• The Transactions of the Korean Institute of Electrical Engineers C
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• v.55 no.1
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• pp.11-15
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• 2006

We propose an optical and an electrical detection methods for detecting various bio-molecules effectively with microcantilevers. The microcantilevers were fabricated employing surface micromachining technique that has attractive advantages in terms of cost efficiency, simplicity and ability of fabricating in array. The fluid cell system for injection of bio-molecular solution is fabricated using polydimethylsiloxane (PDMS) and a fused silica glass. The microcantilever is deflected with respect to the difference of the surface stress caused by the formation of self-assembled bio-molecules on the gold coated side of the microcantilever. It detected cystamine dihydrochloride and glutaraldehyde molecules and analyzed individual concentrations of the cystamine dihydrochloride solution. We confirm that the deflections of bending-up or bending-down are occurred by the bio-molecule adsorption and microcantilever can be widely used to a ${\mu}-TAS$ and a lab-on-a-chip for a potential detection of various bio-molecules.

• Journal of Power Electronics
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• v.9 no.1
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• pp.68-73
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• 2009

Automotive inverters may require current sensors for motor torque control, especially, in applications of hybrid electric vehicles or fuel cell vehicles. In this paper, to achieve a compact, integrated and low cost current sensor, a hall current sensor without magnetic core is introduced for integrating an automotive inverter. The compactness of the current sensor is possible by using integrated magnetic concentrators based on the Hall effect. Magnetic fields caused by three-phase currents are analyzed and a magnetic shield design is proposed for decoupling the cross-coupled field. It offers galvanic isolation, wide bandwidth (>100kHz), and accuracy(< 1%). Using 2D FEM analysis, its performance is demonstrated with design parameters at a U-shaped magnetic shield. The proposed coreless current sensor is tested with rated current to validate the linearity and accuracy.

• Journal of Power Electronics
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• v.16 no.1
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• pp.340-350
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• 2016

A cascaded hybrid multilevel inverter including a reconfiguration technique for low voltage dc distribution applications is proposed in this paper. A PWM generation fault detection and reconfiguration paradigm after an inverter cell fault are developed by using only a single-chip controller. The proposed PWM technique is also modified to reduce switching losses. In addition, the proposed topology can reduce the number of required power switches compared to the conventional cascaded multilevel inverter. The proposed technique is validated by using a 3-kVA prototype. The switching losses of the proposed multilevel inverter are also investigated. The experimental results show that the proposed hybrid inverter can improve system efficiency, reliability and cost effectiveness. The efficiency of proposed system is 97.45% under the tested conditions. The proposed hybrid inverter topology is a promising method for low voltage dc distribution and can be applied for the multiple loads which are required in a data center or telecommunication building.

• Proceedings of the KIEE Conference
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• 1996.11a
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• pp.232-234
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• 1996

The self-refresh mode was introduced as method to reduce power dissipation in DRAM. Because the data retention time of DRAM cell decreases as the ambient temperature rises, the internal period in self-refresh mode must be limited by retention capability at the highest temperature in DRAM specification. Because of this, at room temperature($25^{\circ}C$) unnecessary power dissipation happens, If the period of self-refresh could be modulated as temperature, it is possible to reduce the self-refresh current. In this paper, new temperature detector circuit is suggested as this purpose.

• International journal of advanced smart convergence
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• v.10 no.3
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• pp.81-88
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• 2021

This paper proposes two types of subharmonic RF receiver front-end (called LMV) where, in a single stage, quadrature voltage-controlled oscillator (QVCO) is stacked on top of a low noise amplifier. Since the QVCO itself plays the role of the single-balanced subharmonic mixer with the dc current reuse technique by stacking, the proposed topology can remove the RF mixer component in the RF front-end and thus reduce the chip size and the power consumption. Another advantage of the proposed topologies is that many challenges of the direct conversion receiver can be easily evaded with the subharmonic mixing in the QVCO itself. The intermediate frequency signal can be directly extracted at the center taps of the two inductors of the QVCO. Using a 65 nm complementary metal oxide semiconductor (CMOS) technology, the proposed subharmonic RF front-ends are designed. Oscillating at around 2.4 GHz band, the proposed subharmonic LMVs are compared in terms of phase noise, voltage conversion gain and double sideband noise figure. The subharmonic LMVs consume about 330 ㎼ dc power from a 1-V supply.

• Journal of Environmental Science International
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• v.24 no.5
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• pp.623-631
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• 2015

Microarray technology provides a unique tool for the determination of gene expression at the level of messenger RNA (mRNA). This study, the mRNA expression profiles provide insight into the mechanism of action of cadmium in Fleshy shrimp (Fenneropenaeus chinensis). The ability of genomic technologies was contributed decisively to development of new molecular biomarkers and to the determination of new possible gene targets. Also, it can be approach for monitoring of trace metal using oligo-chip microarray-based in potential model marine user level organisms. 15K oligo-chip for F. chinensis that include mostly unique sets of genes from cDNA sequences was developed. A total of 13,971 spots (1,181 mRNAs up- regulated and 996 down regulated) were identified to be significantly expressed on microarray by hierarchical clustering of genes after exposure to cadmium for different conditions (Cd24-5000 and Cd48-1000). Most of the changes of mRNA expression were observed at the long time and low concentration exposure of Cd48-1000. But, gene ontology analysis (GO annotation) were no significant different between experiments groups. It was observed that mRNA expression of main genes involved in metabolism, cell component, molecular binding and catalytic function. It was suggested that cadmium inhibited metabolism and growth of F. chinensis.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.42 no.11
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• pp.1-8
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• 2005

In this paper, we present design and prototyping of a low-cost, integrated multi-functional micro health sensor chip that can be used or embedded in widely consumer devices, such as cell phone and PDA, for monitoring environmental condition including air pressure, temperature and humidity. This research's scope includes basic individual sensor study, architecture for integrating sensors on a chip, fabrication process compatibility and test/evaluation of prototype sensors. The results show that the integrated TPH sensor has good characteristics of ${\pm}\;1\%FS$ of linearity and hysteresis for pressure sensor and temperature sensor and of ${\pm}\;5\%FS$ of linearity and hysteresis But if we use 3rd order approximation for humidity sensor, full scale error becomes much smaller and this will be one of our future study.

• Journal of Physiology & Pathology in Korean Medicine
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• v.18 no.2
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• pp.468-473
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• 2004

Psoriasis is a chronic inflammatory disease of the skin characterized by epidermal hyperplasia, dermal angiogenesis, infiltration of activated T cells, and increased cytokine levels, and affects 1-3% of the world-wide population. Although many immunological and clinical reports indicate a role for the immune system in the pathogenesis of psoriasis, puzzling questions about psoriasis remain unsolved. During the several decade, immunosuppressor and PUVA treatment are ubiquitously used to psoriasis therapy. But recently, to promote terminal differentiation of keratinocytes, block either NK-Tcell or T-cell activation, and interrupting the angiogenic switch represent another therapeutic opportunity in psoriasis. To keep face with immunological therapy, the needs of newly designed prescription on the psoriasis treatments were demanded. With the object of understand the psoriasis from an orient medical point of view, patients were administrated the GY during several weeks. We investigated the changes of gene expression in involved and uninvolved skin samples during the oriental remedy. Microarray data showed several important results. First, Gene expression profiling is similar to each patient. Second, precursor proteins that organize cornified envelops are decreased at the end of remedy. But genes which related to apoptosis, G-protein signalling, and lipid metabolism are increased. Third, 68.5% of clustering genes localized on the psoriasis susceptibility locus. In our results indicated that GY influence on the keratinocytes hyperproliferation by regulating the gene, which located on the psoriasis susceptibility locus.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.8 no.4
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• pp.53-58
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• 2008

This paper designs sigma-delta D/A Converter with a high resolution and low power consumption. It reorganizes the input data along LJ, RJ, I2S mode and bit mode to the output data of A/D converter. The D/A converter decodes the original analog signal through HBF, Hold and 5th CIFB(Cascaded Integrators with distributed Feedback as well as distributed input coupling) sigma-delta modulation blocks. It uses repeatedly the addition operation in instead of the multiply operation for the chip area and the performance. Also, the half band filters of similar architecture composed the one block and it used the sample-hold block instead of the sinc filter. We supposed simple D/A Converter decreased in area. The filters of the block analyzed using the matlab tool. The top block designed using the top-down method by verilog language. The designed block is fabricated using Samsung 0.35um CMOS standard cell library. The chip area is 1500*1500um.

• JSTS:Journal of Semiconductor Technology and Science
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• v.14 no.3
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• pp.322-330
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• 2014

New effective techniques to repair "small" design errors in integrated circuits are presented. As semiconductor chip complexity increases and the design period becomes tight, errors frequently remain in a fabricated chip making revisions required. Full mask revision significantly increases the cost and time-to-market. However, since many "small" errors can be repaired by modifying several connections among the circuit blocks and spare cells, errors can frequently be repaired by revising metal layers. Metal only revision takes significantly less time and involves less cost when compared to full mask revision, since mask revision costs multi-million dollars while metal revision costs tens of thousand dollars. In our research, new techniques are developed to further reduce the number of metal layers to be revised. Specifically, we partition the circuit blocks with higher error probabilities and extend the terminals of the signals crossing the partition boundaries to the preselected metal repair layers. Our partitioning and pin extension to repair layers can significantly improve the repairability by revising only the metal repair layers. Since pin extension may increase delay slightly, this method can be used for non-timing-critical parts of circuits. Experimental results by using academia and industrial circuits show that the revision of the two metal layers can repair many "small" errors at low-cost and with short revision time. On the average, when 11.64% of the spare cell area and 24.72% of the extended pins are added to the original circuits, 83.74% of the single errors (and 72.22% of the double errors) can be corrected by using two metal revision. We also suggest methods to use our repair techniques with normal commercial vender tools.