• Journal of Sensor Science and Technology
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• v.28 no.4
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• pp.221-224
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• 2019

Based on the results of studies on acetone excretion in diabetic patients, a one - chip sensors array was fabricated by combining acetone-selective sensor materials and volatile-organic-compound sensitive sensor materials. An electonic-nose was implemented using a sensor array and confirmed selectivity for five gases. In this system, the excretion of diabetic patients and controls was sampled with solid phase microextraction fiber and transferred to the sensor array. Although the control and diabetic patients were distinct, several samples failed. In the control group, the results of blood tests were normal, but patients were highly obese. In addition, the gas chromatography mass spectrometry results for the subjects revealed chemicals that are external factors.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.28 no.9
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• pp.1408-1414
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• 2004

The use of flip-chip technology has many advantages over other approaches for high-density electronic packaging. ACF (anisotropic conductive film) is one of the major flip-chip technologies, which has short chip-to-chip interconnection length, high productivity, and miniaturization of package. In this study, thermal fatigue lift of ACF bonding flip-chip package has been predicted. Elastic and thermal properties of ACF were measured by using DMA and TMA. Temperature dependent nonlinear hi-thermal analysis was conducted and the result was compared with Moire interferometer experiment. Calculated displacement field was well matched with experimental result. Thermal fatigue analysis was also conducted. The maximum shear strain occurs at the outmost located bump. Shear stress-strain curve was obtained to calculate fatigue life. Fatigue model for electronic adhesives was used to predict thermal fatigue life of ACF bonding flip-chip packaging. DOE (Design of Experiment) technique was used to find important design factors. The results show that PCB CTE (Coefficient of Thermal Expansion) and elastic modulus of ACF material are important material parameters. And as important design parameters, chip width, bump pitch and bump width were chose. 2$^{nd}$ DOE was conducted to obtain RSM equation far the choose 3 design parameter. The coefficient of determination ($R^2$) for the calculated RSM equation is 0.99934. Optimum design is conducted using the RSM equation. MMFD (Modified Method for feasible Direction) algorithm is used to optimum design. The optimum value for chip width, bump pitch and bump width were 7.87mm, 430$\mu$m, and 78$\mu$m, respectively. Approximately, 1400 cycles have been expected under optimum conditions. Reliability analysis was conducted to find out guideline for control range of design parameter. Sigma value was calculated with changing standard deviation of design variable. To acquire 6 sigma level thermal fatigue reliability, the Std. Deviation of design parameter should be controlled within 3% of average value.

• Asian Journal of Turfgrass Science
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• v.16 no.1
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• pp.19-30
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• 2002

This study was conducted to investigated the effects of rubber chips from used tires on sports turf ground as soil conditioner to improve soil physical properties. The release of heavy metal ions was detected to check the soil contamination by incorporation of recycled rubber chips with topsoil. The effects of the chips were also evaluated as topdressing material to improve surface resilience. The rate of rubber chips showed a positive relationship with soil temperature increasement. Incorporation of rubber chips increased soil temperature on surface at 2.5 cm-depth. The rates of rubber chip showed a negative relationship with ground cover rate of turfgrass in early growth season. However, after 20 weeks, treatment of 10% rubber chips at 2.5 cm-depth showed a prominent cover rate of 70% which was not significantly different with untreated control. Incorporation of rubber chips within topsoil seemed to reduce soil compaction, but the effects was not prominent on physical properties. Rubber chips did not affect chemical properties and heavy metal contamination to soil environment. Rubber chips improved resilience of the compacted ground surface as topdressing material, this effect was prominent when aerification practise was preceded.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.3
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• pp.1687-1689
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• 2013

We performed a case-control study to investigate whether SNPs of CHIP might affect the development of IA in Chinese Han nationality. We believe we are the first to have screened IA patients for mutations in the CHIP gene to determine the association with these variants. The study group comprised 224 Chinese Han nationality patients with at least one intracranial aneurysm and 238 unrelated healthy Han nationality controls. Genomic DNA was isolated from blood leukocytes. The entire coding regions of CHIP were genotyped by PCR amplification and DNA sequencing. Differences in genotype and allele frequencies between patients and controls were tested by the chi-square method. Genotype and allele frequencies of the SNP rs116166850 was demonstrated to be in Hardy-Weinberg equilibrium. No significant difference in genotype or allele frequencies between case and control groups was detected at the SNP. Our data do not support the hypothesis of a major role for the CHIP gene in IA development in the Chinese Han population.

• The Journal of Korean Medicine
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• v.24 no.2
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• pp.148-158
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• 2003

Backgrounds & Objectives: In many recent studies, molecular biological methods have been used to investigate the role of cytokines in pathogenesis and new therapeutic targets of asthma. Recently, as a method of research on the gene expression, they are applying another method which assays multiple gene expressions at the same time by the microarray. In this study, the antioxidant effect, the inhibitory effect against interleukin-4 and the effect on the CD/cytokine gene expression in PBMC (peripheral blood mononuclear cells) was evaluated by using cDNA microarray chip of Chungsangboha-tang. Methods: Experimental studies were performed for the antioxidant effect of Chungsangboha-tang on DPPH (1, 1-diphenyl-2-picrylhydrazyl) solution, for the IL-4-inhibiting effect on BALB/c mouse spleen, and for the gene expression effect on PBMC (peripheral blood mononuclear cells) with microarray. Results: Chungsangboha-tang showed antioxidant effect dose-dependently. Chungsangboha-tang inhibited interleukin-4 dose-dependently and showed significant difference in 10ug/ml and 100ug/ml of test groups. There was no 2 more times upregulated genes than in the control group by using cDNA microarray chip of Chungsangbohn-tang, but there were 140%-200% upregulated genes. There was no 2 more times downregulated genes than in the control group by using cDNA microarray chip of Chungsangboha-Tang, but there was 50%-75% downregulated genes. Conclusions: This study showed that Chungsangboha-tang has an antioxidant effect and inhibition of Interleukin-4, but further studies are necessary with microarray.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.37 no.6
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• pp.34-42
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• 2000

Recently, there is a growing need to develope small-size RF chip inductors operating to GHz to realize high-performance, micro-fabricated wireless communication products. For the development of high-performance RF chip inductors, however, the ferrite-based chip inductors can not be used above 300MHz due to the limitation of the permeability of this material. In this work, small-size, high-performance RF chip inductors utilizing amorphous $Al_2O_3$ core material were investigated. Copper (Cu) with 40${\mu}m$ diameter was used as the coils and the chip inductor size fabricated in this work is $2.1mm{\times}1.5mm{\times}1.0mm$. The external current source was applied after bonding Cu coil leads to gold pads electro-plated on the bottom edges of a core material. The composition of core materials was measured using a EDX. High frequency characteristics of the inductance (L), quality factor (Q), and impedance (Z) of developed inductors were measured using an RF Impedance/Material Analyzer (HP4291B with HP16193A test fixture). The developed inductors have the self-resonant frequency (SRF) of 1 to 3.5 GHz and exhibit L of 22 to 150 nH. The L of the inductors decreases with increasing the SRF. The Z of the inductors has the maximum value at the SRF and the inductors have the quality factor of 70 to 97 in the frequency range of 500 MHz to 1.5 GHz.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.8
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• pp.1424-1429
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• 2007

This paper presents a simple and reliable one-touch type multi-immunosensing lab-on-a-chip (LOC) detecting antibodies as multi-disease markers using electrochemical method suitable for a portable point-of-care system (POCS). The multi-stacked LOC consists of a PDMS space layer for liquids loading, a PDMS valve layer with 50 im in height for the membrane, a PDMS channel layer for the fluid paths, and a glass layer for multi electrodes. For the disposable immunoassay which needs sequential flow control of sample and buffer liquids according to the designed strategies, reliable and easy-controlled on-chip operation mechanisms without any electric power are necessary. The driving forces of sequential liquids transfer are the capillary attraction force and the pneumatic pressure generated by air bladder push. These passive fluid transport mechanisms are suitable for single-use LOC module. Prior to the application of detection of the antibody as a disease marker, the model experiments were performed with anti-DNP antibody and anti-biotin antibody as target analytes. The flow test results demonstrate that we can control the fluid flow easily by using the capillary stop valve and the PDMS check valves. By the model tests, we confirmed that the proposed LOC is easily applicable to the bioanalytic immunosensors using bioelectrocatalysis.

• Journal of the Korean Wood Science and Technology
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• v.15 no.3
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• pp.44-55
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• 1987

In order to study the effect of sawdustboard combined with plastic chips, 0.5mm($T_1$), 1mm($T_2$), 1.4mm($T_3$) thick nylon fiber. polypropylene rope fiber(RP), and 0.23mm thick moth-proof polypropylene net fiber(NP) were cut into 0.5, 1, 2cm long plastic chips. Thereafter, sawdustboard combined with plastic chips prepared as the above and plastic non-combined sawdustboard(control) were manufactured into 3 types of one-, two-, and three layer with 5 or 10% combination level. By the discussions and results at this study, the significant conclusions of mechanical and physical properties were summarized as follows: 1. The MORs were shown in the order of 3 layer> 2 layer> 1 layer among plastic non-combined boards, and $T_3$ < $T_2$ < $T_1$ < RP (NP(5%) < NP(l0%) among plastic combined boards. In 2cm long plastic chip in 1 layer board, the highest strength through all the composition was recognized. 1 layer board showing the lower strength with 0.5cm plastic chip rendered to the bending strength improvement by 2 or 3 layer board composition. On the other hand, 2 or 3 layer combined with 1, 2cm long polypropylene net fiber chips incurred MOR's conspicuous decrease requiring optimum plastic chip combined level and consideration to combined type. 2. MOE in plastic non-combined 3 layer board exhibited sandwich construction effect by higher resin content application to surface layer in the order of 3layer>1layer>2layer with the highest stiffness of the board combined with polypropylene chip, while nylon chip-combined board had little difference from plastic non-combined board. In relevant to length and layer effect, 3 layer board combined with the 0.5cm long polypropylene net fiber chip in 5% and 10% combined level presented 34-43% and 44-76% stiffness increase against plastic non-combined board(control), respectively. Moreover, in 1 layer board, 30% stiffness increase with 10% against 5% combined level in the 1 and 2cm long polypropylene net fiber chip was obtained. 3. Stress at proportional limit(Spl) showing the fiber relationship (r: 0.81-0.97) between MOR presented in the order of 1 layer<2 layer<3 layer in plastic non-combined board. Correspondingly, combined effect by layer and plastic chip length was similar to MOR's. 4. Differently from previous properties(MOR, MOE, Spl). work to maximum load(Wml) of 2 layer board approached to that of 3 layer board. Conforming the above phenomenon. 2 layer combined with 0.5cm long polypropylene net fiber chip kept the greater work than 1 layer. The polypropylene combined board superior to nylon -and plastic non - combined board seemed to have greater anti - failing capacity. 5. Internal bond strength(IB), in contrast to MOR's tendency. showed in the order of T1

• Journal of Institute of Control, Robotics and Systems
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• v.13 no.12
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• pp.1153-1159
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• 2007

This paper presents the hardware implementation of nonlinear PID controllers for the ROBOKER humanoid robot arms. To design the nonlinear PID controller on an FPGA chip, nonlinear functions as well as the conventional PID control algorithm have to be implemented by the hardware description language. Therefore, nonlinear functions such as trigonometric or exponential functions are designed on an FPGA chip. Simulation studies of the position control of humanoid arms are conducted and results are compared. Superior performances by the nonlinear PID controllers are confirmed when disturbances are present. Experiments of humanoid robot arm control tasks are conducted to confirm the performance of our hardware design and the simulation results.

• Proceedings of the KIEE Conference
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• 1993.07a
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• pp.391-394
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• 1993

The acceleration/deceleration control method and interpolated operating are essential to the servo motor control system. In a few years ago, a floating point DSP chip was used for the purpose of processing a lot of calculated amount. But in this paper, we proposed new acceleration/deceleration control method and circular interpolation algorithm without another floating point DSP chip. The validity of proposed algorithms are verified through computer simulation and experimental result.