• Title/Summary/Keyword: source terms

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Tourism Market Segmentation Based on Shopping Information Sources (쇼핑정보원 활용에 따른 해외여행자 시장세분화 및 세분시장 특성 연구)

  • Jeon, Yangjin
    • Journal of the Korea Fashion and Costume Design Association
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    • v.19 no.2
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    • pp.117-128
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    • 2017
  • This study confirmed the types of shopping information sources during travel abroad, and developed a profile of tourists in terms of demographics, travel, and shopping behavior. Shopping information sources and characteristics of shopping products were identified first. Thereafter, travelers were segmented by their information-seeking behavior. An online survey method was used to get data from Korean vacationers in their 20s-50s, while factor analysis, cluster analysis, ${\chi}^2$ test and ANOVA were applied to analyze data. The results were as follows. First, the shopping information sources of overseas tourists were composed of four factors including sources from travel agents/media, information from travel books and local sources, and word-of-mouth sources. Also, four factors in product types and four product attributes were identified. Second, tourists were clustered into two groups, active and passive shopping information seekers, based on shopping source behavior. Third, two groups differed in terms of demographics, showing an older age and higher income for active shopping source seekers. Active shopping information users tended to join package trips with family members, and they were more satisfied with the trip. With regard to shopping, active shopping source seekers spent more money for shopping and preferred all kinds of shopping goods with an emphasis on travel shopping. In conclusion, shopping information sources seemed to be a meaningful tool for segmenting tourists. Rich, older, family tourists would be an major target market for local retailers.

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A Method for Information Source Selection using Teasaurus for Distributed Information Retrieval

  • Goto, Shoji;Ozono, Tadachika;Shintani, Toramatsu
    • Proceedings of the Korea Inteligent Information System Society Conference
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    • 2001.01a
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    • pp.272-277
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    • 2001
  • In this paper, we describe a new method for selecting information sources in a distributed environment. Recently, there has been much research on distributed information retrieval, that is information retrieval (IR) based on a multi-database model in which the existence of multiple sources is modeled explicitly. In distributed IR, a method is needed that would enable selecting appropriate sources for users\` queries. Most existing methods use statistical data such as document frequency. These methods may select inappropriate ate sources if a query contains polysemous words. In this paper, we describe an information-source selection method using two types of thesaurus. One is a thesaurus automatically constructed from documents in a source. The other is a hand-crafted general-purpose thesaurus(e.g. WordNet). Terms used in documents in a source differ from one another and the meanings of a term differ depending on th situation in which the term is used. The difference is a characteristic of the source. In our method, the meanings of a term are distinguished between by the relationship between the term and other terms, and the relationship appear in the co-occurrence-based thesaurus. In this paper, we describe an algorithm for evaluating a usefulness of a source for a query based on a thesaurus. For a practical application of our method, we have developed Papits, a multi-agent-based in formation sharing system. An experiment of selection shows that our method is effective for selecting appropriate sources.

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AE Source Location Techniques in Planar Defects (음향방출에 의한 평면결함의 위치표정 기술)

  • 우창기;이장규;박성완;김봉각;윤종의;인승현
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2002.04a
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    • pp.369-375
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    • 2002
  • The results of source location in terms of AE signal occurred by the spot exciting as suggested in this research, it has been confirmed that AE technique is quite fruitful in figuring out the location of the occurrence, form, size and direction of the defects. Thus, it is expected that the application of the experimental method suggested in this study would make it possible to identify, in the nondestructive way, the location of the defect in the material.

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INFINITELY MANY SOLUTIONS OF A WAVE EQUATION WITH JUMPING NONLINEARITY

  • Park, Q-Heung;Jung, Tack-Sun
    • Journal of the Korean Mathematical Society
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    • v.37 no.6
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    • pp.943-956
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    • 2000
  • We investigate a relation between multiplicity of solutions and source terms of jumping problem in wave equation when the nonlinearity crosses an eigenvalue and the source term is generated by finite eigenfunctions. We also show that the jumping problem has infinitely many solutions when the source term is positive multiple of the positve eigenfunction.

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Study on the Driving property of planar gate light source (전계방출 광원용 플라나 게이트의 구동 특성 연구)

  • Kim, Kwang-Bok;Yang, Dong-Wook;Kim, Tae-Hyeon;Kim, Dae-Jun
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 2008.05a
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    • pp.148-150
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    • 2008
  • In this paper, we report the improved driving methode using planar-gate for field emission light source. Due to the cold cathode in field emission device, it has advantage for driving system in terms of high speed pulse driving with narrow duty ratio. This paper shows that our driving method offers the stable and reliable driving system without rapid electric field variation for field emission light source.

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Verification of MCNP/ORIGEN-2 Model and Preliminary Radiation Source Term Evaluation of Wolsung Unit 1 (월성 1호기 MCNP/ORIGEN-2 모델 검증 및 예비 선원항 계산)

  • Noh, Kyoungho;Hah, Chang Joo
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.13 no.1
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    • pp.21-34
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    • 2015
  • Source term analysis should be carried out to prepare the decommissioning of the nuclear power plant. In the planning phase of decommissioning, the classification of decommissioning wastes and the cost evaluation are performed based on the results of source term analysis. In this study, the verification of MCNP/ORIGEN-2 model is carried out for preliminary source term calculation for Wolsung Unit 1. The inventories of actinide nuclides and fission products in fuel bundles with different burn-up were obtained by the depletion calculation of MCNPX code modelling the single channel. Two factors affecting the accuracy of source terms were investigated. First, the neutron spectrum effect on neutron induced activation calculation was reflected in one-group microscopic cross-sections of relevant radio-isotopes using the results of MCNP simulation, and the activation source terms calculated by ORIGEN-2 using the neutron spectrum corrected library were compared with the results of the original ORIGEN-2 library (CANDUNAU.LIB) in ORIGEN-2 code package. Second, operation history effect on activation calculation was also investigated. The source terms on both pressure tubes and calandria tubes replaced in 2010 and calandria tank were evaluated using MCNP/ORIGEN-2 with the neutron spectrum corrected library if the decommissioning wastes can be classified as a low level waste.

Sensitivity of Input Parameters in the Spectral Wave Model

  • Park, Hyo-Bong
    • Journal of Ocean Engineering and Technology
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    • v.23 no.2
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    • pp.28-36
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    • 2009
  • Many researches have been done to define the physical parameters for the wave generation and transformation over a coastal region. However, most of these have been limited to the application of particular conditions, as they are generally too empirical. To yield more reasonable wave estimation using a spectral wave model, it is important to understand how they work for the wave estimation. This study involved a comprehensive sensitivity test against the spectral resolution and the physical source/sink terms of the spectral wave model using SWAN and TOMAWAC, which have the same physical background with several different empirical/theoretical formulations. The tests were conducted for the East Anglian coast, UK, which is characterized by a complex bathymetry due to several shoals and offshore sandbanks. For the quantitative and qualitative evaluation of the models' performance with different input conditions, the wave elements and spectrums predicted at representative sites the East Anglia coast were compared/analyzed. The spectral resolution had no significant effect on the model results, but the lowest resolution on the frequency and direction induced underestimations of the wave height and period. The bottom friction and depth-induced breaking terms produced relatively high variations in the wave prediction, depending on which formulation was applied. The terms for the quadruplet and whitecapping had little effect on the wave estimation, whereas the triads tended to predict shorter and higher waves by energy transferring to higher frequencies.

Measurement of Nonlinear Time-variant Source Characteristics of Intake and Exhaust Systems in Fluid Machines

  • Jang Seung-Ho;Ih Jeong-Guon
    • The Journal of the Acoustical Society of Korea
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    • v.24 no.3E
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    • pp.87-89
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    • 2005
  • The acoustical sources of intake and exhaust systems in fluid machines are often characterized by the source impedance and strength using linear frequency-domain modeling. In the case of the sources which are nonlinear and time-variant, however, the source parameters were sometimes incorrectly obtained. In this paper, the source model and direct measurement technique are modified in order to evaluate the effect due to nonlinear and periodically time-varying source character as well as the linear property of the reflectivity of in-duct fluid machine source. With a priori known kinematical information of the source, the types of nonlinear time-variant terms can be presumed by a simple physical model, in which there is practically no restriction on the form of the model. The concept of source impedance can be extendable by introducing the linear frequency response function for each nonlinear or time-variant input. Extending the conventional method and adapting the reverse MISO technique, it is possible to develop a direct method that can deal with the nonlinear time-variant source parameters. The proposed direct method has a novel feature that there is no restriction on the probability or spectral natures of the excited sound pressure data. The present method is verified by the simulated measurements for simplified fluid machines. It is thought that the proposed method would be useful in predicting the insertion loss or the radiated sound level from intake or exhaust systems.

Additional Transmission Protocol for Fairness Enhancement in IEEE 802.11 Wireless LANs (IEEE 802.11 무선 랜에서 공평성 향상을 위한 추가 전송 프로토콜)

  • Kang, Tae-Uk;Kim, Sunmyeng
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.65 no.12
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    • pp.2262-2269
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    • 2016
  • In IEEE 802.11 wireless LANs, when a source node with low data rate occupies the channel resource for a long time, network performance degrades. In order to improve performance, the cooperative communication has been proposed. In the previous cooperative communication protocols, relay nodes deliver data packets only for a source node. In this paper, we propose an additional transmission scheme in which relay nodes select an additional source node based on several information and deliver data packets for the original source node and the selected additional source node. The proposed scheme improves performance and provides fairness among source nodes. Performance of the proposed scheme is investigated by simulation. Our results show that the proposed scheme outperforms the previous protocol in terms of fairness index and throughput.