• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.10 no.2
• /
• pp.157-168
• /
• 1999

In this paper the new channel allocation method which is important in designing mobile radio system, is proposed. If the channel is allocated by time-frequency-code sliced and using DAMA scheduler, the blocking probability is lower than TA channel allocation method. With traffic load $\rho$=0.8 and 2% of blocking probability, TFS method can allocate 36 slices compared to 11 slices in TA method. At traffic load $\rho$=0.9 and 1% of blocking probability, the maximum available slices are 13 in TA method, but in TFS method 40 slices are allocated to user, so TFS method is better frequency availability by 3.75 times than TA method. TFS method could be suitable for system planning to multirate communication users.

• The Korean Journal of Physiology and Pharmacology
• /
• v.28 no.5
• /
• pp.413-422
• /
• 2024

Group I metabotropic glutamate receptors (mGluRs) modulate postsynaptic neuronal excitability and epileptogenesis. We investigated roles of group I mGluRs on low extracellular Mg²⁺ concentration ([Mg²⁺]_o)-induced epileptiform activity and neuronal cell death in the CA1 regions of isolated rat hippocampal slices without the entorhinal cortex using extracellular recording and propidium iodide staining. Exposure to Mg²⁺-free artificial cerebrospinal fluid can induce interictal epileptiform activity in the CA1 regions of rat hippocampal slices. MPEP, a mGluR 5 antagonist, significantly inhibited the spike firing of the low [Mg²⁺]_o-induced epileptiform activity, whereas LY367385, a mGluR1 antagonist, did not. DHPG, a group 1 mGluR agonist, significantly increased the spike firing of the epileptiform activity. U73122, a PLC inhibitor, inhibited the spike firing. Thapsigargin, an ER Ca²⁺-ATPase antagonist, significantly inhibited the spike firing and amplitude of the epileptiform activity. Both the IP₃ receptor antagonist 2-APB and the ryanodine receptor antagonist dantrolene significantly inhibited the spike firing. The PKC inhibitors such as chelerythrine and GF109203X, significantly increased the spike firing. Flufenamic acid, a relatively specific TRPC 1, 4, 5 channel antagonist, significantly inhibited the spike firing, whereas SKF96365, a relatively non-specific TRPC channel antagonist, did not. MPEP significantly decreased low [Mg²⁺]_o DMEM-induced neuronal cell death in the CA1 regions, but LY367385 did not. We suggest that mGluR 5 is involved in low [Mg²⁺]_o-induced interictal epileptiform activity in the CA1 regions of rat hippocampal slices through PLC, release of Ca²⁺ from intracellular stores and PKC and TRPC channels, which could be involved in neuronal cell death.

• Journal of Korean Society of Forest Science
• /
• v.107 no.1
• /
• pp.71-80
• /
• 2018

The effect of $SO_2$ treated pads (Sodium metabisulphate 0, 0.5, 1.0, 2.0 g/kg) on the quality of dried persimmons and dried persimmons slices were investigated. The $SO_2$ treated pads did not affect to weight, moisture loss rate, and soluble solid contents of dried persimmons and dried persimmons slices. The color change (${\Delta}E$) of dried persimmons and dried persimmons slices after storage for 8 weeks were the highest (value=6.0, 6.2) in control, whereas that was the lowest (value=4.8, 4.7) under $SO_2$ pad 2.0 g/kg condition, respectively. When we measured the browning degree of dried persimmons, they showed O.D. 0.65, 0.57, 0.29, and 0.18 in serial dilution treated pads with $SO_2$ pad 0, 0.5, 1.0, and 2.0 g/kg. The browning degree data from aforementioned dried persimmons after 8 weeks was similar to that from dried persimmons slices. The decay rate of dried persimmons and dried persimmons slices after storage for 8 weeks were the highest (value=33.3%, 36.7%) in control, whereas that was the lowest (value=3.3%, 6.7%) under $SO_2$ pad 2.0 g/kg condition, respectively. The concentration of residual $SO_2$ in dried persimmons and dried persimmons slices were detected within a safe range of 15.3~30.0 ppm. Therefore, the shelf-life of dried persimmons and dried persimmons slices were lengthened in $SO_2$ treated pads (especially in $SO_2$ pad 2.0 g/kg) for inhibiting of browning and decay.

• Journal of the Korea Computer Graphics Society
• /
• v.25 no.3
• /
• pp.143-152
• /
• 2019

This paper presents two new techniques for solving the two problems of the water curtain: 'shape distortion' caused by gravity and 'resolution degradation' caused by fine satellite droplets around the shape. In the first method, when the user converts a three-dimensional model to a vertical sequence of slices, the slices are evenly spaced. The method is to adjust the time points at which the equi-distance slices are created by the nozzle array. In this method, even if the velocity of a water drop increases with time by gravity, the water drop slices maintain the equal interval at the moment of forming the whole shape, thereby preventing distortion. The second method is called the minimum time interval technique. The minimum time interval is the time between the open command of a nozzle and the next open command of the nozzle, so that consecutive water drops are clearly created without satellite drops. When the user converts a three-dimensional model to a sequence of slices, the slices are defined as close as possible, not evenly spaced, considering the minimum time interval of consecutive drops. The slices are arranged in short intervals in the top area of the shape, and the slices are arranged in long intervals in the bottom area of the shape. The minimum time interval is pre-determined by an experiment, and consists of the time from the open command of the nozzle to the time at which the nozzle is fully open, and the time in which the fully open state is maintained, and the time from the close command to the time at which the nozzle is fully closed. The second method produces water drop sculptures with higher resolution than does the first method.

• Journal of Ginseng Research
• /
• v.24 no.3
• /
• pp.134-137
• /
• 2000

Spontaneous bursting activity was studied in rat thalamocortical slices using extracellular field potential recording to test the potential utilization of ginsenoside Rb$_1$ in controlling overactivated neural systems. In order to induce bursting activity, slices were perfused with Mg$\^$2+/-free artificial cerebrospinal fluid (ACSF). Two major types of spontaneous bursting activity, simple thalamocortical burst complexes (sTBCs) and complex thalamocortical burst complexes (cTBCs), were recorded in Mg$\^$2+/ -free ACSF. Ginsenoside Rb$_1$ selectively suppressed cTBCs. Duration and occurrence rate of cTBCs were reduced by 87.3${\pm}$10.2% and 85.3${\pm}$ 14.7% in the presence of 90 ${\mu}$M ginsenoside Rb$_1$ respectively, while amplitude and intraburst frequency were slightly changed by ginsenoside Rb$_1$. In contrast, ginsenoside Rb$_1$was much less effective in reducing duration and occurrence rate of sTBCs. We also tested effects of ginsenoside Rb$_1$ on bursting activity in the presence of a GABA$\sub$A/ receptor antagonist, bicuculline methiodide (BMI). Ginsenoside Rb$_1$ had no effect in suppressing BMI-induced bursting activities. These results suggest that ginsenoside Rbi may be useful in controlling seizure-like bursting activity under pathological conditions.

• Journal of Biosystems Engineering
• /
• v.41 no.1
• /
• pp.34-42
• /
• 2016

Purpose: This study was performed to improve the drying quality and drying rate of ginseng slices by combining microwave and far-infrared drying techniques. Methods: Based on single-factor experiments and analyses, a quadratic regression orthogonal rotation combination design was adopted to study the effects of the moisture content at the conversion point between the microwave and far-infrared techniques, the ginseng slice thickness and the far-infrared drying temperature on the chip drying time, the surface color difference value, the nutritional composition and the surface shrinkage rate index. Results: Compared to the far-infrared drying alone, the combined microwave and far-infrared drying resulted in an increase in the saponin content of the ginseng slices and reductions in the drying time, surface color difference, and shrinkage rate. Conclusions: We established a mathematical model of the relationships between the surface shrinkage rate index and the experimental factors using the multi-objective nonlinear optimization method to determine the optimal parameter combination, which was confirmed to be the following: microwave and far-infrared moisture contents of 65%, a ginseng slice thickness of 1 mm, and a far-infrared drying temperature of $54^{\circ}C$.

• Journal of Chest Surgery
• /
• v.28 no.3
• /
• pp.228-232
• /
• 1995

Computed tomography[CT is an effective technique for the evaluation of the thorax following blunt trauma. To evaluate multiply injured 30 patients who were diagnosed as hemothorax in emergency room, computed tomography of thorax was done. The thickness of slice was one centimeter and the entire pleural cavity from the apex to the costophrenic angle was included in the evaluation. Integration and addition of the hemothorax area for each CT slice was made and amount of blood in the pleural cavity was estimated. The slice which showed largest area of hemothorax was selected and the height and width of the hemothorax area were measured. The number of slices which showed radiographic evidence of hemothorax was counted. Regression analysis was done and measured amount of hemothorax, the height and width of the hemothorax area for each slice and number of slices were put as variables. And following equation was derived. V=108.3A-0.8B-7.4C+84.7 [R2=0.74 [ V: amount of hemothorax, A: height, B: width, C: number of slices Total amount of blood from thoracic drainage was compared to the measured amount by computed tomography and the relation between the two values was statistically significant.[p=0.001 In conclusion, quantitative estimation of size of hemothorax was possible by the above equation and the process was very helpful for determination policy of treatment of individual patient.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.9 no.1
• /
• pp.172-180
• /
• 2005

Dynamic slicing method decomposes a program into slices and supports to be understood programs easily by software developer or maintainer. In this paper, we propose dynamic slicing algorithm to reduce time to decompose a program. We produce reference-variable set used in right and modify-variable set used in left on the basis of the assignment operator of all sentences and extract Inter-Variable Relationship(VV) for all variables of variable declaration. Proposed algorithm extracts dynamic slices by using them and execution trace of program. In conclusion, proposed algorithm improved the performance by reducing the time to extract dynamic slices by decreasing average comparison count of sentence when the number of criterion variables is three or more.

• The Journal of Internal Korean Medicine
• /
• v.18 no.1
• /
• pp.147-155
• /
• 1997

This study was undertaken to determine whether Salviae-radix (SVR) exraction exerts benefical effect against oxidant-induced inhibition of tetraethylammonium (TEA) uptake which is actively secreted by renal proximal tubules. TEA uptake increased as function of incubation time to 60 min. When renal cortical slices were exposed to 50 mM $H_2O_2$, TEA uptake was significantly inhibited. The inhibition was significantly protected by addition of 0.5% SVR extraction. The benefical effect of SVR was dose-dependent over the concentration range of 0.1-1%; $H_2O_2$ (50 mM)-induced inhibition of TEA uptake was completely protected by 0.5-1% SVR extraction. $H_2O_2$ increased LDH release which was accompanied by an increase in lipid peroxidation in renal cortical slices. These changes were prevented by 0.5% SVR. These results suggest that SVR exerts benefical effect against oxidant-induced impairment of membrane transport function, this effect may be due to by an antioxidant action.

• Proceedings of the Korean Society of Applied Pharmacology
• /
• 1996.04a
• /
• pp.179-179
• /
• 1996

The involvement of the cyclic AMP (cAMP) effector system in the release of endogenous dopamine and acetylcholine from the rat neostriatum was assessed. Forskolin, an activator of adenylate cyclase, was used to enhance CAMP production, and the consequence of this enhancement on the spontaneous and potassium stimulated release of dopamine and acetylcholine was evaluated. Neostriatal slices were prepared from Fischer 344 rats and after a preincubation period the release of each endogenous neurotransmitter was measured from the same slice preparation. To measure acetylcholine release the slice acetylcholinesterase (AChE) activity was inhibited with physostigmine, but the release from slices with intact AChE activity was also determined (choline, instead of acetylcholine was detected in the medium). Under both conditions forskolin induced a significant dose-dependent increase in the potassium-evoked release of dopamine. In the same tissue preparations the release of neither acetylcholine (AChE inhibited) nor choline (AChE intact) was affected by forskolin. The results indicate that the cAMP second messenger system is involved ill neuronal mechanisms that enhance neuronal dopamine release, but stimulation of this second messenger by forskolin does not further enhance neostriatal acetylcholine release.