• Advances in aircraft and spacecraft science
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• 제6권4호
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• pp.297-314
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• 2019

Dynamic stability of a porous metal foam nano-dimension plate on elastic substrate exposed to bi-axial time-dependent forces has been studied via a novel 3-variable plate theory. Various pore contents based on uniform and non-uniform models have been introduced. The presented plate model contains smaller number of field variables with shear deformation verification. Hamilton's principle will be utilized to deduce the governing equations. Next, the equations have been defined in the context of Mathieu-Hill equation. Correctness of presented methodology has been verified by comparison of derived results with previous data. Impacts of static and dynamical force coefficients, non-local coefficient, foundation coefficients, pore distributions and boundary edges on stability regions of metal foam nanoscale plates will be studied.

• 한국운동역학회지
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• 제18권1호
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• pp.21-30
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• 2008

이 연구는 60대 남자 노인의 정상인들과 무릎 관절염 환자들 사이에 보행 시 국부적인 안정성을 비교하기 위해 선형기법의 변이 계수와 비선형 시계열 동역학 기법의 Lyapunov지수(LyE) 및 상관차원(correlation dimension, COD) 방법을 적용해 분석했다. 분석 결과 선형 운동인 발목의 수직 변위를 통해 관찰한 국부적 안정성은 선형 기법의 변이 계수를 통해 관찰한 결과 정상인 집단이 무릎관절염 환자 집단보다 불안한 것으로 나타난 반면에 비선형 기법 관찰에서는 두 집단 차이가 없는 것으로 나타났다. 한편 각형 운동인 무릎의 각 변위를 통해 분석된 국부적 안정성은 선형 분석 결과는 두 집단 차이점을 보이지 않았지만, 비선형 기법 결과인 COD 지수는 무릎 관절염 환자가 크게 나타나 결과적으로 보행 시 국부적 불안을 보였다. 이상 본 연구 결과를 종합해 보면 선형 기법의 결과와 비선형 기법의 결과는 일치하지 않았으며, 또한 무릎 관절염 환자의 보행 시 불안정은 발목의 수직 변위인선형에서 보다 무릎 관절 각 변위인 각형에서 뚜렷하게 나타났다.

• 대한치과보철학회지
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• 제53권3호
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• pp.215-221
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• 2015

심한 마모를 가진 환자의 치료에서 광범위한 보철 수복을 필요로 하는 경우가 있는데, 마모의 원인과 수직 고경의 변화 유무 등을 판단하여 현재 구강상태의 회복과 장기간의 안정성을 이루어야 한다. 수직 고경을 증가시킬 때는 임시 수복을 하고 장기간의 관찰을 통해 환자의 적응을 평가해야 한다. 본 증례의 환자54세 남자 환자로 전반적인 치아 마모와 심미적 불만족을 주소로 내원하였다. 환자의 구강 내 소견 상 교모와 부식이 동반되어 과도한 마모가 발생한 것으로 진단하였다. 수직 고경의 변화를 평가하기 위해 안정위시 악간공극, 발음, 안모, 심미, 임상적 치관 길이, 중절치 절단과 순측 전정과의 수직거리 등을 평가하였고, 교합기의 incisal pin기준으로 수직 고경을 2.5 mm 증가하기로 하였다. 임시 보철물을 이용하여 8주의 안정화 기간 이후 최종 보철물을 제작하였다. 6개월 간 경과 관찰 결과 기능적, 심미적으로 양호한 결과를 보였다.

• The Journal of Asian Finance, Economics and Business
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• 제7권10호
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• pp.73-85
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• 2020

As an effort to achieve sustainable development and increase people's welfare, financial inclusion has become the policy agenda of many countries. Therefore, the effect of financial inclusion on economic growth, poverty, income inequality, and financial stability in several countries in Asia has become the goal and this is the subject of this study. Financial inclusion is measured by 3 dimensions, namely banking penetration, access to banking services, and use of banking services. Poverty ratio below the national poverty line and the Gini coefficient are used as indicators of poverty and income inequality. Financial stability is measured by Bank Z-Score and bank nonperforming loans. The results from the hypothesis test shows that all dimensions of financial stability simultaneously have significant influence on economic growth, poverty, income inequality, and financial stability. On the other hand, the partial impact of financial inclusion dimension on economic growth, poverty alleviation, income inequality, and financial stability in ten countries of Asia has not been optimal. The derived results of this study is required to be interpreted and considered by the Governments of each country in developing strategies for increasing financial inclusion, so that the policy to achieve sustainable development and enhancement of people's welfare can be achieved.

• 대한치과보철학회지
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• 제38권6호
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• pp.814-820
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• 2000

Statement of Problem. Commonly used classification systems do not inform for dentists the dimension of the available bone at a potential implant site although regarding a variety of morphologic and pathophysiologic aspects using schematic graphs. However, for the implantologist the availability of bone substance is most important independent whether it concerns the jaw basis or the alveolus. Purpose of Study. The present article refers to a new evaluation form, to analyze the available bone with regard to optional immediate loading site by site. According to a new systematic implant planning concept will be presented in two case reports. Results. The feasibility of the classification for planning and documentation of immediately loaded implants is presented in two case reports. Conclusion. The factor of bone support for immediate functional stability is important in dental implantology. The new systematic implant planning helps to systematically estimate the dimension (ASCIi classification) of the alveolus site by site to evaluate the possibility of immediate loading. The Gottingen classification thus aids to determine the degree of stability that can be expected for the planned solution.

• 대한치과보철학회지
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• 제50권3호
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• pp.198-203
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• 2012

과도한 치아 마모는 교합면에 손상을 야기하고, 치수 병변, 교합 부조화, 기능장애, 심미적 문제 등을 야기할 수 있다. 과도한 치아 마모를 갖고 있는 환자들을 치료하고자 할 때 수직교합고경(vertical dimension of occlusion, VDO)의 상실 여부와 수복을 위한 악간 공간의 적절성 여부에 기반하여 분류를 할 필요가 있다. 본 증례의 환자는 다수 치아들의 마모를 지닌 50세의 남성으로, 과도한 치아 마모가 있지만 수직교합고경의 상실은 없으며 수복을 위한 악간 공간이 부족하였다. 이러한 경우 수직교합고경을 증가시켜 치료를 진행하는 것을 고려할 수 있다. 수직교합고경의 증가를 필요한 범위 내에서 최소로 줄이고, 증가된 수직교합고경 상에서 안정화 기간을 거친 뒤 안정된 교합 접촉을 제공할 수 있다면, 수직고경 증가를 동반한 치료법은 안정성을 가질 수 있다. 본 남성 환자를 치료하기 위해 수직고경의 증가를 동반하여 전치부와 구치부에서 단일구조 지르코니아를 이용한 고정성 보철물로 수복을 하였다. 일련의 치료과정을 통하여 기능적인 면과 심미적인 면에서 만족스러운 결과를 얻었기에 보고하는 바이다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.680-684
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• 2005

This paper presents a data-based stability analysis of a MIMO linear time-invariant discrete-time system, as an extension of the previous results for a SISO system. In the MIMO case, a similar discussion as in the case of a SISO system is also applied, except that an augmented input and output space is considered whose dimension is determined in relation to both the orders of the input and output vectors and the numbers of inputs and outputs. As certain subspaces of the input and output space, both output data space and closed-loop data space are defined, which contain all the behaviors of a system, respectively, with zero input in open-loop and with a control input in closed-loop. Then, we can derive the data-based stability conditions, in which the open-loop stability can be checked by using a data matrix whose column vectors span the output data space and the closed-loop stability can also be checked by using a data matrix whose column vectors span the closed-loop data space.

• International Journal of Naval Architecture and Ocean Engineering
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• 제13권1호
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• pp.478-492
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• 2021

In this study, hull dimensions of an FPSO were optimized to maximize its operability at Brazil field. In contrast with the previous works which have used simplified models to evaluate some indicators related to stability and hydrodynamic performances of FPSOs for its own optimal design, we developed a generic hull and compartment modeler and sophisticated stability and hydrodynamic calculation modules. With the aid of the developed tools, the hull optimization was performed with initial dimensions of an FPSO originally designed for west Africa field. The optimization results indicated the relative importance of hydrodynamic performances compared with stability performances for the FPSO hull dimensioning by showing that there were 3 active constraints related to them, which were the natural periods of heave and roll and the maximum pitch angle under 1-year return period waves at full load condition. To the author's knowledge, this study is the first attempt to combine altogether the hull and compartment modeling and full set of stability and hydrodynamic calculations precisely to optimize an FPSO's hull dimensions within 30 min. Also, it is worthwhile to mention that the developed methods are generic enough to be applied to all types of ship-shaped offshore platforms.

• Journal of the Korean Wood Science and Technology
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• 제48권5호
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• pp.722-731
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• 2020

The purpose of this research is to determine the efficiency of impregnation using phenol formaldehyde resin to enhance Falcataria wood's stability and better mechanical properties. Impregnation process was carried out after moisture content stabilized at 12% on samples with a dimension of 20 mm × 20 mm × 300 mm at various concentrations and pressure time. Dimensional stability was evaluated by thickness swelling (TS) and anti-swelling efficiency (ASE) and the young's modulus was conducted according to BS 573. The mechanical properties and dimensional stability of impregnated wood were evaluated. Dimensional stability and mechanical properties of Falcataria wood were successfully increased after impregnation. PF impregnation can improve the mechanical properties and the density from 0.26 g/㎤ to 0.30 g/㎤ even with only 10% of weight percent grain. Dimensional stability increases with increasing resin concentration and time pressure. The highest increase in mechanical properties was found at a higher concentration of PF. The penetration of PF into the wood's cell darkens the color of impregnated wood.

• 한국산업융합학회 논문집
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• 제25권3호
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• pp.357-363
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• 2022

In this study, in order to develop an non-slip metal grating, the stability of the grating according to the span of the grating and the gap and height of the bearing bar was evaluated. The optimal shape design of the grating was performed using the results of determining the stability of the grating. The purpose of this study is to determine the stability according to the spacing and height of the bearing bar by applying the design pressure at the design stage to develop the anti-skid grating, and to design the optimal shape for cost reduction. In the optimal design, the target variable was set as the mass, and the optimal design of the grating was performed based on about 20%. Regardless of the height of the bearing bar of the grating, the stress and deformation of the span and the grating showed a proportional tendency to each other, and it was found that the stress decreased as the height of the bearing bar increased. Based on the structural analysis results, an optimal design was performed using mass as the objective variable, and the existing 2mm thickness was changed to 1.6mm, reducing the mass by about 19%. The stress increased by about 4.4% compared to the maximum stress of the existing grating, but the minimum safety factor was 3.1, indicating that the optimally designed grating was stable.