• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 한국정밀공학회 2005년도 춘계학술대회 논문집
• /
• pp.1547-1550
• /
• 2005

ISB panel, inner structured of metal in two skin and bonded, has inner structures which have low relative density, stiffness and strength with low weight of make improvement for that purpose. A kind of Inner structures have various structure types. In this paper, we have studied the Forming Limit Diagram(FLD), thickness variation and stress strain to dimple structure of sheet by analysis of Dynaform and LS-Dyna.

• International Journal of Korean Welding Society
• /
• 제5권1호
• /
• pp.44-52
• /
• 2005

The purpose of this study is to establish a design tool for the shrinkage margin of a deckhouse caused by welding and flame straightening. In order to do it, the effects of heat intensity and internal/external restraint condition on the shrinkage of the simple weldments were investigated, in order to identity the principal factors controlling shrinkage caused by welding process and flame straightening. Based on the results, predictive equations for longitudinal and transverse shrinkage at the welded structure were formulated as the function of heat intensity and in-plane rigidity. These equations were verified by comparing predicted results with the measured results at a panel structure of deckhouse.

• Proceedings of the KIEE Conference
• /
• 대한전기학회 1997년도 하계학술대회 논문집 E
• /
• pp.1749-1751
• /
• 1997

AC PDP with surface micro discharge has a structure that all discharge electrodes are arranged on the front glass panel, and the rear glass panel merely serves as a cover glass to form the micro discharge space. The relationships between the dischage voltage and the structure among such as electrode width, distance between electrodes, discharge space gap, and dielectric layer width are investigated.

• The Journal of Industrial Distribution & Business
• /
• 제6권4호
• /
• pp.27-37
• /
• 2015

Purpose - This study first explores the possible dynamic relationship between ownership structure and firm performance using a panel of 4,900 Chinese-listed small- and medium-sized enterprises (SMEs) from 1999 to 2012. Research design, data, and methodology - We address this issue through a dynamic panel model using a method of moments (GMM) technique and dynamic simultaneous equations to alleviate the potential endogenous problem: unobserved heterogeneity, simultaneity, and dynamic endogeneity. Results - Under the framework of dynamic endogeneity, firm performance has a significantly positive influence on ownership, but not vice versa. Ownership and performance can be explained by their owned lagged values, respectively. Moreover, intertemporal endogeneity exists among ownership, investment, and performance through the application of system dynamic equations, which implies that the relationship among ownership structure, investment, and firm performance is dynamic by nature. Conclusions - This study also significantly contributes to a better understanding of dynamic corporate governance by providing further empirical evidence from the largest capital market in the Asian region.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권1호
• /
• pp.399-402
• /
• 2007

We propose a method to achieve both wide viewing angle (WVA) and narrow viewing angle (NVA) characteristics with a single liquid crystal (LC) panel and a single backlight system by using 3-terminal electrode structure. We could control the viewing angle of a single LC cell by using the horizontal or vertical alignment of LC for the dark state at the front.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권1호
• /
• pp.123-126
• /
• 2007

In this study, a high luminous efficacy AC-PDP panel with long discharge gap and grooved dielectric layer has been studied. By applying this high efficacy concept and optimized driving waveform featuring negative biased sustain, ${\sim}2.6lm/W$ of luminous efficacy was achieved in 42- inch HD panel. Modified fabricating process and new discharge cell structure were investigated to obtain improved uniformity and operating characteristics.

• The Transactions of the Korean Institute of Power Electronics
• /
• 제25권2호
• /
• pp.94-102
• /
• 2020

Considering that the output voltage and current of a single PV panel are limited in PV power generation, a PV array should be constructed by connecting several PV panels in series and parallel to meet the required voltage/power levels for power generation capacity. When a PV array is partially shaded, the maximum power generation depends on the configuration of a PV array and the presence or absence of blocking diodes. This study considers six PV array configurations and the presence or absence of blocking diodes. An optimum connection structure was proposed to maximize power generation in a partial shadow condition. Results were verified through simulation and an experiment.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• 제18권8호
• /
• pp.805-815
• /
• 2008

Transfer path analysis(TPA) and panel contribution analysis(PCA) have been used widely to reduce interior noise of mechanical systems. TPA enables us to decompose interior noise into air-borne and structure-borne noises and estimate the path contribution of noise sources. PCA is also used to identify the noise contribution of each sub-panel in vibro-acoustic systems. In this paper, TPA and PCA are applied to wheel loader, one of the heavy construction equipments. Firstly, TPA for air-borne noise is conducted to estimate the contribution of air-borne sources using pressure transfer function. Thereafter, TPA for structure -borne noise is employed to verify the results of air-borne source quantification through the synthesis of two results. Secondly, PCA is performed by both TPA using pressure transfer function between panels inside the cabin and boundry element method(BEM) for the cabin of wheel loader with various boundary conditions. As a results, it was found that TPA conducted by experiments and PCA accomplished by both experiments and BEM are very effective methods in analyzing the path and contribution of the noises for reducing an interior noise level in the wheel loader system.

• Wind and Structures
• /
• 제23권1호
• /
• pp.1-18
• /
• 2016

This work experimentally and numerically analyzes the flow configurations and the dynamic wind loads on panels of rectangular L/h 5:1 cross section mounted on a structural frame of rectangular bars of L/h 0.5:1, corresponding to a radar structure. The fluid dynamic interaction between panels and frame wakes imposes dynamic loads on the panels, with particular frequencies and Strouhal numbers, different from those of isolated elements. The numerical scheme is validated by comparison with mean forces and velocity spectra of a panel wake obtained by wind tunnel tests. The flow configuration is analyzed through images of the numerical simulations. For a large number of panels, as in the radar array, their wakes couple in either phase or counter-phase configurations, changing the resultant forces on each panel. Instantaneous normal and tangential force coefficients are reported; their spectra show two distinct peaks, caused by the interaction of the wakes. Finally, a scaled model of a rectangular structure comprised of panels and frame elements is tested in the boundary layer wind tunnel in order to determine the influence of the velocity variation with height and the three-dimensionality of the bulk flow around the structure. Results show that the unsteady aerodynamic loads, being strongly influenced by the vortex shedding of the supporting elements and by the global 3-D geometry of the array, differ considerably on a panel in this array from loads acting on an isolated panel, not only in magnitude, but also in frequency.

• Journal of Korean Tunnelling and Underground Space Association
• /
• 제12권6호
• /
• pp.451-461
• /
• 2010

Utilization of the fiber reinforced polymer (FRP) material has been enlarged as a substitution material to the general construction materials having certain long-term problems such as corrosion, etc. However, it could be difficult to apply the FRP material, which has a linear shape generally, to an arch-shaped tunnel structure. Therefore, an attempt has been made in this study to develop a device to form a designed cross section of FRP material by pulling out with a curvature. A sample of the circled FRP product was successfully produced and then the sample has been tested to identify its physical characteristics. Then, intensive feasibility studies on the circled FRP panel to be used for a tunnel lining structure have been carried out by numerical analyses. As a result, it appears that the new circled FRP-concrete composite panel has a high capability to be used for a tunnel lining material without any structural problem.