• Title/Summary/Keyword: Property model

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A Study on Isolation Performance of High Damping Rubber Bearing Through Shaking Table Test and Analysis (진동대 실험 및 해석을 통한 고감쇠 고무받침의 면진성능 연구)

  • Kim, Hu-Seung;Oh, Ju
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.5
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    • pp.601-611
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    • 2016
  • The research, development and use of seismic isolation systems have been increasing with the gradual development of structure safety assurance methods for earthquakes. The High Damping Rubber Bearing (HDRB), one type of seismic isolation system, is a Laminated Rubber Bearing using special High Damping Rubber. However, as its damping function is slightly lower than that of the Lead Rubber Bearing, a similar seismic isolation system, its utilization has not been high. However, the HDRB has a superior damping force to the Natural Rubber Bearing, which has similar materials and shapes, and the existing Lead Rubber Bearing has a maleficence problem in that it contains lead. Thus, studies on HDRBs that do not use lead have increased. In this study, a test targeting the HDRB was done to examine its various dependence properties, such as its compressive stress, frequency and repeated loading. To evaluate the HDRB's seismic performance in response to several earthquake waves, the shaking table test was performed and the results analyzed. The test used the downscaled bridge model and the HDRB was divided into seismic and non-seismic isolation. Consequently, when the HDRB was applied, the damping effect was higher in the non-seismic case. However, its responses on weak foundations, such as in Mexico City, represented increased shapes. Thus, its seismic isolator.

Effects of Aerosol Optical Properties on Upward Shortwave Flux in the Presence of Aerosol and Cloud layers (구름과 에어로솔의 혼재시 에어로솔의 광학특성이 상향 단파 복사에 미치는 영향)

  • Lee, Kwon-Ho
    • Korean Journal of Remote Sensing
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    • v.33 no.3
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    • pp.301-311
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    • 2017
  • Aerosol optical properties as well as vertical location of layer can alter the radiative balance of the Earth by reflecting and absorbing solar radiation. In this study, radiative transfer model (RTM) and satellite-based analysis have been used to quantify the top-of-atmosphere (TOA) radiative effect of aerosol layers in the cloudy atmosphere of the northeast Asia. RTM simulation results show that the atmospheric warming effect of aerosols increases with their height in the presence of underlying cloud layer. This relationship is higher for stronger absorbing aerosols and higher surface albedo condition. Over study region ($20-50^{\circ}N$, $110-140^{\circ}E$) and aerosol event cases, it is possible to qualitatively identify absorbing aerosol effects in the presence of clouds by combining the UV Absorbing Aerosol Index (AAI) derived from Total Ozone Mapping Spectrometer (TOMS), cloud parameters derived from the Moderate Resolution Imaging Spectro-radiometer (MODIS), with TOA Upward Shortwave Flux (USF) from the Clouds and the Earth's Radiant Energy System (CERES). As the regional-mean radiative effect of aerosols, 6 - 26 % lower the USF between aerosols and cloud cover is taken into account. These results demonstrate the importance of estimation for the accurate quantification of aerosol's direct and indirect effect.

Using Balanced Scorecard to Explore Learning Performance of Enterprise Organization

  • Chiu, Chung-Ching;Tsai, Chih-Hung;Chung, Yi-Chan
    • International Journal of Quality Innovation
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    • v.8 no.1
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    • pp.40-75
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    • 2007
  • In the early industrial age which with high intensity of machine and labor, using financial measurement index was good enough to tie in company's mechanization and philosophy of management and been in efficiency. But being comply with "New Economic age," a new economic environment is full of knowledge and information, the enterprise competition had changed from tangible assets, plants to intangible innovation ability of knowledge. As recognizing the new tendency by enterprise, they value gradually the growth and influence from learning. Practice of organization learning not only needs firm structure and be in coordination with both hardware and software, but also needs an affect measurement model to offer enterprise to estimate learning performance. It's a good instrument of financial performance measure mold in the past years, But it's for measuring the past, couldn't formulate enterprise trend to future, hard to estimate investment for future, such as development of products, organization learning, knowledge management etc, as which intangible assets and knowledge ability just the key factors of being win around competition environment in the future. In 1992, Kaplan and Norton brought up Balance Scorecard (BSC) on Harvard Business Review, as an instrument helping enterprise to measure performance, which is being considered to be a most influence management instrument. It added non-financial index such as customer, internal process and learning growth besides traditional financial index, as offering enterprise an index to measure and manage intangible assets and intellectual property. As being aware of organization learning is hard to be ignored in the new economic age, this research is based on learning and growth of BSC, and citing one national material company try to let the most difficult measurement performance of organization learning, to be estimate through BSC, analyze of factor and individual case, to discuss the company how to make the related strategy and vision of organization learning to develop learning and growth of the structure of BSC, subject the matter of out put factors to be discussed, and measure the outcomes as a result of research. The research affect offers (1) the base implement procedure of carrying out BSC; (2) the reference of formulating measurement index while enterprise using BSC to estimate performance of organization learning; (3) the possibility bottleneck maybe forcing while carrying out BSC, to be an improvement or preventive for enterprise.

A Practical Algorithm to Simulate Erosion of On-Shore Zone (실용적 해안선 후퇴 반영 알고리즘)

  • Kim, Hyoseob;Lee, Jungsu;Jin, Jae-Youll;Jang, Changhwan
    • Journal of Wetlands Research
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    • v.15 no.3
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    • pp.423-430
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    • 2013
  • An algorithm to allow shoreline movement during numerical experiment on sediment transport, deposition or resuspension for general coastal morphology is proposed here. The bed slope near shoreline, i.e. mean sea level, is influenced by bed material, tidal current, waves, and wave-induced current, but has been reported to remain within a stable range. Its annual variation is not large, either. The algorithm is adjusting the bathymetry, if the largest bed slope within shoreline band exceeds a given bed slope due to continuous erosion at zones below the shoreline. This algorithm automatically describes retreat of shoreline caused by erosion, when used within a numerical system. The algorithm was tested to a situation which includes a continuous dredging at a point, and showed satisfactory development of concentric circle contours. Next, the algorithm was tested to another situation which includes sinking of eroded part of bed plate, and produced satisfactory results, too. Finally, the algorithm was tested to a movable-bed laboratory experimental conditions. The shoreline movement behind detached breakwater was reasonably reproduced with this algorithm.

The Effects of Technology Commercialization Activities on the Business Performance: Case study of basic science and technology of public research institutes transferred to enterprises (기술사업화 활동이 기업의 경영성과에 미치는 영향: 기업으로 이전된 공공연구기관의 기초·원천기술을 중심으로)

  • Jeong, Myoung-Sun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.4
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    • pp.418-427
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    • 2017
  • In Korea, interest in basic research is growing, in order to ensure the sustainable competitiveness of the main industries and to support world-class technology that can create high added value in the future. However, companies are known to encounter various problems when attempting to market products based on the results of basic research, which is known to be due to their lack of experience of commercialization and related activities. Therefore, in this study, we tried to analyze the effect of the technology commercialization activity stemming from basic science and technology research on the business performance. The technology commercialization activities are divided into experience of commercialization, complete charge department, and consulting on technology commercialization and we developed an analytical model that (distinguishes between?) the technology innovation activities and technology innovation capabilities and analyzed their impact on the business performance. As a result, the importance of technology commercialization activities was confirmed by the fact that it had a positive effect on the business performance, while the technological innovation activity was found to positively affect the management performance, demonstrating that it plays a strategic role in companies. Finally, it was found that the technology innovation capacity partially influences the management performance and that it is necessary to establish a strategic research and development infrastructure.

Analysis of Risk Classification on the Urban Flood Damage in Changwon city (창원시 용도지역별 침수 피해에 따른 위험등급화 분석)

  • Park, Ki-Yong;Jeong, Jin-Ho;Jeon, Won-Sik
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.4
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    • pp.685-693
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    • 2017
  • This study aims to effectively respond to urban local rainstorms by classifying the risk against flood damage for each use district. The risk classification is based on sensitivity analysis of the socio-economic damage caused by local rainstorms in Changwon city, Korea by a Fuzzy model using data, such as the districts that provide institutional bases for land use, land prices, which estimate the property values, and floor area ratios, which measures the density and areas of flood damage. The analysis result indicated that flood damage in five districts of Changwon (Masan happo-gu, Masan Hoewon-gu, Sungsan-gu, Euichang-gu, and Jinhae-gu) is highest in the order of commercial areas, residential areas, industrial areas, and forests, which was attributed to high land price and floor area ratio of commercial areas. On the other hand, specific analysis in Masan Hoewon-gu and Sungsan-gu was different from the previous result, indicating that the risk against flood damage may vary according to the districts depending on their local conditions. The analysis from this study can be applied to future urban planning and be used as a guideline to estimate the potential flood damage. Overall, this study is meaningful in that it proposes an effective management of land use as a new resolution to mitigate of urban flood damage within a broader perspective of climate change and urbanization.

The Relationship between College Students' Team Learning Goal Orientation and Their Team Creativity: The Roles of Team Reflexivity, Team Efficacy, and Positive Group Affective Tone (대학생들의 팀 학습목표 지향성과 팀 창의성의 관계: 팀 성찰, 팀 효능감, 그리고 긍정적 집단 정서 분위기의 역할)

  • Kim, Mihee
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.10
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    • pp.159-168
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    • 2019
  • This study draws on goal orientation theory and proposes the team learning goal orientation as an antecedent of team creativity. In addition, an Input-Process-Output (IPO) model was adopted, in which the team reflexivity, team efficacy, and positive group affective tone (PGAT) are linking mechanisms in the relationship between team learning goal orientation and team creativity. Using 57 teams from three lectures of the college, hierarchical regression analysis was conducted at the team level. The results showed that the team learning goal orientation had positive associations with team creativity, team reflexivity, and team efficacy. In addition, team reflexivity and team efficacy positively predicted the team creativity. Furthermore, the relationship between team learning goal orientation and team creativity was mediated by the team reflexivity and team efficacy. In contrast to predictions, PGAT did not show significant relations with both team learning goal orientation and team creativity. In conclusion, this study integrated the team-learning goal orientation and team creativity literature and contributes to the understanding of team reflexivity as a cognitive process and team efficacy as a motivational process between the team property and team creativity. These results have practical implications for managing teams.

A Performance Comparison of Machine Learning Classification Methods for Soil Creep Susceptibility Assessment (땅밀림 위험지 평가를 위한 기계학습 분류모델 비교)

  • Lee, Jeman;Seo, Jung Il;Lee, Jin-Ho;Im, Sangjun
    • Journal of Korean Society of Forest Science
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    • v.110 no.4
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    • pp.610-621
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    • 2021
  • The soil creep, primarily caused by earthquakes and torrential rainfall events, has widely occurred across the country. The Korea Forest Service attempted to quantify the soil creep susceptible areas using a discriminant value table to prevent or mitigate casualties and/or property damages in advance. With the advent of advanced computer technologies, machine learning-based classification models have been employed for managing mountainous disasters, such as landslides and debris flows. This study aims to quantify the soil creep susceptibility using several classifiers, namely the k-Nearest Neighbor (k-NN), Naive Bayes (NB), Random Forest (RF), and Support Vector Machine (SVM) models. To develop the classification models, we downscaled 292 data from 4,618 field survey data. About 70% of the selected data were used for training, with the remaining 30% used for model testing. The developed models have the classification accuracy of 0.727 for k-NN, 0.750 for NB, 0.807 for RF, and 0.750 for SVM against test datasets representing 30% of the total data. Furthermore, we estimated Cohen's Kappa index as 0.534, 0.580, 0.673, and 0.585, with AUC values of 0.872, 0.912, 0.943, and 0.834, respectively. The machine learning-based classifications for soil creep susceptibility were RF, NB, SVM, and k-NN in that order. Our findings indicate that the machine learning classifiers can provide valuable information in establishing and implementing natural disaster management plans in mountainous areas.

Comparision of Tidal Current Patterns at Keum River Estuary before and after Construction of Keum River Bank and Coastal Structures (금강하굿둑과 각종 해안구조물 설치 전, 후의 금강하구역 해수유동 양상 비교)

  • Jang, Chang-Hwan
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.22 no.4
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    • pp.601-610
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    • 2021
  • The tidal current patterns at Keum River Estuary before and after the construction of coastal structures were compared according to the CASES. The depth-integrated and tidal difference treatment applied FLOW2DH numerical model was used for the tidal current predictions. The test conditions consisted of before construction of coastal structures (CASE1), after construction of coastal structures (CASE2), and the addition of watergate operation(CASE1Q and CASE2Q), and present (CASE3). CASE1 showed a stable tidal current pattern, such as a natural estuary. In CASE2, the tidal current velocities and directions of the Keum River Estuary were changed due to the installed coastal structures. In particular, the tidal current velocities of the Gaeya open channel sections (P5~P9) in CASE2 were calculated to be 10~30% larger than that of CASE1. In the case of the Gunsan Inner Harbor (P4), which is closest to the Geum River Estuary, the ebb flow rate was approximately 250~300% faster than that of other CASEs due to the discharge of the watergate operation for 2.7 hours during the ebb of CASE1Q and CASE2Q. This will affect sediment transport, and it is predicted to lead to seabed changes. CASE3 is considered to be entering the stabilization stage according to the simulation of the tidal current velocities and directions of the Keum River Estuary and the surrounding coastal area.

Study on Flexural Properties of Polyamide 12 according to Temperature produced by Selective Laser Sintering (선택적 레이저 소결 제작 폴리아미드 12 시편의 온도별 굴곡 특성 연구)

  • Kim, Moosun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.11
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    • pp.319-325
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    • 2018
  • The use of 3D printing (Additive Manufacturing) technology has expanded from initial model production to the mass production of parts in the industrial field based on the continuous research and development of materials and process technology. As a representative polymer material for 3D printing, the polyamide-based material, which is one of the high-strength engineering plastics, is used mainly for manufacturing parts for automobiles because of its light weight and durability. In this study, the specimens were fabricated using Selective Laser Sintering, which has excellent mechanical properties, and the flexural characteristics were analyzed according to the temperature of the two types of polyamide 12 and glass bead reinforced PA12 materials. The test specimens were prepared in the directions of $0^{\circ}$, $45^{\circ}$, and $90^{\circ}$ based on the work platform, and then subjected to a flexural test in three test temperature environments of $-25^{\circ}C$, $25^{\circ}C$, and $60^{\circ}C$. As a result, PA12 had the maximum flexural strength in the direction of $90^{\circ}$ at $-25^{\circ}C$ and $0^{\circ}$ at $25^{\circ}C$ and $60^{\circ}C$. The glass bead-reinforced PA12 exhibited maximum flexural strength values at all test temperatures in the $0^{\circ}$ fabrication direction. The tendency of the flexural strength changes of the two materials was different due to the influence of the plane direction of the lamination layer depending on the type of stress generated in the bending test.