• E2M - 전기 전자와 첨단 소재
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• 제9권4호
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• pp.396-403
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• 1996

In this paper, the (S $r_{0.85}$.C $a_{0.15}$)Ti $O_{3}$ of paraelectric grain boundary layer (GBL) ceramics were fabricated, and the analysis of microstructuye and the thermally stimulated current(TSC) were investigated for understanding effects of GBL's interfacial phenomenon on variations of electrical properties. As a result, the three peaks of .alpha., .alpha. and .betha. were obtained at the temperature of -20 [.deg. C], 20[.deg. C] and 80[.deg. C], respectively. The origins of these peaks are that the .alpha. peak observed at -20[.deg. C] looks like to be ascribed to the ionization excitation from donor level in the grain, and the .alpha.' peak observed at 20[.deg. C] appears to show up by detrap of the trapped carrier of border between the oxidation layer and the grain, and the .betha. peak observed at 80[.deg. C] seems to be resulted from hopping conduction of existing carrier in the trap site of the border between the oxidation and second phase. and second phase.

• 한국전기전자재료학회논문지
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• 제16권11호
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• pp.969-974
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• 2003

HgGa$_2$S$_4$ single crystals were grown by the chemical transport reaction method. The HgGa$_2$S$_4$ single crystal crystallized into a defect chalcopyrite structure (I 4). The lattice constants of the single crystal were found to be a = 5.635 $\AA$ and c = 10.473 $\AA$. The direct and indirect optical energy gaps were found to be 2.84eV and 2.78eV, respectively. Photoluminescence peaks of HgGa$_2$S$_4$ single crystal were observed at 2.37 eV, 2.18 eV, and 1.81 eV. In the single crystal, the donor level of 0.25 eV, the acceptor levels of 0.97 eV and 0.41 eV were obtained by TSC, PICTS, and absorption measurements. The photoluminescence peaks were analyzed to relate to the indirect conduction band, the donor level, and the acceptor levels.

• Journal of Power Electronics
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• 제3권3호
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• pp.185-196
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• 2003

In this paper, the single-phase static VAR compensator (SVC) is applied to regulate and stabilize the generated terminal voltage of the single-phase self-excited induction generator (single-phase SEIG) driven by a variable-speed prime mover (VSPM) under the conditions of the independent inductive load variations and the prime mover speed changes The conventional fixed gain PI controller-based feedback control scheme is employed to adjust the equivalent capacitance of the single-phase SVC composed of the fixed excitation capacitor FC in parallel with the thyristor switched capacitor TSC and the thyristor controlled reactor TCR The feedback closed-loop terminal voltage responses in the single-phase SEIG coupled by a VSPM with different inductive passive load disturbances using the single-phase SVC with the PI controller are considered and discussed herem. A VSPM coupled the single-phase SEIG prototype setup is established. Its experimental results are illustrated as compared with its simulation ones and give good agreements with the digital simulation results for the single-phase SEIG driven by a VSPM, which is based on the SVC voltage regulation feedback control scheme.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 춘계학술대회 논문집
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• pp.47-52
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• 2004

$HgGa_2S_4$ single crystals were grown by the chemical transport reaction method. The $HgGa_2S_4$ single crystal crystallized into a defect chalcopyrite structure $(I\bar{4})$. The lattice constants of the single crystal were found to be a=5.635 ${\AA}$ and c=10.473 ${\AA}$. The direct and indirect optical energy gaps were found to be 2.84 eV and 2.78 eV, respectively. Photoluminescence peaks of $HgGa_2S_4$ single crystal were observed at 2.37 eV, 2.18 eV, and 1.81 eV. In the single crystal, the donor level of 0.25 eV, the acceptor levels of 0.97 eV and 0.41 eV were obtained by TSC, PICTS, and absorption measurements. The photoluminescence peaks were analyzed to relate to the indirect conduction band, the donor level, and the acceptor levels.

• 대한전기학회논문지
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• 제34권4호
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• pp.144-152
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• 1985

This paper temperature gradient thermally stimulated surface potentian (TG-TSSP) in measurements are applied to the study of the polarity of trapped and ionic carriers in cross-linked polyethylene (XLPE) filsm. In the thermally stimulated current in uniform temperature (TSC) of XLPE five peaks appear as indicated of the A B C D and E. In this paper A (at about -120$^{\circ}C$) D (at about 70$^{\circ}C$) and E (at about 110$^{\circ}C$) peaks are investigated. A peak is due to the biassing voltage and biassing temperature. Appear in to the glass transition temperature territory and caused in to the polarization of dipole. D peak is due to the depolarization of ionic space charge and E peak due to the detrapping of carriers injected from the electrodes. TG-TSSP and TSSP are measured to study the polarity of ionic carrier (D peak). In the unsatureated region of ionic space charge polarization, TG-TSSP is lower than TSSP during the initial stage of heating. Result of the experiment for E peak, TG-TSSP is higher than TSSP during the initial stage of heating and these results do not depend on the polarity of biassing voltage, and E peak is concerned with positive carriers (Holes).

• E2M - 전기 전자와 첨단 소재
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• 제10권2호
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• pp.97-104
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• 1997

In this paper, in order to investigate the behavior of charged particles on (Sr.Ca)TiO$_{3}$ ceramics with paraelectric properties, the characteristics of electrical conduction and thermally stimulated current was measured respectively. As a result, the conduction mechanism is divided into three regions having different mechanism as the current increased. The region I below 200[V/Cm] shows the ohmic conduction. The region B between 200[V/cm] and 2000[V/cm] can be explained by the Poole-Frenkel emission theory, and the region III above 2000[V/cm] is dominated by the tunneling effect. The three peaks of TSC were obtained at the temperature of -20[.deg. C], 20[.deg. C] and 80[.deg. C], respectively. The origins of these peaks are that the .alpha. peak observed at -20[.deg. C] looks like to be ascribed to the ionization excitation from donor level in the grain, and the .alpha.' peak observed at 20 [.deg. C] appears to show up by hopping conduction of the trapped carrier of border between the oxidation layer and the grain, and the .betha. peak observed at 80[.deg. C] seems to be resulted from hopping conduction of existing carrier in the trap site of the border between the oxidation and second phase.

• Nuclear Engineering and Technology
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• 제53권2호
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• pp.484-497
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• 2021

This paper proposes an extended time uncertainty analysis approach in Level 2 human reliability analysis (HRA) considering severe accident management (SAM) strategies. The method is a time-based model that classifies two time distribution functions-time required and time available-to calculate human failure probabilities from delayed action when implementing SAM strategies. The time required function can be obtained by the combination of four time factors: 1) time for diagnosis and decision by the technical support center (TSC) for a given strategy, 2) time for strategy implementation mainly by the local emergency response organization (ERO), 3) time to verify the effectiveness of the strategy and 4) time for portable equipment transport and installation. This function can vary depending on the given scenario and includes a summation of lognormal distributions and a choice regarding shifting the distribution. The time available function can be obtained via thermal-hydraulic code simulation (MAAP 5.03). The proposed approach was applied to assess SAM strategies that use portable equipment and safety depressurization system valves in a total loss of component cooling water event that could cause reactor vessel failure. The results from the proposed method are more realistic (i.e., not conservative) than other existing methods in evaluating SAM strategies involving the use of portable equipment.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1995년도 추계학술대회 논문집
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• pp.209-212
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• 1995

In this paper, the $(Sr_{0.85}{\cdot}Ca_{0.15})TiO_3$ of paraelectric grain boundary layer (GBL) ceramics were fabricated. The characteristics of electrical conduction and the thermally stimulated current(TSC) were measured respectively. The region I below 200[V/cm] shows the ohmic conduction, the region II between 200[V/cm] and 1000[V/cm] can be explained by the Pool-Frenkel emission theory, and the region III above 2000[V/cm] is dominated by the tunneling effect. As a result, The origins of these peaks are that the ${\alpha}$ peak observed at $-20[^{\circ}C]$ looks like to be ascribed to the ionization excitation from donor level in the grain, and the ${\alpha}^{\prime}$ peak observed at $-20[^{\circ}C]$ appears to show up by detrap of the trapped carrier of border between the oxidation layer and the grain, and the ${\beta}$ peak observed at $80[^{\circ}C]$ seems to be resulted from hopping conduction of existing carrier in the trap site of the border between the oxidation and second phase.

• 대한한의학회지
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• 제35권4호
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• pp.36-51
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• 2014

Objectives: cDNA microarray is an effective method to snapshot gene expression. Functional clustering of gene expressions can identify herbal medicine mechanisms. Much microarray data is available for various herbal medicines. This study compares regulated genes with herbal medicines to evaluate the nature of the drugs. Methods: Published microarray data were collected. Total RNAs were prepared from dissociated hippocampal dissociate cultures which were given hypoxic shock in the presence of each herbal medicine. Up- or downregulated genes higher than Global M value 0.5 were selected, clustered in functional groups, and compared with various herbal treatments. Results: 1. Akt2 was upregulated by Acorus gramineus SOLAND, Arisaema amurense var. serratum $N_{AKAI}$ and Coptis chinensis $F_{RANCH}$, and they belong to Araceae herb. 2. Nf-${\kappa}b1$, Cd5, $Gn{\gamma}7$ and Sgne1 were upregulated by Arisaema amurense var. serratum $N_{AKAI}$, Coptis chinensis $F_{RANCH}$ and Rheum coreanum $N_{AKAI}$. 3. Woohwangcheongsim-won, Sohaphyang-won and Scutellaria baicalensis $G_{EORGI}$ downregulated Scp2 and upregulated Tsc2. Woohwangcheongsim-won and Sohaphyang-won upregulated Hba1 and downregulated Myf6. 4. Sohaphyang-won and Scutellaria baicalensis $G_{EORGI}$ downregulated Slc12a1. 5. Woohwangcheongsim-won and Arisaema amurense var. serratum $N_{AKAI}$ upregulated $Rar{\alpha}$, Woohwangcheongsim-won and Coptis chinensis $F_{RANCH}$ downregulated Rab5a and $Pdgfr{\alpha}$, and Woohwangcheongsim-won and Rheum coreanum $N_{AKAI}$ upregulated $Plc{\gamma}1$ and downregulated Pla2g1b and Slc10a1. Conclusions: By clustering microarray, genes are commonly identified to be either up- or downregulated. These results will provide new information to understand the efficacy of herbal medicines and to classify them at the molecular level.

• KIEE International Transactions on Power Engineering
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• 제3A권1호
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• pp.17-26
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• 2003

In this paper, the comparative steady-state operating performance analysis algorithms of the stand-alone single-phase self-excited induction generator (SEIG) is presented on the basis of the two nodal admittance approaches using the per-unit frequency in addition to a new state variable de-fined by the per-unit slip frequency. The main significant features of the proposed operating circuit analysis with the per-unit slip frequency as a state variable are that the fast effective solution could be achieved with the simple mathematical computation effort. The operating performance results in the simulation of the single-phase SEIG evaluated by using the per-unit slip frequency state variable are compared with those obtained by using the per-unit frequency state variable. The comparative operating performance results provide the close agreements between two steady-state analysis performance algorithms based on the electro-mechanical equivalent circuit of the single-phase SEIG. In addition to these, the single-phase static VAR compensator; SVC composed of the thyristor controlled reactor; TCR in parallel with the fixed excitation capacitor; FC and the thyristor switched capacitor; TSC is ap-plied to regulate the generated terminal voltage of the single-phase SEIG loaded by a variable inductive passive load. The fixed gain PI controller is employed to adjust the equivalent variable excitation capacitor capacitance of the single-phase SVC.