• Electrical & Electronic Materials
• /
• v.10 no.6
• /
• pp.541-547
• /
• 1997

(Pb$_{1-x}$ La$_{x}$)Ti$_{1-x}$ $_4$O$_3$(x=0, 0.02, 0.04, 0.08) ceramic thin films were fabricated by Sol-Gel method. A stock solution of (Pb, La)TiO$_3$ with excess Pb 10 mol% was made and spin-coated on the Pt/Ti/SiO$_2$/Si substrate at 400rpm for 30 seconds. Coated specimens were dried on the hot-plate at 35$0^{\circ}C$ for 10 min and sintered at 500~75$0^{\circ}C$ for 1 hour. The dielectric constant, remanent polarization and coercive field of the PLT(6at.%) thin films sintered at $650^{\circ}C$ were 884, 13.95$\mu$C/$\textrm{cm}^2$ and 8.7kV/cm, respectively. Pyroelectric coefficient, figure of merit of pyroelectric current, voltage responsivity and detectivity of PLT(6at.%) thin films were 3.2$\times$10$^{-8}$ C/$\textrm{cm}^2$K, 1.02$\times$10$^{-8}$ C.cm/J, 2.9 $\times$10$^{-11}$ C.cm/J, 0.29$\times$10$^{-8}$ C.cm/J, respectively.ely.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2020.06a
• /
• pp.48-49
• /
• 2020

Recently the diversification of construction market and the continuous reduction of construction amount are raising the need of alternative delivery method in the construction industry. The foreign advanced companies actively adopted the CM at Risk delivery method where they perform the service of agent CM in the design phase, and agree GMP(Guaranteed Maximum Price) with the client at the time of 50~80% completion of design. Even in Korea they began to apply that method to pilot projects. In CM at Risk, through the early participation of builder, the level of design completion can be improved and the change order and construction period delay can be minimized. On the other hand, GMP is usually calculated when the design is about 80% complete, so there is uncertainty in the construction cost. Therefore, in this research, the increased amounts of construction cost are analyzed in a number of public construction projects, and GMP calculation process is proposed using the analysis results and CBR(Case-Based Reasoning) technique to reduce the construction cost increase in the construction phase.

• KCI Concrete Journal
• /
• v.13 no.2
• /
• pp.33-41
• /
• 2001

This paper presents the crack effect on CIP anchors and prediction of tensile capacity, as governed by concrete cone failure. Single anchors where located at center of concrete specimen. Three different types of cracks such as crack width of 0.2 mm and 0.5 mm, crack depth of 10 cm and 20cm , and crack location of center and off-center point were simulated. Static tensile load was applied to 7/8-in. CIP anchors of 10 cm and 20 cm embedment length in concrete with compressive strength of 280 kgf/$\textrm{cm}^2$. Tested pullout capacities were compared to the values determined using current design methods (such as ACI 349-97, ACI 349 revision and CEB-FIP which is based on CCD Method). The comparison of CCD Method and ACI revision showed almost the same values in uncracked concrete specimen. In cracked concrete, CCD Method predicted conservative values. Three-dimensional non-linear FEM modeling also has been performed to determine the stresses distribution and crack inclination.

• ETRI Journal
• /
• v.28 no.6
• /
• pp.745-760
• /
• 2006

In this paper, we particularly deal with no $F_p$-rational two-torsion elliptic curves, where $F_p$ is the prime field of the characteristic p. First we introduce a shift product-based polynomial transform. Then, we show that the parities of (#E - 1)/2 and (#E' - 1)/2 are reciprocal to each other, where #E and #E' are the orders of the two candidate curves obtained at the last step of complex multiplication (CM)-based algorithm. Based on this property, we propose a method to check the parity by using the shift product-based polynomial transform. For a 160 bits prime number as the characteristic, the proposed method carries out the parity check 25 or more times faster than the conventional checking method when 4 divides the characteristic minus 1. Finally, this paper shows that the proposed method can make CM-based algorithm that looks up a table of precomputed class polynomials more than 10 percent faster.

• Korean Journal of Crystallography
• /
• v.7 no.1
• /
• pp.81-87
• /
• 1996

The mechanism of silicon incorporation has been analyzed for the boat-grown GaAs crystals on the basis of phase equilibrium in the Ga and As system. Comparison was made between silicon concentrations calculated from the thermodynamics of incorporation reaction and carrier concentrations measured from van der Pauw method. For the 1-T HB(single temperature zone horizontal Bridgman) crystals, calculated concentrations were 5.3 ×10 15 (atoms/cm3), measured as 9.8 ×10 15(/cm3) at the seed part. They were calculated to be 1.1 ×10 16(atoms/cm3) and measured as 1.5 ×10 16(/cm3) for the 2-T(double temperature zone) HB crystals. On the other hand, it was found to be closer between the calculated and measured silicon concentrations for the VGF(vertical gradient freeze) crystals, which were grown within half the run time compared with 1-T or 2-T HB method.

• Journal of the Korean housing association
• /
• v.12 no.3
• /
• pp.141-148
• /
• 2001

To design mechanical ventilation for bathroom of apartment houses where air supply and exhaust are taken into consideration, mock-ups of ventilation systems, widely used in bathroom of apartment houses with an area of 100$\textrm{m}^2$, were made and installed in a laboratory. These ventilation mock-ups were available for control of air supply and exhaust, and the sizes of supply openings were 40cm${\times}$1cm, 40cm${\times}$3cm, and 40cm${\times}$5cm. They were installed at five positions, spaced 45cm at a height of 5cm from the floor. The exhaust fan was designed for its operating voltage to be set to five steps(100V, 130V, 150V, 180V and 220V) in order to control its air flow rates. When the size and position of each supply opening were changed with the wind velocity of the exhaust fan set to the step 5, the ventilation rates were measured and analyzed by the concentration decay method of tracer gas method, in order to present an efficient mechanical ventilation system. The results of the study revealed that the ventilations rates would increase in the presence of supply openings, compared to the absence of supply openings, and that the larger the size of the supply opening, the more the ventilation rates. Therefore, it was found necessary to take air supply into consideration.

• The Korean Journal of Soil Zoology
• /
• v.4 no.2
• /
• pp.81-85
• /
• 1999

Efficiencies of hand sorting, vermifuge application and combined methods of them for sampling earthworms in the field were compared. 1) hand sorting : sampling unit of soil (50 cm${\times}$50 cm${\times}$30 cm, width${\times}$length${\times}$depth) was dug out and earthworms were sorted by hands. 2) Vermifuge application : Solution of mustard, pepper or formalin was treated onto the soil surface of smpling unit (50 cm${\times}$50 cm, width${\times}$length). 3) Combined method : In a sampling unit of soil (50 cm${\times}$50 cm${\times}$30 cm, width${\times}$length), hand sorting was carried out into the depth of 10 cm or 15 cm and then vermifuge was treated. Earthworms were collected more in numbers by hand sorting than vermifuge application although it was much more time-consuming and labor intensive. Efficiency of mustard to extract earthworms was as same as formalin but much better than that of pepper. Combined method of hand sorting with mustard treatment was more efficient than vermifuge applications and other combined methods. And it could collect earthworms as many as hand sorting, but was much less time-consuming and labor-intensive than hand sorting. Thus combined method of hand sorting (to the depth of 15 cm) with mustard treatment could be recommended for the sampling of earthworms in the field.

• The Research Journal of the Costume Culture
• /
• v.14 no.5
• /
• pp.699-714
• /
• 2006

The purpose of this study is to suggest a methodology to grasp the design method of industrial slacks pattern for women in their early twenties. The result of this study is as follows: 1. The result of the questionnaire showed that the design of rear center gradient was most important and the rear center gradient was designed by shifting waist line and hip line to a suitable degree.; below the waist by 4cm, the girth was measured and the ease of $0{\sim}1cm$ was applied to it, and the ease of hip girth was $3.2{\pm}1.2cm$, and rear center gradient was $2.2{\pm}1cm$, and front crotch extension was $2.8{\pm}0.5cm$, while rear crotch extension was $6.3{\pm}0.5cm$. 2. By comparing rear center gradient which was selected as an important design item with total crotch length and hip girth, I selected industrial pattern and educational pattern, and evaluated them on human bodies. In the result of ANOVA analysis, there were meaningful differences in 8 items: the ease of front waist girth, the ease of front abdomen, the ease of front hip girth, rumples in the side lines, the location of rear waist line, etc. 3. The design method of slacks pattern suitable for women in their early twenties was suggested as follows: the location of waist girth is below waist by $2.5{\sim}3cm$; the ease of waist girth is $0{\sim}1cm$; the ease of hip girth is $2{\sim}3cm$; total crotch length is body size - 5cm; rear center gradient is $2.5{\pm}0.5cm$; rear crotch extension is $7{\pm}0.5cm$; front crotch extension is 3cm.

• Journal of the Korea Institute of Building Construction
• /
• v.11 no.2
• /
• pp.108-115
• /
• 2011

This study investigates the construction management selection methods for fair competition within the construction management market by analyzing the current status of domestic construction management, the 2010 publication on the status of construction management, and the construction management evaluation criteria. Also, the 2009 publication of top CM service establishments, the average proportion of tender for 120 CM services from 2002 to 2010, and six assessment results which are open to the parties directly involved were statistically analyzed to review the adequacy of the evaluation criteria. This analysis shows that the evaluation criteria for the CM service impedes the development of the construction management industry and companies, since the criteria are decided by the service payment, and the technical skills assessed by technical proposals have no ties with contract prices. Therefore, this study proposes an improvement of the selection methods in accordance with the project characteristics and the technical requirements. However, more research is still needed to derive a detailed classification method of the technical requirement, the owner's evaluation criteria selection, and the preparation of an institutional foundation for the construction manager's post-evaluation.

• The Journal of Korean Medicine
• /
• v.24 no.2
• /
• pp.138-147
• /
• 2003

Objectives : In this study, we investigated the mechanism by which Chelidonium majus (CM) regulates nitric oxide (NO) production. Methods : Using mouse peritoneal macrophages, the mechanism by which CM regulates NO or tumor necrosis $factor-{\alpha}(TNF-{\alpha})$ production was examined. NO release was measured by the Griess method. $TNF-{\alpha}$ production was measured by the ELISA method. The protein extracts were prepared and samples were analyzed for the inducible NOS(iNOS) expression and nuclear factor kappa $B(NF-{\kappa}B)$ activation by Western blotting. Results : When CM was used in combination with recombinant $interferon-{\gamma}{\;}(rIFN-{\gamma})$, there was a marked cooperative induction of NO production. CM had an effect on NO production by itself. The expression of the iNOS gene was increased in $rIFN-{\gamma}$ plus CM-stimulated peritoneal macrophages and almost completely inhibited by pre-treatment with pyrrolidine dithiocarbamate (PDTC), an inhibitor of $NF-{\kappa}B$. The $NF-{\kappa}B$ activation was increased in rIFN-{\gamma} plus CM-induced peritoneal macrophages. The increased production of NO from $rIFN-{\gamma}$ plus CM-stimulated peritoneal rnacrophages was decreased by the treatment with $N^{G}-monomethyl-{_L}-arginine{\;}(N^{G}MMA){\;}N^{\alpha}-Tosyl-Phe$ chloromethyl ketone (TPCK) , and was almost completely inhibited by pre-treatment with PDTC. Furthermore, treatment with CM alone or rIFN-{\gamma} plus CM in peritoneal macrophages caused a significant increase in $TNF-{\alpha}$ production. PDTC decreased CM-induced $TNF-{\alpha}$ production significantly. After CM treatment in HT-29 or AGS cells, cell viability decreased. Conclusions : These findings demonstrate that CM increases the production of NO and $TNF-{\alpha}{\;}by{\;}rIFN-{\gamma}-primed$ macrophages and suggest that NF-B plays a critical role in mediating these effects of CM.