• 제목/요약/키워드: Secondary Sources

검색결과 444건 처리시간 0.231초

조용한 공간 만들기 (방법론과 예) (Design and control of quiet zone (principle and example))

  • 김양한;윤두병;남경욱
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2000년도 춘계학술대회논문집
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    • pp.565-570
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    • 2000
  • In order to make a quiet zone, one can consider methods to generate a secondary sound field that cancels a primary sound field. Active noise control (ANC) is one of the kinds. This paper mainly deals with the issues on determining the optimal positions of control sources and sensors for making a desired quiet zone. The issues address the reason why the positions are important, how the positions are optimized, and what the measure on the optimal positions is in an uncertain sound field. It is also shown that a power control is applicable to a specific uncertain sound field. In addition, this paper shows that a control material method, which passively changes a boundary condition, is essentially found to be on the same road of ANC.

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An Examination of Contemporary Celebrity Endorsement in Fashion

  • Wigley, Stephen M.
    • International Journal of Costume and Fashion
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    • 제15권2호
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    • pp.1-17
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    • 2015
  • This paper examines the contemporary relationship between fashion brands and celebrities. Noting the historic role of celebrities in fashion and their current prevalence in the industry, the paper moves beyond discussion of the motives and effectiveness of celebrity endorsement, and instead explores its nature and practice in the fashion sector. The paper proposes a new definition of celebrity endorsement in fashion, offers a classification of celebrities involved in fashion brand endorsement, and presents a typology examining the contemporary means by which a fashion brand may collaborate with celebrities. The typology is defined in context of the nature, length and cost to the brand of the relationship between it and the celebrity. The methodology uses secondary sources and qualitative primary research in an exploratory agenda in order to propose conclusions and suggest ideas for further research.

Growth regime and environmental remediation of microalgae

  • Hammed, Ademola Monsur;Prajapati, Sanjeev Kumar;Simsek, Senay;Simsek, Halis
    • ALGAE
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    • 제31권3호
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    • pp.189-204
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    • 2016
  • Microalgal bioremediation of CO2, nutrients, endocrine disruptors, hydrocarbons, pesticides, and cyanide compounds have evaluated comprehensively. Microalgal mitigation of nutrients originated from municipal wastewaters, surface waters, and livestock wastewaters has shown great applicability. Algal utilization on secondary and tertiary treatment processes might provide unique and elegant solution on the removing of substances originated from various sources. Microalgae have displayed 3 growth regimes (autotrophic, heterotrophic, and mixotrophic) through which different organic and inorganic substances are being utilized for growth and production of different metabolites. There are still some technology challenges requiring innovative solutions. Strain selection investigation should be directed towards identification of algal that are extremophiles. Understanding and manipulation of metabolic pathways of algae will possible unfold solution to utilization of algae for mitigation of dissolve organic nitrogen in wastewaters.

통계분석을 이용한 경산 지역의 초미세먼지(PM2.5) 농도 특성 파악 (Characteristics of PM2.5 in Gyeongsan Using Statistical Analysis)

  • 이개초;황인조
    • 한국대기환경학회지
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    • 제31권6호
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    • pp.520-529
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    • 2015
  • The ambient $PM_{2.5}$ samples were collected by $PM_{2.5}$ sampler from September 2010 to December 2012 at Daegu University, Gyeongsan. A total of 260 samples were collected and 27 species were analyzed by inductively coupled plasma, ion chromatography, and thermal optical reflectance methods. Factor analysis identified four sources such as biomass burning source/secondary aerosol source, soil source, industry source, and incinerator source/mobile source. Also, backward trajectories were calculated using HYSPLIT 4 (Hybrid single-particle lagrangian integrated trajectory) model and PSCF (Potential source contribution function) model was applied to identify the possible source locations of carbonaceous species and water soluble ions species. PSCF results showed that the possible source locations of most chemical constituents measured in Gyeongsan were the industrial areas in the eastern coast of China, northeast regions of China, the Gobi Desert, and east sea of Korea.

고속 통신 시스템의 신호충실성 향상을 위한 선로 설계 방법론 및 Backplane Boards Testing를 위한 BIST 설계 (A Design Methodology on Signal Paths for Enhanced Signal Integrity of High-speed Communication System and a BIST Design for Backplane Boards Testing)

  • 장종권
    • 한국정보처리학회논문지
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    • 제7권4호
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    • pp.1263-1270
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    • 2000
  • The operation frequency of High-speed Communication System becomes very fast with the advanced technology of VLSI chips and system implementation. There may exist various types of noise sources degrading the signal integrity in this system. The present main system is made of backplane, so faults can be brought whenever a board is removed, replaced or added. This backplane boards testing is a very important process to verify the operation of system. firstly, we model the effects of the internal noises in the High-speed Communication System to the signal line and propose a new design method to minimize these effects. For the design methodology, we derive the characterization value for each mode land them construct the optimal simulation model. We compare the result of own proposing method with that fo the existing methods, through simulation and show that the quality of High-speed Communication System is significantly enhanced. Secondary our proposing BIST for the Backplane Boards Testing is designed to guarantee that there is no fault in the high-speed communication system.

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연료전지 발전 시스템용 고주파 링크 DC-AC 컨버터 (A High Frequency Link Direct DC-AC Converter for Fuel Cell Power Source)

  • 송유진;정봉만;한수빈;정학근;박석인
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2004년도 추계학술대회 논문집
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    • pp.124-126
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    • 2004
  • This paper describes a boost converter cascaded high frequency link direct do-ac converter suitable for fuel cell power sources. A new multi-loop control for a boost converter to reduce the low frequency input current harmonics drawn from fuel cell is proposed. A new PWM technique for the cycloconverter at the secondary to reject the low order harmonics in the output voltages is presented in detail.

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Globalization and Industrial Development: The Nigerian Perspective

  • Adefolaju, Toyin
    • 동아시아경상학회지
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    • 제5권1호
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    • pp.1-9
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    • 2017
  • Nigeria like many other developing countries' eagerness to accelerate socio-economic development has prompted her to adopt several approaches over the years since independence. These have ranged from the import substitution scheme, the indigenisation policy, and structural adjustment programme to the national economic empowerment development strategy. Nigeria has sought to widen her economic base by engaging in increased cross-border trade and investment activities. This is with a view to spurring the process of industrialization and ultimately lowering the level of poverty in the country. This has led to the formulation of various industrial policies and processes, all geared towards integration into the world economy. Using secondary sources, this paper seeks to analyze Nigeria's journey towards industrial development especially within the context of globalization. It concludes by explaining the impact of the new economic paradigm on the country's quest to industrialize and recommends alternative path towards development and growth.

식품중의 아질산염과 N-Nitrosamine에 관한 고찰 (Nitrite and Nitrosamine in food)

  • 우순자
    • 대한가정학회지
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    • 제23권3호
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    • pp.85-101
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    • 1985
  • 1. Nitrate and nitrite may contribute via nitrosation to the human exposure to N-nitroso compounds, especially nitrosamines, which are suspectd to be human carcinogens. 2. Since certain foods contain traces of nitrosamines, one should take the several points into consideration in evaluating the risk. 3. Nitrites, which can appear in the because of natural occurrence or deliberate addition, can react under the acidic conditions of the normal stomach with secondary amines to form nitrosamine. 4. Among the foods esamined, nitrate-nitrite treated meat products cooked bacon, and salted and dried fish are the main contributors of nitrosamines in our diet. 5. Consequently, in order to minimize human exposure to these chemicals, it is obviously essential to develop the alternative sources of nitrite in cured meat products. Thus the emphasis should be placed upon the most effective use of nitrite in curing with the use of acceptable inhibitors of nitrosation such as ascorbc acid or $\alpha$-tocopherol.

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MVRS해수담수화 및 제염기술

  • 김상현;김동국;전원표
    • 한국기술혁신학회:학술대회논문집
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    • 한국기술혁신학회 2001년도 춘계학술대회:발표자료
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    • pp.285-302
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    • 2001
  • At the present time the desalination technology of sea water for portable water in islands employs the RO method. The technology which needs complicated pretreatment processes with various chemicals can generate secondary water pollution and the high maintenance costs such as replacements of filters and membranes make islanders nearly impossible to operate. The MVRS technology for desalination of sea water however has several advantages such as constant production of quality portable water and capability of managing broad operating load. The variable-speed turbo-type vapor compressors employed in the system can utilize wind energy which is abundant in most Korean islands. Salt as a by-product can be produced by applying solar energy to the salt-concentrated waste water from the system. This paper discusses the relating topics such as technical and economical viabilities of the new MVRS desalination system for the production of portable water and salt as a by-product using new & renewable sources of energy.

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다수의 1 차 사용자가 존재하는 무선 인지 네트워크에서의 2 차 사용자 다중 홉 통신 연구 (Multi-Hop Secondary Transmission in Cognitive Radio Networks Having Multiple Primary Sources)

  • 이주현;홍승근;이재홍
    • 한국방송∙미디어공학회:학술대회논문집
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    • 한국방송공학회 2015년도 추계학술대회
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    • pp.41-42
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    • 2015
  • 본 논문에서는 다수 1 차 사용자가 다수 존재하고 2 차 사용자들이 다중 홉 통신을 하는 스펙트럼 공유 방식 무선 인지 네트워크를 분석한다. 다수의 1 차 사용자로부터의 간섭신호를 고려하여 각 2 차 사용자에서의 수신 신호대간섭잡음비를 분석하고 이를 바탕으로 2 차 사용자 네트워크의 불능확률을 구한다. 모의실험을 통해 1 차 사용자의 수가 감소함에 따라 불능확률이 감소한다는 것을 확인하였다.

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