• Fisheries and Aquatic Sciences
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• v.17 no.3
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• pp.355-360
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• 2014

Two pelagic species Siriella izuensis Murano and Fukuoka, 2008 and Siriella japonica Ii, 1964, are reported for the first time from the Korean waters, together with descriptions and illustrations. S. izuensis can be distinguished from its closest relative, Siriella japonica, by the normal inner flagellum of the antennule of males, as opposed to the swollen proximal part in S. japonica, and by the slightly more distinct tendency of alternate arrangement of spines on the distal third lateral margin of the telson than in S. japonica. S. izuensis and S. japonica differ distinctly from other related species by a combination of the triangular rostral plate, the moderate size of the eyes, the form and arrangement of the lateral spines of the telson, and six or seven graded spines on the distal outer margin of the uropodal exopod. A taxonomical key is given for the genus Siriella from the Korea waters.

• Journal of Korean Society for Atmospheric Environment
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• v.24 no.E1
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• pp.54-62
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• 2008

Microbeam PIXE, often called micro-PIXE, is one of powerful tools for analyzing a wide range of elements for various samples. Moreover, it has important applications of interest to the atmospheric science. In the present study, a qualitative elemental imagination for various atmospheric environmental species was attempted using micro-PIXE. Especially, in combination with a novel individual droplet collection method and the micro-PIXE analytical technique, the chemical specification of various individual atmospheric samples could be carried out. Here, we briefly introduce the results of an application of micro-PIXE to the study of atmospheric environment. The detailed spatial resolution of multiple elements for various samples like individual ambient particles, individual raindrops, individual fog droplets, and individual snow crystals could be successfully achieved by scanning 2.6 MeV $H^+$ micro beam ($1{\sim}2{\mu}m$) accelerated by 3 MeV single-end accelerator.

• Journal of Korean Society for Atmospheric Environment
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• v.24 no.E1
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• pp.44-53
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• 2008

This study was undertaken to measure the properties of individual mineral particles in an artificially saturated atmosphere at a vertical extinct mine with 430 m height. By synchrotron radiation X-ray fluorescence (SR-XRF) microprobe analysis, it was possible to determine the elemental composition of residual insoluble particles on individual cloud droplet replicas formed on the Collodion film. The XRF visualized elemental maps enabled us not only to presume the chemical mixing state of particles retained in cloud droplet, but also to estimate their source. Details about the individual mineral particles captured by artificial cloud droplets should be helpful to understand about the removal characteristics of dust particles such as interaction with clouds. Nearly all individual particles captured in cloud droplets are strongly enriched in Fe. Mass of Fe is ranged between 41 fg and 360 fg with average 112 fg. There is a good agreement between single particle analysis by SR-XRF and bulk particle analysis by PIXE.

• Architectural research
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• v.3 no.1
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• pp.61-70
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• 2001

The paper is intended to propose design strength of slender steel reinforced beam-columns by using the modified superposed method. The design of composite members is carried out by a superposed strength method in AIJ (Architectural Institute of Japan) design method. The bearing capacities of the steel part and the concrete part have to be determined separately and then added to a combined capacity. Authors have proposed a new superposed method in a modified form for the slender composite beam-columns and reinforced column. The modified superposed method is adopted for the slender steel reinforced beam-columns. Validation of the modified superposed method is undertaken by comparison with analytical results calculated assuming a sine curve deflected shape of the beam-columns, and with the test results conducted in Japan.

• The Korean Journal of Malacology
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• v.3 no.1
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• pp.35-43
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• 1987

Morphological variations of six Korean and one Japanese populations of Parafossarulus manchouricus were observed. Mean length of shell was 9.36mm(n=376), and mean width was 8.0mm. Average aperture length and width were 4.72 and 3.78mm, respectively. Number of whorl ranged from 3.5 to 5.25(at most 4.5)in all popuiations . Yangsoori population had no spiral line or spiral keel, but ther populations had spiral lines. Number of spiral line on their penultimate shorls ranged 4 to 14.The lips of aperture were generally thickened, except in some Chongpyong, Haman and Fukuoka populations. The most of shell was eroded in only apex part and/ or in othker sculpture, especially Yangsoori population was heavily eroded.

• Proceedings of the IEEK Conference
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• 2002.07c
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• pp.1630-1633
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• 2002

In this paper, we proposed a new control system of the dividing ratio changeable type ADPLL (DCPLL). The DCPLL has been designed by us. However, in the DCPLL, there are some problems such as this curcuit is increased the output jitter on multiple frequency, and the output jitter is large on steady state. Then, the output jitter characteristic on multiple frequency is improved by using “rest-control” system. Also, output jitter decreases by using “W-edge (positive edge h negative edge)” system. We confirmed some characteristics of the DCPLL with the circuit simulator, PSpice.

• JSTS:Journal of Semiconductor Technology and Science
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• v.9 no.1
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• pp.37-50
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• 2009

Evaluation results about area scaling capabilities of various SRAM margin-assist techniques for random $V_T$ variability issues are described. Various efforts to address these issues by not only the cell topology changes from 6T to 8T and 10T but also incorporating multiple voltage-supply for the cell terminal biasing and timing sequence controls of read and write are comprehensively compared in light of an impact on the required area overhead for each design solution given by ever increasing $V_T$ variation (${\sigma}_{VT}$). Two different scenarios which hinge upon the EOT (Effective Oxide Thickness) scaling trend of being pessimistic and optimistic, are assumed to compare the area scaling trends among various SRAM solutions for 32 nm process node and beyond. As a result, it has been shown that 6T SRAM will be allowed long reign even in 15 nm node if ${\sigma}_{VT}$ can be suppressed to < 70 mV thanks to EOT scaling for LSTP (Low Standby Power) process.

• JSTS:Journal of Semiconductor Technology and Science
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• v.10 no.2
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• pp.118-129
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• 2010

A lower-threshold-voltage (LVth) SRAM cell with an elevated cell biasing scheme, which enables to reduce the random threshold-voltage (Vth) variation and to alleviate the stability-degradation caused by word-line (WL) and cell power line (VDDM) disturbed accesses in row and column directions, has been proposed. The random Vth variation (${\sigma}Vth$) is suppressed by the proposed LVth cell. As a result, the LVth cell reduces the variation of static noise margin (SNM) for the data retention, which enables to maintain a higher SNM over a larger memory size, compared with a conventionally being used higher Vth (HVth) cell. An elevated cell biasing scheme cancels the substantial trade-off relationship between SNM and the write margin (WRTM) in an SRAM cell. Obtained simulation results with a 45-nm CMOS technology model demonstrate that the proposed techniques allow sufficient stability margins to be maintained up to $6{\sigma}$ level with a 0.5-V data retention voltage and a 0.7-V logic bias voltage.

• Journal of the Korean Statistical Society
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• v.19 no.1
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• pp.54-70
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• 1990

Consider the extreme problem : min$(\mu-y)'(\mu-y)$ subject to $A\mu \geq 0$, where A is an $n \times p$ matrix, which often occurs in solving the maximum likelihood estimator with ordered restrictions in parameter space. In case the matrix AA' has all non-positive off-diagonal elements, some propositions in this paper guarantee that the above extreme solutions are achieved at most at n sweep out steps in Gaussian eliminations. Some typicla examples of Sweep-the-Negatives method are given.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09a
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• pp.12-13
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• 2006

The spherical and high quality Titanium fine powder "Tilop" has been produced with gas atomization furnace, Sumitomo Titanium Corporation originally designed. Recently, a new process which can produce Ti-alloy(Ti-6Al-4V) powders by utilizing our gas atomization process, of which raw material is sponge titanium pre-mixed with alloy chips or granules has been also developed. The particle size of gas atomized Ti-alloy powder and the mechanical properties of sintered Ti-alloy compacts prepared by metal injection molding were discussed in this study.