• 제목/요약/키워드: Interferences

검색결과 746건 처리시간 0.025초

Numerical investigation on the wave interferences of submerged bodies operating near the free surface

  • Li, Dong;Yang, Qun;Zhai, Lin;Wang, Zhen;He, Chuan-lin
    • International Journal of Naval Architecture and Ocean Engineering
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    • 제13권1호
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    • pp.65-74
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    • 2021
  • A key factor that governs the wave interferences of a submerged body is the dimensionless Froude number. Computational Fluid Dynamics (CFD) is used to describe the resistance force coefficients and the generated waves of two SUBOFF submarine models. Grid independence studies are performed on two cases, totally and shallowly submerged cases, with four sets of computing meshes. The highest peaks are marked by red points at given wavelengths, a line is fitted to those points with a least-squares approximation, and the half wake angle at multiple Froude numbers is defined between the fitted line and the centerline of the free surface. The results show that when the depth of the target is 1.1D, constructive interferences occur at Fn = 0.3 and 0.5, while destructive interference occurs at Fn = 0.35 with distortion of the waveform. The half wake angle is less than 19.47° because of the interference between the bow and stern wave systems.

Interferences Between Work and NonWork In the Context of Smartwork: The Role of Boundary Strength and Autonomy

  • Yong-Young Kim;Sangjo Oh;Heejin Lee;Kyung Jin Cha
    • Asia pacific journal of information systems
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    • 제29권4호
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    • pp.547-570
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    • 2019
  • With the advances of information technologies, the interest in SmartWork including extended version of telework and flexible work are increasing, and various types of SmartWork attempted to make working time and place flexible with the goal of work and life balance. Despite its emphasis on work and life balance, SmartWork is expected to make the boundaries between work and nonwork blur and role conflicts occur more than before, and thus the goal of work and life balance becomes more distant. A number of SmartWork users are significantly increasing in Korea, but little is known concerning the antecedents and mechanisms to explain psychological work and interferences in the SmartWork environment. In this paper, using boundary theory, we empirically investigate factors affecting the interferences at both work and nonwork domains. The results, based on data collected from SmartWork users in one of the biggest telecommunication companies in Korea where SmartWork is adopted and extensively used, suggest the factors may be affecting differently interferences at the work and nonwork domains.

스마트워크 환경에서 업무와 비업무간 간섭에 대한 연구 (A Study on the Interferences Between Work and Nonwork in the Smart Work Context)

  • 오상조;김용영;이희진;이종만
    • 디지털융복합연구
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    • 제12권4호
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    • pp.213-226
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    • 2014
  • 스마트워크를 통해 시간과 공간의 제약을 넘어 수월하게 상호작용할 수 있는 기회가 제공되면서 업무와 비업무 경계가 더욱 희미해지고 있다. 기존 연구들에서는 업무와 비업무 경계의 모호성으로 인해 발생하는 문제로 간섭에 대해 관심을 기울이고 있다. 특히 업무의 비업무 영역에 대한 일방향적인 간섭을 경계가 모호해 지면서 발생하는 부정적 효과로 보는 경향이 있다. 스마트워크로 인해 업무와 비업무 간의 경계가 더욱 모호해짐으로써 간섭이 쉽게 발생할 수 있으며, 이는 스마트워크가 지향하는 일하는 방식의 변화를 통한 일과 삶의 균형을 저해하는 중요한 요인이다. 따라서 간섭에 대해 관심을 갖고 이를 최소화하는 방안을 모색할 필요가 있다. 이 과정에서 업무의 비업무 영역에 대한 간섭뿐 아니라 반대 방향으로의 간섭에 대해서도 고려하는 양방향적 시각이 전제되어야 한다. 본 연구에서는 경계이론을 바탕으로 스마트워크 상황에서 간섭에 영향을 주는 선행요인을 파악하고, 스마트워크를 도입하기 위해 준비 중이거나, 이미 추진하고 있는 조직에서 이를 적절히 진행하기 위해 필요한 과업을 제시하였다.

링크 레벨 시뮬레이션과 시스템 레벨 시뮬레이션에 의한 WCDMA TDD시스템과 cdma2000시스템 간의 상호간섭분석 (Interference Investigation between WCDMA TDD System and cdma2000 System by Link-level Simulation and System-level Simulation)

  • 차인석;장경희;김성진;최용석
    • 대한전자공학회논문지TC
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    • 제41권7호
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    • pp.21-30
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    • 2004
  • WCDMA TDD 시스템의 Capacity는 주로 간섭에 의하여 제한되기 때문에, WCDMA TDD 시스템내의 간섭뿐만 아니라 인접 셀 간섭, 그리고 cdma2000 시스템과의 상호 간섭 효과를 최소화하여야 만이 WCDMA TDD 시스템의 기대용량을 얻을 수 있고, 현재 사용하고 있는 cdma2000 시스템과의 상호간섭을 최소화 할 수 있다. 본 논문에서는 3GPP TR 25.942 를 토대로 보다 정확한 파라미터를 사용하고, 시스템 레벨 시뮬레이션을 통해 WCDMA TDD 시스템과 cdma2000 시스템간의 상호간섭을 다양하고 실질적인 상황 하에서 해석하고, 또한 링크레벨을 고려한 시스템 레벨 시뮬레이션 결과로부터 두 시스템간의 상호간섭을 분석한다. 시뮬레이션 결과로부터 WCDMA TDD 시스템과 cdma2000 시스템 간 상호간섭을 고려한 시스템 용량의 최적화를 위한 조건을 제시한다.

무선통신기반 열차제어시스템 무선설비 설계 연구 (Design of Wireless Communication Based Train Control System)

  • 송용수;이재호;김용규;창상훈
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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    • pp.2755-2761
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    • 2011
  • The purpose of this study was to analyze and improve the communication interferences in the wireless communication equipments of the CBTC applied to a model intelligence train control system. So far, train positions have been traced by the conventional fixed blocking system to control the operation of the trains, but the new CBTC system uses the on-ground location to transmit the train positions wirelessly to the ground control center continuously, so being more vulnerable to communication interferences. Although the researcher analyzed and improved such interferences in the communication equipments of the CBTC system, there remain more rooms for its improvement.

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Intersymbol Interferences Due to Mismatched Roll-off Factors and Sampling-Time Jitter in a Gaussian Noise Channel

  • Park, Seung Keun;Mok, Jin Dam;Na, Sang Sin
    • The Journal of the Acoustical Society of Korea
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    • 제16권2E호
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    • pp.47-54
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    • 1997
  • This paper presents two results on intersymbol interferences in baseband digital communication over an additive white Gaussian noise channel-the interferences due to mismatched square-root raised-cosine filters, in which the filters have different roll-off factors, and / or due to sampling-time jitter. The result for the mismatched filters is that even the jitter-free sampling causes intersymbol interference and it is negligibly small for a wide range of signal-to-noise ratio up to 10dB, for the roll-off factor ranging from 0.2 to 0.5, the mismatch loss being within 0.1dB from the optimum at around 10-6 .For jitter interference an approximation formula for the bit error probability is derived in case of the matched filters, which shows how the roll-off factors and the amount of jitter affect the system performance. The formula is reasonably accurate.

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공동주택 공사의 작업간 간섭 감소 방안에 관한 연구 (A Study on the Measures for Work Interference Reduction in Apartment Construction)

  • 안성훈;김준호;강경인
    • 한국건축시공학회지
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    • 제6권1호
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    • pp.117-122
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    • 2006
  • Apartments construction is a one of largest parts in buildings construction. In apartments construction, work interferences are frequently occurred in work processing because workspaces are very various and numerous. However, though work process is important for mainly influencing to the schedule, quality and cost of apartments construction, these work interferences are considered a kind of uncertainty, which is difficult to anticipate at construction planning stage, in work processing. Therefore, this study proposed the measures for work interference reduction in apartment buildings construction and the actual planning for practices. The results can be summarized as follows: (1) the standard of work process is checked regularly. (2) The scope of work and work process is adjusted. (3) The standard of drawings process and cost about work interferences work profess is established.

Number of Elements in Smart Antenna System effects on both Perfect and Imperfect Power Control or Reverse Link of CDMA Cellular System

  • Uthansakul, Peerapong;Uthansakul, Monthippa
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2002년도 ITC-CSCC -3
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    • pp.1956-1959
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    • 2002
  • Power control (PC) on the reverse link of CDMA cellular system is important to increase system capacity. PC eliminates fluctuations in the received signal level and hence reduces the required signal-to-interference ratio. However, both perfect PC and imperfect PC depend on number of interferences as number of users, which by using smart antenna system can decrease number of interferences in any directions except interferences from the main beam direction. In this paper , number of elements in smart antenna system, which directly relates to the main beam pattern, is studied to find the effects on the outage probability , bit energy-to-interference density ratio (Eb/Io) and the capacities of both perfect and imperfect PC.

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공구간섭으로 인한 미절삭 윤곽의 잔삭가공을 위한 효율적인 공구경로 (An Efficient CleanUp Tool Path for Undercuts Come from Cutter Interferences in Profile Machining)

  • 주상윤;이상헌
    • 한국CDE학회논문집
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    • 제7권3호
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    • pp.184-188
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    • 2002
  • In 2D-Profile machining using cutter radius compensation cutter interferences are very common. To prevent the cutter interferences undercuts are inevitable in some regions of the profile. The undercut regions require cleanup machining using smaller radius tools. This paper considers a procedure of the tool path generation for the cleanup profile machining. And two methods are introduced for an efficient tool path generation. One is how to reduce the machining time by uniting adjacent tool paths of undercut regions, and the other is how to find the tool path with the minimal distance by applying TSP algorithm.

다중의 협대역 간섭 신호에 대한 AGC Applebaum어레이의 성능 분석 (Performance Analysis of AGC Applebaum Array for Multiple Narrowband Interference)

  • 윤동현;이규만;한동석
    • 한국통신학회논문지
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    • 제25권6B호
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    • pp.1092-1099
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    • 2000
  • An adaptive array system can effectively remove all received interferences by using adaptive algorithms even though the received signal condition is not known. The conventional adaptive array systems, however, cannot remove all interferences adaptively and converge very slowly when the eigenvalue spread of the input covariance matrix is large. In the paper, a new adaptive array system called an automatic gain controller (AGC) Applebaum array and its control algorithm are proposed to overcome the performance degradation of conventional Applebaum array in multiple interference conditions. The performance analysis of the proposed AGC Applebaum array is described under the condition of multiple narrowband interferences. Simulation results show the array output signal-to-noise ratio (SNR) of the AGC Applebaum array increases by 30dB compared to that of the conventional Applebaum array in the simulation condition. The gain of the AGC Applebaum array in the incident direction of a weaker interference is also shown to be lower than that of the conventional Applebaum array.

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