• Journal of Power Electronics
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• v.5 no.1
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• pp.67-75
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• 2005

A high efficiency ZVS PWM asymmetrical half bridge converter for a plasma display panel (PDP) sustaining power modules is proposed in this paper. To achieve the ZVS of power switches for the wide load range, a small additional inductor L/sub 1kg/, which also acts as an output filter inductor, is serially inserted into the transformer's primary side. At that point, to solve the problem of ringing in the secondary rectifier caused by L/sub 1kg/, the proposed circuit employs a structure without the output filter inductor, which helps the voltages across rectifier diodes to be clamped at the output voltage. Therefore, no dissipative RC (resistor capacitor) snubber for rectifier diodes is needed and a high efficiency as well as low noise output voltage can be realized. In addition, since it has no large output inductor filter, the asymmetrical half bridge converter features a simpler structure, lower cost, less mass, and lighter weight. In addition, since all energy stored in L/sub 1kg/ is transferred to the output side, the circulating energy problem can be effectively solved. The operational principle, theoretical analysis, and design considerations are presented. To confirm the operation, validity, and features of the proposed circuit, experimental results from a 425W, 385Vdc/170Vdc prototype are presented.

• Applied Chemistry for Engineering
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• v.26 no.4
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• pp.389-393
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• 2015

Recovery of indium from secondary sources have been attracting over years not only because of increasing demand together with development of flat panel display industry but also industrial criticality of indium. Applied technology to recover indium for recycling of end-of-life FPD devices can be broadly divided into three major steps, disassembly or dismantling, enrichment or upgrading, and refining or purification. In addition, advanced technology such as zone-refining can be employed for ultra-high purity products. In this mini-review, we present currently applied technologies for recovery of indium and the outlook for total recycling of FDP devices.

• 한국정보디스플레이학회:학술대회논문집
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• 2004.08a
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• pp.525-528
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• 2004

The ion-induced secondary electron emission coefficient ${\gamma}$ and work function for MgO thin film with $O_2$ plasma treatment has been investigated by ${\gamma}$ -FIB (focused ion beam) system. The MgO thin film deposited from sintered material with $O_2$ plasma treatment is found to have higher ${\gamma}$ and lower work function than those without $O_2$ plasma treatment. The energy of various ions used has been ranged from 100eV to 200eV throughout this experiment. It is found that the highest secondary electron emission coefficient ${\gamma}$ has been achieved for 10 minutes of $O_2$ plasma treatment under RF power of 50W.

• 한국정보디스플레이학회:학술대회논문집
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• 2004.08a
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• pp.507-510
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• 2004

Oblique ion-induced secondary electron emission coefficient(${\gamma}$) with low energy ..and work function ${\phi}_{\omega}$(${\theta}$ = 0 and ${\theta}$ = 20) of the MgO thin film in AC-PDPs has been measured by ${\gamma}$-FIB system. The MgO thin film has been deposited from sintered material under electron beam evaporation method. The energy of $He^+$ ions used has been ranged from 50eV to 150eV. Oblique ion beam has been chosen to be 10 degree, 20 degree and 30 degree. It is found that the higher secondary electron emission coefficient(${\gamma}$) has been achieved by the higher oblique ion beam up to inclination angle of 30 degree than the perpendicular incident ion beam.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08b
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• pp.1384-1387
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• 2007

We have investigated the sputtering and secondary electron emission characteristics of MgO protective layer according to the $O_2$ partial pressure. The MgO layer have been deposited by electron beam evaporation method and have varied the $O_2$ partial pressure as 0, $5.2{\times}10^{-5}$, $1.0{\times}10^{-4}$, and $4.1{\times}10^{-4}$ Torr. It has been known that the secondary electron emission coefficient and the number of defect energy levels increased as the $O_2$ partial pressure increases. So we have investigated the property of sputtering yield according to the $O_2$ partial pressure. We have known that the sputtering yield deceases as the $O_2$ partial pressure increases by using the FIB system.

• Proceedings of the KIPE Conference
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• 2006.06a
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• pp.71-74
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• 2006

A new multi-output LLC resonant converter is proposed for high efficiency and low cost plasma display panel (PDP) power module. In the proposed converter, zero-voltage (ZV) turn-on of the primary MOSFETs and zero-voltage (ZC) turn-on and turn-off of the secondary diodes are guaranteed in the overall input voltage and output load ranges. In addition, the primary MOSFETs and the secondary diodes have the low voltage stresses clamped to input and the output voltages, respectively. Therefore, the proposed converter shows the high efficiency due to the minimized switching and conduction losses. Moreover, by employing the transformer with multiple secondary windings, the proposed converter can have multiple outputs, which show the great crossregulation characteristics. Therefore, the proposed converter is suitable for high efficiency and low cost PDP power module.

• Journal of the Korean Vacuum Society
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• v.11 no.2
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• pp.108-112
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• 2002

We investigated the secondary electron emission characteristics of MgO layer used as the protecting material in a.c. plasma display panel(a.c.-PDPs) using a pulsed ion beam technique, where the surface charging can be effectively suppressed during the measurement. The measurement of the secondary electron emission coefficients ($\gamma$) on the surface of $SiO_2$ was carried out and then, it was found that the yields were dependent on incident ion energies. In addition, it was clearly demonstrated that the sputtering on MgO surface leads to lower yields, which suggests that the surface plays a key role on the operating conditions, such as life time, fast response, and etc.

• Proceedings of the KIPE Conference
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• 2005.07a
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• pp.439-441
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• 2005

A new LLC resonant converter with multiple outputs is proposed for high efficiency and low cost plasma display panel (PDP) power module. In the proposed converter, ZVS turn-on of the primary MOSFETs and ZCS nun-off of the secondary diodes are guaranteed in the overall input voltage and output load range. Moreover, the primary MOSFETs and the secondary diodes have low voltage stresses clamped to input and the output voltage, respectively. Therefore, the proposed converter shows the high efficiency due to the minimized switching and conduction losses. In addition, by employing the transformer, which has the two and more secondary side, the proposed converter can have multiple outputs and they show the great cross-regulation characteristics. As a result, the proposed converter can be implemented with low cost and compact size. The 500W prototype is implemented, which integrates the sustaining and addressing power supplies of PDP power module. The maximum efficiency is 96.8% and the respective output voltages are well regulated. Therefore, the proposed converter is suitable for high efficiency and low cost PDP power module.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.29 no.5
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• pp.26-33
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• 2015

Secondary optical system designed for LED bulb which emits light in all directions was simulated with Energy Star standards. Components of the optical system were LED light source, the cover of the LED bulb and reflector which is to confirm the diffuser plate and LightTools software was used to design the illumination optics. The main points of the secondary optical system design are the location of the LED light source, the shape of the LED bulb cover, the location of the reflection plate, and the scattering properties of the diffusing plate. Mechanism of the LED bulb is that the light emitted from the light source move on to the backward after reflected by the coated light cover from the inside and then the reflected light is scattered by the diffuser plate. The LED bulb was designed to satisfy the standard light distribution and color specifications of the Energy Star(IES LM-79-08).

• Journal of Pharmacopuncture
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• v.25 no.3
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• pp.199-208
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• 2022

Objectives: In recent decades, the trend for treating diabetes mellitus (DM) has shifted toward alternative medicines that are obtained from plant sources. Existing literature suggests that phenolic compounds derived from plants possess promising health-promoting properties. This study aimed to discuss the role of plant-derived phenolic compounds in the effective treatment and management of diabetes. Methods: Information about plant secondary metabolites, phenolic compounds, and their role in the treatment and management of diabetes was collected from different databases, such as Pubmed, ScienceDirect, Scopus, and Google Scholar. Keywords like secondary metabolites, phenolic compounds, simple phenol, flavonoids, lignans, stilbenes, and diabetes were searched. Research and review articles with relevant information were included in the study. Results: Anti-diabetic studies of the four major classes of phenolic compounds were included in this review. The plant-derived phenolic compounds were reported to have potent anti-diabetic activities. However, each class of phenolic compounds was found to behave differently according to various mechanisms. Conclusion: The obtained results suggest that phenolic compounds derived from natural sources display promising anti-diabetic activities. Based on the available information, it can be concluded that phenolic compounds obtained from various natural sources play key roles in the treatment and management of diabetes.