• Title/Summary/Keyword: spreading factor

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QoS Analysis of Wireless Sensor Network with ARQ Scheme (ARQ 방식을 적용한 무선 센서 네트워크의 QoS 해석)

  • Roh, Jae-Sung;Kim, Wan-Tae
    • Journal of Advanced Navigation Technology
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    • v.14 no.1
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    • pp.49-56
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    • 2010
  • Severe energy constraints and the low power consumption require the significance of the energy efficient error control mechanisms in wireless sensor network (WSN). In this paper, an automatic repeat request (ARQ) methodology for the analysis of error control schemes in WSN is presented such that the effects of packet length, the modulation scheme and the interference effect of the wireless channel are investigated. Moreover, an analyis of ARQ error control is provided by considering two major architectures for wireless sensor network, i.e., Mica2 and MicaZ sensor nodes. And the throughput performance of WSN with asynchronous FSK signal and DSSS-OQPSK signal with selective repeat ARQ scheme are analyzed in multiple interference environment, and the probability of receiving a correct bit and packet from target node to sink node is evaluated as a function of the channel parameter, the number of wireless sensor node, and the spreading factor.

A Study on the Impact of Cosmetics Blog Information Characteristics on credibility in the Process of Word of Mouth Acceptance and Word of Mouth Effect (화장품 블로그의 정보특성이 구전수용과정의 신뢰와 구전효과에 미치는 영향)

  • Park, Jeong-Mi;Hwang, Sun-Jin
    • Journal of the Korean Society of Costume
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    • v.62 no.2
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    • pp.13-25
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    • 2012
  • The purpose of this research is to study the influence over confidence and Word-Of-Mouth (WOM) effect in the acceptance process of WOM by information characteristics(consensus, vividness, and message neutrality) of individual cosmetic blog, reflecting that it is widely spreading over the public. Online survey for the consumers using such blogs was performed to collect data(N=200), and credibility analysis through Cronbach-${\alpha}$ and Structural Equation Model(SEM) analysis using AMOS 18.0 were performed. The analysis results are as follows; First, vivid information and neutral message increase WOM effect through the improvement of consumers' credibility whereas information consensus doesn't positively influence over credibility. Second, the examination of a moderating effect by type of cosmetics demonstrated that the consumers of basic cosmetics have most confidence in vivid information, and those of color cosmetics do more confidence in neutral message. Therefore, there is a difference in the credibility factor of online WOM depending on the type of cosmetics consumption so that differentiated information provision strategies for cosmetics groups should be established based on it.

Effective Screening of Antagonist for the Biological Control of Soilborne Infectious Disease (Damping-Off)

  • LEE BAEK-SEOK;LEE HYANG-BOK;CHOI SUNG-WON;YUN HYUN-SHIK;KIM EUN-KI
    • Journal of Microbiology and Biotechnology
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    • v.15 no.4
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    • pp.701-709
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    • 2005
  • An efficient method of selecting an antagonistic strain for use as a biological control agent strain was developed. In this improved method, the surface tension reduction potential of an isolate was included in the 'decision factor,' in addition to two other factors; the growth rate and pathogen inhibition. By using a statistically designed method, an isolate from the soil was selected and identified as Bacillus sp. GB 16. In the pot test, this strain showed the best performance among the isolated strains. The lowest disease incidence rate and fastest seed growth were observed when the Bacillus sp. GB 16 was used. The action of the surface tension reducing component was assumed to enhance the wetting, spreading, and residing of the antagonistic strain in the rhizosphere. This result showed that the improved selection method was quite effective in selecting the best antagonistic strain for the biological control of soilborne infectious plant pathogens.

An Analysis of Operating Experience Reports on the Foreign JIT (해외 JIT에 수록된 운전경험 분석)

  • Lee, Sang-Hoon;Kim, Jae-Hun;Song, Tae-Young
    • Transactions of the Korean Society of Pressure Vessels and Piping
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    • v.10 no.1
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    • pp.70-74
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    • 2014
  • An Operating Experience Report(OER) has written about events and accidents happened at a Nuclear Power Plant(NPP). The purpose of publishing the OER is to prevent the similar event or accident repeatedly by spreading the experience of a single plant to other plants personnel. In this paper, it is analyses that the foreign NPPs' OERs on JIT published by the International Nuclear Agency(WANO, INPO, COG, BE). The analysis introduced in this paper is performed along with the various factors such as type of work, root-cause, and equipment. The root-cause analysis about the OERs shows that the Human-error is the major factor in foreign NPPs, but on the other hand equipment problem is the main part of the Domestic NPPs. The ratio of the foreign NPP's OERs on JIT according to the type of work was applied to KHNP-JIT developed nowadays for the first time in KOREA.

An Analysis of Operating Experience Reports Published in the Domestic Nuclear Power Plants for Resent 5 Years (최근 5년간 국내원전 운전경험보고서 분석)

  • Lee, Sang-Hoon;Kim, Je-Hun;Hur, Nam-Young
    • Transactions of the Korean Society of Pressure Vessels and Piping
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    • v.9 no.1
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    • pp.35-39
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    • 2013
  • The Operating Experience Report(OER) has written about the event and accident happened at a Nuclear Power Plant(NPP). The purpose of publishing the OER is to prevent the similar event or accident repeatedly by spreading the experience of a single plant to other plants personnel. Before initiating the analysis mentioned in this paper, 2,298 review reports for the same number of OER published from 2007 to June 2012 have been written to achieve the correct and objective statistics. The analysis introduced in this paper is performed with the various factors such as year, plant type, equipment, type of work, root-cause. The root-cause analysis is showed that the equipment problem is the major factor in domestic NPPs, but on the other hand human-error is the main part of the foreign NPPs. Moreover, while the number of the man-made event is decreasing, the equipment-made event is rapidly increasing in domestic NPPs.

Experimental Study on the Frost Resistance of Concete Product (콘크리트제품의 동결저항성에 관한 실험적 연구)

  • Sugawara, Takashi;Tsukinaga, Yhoichi;Lee, Sanghun
    • 한국방재학회:학술대회논문집
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    • 2011.02a
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    • pp.91-91
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    • 2011
  • The quality of the surface layer in concrete structures plays an important role in the durability of the concrete. The concrete factory products are made as they improve the appearance of the surface and compressive strength in need. A common criterion to judge the quality of concrete products frequently seen in our daily life appears to be "beauty" in terms of consistent shaping. However, as for most concrete curb in such areas where a large amount of anti-freezing agents(NaCl) and ice and snow melting agents(CaCl2) are spread over roads to ensure road safety during the winter season, since deterioration advances from the surface, scaling is seen on the surface concrete due to deterioration which combined freezing damage and salt damage. Especially, In cold northern districts, the spreading amount of deicing salts increases by regulation of studded tire use, and the scaling of the concrete products, the various parts of concrete structures for roads is increasing in recent years. In this study, L-shape concrete curb were targeted, the permeable form method with the commercial permeable sheet was applied to it and the improvements of the quality were examined. By the permeable form method, surface layers got strengthened, which prevented permeation of the deterioration factor from the outside, and the scaling resistance of the upper surface where the permeable sheet was applied improved exceedingly. It will be expected by applying the permeable form method to various concrete products that frost resistance improves and scaling damage decreases.

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Effect of Earthquake characteristics on seismic progressive collapse potential in steel moment resisting frame

  • Tavakoli, Hamid R.;Hasani, Amir H.
    • Earthquakes and Structures
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    • v.12 no.5
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    • pp.529-541
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    • 2017
  • According to the definition, progressive collapse could occur due to the initial partial failure of the structural members which by spreading to the adjacent members, could result in partial or overall collapse of the structure. Up to now, most researchers have investigated the progressive collapse due to explosion, fire or impact loads. But new research has shown that the seismic load could also be a factor for initiation of the progressive collapse. In this research, the progressive collapse capacity for the 5 and 15-story steel special moment resisting frames using push-down nonlinear static analysis, and nonlinear dynamic analysis under the gravity loads specified in the GSA Guidelines, were studied. After identifying the critical members, in order to investigate the seismic progressive collapse, the 5-story steel special moment resisting frame was analyzed by the nonlinear time history analysis under the effect of earthquakes with different characteristics. In order to account for the initial damage, one of the critical columns was weakened at the initiation of the earthquake or its Peak Ground Acceleration (PGA). The results of progressive collapse analyses showed that the potential of progressive collapse is considerably dependent upon location of the removed column and the number of stories, also the results of seismic progressive collapse showed that the dynamic response of column removal under the seismic load is completely dependent on earthquake characteristics like Arias intensity, PGA and earthquake frequency contents.

Interference Suppression Based on Code Grouping and Groupwise Decorrelation in W-CDMA Downlink (코드그룹화와 그룹단위 역상관을 이용한 W-CDMA 하향링크에서의 다중사용자 간섭억압기법)

  • Ha, Won;Bae, Jung-Hwa;Lim, Byun-Chun;Park, Jin-Woo
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.29 no.6A
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    • pp.631-639
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    • 2004
  • In this paper, we presented a new interference suppression method based on code grouping and groupwise decorrelation for multirate DS-CDMA downlink. The code grouping is accomplished according to the correlation property between the mother code and the child codes in OVSF code tree. Using groupwise decorrelation, the proposed receiver has relatively low computational complexity and does not require any information about interference users, such as code, data, and amplitude. From the simulation results in multipath channels, the proposed receiver is to provide significant performance enhancement.

Effects of Natural Selection, Mutagenesis, and Protoplast Formation and Cell Wall Regeneration on the Production of Aminoglycoside Antibiotics

  • Goo, Yang-Mo;Lim, Hyon-Joo;Lim, Seok-Ran;Kim, Kong-Hwan;Lim, Bun-Sam;Lee, Sae-Bae
    • Archives of Pharmacal Research
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    • v.12 no.4
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    • pp.249-253
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    • 1989
  • High producers or blocked mutants of aminoglycoside antibiotic-producing Streptomyces spp. were selected by application of an agar plug method and by culturing individual colonies in broth. The productivities of aminoglycoside antibiotic producing organisms were increased by selection of a high producer from colonies obtained by spreading spores of wild strain, or survived from treatment of a mutagen or from the colonies regenerated from protoplast-formation and cell-wall regenerations. Some mutagen treated colonies lost the ability to produce antibiotics (5-8%). Some A-factor negative and deostreptamine or streptidine negative mutants were obtained by N-methyl-N'-nitro-N-nitrosomethylguanidine (MNNG) treatment. Many of the survivors from the MNNG treatment lost the ability to produce antibiotics. Major colonies produced less amount of antibiotics ; only few survived colonies produced more antibiotics than the parent. Resistance of Streptomyces spp. against the antibiotics produced by itself was also markedly affected by mutagen treatment.

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Systematic Elicitation of Proximity for Context Management

  • Kim Chang-Suk;Lee Sang-Yong;Son Dong-Cheul
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.6 no.2
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    • pp.167-172
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    • 2006
  • As ubiquitous devices are fast spreading, the communication problem between humans and these devices is on the rise. The use of context is important in interactive application such as handhold and ubiquitous computing. Context is not crisp data, so it is necessary to introduce the fuzzy concept. The proxity relation is represented by the degree of closeness or similarity between data objects of a scalar domain. A context manager of context-awareness system evaluates imprecise queries with the proximity relations. in this paper, a systematic proximity elicitation method are proposed. The proposed generation method is simple and systematic. It is based on the well-known fuzzy set theory and applicable to the real world applications because it has tuning parameter and weighting factor. The proposed representations of proximity relation is more efficient than the ordinary matrix representation since it reflects some properties of a proximity relation to save space. We show an experiments of quantitative calculate for the proximity relation. And we analyze the time complexity and the space occupancy of the proposed representation method.