• 한국산학기술학회논문지
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• 제7권4호
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• pp.709-714
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• 2006

본 연구는 폐기물로 발생되는 부산석회 Core를 연속식 칼럼에 적용하여 수중의 인산염을 효과적으로 제거할 수 있는 방안을 찾고자 수행되었다. 부산석회와 인산염의 칼럼 반응에서 Hydroxyapatite을 형성하여 수중의 인산염을 제거할 수 있는 것으로 나타났으며 부산석회 Core size 1, 2에서 유입수의 인산염 농도에 관계없이 초기 11시간동안 90% 이상의 높은 제거율을 보였다. 또한 부산석회 Core size와 관계없이 유입수 유량이 증가할수록 파과시간이 줄어드는 것을 알 수 있었다.

• Bulletin of the Korean Chemical Society
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• 제31권8호
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• pp.2357-2360
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• 2010

Kinetic studies on the pyridinolysis of aryl dithiocyclopentanecarboxyaltes 2 were carried out at $60.0^{\circ}C$ in acetonitrile. In the aminolysis of 2, the $\beta_X$ values were 0.5 - 0.8 with anilines, and there was no breakpoint. However, in the pyridinolysis of 2, biphasic Bronsted plots were obtained, with a change in slope from a large value ($\beta_X{\cong}0.7$) to a small value ($\beta_X{\cong}0.4$) at $pK_{a}^0$ = 5.2. This was attributed to a change in the rate-limiting step from breakdown to the formation of a zwitterionic tetrahedral intermediate, $T^{\pm}$, in the reaction path, with an increase in the basicity of the pyridine nucleophile. An obvious change in the cross-interaction constant ${\rho}_{XZ}$ from a large positive ($\rho_{XZ}$ = +1.02) value to a small negative value (${\rho}_{XZ}$ = -0.17) supports the proposed mechanistic change.

• Bulletin of the Korean Chemical Society
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• 제32권12호
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• pp.4179-4184
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• 2011

The nucleophilic substitution reactions of bis(2,6-dimethylphenyl) chlorophosphate (5), containing the four ortho-methyl substituents, with X-pyridines are investigated kinetically in MeCN at $65.0^{\circ}C$. The free energy correlations for substituent X variations in the nucleophiles exhibit biphasic concave upwards with a breakpoint at a X = 3-Cl. Unusual positive ${\rho}_X$ (= +5.40) and negative ${\beta}_X$ (= -0.83) values are obtained with the weakly basic pyridines. The pyridinolysis rate of 5 is hundreds times slower compared to that of bis(phenyl) chlorophosphate because of the steric hindrance of the four ortho-methyl substituents in the two phenyl rings. Ion-pair mechanism is proposed and positive ${\rho}_X$ and negative ${\beta}_X$ values are substantiated by an imbalance of the transition state.

• 대한교통학회지
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• 제14권2호
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• pp.7-29
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• 1996

Traffic flow characteristics is analysed on eight multi-lane roads which are unsignalized in urban areas. Data of traffic flow rates by classification and average speed were gathered every ten minutes interval for twenty-four hours. Machine (NC-90A) was used to acquire the field data. The major purpose of this study is to build up speed-density models on urban arterial roads. Five different kinds of models were tested. Those models are Greenshields' model, Greenberg's model, modified Greenberg's model, Underwood's model and Drake's model. The modified Greenberg's model fits best at six points and the Greenshield's model fits best two points out of eight points. The breakpoint(Kb) of modified Greenberg's model is between 10 and 32 pcphpl. Capacity drawn from speed-volume relationships were appeared to be arround 2,000 and 2,200 pcphpl at the Hannam Bridge and the Hannam Overpass and 1,100 and 1,700 pcphpl at Namsan Tunnel(No1) and the beginning point of Gyeong-Bu Expressway.

• 컴퓨터교육학회논문지
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• 제10권6호
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• pp.91-105
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• 2007

이미지로부터 타원을 추출하기 위하여 Hough transform을 많이 이용하고 있다. 그러나 이 방법은 시간과 기억 공간을 많이 소모한다. 그리고 기존의 타원분리 방법은 잡음에 예민하거나 많은 breakpoint를 발생시키는 단점이 있다. 이 논문에서는 면적을 이용하여 잡음이 있는 디지털 곡선으로부터 타원을 분리 및 추출하는 빠른 방법을 제시한다. 실험 결과로, 제시된 방법이 잡음을 가지고 있는 곡선으로부터 타원 호의 분리 및 추출이 가능하며, 추출된 타원과 주어진 곡선간의 거리오차평균이 일정 임계값 범위 내에 있는 것을 보여준다.

• 제어로봇시스템학회논문지
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• 제21권11호
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• pp.1044-1049
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• 2015

This paper proposes an autonomous navigation system of mobile robots for indoor corridor environment. The system uses a laser scanner but does not use reflectors. The laser scanner measures the distance between robot and structures such as wall, pillar, and fixtures. Adaptive breakpoint detector and modified IEPF (iterative endpoint fit) are developed to find mark points from the distance data. The robot path for corridor is then generated using the angle histogram of the mark points. The experimental results are finally presented to show the effectiveness of the proposed method.

• 물과 미래
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• 제23권3호
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• pp.363-371
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• 1990

본연구는 정수처리에 있어서의 적정염소주입제어를 위한 산화환원전위법의 활용가능성에 대한 기초적 검토를 실시한 것이다. 연구실험을 통하여, 원수의 염소화반응에 미치는 pH와 온도 및 산화환원전위의 재현성에 대하여 평가하였다. 수도원수의 불연속점부근에 있어서의 산화환원전위의 검출은 불연속점적정곡선의 작성에 의하여 이루어졌으며, 이로 인하여 본방법의 염소처리제어에의 기본적인 활용가능성이 확인되었다.

• Preventive Nutrition and Food Science
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• 제3권2호
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• pp.123-127
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• 1998

Fixed-bed adsorption was adapted to separate phenolic acids from diluted phenolic solution. Break-through curve was obtained by nonlinear curve fitting method, and breakpoint, saturation time, and mass transfer coeffi-cient were calculated . Break point and saturation time were reached slower with $\rho$-coumaric acid than ferulic acid .The p-coumaric acid, having small molecular weight, is suposedly traveled longer pathway in characoal than ferulic acid. Fixed-bed adsorption iwht gallic acid having more hydroxyl functional group than other phenolic acids showed break point arrival and the largest saturation time. This fact means that there was bigger electrostatic affinity between gallic acid and charcoal than between other phenolic acids and charcoal.

• Asian-Australasian Journal of Animal Sciences
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• 제18권3호
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• pp.396-402
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• 2005

Three experiments were conducted to determine the effects of dietary arginine concentrations on plasma free amino acid (PAA) concentrations in rainbow trout, Oncorhynchus mykiss (Walbaum). The first experiment was conducted to determine appropriate post-prandial and food deprivation sampling times in dorsal aorta cannulated rainbow trout averaging 519${\pm}$9.5 g (mean${\pm}$SD) at $16^{\circ}C$. Blood samples were taken at 0, 2, 3, 4, 5, 6 and 24 h after feeding (0 and 24 h blood samples were taken from the same group of fish). PAA concentrations increased by 2 h post-feeding and the concentration of all essential amino acids except histidine peaked at 5 h and returned to 0 time values by 24 h. In the second experiment dorsal aorta cannulated rainbow trout averaging 528${\pm}$11.3 g (mean${\pm}$SD) were divided into 6 groups of 4 fish to study the effect of dietary arginine levels on PAA. After 24 h food deprivation, each group of fish was fed one of six L-amino acid diets containing graded levels of arginine (0.48, 1.08, 1.38, 1.68, 1.98 or 2.58%) by intubation. Blood samples were taken at 0, 5 and 24 h after feeding. Post-prandial (5 h after feeding) plasma-free arginine concentrations (PParg) showed a breakpoint at 1.03% arginine in the diet and post-absorptive (24 h after feeding) plasma free-arginine concentrations (PAarg) showed a breakpoint at 1.38% arginine. PAarg increased linearly from fish fed diets containing arginine between 0.48% and 1.38%, and the concentrations remained constant from fish fed diets containing arginine at or above 1.38%, but were all below PParg at all time points. Results of the third experiment confirm the results that PParg concentrations from fish fed arginine deficient diets were higher than PAarg (0 or 24 h values). Thus, in contrast to mammals and birds, the PParg when arginine is present in the diet as the most limiting amino acid such that it severely limits growth, increases in plasma rather than decreases.

• 대한임상검사과학회지
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• 제41권1호
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• pp.6-10
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• 2009

Ring chromosome occurs when both telomeres of a chromosome are lost and the remaining portion of the chromosome circularizes to re-establish chromosome stability. This abnormal structure shows mitotic instability unlike the normal chromosomes, causing problems during mitosis. Here, we report one case of "chromosome 4 ring syndrome" on a 6-month-old male patient with growth retardation. Ring chromosome, monosomy, dicentric chromosome were shown by conventional chromosome analysis using peripheral blood. Peripheral blood was used and incubated for 72 hours for chromosome analysis. 3 probes (LSI WHS SpectrumOrange/CEP 4 SpectrumGreen, 4p subtelomere probe, 4q subtelomere probe) were used to detect the origin and breakpoint of ring chromosome 4 by FISH (fluorescense in situ hybridization) technique.