Even in an era where 8-meter class telescopes are common, small telescopes are considered very valuable research facilities since they are available for rapid follow-up or long term monitoring observations. To maximize the usefulness of small telescopes in Korea, we established the SomangNet, a network of 0.4{1.0 m class optical telescopes operated by Korean institutions, in 2020. Here, we give an overview of the project, describing the current participating telescopes, its scientic scope and operation mode, and the prospects for future activities. SomangNet currently includes 10 telescopes that are located in Australia, USA, and Chile as well as in Korea. The operation of many of these telescopes currently relies on operators, and we plan to upgrade them for remote or robotic operation. The latest SomangNet science projects include monitoring and follow-up observational studies of galaxies, supernovae, active galactic nuclei, symbiotic stars, solar system objects, neutrino/gravitational-wave sources, and exoplanets.

Today, conventional CVT equipped vehicle controls engine torque and gear ratio by using engine torque map and shifting map. But this control process is difficult to optimize the fuel economy when the driving mode is changed arbitrary. In this study, I propose the real-time CVT control with considering the power loss of transmission system to improve vehicle fuel economy and drivability. The driving performance and fuel economy of the proposed control logic is analyzed by backward simulation and the validity of new control logic is verified.

Emissions of hazardous substances in automobiles are caused by combustion of internal combustion engines, friction of brake pads and tire wear. In this study, we propose a method to reduce the harmful substances emitted in internal combustion engine by using HHO gas. In order to reduce the exhaust gas of the internal combustion engine, HHO gas having excellent combustion characteristics was added to the combustion chamber. The HHO gas generator was installed in the intake line and the HHO gas was introduced into the combustion chamber with the mixed gas through the intake line. At this time, we compared and analyzed the performance of the engine performance on the presence and absence of HHO gas.

The heat transfer characteristics of a louver fin for a radiator are numerically analyzed to investigate the performance of radiator for automotive. The commercial code FLUENT is utilized to simulate a louver fin to analyze both the flow fields of air and the solid region of lover fin. The numerical analysis is performed with the variation of air mass flow rate. The results show that as mass flow rate increases, louver fin efficiency is nearly constant. The correlation of the average Nu is derived. The results of numerical study is useful in louvered fin design.

The major complaint of hybrid vehicle driver is that real fuel economy is lower than the certified fuel economy. Therefore, it is important to analyze the cause of low fuel economy and to improve the fuel consumption at real driving condition. In this study, the various speed profile is measured by driving urban road with considering different traffic jam. By using backward simulation, the fuel economy characteristics of the acquired driving modes are analyzed. From the simulation results, the operating points of engine and motor analyzed and the cause of decrease of real fuel economy is examined.

The frozen start up characteristics of the two phase closed thermosyphon using water and FC 40 as working fluid to prevents dry out by freezing of water at the condenser when below zero operation condition has been tested and studied. The experimental data showed that the thermosyphon using immiscible 2 fluids thermosyphon start up successfully at a -30℃ cooling condition as melted water by inflow 2nd working fluid to the condenser.

The heat transfer characteristics of a spiral type EGR cooler for a diesel engine are numerically analyzed to investigate the performance of EGR cooler. The commercial code FLUENT is utilized to simulate a single spiral tube with constant wall temperature conditions. The numerical analysis is performed with the variation of exhaust gas flow rate. The results show that as mass flow rate increases, temperature difference between inlet and outlet and efficiency become lower, while heat flux gets higher. The empirical correlation is derived in forms of Nusslet number and Reynolds number based on the numerical results.

Because industrial Vehicles drive and work under heavy load condition, the gear ratio of transmission and the stall torque ratio of torque converter is high. Recently, to reduce the cost of vehicle, many people have interest in applying multi-phase torque converter to vehicle and reducing the gear step. In this study, the target performance of vehicle is analyzed and the performance matching of multi-phase torque converter is studied to equip torque converter to heavy duty folk lift vehicle.

The conventional shifting map is developed to enhance the driving performance and fuel economy. According to the driver’s pedaling of accelerator, TCU controls gear ratio in view point of economy or driving performance. In this paper, various reverse engineering is applied to the driving test results of heavy duty AMT vehicle. With the test results, the performance of propulsion source is estimated and basic performance of vehicle is analized. Also the method to derive the shifting schedule according to power or fuel efficient, is developed and compared with the actual shifting map, and various shifting states is estimated. The developed numerical analysis model will be a stepping stone for the shift pattern development and various shift control research

Many countries of the world has been devoting a lot of effort to reduce carbon emission. In order to reduce carbon emission, the high efficiency engine has been studied in the automotive industry. Of these, the spread and research of the diesel engine in Europe center are active. However the combustion characteristic of diesel engines have disadvantages of much NOx and soot emissions. In this study, the optimum regeneration point of the forced regeneration type DPF(Diesel Particulate Filter) that was equipped in medium-duty diesel vehicles using a mechanical fuel injection system have studied. DPF that is applied to the medium-duty diesel vehicle has a bent inlet pipe. The flow distribution characteristics of DPF according to the influence of the bent pipe have investigated. The flow distribution characteristics of DPF according to variation of the engine operating condition is considered to be useful data In order to decide the optimum regeneration point.

The gas flow and heat transfer inside an EGR cooler for a diesel engine are numerically analyzed to investigate the performance of EGR cooler. The commercial code FLUENT is utilized to simulate a single spiral tube with constant wall temperature condition. The numerical analysis is performed with the variation of exhaust gas flow rates according to engine speed. The computational results agree well with the experimental results published before. The results show that the maximum error rate is about 0.6% for all operating conditions. Thus a single tube model with constant wall temperature condition is appropriate for simulating EGR cooler.

In ruminants, Interferon-τ (IFN-τ) has the role of recognizing pregnancy signals produced by the embryo and it may have an important role during the luteolysis. Therefore, the purpose of the present study was to investigate the effect of IFN-τ on prostaglandin synthesis, cyclooxygenase-2 (COX-2) gene expression in vitro and secretion of progesterone (P4) in vivo. The epithelial and stromal cells isolated from bovine endometrium were cultured with different doses of IFN-τ (0, 0.02, 0.2 and 2 μg/ml). Human chorionic gonadotropin (hCG, 1.5 IU/ml) was used as a positive control. Prostaglandin E2 and F2α levels in the culture media were analyzed by enzyme immunoassays, and total RNA was extracted from the cells for RT-PCR. P4 concentrations in blood samples were assayed by chemiluminescent immunoassay system. In epithelial cells, COX-2 gene expression was increased in the presence of IFN-τ (p<0.05), but it was not significantly different in all groups of stromal cells except 2 μg/ml IFN-τ group (p<0.05). Although IFN-τ did not affect PGE2 and PGF2α production in epithelial cells, it decreased PGE2 and PGF2α production significantly in stromal cells (p<0.05). In vivo experiment, the P4 concentrations in blood sample was significantly increased after injection of 1 μg/ml IFN-τ. These results indicate that PG production was mediated by COX-2 expression in the stromal cells but it did not affect in the epithelial cells, and suggest that treatment of IFN-τ was to improve the implantation environment of uterine by maintenance of high P4 concentration. * This work was carried out with the support of “Cooperative Research Program for Agriculture Science & Technology Development (Project No. PJ907008)” Rural Development Administration, Republic of Korea.