• 한국수산과학회지
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• 제48권4호
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• pp.542-554
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• 2015

Grain size, the content of ignition loss (IL), and the concentrations of chemical oxygen demand (COD), acid volatile sulfide (AVS), and trace metals (Fe, Mn, Cu, Pb, Zn, Cd, Cr, As, and Hg) in surface sediments from the Taehwa River estuary, Ulsan, were measured to evaluate pollution levels and potential ecological risks of organic matter and trace metals in estuarine sediment. The mean grain size (Mz) of sediments in the study region ranged from $-0.8-7.7{\varphi}$ (mean $2.8{\pm}2.4{\varphi}$). Surface sediments in the upstream region of the Taehwa River were mainly composed of coarse sediments compared to the downstream region. The concentrations of IL, COD, AVS and trace metals in the sediment were much higher at downstream sites of Myeongchon Bridge in the vicinity of industrial complexes than at upstream sites of those in the vicinity of the residential areas due to the anthropogenic input of organic matter and trace metals by industrial activities. On the basis of several geochemical assessment techniques [sediment quality guidelines (SQGs), enrichment factor (EF), geoaccumulation index ($I_{geo}$), pollution load index (PLI) and ecological risk index (ERI)], the surfaces sediments in the study region are not highly polluted for trace metals, except for As. However, the higher concentrations in downstream study regions of the Taehwa River could impact benthic organisms including shellfish (i.e. Manila clam) in sediments.

• 한국건설관리학회:학술대회논문집
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• 한국건설관리학회 2006년도 정기학술발표대회 논문집
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• pp.213-220
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• 2006

플랜트건설 산업은 엔지니어링과 기계설비의 조달, 시공이 융합된 복합산업(EPC)으로 건설업체의 수주에 따라 기계 ${\cdot}$ 설비 등 타 분야의 성장을 함께 도모할 수 있는 높은 고부가가치 산업이다. 따라서 플랜트건설 수주의 증대는 향후 건설업체뿐만 아니라 국가경제 전반의 성장에 지대한 영향을 끼치는 중요한 이슈이다. 특히, 근래에 중동지역의 경우 고유가에 자극 받은 국가들의 가스와 석유화학 등의 시설에 대한 지속적인 투자로 플랜트 분야의 수요가 급증하는 등 해외 건설시장에서의 플랜트 분야의 시장이 매우 성장하고 있다. 하지만 국내의 해외플랜트 건설업체들이 미국, 유럽 및 일본의 선진기업들과의 경쟁에서 우의를 점하여, 매출과 이윤을 늘리고 꾸준히 사업을 영위하기 위해서는 플랜트 건설산업의 국제 경쟁력을 조속히 확보하는 것이 필요하다. 따라서 본 연구는 해외 건설시장에서 국내 플랜트 관련 업체들의 프로젝트 수행기술 전반을 향상시켜 지속적인 경쟁력을 확보하기 위하여 플랜트 건설사업의 각종 표준과 프로젝트 관리 및 정보관리체계 등 플랜트 프로젝트 관리의 선진화된 기술을 개발하고자 한다.

• 약학회지
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• 제55권2호
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• pp.81-90
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• 2011

Most antineoplastic agents are nonselective in their mechanism of action, affecting noncancerous as well as cancerous cells, and resulting in acute effects such as irritation of mucous membranes and chronic effects such as genotoxicity, teratogenicity, and carcinogenicity. Healthcare workers occupationally exposed to antineoplastic agents are at risk. The present study aimed to develop and apply methods to monitor occupational exposure to antineoplastic agents, using cyclophosphamide (CP) as the model compound. To monitor environmental and biological exposure, potentially contaminated surfaces were wiped and 24 hour urine samples were collected from workers. Liquid chromatography combined with tandem mass spectrometry was performed, with a limit of detection of 0.05 ng/ml. Measurable amounts of CP were detected on 92% of the sampled surfaces, with a geometric mean of 175.22 $ng/m^2$. Despite the environmental contamination of the model compound, CP was below the detection limit in all urine samples. If workplace contamination cannot be completely avoided, it is importance to reduce exposure to the lowest possible levels. To this aim, efforts to minimize occupational exposure along with biological and environmental monitoring are required. The standardized sampling techniques, and specific and sensitive analytical methods reported in this study may be helpful in assessing occupational exposure and devising strategies to reduce exposure.

• 한국가스학회지
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• 제21권6호
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• pp.81-87
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• 2017

SOFC(Solid Oxide Fuel Cell)는 고온 연료전지 중 하나이며, SOFC 시스템과 스택은 고온 운전 특성을 가지고 있다. 이러한 특성 때문에 시스템 설계 및 재료의 선택, 내구성 확보, 안전성능 확보에 많은 어려움을 가지고 있다. 따라서 SOFC 연료전지의 상용화와 보급을 위해서는 안전성능 평가기술과 평가시스템의 개발이 병행되어야 한다. 본 연구에서는 스택 안전성능 평가시스템의 제작을 위하여 국내 외 SOFC 관련규격 및 스택의 위험요소를 분석하였다. 분석한 자료를 바탕으로 스택 안전성능 평가 시스템의 제작을 위한 평가항목을 도출하였다. 본 연구 결과를 통해 SOFC 연료전지의 보급 활성화와 안전한 사용 환경에 기여할 수 있기를 기대한다.

• 한국구조물진단유지관리공학회 논문집
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• 제15권1호
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• pp.226-234
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• 2011

해양환경 하에서 염화물의 침투를 억제하여 부식 위험을 최소화함으로써 콘크리트 구조물의 공용기간을 연장할 수 있다. 효과적으로 구조물을 관리하기 위해 적절하게 유지관리하는 것이 필요하다. 본 연구에서는 효과적인 유지관리 전략을 세우기 위한 보수된 구조물의 유지관리비용 평가와 연계하여 구조물의 사용수명을 정량적으로 평가하는 방법을 제안하였다. Fick의 제2법칙으로부터 Crank-Nicolson법에 기초한 유한 차분법을 제안하여 보수되지 않은 콘크리트 구조물과 보수된 콘크리트 구조물의 염화물 이온 분포를 예측하였다. 이를 이용하여 보수에 의해 연장 가능한 사용수명과 목표한 공용기간 동안에 필요한 보수 횟수를 평가하였다. 게다가 보수 횟수와 콘크리트 교체 비용을 고려하여 총 유지관리 비용을 산출하였다. 마지막으로 제안된 방법의 적용성 검토를 위해 수치해석 예제를 제시하였다.

• 한국정보통신학회논문지
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• 제20권11호
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• pp.2067-2072
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• 2016

최근 기존 정보보호시스템을 우회하는 공격 기법의 발달로 사용자가 인식하지 못하는 형태의 정보자산에 대한 지속적인 공격으로 위협이 되고 있다. 이는 기존 시스템의 단일 대응이 어려운 APT 공격, 우회접근공격 및 암호화 패킷에 대한 공격 등에 대한 침해예측 시도에 대한 즉각적인 대응을 지원하고 공격지표 위주의 방어 전략으로 정보보호 시스템에 대한 지속적인 모니터링의 수행이 요구되고 있다. 본 논문에서는 지능형지속위협 공격경로차단을 위해 정보자산에 대한 업무영향평가를 통한 예방통제로 중요한 자산 식별하고 위험을 미리 제거하기 위하여 취약성 분석, 위험분석을 통한 정보통제 정책을 수립하고 서버접근에 대한 내 외부 우회네트워크 통제, 암호화통신 감시를 통해 탐지통제를 수립하고 백업과 복구를 통해 연계 제어된 교정통제를 하여 지능화된 침해대응 할 수 있도록 중앙집중식 지능형 정보보호시스템을 제안한다.

• Korean Journal of Acupuncture
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• 제38권2호
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• pp.62-74
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• 2021

Objectives : The aim of this study is to analyze the effect of acupuncture and the details of acupuncture treatment methods on skin wrinkles. Methods : Search was conducted in Pubmed, KISS, and NDSL databases for acupuncture studies on skin wrinkles. The detailed therapeutic techniques of acupuncture used for skin wrinkles and the effect of acupuncture on skin wrinkle improvement were analyzed. Then, the study results using the same indicator were compared through meta-analysis in order to compare the effects of acupuncture with the control group. The quality of randomized controlled trials (RCTs) was assessed using the risk of bias (ROB) assessment tool (Ver. 1.0, Cochrane Collaboration). Results : A total of 10 RCTs and 19 case series were included in this study. The most frequently used therapeutic technique for skin wrinkle improvement was Microneedle therapy system (MTS, n=19), and they were mostly used with aesthetic solutions (13 out of 19 studies). Skin wrinkle related indexes were most commonly used to evaluate skin wrinkle improvement (n=14). Panax Ginseng pharmacopuncture showed the most remarkable effect in improving the range of skin wrinkles and the depth of skin wrinkles. MTS+epidermal growth factor improved the levels of skin hydration, skin elasticity, and variation of skin pigment the most. MTS+Endothelial precursor cell improved the number of skin melanin the most. Three RCTs included in the meta-analysis showed moderate ROB on average. Conclusions : Acupuncture treatment was effective in improving skin wrinkles. However, a precise study design using unified indicators and appropriate controls needs to be performed in further studies in order to establish more convincing evidence of the effectiveness of acupuncture for improving skin wrinkles.

• International Journal of Computer Science & Network Security
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• 제23권5호
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• pp.148-162
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• 2023

Classification systems can significantly assist the medical sector by allowing for the precise and quick diagnosis of diseases. As a result, both doctors and patients will save time. A possible way for identifying risk variables is to use machine learning algorithms. Non-surgical technologies, such as machine learning, are trustworthy and effective in categorizing healthy and heart-disease patients, and they save time and effort. The goal of this study is to create a medical intelligent decision support system based on machine learning for the diagnosis of heart disease. We have used a mixed feature creation (MFC) technique to generate new features from the UCI Cleveland Cardiology dataset. We select the most suitable features by using Least Absolute Shrinkage and Selection Operator (LASSO), Recursive Feature Elimination with Random Forest feature selection (RFE-RF) and the best features of both LASSO RFE-RF (BLR) techniques. Cross-validated and grid-search methods are used to optimize the parameters of the estimator used in applying these algorithms. and classifier performance assessment metrics including classification accuracy, specificity, sensitivity, precision, and F1-Score, of each classification model, along with execution time and RMSE the results are presented independently for comparison. Our proposed work finds the best potential outcome across all available prediction models and improves the system's performance, allowing physicians to diagnose heart patients more accurately.

• 한국지하수토양환경학회지:지하수토양환경
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• 제28권5호
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• pp.1-11
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• 2023

The phenomenon of sediment resuspension in rivers and lakes causes contaminants (heavy metals and nutrients) accumulated in the sediment to leach into the overlying water. As a result, it can lead to changes in toxic effects and eutrophication in the aquatic ecosystem. In this regard, it is important to quantitatively determine the amount of contaminants leached during sediment resuspension. In this study, methods for assessing the amount of released contaminants and the types of contaminants potentially released due to sediment resuspension were studied and summarized. Methods for assessing leaching can be divided into three groups based on the principle of causing resuspension: (i) the oscillating grid chamber method, (ii) the mechanical stirrer method, and (iii) the shaker method. It was confirmed that the types of contaminants that can potentially be released include heavy metals bound to sulfides, as well as exchangeable and labile forms of heavy metals and nutrients. To effectively manage stable aquatic ecosystems in the future, a simplified leaching test method is needed to assess in advance the risks (i.e., changes in toxic effects and eutrophication) that sediment resuspension may pose to aquatic ecosystems.

• Journal of Cardiovascular Imaging
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• 제31권4호
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• pp.159-168
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• 2023

BACKGROUND: The gold standard for diagnosis of cardiac tumours is histopathological examination. Cardiovascular magnetic resonance (CMR) is a valuable non-invasive, radiation-free tool for identifying and characterizing cardiac tumours. Our aim is to understand CMR diagnosis of cardiac tumours by distinguishing benign vs. malignant tumours compared to the gold standard. METHODS: A systematic search was performed in the PubMed, Web of Science, and Scopus databases up to December 2022, and the results were reviewed by 2 independent investigators. Studies reporting CMR diagnosis were included in a meta-analysis, and pooled measures were obtained. The risk of bias was assessed using the Quality Assessment Tools from the National Institutes of Health. RESULTS: A total of 2,321 results was obtained; 10 studies were eligible, including one identified by citation search. Eight studies were included in the meta-analysis, which presented a pooled sensitivity of 93% and specificity of 94%, a diagnostic odds ratio of 185, and an area under the curve of 0.98 for CMR diagnosis of benign vs. malignant tumours. Additionally, 4 studies evaluated whether CMR diagnosis of cardiac tumours matched specific histopathological subtypes, with 73.6% achieving the correct diagnosis. CONCLUSIONS: To the best of our knowledge, this is the first published systematic review on CMR diagnosis of cardiac tumours. Compared to histopathological results, the ability to discriminate benign from malignant tumours was good but not outstanding. However, significant heterogeneity may have had an impact on our findings.