32,168 research outputs found
Compact Single-Stage Micro-Inverter with Advanced Control Schemes for Photovoltaic Systems
No full textThis paper proposes a grid-connected single-stage micro-inverter with low cost, small size, and high efficiency to drive a 320 W class photovoltaic panel. This micro-inverter has a new and advanced topology that consists of an interleaved boost converter, a full-bridge converter, and a voltage doubler. Variable switching frequency and advanced burst control schemes were devised and implemented. A 320 W prototype micro-inverter was very compact and slim with 60-mm width, 310-mm length, and 30-mm height. In evaluations, the proposed micro-inverter achieved CEC weighted efficiency of 95.55%, MPPT efficiency >95% over the entire load range, and THD 2.65% at the rated power. The proposed micro-inverter is well suited for photovoltaic micro-inverter applications that require low cost, small size, high efficiency, and low noise
Dr Choi Hee-Yoon President Korea Institute of Science and Technology Information Republic of Korea
No full textVisit by Dr Choi Hee-Yoon President Korea Institute of Science and Technology Information Republic of Kore
Choi Yoon Seo
No full text학위논문(석사)--아주대학교 교육대학원 :심리치료교육,2019. 2본 연구는 성인 초기 여성의 애착불안, 부적응적 자기초점주의, 자기자비, 이상섭식행동의 관계를 살펴보고, 애착불안과 이상섭식행동 간의 관계에서 부적응적 자기초점주의와 자기자비의 매개효과를 검증하고자 하였다. 이를 위해 연구문제를 첫째, 애착불안과 부적응적 자기초점주의, 자기자비, 이상섭식행동 간의 관계는 어떠한가? 둘째, 애착불안과 이상섭식행동 간의 관계에서 부적응적 자기초점주의와 자기자비는 각각 매개 역할을 하는가? 셋째, 애착불안과 이상섭식행동 간의 관계에서 부적응적 자기초점주의와 자기자비는 이중매개 역할을 하는가? 로 선정하였다. 연구문제를 수행하기 위해 20세에서 40세까지 성인초기 여성 728명을 대상으로 애착불안 척도, 부적응적 자기초점주의 척도, 자기자비 척도, 이상섭식행동 척도를 사용하여 설문조사를 실시하였다. 자료처리는 SPSS 21.0과 Mplus 7.0 프로그램을 사용하여, 구조방정식 모형 분석을 통해 매개효과를 검증하였으며 그 결과는 다음과 같다.
첫째, 각 변인들 간의 상관관계를 살펴본 결과, 애착불안과 부적응적 자기초점주의, 이상섭식행동은 각각 유의미한 정적상관을 나타냈으며, 자기자비는 이상섭식행동과 유의미한 부적상관을 나타냈다. 둘째, 애착불안과 이상섭식행동 간의 관계에서 부적응적 자기초점주의와 자기자비는 부분매개 효과가 있었다. 셋째, 애착불안과 이상섭식행동 간의 관계에서 부적응적 자기초점주의와 자기자비는 이중매개효과가 있었다. 이러한 결과는 이상섭식행동과 관련된 중요한 변인으로 애착불안과 부적응적 자기초점주의와 자기자비가 있음을 확인하였다. 이를 통해서 상담 장면에서 애착불안 수준이 높은 내담자들이 이상섭식행동을 보이는 경우 부적응적 자기초점주의 성향을 낮추고 자기자비 수준을 높임으로써 이상섭식행동이 감소될 수 있다는 치료적 방안을 시사하고 있다.Ⅰ. 서론 1
1. 연구의 필요성 및 목적 1
2. 연구문제 7
Ⅱ. 이론적 배경 8
1. 애착불안 8
2. 이상섭식행동 12
3. 부적응적 자기초점주의 16
4. 자기자비 19
5. 각 변인 간 선행연구 22
Ⅲ. 연구 방법 31
1. 연구 대상 31
2. 측정 도구 32
3. 자료 분석 36
Ⅳ. 연구 결과 38
1. 주요 변인들의 기술통계치 38
2. 각 변인 간 상관관계 40
3. 성인 초기 여성의 애착불안과 이상섭식행동 간의 관계에서
부적응적 자기초점주의와 자기자비의 이중매개효과 43
Ⅴ. 요약 및 결론 54
1. 요약 및 논의 54
2. 결론 및 제언 60
참고문헌 64
부록 76Maste
Active Balancing of Li-ion Battery Cells Using Transformer as Energy Carrier
No full textA circuit for balancing Li-ion battery cells is proposed. This circuit requires one small transformer and N + 3 bilateral switches to equalize the charging states of N serially connected battery cells. The transformer works as an energy carrier, and the switches select two unbalanced cells that require an energy transfer from one to the other cell. The circuit was tested for a 12-cell Li-ion battery under static, cyclic, and dynamic charging/discharging conditions. Under static condition, the power-transfer efficiency was measured as 80.4% at a balancing power of 0.78 W; two 4400-mA·h battery cells at a state of charge (SOC) = 70 and 80% were equalized after 78 min. The results of cyclic and dynamic charging/discharging conditions show that the circuit is appropriate for balancing the Li-ion battery cells for vehicles and energy storage systems.11206sciescopu
Yesterday Yoon Choi and five other high school students visited Lyman Moore Midd
No full textYesterday Yoon Choi and five other high school students visited Lyman Moore Middle School in Portland to speak about drugs and alcohol as part of the school\u27s Drug Awareness and Resistance Education Program (DARE). The high school students didn\u27t preach blind abstinence, but cautioned that people can act differently when they drink or use drugs
Aphelochaeta intinctoria Choi & Jung & Yoon 2018, new species
No full textAphelochaeta intinctoria new species Figures 1 B–C, 3A–F Material examined. Type locality: South Korea, Jeollanam-do Province: Jindo-gun County, Imhoe-myeon, Namdong-ri, 126°09′10″E, 34°21′35″N, 31 Jul. 2016, intertidal soft bottom. Holotype: incomplete specimen (NIBRIV0000325699). Paratypes: one complete specimen (MABIKNA00155291); one incomplete specimen (MABIKNA00155292); one incomplete specimen (MABIKNA00155293); one incomplete specimen (MABIKNA00155294); one incomplete specimen (MABIKNA00155295) on stub for SEM observation. Non-type material: 11 specimens, collection details same as type material (MABIKNA00155296). Description. Holotype. Incomplete; body slender, 4.6 mm long and 0.6 mm maximum wide; thoracic region distinct, consisting of eight uncrowded segments, swollen dorsally, slightly flattened ventrally; ventral groove present; abdominal region as wide as thoracic region with distinct moniliform segments longer than thoracic segments, with a shallow ventral groove; pygidium with simple ventral lobe observed in paratype (Figs. 1 C–D, 3A–C). Prostomium slightly wider than long, distally rounded, eyespots absent, nuchal organs located near posterolateral prostomial border. Peristomium wider than prostomium, with distinct dorsal crest, and with three annulations, third one longest; dorsal crest extending posteriorly over two-thirds of chaetiger 1. Paired dorsal tentacles arising at posterior margin of peristomium, lateral to base of dorsal crest. Branchiae weakly annulated in alcohol; first pair arising from posterior of chaetiger 1 dorsal to notochaetae, and subsequent branchiae at posterior margin of chaetigers. Thoracic parapodia slightly projecting laterally; notopodial lobes very low. Abdominal parapodia rudimentary (Figs. 1 C–D, 3D). Chaetae emerging from lateral body wall, long, simple capillaries, with conspicuous fibrils of varying lengths along one edge; thoracic chaetigers with 7–11 noto- and 6–9 neurochaetae, abdominal chaetigers with 4–7 noto- and neurochaetae; notochaetae slightly longer than neurochaetae (Fig. 3 E–F). Methyl green staining pattern (MGSP). The body is unstained lacking distinct staining patterns (Fig. 3A). Etymology. The composite epithet of the specific name, intinctoria, is a combination of the Latin prefix in- and the Latin tinctorius, meaning “undyed”. This name refers to the fact that the thoracic region does not stain using the methyl green. Habitat/Distribution. This species was collected from sandy mud sediments in the intertidal zone located at Jindo-gun in the southern coast of Korea. Remarks. Aphelochaeta intinctoria n. sp. has distinct moniliform segments in the abdominal region which has been described as a diagnostic feature of A. monilaris (Blake 1996). However, the new species shows several morphological differences from A. monilaris. The dorsal crest on the peristomium of A. intinctoria n. sp. is distinct while it is indistinct in A. monilaris. The first pair of branchiae is located on chaetiger 1 in the new species while in A. monilaris they are on the peristomium. The thoracic region is not expanded in the new species as it is in A. monilaris and the body of A. intinctoria n. sp. does not retain any methyl green stain while there are darkly stained ventral band in the thorax in A. monilaris (Blake 1996; Dean & Blake 2016). The lack of a distinctive staining pattern on the venter of the thorax using methyl green in A. intinctoria n. sp. is shared with A. bullata Doner & Blake, 2009, A. guttata Doner & Blake, 2009, A. malefica Elías & Rivero, 2009, A. multifilis (Moore, 1909), and A. zebra Dean & Blake, 2016 (Blake 1996; Elías & Rivero 2009; Doner & Blake 2009; Dean & Blake 2016). However, A. intinctoria n. sp. is readily separated from these relatives based on the following characteristics: the dorsal tentacles and a pair of the first branchiae are present on the peristomium and chaetiger 1, respectively while in A. bullata, A. guttata, and A. multifilis they are both on the peristomium and in A. malefica and A. zebra both the dorsal tentacles and the first pair of branchiae are on chaetiger 1. The peristomial dorsal crest is distinct while it is indistinct in A. multifilis and A. zebra; the thoracic region is not expanded while it is expanded in A. bullata, A. guttata, A. multifilis, and A. zebra; the prostomium is rounded distally versus pointed in A. malefica (Blake 1996; Elías & Rivero 2009; Doner & Blake 2009; Dean & Blake 2016). Recently, Dean and Blake (2016) have suggested three types of chaetal structures in Aphelochaeta species related to the development of fibrils or denticles on the chaetal surface, fibrillated, microserrated, and smooth. The chaetal structure of A. intinctoria n. sp. has relatively long fibrils of varying lengths (Fig. 2F), belonging to the fibrillated type. While that of A. petila n. sp. has short fibrillar extensions and is assigned to the microserrated type (Fig. 3F).Published as part of Choi, Hyun Ki, Jung, Tae Won & Yoon, Seong Myeong, 2018, Two new species of Aphelochaeta (Annelida: Polychaeta: Cirratulidae) from Korean waters, pp. 586-594 in Zootaxa 4504 (4) on pages 590-592, DOI: 10.11646/zootaxa.4504.4.9, http://zenodo.org/record/260669
A machine learning approach to discover migration modes and transition dynamics of heterogeneous dendritic cells
No full textDendritic cell (DC) migration is crucial for mounting immune responses. Immature DCs (imDCs) reportedly sense infections, while mature DCs (mDCs) move quickly to lymph nodes to deliver antigens to T cells. However, their highly heterogeneous and complex innate motility remains elusive. Here, we used an unsupervised machine learning (ML) approach to analyze long-term, two-dimensional migration trajectories of Granulocyte-macrophage colony-stimulating factor (GMCSF)-derived bone marrow-derived DCs (BMDCs). We discovered three migratory modes independent of the cell state: slow-diffusive (SD), slow-persistent (SP), and fast-persistent (FP). Remarkably, imDCs more frequently changed their modes, predominantly following a unicyclic SD→FP→SP→SD transition, whereas mDCs showed no transition directionality. We report that DC migration exhibits a history-dependent mode transition and maturation-dependent motility changes are emergent properties of the dynamic switching of the three migratory modes. Our ML-based investigation provides new insights into studying complex cellular migratory behavior. Copyright © 2023 Song, Choi, Jeon and Cho.11Nsciescopu
The etiology of sugarcane striate mosaic disease / Yoon Gi Choi.
No full textCopies of author's previously published articles inserted.Includes corrigendum.Bibliography: leaves 97-106.xiii, 106, [69] leaves, [31] leaves of plates : ill. (some col.), maps ; 30 cm.This thesis reports an investigation of the etiology of ScSMD (sugarcane striate mosaic disease) by biological and microscopic studies and by nucleic acid studies. Studies of ScSMD affected sugarcane are followed by the detection, isolation, cloning and partial sequencing of a disease specific dsRNA, and the tentative classification of the putative viral agent from the partial sequence. This study also describes the ScSMD associated virion and an improved protocol for the purification of dsRNA.Thesis (Ph.D.)--University of Adelaide, Dept. of Crop Protection, 199
10.1177_1358863X19879751_Supplementary_tables – Supplemental material for Impact of diabetes mellitus on 5-year clinical outcomes following successful endovascular revascularization for peripheral artery disease
No full textSupplemental material, 10.1177_1358863X19879751_Supplementary_tables for Impact of diabetes mellitus on 5-year clinical outcomes following successful endovascular revascularization for peripheral artery disease by Michael S Lee, Byoung Geol Choi and Seung-Woon Rha in Vascular Medicine</p
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