• Title/Summary/Keyword: cross concept

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Development of Fine Dust Measurement Method based on Ultrasonic Scattering (초음파 산란 기법을 적용한 미세먼지 측정법 개발)

  • Choi, Hajin;Woo, Ukyong;Hong, Jinyoung
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.23 no.7
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    • pp.40-48
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    • 2019
  • New concept of fine dust measurement method is suggested based on ultrasonic scattering. These days, fine dust has been social problem in Korea, and many researches has been conducted including the area structural maintenance. Conventional measurement system such as optical scattering and semiconductor has a limit from environmental factors like relative humidity. However, ultrasound is based on mechanical waves, which perturb mechanical properties of medium such as density and elastic constants. Using the advantage, the algorithm for fine dust measurement is derived and evaluated using 2-D finite difference method. The numerical analysis simulates ultrasonic wave propagation inside multiple scattering medium like fine dust in air. Signal processing scheme is also suggested and the results show that the error of the algorithm is around minimum of 0.7 and maximum of 24.9 in the number density unit. It is shown that cross-section of fine dust is a key parameter to improve the accuracy of algorithm.

A Study on the Performance of Pipe Scale Cleaner using Natural Organic Acid (천연 유기산을 이용한 배관 스케일 세정제 성능에 관한 연구)

  • Kang, Hyung Seok;Yang, Won Suk;Kim, Young Il;Kim, Sean Hay;Choi, Dong Hee
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.29 no.10
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    • pp.530-537
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    • 2017
  • Scales generated inside pipes cause negative effects on heat transfer performance, pressure loss and flow rate due to increased thermal resistance and reduced flow cross-sectional area. If these scales are not prevented or eliminated, thermal-fluid performance of the facilities can be deteriorated, or in extreme cases, accidents such as explosion due to overheating can occur. There are two ways to remove the scales, physically and chemically. Removing the scales physically needs specific machines which are expensive, and removing them chemically may provoke corrosion or shorten the age of the facilities. In this study, an eco-friendly pipe scale cleaner using natural organic acid is developed by applying the concept of a limestone cave generation. The manufactured scale cleaner is applied to remove the scales in industrial, water heating and urinal pipes. The results show that this cleaner removes scales more effectively and safely compared to existing scale treatments. Scale removal efficiencies of this work is 1.2~10.7 times for industrial pipes and 1.8~15.5 times for boiler water heating pipes higher than those of conventional cleaners.

Revisiting of Greenness to Consumers in Green Purchases (소비자의 그린 제품 구매에 있어 "그린" 의미의 재발견)

  • LEE, Han-Suk;HONG, Seongtae
    • Journal of Distribution Science
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    • v.17 no.10
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    • pp.107-114
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    • 2019
  • Purpose - This is longitudinal research which aims to investigate the meaning of greenness to consumers' behavior. Consumers adopt green marketing as a new factor in product buying and consumption and more and more consumers prefer green product and services. Consumers' green buying behavior can be different from other purchasing experiences. There would be changes in the meaning of green as time passed and it can be different from countries to other countries. This study examines focus group studies with several groups. There is a ten-year gap between 2010 focus group and 2019 focus group interviews. With this ten-year gap, we can find the change of greenness to consumers. Research design, data, and methodology - The data were collected from Turkish, Korean, Kazakhstan people. This is a cross-sectional study and focus group interview was designed. We can gain information relevant to the research problem with using focus group study and get some insights into basic needs and attitudes of green marketing. The subjects for green purchase interviewee were confined to under 40 years old's shoppers regardless of gender. The first study was investigated with several groups in 2010 and the second interview were conducted in 2019. Results - Results show that the meaning of greenness for consumer has changed over time in accordance with the growing accordance of environmental sustainability. Basically, green marketing still means valuable, natural, recycle-able, good for health, clean, smart behavior, essential benefit. The concept of greenness significantly evolved since it was investigated in 2010. It moves away from focusing on specific environmental issues to considering global sustainability issues. Especially we found that greenness can be related with globalization, higher education, social status at the 2019 interview. Conclusions - This paper attempted to confirm the green marketing is essential and expands its meaning to various aspect. Usually, we can think green marketing is everywhere, therefore, people don't care about green issues in real. But consumers are adopting green marketing more and more, it can be a means to attract potential consumers. Therefore, companies should provide enough greenness information for people and they might apply greenness communication to attract potential customers.

Comparative Study of Inhabitants' Life Satisfaction in Senior Cohousing Communities between Sweden and Denmark (스웨덴과 덴마크 노인용 코하우징 주민의 생활만족도 비교)

  • Choi, Jung-Shin
    • Journal of the Korean housing association
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    • v.16 no.6
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    • pp.149-160
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    • 2005
  • There is an increasing curiosity in Nordic as well as Far East Asian countries about senior cohousing, where the middle-aged and elderly people, 55+. form a community for independent living. What are the ideas behind senior cohousins? Why are people moving to senior cohousing community? What may senior cohousing provide and mean for individuals and groups of the elderly? Is senior cohousing a sustainable idea for future generations of elderly people? There is a curiosity among elderly people looking for interesting alternatives. Municipalities and state authorities hope that senior cohousing can contribute to the welfare of the elderly as the scope far support by the public sector is decreasing. Actors in the building sector are interested In investment and meeting the demands. In Denmark and Sweden the senior cohousing concept had a revival around 1985. In Denmark there has been a vivid discussion and plenty of books have been published. In Sweden there are few evaluations but an increasing interest. From different points of view, Danish, Swedish and Nordic as well as Far East Asian countries, there is a concern to explore and compare to get more facts and deeper understanding far further actions. This is a comparative study of inhabitants' life satisfaction in cohousing communities in Denmark and Sweden. The study is based on discussions with cohousing providers, study-visits in cohousing communities and a questionnaire to residents themselves. Study-visits took place during springtime and the questionnaires were handled spring and summer of 2002. 655 seniors responded to the questionnaire from 14 seniorbofae llesskaber (rented or housing cooperatives) in Denmark, 11 seniorhus within the SABO sector (municipality owned housing with rental apartments) and 8 housing cooperatives initiated by the Seniorgarden Housing Company in Sweden. Data were analyzed by SPSS program, using frequency, percentage, cross-tab and chi-square test. This paper focused three major areas of interest; 1)characteristics of the inhabitants. 2) participation in common activities and mutual cooperation among residents and 3) evaluative outcomes from the inhabitants' points of view. Mainly the inhabitants expressed quite positive experiences of their living environment and everyday lift and a few difference was found in life satisfaction between Denmark and Sweden.

A Cross-national Study of Social Exclusion - with Special References to Korea and European Countries - (한국의 사회적 배제 성격에 대한 연구 - 유럽연합 회원국과의 비교를 중심으로 -)

  • Moon, Jin-Young
    • Korean Journal of Social Welfare
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    • v.62 no.2
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    • pp.87-107
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    • 2010
  • This paper purports to compare the differences and similarities of social exclusions in Korea with those in the European countries, notably Germany, France, Sweden, Finland, Ireland and U.K. For this purpose, chapter two examines political and social origins of social exclusion as an alternative concept to poverty or unemployment. Chapter three discusses social exclusion paradigms of Silver(1994) in reference to welfare regime theories of Esping-Andersen(1990). Subsequently chapter four, using two artificial social exclusion indicators by principal component analysis, defines the basic nature of social exclusion of Korea in comparison with those of the six European countries. Chapter five duly concludes that social exclusions in Korea are very similar to those of liberal countries (Ireland and U.K.) in that income indicators (poverty and inequality) of Korea are much worse, whereas unemployment rate is relatively low.

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A Study on the Analysis of Structure and Utility of Topic Index, Syntopicon in Great Books ('위대한 저서'의 토픽색인, 신토피콘의 구조와 효용성 분석에 관한 연구)

  • Lee, Byeong-Ki
    • Journal of the Korean Society for Library and Information Science
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    • v.46 no.2
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    • pp.5-28
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    • 2012
  • Great Books of the Western World(GBWW) is a series of books published in 1952 by Encyclopaedia Britannica to present the famous works in 54 volumes. The series is now in its second edition and contains 60 volumes. A syntopicon compiled by M. Adler is a two-volume index, published as volumes 2 and 3 of GBWW. The syntopicon was coined specifically for this undertaking, which means a collection of topics. Syntopicon lists, under each idea, is where every occurrence of the concept can be located in the collection's famous works. This study aims to analyze the structure and utility of topic index, syntopicon in GBWW. The syntopicon consists of 102 chapters on the 102 ideas. Each chapter is broken down into five distinct sections: the introduction, an outline of topics, references, cross-references, and additional readings. The syntopicon can serve as a reference book, as a selection tool of book to be read, instrument of liberal education, instrument of discovery and research, syntopical reading of other reading material, development tool of convergent education, and analysis tool of works.

A Study on the Development of the Active Radar Reflector with Enhanced Structure (개선 된 구조를 갖는 능동 레이더 반사기 개발에 관한 연구)

  • 정종혁;강상욱;조영창;최병진;윤정오;홍영호
    • Proceedings of the Korea Society for Industrial Systems Conference
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    • 2000.05a
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    • pp.59-64
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    • 2000
  • Active radar reflector may be less familiar, since their uses have been limited to military applications, especially the enhancement of the effective radar cross-sections of missile test range in the drone aircraft and missiles. Perhaps the most widely-blown applications of radar transponders are Identification Friend or Foe(IFF) and its civilian counterpart, secondary surveilliance radar for Air Traffic Control(ATC), and most recently, as Search And Rescue Transponder(SART) in the Global Maritime Distress and Safety System(GMDSS). Since it happens frequently accidents on the sea, the problems of the contamination more seriously considered. The conventional navigation buoy and utilities are not sufficient to maintain the safety of the sea and thus new structured concept must be considered. Therefore, this paper propose and implement the active radar reflector with a enhanced structure. The results are shown that the performance of the system is significantly improved comparing with the conventional utilities.

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A Simple Introduction of Extratropical Transition of Tropical Cyclone (TC) and a Case Study on the Latest Three TCs: Shanshan (0613), Yaki (0614), and Soulik (0618) (태풍의 온대성 저기압화에 대한 간단한 소개 및 최근 세 태풍의 사례분석: 산산(0613), 야기(0614), 솔릭(0618)을 중심으로)

  • Choi, Ki-Seon;Kim, Baek-Jo
    • Journal of the Korean earth science society
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    • v.28 no.7
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    • pp.947-956
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    • 2007
  • In this article, the extratropical transition (ET) of tropical cyclone (TC) was investigated based on the case study covering the latest three TCs (Shanshaa Yaki, and Soulik) associated with ET evolution (onset and completion) using the objective 37 diagnostics of Evans and Hart (2003) and Hart (2003). At 500-hPa level, on an onset of ET, all three TCs entered the baroclinic zone. In a vertical cross-section analysis, three TCs before and at an onset of ET kept warm and humid throughout all levels around the TC center. However, these TCs after ET onset became relatively cold and dry over the western part of TC as the typical characteristics of ET concept model. Although our case study was not sufficient, it is concluded that the diagnostics of the ET onset and atmospheric structure change associated with Evans and Hart (2003) and Hart (2003) will be useful in ET operational forecast.

Are the cities that have declined continuously declining, and the cities that have prospered getting continuously prosperous? -The inertia of urban decline and countermeasures- (쇠퇴하는 곳은 계속 쇠퇴하고, 번성하는 곳은 계속 번성하는가? - 도시쇠퇴의 관성과 대응 -)

  • Lee, Young-Sung;Jo, Joon-Hyok;Moon, Ju-Yeol
    • Journal of the Korean Regional Science Association
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    • v.32 no.1
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    • pp.51-66
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    • 2016
  • This study examines a degree of city decline and confirms a existence of inertia in the city decline process, and shows how to set the policy directions of cities as its situation. With understanding these things, we are carefully able to anticipate the future direction of cities'growth or decline. This study analyzes cross-tabulations with the comprehensive decline index, and the demographic-social index, industrial-economical index, physical-environmental index to compose the comprehensive decline index in during 2005~2010. We can confirm the existence of complexity and inertia of city decline. Some cities are likely to have adhesion of decline, and these cities should convert planning tools and concept of past growth era to new one to be used in changed environment in new era. Redefining a perspective for city decline, proper managing a change of physical environment from city decline, and flexible thinking would be requested as countermeasures with adjusting spatial policy framework.

The Ultimate Load Capacity of the Parabolic Arches by Elasto-Plastic Model (탄소성 모델에 의한 포물선 아치의 극한 내하력 평가)

  • 조진구;박근수
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.44 no.3
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    • pp.92-100
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    • 2002
  • The advent or high-strength steel has enabled the arch structures to be relatively light, durable and long-spanned by reducing the cross sectional area. On the other hand, the possibility of collapse may be increased due to the slender members which may cause the stability problems. The limit analysis to estimate the ultimate load is based on the concept of collapse mechanism that forms the plastic zone through the full transverse sections. So, it is not appropriate to apply it directly to the instability analysis of arch structures that are composed with compressive members. The objective of this study is to evaluate the ultimate load carrying capacity of the parabolic arch by using the elasto-plastic finite element model. As the rise to span ratio (h/L) varies from 0.0 to 0.5 with the increment of 0.05, the ultimate load has been calculated fur arch structures subjected to uniformly distributed vertical loads. Also, the disco-elasto-plastic analysis has been carried out to find the duration time until the behavior of arch begins to show the stable state when the estimated ultimate load is applied. It may be noted that the maximum ultimate lead of the parabolic arch occurs at h/L=0.2, and the appropriate ratio can be recommended between 0.2 and 0.3. Moreover, it is shown that the circular arch may be more suitable when the h/L ratio is less than 0.2, however, the parabolic arch can be suggested when the h/L ratio is greater than 0.3. The ultimate load carrying capacity of parabolic arch can be estimated by the well-known formula of kEI/L$^3$where the values of k have been reported in this study. In addition, there is no general tendency to obtain the duration time of arch structures subjected to the ultimate load in order to reach the steady state. Merely, it is observed that the duration time is the shortest when the h/L ratio is 0.1, and the longest when the h/L ratio is 0.2.