• The Transactions of the Korean Institute of Electrical Engineers P
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• v.66 no.4
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• pp.158-162
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• 2017

This paper did basic study on the vertical-axis wind turbine. Namely, This paper was try to find the optimum conditions by using the ANSYS CFX simulation program through the changes of the main-blade angle and sub-blade angle. Main-blade Shape #4 angle $45^{\circ}$ compared to others Shape angle $0^{\circ}$ was increased by 157.2[%] to 263.2[%] in the power output and was increased by 110[%] to 250[%] in the power coefficient. Also, when the Shape #5 Fin length of main-blade doubles, because the power output was 70.8[%] compared to Shape #1 and 27.5[%] compared to Shape #4, and the power coefficient was 60[%] compared to Shape #1 and 28.6[%] compared to Shape #4, the power output and the power efficiency were rather reduced. The output current of Shape #4 was increased 109.9[%] compared to Shape #1 and increased 250[%] compared to Shape #5, and The output voltage of Shape #4 was increased 22.5[%] compared to Shape #1 and increased 3.7[%] compared to Shape #4.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.5 no.4
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• pp.316-321
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• 2005

We designed and implemented fish robots for various purposes such as autonomous navigation, maneuverability control, posture balancing and improvement of quick turns in a tank of 120 X 120 X 180cm size. Typically, fish robots have 30-50 X 15-25 X 10-20cm dimensions; length, width and height, respectively. It is essential to have the ability of quick and smooth turning to avoid collision with obstacles or walls of the water pool at a close distance. Infrared distance sensors are used to detect obstacles, magneto-resistive sensors are used to read direction information, and a two-axis accelerometer is mounted to compensate output of direction sensors. Because of the swing action of its head due to the tail fin movement, the outputs of an infrared distance sensor contain a huge amount of noise around true distances. With the information from accelerometers and e-compass, much improved distance data can be obtained by fuzzy logic based estimation. Successful swimming and smooth turns without collision demonstrated the effectiveness of the distance estimation.

• Journal of Aquaculture
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• v.10 no.1
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• pp.33-37
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• 1997

construct containing reporter gene(pFV4CAT) regulated by carp $\beta$-actin promoter was microinjected into the one-cell stage egg of mud loach (Misgurnus mizolepis), and was successfully expressed, possibly by the integration into the genome. Both mean hatching success and early survival of the microinjected groups were not significantly different with those of control groups (P>0.05). The incidence of transgene was ranged from 7 to 48% based on the PCR and/or Southern blot analyses with the DNA prepared from fin or blood tissue. The spatial and temporal patterns of expression of the pFV4CAT gene, measured by in situ immunohistochemical analysis peroxidase-conjugated anti-CAT antibody, were variable among the experimental individuals. These results suggest that carp $\beta$-actin promoter is effective to express other transgene in mud loach, such that this promoter can be useful in the generation of valuable transgenic mud loach.

• 한국태양에너지학회:학술대회논문집
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• 2009.11a
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• pp.273-278
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• 2009

The experimental study is performed to investigate the optimum design of the system dissipating properly heat from the in-situ solar panel installed on site. For this purpose, six 12-Watts panels, which are set at the different conditions of the solar panels contained phase change material, changing the array of the aluminum fin and honeycomb at the back of the panel, are tested. PCM, which has $44^{\circ}C$ melting point, is chosen in this study. In order to enhance the thermal heat from the absorbed heat in PCM, finned aluminum plate is placed. Furthermore, Aluminum honeycomb is imbedded in the back container to find if it would improve the thermal conductivity of PCM. As a result, the solar panel, which is combined with honeycomb and outward fins with PCM instead of placing the fine inward, is showing the best performance in terms of controling panel temperature and efficiency.

• Transactions of the Korean Society of Automotive Engineers
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• v.11 no.4
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• pp.58-67
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• 2003

An automotive engine cooling system is closely related with overall engine performances, such as reduction of fuel consumption, decrease of air pollution, and increase of engine life. Because of complex reaction between each component, the direct experiment, using a vehicle, takes high cost, long time, and slow response to the system change. Therefore, a computer simulation would provide the designer with an inexpensive and effective tool for design, development, and optimization of the engine cooling system over a wide range of operating conditions. In this work, it has been predicted the thermal performance of the engine cooling system in cases of stationary mode, constant speed mode, and city-drive mode by mathematical modelling of each component and numerical analysis. The components are engine, radiator, heater, thermostat, water pump, and cooling fans. Since the engine model is the most important, that is divided into eight sub-sections. The volume mean temperature of eight sub-sections are simultaneously calculated at a time. For detail calculation, the radiator and heater are also divided into many sub-sections like control volumes in finite difference method. Each sub-section is assumed to consist of three parts, coolant, tube with fin, and air. Hence it has been developed the simulation program that can be used in case of design and system configuration changes. The overall performance results obtained by the program were desirable and the time-traced tendencies of the results agreed fairly well with those of actual situations.

• Journal of Power Electronics
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• v.13 no.6
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• pp.1080-1089
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• 2013

In this paper, the superposition principle of a heat sink temperature rise is verified based on the mathematical model of a plate-fin heat sink with two mounted heat sources. According to this, the distributed coupling thermal impedance matrix for a heat sink with multiple devices is present, and the equations for calculating the device transient junction temperatures are given. Then methods to extract the heat sink thermal impedance matrix and to measure the Epoxy Molding Compound (EMC) surface temperature of the power Metal Oxide Semiconductor Field Effect Transistor (MOSFET) instead of the junction temperature or device case temperature are proposed. The new thermal impedance model for the power converters in Switched Reluctance Motor (SRM) drivers is implemented in MATLAB/Simulink. The obtained simulation results are validated with experimental results. Compared with the Finite Element Method (FEM) thermal model and the traditional thermal impedance model, the proposed thermal model can provide a high simulation speed with a high accuracy. Finally, the temperature rise distributions of a power converter with two control strategies, the maximum junction temperature rise, the transient temperature rise characteristics, and the thermal coupling effect are discussed.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.26 no.8
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• pp.375-380
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• 2014

The purpose of this paper is to investigate the cooling and heating performance of a standalone-type thermoelectric system equipped with a thermoelectric module. The system consists of a blower and two thermoelectric modules with a fin, which is soldered onto both sides of the thermoelectric module and a courtesy light. The thermoelectric system experiment is conducted with the intake voltage to find the optimum cooling and heating performance of each. The results showed that the cooling capacity and coefficient of performance (COP) were 22 W and 0.31, and the heating capacity and COP were 147 W and 1.1, respectively. In the vehicle cooling and heating performance test in a climate wind tunnel, the results showed that the standalone thermoelectric system's cooling performance was slightly better than the base system; and the heating performance of the standalone thermoelectric system was $54.1^{\circ}C$ and the COP was 1.3, compared to the base system.

• International Journal of Air-Conditioning and Refrigeration
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• v.13 no.4
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• pp.196-205
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• 2005

In this paper, recent research trend on heat transfer in impinging jet is reviewed. We focused on submerged jet that air issued into air or liquid issued into liquid. To control and enhance the heat transfer in single jet, researchers have performed a lot of experiments by considering the nozzle geometry, impinging surface and active method such as jet vibration, secondary injection and suction flow. The studies on multiple jet have been mainly focused on finding out the optimum condition and on investigating many different factors concerned with application condition (crossflow, rotation and geometry etc.) and combined techniques (rib turbulator, pin fin, dimple and effusion hole etc.). All most experiments showed the detailed heat transfer data by using liquid crystal method, infrared camera technique and naphthalene sublimation method. Many numerical calculations have been performed to investigate the flow and heat transfer characteristics in laminar jet region. Various turbulence models such as $k-\varepsilon-\bar{\nu^2}$, modified $k-\varepsilon-f_{\mu}$ were applied to the calculation for turbulent jet and the predicted results showed a good agreement with the experimental data. Although a lot of studies on impinging jet have performed consistently up to recently, further studies are still required to understand the flow and heat transfer characteristics more accurately, and to give a guideline for optimum impinging jet design in various applications.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.6 no.3_4
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• pp.112-122
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• 1973

Philometroides carassii (ISHII, 1931) is a parasitic nematode of Carassius auratus and gold fish. Recently a large number of parasitized fishes by this nematode have been reported by fish farmers in Korea. The present investigation was aimed to find out the life cycles of the parasites and effects of chemotherapeutic medicines on the emerged larvae from the adult parasites. Results of the study are summarized as follows : 1. Intermediate host of p. cararsii is a freshwater copepod, Cyclops sp. and the invaded lavae in the body cavity of copepod are capable for parasitizing the fish host after 3 hours of invasion. 2. The lavae eaten directly by the fish host are digested or excreted. 3. The larvae invaded in the fish intestine through the intermediate host pass into the body cavity in 1 to 10 days, and become subadult stage. After 18 to 20 months the subadults parasitic in the body cavity of the Carassius auratus, penetrate through muscle fissile into tile caudal fin where they become adults. Whereas those parasitic in the body cavity of the gold fish, 7 to 8 months the sutadults penetrate through muscle tissue into the caudal fin where they become adults. 1. Male subadults found in the body cavity of the Carassius auratus and gold fish, were larger than females, This is the first record of male subadults occurring in the fish host. 5. Among four different :drugs tested, most of all larvae died in 4 ppm of dipterex in 5 days. But no adults were harmed even in 6 ppm dipterex in 11 days.

• Korean Journal of Ichthyology
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• v.32 no.4
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• pp.199-209
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• 2020

In order to clarify the taxonomic status of the Korean Macroramphosus species, which were previously confused, we investigated morphological and molecular variations of Macroramphosus (18 individuals) from Korea, and Macroramphosus (35 individuals) from Japan and Taiwan, and compared with those of M. scolopax from type locality (Mediterranean Sea). Although the Korean and Japanese specimens of Macroramphosus were clearly divided into two types in the first dorsal spine length (22.8~32.1% in A-type vs. 15.6~21.4% in B-type), distance between the first dorsal fin and second dorsal fin (6.4~9.7% vs. 8.6~13.3%), and body depth (20.0~28.0% vs. 17.3~22.6%), no genetic differences among all individuals of longspine snipefish between them were found at the specific level [d=0.0~3.3% in control region (CR); 0.0~1.3% in cytochrome b (cytb); 0.0~0.5% in cytochrome c oxidase subunit I (COI)]. Whereas, they were well distinguished in genetics (9.9~11.5% in CR; 3.8~4.6% in cytb; 1.2~3.6% in COI) from those of M. scolopax in Mediterranean Sea. It needs the scientific name of the longspine snipefish (M. scolopax) in Korea be changed as M. japonicus (and/or M. sagifue). However, our results could not find evidence of consistency between morphological and mitochondrial DNA variations which suggests that their differentiation event may occur fairly recently. Further studies using more sensitive markers such as microsatellite are needed to clarify the degree of gene flow between the two types.