• Atmosphere
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• v.31 no.5
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• pp.593-606
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• 2021

The Korea Meteorological Administration/National Institute of Meteorological Sciences (KMA/NIMS) has monitored atmospheric CO₂ at Anmyeondo (AMY) World Meteorological Organization (WMO) Global Atmosphere Watch Programme (GAW) regional station since 1999, and expanded its observations at Jeju Gosan Suwolbong station (JGS) in the South and at Ulleungdo-Dokdo stations in the East (ULD and DOK) since 2012. Due to a recent WMO CO₂ scale update and a new filter (NIMS) to select baseline levels at each station, the 22 years of CO₂ data are recalculated. After correction for the new CO₂ scale, we confirmed that those corrected records are reasonable within the compatibility goal (±0.1 ppm of CO₂) between KMA/NIMS and National Oceanic and Atmosphereic Administration (NOAA) flask-air measurements with the new scale. With the new NIMS filter, CO₂ baseline levels are now more representative of the large-scale background compared to previous values, which contained large CO₂ enhancements. Atmospheric CO₂ observed in South Korea is 4 to 8 ppm greater than the global average while the amplitude of seasonal variation is similar (10~13 ppm) to the amplitude averaged over a comparable latitude zone (30°N-60°N). Variations in CO₂ growth rate are also similar, increasing and decreasing similar to global values, as it reflects the net balance between terrestrial respiration and photosynthesis. In 2020, atmospheric CO₂ continued increasing despite the COVID-19 pandemic. Even though fossil emission was reduced (around -7% globally), we still emitted large amounts of anthropogenic CO₂. Overall, since CO₂ has large natural variations and its source was derived from not only fossil fuel but also biomass burning, the small fossil emission reduction could not affect the atmospheric level directly.

• Journal of the Society of Disaster Information
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• v.17 no.1
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• pp.165-175
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• 2021

Purpose: The purpose of this study is to quantitatively present the carbon dioxide(CO₂) emission change according to the application of autonomous driving technology at the network level for waste vehicles in the metropolitan area. Method: The target year was set to 2030, and the analysis method estimated the carbon dioxide (CO₂) emissions for each road link through user equilibrium assignment when unapplied scenario. The application scenario performed traffic assignment using route data on the premise that the group was running in accordance with the application of autonomous driving technology to waste vehicles. In addition, the other means estimated the carbon dioxide emissions through user balance allocation by reflecting the results of the waste vehicle allocation. Result: As a result of the analysis, carbon dioxide(CO₂) emissions were found to be reduced by about 56.9ton/day from the national network level, and the Seoul metropolitan area was analyzed to be reduced by about 54.7ton/day. Conclusion: This study quantitatively presented environmental impacts among various social effects that autonomous driving technology will bring, and in the future, development of various analytical methodologies and related studies should be continuously conducted.

• Journal of Korea Water Resources Association
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• v.55 no.2
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• pp.121-133
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• 2022

The drought resulting from insufficient rainfall compared to the amount in an ordinary year can significantly impact a broad area at the same time. Another feature of this disaster is hard to recognize its onset and disappearance. Therefore, a reliable and fast way of predicting both the suffering area and the amount of water shortage from the upcoming drought is a key issue to develop a countermeasure of the disaster. However, the available drought scenarios are about 50 events that have been observed in the past. Due to the limited number of events, it is difficult to predict the water shortage in a case where the pattern of a natural disaster is different from the one in the past. To overcome the limitation, in this study, we applied the four RCP climate change scenarios to the water balance model and the annual amount of water shortage from 360 drought events was estimated. In the following chapter, the deep neural network model was trained with the SPEI values from the RCP scenarios and the amount of water shortage as the input and output, respectively. The trained model in each sub-basin enables us to easily and reliably predict the water shortage with the SPEI values in the past and the predicted meteorological conditions in the upcoming season. It can be helpful for decision-makers to respond to future droughts before their onset.

• Journal of Nutrition and Health
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• v.55 no.1
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• pp.10-20
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• 2022

This article evaluated levels of Estimated Average Requirements (EARs), Reference Nutrient Intakes (RNIs), and Acceptable Macronutrient Distribution Ranges (AMDRs) of protein using the recently revised Dietary Reference Intakes (DRIs) for Koreans (2020). Dietary protein requirements are based on amounts sufficient to satisfy physiological demands to accomplish nitrogen equilibrium. The same principle was applied to estimate EARs and RNIs, for adults in DRIs conducted in 2015 and 2020 in Koreans. EAR was estimated to be 0.73 g/kg body weight/day, according to data (0.66 g/kg body weight/day) obtained using the nitrogen balance method and adjusted by efficiency of protein use (90%). RNI was calculated as EAR increased by an amount equal to twice the standard deviation of an age group so as to cover 97.5% of the group and was found to be 0.91 g/kg body weight/day. For weaned infants, children, and adolescents, growth requirement was added to estimate EAR. In particular, growth requirement was adjusted by efficiency of protein use in the revised EAR, which led to higher EARs for weaned infants, children, and adolescents of both genders as compared with 2015 DRIs. The AMDR for protein was set at 7%-20% of energy intake, which was the same as 2015 DRIs. Current, average protein intake by the Korean population is almost twice times the EAR, which suggests it might be better to increase the minimal margin for AMDR. However, it was not adjusted in this revision due to lack of evidence.

• Journal of Industrial Convergence
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• v.20 no.12
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• pp.1-9
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• 2022

The objective of this study was to analyze the factors affecting the stages of change of exercise in middle-aged men who work. 170 middle-aged men who work surveyed, 40 to 59 years old, is residing, Chung-Buk and Chung-Nam province, who understand the purpose of this study and agree to participate in this study. This study data is analyzed by using frequency, percentage, standard deviation, t-test, 𝑥² test and Logistic regression analysis. The study show that the exercise self-efficacy(𝛽=.965, p=.003) and the perceived health status(𝛽=.805, p=.025) among middle aged men who work have an effect on the stages of change of exercise meaningfully. That is, the exercise self-efficacy of middle aged men who work who have exercise behavior is 2.6 times higher than middle aged men at work who don't have exercise behavior, and the perceived health status is 2.2 times higher. This study suggests that the development of better exercise practice for middle aged men who work should be aimed at promoting exercise self-efficacy and perceived health status, Based on this, it is necessary to find ways to operate exercise programs at the workplace and community level.

• Ecology and Resilient Infrastructure
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• v.10 no.3
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• pp.51-63
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• 2023

Riverine tree management is crucial in realizing a balance between flood control and ecological preservation, which requires an accurate assessment of the impact of trees on river water elevations. In this study, eight different formulas for evaluating vegetation roughness considering the drag force acting on trees, were reviewed, and the characteristics and applicability of these methods were evaluated from a practical engineering perspective. The study compared the characteristics of vegetation roughness measurement methods for calculated roughness coefficients at different water depths and analyzed factors such as effects of tree canopy width, tree density and diameter, and tree stiffness coefficient, and water level estimation results. A comparison of roughness coefficients at the same water depths revealed that the Kouwen and Fathi-Moghadam formulas and the Fischenich formula yield excessive drag coefficients compared to other formulas. Factors such as channel geometry, tree diameter, and tree density showed varying trends depending on the formula but did not exhibit excessive outliers. Formulas considering the tree stiffness coefficient, such as the Freeman et al.'s formula and the Whittaker et al.'s formula, showed significant variations in drag coefficients depending on the stiffness coefficient. When applied to small- and medium-sized virtual rivers in South Korea using the drag coefficient results from the eight formulas, the results indicated a maximum increase in water level of approximately 0.2 to 0.4 meters. Based on this review, it was concluded that the Baptist et al., Huthoff et al., Cheng, Luhar, and Nepf's formulas, which exhibit similar characteristics and low input data uncertainties, are suitable for practical engineering applications.

• Analyses & Alternatives
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• v.7 no.2
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• pp.35-77
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• 2023

This study aims to solve the entangled loop between demographic transition (DT) and economic growth by analyzing cross-country data. We undertake a national-level group analysis to verify the compressed transition of demographic variables over time. Assuming that the LA (latecomer advantage) on DT over time exists, we verify that the DT of the latecomer is compressed by providing a formal proof of LA on DT over income. As a DT has the double-kinked functions of income, we check them in multiple aspects: early maturation, leftward threshold, and steeper descent under a contour map and econometric methods. We find that the developing countries (the latecomer) have speedy DT (CDT, compressed DT) as well as speedy income such that DT of the latecomers starts at lower levels of income, lasts for a shorter period, and finishes at the earlier stage of economic development compared to that of developed countries (the early mover). To check the balance of DT, we classify countries into four groups of DT---balanced, slow, unilateral, and rapid transition countries. We identify that the main causes of rapid transition are due to the strong family planning programs of the government. Finally, we check the effect of latecomer's CDT on economic growth inversely: we undertake the simulation of the CDT effect on economic growth and the aging process for the latecomer. A worrying result is that the CDT of the latecomer shows a sharp upturn of the working-age population, followed by a sharp downturn in a short period. Compared to early-mover countries, the latecomer countries cannot buy more time to accommodate the workable population for the period of demographic bonus and prepare their aging societies for demographic onus. Thus, we conclude that CDT is not necessarily advantageous to developing countries. These outcomes of the latecomer's CDT can be re-interpreted as follows. Developing countries need power sources to pump up economic development, such as the following production factors: labor, physical and financial capital, and economic systems. As for labor, the properties of early maturation and leftward thresholds on DTs of the latecomer mean that demographic movement occurs at an unusually early stage of economic development; this is similar to a plane that leaks fuel before or just before take-off, with the result that it no longer flies higher or farther. What is worse, the property of steeper descent represents the falling speed of a plane so that it cannot be sustained at higher levels, and then plummets to all-time lows.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.4B
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• pp.335-344
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• 2006

In this study, sequential mixing model (SMM) was proposed based on the Taylor's theory which can be summarized as the fact that longitudinal advection and transverse diffusion occur independently and then the balance between the longitudinal shear and transverse mixing maintains. The numerical simulation of the model were performed for cases of different mixing time and transverse velocity distribution, and the results were compared with the solutions of 1-D longitudinal dispersion model (1-D LDM) and 2-D advection-dispersion model (2-D ADM). As a result it was confirmed that SMM embodies the Taylor's theory well. By the comparison between SMM and 2-D ADM, the relationship between the mixing time and the transverse diffusion coefficient was evaluated, and thus SMM can integrate 2-D ADM model as well as 1-D LDM model and be an explanatory model which can represents the shear flow dispersion in a visible way. In this study, the predicting equation of the longitudinal dispersion coefficient was developed by fitting the simulation results of SMM to the solution of 1-D LDM. The verification of the proposed equation was performed by the application to the 38 sets of field data. The proposed equation can predict the longitudinal dispersion coefficient within reliable accuracy, especially for the river with small width-to-depth ratio.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.125-125
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• 2022

저수지 운영자료는 다목적 댐 경우와 마찬가지로, 유입량, 저수량, 방류량 자료로 구성된다. 여기에 강우량을 포함하여, 실시간으로 관리돼야 한다. 그러나 우리나라 저수지는 저수율 자료만 관리하고 있다. 유입량, 방류량이 없는 것이 아니고 관리를 하지 않는다. 강우량은 전혀 없다. 큰 문제인데, 아직도 그 심각성을 모르고, 대충하면 되는 줄 알고 있다. 가장 기초가 되는 일을 무시하고 물관리를 하고 있는 상황이고, 누구도 그 신뢰성을 믿지 않고 있다. 여기서는 이를 해결하는 방안으로 준 실시간 물수지 모형을 구축하여, 10분 단위, 30분 단위, 1시간 단위로 저수위, 저수량, 유입량, 방류량, 강우량을 연속하여 생산하고 검증하는 체제를 제시한다. 준 실시간의 뜻은 계산에 의하지 않고 유입량을 모의에 의해 적용하고 검증하는 과정이 필요하여, 실시간 보다 하루 이틀 늦게 자료를 생산한다는 의미다. 대상 저수지는 유역 내 강우량 수집이 가능한 유역면적 218.80km², 유효저수량 3,494만m³, 수혜면적 5,117 ha인 탑정지를 선정했다. 탑정지 방류량은 탑정1(폭 7.5m×높이 1.5m), 탑정2(4m×1.6m), 양수장(3m×1.6m) 수로로 관개용수 공급량과, 9연의 수문(9m×7.5m)으로 홍수기 방류량으로 구성된다. 분석기간은 1월1일부터 1시간 단위로 연속하여 기간은 자유롭게 설정하여 검정하는 체제를 갖추고 검증된 결과를 제시토록 했다. 2021년 9월의 1시간 단위의 탑정지 저수지 물수지 모의 결과를 요약하면 다음과 같다. 첫째, 탑정지 유역의 환경부 관리 장선, 양촌, 연산 관측소의 면적우량은 최대 15.3mm, 총 160.4mm(3,510만m³)였고, ONE 모형에 의해 연속유량을 모의한 결과, 유입량은 최대 35.6m³/s, 총 1,464만m³로 유출률 41.7%였다. 둘째, 탑정1, 탑정2, 양수장 수로의 수위자료에 수위-유량 관계식을 적용해 수로유량을 산정한 결과 합하여 최대 16.8m³/s였고, 총 548만m³였으며, 수문 방류량은 최대 20.0m³/s였고, 총 108만m³였다. 셋째, 저수지 수위는 관측수위는 EL.28.21~29.38m, 평균 EL.28.87m, 모의수위는 EL.28.08~29.62m, 평균 EL.28.80m로 나타났고, R²는 0.910로 만족한 결과를 얻었다. 정리하면 저수지 운영자료가 없는데도, 10분, 1시간 단위로 연속으로 유입량, 저수량을 모의하여 관측저수량과 비교한 결과가 괄목할 신뢰도를 나타냈다. 이를 바탕으로 저수량, 유입량, 방류량, 강우량 등 준 실시간 저수지 운영자료 생산체제를 마련한 것으로 결론을 내렸다.

• 한국노년학
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• v.29 no.1
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• pp.135-147
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• 2009

Recently, The number of hypertension is increasing with westernized diet and lack of exercise. Many researchers are trying to treat and prevent hypertension by exercise therapy. However, not only did most of studies analyze the effect and usefulness of exercise related to lowering hypertension, but also there is no analysis of the difference of fitness with regard to hypertension according to ages. It is assumed to be important research work to be continued to identify, from the public health's point of view, the difference of fitness with regard to hypertension according to ages can be a essential data for treating and preventing hypertension. Thus, this study is to identify the difference of fitness according to hypertension of adult female over 20s and emphasize the importance of fitness level to the hypertension. Also, this study is to devise valuable study by examining the difference of cardiovascular function. Subjects were 8889 of adult female over 20s. Subjects visited promotion of health center at Y Gu public health center and took comprehensive medical test including hypertension test in Seoul in Korea. It was divided into normal, prehypertension, stage I hypertension and stage II hypertension group by JNC7. The evaluation of cardiorespiratory function was by resting heart rate and lung capacity, the evaluation of fitness was by cardiorespiratory endurance, muscular endurance, muscular strength, power, agility, balance, and flexibility, and the difference of fitness was analyzed by ANCOVA revising independent variable of BMI, drinking, and smoking which affects hypertension. At result, there was significant difference between normal and hypertension group according to most ages in two variable of all cardiorespiratory function, seven fitness variable. Through this study, it was defined that hypertension group had lower cardiorespiratory function and fitness than normal group.