• Korean Journal of Materials Research
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• v.28 no.8
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• pp.440-444
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• 2018

An effective cleaning method for Ni removal in Ni-induced lateral crystallization(Ni-MILC) poly-Si TFTs and their electrical properties are investigated. The HCN cleaning method is effective for removal of Ni on the crystallized Si surface, while the nitric acid treatment results decrease by almost two orders of magnitude in the Ni concentration due to effective removal of diffused Ni mainly in the poly-Si grain boundary regions. Using the HCN cleaning method after the nitric acid treatment, re-adsorbed Ni on the Si surfaces is effectively removed by the formation of Ni-cyanide complexions. After the cleaning process, important electrical properties are improved, e.g., the leakage current density from $9.43{\times}10^{-12}$ to $3.43{\times}10^{-12}$ A and the subthreshold swing values from 1.37 to 0.67 mV/dec.

• Korean Journal of Optics and Photonics
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• v.14 no.4
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• pp.423-428
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• 2003

In a direct modulated semiconductor laser diode. the structural dependence of current blocking layers was studied in view of the leakage current reduction and the bandwidth expansion. To analyze the leakage current and the parasitic effects, the current-voltage derivation characteristics and the subtraction method were used, respectively. It was shown that the‘inin’type current blocking structure might be the best choice for the purpose of the static and dynamic characteristics.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.23 no.8
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• pp.957-968
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• 1999

Performance tests of an airfoil fan and measurement of flow fields at the impeller exit are carried out to investigate the effects of the tip clearance between the rotor and inlet casing on the impeller performance. The impeller is twelve bladed of NACA 65-810 airfoils and tested with 3 different size of gap; 1, 2, 4mm. The relative decrease of pressure rising performance of the fan is 15 percent for the design flow rate when the gap size is 1 percent of the impeller diameter. The reduction of performance becomes large as the flow rate increases. The leakage flow through the clearance affects the through flow of the impeller, which results in decrease of the slip factor as well as the impeller efficiency. The data base obtained in the present study can be used for the design and flow analysis of the airfoil fans.

• Journal of Korea Society of Digital Industry and Information Management
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• v.13 no.1
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• pp.37-48
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• 2017

As the risk of technical leakage is increasing, technology protection support systems for small and medium-sized businesses have gained attention. This paper analyzed the perception gap of the user and policy-maker regarding technology protection support systems. First, to identify key elements of technology protection support systems and construct measurement factors, interviews with experts are conducted. Then, surveys are conducted to analyze the perception differences between the users and policy-makers. Factor analysis and ANOVA have been utilized to analyze survey results. The result shows that the perception gaps exist in the following areas: management system, cost reduction, copyright protection, customer satisfaction, leakage prevention, and awareness. To enhance the effectiveness of technology protection support systems, this paper suggests technology protection support systems should be customized in terms of the company's size and type of busines.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07b
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• pp.849-852
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• 2002

Recently, amorphous selenium is used as x-ray conversion material for flat-panel x-ray detector. In this paper, we investigated the effect of breakdown under high voltage and leakage current in PN-type multi-layer structure based on p-type a-Se and n-type conductive thin film. Experimental results show that the multi-layer based detector reduced leakage current because n-type CeO2 conductive layer prevent from hole injection into a-Se layer from collection electrode, Also, the breakdown voltage was improved by dielectric layer between a-Se and top electrode.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.33A no.7
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• pp.171-175
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• 1996

Gate insulator for Si field emitter is usually formed by e-beam evaporation. However, the evaported oxide requires densification for a stable process and a reduction of gate leakage which results from its Si-rich and nonstoicheiometric structure. In this study, we have developed the process technology able to densify the evaporated oxide in H$_{2}$O ambient. Using this process, we have fabricted thefield emitter array with 625 emitters per pixel, of which gate hole diameter is 1.4.mu.m, for the pixel, anode current of 14.3.mu.A was extracted at a gate bias of 100V and gate leakage was about 0.27% of the total emission current.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2009.04a
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• pp.282-287
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• 2009

In this paper, 3-stage centrifugal turbo compressor was measured and analyzed numerical simulation for find noise source and was reduced noise with changing designs. For this purpose, it was measured noise level and was analyzed noise frequency at each stage. In order to Find where is noise source, the study was investigated about structure borne noise by using modal analysis and also was checked sound radiation and leakage of noise at inlet and outlet by result of sound intensity. In order to reduce of noise, sound insulation rings were maded and were adhered at joint and noise reduction effects were verified by measurement and numerical simulation. From the analysis results of leakage of noise, this study presented new joint designs, also it was verified by result of numerical simulation.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11a
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• pp.379.1-379
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• 2002

In this paper the leakage prediction and rotordynamic analysis of an annular seal with a smooth rotor and spiral-grooved stator are performed. For developing a theoretical model, the three-control-volume analysis of the circumferentially-grooved seal is expanded by considering pressure reduction due to the pumping effect of spiral groove and pressure flow through the spiral groove. Validation to the present analysis is achieved by comparisons with available experimental data. (omitted)

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.48 no.2
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• pp.89-96
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• 1999

This paper proposes a common-mode voltage reduction method base on SVPWM(Space-Vector Pulsewidth Modulation) in three phase PWM converter/inverter system. By shifting the active voltage vector of inverter and aligning this to the active vector of converter, it is possible to eliminate a common-mode voltage pulse in one control period. Since the proposed PWM method maintains the active voltage vector, it does not affect the control performance of PWM converter/inverter system. Without any extra hardware, overall common mode voltage dv/dt and conrresponding leakage current can be reduced to two-third of the conventional three phase symmetric SVPWM scheme.

• Proceedings of the KIEE Conference
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• 1998.07e
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• pp.1670-1674
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• 1998

Now and then there are many electrical accidents between cable and line post insulator which is degraded by long time using, causing leakage current on the surface of insulator. In this paper it is denied that the 22.9 KV-y distribution lines are protected by binding cover which is needed from fog or rainy moisture, surges occurring by swiching or lightening pulse. It is analyzed to investgate the unballanced transfer characteristics and reflection coefficient by using bidding cover and non-cover. It was tested the radio interference voltage in the test room. In the factory it was tested the amount of leakage current causing on the surface of insulator in the state of no load and 70(%) load.