• 한국물환경학회지
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• 제29권3호
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• pp.438-442
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• 2013

According to Geum-River restoration project, given conditions for management of water environment in the Geum-River were changed. Because of those changes, this study was investigated the establishment of water quality standards and water quality target in the Geum-River basin. For management of water environment in the Geum-River, the sub-basins and watersheds are newly divided and the water quality and ecosystem standards in the sub-basins are reestablished. Considering the consistency of water environment policy and legal system, the legal name of sub-basins and watersheds are unified. TMDL (total maximum daily load) should be implemented in the sub-basin where exceeds the water quality standards and the number of water pollutant among the water quality parameters which exceeds the water quality standards are extremely minimized. The water quality target of water pollutant for implementation of TMDL should be established same or higher concentration of water quality standards.

• 반도체디스플레이기술학회지
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• 제21권3호
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• pp.110-113
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• 2022

Non-playable game character plays an important role in improving the concentration of the game and the interest of the user, and recently implementation of NPC with reinforcement learning has been in the spotlight. In this paper, we estimate an AI target tracking method via reinforcement learning, and implement an AI-based tracking agency of specific target object with avoiding traps through Unity ML-Agents Toolkit. The implementation is built in Unity game engine, and simulations are conducted through a number of experiments. The experimental results show that outstanding performance of the tracking target with avoiding traps is shown with good enough results.

• 상하수도학회지
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• 제33권6호
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• pp.469-480
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• 2019

This study was conducted to evaluate the degradation and mineralization of PPCPs (Pharmaceuticals and Personal Care Products) using a CBD(Collimated Beam Device) of UV/H₂O₂ advanced oxidation process. The decomposition rate of each substance was regarded as the first reaction rate to the ultraviolet irradiation dose. The decomposition rate constants for PPCPs were determined by the concentration of hydrogen peroxide and ultraviolet irradiation intensity. If the decomposition rate constant is large, the PPCPs concentration decreases rapidly. According to the decomposition rate constant, chlortetracycline and sulfamethoxazole are expected to be sufficiently removed by UV irradiation only without the addition of hydrogen peroxide. In the case of carbamazepine, however, very high UV dose was required in the absence of hydrogen peroxide. Other PPCPs required an appropriate concentration of hydrogen peroxide and ultraviolet irradiation intensity. The UV dose required to remove 90% of each PPCPs using the degradation rate constant can be calculated according to the concentration of hydrogen peroxide in each sample. Using this reaction rate, the optimum UV dose and hydrogen peroxide concentration for achieving the target removal rate can be obtained by the target PPCPs and water properties. It can be a necessary data to establish design and operating conditions such as UV lamp type, quantity and hydrogen peroxide concentration depending on the residence time for the most economical operation.

• 한국멀티미디어학회논문지
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• 제23권6호
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• pp.747-755
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• 2020

In this paper, we deal with outlier data problems that occur when constructing a PM_2.5 fine dust forecasting system using a neural network. In general, when learning a neural network, some of the data are not helpful for learning, but rather disturbing. Those are called outlier data. When they are included in the training data, various problems such as overfitting occur. In building a PM_2.5 fine dust concentration forecasting system using neural network, we have found several outlier data in the training data. We, therefore, remove them, and then make learning 3 ways. Over_outlier model removes outlier data that target concentration is low, but the model forecast is high. Under_outlier model removes outliers data that target concentration is high, but the model forecast is low. All_outlier model removes both Over_outlier and Under_outlier data. We compare 3 models with a conventional outlier removal model and non-removal model. Our outlier removal model shows better performance than the others.

• 한국대기환경학회지
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• 제14권6호
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• pp.607-620
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• 1998

The influence of transportation on air quality has been elevating in urban area. Air pollutants from automobiles cause primary and secondary air pollution, and need to be tightly controlled. In this study, the effect of automobile air pollutants on highway vicinity area was evaluated by the comparison of field measurement. and target was for modeling using CALINE3, NO2 was the target for this work. It was found that the concentration predicted by CALINE3 is overestimated at low wind speed and input data of wind speed requires correction. Based on the measured data, the wind speed was modified by effective wind speed equation [Ue=U+0.24·EXP(-pxU)], and there after the accuracy of CALINE3 calculation was improved neighborhood area of highway. It was also observed that weather conditions and traffic volume affect the concentration of air pollution. Finally, the NO2 effect of automobile air pollutants on the vicinity area of highway proved to be up to 400∼600m from the highway.

• 한국환경과학회지
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• 제5권1호
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• pp.7-14
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• 1996

Two experiments were conducted to evaluate breathing zone air quality in Taegu, using automatic analyzers for four air quality standards($SO_2$, $NO_2$, CO, and $O_3$). First, air target compounds were measured for 8 to 12 hours in each of two commercial areas and five residential areas. Second, air target compounds were hourly measured for 24 hours in each of two commercial areas, two residential areas, and an industrial complex area. Based on the first experiment the breathing zone air was more polluted in the commercial area as compared to the residential area, while the second experiment showed that the breathing zone air was polluted rather in the residential are3 as compared to the commercial area. The second experiment also indicated that there was some variation of breathing zone air concentration with time and measuring sites. Diurnal variation of breathing zone air concentrations was consistent with previous studies which measured at building height. The highest breathing zone air concentration was shown in Seongseo industrial complex area. An unusual finding of this study was that $SO_2$ concentration in the breathing zone air of Bisandong, a typical residential area of Taegu, was higher than that of other residential areas, even higher than that of Seongseo industrial complex area.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제45회 하계 정기학술대회 초록집
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• pp.271.1-271.1
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• 2013

Titania is usually used in sun-screens, tooth paste, and other daily used objects as a pigment. However, scientists have focused on titania as photocatalyst due to its excellent activities. By fabricating vanadium doped TiO2 and CuOx co-catalyzed TiO2 nano-size filter, the degradation level of the volatile organic compound (VOC) concentration was tested using 365nm UV LED as light source in a closed chamber. Main purpose for this test is to evaluate the activities of various catalysts for degrading the VOCs which are detrimental to human body and toluene and p-xylene were chosen in the VOC removal test. Target gas materials were injected into the test chamber with dry air as carrier gas which was flowed into the gas washer bottle filled with liquid form of VOC substance. When the VOC gas flows into the chamber, it is circulated by 200 mm fan in order to contact with the set-up filter on the aluminum holder. Target gas concentration in the chamber was monitored using VOC detector (miniRae3000, Raesystems) which was also placed inside the chamber. With the measured concentration, the VOC degradation efficiency and the degradation rate were evaluated and used to compare the catalytic activities.

• 자원리싸이클링
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• 제16권1호
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• pp.28-36
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• 2007

폐 ITO 타겟을 염산에 용해시킨 복합 산용액을 원료로 하여 자체기술에 의해 개발한 분무열분해 반응장치를 통하여 평균입도가 50nm이하인 나노 ITO 분말을 제조하였으며, 반응온도 및 원료용액의 농도 등의 반응인자들의 변화에 따른 ITO 분말의 특성을 파악하였다. 반응온도가 $800^{\circ}C$로부터 $1100^{\circ}C$로 변화함에 따라 생성된 ITO 분말의 평균 입도는 40nm로부터 100nm정도까지 증가하고 있었으며, 조직도 점점 치밀화되면서 각각의 입자들이 독립된 다각형 형태를 나타내었으며, 입도분포는 더욱 불균일하게 나타나고 있었다. 또한 반응온도 증가에 따라 XRD 피크의 강도는 증가하였으며 비표면적은 감소하고 있었다. 원료용액 내의 인듐 성분의 농도가 50g/l로부터 400g/l로 증가됨에 따라 생성된 ITO 분말의 평균입도는 점점 증가하는 반면 입도분포는 더욱 불균일 하였다. 농도가 50g/l인 경우에는 ITO 분말의 평균입도는 30nm 이하이면서 입도분포는 비교적 균일하게 나타나고 있었다. 반면 농도가 포화농도에 가까운 400g/l인 경우에는 분말들의 입도분포는 20nm 정도부터 100nm 이상까지 공존하는 매우 불균일한 형태를 나타내고 있었다. 농도가 증가함에 따라 XRD 피크의 강도는 점점 증가하였으며 비표면적은 점점 감소하였다.

• Safety and Health at Work
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• 제11권3호
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• pp.266-274
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• 2020

Background: From only frequency rate of industrial accidents, it is difficult to define the industry composition of accident statistics in a nation. This study aims to propose and develop a new index for measuring the degree of concentration of industrial accidents using the concept of the Herfindahl-Hirschman Index in the case of European countries. Methods: Using the concept of the Herfindahl-Hirschman Index, the concentration index of accidents in the country is developed, and the conditions of European countries are compared using indexes of frequency rate and concentration ratio. Results: The frequency rate and concentration ratio of fatal and nonfatal accidents in European countries are compared. According to the economic condition and geographical position, different patterns of accidents concentration are presented in terms of frequency rate and concentration ratio. Conclusion: We develop the concentration index of industrial and occupational accidents that identifies the industrial ratio of accident occurrence, and the differentiated strategy can be formulated such as approaches to reducing frequency and prioritizing target industries.

• 한국임상약학회지
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• 제7권2호
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• pp.86-90
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• 1997

This study was to find a more accurate method fur measuring small vancomycin dosages which are commonly used in neonates by comparing single and double dilution method. For single dilution method, 500 mg of vancomycin powder was accurately measured and reconstituted with 5 ml of distilled water to make a concentration of 100 mg/ml. Volumes of 0.05, 0.1, 0.15, 0.2, 0.3, 0.4, and 0.5 ml, which equal the target dosages of 5, 10, 15, 20, 30, 40, and 50 mg, were measured using syringes made by Shina and each sample was further diluted with 2 ml of $5\%$ dextrose. The solution of 100 mg/ml concentration was further diluted with $5\%$ dextrose to make a concentration of 20 mg/ml. Volumes of 0.25, 0.5, 0.75, 1.0, 1.5, 2.0, and 2.5 ml, which correspond to 5, 10, 15, 20, 30, 40, and 50 mg, were sampled by the same Shina's syringe as in single dilution method and then each sample was further diluted to make a total volume of 10 ml. Each sample was analyzed by HPLC. The measured dosages of each sample in both single and double dilution methods were lower than the target dosages; however, e values in double dilution method were higher than those in single dilution method for seven target dosages. Percent target dosages in single dilution method were 65 to $90\%$, while in double dilution method 91 to $94\%$. Statistically significant difference between two groups was shown in 5, 10, 15, 20, and 40 mg dosages (p<0.05). In conclusion, when preparing small vancomycin dosages lower an 20 mg $(volume{\leq}0.2\;ml)$, using Shina's syringes, the double dilution method has a closer value to the target dosage than single dilution method.