• Journal of the Institute of Electronics Engineers of Korea SD
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• v.49 no.7
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• pp.23-29
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• 2012

The LC-based digitally controlled oscillator (LC-DCO), a key component of the all digital phase locked loop (ADPLL), is designed using $0.18{\mu}m$ RFCMOS process with 1.8 V supply. The NMOS core with double cross-coupled pair is chosen to realize wide tuning range, and the PMOS varactor pair that has small capacitance of a few aF and the capacitive degeneration technique to shrink the capacitive element are adopted to obtain the high frequency resolution. Also, the noise filtering technique is used to improve phase noise performance. Measurement results show the center frequency of 2.7 GHz, the tuning range of 2.5 GHz and the high frequency resolution of 2.9 kHz ~7.1 kHz. Also the fine tuning range and the current consumption of the core could be controlled by using the array of PMOS transistors using current biasing. The current consumption is between 17 mA and 26 mA at 1.8V supply voltage. The proposed DCO could be used widely in various communication system.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.2
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• pp.651-658
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• 2021

Because bolts with anti-loosening coatings are used mainly for joining safety-related components in automobiles, accurate automatic screening of these coatings is essential to detect defects efficiently. The performance of the convolutional neural network (CNN) used in a previous study [Identification of bolt coating defects using CNN and Grad-CAM] increased with increasing number of data for the analysis of image patterns and characteristics. On the other hand, obtaining the necessary amount of data for coated bolts is difficult, making training time-consuming. In this paper, resorting to the same VGG16 model as in a previous study, transfer learning was applied to decrease the training time and achieve the same or better accuracy with fewer data. The classifier was trained, considering the number of training data for this study and its similarity with ImageNet data. In conjunction with the fully connected layer, the highest accuracy was achieved (95%). To enhance the performance further, the last convolution layer and the classifier were fine-tuned, which resulted in a 2% increase in accuracy (97%). This shows that the learning time can be reduced by transfer learning and fine-tuning while maintaining a high screening accuracy.

• International Journal of Internet, Broadcasting and Communication
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• v.9 no.4
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• pp.1-7
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• 2017

Clipart is artificial visual contents that are created using various tools such as Illustrator to highlight some information. Here, the style of the clipart plays a critical role in determining how it looks. However, previous studies on clipart are focused only on the object recognition [16], segmentation, and retrieval of clipart images using hand-craft image features. Recently, some clipart classification researches based on the style similarity using CNN have been proposed, however, they have used different CNN-models and experimented with different benchmark dataset so that it is very hard to compare their performances. This paper presents an experimental analysis of the clipart classification based on the style similarity with two well-known CNN-models (Inception Resnet V2 [13] and VGG-16 [14] and transfers learning with the same benchmark dataset (Microsoft Style Dataset 3.6K). From this experiment, we find out that the accuracy of Inception Resnet V2 is better than VGG for clipart style classification because of its deep nature and convolution map with various sizes in parallel. We also find out that the end-to-end training can improve the accuracy more than 20% in both CNN models.

• BMB Reports
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• v.50 no.4
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• pp.162-163
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• 2017

RNA polymerase II-interacting the Set2 methyltransferase co-transcriptionally methylates histone H3 at lysine 36 within the body of genes. This modification facilitates histone deacetylation by Rpd3S HDAC in 3' transcribed regions to suppress cryptic initiation and slow elongation. Although this pathway is important for global deacetylation, no strong effects have been seen on genome-wide transcription under optimized laboratory conditions. In contrast, this pathway slows the kinetics of mRNA induction when target genes are induced upon environmental changes. Interestingly, a majority of Set2-repressed genes are overlapped by a lncRNA transcription that targets H3K36 methylation and deacetylation by Rpd3S HDAC to mRNA promoters. Furthermore, this pathway delays the induction of many cryptic transcripts upon environmental changes. Therefore, the Set2-Rpd3S HDAC pathway functions to fine-tune expression dynamics of mRNAs and ncRNAs.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.49 no.8
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• pp.423-431
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• 2000

This paper presents a systematic approach to the input-output data-based fuzzy modeling for the complex and uncertain nonlinear systems, in which the conventional mathematical models may fail to give the satisfying results. To do this, we propose a new method that can yield a successful fuzzy model using a mGA hybrid schemes with a fine-tuning method. We also propose a new coding method fo chromosome for applying the mGA to the structure and parameter identifications of fuzzy model simultaneously. During mGA search, multi-purpose fitness function with a penalty process is proposed and adapted to guarantee the accurate and valid fuzzy modes. This coding scheme can effectively represent the zero-order Takagi-Sugeno fuzzy model. The proposed mGA hybrid schemes can coarsely optimize the structure and the parameters of the fuzzy inference system, and then fine tune the identified fuzzy model by using the gradient descent method. In order to demonstrate the superiority and efficiency of the proposed scheme, we finally show its applications to two nonlinear systems.

• Journal of KIBIM
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• v.14 no.2
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• pp.13-24
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• 2024

This research suggests a novel visualization approach utilizing Generative AI to render photorealistic architectural alternatives images in the early design phase. Photorealistic rendering intuitively describes alternatives and facilitates clear communication between stakeholders. Nevertheless, the conventional rendering process, utilizing 3D modelling and rendering engines, demands sophisticate model and processing time. In this context, the paper suggests a rendering approach employing the text-to-image method aimed at generating a broader range of intuitive and relevant reference images. Additionally, it employs an Text-to-Image method focused on producing a diverse array of alternatives reflecting architects' styles when visualizing the exteriors of residential buildings from the mass model images. To achieve this, fine-tuning for architects' styles was conducted using the Low-Rank Adaptation (LoRA) method. This approach, supported by fine-tuned models, allows not only single style-applied alternatives, but also the fusion of two or more styles to generate new alternatives. Using the proposed approach, we generated more than 15,000 meaningful images, with each image taking only about 5 seconds to produce. This demonstrates that the Generative AI-based visualization approach significantly reduces the labour and time required in conventional visualization processes, holding significant potential for transforming abstract ideas into tangible images, even in the early stages of design.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.46 no.8
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• pp.117-124
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• 2009

This paper describes a 3 to 5 GHz frequency synthesizer for MB-OFDM (Multi-Band OFDM) UWB (Ultra- Wideband) application using 0.13 ${\mu}m$ CMOS process. The frequency synthesizer operates in the band group 1 whose center frequencies are 3432 MHz 3960 MHz, and 4488 MHz. To cover the overall frequencies of group 1, an efficient frequency planning minimizing a number of blocks and the power consumption are proposed. And, a high-frequency VCO and LO Mixer architecture are also presented in this paper. A new mixed coarse tuning scheme that utilizes the MIM capacitance, the varactor arrays, and the DAC is proposed to expand the VCO tuning range. The frequency synthesizer can also provide the clock for the ADC in baseband modem. So, the PLL for the ADC in the baseband modem can be removed with this frequency synthesizer. The single PLL and two SSB-mixers consume 60 mW from a 1.2 sV supply. The VCO tuning range is 1.2 GHz. The simulated phase noise of the VCO is -112 dBc/Hz at 1 MHz offset. The die area is 2 ${\times}$ 2mm$^2$.

• Journal of IKEEE
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• v.15 no.1
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• pp.29-36
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• 2011

Dithering scheme has been widely used to improve the resolution of DCO(Digitally Controlled Oscillator) in conventional ADPLLs(All Digital Phase Locked Loop). In this paper a new resolution improvement scheme is proposed where a simple DAC is employed to overcome the problems of dithering scheme. A 2.4GHz LC-based DCO has been designed in a $0.13{\mu}m$ CMOS process with an enhanced frequency resolution for wireless local area network applications. It has a frequency tuning range of 900MHz and a resolution of 58.8Hz. The frequencies are controled by varactors in coarse, fine, and DAC bank. The DAC bank consists of an inversion mode NMOS varactor. The other varactor banks consist of PMOS varactors. Each varactor bank is controlled by 8bit digital signal. The designed DCO exhibits a phase noise of -123.8dBc/Hz at 1MHz frequency offset. The DCO core consumes 4.2mA from 1.2V supply.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.7
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• pp.1543-1551
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• 2011

Dithering scheme has been widely used to improve the resolution of DCO(Digitally Controlled Oscillator) in conventional ADPLLs(All Digital Phase Locked Loop). In this paper a new resolution improvement scheme is proposed where a simple DAC(Digital-to-Analog Converter) is employed to overcome the problems of dithering scheme. The frequencies are controled by varactors in coarse, fine, and DAC bank. The DAC bank consists of an inversion mode NMOS varactor. The other varactor banks consist of PMOS varactors. Each varactor bank is controlled by 8bit digital signal. The proposed DCO has been designed in a $0.13{\mu}m$ CMOS process. Measurement results shows that the designed DCO oscillates in 2.8GHz~3.5GHz and has a frequency tuning range of 660MHz and a resolution of 73Hz at 2.8GHz band. The designed DCO exhibits a phase noise of -119dBc/Hz at lMHz frequency offset. The DCO core consumes 4.2mA from l.2V supply. The chip area is $1.3mm{\times}1.3mm$ including pads.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10a
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• pp.189-192
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• 1996

This paper presents a systematic approach to identify a linguistic fuzzy model for a multi-input and single-output complex system. Such a model is composed of fuzzy rules, and its output is inferred by the simplified reasoning. The structure and membership function parameters for a fuzzy model are automatically and simultaneously identified by GA (Genetic Algorithm). After GA search, optimal parameters for the fuzzy model are finely tuned by a gradient method. A numerical example is provided to evaluate the feasibility of the proposed approach. Comparison shows that the suggested approach can produce the linguistic fuzzy model with higher accuracy and a smaller number of rules than the ones achieved previously in other methods.