• The Journal of the Convergence on Culture Technology
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• v.9 no.5
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• pp.529-534
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• 2023

Although line printing technology is capable of high-speed and large area printing, residual stresses generated during the manufacturing process can deform the feedhole, causing nozzle plate crack or ink leaks. Therefore, in this paper, we propose a new thermal inkjet print head that is robust, reliable and more suitable for line-printing. The amount of deformation of the conventional line printing head measured through the experiment was converted into an equivalent load, and the validity of the load estimation method was verified through FEA analysis. In addition, in order to minimize deformation without increasing the head size, the head structure was designed to increase internal rigidity by reinforcing the unit nozzle with a pillar or support wall or by adding a support beam or dry/wet etched bridge. The FEA analysis results show that the feedhole deformation was reduced by up to 90%, and it is confirmed that the suggested print head with dry etched feedhole bridge operates normally without nozzle plate cracks and ink leakage through fabrication.

• Journal of the Korea institute for structural maintenance and inspection
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• v.13 no.5 s.57
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• pp.109-120
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• 2009

This paper introduces a new method to estimate the loss of prestressing force for the externally prestressing tendon. The proposed method that combines of HGA and FEM is able to identify the lost tensile force of a externally prestressed tendon. The identification variables of the proposed method is a exteranlly prestressed tendon of tension, effective nominal diameter, mass per unit length and Rayleigh damping coefficients. First of all, a finite element model system is constructed to consider the effect of damping, and these variables are identified using inverse analysis technique - updating algorithm. Finally, throughout total 3 cases of numerical tests, the numerical propriety of the proposed method is verified. Here, it is seen that the errors in the estimated variables by the proposed method are about 1% except in the case of Rayleigh damping coefficients.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.35 no.4
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• pp.779-789
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• 2015

Because cable-supported bridges have long spans and large members, their movements and geometrical changes by temperatures tend to be bigger than those of small or medium-sized bridges. Therefore, it is important for maintenance engineers to monitor and assess the effect of temperature on the cable-supported bridges. To evaluate how much the superstructure expands or contracts when subjected to changes in temperature is the first step for the maintenance. Thermal movements of a cable-stayed bridge in service are evaluated by using long-term temperatures and displacements data. Displacements data are obtained from extensometers and newly installed GNSS (Global Navigation Satellite System) receivers on the bridge. Based on the statistical data such as air temperatures, each sensor's temperatures, average temperatures and effective temperatures, correlation analysis between temperatures and displacements has been performed. Average temperatures or effective temperatures are most suitable for the evaluation of thermal movements. From linear regression analysis between effective temperatures and displacements, the variation rate's of displacement to temperature have been calculated. From additional regression analysis between expansion length's and variation rate's of displacement to temperature, the thermal expansion coefficient and neutral point have been estimated. Comparing these parameters with theoretical and analytical results, a practical procedure for evaluating the real thermal behaviors of the cable-supported bridges is proposed.

• The Transactions of the Korea Information Processing Society
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• v.3 no.4
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• pp.947-960
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• 1996

The primary goal for developing high performance ATM switching systems is to minimized the probability of cell loss, cell delay and deterioration of throughput. ATM switching element that is the most suitable for this purpose is the shared buffer memory switch executed by common random access memory and control logic. Since it is difficult to manufacture VLIS(Very Large Scale Integrated circuit) as the number of input ports increased, the used of switching module method the realizes 32$\times$32, 150 Mb/s switch utilizing 8$\times$8, 600Mb/s os 16$\times$16, 150Mb/s unit switch is latest ATM switching technology for small and large scale. In this paper, buffer capacity satisfying total-memory-reduction effect by buffer sharing in a shared buffer memory switch are analytically evalu ated and simulated by computer with cell loss level at traffic conditions, and also features of switching network utilizing the switching module methods in small and large-capacity ATM switching system is analized. Based on this results, the structure in outline of 32$\times$32(4.9Gb/s throughput), 150Mb/s switches under research in many countries is proposed, and eventually, switching-network structure for ATM switching system of small and large and capacity satisfying with above primary goals is suggested.

• Journal of the Korean Chemical Society
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• v.39 no.5
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• pp.344-349
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• 1995

The crystal and molecular structure of the title compound has been determined from 2568 reflections collected on an automatic CAD4 diffractometer using graphite-monochromated $Mo-K\alpha$ radiation. The crystal is monoclinic system, space group $P2_1$ with unit cell dimensions $a=8.756(8)\AA$, $b=25.757(2)\AA$, $c=8.628(1)\AA$, $\beta=99.15(4)^{\circ}$, V= 1,921(2) ${\AA}^3$, Z=4, $D_C=1.336\;g/cm^3$, ${\mu}=1.54\;cm^{-1}\;and\;T=298^{\circ}K$. The final R factor was 0.051 for 2049 reflections over $3{\sigma}(Fο).$ The crystal has two asymmetric molecules in the unit cell. The arrangement of sulfon group was shown a distorted tetrahedron structure and N(6), N(6') atoms were deviated from the least-squares planes of the thiadiazine rings, respectively. The molecular packings in the unit cell are linked by the two intermolecular hydrogen bonds of N-H---O type and van der Waals forces.

• Journal of the Korean Chemical Society
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• v.38 no.5
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• pp.339-344
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• 1994

The crystal structure of a methanol sorption complex of dehydrated partially Co(II)-exchanged zeolite A, $Co_4Na_4-A{\cdot}6.5CH_3OH$ (a = 12.169(1) $\AA)$, has been determined by single-crystal X-ray diffraction techniques in the cubic space group Pm$\bar3$m at $21(1)^{\circ}C. $Co_4Na_4$-A was dehydrated at $360^{\circ}C\;and\;2{\times}10^{-6}$ torr for 2 days, followed by exposure to about 104 torr of methanol vapor at $22(1)^{\circ}C$ for 1 hr. The structure was refined to final error indices, $R_1$ = 0.061 and $R_2$ = 0.060 with 147 reflections, for which I > $3\sigma(I).$ In this structure, four $Co^{2+}$ ions and 1.5 $Na^+$ ions per unit cell lie at 6-ring positions: the $Na^+$ ions are recessed 0.44 $\AA$ into the sodalite unit and the Co(II) ions extend ca. 0.55 $\AA$ into the large cavity. 2.5 $Na^+$ ions lie in an 8-oxygen ring plane. The 6.5 methanol molecules are sorbed per unit cell. The 6.5 methanol oxygens, all in the large cavity, associate with the 4 $Co^{2+}$ ions and 2.5 $Na^+$ ions.

• Proceedings of the KAIS Fall Conference
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• 2005.05a
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• pp.159-162
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• 2005

전자빔을 이용하던 CRT(Cathode Ray Tube) 모니터에서 픽셀단위의 LCD(Liquid Crystal Display) 디스플레이 사용으로 휴대용 정보처리 장치들은 급속한 발전을 이루게 되었다. 기존의 CRT 모니터에서 전자빔을 사용하던 방식에서 픽셀(Pixel) 단위의 후면발광 디스플레이를 만들면서 CRT 모니터보다 빠른 응답특성을 나타내며 저 전력일 뿐만 아니라 디스플레이의 두께도 줄일 수 있게 되었다. 휴대가 가능한 디스플레이의 발전으로 노트북이나 PDA와 같은 실시간 정보를 활용 및 처리 할 수 있는 방법들을 제시할 수 있었지만 원활한 활용을 위해 더 적은 전력을 사용하는 방법들이 제시되어야 했다. 이에 따라 저 전력 소모, 빠른 응답특성, 넓은 시야각 그리고 경량화가 가능한 디스플레이가 되기 위한 새로운 디스플레이가 선을 보이게 되었다. 현재 차세대 디스플레이로 각광을 받고 있는 디스플레이 소자로는 OLED(Organic Light Emitting Diode)가 있다 이는 LCD 디스플레이가 가지고 있는 단점을 보완하여 우선적으로 높은 색도가 가능하며 후면발광을 사용하지 않고 자체 발광을 하기 때문에 저 전력 소모가 현실화되었다. 또한 디스플레이의 유동성이 가능하여 휘어질 수 있는 특성을 가지고 있다. 그러나 이러한 유기발광 소자의 경우 높은 발광 효율을 위한 구조적 개선이 필요하며 소자의 수명도 개선해야 한다. 이에 따라 유기발광 소자의 메카니즘에 대한 파악이 필요하게 되며 물리적 구조에 대한 이해가 필요하다. 이를 위해 물리적, 수치적 해석으로 소자의 특성을 파악해 줌으로써 개선된 유기발광 소자 제작이 가능 할 것이다.기에 대한 영향정도를 측정하여 정량적으로 도출하였다. 이를 각 구간에 대해 상호 비교 분석함으로써 대형국책사업에서의 공기지연인자에 대한 분석 방법론을 정립하였고 공기지연 분석 방법론의 현실적 적용을 위한 제언과 그에 따른 개선사항에 대해 도출하였다.있는 발판을 마련하게 된다고 추정하였다. 0.5%가 control사이에서 0.95로 가장 색차가 크게 나타났으며, 그 다음이 냉동분쇄 0.5% 0.83으로 나타나 송이의 첨가율이 높을수록 색차가 크게 나타나는 것을 알 수 있다. 색차가 가장 낮은 제품은 법동분쇄 0.3%, 동결건조 0.3%로 나타났다. 송이양갱의 색(color), 냄새(flavor), 맛(taste), 외관(appearances), 질감(viscosity), 종합적 평가(overall acceptability) 등의 관능평가를 실시한 결과 중 색에 대한 기호도는 냉동분쇄 0.1% 송이양갱이 가장 높은 것으로 나타났으나, 집단간 유의한 차이는 나타나지 않았고, 냄새는 동결건조 0.1%의 송이양갱이 3.38로 가장 점수가 높았으며, 냉동분쇄 0.3%의 송이양갱이 2.81로 가장 낮은 기호도를 나타내었다. 맛에서는 p<0.01수준에서 집단간 유의한 차이를 나타내었는데, 동결건조 0.1%가 그 중 가장 높은 기호도를 나타내었으며, 그 다음이 동결건조 0.5%였다. 가장 낮은 선호도를 나타낸 것은 열풍건조 0.5%였다. 질감은 P<.05 수준에서 집단간 유의미한 차이를 나타내었으며 동결건조 0.1%가 가장 높은 기호도를 나타내었으며, 동결건조 0.5%함유 송이양갱이 1.21로서, 현저히 낮은 기호도를 나타내었다. 종합적인 평가에서는 동결건조 0.1%함유

• Journal of the Korean Chemical Society
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• v.18 no.5
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• pp.329-340
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• 1974

Sulfadiazine, $C_{10}H_{10}N_4O_2S$, forms monoclinic crystals of space group $P21}c$ from a mixture of acetone and ethanol with $a=13.71{\pm}0.04,\;b=5.84{\pm}0.03,\;c=15.11{\pm}0.05{\AA},\;{\beta}=115.0{\pm}0.3^{\circ}$, and four molecules per cell. Three dimensional photographic data were collected with $CuK\alpha$ radiation. The structure was determined using Patterson and Fourier synthesis methods and refined by block diagonal least-squares methods with isotropic thermal parameter for all non-hydrogen atoms. The final R value was 0.15 for the 1517 observed independent reflections. The dihedral angle between the planes through the benzene ring and the pyrimidine ring is $76^{\circ}$. The conformational angle formed by the projection of the S-C(5) bond with that of N(1)-C(1) where the projection is taken along the S-N(1) bond is $77^{\circ}$. The imino nitrogen atom, N(1), and pyrimidine nitrogen atom, N(3), form intermolecular $N-H{\cdots}N$ hydrogen bond between the molecules related by center of symmetry. Amino nitrogen atom, N(4), forms two intermolecular $N-H{\cdots}O$ hydrogen bonds, with O(1) and O(2) atoms of different molecules separated by b. A two dimensional network of hydrogen bonds form infinite molecular sheets parallel to the (100) plane. Adjacent sheets are bound together by van der Waals forces.

• Journal of the Korean Chemical Society
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• v.18 no.2
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• pp.97-109
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• 1974

The crystal and molecular structure of sulfaguanidine monohydrate, $C_7H_{10}N_4O_2S{\cdot}H_2O$, was determined from visually estimated intensity data from Weissenberg photographs. The crystal data are monoclinic, space group $P2_1$/c with four molecules in a unit cell of dimensions, ${\alpha}=7.57{\pm}0.03,\;b=5.44{\pm}0.02,\;c=24.76{\pm}0.06{\AA},\;{\beta}=91.0{\pm}0.2^{\circ}$. The structure has been solved by an interpretation of a Patterson map and with a help of a direct procedure on a projection. The parameters were refined isotropically by block-diagonal least-squares methods using 1542 observed independent reflections to give R = 0.14. By hydrogen bonding a guanidyl nitrogen of a sulfaguanidine molecule is linked to the sulfonyl oxygens of the other molecules indirectly through two different water molecules. The role of water molecule is both a donor and an acceptor in hydrogen-bonding formation and these hydrogen bonds are tetrahedrally oriented. The hydrogen-bonding networks form infinite molecular layers parallel to (001) plane.

• Korean Journal of Crystallography
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• v.8 no.2
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• pp.127-131
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• 1997

The crystal structure of a bromine sorption complex of vacuum-dehydrated Ag+ and Ca2+ exchanged zeolite A(a=12,234(1) Å) has been determined by single-crystal X-ray diffraction methods in the cubic space group Pm3m. The crystal was prepared by flow method using exchange solution in which mole ratio of AgNo3 and Ca(NO3)2 was 1:150 with a total concentration of 0.05M. The crystal was dehydrated at 360℃ and 2 ×10-6 Torr for 2days, followed by exposure to 180 Torr of Br2 vapor for 20min. full-matrix least-squares refinements converged to the final error indices of R1=0.111 and R2=0.101 using 90 reflections for which I>3o(I). About 3.1 Ag+ ions and 4.45 Ca2+ ions lie on the two crystallographically nonequivalent three-fold axes associated with 6-ring oxygens. A total of six bromine molecules are sorbed per unit cell. Each bromine molecule approaches a framework oxide ions axially (Br-Br-O=171(2)', O-Br=3.25(6) Å; and Br-Br=2,61(8) Å by a charge-transfer interaction.