• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.113-113
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• 2023

기후변화로 인한 온도 상승이 대기 중 수분량을 증가시키면서 극한 강우가 전 세계적으로 빈번하게 발생하고 있으며, 이에 따라 대규모 홍수 피해가 지속적으로 초래되고 있다. 본 연구에서는 이러한 현상에 대응하기 위한 노력으로, 대기 연직 기둥 내 총 수분량을 나타내는 총가강수량(Total Precipitable Water, TPW)과 극한 강우사상(Extreme Precipitation, EP) 간의 연관성이 강우지속기간에 따라 어떻게 변하는지 분석하였다. 관측 및 재해석(reanalysis) 데이터를 활용하여 동시극한지수(Concurrent Extremes Index, CEI, 0~1, 1에 가까울수록 강한 연결)로 두 변수 간의 정량적 연결 강도를 살펴보았다. 분석 결과, CEI의 지속 시간에 따른 변동 경향성은 지역에 따라 상당한 차이를 보였다. 지중해와 중앙아시아와 같은 대부분의 중위도 지역에서는 강우의 지속 기간이 길어질수록 CEI 값이 급격히 감소하였다. 그러나 한반도를 포함한 동아시아 지역은 중위도임에도 불구하고 긴 지속 기간의 강우 사상에서도 높은 수준의 CEI 값을 유지하였다. 이러한 동아시아 지역의 경향성은 열대지역과 매우 유사하게 나타났으며, 이는 동아시아 지역의 극한 강우 증가가 기후변화의 직접적인 영향을 받을 수 있음을 시사한다.

• Journal of the Korean earth science society
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• v.44 no.4
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• pp.255-263
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• 2023

Western coastal area of Chungnam, including Cheonsu Bay and Garorim Bay, has suffered from hot and cold extremes. In this study, the extreme sea surface temperature on the western coast of Chungnam was analyzed using the quantile regression method, which extracts the linear regression values in all quantiles. The regional MOHID (MOdelo HIDrodinâmico) model, with a high resolution on a 1/60° grid, was constructed to reproduce the extreme sea surface temperature. For future prediction, the SSP5-8.5 scenario data of the CMIP6 model were used to simulate sea surface temperature variability. Results showed that the extreme sea surface temperature of Cheonsu Bay in August 2017 was successfully simulated, and this extreme sea surface temperature had a significant negative correlation with the Pacific decadal variability index. As a result of future climate prediction, it was found that an average of 2.9℃ increased during the simulation period of 86 years in the Chungnam west coast and there was a seasonal difference (3.2℃ in summer, 2.4℃ in winter). These seasonal differences indicate an increase in the annual temperature range, suggesting that extreme events may occur more frequently in the future.

• Journal of the Korean Society for Precision Engineering
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• v.14 no.8
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• pp.73-81
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• 1997

The hard turning process defined as a single point turning of materials harder than $H_{R}$C 58 differs from conventional turning because of hardness of the work materials and cutting toos needed in the process. In hard turning, tool life is very short, of the order of a few minutes, during which the cutting tool is subjected to the extremes of stress and temperature. In this regard, it is well known that CBN tool is proper for this process in spite of expensive cost. In this research, we studied the feasibility of the use of the low cost cutting tool such as a aTiN coated tool. To this end, a new cooling system was designed with an air-oil method for reducing tool temperature, which is based on the principle of air vortex flow. That is, the outlet temperature of the air becomes aver 20 .deg. C lower than atmosphere temperature by entering pressurized air of 5kgf/c $m^{2}$ into the inlet. This cooled air ejected to the top of the cutting tool lowered tool temperature, which reduced the wear of a TiN coated tool by the 30% of CBN tool life with respect to the same cutting length.h.

• Atmosphere
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• v.33 no.5
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• pp.505-517
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• 2023

This study investigates the impacts of carbon neutrality and air quality control policies on near-term climate change in East Asia, by examining three Shared Socioeconomic Pathways (SSPs) scenarios from five climate models. Specifically, low carbon and strong air quality control scenario (SSP1-1.9), high carbon and weak air quality control scenario (SSP3-7.0), and high carbon and strong air quality control scenario (SSP3-7.0-lowNTCF) are compared. For these scenarios, the near-term climate (2045-2054 average) changes are evaluated for surface air temperature (SAT), hot temperature extreme intensity (TXx), and hot temperature extreme frequency (TX90p). In all three scenarios, SAT, TXx, and TX90p are projected to increase in East Asia, while carbon neutrality reduces the increasing rate of SAT and hot temperature extremes. Air quality control strengthens the warming rate. These opposed mitigation effects are robustly forced in all model simulations. Nonetheless, the impact of carbon neutrality overcomes the impact of air quality control. These results suggest that fast carbon neutrality, more effective than an air quality control policy, is necessary to slowdown future warming trend in East Asia.

• Korean Journal of Applied Biomechanics
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• v.25 no.4
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• pp.441-451
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• 2015

Objective : The purpose of the study was to investigate and compare the differences between Parkinson's disease rating, balance, fall and gait scales. Results : Parkinson's disease rating scales include the Hoehn-Yahr Scale and the Unified Parkinson's Disease Rating Scale (UPDRS). The Hoehn-Yahr Scale can measure disease rates easily; however it is not sensitive enough to evaluate the disease's process and management. UPDRS's advantage is in it's higher inter-reliability score; however it is more complicated to use. Parkinson's balance scales are comprised of the Berg Balance Scale (BBS) and the Activities-Specific Balance Confidence Scale (ABC). BBS has the advantage in that it is cheaper to measure and simple in use. ABC's advantage is especially in it's ability to measure higher functional levels; however it is more difficult measure responses due to scores appearing in both extremes. The Fall Efficacy Scale (FES) and The Survey of Activities and Fear of Falling in the Elderly (SAFE) are Parkinson's fall scales. FES's leverage over SAFE is that it is simpler to measure; however it does not coincide with responses which proves disadvantageous in measuring balance loss in high-level Parkinson's patients. SAFE's advantage is in it's simpler use and ability to be utilized without encountering the fear of fall; however it's at a disadvantage in regards to its use with multilateral aspects providing insufficient inspection. Lastly, the Dynamic Gait Index (DGI) and the Functional Gait Assessment (FGA) are Parkinson's gait scales. DGI is advantageous in its ability to test gait ability when exposed to a variety of external environments; however it is disadvantageous in that it registers higher scores with activities. FGA's advantage is in it's dynamic balance test; however it at a disadvantage with those unable to walk. Conclusion : A researcher of Parkinson's patients must choose each scale while considering their positive and negative characteristics.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.7
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• pp.995-1002
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• 2008

Kura clover (Trifolium ambiguum M. Bieb.) is a rhizomatous perennial legume that has potential as a forage crop in the North-Central USA because of its excellent persistence under environmental extremes. Little information is available about defoliation effects on productivity of mixtures of kura clover with grasses typically grown in this region. Two field trials were conducted to evaluate the effects of defoliation management on yield and species composition of binary mixtures of 'Rhizo' kura clover with 'Comet' orchardgrass (Dactylis glomerata L.), 'Badger' smooth bromegrass (Bromus inermis Leyss.), 'Park' Kentucky bluegrass (Poa pratensis L.), and solo-seeded kura clover near Arlington, WI. Three harvest schedules (three, four, or five times annually) and two cutting heights (4 or 10 cm) were imposed. Infrequent defoliation and lower cutting height produced significantly greater total forage yield, 6.6, 5.8, and 5.2 Mg/ha in 3-, 4-, and 5-harvest systems, respectively; and 6.5 and 5.2 Mg/ha for the 4- and 10-cm cutting height, respectively. Averaged over 3 yr and two environments, mixtures had higher forage productions than solo kura clover (6.3, 5.7, and 6.0 Mg/ha for the Kentucky bluegrass, orchardgrass, and smooth bromegrass mixtures, respectively; compared to 5.2 Mg/ha for solo kura clover). The proportion of kura clover in mixtures increased from yr 1 to yr 2 and was constant from yr 2 to yr 3 (34, 58, and 57%, respectively). We conclude that kura clover has excellent potential as a long-term component of grass-legume mixtures regardless of the cutting height, harvest frequency or grass species, even though the proportion of kura clover in harvested forage was significantly greater with less frequent harvest and shorter cutting height of all mixtures.

• Journal of Korea Water Resources Association
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• v.50 no.1
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• pp.17-28
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• 2017

A recent increase in extreme weather events and flash floods associated with the enhanced climate variability results in an increase in climate-related disasters. For these reasons, various studies based on a high resolution weather radar system have been carried out. The weather radar can provide estimates of precipitation in real-time over a wide area, while ground-based rain gauges only provides a point estimate in space. Weather radar is thus capable of identifying changes in rainfall structure as it moves through an ungauged basin. However, the advantage of the weather radar rainfall estimates has been limited by a variety of sources of uncertainty in the radar reflectivity process, including systematic and random errors. In this study, we developed an ensemble radar rainfall estimation scheme using the multivariate copula method. The results presented in this study confirmed that the proposed ensemble technique can effectively reproduce the rainfall statistics such as mean, variance and skewness (more importantly the extremes) as well as the spatio-temporal structure of rainfall fields.

• Journal of the Korea Convergence Society
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• v.11 no.4
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• pp.151-156
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• 2020

The purpose of this study is to design a process for developing wearable sports helmet devices by utilizing IoT server technology, focusing on sports where helmet wear is essential at sports sites. This enables customized training of athletes by continuously accumulating personal biometric information during training, checking players' condition based on data, and informing them of injury prevention and dangerous situations. In addition, the wearable device that can be useful when the training place is likely to damage the physical health due to heat waves or extremes can provide a foundation for improving the performance. Since such technology can be applied not only to the sports field but also to the society such as the industrial field or the underprivileged, it can be expected to be expandable.

• Journal of the Korean Society of Costume
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• v.50 no.7
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• pp.181-193
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• 2000

The purpose of this study was to establish the marketing strategy, that strengthens the brand royalty of their own in apparel industry and that can induce consumer's brand switching against competitive brand. This might be done by suggesting influencing factors on the brand switching for fashion goods. This study was classified into theoretical and experimental study Experimental study was done, using the survey to prove the models for consumers' responses to brand switching by the theoretical study. The survey was conducted through two preliminary questionnaires. It was used as a criterion to prove the validity of the main survey and analyse the reliability. It analyzed at last five hundred ninety-two women in the age of twenty to thirty years odd who live in Seoul and the suburban of Seoul. Followings are the summary of the results revealed through the experimental study. First, brand switching behavior of consumers far formal dress was attributed to two extremes the inner motivation of variety seeking tendency and communication contact, complex variety seeking group, true variety seeking group, derived variety seeking group, and variety avoiding group. Second, the structure of low dimension related fashion according to factor analysis, which affects brand switching, was composed to involvement in 5-dimension, information search in 3-dimension. Based on the results of this study the types of brand switching in fashion goods can be classified by the variety seeking tendency. as inner motivation, and level of contact communication as a outside stimuli. In addition this study showed a correlation among the factors for brand switching related to variables of fashion.

• International Journal of Human Ecology
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• v.14 no.1
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• pp.115-130
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• 2013

This study reviews the current status of Korean first graders, their experience with early care and education (ECE) programs, and their participation in private and after-school education. The research also examines how school adjustment during the first grade is related to family income, types of ECE programs, and participation in private and after-school education. Using the first year data of the Korean Child and Youth Panel Survey (KCYPS) 2010, this study analyzes 752 first graders who attended only one of two types of ECE programs (child care centers or kindergartens), after which two 25% income extremes were examined. The analysis demonstrates that children from low-income households attended child care centers more often, while children from high-income households attended kindergartens more often. For both low-income and high-income groups, child care centers had a lower starting age and longer attendance periods than did kindergartens. High-income household children started attending ECE programs earlier, experienced more private and after-school education, and received a larger number of private and after-school educational lessons. For the second research purpose, children from low-income families showed better peer relations in school adjustment, while children attending child care centers showed better teacher relations than children attending kindergartens. Children with after-school education also exhibited better peer relations. These findings show the importance of government support for early learning, especially for low-income families and offer a foundation for developing private education polices for early childhood before and after school entry.