0.030). Conclusion: In lung SCC, keratinization is associated with a poor prognosis, and might be associated with smoking.

• 한국농공학회논문집
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• 제54권4호
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• pp.137-145
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• 2012

Sand is one of the essential materials used for social infrastructure construction such as embankment, landfill and backfill. It was known that mechanical properties and shear strength of sand are closely related to relative density. Therefore it is very important to determine accurate relative density. In this study, Portable Cone Penetration Tester (PCPT) was used to estimate the relative density and the internal friction angle of sand. PCPT cone-tip resistance ($q_c$) was measured changing the relative density of the two soil samples.Standard sand (JMJ) and Busan sand (BS). Also, a direct shear test was performed to investigate relationship between relative density and internal friction angle. The size and shape of soil particles were confirmed by using Scanning Electron Microscope (SEM). As a result, the log value of $q_c$ was linearly correlated with relative density and internal friction angle. In particular, the internal friction angle of BS sample was greater than that of JMJ, which was due to difference of the shape and mean size of particles. This result shows that it is important to determine the shape and size of particles as well as relative density to define mechanical property of sand. Through this study, it can be more effectively and conveniently to investigate relative density and shear strength of sand by using PCPT in situ.

• Asian Pacific Journal of Cancer Prevention
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• 제16권18호
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• pp.8031-8039
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• 2016

Background: Preclinical studies have demonstrated that ${\beta}$-adrenergic receptor antagonists could improve the prognosis of breast cancer. However, the conclusions of clinical and pharmacoepidemiological studies have been inconsistent. This review was conducted to re-assess the relationship between beta-adrenoceptor blockers and breast cancer prognosis. Materials and Methods: The literature was searched from PubMed, EMBASE and Web of Nature (Thompson Reuters) databases through using key terms, such as breast cancer and beta-adrenoceptor blockers. Results: Ten publications met the inclusion criteria. Six suggested that receiving beta-adrenoceptor blockers reduced the risk of breast cancer-specific mortality, and three of them had statistical significance (hazard ratio (HR)=0.42; 95% CI=0.18-0.97; p=0.042). Two studies reported that risk of recurrence and distant metastasis (DM) were both significantly reduced. One study demonstrated that the risk of relapse-free survival (RFS) was raised significantly with beta-blockers (BBS) (HR= 0.30; 95% CI=0.10-0.87; p=0.027). One reported longer disease-free interval (Log Rank (LR)=6.658; p=0.011) in BBS users, but there was no significant association between overall survival (OS) and BBS (HR= 0.35; 95% CI=0.12-1.0; p=0.05) in five studies. Conclusions: Through careful consideration, it is suggested that beta-adrenoceptor blockers use may be associated with improved prognosis in breast cancer patients. Nevertheless, larger size studies are needed to further explore the relationship between beta-blocker drug use and breast cancer prognosis.

• Asian Pacific Journal of Cancer Prevention
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• 제17권4호
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• pp.2165-2170
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• 2016

Background: The survival of hepatocellular carcinoma (HCC) patients is usually low due to late diagnosis. Cipto Mangunkusumo Hospital as the largest tertiary referral hospital in Indonesia, has recently improved its modalities for advanced HCC management, but there has not been any evaluation on any improvement in HCC patient survival. Materials and Methods: A retrospective analysis on 114 HCC patients in 2013-2014 were conducted and compared with the database for 77 HCC patients in 1998-1999. Clinical characteristics and treatment received were recorded and the survival of both groups was analyzed using the Kaplan-Meier method and compared using the log-rank test. Results: The percentage of HBV positive patients had increased after fifteen years from 32.5% to 67.5%. Only two patients (1.8%) in 2013-2014 were diagnosed with HCC during surveillance program. Proportions of Barcelona Clinic Liver Cancer A, B, C, and D in 2013-2014 were 1.8%, 42%, 28.1%, and 28.1%, respectively. There was an increase in the use of potentially curative treatment, such as surgical resection or combination of loco-regional therapies. The one-year survival rate increased from 24.1% in 1998-1999 to 29.4% in 2013-2014, while the median survival decreased from 146 days to 138 days, but the difference was not statistically significant (p=0.913). Conclusions: There was no improvement in the median survival of HCC patients after fifteen years because most continued to present at late stages. There is an urgent need for a nationwide implementation of a hepatitis screening program and HCC surveillance education.

• Radiation Oncology Journal
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• 제36권4호
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• pp.325-331
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• 2018

Purpose: Soft tissue sarcoma (STS) is a rare and heterogeneous cancer with over 50 known subtypes. It is difficult to understand the role of adjuvant treatment in STS. We aimed to determine the benefits of adjuvant treatment for a rare STS subset: non-extremity STS with moderate chemosensitivity. Materials and Methods: We reviewed medical records from Pusan National University Hospital and Kosin University Gospel Hospital, which had detailed pathological reports on patients diagnosed between 2006 and 2016. The most important inclusion criterion was resection with curative intent. We grouped STS by chemosensitivity based on reported data and analyzed non-extremity STS with moderate chemosensitivity. Results: We investigated 142 patients with 20 pathological subtypes of STS. Eighty-six patients had extremity STS and 56 had non-extremity STS. Thirty-eight of 56 patients were categorized as having moderate chemosensitivity. Seventeen of 38 patients (44.7%) received adjuvant radiotherapy and 14 (36.8%) received adjuvant chemotherapy. A log-rank test showed longer disease-free survival (DFS) in the adjuvant radiotherapy group than in the group treated without adjuvant radiotherapy (not reached vs. 1.468 years, p = 0.037). Multivariate Cox proportional hazard analysis, with covariates including age, stage, resection margin, adjuvant chemotherapy, and adjuvant radiotherapy, revealed that adjuvant radiotherapy was associated with longer DFS (odds ratio = 0.369, p = 0.045). Overall survival was not correlated with adjuvant radiotherapy. Conclusion: Adjuvant radiotherapy may be associated with longer DFS in patients with non-extremity STS with moderate chemosensitivity.

• IMMUNE NETWORK
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• 제23권5호
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• pp.39.1-39.15
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• 2023

Coronavirus disease 2019 (COVID-19) vaccination may non-specifically alter the host immune system. This study aimed to evaluate the effect of COVID-19 vaccination on hepatitis B surface Ag (HBsAg) titer and host immunity in chronic hepatitis B (CHB) patients. Consecutive 2,797 CHB patients who had serial HBsAg measurements during antiviral treatment were included in this study. Changes in the HBsAg levels after COVID-19 vaccination were analyzed. The dynamics of NK cells following COVID-19 vaccination were also examined using serial blood samples collected prospectively from 25 healthy volunteers. Vaccinated CHB patients (n=2,329) had significantly lower HBsAg levels 1-30 days post-vaccination compared to baseline (median, -21.4 IU/ml from baseline), but the levels reverted to baseline by 91-180 days (median, -3.8 IU/ml). The velocity of the HBsAg decline was transiently accelerated within 30 days after vaccination (median velocity: -0.06, -0.39, and -0.04 log₁₀ IU/ml/year in pre-vaccination period, days 1-30, and days 31-90, respectively). In contrast, unvaccinated patients (n=468) had no change in HBsAg levels. Flow cytometric analysis showed that the frequency of NK cells expressing NKG2A, an NK inhibitory receptor, significantly decreased within 7 days after the first dose of COVID-19 vaccine (median, -13.1% from baseline; p<0.001). The decrease in the frequency of NKG2A⁺ NK cells was observed in the CD56^dimCD16⁺ NK cell population regardless of type of COVID-19 vaccine. COVID-19 vaccination leads to a rapid, transient decline in HBsAg titer and a decrease in the frequency of NKG2A⁺ NK cells.