• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2000년도 하계학술대회 논문집
• /
• pp.585-591
• /
• 2000

The wavelet transform is the most recent technique for processing signals with time-varying spectra. In this paper, the wavelet transform is utilized to improved the assessment and multi-resolution analysis of acoustic emission signals generating in partial discharge. This paper especially deals with the assessment of process statistical parameter using the features extracted from the wavelet coefficients of measured acoustic emission signals in case of applied voltage 20[kv]. Since the parameter assessment using all wavelet coefficients will often turn out leads to inefficient or inaccurate results, we selected that level-3 stage of multi decomposition in discrete wavelet transform. We applied FIR(Finite Impulse Response)digital filter algorithm in discrete to suppression for random noise. The white noise be included high frequency component denoised as decomposition of discrete wavelet transform level-3. We make use of the feature extraction parameter namely, maximum value of acoustic emission signal, average value, dispersion, skewness, kurtosis, etc. The effectiveness of this new method has been verified on ability a diagnosis transformer go through feature extraction in stage of acting(the early period, the last period) .

• 대한두개안면성형외과학회지
• /
• 제19권4호
• /
• pp.300-303
• /
• 2018

Intraorbital wooden foreign bodies may present difficulties in diagnosis due to their radiolucent nature. Delayed recognition and management can cause significant complications. We present a case report that demonstrates these problems and the sequela that can follow. A 56-year-old man presented with a 3-cm laceration in the right upper eyelid, sustained by a slipping accident. After computed tomography (CT) scanning and ophthalmology consultation, which revealed no fractures and suggested only pneumophthalmos, the wound was repaired by a plastic surgery resident. Ten days later, the patient's eyelid displayed signs of infection including pus discharge. Antibiotics and revisional repair failed to solve the infection. Nearly 2 months after the initial repair, a CT scan revealed a large wooden fragment in the superomedial orbit. Surgical exploration successfully removed the foreign body and inflamed pocket, and the patient healed uneventfully. However, the prolonged intraorbital infection had caused irreversible damage to the superior rectus muscle, with upgaze diplopia persisting 1 year after surgery and only minimal muscle function remaining. We report this case to warn clinicians of the difficulties in early diagnosis of intraorbital wooden foreign bodies and the grave prognosis of delayed management.

• 한국수소및신에너지학회논문집
• /
• 제32권6호
• /
• pp.592-611
• /
• 2021

In this study a rarely available high-throughput cycling data set of 124 commercial lithium iron phosphate/graphite cells cycled under fast-charging conditions, with widely varying cycle lives ranging from 150 to 2,300 cycles including in-cycle temperature and per-cycle IR measurements. We worked out own Python codes which reproduced the various data plots and machine learning approaches for cycle life prediction using early cycles and more details not presented in the article and the supplementary information. Particularly, we applied regularized ridge, lasso and elastic net linear regression models using features extracted from capacity fade curves, discharge voltage curves, and other data such as internal resistance and cell can temperature. We found that due to the limitation in the quantity and quality of the data from costly and lengthy battery testing a careful hyperparameter tuning may be required and that model features need to be extracted based on the domain knowledge.

• 임상간호연구
• /
• 제16권2호
• /
• pp.5-16
• /
• 2010

Purpose: The purpose of this study was to develop a motivational enhancement therapy (MET) for coronary artery disease (CAD) patients in early stages of health behavior change and evaluate its effects on health motivation, the stages of change, health behaviors, and cardiovascular risk factors. Methods: Using a non-equivalent control pre-post design, the study was conducted on 42 CAD patients who underwent medical treatment or percutaneous coronary interventions in a hospital. The intervention group (n=21) received the MET (MET 1 during admission, MET 2 after discharge via telephone). The control group (n=21) received a standard care. Data were analyzed using descriptive statistics, ${\chi}^2-test$ and t-test with the SPSS 12.0 program. Results: Participants in the intervention group reported significantly increased scores of health motivation (t=-2.093, p=.043), the stages of change (t=-5.682, p<.001), and health behaviors (t=-3.069, p=.004) and significantly decreased scores of cardiovascular risk factors (t=2.131, p=.039) compared to those of the control group. Conclusion: The findings indicate that the MET is an effective intervention in improving health behaviors and decreasing cardiovascular risk factors for CAD patients.

• 한국수자원학회:학술대회논문집
• /
• 한국수자원학회 2021년도 학술발표회
• /
• pp.142-142
• /
• 2021

An arbitrary representation of an urban drainage sewer system was devised using a geographic information system (GIS) tool in order to calculate the surface and subsurface flow interaction for simulating urban flood. The proposed methodology is a mean to supplement the unavailability of systematized drainage system using high-resolution digital elevation(DEM) data in under-developed countries. A modified DEM was also developed to represent the flood propagation through buildings and road system from digital surface models (DSM) and barely visible streams in digital terrain models (DTM). The manhole, sewer pipe and storm drain parameters are obtained through field validation and followed the guidelines from the Plumbing law of the Philippines. The flow discharge from surface to the devised sewer pipes through the storm drains are calculated. The resulting flood simulation using the modified DEM was validated using the observed flood inundation during a rainfall event. The proposed methodology for constructing a hypothetical drainage system allows parameter adjustments such as size, elevation, location, slope, etc. which permits the flood depth prediction for variable factors the Plumbing law. The research can therefore be employed to simulate urban flood forecasts that can be utilized from traffic advisories to early warning procedures during extreme rainfall events.

• Archives of Plastic Surgery
• /
• 제50권5호
• /
• pp.488-491
• /
• 2023

Silicone breast implant insertion is a commonly performed surgical procedure for breast augmentation or reconstruction. Among various postoperative complications, infection is one of the main causes of patient readmission and may ultimately require explantation. We report a case of infective costochondritis after augmentation mammoplasty, which has rarely been reported and is therefore difficult to diagnose. A 36-year-old female visited the clinic for persistent redness, pain, and purulent discharge around the left anteromedial chest, even after breast implant explantation. Magnetic resonance imaging showed abscess formation encircling the left fourth rib and intracartilaginous and bone marrow signal alteration at the left body of the sternum and left fourth rib. En bloc resection of partial rib and adjacent sternum were done and biopsy results confirmed infective costochondritis. Ten months postoperatively, the patient underwent chest wall reconstruction with an artificial bone graft and acellular dermal matrix. As shown in this case, early and aggressive surgical debridement of the infected costal cartilage and sternum should be performed for infective costochondritis. Furthermore, delayed chest wall reconstruction could significantly contribute to the quality of life.

• 한국재료학회:학술대회논문집
• /
• 한국재료학회 2011년도 춘계학술발표대회
• /
• pp.5-5
• /
• 2011

The research and development of hybrid electric vehicle (HEV), plug-in hybrid electric vehicle (PHEV) and electric vehicle (EV) are intensified due to the energy crisis and environmental concerns. In order to meet the challenging requirements of powering HEV, PHEV and EV, the current lithium battery technology needs to be significantly improved in terms of the cost, safety, power and energy density, as well as the calendar and cycle life. One new technology being developed is the utilization of composite cathode by mixing two different types of insertion compounds [e.g., spinel $LiMn_2O_4$ and layered $LiMO_2$ (M=Ni, Co, and Mn)]. Recently, some studies on mixing two different types of cathode materials to make a composite cathode have been reported, which were aimed at reducing cost and improving self-discharge. Numata et al. reported that when stored in a sealed can together with electrolyte at $80^{\circ}C$ for 10 days, the concentrations of both HF and $Mn^{2+}$ were lower in the can containing $LiMn_2O_4$ blended with $LiNi_{0.8}Co_{0.2}O_2$ than that containing $LiMn_2O_4$ only. That reports clearly showed that this blending technique can prevent the decline in capacity caused by cycling or storage at elevated temperatures. However, not much work has been reported on the charge-discharge characteristics and related structural phase transitions for these composite cathodes. In this presentation, we will report our in situ x-ray diffraction studies on this mixed composite cathode material during charge-discharge cycling. The mixed cathodes were incorporated into in situ XRD cells with a Li foil anode, a Celgard separator, and a 1M $LiPF_6$ electrolyte in a 1 : 1 EC : DMC solvent (LP 30 from EM Industries, Inc.). For in situ XRD cell, Mylar windows were used as has been described in detail elsewhere. All of these in situ XRD spectra were collected on beam line X18A at National Synchrotron Light Source (NSLS) at Brookhaven National Laboratory using two different detectors. One is a conventional scintillation detector with data collection at 0.02 degree in two theta angle for each step. The other is a wide angle position sensitive detector (PSD). The wavelengths used were 1.1950 ${\AA}$ for the scintillation detector and 0.9999 A for the PSD. The newly installed PSD at beam line X18A of NSLS can collect XRD patterns as short as a few minutes covering $90^{\circ}$ of two theta angles simultaneously with good signal to noise ratio. It significantly reduced the data collection time for each scan, giving us a great advantage in studying the phase transition in real time. The two theta angles of all the XRD spectra presented in this paper have been recalculated and converted to corresponding angles for ${\lambda}=1.54\;{\AA}$, which is the wavelength of conventional x-ray tube source with Cu-$k{\alpha}$ radiation, for easy comparison with data in other literatures. The structural changes of the composite cathode made by mixing spinel $LiMn_2O_4$ and layered $Li-Ni_{1/3}Co_{1/3}Mn_{1/3}O_2$ in 1 : 1 wt% in both Li-half and Li-ion cells during charge/discharge are studied by in situ XRD. During the first charge up to ~5.2 V vs. $Li/Li^+$, the in situ XRD spectra for the composite cathode in the Li-half cell track the structural changes of each component. At the early stage of charge, the lithium extraction takes place in the $LiNi_{1/3}Co_{1/3}Mn_{1/3}O_2$ component only. When the cell voltage reaches at ~4.0 V vs. $Li/Li^+$, lithium extraction from the spinel $LiMn_2O_4$ component starts and becomes the major contributor for the cell capacity due to the higher rate capability of $LiMn_2O_4$. When the voltage passed 4.3 V, the major structural changes are from the $LiNi_{1/3}Co_{1/3}Mn_{1/3}O_2$ component, while the $LiMn_2O_4$ component is almost unchanged. In the Li-ion cell using a MCMB anode and a composite cathode cycled between 2.5 V and 4.2 V, the structural changes are dominated by the spinel $LiMn_2O_4$ component, with much less changes in the layered $LiNi_{1/3}Co_{1/3}Mn_{1/3}O_2$ component, comparing with the Li-half cell results. These results give us valuable information about the structural changes relating to the contributions of each individual component to the cell capacity at certain charge/discharge state, which are helpful in designing and optimizing the composite cathode using spinel- and layered-type materials for Li-ion battery research. More detailed discussion will be presented at the meeting.

• 생태와환경
• /
• 제50권1호
• /
• pp.29-45
• /
• 2017

본 연구는 2012년 5월부터 2015년 12월까지 북한강 상류에 위치하는 의암호의 4개 지점에서 시공간적 수질 변동성을 강우 수문인자와 비교 고찰하였다. 조사기간 동안 수온, DO, Conductivity 및 TSS 등 기초 수질요인의 변동은 계절적 영향이 컸다. 특히, 수온성층은 수심이 깊은 댐 부근에서 매년 관찰되었고, 소멸 시기는 8월~10월 사이에 있었다. 질소 계열 영양염의 증가는 유량이 빈약할 때이었고, 인의 증가는 초기 유량 증가와 극심한 가뭄이 지속될 때이었다. Chl-a에 의한 부영양 수준을 초과하는 기간은 2012년, 2014년~2015년에 1~2개월이었으나 2013년에는 4개월 동안 지속되었다. 의암호의 수질 변동성은 댐 중앙부에 상하류로 이어진 하중도와 골재섬의 존재, 도시하천과 하수처리장 방류수 유입이라는 지형적 구조와 오염원의 기반 영향에 대하여, 상류 댐으로부터의 유입량과 의암댐의 방류량 및 방류형태(패턴)에 의한 수위 증감에서 직간접적 관련성과 영향을 찾을 수 있었다. 수질의 시공간적 변이 과정에서 기상(장마, 태풍, 이상강우 및 폭염 더위) 수문(유량과 수위)학적 작용에 기여하는 주요 인자는 펄스, 희석, 역류, 흡수 및 침전 등으로 볼 수 있었다. 의암호의 수질 변동은 매우 역동적이며, 그 영향은 내부 자체뿐만 아니라 발전방류구를 통해 하류 저수지(청평호, 팔당호)에까지 전달될 수 있는 잠재성을 가지고 있다.

• 지질공학
• /
• 제22권4호
• /
• pp.387-398
• /
• 2012

국내 수막재배지는 시설 증대로 인한 지하수 취수량 감소의 어려움을 겪고 있다. 이 연구는 이들 지역 중 청원-충주지역을 대상으로 지하수 이용량 및 배출량을 측정하고, 이를 토대로 국내 수막재배지에서의 지하수 이용량을 추정하였다. 대표 관정들의 모터사양과 1일 지하수 토출 능력과의 관계, 1일 최저 기온 $0^{\circ}C$ 이하의 기록 일수, 최저 기온 변화에 따른 모터 가동 상황 등을 토대로 하여, 청원지역에서 2011년~2012년 겨울철 수막재배에 이용된 지하수 이용량을 추정하면 1 ha 당 $53,138m^3$이 된다. 이에 의한 면적 대비 국내 수막재배지(10,746 ha)의 지하수 이용 총량은 약 5.7억 $m^3$이며, 이는 국내 농업용수 지하수 이용량 16.9억 $m^3$의 33.7%에 해당된다. 2012년 2월 9일부터 22일까지 면적 4 ha의 청원지역 배수로에서 측정한 1일 지하수 배출량은 $2,079{\sim}2,628m^3$ 범위(평균 $2,341m^3$)로서, 수막재배 면적 1 ha 당 1일 평균 지하수 배출량이 $585m^3$인 것으로 나타났다. 수막재배 일수 94일을 적용하면, 청원지역에서 2011년~2012년 겨울철에 수막재배에 이용된 지하수 이용량은 $54,990m^3/ha$이다. 이에 의한 면적 대비 국내 수막재배지의 지하수 이용 총량은 약 5.9억 $m^3$이며, 이는 전체 농업용수 지하수 이용량의 약 34.9%에 해당된다. 충주지역에서는 수막재배지 1 ha 당 1일 지하수 배출량이 $805m^3$ 미만일 것으로 추정되었다. 이 지역에서의 2011년~2012년 겨울철 수막재배 일수 108일을 적용하면, 면적 대비 국내 수막재배지의 지하수 이용량은 전체 농업용수 지하수 이용량의 55% 미만일 것으로 추정된다.

• 가정간호학회지
• /
• 제8권1호
• /
• pp.5-24
• /
• 2001

The purpose of this study was to develop a parenting intervention program and determine the efficacy of the program with low-birth weight infants and their mothers. Nine dyads for the experimental group and twelve dyads for the control group discharged from the Neonatal Intensive Care Unit of a University Hospital in Seoul were recruited for the study. For the intervention group, programmed education and support which focused on the maternal sensitivity of the infant's behavior. rearing environment. motherinfant interaction and infant care were given to each subject. Individual counseling and home visits were provided at discharge, one week after discharge. and one and three months of corrected age in every infant. Structured questionaires were administered and feeding interactions were videotaped and coded by a blinded certified observer. A Quasi-experimental design was conducted for this study. Postpartum depression, maternal self esteem. infant care burden, HOME. mother-infant interaction, and infant development were measured. Results were in favor of the intervention versus the control group. On the Beck depression inventory, intervention mothers showed decreasing trends in depressive symptom vs control mothers although, there were statistically no significant differences between the two groups at each time. The mean score of experimental group was 11.55(mild depression state) at discharge and became 8,6(normal state) at 1 month of corrected age. On the other hand, the mean score of the control group was 13.92(mild depression state) at discharge and became 14.0. Maternal self esteem in both groups improved over time. Infant care burden in both groups was also shown to increase over time. There was a significant difference between the two groups in HOME(p=.0340) at 3 months of corrected age. HOME scores of the experimental group and the control's were 31.10 and 25.58, respectively. Mothers' emotional and language responses were significantly high in the intervention group compared with the control group(p=.0155). Intervention group (53.33) showed a significantly high quality of motherinfant interaction compared with the in control group (42.80)(p =.0340). Intervention group mothers appeared have a better quality of mother-infant interaction behaviors. On the other hand, there was no statistical difference in the infant part between groups. Intervention group infants had higher trends in a general developmental quotient: although, there was no statistical difference between groups. The general developmental quotient of intervention infants was 102.56 and control's was 91.28. However, the developmental quotient of the domain of 'individuality-sociality' was higher in the intervention group infants compared with the control's(p=.0155). The concerns identified by parents revealed two domains of an infants' health management -knowledge and skills in caregiving of lowbirthweight-infants, characteristics of lowbirthweight infants, identifying a developmental milestone, coping with emergency situations and relaxation strategies of mothers from the infant care burden. Interview data with the mothers of low-birth weight infants can be used to develop intervention program contents. Limited intervention time and frequency due to time and cost limitations of this study should be modified. The intervention should be continuously implemented when low-birth weight infants become three years old. An NNNS demonstration appeared to be a very effective intervention for the mothers to improve the quality of mother-infant interactions. Therefore intervening in the mothers of low-birth weight infants as early after delivery as possible is desirable. This study has shown that home visit interventions are worthwhile for mothers only beyond the approach as an essential factor in ability of facilitating a growth fostering environment. In conclusion. the intervention program of this study was very effective in enhancing the parenting for the mothers of low-birth weight infants, resulting in health promotion of low-birth weight infants. The home-visit outreach intervention program of this study will contribute to the health delivery system in this country where there is a lack of continuous follow-up programs for low-birth weight infants after discharge from NICU, if it is activated as part of the home visit programs in community health systems.