• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2020년도 추계국제학술대회
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• pp.14-14
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• 2020

In December 2019, the COVID-19 epidemic was discovered in Wuhan, China, and since has disseminated around the world impacting human health for millions. Herein, in-silico drug discovery approaches were utilized to identify potential candidates as Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2) main protease (M^pro) inhibitors. We investigated several databases including natural and natural-like products (>100,000 molecules), DrugBank database (10,036 drugs), major metabolites isolated from daily used spices (32 molecules), and current clinical drug candidates for the treatment of COVID-19 (18 drugs). All tested compounds were prepared and screened using molecular docking techniques. Based on the calculated docking scores, the top ones from each project under investigation were selected and subjected to molecular dynamics (MD) simulations followed by molecular mechanics-generalized Born surface area (MM-GBSA) binding energy calculations. Combined long MD simulations and MM-GBSA calculations revealed the potent compounds with prospective binding affinities against M^pro. Structural and energetic analyses over the simulated time demonstrated the high stabilities of the selected compounds. Our results showed that 4-bis([1,3]dioxolo)pyran-5-carboxamide derivatives (natural and natural-like products database), DB02388 and Cobicistat (DB09065) (DrugBank database), salvianolic acid A (spices secondary metabolites) and TMC-310911 (clinical-trial drugs database) exhibited high binding affinities with SARS-CoV-2 M^pro. In conclusion, these compounds are up-and-coming anti-COVID-19 drug candidates that warrant further detailed in vitro and in vivo experimental estimations.

• 한국전산유체공학회지
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• 제19권2호
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• pp.86-92
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• 2014

In this paper, prediction of separation trajectory for Two-stage-To-Orbit space launch vehicle has been numerically simulated by using an aerodynamic database based on steady state analysis. Aerodynamic database were obtained for matrix of longitudinal and vertical positions. The steady flow simulations around the launch vehicle have been made by using a 3-D RANS flow solver based on unstructured meshes. For this purpose, a vertex-centered finite-volume method was adopted to discretize inviscid and viscous fluxes. Roe's finite difference splitting was utilized to discretize the inviscid fluxes, and the viscous fluxes were computed based on central differencing. To validate this flow solver, calculations were made for the wind-tunnel experiment model of the LGBB TSTO vehicle configuration on steady state conditions. Aerodynamic database was constructed by using flow simulations based on test matrix from the wind-tunnel experiment. ANN(Artificial Neural Network) was applied to construct interpolation function among aerodynamic variables. Separation trajectory for TSTO launch vehicle was predicted from 6-DOF equation of motion based on the interpolated function. The result of present separation trajectory calculation was compared with the trajectory using experimental database. The predicted results for the separation trajectory shows fair agreement with reference[4] solution.

• 공학교육연구
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• 제6권1호
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• pp.56-64
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• 2003

본 논문에서는 클라이언트/서버 분산 환경을 설계하여 전자회로에 대한 웹 기반 가상실험 시스템을 개발하였다. 제안된 가상실험실은 실제 대학에서 운영되는 실험실 환경을 묘사하도록 구현되었기 때문에 학습자들은 실제 실험실 유사한 실험결과를 가상실험실에서 얻을 수 있다. 제안된 가상실험시스템은 원리학습실, 가상실험학습실, 평가학습실 그리고 전체 관리시스템의 4가지 중요한 구성요소로 이루어져 있다. 제안된 가상실험실을 통해 학습자들은 전자회로 실험과 관련된 개념이나 이론을 학습할 수 있으며, 멀티미터나 신호발생기 그리고 디지털 오실로스코프나 DC전원공급기 같은 계측장비의 동작방법을 웹상에서 학습할 수 있다. 또한 가상실험실에서 일어나는 모든 실험 활동은 전체 관리시스템에 의해 데이터베이스에 기록되어 예비보고서 형태로 출력된다. 웹상에서 데이터베이스의 연결은 PHP에 의해 이루어지며 가상실험실 환경은 각 학습자들에 대해 조금씩 다른 결과가 나타나도록 구성하였다. 마지막으로 가상실험실을 운영한 결과 전체 실험시간과 실험장비의 손상율이 감소되며, 교수생산성이나 학습효율이 증가되는 긍정적인 결과를 얻을 수 있었다.

• Interdisciplinary Bio Central
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• 제1권3호
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• pp.9.1-9.6
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• 2009

Introduction: In the mass spectrometry-based proteomics, biological samples are analyzed to identify proteins by mass spectrometer and database search. Database search is the process to select the best matches to the experimental mass spectra among the amino acid sequence database and we identify the protein as the matched sequence. The match score is defined to find the matches from the database and declare the highest scored hit as the most probable protein. According to the score definition, search result varies. In this study, the difference among search results of different search engines or different databases was investigated, in order to suggest a better way to identify more proteins with higher reliability. Materials and Methods: The protein extract of human mesenchymal stem cell was separated by several bands by one-dimensional electrophorysis. One-dimensional gel was excised one by one, digested by trypsin and analyzed by a mass spectrometer, FT LTQ. The tandem mass (MS/MS) spectra of peptide ions were applied to the database search of X!Tandem, Mascot and Sequest search engines with IPI human database and SwissProt database. The search result was filtered by several threshold probability values of the Trans-Proteomic Pipeline (TPP) of the Institute for Systems Biology. The analysis of the output which was generated from TPP was performed. Results and Discussion: For each MS/MS spectrum, the peptide sequences which were identified from different conditions such as search engines, threshold probability, and sequence database were compared. The main difference of peptide identification at high threshold probability was caused by not the difference of sequence database but the difference of the score. As the threshold probability decreases, the missed peptides appeared. Conversely, in the extremely high threshold level, we missed many true assignments. Conclusion and Prospects: The different identification result of the search engines was mainly caused by the different scoring algorithms. Usually in proteomics high-scored peptides are selected and low-scored peptides are discarded. Many of them are true negatives. By integrating the search results from different parameter and different search engines, the protein identification process can be improved.

• International Journal of Concrete Structures and Materials
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• 제7권4호
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• pp.273-285
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• 2013

An experimental investigation was conducted to compare the shear strength of full-scale beams constructed with chemically-based, self-consolidating concrete (SCC) with conventional concrete (CC). This experimental program consisted of 16 rectangular beams (12 without shear reinforcing and 4 with shear reinforcing in the form of stirrups), 8 beams for each mix design. Additionally, three different longitudinal reinforcement ratios were evaluated within the test matrix. The beam specimens were tested under a simply supported four-point condition. The experimental shear strengths of the beams were compared with both the shear provisions of selected standards (U.S., Australia, Canada, Europe, and Japan) and a shear database of CC specimens. This comparison indicates that chemically-based SCC beams possess comparable shear strength as CC beams.

• 정보처리학회논문지:소프트웨어 및 데이터공학
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• 제2권12호
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• pp.855-864
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• 2013

판단 트리 분류는 데이터 마이닝의 중요한 문제의 하나이고, 데이터 마이닝은 대형 데이터베이스 기술의 중요한 과제가 되고 있다. 그러므로 데이터베이스와 데이터 마이닝 시스템의 결합 노력은 판단 트리 분류와 같은 데이터 마이닝 기능을 지원하는 데이터베이스 기초 기능의 개발로 이어지고 있다. 이런 기초 기능은 분류 알고리즘의 SQL 구현을 지원하는 특수한 데이터베이스 연산들로 구현되며, 특정 알고리즘을 구현하여 데이터베이스 시스템의 구성 모듈로 사용하고 있다. 데이터마이닝 기능을 제공하는 데이터베이스 기초 기능의 개발에는 두 가지 관점이 있다. 하나는 데이터 마이닝 기능을 분석해서 그런 기능들을 제공하는 데이터베이스 공통 기초 기능을 확인하는 것, 다른 하나는 데이터베이스 시스템의 인터페이스의 한 부분으로 이런 기초 기능의 구현을 위한 확장된 메커니즘을 제공하는 것이다. 데이터마이닝에서 어떤 기초 기능들을 DBMS에 저장할 것인가는 어려운 문제 중에 하나이다. 따라서 본 논문에서는 이러한 문제를 해결하기 위하여, 최적화된 판단 트리 분류기를 만들고 데이터베이스 기초 기능에 대해서 기술한다. 판단 트리 분류 알고리즘의 유용한 연산들을 확인하고, 상업적 DBMS에서 이러한 기초 기능의 구현에 대해서 기술하고, 성능 비교를 위한 실험 결과를 제시한다.

• The Korean Journal of Physiology and Pharmacology
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• 제28권1호
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• pp.59-72
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• 2024

To investigate the mechanism of Wenshen Xuanbi Decoction (WSXB) in treating osteoarthritis (OA) via network pharmacology, bioinformatics analysis, and experimental verification. The active components and prediction targets of WSXB were obtained from the TCMSP database and Swiss Target Prediction website, respectively. OA-related genes were retrieved from GeneCards and OMIM databases. Protein-protein interaction and functional enrichment analyses were performed, resulting in the construction of the Herb-Component-Target network. In addition, differential genes of OA were obtained from the GEO database to verify the potential mechanism of WSXB in OA treatment. Subsequently, potential active components were subjected to molecular verification with the hub targets. Finally, we selected the most crucial hub targets and pathways for experimental verification in vitro. The active components in the study included quercetin, linolenic acid, methyl linoleate, isobergapten, and beta-sitosterol. AKT1, tumor necrosis factor (TNF), interleukin (IL)-6, GAPDH, and CTNNB1 were identified as the most crucial hub targets. Molecular docking revealed that the active components and hub targets exhibited strong binding energy. Experimental verification demonstrated that the mRNA and protein expression levels of IL-6, IL-17, and TNF in the WSXB group were lower than those in the KOA group (p < 0.05). WSXB exhibits a chondroprotective effect on OA and delays disease progression. The mechanism is potentially related to the suppression of IL-17 and TNF signaling pathways and the down-regulation of IL-6.

• 소성∙가공
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• 제20권2호
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• pp.146-153
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• 2011

This study aimed at providing an experimental database for the mechanical properties of AZ31B magnesium alloy sheet such as stress-strain curve, yield stress, R-value and forming limit diagram(FLD) at various strain-rates and temperatures. Tensile tests were carried out on specimens having the orientations of $0^{\circ}$, $45^{\circ}$ and $90^{\circ}$ to the rolling direction with different crosshead speeds in the range between 0.008 and 8 mm/s at temperature from 25(room temperature) to $300^{\circ}C$. The influence of the specimen gage length on the tensile properties was investigated. FLD tests were performed at punch speed of 0.1 and 1.0 mm/s in the same temperature range as that of the tensile tests. Swift cup tests were conducted to verify the usefulness of the material database and the reliability of the finite element analysis(FEA). The effects of strain-rate as well as temperature were taken into account in these simulations. It was shown that the FLD-based failure was reasonably well predicted by the thermal-deformation coupled analysis for this rate-sensitive material.

• 한국컴퓨터산업학회논문지
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• 제2권12호
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• pp.1601-1608
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• 2001

디지털 도서관은 자연어 문서와 멀티미디어 자료에 대한 정보 검색 엔진을 필요로 하는 가장 중요한 데이터베이스 시스템이다. 이 논문은 자연어 처리 기법의 정보 검색 엔진과 브라우저에 대한 설계와 실험 결과를 소개한다. 자연어 문서에 대한 정보 검색 과정은 어휘 분석, 구문 분석, 스테밍, 주제어 색인 등의 계산학적 처리를 포함한다. 많은 이미지와 이미지의 제목, 그리고 자연어로 기술된 설명 문서를 포함하는 실험적인 데이터베이스 ‘Earth and Space Science’를 통해서 자연어 문서 분석에 기반하는 정보 검색 기능을 실험하였다. 또한 디지털 도서관 환경에서의 멀티미디어 정보 검색 내용 기반의 이미지 검색 엔진과 병행하는 정보 검색 시스템으로서의 가능성을 보여준다.

• 한국생산제조학회지
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• 제9권4호
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• pp.56-61
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• 2000

Cognition and control of grinding trouble occurring during the grinding process are classified into a quantitative knowledge which depends on experimental data and qualitative knowledge which relies on skilful engineers. Grinding operations include a large number of functional parameters, since there are several ways of coping with grinding trouble. One is the qualitative method which depends on empirical knowledge utilizing the skilful experts from the workship, the other is the quantitative method which utilizes the experimental data obtained by a sensor. But, they are all difficult to accomplish from the grinding trouble-shooting system. The reason is that grinding troubles are now easily controlled in the quantitative method, and therefore, trouble-shooting has mainly relied on the knowledge of skilful engineers. Thus, there is an important issue of how a grinding trouble-shooting system can be designed and what knowledge is utilized among the large amount of grinding trouble information. In this paper, basic strategy to develop the grinding database of rule-based model, which is strongly depended upon experience and intuition , is described.