• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.23 no.12
• /
• pp.106-114
• /
• 2009

This paper addresses unit commitment for microgrid optimization including renewable energy sources, working under deregulated power market. As microgrid supplies both heat and electricity for consumer, operational optimization must be done to meet their demand economically. So renewable energy sources are considered to be negative load, and batteries are used as the load flattening device to raise possibly operational function. In the state of solution, the program is developed to solve out the maximum profit of microgrid using dynamic programming method. Finally, its validity is verified through case study in isolation mode and interconnected mode. The S/W will be used to operate microgrid economically after the market of microgrid is formed.

• KIPS Transactions on Computer and Communication Systems
• /
• v.11 no.1
• /
• pp.9-22
• /
• 2022

Virtual Reality(VR) technology is an interface technology that is actively used in various audio-visual-based applications by showing users a virtual world composed of computer graphics. Since VR-based applications are graphic processing-based applications, expensive computing devices equipped with Graphics Processing Unit(GPU) are essential for graphic processing. This incurs a cost burden on VR application users for maintaining and managing computing devices, and as one of the solutions to this, a method of operating services in cloud environments is being used. This paper proposes a performance management technique to address the problem of performance interference between containers owing to GPU resource competition in container-based high-performance cloud environments in which multiple containers share a single GPU. The proposed technique reduces performance deviation due to performance interference, helping provide uniform performance-based remote VR services for users. In addition, this paper verifies the efficiency of the proposed technique through experiments.

• Korean Journal of Food Science and Technology
• /
• v.33 no.5
• /
• pp.567-573
• /
• 2001

Lactobacilli have been generally recognized as an important lactic acid bacteria present in the normal human intestinal flora. Fifty two Lactobacillus isolates were recovered from the feces of healthy Koreans whose age ranged from thirteen days after birth to 37 years. Among the isolates above, 17 isolates were tentatively identified as strains of Lactobacillus acidophilus and 3 isolates as strains of Lactobacillus casei. For their characterization, these twenty isolates were subjected to the experiments for the resistance to the artificial gastric juice, pH2.5 and bile salt. Interestingly, 3 strains survived pH 2.5 after 3 hour incubation in the artificial gastric juice with more than 75% of survival rate. L. acidophilus a-4 had the highest survival rate of 100%. Four strains including L. acidophilus a-3 grew gradually in MRS broth in the presence of the artificial bile salt. Cholesterol assimilation was also tested for the 20 isolates. The result showed that cholesterol concentration of the medium was reduced by 10 Lactobacillus isolates with more than 60%, as compared to the control. L. acidophilus a-2 had the highest reduction rate of 77%. Judging from these data obtained in vitro, some isolates ware likely to reach the lower small intestine after consumption without a significant loss of viability, suggesting that they had the potential to be developed as a probiotic culture which might lower the cholesterol level in human.

• International Journal of Human Ecology
• /
• v.6 no.2
• /
• pp.85-94
• /
• 2005

The purpose of this study is to analyze the preference of spatial elements for common space planning in senior congregate housing. For the study, 500 potential consumer's residing in Seoul was surveyed using the questionnaire in the social survey methodology. As for the common spaces, gardens, treatment, and exercise rooms were preferred. A combination of both separate and group arrangement of the buildings was preferred, indicating that people wanted separation of the common space and the individual living units. Second, people preferred sharing parts of the common space with their neighbors and as is the traditional custom, preferred to take off their shoes at the entrance to individual units. Third, for the furniture and facilities, they wanted the manager room in the lobby, the small meeting rooms in the public dining room, a fitness center in the activity room, the rack or alcove to store items in front of an individuals unit in the hallway, a chair to sit down in the elevator, and the chair to rest on the stairway landing. Fourth, in terms of priority for planning the senior citizens' community housing, safety, familiarity like a regular home, reduced isolation and loneliness, sense of belonging, economic factors, aesthetic appreciation, daily life supplement, variety, and self-identity were answered in that order.

• Journal of Educational Research in Mathematics
• /
• v.16 no.2
• /
• pp.157-177
• /
• 2006

The concepts of ratio and proportion do not develop in isolation. Rather, they are part of the individual's multiplicative conceptual field, which includes other concepts such as multiplication, division, and rational numbers. The current study attempted to clarify the beginning of this development process. One fourth student, Kyungsu, was encourage to schematize his trial-and-error-based method, which was effective in solving so-called missing-value tasks. This study describes several advancements Kyungsu made during the teaching experiment and analyzes the challenges Kyungsu faced in attempting to schematize his method. Finally, the mathematical knowledge Kyungsu needed to further develop his ratio and proportion concepts is identified. The findings provide additional support for the view that the development of ratio and proportion concepts is embedded within the development of the multiplicative conceptual field.

• The Korean Journal of Food And Nutrition
• /
• v.11 no.3
• /
• pp.340-346
• /
• 1998

The strain YSK-681 has been selected for antibiotic-producing strain against methicillin resistant Staphylococcus aureus(MRSA) form 1,000 strains of actinomycetes which had been isolated from soil. The strain YSK-681 has been identified on the point of morphological, cultural, physiological and chemical characteristics. Forty-one taxonomic unit characters were tested and the data were analysed numerically using the TAXON program. The isolate was classified into the major cluster 29 of Streptomyces and best-matched to Streptomyces lydicus. Therefore, it was concluded that the isolate was identified to be Streptomyces lydicus.

• Journal of Microbiology and Biotechnology
• /
• v.9 no.2
• /
• pp.223-226
• /
• 1999

A bacterial strain producing high level of an extracellular phytase was isolated from cooked rice and identified as a strain of Bacillus sp. and designated as Bacillus sp. KHU-10. Optimum culture conditions were investigated for the maximum productivity of phytase by Bacillus sp. KHU-10. 1.0% Maltose and 1.0% peptone with 0.5% beef extract were the best carbon source and nitrogen source, respectively. The addition of $CaCl_2$, stimulated the enzyme productivity with concentration between 0.01% and 0.2%, in the medium. Although sodium phosphate increased the cell mass, the enzyme activity decreased. Calcium phytate and wheat bran containing phytate did not enhance the enzyme production. Under the optimum medium, the production of the phytase reached the highest level of 0.2 unit/ml after 4 days of incubation.

• Journal of the Korean Magnetic Resonance Society
• /
• v.6 no.1
• /
• pp.69-77
• /
• 2002

During the screening of material which has the antimicrobial activity against aminoglycoside-resistant bacteria, A new material $\varepsilon$-(L-$\beta$-Iysine) polypeptide from a culture medium of Streptomyces sp.(DWGS2) was isolated, and the structure and the physicochemical properties of the new material were elucidated. The new material was separated by column chromatography of the culture medium using Dowex1$\times$2, Silica gel, and Sephadex LH20 etc. The chemical structure and molecular weight were determined with the data of various NMR experiments, MALDI mass, and ESI mass experiments. The antimicrobial activity of $\varepsilon$-(L-$\beta$-Iysine) polypeptide is not only better than equal to the activity of known aminoglycoside type of antibiotics(MIC=3.125 - 6.25ug/mL) but also effective against aminoglycoside-resistant bacteria and fungi. If the mechanism of antimicrobial activity against aminoglycoside- resistant bacteria is figured out, the $\varepsilon$-(L-$\beta$-Iysine) polypeptide can be utilized for the treatment of diseases caused by aminoglycoside-resistant bacteria.

• Journal of Korean Academy of Nursing
• /
• v.14 no.2
• /
• pp.55-62
• /
• 1984

This study was performed from september 26th to October 7th 1981 to investigate the contamination problems of Nurse's hands characterized by var-ious nursing functions. A total of 50 nurse's hands were sampled from 5 different wards of H. University Hospital. The samples were cultured for isolation of microorganisms. The results were as follows: 1. Of 50 Nurses 23 were found to be contaminated by 9 species of bacilli such as Non-fermentative gram negative Bacilli, Gram negative bacilli, Oxidase positive, Enterobacter, Escherichia coli, Pseudomonas aeruginosa, Acinetobacter, Staphylococcus epidermidis, Gaffkya tetragens, Bacillus subtilis. 2. The contaminate rates by wards where they have been serving are; 7 (87.5％) of 8 nurses from Intensive care unit, 7(70%) of 10 nurses from general surgery ward, 3(50%) of 6 nurses from neurosurgery ward, 2(20%) of 10 nurses from orthopedic surgery ward, 4(25%) of 10 nurses from medical ward. 3. The contamination rates by the types of clinical service offered are 6(85.7%) of 7 nurses after wound dressing assist 6 (55.3%) of 13 nurses after vital sign check. 4. No statistical significance could he observed as to the between the rates of contamination of nurse's hands with various nursing functions (0.1

• Journal of ILASS-Korea
• /
• v.18 no.4
• /
• pp.209-214
• /
• 2013

The present study aims to determine the optimized shape for the maximum electric energy production of building integrated photovoltaic system (BIPV) noise barrier through numerical analysis. The shape of BIPV noise barrier is one of the important factors in determining angle difference between direction vector of the sun and normal vector of the sound barrier surface. This study simulated numerically the flow and thermal fields for different angles in the range from $90^{\circ}$ to $180^{\circ}$, and from the results, the amount of isolation onto noise barrier surface was estimated along the angle between ground and top side of noise barrier. The commercial CFD code (Fluent V. 13.0) was used for calculation. It was found that the maximum amount of insolation per unit area was 19.6 MJ for $105^{\circ}$ case during a day in summer and was estimated 12.4 MJ in $150^{\circ}$ case during a day in winter. The results of the summer and winter cases showed the different tendency and this result would be useful in determining the appropriate shape of noise barrier which can be mounted under various circumstances.