• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 D
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• pp.1747-1749
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• 1999

Organic electroluminescent devices (OLEDs) have received a great deal of attention due to their potential application as full-color displays. Europium complexes are known as excellent red color-emitting materials for OLEDs since they show intense photoluminescence at around 610 nm with a sharp spectral bandwidth. In this study, triple-layer and multiple quantum-well structures consisting of Eu$(TTA)_3$(bpy) complex well layer sandwiched triphenyldiamine derivative (TPD) layers were fabricated and their photoluminescent characteristics were investigated. Sharp emission at the wavelength of 615 nm has been observed from the triple-layer and multiple quantum-well structures containing Eu complex. Details on the electrical properties of these structures will be also discussed.

• 한국지진공학회논문집
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• 제20권4호
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• pp.269-276
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• 2016

Seismic performance evaluation of existing building usually needs much time and man power, especially in case of nonlinear analysis. Many data interaction steps for model transfer are needed and engineers should spend much time with simple works like data entry. Those time-consuming steps could be reduced by applying computerized and automated modules. In this study, computational platform for seismic performance evaluation was made with several computerized modules. StrAuto and floor load transfer module offers a path that can transfer most linear model data to nonlinear analysis model so that engineers can avoid a lot of repetitive work for input information for the nonlinear analysis model. And the new nonlinear property generator also helps to get the nonlinear data easily by importing data from structural design program. To evaluate the effect of developed modules on each stages, seismic performance evaluation of example building was carried out and the lead time was used for the quantitative evaluation.

• 한국수소및신에너지학회논문집
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• 제21권4호
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• pp.286-294
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• 2010

According to the propagation of fuel cell system, the importance of that system efficiency is being magnified. Thus, the efficiency improvement of reformer which is the important part of fuel cell system will be required. In structural aspect, the reformer is classified into cylindrical and plate type. Plate type reformer features better maintenance and space efficiency compared with cylindrical type. In this study, we changed the shape of combustion chamber to improve the reforming efficiency. And then we performed the CFD simulation to predict the spacial distribution of temperature. Analysis cased contains with baffles, fins, baffles and fins, and without those. In case of only with-baffle, temperature distributions were uneven because the high temperature stream was concentrated near the baffle end. In case of with-fin, the temperature distributions were relatively even than other cases.

• Journal of Mechanical Science and Technology
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• 제16권12호
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• pp.1613-1626
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• 2002

This paper presents hybrid control of an active suspension system with a full-car model by using H$\sub$$\infty$/ and nonlinear adaptive control methods. The full-car model has seven degrees of freedom including heaving, pitching and rolling motions. In the active suspension system, the controller shows good performance: small gains from the road disturbances to the heaving, pitching and rolling accelerations of the car body. Also the controlled system must be robust to system parameter variations. As the control method, H$\sub$$\infty$/ controller is designed so as to guarantee the robustness of a closed-loop system in the presence of uncertainties and disturbances. The system parameter variations are taken into account by multiplicative uncertainty model and the system robustness is guaranteed by small gain theorem. The active system with H$\sub$$\infty$/ controller can reduce the accelerations of the car body in the heaving, pitching and rolling directions. The nonlinearity of a hydraulic actuator is handled by nonlinear adaptive control based on the back-stepping method. The effectiveness of the controllers is verified through simulation results in both frequency and time domains.

• The Korean Journal of Pain
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• 제11권2호
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• pp.317-320
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• 1998

Since Reiestad and Str$\ddot{o}$mskag reported interpleural installation of local anesthetic solutions as a technique for the management of postoperative pain in the patients undergoing cholecystectomy, renal surgery and breast surgery, many physician applied this technique for upper abdominal pain from various reasons such as technically simple, effective pain relief, less respiratory depression. So we tried interpleural analgesia in two patients who suffered from severe upper abdominal pain. One had upper abdominal pain due to chronic pancreatitis and the other had right upper abdominal pain after PTBD (percutaneous transhepatic bile drainage) for biliary cirrhosis and systemic jaundice. Both were injected 10 ml of 1% lidocaine and infused continuously with 1% lidocaine (2 ml/hr) using 2-Day Baxter$^{(R)}$ infusor. After bolus injection of lidocaine, pain scores (VAS 0~100) were recorded below 25mm and had not exceed that level during continuous infusion. After removing the catheters, two patients were all satisfied with this therapy. Our experiences with this technique showed that continuous infusion of local anesthetics through an interpleural catheter is effective in the control of refractory upper abdominal pain without any complication.

• 한국동물번식학회:학술대회논문집
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• 한국동물번식학회 2001년도 춘계학술발표대회
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• pp.77-77
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• 2001

본 연구는 돼지 동결정액의 번식성적을 개선코자 기존의 maxi-straw와 cryogenic-vial을 이용하여 포장방법에 따른 동결방법과 융해방법별 정액성상 및 번식성적을 비교하였다. 동결방법은 두 가지 포장방법 모두 정액의 양(5$m\ell$)과 농도(5.0$\times$$10^{9}$/dose)가 동일한 조건으로 처리하였으며, LYE(Lactose egg york extender) 보존액으로 희석하여 액체질소 상단 15cm에서 20분간 동결하였다. 융해방법은 maxi-straw는 52$^{\circ}C$에서 45초간 cryogenic-vial은 52$^{\circ}C$에서 190초간 융해하여 $25^{\circ}C$로 가온 된 80$m\ell$ BTS (Beltsville thawing solution) 보존액과 혼합하였다. 정액성상검사는 정자자동분석기(SAIS : Sperm Analysis Image System, Korea)를 이용하였다. 총활력(TM : Total motility)과 정자의 빠르기(VCL : Curve linear velocity)는 maxi-straw가 54.3%와 46.6%로 cryogenic-vial의 35.6%와 36.6%보다 우수하였다(P<0.05). 정자의 직진성(STR : Straightness)과 NAR은 maxi-straw가 53.2%와 32.6%로 cryogenic-vial의 47.3%와 29.8%와 비슷한 경향을 나타내었다. 수태율과 분만율 및 총산자수는 maxi-straw가 77.3%, 68.2% 및 8.0두로 조사되어 cryogenic-vial포장방법의 66.7%, 61.9% 및 7.4두보다 다소 우수하였으나 통계적인 유의차는 인정되지 않았다. 이상의 결과로 볼 때 cryogenic-vial방법이 새로운 돼지 동결정액 포장방법의 가능성을 나타낸다고 사료된다.

• Earthquakes and Structures
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• 제12권2호
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• pp.223-236
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• 2017

Seismic assessment and rehabilitation of Monumental Buildings constitute an important issue in many regions around the world to preserve cultural heritage. On the contrary, many recent earthquakes have demonstrated the high vulnerability of this type of structures. The high nonlinear masonry behaviour requires ad hoc refined finite element numerical models, whose complexity and computational costs are generally unsuitable for practical applications. For these reasons, several authors proposed simplified numerical strategies to be used in engineering practice. However, most of these alternative methods are oversimplified being based on the assumption of in-plane behaviour of masonry walls. Moreover, they cannot be used for modelling the monumental structures for which the interaction between plane and out-plane behaviour governs the structural response. Recently, an innovative discrete-modelling approach for the simulation of both in-plane and out of-plane response of masonry structures was proposed and applied to study several typologies of historic structures. In this paper the latter model is applied with reference to a real case study, and numerically compared with an advanced finite element modelling. The method is applied to the St.Venerio church in Reggiolo (Italy), damaged during the 2012 Emilia-Romagna earthquake and numerically investigated in the literature.

• 동아시아식생활학회지
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• 제16권3호
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• pp.344-348
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• 2006

This study was carried out to survey the effect of medicinal herbs on the growth of 3 strains of lactic starter cultures in MRS broth by the addition of 0, 1, 3, 5, and 10% water extract, after 30 hrs incubation. The pH, titratable acidity and O.D. of lactic acid bacteria were investigated to obtain fundamental knowledge for the development a new product. The effects of medicinal herbs extracts on the growth of lactic acid bacteria were variable depending upon the species of lactic acid bacteria and medicinal herbs extract. Growth of Str. thermohilus was activated by addition of 1 and 3% Angelica gigas water extract, but the basal medium plus 5 and 10% extract and growth of L. acidophilus and Bif. longum were depressed by the addition of extract. The pH and acid production ability dropped slightly in the basal medium plus 1 and 3% of extract. The other samples following the same trend as the control.

• 대한인간공학회지
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• 제29권1호
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• pp.33-37
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• 2010

This study was aimed at developing 1) iso-perception maps for various groups of drivers in terms of age, gender, and anthropometry and 2) the experiment framework required for obtaining subjective and objective measures. A total of 9 maps, which describe drivers' perceptions regarding their static behaviors inside a typical mid-size sedan, can be used to improve the utilization of the limited driver workspace, and to select better design alternatives for occupant packaging. An adjustable seating buck, $a^{***}$-camera motion capture system (Vicon), and $a^{**}$-channel EMG system were used for the experiment. Each iso-perception map was developed while H-PT, steering wheel center, or TGS knob center was moved to each of pre-defined positions relative to driver-selected positions. Adjustable ranges or positions of the seat, steering wheel, and TGS lever described in iso-perception maps can be used to determine better package layout alternatives.

• 천문학회지
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• 제40권4호
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• pp.131-132
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• 2007

The research of OH maser emission sources with high angular resolution is complicated by the effects of interstellar scattering: more over, most of the OH maser sources are located in the galactic plane where the scattering is largest. However, the data available from pulsar studies on the spatial distribution of the amount of scattering indicate that there is a strong non-uniformity in the distribution of the amount of scattering material. There are directions in the galactic plane where the scattering is an order of magnitude higher than the average, as well as directions where the scattering is much lower. The latter provide an opportunity to investigate OH masers with the full angular resolution offered by very long baseline interferometry instruments, like the VLBA, and measure their true angular size, shape and brightness temperature. We have observed approximately 100 OH maser sources, distributed all over the northern hemisphere, with the VLBA in order to study the scattering properties of the interstellar medium.