• Title/Summary/Keyword: model reduction method

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A Study on Land Acquisition Priority for Establishing Riparian Buffer Zones in Korea (수변녹지 조성을 위한 토지매수 우선순위 산정 방안 연구)

  • Hong, Jin-Pyo;Lee, Jae-Won;Choi, Ok-Hyun;Son, Ju-Dong;Cho, Dong-Gil;Ahn, Tong-Mahn
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.17 no.4
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    • pp.29-41
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    • 2014
  • The Korean government has purchased land properties alongside any significant water bodies before setting up the buffers to secure water qualities. Since the annual budgets are limited, however, there has always been the issue of which land parcels ought to be given the priority. Therefore, this study aims to develop efficient mechanism for land acquisition priorities in stream corridors that would ultimately be vegetated for riparian buffer zones. The criteria of land acquisition priority were driven through literary review along with experts' advice. The relative weights of their value and priorities for each criterion were computed using the Analytical Hierarchy Process(AHP) method. Major findings of the study are as follows: 1. The decision-making structural model for land acquisition priority focuses mainly on the reduction of non-point source pollutants(NSPs). This fact is highly associated with natural and physical conditions and land use types of surrounding areas. The criteria were classified into two categories-NSPs runoff areas and potential NSPs runoff areas. 2. Land acquisition priority weights derived for NSPs runoff areas and potential NSPs runoff areas were 0.862 and 0.138, respectively. This implicates that much higher priority should be given to the land parcels with NSPs runoff areas. 3. Weights and priorities of sub-criteria suggested from this study include: proximity to the streams(0.460), land cover(0.189), soil permeability(0.117), topographical slope(0.096), proximity to the roads(0.058), land-use types(0.036), visibility to the streams(0.032), and the land price(0.012). This order of importance suggests, as one can expect, that it is better to purchase land parcels that are adjacent to the streams. 4. A standard scoring system including the criteria and weights for land acquisition priority was developed which would likely to allow expedited decision making and easy quantification for priority evaluation due to the utilization of measurable spatial data. Further studies focusing on both point and non-point pollutants and GIS-based spatial analysis and mapping of land acquisition priority are needed.

An Analysis of the Impacts of FDI Types on CO2 Emissions - Focus on Scale Effects and Technique Effects - (FDI 유형별 CO2 배출량에 미치는 영향 분석 - 규모효과와 기술효과를 중심으로 -)

  • Hwang, Yun-Seop;Park, Junghoon;Lee, Sang Whi
    • International Commerce and Information Review
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    • v.17 no.3
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    • pp.379-402
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    • 2015
  • The purpose of this study is to determine whether there is a significant difference in impacts decomposed into scale effects and technique effects on $CO_2$ emissions between Greenfield FDI and M&A FDI flows into Korean manufacturing sectors, ultimately leading to clarify the relationship between FDI and environmental pollution. To this end, the research constructed a simultaneous model to analyze coincidental relationship of influence and interactions between each variable. Archival data, spanning the 15 years period from 1995 to 2009, is industry-level panel data on 13 Korean manufacturing sectors, and it is empirically analyzed with three-stage least squares (3SLS) method. Key findings can be summarized into two parts. First of all, Greenfield FDI has a greater impact on increasing industrial gross output, resulting in more $CO_2$ emissions than M&A FDI through scale effects. Secondly, technique effects of FDI have a bigger impact on $CO_2$ emissions than scale effects, implying that this inflow of FDI into Korea contributes positively to the reduction of $CO_2$ emissions. These findings are expected to play a meaningful role in establishing FDI policies with consideration of the environment by giving the implication that different incentives for each FDI type should be considered to maximize the effect of environmental protection.

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A STUDY ON THE MARGINAL FIT OF COLLARLESS METAL CERAMIC FIXED PARTIAL DENTURES

  • Yoon Jong-Wook;Yang Jae-Ho;Han Jung-Seok;Lee Jae-Bong
    • The Journal of Korean Academy of Prosthodontics
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    • v.43 no.6
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    • pp.707-716
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    • 2005
  • Statement of problem. Collarless metal ceramic fixed partial dentures(FPDs) had an esthetic problem such as opaque reflection in cervical region. To overcome this, modified coping which removed its facial cervical metal could be used. The marginal quality could be worsen according to the amount of its facial metal reduction. Purpose. The purpose of this study was to evaluate marginal fits of collarless metal ceramic FPDs with retainers of modified copings. Material and method. Dentoform maxillary left central incisor and right lateral incisor were prepared for 3-unit collarless metal ceramic FPD and fixed in yellow stone. This model was duplicated to PBT resin dies via CAD/CAM and injection molding. Four different facial margin design groups were investigated. Group A was a coping with a thin facial metal collar, group B was a collarless coping with its facial metal to the shoulder, group C was a collarless coping with its facial metal 1 mm short of the shoulder, and group D was a collarless coping with its facial metal 2 mm short of the shoulder. Seven collarless metal ceramic FPDs per group were fabricated. They were cemented to PBT resin dies with resin cement. After removal of pontics, each retainers were separated and observed under Accura 2000 optical microscope. Then, retainers were embeded in orthodontic resin and cross sectioned faciopalatally. Internal marginal fits of midfacial porcelain margins were observed under FE-SEM. Result and conclusion. Within the limitations of this in vitro study. The following conclusions were drawn. 1. Mean marginal gaps of collarless FPDs were in the $50-60{\mu}m$ range. 2. In midfacial margin, marginal discrepancies were greater in group A than in the experimental groups(p<0.05). 3. In midpalatal margin, marginal gaps were greater in group C and D than in group A and B(p<0.05). 4. Marginal fits of porcelain margins were better than those of metal margins in collarless metal ceramic FPDs. 5. In both teeth, internal marginal gaps of group C and D were greater than those of group A and B(p<0.05).

A Experimental Study on Vibration Attenuation of a Plate with Eddy Current Damper (와전류 감쇠기를 적용한 평판의 진동 저감에 관한 실험적 연구)

  • Pyeon, Bong-Do;Kim, Jong-Hyuk;Bae, Jae-Sung;Hwang, Jai-Hyuk
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.48 no.5
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    • pp.355-361
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    • 2020
  • Among these satellites, low - orbit small satellites with military characteristics require multi - target observation, and demand for high-resolution photographs and images is increasing. Fast maneuverability is the most important factor for high-resolution images and multi - target observations. However, in the case of a small satellites, it is possible to perform the attitude maneuver if it has high speed, but the residual vibration occurs when the attitude maneuver is completed and the next attitude maneuver is completed. In this study, to verify the vibration characteristics of the plate generated after attitude maneuver, an experimental fixture for simulating the attitude maneuver was fabricated and tested. In addition, Eddy Current Damper (ECD) using Eddy Current Brake system (ECB) is proposed as a passive damping method using permanent magnet to reduce vibration. A mathematical model was established to apply ECD and it was experimentally implemented according to the magnetic flux density and the air gap of the permanent magnet. One plate of four solar panels (plate) was specified, the residual vibration reduction performance after the test was verified experimentally.

The P300 Source Localization in the Patients with Obsessive-Compulsive Disorder using the LORETA Imaging and SPM (강박장애에서 LORETA 영상을 이용한 P300 국소원의 통계적 분석)

  • Park, Sung-Kun;Choi, Jung-Seok;Yu, Soh-Young;Lee, Bo Reom;Kang, Seung-Suk;Roh, Kyu Sik;Ha, Tae-Hyun;Kwon, Jun Soo
    • Korean Journal of Biological Psychiatry
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    • v.10 no.2
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    • pp.168-176
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    • 2003
  • Objectives:We investigated the characteristics of P300 generators in obsessive-compulsive disorder(OCD) patients by using voxel-based statistical parametric mapping of current density images. Methods:P300 generators, produced by a rare target tone of 1500Hz under a frequent non-target tone of 1,000Hz, were measured in 15 right-handed OCD patients and 15 controls. Low Resolution Electromagnetic Tomography(LORETA), using a realistic head model of the boundary element method based on individual MRI, was applied to the 128-channel EEG. Statistical parametric mapping(SPM) was applied for the statistical analysis. Results:We found that both groups had the mean current density of P300 in the parietal, temporal and prefrontal lobe. There was a trend for decreased current density in the prefrontal area in OCD patients. The statistical comparison showed current density increase in the supraparietal area, a statistically significant longer P300 latency and a trend for reduced P300 amplitude in OCD patients. Conclusion:It suggests that P300 source of both groups exists in multiple brain regions at the same time. And both groups had no statistically significant differences in the current density of P300 except for increased current density in the supraparietal area in OCD patients. But, considering the statistically significant longer P300 latency, a trend for reduced P300 amplitude and relative mean current density reduction in the prefrontal area in OCD patients, this study suggests that the frontal lobe may have a reduced normal inhibitory process in OCD patients.

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Assessment factors for the Selection of Priority Soil Contaminants based on the Comparative Analysis of Chemical Ranking and Scoring Systems (국내.외 Chemical Ranking and Scoring 체계 비교분석을 통한 우선순위 토양오염물질 선정을 위한 평가인자 도출)

  • An, Youn-Joo;Jeong, Seung-Woo;Kim, Tae-Seung;Lee, Woo-Mi;Nam, Sun-Hwa;Baek, Yong-Wook
    • Journal of Soil and Groundwater Environment
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    • v.13 no.6
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    • pp.62-71
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    • 2008
  • Soil quality standards (SQS) are necessary to protect the human health and soil biota from the exposure to soil pollutants. The current SQS in Korea contain only sixteen substances, and it is scheduled to expand the number of substances. Chemical ranking and scoring (CRS) system is very effective to screen the priority chemicals for the future SQS in terms of their toxicity and exposure potential. In this study, several CRS systems were extensively compared to propose the assessment factors that required for the screening of soil pollutants The CRS systems considered in this study include the CHEMS-1 (Chemical Hazard Evaluation for Management Strategies), SCRAM (Scoring and Ranking Assessment Model), EURAM (European Union Risk Ranking Method), ARET (Accelerated Reduction/Elimination of Toxics), CRSKorea, and other systems. The additional assessment factors of CRS suitable for soil pollutants were suggested. We suggest soil adsorption factor as an appropriate factor of CRS system to consider chemical transport from soil to groundwater. Other factors such as soil emission rate and cases of accident of soil pollutants were included. These results were reflected to screen the priority chemicals in Korea, as a part of the project entitled ‘Setting the Priority of Soil Contaminants'.

Optimal Site Selection of Carbon Storage Facility using Satellite Images and GIS (위성영상과 GIS를 활용한 CO2 지중저장 후보지 선정)

  • Hong, Mi-Seon;Sohn, Hong-Gyoo;Jung, Jae-Hoon;Cho, Hyung-Sig;Han, Soo-Hee
    • Korean Journal of Remote Sensing
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    • v.27 no.1
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    • pp.43-49
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    • 2011
  • In the face of growing concern about global warming, increasing attention has been focused on the reduction of carbon dioxide emissions. One method to mitigating the release of carbon dioxide is Carbon Capture and Storage (CCS). CCS includes separation of carbon dioxide from industrial emission in plants, transport to a storage site, and long-term isolation in underground. It is necessary to conduct analyses on optimal site selection, surface monitoring, and additional effects by the construction of CCS facility in Gyeongsang basin, Korea. For the optimal site selection, necessary data; geological map, landcover map, digital elevation model, and slope map, were prepared, and a weighted overlay analysis was performed. Then, surface monitoring was performed using high resolution satellite image. As a result, the candidate region was selected inside Gyeongnam for carbon storage. Finally, the related regulations about CCS facility were collected and analyzed for legal question of selected site.

Analysis on Temperature Distribution and Current-Carrying Capacity of GIL Filled with Fluoronitriles-CO2 Gas Mixture

  • Chen, Geng;Tu, Youping;Wang, Cong;Cheng, Yi;Jiang, Han;Zhou, Hongyang;Jin, Hua
    • Journal of Electrical Engineering and Technology
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    • v.13 no.6
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    • pp.2402-2411
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    • 2018
  • Fluoronitriles-$CO_2$ gas mixtures are promising alternatives to $SF_6$ in environmentally-friendly gas-insulated transmission lines (GILs). Insulating gas heat transfer characteristics are of major significance for the current-carrying capacity design and operational state monitoring of GILs. In this paper, a three-dimensional calculation model was established for a GIL using the thermal-fluid coupled finite element method. The calculated results showed close agreement with experimentally measured data. The temperature distribution of a GIL filled with the Fluoronitriles-$CO_2$ mixture was obtained and compared with those of GILs filled with $CO_2$ and $SF_6$. Furthermore, the effects of the mixture ratio of the component gases and the gas pressure on the temperature rise and current-carrying capacity of the GIL were analyzed. Results indicated that the heat transfer performance of the Fluoronitriles-$CO_2$ gas mixture was better than that of $CO_2$ but worse than that of $SF_6$. When compared with $SF_6$, use of the Fluoronitriles-$CO_2$ gas mixture caused a reduction in the GIL's current-carrying capacity. In addition, increasing the Fluoronitriles gas component ratio or increasing the pressure of the insulating gas mixture could improve the heat dissipation and current-carrying capacity of the GIL. These research results can be used to design environmentally-friendly GILs containing Fluoronitriles-$CO_2$ gas mixtures.

Effect of PVP on the Physical Stability of O/W Emulsion (O/W 유제의 물리적 안정성에 대한 PVP의 영향)

  • Oh, In-Joon;Lee, Mi-Young;Lee, Jeong-Min;Lee, Yong-Bok;Shin, Sang-Chul;Choi, Bo-Guil;Kim, Chong-Kook
    • Journal of Pharmaceutical Investigation
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    • v.27 no.4
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    • pp.287-293
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    • 1997
  • To make a stable o/w emulsion, the effects of egg lecithin as an emulsifier and polyvinylpyrrolidone (PVP) as an auxiliary emulsifier on the physical stability of emulsion were investigated. The oil-in-water emulsion system was manufactured by microfluidizer and evaluated the physical stability. Average particle size and size distribution of emulsion was measured by dynamic light scattering analyzer and interfacial tension was measured. From the interfacial tension tested, critical micelle concentration of the egg lecithin was 0.1 %w/v and optimal concentration for the preparation of emulsion was 1.0 %w/v. The mean particle size was about $0.2\;{\mu}m$ which was suitable for injections. The short-term accelerated stability studies were conducted by centrifugation, freeze-thaw method and shaking of the emulsion samples. The addition of PVP was caused the reduction in the particle size and improved the physical stability of emulsion. These results suggested that a mixed interfacial film comprising the egg lecithin and PVP was formed at the o/w interface and it was effective in preventing phase separation under thermic or mechanical stress. We used antineoplaston A10 (A10) as a model drug which is peptide and amino acid derivative having a action to the living organism against the development of neoplastic growth by a nonimmunological progress. It has a poor solubility in water and there may be a difficulty in formulation of A10. Emulsion formulation study about A10 was performed. Solubility of A10 in emulsion was about five times as high as that in water. From the results of solubility and partition coefficient, almost A10 molecules in o/w emulsion exist in the interface between oil and water.

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Investigation of image preprocessing and face covering influences on motion recognition by a 2D human pose estimation algorithm (모션 인식을 위한 2D 자세 추정 알고리듬의 이미지 전처리 및 얼굴 가림에 대한 영향도 분석)

  • Noh, Eunsol;Yi, Sarang;Hong, Seokmoo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.7
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    • pp.285-291
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    • 2020
  • In manufacturing, humans are being replaced with robots, but expert skills remain difficult to convert to data, making them difficult to apply to industrial robots. One method is by visual motion recognition, but physical features may be judged differently depending on the image data. This study aimed to improve the accuracy of vision methods for estimating the posture of humans. Three OpenPose vision models were applied: MPII, COCO, and COCO+foot. To identify the effects of face-covering accessories and image preprocessing on the Convolutional Neural Network (CNN) structure, the presence/non-presence of accessories, image size, and filtering were set as the parameters affecting the identification of a human's posture. For each parameter, image data were applied to the three models, and the errors between the actual and predicted values, as well as the percentage correct keypoints (PCK), were calculated. The COCO+foot model showed the lowest sensitivity to all three parameters. A <50% (from 3024×4032 to 1512×2016 pixels) reduction in image size was considered acceptable. Emboss filtering, in combination with MPII, provided the best results (reduced error of <60 pixels).