• 제목/요약/키워드: density character

검색결과 134건 처리시간 0.03초

도시교통체계와 에너지효율성의 관계분석 (Relationships between Urban Transportation System and Energy Efficiency)

  • 신용은;강민우;임미
    • 대한교통학회지
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    • 제28권2호
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    • pp.161-169
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    • 2010
  • 도시교통체계에 의한 에너지소비는 교통체계 자체의 특성 뿐 아니라 도시의 공간구조에도 크게 영향을 받는다. 그러나 현재까지 이와 같은 주제에 관한 연구가 매우 미미한 실정이다. 본 연구는 도시의 공간적 특성과 교통체계의 특성을 동시에 고려하고 교통 에너지 소비에 영향을 미치는 요소와 요소 간 관계 분석에 주목적을 둔다. 이를 위해 도시와 교통체계가 지닌 주요 특성을 기반으로 도시모형을 구축하여 교통체계에 의한 에너지 소비 산정식을 도출하였다. 도출된 모형과 산정식을 기반으로 에너지 소비량과 통행거리, 에너지계수 및 수단분담율이 에너지 소비에 미치는 영향을 수치적 민감도 분석을 시행하여 파악하였다. 그 결과 교통에너지 소비에 미치는 영향력으로 수단분담율이 가장 큰 것으로 파악되었으며, 또한 주거 및 고용밀도와 기술발전에 따른 에너지효율성도 에너지 소비량에 매우 민감한 변수로 파악되었다.

불규칙 조명 환경에 강인한 번호판 문자 분리 기법 (Robust Scheme of Segmenting Characters of License Plate on Irregular Illumination Condition)

  • 김병현;한영준;한헌수
    • 한국컴퓨터정보학회논문지
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    • 제14권11호
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    • pp.61-71
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    • 2009
  • 자동차의 번호판은 차량의 등록 정보를 확인할 수 있는 유일한 방법이다. 불법 주정차 단속 및 주차 관리 시스템에 차량의 등록 정보를 확인하기 위해 카메라를 이용한 무인 인식시스템의 개발이 활발히 연구되고 있다. 하지만, 일반 도로상에서 날씨나 주변 장애물들은 자동차 번호판 상에 조명 변화를 일으켜 번호판 문자의 추출을 어렵게 한다. 본 논문은 번호판 영상을 개선하여 조명변화에 강인한 문자 추출 알고리즘을 제안한다. 제안하는 기법은 번호판 영상의 명암 대비도를 높이기 위해 Chi-Square 확률 밀도 함수를 이용한다. 또한, 정확한 문자영역을 추출하기 위해, 적응적인 문턱값을 적용함으로써 고품질의 이진화 영상을 얻는다. 번호판의 문자들을 추출하는 일련의 과정에서 방해가 되는 잡음들을 전처리와 레이블링을 통해 제거한다. 마지막으로 번호판의 문자들은 번호판의 기하학적 특징을 이용한 이진화 영상의 프로파일링으로부터 추출된다.

벼 기계이앙 소비재배시 적정 재식밀도 구명 (Optimum Planting Density in Low Fertilizing Culture of Machine Transplanting in Rice)

  • 최원영;문상훈;박홍규;최민규;김상수;김정곤
    • 한국작물학회지
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    • 제51권5호
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    • pp.379-385
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    • 2006
  • 가. 재식밀도가 높을수록 주당 경수는 적었으나 단위면적 당 경수는 많았으며, 엽면적지수가 높았고, 지상부건물중도 무거웠다. 나. 재식밀도와 질소시비량간에는 출수기 차이는 없었고, 품종간에는 소비벼는 8월 8일, 남평벼는 8월 14일이었다. 다. 도복관련 형질은 질소시비량이 많고 재식밀도가 높을수록 도복지수가 높았으며, 절간장은 질소시비량이 많을수록 컸으며 품종간에는 소비벼가 $1{\sim}3$절간은 컸으며 $4{\sim}5$절간은 남평벼가 컸고 그 차이는 N9 kg/10a 시용구에서 더컸다. 라. $m^{2}$당 수수는 시비량에 관계없이 재식밀도가 높을수록 많은 경향이었으며, 쌀수량은 6 kg/10a의 질소 수준에서는 소비벼는 90주, 남평벼는 80주가 많았으며, 9 kg10a 질소수준에서는 소비벼는 100주, 남평벼는 110주에서 많았다. 마. 현미의 완전미 비율은 재식밀도가 낮을수록 높았으며, 질소시비량간에는 두품종 모두 6 kg/10a 시용구가 9kg/10a 시용구보다 높았다.

Theoretical Studies on Electronic Structure and Absorption Spectrum of Prototypical Technetium-Diphosphonate Complex 99mTc-MDP

  • Qiu, Ling;Lin, Jian-Guo;Gong, Xue-Dong;Ju, Xue-Hai;Luo, Shi-Neng
    • Bulletin of the Korean Chemical Society
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    • 제32권7호
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    • pp.2358-2368
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    • 2011
  • Density functional theory (DFT) and time-dependent density functional theory (TDDFT) calculations, employing the B3LYP method and the LANL2DZ, 6-31G$^*$(LANL2DZ for Tc), 6-31G$^*$(cc-pVDZ-pp for Tc) and DGDZVP basis sets, have been performed to investigate the electronic structures and absorption spectra of the technetium-99m-labeled methylenediphosphonate ($^{99m}Tc$-MDP) complex of the simplest diphosphonate ligand. The bonding situations and natural bond orbital compositions were studied by the Mulliken population analysis (MPA) and natural bond orbital (NBO) analysis. The results indicate that the ${\sigma}$ and ${\pi}$ contributions to the Tc-O bonds are strongly polarized towards the oxygen atoms and the ionic contribution to the Tc-O bonding is larger than the covalent contribution. The electronic transitions investigated by TDDFT calculations and molecular orbital analyses show that the origin of all absorption bands is ascribed to the ligand-to-metal charge transfer (LMCT) character. The solvent effect on the electronic structures and absorption spectra has also been studied by performing DFT and TDDFT calculations at the B3LYP/6-31G$^*$(cc-pVDZ-pp for Tc) level with the integral equation formalism polarized continuum model (IEFPCM) in different media. It is found that the absorption spectra display blue shift in different extents with the increase of solvent polarity.

A first-principles theoretical investigation of the structural, electronic and magnetic properties of cubic thorium carbonitrides ThCxN(1-x)

  • Siddique, Muhammad;Rahman, Amin Ur;Iqbal, Azmat;Azam, Sikander
    • Nuclear Engineering and Technology
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    • 제51권5호
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    • pp.1373-1380
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    • 2019
  • Besides promising implications as fertile nuclear materials, thorium carbonitrides are of great interest owing to their peculiar physical and chemical properties, such as high density, high melting point, good thermal conductivity. This paper reports first-principles simulation results on the structural, electronic and magnetic properties of cubic thorium carbonitrides $ThC_xN_{(1-x)}$ (X = 0.03125, 0.0625, 0.09375, 0.125, 0.15625) employing formalism of density-functional-theory. For the simulation of physical properties, we incorporated full-potential linearized augmented plane-wave (FPLAPW) method while the exchange-correlation potential terms in Kohn-Sham Equation (KSE) are treated within Generalized-Gradient-Approximation (GGA) in conjunction with Perdew-Bruke-Ernzerhof (PBE) correction. The structural parameters were calculated by fitting total energy into the Murnaghan's equation of state. The lattice constants, bulk moduli, total energy, electronic band structure and spin magnetic moments of the compounds show dependence on the C/N concentration ratio. The electronic and magnetic properties have revealed non-magnetic but metallic character of the compounds. The main contribution to density of states at the Fermi level stems from the comparable spectral intensity of Th (6d+5f) and (C+N) 2p states. In comparison with spin magnetic moments of ThSb and ThBi calculated earlier with LDA+U approach, we observed an enhancement in the spin magnetic moments after carbon-doping into ThN monopnictide.

해역에서의 지형성 저열효과를 고려한 성층유동 수치모델에 관한 연구 (A Study on the Numerical Model of Current of Strafication Considering the Topographic Heat Accumulation Effect in the Coastal Area)

  • 윤종성;김명규;한동진;김가야
    • 한국해양공학회지
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    • 제22권5호
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    • pp.61-68
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    • 2008
  • In Jinhae-Masan bay, a typical semi-dosed bay in Korea, the water quality is severely deteriorated because of the dosed topographic character and the inflow of nutrients from the land. There have been attempts to apply a water quality model dealing with the entrophication phenomenon and the oxygen-deficient mass in the bay in summer, but there have been few examples of models that have considered the phenomenon of stratification in the proper order, and then it is performed the model of water quality. Therefore, this study collected and analyzed the pre-observed water temperature data from Jinhae-Masan bay in summer and then constructed a density model using the topographic heat accumulation effect and inflow from the river to examine the temperature stratification. The simulation results show that this model could demonstrate the temperature stratification in the Jinhae-Masan bay very well.

Microbial linguistics: perspectives and applications of microbial cell-to-cell communication

  • Mitchell, Robert J.;Lee, Sung-Kuk;Kim, Tae-Sung;Ghim, Cheol-Min
    • BMB Reports
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    • 제44권1호
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    • pp.1-10
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    • 2011
  • Inter-cellular communication via diffusible small molecules is a defining character not only of multicellular forms of life but also of single-celled organisms. A large number of bacterial genes are regulated by the change of chemical milieu mediated by the local population density of its own species or others. The cell density-dependent "autoinducer" molecules regulate the expression of those genes involved in genetic competence, biofilm formation and persistence, virulence, sporulation, bioluminescence, antibiotic production, and many others. Recent innovations in recombinant DNA technology and micro-/nano-fluidics systems render the genetic circuitry responsible for cell-to-cell communication feasible to and malleable via synthetic biological approaches. Here we review the current understanding of the molecular biology of bacterial intercellular communication and the novel experimental protocols and platforms used to investigate this phenomenon. A particular emphasis is given to the genetic regulatory circuits that provide the standard building blocks which constitute the syntax of the biochemical communication network. Thus, this review gives focus to the engineering principles necessary for rewiring bacterial chemo-communication for various applications, ranging from population-level gene expression control to the study of host-pathogen interactions.

요소.포름알데히드 수지가공 셀룰로오스계 직물의 열특성 (The Thermal Characteristics of Cellulose Fabrics Finished with Urea-Formaldehyde Resin)

  • Song, Wha Soon
    • 한국염색가공학회지
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    • 제5권4호
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    • pp.79-91
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    • 1993
  • The purpose of this study is to prepare the newer, more comfortable of urea-formaldehyde resin finished fabrics. The methods of this study are by making examinations and comparisons the relations between the thickness, fabrics counts, weight, moisture regain and crease recovery of cotton and viscose rayon fabrics caused by condition of urea-formaldehyde resin finishing and warm retaining ability and warm-cool sense. The analytic results of thermal character in state of fabrics material finished with urea-formaldehyde are as follows: 1. The warm retaining ability has no correlation with mixing ratio of resin but the increase of the warm retaining ability has correlation with the increase of concentration of urea-formaldehyde resin. 2. The result pf multiple regression analysis for effect of physical property according to the concentration of resin to the warm retaining ability revealed as below. As the weight, thickness and density increase and moisture regain decreases, the warm retaining ability increases. 3. The qmax value has no correlation with mixing ratio of resin but the increase of the qmax value has correlation with the increase of resin concentration. In the end, the effect of it promotes cool sense. 4. The result of multiple regression analysis for effect of physical property according to the concentration of resin to the qmax value revealed as below. As he weight and thickness increase, the qmax value decrease. But, as the density and crease recovery increase, the qmax value increase.

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Efficiency Estimation of Toxicity Free Eire Resistance Cable

  • Yoon, Hun-Ju;Hon, Jin-Woong
    • Transactions on Electrical and Electronic Materials
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    • 제3권3호
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    • pp.34-38
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    • 2002
  • In this paper, efficiency estimation of toxicity fee fire resistance cable experiments was measured smoke density of toxicity free fire resistance polyolefin insulation material and electric field dependence of tree shape in low density polyethylene (LDPE). One of the most serious causes of failure in high-voltage cables, can be an electrical discharge across an internal gab or void in the insulating material. Treeing due to partial discharge is one of the main causes of breakdown in the insulating materials and reduction of the insulation life. Therefore the necessity for establishing a method to diagnose the aging of insulation materials and to predict the breakdown of insulation and research of the fire resistance character has become important. First, we have studied on electric field dependence of tree shape in LDPE about treeing phenomena occurring on the high electrical field. Second, the measurement method is the attenuation quantity of irradiation by smoke accumulating with in a closed chamber due to non-flaming heat decomposition and flaming combustion. A main cause of fire-growth and generating toxic gas when, it bums, should be dealt with great care in life. safety design. The fire gases were occurred carbon monoxide and decomposition than in polyolefin due to incomplete combustion of PVC, which has high content of carbon in chemical compound.

바둑돌부전나비(Taraka hamada)의 야외 생태학적 특성 조사 (A ecological survey of Taraka hamada (Druce) (Lepidoptera, Lycaenidae) in Korea)

  • 이영보;박해철;한태만;김성현;김남정
    • 한국잠사곤충학회지
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    • 제52권1호
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    • pp.16-24
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    • 2014
  • 2010년부터 2012년까지 전국 각지 야외에서 조사한 바둑돌부전나비의 생태학적 특성은 다음과 같다. 1. 이대에 서식하는 일본납작진딧물은 바둑돌부전나비 유충의 먹이로서 지표로부터 폭넓게 분포하였으며, 조사 8회 차인 6월 13일부터 밀도가 현저히 감소하였다. 2. 일본납작진딧물과 바둑돌부전나비가 가장 많은 밀도를 보이는 곳은 줄기와 가장 인접한 부위이었다. 3. 바둑돌부전나비의 유충 예상 령수는 4령으로 추측된다. 4. 바둑돌부전나비 성충의 야외 노출 시 생존시간 조사 결과, 2분 이내에 사망하는 것으로 조사 되었다.