• Journal of Oral Medicine and Pain
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• v.23 no.1
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• pp.85-99
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• 1998

In order to estimate the tooth-age by degree of attrition, the author has studied 605 stone models from 1996 to 1997. All of the attrition were classified and analyzed by 8 degrees. The result were as follows : 1. The degree of attrition in male was higher than that in female for same age group and especially, canine and first premolar showed the most prominent difference in sex. 2. The most severe attrition in posterior teeth was first molar followed by second molar, first premolar and second premolar in decreasing order of sequence. 3. The coefficient of correlation and relation equations by the degree of attrition were obtained.

• Journal of applied mathematics & informatics
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• v.36 no.3_4
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• pp.307-315
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• 2018

Let G be a simple connected graph with n vertices and m edges, with a sequence of vertex degrees $d_1{\geq}d_2{\geq}{\cdots}{\geq}d_n$ > 0. A vertex-degree topological index, referred to as harmonic index, is defined as $H={\sum{_{i{\sim}j}}{\frac{2}{d_i+d_j}}$, where i ~ j denotes the adjacency of vertices i and j. Lower and upper bounds of the index H are obtained.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.11a
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• pp.686-691
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• 2010

Flash boiling takes place when the thermodynamic state of the liquid deviates from its saturation limit over which the liquid temperature exceeds by a certain degree of superheat. The liquid jet introduced into the lower pressure zone than the liquid saturation pressure experiences a sequence of the atomization and disintegrated into numerous faster and smaller droplets. In the present study spray characteristics for a flash swirl spray were experimentally investigated. Injectant temperature is raised by a high frequency dielectric heating method and local spray characteristics are instantly measured by Global Sizing Velocimetry (GSV, TSI Inc.). Dependence of dimensionless superheat degree and injection pressure on total and local SMDs and mean droplet size is quantitatively examined. The flash swirl spray has the relation in the injection pressure and nozzle diameter in order to determine the spray quality, including the dimensionless superheat degree. Small droplets occur in the void core and local droplet size distributions largely depend on the dimensionless superheat degree and the injection pressure.

• Journal of Life Science
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• v.10 no.1
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• pp.32-36
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• 2000

Solitary long terminal repeats(LTRs) of human endogenous retrovirus K family(HERV-K) have been found to be coexpressed with sequences of closely located genes. It has been suggested that HERV-K LTR-like elements entered the primate genome approximately 33-40 million years ago. WE investigated the presence of HERV-K LTR elements in New World monkeys using PCR amplification. Six LTR elements of HERV-K family were identified from New World monkeys, represented by the squirrel and night monkeys. They showed a high degree of sequence homology(96-99%) with the human-specific HERV-K LTR elements. Phylogenetic analysis reveals that an LTR element (SM-1) from the squirrel monkey and another LTR element (NM-1) from the night monkey are very closely related to the human-specific HERV-K LTR elements with low degree of divergence. This finding suggests that some of LTR elements of HERV-K family have recently been proliferated in New World monkeys. A sequence in chromosome Xq26(AL034407) \ulcorner contains an HERV-K LTR element was shown to be present in the human genome, but is absent in the bonobo, chimpanzee, gorilla, orangutan, and gibbon. It has more than 99% homology to other human-specific HERV-K LTR elements. This sequence thus represents and isolated insertion of an evolving class of elements that may have made a particular contribution to human genomic plasticity.

• The korean journal of orthodontics
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• v.46 no.1
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• pp.3-12
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• 2016

Objective: The purpose of this study was to compare the precision of three-dimensional (3D) images acquired using iTero$^{(R)}$(Align Technology Inc., San Jose, CA, USA) and Trios$^{(R)}$(3Shape Dental Systems, Copenhagen, Denmark) digital intraoral scanners, and to evaluate the effects of the severity of tooth irregularities and scanning sequence on precision. Methods: Dental arch models were fabricated with differing degrees of tooth irregularity and divided into 2 groups based on scanning sequence. To assess their precision, images were superimposed and an optimized superimposition algorithm was employed to measure any 3D deviation. The t-test, paired t-test, and one-way ANOVA were performed (p < 0.05) for statistical analysis. Results: The iTero$^{(R)}$ and Trios$^{(R)}$ systems showed no statistically significant difference in precision among models with differing degrees of tooth irregularity. However, there were statistically significant differences in the precision of the 2 scanners when the starting points of scanning were different. The iTero$^{(R)}$ scanner (mean deviation, $29.84{\pm}12.08{\mu}m$) proved to be less precise than the Trios$^{(R)}$ scanner ($22.17{\pm}4.47{\mu}m$). Conclusions: The precision of 3D images differed according to the degree of tooth irregularity, scanning sequence, and scanner type. However, from a clinical standpoint, both scanners were highly accurate regardless of the degree of tooth irregularity.

• Journal of the Korean Society of Safety
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• v.27 no.6
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• pp.192-204
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• 2012

For a severe accident of nuclear power plant, an approach to estimation of the radiological source term using a severe accident code(MELCOR) has been proposed. Although the MELCOR code has a capability to estimate the radiological source term, it has been hardly utilized for the radiological consequence analysis mainly due to a lack of understanding on the relevant function employed in MELCOR and severe accident phenomena. In order to estimate the severe accident source term to be linked with the radiological consequence analysis, this study proposes 4-step procedure: (1) selection of plant condition leading to a severe accident(i.e., accident sequence), (2) analysis of the relevant severe accident code, (3) investigation of the code analysis results and post-processing, and (4) generation of radiological source term information for the consequence analysis. The feasibility study of the present approach to an early containment failure sequence caused by a fast station blackout(SBO) of a reference plant (OPR-1000), showed that while the MELCOR code has an integrated capability for severe accident and source term analysis, it has a large degree of uncertainty in quantifying the radiological source term. Key insights obtained from the present study were: (1) key parameters employed in a typical code for the consequence analysis(i.e., MACCS) could be generated by MELCOR code; (2) the MELOCR code simulation for an assessment of the selected accident sequence has a large degree of uncertainty in determining the accident scenario and severe accident phenomena; and (3) the generation of source term information for the consequence analysis relies on an expert opinion in both areas of severe accident analysis and consequence analysis. Nevertheless, the MELCOR code had a great advantage in estimating the radiological source term such as reflection of the current state of art in the area of severe accident and radiological source term.

• The Journal of the Korea institute of electronic communication sciences
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• v.7 no.2
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• pp.263-269
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• 2012

Code-Division Multiple-Access(CDMA) allows several users simultaneous access to a common channel by assigning a distinct pseudonoise sequence called spectrum code to each user. Each user in a CDMA system uses a assigned spectrum code to modulate their signal. Choosing the codes used to modulate the signal is very important in the performance of CDMA systems. The best performance will occur when there is good separation between the signal of a desired user and the signals of other users. The receiver synchronizes the code to recover the data. The use of an independent code allows multiple users to access the same frequency band at the same time. In this paper we propose a generalized model of non-linear binary sequence using trace function and analyze cross-correlation of these sequences. These sequences with low correlation, large linear span and large family size, in a direct-sequence spread spectrum communication system, help to minimize multiple access interference, increase security degree of system and enlarge user number.

• Journal of Microbiology and Biotechnology
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• v.8 no.3
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• pp.214-221
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• 1998

A Brevibacterium ammoniagenes gene coding for glucose/mannose-specific enzyme II ($EII^{Glc}$) of the phosphoenolpyruvate-dependent phosphotransferase system (PTS) was cloned by complementing an Escherichia coli mutation affecting a ptsG gene, and the complete DNA nucleotide sequence was determined. The cloned gene was identified to be a ptsG, which enables the E. coli transportment to use glucose more efficiently than mannose as the sole carbon source in an M9 minimal medium. The ptsG gene of B. ammoniagenes consists of an open reading frame of 1,983 nucleotides putatively encoding a polypeptide of 661 amino acid residues and a TAA stop codon. The deduced amino acid sequence of the B. ammoniagenes $EII^{Glc}$ shows, at $46\%$, the highest degree of sequence similarity with the Corynebacterium glutamicum EII specific for both glucose and mannose. In addition, the $EII^{Glc}$ shares approximately $30\%$ sequence similarities with sucrose-specific and ${\beta}$-glucoside-specific EIIs of the several bacteria belonging to the glucose-PTS class. The 161-amino-acid C-terminal sequence of $EII^{Glc}$ is also similar to that of E. coli enzyme $IIA^{Glc}$, specific for glucose ($EIIA^{Glc}$). The B. ammoniagenes $EII^{Glc}$ consists of three domains; a hydrophobic region (EIIC) and two hydrophilic regions (EIIA, EIIB). The arrangement of structural domains, IIBCA, of the $EII^{Glc}$ is identical to those of EIIs specific for sucrose or ${\beta}$-glucoside. While the domain IIA was removed from the B. ammoniagenes $EII^{Glc}$ the remaining domains IIBC were found to restore the glucose and mannose-utilizing capacity of E. coli mutant lacking $EII^{Glc}$ activity with $EIIA^{Glc}$ of the E. coli mutant. $EII^{Glc}$ contains a histidine residue and a cysteine residue which are putative phosphorylation sites for the protein.

• Journal of KIISE:Databases
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• v.32 no.6
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• pp.628-640
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• 2005

The XML is well accepted in several different Web application areas. As soon as many users and applications work concurrently on the same collection of XML documents, isolating accesses and modifications of different transactions becomes an important issue. When an XML document correctly corresponds to the rules laid out in a DTD or XML schema, it is also said to be valid. The valid XML document's validity should be guaranteed after the document is updated. The validation method mentioned above, however, results in lower degree of concurrency. For getting higher degree of concurrency and minimizing the range of the XML document validity, a new validation method based on a specific locking method is required. In this paper we propose the sequence group validation method for minimizing the range of the XML document validity. We also propose the boundary locking method for isolating accesses and modifications of different transactions while supporting the valid XML document's validity. Finally, the results of some experiments show the validation and locking methods increase the degree of transaction concurrency.

• Journal of Welding and Joining
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• v.28 no.4
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• pp.33-40
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• 2010

The purpose of this study is to establish a predictive equation of transverse residual stress at the thick FCA butt weldment of large container vessel. The variables used were restraint degree, yield strength of base material, thickness of weldment and welding heat input. Restraint degree at the thick weldment of container ship having the various welding sequence was calculated using FEA. From the result, the H-type specimen was designed to reproduce the level of restraint degree at the actual weldment of containership. Based on the results, the predictive equations of the mean value and the distribution of transverse residual stress at each location of the weldment were established using dimensional analysis and multiple-regression method. The predictive equations were verified by comparing with those measured by XRD in the actual weldment of the ship.