• Journal of the Institute of Electronics Engineers of Korea SD
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• v.41 no.8
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• pp.93-98
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• 2004

A low power SRAM using elevated source level memory cells is proposed to save the write power of SRAM. It reduces the swing voltages of the bit lines and data bus by elevating the source level of the memory cells from GND to $V_{T}$ and lowering the precharge level of the bit lines and data bus from $V_{DD}$ to $V_{DD}$ - $V_{T}$. It saves the write power of SRAM without area overhead and speed degradation. An SRAM with 8K${\times}$32bits is fabricated in a 0.25um CMOS process. It saves 45% of the power in write cycles at 300MHz with 2.5V. The maximum operating frequency is 330MHz.

• The Journal of the Acoustical Society of Korea
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• v.25 no.8
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• pp.383-388
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• 2006

This Paper presents a novel approach to single channel microphone speech enhancement in noisy environments. Widely used noise reduction techniques based on the spectral subtraction are generally expressed as a spectral gam depending on the signal-to-noise ratio (SNR). The well-known decision-directed(DD) estimator of Ephraim and Malah efficiently reduces musical noise under the background noise conditions, but generates the delay of the a prioiri SNR because the DD weights the speech spectrum component of the Previous frame in the speech signal. Therefore, the noise suppression gain which is affected by the delay of the a priori SNR, which is estimated by the DD matches the previous frame rather than the current one, so after noise suppression. this degrades the noise reduction performance during speech transient periods. We propose a computationally simple but effective speech enhancement technique based on the sigmoid type function for the weight Parameter of the DD. The proposed approach solves the delay problem about the main parameter, the a priori SNR of the DD while maintaining the benefits of the DD. Performances of the proposed enhancement algorithm are evaluated by ITU-T p.862 Perceptual Evaluation of Speech duality (PESQ). the Mean Opinion Score (MOS) and the speech spectrogram under various noise environments and yields better results compared with the fixed weight parameter of the DD.

• Journal of the Korean Institute of Telematics and Electronics T
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• v.36T no.3
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• pp.64-71
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• 1999

In this paper, two degree of freedom parallelogram link mechanism is used as DD(Direct-drive) robot mechanism. In parallelogram link mechanism, two motors being established in each base frame, the mass of motor itself is not loaded to anther motor; the number of links are increased, the mass of arm being lighter; with the estabilishment of link parameter, nonlinearity such as the centrifugal force disappears; at the same time anti-interference between motors can be realized. And to realize highy-accurate drive of parallelogram link DD robot manipulator, to improve the learning speed through the design of leaning control system using neural network, to raise adapting power to the varied work objects; the learning control algorithm is composed of neural network and feedback controller in this paper.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.2
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• pp.324-330
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• 2004

To integration the field device as a control system correctly in fielders systems. We have to offer the DD(Device Description) with the function and internal parameter into the configuration software. The DD which is written in the DDL(Device Description Lansuage) is made as IEC 61804-PART 2 and it is used in Profibus, Foundation Field bus, HART. However, the DD is dependent to the fieldbus and it doesn't have a suitable form in the industrial Ethernet. Therefore, in this paper, we described the internal function and parameter of the Field device as XDD(XML for Device Description) by using XML (extensible Markup Language) which isn't dependent to fieldbus and has a suitable form for industrial ethernet. Futhermore, we present the possibility of XDD's application in the distributed control system by examining the possibility of ethernet's development in the industrial area.

• Interaction and multiscale mechanics
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• v.1 no.4
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• pp.437-448
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• 2008

This paper examined the stability of high-dense dislocation substructures (HDDSs) associated with martensite laths in High Cr steels supposed to be used for FBR, based on a series of dislocation dynamics (DD) simulations. The DD simulations considered interactions of dislocations with impurity atoms and precipitates which substantially stabilize the structure. For simulating the dissociation processes, a point defect model is developed and implemented into a discrete DD code. Wall structure composed of high dense dislocations with and without small precipitates were artificially constructed in a simulation cell, and the stability/instability conditions of the walls were systematically investigated in the light of experimentally observed coarsening behavior of the precipitates, i.e., stress dependency of the coarsening rate and the effect of external stress. The effect of stress-dependent coarsening of the precipitates together with application of external stress on the subsequent behavior of initially stabilized dislocation structures was examined.

• Journal of Sensor Science and Technology
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• v.33 no.3
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• pp.152-157
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• 2024

In this study, we propose a novel 8T ternary SRAM that can process three logic values (0, 1, and 2) with only two additional transistors, compared with the conventional 6T binary SRAM. The circuit structure consists of positive and negative ternary inverters (PTI and NTI, respectively) with carbon-nanotube field-effect transistors, replacing conventional cross-coupled inverters. In logic '0' or '2,' the proposed SRAM cell operates the same way as conventional binary SRAM. For logic '1,' it works differently as storage nodes on each side retain voltages of V_DD/2 and V_DD, respectively, using the subthreshold current of two additional transistors. By applying the ternary system, the data capacity increases exponentially as the number of cells increases compared with the 6T binary SRAM, and the proposed design has an 18.87% data density improvement. In addition, the Synopsys HSPICE simulation validates the reduction in static power consumption by 71.4% in the array system. In addition, the static noise margins are above 222 mV, ensuring the stability of the cell operation when V_DD is set to 0.9 V.

• Journal of Institute of Control, Robotics and Systems
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• v.11 no.8
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• pp.733-739
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• 2005

Device Description that is described as C-based DDL(Device Description Language) should be provided for the control system to use the progressive function of field device in the distributed control system. DD expresses field device function itself and parameter. DD is used to set a necessary function far a control strategy in the central control system. DD technology which was adopted as international standard IEC 61804-Part 2 is being used in PROFIBUS, Foundation Fieldbus and HART. However, the DD is dependent to the fieldbus and it doesn't have a suitable form in the industrial Ethernet. This paper presents the possibility of a change from EDD(Electronic Device Description) and GSD(General Slave Data) used for integrating field devices to XDD(XML for Device Description) and verifies it's effectiveness. Also, this paper presents research assignment on the XML application in the distributional system from now on by examining the possibility of Ethernet`s development in the industrial area.

• Archives of Pharmacal Research
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• v.28 no.2
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• pp.232-237
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• 2005

Mast cells play an important role in allergic inflammation by releasing their bioactive mediators. The function of mast cells is enhanced by stimulation because of the induction of specific genes and their products. While many inducible genes have been elucidated, we speculated that a significant number of genes remain to be identified. Thus, we applied differential display (dd) PCR to establish a profile of the induced genes in bone marrow-derived mast cells (BMMCs) after they were co-cultured with 3T3 fibroblasts. To date, 150 cDNA fragments from the connective-type mast cells (CTMCs) were amplified. Among them, thirty cDNA fragments were reamplified for cloning and sequencing. The ddPCR strategy revealed that serine proteases were the most abundant genes among the sequenced clones induced during the maturation. Additionally, unknown genes from the co-culture of BMMCs with 3T3 fibroblasts were identified. We confirmed their induction in the CTMCs by Northern blot analysis and RT-PCR. Characterization of these induced genes during the maturation processes will provide insight into the functions of mast cells.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.17 no.12
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• pp.3310-3329
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• 2023

This work designs an eighteen-channel bidirectional Intensity Modulation with Direct Detection (IM/DD) Wavelength Division Multiplexing-Passive Optical Network (WDM-PON) system. The proposed system meets the requirement of the ITU-T 5G fronthaul link suggested design in G-series Recommendations-Supplement 66. The newly designed system, with a 25Gb/s/λ data rate (450Gbps as a system capacity), has been tested and simulated using OptiSystem V.19 software. The system has been evaluated by the BER with respect to variable the optical span and CW laser power. Based on the ITU-T recommendations, the simulation results demonstrate that this system might be used as an F1 and as an Fx 5G fronthaul link for functional split choices starting from options 1 to 7a. These options are required under 25Gbps/λ for each upstream and downstream link direction. Furthermore, the proposed system utilized a bidirectional single-mode optical fiber within short optical spans of up to 10 km. The proposed system is characterized by a low-cost, simple, DSP-free and amplifier-free system with a reasonable system capacity.

• Journal of Oral Medicine and Pain
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• v.41 no.2
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• pp.41-47
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• 2016

Purpose: The purpose of this study was to analyze the size and morphology of mandibular condyle and mandibular fossa between temporomandibular joint (TMJ) disc displacement (DD) patients and healthy subjects using cone-beam computed tomography (CBCT). Methods: Twenty healthy subjects and twenty TMJ DD patients participated in this study respectively. We made five measurements in mandibular condyle (medio-lateral dimension, antero-posterior dimension, condyle height, intercondylar distance and intercondylar angle) and two measurements in mandibular fossa (mandibular fossa depth and articular eminence angle) using CBCT image. Results: There was no difference between two groups in medio-lateral dimension. In case of antero-posterior dimension, average of healthy controls was larger than that of TMJ DD patients, but that was not significant statistically. There were no significant differences between two groups in condyle height. Comparing intercondylar distance and intercondylar angle between two groups, there was no significant difference between two groups. In comparison of mandibular fossa depth and articular eminence angle, there was no significant difference between two groups. Conclusions: We couldn't find any definite relationship between TMJ morphology and TMJ DD.