• Journal of Broadcast Engineering
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• v.6 no.3
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• pp.246-259
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• 2001

Due to recent rapid deployment of Internet streaming service and digital broadcasting service, the issue of how to efficiently support streaming workload in so called "Internet Home Appliance" receives prime interests from industry as well as academia. The underlying dilemma is that it may not be feasible to put cutting edge CPU, boards, disks and other peripherals into that type of device. The primary reason is its cost. Usually, Internet Home Appliances has its dedicated usage, e.g. Internet Radio, and thus it does not require high-end CPU nor high-end Va subsystem. The same reasoning applies to I/O subsystem. In Internet Home Appliances dedicated to handle compressed moving picture, it is not equipped with high end SCSI disk with fast rotational speed. Thus, it is mandatory to devise elaborate software algorithm to exploit the available hardware resources and maximize the efficiency of the system. This paper presents our experiences in the design and implementation of a new multimedia file system which can efficiently deliver the required disk bandwidth for a periodic I/O workload. We have implemented the file system on the Linux operating system, and examined itsperformance under streaming I/O workload. The results of the study show that the proposed file system exhibits superior performance than the Linux Ext2 file system under streaming I/O workload. The result of this work not only contribute to advance the state f art file system technology for multimedia streaming but also put forth the software which is readily available and can be deployed. deployed.

• The Korean Journal of Mycology
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• v.48 no.4
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• pp.397-405
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• 2020

Beech mushroom (Hypsizygus marmoreus) is one of the most popular mushrooms in Japan, China, and Korea because of its delicious taste, nutritious value, and unique crunchy texture. In 2018-2019, unusual signs on the mushroom were observed in mushroom farms in Gyeongnam Province. The main signs were the inhibition of mycelial growth and primordial formation on the surface of mushroom media. When green mold caused contamination at early stage, the rate of pinhead formation by the mushroom greatly decreased to 46.5-71.5%. Conidia of the causal green mold were ellipsoidal, dark green, and measured 2.0-3.1㎛ long. The optimum temperature for mycelial growth of the green mold was 25℃. The phylogenetic tree obtained from the internal transcribed spacer (ITS) rDNA sequences showed that the isolated green mold corresponded to Penicillium brevicompactum (100.0%). This is the first report of green mold contamination caused by P. brevicompactum on H. marmoreus.

• Economic Analysis
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• v.25 no.2
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• pp.54-95
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• 2019

The purpose of this study is to analyze quantitatively and qualitatively the effects of the increase in online shopping and its effects on real-world commercial outlets. The empirical analysis of this study is based on the results of "Census on Establishments" and "Online Shopping Survey" that cover 15 years, from 2002 to 2016. According to the results of this study, the increase in the number of online transactions affects the decrease in the number of stores in the real-world retail sector. However, non-specialized large stores and chain convenience stores showed an increase in the number of stores. In addition, the number of F&B stores increased the most in line with the increase in online transactions. This is because the increase in online transactions and in internet users led to the use of more delivery applications and the introduction of popular places on blogs or through social media. Street-level rents for medium and large-sized locations increased. In other words, it is seen that the demand for differentiated real-world stores that provide a good user experience increases, even though online transactions also increase. These results suggest that real-world stores should provide good user experiences in their physical locations with a certain size and assortment of goods.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.10
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• pp.1343-1356
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• 2008

The evaluation of microbiological quality for school food samples collected from 19 selected middle and high schools located in Seoul was undertaken. Eighty-nine food samples consisting of 38 non-pretreated vegetables, 13 pre-washed and cut vegetables, 9 meats and poultry, 3 fish and shellfish, 7 dried fish, and shellfish and 20 processed foods were collected. Aerobic plate count, total coliforms, and Escherichia coli (E. coli ) were detected using $Petrifilm^{TM}$, and the food-borne pathogens were screened by multiplex PCR with species-specific primer sets. Sequentially, the quantitative and confirmative test of the food-borne pathogens were carried out with the selective media and biochemical kits. The contamination of coliform counts was observed on the pre-washed vegetables ($3.4{\sim}4.3\;log\;CFU/g$) and meats ($2.2{\sim}4.3\;log\;CFU/g$). Also, the cooked foods were heavily contaminated with coliform, ranging from 1.0 to $5.5\;log\;CFU/g$. E. coli counts were found in 16 raw and cooked food samples, exceeding the microbiological standards for the guideline of safety management for school foods. Through PCR detection, B acillus cereus was detected in 32 raw and cooked foods, and quantitatively found in pre-washed carrot, radish, and pan-broiled dried shrimp and filefish ranging from $2.3{\sim}3.6\;log\;CFU/g$, respectively. E. coli O157:H7 was detected on frozen pork sample and was confirmed with API kit. Campylobacter jejuni was found in 3 ready-to-eat type vegetables. Vibrio parahaemolyticus were found in 4 pre-washed vegetables and 2 cooked foods, indicating unsatisfactory quality based upon the microbiological standards of ready-to-eat vegetables and cooked foods by Korea Food and Drug Administration. Salmonella spp. was detected in frozen chicken sample and confirmed by API kit and latex antisera agglutination.

• Proceedings of the Membrane Society of Korea Conference
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• 1999.07a
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• pp.39-42
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• 1999

Perfluoropolymers represent the ultimate resistance to hostile chemical environments and high service temperature, attributed to the presence of fluorine in the polymer backbone, i.e. to the high bond energy of C-F and C-C bonds of fluorocarbons. Copolymers of Tetrafluoroethylene (TEE) and 2, 2, 4Trifluoro-5Trifluorometoxy- 1, 3Dioxole (TTD), commercially known as HYFLON AD, are amorphous perfluoropolymers with glass transition temperature (Tg)higher than room temperature, showing a thermal decomposition temperature exceeding 40$0^{\circ}C$. These polymer systems are highly soluble in fluorinated solvents, with low solution viscosities. This property allows the preparation of self-supported and composite membranes with desired membrane thickness. Symmetric and asymmetric perfluoropolymer membranes, made with HYFLON AD, have been prepared and evaluated. Porous and not porous symmetric membranes have been obtained by solvent evaporation with various processing conditions. Asymmetric membranes have been prepared by th wet phase inversion method. Measure of contact angle to distilled water have been carried out. Figure 1 compares experimental results with those of other commercial membranes. Contact angles of about 120$^{\circ}$for our amorphous perfluoropolymer membranes demonstrate that they posses a high hydrophobic character. Measure of contact angles to hexandecane have been also carried out to evaluate the organophobic character. Rsults are reported in Figure 2. The observed strong organophobicity leads to excellent fouling resistance and inertness. Porous membranes with pore size between 30 and 80 nanometers have shown no permeation to water at pressures as high as 10 bars. However high permeation to gases, such as O2, N2 and CO2, and no selectivities were observed. Considering the porous structure of the membrane, this behavior was expected. In consideration of the above properties, possible useful uses in th field of gas- liquid separations are envisaged for these membranes. A particularly promising application is in the field of membrane contactors, equipments in which membranes are used to improve mass transfer coefficients in respect to traditional extraction and absorption processes. Gas permeation properties have been evaluated for asymmetric membranes and composite symmetric ones. Experimental permselectivity values, obtained at different pressure differences, to various single gases are reported in Tab. 1, 2 and 3. Experimental data have been compared with literature data obtained with membranes made with different amorphous perfluoropolymer systems, such as copolymers of Perfluoro2, 2dimethyl dioxole (PDD) and Tetrafluorethylene, commercialized by the Du Pont Company with the trade name of Teflon AF. An interesting linear relationship between permeability and the glass transition temperature of the polymer constituting the membrane has been observed. Results are descussed in terms of polymer chain structure, which affects the presence of voids at molecular scale and their size distribution. Molecular Dyanmics studies are in progress in order to support the understanding of these results. A modified Theodoru- Suter method provided by the Amorphous Cell module of InsightII/Discover was used to determine the chain packing. A completely amorphous polymer box of about 3.5 nm was considered. Last but not least the use of amorphous perfluoropolymer membranes appears to be ideal when separation processes have to be performed in hostile environments, i.e. high temperatures and aggressive non-aqueous media, such as chemicals and solvents. In these cases Hyflon AD membranes can exploit the outstanding resistance of perfluoropolymers.

• Journal of Wetlands Research
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• v.20 no.4
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• pp.424-431
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• 2018

Stormwater runoff containing considerable amounts of pollutants such as particulates, organics, nutrients, and heavy metals contaminate natural bodies of water. At present, best management practices (BMP) intended to reduce the volume and treat pollutants from stormwater runoff were devised to serve as cost-effective measures of stormwater management. However, improper design and lack of proper maintenance can lead to degradation of the facility, making it unable to perform its intended function. This study evaluated an infiltration trench (IT) that went through a series of maintenance operations. 41 monitored rainfall events from 2009 to 2016 were used to evaluate the pollutant removal capabilities of the IT. Assessment of the water quality and hydrological data revealed that the inflow volume was the most relative factor affecting the unit pollutant loads (UPL) entering the facility. Seasonal variations also affected the pollutant removal capabilities of the IT. During the summer season, the increased rainfall depths and runoff volumes diminished the pollutant removal efficiency (RE) of the facility due to increased volumes that washed off larger pollutant loads and caused the IT to overflow. Moreover, the system also exhibited reduced pollutant RE for the winter season due to frozen media layers and chemical-related mechanisms impacted by the low winter temperature. Maintenance operations also posed considerable effects of the performance of the IT. During the first two years of operation, the IT exhibited a decrease in pollutant RE due to aging and lack of proper maintenance. However, some events also showed reduced pollutant RE succeeding the maintenance as a result of disturbed sediments that were not removed from the geotextile. Ultimately, the presented effects of maintenance operations in relation to the pollutant RE of the system may lead to the optimization of maintenance schedules and procedures for BMP of same structure.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.8
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• pp.831-838
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• 2008

This study investigated the characteristics of nitrogen removal and microbial community in a lab-scale A$_2$O activated sludge process filled with the fluidized media at an aerebic basin. The change of microbial community was monitored based on quinone profiles of activated sludge according to feeding sewage with/without external carbon source. Low C/N ratio(COD$_{Cr}$/T-N of 1.24) sewage was fed. The obtained results from this study were as follows; Ubiquinone(UQ) in the influent was in the descending order of UQ-8, UQ-10 and UQ-9. Menaquinone(MK) was simpler and much less than UQ. The ratio of UQ/MK was less than 0.41 and the dissimilarity was below 0.26. Without an external carbon source, MK-8 was the dominant species and there were 3 kinds of quinone species and low DQ and EQ values in an anaerobic basin. The ratio of UQ/MK increased to 2.3 in an anoxic basin. In an oxic basin, UQ-7 and UQ-8 were the dominant species. UQ-7 was dominating in suspended microorganisms, while UQ-8 was in attached microorganisms. With an external carbon source addition, MK-8 decreased but UQ-8 increased in an anaerobic basin. So did quinone species, DQ and EQ values. There was also a change in an anoxic basin with the improvement of denitrification. UQ-8 decreased instead, MK-7 and MK-8 increased. UQ/MK ratio decreased 2.3 to 1.4. It means that the dominant species change from Pseudomonas sp. to Bacillus and Micrococcus species. etc. In an oxic basin, UQ-8 replaced UQ-7 in suspended microorganisms and UQ-10 replaced UQ-8 in attached microbials. This seemed related with the growth of Nitrosomonas and Nitrobactor species.

• Journal of Korean Academy of Nursing Administration
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• v.1 no.2
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• pp.246-267
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• 1995

Recently the request of the patients to participate in the medical courses has been expanding due to the elevated sense of right on the people's health, merchandised medical treatment by mass supply, human right declaration of the patients, generalized medical informations by the mass media and the change of human relation between the medical personnels and the patients. Under these phenomena the patients have been in the thought of solving such accidents only by regulation of the laws which they think to be all powerful, Such trends are same in the area of nursing service. Also today the accident by the nurses have been increasing by the area of the nurses having been expanded and their independent roles having been increased. Such nursing accidents are the important subject which the professional occupation of the nurse has been facing but legal protective capability of the nurses has been very weak. Therefore this study has examined the degree of the experience of the nursing accident that happens in the clinical nursing scenes in the general hospital to provide the basic materials for the protection and the counter measures of the nursing accident. The following is the conclusion based by the above examination. 1) The experience degree of the whole nursing accidents has been appeared as 1.90 in average. And the degree according to service area has been 1.77 in the area of supervising management of patients, 1.54 in the area of the same management of patients by head-nurses, 1.84 in the area of doctors' treatment performances, 14 in the enforcement and education areas of the nursing technology, 2.04 in the area of observing patients and judgement and 2.07 in the area of nursing records and maintaining confidentials. Accordingly there has been higher degree of accidental experiences in the independent service areas of the patients than in the dependent ones directed by the doctors. 2) The perception of the nurses showed that the cause of the nursing accident has been due to the heavy work of the nurses with the 60.4% of the response rate, the highest rate. They report the accident to the head nurse first by 2/3 nurses after accident. And the hour of the accident has been frequently happened regardless of service hours with 48.1% in response rate, the highest rate, and the nursing accident happens in the night more than the daytime with the rate of 37.5% at night while 14. 4% daytime. 3) The nurses are in the perception that the patients are responsible for the accident with 48.2% response rate while 43.9% rate in response showed that it has been caused by many people. They are in the perception that 41.7% when the nursing power was lacking, 46.7% lower recognition of actual state about indivitual patient in the section of technical speciality and 35.8% when the patients were not cooperative and 37.8% when the wards were dirty and in disorder. 4) the attitude of the patients after the various nursing accidents has been violent words in 72.7%, violence in 17.4% and 3.9% in attending the court by the sue of the patient's side(18 nurses). 5) The action of the hospital has been : requesting the submission of the story of the accident in 22.8%, the report of the accidents in 14.4%, thus the written statement disposal was most, 4.5% was the transfer to the other departments when the accident was larger or the patients' guardians protested strongly and 0.6% of the dismissals of the nurses. 6) In regard to the responsiblity of the nurse accidents, 78.9% was the highest rate of supplying the nursing manpowers, 48.4% of mutual cooperation of the medical personnels, 37.2% of strengthening the education for the nurses and hospital facilities reformation in 32.7%. 7) The review of relation between the general characters of the object of the study and the degree of experience of nursing accidents showed the significant differences in ages (F=4.04, p=0.000).

• Development and Reproduction
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• v.6 no.2
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• pp.105-110
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• 2002

Numerous hormones are involved in the regulation of reproduction. Among them, estrogen and progesterone are the most important ovarian steroid hormones regulating female fertility. On the other hand, diverse stressors impede female receptivity and fertility. Since norepinephrine(NE) and epinephrine(E) are released from the adrenal during stress, it might play a role in stress-induced disruptions of fEmale reproductive parameters. The present study was performed to analyze the changes in adrenal catecholaminergic activities in cycling rats. The tissue content and secretion level of catecholamines were determined by high performance liquid chromatography coupled with electrochemical detector(HPLC-ECD). Adrenomedullary content of norepinephrine(NE) was increased on proestrus stage (59.47 $\pm$ 6.86 ug/gland), peaked on diestrus I stage(65.22 $\pm$ 5.99 ug/gland), and was nadir on diestrus II stage(41.63 $\pm$ 1.33 ug/gland). The highest E content was observed on proestrus stage(361.86 $\pm$ 15.58 ug/gland) while the lowest level was on diestrus II stage(285.58 $\pm$ 12.25 ug/gland). In addition to these observations, a significant reduction of the NE : E ratio was observed (1 : 4.81 on diestrus I vs 1 : 6.13～7.02 on other stages). In vitro secretion of adrenal NE and E was increased on proestrus stage, peaked on estrus stage, and decreased on diestrus II stage. Interestingly, the NE : E ratio in conditioned media was significantly increased on estrus stage (1 : 3.32 vs 1 : 2.34～2.65 on other stages. The biosynthesis of NE and E is mediated by tyrosine hydroxylase(TH) and phenylethanolamine-N-methyltransferase(PNMT) which acts conversion of tyrosine into DOPA and NE into E, respectively. These finding demonstrated that sex steroids, during setrous cycle, seem to be able to modify the adrenal catecholamines biosynthesis and secretion with stage-specific manner by modulation of the enzyme activities.

• Investigative Magnetic Resonance Imaging
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• v.17 no.1
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• pp.1-7
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• 2013

Purpose : The purpose of this study is to correlate the imaging findings and the clinical findings in patients with transient splenial lesions (TSL). Materials and Methods: Total of 7 patients (M: F = 4: 3; age range 11 - 38 years, mean age 25.5 years) were studied between November 2006 and April 2011. The MRI findings and clinical findings in all patients were retrospectively reviewed. The location, MR signal intensity, restricted diffusion, enhancement pattern and reversibility from the follow up images were reviewed. Clinical features were reviewed with respect to the presented symptoms, signs, treatment and outcome. Results: The lesions were located in the splenium of corpus callosum in all patients. All lesions showed high signal intensity on diffusion weighted imaging (DWI), and six patients showed restricted diffusion on the apparent diffusion coefficient (ADC) map. ADC map was not available in one patient. All lesions (n = 7) showed high signal intensity on the T2 weighted image (T2WI). Five of the patients (71.4%) with follow up images (range 7 - 34 days) showed complete resolution of focal high signal intensity on DWI, with recovery of ADC values as well as T2WI. After contrast media administration, none of the lesions showed any enhancements. All lesions with various etiologies including TB medication were developed in younger age patients and showed reversibility after the acceptable period of minimum 7 days with conservative treatment. Conclusion: All TSL showed nonspecific imaging findings, including restricted diffusion on DWI and ADC map on the initial images. However, reversibility of the lesions and the young age preference can be a characteristic finding of TSL with acceptable period of minimum 7 days. In addition, to keep it in mind that various etiologies including TB medication may cause TSL, is important for radiologists as well as clinicians.