• Proceedings of the IEEK Conference
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• 2003.07b
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• pp.1105-1108
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• 2003

In this paper, we have fabricated the hydrogenated n-channel polysilicon thin film transistor (TFT) with LDD structure and have analyzed the hot carrier degradation characteristics by electrical stress. We have compared the threshold voltage (Vth), sub-threshold slope (S), and trans-conductance (Gm) for devices with LDD (Lightly Doped Drain) structure and non-LDD at same active sizes. We have analyzed the hot carrier effects by the hydrogenation in devices. As a analyzed results, the threshold voltage, sub-threshold slope for n-channel poly-si TFT were increased, trans-conductance was decreased. The effects of hydrogenation in n-channel poly-si TFT with LDD structure were shown the lower variations of characteristics than devices of the non-LDD structure with nomal process.

• Proceedings of the IEEK Conference
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• 2001.06a
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• pp.13-16
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• 2001

In this paper, We have investigated the SER performance of a OFDM/QPSK system with carrier-frequency offset in a frequency non-selective fading channel. Adaptive linear equalizer is adopted to OFDH/QPSK systems for compensation of performance degradation according to the non-selective fading and carrier frequency offset. As a result of performance analysis, the more frequency offset is, the worse performance of OFDH/QPSK system is. However, when OFDH/QPSK system adopts the adaptive linear equalizer, the SER performance is enhanced to the limit range

• Journal of Communications and Networks
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• v.6 no.2
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• pp.112-122
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• 2004

A nonlinear spectral-line method utilizing the fourth absolute moment of the receiver discrete Fourier transform output is proposed as a non-data-aided fine carrier frequency synchronization algorithm for OFDM receivers. A simple modification of the algorithm resulting in low implementation complexity is also developed. Analytic expressions are derived for the steady-state frequency error variances of the algorithms and verified to be very accurate via computer simulations over AWGN and frequency selective multipath channels. Numerical results show that the proposed algorithms provide reliable and excellent steady-state performance, especially with PSK modulation. Also, the proposed algorithms are insensitive to symbol timing offsets, only requiring a coarse symbol timing recovery.

• Journal of Information Processing Systems
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• v.10 no.2
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• pp.163-175
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• 2014

This paper will focus on improving the performance of orthogonal frequency division multiplexing (OFDM) in Rayleigh fading environments. The proposed technique will use a previously published method that has been shown to improve OFDM performance in independent fading, based on ordered sub-carrier selection. Then, a simple non-iterative method for finding the optimal bit-loading allocation was proposed. It was also based on ordered sub-carrier selection. We compared both of these algorithms to an optimal bit-loading solution to determine their effectiveness in a correlated fading environment. The correlated fading was simulated using the JTC channel models. Our intent was not to create an optimal solution, but to create a low complexity solution that can be used in a wireless environment in which the channel conditions change rapidly and that require a simple algorithm for fast bit loading.

• Proceedings of the Korean Vacuum Society Conference
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• 2015.08a
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• pp.191.2-191.2
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• 2015

Details of carrier dynamics in self-assembled quantum dots (QDs) with a particular attention to nonradiative processes are not only interesting for fundamental physics, but it is also relevant to performance of optoelectronic devices and the exploitation of nanocrystals in practical applications. In general, the possible processes in such systems can be considered as radiative relaxation, carrier transfer between dots of different dimensions, Auger nonradiactive scattering, thermal escape from the dot, and trapping in surface and/or defects states. Authors of recent studies have proposed a mechanism for the carrier dynamics of time-resolved photoluminescence CdTe (a type II-VI QDs) systems. This mechanism involves the activation of phonons mediated by electron-phonon interactions. Confinement of both electrons and holes is strongly dependent on the thermal escape process, which can include multi-longitudinal optical phonon absorption resulting from carriers trapped in QD surface defects. Furthermore, the discrete quantized energies in the QD density of states (1S, 2S, 1P, etc.) arise mainly from ${\delta}$-functions in the QDs, which are related to different orbitals. Multiple discrete transitions between well separated energy states may play a critical role in carrier dynamics at low temperature when the thermal escape processes is not available. The decay time in QD structures slightly increases with temperature due to the redistribution of the QDs into discrete levels. Among II-VI QDs, wide-gap CdZnTe QD structures characterized by large excitonic binding energies are of great interest because of their potential use in optoelectronic devices that operate in the green spectral range. Furthermore, CdZnTe layers have emerged as excellent candidates for possible fabrication of ferroelectric non-volatile flash memory. In this study, we investigated the optical properties of CdZnTe/ZnTe QDs on Si substrate grown using molecular beam epitaxy. Time-resolved and temperature-dependent PL measurements were carried out in order to investigate the temperature-dependent carrier dynamics and the activation energy of CdZnTe/ZnTe QDs on Si substrate.

• Journal of Radiopharmaceuticals and Molecular Probes
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• v.10 no.1
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• pp.73-81
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• 2024

Coronavirus disease 2019 (COVID-19) is a respiratory disease caused by the SARS-CoV-2 coronavirus, which had been identified in Wuhan, China, in December 2019. COVID-19 is a serious threat to human health and spread worldwide. World Health Organization (WHO) has declared the COVID-19 pandemic. It is important that vaccines and therapeutics are developed to control COVID-19. Among these, vaccines using COVID-19 mRNA platforms have various advantages, including a short development cycle, an easy industrialization, a simple production process, flexibility for new variants, and the capacity to induce better immune responses. This review summarizes the structure and characteristics of coronaviruses and introduces the use of non-clinical pharmacokinetic evaluation with C-14 in mRNA vaccine development. The in vitro stability of C-14 labeled mRNA carrier ([¹⁴C]mRNA carrier) was evaluated and found to be stable for up to 144 hours in rat serum. The [¹⁴C]mRNA carrier was distributed mostly to the administration site in rats, but slowly distributed to other organs after 48 hours. Most of the [¹⁴C]mRNA carrier remained in the administered muscle and was slowly excreted from the body through urine after 72 hours. There was no statistical difference in the distribution and excretion after intramuscular administration of the [¹⁴C]mRNA carrier to male and female rats. Through this paper, it is expected to contribute to the development of drug carriers through various studies using C-14.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.29 no.1
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• pp.1-10
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• 1984

The main objective of this experiment was to investigate the selection efficiency for clear rice by the application of the wx-carrier technique in rice. Twelve semi-dwarf waxy lines were bred through backcrosses to the two recurrent semi-dwarf parents, IR667 and IR1317, utilizing six different waxy cultivars as waxy donor parent. These waxy lines were crossed to three clear non-waxy varieties, IR24, Suweon 287 and Suweon294. Their F$_3$ seeds were separated into waxy and non-waxy and the clearness of non-waxy grains were counted. The results are summarized as follows: l. Mean clearness per plant for twelve waxy lines ranged from 3.7% to 78.9% at the 35 days after heading. It was higher in the lines which utilized IR 1317 as recurrent parent and it was lower in the lines which utilized IR667 as recurrent parent. Mean clearness per plant for recurrent parent, IRl317 and IR667 were 47.6% and 5.6% respectively. The clear non-waxy parents; Suweon287, IR24 and Suweon294 showed 83.7% 80.5% and 73.5% clearness respectively. 2. Mean clearness of F$_3$ seeds of the crosses between different waxy parents and IR24, Suweon 294 and Suweon 287 ranged 16.7-73.9%, 21.9-42.9% and 10.6-26.9%, respectively. IR24 crosses showed the highest mean clearness. 3. Highly positive correlation was found between the clearness of F$_3$ seeds of Suweon 287 crosses and those of Suweon294. 4. Significant differences were observed in mean clearness of F$_3$ seeds of the crosses between the different waxy lines, which was bred through the same number of backcrosses to the same recurrent parent, and a clear non-waxy parent. Crosses of IR1317 recurrent parent showed higher mean clearness than those of IR667 recurrent parent. 5. In some crosses, clearness was higher in homo-non-waxy than in hetero-non-waxy, but, in other crosses it was higher in hetero-non-waxy. Thus no distinct pattern in the segregation of clearness was observed along the homo-non-waxy or hetero-non-waxy. 6. From the results it was concluded that, the selection efficiency for the clear rice can be improved by choosing the proper waxy parent, as well as proper recurrent parent under the wx-carrier technique.

• The Korean Journal of Pain
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• v.31 no.2
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• pp.102-108
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• 2018

Background: Nefopam is a non-opioid, non-steroidal analgesic drug with fewer adverse effects than narcotic analgesics and nonsteroidal anti-inflammatory drugs, and is widely used for postoperative pain control. Because nefopam sometimes causes side effects such as nausea, vomiting, somnolence, hyperhidrosis and injection-related pain, manufacturers are advised to infuse it slowly, over a duration of 15 minutes. Nevertheless, pain at the injection site is very common. Therefore, we investigated the effect of warmed carrier fluid on nefopam injection-induced pain. Methods: A total of 48 patients were randomly selected and allocated to either a control or a warming group. Warming was performed by diluting 40 mg of nefopam in 100 ml of normal saline heated to $31-32^{\circ}C$ using two fluid warmers. The control group was administered 40 mg of nefopam dissolved in 100 ml of normal saline stored at room temperature ($21-22^{\circ}C$) through the fluid warmers, but the fluid warmers were not activated. Results: The pain intensity was lower in the warming group than in the control group (P < 0.001). The pain severity and tolerance measurements also showed statistically significant differences between groups (P < 0.001). In the analysis of vital signs before and after the injection, the mean blood pressure after the injection differed significantly between the groups (P = 0.005), but the heart rate did not. The incidence of hypertension also showed a significant difference between groups (P = 0.017). Conclusions: Use of warmed carrier fluid for nefopam injection decreased injection-induced pain compared to mildly cool carrier fluid.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.7 no.4
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• pp.221-227
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• 2007

This paper introduces an on-line particle-filtering-based framework for failure prognosis in nonlinear, non-Gaussian systems. This framework uses a nonlinear state-space model of the plant(with unknown time-varying parameters) and a particle filtering(PF) algorithm to estimate the probability density function(pdf) of the state in real-time. The state pdf estimate is then used to predict the evolution in time of the fault indicator, obtaining as a result the pdf of the remaining useful life(RUL) for the faulty subsystem. This approach provides information about the precision and accuracy of long-term predictions, RUL expectations, and 95% confidence intervals for the condition under study. Data from a seeded fault test for a UH-60 planetary carrier plate are used to validate the proposed methodology.

• Journal of Korean Library and Information Science Society
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• v.16
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• pp.99-128
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• 1989

The purpose of this study is to examine the problems of the each cataloging rules about the physical description area that generated the greatest controversy in the cataloging of microcomputer software, and to suggest solutions of these problems. The results of the study can be summarized as follows: 1. Because the physical description area of materials is to identify the physical attributes of the carrier, file description might better described in the material specific details area. 2. Integrated software that related file is linked together need to be used terms that represented any type of software 3. It is desirable that the term 'computer' is to be used as a modifier to devide the carrier of microcomputer and other non book materials. 4. System requirements would better described in a note area rather than physical, description area. 5. It is desirable that other physical details such as recording density, tracks, etc., is to describe in the physical description area, since such information is to represent specifics of the carrier.