• 제목/요약/키워드: Hole finding

검색결과 61건 처리시간 0.025초

The black hole mass-stellar velocity relation of the present-day active galaxies

  • 우종학
    • 천문학회보
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    • 제35권1호
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    • pp.79-79
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    • 2010
  • To investigate whether the present-day active galaxies follow the same black hole mass vs. stellar velocity dispersion (MBH-$\sigma*$) relation as quiescent galaxies, we measured the velocity dispersions of a sample of local Seyfert 1 galaxies, for which black hole masses were measured via reverberation mapping. We measured stellar velocity dispersions from high S/N optical spectra centered on the Ca II triplet region (${\sim}8500^{\circ}A$), obtained at the Keck, Palomar, and Lick Observatories. For two objects, in which the Ca II triplet region was contaminated by nuclear emission, we used high-quality H-band spectra obtained with the OH-Suppressing Infrared Imaging Spectrograph and laser-guide star adaptive optics at the Keck-II Telescope. Combining our new measurements with data from the literature, we assemble a sample of 24 active galaxies with stellar velocity dispersions and reverberation MBH in the range of black hole mass 106< MBH /$M{\odot}$ < 109,toobtainthefirstreverberationmappingconstraintsontheslopeandintrinsicscatteroftheMBH- $\sigma*$ relation of active galaxies. Assuming a constant virial coefficient f for the reverberation MBH, we find a slope ${\beta}=3.55{\pm}0.60$ and the intrinsic scatter ${\sigma}int=0.43{\pm}0.08$ dex in the relation log (MBH/M${\odot}$)=$\alpha+\beta$ log(${\sigma}*$/200 km s-1), which are consistent with those found for quiescent galaxies. We derive an updated value of the virial coefficient f by finding the value which places the reverberation masses in best agreement with the MBH - $\sigma*$ relation of quiescent galaxies; using the quiescent MBH - $\sigma*$ relation determined by Gultekin et al. we find log f=0.72+0.09 (or $0.71{\pm}0.10$) with an intrinsic scatter of $0.44{\pm}0.07$ (or 0.46+0.07) dex. No correlations between f and parameters connected to the physics of accretion (such as the Eddington ratio or line-shape measurements) are found. The uncertainty of the virial coefficient remains one of the main sources of the uncertainty in black hole mass determination using reverberation mapping, and therefore also in single-epoch spectroscopic estimates of black hole masses in active galaxies.

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Effect of Hole-Transporting Layer and Solvent in Solution Processed Highly-Efficient Small Molecule Organic Light-Emitting Diodes

  • Jo, Min-Jun;Hwang, Won-Tae;Chae, Hee-Yeop
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2012년도 제43회 하계 정기 학술대회 초록집
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    • pp.250-250
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    • 2012
  • Organic light-emitting diodes (OLED) and polymer light emitting diodes (PLED) have been regarded as the candidate for the next generation light source and flat panel display. Currently, the most common OLED industrial fabrication technology used in producing real products utilizes a fine shadow mask during the thermal evaporation of small molecule materials. However, due to high potential including low cost, easy process and scalability, various researches about solution process are progressed. Since polymer has some disadvantages such as short lifetime and difficulty of purifying, small molecule OLED (SMOLED) can be a good alternative. In this work, we have demonstrated high efficient solution-processed OLED with small molecule. We use CBP (4,4'-N,N'-dicarbazolebiphenyl) as a host doped with green dye (Ir(ppy)3 (fac-tris(2-phenyl pyridine) iridium)). PBD (2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole) and TPD (N,N'diphenyl-N,N'-Bis (3-methylphenyl)-[1,1-biphenyl]-4,4'-diamine) are employed as an electron transport material and a hole transport material. And TPBi (2,2',2''-(1,3,5-phenylene) tris (1-phenyl-1H-benzimidazole)) is used as an hole blocking layer for proper hole and electron balance. With adding evaporated TPBi layer, the current efficiency was very improved. Among various parameters, we observed the property of OLED device by changing the thickness of hole transporting layer and solvent which can dissolve organic material. We could make small molecule OLED device with finding proper conditions.

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전두골 결손 마우스 모델의 골형성 자동 분석 (Automatic Analysis of Bone Formation in a Mouse Model of Frontal Bone Defect)

  • 강선경;정성태
    • 한국멀티미디어학회논문지
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    • 제18권9호
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    • pp.997-1007
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    • 2015
  • In this paper, we propose a method for automatically analyzing the bone formation in a mouse model of frontal bone defect. We perforate two holes of 0.8mm diameter in the frontal bone and observe the bone formation process using a micro CT. Because the conventional analysis software of the micro CT does not support automatic analysis of the bone formation status, we have to use a manual analysis method. However the manual analysis is very cumbersome and requires a lot of time, we propose an automatic analysis method. It rotates the image around three axes directions so that the mouse's skull come into regular position. It calculates the cumulative image of the voxel values for the perforated bone surface. It estimates the hole location by finding the darkest point in the cumulative image. The proposed method was applied to 24 CT images of saline administration group and PTH administration group and hole location was estimated. BV/TV index was calculated for the estimated hole to evaluate the bone formation status. Experimental results showed that bone formation process is more active in PTH administration group. The method proposed in this paper could replace successfully the cumbersome and time consuming manual job.

Central nervous system depressant activity of Leucas aspera root

  • Rahman Shafiur;Sarder Mokaddez;Ali Yusuf;Rashid Abdur
    • Advances in Traditional Medicine
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    • 제6권3호
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    • pp.174-178
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    • 2006
  • The ethanolic extract of Leucas aspera root was studied for its effect on the central nervous system (CNS) using pentobarbitone induced sleeping time test, the open field test and the hole cross test in Swiss albino mice. The present investigation revealed that the extract at the doses of 250 and 500 mg/kg, significantly prolonged the pentobarbitone induced sleeping time in mice though the onset of sleep was delayed as compared to control. In open field test the depressing effect was prominent from the second observation period (30 min) and persisted throughout the entire experimental period (240 min). In the hole cross test, the depressing effect was observed significant from the third observation period (60 min) and persisted up to the seventh observation period (240 min) except at fourth observation (90 min) for 250 mg dose group and depressing effect was significant from second observation (30 min) up to seventh observation period (240 min) for 500 mg dose group. These results support the finding that Leucas aspera root may contain biologically active constituent(s) having CNS activity.

Central nervous system depressant activity of Diospyros peregrina bark

  • Shilpi, Jamil Ahmad;Uddin, Shaikh Jamal;Rouf, Razina;Billah, Md. Morsaline
    • Advances in Traditional Medicine
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    • 제4권4호
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    • pp.249-252
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    • 2004
  • The methanol extract of Diospyros peregrina bark was studied for its effect on the central nervous system (CNS) using the pentobarbitone induced sleeping time test, the open field test and the hole cross test in Swiss albino mice. The present investigation revealed that the extract, at the doses of 250 and 500 mg/kg, significantly prolonged the pentobarbitone induced sleeping time in mice though the onset of sleep was delayed as compared to the control. In open field test, the depressing effect was prominent from the second observation period (30 min) and persisted throughout the entire experimental period (240 min). In the hole cross test, the depressing effect was observed from the second observation period (30 min) and persisted up to fifth observation period (120 min) for 250 mg dose group and up to sixth observation period (180 min) for 500 mg dose group. These results support the finding that D. peregrina bark extract at the above doses has CNS depressing effects and indicate that D. peregrina bark may contain biologically active constituent(s) having CNS depressant activity.

근사함수를 이용한 스틸휠의 디스크 홀의 최적화 (Optimal Design of the Steel Wheel's Disc Hole Using Approximation Function)

  • 임오강;유완석;김우현;조재승
    • 한국전산구조공학회논문집
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    • 제16권1호
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    • pp.105-111
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    • 2003
  • 승용차의 휠은 타이어와 차체 무게를 지지하며, 회전력과 정지력을 노면으로 전달한다. 휠의 경량화는 차량의 연료효율에 효과적이므로, 스틸휠이 무게를 최소화하도록 디스크 홀이 형상을 최적화 하였다. 설계모델은 Pro/ENGINEER를 사용하여 설정하고, 설계모델의 해석은 ANSYS를 이용하였다. 범용 소프트웨어간의 직접적인 자료의 전달이 어려우므로 두 프로그램을 병합 사용하기 위해, 반응표면법을 이용한 근사함수를 구하였다. 5수준의 요인배치법의 실험값을 사용하여 최대응력과 최대 변위를 추출하였다. 초기 모델은 14인치 승용차용 스틸휠을 사용하였고, 디스크 홀의 폭을 설계변수로 선택하였다. 순차이차계획법과 활성화제약조건을 사용하는 PLBA(Pahenichny-Lim-Belegundu-Arora) 알고르즘을 이용하여 최적해를 구하였다.

골프장의 시각적선호분석 -대구 칸트리 클럽을 사례로- (Analysis on Visual Preference of Golf Course -The case of Tae-gu Country Club-)

  • 김용수;성영탁
    • 한국조경학회지
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    • 제21권1호
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    • pp.13-30
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    • 1993
  • The purpose of this study was to present data to the landscape planning and design through analyzing correlation between visual preference of users and nonusers and the landscape of hole in golf couses. Stimulus objects were selected from the 18 holes in Tae-gu Country Club. Preference value was judged through photo simulation by 35 subjects photographed at Tee and Interpoint (IPI, IP2), and classified into three landscape types and nine landscape components from photo analysis by researcher. For test of difference between groups toward each stimulus, t-test was used, and Duncantest, Correlation analysis for finding out correlation between preference degree and the landscape of each hole. The results of this study were as follows: As a result of analysis of preference value between groups for each hole, it has been shown that there was scarcely difference with each other. Form the relation between preference degree and spacial structure of hole, the holes making up a superior preference group have been shown that the greater part of the holes had a downward slope or a gentle slope mostly and then a visible ratio of fairway was high, and had diversified scenery by a lotus pond, a solitary planting tree, the roll of a fairway, facilities for convenience, etc. The holes making up a low-ranking preference group have been shown that the greater part of the holes had upward slope or a similar slope to it and had characteries of the bad condition of lawn, the nearby factories and odors, the monotonous scenery of a fairway, an unreasonable mixing of holes, etc. From the relation between preference degree and landscape components forming hole, it has been shown that the preference degree between users and nonusers had positive correlation to the occupied ratio of space of landscape components at Tee and Approach. At Tee, it has been shown that the preference degree of two groups were related with a lawn surface of fairway negatively, a lotus pond, a sky positively, and the preference degree of nonusers was related with iron-top for electric transmission positively. At Approach, it has been shown that the preference degree of two groups were related with iron-top for electric transmission negatively, and the preference degree of nonusers was related with a building positively. From the relation between preference degree group to each hole and the occupied ratio of space of landscape types, it has been shown that the constituent ratio of a high-ranking group was 1:2.4:2.2 and a low-ranking group was 1:4.1:5.1 among vertical type, horizontal type and background at Tee, but the constituent ratio of space of a high-ranking group was similar to a low-ranking group at Approach.

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전산유체역학을 이용한 워터펌프 축력 저감 (Reduction of the Axial Force of Water Pump Using CFD)

  • 조석현;신동성
    • 한국자동차공학회논문집
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    • 제20권3호
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    • pp.83-87
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    • 2012
  • Computational Fluid Dynamics (CFD) method has been used to investigate the axial force of automotive water pump. As the excessive axial force can make some unexpected problems like impeller interference and coolant leakage we have focused on finding the cause of axial force and its reduction in this paper. First, we have tested the closed type water pump with and without balance hole by the calculation methods. By examining the pressure contour around the impeller, we have found that the axial force arises not only from the pressure difference around shroud but also from the pressure difference around hub. So we have tested two impellers - one is normal open type impeller and the other is open type impeller with modified hub. The results show that the axial force reduction is about 150~200N for normal one and 700N@3000RPM for modified impeller. And the hydraulic efficiency which is important in aspect of engine fuel efficiency is reduced about 6.5% for normal one but increased 4%@3000RPM for modified impeller.

피코초 레이저 드릴링 공정 및 플랫폼 (Picoseconds Laser Drilling and Platform)

  • 서정;신동식;손현기;송준엽
    • 한국정밀공학회지
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    • 제27권10호
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    • pp.40-44
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    • 2010
  • Laser drilling is an enabling technology for Through Silicon Via (TSV) interconnect applications. Recent advances in picoseconds laser drilling of blind, micron sized vias in silicon is presented here highlighting some of the attractive features of this approach such as excellent sidewall quality. In this study, we dealt with comparison of heat affection around drilled hole between a picosecond laser and a nanosecond laser process under the UV wavelength. Points which special attention should be paid are that picosecond laser process lowered experimentally recast layer, surface debris and micro-crack around hole in comparison with nanosecond laser process. These finding suggests that laser TSV process has possibility to drill under $10{\mu}m$ via. Finally, the laser drilling platform was constructed successfully.

강도-응력 간섭모델을 적용한 철도차량용 차륜의 피로강도 및 신뢰성 평가법 (An Evaluation Method of Fatigue Strength and Reliability in a Railway Wheel with an Application of Strength-Stress Interference Model)

  • 박병노;김기환;김호경
    • 한국철도학회논문집
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    • 제5권2호
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    • pp.118-124
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    • 2002
  • The failure probability of wheel beyond 10$\^$7/ cycles is achieved by the strengths-stress interference model for the evaluation of fatigue strength and reliability in the wheel, From plane bending fatigue test results, the fatigue life (N$\_$f/) for the smooth and 200㎛ holed specimens can be represented as $\sigma$$\_$a/ = 1326N$\_$f/$\^$-0.10/ and $\sigma$$\_$a/ = 2894N$\_$f/$\^$-0.18/. Respectively, fatigue strength of the wheel at beyond 10$\^$7/cycles was about 332 MPa. And, the fatigue strength for the specimen with a micro hole (d=200㎛) which simulated an inclusion on the wheel surface was about 235 MPa. Thus, a micro hole (d=200㎛) caused about 30% reduction of fatigue strength of the specimen. The failure probabilities for the smooth and micro-holed specimens, derived from the strength-stress interference model, are 0.0148% and 13.05%, respectively. The current finding suggests that at least 200 ㎛ sized inclusion, which might be produced during manufacturing process, will cause a critical effect on integrity of the railway vehicle.