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Direction Finding Problem에서의 신호원 갯수 추정 신뢰도에 관한 AIC와 MDL의 비교 (Comparisons of AIC and MDL on Estimation Reliability of Number of Soureces in Direction Finding Problem)

  • 이일근
    • 한국통신학회논문지
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    • 제15권10호
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    • pp.842-849
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    • 1990
  • 본 논문에서는 array processing에서, sensor array를 통해 들어오는 source signal들의 개수를 결정하는 방법들을 판정의 정확도의 관점에서 연구 고찰한다. 첫번째 방법은 Akaike의 Akaike's Information Criterion(AIC)이고, 다른 하나는 Schwartz와 Rissanen의 Minimum Description Length(MDL)이다. 실용적인 측면에서 볼 때, 신호대잡음비 (S/N)가 매우 낮은 상태에서 얻어진 한정된 양의 data를 이용하여 제한된 갯수의 sensor들로 이루어진 array로 부터, 매우 근접해 있는 source signal들의 갯수를 예측해 내는 것은 대단히 중요한 일이다. 본 논문은 simulation 결과를 통하여, source signal들이 근접해 있을수록, array의 sensor 갯수가 줄어들수록, 이용할 data의 양이 한정될수록 또 S/N가 낮아질수록, AIC이 MDL에 비해서 높은 신뢰도를 가짐을 보여준다.

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오픈소스 소프트웨어의 품질 수준 평가 방법 (Quality Evaluation Method of Open Source Software)

  • 박주병;양해술
    • 한국산학기술학회논문지
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    • 제13권5호
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    • pp.2353-2359
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    • 2012
  • 현재 오픈소스 소프트웨어 사용은 날로 증가하고 있는 추세이다. 그러나 오픈소스 소프트웨어 품질에 관한 문제는 그 중요성이 충분히 고려되지 못하고 있는 현실이다. 오픈소스 소프트웨어 품질문제 현황과 지속적인 사용 증가에 대해 전망을 고려할 때 오픈소스 소프트웨어의 품질평가 기술에 대한 개발이 절실히 요구되고 있으나 지금까지의 품질평가 기술 및 국내외 소프트웨어 품질인증 기관의 품질평가 제도는 상용 소프트웨어 제품에 국한되어 있는 것이 현실이다. 따라서 본 논문에서는 오픈소스 소프트웨어를 정량적으로 평가 할 수 있는 평가항목을 구성하였고, 조사된 관련 자료의 통계적인 집계를 통해 평가기준을 확립하였다. 이 평가기준을 통해 오픈소스 소프트웨어를 평가하였다.

소프트웨어 소스 코드의 저작권 관리를 위한 디지털 라이센스의 검색 (Digital License Searching for Copyright Management of Software Source Code)

  • 차병래
    • 한국콘텐츠학회논문지
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    • 제7권1호
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    • pp.21-31
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    • 2007
  • 지적재산권 제도는 21세기 정보화 사회의 발전에 있어서도 중요한 역할을 하고 있다. 국가 경쟁력 제고를 위해서도 디지털콘텐츠에서 확대하여 소프트웨어 소스 코드에 대한 지적재산권 제도와 기술의 정비는 매우 중요한 의미를 지닌다. 소프트웨어 소스코드의 소유권 분쟁이 발생 시 소유권을 증명하기 위해서는 원본의 소프트웨어 소스코드를 판별해야만 하는 문제점을 갖고 있다. 본 연구에서는 소프트웨어 소스코드의 원본 판별을 지원하기 위한 소프트웨어 소스코드의 디지털 라이센스는 소스코드의 예약어를 파싱하여 계층구조를 갖는 XML 파일로 표현하며, 복잡한 소스코드 대신에 소프트웨어 소스코드의 아키텍처를 트리구조 형태로 표현할 수 있다. 그리고 디지털 라이센스를 검색하기 위한 색인 및 검색에 대한 연구를 수행한다.

지도 정보를 활용한 저사양 GPS의 위치 정확도 향상 기법 (Low-end GPS Position Accuracy Enhancement Method by using Map Information)

  • 최덕선;강정민;김한솔;박진배
    • 전기학회논문지
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    • 제65권4호
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    • pp.659-665
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    • 2016
  • In this paper, we propose a novel position accuracy enhancement method of a low-end GPS using digital map information. The latest digital map has various kinds of information on geographical features. The proposed method uses position information of lane marks among the geographical features. We define the position information of lane marks as the reference points. The position information of a low-end GPS acquired for a period of time is defined as the source points. In the proposed method, rotation and translation matrices between the reference and the source points are calculated by using an Iterative Closest Point(ICP) algorithm. The source points are transformed by the obtained rotation and translation matrices. Finally, the transformed source points are projected on the reference points. Through these processes, the position accuracy of a low-end GPS is ultimately enhanced. To verify the proposed method, the various real experimental results are presented.

PMF 모델을 이용한 대기 중 PM-10 오염원의 확인 (Source Identification of Ambient PM-10 Using the PMF Model)

  • 황인조;김동술
    • 한국대기환경학회지
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    • 제19권6호
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    • pp.701-717
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    • 2003
  • The objective of this study was to extensively estimate the air quality trends of the study area by surveying con-centration trends in months or seasons, after analyzing the mass concentration of PM-10 samples and the inorganic lements, ion, and total carbon in PM-10. Also, the study introduced to apply the PMF (Positive Matrix Factoriza-tion) model that is useful when absence of the source profile. Thus the model was thought to be suitable in Korea that often has few information about pollution sources. After obtaining results from the PMF modeling, the existing sources at the study area were qualitatively identified The PM-10 particles collected on quartz fiber filters by a PM-10 high-vol air sampler for 3 years (Mar. 1999∼Dec.2001) in Kyung Hee University. The 25 chemical species (Al, Mn, Ti, V, Cr, Fe, Ni, Cu, Zn, As, Se, Cd, Ba, Ce, Pb, Si, N $a^{#}$, N $H_4$$^{+}$, $K^{+}$, $Mg^{2+}$, $Ca^{2+}$, C $l^{[-10]}$ , N $O_3$$^{[-10]}$ , S $O_4$$^{2-}$, TC) were analyzed by ICP-AES, IC, and EA after executing proper pre - treatments of each sample filter. The PMF model was intensively applied to estimate the quantitative contribution of air pollution sources based on the chemical information (128 samples and 25 chemical species). Through a case study of the PMF modeling for the PM-10 aerosols. the total of 11 factors were determined. The multiple linear regression analysis between the observed PM-10 mass concentration and the estimated G matrix had been performed following the FPEAK test. Finally the regression analysis provided source profiles (scaled F matrix). So, 11 sources were qualitatively identified, such as secondary aerosol related source, soil related source, waste incineration source, field burning source, fossil fuel combustion source, industry related source, motor vehicle source, oil/coal combustion source, non-ferrous metal source, and aged sea- salt source, respectively.ively.y.

해면 산란효과에 의한 선박 방사소음 추정치 오차 (Error Characteristics of Ship Radiated Noise Estimation by Sea Surface Scattering Effect)

  • 박규칠;박지현;서철원;최재용;이필호;윤종락
    • 한국소음진동공학회논문집
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    • 제23권6호
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    • pp.563-573
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    • 2013
  • The ship radiated noise level fluctuates by the interference between direct and reflected paths. The effect of sea surface reflection path on interference depends strongly on sea surface roughness. This paper describes error characteristics of ship acoustic signature estimation by sea surface scattering effect. The coherent reflection coefficient which explains a magnitude of sea surface scattering and its resultant interference acoustic field is analyzed quantitatively as a function of a grazing angle, effective surface height, frequency, source-receiver range and depths of source and receiver. Theoretical interference acoustic field is compared with experimental result for two different sea surfaces and five different frequencies by changing source-receiver range. It is found that both matches well each other and a magnitude of interference acoustic field is decreasing by increasing a grazing angle, effective surface height, frequency, and depths of source and receiver and decreasing source-receiver range. For given experimental conditions, the transmission anomaly which is a bias error of ship acoustic signature estimation, is about a range of 1~3 dB. The bias error of an existing ship radiated noise measurement system is also analyzed considering wind speed, source depth and frequency.

Mobility-Sensitive Multicast Protocol in NEMO

  • Li, Long-Sheng;Chi, Hung-I;Xie, Kai-Chung;Chan, Din-Yuan
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제16권6호
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    • pp.1994-2017
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    • 2022
  • In view of the past, the mobility of the multicast source in the mobility networks is seldom discussed in the traditional multicast protocols. It is a heavy cost for the traditional multicast protocols to reconstruct the multicast tree in the Network Mobility (NEMO) environment. This article proposes an alternative multicast protocol, referred to as Mobility-Sensitive Multicast protocol (MSM), for the NEMO environment. The MSM can be considered as an alternative version of the Multicast Listener Discovery (MLD) protocol to maintain the multicast tree in the NEMO. There are two obvious contributions for the MSM. Reconstruct mechanism could rebuild the multicast tree for the mobility of the multicast source. Multi-group suppression mechanism reduce the multicast tree maintaining cost for the mobility of the multicast members. Through the performance evaluations and analyses, the MSM has less cost to maintain the multicast tree than the traditional multicast protocols, especially for a large numbers of multicast groups. Moreover, the MSM allows the mobility of the multicast source to reconstruct the multicast tree easily.

QoS Based Routing Algorithm with Crank-Back Ability

  • Kanthavong, Somphone;Tangtisanon, Prakit;Lertwatechakul, Mayuree
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2003년도 ICCAS
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    • pp.2413-2417
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    • 2003
  • This paper proposes an improvement of a QoS based routing protocol. The hierarchical source routing algorithm[4] was improved by including of the Crank-Back algorithm[2]. The Crank-Back capability is the ability to solve the problem of selecting the wrong route because of using unsynchronized routing information in the ingress router. In order to reduce time of reversing the call-setup process back to the ingress router, spare-route information is included with a call-setup packet. Spare-route information could be used by every router to find the next appropriated link itself when insufficient resource of the selected link was found. The proposed algorithm improves the performance of the source routing call-setup process significantly.

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스포츠 캐주얼웨어 소비자의 패션 라이프 스타일과 정보원과의 관계 (A Relationship with Sports Casualwear Consumer′s Fashion life Style and information source)

  • 박경연;유태순
    • 복식
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    • 제50권4호
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    • pp.103-115
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    • 2000
  • The purpose of this study is to provide consumers with practical information for reasonable purchasing by analyzing apparel purchasing behavior. information source use, demographic differences in terms of life style patterns, moreover, to support apparel manufacturers in producing goods and making a plan by developing more effective advertisements and efficient marketing strategy, such as media strategy. This study targeted 832 men and women wearing sports casual wear. Information source is used to analyze the data and MANOVA, ANOVA. Scheffe is employed for post-inspection and demographic bases are based on the frequency of each type. The followings are the conclusions of this study : 1. In case of print media, TV, PC factor, fashion advocates and individuality advocates most frequently used information source. In case of purchasing experience factor, individuality advocates skewed higher frequency than conformity type. and then, in case of observation information use factor, individuality advocates were ranked as the highest and conformity type as the lowest. In case of human information use factor, fashion advocates and individuality advocates showed higher frequency than practical type and conformity type. 2 In case of female, Individuality advocates was ranked as the highest. In case of male, practical type and conformity type were rank as the highest. Fashion advocates ranked as the lowest in any case. 3. Individuality advocates were ranked as the highest among people aged 14 to 16, practical type among 17 to 19, conformity type among 20 to 23, conformity type among over 20. 4. Middle school students tended to be the individuality advocates, high school students the practical type, university students the practical type and the conformity type, and company workers conformity type.

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Blind Source Separation for OFDM with Filtering Colored Noise and Jamming Signal

  • Sriyananda, M.G.S.;Joutsensalo, Jyrki;Hamalainen, Timo
    • Journal of Communications and Networks
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    • 제14권4호
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    • pp.410-417
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    • 2012
  • One of the premier mechanisms used in extracting unobserved signals from observed mixtures in signal processing is employing a blind source separation (BSS) algorithm. Orthogonal frequency division multiplexing (OFDM) techniques are playing a prominent role in the sphere of multicarrier communication. A set of remedial solutions taken to mitigate deteriorative effects caused within the air interface of OFDM transmission with aid of BSS schemes is presented. Four energy functions are used in deriving the filter coefficients. Energy criterion functions to be optimized and the performance is justified. These functions together with iterative fixed point rule for receive signal are used in determining the filter coefficients. Time correlation properties of the channel are taken advantage for BSS. It is tried to remove colored noise and jamming components from themixture at the receiver. Themethod is tested in a slow fading channel with a receiver containing equal gain combining to treat the channel state information values. The importance is that, these are quite low computational complexity mechanisms.