• Transactions of the Korean Society of Mechanical Engineers
• /
• v.19 no.2
• /
• pp.433-442
• /
• 1995

For the line search of a multi-variable optimization, an efficient algorithm is presented. The algorithm sequentially employs several polynomial approximations such as 2-point quadratic interpolation, 3-point cubic interpolation/extrapolation and 4-point cubic interpolation/extrapolation. The order of polynomial function is automatically increased for improving the accuracy of approximation. The method of approximation (interpolation or extrapolation) is automatically switched by checking the slope information of the sample points. Also, for selecting the initial step length along the descent vector, a new approach is presented. The performance of the proposed method is examined by solving typical test problems such as mathematical problems, mechanical design problems and dynamic response problems.

• JSTS:Journal of Semiconductor Technology and Science
• /
• v.3 no.3
• /
• pp.139-144
• /
• 2003

We report the results of extensive mixed mode simulations and theoretical analysis to quantify the contribution of the edge direct tunneling (EDT) current on the total gate leakage current of 80nm NMOSFET with SiO2 gate dielectric. It is shown that EDT has a profound impact on basic analog circuit building blocks such as sample-hold (S/H) circuit and the current mirror circuit. A transistor design methodology with zero gate-source/drain overlap is proposed to mitigate the EDT effect. This results in lower voltage droop in S/H application and better current matching in current mirror application. It is demonstrated that decreasing the overlap length also improves the basic analog circuit performance metrics of the transistor. The transistor with zero gate-source/drain overlap, results in better transconductance, input resistance, output resistance, intrinsic gain and unity gain transition frequency.

• Biotechnology and Bioprocess Engineering:BBE
• /
• v.5 no.3
• /
• pp.169-173
• /
• 2000

On human chromoscomes, a short sequence of DNA is known to repeat a number of times. These are called variable number of tandem repeat (VNTR) or short tandem respeat (STR) which has a short core. VNTR and STR are used in the filed of forensic science, evolution, and anthropology. In this work, we examined allele frequencies of one VNTR (YNZ22) and three STRs (NeuR, D21S11, Humth01) in a korean population sample by polymerase chain reaction (RCP) followed by high-resolution polyacrylamide gel electro-phoresis (PAGE) with silver stain. Subsequently, the polymorphism information content (PIC) was calculated : the hifhest PIC was observed in the NeuR locus (0.95680) and lowest in the Humth01 locus (0.75809).

• Proceedings of the Korea Crystallographic Association Conference
• /
• 2002.11a
• /
• pp.36-36
• /
• 2002

To Establish of standard technique of length measurent in 2D plane, we develope AFM system. The XY scanner scans the sample only in XY plane, while the Z scanner scans the specimen only in Z-direction. Cantilever tip is controlled to has constant height relative to speciman surface by feedback of PSPD signal. To acquire high accuracy, Z-axis measuring sensor will be added.(COXI or others). In this paper we design XYZ stage suitable for this AEM system. For XY stage, single module parallel-kinnematic flexure stage is used which has high orthogonality and minimum out-of-plane motion. To obtain best performance optimal design is performed. For XY stage, to be robust about parasitic motion optimal design of maximizing Z and tilt stiffness is performed under the constraint of motion range and stage size. And for Z stage, optimal design of maximizing 1st resonant frequency is performed. Because if resonant frequency is get higher, scan speed is improved. So it makes reduce the error by sensor drift. Resultly XYZ stage each have 1st natural frequency of 115㎐, 201㎐, 2.66㎑ and range 109㎛, 110㎛, 12㎛.

• Journal of Genetic Medicine
• /
• v.3 no.1
• /
• pp.15-19
• /
• 1999

We have investigated the genetic variation in the human apo B mRNA editing protein (apobec-1) gene. Exon 3 of the apobec-1 gene was amplified by polymerase chain reaction. After detection of an additional band by single strand conformational polymorphism (SSCP) analysis, sequencing of the SSCP-shift sample revealed a single-base mutation. The mutation was a CGG transversion at codon 80 resulting in a lleRMet substitution. This substitution was confirmed by restriction fragment length polymorphism analysis since a Pvull site is abolished by the substitution. Population and family studies confirmed that the inheritance of the genotypes for apobec-1 gene polymorphism is controlled by two codominant alleles (P1 and P2). A significant difference in plasma triglyceride was detected among the different apobec-1 genotypes in the CAD patients (P<0.05). Our study could provide the basis for elucidating the interaction between genetic variation of the apobec-1 gene and disorders related to lipid metabolism.

• Advances in aircraft and spacecraft science
• /
• v.4 no.3
• /
• pp.269-280
• /
• 2017

The natural vibration analysis of microbeams resting on visco-Pasternak's foundation is presented. The thermoelasticity theory of Green and Naghdi without energy dissipation as well as the classical Euler-Bernoulli's beam theory is used for description of natural frequencies of the microbeam. The generalized thermoelasticity model is used to obtain the free vibration frequencies due to the coupling equations of a simply-supported microbeam resting on the three-parameter viscoelastic foundation. The fundamental frequencies are evaluated in terms of length-to-thickness ratio, width-to-thickness ratio and three foundation parameters. Sample natural frequencies are tabulated and plotted for sensing the effect of all used parameters and to investigate the visco-Pasternak's parameters for future comparisons.

• Bulletin of the Korean Chemical Society
• /
• v.14 no.2
• /
• pp.250-255
• /
• 1993

A dual capillary column system is described for the simultaneous analysis of a given sample and measurement of retention index (RI) and area ratio (AR) values of each peak on two capillary columns of different polarity, DB-5 & DB-1701 from a single injection. Both capillary columns were connected to either a splitless injector or an on-column injector via a deactivated fused-silica capillary tubing of 1 m length and a 'Y' splitter. Both injection modes allowed to measure RI and AR values with high reproducibility (<0.01% RSD) and high accuracy (<10% RE), respectively with the exception that the trace and high boiling solutes required the on-column mode for the accurate quantification and AR comparison. When the dual capillary column system in on-column injection mode was applied to the blind samples containing organic acids, each acid was positively indentified by the combined computer RI library search-AR comparison.

• Journal of Species Research
• /
• v.11 no.3
• /
• pp.188-193
• /
• 2022

Araeosoma owstoni Mortensen, 1904, a newly recorded sea urchin, was collected from the Korea Strait by trawling during a research expedition in April 2017. The specimen was damaged and was severely peeled off on the aboral side during trawling. However, a test and the surface of the oral side of the sample were well preserved, allowing us to successfully identify it. The species was distinguished by the large and flexible test, the tiny apical section, and the interambulacra width which is twice of the ambulacra. Pedicellaria tridentate and triphyllous were presents, but tetradactyle pedicellaria was absent due to severe peeling on the aboral side. Moreover, a length of 1,212 bp sequence from mitochondrial COI gene was obtained and this sequence covered the general DNA barcoding region. The mean of interspecific divergence within A. owstoni from Korea and other eight species of Araeosoma from the GenBank was 6.8%. This value indicated that our species was clearly distinguishable from the others. Thus, the first Araeosoma species occurring in South Korea is presented in this study.

• The Plant Pathology Journal
• /
• v.15 no.4
• /
• pp.247-250
• /
• 1999

Wasabies showing mosaic symptoms were collected and extracted for virus purification. Tobacco mosaic virus (TMV) was identified as causal agent by electron microscopy and nucleic acid and coat protein analyses. TMV strains were determined by enzyme-linked immunosorbent assay (ELISA). TMV was identified as W and C strain in wasabi. The results of host reaction indicated that this virus induced local lesions on Nicotiana tabacum cv. Bright Yellow and N. glutinosa, leaf spots on Chenopodium amaranticolor and mosaic symptoms on wasabi. Rot shape virus particles were observed and was about 300 nm in length. About 6.5 kb single RNA molecule was observed from extracted viral RNA sample and 26 KDa coat protein was detected in denatured acrylamide gel. Infection ratio of TMV was 8% for the first cultivation year, but was 22% for the second year when TMV-W antiserum was used. The results of this experiment showed that infection ratios of both TMV-W and TMV-C strains were higher compared to that of TMV-P strain.

• Korean Journal of Pharmacognosy
• /
• v.11 no.2
• /
• pp.75-80
• /
• 1980

The decoctions and extracts were prepared on the traditionally prescribed four kinds (Kejigamcho-tang, Kejibanha-tang, Keji-tang, Kejiinsam-tang) of preparations containing Cinnamoni Raulus. The contents of cinnamic acid and cinnamic aldehyde in these preparations were determined by high performance liquid chromatography using reverse phase partition column, and 12% MeOH as eluting solvent. The sample was determined using the two wave length, 254nm and 280nm. This method was sucessfully applied to the analysis of cinnamic acid and cinnamic aldehyde of various preparations containing Cinnamons.