• Journal of Life Science
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• v.20 no.12
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• pp.1882-1888
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• 2010

To develop probiotics, a kind of Lactobacillus sp. was isolated from infant feces. The bacterium was identified as Lactobacillus rhamnosus through 16S rDNA sequence analysis. The strain was a facultative anaerobe which grew better in aerobic conditions. The bacterium lowered the pH of the culture solution down to 2.4 during 48 hr in the MRS medium. The strain inhibited the growth of 6 pathogens - S. aureus, L. monocytogens, S. typhimurium, E. coli O-157, V. parahaemolyticus and P. aeruginosa. When the Lactobacillus were fed to chickens, along with commercial feed, for one month, amounts of $H_2S$ and $NH_3$ in the feces of the chicken decreased to 50% and 70%, respectively, compared to those of control group chickens. Amounts of other bad smells such as $(CH_3)SH$, $(CH_3)_2S$ and $(CH_3)_2S_2$ were not much different in the Lactobacillus-fed chickens compared to the control group. On the other hand, egg weights of the chickens fed Lactobacillus were higher by about $5{\pm}1\;g$ than those in the control group.

• Korean Journal of Heritage: History & Science
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• v.54 no.3
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• pp.192-203
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• 2021

This paper investigates the process of change in the meaning of the term gongye (工藝) (nowadays it means craft) during Korea's transition to the modern era. The Annals of the Joseon Dynasty (朝鮮王朝實錄) will serve as the basis for the examination of pre-modern usage, and the Korea-United States Treaty of 1882 for the changes that occurred between the translation from Chinese and from Japanese following the opening of the port . After the port opened, the meaning of gongye, which once broadly referred to the wide range of work of people from different fields, was narrowed down to singularly represent the manufacturing industry. Following the example of Japan, the first East Asian country to succeed in modernization, this new meaning of gongye was generally used in the context of embracing Western culture and creating industry. As industrialization emerged as a national mission, and new terminology was needed to express these new concepts, the Chinese characters used by the Japanese to translate Western concepts were directly imported and used without making any changes. Gongye was similar in meaning to gongeop (工業) (nowadays it means industry) at the time, and the two terms were used interchangeably. However, following the Japanese annexation of Korea, the cultural administration of the Governor-General imbued the term with artistic concepts, and gongye was differentiated from gongeop, As such, examining the establishment of terminology and concepts can be helpful for understanding the contradictions and problems of the Korean crafts scene, which were derived from a period in the past called the modern era.

• Proceedings of the KSME Conference
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• 2007.05b
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• pp.1882-1887
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• 2007

In the present experimental study, the effect of interfacial tensions on pressure drop of air-water two-phase flow in round mini-channels was investigated. A glass (highly wettable) tube and a Teflon (poorly wettable) tube, both in 350 mm length but 1.8 mm and 1.59 mm in inner diameters each, were used for the tests. All the experiments were performed only in the plug flow regime, confirmed by visualization. In the glass tube, the gas plugs were surrounded by the liquid film along the inner periphery. On the other hand, the inner wall remained dry at the gas portion in the Teflon tube. The pressure drop of the plug flow in the Teflon tube without the liquid film) appeared much larger than in the glass tube (with the liquid film) due to dissipation of energy by movement of the wetting lines. In this paper, various correlations on the two-phase pressure drop of plug flows were compared and a modified correlation was proposed, taking account of the surface wettability.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.1879-1882
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• 2005

Due to increase of demands on safety and convenience for automotive vehicle, the use of DC motor, such as power window, seat adjusting, pedal adjusting, sunroof, electric shift motor and so on, is increasing rapidly in the whole world. Worm gear is an important part to transmit torque to another gear in gear mechanism of automotive DC motor. But with current forming process, it has some problems in manufacturing and the quality. Also, the characteristics of automotive parts such as price and mass-production limit the quality improvement. Recently several methods are used in order to reduce a worm screw machining time and to maintain precision. In this paper, we introduce whirling tool machining and side milling cutter machining as effective manufacturing method of worm screw and study on the cutting force of side milling cutter and whirling tool in worm screw machining.

• Korean Institute of Interior Design Journal
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• v.15 no.5 s.58
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• pp.12-19
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• 2006

The artistic features of German Expressionism in the early twentieth century are often recognized for its abstract and emotional representation in art and architecture. Expressionism departed from the paintings, notably the works of Der Blaue Reiter and the Bruck, but the architectural works with curve and organic features were also taken as expressive. German architects Hans Scharoun (1893-1972) and Hugo Haring (1882-1958), in this regard, have long been regarded as Expressionist architects, but recent studies suggest that their architectural designs include a profound idea of modem functional building. Scharoun and Haring held a socialist utopian vision as other modernists have also had, but their inherent view upon modern architecture was function which was mistakenly viewed as Expressionism in earlier documents. This paper intends to exemplify how Expressionism is inappropriate to represent the expressive presentations of Scharoun and Haring. Despite the fact that their designs possess certain expressionist elements, their works can also be constructed as an advanced functionalism. Many young architects in Germany were not given chances to build due to economic hardship after the First World War, and they were naturally led to imagery sketch designs for future architecture. Abstract Idea was freely exposed in its preliminary visual form, and it is also uneasy to draw a borderline between expressive presentation and the Expressionism itself.

• Journal of Microbiology and Biotechnology
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• v.16 no.12
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• pp.1882-1889
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• 2006

A 16S rDNA clone library was generated to investigate the bacterial diversity in intertidal sediment from the coast of the Yellow Sea, P. R. China. A total of 102 clones were sequenced and grouped into 73 OTUs using a phylogenetic approach. The sequenced clones fell into 11 bacterial lineages: Proteobacteria, Bacteroidetes, Planctomycetes, Chloroflexi, Acidobacteria, Actinobacteria, Firmicutes, Spirochaetes, and candidate divisions of BRCl, OP3, and OP1l. Based on a phylogenetic analysis of these bacteria, together with the ten most closely related sequences deposited in the GenBank, it was concluded that intertidal bacteria are most likely derived from marine bacteria with a remarkable diversity, and some are particularly abundant in intertidal sediment.

• Journal of Electrical Engineering and Technology
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• v.12 no.5
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• pp.1872-1882
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• 2017

Medium voltage drive systems driven by high-power multi-level inverters operating at low switching frequency can reduce the switching losses of the power device and increase the output power. Employing subsection synchronous current harmonic minimum pulse width modulation (CHMPWM) technique can maintain the total harmonic distortion of current at a very low level. It can also reduce the losses of the system, improve the system control performance and increase the efficiency of DC-link voltage accordingly. This paper proposes a subsection synchronous CHMPWM approach of active neutral point clamped five-level (ANPC-5L) inverter under low switching frequency operation. The subsection synchronous scheme is obtained by theoretical calculation based on the allowed maximum switching frequency. The genetic algorithm (GA) is adopted to get the high-precision initial values. So the expected switching angles can be achieved with the help of sequential quadratic programming (SQP) algorithm. The selection principle of multiple sets of the switching angles is also presented. Finally, the validity of the theoretical analysis and the superiority of the CHMPWM are verified through both the simulation results and experimental results.

• Journal of Mechanical Science and Technology
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• v.15 no.12
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• pp.1882-1891
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• 2001

The present paper investigated the effect of ultrasonic vibrations on the melting process of a phase-change material (PCM). Furthermore, the present study considered constant heat flux boundary conditions unlike many of the previous researches adopted constant wall temperature conditions. Therefore, in the present study, modified dimensionless parameters such as Ste* and Ra* were used. Also, general relationships between melting with ultrasonic vibrations and melting without ultrasonic vibrations were established during the melting of PCM. Experimental observations show that the effect of ultrasonic vibrations on heat transfer is very important throughout the melting process. The results of the present study reveal that ultrasonic vibrations accompany the effects like agitation, acoustic streaming, cavitation, and oscillating fluid motion. Such effects are a prime mechanism in the overall melting process when ultrasonic vibrations are applied. They enhance the melting process as much as 2.5 tildes, compared with the result of natural melting. Also, energy can be saved by applying ultrasonic vibrations to the natural melting. In addition, various time-wise dimensionless numbers provide conclusive evidence of the important role of ultrasonic vibrations on the melting phenomena.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.1882-1889
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• 2007

Surveying rocks for engineering aims for prediction of geological feature of the construction site. Conventionally, survey information at outcrops and bore holes are projected to the construction sites, such as tunnel and slopes, and rock properties of the sites are predicted by interpretations of specialists. This system, the "Fracjection", aims to assist the specialist for visualization of the projected fractures from borehole and outcrop survey. The Fracjection accepts the BIPS and outcrop survey data to its database and allows plotting them in AutoCad map. The software also reads elevation data from contours of the topographic map and constructs DEM of the construction sites. With user's guide, it generates 3D excavation sites such as slopes and tunnels at the topographic map. The s/w projects borehole and outcrop surveyed fractures onto the modeled excavation surface and allows analysis of failure criteria, such as plane, wedge, and toppling failures by built-in stereonet function. Projected fractures can further be analyzed for structural homogeneities and rock mass quality. Moving window style correlation comparison of stereonet plots are used for formal analyses, and RQD type counts of the projected fractures are adopted for the latter analyses.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.1877-1882
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• 2007

The Yongsan International Business District development work is a 20 billion$ project to raise facilities for national business, trade, residence, and culture. The project site is $566,800m^2$ and it covers the railroad maintenance center and Dongbuichon-dong. Developing railroad station region used to be done by private investment. However, problems existed; simple function as a massive selling market, traffic jam caused by massive market users, inadequacy to transfer to other transportations, interruption of the pedestrian way and separation of zone of life by the station. To solve this problem it is important to consider developing cases of other countries and devise a plan that is applicable to our circumstances. In the study, we compared our station development case with foreign station development cases and analyze the element for the plan what we should consider in our station development. In addition, The results of the study can be used as a preliminary data in the future planning the Yongsan International Business District development.