• Title/Summary/Keyword: Distribution model

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A Numerical Study on the Effects of Urban Forest and Street Tree on Air Flow and Temperature (도시숲과 가로수가 대기 흐름과 기온에 미치는 영향에 관한 수치 연구)

  • Kang, Geon;Choi, Wonsik;Kim, Jae-Jin
    • Korean Journal of Remote Sensing
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    • v.38 no.6_1
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    • pp.1395-1406
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    • 2022
  • This study investigated the effects of the urban forest and street trees on flow and temperature distribution in the Daegu National Debt Redemption Movement Memorial Park. For this, we implemented tree-drag and tree-cooling parameterization schemes in a computational fluid dynamics (CFD) model and validated the simulated wind speeds, wind directions, and air temperatures against the measured ones. We used the wind speeds, wind directions, air temperatures predicted by the local data assimilation and prediction system (LDAPS) as the inflow boundary conditions. To investigate the flow and thermal characteristics in the presence of trees in the target area, we conducted numerical experiments in the absence and presence of trees. In the absence of trees, strong winds and monotonous flows were formed inside the park, because there were no obstacles inducing friction. The temperature was inversely proportional to the wind speed. In the presence of trees, the wind speeds(temperatures) were reduced by more than 40 (5)% inside the park with a high planting density due to the tree drag (cooling) effect, and those also affected the wind speeds and temperatures outside the park. Even near the roadside, the wind speeds and temperatures were generally reduced by the trees, but the wind speeds and air temperatures increased partly due to the change in the flow pattern caused by tree drag.

Feasibility Study for Derivation of Tropospheric Ozone Motion Vector Using Geostationary Environmental Satellite Measurements (정지궤도 위성 대류권 오존 관측 자료를 이용한 대류권 이동벡터 산출 가능성 연구)

  • Shin, Daegeun;Kim, Somyoung;Bak, Juseon;Baek, Kanghyun;Hong, Sungjae;Kim, Jaehwan
    • Korean Journal of Remote Sensing
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    • v.38 no.6_1
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    • pp.1069-1080
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    • 2022
  • The tropospheric ozone is a pollutant that causes a great deal of damage to humans and ecosystems worldwide. In the event that ozone moves downwind from its source, a localized problem becomes a regional and global problem. To enhance ozone monitoring efficiency, geostationary satellites with continuous diurnal observations have been developed. The objective of this study is to derive the Tropospheric Ozone Movement Vector (TOMV) by employing continuous observations of tropospheric ozone from geostationary satellites for the first time in the world. In the absence of Geostationary Environmental Monitoring Satellite (GEMS) tropospheric ozone observation data, the GEOS-Chem model calculated values were used as synthetic data. Comparing TOMV with GEOS-Chem, the TOMV algorithm overestimated wind speed, but it correctly calculated wind direction represented by pollution movement. The ozone influx can also be calculated using the calculated ozone movement speed and direction multiplied by the observed ozone concentration. As an alternative to a backward trajectory method, this approach will provide better forecasting and analysis by monitoring tropospheric ozone inflow characteristics on a continuous basis. However, if the boundary of the ozone distribution is unclear, motion detection may not be accurate. In spite of this, the TOMV method may prove useful for monitoring and forecasting pollution based on geostationary environmental satellites in the future.

Analysis of the Contribution of Biomass Burning Emissions in East Asia to the PM10 and Radiation Energy Budget in Korea (동아시아의 생체연소 배출물에 대한 한국의 미세먼지 기여도 및 복사 에너지 수지 분석)

  • Lee, Ji-Hee;Cho, Jae-Hee;Kim, Hak-Sung
    • Journal of the Korean earth science society
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    • v.43 no.2
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    • pp.265-282
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    • 2022
  • This study analyzes the impact of long-range transport of biomass burning emissions from northeastern China on the concentration of particulate matter of diameter less than 10 ㎛ (PM10) in Korea using the Weather Research and Forecasting model coupled with Chemistry (WRF-Chem). Korea was impacted by anthropogenic emissions from eastern China, dust storms from northern China and Mongolia, and biomass burning emissions from northeast China between April 4-and 7, 2020. The contributions of long-range PM10 transport were calculated by separating biomass burning emissions from mixed air pollutants with anthropogenic emissions and dust storms using the zeroing-out method. Further, the radiation energy budget over land and sea around the Korean Peninsula was analyzed according to the distribution of biomass burning emissions. Based on the WRF-Chem simulation during April 5-6, 2020, the contribution of long-range transport of biomass burning emissions was calculated as 60% of the daily PM10 average in Korea. The net heat flux around the Korean Peninsula was in a negative phase due to the influence of the large-scale biomass burning emissions. However, the contribution of biomass burning emissions was analyzed to be <45% during April 7-8, 2020, when the anthropogenic emissions from eastern China were added to biomass burning emissions, and PM10 concentration increased compared with the concentration recorded during April 5-6, 2020 in Korea. Furthermore, the net heat flux around the Korean Peninsula increased to a positive phase with the decreasing influence of biomass burning emissions.

Surface soil moisture memory using stored precipitation fraction in the Korean peninsula (토양 내 저장 강수율을 활용한 국내 표층 토양수분 메모리 특성에 관한 연구)

  • Kim, Kiyoung;Lee, Seulchan;Lee, Yongjun;Yeon, Minho;Lee, Giha;Choi, Minha
    • Journal of Korea Water Resources Association
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    • v.55 no.2
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    • pp.111-120
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    • 2022
  • The concept of soil moisture memory was used as a method for quantifying the function of soil to control water flow, which evaluates the average residence time of precipitation. In order to characterize the soil moisture memory, a new measurement index called stored precipitation fraction (Fp(f)) was used by tracking the increments in soil moisture by the precipitation event. In this study, the temporal and spatial distribution of soil moisture memory was evaluated along with the slope and soil characteristics of the surface (0~5 cm) soil by using satellite- and model-based precipitation and soil moisture in the Korean peninsula, from 2019 to 2020. The spatial deviation of the soil moisture memory was large as the stored precipitation fraction in the soil decreased preferentially along the mountain range at the beginning (after 3 hours), and the deviation decreased overall after 24 hours. The stored precipitation fraction in the soil clearly decreased as the slope increased, and the effect of drainage of water in the soil according to the composition ratio of the soil particle size was also shown. In addition, average soil moisture contributed to the increase and decrease of hydraulic conductivity, and the rate of rainfall transfer to the depths affected the stored precipitation fraction. It is expected that the results of this study will greatly contribute in clarifying the relationship between soil moisture memory and surface characteristics (slope, soil characteristics) and understanding spatio-temporal variation of soil moisture.

Improvement Effect of Corni Fructus 30% Ethanol Extract by MIA-Induced Osteoarthritis Animal Model (MIA로 골관절염 유발된 동물모델에서 산수유(山茱萸) 30% Ethanol 추출물의 개선 효과)

  • Kim, Min Ju;Lee, Jin A;Shin, Mi-Rae;Park, Hae-Jin;Roh, Seong-Soo
    • The Korea Journal of Herbology
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    • v.35 no.1
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    • pp.35-44
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    • 2020
  • Objectives : The objective of this study was to investigate the therapeutic effect of Corni Fructus 30% ethanol extract (CFE) on the monosodium iodoacetate (MIA)-induced osteoarthritis rats. Methods : The subjects were divided into 4 groups ; Normal group (N, n=10), MIA-induced osteoarthritis control group (Con, n=10), indomethacin 5 mg/kg treated group (INDO, n=10), CFE 200 mg/kg treated group (CFE, n=10). Blood and articulation tissues were collected after two weeks of drug administration. Oxidative stress was analyzed with reactive oxygen species (ROS), peroxynitrite (ONOO-). And the Nuclear factor erythroid-2 (Nrf2), heme oxygenase-1 (HO-1), superoxide dismutase (SOD), catalase, glutathione peroxidase-1/2 (GPx-1/2), Nuclear Factor Kappa B p65 (NF-κBp65), cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), tumor necrosis factor-alpha (TNFα), interleukin-6 (IL-6), Interleukin 1β (IL-1β), matrix metalloproteinase-1 (MMP-1), and tissue inhibitor of metalloproteinases-1 (TIMP-1) were investigated by western blot. Results : The administration of CFE showed a significant reduction of changes in relative hind paw weight distribution. Reactive oxygen species (ROS) and peroxy nitrite (ONOO-) levels of articulation tissues were significantly decreased in CFE compared to the control group. Western blot measurements of Nrf2, HO-1, SOD, catalase, GPx-1/2 showed that the CFE group was increased compared to the Con group. And western blot measurements of NF-κBp65, COX-2, iNOS, TNFα, IL-6, IL-1β showed that the CFE group was reduced compared to the Con group. Also CFE group decreased MMP-1 and increased TIMP-1. Conclusion : Based on the above results, it can be seen that osteoarthritis is improved when Corni Fructus 30% ethanol extract treated.

Numerical Study on Impact Resistance of Nonuniform Nacre-patterned Multi-layer Structures (비균일 진주층 모사 다층형 복합재료의 내충격성에 관한 수치해석)

  • Lee, Tae Hee;Ko, Kwonhwan;Hong, Jung-Wuk
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.35 no.4
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    • pp.215-226
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    • 2022
  • Significant efforts have been devoted to developing high-performance composite materials by emulating the structure of biological creatures with superior mechanical characteristics. Nacre has been one of the most sought-after natural structures due to its exceptional fracture toughness compared with the constituent materials. However, the effect of manipulating the nacre-like geometry on the impact performance has not been fully investigated thus far. In this study, composites of randomly manipulated nacreous geometry are numerically developed and the impact performance is analyzed. We develop an algorithm by which the planar area of platelets in the nacre-like design is randomly resized. Thereafter, the numerical models of nonuniform nacre-patterned multi-layer structures are developed and the drop-weight impact simulation is performed. The impact behaviors of the model are evaluated by using the ratio of absorbed energy, the von Mises stress distribution, and the impact force-time curve. Therefore, the effect of the geometric irregularity on the nacre-patterned design is elucidated. This insight can be efficiently utilized in establishing the optimum design of the nacre-patterned structure.

A study of artificial neural network for in-situ air temperature mapping using satellite data in urban area (위성 정보를 활용한 도심 지역 기온자료 지도화를 위한 인공신경망 적용 연구)

  • Jeon, Hyunho;Jeong, Jaehwan;Cho, Seongkeun;Choi, Minha
    • Journal of Korea Water Resources Association
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    • v.55 no.11
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    • pp.855-863
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    • 2022
  • In this study, the Artificial Neural Network (ANN) was used to mapping air temperature in Seoul. MODerate resolution Imaging Spectroradiomter (MODIS) data was used as auxiliary data for mapping. For the ANN network topology optimizing, scatterplots and statistical analysis were conducted, and input-data was classified and combined that highly correlated data which surface temperature, Normalized Difference Vegetation Index (NDVI), Enhanced Vegetation Index (EVI), time (satellite observation time, Day of year), location (latitude, hardness), and data quality (cloudness). When machine learning was conducted only with data with a high correlation with air temperature, the average values of correlation coefficient (r) and Root Mean Squared Error (RMSE) were 0.967 and 2.708℃. In addition, the performance improved as other data were added, and when all data were utilized the average values of r and RMSE were 0.9840 and 1.883℃, which showed the best performance. In the Seoul air temperature map by the ANN model, the air temperature was appropriately calculated for each pixels topographic characteristics, and it will be possible to analyze the air temperature distribution in city-level and national-level by expanding research areas and diversifying satellite data.

Impacts of Perceived Innovativeness of Convenience Store on Consumer Brand Engagement and Store Loyalty (편의점의 혁신성이 인지적 인게지먼트와 정서적 인게이지먼트, 그리고 점포충성도에 미치는 영향)

  • LEE, Young-Eun;LEE, Yong-Ki
    • The Korean Journal of Franchise Management
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    • v.13 no.1
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    • pp.35-46
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    • 2022
  • Purpose: With the rapid changes in the technical development and the trend of consumption trend, the convenience store industry is facing an unprecedented competitive situation in the consumption environment where the boundary between online and offline is broken due to the stagnation of offline distribution channels and the spread of online shopping. The biggest innovation strategy of the major convenience store brands in recent years are introducing the O2O (Online to Offline) platform and presenting new products and services beyond the boundaries of online and offline to transform themselves into Omni Channel stores. The study is designed to analyze the effect of innovativeness of convenience store as a stimulus in O2O platform which customers perceive on store loyalty, the final response to external stimuli, through customer engagement with convenience store brands. Specifically, the innovativeness of convenience stores was divided into types of core activities in corporate marketing and focused on innovations in services, products(proposals), promotions and experiences. Research design, data, and methodology: Various hypotheses have been developed to achieve this research purpose. The data were collected from 1,128 questionnaires the age between 15 and 60 who had experience using retail store apps and delivery apps and were analyzed using SPSS 22.0 and SmartPLS 3.3.7 program. Measurement model analysis was carried out to assess convergent and discriminant validity. Also, common method bias was tested using the values of VIF (variance inflation factor). The hypotheses were tested using structural equation modeling with SmartPLS 3.3.7 program. Results: First, service innovation has a positive effect on cognitive engagement. Second, product, promotion and experience innovation have a positive effect on cognitive and affective engagement. Third, cognitive influences affective engagement. Finally, both cognitive and affective engagement affect store loyalty, but affective engagement has a stronger effect on store loyalty than cognitive engagement. Conclusions: All four types of innovation and cognitive engagement have a positive effect on emotional engagement, which has a stronger effect on store loyalty than cognitive engagement. Thus, while innovation can build loyalty through emotional engagement, innovation strategies must be designed and pursued with caution in terms of impact through cognitive engagement may not achieve the planned goals.

Assessment of diet quality of adults from North Korea: using nutrition quotient (NQ) for Korean adults (북한이탈주민의 식사의 질 평가: 성인 영양지수를 기반으로)

  • SaeByeol Kwon;Kyoung-Nam Kim;Moon-Kyung Shin
    • Journal of Nutrition and Health
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    • v.56 no.2
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    • pp.217-230
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    • 2023
  • Purpose: The purpose of this study was to assess the diet intake status and quality of adults from North Korea who had lived in Seoul and Gyeonggi-do, using the nutrition quotient (NQ) for Korean adults. Methods: A number of 166 adults aged from 20 to 64 years were enrolled as study subjects. A structured questionnaire was used to collect information on their demographic characteristics, food consumption frequency, eating behaviors, and NQ. The NQ score was then used to measure the overall diet quality. The NQ score was composed of four major age-based categories. 'Balance', 'Diversity', 'Moderation', and 'Dietary behavior' were utilized as scores for measurements within each of the four categories. The scores for all four categories were summed up, resulting in the total NQ score. Participants' age groups were stratified by 20's, 30's, 40', and over 50's. A χ2 test and generalized linear regression (GLM) model were used to assess a significance for difference of subject distribution in categorical and continuous variables in the food consumption frequency, eating behaviors, and NQ scores. Results: Participants in younger age groups were more likely to report consumption of ramyeon, fast food, sweet and greasy baked products, processed beverage, delivery food, and night snacks than the older age groups. Most importantly, participants in 20's age group were less likely to report the total NQ and moderation score than the 50's age group. Conclusion: In this study, the 20's age group displayed a lower NQ characteristic for an unbalanced diet. Therefore, it is imperative for adults from North Korea to be given individualized diet instructions along with nutritional education programs.

A Study on the 3D Precise Modeling of Old Structures Using Merged Point Cloud from Drone Images and LiDAR Scanning Data (드론 화상 및 LiDAR 스캐닝의 정합처리 자료를 활용한 노후 구조물 3차원 정밀 모델링에 관한 연구)

  • Chan-hwi, Shin;Gyeong-jo, Min;Gyeong-Gyu, Kim;PuReun, Jeon;Hoon, Park;Sang-Ho, Cho
    • Explosives and Blasting
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    • v.40 no.4
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    • pp.15-26
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    • 2022
  • With the recent increase in old and dangerous buildings, the demand for technology in the field of structure demolition is rapidly increasing. In particular, in the case of structures with severe deformation of damage, there is a risk of deterioration in stability and disaster due to changes in the load distribution characteristics in the structure, so rapid structure demolition technology that can be efficiently dismantled in a short period of time is drawing attention. However, structural deformation such as unauthorized extension or illegal remodeling occurs frequently in many old structures, which is not reflected in structural information such as building drawings, and acts as an obstacle in the demolition design process. In this study, as an effective way to overcome the discrepancy between the structural information of old structures and the actual structure, access to actual structures through 3D modeling was considered. 3D point cloud data inside and outside the building were obtained through LiDAR and drone photography for buildings scheduled to be blasting demolition, and precision matching between the two spatial data groups was performed using an open-source based spatial information construction system. The 3D structure model was completed by importing point cloud data matched with 3D modeling software to create structural drawings for each layer and forming each member along the structure slab, pillar, beam, and ceiling boundary. In addition, the modeling technique proposed in this study was verified by comparing it with the actual measurement value for selected structure member.