• Bulletin of the Korean Chemical Society
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• 제10권1호
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• pp.1-5
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• 1989

The nonempirical molecular connectivity indexes of a number of mono- and disubstituted purines were calculated. Very good correlations were obtained between anticancer activity (log 1/c) and toxic activity (log 1/) of tIhese compounds and their molecular connectivity indexes and physicochemical constants. Our structure-activity relationship is discussed briefly in relation to theories of general QSAR.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권2호
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• pp.747-763
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• 2018

Information Technology (IT) plays an increasingly important role for small and medium-sized enterprises. It has become fundamental for these companies to protect information and IT assets in relation to risks and threats that have grown in recent years. This study aims to understand the importance and structure of an information security policy, using a quantitative study that intends to identify the most important and least relevant elements of an information security policy document. The findings of this study reveal that the top three most important elements in the structure of a security policy are the asset management, security risk management and define the scope of the policy. On the other side, the three least relevant elements include the executive summary, contacts and manual inspection. Additionally, the study reveals that the importance given to each element of the security policy is slightly changed according to the sectors of activity. The elements that show the greatest variability are the review process, executive summary and penalties. On the other side, the purpose of the policy and the asset management present a stable importance for all sectors of activity.

• 한국지능시스템학회논문지
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• 제18권4호
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• pp.512-517
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• 2008

사회고령화, 장애인구 증가는 장애인을 위해 특화된 서비스를 제공하기 위한 유비쿼터스 컴퓨팅 관련기술의 개발이 필요함을 나타낸다. 이를 위해 기존의 일방적인 관계가 아닌 사용자와 유비쿼터스 환경간의 상호작용이 지원되는 상황인식 및 서비스 추론 기술의 개발이 필요하다. 기존의 상황인식과 관련 연구는 불확실한 실세계를 도메인으로 하기 때문에 전문가 시스템을 바탕으로 베이지안 네트워크(이하, BN)와 같은 확률 기반 표현 모델을 통해 주어진 상황을 인식하였다. 본 논문에서는 다변화하는 환경과 사용자나 개발자의 개입을 최소화한 상태에서의 상황인식을 고려하여 장애활동보조 서비스 어플리케이션 도메인을 정의하고 온톨로지를 기반으로 상황정보 모델을 정의한다. 결정된 상황정보모델을 이용해 BN의 구조학습을 적용한 후 응용서비스 개발의 차원에서 장애인을 위한 서비스, Activity를 결정한다. 최종적으로 BN의 Conditional Probability Table를 적절하게 정의한 후 주어지는 임의의 상황에서의 사용자의 Activity와 Service 상태변수 값을 확률 값을 표현함으로써 상황인식의 결과를 도출한다.

• Toxicological Research
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• 제22권1호
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• pp.23-30
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• 2006

Among poly aromatic hydrocarbons, dioxin and PCBs are the most controversial environmental pollutants in our modern life. These pollutants are known as human carcinogens, and liver is the most sensitive target in animal cancer models. Specific aims of the study were focused on the mechanism of carcinogenesis in hepatocytes and the structure-activity relation among these diverse environmental chemicals. Because key mechanisms of dioxin-induced carcinogenesis in human epithelial cell model are the alteration of signal transduction pathway and PKC isoforms, the alteration of the signal transduction pathways and other factors associated with carcinogenesis were studied. Rat hepatocytes cultured under the sandwich protocols were exposed with the various concentration of dioxins and PCBs, and signal transduction pathway, protein kinase C isoforms, oxidant stress, and apoptotic nuclei were evaluated. Since it is important to understand the structure-activity relation among these chemicals to properly assess the carcinogenic potentials, the study analyzed the parameters associated with carcinogenic processes, based on their structural characteristics. In addition, signal transduction pathways and PKC isoforms involved in inhibition of UV-induced apoptosis were also analyzed to elaborate the tumor promotion mechanism of these chemicals. Induction of apoptosis by UV irradiation was optimal at $60\;J/m^2$ in primary hepatocyte in culture. Compared to non coplanar PCBs such as PCB 114 and PCB 153, coplanar PCBs such as PCB 77 and PCB126 showed a stronger inhibition of apoptosis induced by UV irradiation. Production of reactive oxygen species (ROS) was more stimulated by non-coplanar PCBs than coplanar PCBs with the most potent induction of ROS by chlorinated non-coplanar PCB. As compared to the level of induction by PCB126, non-coplanar PCB153 showed a higher increase of intracellular concentrations. Besides the alteration of intracellular calcium concentration, translocation of PKC from cytosolic fraction to membrane fraction was clearly observed upon the exposure of non-coplanar PCB. Taken together, the present study demonstrated that there is a potent structure-activity relationship among PCB congeners and the mechanism of PAH-induced carcinogenesis is structure-specific. The study suggested that more diverse pathways of PAH-induced carcinogenesis should be taken into account beyond the boundary of Ah receptor dogma to assess the health impact of PAH with more accuracy.

• 한국독성학회:학술대회논문집
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• 한국독성학회 2005년도 춘계 국제심포지엄 및 학술대회
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• pp.114-114
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• 2005

• 한국미생물·생명공학회지
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• 제27권1호
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• pp.54-61
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• 1999

Measurement of inhibition of bioluminescence in Photobacterium phosphoreum has been porposed as a sensitive and rapid procedure to monitor toxic substances. However, at first, $EC_{50}$ which shows degree of toxicity to each toxic substances must be calculated. QSAR (Quantitative Structure Activity Relationship) model can be used to estimate $EC_{50}$ to save time and endeavor. Moderately high correlation coefficients ($r^2{\geq}$ 0.97) were calculated from the linear correlation between $EC_{50}$ and molecular connectivity indices of CAHs (chlorinated aliphatic hydrocarbons)such as $^0X$, $^0X^V$, $^1X$, $^2X$ and $^3X^v_c$ and quadratic correlation between $EC_{50}$ and $^0X$, $^0X^V$, $^2X^V$, $^3X_c$, $^3X^V_c$ and P. It shows that the molecular connection indices in carbon structure is contributed to biological characters with linear relation and that in the other one with quadratic relation. The $EC_{50}$ of chlorophenol derivatives had quadratic relation with the value of octanol/water prtition coefficients ($r^2$=0.99) and linear and quadratic relation with the number of chlorine compound (($r^2{\geq}$0.94). This confirms the already known trend of increasing toxicity with increasing ability of a compound to diffuse through cell membrane and number of chlorine substitution.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.935-940
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• 2005

We are faced with water pollutions on a population explosion. Considering the importance, we research European rivers based on OECD reports. Observations in the reports have defects that make evaluation of environmental situations be difficult. By using interpolations in the compensation quantitative structure-activity relation ships (CQSAR), we complement the defects in the water quality of rivers through big cities. Thus, we get complete data set for dissolved oxygen, biochemical oxygen demand, and total phosphorus. Using the data set, we examine re-naturalization of the Rhein and the Donau in Germany. We investigate the effect of dams between Slovakia and Hungary, by using reconstructions of neural networks in CQSAR. The reconstructions have functions to extract a principal relation. On the investigation, we examine assertions of conservation groups. As the result, we confirm the re-naturalization is effective, and find a negative effect of the dam construction on changes of dissolved oxygens in the Hungary Donau. We investigate the Seine and the Thames, too.

• Archives of Pharmacal Research
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• 제23권6호
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• pp.579-584
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• 2000

To explore the effect of substituents' on phenyl motif on sulfonyl function of novel anticancer 4-phenyl-1-benzenesulfonylimidazolidinones (1), electron donating or withdrawing sub-stituents were introduced at 3 or 4-position and the analogs were tested against human lung (A549) and colon (HCT-15) cancer cell lines. Quantitative structure activity relation-ship of the 4-substituted series shows that only STERIMOL L values are well correlated. The increment of substituent's volume enhances the activity against both cell lines. The small substituent at 3-position additionally increases the activity. However naphthyl group in place of phenyl reduces the activity, Therefore the phenyl motif with sterically large substituent at 4-position and small substituent at 3-position may be important for their activity. Integration of these substituents' effects into the structural design led to discover the more potent analog, 4-phenyl-1-(N-acetylindoline-5-sulfonyl) imidazolidinone (1n).

• 천문학회보
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• 제37권1호
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• pp.87.1-87.1
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• 2012

We use three-dimensional magnetohydrodynamic simulations to investigate how the dynamic state of emerging magnetic field is related to the twist of field lines. Emergence of magnetic field is considered as one of the key physical process producing solar activity such as flares, jets, and coronal mass ejections. To understand these activities we have to know dynamic nature and electric current structure provided by emerging magnetic field. To demonstrate dynamic nature of field lines, we focus on the factors such as curvature of magnetic field line and scale height of magnetic field strength. These factors show that strong twist case forms two-part structure in which the central part is close to a force-free state while the outer marginal part is in a fairly dynamic state. For weak twist case, it still shows two-part structure but the tendency becomes weaker than strong twist case. We discuss how the curvature distribution affects the dynamic nature of emerging magnetic field. We also investigate electric current distribution provided by emerging field lines to show a possible relation between electric current structure and sigmoid observed in a preflare phase.

• 무역학회지
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• 제48권2호
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• pp.175-195
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• 2023

해상운송은 개별 국가만이 아니라 세계 경제에 높은 영향력을 미치며, 글로벌가치사슬(GVSc)을 통한 분업 실현에 이바지 하고 있으며 이러한 국제분업 활동은 일상화되어 있다. 해상운송업 사이에도 국제분업을 통한 글로벌 가치사슬(GVSs)이 존재하며 국가 간 해상운송업 사이 혹은 관련 산업 사이에도 거래관계가 발생해 상호 연관구조가 긴밀한 국가들이 있다. 이에 본 연구에서는 아시아개발은행(ADB)에서 1년 단위로 발표하는 국제산업연관표(WIOT)을 이용하여 63개 국가 중에서 세계 30대 선박 보유국 안에 포함되면서 수상운송업의 총 산출액이 높은 14개 국가를 대상으로 수상운송업 간의 상호 연관구조를 분석하였다. 분석을 통해서 우리나라 수상운송업과 높은 연관구조를 가진 국가와 우리나라 수상운송업의 특징을 확인하였다. 분석 결과 우리나라는 투입구조에서 국산 중간재비중이 약 70%로 유럽의 주요 해운 국가 대비 국내산 이용 비율이 높았다. 하지만 2000년 이후로 꾸준히 국외 중간투입이 증가하면서 국외 산업과 연관구조가 높아졌으며, 발생하는 부가가치는 하락하였다. 줄어드는 부가가치에 비해 국내 산업으로 생산유발계수는 크게 변화가 없어 같은 금액 투자에도 국내에 미치는 경제적 영향은 줄어든 것으로 평가되어 해운산업의 부가가치를 높이기 위한 정책적인 방안이 필요한 것으로 생각된다. 우리나라 수상운송업과 높은 연관구조를 가진 국가는 투입구조 상에서는 미국(USA), 배분구조에서는 싱가포르(SIN), 일본(JPN) 순으로 해당 국가의 생산활동에 높은 영향을 받는 것을 확인하였다. 생산유발계수를 통한 연관구조를 보면 우리나라 수상운송업과 높은 연관구조를 가진 국가의 수상운송업은 싱가포르(SIN)이다. 싱가포르(SIN)는 유럽 항로의 중간지역으로 우리나라 수상운송업과 상호 간에 높은 생산유발효과를 주고받는 것을 확인할 수 있었다.