• Title/Summary/Keyword: Rate of penetration

검색결과 873건 처리시간 0.034초

발사체 관통 콘크리트 충격손상 모델 (Impact damage model of projectile penetration into concrete target)

  • 박대효;노명현
    • 한국콘크리트학회:학술대회논문집
    • /
    • 한국콘크리트학회 2006년도 춘계 학술발표회 논문집(II)
    • /
    • pp.633-636
    • /
    • 2006
  • Impact damage modeling of concrete under high strain rate loading conditions is investigated. A phenomenological penetration model that can account for complicated impact and penetration process such as the rate and loading history response of concrete, the microstructure-penetration interaction etc. is discussed. Constitutive law compatible with Second Law of thermodynamics and coupled damage and plasticity modelling based on continuum damage mechanics are also examined. The purpose of this paper is preliminarily to study with respect to impact and penetration models for concrete before the development of that model.

  • PDF

제주도에서 전기자동차 보급이 전력계통에 미치는 영향 (The Effects of Penetration of the Electric Vehicles on the Electric Power Grid in the Jeju Island)

  • 오성보;이개명;황충구
    • 전기학회논문지
    • /
    • 제63권1호
    • /
    • pp.10-17
    • /
    • 2014
  • The Jeju Special Self-Government Provincial Government has made the plan penetrating gradually electric vehicles(EVs) in the Jeju Special Self-Government Province(Jejudo). However the effects of EVs penetration on the electrical grid of the Jejudo is not reported. In this paper the yearly electric energy consumed by the EVs was calculated and the effects of the EV penetration on the peak power of the grid were analyzed in the Jejudo for the future 10 years, and we hope that our study results will help the governors realize the EVs penetration plan in the Jejudo. The calculation results show that the rate of the electric energy used by the EVs will become to 2.9% at its maximum at the 2017 year when the penetration rate of EVs in passenger cars becomes 10%, and the rate of the electric energy consumed by the EVs will become to 9.4% at its maximum at the 2020 year when the penetration rate of EVs in passenger cars becomes 30%. The concepts of smart-charging capacity and 100%-valley-filling charging capacity of the grid were defined and calculated for the Jeju Grid, and the grid was analyzed to have the sufficient EV charging capacity until the 2022 year.

고출력 연속발진 레이저에 의한 금속 관통율 모델링 (Modeling of Metal Penetration Rate by a High Power Continuous Wave Laser)

  • 신완순;고해석;박병서;강응철
    • 한국군사과학기술학회지
    • /
    • 제15권5호
    • /
    • pp.705-711
    • /
    • 2012
  • The purpose of this study is to develop the model to estimate the penetration rate of metal under a high power continuous wave laser irradiation. To estimate it, an empirical modeling is more practical when the penetration phenomena of metal by laser irradiation is too complex to be analyzed by the numerical simulation. When several methods published earlier were applied to our results, we found out that their methods were not appropriate as the model. Therefore, we suggested the new empirical method considering effective intensity as a key variable. As a result, we confirmed that the new method was effective to model the penetration rate of SUS304 metal and expected that it could be available to other metals.

석면 함유 천장재의 안정화제 희석에 따른 침투깊이 연구 (A Study of Penetration Depth into Ceiling Materials containing Asbestos according to Dilution Rate of Scattering Prevention Agent)

  • 신현규;최용규;전보람;하주연
    • 한국산업보건학회지
    • /
    • 제25권1호
    • /
    • pp.82-88
    • /
    • 2015
  • Objectives: This study is designed to analyze the penetration performance into ceiling materials containing asbestos of scattering prevention agents and investigate the change in penetration depth and viscosity according to the dilution rate of anti-scattering agents diluted with distilled water. Methods: Five different types of scattering prevention agents were spread on plate-type asbestos ceiling materials. The penetration depth of each coated ceiling material was measured by energy dispersive spectroscopy (EDS) analysis, based on X-ray fluorescence (XRF) results of the non-coated ceiling materials. Test equipment installed the ceiling materials and 60 minutes were collected at a flow rate of $10{\ell}/min$ at a filter of 25 mm. Results: An EDS analysis of the cross-section of ceiling materials constructed with a scattering prevention agent revealed that potassium is detected in the process of penetrating hardener solidification and this element could be an indicator for infiltration. When anti-scattering agents with different viscosities were constructed and the penetration depth was analyzed by potassium detection assessment using EDS, the depth results with viscosities of 5.0, 2.5, and 1.9 cP were 98.5, 103, and $147{\mu}m$, respectively. Penetration performance improved with decrease in viscosity. Conclusions: For asbestos ceiling materials, it is concluded that a higher dilution rate of the scattering prevention agent leads to lower viscosity, and hence a deeper penetration depth from $156{\mu}m$ to 3 mm. The asbestos anti-scattering properties according to the penetration depth will be confirmed through further study.

냉동보존된 햄스터 난자를 이용한 인간정자의 생식력 평가 (Assessment of Fertilizing Capacity of Human Spermatozoa Using Cryopreserved Hamster Oocytes)

  • 방명걸;정구민;김석현;신창재;김정구;문신용;이진용;장윤석
    • Clinical and Experimental Reproductive Medicine
    • /
    • 제19권2호
    • /
    • pp.153-162
    • /
    • 1992
  • To solve the logistical problems of the sperm penetration assay (SPA) to provide just a sufficient number of hamster ova exactly when they are needed, a new method to cryopreserve the ova has been devised (1-step dehydration and 2-step thawing). After freezing & thawing of zona-intact (ZI) and zona-free (ZF) hamster ova according to this new method, the frozen-thawed ova were compared with fresh, control ova (FO) in terms of the degree of sperm penetration in SPA using semen samples from fertile donors, subfertile, and infertile male. Each sperm sample was capacitated for 42 hours inTEST-Yolk Buffer before insemination in SPA. In fertile doner, both the penetration rate and penetration index were lower in SPA using frozen ova (ZI; 92.4%, 6.2, ZF; 63.7%, 3.9) than those of SPA using fresh ova (99.3%, 8.4). There was a significant correlation between the penetration index of SPA using FO and ZI (p<0.001), and between those of SPA using FO and ZF and ova (p<0.001). In subfertile patient, both the penetration rate and penetration index were lowered in frozen ova (ZI; 62.3%, 1.3, ZF; 21.8%, 0.4) than those of fresh ova (74.8%, 1.8). There were significant correlation between the penetration rate and penetration index in ZI ova (p<0.05 and p<0.001, respectively). In infertile patient, both the penetration rate and penetration index were ZI; 3.1%, 0.0, ZF;0.0%, 0.0, respectively. There were significant correlation between the penetration rate and penetration index in ZI ova (p<0.05).

  • PDF

변형률속도-의존 구성모델의 현장 시험 적용 (Application of Field test to the Rate-dependent relation in Constitutive model)

  • 송용선
    • 한국산학기술학회논문지
    • /
    • 제9권2호
    • /
    • pp.470-474
    • /
    • 2008
  • 본 연구에서는 실제 현장에서 수행한 피에조콘관입 및 소산시험결과와 변형률 속도를 고려한 구성모델의 이론적 해석을 비교하였다. 이를 위하여 변형률 속도 의존적 구성모델의 수학적 유도과정을 전개하였다. 해석 결과 변형률속도를 무시한 구성모델보다 변형률속도-의존 구성모델을 활용한 지반의 거동 해석이 비의존적 구성모델인 경우의 해석 보다 현장의 시험결과와 잘 일치하므로 변형률속도-의존 구성모델의 적용이 바람직하다.

A Novel Organogel System Capable of Enhancing Skin Penetration Characteristics of Acyclovir

  • Lee, Sang-Kil;Lee, Jae-Hwi;Choi, Young-Wook
    • Journal of Pharmaceutical Investigation
    • /
    • 제36권6호
    • /
    • pp.401-403
    • /
    • 2006
  • Topical preparations such as cream for Acyclovir(ACV), a potent anti-viral agent for the treatment of herpes simplex and herpes zoster, have been marketed in the world since 1993. However, the skin penetration rate of ACV from generic cream formulations sold in Europe has been found to be lower than the original $Zovirax^{\circledR}$ cream. In this study, we formulated ACV into a novel organogel system and compared the skin penetration characteristics with $Zovirax^{\circledR}$ cream. The rate and amount of skin penetration of ACV from the organogels were 6.3-fold greater than those obtained with $Zovirax^{\circledR}$ at an ACV concentration of 5%. The solubilizing effect of oil phase and anti-nucleation effect exhibited by sodium alginate contained in water phase are most likely attributed to enhanced ACV skin penetration property.

국산 신문용지에서 잉크침투속도 변화에 따른 인쇄적성에 관한 연구 (A Study on the Rate of Ink Penetration of Korean Newspapers)

  • 김종경;윤종태
    • 한국인쇄학회지
    • /
    • 제24권1호
    • /
    • pp.67-76
    • /
    • 2006
  • Measuring ink penetration is one of the best ways to know paper printability. Ink penetration was effected by physical properties of newspapers. This study was carried out for the purpose of improvement printability with ink penetration of Korean newspapers. The samples were prepared by means of 7 Newspaper manufacture company in Korea, and were tested by IGT printability tester. The results of this experiments showed that the rate of ink penetration, roughness and porosity are proportioned. While, ink penetration, paper formation, ash content and smoothness of paper are in inverse proportioned.

  • PDF

불균형 데이터 처리를 통한 머신러닝 기반 TBM 굴진율 이상탐지 개선 (Enhancing machine learning-based anomaly detection for TBM penetration rate with imbalanced data manipulation)

  • 권기범;황병현;박현태;오주영;최항석
    • 한국터널지하공간학회 논문집
    • /
    • 제26권5호
    • /
    • pp.519-532
    • /
    • 2024
  • TBM (tunnel boring machine) 터널 프로젝트의 리스크 관리 측면에서 굴진율 예측은 중요하며, 이를 위한 머신러닝 기반 TBM 굴진율 예측 연구가 지속적으로 진행되어 왔다. 그러나, 기존 연구의 머신러닝 예측 모델은 정상 굴진율과 이상 굴진율 간의 불균형 데이터를 고려하는 데 한계가 있다. 본 연구에서는 데이터 증강 기법을 통해 불균형 데이터를 처리하여 머신러닝 기반 TBM 굴진율 이상탐지 성능을 개선하였다. 먼저, 상관관계 분석을 통해 유사 변수를 제거하여 6가지 입력특성을 선정하였다. 또한, 하위 10%와 상위 10%의 굴진율을 각각 이상 등급으로, 그 외 범위의 굴진율을 정상 등급으로 굴진율 등급을 구분하였다. 기존 학습 데이터와 SMOTE (synthetic minority oversampling technique)를 통해 증강된 학습 데이터를 각각 XGB (extreme gradient boosting)에 적용한 XGB 모델과 XGB-SMOTE 모델을 구축하였다. 굴진율 등급 예측 성능을 비교한 결과, XGB 모델은 정상 굴진율에 대한 예측 성능은 우수하나 이상 굴진율 예측 성능은 상대적으로 낮게 도출되었다. 반면, XGB-SMOTE 모델은 모든 굴진율 등급에서 일관되게 우수한 예측 성능을 보였다. 이는 SMOTE를 통한 이상 굴진율 데이터의 증강이 이상 굴진율을 유발하는 지반조건과 TBM 운영인자 간의 패턴 학습 수준을 향상시켰기 때문으로 판단된다. 결론적으로, 본 연구는 머신러닝 기반 TBM 굴진율 이상탐지 시 데이터 증강 기법을 활용한 불균형 데이터 처리가 효과적임을 보여준다.

A MODEL FOR THE PENETRATION RATE OF A BOUSSINESQ STARTING FORCED PLUME

  • LAW ADRIAN WING-KEUNG;AI JIAO JIAN;YU S.C.M
    • 한국수자원학회:학술대회논문집
    • /
    • 한국수자원학회 2005년도 학술발표회(2)
    • /
    • pp.951-951
    • /
    • 2005
  • The characteristics of Boussinesq starting forced plumes were investigated in this study. Two distinct periods in the transient plume penetration were identified, namely the Period of Flow Development (PFD) and Period of Developed Flow (PDF). PFD refers to the time period whereby the penetration rate is governed by the complex vortex dynamics initiated by the exit conditions that can include vortex coalescence, vortex leapfrogging, pinching off of the head vortex from the trailing stem and the eventual reconnection. The pinch-off and reconnection leads to an overshoot of the plume front which is a common observation reported in previous studies. The penetration rate in PDF is more predictable and depends on the continuous feeding of buoyancy and momentum into the head vortex by the trailing buoyant-jet stem. Similarity solutions are developed for PDF to describe the temporal variation of the penetration rate, by incorporating the behavior of an isolated buoyant vortex ring and recent laboratory results on the trailing buoyant jet. In particular, the variations of velocity ratios between the head vortex and trailing buoyant jet are analytically computed. To verify the similarity solutions, experiments were conducted on vertical starting forced plumes using planar laser induced fluorescence (PLIF).

  • PDF