• Corrosion Science and Technology
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• v.6 no.6
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• pp.282-285
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• 2007

Smaller size and higher integration of electronic systems make narrower interconnect pitch not only in chip-level but also in package-level. Moreover electronic systems are required to operate in harsher conditions, that is, higher current / voltage, elevated temperature / humidity, and complex chemical contaminants. Under these severe circumstances, electronic components respond to applied voltages by electrochemically ionization of metals and conducting filament forms between anode and cathode across a nonmetallic medium. This phenomenon is called as the electrochemical migration. Many kinds of metal (Cu, Ag, SnPb, Sn etc) using in electronic packages are failed by ECM. Eutectic SnPb which is used in various electronic packaging structures, that is, printed circuit boards, plastic-encapsulated packages, organic display panels, and tape chip carriers, chip-on-films etc. And the material for soldering (eutectic SnPb) using in electronic package easily makes insulation failure by ECM. In real PCB system, not only metals but also many chemical species are included. And these chemical species act as resources of contamination. Model test systems were developed to characterize the migration phenomena without contamination effect. The serpentine-shape pattern was developed for analyzing relationship of applied voltage bias and failure lifetime by the temperature / humidity biased(THB) test.

• IEMEK Journal of Embedded Systems and Applications
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• v.11 no.2
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• pp.97-105
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• 2016

Microcontrollers (MCUs) for endpoint smart sensor devices of internet-of-thing (IoT) are being implemented as system-on-chip (SoC) with on-chip instruction flash memory, in which user firmware is embedded. MCUs directly fetch binary code-based instructions through bit-line sense amplifier (S/A) integrated with on-chip flash memory. The S/A compares bit cell current with reference current to identify which data are programmed. The S/A in reading '0' (erased) cell data consumes a large sink current, which is greater than off-current for '1' (programmed) cell data. The main motivation of our approach is to reduce the number of accesses of erased cells by binary code level transformation. This paper proposes a built-in write/read path architecture using binary code inversion method based on hot-spot region detection of instruction code access to reduce sensing current in S/A. From the profiling result of instruction access patterns, hot-spot region of an original compiled binary code is conditionally inverted with the proposed bit-inversion techniques. The de-inversion hardware only consumes small logic current instead of analog sink current in S/A and it is integrated with the conventional S/A to restore original binary instructions. The proposed techniques are applied to the fully-custom designed MCU with ARM Cortex-M0$^{TM}$ using 0.18um Magnachip Flash-embedded CMOS process and the benefits in terms of power consumption reduction are evaluated for Dhrystone$^{TM}$ benchmark. The profiling environment of instruction code executions is implemented by extending commercial ARM KEIL$^{TM}$ MDK (MCU Development Kit) with our custom-designed access analyzer.

• Journal of Sasang Constitutional Medicine
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• v.18 no.3
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• pp.131-144
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• 2006

1. Objectives This research uses the DNA chip, which includes 16,383 gene code, and various statistic prediction way that shows objectification index for the objectification of constitution diagnosis. 2. Methods Drawing blood whose constitution is confirmed, and analyze its gene information by using 1.7k DNA chip to find the gene correlation through multivariate statistical method. 3. Results and Conclusions Distinctive genes such as AK001919, U09384, NM_001805, X99962, NM_004796, AK026738, AL050148, BC002538, AK027074, AK026219, AF087962, AL390142, NM_015372, AL157466, NM_002446, AK024523, NM_014706, NM_014746 and AL137544 were related to Taeumin; AL157448, NM_005957, NM_005656, NM_017548, AK027246, NM_003025, NM_012302 and NM_005905 were represented in Soeumin, while AK026503, AF147325, NM_002076, AF147307, AK001375, NM_003740, NM_005114, AB007890, NM_005505, NM_015900, NM_014936, Z70694, AB023154, U52076, NM_004360, NM_005835, NM_017528, AF087987, NM_014897, AK021720, NM_006420, AJ277915, AK002118 and AK021918 were for Soyangin. This study figured out the possibility to develop the prediction system by sorting each constitution's gene, and research each constitution's distinctive character of manifestation pattern.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.18 no.5 s.120
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• pp.563-568
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• 2007

In this paper, the proposed package antenna, which is meander line structure with short pin, is miniaturized to realize RF-SoP at 900 MHz RFID band. The RFID BGA(Ball Grid Array) chip is put in a cavity of LTCC Layers. The coupling and cross talk, which are happen between BGA chip and proposed package antenna, are reduced by faraday cage, which consists of ground and via fences, is realized to enhance the isolation between BGA chip and antenna. The proposed antenna structure is focused on the package level antenna realization at low frequency band. The novel proposed package antenna size is $13mm{\times}9mm{\times}3.51mm$. The measured resonance frequency is 0.893 GHz. The impedance bandwidth is 9 MHz. The maximum gain of radiation pattern is -2.36 dBi.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.7 no.3
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• pp.86-95
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• 2004

This study was conducted to develop recycle revegetation methods for the restoration of the steep slopes by using fresh wood chip from construction sites. In general, the fresh wood chips can be used as soil media for the restoration works, because they can increase infiltration of rainfall and give enough porous to breathe and elongate for the root growth as well as economic value. The experiment was carried out to compare the effect of fresh wood chips from different mixing with soil, organic material and macromolecular compound which used for slope restoration works conducted by Hyunwoo green(Ltd.). The main results by monitoring for two years are summarized as follows; 1. The soil media made with low percentage of fresh wood chip covered quickly by herb plants. Especially, the soil mixture Type C (wood chip 20%) showed 80 percent ground coverage within two months after seeding. 2. The soil mixture type E (wood chip 40%) and type F (wood chip 50%) which contains more fresh wood chips than soil type C was under 30 percent ground coverage because wood plants are germinated well. If the restoration works aims at making forest, then the soil type E and F would be recommended than using soil type C. 3. Among the woody plants, Ailanthus alfissima, Pinus rigida, Pinus densiflora, and Albizzia julibrissin showed high percentage of germination rates and vigorous growth. In case of shrubs, Lespedeza cyrtobotria and Indigofera pseudo-tintoria scored high percentage of germination rates. 4. In native plants, Chrysanthemum indicum, Artemisia princeps, Lutos corniculatus and Imperata cylindrica showed high percentage of appearance. In case of introduced herbs, Coreopsis lanceolata, Coreopsis tinctoria and Oenothera oborata grew so vigorously. 5. The soil types which including fresh wood chips over 30-40 percentage showed the most diverse plant composition and the most effective germination rates and growth pattern with woody plants. 6. This works to develop recycle revegetation methods using fresh wood chips need more efforts for monitoring the exact effect of fresh wood chips as the soil media.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.4
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• pp.833-838
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• 2011

RFID system in manufacturing industry is used to collect, categorize, and process the data of products. To install RFID system for a large factory, a large amount of wired data communication network is necessary for RS232 communication. If the installed location of RFID system in the factory is changed or extended, a reinstallment is required for the already installed wired data network. A large amount of time/financial reinvestment is necessary for such reinstallation. By using wireless data communication network, however, the initial installation and reinstallation are very simple. In this paper, we implemented a wireless communication system and RFID system. We used the CC1020 chip for wireless communication system and EM4095 chip for RFID system. CC1020 chip enables highly-reliable data communication, and by setting a simple status register, it can switch between transmitting/receiving status and it can choose the desired frequency of either 400 MHz or 900 MHz. Also, Communication range is 50 m, if external antenna is used. EM4095 is a chip for RFID reader system with the carrier frequency of 125 KHz. This chip can implement the reader system by connecting a small number of components. And EM4100 was used for RFID system. EM4100 is read-only type. Atmega128 is used to control a wireless communication system and RFID system. We confirm that the system can communicate without error up to 50 m from sender. In the paper, the circuit diagram and operation program for CC1020 and RFID system are presented. The system used in the experiment is shown in pictures, and the data movement pattern of CC1020 is shown in the diagram, and the performance of each transmission method is presented.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.1
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• pp.684-692
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• 2016

In the manufacturing process of the LQFP/TQFP (Low-profile Quad Flat Package/Thin Quad Flat Package), the requirement of a 3 dimensional inspection is increasing rapidly and a 3D inspection of the shape of a chip has become an important report of quality control. This study developed a 3 dimensional measurement system based on PMP (Phase Measuring Profilometry) for an inspection of the LQFP/TQFP chip and image processing algorithms. The defects of the LQFP/TQFP chip were classified according to the dimensions. The 2 dimensional optical system was designed by the dorm illumination to achieve constant light distribution, In the 3 dimensional optical system, PZT was used for moving 90 degree in phase. The problem of 2 ambiguity was solved from the measured moir? pattern using the ambiguity elimination algorithm that finds the point of ambiguity and refines the phase value. The proposed 3D measurement system was evaluated experimentally.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.18 no.5 s.120
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• pp.539-546
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• 2007

In this paper, a 3-D EM simulation methodology for on-chip spiral inductor analysis has provided and it is shown that the methodology can be adapted to the highly predictable design for CMOS VCO. LC-resonator type VCO have fabricated by using standard 0.25 um CMOS process. And the LC VCO layout case which has pattern ground shielded inductors and the other layout case which has no pattern grounded inductors were fabricated for the verification of their effects on the VCO's phase noise by reducing the Q-factor of inductors. Fabricated VCO has 3.094 GHz, -12.15 dBm output at the tuning voltage of 2.5 V, and from the simulation, Q-factor of the pattern grounded inductor has increased 8% at 3 GHz, and from the measurement results, the phase noise has reduced by 9 dB at the 3 MHz off-set frequency for the pattern grounded inductor layout case.

• Journal of the Korean Ceramic Society
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• v.39 no.3
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• pp.286-293
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• 2002

Microstructure and the electrical porperties of a ZnO-based multilayered chip-type varistor(abbreviated as MLV) with Ag/Pd(7:3) inner electrode have been studied as a function of firing of temperature. At 1100$^{\circ}$C, inner electrode layers began to show nonuniform thickness and small voids, which resulted in significant disappearance of the electrode pattern and delamination at 1100$^{\circ}$C. MLVs fired at 950$^{\circ}$C showed large degradation in leakage current, probably due to incomplete redistribution of liquid and transition metal elements in pyrochlore phase decomposition. Those fired at 1100$^{\circ}$C and above, on the other hand, revealed poor varistor characteristics and their reproductibility, which are though to stem from the deformation of inner electrode pattern, the reaction between electrode materials and ZnO-based ceramics, and the volatilization of $Bi_2O_3$. Throughout the firing temperature range of 950∼1100$^{\circ}$C, capacitance and leakage current increased while breakdown voltage and peak current decreased with the increase of firing temperature, but nonlinear coefficient and clamping ratio kept almost constant at ∼30 and 1.4, respectively. In particular, those fired between 1000$^{\circ}$C and 1050$^{\circ}$C showed stable varistor characteristics with high reproducibility. It seems that Ag/Pd(7:3) alloy is one of the electrode materials applicable to most ZnO-based MLVs incorporating with $Bi_2O_3$ when cofired up to 1050$^{\circ}$C.

• Journal of Korea Multimedia Society
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• v.13 no.7
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• pp.943-949
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• 2010

This paper presents some improvements on VLSI implementation of lifting-based 9/7 wavelet transform by optimization hardware multiplication. The proposed solution requires less logic area and power consumption without performance loss compared to previous wavelet filter structure based on lifting scheme. This paper proposes a better approach to the hardware implementation using Lefevre algorithm based on extensions of Pattern search methods. To compare the proposed structure to the previous solutions on full multiplier blocks, we implemented them using Verilog HDL. For a hardware implementation of the two solutions, the logical synthesis on 0.18 um standard cells technology show that area, maximum delay and power consumption of the proposed architecture can be reduced up to 51%, 43% and 30%, respectively, compared to previous solutions for a 200 MHz target clock frequency. Our evaluation show that when design VLSI chip of lifting-based 9/7 wavelet filter, our solution is better suited for standard-cell application-specific integrated circuits than prior works on complete multiplier blocks.