• Journal of IKEEE
• /
• v.11 no.1 s.20
• /
• pp.54-60
• /
• 2007

In this study novel ESD protection device, namely, N/P-type Low Voltage Triggered SCR, has been proposed, for high speed I/O interface. Proposed device could lower high trigger voltage($\sim$20V) of conventional SCR and reduce latch-up phenomenon of protection device during the normal condition. In this Study, the proposed NPLVTSCR has been simulated using TMA MEDICI device simulator for electrical characteristic. Also the proposed device's test pattern was fabricated using 90nm TSMC's CMOS process and was measured electrical characteristic and robustness. In the result, NPLVTSCR has 3.2V $\sim$ 7.5V trigger voltage and 2.3V $\sim$ 3.2V holding voltage by changing PMOS gate length and it has about 2kV, 7.5A HBM ESD robustness(IEC61000-4-2).

• Journal of Broadcast Engineering
• /
• v.28 no.3
• /
• pp.267-274
• /
• 2023

There is a problem that the size of the dataset is insufficient due to the limitation of the collection of the medical image public data, so there is a possibility that the existing studies are overfitted to the public dataset. In this paper, we compare the performance of eight (Unet, X-Net, HarDNet, SegNet, PSPNet, SwinUnet, 3D-ResU-Net, UNETR) medical image semantic segmentation models to revalidate the superiority of existing models. Anatomical Tracings of Lesions After Stroke (ATLAS) V1.2, a public dataset for stroke diagnosis, is used to compare the performance of the models and the performance of the models in ATLAS V2.0. Experimental results show that most models have similar performance in V1.2 and V2.0, but X-net and 3D-ResU-Net have higher performance in V1.2 datasets. These results can be interpreted that the models may be overfitted to V1.2.

• Clinical and Experimental Vaccine Research
• /
• v.12 no.2
• /
• pp.116-120
• /
• 2023

Purpose: In Japan, the data on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibody titers after the booster dose of the coronavirus disease 2019 (COVID-19) vaccine are insufficient. The aim of this study is to evaluate changes in SARS-CoV-2 antibody titers before, 1, 3, and 6 months after the booster dose of the BNT162b2 COVID-19 vaccine among health care workers. Materials and Methods: A total of 268 participants who received the booster dose of the BNT162b2 vaccine were analyzed. SARS-CoV-2 antibody titers were measured before (baseline) and at 1, 3, and 6 months after the booster dose. Factors associated with changes in SARS-CoV-2 antibody titers at 1, 3, and 6 months were analyzed. Cutoff values at baseline were calculated to prevent infection of the omicron variant of COVID-19. Results: The SARS-CoV-2 antibody titers at baseline, and 1, 3, and 6 months were 1,018.3 AU/mL, 21,396.5 AU/mL, 13,704.6 AU/mL, and 8,155.6 AU/mL, respectively. Factors associated with changes in SARS-CoV-2 antibody titers at 1 month were age and SARS-CoV-2 antibody titers at baseline, whereas changes in SARS-CoV-2 antibody titers at 3 and 6 months were associated with the SARS-CoV-2 antibody titers at 1 month. The cutoff values of the SARS-CoV-2 antibody titers at baseline were 515.4 AU/mL and 13,602.7 AU/mL at baseline and 1 month after the booster dose, respectively. Conclusion: This study showed that SARS-CoV-2 antibody titers increase rapidly at 1 month after the booster dose of the BNT162b2 vaccine and begin to decrease from 1 to 6 months. Hence, another booster may be needed as soon as possible to prevent infection.

• Journal of Practical Agriculture & Fisheries Research
• /
• v.20 no.2
• /
• pp.31-38
• /
• 2018

This study was conducted to investigate the possibility of biochar as an alternative medium to peatmoss using for Aster spathulifolius. We cultivated A. spathulifolius in four potting media with different mixing rates (v/v) of peatmoss (P) and biochar (B) as follows: B0+P3, B1+P2, B2+P1, and B3+P0 with vermiculite 3 + perlite 3. Also, we analyzed the chemical properties of media and the plant growth characteristics. The results were as follows: In case of media's chemical condition, B0+P3 and B1+P2 treatments showed higher tendency (p < 0.05). Plant height on B0+P3 and B1+P2 treatments was much higher than that on other treatments (p < 0.05). Root length on B1+P2 treatment was higher than on B0+P3 treatment (p < 0.05). B0+P3 and B1+P2 treatments showed higher number of leaves and dry biomass than other treatments. Therefore, our results support that Biochar : Peatmoss : Vermiculite : Perlite (1/3 : 2/3 : 1 : 1, v/v) could be a more economical potting medium for A. spathulifolius than peatmoss : vermiculite : perlite (1 : 1 : 1, v/v).

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.38 no.3
• /
• pp.217-225
• /
• 2002

The authors examined the response of electrocardiogram(ECG) of Nile tilapia, Oreochromis niloticus [Linnaeus] to light stimuli. The experiments were performed in such a way that three levels of light stimuli(10, 100 and 400 lu$\chi$) were given to fishes with an electrode inserted into their bodies and then their ECGs were recorded continuously for 60 minutes in 16~18$^{\circ}C$. The results which are divided into by day and by night and then analyzed by fishes' conditions are as follows; 1. Nile tilapias reached a stable condition 3 minutes after anesthesia. In stable condition, the heart rate average was 47.6beat/min by day and 45.1beat/min by night. And the action potential average was 1.0.4$mutextrm{V}$ by day and 1.24$mutextrm{V}$ by night. 2. The heart rate average by three levels of light stimuli was, \circled1 In stimulus condition, in case of 10 lu$\chi$ 39.7beat/min by day and 38.2beat/min by night, in case of 100 lu $\chi$8.7beat/min by day and 36.9beat/min by night, and in case of 40.0. lux 36.8 beat/min by day and 35.8beat/min by night. \circled2 In recovery condition, in case of 10 lu$\chi$ 47.1beat/min by day and 46.0beat/min by night, in case of 100 lu$\chi$ 47.2beat/min by day and 45.6 beat/min by night, and in case of 400 lu$\chi$ 48.1beat/min by day and 46.6beat/min by night. 3. The action potential average by three levels of light stimuli was, \circled1 In stimulus condition, in case of 10 lu$\chi$ 1.22$mutextrm{V}$ by day and 0.71$mutextrm{V}$ by night, in case of 100 lu$\chi$ 0..63$mutextrm{V}$ by day and 0.90$mutextrm{V}$ by night, and in case of 400 lu$\chi$ 1.39$mutextrm{V}$ by day and 1.63$mutextrm{V}$ by night \circled2 In recovery condition, in case of 10 lu$\chi$ 1.26$mutextrm{V}$ by day and 1.59$mutextrm{V}$ by night, in case of 100 lu$\chi$ 2.63$mutextrm{V}$ by day and 3.65$mutextrm{V}$ by night, and in case of 400. lu$\chi$ 2.52$mutextrm{V}$ by day and 3.67$mutextrm{V}$ by night.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.38 no.4
• /
• pp.278-283
• /
• 2002

The response of electrocardiogram(ECG) of Nile tilapia, Oreochromis niloticus [Linnaeus] was studied to the electric stimulus which was given to a certain part of body The experiments were performed in such a way that three levels of electric stimulus (20, 30, 40 Vp ； 10 msec) were given to fishes with electrode inserted into their bodies and then their ECGs were recorded continuously for 60 minutes in the water temperature of 16~18$^{\circ}C$ The results of the experiments were divided by day and night, and then were analyzed by experimental conditions as follows; 1. Nile tilapia reached a stable condition within 3 minutes after the electrode inserted into their bodies during anesthesia. In stable condition, the heart rates average was 45.8 beat/min during daytime and 45.0 beat/min at night. The action potentials average was 1.76 $mutextrm{V}$during daytime and 1.75 $mutextrm{V}$ at night. 2. The heart rates average by three levels of electric stimulus were \circled1 In the stimulus condition, the heart rates were 34.9 beat/min during daytime and 33.4 beat/min at night for the 20 Vp level, 36.8 bea/min during daytime and 36.0 beat/min at night for the 30 Vp level, and 38.0 beat/min during daytime and 36.4 beat/min at night for the 40Vp level. \circled2 In the recovery condition, the action potentials were 45.5 beat/min during daytime an 45.1 beat/min at night for the 20Vp level, 47.9 beat/min during daytime and 49.0 beat/min at night for the 30Vp level, and 51.4 beat/min during daytime and 50.7 beat/min at night for the 40Vp level 3. The action potentials average by three levels of electric stimulus were, \circled1 In the stimulus condition, action potentials were 2.54 $mutextrm{V}$ during daytime and 2.39 $mutextrm{V}$ at night for the 20 Vp level, 3.30 $mutextrm{V}$ during daytime and 2.30 $mutextrm{V}$ at night for the 30 Vp level and 6.05 $mutextrm{V}$ during daytime and 3.23 $mutextrm{V}$ at night for the 40 Vp level. \circled2 In the recovery condition, action potentials were 1.92 $mutextrm{V}$ during daytime and 1.95 $mutextrm{V}$ at night for the 20 Vp level and 2.78 $mutextrm{V}$ during daytime and 2.21 $mutextrm{V}$ at night for the 30Vp level and 3.6 0 $mutextrm{V}$ during daytime and 2.98 $mutextrm{V}$ at night for the 40 Vp level.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.20 no.1
• /
• pp.31-37
• /
• 2015

This paper proposes a 3.3-kW bi-directional EV charger with V2G and V2H functions. The bi-directional EV charger consists of a DC-DC converter and a DC-AC inverter. The proposed EV charger is suitable for wide battery voltage control due to the two-stage configuration of the DC-DC converter. By employing a fixed-frequency series loaded resonant converter as the isolated DC-DC converter, zero-current-switching can be achieved regardless of battery voltage variation, load variation, and power flow. A 3.3-kW prototype of the proposed EV charger has been built and verified with experiments, and indicates a maximum efficiency of 94.39% and rated efficiency of 94.23%.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 1998.06a
• /
• pp.151-154
• /
• 1998

The layered trivanadate, LiV$_3$O$_{8}$ has been investigated as a cathode material for secondary lithium batteries. Early in its development the preparation method of LiV$_3$O$_{8}$ strongly influenced its electrochemical properties, such as discharge capacity, rate capability and cycling efficiency. In the present experiment, a new synthesis route has been applied to obtain LiV$_3$O$_{8}$ . Instead of the conventional high temperature technique leading to the crystalline form, a solution technique producing the amorphous form has been used. This material, after dehydration, shows an electrochemical performance exeeding that of the crystalline one. The rationale for this behavior mainly lies in microscopic factors, i.e., in the possibility for the unit cell of amorphous LiV$_3$O$_{8}$ to insert up to 9 Li$^{+}$, instead of six for crystalline LiV$_3$O$_{8}$ . The ultrasonically treated products in water were characterized by XRD, TGA, DSC, and SEM. These measurements showed that the ultrasonic treatment process of crystalline LiV$_3$O$_{8}$ causes a decrease in crystallinity and considerable increases in specific surface area and interlayer spacing.g.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.30 no.8
• /
• pp.479-483
• /
• 2017

The effect of $NH_3$ plasma treatment on device characteristics was confirmed for an optimized thin film transistor of poly-Si formed by ELA. When C-V curve was checked for MIS (metal-insulator-silicon), Dit of $NH_3$ plasma treated and MIS was $2.7{\times}10^{10}cm^{-2}eV^{-1}$. Also in the TFT device case, it was decreased to the sub-threshold slope of 0.5 V/decade, 1.9 V of threshold voltage and improved in $26cm^2V^{-1}S^{-1}$ of mobility. Si-N and Si-H bonding reduced dangling bonding to each interface. When gate bias stress was applied, the threshold voltage's shift value of $NH_3$ plasma treated device was 0.58 V for 1,000s, 1.14 V for 3,600s, 1.12 V for 7,200s. As we observe from this quality, electrical stability was also improved and $NH_3$ plasma treatment was considered effective for passivation.

• Journal of IKEEE
• /
• v.27 no.3
• /
• pp.308-312
• /
• 2023

The gate current sensing structure was proposed to more effectively control the regulation of the output voltage when the LDO regulator occurs in an overshoot or undershoot situation. In a typical existing LDO regulator, the regulation voltage changes when the load current changes. However, the operation speed of the pass transistor can be further improved by supplying/discharging the gate terminal current in the pass transistor using a gate current sensing structure. The input voltage of the LDO regulator using the gate current sensing structure is 3.3 V to 4.5 V, the output voltage is 3 V, and the load current has a maximum value of 250 mA. As a result of the simulation, a voltage change value of about 12 mV was confirmed when the load current changed up to 250 mA.