• Smart Structures and Systems
• /
• v.17 no.5
• /
• pp.753-771
• /
• 2016

This paper addresses the free and transient responses of a SDOF linear complex stiffness system by making use of the Hilbert transform and the convolution integral. Because the second-order differential equation of motion having the complex stiffness give rise to the conjugate complex eigen values, its time-domain analysis using the standard time integration scheme suffers from the numerical instability and divergence. In order to overcome this problem, the transient response of the linear complex stiffness system is obtained by the convolution integral of a green function which corresponds to the unit-impulse free vibration response of the complex system. The damped free vibration of the complex system is theoretically derived by making use of the state-space formulation and the Hilbert transform. The convolution integral is implemented by piecewise-linearly interpolating the external force and by superimposing the transient responses of discretized piecewise impulse forces. The numerical experiments are carried out to verify the proposed time-domain analysis method, and the correlation between the real and imaginary parts in the free and transient responses is also investigated.

• International journal of advanced smart convergence
• /
• v.5 no.2
• /
• pp.73-79
• /
• 2016

Remote sensing and measurement are of paramount importance of providing information on the state of water quality in water bodies. The formation and growth of cyanobacteria is of serious concern to in land aquatic life forms and human life. The main cause of water quality deterioration stems from anthropogenic induced eutrophication. The goal of this research to quantify and determine the spatial distribution of cyanobacteria concentration in the water using remote sensing technique. The standard approach to measure water quality based on the direct measurement of the fluorescence of the chlorophyll a in the living algal cells and the same approach used to detect the phycobilin pigments found in blue-green algae (a.k.a. cyanobacteria), phycocyanin and phycoerythrin. This paper propose the emerging sensor design to measure the water quality based on the optical analysis by fluorescence of the phycocyanin pigment. In this research, we developed an method to sense and quantify to derive phycocyanin intensity index for estimating cyanobacteria concentrations. The development of the index was based on the reflectance difference between visible light band 620nm and 665nm. As a result of research this paper presents, an optical biological sensor design information to measure the Phycocyanin parameters in water content.

• International journal of advanced smart convergence
• /
• v.7 no.2
• /
• pp.38-46
• /
• 2018

This study proceeded an experiment that can increase such physiological properties of heated radish extract. During the extraction of radish, including the byproduct, an increase in antioxidant properties of radish according the heating temperature was performed. Upon the extracts of radish bark and radish green extract(mucheong), the physiological functionalities and antioxidant activity were investigated. As a result, the color of radish ethanol extract in dependence of heating temperature, showed light brown color at low heating temperature and black color from $150^{\circ}C$. The total polyphenol content significantly increased as a result of heat treatment; 6.7 times and 22 times higher than the control at $110^{\circ}C$ and $150^{\circ}C$, respectively. DPPH radical scavenging ability and antioxidant property increased with increasing heating temperature; in comparison to heat-treated radish at $110^{\circ}C$ and $150^{\circ}C$, $IC_{50}$ decreased by 1/22 times. $IC_{50}$ of the control was 23times higher than $150^{\circ}C$ heat treated radish (Control $IC_{50}$:130.305). According to the graph that represents ABTS activity, antioxidant activity increased in dependence of heat treatment likewise to the total polyphenol content and DDPH radical scavenging activity. Upon heat treatment at $150^{\circ}C$, antioxidant activity in consequence of ABTS assay increased 23 times higher than the control.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.20 no.6
• /
• pp.526-534
• /
• 2009

The magnetic field of the extremely low frequency that occurs in the substation facilities was surveyed to present ways to broaden understanding of the magnetic field characteristics. We have investigated the level of the magnetic fields in the substation areas and control rooms of 25 substations in the metropolitan area in accordance with the measurement method of IEC CISPR(IEC/TC106 PT 62110). We propose objective and reliable policy approaches such as the electromagnetic field certification system to more accurately understand the property of magnetic field.

• Smart Structures and Systems
• /
• v.26 no.5
• /
• pp.641-656
• /
• 2020

The finite element solutions of thermal buckling load values of the graded sandwich curved shell structure are reported in this research using a higher-order kinematic model including the shear deformation effect. The numerical buckling temperature has been computed using an in-house specialized code (MATLAB environment) prepared in the framework of the current mathematical formulation. In addition, the mathematical model includes the excess structural distortion under the influence of elevated environment via Green-Lagrange nonlinear strain. The corresponding eigenvalue equation has been solved to predict the critical buckling temperature of the graded sandwich structure. The numerical stability and the accuracy of the current solution have been confirmed by comparing with the available published results. Thereafter, the model is extended to bring out the influences of structural parameters i.e. the curvature ratio, core-face thickness ratio, support conditions, power-law indices and sandwich types on the thermal buckling behavior of graded sandwich curved shell panels.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
• /
• v.53
• /
• pp.155-180
• /
• 2012

Korea has the plans to improve nation and corporate global competitiveness through reducing the logistics costs. Ministry of Knowledge Economy, as the government department of in charge of the plan, establish industrial logistics policies in 2002 and 2007 and it's about time to set up the third industrial logistics policy in 2012. There are new trends for the logistics environment in terms of environment-friendly logistics, logistics securities, win-win collaboration etc. This study propose some harmonious plans between logistic productivity and the new trends in the field of logistics. For the purpose of that, we have evaluated the second industrial logistics policy. We propose the vision and objectives of the new industrial logistics policy. The vision is entering the line of industrial logistics developed nations through the sustainable logistics innovation, and the objects are smart & green logistics, win-win collaboration, lead the new logistics trends etc. We also propose the set the system and rules to push promote the new plan. In addition, industrial logistics is the new terminology setting out use by Ministry of Knowledge Economy.

• Proceedings of the KIPE Conference
• /
• 2010.07a
• /
• pp.240-241
• /
• 2010

Research on modification and replacement of conventional AC distribution system to DC distribution system has been widely conducted. When DC system is applied, it is possible to improve energy transferring efficiency because most of the home appliances are electric loads which require DC input voltage. Furthermore, compatibility with renewable energy sources and secondary batteries should be improved as they are DC based power sources. To design energy efficient DC system, it is important to understand the load characteristics of the electric devices. In this paper, the electric appliances are classified to 3 types: motor, heating, and electric loads and their typical power consumptions are shown. Load patterns of load which can be used in analyzing the designed system are modeled according the statistics. Feasibility of the developed load patterns are verified by applying it in distribution system design tool.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.22 no.2
• /
• pp.11-16
• /
• 2014

Korea is the urgent need to diversify the bio-energy raw materials because we have narrow area of land cultivated plants and lack the bio-mass resources. Using a resource-rich the marine environment enclosed on three sides by the sea. Through bio-energy production-technical and carbon dioxide reduction measures which will be a very effective alternative. Sustainable development about algae bio-energize industry through SSaM-GG(Smart, Shared and Mutual-Green, Growth) is expected. Algae has high carbon dioxide absorption factor, extracting oil from algae is thirty times much more than sunflower.

• Journal of the Korean Institute of Rural Architecture
• /
• v.22 no.2
• /
• pp.35-42
• /
• 2020

The new urbanization is one of prestige growth engines to lead the next generation of China economy, it promotes new sustainable urban development models guided by various planning polices to improve urban livability and sustainability in accommodation with economy, social, and environmental consideration. The expanding urban periphery to rural area should leverages existing assets, infrastructure, local context and plans as a showcase of environmental and economic balance in a responsibly high-density, green community designed to human development and ecological settlement. The Beijing Chaoyang District and Tianjin Binhai area are a strategic advancement in the policy of building one of the most powerful economic regions, the Bohai Rim. Recently released 'Jingjinji development plan' supports various urbanization policies and encourages sustainable developments including 2 significant city center projects which are under way in global attention. The study compared on the characters of development policies and the cutting-edge smart design strategies by which they are applied, the master plan of the Beijing Chaoyang District expansion plan and Tianjin Yujiapu CBD project embrace innovative sustainable technologies.

• Smart Structures and Systems
• /
• v.20 no.5
• /
• pp.595-605
• /
• 2017

The present article reported the thermal buckling strength of the sandwich shell panel structure and subsequent improvement of the same by embedding shape memory alloy (SMA) fibre via a general higher-order mathematical model in conjunction with finite element method. The geometrical distortion of the panel structure due to the temperature is included using Green-Lagrange strain-displacement relations. In addition, the material nonlinearity of SMA fibre due to the elevated thermal environment also incorporated in the current analysis through the marching technique. The final form of the equilibrium equation is obtained by minimising the total potential energy functional and solved computationally with the help of an original MATLAB code. The convergence and the accuracy of the developed model are demonstrated by solving similar kind of published numerical examples including the necessary input parameter. After the necessary establishment of the newly developed numerical solution, the model is extended further to examine the effect of the different structural parameters (side-to-thickness ratios, curvature ratios, core-to-face thickness ratios, volume fractions of SMA fibre and end conditions) on the buckling strength of the SMA embedded sandwich composite shell panel including the different geometrical configurations.