• The Transactions of the Korean Institute of Electrical Engineers
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• v.45 no.2
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• pp.319-324
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• 1996

Using random pulse stream, a number can be transformed to the pulse stream with the probability value. So the digital value are computed by simple digital gates. Thus it will be possible to build a small and strong noise immunity processing element. We propose a faster convergence algorithm using a new methods for better performance of Random Number Generator(RNG) an the nonlinear transfer function(Sigmoid function)in this paper. And a feedback circuit were fitted for pulse stream in this paper. We proposed method is simulated with C program language and conformed by circuit implementation. Finally a system for hand written number recognition is constructed by FPGA and its performance verified.

• Journal of information and communication convergence engineering
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• v.16 no.2
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• pp.106-113
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• 2018

Although deep learning methods of convolutional neural networks (CNNs) and long-/short-term memory (LSTM) are widely used for text categorization, they still have certain shortcomings. CNNs require that the text retain some order, that the pooling lengths be identical, and that collateral analysis is impossible; In case of LSTM, it requires the unidirectional operation and the inputs/outputs are very complex. Against these problems, we thus improved these traditional deep learning methods in the following ways: We created collateral CNNs accepting disorder and variable-length pooling, and we removed the input/output gates when creating bidirectional LSTMs. We have used four benchmark datasets for topic and sentiment classification using the new methods that we propose. The best results were obtained by combining LTSM regional embeddings with data convolution. Our method is better than all previous methods (including deep learning methods) in terms of topic and sentiment classification.

• Progress in Superconductivity and Cryogenics
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• v.8 no.2
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• pp.17-19
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• 2006

A novel clock distribution technique for pipelined-RSFQ logics using variable Bias Currents of JTLs as delay-medium is newly proposed. RSFQ logics consist of several logic gates or blocks connected in a pipeline structure. And each block has variable delay difference. In the structure, this clock distribution method generates a set of clock signals for each logic blocks with suitable corresponding delays. These delays, in the order of few to tens of pS, can be adjusted through controlling bias current of JTL of delay medium. While delays with resistor value and JJ size are fixed at fabrication stage, delay through bias current can be controlled externally, and thus, is heavily investigated for its range as well as correct operation within current margin. Possible ways of a standard delay library with modular structure are sought for further modularizing Pipelined-RSFQ applications. Simulations and verifications are done through WRSpice with Hypres 3-um process parameters.

• Journal of the Korean Society of Safety
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• v.35 no.1
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• pp.97-106
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• 2020

The objective of this paper is to suggest a new quantification method for multi-unit probabilistic safety assessment (PSA) that removes the overestimation error caused by the existing delete-term approximation (DTA) based quantification method. So far, for the actual plant PSA model quantification, a fault tree with negates have been solved by the DTA method. It is well known that the DTA method induces overestimated core damage frequency (CDF) of nuclear power plant (NPP). If a PSA fault tree has negates and non-rare events, the overestimation in CDF drastically increases. Since multi-unit seismic PSA model has plant level negates and many non-rare events in the fault tree, it should be very carefully quantified in order to avoid CDF overestimation. Multi-unit PSA fault tree has normal gates and negates that represent each NPP status. The NPP status means core damage or non-core damage state of individual NPPs. The non-core damage state of a NPP is modeled in the fault tree by using a negate (a NOT gate). Authors reviewed and compared (1) quantification methods that generate exact or approximate Boolean solutions from a fault tree, (2) DTA method generating approximate Boolean solution by solving negates in a fault tree, and (3) probability calculation methods from the Boolean solutions generated by exact quantification methods or DTA method. Based on the review and comparison, a new intersection removal by probability (IRBP) method is suggested in this study for the multi-unit PSA. If the IRBP method is adopted, multi-unit PSA fault tree can be quantified without the overestimation error that is caused by the direct application of DTA method. That is, the extremely overestimated CDF can be avoided and accurate CDF can be calculated by using the IRBP method. The accuracy of the IRBP method was validated by simple multi-unit PSA models. The necessity of the IRBP method was demonstrated by the actual plant multi-unit seismic PSA models.

• The Korean Journal of Nuclear Medicine Technology
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• v.23 no.2
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• pp.25-28
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• 2019

Purpose In patients with unusual kidney position after $^{99m}Tc-DTPA$ renal dynamic imaging study, the GFR(Glomerular Filtration Rate) values are significantly different according to the depth of the kidney. Thus, we tried to compare the difference of the GFR values between the depth measurement methods and in-vitro test. 30 adult patients who were subjected to renal study. 27 patients were in usual position and 3 patients were in unusual. $555{\pm}37MBq$ of $^{99m}Tc-DTPA$ was administrated to all patients. GE infinia gamma camera was used. GFR values were obtained in-vivo(gates method) and in-vitro(blood). The kidney depth in-vivo was calculated by three methods(tonnensen, manual, taylor). In-vitro, GFR was performed by blood test. Differences in the mean values of GFR and correlation between depth and GFR values were evaluated using the SPSS 12.0 statistical program. The GFR values for 27 patients with kidney in the usual position are as follows(1.tonnensen 2.manual 3.taylor 4.invitro); $69.3{\pm}4.2$, $88.2{\pm}5.6$, $77.8{\pm}4.3$, $82.2{\pm}5.8ml/min$. The three unusual cases are as follows, first(congenital renal anomaly): 66.4, 101.24, 69.07, 94.8 ml/min. second(transplantation kidney): 12.22, 29.99, 19.36, 23.5 ml/min. third(horseshoe kidney): 37.37, 93.54, 35.9, 92.5 ml/min. There was a difference between tonnensen and manual in the usual position of the kidney(p<0.05). There was no significant difference between the other methods. However, there was a significant difference in case of the unusual position of the kidneys. Correlation analysis between both kidney depth and GFR value shows person correlation as follows; Rt kidney: 0.298, Lt kidney: 0.322. When compared with the GFR values in-vitro test, it was useful to calculate the GFR value by measuring the kidney depth using a manual formula in the unusual position of the kidneys. GFR values and kidney depth were significantly related.

• Journal of the Korean Institute of Telematics and Electronics C
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• v.36C no.6
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• pp.37-43
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• 1999

Two-way addressing method has been proposed for efficient VLSI implementation of Euclidean calculation circuit for pipelined Reed-Solomon decoder. This new circuit is operating with single clock while exploiting maximum parallelism, and uses register addressing instead of register shifting to minimize the switching power. Logic synthesis shows the circuit with the new scheme takes 3,000 logic gates, which is about 40% reduction from the previous 5,000 gate implementation. Computer simulation also shows the power consumption is about 3mW. The previous implementation with multiple clock consumed about 5mW.

• Proceedings of the Materials Research Society of Korea Conference
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• 2012.05a
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• pp.66.1-66.1
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• 2012

Although all printed cost-less radio frequency identification (RFID) tags have been considered as a core tool for bringing up a ubiquitous society, the difficulties in integrating thin film transistors (TFTs), diodes and capacitors on plastic foils using a single in-line printing method nullify their roles for the realization of the ubiquitous society1,2. To prove the concept of all printed cost-less RFID tag, the practical degree of the integration of those devices on the plastic foils should be successfully printed to demonstrate multi bit RFID tag. The tag contains key device units such as 13.56 MHz modulating TFT, digital logic gates and 13.56 MHz rectifier to generate and transfer multi bit digital codes via a wireless communication (13.56 MHz). However, those key devices have never been integrated on the plastic foils using printing method yet because the electrical fluctuation of fully printed TFTs and diodes on plastic foils could not be controlled to show the function of desired devices. In this work, fully gravure printing process in printing 13.56 MHz operated 32 bit RFID tags on plastic foils has been demonstrated for the first time to prove all printed RFID tags on plastic foils can wirelessly generate and transfer 32 bit digital codes using the radio frequency of 13.56 MHz. This result proved that the electrical fluctuations of printed TFTs and diodes on plastic foils should be controlled in the range of maximum 20% to properly operate 32 bit RFID tags.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.33A no.3
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• pp.107-116
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• 1996

Recently, the flash memory has been abstracting great attention in the semiconductor market in the world because of its potential applications as mass storage devices. One of the most significant barriers to the scalling-down of the stacked-gate devices such as EPROM's and flash EEPROM's is the large subthreshold leakage in the unselected cells connected with the bit line of a selected cell in the array during programming. The large subthreshold leakge is majorly due to the capacitive coupling between the floating gates of the unselectd cells and the bit line of selected cell. In this paper, a new programming method to redcue significantly the drain turn-on leakage in the unselected cells during programming has been studied, where a little positive voltage (0.25-0.75V) is applied to the soruce during programming unlike the conventional programming method in which the source is grounded. The resutls of the PISCES simulations and the electrical measurements for the standard EPROM with 0.35.mu.m effective channel length and 1.0.mu.m effective channel width show that the subthreshold leakage in the unselectd cells is significantly large when the source is grounded, whereas it is negligibly small when the source is biased ot a little positive voltage during programming. On the other hadn, the positive bias on the source is found to have little effects on the programming speed of the EPROM.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.7 no.2
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• pp.47-54
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• 1982

In this paper, a improved per-channel PCM Coder with 1-bit interpolation is proposed. The coder converts a telephone signal to 15-segments u-law PCM signal of a large dynamic range. The A/D conversion technique of the proposed converter requires a feedback loop around a quantizer operates at high speed, and a accumulater for accumulating the quantized values to provide PCM outputs. To obtain both linear and compressed PCM signals a improved table look-up method is presented. The operations of the proposed converter are certified through the experiments to be good. The experimental circuit comprises TTL logic gates, a resistive D/Z converter and a simple differential amplifier. From the results of the experiments, it is known that the proposed converter has many advantage to be adopted economically for per-channel onverter used in rural area service.

• Corrosion Science and Technology
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• v.7 no.6
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• pp.328-331
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• 2008

Corrosion behaviour of water intake gate steel structures with different protective measures was investigated. Five material alternatives were taken for investigation, including: imported and recycled stainless steel, carbon steel with hot zinc spraying, painting and composite coatings. Results of corrosion rate for carbon steel, SUS 304, hot zinc spray coats in three water systems of Mekong river basin (saline, blackish and fresh) were also presented. Corrosion rate of carbon steel decreased with decreasing salinity in the investigated water environments. Meanwhile, these values for zinc coated steel, behaved by another way. Environmental data for these systems were filed and discussed in relation with corrosion characteristics. Method of Life Cycle Assessment (LCA) was applied in materials selection for water intake gate construction. From point of Life Cycle Cost (LCA) the following ranking was obtained: Zinc sprayed steel < Recycled stainless steel < Composite coated steel < Painting steel < SUS 304 From investigated results, hot zinc spray coating has been applied as protective measure for steel structures of water intake systems in Mekong river basin.