• The Journal of Asian Finance, Economics and Business
• /
• 제7권9호
• /
• pp.673-685
• /
• 2020

Financial literacy is one of the sustainable development goals of huge concern of governments. Governments explore solutions addressing policies to improve financial literacy. Nevertheless, financial management has such a broad scope and is not just limited to knowledge. As human nature, individuals are born with different confidence levels that include various financial abilities. This study aims to investigate the household-financial efficacy through the application of psychometric instruments, risk preference, and demographic characteristics toward consumption decision behavior. The research is based on a survey 479 households in the peninsular Malaysia, and utilizes the structural equation model, cluster proportional and systematic random sampling, and two measurements - composite reliability and average variance extracted. Results show that households' financial efficacy is one of the critical factors that explain the households' consumption decision behavior. Also, risk preference, gender and area location (rural or urban) of the household determined the consumption decision behavior of the household. The effectiveness of consumption decision is not only determined by financial literacy, but also financial efficacy. The implications of this paper may help to design policies in narrowing the broad gap between the rural and urban level of financial efficacy. The government needs to take appropriate actions to fix it.

• 한국전기전자재료학회논문지
• /
• 제18권1호
• /
• pp.30-37
• /
• 2005

The microwave dielectric properties and their related structural characteristics in solid solutions of (1-$\chi$) Ba($Mg_{1/3}$Nb$_{2/3}$) $O_3$-$\chi$La(Mg$_{2/3}$Nb$_{1}$3) $O_3$(BLMN) have been investigated by measuring the dielectric constant($\varepsilon$r), Q value and temperature coefficient of resonant frequency($\tau$f) and by observing the crystal structure using high resolution transmission electron microscopy (HRTEM). Microwave dielectric properties showed characteristic features for specific composition. Dielectric constant($\varepsilon$$_{r}$) showed maximum value at the composition which corresponds to the phase boundary between 1 : 2 ordered and 1 : 1 ordered structure. The increase in $\varepsilon$$_{r}$ may be caused by the rattling of ions by incorporating smaller ions and the disordered structure. The variation of temperature coefficient of resonant frequency($\tau$$_{f}$) was investigated in terms of oxygen octahedra tilting.dra tilting.

• 한국진공학회지
• /
• 제14권3호
• /
• pp.147-152
• /
• 2005

실시간 x-선 산란기법을 이용해 p형 질화물 위에 성장된 $Ni(400\;\AA)/Au(400\;\AA)$ 박막의 공기 중에서 산화과정 동안 일러나는 구조적인 변화를 조사하였다. 350 "C의 열처리 온도에서 산화과정 동안 니켈과 금 박막들이 서로 섞인다는 것을 확인하였고 금의 회절 프로파일의 우측 부근에서 니켈의 양이 서로 다른 금 고용체의 새로운 상이 형성되는 것을 발견하였다. 또한, 이런 금 고용체에 포함된 니켈 원자는 산화가 더욱 진행함으로써 바깥쪽으로 확산하여 산소와 결합하여 NiO의 새로운 상이 형성되는 것을 알 수 있었다. $650^{\circ}C$의 열처리 온도에서는 완전히 산화가 일어났음에도 불구하고 금(111) 벌크 회절 프로파일에 소량의 니켈 원자가 포함되어 있음을 확인하였다.

• 한국강구조학회 논문집
• /
• 제10권2호통권35호
• /
• pp.201-209
• /
• 1998

강섬유보강 적층복합구조물에서 온도의 변화는 구조물의 응답에 중요한 영향을 미칠수 있다. 온도의 급작스런 변화는 재료의 강도와 성질을 현저히 저하시켜 구조물의 대변형, 좌굴, 고응력상태를 유발하는 중요한 인자가 된다. 본 연구에서는 등분포로 재하된 온도하중에 의한 적층복합판의 온도좌굴에 관한 해석을 수행하였다. 전단변형의 효과를 정확히 고려하기위해 5개의 변수로 구성된 고차전단변형이론을 적용하였다. 적층판의 배열각도, 적층판의 수, 폭-두께비의 변화, 형상비의 변화에 따른 임계좌굴온도를 구하여 1차전단변형이론에 의한 결과와 고전적이론에 의한 결과와 비교분석하였다.

• 한국소음진동공학회논문집
• /
• 제22권11호
• /
• pp.1071-1077
• /
• 2012

Low frequency noises(up to about 200 Hz) such as booming are mainly caused by particular modes, and in general the solutions may be found based on mode controls where conventional methods such as FEM can be used. However, at higher frequencies between 0.3~1 kHz, as the number of modes rapidly increases, radiation characteristics from structures, performances of damping sheets and sound packages may be more crucial rather than particular modes, and consequently the conventional FEM may be less practical in dealing with this kinds of structure-borne problems. In this context, so-called 'mid-frequency simulation model' based on FE-SEA hybrid method is studied and validated to reduce noise in this frequency region. Energy transmission loss(i.e. air borne noise) is also studied. A dash panel component is chosen for this study, which is an important path that transmits both structure-borne and air borne energies into the cavity. Design modifications including structural modifications, attachment of damping sheets and application of different sound packages are taken into account and the corresponding noise characteristics are experimentally identified. It is found that the dash member behaves as a noise path. The damping sheet and sound packages have similar influences on both sound radiation and transmission loss. The comparison between experiments and simulations shows that this model could be used to predict the tendency of noise improvement.

• 한국측량학회지
• /
• 제16권2호
• /
• pp.299-309
• /
• 1998

국가평면좌표계는 GIS/LIS의 구축에 있어 가장 기본적인 요소이며 위치정보를 나타내는데 기준이 되고 있다. 우리나라의 국가기본도에서는 1910년대에 동경원점을 기준으로 하는 3개의 평면좌표계를 채택하고 Gauss-Schreiber 투영법을 적용한 바 있으며 그 후 Gauss-Kruger 투영법으로 변경되었다 본 연구에서는 토지조사사업에서 구축된 기존의 지도좌표계의 계산체계와 투영법에 있어서 불명확함으로 인하여 내재되어 있는 구조적인 문제점을 분석하고 10.405"에 대한 처리방안을 제시하고자 하였으며, GIS/LIS에서 공간데이터의 관리와 GPS의 활용에 적합한 새로운 수치지도 좌표계의 도입을 위하여 외국의 사례를 분석하고 검토하였다. 새로운 지도좌표계는 한반도 전역을 포괄할 수 있도록 경도 $127^\circ\;30'$ 을 중앙자오선으로 하고 TM 투영법에 의한 단일좌표계로 설정하는 방안이 제시되었으며, 지구중심좌표계에 의한 GRS80타원체를 채택할 것을 제안하였다.안하였다.

• Earthquakes and Structures
• /
• 제9권6호
• /
• pp.1133-1152
• /
• 2015

A frequency-domain method is developed for evaluating the earthquake input energy to two building structures connected by viscous dampers. It is shown that the earthquake input energies to respective building structures and viscous connecting dampers can be defined as works done by the boundary forces between the subsystems on their corresponding displacements. It is demonstrated that the proposed energy transfer function is very useful for clear understanding of dependence of energy consumption ratios in respective buildings and connecting viscous dampers on their properties. It can be shown that the area of the energy transfer function for the total system is constant regardless of natural period and damping ratio because the constant Fourier amplitude of the input acceleration, relating directly the area of the energy transfer function to the input energy, indicates the Dirac delta function and only an initial velocity (kinetic energy) is given in this case. Owing to the constant area property of the energy transfer functions, the total input energy to the overall system including both buildings and connecting viscous dampers is approximately constant regardless of the quantity of connecting viscous dampers. This property leads to an advantageous feature that, if the energy consumption in the connecting viscous dampers increases, the input energies to the buildings can be reduced drastically. For the worst case analysis, critical excitation problems with respect to the impulse interval for double impulse (simplification of pulse-type impulsive ground motion) and multiple impulses (simplification of long-duration ground motion) are considered and their solutions are provided.

• Structural Engineering and Mechanics
• /
• 제37권2호
• /
• pp.149-162
• /
• 2011

The aim of this research is a comprehensive review and evaluation of beam theories resting on elastic foundations that used to model mode-I delamination in multidirectional laminated composite by DCB specimen. A compliance based approach is used to calculate critical strain energy release rate (SERR). Two well-known beam theories, i.e. Euler-Bernoulli (EB) and Timoshenko beams (TB), on Winkler and Pasternak elastic foundations (WEF and PEF) are considered. In each case, a closed-form solution is presented for compliance versus crack length, effective material properties and geometrical dimensions. Effective flexural modulus ($E_{fx}$) and out-of-plane extensional stiffness ($E_z$) are used in all models instead of transversely isotropic assumption in composite laminates. Eventually, the analytical solutions are compared with experimental results available in the literature for unidirectional ($[0^{\circ}]_6$) and antisymmetric angle-ply ($[{\pm}30^{\circ}]_5$, and $[{\pm}45^{\circ}]_5$) lay-ups. TB on WEF is a simple model that predicts more accurate results for compliance and SERR in unidirectional laminates in comparison to other models. TB on PEF, in accordance with Williams (1989) assumptions, is too stiff for unidirectional DCB specimens, whereas in angle-ply DCB specimens it gives more reliable results. That it shows the effects of transverse shear deformation and root rotation on SERR value in composite DCB specimens.

• 한국재료학회지
• /
• 제30권9호
• /
• pp.447-452
• /
• 2020

In this work, α-Fe₂O₃ nanocrystals are synthesized by co-precipitation method and used as adsorbent to remove Cr⁶⁺, Cd²⁺, and Pb²⁺ from wastewater at room temperature. The prepared sample is evaluated by XRD, BET surface area, and FESEM for structural and morphological characteristics. XRD patterns confirm the formation of a pure hematite structure of average particle size of ~ 40 nm, which is further supported by the FESEM images of the nanocrystals. The nanocrystals are found to have BET specific surface area of ~ 39.18 m² g^-1. Adsorption experiments are carried out for the different values of pH of the solutions, contact time, and initial concentration of metal ions. High efficiency Cr⁶⁺, Cd²⁺, and Pb²⁺ removal occur at pH 3, 7, and 5.5, respectively. Equilibrium study reveals that the heavy metal ion adsorption of the α-Fe₂O₃ nanocrystals followed Langmuir and Freundlich isotherm models. The Cr⁶⁺, Cd²⁺, and Pb²⁺ adsorption equilibrium data are best fitted to the Langmuir model. The maximum adsorption capacities of α-Fe₂O₃ nanocrystals related to Cr⁶⁺, Cd²⁺, and Pb²⁺ are found to be 15.15, 11.63, and 20 mg g^-1, respectively. These results clearly suggest that the synthesized α-Fe₂O₃ nanocrystals can be considered as potential nano-adsorbents for future environmental and health related applications.

• Bulletin of the Korean Chemical Society
• /
• 제29권7호
• /
• pp.1335-1343
• /
• 2008

Theoretical studies on the un-catalyzed and catalyzed aminations of ketene with $NH_3$ and $(NH_3)_2$, respectively, were studied using MP2 and hybrid density functional theory of B3LYP at the 6-31+G(d,p) and 6- 311+G(3df,2p) basis sets in the gas phase and in benzene and acetonitrile solvents. In the gas phase reaction, the un-catalyzed mechanism was the same as those previously reported by others. The catalyzed mechanism, however, was more complicated than expected requiring three transition states for the complete description of the C=O addition pathways. In the un-catalyzed amination, rate determining step was the breakdown of enol amide but in the catalyzed reaction, it was changed to the formation of enol amide, which was contradictory to the previous findings. Starting from the gas-phase structures, all structures were re-optimized using the CPCM method in solvent medium. In a high dielectric medium, acetonitrile, a zwitterions formed from the reaction of $CH_2$=C=O with $(NH_3)_2$, I(d), exists as a genuine minimum but other zwitterions, I(m) in acetonitrile and I(d) in benzene become unstable when ZPE corrected energies are used. Structural and energetic changes induced by solvation were considered in detail. Lowering of the activation energy by introducing additional $NH_3$ molecule amounted to ca. −20 $\sim$ −25 kcal/mol, which made catalyzed reaction more facile than un-catalyzed one.