• The Korean Journal of Pain
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• 제10권1호
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• pp.34-41
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• 1997

Background : Patient-controlled analgesia(PCA) is a safe and effective technique for providing postoperative pain relief. Studies that compare epidural vs intravenous routes of opiate administration show conflicting results. We designed a prospective, randomized, controlled study to evaluate the safety and efficacy of epidural(EPI-PCA) morphine-bupivacaine versus intravenous (IV-PCA) nalbuphine when administered with a PCA system. Methods : Forty healthy women were randomly assigned to receive an epidural bolus of morphine 3 mg and 0.5% bupivacaine 10 ml, followed by a EPI-PCA with 0.01% morphine and 0.143% bupivacane (basal infusion 1 ml/hr, bolus 1 ml, lock-out interval 30 min) or intravenous bolus of nalbuphine 0.1 mg/kg followed by a IV-PCA with nalbuphine(basal infusion 1 mg/hr, bolus 1 ml, lock-out interval 20 min) for pain relief after cesarean delivery. This study was conducted for 2 days after cesarean section to compare the analgesic efficacy, side effects, patient satisfaction either as EPI-PCA or as IV-PCA. Results : EPI-PCA group had significant lower visual analog pain scale(VAS) at immediate postoperative period, whereas no significant difference was observed when pain was assessed at other time sequence. Urinary retention and pruritus were more frequent with EPI-PCA group, although the incidence of other side effects were the same. Conclusions : Although EPI-PCA with morphine-bupivacaine was of significantly lower VAS at immediate postoperative period, IV-PCA with nalbuphine is a safe and effective alternative to EPI-PCA with morphine-bupivacaine for providing pain relief after cesarean delivery. Further studies about IV-PCA with nalbuphine are needed to control the immediate postoperative pain and to further improve effective pain management.

• Investigative Magnetic Resonance Imaging
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• 제21권4호
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• pp.223-232
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• 2017

Purpose: To report the use of multiband accelerated echo-planar imaging (EPI) for resting-state functional MRI (rs-fMRI) to achieve rapid high temporal resolution at 3T compared to conventional EPI. Materials and Methods: rs-fMRI data were acquired from 20 healthy right-handed volunteers by using three methods: conventional single-band gradient-echo EPI acquisition (Data 1), multiband gradient-echo EPI acquisition with 240 volumes (Data 2) and 480 volumes (Data 3). Temporal signal-to-noise ratio (tSNR) maps were obtained by dividing the mean of the time course of each voxel by its temporal standard deviation. The resting-state sensorimotor network (SMN) and default mode network (DMN) were estimated using independent component analysis (ICA) and a seed-based method. One-way analysis of variance (ANOVA) was performed between the tSNR map, SMN, and DMN from the three data sets for between-group analysis. P < 0.05 with a family-wise error (FWE) correction for multiple comparisons was considered statistically significant. Results: One-way ANOVA and post-hoc two-sample t-tests showed that the tSNR was higher in Data 1 than Data 2 and 3 in white matter structures such as the striatum and medial and superior longitudinal fasciculus. One-way ANOVA revealed no differences in SMN or DMN across the three data sets. Conclusion: Within the adapted metrics estimated under specific imaging conditions employed in this study, multiband accelerated EPI, which substantially reduced scan times, provides the same quality image of functional connectivity as rs-fMRI by using conventional EPI at 3T. Under employed imaging conditions, this technique shows strong potential for clinical acceptance and translation of rs-fMRI protocols with potential advantages in spatial and/or temporal resolution. However, further study is warranted to evaluate whether the current findings can be generalized in diverse settings.

• Journal of the Optical Society of Korea
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• 제19권6호
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• pp.687-694
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• 2015

A photoluminescence (PL) imaging method using a vision camera was employed to inspect InGaN/GaN quantum-well light-emitting diode (LED) epi-wafers. The PL image revealed dark spot defective regions (DSDRs) as well as a spatial map of integrated PL intensity of the epi-wafer. The Shockley-Read-Hall (SRH) nonradiative recombination coefficient increased with the size of the DSDRs. The high nonradiative recombination rates of the DSDRs resulted in degradation of the optical properties of the LED chips fabricated at the defective regions. Abnormal current-voltage characteristics with large forward leakages were also observed for LED chips with DSDRs, which could be due to parallel resistances bypassing the junction and/or tunneling through defects in the active region. It was found that the SRH nonradiative recombination process was dominant in the voltage range where the forward leakage by tunneling was observed. The results indicated that the DSDRs observed by PL imaging of LED epi-wafers were high density SRH nonradiative recombination centers which could affect the optical and electrical properties of the LED chips, and PL imaging can be an inspection method for evaluation of the epi-wafers and estimation of properties of the LED chips before fabrication.

• 대한건축학회논문집:구조계
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• 제36권5호
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• pp.177-185
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• 2020

The building energy performance indicator, called Energy Performance Index (EPI), has been used for the past decades in South Korea. It has a list of design variables assigned with weighting factors (a, b). Unfortunately, the current EPI method is not performance-based but very close to a prescriptive rating. With this in mind, this study aims to propose a new performance-based EPI method. For this purpose, a global sensitivity analysis method, Sobol, is employed. The Sobol method is suitable for complex nonlinear models and can decompose all the output variance due to every input. The Sobol sensitivity index of each variable is defined as 0 to 1 (0 to 100%), and the sum of all sensitivity indices is equal to 1 (100%). In this study, an office building was modeled using EnergyPlus and then the Latin Hypercube Sampling (LHS) was conducted to generate a surrogate model to EnergyPlus. The sensitivity index was suggested to replace weight (a) in the existing EPI. In addition, the discrete weight (b) in the existing EPI was replaced by a set of continuous regression functions. Due to the introduction of the sensitivity index and the continuous regression functions, the new proposed approach can provide far more accurate outcome than the existing EPI (R²: 0.83 vs. R²: 0.01 for cooling, R²: 0.66 vs. R²: 0.01 for total energy). The new proposed approach proves to be more rational, objective and performance-based than the existing EPI method.

• Bulletin of the Korean Chemical Society
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• 제23권9호
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• pp.1189-1216
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• 2002

• 대한전자공학회논문지
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• 제5권4호
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• pp.1-8
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• 1968

TANT회로라함은 진입력만을 NAND게이트만으로 구성되는 3단회로를 말한다. 본논문에서는 임의의 Boole함수에 대한 최소수게이트의 TANT회로를 발견하는 방법을 제시한 것이다. 합성절차의 첫 단계는 Quine-McCluskey의 절차 또는 기타방법에 의하여 essential prime implicants(EPI)를 정하고 채　두년산법을 적용하여 EPI와 동일한 두부를 갖는 prime implicants(PI)를 유도하는 것이다. 두째 단계로 동일한 두부를 갖는 EPI 및 PI를 통합하고 유용한 미부요소를 발생시키는 것이다. 그 다음에 이들 미부요소중에서 공통요소를 선정하는데 이 단계는 C-C표를 이용하는 것과 상통한 점이 있다. 마지막 단계로 용장한 PI를 삭제함으로써 입력수를 줄이는 것이다. 이 방법에 의하면 입력수가 5 및 6의 경우에는 수동적으로 용이하게 해를 얻을 수 있다.

• Child Health Nursing Research
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• 제17권4호
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• pp.281-287
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• 2011

Purpose: The study was done to explore growth variation in head circumference (HC) in extremely premature infants (EPI) with brain injury. Methods: A retrospective cohort study was conducted with 79 cohort samples from the archives of the catch-up growth project. Mean age of the infants was 29.2 weeks of gestation and mean HC, 27.1 cm at birth. Their HC measurements were retrieved from the archives up to 6 month of corrected age (CA) and analyzed against history of brain injury during hospitalization. Results: Overall growth retardation in HC was observed in the cohort sample compared to longer gestation premature infants. EPI with brain injury showed decreased HC compared to infants without brain injury, and resulting growth variation across 6 month of CA. Highest retardation in HC growth was observed in male infants with brain injury. Conclusion: Extreme preterm birth itself may function as a major obstacle against HC growth toward term age in EPI. Sustainability of brain injury could be observed with higher HC growth retardation after term. Evolutionary favor to female infants may exist in HC growth of EPI. Intensive education on HC monitoring is highly suggested for parents of EPI, particularly with children with brain injury.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2001년도 추계종합학술대회
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• pp.665-668
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• 2001

최근 소자의 크기가 작아짐에 따라 집적도가 향상되었으며 크기 감소로 인한 전류-전압 특성의 열화 및 기생 커패시턴스에 의한 성능감쇠가 발생하였다. 이런 문제들을 해결하기 위해 여러 가지 구조들이 개발되고 있으며 본 논문에서는 고농도로 도핑된 ground plane 층위에 적층하여 만든 EPI 구조에 대해 조사 분석하였다. 이 구조의 특성과 임팩트 이온화 및 전계 그리고 I-V 특성 곡선을 저농도로 도핑된 LDD(Lightly Doped Drain) 구조와 비교 분석하였다. 소자의 채널 길이는 0.l0$\mu\textrm{m}$부터 0.06$\mu\textrm{m}$까지 0.01$\mu\textrm{m}$씩 스케일링하여 시뮬레이션 하였다.

• 약학회지
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• 제49권1호
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• pp.68-73
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• 2005

Epi-xanthatin analogs containing hydrophilic substituents such as carboxylic acid, alcohol, morpholine, amino acid, and glucose derivatives were synthesized and their in vitro cytotoxicity and in vivo antitumor activity were evaluated. The target compounds were generally cytotoxic against tumor cell lines of human origin with $ED_{50}$ values of $0.1{\sim}30{\mu}g/ml$, except the highly hydrophilic analog 6 containing aspartic acid. Contrary to the potent cytotoxicity weakly hydrophilic analogs 2 and 8 were not active in vivo, or even toxic to the test animals. As a result, hydrophilic analog of epi-xanthatin did not show in vitro cytotoxicity and hydrophobic analogs did not show in vivo antitumor activity, thus it is presumed that amphiphilic analogs or those with medium hydrophilicity would exhibit the antitumor potency in vivo.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2002년도 Proceedings of International Symposium on Remote Sensing
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• pp.524-529
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• 2002

In this paper, we report the development of two DEM (digital elevation model) generation algorithms over urban areas from an IKONOS stereo pair. One ("EpiMatch") is originally developed for SPOT images and modified for IKONOS images. It uses epipolar geometry for accurate DEM generation. The other is based on graph-cut algorithm in 3D voxel space. This algorithm is believed to work better on height discontinuities than EpiMatch. An IKONOS image pair over Taejon city area was used for tests. Using ground control points obtained from differential GPS, camera model was set up and stereo matching applied. As a result, two DEMs over urban areas were produced. Within a DEM from EpiMatch small houses appear as small "cloudy" patches and large apartment and industrial buildings are visually identifiable. Within the DEM from graph-cut we could achieve better height information on building boundaries. The results show that both algorithms can generate DEMs from IKONOS images although more research is required on handling height discontinuities (for "EpiMatch") and on faster computation (for "Graph-cut").