• Title/Summary/Keyword: Observation Scale

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Validation of Complementary Relationship Hypothesis for Evapotranspiration in Multipurpose Dam Basins (다목적댐유역에서의 증발산 보완관계가설 검증)

  • Kim, Jihoon;Kang, Boosik;Kim, Jin-Gyeom
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.37 no.3
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    • pp.549-559
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    • 2017
  • The complementary relationship hypothesis for areal evapotranspirations was validated in the regional-scale area of multipurpose dam basins in Korea and the long-term water balances were indirectly identified. Annual actual evapotranspiration ($ET_A$) was assumed the difference between total annual precipitation and total annual inflow and the available moisture was assumed the total precipitation. The seasonally varying pan coefficient (kp) is estimated as the ratio of the $ET_{pan}$ and the evapotranspiration calculated by FAO Penman-Monteith equation ($ET_{PM}$). The complementary relationships using ground observation data of $ET_P$ and $ET_A$ in the multipurpose dam basins follow generally the typical pattern that $ET_P$ and $ET_A$ is complementary and converges to equivalent evapotranspiration ($ET_W$) under the extreme wet environment. However, $ET_A$ of Juam dam was estimated relatively greater than other basins and exceeds even $ET_P$ at certain range with high moisture availability, which can be understood as the results of possible over-estimation of precipitation or under-estimation of dam inflow. It is expected that the use of evapotranspiration complementary relationship for validating hydrological water balances will contribute to controlling uncertainties in estimating dam inflows during flood season in particular.

Demonstration of Zr Recovery from 50 g Scale Zircaloy-4 Cladding Hulls using a Chlorination Method (50 g 규모의 Zircaloy-4 피복관으로부터 염소화 방법을 이용한 Zr 회수 거동 연구)

  • Jeon, Min Ku;Lee, Chang Hwa;Lee, You Lee;Choi, Yong Taek;Kang, Kweon Ho;Park, Geun Il
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.11 no.1
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    • pp.55-61
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    • 2013
  • The recovery of Zr from Zircaloy-4 (Zry-4) cladding hulls using a chlorination method was demonstrated for complete conversion of Zr into $ZrCl_4$. A chlorination reaction was performed by reacting Zry-4 hulls for 8 h under a 70 cc/min $Cl_2$ + 70 cc/min Ar flow at $380^{\circ}C$. The initial weight of the reactant (51.7 g) decreased to 0.49 g after 8 h of operation, which is only 0.95wt% of the initial weight. The weight of the total reaction products was 121.7 g with a high Zr purity of 99.80wt%. Fe and Sn were identified as major (0.18wt%) and minor (0.02wt%) impurities of the reaction products, respectively. It was also shown that Zr exhibited a high recovery ratio of 96.95wt% with a relatively small experimental loss of 2.34wt%. Observation of the reaction residues revealed that the chlorination reaction was dominant along the longitudinal direction, and surface oxide layers remained as reaction residues. The high purity and recovery ratio of Zr proposed the feasibility of the chlorination technique as an effective hull waste treatment method.

Improving the Usage of the Korea Meteorological Administration's Digital Forecasts in Agriculture: IV. Estimation of Daily Sunshine Duration and Solar Radiation Based on 'Sky Condition' Product (기상청 동네예보의 영농활용도 증진을 위한 방안: IV. '하늘상태'를 이용한 일조시간 및 일 적산 일사량 상세화)

  • Kim, Soo-ock;Yun, Jin I.
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.17 no.4
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    • pp.281-289
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    • 2015
  • Information on sunshine duration and solar radiation are indispensable to the understanding of crop growth and development. Yet, relevant variables are not available in the Korea Meteorological Administration's (KMA) digital forecast. We proposed the methods of estimating sunshine duration and solar radiation based on the 'sky condition' of digital forecast products and validated using the observed data. The sky condition values (1 for clear, 2 for partly cloudy, 3 for cloudy, and 4 for overcast) were collected from 22 weather stations at 3-hourly intervals from August 2013 to July 2015. According to the observed relationship, these data were converted to the corresponding amount of clouds on the 0 to 10 scale (0 for clear, 4 for partly cloudy, 7 for cloudy, and 10 for overcast). An equation for the cloud amount-sunshine duration conversion was derived from the 3-year observation data at three weather stations with the highest clear day sunshine ratio (i.e., Daegwallyeong, Bukgangneung, and Busan). Then, the estimated sunshine hour data were used to run the Angstrom-Prescott model which was parameterized with the long-term KMA observations, resulting in daily solar radiation for the three weather stations. Comparison of the estimated sunshine duration and solar radiation with the observed at those three stations showed that the root mean square error ranged from 1.5 to 1.7 hours for sunshine duration and from 2.5 to $3.0MJ\;m^{-2}\;day^{-1}$ for solar radiation, respectively.

Case Study of the Stability of a Large Cut-Slope at a Tunnel Portal (터널 입구부 대절토 사면 안정성 사례 연구)

  • Park, Dong Soon;Bae, Jong-Soem
    • The Journal of Engineering Geology
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    • v.25 no.1
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    • pp.115-129
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    • 2015
  • The cut-slope of a large-sectional tunnel portal is recognized as a potential area of weakness due to unstable stress distribution and possible permanent displacement. This paper presents a case study of a slope failure and remediation for a large-scale cut-slope at a tunnel portal. Extensive rock-slope brittle failure occurred along discontinuities in the rock mass after 46 mm of rainfall, which caused instability of the upper part of the cut-slope. Based on a geological survey and face mapping, the reason for failure is believed to be the presence of thin clay fill in discontinuities in the weathered rock mass and consequent saturationinduced joint weakening. The granite-gneiss rock mass has a high content of alkali-feldspar, indicating a vulnerability to weathering. Immediately before the slope failure, a sharp increase in displacement rate was indicated by settlement-time histories, and this observation can contribute to the safety management criteria for slope stability. In this case study, emergency remediation was performed to prevent further hazard and to facilitate reconstruction, and counterweight fill and concrete filling of voids were successfully applied. For ultimate remediation, the grid anchor-blocks were used for slope stabilization, and additional rock bolts and grouting were applied inside the tunnel. Limit-equilibrium slope stability analysis and analyses of strereographic projections confirmed the instability of the original slope and the effectiveness of reinforcing methods. After the application of reinforcing measures, instrumental monitoring indicated that the slope and the tunnel remained stable. This case study is expected to serve as a valuable reference for similar engineering cases of large-sectional slope stability.

Short-Term Results of Subpectoral Tenodesis of the Proximal Biceps Tendon Using by Interference Screw (간섭나사를 이용한 흉근하 상완 이두근 건 고정술의 단기 추시 결과)

  • Kim, Jeong-Woo;Kang, Hong-Je
    • Clinics in Shoulder and Elbow
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    • v.13 no.1
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    • pp.7-13
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    • 2010
  • Purpose: Our purpose was to retrospectively analyze clinical results of subpectoral tenodesis of the proximal biceps tendon using an interference screw. Materials and Methods: We reviewed 23 cases of patients receiving tenodesis of the proximal biceps tendon between January 2008 and January 2009 for whom we had follow-up data for at least 1 year. Twenty-three cases were operated on using subpectoral tenodesis; 16 of these cases had a rotator cuff tear. The results were judged using a visual analog scale (VAS), ASES, tenderness on the biceps groove, fixation failure and the degree of deformity (BAD). Results: VAS and ASES scores were significantly improved in all patients by the time of the final observation. There were no significant complications or fixation failures. The patients without a tear of the rotator cuff had a better result than patients with a tear of the rotator cuff, but the difference between the two groups was not significant (p>0.05). Conclusion: In patients with pathology of the long head of the biceps brachii, benefits of subpectoral interference screw tenodesis include pain relief, maintenance of functional biceps, muscle strength, and cosmesis. Subpectoral biceps tenodesis using interference screw fixation appears to be a promising, reproducible, reliable technique for addressing anterior shoulder pain related to pathology of the long head of the biceps brachii.

A Study on Space Design and Space Uses of Community Based Small Public Libraries - Focused on the Cases of Ann Arbor District Library in the United States - (소규모 지역 공공도서관의 공간 구성과 이용 특성 연구 - 미국 앤아버 공공도서관 브랜치의 사례조사를 중심으로 -)

  • Moon, Eun-Mi
    • Korean Institute of Interior Design Journal
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    • v.19 no.5
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    • pp.217-225
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    • 2010
  • Today's public libraries in communities are on the processes of changes to integrate information and communication technology into traditional library system in order to support current users' demands for the new digital era. The purpose of this study is to examine the changing characters on space design and space uses of community based public libraries by conducting case studies of three branch libraries which were built after 2004 in Ann Arbor, Michigan in the United States. As the conclusion of this research, the findings of the case studies are utilized as basic data for planning and design guidelines for public libraries as community resources. The study summarizes the characteristics of space design and space uses in public libraries as follow; first, the floor plans of small-scale public libraries are open visually as well as spatially. The space organization of the libraries is arranged by potential noise levels, as placing noisy spaces near the entrance halls and quiet spaces at the back. Main book shelves are located in the middle of the library buildings, while seats are arranged along the window sides. By placing various kinds of furniture in open reading areas, library users can select different types of seats and tables for their comforts. Second. the survey of observation also finds that a large number of users often use library computers and personal computers to connect the internet at the libraries. These personal computer users who are new user group in community based libraries preferred to sit in casual study areas and individual tables with one or two seats only. Third, the libraries, in addition, develop and provide various programs and events for people in communities. Especially, the programs for children, the elderly and new comers from the abroad are well prepared, thus provide opportunities for them to visit the libraries in regular bases. The survey finds that family entertainment and leisure activities are the important parts of the program as well as renting music CD and movie DVD are also important reasons for people to come. Thus, the libraries prepare high quality children's space and CD shelves near the entrance hall.

Past and Future Regional Climate Change in Korea

  • Kwon, Won-Tae;Park, Youngeun;Min, Seung-Ki;Oh, Jai-Ho
    • The Korean Journal of Quaternary Research
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    • v.17 no.2
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    • pp.161-161
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    • 2003
  • During the last century, most scientific questions related to climate change were focused on the evidence of anthropogenic global warming (IPCC, 2001). There are robust evidences of warming and also human-induced climate change. We now understand the global, mean change a little bit better; however, the uncertainties for regional climate change still remains large. The purpose of this study is to understand the past climate change over Korea based on the observational data and to project future regional climate change over East Asia using ECHAM4/HOPE model and MM5 for downscaling. There are significant evidences on regional climate change in Korea, from several variables. The mean annual temperature over Korea has increased about 1.5∼$1.7^{\circ}C$ during the 20th century, including urbanization effect in large cities which can account for 20-30% of warming in the second half of the 20th century. Cold extreme temperature events occurred less frequently especially in the late 20th century, while hot extreme temperature events were more common than earlier in the century. The seasonal and annual precipitation was analyzed to examine long-term trend on precipitation intensity and extreme events. The number of rainy days shows a significant negative trend, which is more evident in summer and fall. Annual precipitation amount tends to increase slightly during the same period. This suggests an increase of precipitation intensity in this area. These changes may influence on growing seasons, floods and droughts, diseases and insects, marketing of seasonal products, energy consumption, and socio-economic sectors. The Korean Peninsular is located at the eastern coast of the largest continent on the earth withmeso-scale mountainous complex topography and itspopulation density is very high. And most people want to hear what will happen in their back yards. It is necessary to produce climate change scenario to fit forhigh-resolution (in meteorological sense, but low-resolution in socio-economic sense) impact assessment. We produced one hundred-year, high-resolution (∼27 km), regional climate change scenario with MM5 and recognized some obstacles to be used in application. The boundary conditions were provided from the 240-year simulation using the ECHAM4/HOPE-G model with SRES A2 scenario. Both observation and simulation data will compose past and future regional climate change scenario over Korea.

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Study on Poverty of the Middle Aged Men Living in Chokbang Area (쪽방거주 중고령 남성의 빈곤 사례연구)

  • Kim, Dong-Seon;Mo, Seon-Hee
    • The Journal of the Korea Contents Association
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    • v.20 no.5
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    • pp.222-235
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    • 2020
  • This study examines the poverty progress and its factors which drove the lives of the middle-aged men in Chokbang area. The observed examples are the retired government officials and the self-employed who have been classified as the ones in the economically-middle class but currently as the welfare recipients. According to the results of in-depth interview and observation, the poverty of the observed has undergone the progress of trigger, worsening, breakup, desperation and stabilizing stages. The poverty factors found in this study could be categorized into two factors; circumstantial factors(bankruptcy after IMF, debt guarantee for relatives) and inner factors(the participants' behavior and characteristics). The circumstantial factors worked mainly in the trigger stage and the inner factors contributed to worsening economic crisis and facilitating the progress. According to the result, this study suggests not only individual-scale measures such as encouragement of familial bond or medical treatment of the alcoholism but also social measures including proper regulation of shark loan and opportunity supply to exit from poverty.

Review on Wandering Behavior in Persons with Dementia (치매 노인의 배회행동에 관한 문헌 조사)

  • HongSon, Gwi-Ryung
    • Perspectives in Nursing Science
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    • v.3 no.1
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    • pp.35-45
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    • 2006
  • In Korea, about 8.3% over aged 65 are suffering from Alzheimer's disease or other type of dementia. Among dementia-related behaviors, wandering is the one of strongest factors on burden and stress of caregivers. On Lee and Kwon's report with community living persons with dementia, upto 85% of caregivers reported wandering as a problem. Wandering is a frequently encountered problem in communities and long-term care facilities, but it is among least understood dementia. related behavior. Despite the prevalence of wandering, its significant adverse outcomes, and the increase in persons with dementia in Korea, no systematic research has been conducted in Korea. The purpose of this study is to review on literature related to wandering behavior among persons with dementia. The specific topics related to wandering are included: definition, the prevalence of dementia and wandering behavior, the influencing factor on wandering, outcomes of wandering behavior, and the measurement method. Wandering is defined as "aimless walking" and "Meandering, aimless or repetitive locomotion that exposes one to harm and is incongruent with boundaries, limits, or obstacles". Wandering is viewed as a problematic behavior, however, it has to be understood as need-driven compromised behavior. For example, wandering may be an expression of searching for familiar person and/or place. Recently, in Korea, there is an effort for establishing the therapeutic environment for elders who are wanderers in long-term-care facilities. Cognitive impairment of persons with dementia is found to be a consistent factor on wandering behavior through many national and international studies. The adverse outcomes of wandering are serious problem in persons with dementia as well as their caregivers. The adverse outcomes include falls, fractures, getting lost, use of restraints, or even death. In fact, wandering is one of the major reasons for a patient to be institutionalized. For measurement of wandering behavior, two methods are broadly used: observation using stop watch, and survey form. A revised instrument of the Korean version of Algase wandering scale (K_RAWS) is established the psychometric properties (Son, Song, & Lim, 2006) demonstrating valid and reliable instrument in measuring wandering behavior among persons with dementia who are residing in communities. K_RAWS has a 39 items with six subscales including persistent walking, repetitive walking, spatial disorientation, eloping behavior, negative outcome, and mealtime impulsivity. In conclusion, studies including the prevalence of wandering behavior and predictive factors on wandering should be conducted to understand wandering clearly before developing any types of intervention.

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Assessing the skills of CMIP5 GCMs in reproducing spatial climatology of precipitation over the coastal area in East Asia (CMIP5 GCM의 동아시아 해안지역에 대한 공간적 강우특성 재현성 평가)

  • Hwang, Syewoon;Cho, Jeapil;Yoon, Kwang Sik
    • Journal of Korea Water Resources Association
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    • v.51 no.8
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    • pp.629-642
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    • 2018
  • Future variability of the spatial patterns of rainfall events is the point of water-related risks and impacts of climate change. Recent related researches are mostly conducted based on the outcomes from General Circulation Models (GCMs), especially Coupled Model Intercomparison Project, phase 5 (CMIP5) GCMs which are the most advanced version of climate modeling system. GCM data have been widely used for various studies as the data utility keep getting improved. Meanwhile the model performances especially for raw GCM outputs are rarely evaluated prior to the applications although the process would essential for reasonable use of model forecasts. This study attempt to quantitatively evaluate the skills of 29 CMIP5 GCMs in reproducing spatial climatologies of precipitation in East Asia. We used 3 different gridded observational data as the references available over the study area and calculated correlation and errors of spatial patterns simulated by GCMs. As a result, the study presented diversity of the GCM evaluation in the performance, rank, or accuracy by different configurations, such as target area, evaluation method, and observation data. Yet, we found that Hadley-centre affiliated models comparatively performs better for the meso-scale area in East Asia and MPI_ESM_MR and CMCC family showed better performance specifically for the korean peninsula. We expect that the results and thoughts of this study would be considered in screening suitable GCMs for specific area, and finally contribute to extensive utilization of the results from climate change related researches.