• 제목/요약/키워드: Level Shift

검색결과 897건 처리시간 0.031초

IoT 기반 실시간 시각화 알고리즘을 이용한 스마트가드닝 시스템 설계 및 구현 (Design and Implementation of Smart Gardening System Using Real-Time Visualization Algorithm Based on IoT)

  • 손수아;박석천
    • 인터넷정보학회논문지
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    • 제16권6호
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    • pp.31-37
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    • 2015
  • 최근 사물인터넷 발달로 인하여 센서에서 발생되는 데이터가 폭증하고 있다. 이러한 패러다임의 변화로 즉각 행동이 요구되는 여러 산업현장에서 실시간으로 발생되는 데이터들의 분석이 필요하게 되었으며, 실시간 시각화 분석이 대두되고 있다. 그러나 기존 시각화 시스템은 데이터를 저장 후에 시각화를 하기 때문에 서버의 응답시간이 실시간에 준하는 ms수준의 처리를 보장하지 못하며, 처리할 자원을 보유하고 있지 않아 주요 자원이 될 데이터를 폐기하는 문제가 발생한다. 따라서 본 논문에서는 가드닝 환경에서 IoT 센싱 정보를 활용하여 실시간 시각화 알고리즘을 적용한 스마트가드닝 시스템을 설계 및 구현하였다. 제안 시스템의 성능 평가를 위하여 서버의 응답시간을 측정하였고, 테스트 결과 제안하는 실시간 시각화 알고리즘의 응답 속도는 실시간에 준하는 ms수준의 처리를 보장함을 확인하였다.

습식 DCT(Dual Clutch Transmission) 클러치 팩 내부에서의 체결 동작에 따른 변속기유 거동 연구 (Study on the Lubricant Flow Behaviors in the Wet Clutch Pack System of Dual Clutch Transmission)

  • 김우정;이상호;장시열
    • Tribology and Lubricants
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    • 제33권3호
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    • pp.85-91
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    • 2017
  • This work studies the flow behaviors in the gap between the friction pad and separator in wet-clutch systems. The fluid volume of the lubricant is modeled using the entire system of wet-clutch pack of a dual clutch transmission that has larger outer radius of odd gear shifts and smaller inner radius of even gear shifts. Flow behaviors in the gap of the clutch pad are computed using the gear shift modes that consider the real relative velocities between the friction pad and separator. Flow behaviors in the gap of the disengaged clutch pad are mainly investigated for the wet-clutch system, whereas the engaged clutch pad is modeled with no fluid rate through the contacting surfaces. The developed hydrodynamic fluid pressures and velocity fields in the clutch pad gap are computed to obtain the relevant information for managing flow rates in wet-clutch packs under dual operating conditions during gear shifts. These hydrodynamic pressures and velocity fields are compared on the basis of each gear level and gap location, which is necessary to determine the effects of groove patterns on the friction pad. Shear stresses in the gap locations are also computed on the basis of the gear level for the inner and outer clutch pads. The computed results are compared and used for the design of cooling capacity against frictional heat generation in wet-clutch pack systems.

Temperature and Coverage Dependent Quasi-reversible Two-photon Photoemission of 1-phenyl-1-propyne on Cu(111)

  • Sohn, Young-Ku;Wei, Wei;Huang, Weixin;White, John M.
    • Bulletin of the Korean Chemical Society
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    • 제32권6호
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    • pp.1980-1984
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    • 2011
  • A temperature- and coverage-dependant quasi-reversible change in two-photon photoemission (2PPE) of chemisorbed 1-phenyl-1-propyne (PP) on Cu(111) is reported. For PP on Cu(111) at 300 K probed at a photon energy of 4.13 eV, two broad peaks of comparable intensity show final state energies of 7.25 and 7.75 eV above the Fermi level. The former peak could be assigned to the first image potential state (IS, n = 1) and/or unoccupied molecular orbital (UMO), located at 3.1 eV above the Fermi level. The latter is plausibly attributed to a mix of unoccupied higher-order IS (and/or UMO) and occupied surface state (SS) of Cu(111). With decreasing the temperature, the former 2PPE peak shows a shift in position by about 0.2 eV, and the latter exhibits a dramatic increase in intensity. In the system, intermolecular interactions (and/or order-disorder transition) of PP and substrate lattice temperature may play a significant role in change in photoexcitation lifetime (or excitation cross-section), and the unoccupied molecular orbital (UMO)-metal (IS) charge transfer coupling. Our unique 2PPE results provide a deeper insight for understanding photoexcitation charge transfer with temperature in an organic molecule/metal system.

산업장 근로자들의 피로자각증상과 요통 (Industrial Fatigue and Low Back Pain of the Workers)

  • 김순례;문정순
    • 지역사회간호학회지
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    • 제7권2호
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    • pp.400-409
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    • 1996
  • To investigate industrial fatigue and low back pain, the questionaire survey for subjective symptoms of fatigue and low back pain was carried out among 591 male workers aged 20-55 employed in an automobile industry in Korea. Workers participated to this study were divided into low back pain group(LBP) and control group, according to the self-reports by written questionaires. The subjective sysptoms of fatigue comprised three groups of 10 items each, representing dullness and sleepiness(level of cerebral activation), difficulty in concentration(level of motivation) and bodily projection of fatigue. The resultant data were processed for $\chi^2-test$, t-test and a pearson's correlation coefficient to confirm the relationships. The results were as follows: 1. 30 items of fatigue subjective symptoms exeptone item, 'lack in perseverance', were directly associated with low back pain. 2. The percentage of fatigue complaint were sig nificantly higher in LBP group. 3. Of the 30 items of fatigue subjective symptoms, the highest percentage was accounted for 'eye strain'(27.9%), followed by 'whole body feels tired' and 'legs feel heavy'(22.9%), 'feel like lying'(21.4%), 'feel a pain in the low back'(18.7%), 'feel drowsy'(16.4%) and 'feel stiffness in the neck or the shoulders'(16.2%) in the order of sequence. 4. The average weighted score for the first group of fatigue items(dullness and sleepiness) was the largest among three groups and was followed by the second group(difficulty in concentration) and the third group(bodily projection of fatigue) in the order of sequence, suggesting the heavier shift work stress of the workers. 5. In the groups of the aged 30-40, work duration of 5-7yrs, heavy work amount and irregular work speed, significant high fatigue complaints were revealed in terms of eye strain, whole body feels tired, legs feel heavy, feel like lying, feel a pain in the low back and feel stiffness in the neck or the shoulders. 6. A significant negative correlations were shown between age, work duration and eleven subjective symptoms while positive reciprocal correlations were shown between eleven items with one another.

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Morphology-dependent Nanocatalysis: Rod-shaped Oxides

  • Shen, Wenjie
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
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    • pp.130-131
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    • 2013
  • Nanostructured oxides are widely used in heterogeneous catalysis where their catalytic properties are closely associated with the size and morphology at nanometer level. The effect of particle size has been well decumented in the past two decades, but the shape of the nanoparticles has rarely been concerned. Here we illustrate that the redox and acidic-basic properties of oxides are largely dependent on their shapes by taking $Co_3O_4$, $Fe_2O_3$, $CeO_2$ and $La_2O_3$ nanorods as typical examples. The catalytic activities of these rod-shaped oxides are mainly governed by the nature of the exposed crystal planes. For instance, the predominant presence of {110} planes which are rich in active $Co^{3+}$ on $Co_3O_4$ nanorods led to a much higher activity for CO oxidation than the nanoparticles that mainly exposed the {111} planes. The simultaneous exposure of iron and oxygen ions on the surface of $Fe_2O_3$ nanorods have significantly enhanced the adsorption and activation of NO and thereby promoted the efficiency of DeNOx process. Moreover, the exposed surface planes of these rod-shaped oxides mediated the reaction performance of the integrated metal-oxide catalysts. Au/$CeO_2$ catalysts exhibited outstanding stability under water-gas shift conditions owing to the strong bonding of gold particle on the $CeO_2$ nanorods where the formed gold-ceria interface was resistant towards sintering. Cu nanoparticles dispersed on $La_2O_3$ nanorods efficiently catalyzed transfer dehydrogenation of primary aliphatic alcohols based on the uniue role of the exposed {110} planes on the support. Morphology control at nanometer level allows preferential exposure of the catalytically active sites, providing a new stragegy for the design of highly efficient nanostructured catalysts.

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역량기반의 전문대학 교육과정 개선 방안 (Development of the College Curriculum using the Competency-based Model)

  • 최길성
    • 한국콘텐츠학회논문지
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    • 제10권10호
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    • pp.464-478
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    • 2010
  • 최근 교육개혁과 관련하여 자주 언급되고 있는 '역량'이라는 단어는 학문과 지식을 중시했던 기존 교육이 현실 사회 적응력을 중시한 교육으로 변화됨을 나타낼 때 주로 사용된다. 전문대학의 교육도 장차 직업생활에서 요구되는 실천적 역량을 갖춘 인재를 양성하는데 적합하도록 교육과정의 개선이 요구된다. 본 연구는 전문대학 교육과정 운영 실태에 대한 문제점을 파악하여 해결방안을 모색해 보았으며, 역량기반 교육모델에 대한 선행연구 자료를 검토하여 전문대학 교육과정에 적용 가능성을 분석하여, 도입이 타당함을 제시하였다. 또한 한국산업인력공단에서 개발한 직업기초능력 표준을 직업교육의 교과내용으로 반영하고 이를 운영할 수 있는 방안을 제시함으로써, 효과적으로 교육과정을 개선시킬 수 있는 방안을 제시하였다.

임상간호사의 윤리적 이슈 경험과 윤리교육 요구 (Experiences of Ethical Issues and Needs for Ethics Education in Clinical Nurses)

  • 신자현;정석희;이명하;양영란
    • 간호행정학회지
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    • 제21권3호
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    • pp.327-339
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    • 2015
  • Purpose: This study was done to identify the experiences of ethical issues and needs for ethics education in clinical nurses. Methods: A cross-sectional survey was used and data were collected in 2013. Participants were 428 clinical nurses working in the general units of seven medical hospitals. The Ethical Issues in Clinical Practice Tool was used. Data analysis was performed using SPSS/WIN 19.0. Results: 'Providing care with a possible risk to your health' was the most frequent and disturbing ethical problems for nurses. The highest helpful ethical topic was 'the patients' right, autonomy and informed consent'. The ethical issue experience was significantly different according to education level, work units, and type of employment. The necessity of ethics education was statistically different according to age, religion, level of education, duration of working as RN, position, shift type, and continuing education about nursing ethics. Conclusion: The results of this study show that nursing educators need to provide practical ethics education based on frequent ethical issues and helpful education topics. These findings can be used in developing effective education strategies for clinical nurses and nursing organizations to improve nurses' ethical decision-making abilities.

시맨틱 위키를 이용한 RDF/OWL과 토픽맵 사이의 상호운용성 (The Interoperability between RDF/OWL and Topic Maps using the Semantic Wiki)

  • 김훈민;양정진
    • 한국전자거래학회지
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    • 제12권1호
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    • pp.123-133
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    • 2007
  • 시맨틱 웹과 웹 2.0의 개념이 등장하며 시작된 차세대 웹은 기존의 자원 중심의 서비스를 바꾸고 있다. 즉, 관심의 초점이 이미 풍부해진 자원 자체가 아닌 그 자원을 설명하는 메타 정보로 옮겨지고 있는 것이다. W3C와 ISO에서는 이러한 메타 정보를 기술하기 위한 표준으로 각각 RDF(Resource Description Language)와 토픽맵(Topic Maps)을 정의하여 발표하였다. 그러나 메타 정보를 XML형태로 직접 기술하는 방법은 사용자 참여가 중요시되는 차세대 웹에서 일반 사용자들의 진입을 막을 수 있다. 이러한 문제 해결의 한 방법으로 기존의 WikiWikiWeb 시스템을 확장한 시맨틱 위키(semantic wiki)가 등장하였으며 사용자는 간단한 문법을 통해 위키 페이지에 대한 RDF 메타 정보를 생성할 수 있게 되었다. 본고에서는 토픽맵 기반의 시맨틱 위키와 현재 구현된 RDF 기반의 시맨틱 위키 사이의 메타 정보 상호운용성을 위한 방법을 RDFTM Task Force에서 제시한 방법론을 기초로 살펴보고, 상위의 Wiki 문법을 통해 하위 단의 변환문제가 자연스럽게 해결될 수 있음을 보인다.

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Overview of Seismic Loads and Application of Local Code Provisions for Tall Buildings in Baku, Azerbaijan

  • Choi, Hi Sun;Sze, James;Ihtiyar, Onur;Joseph, Leonard
    • 국제초고층학회논문집
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    • 제3권1호
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    • pp.65-71
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    • 2014
  • Baku, the capital of Azerbaijan, has seen a boom in construction in recent years. The old Baku city has been rapidly transforming into a new hub of high-rise buildings and lively cultural centers hosting the Euro Vision Song Contest in 2012 and European Games in 2015. A major population shift to Baku from its suburbs and the countryside has resulted in the doubling of Baku's population in the 4 years between 2009 and 2013. As of January 2013, Baku's population reached four million people, 43% of the citizens in Azerbaijan according to The State Statistical Committee of Azerbaijan. With this trend, the city needs more high-rise buildings to accommodate rapidly increasing demands for more housing and business space. Until the Azerbaijan Seismic Building Code was published in 2010 and became effective, many different seismic criteria, in terms of building codes and seismic intensities, were used for all new high-rise projects in Baku. Some designers used the SNIP (Russian) code with seismic level 9 or level 8 with 1 point penalty. Others used the Turkish code with Seismic Zone 1, UBC 97 with Zone 2 through 4, or IBC with Sa = 0.75 g through 1.0 g. The seismic intensity is now clarified with the Azerbaijan Seismic Building Code. However, the Azerbaijan Seismic Building Code is appropriate for low-rise buildings applications but may be inappropriate for high-rise project applications. This is because the code-defined response spectrum yields unrealistically conservative seismic forces for high-rise buildings with long periods, as compared to those determined by other internationally accepted building codes. This paper provides observations and recommendations for code-based seismic load assessment of high-rise buildings in the Baku area.

간호사들의 임상근무의 어려움 관련 주요 요인과 임상근무 활성화 방안 분석 - 현장에서 근무하는 간호사 대상 - (The main difficulties related factors of nurses' clinical work and clinical work plan activation analysis - focus on the nurses working in the field -)

  • 박수경;조경미
    • 한국병원경영학회지
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    • 제21권3호
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    • pp.11-21
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    • 2016
  • The purpose of this study is to investigate the degree of difficulty and turnover of nurses working in the field and to derive clinical work activation and supply policy improvements. Data was collected from December, 2014 to January, 2015, from 23 hospitals, and participants were 3,887 nurses working in the field, Survey details : the difficulty of the clinical work of nurses working in hospitals, turnover intentions status and policy proposals for clinical research work enabled General characteristics, difficulties in clinical working, turnover intention and clinical work plan activation are frequency analysis. The difference between each of the variables in accordance with the general characteristics are one-way ANOVA analysis, Correlation analysis of the variables is also a Pearson correlation coefficients. 'difficulties in clinical working' was a statistically significant difference depending on the type of hospital, nursing class, number of beds, location, age, position, employment, gender, working form, working department, salary, career, and degree level. 'turnover intention' was a statistically significant difference depending on nursing rate, number of beds, region, age, position, sex, shifts, departments, annual income, and career. 'policy recommendation' was a statistically significant difference depending on type of hospital, nursing rate, age, position, employ, shifts, departments, annual income, degree level and career 'difficulties in clinical working' is 'turnover intention' (p<.001), 'policy recommendations' (p<.001) and had a significant positive correlation. and 'turnover intention' had a "policy recommendation" significant positive correlation with the relationship (p<.001) The most difficulties point of the nurses working in the field are the environment, such as shift, urgent and dangerous. Major policy proposals are improve treatment such as wages, and welfare.