• Proceedings of the Korean Vacuum Society Conference
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• 2007.08a
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• pp.340-340
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• 2007

• Proceedings of the Korean Fiber Society Conference
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• 1995.10a
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• pp.78-79
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• 1995

• Polymer(Korea)
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• v.33 no.5
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• pp.501-508
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• 2009

The thermal degradation experiment of sodium salt of poly (${\gamma}$-glutamic acid) (PGGNa) has been carried out in both its solid phase and solution phase at the range of $57{\sim}120^{\circ}C$ and their molecular weight decreasing effect was analyzed as a function of time by means of viscometry and light scattering. Based on the solid phase degradation results, it was supposed that the bond scission rate in a polymer chain kept constant and that the bond scission was occurred on a randomly located position in a polymer chain. For the degradation in solution phase, it was also found that all data at various temperatures were dropped on a single master curve when the reduced time $t/t^*$ was used in the plot of the reciprocal intrinsic viscosity (or molecular weight). This degradation curve in solution phase could be expressed as the sum of a single exponential and a linear equation and especially, the single exponential character appeared only at the beginning stage. The activation energy was measured as $107{\sim}115$ kJ/mol in this study and agreed with the literature values.

• Proceedings of the KIEE Conference
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• 2006.10d
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• pp.59-61
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• 2006

The single phase switched reluctance motor(SRM) is simpler in control circuit because the number of switching devices is fewer than the poly phase SRM. The energy density per unit volume is very big because all stator poles are excited simultaneously by a single switching power source. But it must be provided a starting device on account of not being generated the starting torque at specific rotor positions. And also it has some demerits that have a torque ripple, noise and vibration because of being excited by switching pulse power source. Therefore, to make up for these demerits, it is realized many studies for the structure design used by computer and the operating methods by power electronics technique. In this paper, we'll present the comparison of the single phase SRM with the various rotor pole face types, as like stepped rotor pole face type and general rotor pole face type. For the torque characteristics analysis.

• JSTS:Journal of Semiconductor Technology and Science
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• v.14 no.2
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• pp.246-251
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• 2014

In this paper, a high-speed CMOS Image Sensor (CIS) based on a 10-bit two step Single Slope A/D Converter (SS-ADC) is proposed. The A/D converter is composed of both 5-bit coarse ADC and a 6-bit fine ADC, and the conversion speed is 10 times faster than that of the single-slope A/D convertor. In order to reduce the pixel noise, further, a Hybrid Correlated Double Sampling (H-CDS) is also discussed. The proposed A/D converter has been fabricated with 0.13um 1-poly 4-metal CIS process, and it has a QVGA ($320{\times}240$) resolution. The fabricated chip size is $5mm{\times}3mm$, and the power consumption is about 35 mW at 3.3 V supply voltage. The measured conversion speed is 10 us, and the frame rate is 220 frames/s.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.19 no.7
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• pp.601-604
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• 2006

In this paper, we propose the single poly-Si Flash EEPROM device with a new structure which does not need the high voltage switching circuits. The device was designed, fabricated and characterized. From the measurement results, it was found that the program, the erase and the read operations worked properly. The threshold voltage was 3.1 V after the program in which the control gate and the drain were biased with 12 V and 7 V for $100{\mu}S$, respectively. And it was 0.4 V after the erase in which the control gate was grounded and the drain were biased with 11 V for $200{\mu}S$. On the other hand, it was found that the program and the erase speeds were significantly dependent on the capacitive coupling ratio between the control gate and the floating gate. The larger the capacitive coupling ratio, the higher the speeds, but the target the area per cell. The optimum structure of the cell should be chosen with the consideration of the trade-offs.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.334-334
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• 2006

Helical polymers like polyisocyanates with single screw sense are essential to exhibit sophisticated functions like molecular recognition, self-replication, chirality memory and catalytic activity. One approach that has not been explored is the effect on handedness of the polyisocyanates through end-capping with a chiral residue. Induction of chirality in poly(n-hexyl isocyanate) was studied by end-capping with chiral (R and S) 2-bromo-3-methylbutyryl chloride(R-BMBC and S-BMBC). We have shown that a control over living anionic polymerization of HIC by using a suitable initiator affords an opportunity to introduce chiral end-groups with 100% yield and in high purity. This has resulted in helicity induction through extended lengths several orders of magnitude.

• Korean Journal of Materials Research
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• v.16 no.9
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• pp.571-577
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• 2006

We fabricated thermal evaporated 10 nm-Ni/(poly)Si and 10 nm-Ni/1 nm-Ir/(poly)Si films to investigate the thermal stability of nickel monosilicide at the elevated temperatures by rapid annealing them at the temperatures of $300{\sim}1200^{\circ}C$ for 40 seconds. Silicides for salicide process was formed on top of both the single crystal silicon actives and the polycrystalline silicon gates. A four-point tester is used for sheet resistance. Scanning electron microscope and field ion beam were employed for thickness and microstructure evolution characterization. An x-ray diffractometer and an auger depth profile scope were used for phase and composition analysis, respectively. Nickel silicides with iridium on single crystal silicon actives and polycrystalline silicon gates showed low resistance up to $1200^{\circ}C$ and $800^{\circ}C$, respectively, while the conventional nickel monosilicide showed low resistance below $700^{\circ}C$. The grain boundary diffusion and agglomeration of silicides led to lower the NiSi stable temperature with polycrystalline silicon substrates. Our result implies that our newly proposed Ir added NiSi process may widen the thermal process window for nano CMOS process.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.05b
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• pp.331-334
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• 2000

The organic electroluminescent(EL) device has gathered much interest because of its large potential in materials and simple device fabrication. We fabricated EL devices which have a blended single emitting layer containg poly(Nvinylcarbazole)[PVK] and poly(3-dodecylthiophene)[P3DoDT]. The molar ratio between P3DoDT and PVK changed with 1:0, 2:1 and 1:1. To improve the external quantum efficiency of EL devices, we applied insulating layer, LiF layer between polymer emitting layer and AI electrode. All of the devices emit orange-red light and it's can be explained that the energy transfer occurs from PVK to P3DoDT. Within the molar ratio 1:0, 2:1 and 1:1, the energy transfer was not saturated, which results in the not appearance of PVK emission in the blue region. In the voltage-current and voltage-light power characteristics of devices applied LiF layer, current and light power drastically increased with increasing with applied voltage. In the consequence of the result, the light power of the device have a molar ratio 1:1 with LiF layer was about 10 times larger than that of the device without PVK at 6V.

• Journal of the Korean Institute of Telematics and Electronics C
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• v.35C no.12
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• pp.77-84
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• 1998

A voltage controlled chaotic circuit has been designed in integrated circuit and fabricated by using 0.8$\mu\textrm{m}$ single poly CMOS technology. The fabricated chaotic circuit consist of sample and hold circuits, op-amps, nonlinear function generator and two phase clock generator. The test results of the chaotic circuit show that periodic state, quasi-periodic state and chaotic state can be obtained according to the input control voltage with the ${\pm}$2.5V power supply and clock rate of 20kHz. In addition, two dimensional chaotic patterns have been observed by connecting this circuit in parallel or series