Showing papers in "Journal of The Korean Institute of Electrical and Electronic Material Engineers in 2012"
TL;DR: In this article, a road energy harvester was designed and fabricated to convert mechanical energy from the vehicle load to electrical energy, which is composed of 24 piezoelectric cantilevers and a vehicle load transfer mechanism.
Abstract: A road energy harvester was designed and fabricated to convert mechanical energy from the vehicle load to electrical energy. The road energy harvester is composed of 24 piezoelectric cantilevers and a vehicle load transfer mechanism. Applying a vehicle load transfer mechanism rather than directly installing energy harvesters under roads decreases the area of road construction and allows more energy harvesters to be installed on the side of the road. The power generation amount with respect to the vehicular velocity change was assessed by installing the vehicle load transfer mechanism and the energy harvester in the form of speed bumps and underground. The energy harvester installed in a speed bump form generated power of 7.61 mW at the vehicular velocity of 20 km/h. Also, power generation of the energy harvester installed in the underground form was 63.9 mW at the vehicular velocity of 28 km/h. Although the number of piezoelectric cantilevers was reduced by 1/3 to 24 in comparison to the previous research results with 72 piezoelectric cantilevers, similar power generation characteristic value was obtained within the vehicular velocity of 20 km/h by altering the vehicle load transfer mechanism and cantilever vibration method.
9 citations
TL;DR: In this article, D. K. Park, Y. Y. Choi, H. Hwang, S. B. Kim, and D. H. Jeon, Thin Solid Films, 519, 8109 (2011).
Abstract: [1] H. Q. Chiang, J. F. Wager, R. L. Hoffman, J. Jeong, and D. A. Keszler, Appl. Phys. Lett., 86, 013503 (2005).[2] S. H. Bang, S. J. Lee, J. H. Park, S. Y. Park, Y. B. Ko, C. H. Choi, H. J. Chang, H. H. Park, and H. T. Jeon, Thin Solid Films, 519, 8109 (2011).[3] D. C. Paine, B. Yaglioglu, Z. Beiley, and S. H. Lee, Thin Solid Films, 516, 5894 (2008).[4] Y. J. Cho, J. H. Shin, S. M. Bobade, Y. B. Kim, and D. K. Choi, Thin Solid Films, 517, 4115 (2009).[5] Z. Yuan, X. Zhu, X. Wang, X. Cai, B. Zhang, D. Qiu, and H. Wu, Thin Solis Films, 519, 3254 (2011).[6] A. Dey, D. R. Allee, and L. T. Clark, Solid State Electron, 62, 19 (2011).[7] K. Nomura, H. Ohta, K. Ueda, T. Kamiya, M. Hirano, and H. Hosono, Science, 300, 1269 (2003).[8] J. S. Park, K. S. Kim, Y. G. Park, Y. G. Mo, H. D. Kim, and J. K. Jeong, Adv. Mater., 21, 329 (2009).[9] A. Suresh and J. F. Mutha, Appl. Phys. Lett., 92, 033502 (2008).[10] D. H. Cho, S. H. Yang, C. W. Byun, M. K. Ryu, S. H. Ko Park, C. S. Hwang, S. M. Yoon, and H. Y. Chu, IEEE Electron Device Lett., 31, 48 (2009).[11] K. C. Park and T. Y. Ma, J. KIEEME, 24, 641 (2011).[12] D. K. Schroder, Semiconductor Material and Device Characterization (A Wiley-Interscience publication, 1990) p. 231.[13] D. K. Schroder, Semiconductor Material and Device Characterization (A Wiley-Interscience publication, 1990) p. 285.
4 citations
TL;DR: In this paper, the authors conducted a study on how the heat radiation of light emitting diode (LED) luminaires affects the indoor temperature increase and found that the effect was compared with that of a 20 W compact fluorescent lamp (CFL) and a 50 W MR16 halogen lamp which are most widely used inside of cruises, a LED downlight and a 4W MR16 LED replacing each of them.
Abstract: This paper conducted a study on how the heat radiation of light emitting diode(LED) luminaires affects the indoor temperature increase. The effect was compared with that of a 20 W compact fluorescent lamp(CFL) and a 50 W MR16 halogen lamp which are most widely used inside of cruises, a LED downlight and a 4W MR16 LED replacing each of them. We installed a luminarie inside a thermally shielded chamber, measuring the temperature changes under the same volume every 5 minutes and compared the result with theoretically calculated heat radiation. The temperature changes in the chamber was measured four times, on seven hours` period in order to keep sufficient time once the temperature reaches the thermal equilibrium state. The results showed that the temperature of the 20 W E26 CFL and the 10 W LED downlight increased by and respectively, while that of the 50 W halogen MR16 and the 4 W LED MR16 increased by and respectively. The experimental heat radiation were calculated from the results and the experimental heat radiation of the CFL and the LED downlight were 171.5 cal and 86.5 cal, and those of the halogen MR16 and the LED MR16 were 275.3 cal and 36.5 cal. Therefore, the heat radiation was reduced by 49.5% and 86.7%, respectively, by replacing conventional light source with LED. In conclusion, we can expect a reduction of power consumption in air condition system and the effect on indoor temperature increase by application of LED luminaires.
4 citations
TL;DR: In this paper, the movement and response time of charged particles according to particle-inserting methods were analyzed to understand the variation of quantity of q/m of the charged particles, which is a very important factor in electrical and optical characteristics of a charged particle type display.
Abstract: We analyzed the movement and response time of charged particles according to particle-inserting methods to understand the variation of quantity of q/m of charged particles, which is a very important factor in electrical and optical characteristics of the charged particle type display, such as lifetime, response time, contrast ratio, reflectivity, etc. For our study we used white and black charged particles of which diameter is , prepared pieces of ITO(indium tin oxide) coated glass substrate, and formed ribs on the glass substrates. The width of a rib is and the cell size is . As the particle-inserting methods, the white and black charged particles were respectively inserted into a front and a rear panel with a very small electric field and also the mixture of the white and black charged particles were inserted into a rear panel. As a result of the driving characteristics of charged particles, the factors about variation of quantity of q/m according to the particle inserting method was experimentally demonstrate, showing very different driving voltage, response time, the particle movement, etc.
3 citations
TL;DR: In this paper, the efficiency of DSSCs made with photoelectrode of 18 thickness and the gap difference between the substrate 28 shows a highest 4.805% efficiency.
Abstract: DSSCs efficiency by thickness of photoelectrode and thickness differences between two substrates studied. DSSCs is made of the doctor blade method and photoelectrode annealing temperature elevated in a different ways. In addition, cells efficiencies of according to the different thickness between photoelectrode substrate and Pt counter electrode was measured. Efficiency of DSSCs made with photoelectrode of 18 thickness and the gap difference between the substrate 28 shows a highest 4.805% efficiency.
3 citations
TL;DR: In this paper, the trench gate IGBT is optimized for highvoltage low power design, and the performance of 1,200 V NPT Planer IGBT and 1, 200V NPT Trench IGBT for class has been studied.
Abstract: Development of new efficient, high voltage switching devices with wide safe operating area and low on-state losses has received considerable attention in recent years. One of those structures with a very effective geometrical design is the trench gate Insulated Gate Bipolar Transistor(IGBT).power IGBT devices are optimized for high-voltage low-power design, decided to aim. Class 1,200 V NPT Planer IGBT, 1,200 V NPT Trench IGBT for class has been studied.
3 citations
TL;DR: In this paper, a lead-free 0.98NKN-0.02LST+1.0mol% ceramics sintered at, piezoelectric constant of sample showed the optimum values of 207 pC/N.
Abstract: Lead-free (hereafter 0.98NKN-0.02LST) ceramics doped with were prepared using a conventional mixed oxide method. The specimen showed superior structural and electrical properties when 1 mol% was doped. For the 0.98NKN-0.02LST+1.0mol% ceramics sintered at , piezoelectric constant () of sample showed the optimum values of 207 pC/N. The 0.98NKN-0.02LST+1.0 mol% ceramics are a promising candidate for lead-free piezoelectric materials.
3 citations
TL;DR: In this article, a Finite Element Analysis (FEA) was used to optimize the structure of ultrasonic instrument in vibration system, which revealed that influence of several tips on property were minimized and it showed good property at the frequency range of 22~32 kHz.
Abstract: A piezoelectric ultrasonic bone surgical instrument, usually used to remove the tartar out of teeth or to cut the dentine of the tooth, is a recently popular instrument for dental treatment due to its several merits such as small size, low-electric power and precision control of surgical operation. It has typically two parts of a tip and vibration system which is also composed of head, piezoelectric elements and tail-mass. In order to improve the performance of the instrument, it is important to standardize the size of the vibration system without tip for high performance. In this study, a Finite Element Analysis (FEA) was utilized to optimize the structure of ultrasonic instrument in vibration system. Consequently, this study revealed that influence of several tips on property were minimized and it showed good property at the frequency range of 22~32 kHz.
3 citations
TL;DR: In this article, considering the variables that affect the breakdown voltage and optimization of parameters, a 600 V Super Junction MOSFET Field ring was used to improve the breakdown characteristic using edge termination technology.
Abstract: Power semiconductor devices are widely used as high voltage applications to inverters and motor drivers, etc. The blocking voltage is one of the most important parameters for power semiconductor devices. Generally most of field effect concentrations shows on the edge of power devices. Can be improve the breakdown characteristic using edge termination technology. In this paper, considering the variables that affect the breakdown voltage and optimization of parameters result for 600 V Super Junction MOSFET Field ring.
3 citations
TL;DR: In this paper, four elastic springs (A, B, C, and D) were selected as cantilever's supporter, each elastic spring has a different spring constant (S) and it is considered that the lower spring constant lead to a lower resonance frequency of the SPCS.
Abstract: Spring supported piezoelectric cantilever structures (SPCS) were fabricated for vibration-based energy harvester application. We selected four elastic springs (A, B, C, and D type) as cantilever`s supporter, each elastic spring has a different spring constant (S). The C type of SPCS (: 4,649 N/m) showed a extremely low resonance frequency of 81 Hz along with the highest power output of 38.5 mW while the A type of SPCS (: 40,629 N/m) didn`t show a resonance frequency while. Therefore, it is considered that the lower spring constant lead to a lower resonance frequency of the SPCS. In addition, a tip mass (18 g) at one end of the SPCS could further reduce the resonance frequency without heavy degradation of power output.
2 citations
TL;DR: In this article, the warpage of planar planer SOFC was evaluated with and without electrodes in a planar-type SOFC module and double electrode printed on the electrolyte.
Abstract: A layered planer SOFC module was designed from planar-type SOFC. It was prepared by multi-layered ceramic technology. To form the cathode and the anode in the layered structure, reliable channels should be made on the both side of electrolyte perpendicularly. However, monolithic SOFC using multi-layered ceramic technology hasn't been studied another group, and the warpage of electrolyte in the channel, also, hasn't been studied, when electrode is printed on the electrolyte. In this study, the channels are prepared with electrode printing, and their warpage are evaluated. In the case of YSZ without electrode, the warpages are nothing in the limit of measurement using optical microscope. The warpage of 'YSZ-NiO printed' increases than that of 'NiO printed', and also, the case of 'double electrode printed' is similar to 'YSZ-NiO printed'. It is thought that, in the printed electrolyte, the warpage is related to the difference of the sintering behavior of each material.
TL;DR: In this paper, a TCAD assessment of 30-V class n-channel EDMOS transistors with DWFG (dual work function gate) structure is described, where the gate is composed of both p-and n-type doped region on source and drain side.
Abstract: In this paper, TCAD assessment of 30-V class n-channel EDMOS (extended drain metal-oxide-semiconductor) transistors with DWFG (dual work function gate) structure are described. Gate of the DWFG EDMOS transistor is composed of both p- and n-type doped region on source and drain side. Additionally, lengths of p- and n-type doped gate region are varied while keeping physical channel length. Two-dimensional device structures are generated trough TSUPREM-4 and their electrical characteristics are investigated with MEDICI. The DWFG EDMOS transistor shows improved electrical characteristics than conventional device - i.e. higher transconductance (), better drain output current (), reduced specific on-resistances () and higher breakdown characteristics ().
TL;DR: In this paper, the optimal design of the optical compensation film for the TN-LCDs has been studied and the authors have confirmed that the optical characteristics of the TLDs with the biaxial films have been improved considerably compared with the TLD compensated by the combination of the uniaxIAL films.
Abstract: In this paper, we have studied on the optimal design of the optical compensation film for the TN-LCDs. To have wide viewing angle panels, several methods such as multi-domain method, optical path method, and phase compensation method have been proposed. Among these methods, this paper focused on the phase compensation method. In the phase compensation method, the phase retardation generated from the optical birefringence for the off-axis incident is compensated by using optical films with refractive anisotropy. To compensate the phase retardation of the TN-LCDs, we have proposed design concept for the biaxial optical films and analyzed the optical performance for the proposed structures. The calculation of the dynamic motion of the liquid crystals was based on the Ericksen-Leslie theory and the optical performance of the TN-LCD was calculated from the Extended Jones Matrix Method. From the results, we have confirmed that the optical characteristics of the TN-LCDs with the biaxial films have been improved considerably compared with the TN-LCDs compensated by the combination of the uniaxial films.
TL;DR: In this paper, transparent conducting Al-doped Zinc Oxide (AZO) films with a thickness of 150 nm were prepared on corning glass substrate by the RF magnetron sputtering with using a AZO (: 2 wt%) target at room temperature.
Abstract: In this study, transparent conducting Al-doped Zinc Oxide (AZO) films with a thickness of 150 nm were prepared on corning glass substrate by the RF magnetron sputtering with using a Al-doped zinc oxide (AZO), (: 2 wt%) target at room temperature. This study investigated the effect of rapid thermal annealing temperature and oxygen ambient on structural, electrical and optical properties of Al-doped zinc oxide (AZO) thin films. The films were annealed at temperatures ranging from 400 to by using Rapid thermal equipment in oxygen ambient. The effect of RTA treatment on the structural properties were studied by x-ray diffraction and atomic force microscopy. It is observed that the Al-doped zinc oxide (AZO) thin film annealed at at 5 minute oxygen ambient gas reveals the strongest XRD emission intensity and narrowest full width at half maximum among the temperature studied. The enhanced UV emission from the film annealed at at 5 minute oxygen ambient gas is attributed to the improved crystalline quality of Al-doped zinc oxide (AZO) thin film due to the effective relaxation of residual compressive stress and achieving maximum grain size.
TL;DR: In this paper, the effect of design parameter variation on electrical properties of TDMOS, were analyzed by computer simulation, and the optimization was performed to get 65% higher breakdown voltage and 17.4% on resistance enhancement.
Abstract: Protected Circuit Module protects battery from over-charge and over-discharge, also prevents accidental explosion. Therefore, power MOSFET is essential to operate as a switch within the module. To reduce power loss of MOSFET, the on state voltage drop should be lowered and the switching time should be shorted. However there is trade-off between the breakdown voltage and the on state voltage drop. The TDMOS can reduce the on state voltage drop. In this paper, effect of design parameter variation on electrical properties of TDMOS, were analyzed by computer simulation. According to the analyzed results, the optimization was performed to get 65% higher breakdown voltage and 17.4% on resistance enhancement.
TL;DR: A technique to extract the features of object without regard to change of the object scale is proposed to support real-time operation and adopts SURF(Speeded up Robust Features) which enables fast feature detection.
Abstract: In a real-time indoor place recognition system using image features detection, specific markers included in input image should be detected exactly and quickly. However because the same markers in image are shown up differently depending to movement, direction and angle of camera, it is required a method to solve such problems. This paper proposes a technique to extract the features of object without regard to change of the object scale. To support real-time operation, it adopts SURF(Speeded up Robust Features) which enables fast feature detection. Another feature of this system is the user mark designation which makes possible for user to designate marks from input image for location detection in advance. Unlike to use hardware marks, the feature above has an advantage that the designated marks can be used without any manipulation to recognize location in input image.
TL;DR: In this article, a bolt-clamped ultrasonic viscometer was designed and fabricated using a pair of ring-shaped piezoelectric ceramic resonators for its compactness and low operation frequencies.
Abstract: A bolt-clamped ultrasonic viscometer was designed and fabricated using a pair of ring-shaped piezoelectric ceramic resonators. For its compactness and low operation frequencies, simulation of piezoelectric resonators was carried out using an ATILA program. Ring-shaped resonators using ceramics were prepared by a conventional ceramic processing, which were then clamped with a pair of metal caps. The fabricated sensor module with a small volume of less than 1 and an operation frequency as low as 26.5 kHz showed a good relationship between its quality factor and the viscosity of oil.
TL;DR: In this paper, the authors fabricated piezoelectric unimorph cantilever generators (UCG) using + 0.2wt% + 1.0 wt% (PZCN) thin films, which were tailored with same width and thickness but different lengths from 7.7 to 57.7 mm.
Abstract: We fabricated piezoelectric unimorph cantilever generators (UCG) using + 0.2 wt% + 1.0 wt% (PZCN) piezoelectric thick films, which were produced by a tape casting method. The PZCN thick films were tailored with same width and thickness but different lengths from 7.7 to 57.7 mm in order to evaluate optimized UCG for energy harvesting device applications. When the length of PZCN film was increased, the resonance frequency of UCG was slightly increased from 7 Hz to 8 Hz, which could be due to enlarged area of the highly stiff piezo-ceramic film. However, the output power was proportionally increased with the length of PZCT film and it reached 4.68 mW (1.221 ) when the film`s length was 57.7 mm under 25 g of tip mass at 8 Hz, which is sufficient for micro-scale device applications.
TL;DR: Wang et al. as discussed by the authors proposed automatic drawing conformity inspection system based on computer vision technologies such as image feature matching and bilinear interpolation, which is a lot faster when comparing with manual system.
Abstract: To evaluate whether or not their product is in conformity with its drawing, today`s factories manufacturing rubber and/or plastic products use manual process. In manual conformity inspection process, a person decides conformity as comparing drawing to image of product with his eyes. The manual process is tedious and time-consuming in addition that it is impossible to automatically record various informations related to inspection. To solve such problems, this paper proposes automatic drawing conformity inspection system based on computer vision technologies such as image feature matching and bilinear interpolation. The test results show that proposed system is a lot faster when comparing with manual system.
TL;DR: In this article, it was considered that the carbon coatings could be depended on the positions of the particles during the plasma state formed by an explosion, and the HR-TEM images of the nanopowders produced in methanol showed that the some particles have been coated with carbon like materials.
Abstract: Zn wires have been electrically exploded in methanol or distilled water using the pulsed power technologies. The nanopowders produced by the explosions have been observed by using SEM and TEM, and analyzed its phase by using EDS and XRD. The nanopowders produced in distilled water showed ZnO phase only. On the other hands, the nanopowder produced in methanol showed mixed phases with Zn and ZnO. The HR-TEM images of the nanopowders produced in methanol showed that the some particles have been coated with carbon like materials. It is considered that the carbon coatings could be depended on the positions of the particles during the plasma state formed by explosion.
TL;DR: In this article, the dielectric constant (100) of the SBNO thin film was obtained by RTA above, and the voltage dependence of voltage loss showed a value within 0.03 in voltage ranges of -5~+5 V.
Abstract: The (SBNO) thin films were deposited on Si substrate by RF magnetron sputtering method at of substrate temperature. And the SBNO thin films were annealed at using RTA (rapid thermal annealing). The grain of SBNO thin films were increased with the increase of annealing temperature. The dielectric constant (100) of SBNO thin film was obtained by RTA above . The voltage dependence of dielectric loss showed a value within 0.03 in voltage ranges of -5~+5 V. Also, the dielectric constant characteristics showed a stable value with the increase of frequency.
TL;DR: In this article, a new water energy harvester module, which is composed of piezoelectric bimorph cantilevers, harvesting circuit and a shaft with 16 impellers at the center axis, was fabricated for energy harvesting application.
Abstract: A new water energy harvester module, which is composed of piezoelectric bimorph cantilevers, harvesting circuit and a shaft with 16 impellers at a center axis, was fabricated for energy harvesting application. High energy density Pb(Zr0.54Ti0.46)O3 + 0.2 wt% Cr2O3 + 1.0 wt% Nb2O5 (PZT-CN) thick film obtained by tape casting method was used for the bimorph cantilever. The PZT-CN bimorph cantilever with a proof mass of 49 g exhibited extremely high output power of 22.5 mW (24 mW//cm 3 ) at resonance frequency of 11 Hz. In addition, the fabricated water energy harvester has a cylindrical structure with 48 bimorph cantilevers clamped at inner surface. A significantly high output power of 433 mW was obtained at a rotation speed of 120 rpm with a resistive load of 500 Ω for the water energy harvester.
TL;DR: In this paper, a road energy harvester was designed and fabricated to convert mechanical energy from the vehicle load to electrical energy, which is composed of 16 piezoelectric cantilevers.
Abstract: A road energy harvester was designed and fabricated to convert mechanical energy from the vehicle load to electrical energy. The road energy harvester is composed of 16 piezoelectric cantilevers. We fabricated prototypes using a vehicle load transfer mechanism. Applying a vehicle load transfer mechanism rather than directly installing energy harvesters under roads decreases the area of road construction and allows more energy harvesters to be installed on the side of the road. The power generation amount with respect to the vehicular velocity change was assessed by installing the vehicle load transfer mechanism form and underground form. The energy harvester installed in the underground form generated power of 4.52 mJ at the vehicular velocity of 50 km/h. Also, power generation of the energy harvester installed in the vehicle load transfer mechanism form was 48.65 mJ at the vehicular velocity of 50 km/h.
TL;DR: In this article, ZnO nanowires were synthesized by hydrothermal technique and they were preserved by preheating in autoclave type synthesis equipment with various pre-heating time of 1 h difference.
Abstract: ZnO nanowires were synthesized by hydrothermal technique. Prepared synthesis aqueous solutions were preserved by preheating in autoclave type synthesis equipment with various preheating time of 1 h difference. ITO-coated corning glass substrates deposited with AZO seed layers were then inserted in the preheated synthesis aqueous solutions and ZnO nanowires were grown for 180 min at . Density, length and aspect ratio of the grown ZnO nanowires were investigated. Composition, structural and optical properties of the grown ZnO nanowires were analyzed. Characteristics of the ZnO nanowires were comparatively studied in relation with ion concentration measured directly after the preheating of synthesis aqueous solution.
TL;DR: In this article, diagnostic tests were performed on two water-cooled turbine generators, which have been in service for 13 and 17 years, respectively, to evaluate cooling water leakage and absorption, and the test results of measured electrical properties such as dissipation factor(), capacitance and AC leakage current for watercooled generator stator windings with wet bars are reported.
Abstract: Insulation breakdown of water-cooled generator stator windings occurs frequently due to leakage of cooling water and absorption into the insulation material Leakage and absorption problems of water-cooled stator windings are often found during regular preventive maintenance To evaluate cooling water leakage and absorption, diagnostic tests were performed on two water-cooled turbine generators, which have been in service for 13 and 17 years, respectively The test results of the measured electrical properties such as dissipation factor(), capacitance and AC leakage current for water-cooled generator stator windings with wet bars are reported in this paper
TL;DR: In this article, the effect of Ta-substitution on dielectric and piezoelectric properties of non-stoichiometric ceramics was investigated.
Abstract: In this study non-stoichiometric ceramics were prepared by the conventional soild-state teaction method. The effect of Ta-substitution on the dielectric and piezoelectric properties were investigated. X-ray diffraction analysis of all the specimens less than x
TL;DR: In this article, the authors synthesized the crystalline by sol-gel method controlled by the quantity ratio of Nitric acid and Ammonium hydroxide additives, and the best efficiency was obtained by 0.05 M ammonium hyroxide and that results of Voc, Jsc, FF, and efficiency were 0.68 V, 3.28 mA, 58.14 and 5.21%, respectively.
Abstract: The sol-gel method has been widely used to synthesize the for dye sensitized solar cells and has advantages of easily fabrication process, controlling the phase and getting transparent thin-film composed of the . In this paper, we synthesized the crystalline by sol-gel method controlled by the quantity ratio of Nitric acid and Ammonium hydroxide additives. The best efficiency result was obtained by 0.05 M Ammonium hydroxide and that results of Voc, Jsc, FF, and efficiency were 0.68 V, 3.28 mA/, 58.14 and 5.21%, respectively.
TL;DR: In this paper, a multi-string power balancing system for streetlight was developed, the components of the system were developed, unit converters, MPPT control unit, a bank of Li-ion battery and controls the charging and discharging.
Abstract: In this paper, multi-string power balancing system for streetlight was developed. Accordingly, the components of the system was developed, unit converters, MPPT control unit, a bank of Li-ion battery and controls the charging and discharging. Loss by improving the efficiency of the system through the parallel operation of the unit converter output will be reduced. And by improving the efficiency of the system through the unit converter parallel operation, output losses will be reduced. Charging and discharging efficiency of the device used in a typical solar streetlight is calculated based on the maximum power input. Because of the variation of the input power has a weakness. In this paper, flexible to changes in the input, and a system was developed to minimize the cost per watt. Measure the performance of the unit module from the system, the result was more than 91%. And the charging capacity 12 V/105 Ah, module power 180 W, respectively. Should expect to be able to improve performance through continuous monitoring in the future.
TL;DR: In this paper, the authors used attaching film and metal sheet for heat dissipation of high brightness organic light emitting diode (OLED), red emitting OLED of ITO (150 ㎚) / 2-TNATA (50 㐵) / NPB (30 ǫ) / Alq3 : 1 vol.
Abstract: To study the encapsulation method for heat dissipation of high brightness organic light emitting diode (OLED), red emitting OLED of ITO (150 ㎚) / 2-TNATA (50 ㎚) / NPB (30 ㎚) / Alq3 : 1 vol.% Rubrene (30 ㎚) / Alq3 (30 ㎚) / LiF (0.7 ㎚) / Al (200 ㎚) structure was fabricated, which on Alq3 (150 ㎚) / LiF (150 ㎚) as buffer layer and Al as protective layer was deposited to protect the damage of OLED, and subsequently it was encapsulated using attaching film and metal sheet. The current density, luminance and power efficiency was improved according to thickness of Al protective layer. The emission spectrum and the Commission International de L'Eclairage (CIE) coordinate did not have any effects on encapsulation process using attaching film and metal sheet The lifetime of encapsulated OLED using attaching film and metal sheet was 307 hours in 1,200 ㎚ Al thickness, which was increased according to thickness of Al protective layer, and was improved 7% compared with 287 hours, lifetime of encapsulated OLED using attaching film and flat glass. As a result, it showed the improved current density, luminance, power efficiency and the long lifetime, because the encapsulation method using attaching film and metal sheet could radiate the heat on OLED effectively.
TL;DR: In this article, thickness vibration mode piezoelectric devices for AE sensor application were simulated using ATILA FEM program, and then fabricated Trajectory resonant displacement and electro mechanical coupling factors of the P2P devices were investigated.
Abstract: Department of Electrical Engineering, Chungju National University, Chungju 380-702, Korea(Received January 11, 2012; Revised January 17, 2012; Accepted January 20, 2012)Abstract: In this study, thickness vibration mode piezoelectric devices for AE sensor application were simulated using ATILA FEM program, and then fabricated Trajectory resonant displacement and electro mechanical coupling factors of the piezoelectric devices were investigated The simulation results showed that excellent displacement and electro mechanical coupling factor was obtained when the ratio of diameter/thickness(Ф/T) was 075 The piezoelectric device of Ф/T= 075 exhibited the optimum values of fr= 183 kHz, displacement= 444 × 10