• 제목/요약/키워드: Opposed-flow

검색결과 64건 처리시간 0.03초

백드래프트의 중력흐름에 미치는 구획실 내부 초기조건 및 개구부 형상의 영향 (Effects of Initial Condition and Opening Geometry of a Compartment on the Gravity Current in the Backdraft)

  • 박지웅;오창보;한용식;도규형
    • 한국안전학회지
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    • 제30권6호
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    • pp.18-25
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    • 2015
  • Computational study of a gravity current prior to the backdraft was conducted using fire dynamic simulator (FDS). Various initial conditions of mixture compositions and compartment temperature as well as four opening geometries (Horizontal, Door, Vertical, and Full opening) were considered to figure out their effects on the gravity current. The density difference ratio (${\beta}$) between inside and outside of compartment, the gravity current time ($t_{grav}$) and velocity ($v_{grav}$), and non-dimensional velocity ($v^*$) were introduced to quantify the flow characteristics of the gravity current. Overall fluid structure of the gravity current at the fixed opening geometry showed similar development process for different ${\beta}$ conditions. However, $t_{grav}$ for entering air to reach the opposed wall to the opening geometry increased with ${\beta}$. Door, Vertical, and Horizontal openings where openings are attached on the ground showed similar development process of the gravity current except for Horizontal opening, which located on the middle of the opening wall. The magnitude of $v_{grav}$ at fixed ${\beta}$ was, from largest to smallest, Full > Vertical > Door > Horizontal, but it depended on both the size and location of the opening. On the other hand, $v^*$ was found to be independent to ${\beta}$, and only depended on the geometry of the opening.

ALEX1 Regulates Proliferation and Apoptosis in Breast Cancer Cells

  • Gao, Yue;Wu, Jia-Yan;Zeng, Fan;Liu, Ge-Li;Zhang, Han-Tao;Yun, Hong;Song, Fang-Zhou
    • Asian Pacific Journal of Cancer Prevention
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    • 제16권8호
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    • pp.3293-3299
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    • 2015
  • Background: Arm protein lost in epithelial cancers, on chromosome X (ALEX) is a novel subgroup within the armadillo (ARM) family, which has one or two ARM repeat domains as opposed to more than six-thirteen repeats in the classical Armadillo family members. Materials and Methods: In the study, we explore the biological functions of ALEX1 in breast cancer cells. Overexpression of ALEX1 and silencing of ALEX1 were performed with SK-BR3 and MCF-7 cell lines. Cell proliferation and colony formation assays, along with flow cytometry, were carried out to evaluate the roles of ALEX1. Results: ALEX1 overexpression in SK-BR3 breast cancer cells inhibited proliferation and induced apoptosis. Furthermore, depletion of ALEX1 in MCF-7 breast cancer cells increased proliferation and inhibited apoptosis. Additional analyses demonstrated that the overexpression of ALEX1 activated the intrinsic apoptosis cascades through up-regulating the expression of Bax, cytosol cytochrome c, active caspase-9 and active caspase-3 and down-regulating the levels of Bcl-2 and mitochondria cytochrome c. Simultaneouly, silencing of ALEX1 inhibited intrinsic apoptosis cascades through down-regulating the expression of Bax, cytosol cytochrome c, active caspase-9, and active caspase-3 and up-regulating the level of Bcl-2 and mitochondria cytochrome c. Conclusions: Our data suggest that ALEX1 as a crucial tumor suppressor gene has been involved in cell proliferation and apoptosis in breast cancer, which may serve as a novel candidate therapeutic target.

Sous Vide Cook-chill 법으로 생산된 삼치 데리야끼 조림의 레몬즙 첨가에 따른 미생물적 품질평가 (Evaluation of the Microbiological Quality of Glazed Spanish Mackerel in Teriyaki Sauce by Adding Lemon Juice Using Sous Vide Cook-chill Method)

  • 김혜영;고성희;이경연
    • 한국식품조리과학회지
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    • 제24권5호
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    • pp.713-721
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    • 2008
  • The principal objective of this study was to evaluate the microbiological quality of Glazed Spanish Mackerel in Teriyaki sauce by adding Lemon juice, using a Sous vide Cook-chill method. The control was prepared by mixing 100 g of cut Spanish Mackerel and 15 mL of Teriyaki sauce. 1.5 mL lemon juice was added to 15 mL of Teriyaki sauce. The product was stored at below $3^{\circ}C$, and its microbiological quality was assessed over varying storage periods (0, 5, 10, 15 days). Total Plate Counts at product flow showed no significant difference between the control and the lemon juice-added sample. However, the coliform counts at the end of mixing each sauce were detected at low levels of 1.65 Log CFU/g in the lemon juice-added sample, as opposed to 2.63 Log CFU/g in the controls (p<0.05). The microbiological quality by storage day was relatively high in the lemon juice-added samples. After reheating, the Total Plate Counts and Coliform counts of the lemon juice-added samples satisfied the standard applied in the processed food (5.0 and 2.0 Log CFU/g, respectively). It can be concluded that the addition of Lemon juice was more effective in ensuring the safety and extending the shelf life of Sous vide Glazed Spanish Mackerel in Teriyaki sauce.

정서-색채 이론에 기반한 게임 캐릭터의 동적 얼굴 색 제어 (Facial Color Control based on Emotion-Color Theory)

  • 박규호;김태용
    • 한국멀티미디어학회논문지
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    • 제12권8호
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    • pp.1128-1141
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    • 2009
  • 게임 산업이 성장하면서 게임 그래픽 분야는 가장 빠르게 발전하고 있으며 지금은 실제 사진과 컴퓨터 그래픽을 구분하기 힘든 정도로 그래픽 기술은 양적으로나 질적으로 성장했다. 그러나 이러한 발전에도 불구하고 새롭게 출시되는 게임에 등장하는 캐릭터는 정서를 표현하지 않거나 소극적으로 표현하고 있다. 일반적으로 사람들은 얼굴의 표정이나 얼굴의 색(안색)에서 많은 정서 정보를 인지하는 것은 누구나 아는 사실이다. 그러므로 컴퓨터의 게임 환경에서 등장하는 캐릭터에게도 얼굴의 색의 변화를 통하여 유저에게 게임의 사실적인 느낌을 줄 수 있다. 본 논문에서는 기존의 맥박과 피부 온도만을 이용한 방법과는 다른 인간의 정서 이론을 기반한 정서 모형과 애니메이션의 정서표현 색 그리고 성격이론을 기반한 정서의 반응 속도를 결합하여 게임 캐릭터의 얼굴의 색을 동적으로 변화시켜 정서를 표현할 수 있는 얼굴 색 적응 기술 (Facial Color Adaptive Technique: FCAT)를 제안한다. 실제 얼굴 색 적응 기술을 이용하여 만든 얼굴색 모형(Facial Color Model : FCM)과 애니메이션 콘텐츠의 정서표현을 비교한 결과 정서 표현 색상과 변화율이 애니메이션과 유사하게 시뮬레이션 되었다. 또한 2차원 이미지뿐만 아니라 3차원 이미지에도 적용이 가능함을 확인 하였다.

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액체-고체 접촉대전을 위한 PET 기판 기반 ODA/PDMS 딥 코팅 제조 및 평가 (Synthesis and Evaluation of Superhydrophobic ODA/PDMS Dip Coating on PET for Liquid-Solid Contact Electrification)

  • 박선영;강현규;변도영;조대현
    • Tribology and Lubricants
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    • 제37권2호
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    • pp.71-76
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    • 2021
  • As opposed to using fossil fuels, we need to use eco-friendly resources such as sunlight, raindrops and wind to produce electricity and combat environmental pollution. A triboelectric nanogenerator (TENG) is a device that converts mechanical energy into electricity by inducing repetitive contact and separation of two dissimilar materials. During the contact and separation processes, electron flow occurs owing to a change in electric potential of the contacting surface caused by contact electrification and electrostatic induction mechanisms. A solid-solid contact TENG is widely known, but it is possible to generate electricity via liquid-solid contact. Therefore, by designing a hydrophobic TENG, we can gather electricity from raindrop energy in a feasible manner. To fabricate the superhydrophobic surface of TENGs, we employ a dip coating technique to synthesize an octadecylamine (ODA)- and polydimethylsiloxane (PDMS)-based coating on polyethylene terephthalate (PET). The synthesized coating exhibits superhydrophobicity with a contact angle greater than 150° and generates a current of 2.2 ㎂/L while water droplets fall onto it continuously. Hence, we prepare a box-type TENG, with the ODA/PDMS coating deposited on the inside, and place a 1.5 mL water droplet into it. Resultantly, we confirm that the induced vibration causes continuous impacts between the ODA/PDMS coating and the water, generating approximately 100 pA for each impact.

서술 전략의 전환-「진보의 전초기지」에서 『어둠의 핵심』으로 (The Conversion of Narrative Strategy: from "An Outpost of Progress" to Heart of Darkness)

  • 이만식
    • 영어영문학
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    • 제57권4호
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    • pp.625-649
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    • 2011
  • Even though "An Outpost of Progress" and Heart of Darkness were based upon Joseph Conrad the sailor's same experience in Congo Free State, their narrative strategies are quite different. The realistic representation of "An Outpost of Progress," with which Conrad was not satisfied at all, was converted into the modernistic narrative strategy of Heart of Darkness so that the sympathetic power of the story should be improved. The conservative value system of realism is expressed by the omniscient author in "An Outpost of Progress," whereas the frame narrator of Heart of Darkness is proved to be an unreliable one whose norms and behavior are not in accordance with the implied author. The glorious history of the British Empire, which was proudly presented by the frame narrator at the beginning of Heart of Darkness, was strongly opposed by Marlow, another narrator, who said that the British Empire had been "one of the dark places of the earth" when ruled by the Roman Empire. The feeling of the frame narrator was uneasily changed into the gloomy mood when he described the Thames as the flow which "seemed to lead into the heart of an immense darkness" at the end of Heart of Darkness. Similar to the straightforward narrative strategy of representation in "An Outpost of Progress," the realistic approach of Part I in Heart of Darkness is considered by Conrad as insufficient to reveal the darkest truth of imperialism, which was declared by Kurtz as "The Horror! The Horror!" Thus Conrad uses the Chinese-box structure, in which Kurtz' episode is enveloped by Marlow's tale which is enclosed by the frame narrator's story, in order to penetrate into the mind of ordinary readers in the novelist's age of New Colonialism, while attacking the ideology itself of imperialism instead of critisizing its inefficiency and individualism.

딥러닝을 이용한 창상 분할 알고리즘 (Development of wound segmentation deep learning algorithm)

  • 강현영;허연우;전재준;정승원;김지예;박성빈
    • 대한의용생체공학회:의공학회지
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    • 제45권2호
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    • pp.90-94
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    • 2024
  • Diagnosing wounds presents a significant challenge in clinical settings due to its complexity and the subjective assessments by clinicians. Wound deep learning algorithms quantitatively assess wounds, overcoming these challenges. However, a limitation in existing research is reliance on specific datasets. To address this limitation, we created a comprehensive dataset by combining open dataset with self-produced dataset to enhance clinical applicability. In the annotation process, machine learning based on Gradient Vector Flow (GVF) was utilized to improve objectivity and efficiency over time. Furthermore, the deep learning model was equipped U-net with residual blocks. Significant improvements were observed using the input dataset with images cropped to contain only the wound region of interest (ROI), as opposed to original sized dataset. As a result, the Dice score remarkably increased from 0.80 using the original dataset to 0.89 using the wound ROI crop dataset. This study highlights the need for diverse research using comprehensive datasets. In future study, we aim to further enhance and diversify our dataset to encompass different environments and ethnicities.

정보화(情報化) 시대(時代)에서의 통신(通信) 및 방송위성이용(放送衛星利用)에 따르는 법적(法的) 문제(問題) 분석(分析)과 대응방안 연구(硏究) (A Study on Legal Issues in Telecommunication and Direct Broadcasting by Uses of Artificial Satellites)

  • 이영진
    • 항공우주정책ㆍ법학회지
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    • 제9권
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    • pp.445-488
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    • 1997
  • In the forthcoming 21st century new technical and scientific developments in outer space demands new approaches towards the problems arising in several fields of the use and exploitation of outer space including practical applications. The main purposes of this study are to analyze the legal problems of geostationary orbital position, telecommunication, direct television broadcasting by uses of artificial satellites. Communication via artificial Earth satellites was one of the first applications of space technology and is now one of the most developed field. From the technical and economic standpoints the advantages of world-wide satellites communication system are too all obvious. However, as the practical uses of space technology become more freguent, the legal conflicts among nations have become more divisive. One of the problem grown in uses of artificial satellites is that of the increasing shortage of suitable orbital slot positions for satellites, especially in geostationary orbit. Legal status of geostationary orbit as a limited resourece have to be reviewed in consideration of the side effect of the "First use, first-served" principle. The geostationary orbit is to be used for the benifits of all mankind and to be guaranteed for each state institutionaly in order to have eguitable access to the use of the orbit. Rapid increase of satellites broadcasting system in not only developed countries but also in developing countries opened up new possibilities with one another's scientific and cultural achievements. But there is also a potential danger that this powerful new instrument of influencing public opinion will be abused. Such a danger incudes spill-over or harmful interference. This controversial issue brings about the question whether prior consent from the receiver nation is needed to broadcast across international boundaries. Some states have rejected prior consent because it interfere with the free flow of information. Many other countries have opposed that opinion as an invasion and violation of sovereignty and as a violation of the 1967 Treaty and the UN Charter. Since declaration of the First Year of Outer Space in 1985, our country have promoted the plan of launching communication and broadcasting satellites. With the Koreasat launched in 1995 as the start, a real satellite-telecommunication era was opened in korea. According to this new development of our country, there will also rise various legal problems related to satellite broadcasting and telecommunication such as the inflow of foreign programs, the permeation of culture and the infringement of program copyright. Consequently the effective reactions to these problems in satellite-communication era should be tried including international cooperation. It is therefore to take into careful consideration the legal issues which may arise in outer space activities and to formulate positive policy on international cooperation with surrounding or advanced countries and international organization concerned. For this purpose the United Nations also prepares the UNISPACE III in 1999, to enable the international community to meet a more promising 21st century.

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균열 암반 매질에서의 핵종의 붕괴사슬 이동을 위한 연속시간 마코프 프로세스 모델 (Continuous Time Markov Process Model for Nuclide Decay Chain Transport in the Fractured Rock Medium)

  • 이연명;강철형;한필수;박헌휘;이건재
    • Nuclear Engineering and Technology
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    • 제25권4호
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    • pp.539-547
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    • 1993
  • 이전에 제시한 모델 1-3을 다시 확장하여 균열 암반에서의 일차원적 핵종이동에 관한 추계적인 모델을 제시하였다. 이 모델은 처분장 근처의 암반내의 균열을 통한 무한 길이를 갖는 핵종의 붕괴 사슬에 의한 이동을 연속시간 마코프 프로세스를 이용하여 모사한다. 이전의 결정론적 해석해에 의한 모델들이 균일한 다공성매질과 같은 단순성을 요구하고 핵종의 붕괴사슬의 수를 제한하며 균열암반매질내에서의 이동의 경우에는 균열에서 암반으로의 확산등이 고려되지 않거나 그 해의 형태가 복잡하다. 또다른 결정론적인 해를 제시하는 수치모델의 경우에도 해를 얻기 위한 과정이 상당히 복잡하고 정확한 해를 제공하지는 못한다. 이에 반해 이 모델은 매질에서의 핵종의 농도에 관한 기대값과 그 분산으로서 비교적 용이하게 해를 제시한다. 모델을 검증하고 그 효율성가 정착성을 예시하기 위하여 암반으로의 확산이 무시된 단순화된 매질에 대하여 3개의 붕괴 사슬을 갖는 가상의 핵종에 대하여 이동거리와 시간에 대한 농도에 대하여 정확한 해석해와의 비교가 행하여 졌다. 매질을 나눈 구획의 수에 종속 하는 수치분산을 보정하여 계산된 결과에서 이 모델이 해석해와 잘 일치하는 것을 알 수 있었다.

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인공자장발생장치와 자기 컴퍼스의 성능 (Helmholtz Coil and Performance of Magnetic Compass)

  • 안영화;정공흔;안장영;신형일
    • 수산해양기술연구
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    • 제19권2호
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    • pp.111-116
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    • 1983
  • 국산 자기컴퍼스의 제작에 필요한 기초자료를 제공하기 위하여 인공자기장 발생장치를 제작하여 그 특성을 조사하였고, 인공자장내에서의 자기컴퍼스의 제진 특성을 시험하여 자기컴퍼스의 성능을 부석, 검토한 결과는 다음과 같다. 1. 코일의 굵기 1mm, 직경 1 m, 권회수 117회인 인공자장발생장치의 전류(I sub(i))와 자장의 세기와의 사이에는 수직자장: Z(Gauss)=0.34+1.506 I sub(i) 수평자장: H(Gauss)=0.1834+1.506 I sub(i)의 관계가 있다. 2. T190형 자기컴퍼스는 T165형 자기컴퍼스에 비하여 전 tnbud자장 범위에서 주기는 길었으며, 진폭은 0.08 Gauss 이상에서는 크고, 그 이하에서는 작은 경향을 보였다. 3. 수평자장이 강할수록 주기와 자기자오선에 복귀하는 시간은 짧아지고, 진폭과 주행각은 커졌으며, 제진곡선의 주요점까지의 경과시간(Ti)은 수평자장(H)의 -0.65승에 비례하였고, 과행각(P sub(i))은 0.18승에 비례하였다.

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