• Title/Summary/Keyword: Case-Study

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An experimental study on measurement of combustion rate of combustible substances (가연성(可燃性) 물질(物質)의 중량(重量) 연소속도(燃燒速度) 측정(測定)에 관(關)한 실험적(實驗的) 연구(硏究))

  • Park, Young-Zo;Han, Eung-Gyo;Kim, Sang-Wook;Park, Won-Young
    • Journal of the Korean Society of Safety
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    • v.2 no.1
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    • pp.11-16
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    • 1987
  • A study was performed on combustion rates of three kinds of combustible substances under a few different combustion conditions. To measure the combustion rates by weight method, I contrived an apparatus using a sensitive load cell. The experimental results by the combustion tests of various combustible substances shows that the combustion circumstances, eg., air supply condition and the existence of flammable oil. And it is found that the time constant T in case of oil absence is smaller than that in case of oil existence, and the time constant T in case of enforced air-entrained condition is greater that in case of natural air-entrained condition.

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Second-Order Learning for Complex Forecasting Tasks: Case Study of Video-On-Demand (복잡한 예측문제에 대한 이차학습방법 : Video-On-Demand에 대한 사례연구)

  • 김형관;주종형
    • Journal of Intelligence and Information Systems
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    • v.3 no.1
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    • pp.31-45
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    • 1997
  • To date, research on data mining has focused primarily on individual techniques to su, pp.rt knowledge discovery. However, the integration of elementary learning techniques offers a promising strategy for challenging a, pp.ications such as forecasting nonlinear processes. This paper explores the utility of an integrated a, pp.oach which utilizes a second-order learning process. The a, pp.oach is compared against individual techniques relating to a neural network, case based reasoning, and induction. In the interest of concreteness, the concepts are presented through a case study involving the prediction of network traffic for video-on-demand.

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A Numerical Study on NOx Emission of the Swirl Premixed burner for Several Chemical Reaction Mechanisms (스월 예혼합 버너의 화학반응식에 따른 NOx 특성에 대한 수치적 연구)

  • Cho, Cheonhyeon;Baek, Gwangmin;Sohn, Chae Hoon;Cho, Ju Hyung;Kim, Han Seok
    • 한국연소학회:학술대회논문집
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    • 2012.11a
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    • pp.133-135
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    • 2012
  • This study presents the prediction of NOx and mixing characteristics with several chemical reaction mechanisms of methane in EV burner of double cone. Experimental results are compared with numerical results for validation. Mixing characteristics are analyzed at monitoring points based on the modified unmixedness. The mixing characteristics were improved in a certain case, the lance injection case. In 1-step reaction case, inside of the cone, flame was formed and lots of NOx was generated because the fuel injected from the lance was overestimated. In 2-step reaction case, numerical results showed a good agreement with experimental results in a qualitative manner.

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Gaussian process approach for dose mapping in radiation fields

  • Khuwaileh, Bassam A.;Metwally, Walid A.
    • Nuclear Engineering and Technology
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    • v.52 no.8
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    • pp.1807-1816
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    • 2020
  • In this work, a Gaussian Process (Kriging) approach is proposed to provide efficient dose mapping for complex radiation fields using limited number of responses. Given a few response measurements (or simulation data points), the proposed approach can help the analyst in completing a map of the radiation dose field with a 95% confidence interval, efficiently. Two case studies are used to validate the proposed approach. The First case study is based on experimental dose measurements to build the dose map in a radiation field induced by a D-D neutron generator. The second, is a simulation case study where the proposed approach is used to mimic Monte Carlo dose predictions in the radiation field using a limited number of MCNP simulations. Given the low computational cost of constructing Gaussian Process (GP) models, results indicate that the GP model can reasonably map the dose in the radiation field given a limited number of data measurements. Both case studies are performed on the nuclear engineering radiation laboratories at the University of Sharjah.

A Study on Castability and Roughness of the Casts Using Non-precious Alloys (비귀금속 합금을 이용한 주조체의 주조성과 Roughness에 관한 연구)

  • Kim, Jang-Ju
    • Journal of Technologic Dentistry
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    • v.20 no.1
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    • pp.5-11
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    • 1998
  • The purpose of this study is to evaluate the castability and surface roughness of the casts using Non-percious alloys. For samples of 25 wax patterns, it is made from eight layers of sheet wax, arranged in the escalating layers. After fabricated wax patterns, using 5 kinds of Ni-Cr alloys is casted, and the casts are sandblasted. To castability, magnifier is used and values of surface roughness of the casts is measured with profilometer(tracing length 1.75mm, cutoff value 0.25mm) The results are as follows : 1. The castanbility of alloys, in case of C alloys, showed with $8.0{\pm}0.0000$, and in case of CS alloys and N alloys showed equal with $7.8{\pm}0.4472$, respectively. T alloys and V alloys showed equal with $7.2{\pm}0.4472$, respectively. 2. The values of surface roughness of the casts are decreased more T alloys than in case of order alloys, and in order, increased in case of CS alloys, C alloys, V alloys, N alloys, respectively.

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A Study of Chaotic Responses of an Elastic-Plastic Beam Model to Periodic Impulsive Force (주기적인 충격력을 받는 탄소성 보의 케이오틱거동 연구)

  • 이재영
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.19 no.5
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    • pp.1158-1167
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    • 1995
  • In this study, the dynamic instabilities of a beam, subjected to periodic short impulsive loading, are investigated using simple 2-DoF beam model. The behaviors of beam model whose axial motions are constrained are studied for the case of elastic and elastic-plastic behavior. In the case of elastic behavior, the chaotic responses due to the periodic pulse are identified, and the characteristics of the behavior are analysed by investigating the fractal attractors in the Poincare map. The short-term and long-term responses of the beam are unpredictable because of the extreme sensitivities to parameters, a hallmark of chaotic response. In the case of elastic-plastic behavior, the responses are governed by the plastic strains which occur continuously and irregularly as time increases. Thus the characteristics of the response behavior change continuously due to the plastic strain increments, and are unpredictable as well as the elastic case.

Case studies on BIM-based architectural environment performance analysis (건축정보모델링(BIM)기반 건축 환경 성능 사례 분석)

  • Moon, Hyun-Jun;Choi, Min-Seok;Park, Jin-Woo;Ryu, Seung-Ho
    • Proceedings of the SAREK Conference
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    • 2009.06a
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    • pp.1412-1417
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    • 2009
  • BIM(Building Information Modeling) is considered a new paradigm and a powerful method in building design, construction and maintenance. However, it is still hard to implement environmental performance analysis using BIM in design stages. This study aims to reveal practical problems and evaluate interoperability between building design information and performance analysis with case studies. Three case studies are performed using two environmental analysis programs (IES/VE, EnergyPlus) and BIM-based architectural design programs (Revit, GoogleSketchUp) in this paper.

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A Case Report of Delayed Healing in Femoral Shaft Fractured Child (대퇴골 간부 골절 후 골절유합이 지연된 환아의 한의치료 증례보고)

  • Sung, Hyun-Kyung;Kim, Jang-Hyun;Min, Sang-Yeon
    • The Journal of Pediatrics of Korean Medicine
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    • v.25 no.1
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    • pp.63-71
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    • 2011
  • Objectives: The purpose of this study is to report the clinical effects of oriental medical treatment on delayed healing in femoral shaft fractured child. Methods: We treated the patient with herb medicine named Kamiboatang and Pyritum. Child took Kamiboatang and Pyritum for 2 months, and Kamiboatang for 1 month. After 3 months treatments, we examined the case with radiological findings. Results: The patient's delayed femoral shaft fracture was improved after 3 months oriental medical treatment. Conclusions: This case showed that oriental medical treatment on delayed healing in femoral shaft fractured child was effective. To prove the effectiveness of Kamiboatang and Pyritum, the more clinical study of Oriental medical treatment for this case might be also needed.

One Clinical Study on Strabismus Patient of Abducence Nerve Paralysis with Oriental Medicine (제6 뇌신경 마비로 진단된 마비성(痲痺性) 사시(斜視) 환아(患兒) 1례(例) 보고(報告))

  • Cheon, Jin-Hong;Min, Sang-Yeon;Kim, Jang-Hyun
    • The Journal of Pediatrics of Korean Medicine
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    • v.24 no.3
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    • pp.26-32
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    • 2010
  • Objectives: This study is to report a case of the paralytic strabismus with herbal medicine and acupuncture. Strabismus refers to the oculomotor muscles imbalance resulted from improper alignment of the visual axis of the two eyes. Our goal is to know the effectiveness and safety in children from oriental medicine. Methods: We treated the case by using herbal medicine, acupuncture, and etc. Results: We found that the case was recovered perfectly in short term(24days) without any side effects or complaints. Therefore, we try to apply this treatment in many children cases and to set as a guideline protocol to treat for children. Conclusions: The case showed proper oriental medical treatment is better choice for therapy than surgery or observation.

A Study on Combustion Characteristics of Turbulent Spray Flame by the Dual Swirler (2중스월류에 의한 난류분무화염의 연소특성 연구)

  • Lee, Kang-Yeop;Hwang, Sang-Soon
    • Journal of the Korean Society of Combustion
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    • v.5 no.1
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    • pp.67-79
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    • 2000
  • An Experimental study was conducted on spray combustion using dual swirlers at different outlet angle; co-swirl and counter-swirl. To understand the characteristics of turbulent spray combustion of dual swril flow(DSF), the axial helical annular vaned swirlers with various swirl ratios and combination of angle and direction were designed. and temperature measurements of a rapidly thermocouple insertion and measurements of soot volume fraction and microstructure using thermophoretic sampling particle diagnostic(TSPD) as TEM were carried out. The NOx, $CO_2,\;O_2$, etc. was analyzed using emission gas analyzer. The results show that flame stability were maintained under very lean condition. for both co-swirl and counter-swirl case. And though Counter-swirl case kept the higher temperature region compared to co-swirl case, Counter-swirl combustion represented less NOx emission and soot formation than co-swirl case.

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