• 제목/요약/키워드: AEM

검색결과 101건 처리시간 0.019초

전기화학 캐퍼시터용 PVC기반 가교 음이온교환 멤브레인의 제조 및 특성 (Preparation and Characterization of a Cross-Linked Anion-Exchange Membrane Based on PVC for Electrochemical Capacitor)

  • 김영지;김수연;최성호
    • 한국응용과학기술학회지
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    • 제38권3호
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    • pp.903-913
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    • 2021
  • 본 연구에서는 싸이크론 헥산에서 PVC와 트리에틸디아민 (TEDA), 1,4-디메틸피페라진(DMP) 및 1,4-비스(이미다졸-1-일메틸)벤젠을 각각 치환반응시켜서3가지 형태의 PVC 멤브레인, AEM-1, AEM-2, and AEM-3를 제조하였다. AEM-1, AEM-2, and AEM-3멤브레인의 성공적인 제조 여부를 이온전도도(S/cm), 물함수율 (%), 접촉각, 이온교환능력 (meq/g), 열분석, SEM 및 XPS 분석 통하여 확인하였다. 또한, 제조된 가교 음이온 PVC멤브레인을 사용하여 유기전해질에서 전기화학 캐퍼시터 실험을 수행한 결과, 제조된 AEM-1, AEM-2 AEM-3 멤브레인의 경우 유기전해질에서 충/방전실험결과 매우 안정적임을 확인 할 수 있었다. 이러한 결과로 치환반응 후에 용매 캐시팅법으로 제조된 PVC기반 멤브레인 (AEM-1, AEM-2, 및 AEM-3)의 경우 유기전기화학캐퍼시터 (슈퍼캐퍼시터)용 분리막으로 사용될 수 있다.

액상 amine 광개시제에 따른 치과용 복합수지의 중합효율 (Photopolymerization Efficiency of Dental Resin Composites with Novel Liquid Amine Photoinitiators)

  • 선금주
    • 치위생과학회지
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    • 제8권3호
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    • pp.109-115
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    • 2008
  • 치과용 가시광선 중합형 복합수지의 광중합효율을 높이기 위해 2종의 새로운 액체형 amine 개시제인 MA, MPT와 현재 가장 많이 사용되고 있는 개시제인 AEM을 CQ, PD, DA에 각각 첨가하고 UDMA의 광중합효율을 알아본 결과 다음과 같은 결론을 얻었다. 1. 조사시간이 증가됨에 따라 amine 개시제의 종류에 관계없이 광중합효율이 점차 증가되었으며, 약 60초까지 조사였을 때에는 광중합효율이 급격히 증가되었으나 그 이상 조사하여도 광중합효율이 크게 증가되지 않았다. 2. AEM, MA와 MPT를 사용하였을 경우 모두 CQ > PD > DA의 순으로 광중합효율이 우수하게 나타났으나 AEM을 사용하였을 때 PD와 CQ는 큰 차이를 보이지 않았다. 3. CQ의 광중합효율은 새로운 광개시제인 MA와 MPT를 사용하였을 때가 범용으로 사용되고 있는 amine 개시제인 AEM을 사용하였을 경우보다 중합효율이 증가하는 결과를 보였다. 4. PD의 광중합효율은 MA와 함께 사용하였을 경우가 가장 높게 나타났으나 AEM의 경우와 큰 차이를 보이지는 않았다. 5. 이상의 결과로부터 MA와 CQ 및 PD를 함께 사용한 새로운 광중합시스템이 광중합효율을 높이는데 효율적인 것을 알 수 있었다.

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배열 안테나용 AEM형 FSS 레이돔 설계 (Design of AEM FSS-Radome for Array Antenna)

  • 김상근;이기태;서일성
    • 한국전자파학회논문지
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    • 제22권12호
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    • pp.1180-1183
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    • 2011
  • 본 논문에서는 단위-셀 EM 시뮬레이션 기법을 통해 주파수 선택적 전파투과막(FSS: Frequency Selective Surface)을 갖는 AEM(Advanced Enclosed Mast) 레이돔을 설계하고, $16{\times}16$ 배열안테나 방사 패턴 시험을 통해 레이돔의 성능을 검증하였다. 측정한 결과, 평면파 입사 조건을 가정한 시뮬레이션 결과와 원전계 및 근전계 조건에 레이돔을 두고 시험한 결과가 서로 잘 일치하는 결과를 확인하였다. 이 결과들을 통해 검증된 AEM형 FSS 레이돔을 활용하여 기존 마스트 대비 안테나의 RCS를 줄이는 것이 가능할 것이다.

Do Earnings Manipulations Matter Differently in Different Markets of China? Cost of Capital Consequences

  • Sohn, Byungcherl Charlie;Shim, Hoshik
    • Asia Pacific Journal of Business Review
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    • 제4권1호
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    • pp.1-34
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    • 2019
  • This study investigates whether and how a firm's cost of equity capital is influenced by the extent of a firm's real earnings management (REM). Using a large sample of Hong Kong and Chinese firms over the 9-year period 2009-2017, we find that our implied cost of equity estimates are positively associated with both the extent of REM and the extent of accrual-based earnings management (AEM), but the positive association is stronger for REM than for AEM. We also provide evidence suggesting that the effect of AEM and REM on the cost of equity is more pronounced for Hong Kong firms than Chinese firms, and within Chinese firms, it is less pronounced for the state-owned enterprises (SOEs). Collectively, our results suggest that while both REM and AEM exacerbate the quality of earnings used by outside investors, REM does so to a greater extent than AEM, and thus the market demands a higher risk premium for REM activities than for AEM activities and that this cost of capital-increase effect is more prominent in a developed market like Hong Kong and mitigated by state ownership in China because of investors' expectations for a lower level of detriments to firm fundamentals by REM due to government's protection in a less developed market like China.

LIBS와 이온교환막을 활용한 모르타르 단면 침투 황산염과 염화물 분석 (A Comparative Study of Sulfate and Chloride Intrusion in Mortar Sections: An Approach Using Laser Induced Breakdown Spectroscopy and Ion Exchange Membrane)

  • 박원준
    • 한국건축시공학회지
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    • 제23권3호
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    • pp.221-229
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    • 2023
  • 본 연구에서는 모르타르 내 침투 염화물과 황산염 분석을 단면 깊이별 용출액을 대상으로 음이온교환막(AEM)과 LIBS를 활용하여 수행하였다. 염화물(황산염) 농도별로 침지한 모르타르를 대상으로 IC 분석과 LIBS 분석을 동시에 진행하였다. 실험 결과로, Cl(837.59nm) 및 S(921.3nm)의 파장에서 AEM은 동일 침투 농도에서 paper substrate보다 높은 LIBS 강도가 측정되었고, LIBS 강도와 Cl농도 사이의 높은 상관관계가 확인되었다. 동일 깊이 IC 분석 농도 결과와 비교할 때, AEM을 활용하여 높은 강도를 얻을 수 있었다. AEM을 통해 저농도 구간의 LIBS 강도 향상과 오차 저감을 확인하였으나, S(921.3nm)의 경우는 저농도 구간에 대한 LIBS 신호 감도의 향상이 향후 필요할 것으로 보인다.

요추부 불안정성을 가진 요통환자의 복부 드로우-인 기법과 복부 확장 기법을 이용한 체간안정화운동의 효과 비교 (Comparison of the Effects of Abdominal Draw-In and Expansion Maneuvers on Trunk Stabilization in Patients With Low Back Pain and Lumbar Spine Instability)

  • 이호준;김선엽
    • 한국전문물리치료학회지
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    • 제22권1호
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    • pp.37-48
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    • 2015
  • This study aimed to investigate the effect of the abdominal drawing-in maneuver (ADIM) and abdominal expansion maneuver (AEM) on trunk stabilization, as well as trunk muscle activities and differences in quadruple visual analogue scale, Korean Oswestry Disability Index, and Fear Avoidance Beliefs Questionnaire scores, in patients with chronic low back pain and lumbar spine instability. To increase intra-abdominal pressure during the trunk stabilization exercise, the technique of pushing the abdomen out using diaphragmatic abdominal breathing suggested by Pavel Koral was used, which we termed the AEM. Fifty patients who tested positive on more than three of the five lumbar spine instability tests were separated from 138 patients with chronic low back pain of these patients, 16 were placed in the control group (trunk stabilization exercise), 17 were placed in the ADIM group (trunk stabilization exercise with ADIM), and 17 were placed in the AEM group (trunk stabilization exercise with AEM). Each group participated in the study for 30 minutes three times weekly for 4 weeks. Surface electromyography was used to measure the trunk muscle activities during the kneeling forward and supine bridging positions, and one-way repeated analysis of variance was used to determine the statistical significance of the trunk muscle activities in the rectus abdominis, internal oblique (IO), erector spinae, and multifidus (MF) muscles. The ADIM and AEM groups showed relatively larger improvements in psychosocial and functional disability level than control group. There were significant changes among the three groups, those from the measured values of the AEM group was significantly higher than the other two groups in changes in IO and MF trunk muscle activities (p<.05). This finding demonstrates that trunk stabilization exercises with AEM is more effective than ADIM for increasing trunk deep muscle activity of chronic low back pain patients with lumbar spine instability.

Effects of the Abdominal Drawing-in Maneuver and the Abdominal Expansion Maneuver on Grip Strength, Balance and Pulmonary Function in Stroke Patients

  • Yoon, Mi-Ra;Choi, Ho-Suk;Shin, Won-Seob
    • The Journal of Korean Physical Therapy
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    • 제27권3호
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    • pp.147-153
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    • 2015
  • Purpose: The purpose was to determine whether the application of the abdominal drawing-in maneuver (ADIM) and abdominal expansion maneuver (AEM) to stroke patients would affects their trunk stability, balance, pulmonary function, and grip strength. Methods: The subjects were 36 stroke patients who were randomly and equally assigned to an ADIM group (n=12), an AEM group (n=12), and a control group (n=12). The intervention was applied to each group three times per week, 30 minutes each time, for four weeks. Outcome measures were grip strength, modified functional reach test (mFRT) and pulmonary function. Pulmonary function were measured force expiratory volume at one second (FEV1), forced vital capacity (FVC), FEV1/FVC and peak expiratory flow (PEF) values. Results: The results of the three groups showed statistically significant improvements in grip strength. The AEM group showed significantly greater differences in grip strength than either the ADIM group or the control group. In the anterior mFRT, the ADIM group showed significantly improvements than the control group. The ADIM and AEM groups were showed statistically significant greater improvements in PEF between the baseline and post-intervention and the post-analysis revealed that the AEM group showed significantly greater improvements than the control group. Conclusion: The results of this study indicate that the ADIM and AEM were effective in improving the PEF of pulmonary function. The ADIM was more effective than AEM in trunk stabilization.

Comparison on postural control between abdominal draw-in maneuver and abdominal expansion maneuver in persons with stroke

  • Choi, Ho-Suk;Shim, Yu-Jin;Shin, Won-Seob
    • Physical Therapy Rehabilitation Science
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    • 제5권3호
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    • pp.113-119
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    • 2016
  • Objective: The effect of abdominal expansion maneuver (AEM) and abdominal draw-in maneuver (ADIM) on postural control in an unsupported position in stroke patients. Design: Randomized controlled trial. Methods: A total of 36 persons with hemiplegic stroke participated in this study. The subjects were randomly divided into an AEM experimental group (n=12), an experimental ADIM group (n=12), and a control group (n=12). We collected the general characteristics of all subjects and the pre-test results before the intervention and after 4 weeks of the intervention. The trunk stabilization training of the ADIM and AEM group were performed 15 minutes a day, 3 times a week for 4 weeks, and general physical therapy was performed 2 times a day, 30 minutes per session, 5 times a week for all three groups. The control group received joint mobilizations, muscle strengthening, endurance strengthening, and gait exercises along with treatment of the central nervous system, such as neuro-developmental treatment, mat, and gait training. The AEM is an inspiratory phase of tidal breathing expanding the lateral lower ribcage in a lateral direction with minimal superior movements of the chest. Then the lower abdomen expands and the navel moves in an anterior-caudal direction. The ADIM is a repeated contraction and relaxation of the anal sphincter during inspiration. The navel pulls the lower abdomen to the direction of the spine without the movement of the trunk and pelvis. Results: Before and after the interventions, medial-lateral axis movement distance, anterior-posterior axis movement distance, sway mean velocity, and sway area 95% was a statistically significant change in all three groups (p<0.05). The post-hoc test showed a significant improvement in medial-lateral axis movement distance, anterior-posterior axis movement distance, sway mean velocity, and sway area in the AEM group compared with the control group, and in the ADIM group compared with the control group (p<0.05). Conclusions: In conclusion, both AEM training and ADIM training are necessary interventions to maintain the independent sitting position according to the characteristics of the patient.

AEM을 이용한 철근콘크리트 모형 구조물의 붕괴 모델링 (Collapse Modeling of model RC Structure Using Applied Element Method)

  • 박훈;석철기;김승곤
    • 터널과지하공간
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    • 제19권1호
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    • pp.43-51
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    • 2009
  • 구조물의 비선형 적인 대변위 붕괴거동을 해석하기 위해 다양한 수치 해석에 대한 연구가 진행되어 왔다. 본 연구에서는 새로운 수치해석 기법인 Applied Element Method (AEM)를 이용하여 철근 콘크리트 모형 구조물의 발파해체 붕괴거동을 모사하였다. 보형 구조물의 발파해체 붕괴거동과 수치해석으로 모사된 구조물의 붕괴거동을 X 방향(수평방향)의 변위와 Z 방향(수직방향)의 변위에 대해 비교한 결과, 수치해석에서 모사된 구조물의 붕괴거동은 실제 모형 구조물은 붕괴거동을 사실적으로 모사할 수 있음을 확인하였다.

A Study on Earnings Management in Companies Achieving Sustainability: Accruals-based and Real Earnings Management

  • JI, Sang-Hyun;OH, Han-Mo;YOON, Ki-Chang;AN, Sang-Bong
    • 유통과학연구
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    • 제17권9호
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    • pp.103-115
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    • 2019
  • Purpose - We attempted to verify the level of ethics of firms achieving sustainable management from the aspect of reliability of accounting information. Specifically, we evaluated the effects of sustainable management on accruals-based earning management (AEM) and real earning management (REM). Research design, data, and methodology - We employed the issuance of sustainability reports in addition to the indices of social responsibility and environmental-management evaluation of the Korea Corporate Governance Service in order to measure sustainability management. AEM was measured using discretionary accruals and calculated using the operant Jones model. Specifically, REM was measured using the methodology suggested by prior studies. The sample of our study consisted of 1,418 years of public listed firms in the Korea Stock Exchange from 2015 to 2017. Results - First, the level of AEM in firms achieving sustainable management was lower than the other. Second, the level of REM in these firms was lower than the other. Nonetheless, another analysis showed that the level of governance control affects the level of earning management and that the levels of AEM and REM were generally lower in firms achieving sustainable management than the others. Conclusions - We expected that firms achieving external ethics tend to have a higher level of internal ethics than others.