• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.8 no.2
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• pp.219-229
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• 1996

In the free molecular flow range, the pumping performance of a turbomolecular pump has been predicted by calculation of the transmission probability employing the integral method and the test particle Monte-Carlo method. The velocities of molecules incident upon a moving blade are given by the random numbers, which are sampled from the Maxwell molecular velocity distribution function. The present results agree quantitatively with the previous known numerical results. For a multi-stage pump, the velocity profile of molecules between two blade rows is not Maxwell distribution. In this case, the Monte-Carlo method is employed to calculate the overall transmission probability for the entire set of blade rows. When the results of the approximate method combining the single stage solutions are compared with those of the Monte-Carlo method for the pump having six rows at C=0.6, the approximate method overestimates as much as 36% in the maximum compression ratio and 19% in the maximum pumping speed than does the Mote-Carlo method.

• Journal of the Optical Society of Korea
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• v.16 no.1
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• pp.36-41
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• 2012

Polymethylmethacrylate powders are commonly used to improve the spreadability and blurring effects of powder foundation cosmetics. In this study, the opacity and haze effect of four types of polymethylmethacrylate powders and their 10wt% powder foundation formulation was evaluated. The distorted random hemispherical particulates with both concave and convex portions showed the highest haze and opacity value as a single powder substance. And as a formulated phase, the powder foundation formulation containing particulates with fine pores provided the highest haze and opacity value. We also examined the quantity of reflected light over the angular range $20-75^{\circ}$ by polarized light goniophotometry. The total reflected light intensity, surface-reflected light, and internally reflected light were characterized. These studies demonstrated that hemispherical PMMA powders produce natural brilliance by creating high internally reflected light which is similar to the total reflection profile of artificial skin.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.11
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• pp.4477-4487
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• 2015

In this review we summarize the results of studies employing high-throughput methods of profiling of HPV-associated cervical intraepithelial neoplasia (CIN) and squamous cell cervical cancers at key intracellular regulatory levels to demonstrate the unique identity of the landscape of molecular changes underlying this oncopathology, and to show how these changes are related to the 'natural history' of cervical cancer progression and the formation of clinically significant properties of tumors. A step-wise character of cervical cancer progression is a morphologically well-described fact and, as evidenced by genome-wide screenings, it is indeed the consistent change of the molecular profiles of HPV-infected epithelial cells through which they progressively acquire the phenotypic hallmarks of cancerous cells. In this sense, CIN/cervical cancer is a unique model for studying the driving forces and mechanisms of carcinogenesis. Recent research has allowed definition of the whole-genome spectrum of both random and regular molecular alterations, as well as changes either common to processes of carcinogenesis or specific for cervical cancer. Despite the existence of questions that are still to be investigated, these findings are of great value for the future development of approaches for the diagnostics and treatment of cervical neoplasms.

• The Korean Journal of Malacology
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• v.17 no.1
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• pp.1-6
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• 2001

The genetic relationship was examined with PCR-RAPD markers among three scallop species, Chlamys farreri farreri, Patinopecten yessoensis, and Agropecten irradians. Six primers were selected from 60 primers used to compare PCR-RAPD profiles among species. All primers showed distinct RAPD band patterns between the three species. In Chiamys farreri farreri, the morphological characteristics such as shell size and color were considerably different between the two geographical populations. RAPD profile, however, showed that no significant genetic differences were found between the two geographical populations. Polymorphic alleles were observed within a population of each species. Thus, PCR-RAPD markers are useful in identifying scallop species and in understanding scallop population genetic structure.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.23 no.11 s.170
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• pp.1960-1969
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• 1999

This paper presents dynamic modeling and controller design of a tracked vehicle installed with the double rod type ERSU(electro-rheological suspension unit). A 16 degree-of-freedom model for the tracked vehicle is established by Lagrangian method followed by the formulation of a new sky-ground hook controller. This controller takes account for both the ride quality and the steering stability. The weighting parameter between the two performance requirements is adopted to adjust required performance characteristics with respect to the operation conditions such as road excitation. The parameter is appropriately determined by employing a fuzzy algorithm associated with the vehicle motion. Computer simulations are undertaken in order to demonstrate the effectiveness of the proposed control system. Acceleration values at the driver's seat are analyzed under bump road profile, while frequency responses of vertical acceleration are investigated under random road excitation.

• Journal of Korean Society for Quality Management
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• v.40 no.3
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• pp.286-294
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• 2012

Purpose: In this study, we propose the ESS process model which, in order to improve reliability of electronic equipment, can be referenced in both development and production phases. Methods: ESS guidelines such as MIL handbooks or private sector ESS guidelines are used for devising the proposed ESS model. Especially, proposed model is customized by using those references in order to be optimized in the domestic development and production phases. Results: ESS-related-requirements which is specified in the Technical Data Package(TDP) for the area of guided missile systems are analyzed. Current status of the requirement and screening strength are analyzed for those systems to show what kind of weak points should be improved. Conclusion: A ESS guideline which is applicable to the domestic weapon acquisition environment is proposed. As such, the necessity and detail guidelines of the proposed model are explained.

• Journal of Mushroom
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• v.16 no.3
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• pp.140-146
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• 2018

Pleurotus eryngii is one of the most commercially important mushrooms cultivated in Korea. However, the shelf-life of the fruiting body is short, limiting its export. A new hybrid strain H17 of P. eryngii was developed to extend the shelf-life by mono-mono crossing between monokaryotic strains derived from DanBi and KNR2774. Although the cultivation period of H17 was slightly longer than that of the reference cultivar Kenneutari No.2, the quality did not change and remained normal after a period of 65.0 days at $4^{\circ}C$. This result was significantly different from that of the reference cultivar Kenneutari No.2. Analysis of the genetic characteristics of the new hybrid strain H17 revealed a different profile from that of the parental and reference cultivars when random amplification of polymorphic DNA (RAPD) primers was used. These results demonstrate that H17 is a new cultivar with improved storability after harvesting.

• Journal of Microbiology and Biotechnology
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• v.20 no.3
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• pp.563-568
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• 2010

The Val289 residue in the $\alpha$-amylase of Bacillus amyloliquefaciens, which is equivalent to the Ala289 and Val286 residues in the $\alpha$-amylases of B. stearothermophilus and B. licheniformis, respectively, was studied by site-directed mutagenesis. This residue was substituted with 10 different amino acids by random substitution of the Val codon. In these mutant $\alpha$-amylases, Val289 was substituted with Ile, Tyr, Phe, Leu, Gly, Pro, Ser, Arg, Glu, and Asp. Compared with the wild-type $\alpha$-amylase, the mutant $\alpha$-amylase Val289Ile showed 20% more hydrolytic activity, whereas Val289Phe and Val289Leu showed 50% lesser activity. On the other hand, the mutant $\alpha$-amylases Val289Gly, Val289Tyr, Val289Ser, and Val289Pro showed less than 15% activity. The substitution of Val289 with Arg, Asp, or Glu resulted in complete loss of the $\alpha$-amylase activity. Interestingly, the mutant $\alpha$-amylase Val289Tyr had acquired a transglycosylation activity, which resulted in the change of product profile of the reaction, giving a longer oligosaccharide.

• Corrosion Science and Technology
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• v.3 no.4
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• pp.166-171
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• 2004

Recent developments in Bridge Management Systems (BMS) and in Life-Cycle Cost (LCC) of bridges, have raised the need for evaluation procedure of future condition (Deterioration) of a bridge. Predicting future deterioration is not an easy task due to limited past data to extrapolate from and also due to difficulty in measuring actual deterioration such as section loss of steel on an actual steel bridge. Also, increase in live load and reduction of resistance are random variables, thus a probabilistic approach should be adopted for determining the future deterioration. Due to difficulties in evaluation of future deterioration on steel bridges, accepting uncertainties within a reasonable error, a deterministic procedure using bridge condition rating can be a useful tool for projection of future condition of bridges to identify repair and maintenance needs. The object of this paper is to determine applicability of evaluating deterioration of steel bridge components based on Bridge condition ratings. Bridge condition ratings of bridge components show wide variation for bridges of same age and does not directly correlate well with the age of the bridge and/or deterioration of the bridge. High uncertainty can be reduced by breaking down the rating and by sensitivity analysis. From refined condition rating data, generalized deterioration profile of structures based on age can be derived. Examples are shown for sample bridges in USA. Approximately, 3,000 short to medium span steel bridges were listed in the inventory database. Results show wide variation of rating factors but by subdividing the Bridge condition ratings for various categories general deterioration profiles of steel bridges can be determined.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.19 no.12
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• pp.2376-2385
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• 1994

In receiving the digital TV signal, both decoding delay and the channel hopping delay are very critical factors in applications. The intra-slice coding in the MPEG-2 SIMPLE PROFLE of No B-picture is one of the primary methods for short delay time in video decoding. It has the advantage of short decoding delay, but has the drawback of long channel hopping delay time. In this paper, we propose a method to reduce the channel delay with negligible loss in SNR performance. It is shown that dividing pictures into several regions of slices and adding some restriction in motion vector search for inter-frame coding. hence the random acess points are effectively increased. and the channel hopping delay is reduced.