• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.123-123
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• 2021

도시하천유역이나 복합유역 등 지역적 성향을 고려한 도달시간 산정에 관한 연구는 현재까지도 미흡한 실정이다. 소규모 유역의 홍수량을 산정할 경우 유하시간보다 유입시간 비중이 상대적으로 크다. 그러나 유하시간만을 고려하여 도달시간을 산정할 때, 소규모 유역의 경우 하도가 없고 유역면적이 5km² 내외 또는 하도의 저류 효과를 기대할 수 없는 경우 도달시간이 짧아 홍수량이 과대 산정된다. 이를 극복하고자 재해영향성평가등의 협의 실무지침에서는 도달시간 이외에 매개변수인 저류상수를 인위적으로 증가시키는 방법을 제안하고 있다. 하지만 이 방법 역시 유역의 물리적인 특성을 나타내는 변수를 왜곡한다는 근복적인 문제를 완전히 해결하지 못하였다. 이에 본 연구에서는 기존 중·대규모 하천을 대상으로 수행된 연구결과를 바탕으로 제안된 홍수 도달시간 산정방법의 한계를 극복하고, 유입시간이 지배적인 소규모 복합유역에 적용 가능한 도달시간 산정방안을 제시하고자 한다. 이를 위해 실증실험을 통해 기존 유입시간 산정식을 개선하고, 도시수문 모니터링 시범유역에 적용하여 정확성을 평가하고자 하였다. 먼저, 홍수도달 시간 측정을 위한 강우유출 실내 실험장치를 제작하였다. 실험장치는 본체(길이3m×폭1.2m×높이0.8m)와 경사조절 장치(0~15도)를 포함하고 있다. 본체 전면부를 타공(ø10mm)하고 상·하단에서 지표와 기저유출을 집수하여 티핑버킷으로 유량을 측정하였고, 토체 내에는 토양수분센서를 설치하여 강우유출 발생시간 동안 토양수분 변화를 측정하였다. 본 연구에서는 하도흐름인 유하시간(Kraven 공식)을 계산하여 도달시간을 산정하기 보다 지표면 흐름인 유입시간(Kerby 공식)에 보정계수를 도입하여 도달시간을 산정하는 방안을 검토하였다. 실험 결과, 불투수 면적비율이 증가함에 따라 도달시간은 감소하고, 불투수 유역이 하류에 위치할수록 유출발생시간이 빨라졌다. 실증실험 결과를 바탕으로 도시수문 모니터링 시범유역에 적용하여 기존 유하시간과 저류상수를 보정하는 도달시간 산정방식(연속형 Kraven)과 유입시간을 보정한 도달시간 산정(수정 Kerby)으로 도출된 유출량을 실측 유량과 비교하였다. 그 결과 제안된 홍수도달시간 산정식에서 모의된 홍수량이 기존 방식과 유사하거나 우수한 첨두홍수량을 보였으며, 설계자 임의성이 배제된 일관성있는 해석값을 제시해 줄 것으로 판단된다.

• The Journal of the Convergence on Culture Technology
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• v.10 no.1
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• pp.325-335
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• 2024

In this study, I investigated cases of operating Sustainable Development Goals (SDGs) sustainable design courses based on interdisciplinary education for diverse design major students in the fashion design department. Through literature review, we examined the necessity of this course operation and analyzed the course through class design, execution, and operational results. Sustainable design courses were organized for 2nd to 4th-year students, promoting integrated learning for fashion design and various design majors to enhance interdisciplinary skills based on the in-depth study of SDGs issues. The educational content in the classes focused on the sustainable development goals achieved through upcycling design of waste PET bottle fibers developed by local industries, aiming to pursue sustainable values of designers through problem discovery and resolution. Students developed various upcycled products, evaluated metrics, and assessed satisfaction levels. Through this process, students gained an understanding of the practical value of SDGs, recognized the importance of sustainable development through design approaches for solving local issues, and acknowledged the significance of interdisciplinary education with various design majors.

• Journal of Aerospace System Engineering
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• v.18 no.4
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• pp.109-116
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• 2024

The validity of the analysis results was confirmed based on the insulation test results, and the vaporization mass generated in the common bulkhead was calculated to evaluate the common bulkhead propellant tank's insulation performance. The analysis results were validated by comparing the transient heat transfer analysis with the insulation test results. A transient heat transfer analysis was subsequently conducted on the common bulkhead propellant tank, considering the internal heat conduction in the propellant tank and natural convection heat transfer due to the outside air. This analysis extracted the heat flux generated in the common bulkhead and quantified the vaporization mass, a key indicator of insulation performance. Consequently, the vaporization mass was calculated at 0.09 kg, below the insulation design standard of 0.12 kg for the common bulkhead propellant tank, confirming it meets the insulation performance standard.

• Journal of Soil and Groundwater Environment
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• v.13 no.3
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• pp.37-44
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• 2008

Soil ecology has important roles in global ecosystems. However, soil ecological quality information is being ignored when assessing ecological impact of construction actions. And methods for classifying and assessing soil ecological quality have been very little established in comparison to those for animal and plant ecosystems. In this study, it was examined whether soil ecological quality information has influence on determining an eco-friendly route for a road construction project. For this, sensitivity analysis was systematically performed by varying the relative significance (weights) of soil ecological quality information among natural environmental and ecological factors. When the weight of soil ecological quality was greater than just 14%, the soil ecological quality information significantly influenced the determination of the eco-friendly routes for a specific road construction project. This demonstrates that soil ecological quality information has to be considered for more reliable environmental impact assessment, and also supports the validity of use of soil ecological quality information and its mapping technique in planning and siting of eco-friendly construction projects.

• Journal of Korean Society of Environmental Engineers
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• v.29 no.3
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• pp.348-356
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• 2007

Statistical and probabilistic method was used in the analysis of data, which is the most effective one in describing the various natures, and the methodology relating the results with the design was developed. Influents and effluents of three treatment plants were analyzed and the focus was made on BOD, COD, SS, IN, TP The fluctuations of influent such as BOD, COD, SS were extremely large and their standard deviations(st.dev) were more than 10 mg/L. but those of TN, TP were small; the st.dev was 6.6 mg/L for TN, 0.6 mg/L for TP, respectively. But, effluent concentration showed consistent pattern regardless of the influent fluctuations, the st.dev was ranged between 0.28 and 4.48 mg/L. Effluent distributional characteristics were as follows; BOD, COD were distributed normally, but SS, TN, and TP, log-normally; unsymmetric and skewed to the right. The coefficient of reliability(COR) based on the results of statistics of data was introduced to evaluate the process performance an4 to reflect the process performance to the process design. The coefficient of reliability relates the design value(the goal) with the standards and it can be used in operating treatment facilities under a certain reliability level and/or in evaluating the reliability of the treatment facilities on operation. Each treated water quality of effluent showed the half of water quality standards in the level of 50% percentile and all treatment plant was achieved 100% probability of water quality standards. It was concluded that the variability of the process performance should be reflected to the design procedure and the standards through the analysis based on the statistics and the probability.

• Journal of Digital Convergence
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• v.19 no.3
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• pp.203-209
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• 2021

In this study, a prototype design model was proposed for developing an online recruitment system through multi-dimensional data crawling and social media analysis, and validates text information and video interview in job application process. This study includes a comparative analysis process through text mining to verify the authenticity of job application paperwork and to effectively hire and allocate workers based on the potential job capability. Based on the prototype system, we conducted performance tests and analyzed the result for key performance indicators such as text mining accuracy and interview STT(speech to text) function recognition rate. If commercialized based on design specifications and prototype development results derived from this study, it may be expected to be utilized as the intelligent online recruitment system technology required in the public and private recruitment markets in the future.

• Journal of Digital Convergence
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• v.11 no.8
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• pp.1-10
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• 2013

Even though the importance of reading voters' share of mind increases in political campaign, there is no research which analyzes engagement in perspective of political campaign. Therefore, the purpose of this research is to calculate political engagement index which is qualitative indicator about political campaign's immersion in candidate in perspective of engagement and provide scientific data for political advertisement and publicity strategy. For this purpose, A and B candidates who ran for 18th president in December 19th, 2012 are selected for subjects of the research. The young people whose voter participations are low in this presidential election are selected as subjects for responding questionnaire and are surveyed. This research is qualitative evaluation which tires to supplement a limit of qualitative analysis of content by surpassing quantitative evaluation including advertisement, promotion, public opinion on politics, ratings, etc. Evaluation attribute is designed to distribute 8 PEI into 0~100 score. If PEI is more than 50, then the score indicates immersion above average. If PEI is lower than 50, then the score indicates immersion below average. The model of the research will contribute to development of methodological research of political campaign strategy. Also, in the future, this model can be used as micro-targeting in each political campaign's election strategy.

• Journal of dental hygiene science
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• v.15 no.4
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• pp.407-412
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• 2015

This study investigated flexural properties of indirect Gum-shade composite resins for esthetic improvement. The material utilized in this study was Crea.lign, Twiny flow and Twiny paste (TP). Ten specimens were fabricated with a dimension of $25{\times}2{\times}2mm$ according to the ISO 4049. After fabrications, specimens were stored in the distilled water for 24 hours at the temperature of $37^{\circ}C$. Three-point bending test was performed in universal testing machine (Instron 3344; Instron, USA) at a crosshead speed of 1 mm/min until the failure occurred. TP exhibited a higher flexural strength (FS) and flexural modulus (FM) compared to the flowable materials. There were significant differences among the three materials in FS and FM. However, there was no significant difference in work of fracture (WOF) in all tested materials (p>0.05). In Weibull analysis, TP showed the greatest Weibull modulus which means a higher reliability of the materials. Also, Gum-shade composite resins revealed a strong correlation in all flexural properties. There was a positive correlation in FS-FM ($r^2=0.99$) and a negative correlation between FS-WOF and FM-WOF ($r^2>0.97$). Therefore, this confirmed that flexural property was important for mechanical behavior evaluation and useful information. To addition, this improved among mechanical properties correlation of materials as important factor.

• Korean Journal of Ecology and Environment
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• v.42 no.3
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• pp.271-279
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• 2009

Vinyl chloride (VC) is a known human carcinogen, and it is released to multi-environmental media via several exposure routes. VC was potentially evaluated as a water quality pollutant based on human health risk assessment in Korean water environments. In this study, we investigated physicochemical and toxicological properties of VC, human health and ecological risk assessment, and the regulation of VC as a water quality pollutant in developed countries. Currently there are no standard or guideline values of VC in Korean legal system for the protection of human health and aquatic ecosystem, except that it is designated as a specific toxic substance and a water quality pollutant. Human health risk assessment of VC was previously performed based on the limited water quality monitoring data. The monitoring level of VC in Korean water system is more higher than other countries'. VC was assessed as potential hazardous chemical based on the US EPA's cancer risk assessment. There were a few ecotoxicity data of VC available using very limited kinds of aquatic organisms, and the toxicity results obtained seem to be overestimated without considering the losses of VC in open exposure system. Therefore it is needed to monitor the VC in various areas and to carry out the ecotoxicity research using multi-level organisms. We expect that these results can be useful information for implementing VC as a water quality pollutant in legal system for the protection of human health and aquatic ecosystem in near future.

• Journal of Radiation Protection and Research
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• v.40 no.3
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• pp.162-167
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• 2015

Although the perfomance indicators of the nuclear power plants in Korea show optimal, it requires detailed analysis and discussion centered on the radiation dose. As analysis methods, analysis on the radiation dose of nuclear power plants over the past five years was assessed by comparing the relevant radiation dose of radiation workers and per capita average annual radiation dose of the world's major nuclear power stations was also analyzed. The radiation workers over the annual radiation dose limit of 50 mSv were not. The contrast ratio of the radiation exposure according to the reactor type was the normal operation of PHWR was 6.2% higher than those of the PWR. This shows the radiation work of PHWR during normal driving operation is much more than those of PWR. According to the Performance Indicators of the World Association of Nuclear Operator, the annual radiation dose per unit in 2013 showed 527 man-mSv of Korea is the best country among the major nuclear power generating states, the world average was 725 man-mSv. The annual per capita radiation dose is about 80% less than 1 mSv of the public dose limit and also the average per capita dose showed a very low level as 0.82 mSv. Workers in related organizations showed 1.07 mSv, the non-destructive inspection agency workers showed 3.87 mSv. The remarkable results were due to radiation reduced program such as development of radiation shielding and radiation protection. In conclusion, the radiation exposured dose of nuclear power plants workers in Korea showed a trend which is ideally reduced. But more are expected to be difficul and the psychological insecurity against the operation of the nuclear power plants is existed to the residents near the nuclear power plants. So the radiation dose reduction policy and radiation dose follow up study of nuclear power plants will be continously excuted.