• Journal of Embryo Transfer
• /
• v.10 no.3
• /
• pp.183-191
• /
• 1995

This experiment was carried out to study the determination of survival of vitrified and thawed mammal follicular oocytes by FDA-test. Oocytes were divided into 3 groups according to attachment of cumulus cell. Group A oocytes were tightly surrounded by cumulus cell, group B oocytes were partially surrounded by cumulus cell, and group C oocytes were poorly surrounded by cumulus cell. Vitrification solution developed by our previous study (Kim et al, 1992) which consisted of permeable agent (20 % glycerol + 10 % ethylene glycol) and nonpermeable agent (30 % Ficoll + 10 % sucrose). Oocytes (7~10) loaded into 0.25 ml straw after 10 min equilibration were plunged into liquid nitrogen (- 196$^{\circ}C$) directly. The FDA-score of vitrified and thawed group A oocytes was higher in rat (4.2) than in rabbit (3.9), cow (3.8), mouse (3.4) and porcine (2.4), however that of cumulus cell was higher in rabbit (4.7) than in rat (4.1), cow (2.9), porcine (2.6) and mouse (1.4). The FDA-score of vitrified and thawed group B oocytes were 3.1 (cow), 2.9 (rabbit), 2.9 (mouse), 2.6 (rat) and 2.5 (porcine), respectively. However that of cumulus cell was higher in rabbit (3.7) than in porcine (2.6), rat (2.3), cow (1.7) and mouse (0.3). The FDA-score of vitrified and thawed group C oocytes was higher in mouse (4.1) than in cow (2.9), rabbit (2.6), rat (1.3) and porcine (1.1). As shown in the above results, The survival rates of oocytes were higher in group A than in group B and C except in mouse and cow. These results suggest that the survival of cumulus cell as well as follicular oocytes can be reliably judged by their fluorescence with FDA-test.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2009.05a
• /
• pp.345-349
• /
• 2009

This test cell is developed to the institutes or laboratories research and study gas turbine engine for academic purpose with this test data to provide the fundamentals of operational mechanism and structural configuration, and further to verify thermodynamic calculation The test cell is installed to monitor and compare real-time data with reference engine model performance simulation data. using by NI DAQ(Data acquisition)device and LabVIEW program based on 30lbf-micro turbojet engine.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2010.11a
• /
• pp.495-498
• /
• 2010

This test cell is developed to the institutes or laboratories research and study gas turbine engine for academic purpose with this test data to provide the fundamentals of operational mechanism and structural configuration, and further to verify thermodynamic calculation The test cell is installed to monitor and compare real-time data with reference engine model performance simulation data. using by NI DAQ(Data acquisition)device and LabVIEW program based on 80 lbf-micro turbojet engine.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.14 no.3
• /
• pp.1054-1060
• /
• 2013

Fuel tank of a rotorcraft has a great influence on the survivability of crews. For a long time, US army has tried to develop the proper material for fuel cell of a military rotorcraft. As a result, the design specification of fuel cell, MIL-T-27422A, was issued for the first time on 1961. Through a few revisions, it has been developed to ML-DTL-27422D in 2007. It should be assured that fuel cell satisfies the requirement defined in MIL-DTL-27422D. The qualification test of this specification is classified into Phase I test for material and Phase II for fuel cell itself. This paper studies test conditions and procedures of slosh & vibration, gunfire resistance and crash impact test. They are considered as the most important tests which have a high possibility of failure. The rational consideration of this paper can improve the ability for estimating not only the validity of test procedure and test condition but test result. Based on the rational consideration, it is expected that the ability of the systematic development can be improved.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.14 no.5
• /
• pp.65-72
• /
• 2006

In new generation vehicle technologies, a fuel cell vehicle becomes more important, by virtue of their emission merits. In addition, a fuel cell is considered as a major source to generate the electricity for vehicles in near future. This paper focuses on modeling of not only an electric vehicle and but also a fuel cell vehicle to estimate performances. And an EV cart is manufactured to verify the modeling. Speed, voltage, and current of the vehicle and modeling are compared to estimate them at acceleration test and driving mode test. The estimations are also compared with the data of the Ballard Nexa fuel cell stack. In order to investigate a fuel cell based vehicle, motor and fuel cell models are integrated in a electric vehicle model. The characteristics of individual components are also integrated. Calculated fuel cell equations show good agreements with test results. In the fuel cell vehicle simulation, maximum speed and hydrogen fuel consumption are estimated. Even though there is no experimental data from vehicle tests, the vehicle simulation showed physically-acceptable vehicle characteristics.

• Proceedings of the KIPE Conference
• /
• 2016.07a
• /
• pp.313-314
• /
• 2016

본 논문에서는 리튬이온(Li-Ion) 배터리 셀(Cell)의 Shock test와 Vibration test 기반 18650 원통형 셀 내부 전기적 특성 변화를 분석하였다. 전류적산법을 기반으로 방전 용량을 측정하였고, OCV(Open Circuit Voltage) 측정 및 HPPC(Hybrid Pulse Power Characterization) test를 기반으로 내부 저항을 측정하고 진동 및 충격 시험 전 후의 파라미터를 비교 분석하였다.

• Journal of the Korean Data and Information Science Society
• /
• v.16 no.3
• /
• pp.609-620
• /
• 2005

In the secondary data analysis for categorical data, situations often arise in which the estimated cell variances are available, but not the full matrix of variances. In this case researchers are often inclined to use Pearson-type test statistics for homogeneity. However, for a complex sample observed cell proportions are not distributed as multinomial and Pearson-type test statistic generally is not distributed asymptotically as chi-square distribution. This paper evaluates powers for Wald test and Pearson-type test and the first order corrected test of Pearson-type test for homogeneity. The resulting power curves indicate that as the misspecification effect increases, the amount of inflation of significance level and the loss of power Pearson-type test are getting more severe.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2008.03a
• /
• pp.173-181
• /
• 2008

Gas turbine engine for aircraft are usually operated at the altitude condition which is quite different from the ground condition. In order to measure the precise performance data at the altitude condition, the engine should be tested at the altitude condition by a real flight test or an altitude simulation test with an altitude test facility. In this paper describes the design of altitude test facility for turbo shaft engine. This facility will be located in test cell #2 at the Korea Aerospace Research Institute. Test Cell #2 will be used for altitude testing engines with mass flow rate up to 40kg/s and inlet temperatures in the range from $-65^{\circ}C$ to $200^{\circ}C$. The existing compressor/exhauster station with heater & cooler system will be used to simulate altitude conditions in Test Cell #2.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.14 no.4
• /
• pp.219-225
• /
• 2014

The New efficient Mux-based scan latch cell design and scan test of LOS/LOC modes are proposed for detection of delay faults in digital logic circuits. The proposed scan cell design can support LOS(Launch-off-Shift) and LOC(Launch-off-Capture) tests with high fault coverage and low scan power and it can alleviate the problem of the slow selector enable signal and hold signal by supporting the logic capable of switching at the operational clock speeds. Also, it efficiently controls the power dissipation of the scan cell design during scan testing. Functional operation and timing simulation waveform for proposed scan hold cell design shows improvement in at-speed test timing in both test modes.

• Toxicological Research
• /
• v.13 no.3
• /
• pp.251-256
• /
• 1997

Toluene inhalation increases glutamate level and its receptor in various brain regions. In this study, nitric oxide synthase (NOS) activities were investigated in various rat brain regions using NADPH diaphorase staining method which examined histochemical changes of NOS in the neural cells. Also, in vitro LDH leakage assay and MTT test were performed to investigate the toxic influences of toluene in cultured granule cell of rat cerebellum which was significantly affected with toluene in vivo. Rats were exposed to toluene of 10000 ppm for 3 days. 7 days and 14 days by 20 min $\times$ 2 times a day. NADPH diaphorase staining was processed in the different brain regions after inhalation. NADPH diaphorase staining density was not significantly changed at 3 days inhalation group, but the density decreased in proportion to the duration of toluene inhalation. Over 30% of staining density was decreased at 14 days group which was maximum duration of inhalation in this study. The tendency of staining density decrease was significant in granule cell of cerebellum. Cell death by toluene exposure was observed in cultured cerebellar granule cell. $EC_{50}$ measured with LDH leakage assay and MTT test were 43 mM and 72 mM respectively.