scholarly journals BREADTH-FIRST SEARCH APPROACH TO ENUMERATION OF TREE-LIKE CHEMICAL COMPOUNDS

2013 ◽  
Vol 11 (06) ◽  
pp. 1343007 ◽  
Author(s):  
YANG ZHAO ◽  
MORIHIRO HAYASHIDA ◽  
JIRA JINDALERTUDOMDEE ◽  
HIROSHI NAGAMOCHI ◽  
TATSUYA AKUTSU
Keyword(s):  
Chemical Compounds ◽  
Search Space ◽  
Breadth First Search ◽  
Tree Graphs ◽  
Molecular Tree ◽  
Computer Scientists ◽  
Long Time ◽  
Search Order ◽  
Enumeration Algorithms ◽  
Search Approach

Molecular enumeration plays a basic role in the design of drugs, which has been studied by mathematicians, computer scientists, and chemists for quite a long time. Although many researchers are involved in developing enumeration algorithms specific to drug design systems, molecular enumeration is still a hard problem to date due to its exponentially increasing large search space with larger number of atoms. To alleviate this defect, we propose efficient algorithms, BfsSimEnum and BfsMulEnum to enumerate tree-like molecules without and with multiple bonds, respectively, where chemical compounds are represented as molecular graphs. In order to reduce the large search space, we adjust some important concepts such as left-heavy, center-rooted, and normal form to molecular tree graphs. Different from many existing approaches, BfsSimEnum and BfsMulEnum firstly enumerate tree-like compounds by breadth-first search order. Computational experiments are performed to compare with several existing methods. The results suggest that our proposed methods are exact and more efficient.

scholarly journals Parallelization of enumerating tree-like chemical compounds by breadth-first search order

2015 ◽  
Vol 8 (S2) ◽  
Author(s):  
Morihiro Hayashida ◽  
Jira Jindalertudomdee ◽  
Yang Zhao ◽  
Tatsuya Akutsu
Keyword(s):  
Chemical Compounds ◽  
Breadth First Search ◽  
Search Order

Bacterial presence in polar regions associated with environment modification by chemical compounds including contaminants

2017 ◽  
Vol 25 (4) ◽  
pp. 481-491 ◽  
Author(s):  
Klaudia Kosek ◽  
Katarzyna Jankowska ◽  
Żaneta Polkowska
Keyword(s):  
Bacterial Communities ◽  
Chemical Compounds ◽  
Freshwater Ecosystems ◽  
Trophic Levels ◽  
Polar Regions ◽  
Bacterial Cells ◽  
Chemical Contamination ◽  
Climate Conditions ◽  
Biological Communities ◽  
Long Time

Microbes are omnipresent and diverse members of all biological communities. In marine and freshwater ecosystems, microorganisms form the base of the food chain supporting higher trophic levels. Even though microbes are generally thought to live in warm regions of Earth, many of them develop in cold climates. Polar regions remain relatively protected from widespread anthropogenic disturbances, which is a consequence of thier remoteness and extreme climate conditions. For a long time these regions were considered to be free from chemical contamination until scientists discovered a presence of pollutants there. Chemical contamination may induce serious disorders in the integrity of polar ecosystems influencing the growth of bacterial communities. Xenobiotics including persistent organic pollutants are transported thousands of kilometers by the air and ocean currents, and they are deposed in high-latitude regions and accumulate in all elements of the environment including bacterial communities. It is important to determine their concentration levels in bacterial cells to assess the possibility of contaminants becoming transferred to higher trophic levels; however, some species of bacteria are capable of metabolizing xenobiotics, which makes them less toxic or even removes them from the environment.

scholarly journals Breadth First Search Approach for Shortest Path Solution in Cartesian Area

2018 ◽  
Vol 1019 ◽  
pp. 012038 ◽  
Author(s):  
Robbi Rahim ◽  
Dahlan Abdullah ◽  
Saiful Nurarif ◽  
Mukhlis Ramadhan ◽  
Badrul Anwar ◽  
...  
Keyword(s):  
Shortest Path ◽  
Breadth First Search ◽  
Search Approach

INDEX-MAXMINER: A NEW MAXIMAL FREQUENT ITEMSET MINING ALGORITHM

2008 ◽  
Vol 17 (02) ◽  
pp. 303-320 ◽  
Author(s):  
WEI SONG ◽  
BINGRU YANG ◽  
ZHANGYAN XU
Keyword(s):  
Search Strategy ◽  
Search Space ◽  
Frequent Itemset ◽  
Breadth First Search ◽  
Hybrid Search ◽  
Itemset Mining ◽  
Frequent Item ◽  
Enumeration Tree ◽  
Frequent Items ◽  
Mining Algorithms

Because of the inherent computational complexity, mining the complete frequent item-set in dense datasets remains to be a challenging task. Mining Maximal Frequent Item-set (MFI) is an alternative to address the problem. Set-Enumeration Tree (SET) is a common data structure used in several MFI mining algorithms. For this kind of algorithm, the process of mining MFI's can also be viewed as the process of searching in set-enumeration tree. To reduce the search space, in this paper, a new algorithm, Index-MaxMiner, for mining MFI is proposed by employing a hybrid search strategy blending breadth-first and depth-first. Firstly, the index array is proposed, and based on bitmap, an algorithm for computing index array is presented. By adding subsume index to frequent items, Index-MaxMiner discovers the candidate MFI's using breadth-first search at one time, which avoids first-level nodes that would not participate in the answer set and reduces drastically the number of candidate itemsets. Then, for candidate MFI's, depth-first search strategy is used to generate all MFI's. Thus, the jumping search in SET is implemented, and the search space is reduced greatly. The experimental results show that the proposed algorithm is efficient especially for dense datasets.

Deep Analysis on Bioindustry Prospects of 40°С Volatiles of Cinnamomum camphora Branches

2011 ◽  
Vol 480-481 ◽  
pp. 266-271
Author(s):  
Qi Mei Liu ◽  
Dang Quan Zhang ◽  
Kuan Peng ◽  
Wan Xi Peng
Keyword(s):  
Acetic Acid ◽  
Ethyl Ester ◽  
Chemical Compounds ◽  
Chemical Components ◽  
Cinnamomum Camphora ◽  
Propenoic Acid ◽  
Long Time ◽  
Industrial Materials ◽  
Analytical Result ◽  
Main Components

Cinnamomum camphora has been used to heal some specific diseases in the Chinese Folk for a long time. In order to explore the wide utilization in biomedicine and spicery, the chemical components of helium volatiles from the fresh branches of C. camphora were studied by TD-GC/MS. The analytical result by TD-GC/MS showed that 50 peaks were obtained from the helium volatiles from the fresh branches of C. camphora and 46 chemical compounds representing 99.993% of the total areas were identified. The results showed that the main components were as: Bicyclo[2.2.1]heptan-2-one, 1,7,7-trimethyl-, (1R)- (9.620%), 3-Cyclohexene-1- methanol, .alpha.,.alpha.4-trimethyl- (9.425%), 1,3-Benzodioxole, 5-(2-propenyl)- (8.223%), Bicyclo[2.2.1]heptane, 2-methyl-3-methylene-2-(4-methyl-3-pentenyl)-, (1S-exo)- (7.541%), Tricyclo[2.2.1.0(2,6)]heptane, 1,7-dimethyl-7-(4-methyl-3-pentenyl)-, (-)- (6.884%), Bicyclo[3.1.1] hept-2-ene, 2,6-dimethyl-6-(4-methyl-3-pentenyl)- (6.050%), Bicyclo[2.2.1]heptan-2-one, 1,7,7- trimethyl-, (1S)- (4.678%), 1,3-Benzodioxole, 5-(2-propenyl)- (4.500%), Naphthalene, 1,2,3,5,6,8a- hexahydro-4,7-dimethyl-1-(1-methylethyl)-, (1S-cis)- (4.491%), 3-Cyclohexen-1-ol, 4-methyl-1- (1-methylethyl)-, (R)- (4.254%), Copaene (4.120%), Tricyclo[2.2.1.0(2,6)]heptane, 1,7-dimethyl-7- (4-methyl-3-pentenyl)-, (-)- (4.097%), Acetic acid, 1,7,7-trimethyl-bicyclo[2.2.1]hept-2-yl ester (3.574%), Borneol 3.334%), 3-(4-N,N-Dimethylaminophenyl)propenoic acid, 2- (diethoxyphosphinyl)-, ethyl ester (2.809%), Eucalyptol (2.096%), 1,6,10-Dodecatriene, 7,11- dimethyl-3-methylene-, (Z)- (1.885%), (-)-Isosativene (1.664%), 1,6,10-Dodecatrien-3-ol, 3,7,11-trimethyl- (1.407%), Cyclohexene, 1-methyl-4-(5-methyl-1-methylene-4-hexenyl)-, (S)- (1.218%), 1,4-Methanoazulene, decahydro-4,8,8-trimethyl-9-methylene-, [1S-(1.alpha.,3a.beta., 4.alpha.,8a.beta.)]- (1.174%), .alpha.-Caryophyllene (1.156%), etc. The analytical result suggested that the helium volatiles from the fresh branches of C. camphora can be applicable to biomedicine and spicery industrial materials.

scholarly journals Efficient Breadth-First Reduct Search

Mathematics ◽  
2020 ◽  
Vol 8 (5) ◽  
pp. 833
Author(s):  
Veera Boonjing ◽  
Pisit Chanvarasuth
Keyword(s):  
Information System ◽  
Search Strategy ◽  
Search Space ◽  
Graph Search ◽  
Search Problem ◽  
Breadth First Search ◽  
Time And Space ◽  
First Order ◽  
Pruning Rule

This paper formulates the problem of determining all reducts of an information system as a graph search problem. The search space is represented in the form of a rooted graph. The proposed algorithm uses a breadth-first search strategy to search for all reducts starting from the graph root. It expands nodes in breadth-first order and uses a pruning rule to decrease the search space. It is mathematically shown that the proposed algorithm is both time and space efficient.

High Efficient Data Embedding in Image Steganography Using Parallel Programming

2018 ◽  
pp. 67-80
Author(s):  
Usha B. A.
Keyword(s):  
The Internet ◽  
Data Embedding ◽  
File Formats ◽  
High Efficient ◽  
Other Information ◽  
Computer Scientists ◽  
Long Time ◽  
Efficient Data ◽  
Weak Points ◽  
Time Required

Steganography is the art of hiding the fact that communication is taking place, by hiding information in other information. Many different carrier file formats can be used, but digital images are the most popular because of their frequency on the Internet. For hiding secret information in images, there exist a large variety of steganographic techniques some are more complex than others and all of them have respective strong and weak points.. As embedding data in an image, is independent of one another. Parallelism can be used to achieve considerable time gain. nography, although it has made communication safe, it has its own drawbacks. One among it is time required to embed data in pixels of the image. This problem is bugging computer scientists from long time. This paper discusses a method which makes OpenMP parallel library to parallelize embedding of data, which basically reduces the time by almost fifty percent and to achieve PSNR ranging from 30 to 50 after embedding data in the pixels of the image.

scholarly journals A New Approach for Modelling Gene Regulatory Networks Using Fuzzy Petri Nets

2010 ◽  
Vol 7 (1) ◽  
pp. 1-16 ◽  
Author(s):  
Raed I. Hamed ◽  
S. I. Ahson ◽  
R. Parveen
Keyword(s):  
Gene Regulatory Networks ◽  
Regulatory Networks ◽  
Fuzzy Model ◽  
Fuzzy Reasoning ◽  
Search Space ◽  
Expression Level ◽  
Regulatory Relationship ◽  
Computer Scientists ◽  
Fuzzy Petri Nets ◽  
Gene Regulatory

SummaryGene Regulatory Networks are models of genes and gene interactions at the expression level. The advent of microarray technology has challenged computer scientists to develop better algorithms for modeling the underlying regulatory relationship in between the genes. Fuzzy system has an ability to search microarray datasets for activator/repressor regulatory relationship. In this paper, we present a fuzzy reasoning model based on the Fuzzy Petri Net. The model considers the regulatory triplets by means of predicting changes in expression level of the target based on input expression level. This method eliminates possible false predictions from the classical fuzzy model thereby allowing a wider search space for inferring regulatory relationship. Through formalization of fuzzy reasoning, we propose an approach to construct a rule-based reasoning system. The experimental results show the proposed approach is feasible and acceptable to predict changes in expression level of the target gene.

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