• Journal of Environmental Science International
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• v.32 no.8
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• pp.521-531
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• 2023

This study analyzed the impact of recirculation on high-concentration PM_2.5 in the coastal area. Through the analysis of observational data, it was observed that the development of sea breeze led to an increase in PM_2.5 and SO₄^2- concentrations. Hysplit backward trajectory analysis confirmed the occurrence of air mass recirculation. Results from WRF and CMAQ numerical simulations indicated that pollutants transported from land to sea during the night were re-transported to the land by daytime sea breeze, leading to high-concentration PM_2.5 in Busan. To quantitatively investigate the recirculation a recirculation factor (RF) was calculated, showing an increase in RF values during high-concentration PM_2.5 episodes. However, the RF values varied slightly depending on the time resolution of meteorological data used for the calculations. This variation was attributed to the terrain characteristics at observation sites. Additionally, during long-range transported days leading to nationwide high-concentration PM_2.5 events, synoptic-scale circulation dominated, resulting in weaker correlation between PM_2.5 concentration and RF values. This study enhances the understanding of the influence of recirculation on air pollution. However, it is important to consider the impact of temporal resolution and terrain characteristics when using RF for evaluating recirculation during episodes of air pollution.

• Journal of Digital Convergence
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• v.18 no.6
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• pp.1-7
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• 2020

Amid growing interest in recycling around the world, the amount of waste is increasing despite the separate discharge efforts of each household, and it is difficult to find accurate data on recycling household waste. Also, recycling segregation is already settled in our daily lives, but we face a serious problem in which a significant portion of the recyclables collected are re-waste. In this study has been proposed a cash compensation system for recyclables, which is paid cash when the recyclables are washed clean and discharged. The cash compensation system proposed in this study could re-use 100% of the discharged recyclables, resulting in rewards for good deeds for individuals, greater returns for businesses and reduced disposal costs for local governments. In addition, it is expected that the government will be able to secure data related to the recycling of domestic waste, which will contribute to the management of recyclables at the national level.

• Journal of the Korean Society of Marine Environment & Safety
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• v.14 no.4
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• pp.333-338
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• 2008

The coastal zone is a delicate and dynamic area in which the majority of a water kinetic energy is dissipated. These processes are subsequent to the transport of the beach materials. In comparison to emerged breakwaters, submerged structures permit the passage of some wave energy and in turn allow for circulation along the shoreline zone. This research aims to examine the beach erosion prevention capability of submerged structure by laboratory model. The flow characteristics behind a submerged obstacle with bottom gap were experimentally investigated at Re = $1.2{\times}10^4$ using the two-frame PIV(CACTUS 2000) system. Streamline curvature field behind the obstacle has been obtained by using the data of time-averaged mean velocity information. And the large eddy structure in the separated shear layer seems to have signification influence on the development of the separated shear layer. As bottom gap size increases, the recirculation occurring behind the obstacle moves toward downstream and its strength is weakened.

• Journal of Haehwa Medicine
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• v.15 no.2
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• pp.75-93
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• 2006

Chang San-roe re-explained the contents from the 30th question to the 47th question of "Nan Jing" which refered to the Chang-Pu and physiological theories as follows through the western theory which wss different from the tranditioonal chinese theory 1. "Nan Jing" refered to the circulation and the coming into being of Yeong-Wi. He denied that it was classified Yeong from Wi or Eum from Yang. 2. He denied that Sam-Cho was separated to three parts and the theory of "Sam-Cho is name only, not shape", using western medical theory. 3. He denied the view about "Left side is kidney, right side is Myung-Mun" because it was incorrect that kidney was separated to two parts which were Su and Hwa or Eum and Yang 4. Re-explaining the contents of "Nan Jing"- the portions of heart and lungs, the rising and falling of liver and lungs, the relationships of five viscera and sound color smell taste fluid, the relationships of five viscera and nine hole, the relationships of five viscera and O-Chu, the physiological difference of the old and the young owing to the deflection of Yeong-Wi Chi-Heol- he thought that viewing the human body using theory of Eum and Yang, Five elements(五行) was a far-fetched interpretation, so he denied the tranditional chinese theory which understood human body's organs, physiology, pathology. 5. He explained the contents of "Nan Jing"- the portions of the colon and the small intestines, the funtion of the six bowls, the corespondence of Chang-Pu, physical peculiarity of liver, the anatomical aspects which were the sizes, weights, volumes and shapes of the Chang-Pu and the alimentary canal, Chil-Chung-Mun, Pal-Hoe-Hyeolthrough western anatomy and physiology in detail.

• Journal of Korean Neurosurgical Society
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• v.39 no.4
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• pp.286-291
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• 2006

Objective : We evaluate the effect of the copolymer-coated coils on immediate occlusion of the aneurysm, preventing rupture, and decreasing compaction or re-growth. Methods : Thirty-five aneurysms treated between September 2003 and December 2004 using Matrix detachable coil were reviewed. Study population consisted of 12 men and 23 women ranging in age from 34 to 75 years[mean, 55.1 years]. Twenty-two aneurysms were ruptured and 23 aneurysms were located in the anterior circulation. Follow-up angiography was obtained in 16 patients after 6 months from the procedure. Results : Initial complete occlusion was achieved in 17 aneurysms[48.6%], and the others remained as a residual neck in 8 aneurysms[22.8%] and residual sac in 10 aneurysms[28.6%]. Among these incompletely occluded aneurysms, 7 aneurysms were performed follow-up angiography. And 6 of them converted into complete occlusion. In the other hands, among 17 aneurysms achieved complete occlusion initially, 9 aneurysms were performed follow-up angiography. Recurrence due to coil compaction occurred in one aneurysm and the others maintained complete occlusion. There was one mortality case due to thromboembolic complication. Conclusion : In spite of difficulty in achieving complete occlusion with Matrix coil system, there is no rupture or re-rupture during follow-up period. Follow-up angiography shows many conversions of residual sac into complete occlusion. Embolization using Matrix coil system is safe and effective, but the effects of PGLA copolymer need further investigation.

• Proceedings of the Korea Water Resources Association Conference
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• 2018.05a
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• pp.154-154
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• 2018

To interpret the climate projections for the future as well as present, recognition of the consequences of the climate internal variability and quantification its uncertainty play a vital role. The Korean Peninsula belongs to the Far East Asian Monsoon region and its rainfall characteristics are very complex from time and space perspective. Its internal variability is expected to be large, but this variability has not been completely investigated to date especially using models of high temporal resolutions. Due to coarse spatial and temporal resolutions of General Circulation Models (GCM) projections, several studies adopted dynamic and statistical downscaling approaches to infer meterological forcing from climate change projections at local spatial scales and fine temporal resolutions. In this study, stochastic downscaling methodology was adopted to downscale daily GCM resolutions to hourly time scale using an hourly weather generator, the Advanced WEather GENerator (AWE-GEN). After extracting factors of change from the GCM realizations, these were applied to the climatic statistics inferred from historical observations to re-evaluate parameters of the weather generator. The re-parameterized generator yields hourly time series which can be considered to be representative of future climate conditions. Further, 30 ensemble members of hourly precipitation were generated for each selected station to quantify uncertainty. Spatial map was generated to visualize as separated zones formed through K-means cluster algorithm which region is more inconsistent as compared to the climatological norm or in which region the probability of occurrence of the extremes event is high. The results showed that the stations located near the coastal regions are more uncertain as compared to inland regions. Such information will be ultimately helpful for planning future adaptation and mitigation measures against extreme events.

• Journal of Korean Medicine for Obesity Research
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• v.21 no.2
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• pp.80-94
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• 2021

Objectives: The purpose of this study is to re-evaluate the importance of questions of obesity syndrome differentiation (OSD) questionnaire based on real-world survey and to explore the possibility of simplifying OSD types. Methods: The OSD frequency was identified, and variance threshold feature selection was performed to filter the questions. Filtered questions were clustered by K-means clustering and hierarchical clustering. After principal component analysis (PCA), the distribution patterns of the subjects were identified and the differences in the syndrome distribution were compared. Results: The frequency of OSD in spleen deficiency, phlegm (PH), and blood stasis (BS) was lower than in food retention (FR), liver qi stagnation (LS), and yang deficiency. We excluded 13 questions with low variance, 7 of which were related to BS. Filtered questions were clustered into 3 groups by K-means clustering; Cluster 1 (17 questions) mainly related to PH, BS syndromes; Cluster 2 (11 questions) related to swelling, and indigestion; Cluster 3 (11 questions) related to overeating or emotional symptoms. After PCA, significant different patterns of subjects were observed in the FR, LS, and other obesity syndromes. The questions that mainly affect the FR distribution were digestive symptoms. And emotional symptoms mainly affect the distribution of LS subjects. And other obesity syndrome was partially affected by both digestive and emotional symptoms, and also affected by symptoms related to poor circulation. Conclusions: In-depth data mining analysis identified relatively low importance questions and the potential to simplify OSD types.

• Journal of the Korean Institute of Landscape Architecture
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• v.32 no.3
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• pp.1-17
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• 2004

The focus of this study is the promotion of green area volumes and their naturalness, water circulation system, decline of entropy, creation of biological habitats and linkage of separated urban green space. Re-presentative urban biotope survey sites were categorized as urban biotope, semi-natural biotope, and natural forest. In the urban biotope, a residential biotope was constructed near the Han river and in mountain areas. The green-area ratio at the housing complex was about 25%. GVZ(Grunvolumenzahl) was 0.35m$^3$/m$^2$ at the 5∼10-story housing complex, and 1.53m$^3$/m$^2$ over the 11-story. As for the green-area structure of the housing complex, canopy layer, understory layer, and shrub layer were not differentiated and the green-area volume was not high enough. The green-area ratio of school areas as a public area biotope was 5∼20%. GVZ was 1.12m$^3$/m$^2$ at Myungduk High School, and 1.78m$^3$/m$^2$ at Jeonggok Elementary School. In order to convert the urban biotope into an ecological area, green areas around the buildings should be connected to urban buffer green areas, and multi-layer structures should be established with natural plant species. In the semi-natural biotope, neighbor parks were created park in the vicinity of the natural forests. GVZ was 0.28m$^3$/m$^2$, and plantation was established with single layer structure and was definitely insufficient for the area. The urban buffer green areas have been established in strip corridors with the width of 20∼123m. In those areas, GVZ was 0.16∼0.27m$^3$/m$^2$ and had a deficient canopy layer, understory layer, and shrub layer. Soil conditions were not favorable for tree growth. In the natural biotope, GVZ of the plantation was 1.03∼1.5m$^3$/m$^2$ but the high crown closure of this area reduces the chance of species change and succession. GVZ of natural forest was 2.53∼2.57m$^3$/m$^2$. It is desirable to plant diverse plants and the natural forest should be succeeded by broad-leaf deciduous tree species. To improve the value of biotope at Kangseo-Gu, building height needs to be limited to reduce the environmental deterioration in the city. In order to maintain the water circulation system, water-permeable material is recommened when the urban surface areas are paved. The establishment of a water circulation system will improve ground water levels, soil moisture, water quality, and habitats. In order to improve biological diversity, it is desirable to have multi-layer structures in urban green areas with native species.

• Proceedings of the KSME Conference
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• 2001.06e
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• pp.219-222
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• 2001

The objective of the present study is to evaluate the effects of the stenting shapes on flow velocity and wall shear stress in angulated coronary stenosis by computer simulation. Coronary angiogram and Doppler ultrasound measurement in the patients with angulated coronary stenosis were obtained. Inlet wave velocity distribution obtained from in vivo intracoronary Doppler data was used for the numerical simulation. Spatial pattern of blood flow velocity and recirculation area were drawn through out the selected segment of coronary models. Wall shear stresses in the intracoronary stent models were calculated from three-dimensional computer simulation. A negative shear stress region, which is consistent with re-circulation area on flow pattern, was noted on the inner wall of post-stenotic area of pre-stenting model. The negative shear stress was disappeared after stenting. Shear stress in the post-stenting model was markedly reduced up to about two orders of magnitude compared to that of the pre-stenting model.

• Journal of Korea Game Society
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• v.9 no.5
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• pp.73-82
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• 2009

Many organizations at home and abroad have been developing Metadata for reservation and administration of resources in every field. So we developed a game contents Metadata model for the purpose of reusing game contents, reserving copyrights, managing its life cycle, supporting efficiency of searches, and so on. We proceeded with this study by mapping, re-defining, and adding through the analysis of international Metadata standards and the survey of characteristics of game. Developed model is composed of 13 essential elements, 15 selective elements, and expressed by XML. Then we verified the effectiveness of this model's through expert groups' questionnaires, and showed the significance of the development through comparative analysis with the standard models. Accordingly we guess this study will be helpful to stable growth in rapidly growing game industry.