• 제목/요약/키워드: natural selection

검색결과 1,016건 처리시간 0.034초

A Note on Smoothing Distribution Function Estimation

  • Chu, In-Sun;Choi, Jae-Ryong
    • Communications for Statistical Applications and Methods
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    • 제4권3호
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    • pp.911-915
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    • 1997
  • The purpose of this paper is to consider the problem of selection of optimal smoothing parameter for kernel-type distribution function estimator, which asymptotically minimizes mean Hellinger distance.

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IT 제안서의 기술평가에서의 퍼지 TOPSIS 응용 (An Application of fuzzy TOPSIS in evaluating IT proposals)

  • 정기호
    • 디지털산업정보학회논문지
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    • 제13권1호
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    • pp.197-211
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    • 2017
  • In recent years, it is natural that the development and the maintenance of information systems are strongly dependent on outside service providers for economic reasons, especially in public sector. There has been an unexpected growth in the number of selection activities for outsourcing related works. At this time, selection of the contractor generally considers the proposals received based on the RFP(requested for proposal) and determines the ranking by experts committee. However, it is difficult even for expert giving a specific numeric score in weighting criteria or rating alternatives. In this context, an extended fuzzy TOPSIS method is applied for selection problem of IT proposals. A numerical illustration is also provided to demonstrate the applicability of the approach. This approach is very practical to help decision makers in assessing proposals during the selection phase under uncertainties.

웰빙 트랜드가 메뉴 선택에 미치는 영향에 관한 연구 (A Study on the Effects of Well-being Trend on Menu Selection Behavior)

  • 박근한;박헌진;정진우
    • 한국조리학회지
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    • 제14권3호
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    • pp.45-57
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    • 2008
  • The purpose of this study is to initiate a systematic approach to maximize profits through continuous development of menu and build a strong image of Western restaurants located inside hotels by identifying their guests' knowledge and concern and menu selection behavior in well being trend. Findings from the analysis are as follows. First, among the Western menu selection behavior, organic grain and seafood, seasonal event menu, less spicy and more natural cooking methods are favored as the most important consideration. Second, customers' knowledge and concern in well being trend and menu selection behavior were found to be statistically significant. Third, customers' awareness in health and obesity were found to be statistically significant to the concern in well being trend. Fourth, demographical characteristics of customers such as gender, marital status, age, income level and education were tested for their relationships with knowledge and concern in well being trend.

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Digital Shade Analysis System을 이용한 전치부의 색조 특성에 관한 연구 (SHADE ANALYSIS OF ANTERIOR TEETH USING DIGITAL SHADE ANALYSIS SYSTEM)

  • 김희은;조인호;임주환;임헌송
    • 대한치과보철학회지
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    • 제41권5호
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    • pp.565-581
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    • 2003
  • Statement of problem : A scientific examination and understanding of overall aspects of the natural dentition is the first step involved in making a satisfactory selection in the shade of an aesthetic prosthesis. Proper natural shade selection of the prosthetic restoration that is in harmony with the remaining dentition is as important aesthetically, as harmony of form and function in the anterior dentition. Clinically, the most commonly applied method of shade selection has been visual, but because of the subjective nature inherent to this method, shade selection results are variable and can be influenced by such factors as the technician, the type of shade guide used, and the type and intensity of the lighting. Purpose : The purpose of this study was to develop a more objective and scientific approach to examining and understanding the shade of teeth, which has in turn lead to the development of a number of shade analysis devices that present a more objective method of shade analysis. Material and Method : In this study, the shades of healthy anterior teeth were examined and analyzed using the recently developed digital shade analysis of the $ShadeScan^{TM}$ System. The study examined 80 individuals in their twenties, 40 males and 40 females, presenting 6 healthy, unrestored maxillary anterior teeth. Tooth brushing and oral prophylaxis were performed prior to evaluation. The ShadeScan handpiece was used to acquire images of the 6 maxillary anterior teeth. These images were analyzed using the Vita/Classical mode of the $ShadeScan^{TM}$ Software, and shade maps of each tooth were acquired and divided into cervical, middle, and incisal thirds. The shade distribution of each third, left and right symmetry, and gender differences were investigated and analyzed. Results : The results of the study are as follows : 1. An overwhelming majority of the examined teeth were found to possess shades belong to Group A, with the greatest variations occurring at the middle and cervical thirds of the maxillary central and lateral incisors, in both male and female subjects. 2. Canines of both male and female subjects showed left and right symmetry with uniform shade distribution of A4 and C4, while the lateral and central incisors showed left-right symmetry of the incisal 1/3 with a uniform shade distribution of A2 and A3 shades 3. No significant differences in shade distribution were seen between genders in maxillary canines, whereas maxillary central and lateral incisors showed differences at the middle and cervical thirds between male and female subjects The results of this study show that with the exception of maxillary canines, maxillary anterior teeth display a diverse shade distribution as well as gender differences. Conclusion : Clinically, when making a shade selection using the existing shade guide, one must consider the fact that even a single tooth consists of a variety of shades. The results of this study show that when selecting a shade from a number of groups is difficult, shades from A group are the most consistent with the natural shade or maxillary anterior teeth.

Control Effect of Stenotrophomonas maltophilia BW-13 strain to the lettuce Bottom rot

  • Park, Jong-Young;Kim, Hyun-Ju;Bak, Joung-Woo;Lee, Kwang-Youll;Jun, Ok-Ju;Lee, Jin-Woo;Jung, Soon-Je;Moon, Byung-Ju
    • 한국식물병리학회:학술대회논문집
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    • 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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    • pp.103.1-103
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    • 2003
  • An antagonistic bacteria, Stenotrophomonas maitophilia BW-13 strain which was effectively inhibited mycerial growth of Bottom rot pathogen, Rhizoctonia solani PY-1 strain was isolated from the rhizosphere of the lettuce in Uiryeong-Gun, Gyeongsangnam-Do from 2002 to 2003. For the biological control, the most suitable inoculum and its density of pathogen, PY-1 strain ware tested prior biological control test, For the pathogenicity test, A inoculum (wheat bran)sawdust+rice bran+PDB) showing disease incidence of 100% was selected as the most suitable inoculum, which showed more effective than B inoculum (sawdust+rice bran+DW) and mycelial disc. also, In selection of the amount of inoculum (40g, 50g, 60g, 70g, 80g), most suitable amount of inoculum of pathogen determined as 40g showing disease incidence of 80%. For the selection of effective microorganism to control bottom rot on lettuce, about 200 isolates were isolated from the diseased soil and lettuce leaves, and examined their antifungal activity to the pathogen on PDA. As the pots assay, BW-13 strain showed the highest control value as 90%, and followed by R-13 and R-26 strain as 80% and 60%, respectively. Selected BW-13 isolates identified as 5. maltophilia (GeneBank accession no. AJ293473.1, 99%) by 16S rRNA sequencing. This is the first report on the biological control using by S. maltophilia to the bottom rot pathogen, Rhizoctonia solani PY-1 strain.

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Candidate Path Selection Method for TCP Performance Improvement in Fixed Robust Routing

  • Fukushima, Yukinobu;Matsumura, Takashi;Urushibara, Kazutaka;Yokohira, Tokumi
    • IEIE Transactions on Smart Processing and Computing
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    • 제5권6호
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    • pp.445-453
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    • 2016
  • Fixed robust routing is attracting attention as routing that achieves high robustness against changes in traffic patterns without conducting traffic measurement and performing dynamic route changes. Fixed robust routing minimizes the worst-case maximum link load by distributing traffic of every source-destination (s-d) router pair onto multiple candidate paths (multipath routing). Multipath routing, however, can result in performance degradation of Transmission Control Protocol (TCP) because of frequent out-of-order packet arrivals. In this paper, we first investigate the influence of multipath routing on TCP performance under fixed robust routing with a simulation using ns-2. The simulation results clarify that TCP throughput greatly degrades with multipath routing. We next propose a candidate path selection method to improve TCP throughput while suppressing the worst-case maximum link load to less than the allowed level under fixed robust routing. The method selects a single candidate path for each of a predetermined ratio of s-d router pairs in order to avoid TCP performance degradation, and it selects multiple candidate paths for each of the other router pairs in order to suppress the worst-case maximum link load. Numerical examples show that, provided the worst-case maximum link load is less than 1.0, our proposed method achieves about six times the TCP throughput as the original fixed robust routing.

THE INFRARED MEDIUM-DEEP SURVEY. V. A NEW SELECTION STRATEGY FOR QUASARS AT z > 5 BASED ON MEDIUM-BAND OBSERVATIONS WITH SQUEAN

  • JEON, YISEUL;IM, MYUNGSHIN;PAK, SOOJONG;HYUN, MINHEE;KIM, SANGHYUK;KIM, YONGJUNG;LEE, HYE-IN;PARK, WOOJIN
    • 천문학회지
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    • 제49권1호
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    • pp.25-35
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    • 2016
  • Multiple color selection techniques are successful in identifying quasars from wide-field broadband imaging survey data. Among the quasars that have been discovered so far, however, there is a redshift gap at 5 ≲ z ≲ 5.7 due to the limitations of filter sets in previous studies. In this work, we present a new selection technique of high redshift quasars using a sequence of medium-band filters: nine filters with central wavelengths from 625 to 1025 nm and bandwidths of 50 nm. Photometry with these medium-bands traces the spectral energy distribution (SED) of a source, similar to spectroscopy with resolution R ~ 15. By conducting medium-band observations of high redshift quasars at 4.7 ≤ z ≤ 6.0 and brown dwarfs (the main contaminants in high redshift quasar selection) using the SED camera for QUasars in EArly uNiverse (SQUEAN) on the 2.1-m telescope at the McDonald Observatory, we show that these medium-band filters are superior to multi-color broad-band color section in separating high redshift quasars from brown dwarfs. In addition, we show that redshifts of high redshift quasars can be determined to an accuracy of Δz/(1 + z) = 0.002 - 0.026. The selection technique can be extended to z ~ 7, suggesting that the medium-band observation can be powerful in identifying quasars even at the re-ionization epoch.

Raman Spectroscopic Study of Benzonitrile on Silver Surface

  • Boo, Doo-Wan;Kim, Kwan;Kim, Myung-Soo
    • Bulletin of the Korean Chemical Society
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    • 제8권4호
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    • pp.251-254
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    • 1987
  • The surface-enhanced Raman scattering(SERS) of benzonitrile in a silver sol was investigated. It was concluded that the molecule adsorbed onto the silver surface via the nitrogen lone pair electrons. Using the surface selection rule, the orientation of the benzene ring with respect to the surface plane could not be determined conclusively. However, it seemed likely that benzonitrile is adsorbed edge-on to the surface. It was demonstrated that the SERS technique provides a useful method for detailed characterization of the chemisorbed layer.

의복구매동기와 의복구매행동에 대한 연구-여대생을 중심으로 (A Study on Clothing Buying Motive and Clothing Buying Behavior)

  • 박혜선;권정문;김천유;이한구;최헌수
    • 자연과학논문집
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    • 제9권1호
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    • pp.131-143
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    • 1997
  • 본 연구는 서울 및 대전에 거주하는 20대 초반 여대생 352명을 대상으로 의복구매동기와 의복구매행동을 연구하였다. 여대생들의 의복구매동기를 요인분석한 결과, 유행 및 개성추구요인, 경제적요인, 지위요인, 광고 및 충동구매요인등 4개요인으로 분류되었으며, 여대생들의 의복구매행동을 요인분석한 결과, 정보원사용요인은 인적요인, 전파요인, 광고 및 관찰정보요인 3개 요인으로, 의복선택기준은 실용성요인, 디자인요인, 마케팅요인, 유행 및 지위요인등 4개요인으로, 점포선택기준은 상품요인, 서비스요인, 2개 요인으로 분류되었다. 또한 의복구매동기와 의복구매행동 상호간에서 상관이 있는 것으로 나타났으며, 용돈과 전공에 따라서도 의복구매동기와 의복구매행동에 차이가 있는 것으로 나타났다.

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생물다양성 증진을 위한 유휴농경지의 습지 복원 적지선정에 관한 연구 - 군포시 반월천 유역 사례로 - (Wetland Restoration Site Selection for Promoting Biodiversity in Abandoned Rice Paddy Fields - Focusing on Gounpo Ban-wol Stream Watershed -)

  • 임유라;김귀곤
    • 한국환경복원기술학회지
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    • 제12권1호
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    • pp.52-66
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    • 2009
  • The increase of rice productivity, the decrease of rice demand, aging farmers, and the market-opening of rice along with the domestic and international conditions changes have been led to the increase of the abandoned rice paddy fields. Such abandoned rice paddy fields have been left in many areas and most of them have become wetlands. The purpose of this study is methodology of selection to the wetland for development in the abandoned rice paddy fields along with surroundings. The selection of habitat suitability index assessment study to conservation and restoration was done through hydrology, wild animals habitation, wetland vegetation, outside disturbance, and natural purification capacity assessment. In addition, the same method was applied to assessment items and standards for both the restoration site selection and the type of restoration. Both assessment items and standards were applied to the sites, drawn on the maps, and overlayer for the comprehensive map, and then the wetland suitability index was applied to the suitable site. The development technique was applied to 10 sites near the Banwol Stream watershed in Gunpo, Gyeonggi province. The selection of conservation, restoration, and the optimal sites can lead to not only the biodiveristy increase in agricultural or semi natural areas but also to the establishment of ecological networks in national level.