• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 춘계학술대회 논문집
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• pp.389-394
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• 1997

Consider a tetrhedron is composed of six dihedral angles .phi.(i=1,2..., 6), and a vertex of a tetrahedron is also three dihedral angles. It will assume that a vertex A, for an example, is composed of there angles definded such as .alpha..betha. and .gamma. !. then there is a corresponding angle can be given as .phi1.,.phi2.,.phi3.. Here, in order to differentiate between a conventional triangle and dihedral angle, if a dihedral angle degined in this paper is symbolized as .phi..LAMBDA.,the value of cos.theta.of .phi./sab a/, in a trigonometric function rule,can be defined to tecos.phi..LAMBD/sab A/., and it is defined as a tetradedral cosine .phi. or simply called a tecos.phi.. Moreover, in a simillar method, the dihedral angle of tetrahedron .phi..LAMBDA. is given as : value of sin .theta. can defind a tetra-sin.phi..LAMBDA., and value of tan .theta. of .phi..LAMBDA. is a tetra-tan .phi..LAMBDA. By induction it can derive that a tetrahedral geometry on the basis of suggesting a geometric tetrahedron

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 춘계학술대회 논문집
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• pp.799-804
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• 1997

This paper is concerned with the heat flux distribution and energy partition for creep-feed grinding. Form measurements of transient grinding temperatures in the workpiece sub-surface using an embeded thermocouple, the overall energy partition to the workpiece was estimated form moving heat source theory for a triangular heat flux distribution as 3.0% for down grinding and 4.5% for up grinding. The higher energy partition for up grinding can be attributed to the need to satisfy thermal compatibility at the grinding zone. The influence of cooling outside the grinding zone can be analytically taken into account by specifying convective heat transfer coefficients on the workpiecs surface h /sab a/ heat source (grinding zone) and h /sab b/ behind the heat source. The smaller energy patition together with slightly lower grinding power favors down grinding over up grinding.

• 한국토양비료학회지
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• 제45권4호
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• pp.582-592
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• 2012

Microorganisms present in the rhizosphere soil plays a vital role in improving the plant growth and soil fertility. Many kinds of fertilizers including chemical and organic has been approached to improve the productivity. Though some of them showed significant improvement in yield, they failed to maintain the soil properties. Rather they negatively affected soil eventually, the land became unsuitable for agricultural. To overcome these problems, microorganisms have been used as effective alternative. For past few decades, plant growth promoting rhizobacteria (PGPR) and arbuscular mycorrhizal fungi (AMF) have been used as effective inoculants to enhance the plant growth and productivity. PGPR improves the plant growth and helps the plant to withstand biotic and abiotic stresses. AM fungi are known to colonize roots of plants and they increase the plant nutrient uptake. Spore associated bacteria (SAB) are attached to spore wall or hyphae and known to increase the AMF germination and root colonization but their mechanism of interaction is poorly known. Better understanding the interactions among AMF, SAB and PGPR are necessary to enhance the quality of inoculants as a biofertilizers. In this paper, current knowledge about the interactions between fungi and bacteria are reviewed and discussed about AMF spore associated bacteria.

• 미생물학회지
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• 제35권1호
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• pp.13-17
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• 1999

Shigella sonnei 는 인체의 장내 감염을 일으키는 병원균의 일종이며, 본 연구에 사용된 S.sonnei KNIH104S는 국내에서 쉬겔라증을 나타내는 환자로부터 분리하였다. S. sonnei KNIH104s의 염색체로부터 aspartate $\beta$-semial-dehyde dehydrogenase를 암호화하는 asd 유전자를 포함하는 1.7 kb BamHI 절편을 pBluescript SK(+) 벡터를 이용하여 클로닝하였으며 pSAB17이라 명명하였다. asd 결실돌연변이주인 E.coli $\chi$6097은 세포벽을 구성하는 중요한 성분인 DL-$\alpha$, $\varepsilon$-diaminopimelic acid가 없는 Luria-Bertani 배지에서 생장함을 확인하였다. 클로닝된 asd 유전자의 염기서열 분석결과 ATG 개시코돈 및 TAA 종결코돈을 지니는 1,104 bp 로 이루어져 있으며, 여기서 유추한 아미노산은 367개로 분자량 40.0 kDa 의 폴리펩타이드를 만들어내고 있다. 염기서열은 대장균의 asd 유전자와 한 부위에서 다르게 나타났지만 아미노산의 서열은 동일함을 알 수 있었다. 그리고 pBluescript SK(+) 벡터와 본 연구에서 클로닝된 asd 유전자를 이용하여 balanced-lethal vector인 pSKA47 및 pSKA47A를 제조하였다.

• 한국미생물·생명공학회지
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• 제46권3호
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• pp.261-268
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• 2018

Differences in host ethnicities and geographical distributions may influence the genetic variation and pathogenesis of Helicobacter pylori strains, particularly with respect to those with a high risk of gastric cancer and in Asian Enigma regions. We simultaneously identified H. pylori virulence-associated genes involved in inflammation and cell damage in Thai and Korean dyspeptic patients. The virulence-associated gene cagA, cagA genotypes (East Asian and Western type cagA), vacA genotypes (s- and m-), oipA, and sabA were detected in Thai and Korean dyspeptic patients by polymerase chain reaction (PCR), real-time PCR, and DNA sequence analysis. Comparisons between the two regions showed that cagA, East Asian type cagA, and vacA s1/m1 in Korean dyspeptic patients occurred at rates of 100%, 86.67%, and 88.89%, respectively (p < 0.05). The oipA- and sabA-positive samples were significantly more predominant in the Korean population (95.56%, 91.11%) than in the Thai population (32%, 34%). DNA sequence analysis revealed differences in the patterns of cytosine-thymine dinucleotide repeats of oipA and sabA among the two populations of dyspeptic patients. Our results indicate that the H. pylori strains detected in the two regions were divergent, and strains colonizing the Korean dyspeptic patients may be more virulent than those in the Thai population. Our data may help explain H. pylori pathogenesis in Asian Enigma areas with a low gastric cancer incidence. However, other factors involving H. pylori infection in these two regions should be further analyzed.

• 한국환경생태학회지
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• 제29권3호
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• pp.421-430
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• 2015

본 연구는 천수만 조하대에 서식하는 대형저서동물의 군집을 분석하여 방조제 건설에 따른 천수만 저서생태계의 변화를 이해하고자 하였다. 생태학적인 변화를 이해하기 위하여 대형저서동물의 분포, 우점종, 시.공간적 변화 그리고 유기물 오염을 분석하였다. 천수만에는 총 252종이 출현하였고, 출현밀도는 $681ind./m^2$이었다. 종 다양도는 모든 계절에서 방조제를 기준으로 만 입구 지역으로 갈수록 증가하는 양상이었다. 천수만 내 연중 우점한 대형저서동물은 송곳갯지렁이로 나타났다. 우점종 출현양상은 종 다양도 그리고 정점별 퇴적물 내 유기물 함량과 상관관계를 갖는 것으로 확인되었다. BPI분석 결과, 방조제 인근 정점에서는 4~5등급으로 유기물 오염이 진행된 것으로 확인되었고, 만 입구 지역에서는 1~3등급으로 상대적으로 유기물 오염이 되지 않은 것으로 확인되었다. SAB-curve 분석 결과, 방조제를 기준으로 만 입구로 갈수록 생태계 전이지역이 감소하는 것으로 나타났다.

• 한국물환경학회지
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• 제25권5호
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• pp.727-734
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• 2009

This study was carried out to evaluate the high rate biological reactor such as lab scale reactor before the application in site, and to get the basic data for possibility using liquid fertilizer with the effluent from biological reactor when the centrifugal machine was applied. The total volume of this reactor in 6 L, in composted of anoxic reactor (2 L), aerobic reactor (2 L), and nitification reactor (2 L). BOD removal efficiency rates when centrifugal machine was applied after effluent from biological reactor are over than 95%. This biological reactor was required post process to satisfy the effluent standards, and was need centrifugal machine to control the washout of microbes in the reactor. T-N removal efficiency rate in HRT 24 hr with centrifugation is 80.0%, and it is desirable to operate less than $1.3kgN/m^3{\cdot}d$ for 70% of T-N removal efficiency rate. T-P removal efficiency rate in HRT 24 hr is 68.2%, and become higher 71.3% after centrifugation. Considering in the 28.6% T-N removal efficiency rate, the nitrogen contents of the effluent from reactor is 0.34% to satisfy the liquid fertilizer.

• 천문학회지
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• 제46권3호
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• pp.141-149
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• 2013

We analyze the spiral structure of 1725 nearby spiral galaxies with redshift less than 0.02. We use the color images provided by the Sloan Digital Sky Survey. We determine the arm classes (grand design, multiple-arm, flocculent) and the broad Hubble types (early, intermediate, late) as well as the bar types (SA, SAB, SB) by visual inspection. We find that flocculent galaxies are mostly of late Hubble type while multiple-arm galaxies are likely to be of early Hubble type. The fractional distribution of grand design galaxies is nearly constant along the Hubble type. The dependence of arm class on bar type is not as strong as that of the Hubble type. However, there is about a three times larger fraction of grand design spirals in SB galaxies than in SA galaxies, with nearly constant fractions of multiple-arm galaxies. However, if we consider the Hubble type and bar type together, grand design spirals are more frequent in early types than in late types for SA and SAB galaxies, while they are almost constant along the Hubble type for SB galaxies. There are clear correlations between spiral structures and the local background density: strongly barred, early-type, grand design spirals favor high-density regions, while non-barred, late-type, flocculent galaxies are likely to be found in low-density regions.

• 마이크로전자및패키징학회지
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• 제21권3호
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• pp.1-6
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• 2014

차세대 전자소자는 입출력(I/O) 핀 수의 증가, 전력소모의 감소, 소형화 등으로 인해 fine-pitch 배선 시스템이 요구되고 있다. Fine-pitch 특히 10 um 이하의 fine-pitch에서는 기존의 무연솔더나 Cu pillar/solder cap 구조를 사용할 수 없기 때문에 Cu-to-Cu bumpless 배선 시스템은 2D/3D 소자 구조에서 매우 필요한 기술이라 하겠다. Bumpless 배선 기술로는 BBUL 기술, 접착제를 이용한 WOW의 본딩 기술, SAB 기술, SAM 기술, 그리고 Cu-to-Cu 열압착 본딩 기술 등이 연구되고 있다. Fine-pitch Cu-to-Cu interconnect 기술은 연결 방법에 상관없이 Cu 층의 불순물을 제거하는 표면 처리 공정, 표면 활성화, 표면 평탄도 및 거칠기가 매우 중요한 요소라 하겠다.

• 천문학회보
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• 제39권1호
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• pp.40.1-40.1
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• 2014

We have classified barred galaxies for 418 RC3 sample galaxies within z < 0.01 from SDSS DR7 using the visual inspection, ellipse fitting method and Fourier analysis. We found the bar fraction to be ~60%, 43% and 70% for each method and that the ellipse fitting method tends to miss the bar when a large bulge hides the transition from bar to disk in early spirals. We also confirmed that the Fourier analysis cannot distinguish between a bar and spiral arm structure. These systematic difficulties may have produced the long-time controversy about bar fraction dependence on Hubble sequence, mass and color. We designed a new method to fine bars by analyzing the ratio map of bar strength in polar coordinates, which yields the bar fraction of ~27% and ~32% for SAB and SB, respectively. The consistency with visual inspection reaches around 70%, and roughly 90% of visual strong bar are classified as SAB and SB in our classification. Although our method also has a weakness that a large bulge lowers the value of bar strength, the missing bar fraction in early spirals is reduced to the level of ~1/4 compared to the ellipse fitting method. Our method can make up for the demerits of the previous automatic classifications and provide a quantitative bar classification that agrees with visual classification.