• E2M - 전기 전자와 첨단 소재
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• 제9권8호
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• pp.789-798
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• 1996

The double nitride layer Metal Nitride Oxide Semiconductor(MNOS) structures were fabricated by variating both gas ratio and nitride thickness, and by duplicating nitride deposited and one nitride layer MNOS structure to improve nonvolatile memory characteristics of MNOS structures by Low Pressure Chemical Vapor Deposition(LPCVD) method. The nonvolatile memory characteristics of write-in, erase, memory retention and degradation of Bias Temperature Stress(BTS) were investigated by the homemade automatic .DELTA. $V_{FB}$ measuring system. In the trap density double nitride layer structures were higher by 0.85*10$^{16}$ $m^{-2}$ than one nitride layer structure, and the AVFB with oxide field was linearly increased. However, one nitride layer structure was linearly increased and saturated above 9.07*10$^{8}$ V/m in oxide field. In the erase behavior, the hole injection from silicon instead of the trapped electron emission was observed, and also it was highly dependent upon the pulse amplitude and the pulse width. In the memory retentivity, double nitrite layer structures were superior to one nitride layer structure, and the decay rate of the trapped electron with increasing temperature was low. At increasing the number on BTS, the variance of AVFB of the double nitride layer structures was smaller than that of one nitride layer structure, and the trapped electron retention rate was high. In this paper, the double nitride layer structures were turned out to be useful in improving the nonvolatile memory characteristics.

• The Korean Journal of Physiology and Pharmacology
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• 제22권5호
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• pp.577-584
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• 2018

Bladder dysfunction is a common complication of diabetes mellitus (DM). However, there have been a few studies evaluating bladder smooth muscle contraction in DM in the presence of pharmacological inhibitors. In the present study, we compared the contractility of bladder smooth muscle from normal rats and DM rats. Furthermore, we utilized pharmacological inhibitors to delineate the mechanisms underlying bladder muscle differences between normal and DM rats. DM was established in 14 days after using a single injection of streptozotocin (65 mg/kg, intraperitoneal) in Sprague-Dawley rats. Bladder smooth muscle contraction was induced electrically using electrical field stimulation consisting of pulse trains at an amplitude of 40 V and pulse duration of 1 ms at frequencies of 2-10 Hz. In this study, the pharmacological inhibitors atropine (muscarinic receptor antagonist), U73122 (phospholipase C inhibitor), DPCPX (adenosine $A_1$ receptor antagonist), udenafil (PDE5 inhibitor), prazosin (${\alpha}_1$-receptor antagonist), verapamil (calcium channel blocker), and chelerythrine (protein kinase C inhibitor) were used to pretreat bladder smooth muscles. It was found that the contractility of bladder smooth muscles from DM rats was lower than that of normal rats. In addition, there were significant differences in percent change of contractility between normal and DM rats following pretreatment with prazosin, udenafil, verapamil, and U73122. In conclusion, we suggest that the decreased bladder muscle contractility in DM rats was a result of perturbations in $PLC/IP_3$-mediated intracellular $Ca^{2+}$ release and PDE5 activity.

• 대한디지털의료영상학회논문지
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• 제14권2호
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• pp.57-61
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• 2012

To compare the accuracy of breath-hold magnetic resonance imaging sequences to establish the most effective superparamagnetic iron oxide-enhanced sequence for detection of hepatic metastases. A total of 100 patients(50men and 50women, mean age: 60years) with liver disease(including malignant and benign liver lesions) were investigated at 3.0T machine (GE, General Electric Medical System, Excite HD) with 8Ch body coil. Pulse sequence for MR imaging decided to the FS-T2-FSE-RT(TR/TE/Thick./Freq./Phase=12857ms/100ms/7mm/512/384), MGRE(TR/TE/Thick./Freq./Phase=100ms/9.7ms/7mm/384/288), in-out of phase echo(TR/$TE_1$, $TE_2$/Thick./Freq./Phase=140ms/2.4, 5.8ms/7mm/352/300), Images obtained before the injection of SPIO. Six sequences were optimized for lesion detection: FS-T2-FSE-RT, multigradient recalled echo data image(MGRE), T2-weighted MGRE with an 9.7msec echo time. Images were reviewed independently by five blinded observers. The accuracy of each sequence was measured by using picture archiving communication system analysis. All results were correlated with findings at multidectator computed tomography examination. Differences between the mean results of the six observers were measured by using paired student t-test analysis. Postcontrast T2-weighted MGRE sequences were the most accurate and were significantly superior to postcontrast FS-T2-FSE-RT, T2-weighted MGRE, in-out of phase MR sequences(p < .05). For all lesions that were malignant or smaller than 1 cm, respectively, contrast to noise ratio of pre and postcontrast sequences were -1and -0.3 for T2-weighted FSE, 0.53 and 4.5 in-out of phase, 7, 7.08, 5.08, 3.32, 1.7, 1.16, 0.79, 0.68 for GRE with 2.9, 7.5, 12.1, 16.6, 21.2, 25.8, 30.4, 35.0 TE values. Breath-hold various TE precontrast sequences offer improvement in sensitivity compared with fixed multigradient recalled echo sequences alone.

• Journal of Dental Anesthesia and Pain Medicine
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• 제18권1호
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• pp.35-40
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• 2018

Background: The sight of dental injection can bring about severe anxiety in children. Therefore, an alternative method that is convenient, effective, and keeps the needle hidden making it child friendly is necessary. The objective of the study was to compare the efficacy of a camouflaged syringe and conventional syringe on behavior and anxiety in 6-11-year-old children during local anesthesia administration. Methods: The study was a randomized, crossover clinical study including 30 children. Children were separated into two groups. Group 1 consisted of 15 children aged 6-8 years while group 2 consisted of 15 children aged 9-11 years. This study involved two sessions wherein all the children were injected using conventional and camouflaged syringes in separate sessions. Their behavior was assessed using the Faces, Legs, Activity, Cry, Consolability (FLACC) behavior pain scale and anxiety was assessed by measuring changes in pulse rate. Patient and operator preferences were compared. Results: The results showed a lower mean change in pulse rate and FLACC scores in the camouflaged group, suggesting a positive behavior and lesser anxiety with camouflaged syringes than with conventional syringes. Conclusions: The use of camouflaged syringes for anesthesia was demonstrated to be effective in improving the behavior of children and decreasing their anxiety, and is therefore recommended as an alternative to the use of conventional syringes for local anesthesia.

• 한국가스학회지
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• 제14권4호
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• pp.56-62
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• 2010

본 논문은 LPG 엔진의 전자제어센서에 대한 고장사례를 분석하고 고찰한 연구이다. LP가스의 연료 분사량을 컨트롤하는 크랭크 각도센서의 기능이상은 불규칙하고 불균일한 파형형태로 나타나고 있다. 크랭크 각도센서의 노이즈에 관련된 파형은 톱니형의 불규칙한 피크형상으로 나타났고, 2.46V 정도의 노이즈 레벨이 간헐적으로 발생하고 있다. 1번 TDC센서의 내부불량으로 인해 발생한 고장사례는 엔진의 출력을 떨어뜨리고 시동을 간헐적으로 꺼지게 하는 문제점을 초래한다. 산소센서의 성능이상은 센서의 배선에서 연결이 단절되었기 때문에 발생한 것으로 차량의 울컥거리는 현상과 엔진의 부조화 현상이 나타나고 있다. 에어 크리너를 이종품으로 사용한 경우는 신기가 정상적으로 공급되지 못했기 때문에 차량의 가속불량과 엔진의 부조화 현상이 발생하는 원인으로 작용하고 있었다.

• 한국전자통신학회논문지
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• 제14권5호
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• pp.853-862
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• 2019

본 논문에서는 낮은 MTBF와 높은 정비비용이 소모되는 TWTA(: Travelling Wave Tube Amplifier) 방식의 탐색레이더 송신장치를 대체하기 위해서 4.5kW X-대역 SSPA(: Solid State Power Amplifier) 방식의 송신장치를 설계하였다. 송신장치는 평균송신출력 520W와 최대송신출력 4.0kW 이상의 성능을 목표로 설계되었다. 특히 점진적 성능저하 기능을 구현하여, 200W 전력증폭기조립체의 40%(13개 조립체 모듈)의 고장 수준까지는 기존의 TWTA 송신장치보다는 우수한 성능이 유지되도록 설계하였다. 설계된 송신장치에 대해서 X-대역 유효범위를 대상으로 실험한 결과, 최대송신출력 6.1kW, 불요파 69.16dBc, 상승시간 15.2ns, 하강시간 16.3ns 등의 성능값을 확인하였다. 아울러 고장인가를 통하여 점진적 성능저하 기능에 따른 출력전력의 변화를 실험을 통해 확인하였다.

• Current Optics and Photonics
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• 제5권2호
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• pp.186-190
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• 2021

In this study, a compact, picosecond, mid-infrared 3.8 ㎛ MgO:PPLN optical parametric oscillator (OPO) laser output with high peak power is realized using a master oscillator power amplifier (MOPA) 1 ㎛ solid-state laser seeded by a picosecond fiber laser as the pump source. The pump source was a 50 MHz and 10 ps fiber seed source. After AOM pulse selection and two-stage solid-state amplification, a 1,064 nm laser output with a repetition frequency of 1-2 MHz, pulse width of 9.5 ps, and a maximum average power of 20 W was achieved. Furthermore, a compact short cavity with a unsynchronized pump is adopted through the design of an OPO cavity structure. When the injection pump power was 15 W and the repetition frequency was 1 MHz, the average output power of idler light was 1.19 W, and the corresponding peak power was 119 kW. The optical conversion efficiency was 7.93%. When the repetition frequency was increased to 2 MHz, the average output power of idler light was 1.63 W, the corresponding peak power was 81.5 kW, and the optical conversion efficiency was 10.87%. At the same time, the output wavelength was measured at 3,806 nm, and the beam quality was MX2 = 3.21 and MY2 = 3.34.

• Nuclear Engineering and Technology
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• 제54권11호
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• pp.4134-4145
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• 2022

The collimator is one of the high-heat-flux components used to avoid a series of vacuum and thermal problems. In this paper, the heat load distribution throughout the collimator is first calculated through experimental data, and a transient thermodynamic simulation analysis of the original model is carried out. The error of the pipe outlet temperature between the simulated and experimental values is 1.632%, indicating that the simulation result is reliable. Second, the model is optimized to improve the heat transfer performance of the collimator, including the contact mode between the pipe and the flange, the pipe material and the addition of a twisted tape in the pipe. It is concluded that the convective heat transfer coefficient of the optimized model is increased by 15.381% and the maximum wall temperature is reduced by 16.415%; thus, the heat transfer capacity of the optimized model is effectively improved. Third, to adapt the long-pulse steady-state operation of the experimental advanced superconducting Tokamak (EAST) in the future, steady-state simulations of the original and optimized collimators are carried out. The results show that the maximum temperature of the optimized model is reduced by 37.864% compared with that of the original model. The optimized model was changed as little as possible to obtain a better heat exchange structure on the premise of ensuring the consumption of the same mass flow rate of water so that the collimator can adapt to operational environments with higher heat fluxes and long pulses in the future. These research methods also provide a reference for the future design of components under high-energy and long-pulse operational conditions.

• Journal of Dental Anesthesia and Pain Medicine
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• 제24권2호
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• pp.119-128
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• 2024

Background: In pediatric dentistry, fear and anxiety are common among children. Local anesthetics (LA) are widely used to control pain and reduce discomfort in children during dental treatment. Topical anesthetics play a vital role in reducing pain and the unpleasant sensation of a needle puncture in children. Peppermint oil has been extensively used for various diseases. However, its anesthetic properties remain unknown. Peppermint oil, used in mouthwashes, toothpastes, and other topical preparations has analgesic, anesthetic, and antiseptic properties. This study aimed to compare and evaluate pain perception following the topical application of peppermint oil versus lignocaine spray before an intraoral injection in children, aged 8-13 years. Method: Fifty-two children, aged between 8-13 years, who required local anesthesia for dental treatment were divided into two groups of 26 each by simple random sampling (Group 1: 0.2% peppermint oil and Group 2: lignocaine spray). In both groups, physiological measurements (e.g., heart rate) were recorded using pulse oximetry before, during, and after the procedure. Objective pain measurement (Sound Eye Motor (SEM) scale) during administration and subjective measuremeant (Wong-Baker Faces Pain Rating Scale (WBFPRS)) after LA administration were recorded. This was followed by the required treatment of the child. Physiological parameters were compared between the two groups using an independent t-test for intergroup assessment and a paired t-test and repeated-measures ANOVA for intragroup comparisons. The Mann-Whitney U test was used to analyze the pain scores. Results: Intragroup mean heart rates, before, during, and after treatment were statistically significantly different (P < 0.05). However, the intergroup mean pulse rates did not differ significantly between the two groups. The mean WBFPS score in the lignocaine spray group was 4.133 ± 2.06 was statistically different from that of the peppermint oil group (0.933 ± 1.03; P < 0.001^*). The mean SEM score was significantly lower in the peppermint oil group than that in the lignocaine spray group (P = 0.006). No negative effects were observed in this study. Conclusion: 0.2% peppermint oil was effective in reducing pain perception.

• 기본간호학회지
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• 제18권4호
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• pp.506-519
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• 2011

Purpose: The purpose of this study was to identify content of Fundamental Nursing Practice (FNP) and the educational needs for nursing practice items in schools of nursing. Methods: Participants were 81 professors who were teaching FNP and 166 clinical nurses. The research questionnaire included 148 practice items, which were selected by content analysis of 7 FNP textbooks. Data were collected from May 20 to July 27, 2011 and analyzed using descriptive statistics and t-test with SPSS 17.0. Results: The research findings showed that : 1) the seven items included in the education content of all schools of nursing were putting on sterile gloves, checking radial pulse, checking blood pressure in the arm, Foley catheterization, injection preparation with ampule, intramuscular injection in the buttocks, and mixing intravenous fluid. Fifty items were included in the content in more than 80% of the schools. 2) Educational domains needing emphasis were medication, infection control, health assessment, oxygenation, urinary elimination, activity/positioning, and nutrition. There were significant differences in reported educational needs between professors and clinical nurses for 62.8% of practice items. Conclusions: Results indicated that standardization of FNP education contents using the findings of this study should lead to improvement in quality of FNP education.