• Fisheries and Aquatic Sciences
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• v.3 no.2
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• pp.78-82
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• 2000

The influence of daily water temperature changes on chemiluminescent (CL) response of phagocytes, plasma glucose level and mortality in cultured gray mullet (Mugil cephalus) was investigated. Among three experimental temperature groups, the fish in group I and group II were maintained constantly at $27^{\circ}C$ and $29^{\circ}C$, respectively, and those in group III were suffered daily elevation of water temperature from $27^{\circ}C$ to $29^{\circ}C$ for 5 hours, then restored again to $27^{\circ}C$. After 1 week of maintaining at each experimental tank, the fish in group III showed significantly lower CL peak value (p < 0.01) and higher plasma glucose levels (p < 0.05) than those in group I and group II. The cumulative mortality of group III was $86.9\%$ within 3 days after being subjected to acute handling stress. On the other hand, the cumulative mortalities of group I and group II were $12.5\%$ and $19.2\%$, respectively. In conclusion, gray mullet farms, especially, in the vicinity of thermoelectric power plants should avoid stressing the fish during periods of high water temperature.

• Biomolecules & Therapeutics
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• v.8 no.2
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• pp.199-205
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• 2000

On the inter-order protoplast fusants of Lentinus edodes and Ganoderma lucidum was the antitumor activity test performed and the fusant P22 was selected. The hot water extract of the cultured mycelia of P22 were purified by DEAE-cellulose chromatographya and the resulting purified fraction was designated as P22A. It was found to be a proteoglycan whose molecular weight was 47 kDa. When examined for immunopotentiation activity, P22A increased the number of colony forming unit in the bone marrow stem cells to 3-folds. It also potentiated the secretion of nitric oxide in activated macrophages to 2-folds. In humoral immune response, it increased the activities of the alkaline phosphatase in differentiated B cells to 1.6-folds and the number of plaque forming cells to 1.8-folds. In cellular immune response, it restored the depressed response of delayed type hypersensitivity in tumor bearing mice to normal level. These results suggest that P22A have potential to restore the decreased immune activity of the tumor bearing mice to normal level.

• Transactions of the Korean Society of Automotive Engineers
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• v.8 no.3
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• pp.171-180
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• 2000

This paper deals with the whole-body vibration and ride quality evaluation in the vertical direction. The responses of the floor, hip, back, and head in four subjects were measured for various seats when the floor was excited by random vibration with r.m.s of 1.2m/s2 in the vertical direction. In the transmissibility between the hip and floor, the fundamental mode is observed at 4.4 Hz. In the transmissibility between the head and floor, the fundamental mode at 4.4Hz and the second mode at 7.6Hz are observed. It is shown that the head motion is 41% larger than the hip motion and the response of female subject is larger than that of male subject. The response without backrest also was compared with that with backrest. From these human responses ride quality of five seats were evaluated by the ride value such as transfer ration having frequency weighting function is the statistical sense. It is observed that the seat having high damping property can reduce the most acceleration exposed to hip in the statistical sense for all ride valves, while the seat having different seat spring doesn't show statistical difference.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.49 no.7
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• pp.388-393
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• 2000

Hydrogen-sensing behaviors of Pd- and Pt-SiC Schottky diodes, fabricated on the same SiC substrate, have been systematically compared and analyzed as a function of hydrogen concentration and temperature by I-V and$\DeltaI-t$ methods under steady-state and transient conditions. The effects of hydrogen adsorption on the device parameters such as the barrier height are investigated. The significant differences in their hydrogen sensing characteristics have been examined in terms of sensitivity limit, linearity of response, response rate, and response time. For the investigated temperature range, Pd-SiC Schottky diode shows better performance for H2 detection than Pt-SiC Schottky diode under the same testing conditions. The physical and chemical mechanisms responsible for hydrogen detection are discussed. Analysis of the steady-state reaction kinetics using I-V method confirmed that the atomistic hydrogen process is responsible for the barrier height change in the diodes.

• Animal cells and systems
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• v.4 no.3
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• pp.293-297
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• 2000

The present investigation was performed to elucidate the effect of pretreatment with low dose ultraviolet radiation (UV) and ethyl methanesulfonate (EMS) on cell survival by trypan blue dye exclusion method and plasma membrane glycoconjugates by lectin-cytochemistry in sarcoma 180 (S180) cells. Pretreatment with 2 J/$m^2$ UV or 2 mM EMS increased the percentage of survival of cells subsequently treated with high dose UV (10 or 20 J/$m^2$) or EMS (10 or 20 mM), respectively. Staining intensity of concanavalin A (Con A) of the cells pretreated with 2J/$m^2$ UV or 2 mM EMS and subsequently treated with 10 or 20 mM EMS was stronger than that of the cellstreated with 10 or 20 mM EMS. These results suggest that there is an adaptive response on cell survival to EMS or UV in S180 cells. And the results show a change in mannose-containing glycoconjugates of plasma membrane in S180 cells pretreated with EMS or UV and subsequently treated with EMS.

• Proceedings of the KIEE Conference
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• 2000.07d
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• pp.3178-3180
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• 2000

In this thesis, a controller which is appropriate for uses of scanner with small error and high speed response is proposed. Recently the application field of scanner is on increase. In case of applying to laser marking, the error of scanner has bad effect to quality. Also it can make difficulties in applying laser show that makes images, unless the high speed response is not realized. For these reasons, a controller that can adjust error and response is need. Because scanner must respond to step input that is put between a few millisecond and hundreds of microsecond with small revolution angle ranges, it is advantageous to have small inertia and large torque. First, the property of scanner is treated, and then using Op-amp and passive components and applying feedback compensation PID controller to design, the effects by controller coefficients are introduced.

• Proceedings of the KIEE Conference
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• 2000.11b
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• pp.361-364
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• 2000

In this study, the system which can make the generator's output voltage more stable by using the inverter in terms of PWM method, is designed It is one of the method reducing velocity of the wind in the process of the wind power generation. Thus, in this system, it is necessary to use a excellent current control inverter. So pulse with modulation method with a high-speed switching element is introduced to control the output current. And also, in order to get a fast response when the standard current generated by the vector control algorithm is supplied with the generator, the output control system with the fast response character and the best current control character is suggested. In this way, the result from the introduction of the control system is that a response character to the changable velocity of the wind is excellent, causing the remarkable reduction of the percentage of the harmonic and the outstanding stability of the variation of the output voltage.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.45 no.5
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• pp.282-287
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• 2000

Soybean [Glycine max (L.) Merrill] crops, grown in a rice soybean rotation, can suffer when grown in soil with excessive moisture. The objective of this work were to determine the reduction in growth and yield, responses of vegetative and reproductive growth of soybean to excessive soil moisture achieved by prolonged irrigation. Responses of different cultivars were determined at growth stages from V6 to R8 to clarify the sensitive growth stages or characteristics to excessive soil moisture. Cultivar differences in response to excessive soil moisture condition were conspicuous in seed dry weight and harvest index (HI) but not in the response of seed number or pod number per plant. The timing of irrigation causing the condition of excessive soil moisture influenced the vegetative or reproductive traits. Soybean plants were more affected by irrigation commencing at the pre-flowering than at the post-flowering stage. Post-flowering irrigation did not reduce growth of vegetative organs significantly; in fact the growth of stems and leaves was facilitated by the prolonged irrigation commencing at flowering. Differences between cultivar response to prolonged irrigation were assumed to relate to the reduced amount of assimilates translocated to the reproductive organ.

• Animal cells and systems
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• v.4 no.4
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• pp.337-340
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• 2000

The photosynthetic and stomatal responses of several woody plants (Powlonia coreana, Firmiana simplex, Quercus acutissima Q. variabilis and Q. serrata) to SO$_2$ were investigated in order to understand their ecophysiological tolerance to $SO_2$ Of the plants, P, coreana showed the largest reduction in its photosynthesis in response to exposure of 0.4 ppm $SO_2$ for 20 h. Fumigation of 0.7 ppm $SO_2$ for 20 h caused complete leaf necrosis of P. coreana and f simplex, which made them unavailable for the measurement of photosynthesis. Q. variabilis exhibited the smallest reduction in photosynthesis following exposure of 0.7 ppm $SO_2$ for 20 h. Both stomatal- and non-stomatal inhibition of the plants by $SO_2$ were determined according to equations by lkeda et at. (1992). When exposed to 0.4 ppm $SO_2$ for 20 h, F. simplex and P. coreana showed the lowest stomatal and non-stomatal inhibition, respectively, while Q. variabilis and Q. serrata exhibited the lowest stomatal and non-stomatal inhibition, respectively, in response to 0.7 ppm $SO_2$ for 20 h. The data are discussed with regard to resistance mechanisms of other plants to $SO_2$ exposure and implications for restoration of declined Korean forests.

• Asia-Pacific Journal of Business
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• v.13 no.4
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• pp.135-149
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• 2022

Purpose - The primary objective of this article is to investigate the impact of U.S. monetary policy on institutional / individual / foreign investor reactions in the Korean stock market. Design/methodology/approach - This study employs a high frequency event study methodology to identify U.S. monetary policy shocks and quantify the impact of identified shocks on investor reactions. The dependent variable in the regression model is net stock purchase, while the explanatory variables are U.S. monetary policy shocks. The model is estimated for the period 2000-2019, including 156 FOMC meetings. Findings - Foreign investors immediately sell stocks in response to contractionary U.S. monetary shocks. They do not, however, react to anticipated changes in monetary policy rates, confirming the rationality of foreign investors. Individual investors demonstrate the opposite response, indicating that a non-trivial proportion of individual investors are irrational. Research implications or Originality - This study adds to the current literature on the effect of U.S. monetary policy on the Korean stock market. This study demonstrates a heterogeneous response to U.S. monetary policy shocks, validating the rational investment behavior of foreign investors, while individual investors exhibit a certain degree of irrationality. Methodologically, this study adds to the literature by quantifying the impact of U.S. monetary policy employing a sharper identification method allowing a simple and consistent estimation.