• 제목/요약/키워드: External Impact

검색결과 941건 처리시간 0.024초

체외 전기자극기가 심장에 미치는 영향의 분석 및 평가 (Analysis of an External Stimulator's Impact on the Heart)

  • 김문수;최성욱
    • 대한기계학회논문집B
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    • 제35권11호
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    • pp.1213-1217
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    • 2011
  • 의료용 자극기는 병원과 가정에서 환자의 통증 경감 및 재활 치료를 위해 사용되는 의료기기이다. 전기자극기의 자극 펄스가 심장에 유입되면 부정맥 및 심실세동 등의 심각한 부작용을 초래할 수 있다. 의료용 자극기에서 공급하는 자극 펄스의 전달 거리를 측정하고 심장이 전기 자극의 위험 범위 밖에 위치하도록 자극의 크기 및 자극 부위를 제한할 필요가 있다. 전기 자극기는 초당 60 회의 빈도로 0.001Joule 전기 펄스를 가하도록 설계되었다. 전기 자극기의 성능 및 인체에 미치는 영향을 측정하기 위해 생리 식염수를 이용한 생체 조직의 모델을 제작하였고, 이를 이용하여 거리에 따른 전기장의 감쇄 정도를 측정하였다. 본 연구에서 개발한 전기 자극기를 동물실험에 적용한 후 심장 주변에 전기자극을 가했을 때 심장에서 나타나는 위험요인을 관찰하고 직류전류가 흘렀을 때 심장에서 나타나는 현상과 비교하였다.

평지붕 PV거치 시스템의 형태에 따른 풍압영향에 관한 기초연구 (A Basic Study on the Effect of the Wind Pressure according to Form on the Flat Roof mounted PV System)

  • 윤두영;이응직
    • 한국태양에너지학회 논문집
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    • 제33권5호
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    • pp.105-112
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    • 2013
  • The new renewable energy became popular as a clean and sustainable alternative energy under the circumstances that the entire world is facing severe abnormal climate due to the use of fossil fuel, and among which, solar energy can be obtained anywhere and is not difficult to apply it into the existing buildings, which makes it possible to be widely distributed. However, as PV module is installed into a single plate system, it shows structural weaknesses which are vulnerable to wind load and give loss to design elements in external appearance. Accordingly, this study planned one-step parallel system to complement the problems occurring from a single plate system and used STAR-CCM+ V.8 made by CD-Adapco, a computational fluid dynamics(CFD) simulation tool to measure wind load stability and support based on the design standards for a single plate system and one-step parallel system. Building height was limited to less than 10m and wind speed was given when increasing from 35m/s to 50m/s by 5m/s on PV system installed into the flat roof. In this case, our analysis suggested that step-one parallel system was in class 7-9 according to Beaufort's wind power classification, which did not have an impact on the fixed PV system, and the single plate system is considered to cause risks in designing wind speed in central districts because it is more than wind power class 12.

이동성을 구비한 능동위상배열안테나 근접전계 스캐너 설계 및 성능 검증 (Design and Performance Verification of Active Phased Array Antenna Near-Field Scanner with Mobility)

  • 유우성;김성균;권용욱;정기용;장헌순
    • 전기전자학회논문지
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    • 제21권1호
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    • pp.30-38
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    • 2017
  • 사이트에 설치되어 운용 중인 능동위상배열레이다가 외부의 충격 또는 장기간 운용에 따른 성능열화가 의심될 경우, 위상배열안테나의 이상여부를 확인해야 한다. 하지만, 위상배열안테나를 측정하기 위해서는 무반향성 챔버에서 근접전계 시험이 수행되어야 하므로, 레이다 장치의 분해 및 운송을 위해 많은 시간과 비용이 투입되어야 하고 레이다 시스템의 운용 가용도가 나빠지게 된다. 따라서, 본 논문에서는 사이트에서 위상배열안테나의 이상여부를 확인할 수 있도록 이동성을 구비한 능동위상배열안테나 근접전계 스캐너를 제안하고, 무반향성 챔버에서 측정한 데이터와 비교하여 크기 ${\pm}0.5dB$와 위상 ${\pm}1.5^{\circ}$ 오차수준으로 측정유효성을 검증하였다.

제조기업의 기술혁신활동과 영향요인의 구조적 관계에 관한 연구 (A Study on the Structural Relations between Technological Innovation Activities of Manufacturers and Factors of Their Effects)

  • 나상균
    • 대한안전경영과학회지
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    • 제13권3호
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    • pp.133-143
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    • 2011
  • It seems required to determine what might affect the technological innovation activities of manufacturing companies and what kind of role they could play for them to carry out technological innovation activities in an effective way. The objective of the present study is thus to conduct a depth empirical analysis of the structural relations among business environment, technological innovation activities and performance of manufacturing companies. From the analysis, following outcomes could be drawn: First, with regard to the relationship between business environment and technological innovation activities of manufacturing companies, it has become clear that the external environment is a factor that can influence technological innovation activities such as management of technical property, technological innovation system as well as technical network, while it exercises no impact upon adaptation of manufacturers to new technologies. The internal environment, on the other hand, turns out to have influence on such overall factors of technological innovation activities as management of technical property, technological innovation system, adaptation to new technologies and technical network; and Second, as for the relationship between technological innovation activities and their performance, it has been obvious that management of technical property and technological innovation system, both factors of technological innovation activities, affect the performance of product development and financial achievements of manufacturing companies. Their adaptation to new technologies will also affect their performance of product development as well as financial achievements. These findings suggest that it is important for manufacturing companies to set up an operating system that may be able to upgrade the practical applicability of their technological development activities in an attempt to promote performance of their technological innovation activities.

사회복지조직의 조직효과성 연구경향 분석 (Organizational Effectiveness of Social Welfare Organizations: What Can We Learn From Past Research? A Review)

  • 박지혜;박은주;조상미
    • 한국사회복지학
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    • 제61권1호
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    • pp.33-55
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    • 2009
  • 본 연구는 1980년 이후 사회복지조직의 효과성 연구를 다룬 논문 20편의 연구경향을 파악함으로써 사회복지조직의 조직현상에 대한 이해 도모, 조직관리에의 실천적 함의 제공 및 향후 사회복지조직의 조직효과성 연구에 대한 제언을 하고자 하였다. 분석결과, 대부분의 연구가 사회복지관과 생활시설을 대상으로 이루어졌으며, 조직효과성의 이론적 기반으로 내부과정접근모델이 가장 많이 적용되고 있어, 향후 사회복지조직의 성장과 외부의 요구에 부응하기 위해서는 다양한 조직과 지표 및 연구방법론의 활용이 필요한 것으로 파악되었다. 조직관리 측면에서 조직효과성에 긍정적인 영향을 주는 집단적 개발적 조직문화, 분권적 조직구조, 변혁적 리더십, 외부와의 개방적 관계 활용을 제안하였다.

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자동차용 강화유리와 그 시험방법에 대한 연구 (A Study on Toughened Glass Used for Vehicles and Its Testing Methods)

  • 안호순;권해붕;이광범;전상우;손영삼
    • 자동차안전학회지
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    • 제7권3호
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    • pp.14-18
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    • 2015
  • Toughened glass is known to have about four times larger external impact resistance than that of original glass. This study is aimed to verify that ceramic-printed toughened glass does not meet of GTR(Global Technical Regulations) No. 6 and its strength is lower than that of original glass through tests. The tests were conducted on the test pieces of original glass, toughened glass, and ceramic-printed toughened glass from five glass manufacturers. In Test 1, a 227g steel ball was dropped from a height of 2 meters, and damage was checked according to the test method of GTR No. 6. In Test 2, a steel ball was freely dropped from different heights and limited damage height was determined. In the result of Test 1 according to the test method of GTR No. 6, while all five test pieces of toughened glasses were not damaged, all the ceramic-printed toughened glass from the five manufacturers were damaged. In the result of Test 2, none of the five test pieces of toughened glass were damaged by a 10m ball drop, meanwhile, the original glasses were damaged by an average of 3m ball drop. And the results of the tests show that the ceramic-printed toughened glass does not have the features of toughened glass due to its very low strength. Therefore, this study contributes to the safety of consumers by considering the GTR No. 6, and by revising the toughened glass test method.

Knitwear Consumers′Demographic Characteristics and Evaluation Criteria

  • Han, Sung-Ji;Kim, Moon-Sook
    • The International Journal of Costume Culture
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    • 제3권2호
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    • pp.136-146
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    • 2000
  • The purpose of this study was to investigate the effect of demographic characteristics and general buying characteristics of knitwear consumers on evaluation criteria and information source searching. In this study, a self-administered questionnaire was distributed to young career women and female undergraduate students. Of 580 questionnaires, 496 were used in the following analysis. The data was analyzed with the SPSS package. The research method used factor and reliability analysis to segment consumers by their knitwear evaluation criteria. T-test, one-way ANOVA and χ²were used to characterize the impact of characteristics of the consumer on knitwear evaluation criteria and information source searching in buying knitwear. The results of this study were as follows. First, the information sources of consumers were significantly different depending on their demographic characteristics(age). According to the difference in relationship between the age of consumers and information sources, the younger the consumer, the more information in fashion magazine, the older, in fashion advertisement on catalog. Second, the knitwear evaluation criteria of consumers was classified according to six characteristics - quality, price, aesthetic, situation, self-expression and external. Their knitwear evaluation criteria were significantly different depending on demographic characteristics(job, age, education, marital status) and the general buying characteristics of knitwear(annual knitwear/clothing buying expense and frequency). Career women and married women placed significant importance on practical aspects like quality and price characteristics, while undergraduate students and single women placed significant importance on practical aspects like quality and price characteristics, while undergraduate students and single women placed significant importance on aesthetic and self-expression characteristics. Also, a group with higher annual knitwear/clothing buying expense and frequency considered aesthetic and self-expression characteristics more important. The lower the annual knitwear/clothing buying expense and frequency, the higher a group considered quality and price characteristics more important.

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모바일 서비스에 기반한 유비쿼터스 컴퓨팅의 사용자 수용에 영향을 미치는 요인 (Factors Affecting User Acceptance of Ubiquitous Computing based on Mobile Services)

  • 노미진;김병곤;박순창
    • Journal of Information Technology Applications and Management
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    • 제18권1호
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    • pp.55-74
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    • 2011
  • The growth in the use of ubiquitous computing based on mobile services as an enabler to conduct business more effectively has been phenomenal. Technology acceptance model (TAM) has been applied in different contexts to examine a wide range of information technologies (IT). As more and more companies are finding ways to utilize ubiquitous computing based on mobile services, an important issue is to understand what factors will impact the decisions of consumers in adopting the services. Based on TAM with three additional groups of external factors, i.e., service-related factors (ubiquitous access, context awareness) and technology-related factors (perceived security risk, network connectivity) that are theoretically justified as having influence on both perceived usefulness and perceived ease of use which are additionally considered, a research model for the investigated technology acceptance was developed and empirically examined, using responses from more than intended users of ubiquitous computing based on mobile services. The specific purposes of this study are as follows. Firstly, this study is to identify service beliefs considering unique characteristics for ubiquitous services such as perceived ubiquitous access and perceived context awareness. Secondly, this study is to investigate network characteristics beliefs such as perceived security and perceived connectivity. Thirdly, this paper investigates the relationship among variables such as ubiquitous characteristics, network characteristics, behavioral beliefs, and intention to use ubiquitous web services. This study uses a structural equation model to test the research model. The major results of this study are as follows. Firstly, ubiquitous access has a influence on perceived usefulness and perceived ease of use. Context awareness has an influence on perceived usefulness. Secondly, User familiarity has an influence on perceived usefulness and perceived ease of use, and intention to use. User innovativeness has an influence on perceived ease of use. Thirdly, perceived security risk has an influence on perceived usefulness and perceived ease of use. Network connectivity has an influence on perceived usefulness and perceived ease of use. Fourth, there exist differential effects among factors in structural model among information, transaction, and entertainment services.

결정형이 생체이용률에 미치는 영향 (Effect of Crystal Form on Bioavailability)

  • 손영택
    • Journal of Pharmaceutical Investigation
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    • 제34권6호
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    • pp.443-452
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    • 2004
  • Habit is the description of the outer appearance of a crystal. If the environment of a growing crystal affects its external shape without changing its internal structure, a different habit results. Crystal habit and the internal structure of a drug can affect bulk and physicochemical properties, which range from flowability to chemical stability. A polymorph is a solid crystalline phase of a given compound resulting from the possibility of at least two different arrangements of the molecules of that compound in the solid state. Chemical stability and solubility changes due to polymorphism can have an impact on a drug's bioavailability and its development program. During crystallization from a solution, crystals separating may consist of a pure component or be a molecular compound. Solvates are molecular complexes that have incorporated the crystallizing solvent molecule in their lattice. When the solvent incorporated in the solvate is water, it is called a hydrate. To distinguish solvates from polymorphs, which are not molecular compounds, the term pseudopolymorph is used. Identification of possible hydrate compounds is important since their aqueous solubilities can be significantly less than their anhydrous forms. Conversion of an anhydrous compound to a hydrate within the dosage form may reduce the dissolution rate and extent of drug absorption. An amorphous solid may be treated as a supercooled liquid in which the arrangement of molecules is random. Amorphous solids lack the three-dimensional long-range order found in crystalline solids. Since amorphous forms are usually of higher thermodynamic energy than corresponding crystalline forms, solubilities as well as dissolution rates are generally greater. A study on crystal form includes characterization of (l)crystal habit, (2)polymorphism, (3)pseudopolymorphism, (4)amorphous solid.

수학적 사고력 측정을 위한 수학 평가 도구의 개발 (Development of the Items for the Assessment of Mathematical Thinking)

  • 신준식;고정화;박문환;박성선;서동엽
    • 한국초등수학교육학회지
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    • 제15권3호
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    • pp.619-640
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    • 2011
  • 본 연구는 수학적 추론, 문제해결, 의사소통과 관련된 평가 문항을 소개하고, 평가 문항에 대한 5 학년 학생들의 반응을 보다 심층적으로 분석한 연구이다. 수학적 추론은 연역 추론, 귀납 추론, 유비 추론으로, 문제해결은 외적 문제해결과 내적 문제해결로, 의사소통은 말하기, 읽기, 쓰기, 듣기로 나누어 각각의 예시 문항과 학생들의 반응을 소개하였다. 수학적 추론 문항은 각각의 추론 능력을 발휘할 수 있는 문항의 개발이 중요하며, 5학년 학생들 중 일부는 이러한 능력을 보여주었다. 의사소통의 각각의 형식보다는 문항에 내재된 수학적 상황이 학생들의 반응에 더 많은 영향을 미치는 것으로 나타났다. 본 연구로부터 수학 평가 문항에 대한 지속적인 연구가 필요하고, 수학 평가에서 인지적 영역의 설정과 활용 방안에 대한 연구가 필요하며, 수학 평가 문항 개발과 관련된 교사 연수의 필요성을 제안하였다.

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