• Journal of the korean society of oceanography
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• v.37 no.4
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• pp.232-241
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• 2002

The potential role of environmental factors on extractable lipofuscin accumulation rate in the blue crab was studied by examining the effect of temperature on laboratory reared blue crabs and the effect of trace metals from samples collected at impacted sites (Baltimore Harbor) and a relatively pristine site (outdoor ponds at Horn Point Laboratory, Cambridge, MD, USA). Lipofuscin levels did not significantly related with sampling sites or heavy metal concentrations in the crab tissue. Heavy metal body burden was highly variable among sampling sites and tissue types but significantly higher for both impacted areas (Curtis Creek and Inner Harbor) in comparison to the reference site. Among tissue types, gills showed the highest metal concentrations with the exception of Hg, which was highest in muscle tissue. For two groups of crabs that were held at either ambient (4 to 1$0^{\circ}C$) or heated seawater (19$^{\circ}C$) for two months, normalized-lipofuscin levels were significantly different (P-0.001). Results suggest that temperature may affect lipofuscin accumulation (=0.25ng-lipofuscin/mg-protein/temperature-degree day). Therefore, temperature should be considered for accurate age calibration of crab populations using lipofuscin.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.10 no.1
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• pp.223-234
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• 2000

Objective - To evaluate the usefulness of chromium in erythrocytes as a biological marker of exposure to hexavalent chromium in chromate producers and chrome platers Methods - Blood and urine samples were ramdomly obtained from chromate producers (n=34) and chrome platers (n=35), and non-exposed workers (n=75), chromium level in erythrocytes and plasma, and urine were measured. Different chromium exposure workers were assessed through measurements of airborne hexavalent chromium concentrations using a personal air sampler. Linear associations between variables were evaluated with correlation analysis. Results - The chromate producers had mean chromium levels in erythrocytes five fold as higher than the chrome platers, and fifteen fold higher than non-exposed group. Among the chromium exposed workers, airborne hexavalent chromium was positively and strongly correlated with in erythrocytes (r=0.689, p<0.01), and erythrocytes chromium was inversely correlated with hematocrit (r=-0.441, p<0.01), hemoglobin (r=-0.465, p<0.01) and the number of red blood cells (r=-0.28, p<0.05). Conclusions - In conclusion, this study suggests that chromium in erythrocytes is a good indicator of the chromium body burden caused by exposure to hexavalent chromium.

• Earthquakes and Structures
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• v.18 no.3
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• pp.321-335
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• 2020

The aim of the present contribution is to consider and underline the essential interactions among the historical knowledge, the seismic vulnerability assessment, the investigation experimental tools, the preservation of the architectural quality and the strengthening design in regard to architectural heritage conservation. These topics are argued in relation to Palazzo Murena in Perugia, designed in the eighteenth century by the famous Architect Luigi Vanvitelli, and currently headquarters of the city's University. Based on the surveys and the visual inspections, a preliminary a priori global analysis has been performed by means of the FME method. The obtained results permitted to plan an experimental tests campaign inclusive of structural health monitoring. The new achieved "knowledge" of the building allowed to refine the seismic safety assessment. In particular it was highlighted that the "mezzanine floor" can be a vulnerable element of the building with the collapse of its masonry walls. Preserving the architectural characteristics, a local reinforcement intervention is proposed for the above-mentioned level; this consists of the application of plaster with FRCM, assuring an adequate strength, without burden the masonry structure with additional weight, and therefore a decreasing of the seismic vulnerability. The necessity to consider, in this ongoing research, other local mechanisms is highlighted in the unfolding of the last part of work.

• Smart Structures and Systems
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• v.22 no.4
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• pp.399-411
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• 2018

The difficulty in modeling complex nonlinear structures lies in the presence of significant sources of uncertainties mainly attributed to sudden changes in the structure's behavior caused by regular aging factors or extreme events. Quantifying these uncertainties and accurately representing them within the complex mathematical framework of Structural Health Monitoring (SHM) are significantly essential for system identification and damage detection purposes. This study highlights the importance of uncertainty quantification in SHM frameworks, and presents a comparative analysis between intrusive and non-intrusive techniques in quantifying uncertainties for SHM purposes through two different variations of the Kalman Filter (KF) method, the Ensemble Kalman filter (EnKF) and the Polynomial Chaos Kalman Filter (PCKF). The comparative analysis is based on a numerical example that consists of a four degrees-of-freedom (DOF) system, comprising Bouc-Wen hysteretic behavior and subjected to El-Centro earthquake excitation. The comparison is based on the ability of each technique to quantify the different sources of uncertainty for SHM purposes and to accurately approximate the system state and parameters when compared to the true state with the least computational burden. While the results show that both filters are able to locate the damage in space and time and to accurately estimate the system responses and unknown parameters, the computational cost of PCKF is shown to be less than that of EnKF for a similar level of numerical accuracy.

• Journal of muscle and joint health
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• v.3 no.2
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• pp.151-165
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• 1996

The purpose of this study is to describe the acknowledgement of the cause of the illness in the patients with RA. I used naturalistic inquiry as a research methodology. The purposive sampling was conducted. 23 subjects who experienced RA, lived in middle-sized city in Korea, and 19 women and 4 men. I collected data using indepth structured interview, "What is the acknowledgement of the cause of the illness?" I used inductive data analysis-such as unitizing and categorizing. This process is used constant comparative method. Summerising the results of this study, the acknowledgement of the cause of the illness are composed of physical constitution, fatalism, the attribution of physical overload, the attribution of stress, the lack of nutrition. The factors which affect the acknowledgement of the cause of the illness are composed of internal factors, external factors, environmental factors. The internal factors are the weakness of the childhood, the illness experience in the family members, juvenile rheumatoid arthritis, personality, lack of nutrition. The external factors are pregnancy, delivery, role burden and conflict, economic problem. The environmental factors are humid condition, abrupt environmental change. It is needed to explaine the coping pattern according to the acknowledgement of the cause of the illness in the next research.

• International Journal of Internet, Broadcasting and Communication
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• v.15 no.2
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• pp.144-156
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• 2023

Smart agriculture is a rapidly growing field that seeks to optimize crop yields and reduce risk through the use of advanced technology. A key challenge in this field is the need to create a comprehensive smart farm system that can effectively monitor and control the growth environment of crops, particularly when cultivating new varieties. This is where fuzzy theory comes in, enabling the collection and analysis of external environmental factors to generate a rule-based system that considers the specific needs of each crop variety. By doing so, the system can easily set the optimal growth environment, reducing trial and error and the user's risk burden. This is in contrast to existing systems where parameters need to be changed for each breed and various factors considered. Additionally, the type of house used affects the environmental control factors for crops, making it necessary to adapt the system accordingly. While developing such a framework requires a significant investment of labour and time, the benefits are numerous and can lead to increased productivity and profitability in the field of smart agriculture. We developed an AI platform for optimal control of facility houses by integrating data from mushroom crops and environmental factors, and analysing the correlation between optimal control conditions and yield. Our experiments demonstrated significant performance improvement compared to the existing system.

• Structural Engineering and Mechanics
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• v.65 no.2
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• pp.173-181
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• 2018

In this paper, finite element (FE) model updating based on multi-objective optimization with the surrogate model for a steel plate girder bridge is investigated. Conventionally, FE model updating for bridge structures uses single-objective optimization with finite element analysis (FEA). In the case of the conventional method, computational burden occurs considerably because a lot of iteration are performed during the updating process. This issue can be addressed by replacing FEA with the surrogate model. The other problem is that the updating result from single-objective optimization depends on the condition of the weighting factors. Previous studies have used the trial-and-error strategy, genetic algorithm, or user's preference to obtain the most preferred model; but it needs considerable computation cost. In this study, the FE model updating method consisting of the surrogate model and multi-objective optimization, which can construct the Pareto-optimal front through a single run without considering the weighting factors, is proposed to overcome the limitations of the single-objective optimization. To verify the proposed method, the results of the proposed method are compared with those of the single-objective optimization. The comparison shows that the updated model from the multi-objective optimization is superior to the result of single-objective optimization in calculation time as well as the relative errors between the updated model and measurement.

• Environmental Analysis Health and Toxicology
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• v.21 no.4 s.55
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• pp.337-347
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• 2006

이 연구의 목적은 자원회수시설 근로자 및 인근 지역 거주 주민의 혈중다이옥신류 농도를 평가하고, 혈중 다이옥신류 농도에 영향을 미치는 요인을 평가하는 것이다. $2002{\sim}2004$년까지 대상 자원회수시설에 3년 이상 근무한 근로자 31명과 시설로부터 300 m이내 지역에서 3년 이상 거주한 주민 68명을 선정하여 혈액을 채취하였다. 참고 자료로 대상 자원회수시설에 영향을 받지 않는 도시 지역에 거주하는 일반 주민 11명을 함께 평가하였다. 혈액 채취 시 개인 특성에 대한 설문조사도 함께 실시하였다. 시설 근로자의 혈중 다이옥신류 농도는 평균 $2.09{\sim}66.67pg/g$ lipid, 인근 거주 주민은 $1.00{\sim}29.33pg/g$ lipid, 일반 도시 주민은 $5.29{\sim}35.93pg/g$ lipid로 측정되었다. 시설 인근 지역 거주 주민 및 일반 도시 주민 중 비 흡연자의 인체 부하량은 각각 3.0 ng TEQ/g lipid와 4.5 ng TEQ/g lipid로 평가되었다. 대상군의 특성에 따른 혈중 다이옥신류 농도 차이는 관찰되지 않았으며, 연령과 유의한 양의 상관성이 있었다.

• Safety and Health at Work
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• v.1 no.2
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• pp.134-139
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• 2010

Objectives: The lung cancer mortality in Korea has increased remarkably during the last 20 years, and has been the first leading cause of cancer-related deaths since 2000. The aim of the current study was to examine the time trends of occupational lung cancer and carcinogens exposure during the period 2006-2009 in South Korea, by assessing the proportion of occupational burden. Methods: We defined occupational lung cancer for surveillance, and developed a reporting protocol and reporting website for the surveillance of occupational lung cancer. The study patients were chosen from 9 participating university hospitals in the following 7 areas: Seoul, Incheon, Wonju, Daejeon, Daegu, Busan, and Gwangju. Results: The combined proportion of definite and probable occupational lung cancer among all lung cancers investigated in this study was 10.0%, 8.6%, 10.7%, and 15.8% in the years 2006 to 2009, respectively, with an average of 11.7% over the four-year study period. The main carcinogens were asbestos, crystalline silica, radon, polyaromatic hydrocarbons (PAHs), diesel exhaust particles, chromium, and nickel. Conclusion: We estimated that about 11.7% of the incident lung cancer was preventable. This reveals the potential to considerably reduce lung cancer by intervention in occupational fields.

• Environmental Analysis Health and Toxicology
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• v.28
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• pp.8.1-8.5
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• 2013

Cancer has been the leading cause of death in Korea for the last 30 years. Cancer patients' 5-year survival rate between 2005 and 2009 was 62.0%, representing a highly advanced standard of care, as much as developed countries in the EU and the US. The Korean government formulated its first 10-year plan for cancer control in 1996 and has been carrying out a second 10-year plan for cancer control since 2006. But despite the Korean government's efforts, the cancer burden in Korea continues to increase. Many separate laws have gone into effect concerning the management of carcinogen exposure. However, there are no integrated regulatory laws or management systems against carcinogen exposure in Korea. Dead zones remain where carcinogen exposure cannot be controlled properly in Korea. In this paper, we suggest the need to establish a national carcinogen list based on international harmonization as a prerequisite for a paradigm shift in cancer control policy from treatment to primary prevention.