• Earthquakes and Structures
• /
• 제4권2호
• /
• pp.133-155
• /
• 2013

The earthquake responses are studied for the tall flexible structures such as TV towers when the vertical eccentricities between the discrete nodes and the corresponding centroids of investigated lumps are considered. In practical analyses, the tall flexible structures can be made into a spatial-discrete system of some certain length of beam elements with different lengths and cross-sectional areas. These elements are used to construct the investigated lumps in this paper. The different cross-sectional areas and the different lengths of two adjacent elements lead to the appearance of vertical eccentricity between the discrete node and the centroid of investigated lump within the same investigated lump. Firstly, the governing equations are established for a typical investigated lump. Secondly, the calculating formulae of the forces and moments acting on the investigated lump are derived and provided. Finally the new dynamic equilibrium equations with modified mass matrix and assemblage of stiffness matrix have been derived for the stick MDOF model based on beam theory when the existing vertical eccentricities are considered. Numerical results demonstrate that these vertical eccentricities should be considered in order to obtain the accurate earthquake responses for the tall flexible structures.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 2003년도 춘계전력전자학술대회 논문집(1)
• /
• pp.313-316
• /
• 2003

Investigated about topology of each component of transformer and material choice method and property in this paper. Component of transformer is bobin, winding, insulating paper, Varnish etc. And, experiment and investigated special quality by primary winding of transformer and composition of secondary winding. Investigated loss of transformer and EMI decrease method. Investigated method to select winding size that consider frequency.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2003년도 하계학술대회 논문집 C
• /
• pp.1601-1603
• /
• 2003

Investigated about topology of each component of transformer and material choice method and property in this paper. Component of transformer is bobin winding, insulating paper, Varnish etc. And experiment and investigated special quality by primary winding of transformer and composition of secondary winding. Investigated loss of transformer and EMI decrease method. Investigated method to select winding size that consider frequency.

• 대한화학회지
• /
• 제57권1호
• /
• pp.20-24
• /
• 2013

The effect of the DFT methods and basis sets on harmine molecule has been investigated. 26 DFT methods with 6 basis sets were used. Two main comparison chosen DFT methods in this work has been investigated. It is concluded that this contribution is very important and cannot be neglected. In the following analysis, changes in energy levels were investigated by two different methods. Considering a specific basis set, changes in energy levels were obtained using different DFT methods. A specific DFT method is chosen and changes in energy levels have been investigated by means of various basis sets. Effect of the choice of basis sets on geometrical parameters on harmine molecule has also been investigated.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2007년도 제38회 하계학술대회
• /
• pp.1371-1372
• /
• 2007

In this study, in order to confirm the application possibility to the molecular electronic device, morphlogical property of the Arachidic acid was investigated. We have investigated morphology by BAM image and AFM. ${\pi}$-A curves investigated surface pressure of this LB film from liquid to solid state ranged between 40 to 45 mN/m. BAM images investigated the different states of Arachidic Acid LB film. When the surface pressure reaches at 40 mN/m, the monolayer was deposited onto the hydrophilic glass substrates by Y-type deposition. We also investigated the frequency characteristics of LB modified glass by QCM. We investigated morphology of arachidic acid by AFM. As a result, we obtained the frequency characteristic and morphology of LB films from controlling the deposited layers.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2004년도 춘계학술대회 논문집
• /
• pp.826-831
• /
• 2004

In this study. problems caused during production process of stainless steel carbody are investigated and solutions are found out. Roll forming process to make complex shape is introduced and surface crack on high strength stainless steel plate is investigated. Also, surface indentation is discussed and the effect of welding condition is clarified. Insulated tip to reduce the indentation is recommended for improvement of surface smoothness. Lastly. corrosion of welded joint is discussed and the effects of material, stress and environment are investigated.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2001년도 ICCAS
• /
• pp.155.3-155
• /
• 2001

Researches of multi-robot system are active in these days. The most remarkable characteristic of multirobot system is that the robots work cooperatively and achieve the task which a single robot cannot do. It is essential to investigate number effect of multi-robot system. In this paper, we chose foraging task and investigated their behavior. At first, we investigated the foraging behavior in case that interaction range is Infinite. Secondly, we investigated the behavior in case that interaction range is finite. In both case, we find out there is an optimum interaction duration.

• 전기의세계
• /
• 제24권5호
• /
• pp.82-90
• /
• 1975

This study investigated the deterioration phenomena of the Polyethylene surface contaminated with organic(Saccharose) or inorganic(NaCl) matters through electrical and optical experiments. And also these experimental results relatively well coincided with which was treated by theoretical process. On the electrical experiment, relation between electric field intensity in corona discharge and time reached to the breakdown, and relation between total amount of charges discharged and increment of applied voltage were investigated. On the optical experiment, discharge time dependence of surface deterioration rate and process of surface deterioration in the X-ray diffraction pattern were investigated. It was concluded that chemical effects by the corona discharge deteriorated insulation characteristics of Polyethylene surface.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1998년도 하계학술대회 논문집 G
• /
• pp.2539-2540
• /
• 1998

The characteristics of the electroplated nickel were investigated for the MEMS applications. Nickel sulfate bath was used and saccharine was added as the brightener. The effects of the brightener concentration were investigated by comparison of the surface morphology and the hardness of the electroplated nickel. The polarization characteristics were also investigated. The best results were obtained at 1g/$\ell$ saccharin addition.

• 한국표면공학회지
• /
• 제32권3호
• /
• pp.331-335
• /
• 1999

Electroless plating nickel has superior mechanical property to electroplated nickel. Furthermore nickel can be coated on nonconducting substrate. In this research, electroless plating of nickel were conducted in different bath condition to find optimum conditions of electroless nickel plating for MEMS applications. The selectivity of activation method on several substrates was investigated. The effects of nickel concentration, reducing agent concentration and inhibitor on deposition rate were investigated. The effect of pH on deposition rate and content of phosphorous in deposited nickel was also investigated.