• Journal of Environmental Science International
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• v.22 no.2
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• pp.251-257
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• 2013

Discharge data examine the process of hydrologic cycle and used significantly in water resource planning and irrigation and flood control planning. It makes high quality discharge data, they carry out research on standard and method of discharge measurement, and equipment improvement. Now various flow meters are utilized to make discharge data in Korea. However, accuracy of equipment and exprerimental research data from measurement are not enough. ADCP(Acoustic Doppler Current Profiler) have been introduced and utilized for flow measurements since the end of 1980's. ADCP flow method is a formal method for flow measurement can easily applyd to relatively large rivers gradually recognized. This equipment can measure the non-contact three-dimensional velocity and water depth data very quickly and efficiently. Also, spatial and temporal resolution of the data is more accurate than any other flow measurement methods which measure flow rate by velocity - area measurement method. In this paper, the velocity is measured using various flow meter and verified the effectiveness by applying from the ADCP in Geum-river. Various flow meters which are med for discharge measurements are VALEPORT002, FLOW TRACKER, PRICE AA and ADCP. The average of five times flow measurement result by ADCP was $10.412m^3/s$, with a standard deviation of 0.68. The repeat test by ADCP and comparison between ADCP and other flow devices to verify the most import factor, flow measurement accuracy. In the result, repeat test of the ADCP showed similar values, flow values were similar to other velocity device results and the average error is 7.7%.

• Journal of the Korea Safety Management & Science
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• v.15 no.3
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• pp.1-6
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• 2013

This study was conducted to compare the value of the working environment measurement with the expected exposure value drawn by using a program, thereby going to investigate whether it is available to the risk assessment of domestic workplace. We used the ECETOC TRA program which is one of the exposure predictive models. Four kinds of substances were measured in two workplace which was exposed to organic solvents and one kind of substance was measured in three workplace which was exposed to dusts and then an exposure assessment of chemical risk factors was conducted. The result value of the working environment measurement, solid substance exceeded standard in one site, and it was found that the other solid and liquid substances were within the standard. The value of the exposure assessment program showd the same result; it was higher than the value of the working environment measurement, suggesting that due to its nature, the exposure assessment program is run only on the worst situation. Therefore, it was found that when the exposure assesment program is used, variables should be substituted only after accurately assessing the workplace and it is a good idea to assess the risk beforehand with the exposure assessment program in the case of the workplace which employs no more than 5 people and where it is hard to assess the working environment.

• Safety and Health at Work
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• v.11 no.3
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• pp.291-300
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• 2020

Background: The study aimed to determine the association of individual cognitive ability in late midlife with labor market participation among older workers. Methods: This prospective cohort study estimates the risk of long-term sickness absence, disability pension, early retirement, and unemployment from scores on the Intelligenz-Struktur-Test 2000R by combining data from 5076 workers from the Copenhagen Aging and Midlife Biobank with a register on social transfer payments. Analyses were stepwise adjusted for age, gender, physical and psychosocial work environment, health behaviors, occupational social class, education, and chronic diseases. Results: In the fully adjusted model, low cognitive ability (≥1 standard deviation below the mean for each gender) and high cognitive ability (≥1 standard deviation above the mean for each gender) were not associated with risk of any of the four labor market outcomes. Conclusion: Individual cognitive ability in late midlife was not associated with risk of long-term sickness absence, disability pension, early retirement, and unemployment in the fully adjusted model. Thus, no direct effect of individual cognitive ability in late midlife was observed on the risk of permanently or temporarily leaving the labor market.

• Journal of the Korea Institute of Building Construction
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• v.2 no.4
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• pp.169-176
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• 2002

To study of binder and fine aggregate a lot of replacement fly-ash concrete, initial characteristics, standard environment of curing temperature $20^{\circ}C$, hot-weather environment, cold weather environment of curing temperature $5^{\circ}C$. Flash concrete tested slump, air contest, setting and Hardening concrete valuated setting period of form, day of age 3, 7, 28 compression strength in sealing curing. Underwater curing specimen compression strength of age 3. 7, 28day used strength change accordingly fly-ash concrete curing temperature. Purpose of study is consultation materials in field that variety of fly-ash replacement concrete mix proportion comparison and valuation. (1) Setting test result, fly-ash ratio of replacement higher delay totting time. Same volume of fly-ash ratio of replacement is lower fly-ash ratio of replacement fine aggregate delay setting time. Setting test in curing temperature $35^{\circ}C$ over twice fast setting in curing temperature $20^{\circ}C$ and all specimen setting delay in curing temperature $5^{\circ}C$. F40 specimen end of setting about 30 time. (2) Experiment result age 28day compression strength more fisher plan concrete then standard environment in curing temperature $20^{\circ}C$, cold weather environment in curing temperature $5^{\circ}C$, most strength F43 is hot-weather environment in curing temperature $35^{\circ}C$ replacement binder 25%, fine aggregate 15%. (3) Hot-weather environment replacement a mount of fly-ash is a same of plan concrete setting period of form. Age 28day compression strength replacement a mount of fly-ash more hot-weather concrete then plan concrete.

• Journal of Korean Society on Water Environment
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• v.39 no.5
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• pp.390-395
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• 2023

The feasibility of applying the shortcut nitrogen removal process to treat livestock wastewater on individual farms was examined, and appropriate operating parameters were established. As a result,, it was determined that the nitrification reaction was carried out under 550 mg/L of ammonium nitrogen concentration, but it was less effective under conditions of high ammonia concentration. Consequently, it was confirmed that a partial injection of inflow water was necessary to minimize the effects of ammonia toxicity. Following the sequential batch reactor (SBR) operation results, it was difficult to achieve the effluent quality standard without an external carbon source. Also, selection of the appropriate hydraulic retention time was critical for the optimal SBR operation. Following the livestock farm application, with external carbon source injecting, the total nitrogen concentration in the effluent was 85.1 mg/L. This result revealed that the standard could be accomplished through a single treatment on individual livestock farms. The ratio of nitrite nitrogen to ammonia nitrogen in the effluent was verified to be suitable for implementing the anammox process with a 10 days of hydraulic retention time. This study demonstrated the potential applicability of process in the future. However, in order to apply to livestock farms, managing variations in wastewater load across individual farms and addressing reduced nitrogen oxidation efficiency during the winter season are crucial.

• Land and Housing Review
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• v.8 no.3
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• pp.171-180
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• 2017

In 1990s, as the extreme weather events according to the global warming climate change are occurred frequently all around the world and the scale of the damage increases, the developed countries are promoting various policies for reducing greenhouse gas emissions setting the goal of greenhouse gas reduction with the level of State and local government. Especially for the greenhouse gas reduction of buildings and the inducement of eco-friendly design, the green certification system is strengthened with the assessment of energy and greenhouse management, and recently, according to the policy change of climate and energy, the certification system expanded from the buildings to the level of city and district is piloted. So this research is to understand the main contents and the assessment system of domestic green building certification system implemented in March 2013 in response to the policy change of climate and energy and to suggest the basic data for the improvement of present domestic greenhouse certification standard through the analysis of actual certification and the main case analysis of international green certification system. Recently in developed countries, in 1990s, for the reduction of building's greenhouse gas emission and the inducement of eco-friendly design, from the building of LEED, BREEAM, DGNB to the level of city and district such as LEED Neighborhood Development, BREEAM Communities, DGNB Stadtquartiere, the system is expanded and piloted. On the contrary, as for the domestic standard of green building certification system, the distribution ratio according to the assessment items in each category consists of the assessment system based on the buildings, and just the simple adjustment of some items and the improvement of weighted value are performed. Actually, as a result of selecting the 30 districts of apartment housing with the most certification performance by use among the 49 buildings certified by Institute of Land & Housing from December 2014 to July 2016 and analyzing the assessment score, the certification level is determined by the sectors of high distribution like indoor environment and energy not by the ineffective sector of external environment with low distribution so this system has a limitation to perform the practical means for the policy change of climate and energy. Thus for the national green building certification standards, the assessment system in the sector of external environment is to complemented and furthermore, reflecting domestic reality, through the introduction of certification system and the assessment system with the level of city and district, this system should be improved to meet the international certification standard.

• The Journal of Sustainable Design and Educational Environment Research
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• v.10 no.1
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• pp.34-41
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• 2011

Global environment is getting deteriorated at an alarming rate. Eco-school could be one of the effective solutions to project our environment and a good sample of architecture to economize in total energies, resources and greenhouse gases. In case of our country, the study of eco-school planning is not sufficient compared with other countries, so this paper would be a good study on the indoor environment of the classroom by surveying their opinions and ideas from the group of users in school facility. The result of this study shows that the proper installation of building equipment and nature ventilation system is necessary to provide delightful environment for the students and to save the energy. To ensure that we have adequate saving and protection it is necessary to change the existing appraisal standard.

• Proceedings of KOSOMES biannual meeting
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• 2017.04a
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• pp.194-194
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• 2017

• Journal of Korean Society for Atmospheric Environment
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• v.15 no.4
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• pp.495-503
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• 1999

Airborne particulate matter $(PM_{10})$ collected using high volume air sampler and silica fiber filter were analyzed by Instrumental Neutron Activation Analysis(INAA), Inductively Coupled Plasma Atomic Emission Spectrometry(ICP-AES) and Atomic Absorption Spectrometry(AAS), and the results were compared with each other. 30~40 trace elements in environmental standard reference materials(NIST SRM 1648 and NIES CRM No.8) were analyzed for the analytical quality control. The relative error for two-third of elements detected was less than 10%, and the standard deviation was less than 15%. During the sampling period for 24 hours, the mass concentration of total suspended particulate was 36.1$\mu\textrm{g}$/㎥ and the value is lower than the critical level in Korea. In the results of NAA, the elements of Al, As, Ba, Fe, La, Mg, Na, Sb, Zn were well agreed with those of other methods. In statistical estimation between different methods, the deviation of Al, Ba, Cr, Fe was less than 10% and quite reliable.

• Journal of Korean Society for Atmospheric Environment
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• v.23 no.1
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• pp.132-140
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• 2007

Concentrations of atmospheric fine particles in Chungnam were measured at 7 sampling sites during 2005. The daily average concentrations of PM 10, PM2.5, and PM1 ranged from 14.9 to $136.5{\mu}g/m^3$, 8.2 to $113.2{\mu}g/m^3$, and 5.7 to $107.5{\mu}g/m^3$, respectively, and the highest levels were observed at Yeongi site. The lowest concentrations for the all size fractions of particulate were observed at Taean located at the west end of the peninsula. The daily average PM10 concentrations were below the current National Standard at all sites, while the daily average PM2.5 concentrations frequently exceeded the US Standard at Cheonan, Dangjin, Boryeong, and Yeongi sites. The frequencies of PM2.5 concentrations exceeding the US standard at Cheonan, Dangjin, Boryeong, and Yeongi were 10.8%, 6.7%, 6.7%, and 26.7%, respectively. In addition, $68{\sim}80%$ of PM10 was in the PM2.5 fraction indicating that fine particles were the major component of atmospheric particles in Chungnam.