• 제목/요약/키워드: special environments

검색결과 356건 처리시간 0.026초

Insect Adaptations to Changing Environments - Temperature and Humidity

  • Singh, Tribhuwan;Bhat, Madan Mohan;Khan, Mohammad Ashraf
    • International Journal of Industrial Entomology and Biomaterials
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    • 제19권1호
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    • pp.155-164
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    • 2009
  • The most important factors in environment that influence the physiology of insects are temperature and humidity. Insects display a remarkable range of adaptations to changing environments and maintain their internal temperature (thermoregulation) and water content within tolerable limits, despite wide fluctuations in their surroundings. Adaptation is a complex and dynamic state that widely differs in species. Surviving under changing environment in insects depends on dispersal, habitat selection, habitat modification, relationship with ice and water, resistance to cold, diapause and developmental rate, sensitivity to environmental signals and syntheses of variety of cryoprotectant molecules. The mulberry silkworm (Bombyx mori) is very delicate and sensitive to environmental fluctuations and unable to survive naturally because of their domestication since ancient times. Thus, the adaptability to environmental conditions in the silkworm is quite different from those of wild insects. Temperature, humidity, air circulation, gases and photoperiod etc. shows a significant interaction in their effect on the physiology of silkworm depending upon the combination of factors and developmental stage affecting growth, development, productivity and quality of silk. An attempt has been made in this article to briefly discuss adaptation in insects with special emphasis on the role of environmental factors and their fluctuations and its significance in the physiology of mulberry silkworm, B. mori.

전문대학 실내건축과 교과과정개편에 관한 연구 (A Study on the Reform-Curriculum of Interior-Architecture in a Junior College)

  • 신정진
    • 한국실내디자인학회논문집
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    • 제7호
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    • pp.38-44
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    • 1996
  • To improve and replete many problems which are discovered the present condition and cases of interior architecture education previously, 1) Adopted the sixth semester, the ninth semester of 3 -year course of study as a reform of the school system. 2) Building up Design -basic understandings of design , Design Resources -layout course, factor course and Design Communication three -steps of systematic -educational course of methodical course fro transmitting and 3) Classifying interior space designer , interior factor designer, interior decorator, special -space designer as practical parts. 4) Divided three fields : layout, construction work, factor design , related to interior design works. 5) Also, divided like (Table-2), job-analysis and formation of relating course into layout and construction work. 6) Analyzed and (Table-3) the present condition of four domestic Junior college (Seoul and kyong -ki areas) as a case study. 7) Analyzed and surveyed (Table-4) three American colleges, sixth semester and ninth semester of three year course of study and 8) Have to solidify practical computer education, foreign language education as the terms desired keeping pace with internationalization and the changes of opening periods. 9) As above-mentioned, reenforcing the fundamental education of lower grades and needs fractionizing special education of higher grades. Finally, needs to be prepared the environments which enable to develop the marked educational goals & contents and then be exeucted, which make one do his responsibility after setting out in the world, satisfying a periods wishies : many competent experts that can be produced.

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A Spatial Audio System Using Multiple Microphones on a Rigid Sphere

  • Lee, Tae-Jin;Jang, Dae-Young;Kang, Kyeong-Ok;Kim, Jin-Woong;Jeong, Dae-Gwon;Hamada, Hareo
    • ETRI Journal
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    • 제27권2호
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    • pp.153-165
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    • 2005
  • The main purpose of a spatial audio system is to give a listener the same impression as if he/she were present in a recorded environment. A dummy head microphone is generally used for such purposes. Because of its human-like shape, we can obtain good spatial sound images. However, its shape is a restriction on its public use and it is difficult to convert a 2-channel recording into multi-channel signals for an efficient rendering over a multi-speaker arrangement. In order to solve the problems mentioned above, a spatial audio system is proposed that uses multiple microphones on a rigid sphere. The system has five microphones placed on special points of the rigid sphere, and it generates audio signals for headphone, stereo, stereo dipole, 4-channel, and 5-channel reproduction environments. Subjective localization experiments show that front/back confusion, which is a common limitation of spatial audio systems using the dummy head microphone, can be reduced dramatically in 4-channel and 5-channel reproduction environments and can be reduced slightly in a headphone reproduction.

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Effects of convection on physical vapor transport of Hg2Cl2 in the presence of Kr - Part I: under microgravity environments

  • Lee, Yong Keun;Kim, Geug-Tae
    • 한국결정성장학회지
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    • 제23권1호
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    • pp.20-26
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    • 2013
  • Special attention in the role of convection in vapor crystal growth has been paid since some single crystals under microgravity environments less than 1 $g_0$ exhibits a diffusive-convection mode and much uniformity in front of the crystal regions than a normal gravity acceleration of 1 $g_0$. The total molar fluxes show asymmetrical patterns in interfacial distribution, which indicates the occurrence of either one single or more than one convective cell. As the gravitational level decreases form 1 $g_0$ down to $1.0{\times}10^{-4}\;g_0$, the intensity of convection, indicative of the maximum molar fluxes, is reduced significantly for ${\Delta}T=30K$ and 90 K. The total molar fluxes decay first order exponentially with the partial pressure of component B, PB (Torr) for 20 Torr ${\leq}PB{\leq}$ 300 Torr, and two gravity accelerations of $g_y=1\;g_0$ and 0.1 $g_0$.

인간생태학적 접근방법에 의한 소비자행동연구 - 住宅情報探索행동을 중심으로- (A Study on Consumer Behavior by the human Ecological Approach -with Special Attention to housing prepurchasing behavior-)

  • 박혜선;김기옥
    • 가정과삶의질연구
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    • 제6권1호
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    • pp.95-116
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    • 1988
  • this study has dual purposes; one is to develope a new theoretical framework in consumer behavior area by applying the human ecological approach, and the other is to test the theory empirically area by applying the human ecological approach, and the other is to test the theory empirically by examining prepurchasing behavior of housing. Research methods adopted in this study are library search and survey research with self-administered questionnaires. The statistical methods used in the survey research are factor analysis, chi square test, and multivariate analysis with crosstablulations. According to the human ecological approach, ecological environments are important sources of consumer needs which , in turn, are satisfied by purchasing behavior in the market. Within this theoretical framework, consumers con improve the quality to life by perceving clearly what their needs are thereby making the most possible efficient purchasing decision making. The major findings of the empirical research on the basis of the theoretical framework are as follows; 1) Housing needs significantly vary with different ecological environment. 2) consumer information search behavior does not differ significantly by housing needs. 3) Housing needs turn out to be an intervening variable between ecological environments and consumer information search behavior. the results of this study show that the human ecological approach is useful in consumer behavior studies. The empirical result that consumer needs are not significantly satisfied by consumer behavior suggests a now direction in consumer education.

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재질 열화와 프레팅 피로거동 평가에 관한 연구 (A Study on Material Degradation and Fretting Fatigue Behavior)

  • 권재도;최성종;성상석
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2001년도 춘계학술대회논문집A
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    • pp.157-162
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    • 2001
  • Fretting is a potential degradation mechanism of structural components and equipments exposed to various environments and loading conditions. The fretting degradation, for example, can be observed in equipments of nuclear, fossil as well as petroleum chemical plants exposed to special environments and loading conditions. It is well known that a cast stainless steel(CF8M) used in a primary reactor coolant(RCS) degrades seriously when that material is exposed to temperature range ken $290^{\circ}C{\sim}390^{\circ}C$ for long period. This degradation can be resulted into a catastrophical failure of components. In the present paper, the characteristics of the fretting fatigue are investigated using the artificially aged CF8M specimen. The specimen of CF8M are prepared by an artificially accelerated aging technique holding 1800hr at $430^{\circ}C$ respectively. Through the investigations, the simple fatigue endurance limit of the virgin specimen is not altered from that obtained from the fatigue tests imposed the fretting fatigue. The similar tests are performed using the degraded specimen. The results are not changed from those of the virgin specimen. The significant effects of fretting fatigue imposed on both virgin and degraded specimen on the fatigue strength are not found.

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STATE-OF-THE-ART TECHNOLOGY USING GENETICALLY-ENGINEERED BIOLUMINESCENT BACTERIA AS ENVIRONMENTAL BIOSENSORS

  • Gu, Man-Bock
    • 한국미생물생명공학회:학술대회논문집
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    • 한국미생물생명공학회 2000년도 Proceedings of 2000 KSAM International Symposium and Spring Meeting
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    • pp.94-99
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    • 2000
  • Bioluminescence is being used as a prevailing reporter of gene expression in microorganisms and mammalian cells. Bacterial bioluminescence draws special attention from environmental biotechnologists since it has many advantageous characteristics, such as no requirement of extra substractes, highly sensitive, and on-line measurability. Using bacterial bioluminescence as a reporter of toxicity has replaced the classical toxicity monitoring technology of using fish or daphnia with a cutting-edge technology. Fusion of bacterial stress promoters, which control the transcription of stress genes corresponding to heat-shock, DNA-, or oxidative-damaging stress, to the bacterial lux operon has resulted in the development of novel toxicity biosensors with a short measurement time, enhanced sensitivity, and ease and convenient usage. Therefore, these recombinant bioluminescent bacteria are expected to induce bacterial bioluminescence when the cells are exposed to stressful conditions, including toxic chemicals. We have used these recombinant bioluminescent bacteria in order to develop toxicity biosensors in a continuous, portable, or in-situ measurement from for air, water, and soil environments. All the data obtained from these toxicity biosensors for these environments were found to be repeatable and reproducible, and the minimum detection level of toxicity was found to be ppb (part per billion) levels for specific chemicals.

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모바일 플랫폼 상황이해엔진 (A Context-Aware Engine for Mobile Platforms)

  • 이선아;이건명;이지형
    • 한국지능시스템학회논문지
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    • 제15권3호
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    • pp.300-305
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    • 2005
  • 지능로봇이나 유비쿼터스 환경에서는 주변의 상황정보를 파악하여 이를 바탕으로 적당한 서비스를 제공하는 것이 필요하다. 상황에 따른 서비스를 탐색하여 제공하는 유용한 플랫폼으로 규칙기반 시스템을 활용하는 연구가 많이 진행되어왔다. 이 논문에서는 상황이해 서비스를 위한 규칙기반 시스템의 특성에 대해서 기술하고, 이를 바탕으로 설계하여 구현한 규칙기반 상황이해 서비스 엔진에 대해서 기술한다 구현한 상황이해 엔진은 임베이드 환경을 비롯한 모바일 환경에서도 동작할 수 있도록 수행속도와 메모리요구량에 대한 고려를 하여 설계되었다.

FH/CDMA를 위한 동기화 기술의 성능 고찰 (Consideration of Performance in Synchronization of Frequency Hopping / Code Division Multiple Access System)

  • 이승대;방성일;진년강
    • 한국전자파학회지:전자파기술
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    • 제5권4호
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    • pp.18-29
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    • 1994
  • 본 논문에서는 주파수 도약 시스댐의 성능을 좌우하는 동기화 시스템에서 초기동기시스템으로는 stepped s serial search 방식과 정합필터방식에 대한 성능을 고찰하였으며 동기추적 시스템으로 delay lock loop 방식을 이동무선채널에 적용하여 그 성능을 해석하였다. 그 결과 Rayleigh 페이딩 뿐만 아니라 Rician 페이딩이 존재 하는 이동무선채널에서 stepped serial search 방식이 회로구성이 비교적 간단하고 특별한 하드웨어의 교체없이 단순히 도약 주파수를 증가시킴으로써 시스템의 성능을 개선할 수 있음을 보였다. 또한 동기추적 시스템 역시 lock 상태수와 도약주파수 M이 증가할수록 평균 유지시간이 길어짐을 알 수 있다.

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Crosslinkable Warm-melt-Polyurethanes Offer Instant-fix Characteristics

  • Merz, Peter W.
    • 접착 및 계면
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    • 제3권1호
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    • pp.37-42
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    • 2002
  • Adhesives are becoming increasingly accepted for advanced engineering/boding tasks. Therefore the understanding of the basic principles and the benefits of elastic bonding and structural bonding respectively is of utmost importance. Structural bonding means adhesive performance in load-bearing environments. Furthermore. the time to achieve handling strength has an impact on the economics of an assembly line. The paper gives briefly a summary about the fundamentals of elastic bonding and discusses different adhesive systems in the context of handling strength. Hereby the focus lies on the Warm Melt Technology, and its potential is compared to standard adhesives (l-part, 2-part and Booster Technology, a special 2-C system). Examples illustrate their economical benefits. Main Points : ${\bullet}$ The basic principles and benefits of elastic bonding ${\bullet}$ Warm-melt Technology in comparison with standard adhesives ${\bullet}$ Handling strength an economic issue ${\bullet}$ Combination with Booster-Technology, a special 2-C PUR system ${\bullet}$ Presentation of real world applications Learning Objectives: ${\bullet}$ Fundamentals of elastic bonding ${\bullet}$ Warm-melt Technology: correlation between chain length and cristallinity ${\bullet}$ Handling strength and curing speed of various systems in comparison ${\bullet}$ Real world applications illustrate the potential of the Warm-melt Technology.

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