• 제목/요약/키워드: Effective area

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An Integrative Review on Augmented Reality/Virtual Reality Simulation Programs in the Mental Health Area for Health Professionals

  • Han, Soolgi
    • International Journal of Contents
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    • 제15권4호
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    • pp.36-43
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    • 2019
  • This is an integrative review paper of Augmented Reality (AR)/Virtual Reality (VR) simulation programs in the mental health area including the analysis of the general characteristics, contents, and the impact of the interventions studies. The keywords used to search the studies were "AR/VR" and "medical/nursing students". The author and a postdoctoral research fellow searched four electronic databases: Web of Science, PubMed, EmBase, and CINHA, and as a result nine studies met the inclusion criteria. Among the selected studies AR/VR simulation programs in the mental health area for healthcare professionals were found to be effective in clinical skills as well as for the interpersonal relationship and the stigma of mentally ill patients. Providing an opportunity to experience a safe and effective tool is important when educating health professionals and AR/VR simulation programs are safe and effective. Thus, standardized AR/VR simulation programs are needed to be developed for health professionals.

연료분사노즐의 니들밸브 형상변화에 따른 분무특성에 관한 연구 (A study on Spray Characteristic of Fuel Injection Nozzle with Geometrical Shape Changes of Needle Valve)

  • 채재우
    • 오토저널
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    • 제9권4호
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    • pp.35-40
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    • 1987
  • The experimental study, using constant pressure injection system, is carried out to investigate the effect of the geometrical shape changes of the needle valve of the effective flow area, the spray angle and the Sauter's Mean Diameter according to needle valve lift for a pintle-type injection nozzle. The results are as follows: 1) With the increase of the needle valve lift, the effective flow area is increased, the spray angle is at first increased and later decreased, and the Sauter's Mean Diameter is decreased. 2) It is also shown that the spray angle is maximum at the rapidly increased region of the effective flow area.

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Dispersion and Nonlinear Properties of Elliptical Air Hole Photonic Crystal Fiber

  • Rao, MP Srinivasa;Singh, Vivek
    • Current Optics and Photonics
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    • 제2권6호
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    • pp.525-531
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    • 2018
  • The effect of eccentricity on dispersion and nonlinear properties of a photonic crystal fiber having elliptical air holes is investigated using a fully vectorial effective index method. It is found that the effective refractive index increases with increase of eccentricity. The dependence of dispersion and nonlinear properties of the PCF on the eccentricity of the air hole is investigated. It is revealed that eccentricity of the air hole affects the zero dispersion wavelength. Further, the nonlinear properties such as mode field area, nonlinear coefficient and self phase modulation of the Photonic crystal fibers are analyzed. The mode field area increases and the nonlinear coefficient decreases with increase in eccentricity. The variation of the self phase modulation with elliptical air hole is also discussed.

이동통신망에서 영역분할 방식의 위치관리 기법 (Location Management using LA-Division Scheme in Personal Communication Systems)

  • 박노열;장인갑;홍정완;이창훈
    • 산업공학
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    • 제16권4호
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    • pp.507-514
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    • 2003
  • In personal communication systems location management of mobile terminals is required to connect incoming calls to the mobile terminals. Investigation of effective location update and paging strategies is important to reduce the cost of location management. In this study, we propose a paging strategy considering the mobile terminals' residence patterns. The first paging area is characterized by the set of cells in the location area where mobile terminals usually stay for a significant period of time. The rest of cells in the location area are included into the second paging area. To reduce the paging cost the first paging area is decided by reflecting various residence patterns of mobile terminals. For an incoming call, the sequential paging is performed in the order of the paging area. Thus the paging cost is greatly reduced, especially when the called mobile terminal is located in the first paging area. The proposed strategy is expected to be more effective than an existing strategy that uses the anchor cell in the location area.

이동 통신망에서 영역 분할 방식을 이용한 페이지 비용 감소 방안 (Reducing Paging Cost Using LA-Division Scheme in Personal Communication Systems)

  • 박노열;장인갑;홍정완;이창훈
    • 한국경영과학회:학술대회논문집
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    • 한국경영과학회/대한산업공학회 2003년도 춘계공동학술대회
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    • pp.425-432
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    • 2003
  • In personal communication systems, location management of mobile terminals is required to connect incoming calls to the mobile terminals. Investigation of effective location update and paging strategies is important to reduce the cost of location management. In this study, we propose a paging strategy considering the mobile terminals' residence patterns. The first paging area is introduced, which is characterized by the set of cells in the location area where mobile terminals usually stay for a significant period of time. We propose the decision criterion of the first paging area by comparing the cost against zone-based strategy. For an incoming call. we perform the sequential paging by the order of the first paging area and the rest of cells in the location area called by the second paging area. Thus the paging cost is greatly reduced, especially when the called mobile terminal is located in the first paging area. The proposed strategy is expected to be more effective than existing strategy using anchor cell in the location area because it reflects various residence patterns of mobile terminals.

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디지털 오디오 인터페이스용 개선된 20Mb/s CMOS 광수신기 (Improved 20Mb/s CMOS Optical Receiver for Digital Audio Interfaces)

  • 유재택;김길수
    • 대한전자공학회논문지SD
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    • 제44권3호
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    • pp.6-11
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    • 2007
  • 본 논문에서는 고성능 디지털 오디오 인터페이스용 CMOS 광수신기의 면적 감소와 펄스폭 왜곡을 감소시키기 위한 2종의 CMOS 광수신기를 제안한다. 면적 감소와 펄스폭 왜곡 감소를 위한 2종의 제안하는 회로는 이중 출력을 생성하는 전치 증폭기 광수신기와 문턱 전압을 수렴하는 레벨 변환기 광수신기이다. 제안한 회로들의 성능을 검증하기 위해 $0.25{\mu}m$ CMOS 공정을 이용하여 칩이 제작되었으며, 측정 결과 이중 출력 전치 증폭기를 이용한 광수신기의 경우, $270\times120{\mu}m^2$ 유효 면적을 차지하고 ${\pm}3%$ 이내의 펄스폭 왜곡을 나타내며, 문턱 전압 수렴형 레벨 변환기를 이용한 광수신기의 경우 $410\times140{\mu}m^2$의 유효 면적을 차지하고 ${\pm}2%$ 이내의 펄스폭 왜곡을 나타내므로, 고성능 디지털 오디오 인터페이스용 광수신기의 면적과 펄스폭 왜곡을 효과적으로 감소시킬 수 있었다.

다공성 미디아에 있어서 유효확산계수 (Effective Diffusion Coefficient in the Porous Media)

  • Jeehyeong Khim
    • 한국토양환경학회지
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    • 제1권2호
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    • pp.83-90
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    • 1996
  • 토양내에서의 가스나 증기상의 오염물질의 이동은 여러 가지 현상에 의해서 일어나고 있으나 농도차에 의해서 일어나는 확산이 가장 중요하다. 그런데 토양내에서의 확산은 토양 입자들로 인한 확산 부피의 감소, 또 확산경로의 불규칙성, 확산 경로에 있어서 단면적의 변화 등으로 인해 대기중에서 일어나는 확산과는 다른 면을 보인다. 본 논문에서는 이러한 현상을 설명하기 위하여 흔히 사용되는 굴절계수(toruosity), 유효확산계수(effective diffusion coefficient)의 서로 다른 그러나 같은 이름으로 사용되는 많은 정의들과 다양한 수학적 모델들에 대한 비교 검토가 이루어졌다. 굴절계수나 유효확산계수를 사용할 때는 각각의 경우 정의와 각 식의 특징에 대하여 세밀한 검토와 주의가 행하여져야 한다.

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인천 지역 준설토의 비선형 압밀특성 연구 (Characterization of Non-linear Consolidation of Dredged Soil from Incheon Area)

  • 옥영석;안용훈;이철호;최항석
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2008년도 추계 학술발표회
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    • pp.1693-1706
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    • 2008
  • It is of importance to determine the zero effective stress void ratio($e_{00}$), which is the void ratio at effective stress equal to zero, and the relationships of void ratio-effective stress and of void ratio-hydraulic conductivity for characterizing non-liner finite strain consolidation behavior for ultra-soft dredged materials. The zero effective stress void ratio means a transitional status from sedimentation to self-weight consolidation of very soft soil deposits, and acts as a starting point for self-weight consolidation in the non-linear finite strain numerical analysis such as PSDDF. In this paper, a new method for determining the zero effective stress void ratio has been introduced with the aid of measuring electrical resistivity of the specimen. A correlation between the zero effective stress void ratio and the initial slurry void ratio has been proposed, which can be used in PSDDF analysis as an input parameter. Combining all of the accessible experimental data, the consolidation characteristics of a dredged soil from the Incheon area has been studied in detail.

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설계 유효범위 이상에서의 RBN/DGPS정밀도 및 신뢰성에 관한 연구 (A Study on Accuracy and Reliability Characteristics of RBN/DGPS over the Designed Effective Service Area)

  • 고광섭;심재관;최창묵;정세모
    • 한국항해학회지
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    • 제24권3호
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    • pp.157-165
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    • 2000
  • When the GPS system was come to the operation, the U.S Coast Guard initiated development of differential GPS system based on a marine radiobeacon. It has rapidly been spread out to many countries. DGPS equals to P(Y) code in a positioning accuracy. USA has recently determined to expand the coverage of DGPS to inland in order to install a nationwide DGPS chain. Korea is under processing for improving the DGPS as a nationwide positioning system. Before expanding the service area inside Korea, we need to verify the relation between the field strength and DGPS accuracy for the service area. The Japanese DGPS data is received in the southern Part of the Korean peninsula. The Korean DGPS was not a complete system, so we selected the Japanese DGPS data as a model for the study. This paper investigate accuracy and reliability characteristics of RBN/DGPS over the effective service area. Through the experimental and simulation study, we obtained the reliable and stable positioning accuracy in the southern part of the Korean peninsula. In addition, the characteristics of RBN/DGPS were examined in the land over the effective coverage from Japan. The results would be a basic reference to research the RBN/NDGPS in Korea.

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VFSMOD-w 모형과 유전자 알고리즘을 이용한 식생여과대의 최적화 (Optimization of Vegetative Filter Strip using VFSMOD-w model and Genetic-Algorithm)

  • 박윤식;현근우
    • 한국물환경학회지
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    • 제30권2호
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    • pp.159-165
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    • 2014
  • Vegetative Filter Strip (VFS) is one of effective Best Management Practices (BMPs) to prevent sediment-laden water problem, is installed at the edge of source area such agricultural area so that sediment occurred in source area is trapped by VFS before it flow into stream or river. Appropriate scale of it needs to be simulated before it is installed, considering various field conditions. In this study, a model using VFSMOD-w model and Genetic Algorithm to determine effective VFS length was developed, it is available to calibrate input parameter related to source area sediment yield through thousands of VFSMOD-w simulations. Useful DBs, moreover, are stored in the model so that very specific input parameters can be used with reasonable values. Compared simulated values to observed data values for calibration, R2 and Nash-Stucliffe model efficiency coefficient were 0.74 and 0.65 in flow comparison, and 0.89 and 0.79 in sediment comparison. The model determined 1.0 m of Filter Length, 0.18 of Filter Slope, and 0.2 cm of Filter Media Spacing to reduce 80% of sediment by VFS. The model has not only Auto-Calibration module also DBs for specific input parameters, thus, the model is expected to be used for effective VFS scale.