• 제목/요약/키워드: MegaStudy

검색결과 471건 처리시간 0.027초

3상 3선식 Plug-In MCCB의 인장력 및 접촉저항 평가에 관한 연구 (Study on the Evaluation of the Tension and Contact Resistance of a 3 Φ 3 W Plug-In MCCB)

  • 이병설;최충석
    • 한국안전학회지
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    • 제28권4호
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    • pp.43-47
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    • 2013
  • The purpose of this paper is to evaluate the performance of a Plug-In MCCB developed for rapid power supply restoration when the MCCB is installed in a power system and to verify its reliability. Since the developed 3 ${\Phi}$ 3 W Plug-In MCCB can be installed on and removed from a bus bar by one touch using a plug housed at the rear, it can be replaced in a short period of time. Therefore, it can quickly respond to the normalization of a power system. When the Plug-In MCCBB is installed on a bus bar, the resistance between each phase and plug was measured to be 0.46 $m{\Omega}$ in average. When the Plug-In MCCB is installed, the tension in the vertical direction was measured to be 112.78 N in average, which is greater than the tension of 50 N specified in the related regulation. The withstanding voltage tests performed 5 times repeatedly by applying 6 kV to the developed Plug-In MCCB for 60 seconds shows good withstanding voltage characteristics. In addition, both the general waterproof test using a water injection method and the insulation resistance analysis using a Mega meter showed good waterproof and insulation characteristics.

우리나라 국민의 우주위험인식 수준과 국가 재난정책 (Public's Recognition of the Space Object's Re-entry Situations and the National Space Disaster Management Policy)

  • 김시은;조성기;홍정유
    • 한국안전학회지
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    • 제31권6호
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    • pp.84-92
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    • 2016
  • Since the mankind started its space mission, the number of artificial space objects has been increasing exponentially. It contains not just the space machines which are in use but the machines which are out of order. Meantime, those dead machines are being a serious danger, a real threat to human's lives and property because of it could re-enter into the earth's atmosphere and fall to the ground causing mega-disaster. As the number of space activities gets growing so far, the re-entry of the space objects will be a lot more happened in the future. Therefore, not just natural space object like asteroids but the artificial space object like artificial satellite and space station can cause the disaster by falling to the ground. To protect our nation and our property, the government has set up the space disaster management center in Korea astronomy and Space science Institute. In this study, we surveyed public's recognition of the space object's re-entry situation and analyzed it to contribute building national space disaster management policy.

Molecular Characterization of Selected Local and Exotic Cattle Using RAPD Marker

  • Khatun, M. Mahfuza;Hossain, Khondoker Moazzem;Rahman, S.M. Mahbubur
    • Asian-Australasian Journal of Animal Sciences
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    • 제25권6호
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    • pp.751-757
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    • 2012
  • In order to develop specific genetic markers and determine the genetic diversity of Bangladeshi native cattle (Pabna, Red Chittagong) and exotic breeds (Sahiwal), randomly amplified polymorphic DNA (RAPD) analysis was performed using 12 primers. Genomic DNA was extracted from 20 cattle (local and exotic) blood samples and extracted DNA was observed by gel electrophoresis. Among the random primers three were matched and found to be polymorphic. Genetic relations between cattle's were determined by RAPD polymorphisms from a total of 66.67%. Statistical analysis of the data, estimating the genetic distances between cattle and sketching the cluster trees were estimated by using MEGA 5.05 software. Comparatively highest genetic distance (0.834) was found between RCC-82 and SL-623. The lowest genetic distance (0.031) was observed between M-1222 and M-5730. The genetic diversity of Red Chittagong and Sahiwal cattle was relatively higher for a prescribed breed. Adequate diversity in performance and adaptability can be exploited from the study results for actual improvement accruing to conservation and development of indigenous cattle resources.

Causal Relationship Between Indian Ports' Originated Container Traffic and Total Transshipments of Port of Colombo: A Granger Causality Analysis

  • Bandara, Sooriya;Ryoo, Dong-Keun;Ahn, Ki-Myung
    • 한국항해항만학회지
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    • 제42권5호
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    • pp.357-364
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    • 2018
  • Colombo noticeably became the most economical gateway to the Indian subcontinent, in terms of cost as well as time. The Colombo Port Expansion Project (CPEP) started commencement with the purpose of accommodating mega ships, under the long-term strategies of making Colombo the hub of South Asia. In this context, the purpose of this study is to investigate the causal relationship between Indian ports' originated container traffic, and total transshipments of the port of Colombo, and also to identify the nature of the causality between the two variables, evaluating Granger causality test results. It finds unidirectional causality from total transshipments of Colombo to Indian ports' originated transshipments in the port of Colombo. It suggested that ongoing port expansion projects, opening up for new markets and attracting new shipping lines in the port of Colombo, have generated significant impact on Indian ports' container traffic, via the port of Colombo. Findings would be valuable for future forecasting of container traffic in Colombo port and the policy-making process in the port as well.

Genotyping of Giardia duodenalis Isolates from Dogs in Guangdong, China Based on Multi-Locus Sequence

  • Zheng, Guochao;Alsarakibi, Muhamd;Liu, Yuanjia;Hu, Wei;Luo, Qin;Tan, Liping;Li, Guoqing
    • Parasites, Hosts and Diseases
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    • 제52권3호
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    • pp.299-304
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    • 2014
  • This study aimed to identify the assemblages (or subassemblages) of Giardia duodenalis by using normal or nested PCR based on 4 genetic loci: glutamate dehydrogenase (gdh), triose phosphate isomerase (tpi), ${\beta}$-giardin (bg), and small subunit ribosomal DNA (18S rRNA) genes. For this work, a total of 216 dogs' fecal samples were collected in Guangdong, China. The phylogenetic trees were constructed with MEGA5.2 by using the neighbor-joining method. Results showed that 9.7% (21/216) samples were found to be positive; moreover, 10 samples were single infection (7 isolates assemblage A, 2 isolates assemblage C, and 1 isolate assemblage D) and 11 samples were mixed infections where assemblage A was predominant, which was potentially zoonotic. These findings showed that most of the dogs in Guangdong were infected or mixed-infected with assemblage A, and multi-locus sequence typing could be the best selection for the genotype analysis of dog-derived Giardia isolates.

Fracture characterization with high frequency single-hole EM survey

  • Seo, Soon-Jee;Song, Yoon-Ho;Kim, Hee-Joon;Lee, Ki-Ha;Suh, Jung-Hee
    • 대한자원환경지질학회:학술대회논문집
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    • 대한자원환경지질학회 1999년도 춘계 공동학술발표회
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    • pp.90-93
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    • 1999
  • We present a high frequency electromagnetic (EM) inversion scheme for detecting and characterizing a fracture using single-hole data. At high frequencies, say above tens of mega-hertz, since displacement currents cannot be ignored, electrical permittivity as well as electrical conductivity is to be considered together for analyzing the EM scattering data. In this paper, we have developed a three-step inversion scheme to map the fracture and to evaluate its electrical conductivity and permittivity. We performed EM profiling along the z-axis using three-component receivers for each source. The model was excited by a vertical magnetic dipole and the resistant magnetic fields were inverted using the non-linear least-squares method. Background resistivity and permittivity were easily obtained using vertical magnetic fields below 1 MHz and above 10 MHz, respectively. Both the vertical and dipping sheets were successfully mapped using the phase difference between 40 and 41 MHz. The electrical property of the sheet was well resolved using the information obtained in the previous two steps and secondary magnetic fields. Our study shows the potential of imaging the fracture in single-hole survey environment using the high frequency EM method.

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모자 제품의 구매 행동과 평가 기준 (Purchasing Behavior and Evaluation Criteria on Hat Products)

  • 김차현;박재옥
    • 복식문화연구
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    • 제17권6호
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    • pp.1068-1082
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    • 2009
  • The purpose of this study was to investigate empirically the consumer behavior regarding the purchase of millinery items in relation to their evaluation criterion and demographic characteristics. The survey was carried out to 395 individuals in their 20s and over who were quota sampled according to age and gender. The collected data were statistically treated with the SPSS 12.0 program in terms of descriptive statistics, cross tabulation, t-test, one-way ANOVA, factor analysis, Cronbach's $\alpha$ coefficient and Duncan-test. The 20s and 50s over were more interested in hat products than other ages. Female consumers obtained the most information about hat products from store visits, TV and magazines. On the other hand, male consumers had it from the acquaintances and internet. Younger consumers more often utilized internet to have it. Their main purchase location was department stores. The younger purchased it more in traditional market, the older purchased it more in mega wholesale market or discount store. The consumers of hat products considered the intrinsic classification most when buying hats. The evaluation criteria employed by them were aesthetics, quality, and external attributes. Hat consumers were more concerned about aesthetics attributes than the other two criteria. Female consumers and consumers who are more interested in the hat and have a higher level of education and income considered aesthetics attributes most important.

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Progress Report : Research on Detailed Morphology of Cluster Galaxies

  • Oh, Seulhee;Yi, Sukyoung K.;Sheen, Yun-Kyeong;Kyeong, Jaemann;Sung, Eon-Chang;Kim, Minjin;Park, Byeong-Gon
    • 천문학회보
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    • 제39권1호
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    • pp.46.2-46.2
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    • 2014
  • Galaxy morphology is involved complex effects of both secular and non-secular evolution of galaxies. Although it is a final product of a galaxy evolution, it may give a clue for the process that the galaxy suffer. Galaxy clusters are the sites where the most massive galaxies are found, and the most dramatic merger histories are embedded. Morphology study in nearby universe, e.g. Virgo cluster, is well established, but for clusters at z ~ 0.1 it is only focused on bright galaxies due to observational limits. Our optical deep imaging of 14 Abell clusters at z = 0.014 - 0.16 using IMACS f/2 on a Magellan Badde 6.5-m telescope and MegaCam on a 3.8-m CFHT enable to classify detailed morphology. For the galaxies in our data, we investigated their morphology with several criteria related to secular or merger related evolution. Our research on detailed morphology of thousands of galaxies through deep imaging would give a general census of cluster galaxies and help to estimate the evolution of cluster galaxies.

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별탄생 은하의 별 생성에 대한 병합 작용의 기여도 연구 (The Contribution of Mergers on Star Formation in Nearby UV-Bright Galaxies)

  • 임구;임명신;최창수;윤용민
    • 천문학회보
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    • 제41권1호
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    • pp.70.2-70.2
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    • 2016
  • Star formation in galaxies is one of the key factors in galaxy evolution. It is believed that star formation is triggered and enhanced by mergers among galaxies or secular evolution. However, how much these two mechanisms contribute on star formation is not well known yet. Recently, many other studies show observational evidences of faint merger features(tidal tails, stellar streams) around nearby galaxies with deep optical imaging. This study aims to investigate the fraction of star forming galaxies exhibiting faint features to total galaxies. We are analyzing samples of 76 star forming galaxies (NUV < -18) to find merger features from stacked B, R band frames taken at Maidanak 1.5m, McDonald 2.1m telescope and g, r frames from Canada-France-Hawaii Telescope (CFHT) MegaCam archival data. With the fraction, we can expect to know the contribution of mergers on star formation to galaxies.

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초대형 컨테이너선박의 기항에 따른 컨테이너 터미널 장치장 규모 확대방안의 경제성 비교 (An Economical Efficiency Comparison for Extend Method of Container Terminal Yard Scale followed by the Call of the Mega Ship)

  • 송용석
    • 한국항해항만학회지
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    • 제33권5호
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    • pp.353-359
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    • 2009
  • 국내 컨테이너 터미널의 대부분 컨테이너 처리량에 비해 장치장 규모가 협소한 편이다. 장치장이 협소한 이유는 터미널 개발 시 적용된 이론적인 안벽 처리능력이 실제 처리능력과 차이가 나기 때문이다. 또한 최근 선박이 대형화 되면서 터미널들이 안벽장비를 추가 투입함으로써 안벽 생산성을 당초보다 크게 향상시킨 현실에 기인하기도 한다. 본 연구에서는 터미널 운영 현실을 반영하여 하역 능력을 재산정하고 10,000TEU에 이르는 초대형 선박을 대상으로 하여 소요 장치장 규모를 산정 한 후 기존 터미널의 장치장 규모와 경제성을 비교하는 것을 주목적으로 한다.