• 제목/요약/키워드: artificial cross

검색결과 384건 처리시간 0.023초

In vitro culture of skin cells on a crosslinked gelatin based scaffold for artificial skin

  • Shin, In-Soo;Kwon, Oh-Hee;Kim, Soon-Nam;Hong, Choong-Man;Lee, Ki-Hong;Oh, Ho-Jung;Yoo, Si-Hyung;Lim, Jae-Hyun;Choi, Seung-Eun
    • 대한약학회:학술대회논문집
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    • 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-2
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    • pp.100.2-101
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    • 2003
  • To satisfy the increasing medical demanding especially for sever burn patients to regenerate full thickness wound cure, this study developed dermis with gelatin based scaffold and perform the biocompatibility tests. To prepare scaffold 30% of gelatin was mixed with sieved salt and dried in the mold to shape then, cross linked with a water-soluble cross-linker, EDAC. Preparing the cell for seeding from a rabbit skin, the fibroblast and keratinocyte were successfully isolated and cultured in vitro. After cell and scaffold were ready, the fibroblast was seeded to the scaffold (∼10$\^$6/ cell/cm ) for preparing dermis and keratinocyte was cultured until forming the sheet. (omitted)

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백령도와 수도권의 황사 수송 시간과 바람장 분석 (Analysis of Asian Dust Transportation Time and Wind Farm in Baengnyeongdo Island and the Metropolitan Area)

  • 조원기;강동환;박경덕;양민준
    • 한국환경과학회지
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    • 제31권6호
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    • pp.525-533
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    • 2022
  • Baengnyeongdo, located within the Asian dust stream, is an ideal place to analyze Asian dust moving into the West Sea due to its low emission of artificial pollutants. Baengnyeongdo is being used to analyze the vertical distribution of dust from the lower atmosphere to the upper layer through remote observation. This study compared the ground concentration of dust between Baengnyeongdo and the metropolitan area, estimated the lag time of transport of Asian dust from Baengnyeongdo to the metropolitan area, and examined the homogeneity of upper winds using the rawinsonde method. The results showed that the cross correlation coefficient was higher and the lag time was shorter for each observation station when the distance from Baengnyeongdo was shorter. The upper wind at Baengnyeongdo is dominated by the west/northwest wind. It is the basis for the correlation of dust concentration between Baengnyeongdo and the metropolitan area located to the east. In the future, upper wind data and Asian dust concentration data over the West Sea and Baengnyeongdo are expected to contribute to research related to the movement and prediction of Asian dust and preparation for Asian dust in the metropolitan area.

Machine Learning Based Hybrid Approach to Detect Intrusion in Cyber Communication

  • Neha Pathak;Bobby Sharma
    • International Journal of Computer Science & Network Security
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    • 제23권11호
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    • pp.190-194
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    • 2023
  • By looking the importance of communication, data delivery and access in various sectors including governmental, business and individual for any kind of data, it becomes mandatory to identify faults and flaws during cyber communication. To protect personal, governmental and business data from being misused from numerous advanced attacks, there is the need of cyber security. The information security provides massive protection to both the host machine as well as network. The learning methods are used for analyzing as well as preventing various attacks. Machine learning is one of the branch of Artificial Intelligence that plays a potential learning techniques to detect the cyber-attacks. In the proposed methodology, the Decision Tree (DT) which is also a kind of supervised learning model, is combined with the different cross-validation method to determine the accuracy and the execution time to identify the cyber-attacks from a very recent dataset of different network attack activities of network traffic in the UNSW-NB15 dataset. It is a hybrid method in which different types of attributes including Gini Index and Entropy of DT model has been implemented separately to identify the most accurate procedure to detect intrusion with respect to the execution time. The different DT methodologies including DT using Gini Index, DT using train-split method and DT using information entropy along with their respective subdivision such as using K-Fold validation, using Stratified K-Fold validation are implemented.

Exploring Machine Learning Classifiers for Breast Cancer Classification

  • Inayatul Haq;Tehseen Mazhar;Hinna Hafeez;Najib Ullah;Fatma Mallek;Habib Hamam
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제18권4호
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    • pp.860-880
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    • 2024
  • Breast cancer is a major health concern affecting women and men globally. Early detection and accurate classification of breast cancer are vital for effective treatment and survival of patients. This study addresses the challenge of accurately classifying breast tumors using machine learning classifiers such as MLP, AdaBoostM1, logit Boost, Bayes Net, and the J48 decision tree. The research uses a dataset available publicly on GitHub to assess the classifiers' performance and differentiate between the occurrence and non-occurrence of breast cancer. The study compares the 10-fold and 5-fold cross-validation effectiveness, showing that 10-fold cross-validation provides superior results. Also, it examines the impact of varying split percentages, with a 66% split yielding the best performance. This shows the importance of selecting appropriate validation techniques for machine learning-based breast tumor classification. The results also indicate that the J48 decision tree method is the most accurate classifier, providing valuable insights for developing predictive models for cancer diagnosis and advancing computational medical research.

hERG 이온채널 저해제에 대한 2D-QSAR 분석 (2D-QSAR analysis for hERG ion channel inhibitors)

  • 전을혜;박지현;정진희;이성광
    • 분석과학
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    • 제24권6호
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    • pp.533-543
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    • 2011
  • hERG (human ether-a-go-go related gene) 이온채널은 심장 재분극의 중요 요소이며 이 채널의 저해제는 부정맥과 돌연사를 유발할 수 있다. 따라서, 신약개발과정에서 후보물질이 hERG 이온채널의 잠재적인 저해제일 경우에는 심장독성 부작용을 유발하므로, 이를 최소화하고자 많은 노력이 집중되고 있다. 본 연구는 HEK(인간 배아 신장)세포에서 얻은 202개 유기화합물의 $IC_{50}$ 데이터를 이용하여 2차원 구조-활성의 정량적 관계(2D-QSAR)방법으로 예측하는 모델을 개발하였다. hERG이온채널 저해제의 기계 학습방법으로는 다중선형회귀(Multiple Linear Regression), 서포트 벡터 머신(Support Vector Machine: SVM)방법과 인공신경망(Artificial Neural Network)방법이며, 교차검증을 적용한 모집단 기반 전진선택(forward selection)방법과 결합하여 각 학습모델에 적합한 최적의 표현자들을 결정하였다. 가장 우수한 방법은 14종의 표현자를 사용한 인공신경망방법($R^2_{CV}$=0.617, RMSECV=0.762, MAECV=0.583)이었고, 다중선형회귀방법을 통해서 hERG이온채널 저해물질의 구조적 특징과 수용체와의 상호작용을 설명할 수 있다. QSAR모델의 검증은 교차검증과 Y-scrambling test방법으로 수행하였다.

배 검은별무늬병 저항성 "원교 나-흑성 2호" (Scab (Venturia nashicola) Resistant Pear, "Wonkyo Na-heukseong 2")

  • 신일섭;황해성;신용억;허성;김기홍;강삼석;김윤경
    • 한국육종학회지
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    • 제41권3호
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    • pp.354-357
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    • 2009
  • Venturia nashicola에 의한 검은별무늬병 저항성 품종을 육성하기 위하여 저항성 유전자원 탐색을 1997~1999년까지 국립원예특작과학원 포장검정 및 인공 접종을 실시하여 저항 성친으로 서양배 "청마려"을 선발하였다. 농촌진흥청 국립원예특작과학원 과수과에서 고품질 만생종 "만수"에 "청마려"를 1997년에 교배하여 저항성 우량 계통인 중간모본 "원교나-흑성 2호" 을 2008년에 선발하였다. 2008년 만개일은 4월 19일로 "만수" 보다 1일 늦고, "청마려"보다 7일 정도 빠르며 수세는 강하고 수자는 직립형이다. 검은별무늬병에 "청마려"와 "Bartlett"과 같이 강하고 "신고", "원황"등 국내 주요 재배 품종들과 교배 친화성이 있다. 과실은 만개 후 180일경에 성숙되어 양친에 비해 20일 정도 성숙 일수가 짧으며, 과형은 방추, 과피는 황녹갈색이다. 평균과중은 484 g, 당도는 $13.2^{\circ}Brix$이며 과즙량은 중~다이다 석세포가 적고 동양배의 아삭아삭함이 있다.

디지털 스캔 데이터를 활용한 무치악 치조제 관계의 평가와 인공치 선택: 편측 교차교합의 가철성 의치 수복 증례 (Use of digital scan data for evaluation of edentulous ridge relationship: A case report for removable prosthesis with unilateral cross bite)

  • 김정훈;김종은;박영범;이근우
    • 대한치과보철학회지
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    • 제57권3호
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    • pp.304-311
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    • 2019
  • 치아가 발거된 치조제는 수직, 수평적인 골흡수가 점진적으로 일어나게 되며 흡수의 양상은 수평적으로 서로 다르게 나타난다. 이로 인해 상대적으로 하악궁이 상악궁에 비해 확장되는 경향을 보이며, 상악과 하악 치조제 간의 위치관계에 따라 적합한 인공치 배열 방법을 선택하여 의치의 안정을 도모해야 한다. 본 증례는 77세 남자환자로 기존에 사용하던 상악 총의치, 하악 국소의치의 재제작을 희망하였다. 상악과 하악 치조골의 흡수정도에서 차이를 보여 치조제 간의 위치관계에 대한 정확한 평가가 필요하였고, 이를 위해 치과용 CAD 소프트웨어를 활용했다. 교합기에 부착된 주모형과 교합제를 스캔하여 디지털 스캔 데이터로 변환하고, CAD 소프트웨어 상에서 치조정간선의 법칙에 따라 상악과 하악 치조제간의 위치관계를 평가하여 우측 구치부를 편측 교차교합으로 배열하였다. 보철물 완성 후 주기적인 검진을 거친 결과 의치는 적절한 유지, 안정, 지지를 얻었고 환자 또한 심미적, 기능적으로 만족하였다. 본 증례에서는 상악의 완전 무치악, 하악의 부분 무치악 환자에서 치조제간의 위치관계에 대한 정확한 평가를 위해 디지털 기술을 활용하였으며, 이를 통해 보철치료의 임상 및 기공과정을 보다 효율적으로 진행할 수 있었기에 이를 보고하고자 한다.

로타리킬른 소성 골재 물성예측을 위한 전기로 실험 (Experiments of electric furnace simulator for property prediction of the artificial lightweight aggregate sintered by rotary kiln)

  • 류유광;김유택
    • 한국결정성장학회지
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    • 제18권3호
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    • pp.125-130
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    • 2008
  • 소형 전기로 및 이동장치가 있는 시뮬레이터를 사용하여 로타리킬른에서 생산되는 인공경량골재의 물성을 예측 할 수 있다면 대규모 로타리 킬른을 사용하여 인공경량골재 시제품 생산할 때 필요한 물자와 시간을 대폭 절감할 수 있다. 본 실험에서는 생산될 인공경량 골재의 물성을 정확히 예측할 수 있는 시뮬레이터를 제작하여 실제 로타리 킬른에서 생산된 골재의 물성과 비교함으로써 그 유용성을 검토하고자 하였다. 골재의 물성을 예측하기 위해서 8 mm 크기의 에코 인공경량 골재를 사용하였고 시뮬레이터의 분위기를 탄소를 이용해 조절하였다. 시뮬레이터와 로타리킬른에서 소성된 골재의 비중, 흡수율, 골재의 단면의 면적을 측정하고 비교하였다. 산화 분위기와 달리 환원분위기에서 소성된 시편은 탄소량이 증가할수록 비중이 증가하였으며 흡수율은 탄소 첨가량이 증가할수록 증가하는 경향을 보였다. 소성분위기는 환원 분위기 조성을 위해 탄소분말 0.7g을 첨가하였을 때 로라리 킬른과 가장 흡사한 분위기가 형성되는 것으로 판단되며, 두 골재의 물성 역시 비슷하였다.

Predicting residual moment capacity of thermally insulated RC beams exposed to fire using artificial neural networks

  • Erdem, Hakan
    • Computers and Concrete
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    • 제19권6호
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    • pp.711-716
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    • 2017
  • This paper presents a method using artificial neural networks (ANNs) to predict the residual moment capacity of thermally insulated reinforced concrete (RC) beams exposed to fire. The use of heat resistant insulation material protects concrete beams against the harmful effects of fire. If it is desired to calculate the residual moment capacity of the beams in this state, the determination of the moment capacity of thermally insulated beams exposed to fire involves several consecutive calculations, which is significantly easier when ANNs are used. Beam width, beam effective depth, fire duration, concrete compressive and steel tensile strength, steel area, thermal conductivity of insulation material can influence behavior of RC beams exposed to high temperatures. In this study, a finite difference method was used to calculate the temperature distribution in a cross section of the beam, and temperature distribution, reduction mechanical properties of concrete and reinforcing steel and moment capacity were calculated using existing relations in literature. Data was generated for 336 beams with different beam width ($b_w$), beam account height (h), fire duration (t), mechanical properties of concrete ($f_{cd}$) and reinforcing steel ($f_{yd}$), steel area ($A_s$), insulation material thermal conductivity (kinsulation). Five input parameters ($b_w$, h, $f_{cd}$, $f_{yd}$, $A_s$ and $k_{insulation}$) were used in the ANN to estimate the moment capacity ($M_r$). The trained model allowed the investigation of the effects on the moment capacity of the insulation material and the results indicated that the use of insulation materials with the smallest value of the thermal conductivities used in calculations is effective in protecting the RC beam against fire.

The effect of artificial shrinkage and assisted hatching on the development of mouse blastocysts and cell number after vitrification

  • Kim, Hye Jin;Lee, Ki Hwan;Park, Sung Baek;Choi, Young Bae;Yang, Jung Bo
    • Clinical and Experimental Reproductive Medicine
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    • 제42권3호
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    • pp.94-100
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    • 2015
  • Objective: The goal of this study was to ascertain optimal assisted hatching (AH) method in frozen embryo transfer. We compared the effect of depending on whether mechanical or laser-AH was performed before or after the vitrification of embryo development rate and blastocyst cell numbers. Methods: In order to induce superovulation, pregnant mare's serum gonadotropin followed by human chorionic gonadotropin were injected into 4- to 5-week-old female mice. 2-cell embryos were then collected by flushing out the oviducts. The Expanded blastocysts were recovered after the collected embryos were incubated for 48 hours, and were then subjected to artificial shrinkage (AS) and cross-mechanical AH (cMAH) or quarter-laser zona thinning-AH (qLZT-AH) were carried out using the expanded blastocysts before or after vitrification. After 48 hours of incubation, followed by vitrification and thawing (V-T), and blastocysts were fluorescence stained and observed. Results: The rate of formation of hatched blastocysts after 24 and 72 hours of incubation was significantly higher in the AS/qLZT-AH/V-T group than in the other groups (p<0.05). The cell number of the inner cell mass was higher in AS/V-T/non-AH and AS/V-T/cMAH groups than those of others (p<0.05). In the control group, the number of trophectoderm and the total cell number were higher than in the AS-AH group (p<0.05). Conclusion: The above results suggest that AS and AH in vitrification of expanded blastocysts lead to the more efficient formation of hatched blastocysts in mice.