• 제목/요약/키워드: Macro Model

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전자빔 용해 방법으로 제조된 정형외과 임플란트용 Ti-6Al-4V 합금의 재료 특성 분석 (Material Characteristics of Ti-6Al-4V Alloy Manufactured by Electron Beam Melting for Orthopedic Implants)

  • 강관수;정용훈;장태곤;양재웅;정재영;박광민;우수헌;박태현
    • 한국표면공학회:학술대회논문집
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    • 한국표면공학회 2018년도 춘계학술대회 논문집
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    • pp.25-25
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    • 2018
  • Electron beam melting (EBM) is one of powder based additive manufacturing technology used to produce parts for high geometrical complexity and directly with three-dimensional computer aided design (CAD) model. It is kind of the most promising methods with additive manufacturing for a wide range of medical applications, such as orthopedic, dental implant, and etc. This research has been investigated the microstructure and mechanical properties of as fabricated and hot iso-static pressing (HIP) processed specimens, which are made by an Arcam A1 EBM system. The Ti-6Al-4V titanium alloy powder was used as a material for the 3 dimensional printing specimens. Mechanical properties were conducted with EBM manufacturing and computer numerical control (CNC) machining specimens, respectively. Surface morphological analysis was conducted by scanning electron microscopy (SEM) for their surface, dissected plan, and fractured surface after tensile test. The mechanical properties were included tensile stress-strain and nano-indentation test as a analysis level between nano and macro. As following highlighted results, the stress-strain curves on elastic region were almost similar between as fabricated and HIP processed while the ductile (plastic deformed region) properties were higher with HIP than that of as fabricated processed.

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Modeling and SINR Analysis of Dual Connectivity in Downlink Heterogeneous Cellular Networks

  • Wang, Xianling;Xiao, Min;Zhang, Hongyi;Song, Sida
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제11권11호
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    • pp.5301-5323
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    • 2017
  • Small cell deployment offers a low-cost solution for the boosted traffic demand in heterogeneous cellular networks (HCNs). Besides improved spatial spectrum efficiency and energy efficiency, future HCNs are also featured with the trend of network architecture convergence and feasibility for flexible mobile applications. To achieve these goals, dual connectivity (DC) is playing a more and more important role to support control/user-plane splitting, which enables maintaining fixed control channel connections for reliability. In this paper, we develop a tractable framework for the downlink SINR analysis of DC assisted HCN. Based on stochastic geometry model, the data-control joint coverage probabilities under multi-frequency and single-frequency tiering are derived, which involve quick integrals and admit simple closed-forms in special cases. Monte Carlo simulations confirm the accuracy of the expressions. It is observed that the increase in mobility robustness of DC is at the price of control channel SINR degradation. This degradation severely worsens the joint coverage performance under single-frequency tiering, proving multi-frequency tiering a more feasible networking scheme to utilize the advantage of DC effectively. Moreover, the joint coverage probability can be maximized by adjusting the density ratio of small cell and macro cell eNBs under multi-frequency tiering, though changing cell association bias has little impact on the level of the maximal coverage performance.

The Factors Affecting Corporate Income Tax Non-Compliance: A Case Study in Vietnam

  • NGUYEN, Loan Thi;NGUYEN, Anh Hong Viet;LE, Hac Dinh;LE, Anh Hoang;TRUONG, Tu Tuan Vu
    • The Journal of Asian Finance, Economics and Business
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    • 제7권8호
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    • pp.103-115
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    • 2020
  • In many countries, the Government enacts tax laws in order to manage tax collection and regulate the macro-economy. According to Noor, Jamaludin, Omar, and Aziz (2013), tax non-compliance is a growing concern because of its negative effects on the state budget. The main objectives of this article are to identify the factors affecting corporate income tax non-compliance of enterprises in Ho Chi Minh City in accordance with the current situation of Vietnamese tax administration. We use several research methods, including the exploitation of information and practical experiences from both taxpayers and tax authorities; with Probit regression model on a sample of 187 enterprises that have been inspected or examined by tax authorities in Vietnam during the period from 2013 to 2017.The article identified eight factors affecting corporate income tax (CIT) non-compliance: (1) working capital/total assets; (2) revenue/total assets; (3) total debt/total assets; (4) loss in the previous year; (5) receivables/revenue; (6) the size of enterprises; (7) tax administrative penalties/tax payable; and (8) business field. In particular, the tax non-compliance was studied as a violation of Vietnamese tax laws by enterprises declaring an insufficient amount of CIT payable to the State budget.

스웨덴의 영유아 영양권장량 및 유아교육기관을 위한 급식지침 (Recommended Dietary Allowances for Young Children and Food Guideline for Preschool Children in Sweden)

  • 박은숙;이영환;이진숙
    • 대한지역사회영양학회지
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    • 제9권6호
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    • pp.742-752
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    • 2004
  • The purpose of this study is to offer information related to recommended dietary allowances for young children and food guidelines for preschool children in Sweden. Sweden, located in Europe, is the most developed country for young child care system. Swedish nutrition policy background, Swedish recommended dietary allowances for young children, and food guidelines of early childhood education center in Sweden were used. The number of Swedish child care centers increased from 70,000 in 1970 to 700,000 in 2000. The Swedish Institute of Public Health promoted children's indoor and outdoor activity. The aim of the Swedish public health contains children's safety, good food habits, and eating food safely. Swedish Food Administration made recommended dietary allowance and food guidelines for children care centers. The aim of food guidelines was to increase energy, calcium, iron, and dietary fiber intake. Swedish RDA contains minimum and maximum intake as well as mean intake for macro and micro nutrients. The fat intake ratio of energy is increased for younger children. For preschool children, the food guideline is determined by dietary allowances for breakfast, lunch, and snack respectively. Food guideline contains meal time schedule, menu for each meal using food model, amount of food for age group, and recommended dietary allowance for each meal. It is recommended for Korean early childhood education center: 1) Korean RDA for young children should be made range of intake, minimum and maximum intake. 2) Food guideline should be make for Korean child care center. 3) Korean child care centers should offer an afternoon snack twice for children who return home late. 4) Nutrition education program for preschool teachers should be developed for children's good eating habits and health promotion.

Impact of rock microstructures on failure processes - Numerical study based on DIP technique

  • Yu, Qinglei;Zhu, Wancheng;Tang, Chun'an;Yang, Tianhong
    • Geomechanics and Engineering
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    • 제7권4호
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    • pp.375-401
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    • 2014
  • It is generally accepted that material heterogeneity has a great influence on the deformation, strength, damage and failure modes of rock. This paper presents numerical simulation on rock failure process based on the characterization of rock heterogeneity by using a digital image processing (DIP) technique. The actual heterogeneity of rock at mesoscopic scale (characterized as minerals) is retrieved by using a vectorization transformation method based on the digital image of rock surface, and it is imported into a well-established numerical code Rock Failure Process Analysis (RFPA), in order to examine the effect of rock heterogeneity on the rock failure process. In this regard, the numerical model of rock could be built based on the actual characterization of the heterogeneity of rock at the meso-scale. Then, the images of granite are taken as an example to illustrate the implementation of DIP technique in simulating the rock failure process. Three numerical examples are presented to demonstrate the impact of actual rock heterogeneity due to spatial distribution of constituent mineral grains (e.g., feldspar, quartz and mica) on the macro-scale mechanical response, and the associated rock failure mechanism at the meso-scale level is clarified. The numerical results indicate that the shape and distribution of constituent mineral grains have a pronounced impact on stress distribution and concentration, which may further control the failure process of granite. The proposed method provides an efficient tool for studying the mechanical behaviors of heterogeneous rock and rock-like materials whose failure processes are strongly influenced by material heterogeneity.

서남해안 2.5GW 해상풍력단지 조성을 위한 설치 일정계획 (Installation Scheduling for the Development of Southwest Coast 2.5GW Offshore Wind Farm)

  • 고현정
    • 한국항만경제학회지
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    • 제33권2호
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    • pp.83-96
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    • 2017
  • 지구 온난화에 대처하는 일환으로 신재생에너지 가운데 세계 각국은 해상풍력단지 개발에 투자를 집중하고 있다. 그러나 해상풍력단지 개발은 해상에서의 구조물 운송, 설치 등의 해상작업이 요구됨에 따라 투자비용이 육상풍력단지 보다 높은 단점이 있다. 특히 해상기상 여건으로 인한 설치기간 지연은 해상풍력단지 운영의 경제성에도 영향을 끼치는 요소이다. 따라서 본 연구에서는 국내 해상의 기상여건을 고려하여 해상풍력단지 조성의 최적 일정계획을 거시적 측면에서 분석하고자 하였다. 이를 위해 수리적 모델을 개발하였고, 이를 이용하여 국내 서남해안 2.5GW 해상풍력단지 조성사업에 적용하였다. 해상 기상여건은 기상청의 자료를 활용하였고, 모델에 사용된 입력 자료는 해외의 선행 사례를 바탕으로 현실성을 최대한 반영하고자 하였다. 그 결과 해상풍력터빈 35기를 설치하는데 6개월이 소요되는 것으로 분석되었다. 특히 겨울을 피하여 작업하는 것이 비용을 최소화할 수 있는 것으로 분석되었다.

Analysis of the load distribution and contact safety factor of PTO gears of a 71 kW class agricultural tractor

  • Baek, Seung-Min;Kim, Wan-Soo;Kim, Yeon-Soo;Lee, Nam-Gyu;Kim, Nam-Hyeok;Kim, Yong-Joo
    • 농업과학연구
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    • 제47권2호
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    • pp.327-335
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    • 2020
  • The purpose of this study was to analyze the load distribution and contact safety factor for the power take off (PTO) gear of a 71 kW class agricultural tractor. In this study, a simulation model of the PTO gear-train was developed using Romax DESGINER. The face load factor and contact safety factor were calculated using ISO 6336:2006. The simulation time was set at 2,736 hours considering the lifetime of the tractor, and the simulation was performed for each PTO gear stage at the engine rated power conditions. As a result of the simulation, the face load factors for the driving gear at the PTO 1st, 2nd and 3rd stages were 1.644, 1.632, and 1.341, respectively. The contact safety factors for the driving gear at the PTO 1st, 2nd and 3rd stages were 1.185, 1.216, and 1.458, respectively. As the PTO gear stage was increased, the face load factor decreased, and the contact safety factor increased. The load distributions for all the PTO gears were concentrated to the right of the tooth width. This causes stress concentrations and shortens the lifespan of the gears. Therefore, it is necessary to improve the face load factor and the contact safety factor with macro-geometry and micro-geometry.

Exploring the Performance of Australian Construction Industry in a Recent Global Recession

  • Alfred, Olatunji Oluwole
    • Journal of Construction Engineering and Project Management
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    • 제1권3호
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    • pp.1-8
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    • 2011
  • Available data on the recent global financial crisis (GFC) show that it lasted between the second quarter (Q2) of 2007 and the fourth quarter (Q4) of 2009. Australia is one of the first economies to fully recover from this crisis. This study explorles the role played by the Australian construction industry in stimulating economic growth during the recession. In order to investigate the macro-variability trend during the financial crisis, data were collected and analysed relating to the quarterly GDP of Australia and selected countries between Q1 2000 and Q4 2009. Specifically, changes in the construction industry's GDP were compared with aggregate GDP changes in Australian economy and similar indices in the 'Group of 7' (G7) countries and Organisation for Economic Co-operation and Development (OECD) countries. Moreover, specific attention was focused on Germany, France, Japan, United States of America (USA) and United Kingdom (UK). Graphical and Pearson's correlation methods were used to analyse the relationships between changes in construction GDP and Australia's overall economic growth during the recession. In addition, an attempt was made to develop a regression model for predicting economic growth during the recent recession using changes in gross fixed capital formation (GFCF), changes in construction GDP and the impact of these changes on national economy. Analysis shows a slight contraction in construction activities during the crisis; however construction triggered significant growth in the economy during the crisis period and afterwards. This appears to be the major difference between Australia and other major economies that have experienced a longer recession.

일반인의 환자안전활동 경험, 환자안전인식 및 환자참여 의지 간의 관계에 관한 융합연구 (A Convergence Study on the Relationship among Patient Safety Activity Experience, Patient Safety Perception and Willingness to Participate in the General Population)

  • 신선화
    • 한국융합학회논문지
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    • 제11권9호
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    • pp.405-415
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    • 2020
  • 본 연구는 일반인을 대상으로 환자안전활동 경험, 환자안전인식 및 환자참여 의지 간의 관계를 살펴보고자 수행하였다. 또한, 일반인의 환자안전 참여를 증가시키기 위한 환자안전교육 프로그램을 개발하는데 기초자료를 제공하고자 한다. 본 연구는 2019년 11월에 온라인 설문을 통해 195명의 단면 조사를 수행하였다. 대상자는 최근 1년 이내에 종합 병원에 입원한 경험이 있는 일반인으로 하였다. 수집한 자료는 SPSS PROCESS Macro (Model 4)를 이용하여 매개효과를 분석하였다. 연구결과, 환자안전활동 경험은 환자안전인식에 유의한 직접효과가 있었고, 환자안전인식은 환자참여 의지에 유의한 직접효과가 있었다. 그리고 환자안전인식은 환자안전활동 경험과 환자참여 의지 간의 관계에서 매개효과가 유의하게 나타났다. 이러한 결과를 토대로 일반인의 환자참여 의지를 증가시키기 위한 방안으로 의료기관에서 수행하는 환자안전활동에 대한 홍보와 교육을 통해 환자안전인식을 향상시키는 것이 필요함을 강조하였다.

진성리더십과 그릿이 사회적기업 구성원의 행복과 직무재창조에 미치는 영향 - 충청북도 사회적기업을 대상으로 - (The Effect of Authentic Leadership and Grit on the Happiness and Job Crafting of Social Enterprise Employee - Focused on Social Enterprise in Chungbuk -)

  • 하덕천;엄성준;리신호
    • 농촌계획
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    • 제26권4호
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    • pp.117-129
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    • 2020
  • The purpose of this study is to verify the effect of the authentic leadership of social enterprise leaders on the happiness and job crafting of employees, the mediation effect of job crafting in the authentic leadership of the leader and the happiness of the employees, and the coordination effect by the Grit of the employees. For verification, the relationship between authentic leadership and job crafting, happiness and grit and seven research theories were established. In addition, 47 questionnaires were drawn through prior research on happiness, authentic leadership, job crafting, and grit, and five executives and workers of social enterprises in Chungcheongbuk-do(Province) were surveyed on a five-point Likert scale. The collected survey data were conducted through the SPSS and AMOS for basic statistical analysis. The Macro Process of the bootstrap method was used to verify the mediation effects, the regulated effects. This study has conducted exploratory and confirmatory factor analysis, correlation analysis, structural model analysis through the survey results and the analysis results verify the hypothesizes. The study found that authentic leadership affects the happiness and job crafting of employees, and that job crafting affects the happiness of employees, and the relationship between authentic leaders and employees affects job crafting. It has also been shown that the Grit of its employees affects their job crafting and happiness and also has a mediation effect on job crafting and happiness. In the policy environment of the changing rural development project, the social economy establishment plan for the virtuous circle of resources in the region should be considered, and education programs should be introduced to improve the authentic leadership of the leaders.