• 대한간호학회지
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• 제26권1호
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• pp.107-126
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• 1996

The Purpose of this study was to build a substantive theory about the experience of postpartum depression. The qualitative research method used was rounded theory. The interviewees were eight others who had experienced postpartum depression. The data were collected through in-depth interviews with audiotape recording done by the investigator over a period of twelve months. he data were analyzed simultaneously by a constant comparative method in which new data were continuously coded into categories and properties according to Strauss and Corbin's methodology. Analysis the grounded data resulted in 28 concepts being identified. Eight categories emerged from the analysis. The categories were regret, loss of freedom, isolation of oneself, heartache, loss, emotional upset, avoidance, recovery. These substantive categories are consistent with precious research results. Causal conditions included : regret, loss of freedom. Phenomena : heartache, loss, emotional upset. Context : isolation oneself. Intervention condition : avoidance. Action/interaction strategies : desire for recovery. Consequences : recovery. These categories were synthesized into the core concept-The process of filling the empty loss of self. The process of the experienced postpartum depression was ① change after delivery, ② searching for a reason for depression, ③ effort to recover from postpartum depression, ④ recovery from postpartum depression and return to previous life. The process of recovery from postpartum depression was proceeded by ① support from others, especially husband, ② resolution of stressful life events, ③ reconstructing of life goals and resolution strategies, ④ acceptance of depression and seeking psychiatric treatment. Seven hypotheses were derived from the analysis. ① Mothers who experienced stressful life event and economic problem are more depressive. ② Mothers who have conflict with parents are more depressive. ③ The more somatic symptoms, the more depression. ④ Social support facilitates recovery from postpartum depression. ⑤ Mothers who have lower self-esteem are more depressive. ⑥ Mother's role overload disturbs recovery from postpartum depression. ⑦ Ideal maternal identity facilitates recovery from postpartum depression. Through this substantive theory, nurses can understand the importance of postpartum depression management.

• 정보처리학회논문지:소프트웨어 및 데이터공학
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• 제2권4호
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• pp.281-290
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• 2013

IT자산은 조직의 경영목적을 지원해주는 핵심영역이며, IT자산의 장애 발생시 신속한 처리를 지원하는 것은 매우 중요하다. 본 연구에서는 IT자산의 장애가 발생할 경우, 장애해결을 위하여 기존의 장애 데이터를 기초로 장애처리 예측 기법을 제시한다. 제안한 장애처리 예측 기법은 첫째, 기존의 장애처리 데이터를 전처리하여 장애처리 유형별로 분류하고 둘째, 분류된 장애처리 유형과 장애 발생 후 접수된 내용을 키워드 매핑시키는 규칙을 제정하였으며 셋째, 제정된 규칙에 의하여 장애 발생 후 장애처리 방법이 사전에 예측 가능한 기계학습 프로세스를 제시하였다. 제시한 기계학습 프로세스의 유효성을 입증하기 위하여 A사에서 6개월 동안 접수된 33,000여건의 전산기기 장애 데이터를 실험한 결과 장애처리 예측의 적중률이 약 72%였으며, 지속적인 기계학습을 통하여 81%로 향상되었다.

• Nuclear Engineering and Technology
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• 제54권1호
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• pp.110-116
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• 2022

Human failure event (HFE) dependency analysis is a part of human reliability analysis (HRA). For efficient HFE dependency analysis, a maximum number of minimal cut sets (MCSs) that have HFE combinations are generated from the fault trees for the probabilistic safety assessment (PSA) of nuclear power plants (NPPs). After collecting potential HFE combinations, dependency levels of subsequent HFEs on the preceding HFEs in each MCS are analyzed and assigned as conditional probabilities. Then, HFE recovery is performed to reflect these conditional probabilities in MCSs by modifying MCSs. Inappropriate HFE dependency analysis and HFE recovery might lead to an inaccurate core damage frequency (CDF). Using the above process, HFE recovery is performed on MCSs that are generated with a non-zero truncation limit, where many MCSs that have HFE combinations are truncated. As a result, the resultant CDF might be underestimated. In this paper, a new method is suggested to incorporate HFE recovery into the MCS generation stage. Compared to the current approach with a separate HFE recovery after MCS generation, this new method can (1) reduce the total time and burden for MCS generation and HFE recovery, (2) prevent the truncation of MCSs that have dependent HFEs, and (3) avoid CDF underestimation. This new method is a simple but very effective means of performing MCS generation and HFE recovery simultaneously and improving CDF accuracy. The effectiveness and strength of the new method are clearly demonstrated and discussed with fault trees and HFE combinations that have joint probabilities.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2001년도 Proceedings ICPE 01 2001 International Conference on Power Electronics
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• pp.591-599
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• 2001

The paper identifies a severe form of core saturation instability in an DC/AC interaction system. It then seeks solutions to the problem by HVDC control means. This is achieved by a proper design of the Voltage Dependent Current Order Limiter (VDCOL), the Current Regulator and Timing Pulse generator. Supplementary control loops have also been introduced to result in a satisfactory performance as compared to that obtained one with the use of uncharacteristic harmonic filter on the AC side. Robustness of all the options has been demonstrated through recovery performance of the DC link in response to both I-phase and 3-phase 5 cycle faults on both rectifier and inverter commutating buses.

• JSTS:Journal of Semiconductor Technology and Science
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• 제3권4호
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• pp.194-198
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• 2003

A 16-bit adiabatic low-power Micro-processor core is designed. The processor consists of control block, multi-port register file and ALU. A simplified four-phase clock generator is designed to provide supply clocks for adiabatic processor. All the clock line charge on the capacitive interconnections is recovered to recycle the energy. Adiabatic circuits are designed based on ECRL(efficient charge recovery logic) and $0.35\mu\textrm$ CMOS technology is used. Simulation results show that the power consumption of the adiabatic Microprocessor core is reduced by a factor of 2.9~3.1 compared to that of conventional CMOS Microprocessor

• Journal of the korean society of oceanography
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• 제34권3호
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• pp.179-183
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• 1999

A light-weight multiple piston corer to meet increasing coring needs in areas where R/V access is limited, is designed and discussed. Hydraulically-damped and spring-driven piston system not only virtually undisturbed surface sediments but also facilitate the recovery and subsequent operation including pore water extraction and core slicing on board the ship. It is designed as compact, light-weight and easy to dissemble that whole gear can be carried by small passenger vehicle yet it permits thick-walled core tube for thermal insulation or large opening core tubes. Because single spring instead of heavy weights of conventional gravity-driven multiple corers is used, this device is very simple and cheap to construct.

• Journal of Power Electronics
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• 제2권4호
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• pp.297-304
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• 2002

The paper identifies a severe form of core saturation instability in a DC/AC interaction system. It then seeks solutions to the problem by HVDC control means. This is achieved by a proper design of the Voltage Dependent Current Order Limiter (VDCOL), the Current Regulate. and Timing Pulse generator. Supplementary control loops have also been introduced to result in a satisfactory performance as compared to that obtained one with the use of uncharacteristic harmonic filter on the AC side. All the options have been demonstrated through recovery performance of the DC link in response to both 1-phase and 3-phase 5 cycle faults on both rectifier and inverter commutating buses.

• Nano
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• 제13권10호
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• pp.1850122.1-1850122.6
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• 2018

Vertically aligned $WO_3$-CuO core-shell nanorod arrays for $NH_3$ sensing are prepared. The sensor is fabricated by preparing $WO_3$-CuO nanorod arrays directly on silicon wafer with interdigital Pt electrodes. The $WO_3$-CuO nanorod arrays are characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD). The sensor based on the vertically aligned $WO_3$-CuO nanorod arrays exhibits ultrasensitive $NH_3$ detection, indicating p-type behavior. The optimum sensing temperature is found to be about $150^{\circ}C$. Both response and recovery time to $NH_3$ ranging from 50 ppm to 500 ppm are around 10-15 s. A possible $NH_3$ sensing mechanism of the vertically aligned hybrid nanorod arrays is proposed.

• 한국방재학회 논문집
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• 제5권4호
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• pp.29-36
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• 2005

본 연구는 부산 가덕도 부근 해성점토에 대하여 일축압축시험을 실시하여 일축압축강도, 최대강도에서의 변형률, 심도와의 관계를 비교 및 분석하였으며 시료에 포함되어 있는 불순물과 시료채취시 충진율이 흙의 일축압축강도와 교란도에 미치는 영향을 파악하였다. 시험결과 시료의 일축압축강도는 최대강도에서의 변형률이 증가함에 따라 감소하는 결과를 보였으며 채취 심도가 깊을수록, 시료채취시의 충진율이 좋을수록 증가하는 추세를 보였다. 특히 시료 충진율의 증가는 일축압축강도 증가를 가져왔고 시료의 등급 또한 높여주었다.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2012년도 학술발표회
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• pp.643-643
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• 2012

Increasing energy prices and growing concerns about global warming address the need to improve energy self-sufficiency in many industrial and municipal sectors. Wastewater treatment plants (WWTPs) are representative of energy-consuming facilities in Korea, accounting for 5% of national energy consumption. We present renewable energy technologies and energy self-sufficiency scenarios in a municipal WWTP ($30,000m^3d^{-1}$) located in Yongin, South Korea. By employing photovoltaics (PV, 135 kW), small hydropower turbine (10 kW), and thermal energy from treated effluent (25 RT: refrigeration ton) within the WWTP, a total of 142 tonne of oil equivalent (toe) of energy was estimated to be generated, accounting for $365ton\;CO_2\;yr^{-1}$ of greenhouse gas emission reduction. Core renewable technologies under consideration include 1) hybrid solar PV system consisting of fixed PV, dual-axis PV, and building integrated PV, 2) low-head small hydropower plant specifically designed for treated effluent, 3) effluent heat recovery system for heating and air conditioning. In addition to these core technologies, smart operation and management scheme will be presented for enhancing overall energy savings and distribution within the WWTP.