• 제목/요약/키워드: IS1081

검색결과 203건 처리시간 0.024초

Voltage Source Equipment for the Grid Fault Testing and Analysis of Total Harmonic Distortion According to PWM Methods

  • Gwon, Jin-Su;Kim, Chun-Sung;Kang, Dae-Wook;Park, Jung-Woo;Kim, Sungshin
    • Journal of Power Electronics
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    • 제14권6호
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    • pp.1081-1092
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    • 2014
  • Renewable energy is being spotlighted as the electric power generating source for the next generation. Due to an increase in renewable energy systems in the grid system, their impact on the grid has become non-negligible. Thus, many countries in the world, including Europe, present their own grid codes for grid power conversion devices. In order to experiment with these grid codes, grid fault test equipment is required. This paper proposes both equipment and a control method, which are constructed with a 7-level cascaded H-bridge converter, that are capable of generating various grid faults. In addition, the Pulse Width Modulation (PWM) method for multilevel converters is compared and analyzed. The proposed structure, the control method, and the PWM method are verified through simulation and experimental results.

Financial Capability and Differences in Age and Ethnicity

  • MOKHTAR, Nuradibah;SABRI, Mohamad Fazli;HO, Catherine Soke Fun
    • The Journal of Asian Finance, Economics and Business
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    • 제7권10호
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    • pp.1081-1091
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    • 2020
  • The objective of this study is to disclose the effect of socio-demographic characteristics such as, age and ethnicity which is comprised of Malay, Chinese, Indian and Others on four financial capability domains namely planning ahead, managing money, choosing products and staying informed. A closed ended self-administered questionnaire was disseminated to a total of 2000 respondents among four types of groups which consist of FELDA or rural area residents, private sector employees, government sector employees and youth in institutions of higher learning in Malaysia. Those four groups were selected to cover a wide range of Malaysian population. 500 respondents were involved in this study for each types of groups through purposive sampling technique. Analysis of Variance (ANOVA) and analysis via Statistical Package for Social Science (SPSS) was utilized in this study. The results revealed that age has significant effect on planning ahead, managing money, choosing products and staying informed. Whereas, ethnicities were found to have no effect on financial capability except planning ahead domain. It is suggested that more devotion should be placed on research and professional training in building respondents' financial capability. Furthermore, government and non-government organizations should develop a comprehensive approach to intensify their financial capability and upgrade their standards of living especially of financially vulnerable households.

오일 및 가스 플랫폼의 해체에 관한 연구 (A Study on the Decommissioning of Oil and Gas Platform)

  • 전창수
    • 한국산업융합학회 논문집
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    • 제23권6_2호
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    • pp.1081-1091
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    • 2020
  • The most recent issue of offshore plants that produce oil and gas are the decommissioning engineering of aged or discontinued platforms. There are many platforms that are being dismantled in the United States, Europe, and areas in Southeast Asia. In particular, more than 400 old platforms in Southeast Asia (Indonesia, Malaysia) are preparing to dismantle. They are spread out across Southeast Asia with a water level of 50 meters and small-scale of less than 10,000 tons. However, this offshore plant decommissioning market is a very suitable market for small and medium-sized shipyards in Korea to enter with their established equipment and engineers. Platform decommissioning is conducted according to decommissioning procedures. However, there are some difficulties in market advances as no developed case studies or process models are established on how platform structures and components are to be dismantled and how the dismantled material is to be reused and recycled. Therefore, this study presented domestic and foreign regulations on the reuse and recycling of oil and gas producing offshore plant platforms, case analyses on developed decommissioning engineering, platform reuse and recycling guidelines, and platform and pipeline decommissioning processes and methods.

Jonckheere-Terpstra 추세 검정통계량에 근거한 비모수적 층화분석법 (A Nonparametric Stratified Test Based on the Jonckheere-Terpstra Trend Statistic)

  • 조도연;양수;송혜향
    • 응용통계연구
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    • 제23권6호
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    • pp.1081-1091
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    • 2010
  • 각 의료기관에서 수집될 수 있는 환자수가 한정되어 있는 질병의 경우에는 주로 다기관연구로써 임상연구가 진행된다. Jonckheere (1954)와 Terpstra (1952)의 추세 검정법으로 분석해야 하는 독립된 여러 군의 자료를 다기관에서 수집한 경우에 이질성을 고려하여 각 연구기관을 하나의 층으로 보아 층화분석법으로 분석하지 않으면 옳지 않은 결론에 도달할 수가 있다. 본 논문에서는 van Elteren (1960)이 제시한 Wilcoxon (1945) 검정통계량의 층화분석법을 이용하여 Jonckheere (1954)와 Terpstra (1952)의 추세 검정통계량에 근거한 층화분석법을 제시한다. 예제 자료에 이 층화분석법을 적용하며 효율성을 모의실험으로 알아본다.

Revisiting Use of Growth Factors in Myelodysplastic Syndromes

  • Newman, Kam;Maness-Harris, Lori;El-Hemaidi, Ihab;Akhtari, Mojtaba
    • Asian Pacific Journal of Cancer Prevention
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    • 제13권4호
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    • pp.1081-1091
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    • 2012
  • Myelodysplastic syndromes (MDS) represent a heterogeneous group of clonal hematologic neoplasms characterized by morphologic dysplasia, aberrant hematopoiesis and peripheral blood refractory cytopenias. MDS is recognized to be associated with an increased risk of symptomatic anemia, infectious complications and bleeding diathesis, as well as a risk of progression to acute myeloid leukemia, particularly in patients with a high IPSS score. The advent of use of hematopoietic growth factors such as granulocyte colony-stimulating factor (G-CSF) and recombinant erythropoietin (EPO) has improved symptoms in MDS patients in addition to some data that suggest there might be an improvement in survival. G-CSF is an effective therapeutic option in MDS patients, and it should be considered for the management of refractory symptomatic cytopenias. G-CSF and EPO in combination can improve outcomes in appropriate MDS patients such as those with lower-risk MDS and refractory anemia with ring sideroblasts (RARS). This article reviews use of growth factors for lower-risk MDS patients, and examines the data for G-CSF, EPO and thrombopietic growth factors (TPO) that are available or being developed as therapeutic modalities for this challenging disease.

더덕으로부터 면역세포 활성 성분의 분리 (Isolation of Active Components on Immunocytes from Codonopsis Lanceolatae)

  • 서정숙;은재순
    • Journal of Nutrition and Health
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    • 제31권6호
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    • pp.1076-1081
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    • 1998
  • The purpose of this research was to isolate an active component on immunoytes from 70% MeOH extract of Codonopsis lanceolatae Radix(CLE). CLE was fractionated successively with hexane, methylene chloride, n-butyl alcohol and water, and then the water fraction was separated with molecularporous membrane tubing(m.w. 3,500). Each fraction(50mg/kg) was administered p.o. once a day for 7 days in BALB/c mice respectively. None of these fractions affected the apoptosis and mitochondrial transmembrane potential in thymocyte. Hexane and methylene chloride fractions decreased CD4$^{[-10]}$ CD8$^{+}$ single-positive cells, and the water fraction enhanced CD4$^{+}$ CD8$^{[-10]}$ single-positive cells in thymocyte. The proliferation of thymocytes was decreased by the fraction hexane, but was enhanced by the water fraction. Hexane, methylene chloride and butyl alcohol fractions suppressed the production of nitric oxide, which was not affected by the water fraction. Hexane and butyl alcohol fraction suppressed the phagocytic activity, but water fraction enhanced it. The components(m.w. 3,500 above) separated from the water fraction enhanced the proliferation of thymocyte, the population of CD4$^{+}$ CDB$^{[-10]}$ single-positive cells, and phagocytic activity in macrophage. These results suggest that the stimulative components of proliferation, TH population and phagorytc activity is in the water fraction, and the molecular weight is 3,500 above. (Korean J Nutrition 31(6) : 1076~1081, 1998) 1998)

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영구자석 형상 변형을 통한 동기발전기 고조파 저감 (Harmonic Reduction of Synchronous Generator by Permanent Magnet Shape Deformation)

  • 변범석;박의종;김용재
    • 한국전자통신학회논문지
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    • 제17권6호
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    • pp.1081-1088
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    • 2022
  • 동기발전기의 고조파는 철손과 동손을 증가시켜 발열의 원인이 된다. 이를 감소시키기 위하여 전기자의 권선법을 분포권, 단절권을 이용하여 고조파를 감소시키는 방법이 있으나 본 논문에서는 영구자석의 형상을 기존에 연구되었던 방법이 아닌 새로운 형상 변형을 통해 고조파를 감소시키며 기전압의 파형을 개선하고자 한다. 형상 변형 방법으로 영구자석의 양단을 절단하고 설정값에 따라 영구자석의 면적을 증가, 감소시켜 공극의 길이를 조절한다. 이때 자속밀도의 분포를 다르게 하여 이에 따른 기전압과 왜형률을 비교하였다. 이를 통해 논문에 기술된 영구자석의 형상 변화 모델들을 비교하고 가장 효과적인 변형 방법을 나타냈다.

항만 물류처리를 위한 EDI 문서 처리 시스템 (EDI Document Processing System for Port Logistics)

  • 함종완;반태학;정회경
    • 한국정보통신학회논문지
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    • 제15권5호
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    • pp.1081-1086
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    • 2011
  • 최근 항만 물류 처리를 위한 EDI(Electronic Data Interchange) 문서 처리가 급증하여 이의 처리 시스템 사용이 증가하고 있다. 그러나, 기존의 시스템은 EDI 문서를 스크립트 방식으로 처리하였으나, 스크립트 작성이 복잡하고, 문서 처리 효율이 낮아 사용량 증가에 따른 처리 수요를 따라가지 못하고 있다. 이에, 본 논문은 스크립트 방식을 바이너리 방식으로 바꾸어 처리하는 시스템을 설계 및 구현하였다. 또한 항만 물류에 사용되는 12종의 EDI 문서를 개발하였다. 이에 따라, 기존 방식에 비해 문서 처리 속도가 약 12배 정도 개선되어 항만 물류 EDI 문서 처리 시스템에 활용될 수 있을 것으로 기대된다.

Experiment on Intermediate Feature Coding for Object Detection and Segmentation

  • Jeong, Min Hyuk;Jin, Hoe-Yong;Kim, Sang-Kyun;Lee, Heekyung;Choo, Hyon-Gon;Lim, Hanshin;Seo, Jeongil
    • 방송공학회논문지
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    • 제25권7호
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    • pp.1081-1094
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    • 2020
  • With the recent development of deep learning, most computer vision-related tasks are being solved with deep learning-based network technologies such as CNN and RNN. Computer vision tasks such as object detection or object segmentation use intermediate features extracted from the same backbone such as Resnet or FPN for training and inference for object detection and segmentation. In this paper, an experiment was conducted to find out the compression efficiency and the effect of encoding on task inference performance when the features extracted in the intermediate stage of CNN are encoded. The feature map that combines the features of 256 channels into one image and the original image were encoded in HEVC to compare and analyze the inference performance for object detection and segmentation. Since the intermediate feature map encodes the five levels of feature maps (P2 to P6), the image size and resolution are increased compared to the original image. However, when the degree of compression is weakened, the use of feature maps yields similar or better inference results to the inference performance of the original image.