• Korean Journal of Clinical Laboratory Science
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• v.51 no.2
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• pp.164-170
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• 2019

The absorption and release capacities, survival efficiency, and recovery rates of five kinds of transport media were evaluated based on the swab elution method (Quantitative) of CLSI (Clinical and Laboratory Standards Institute) M40-A2. Liquid media showed mostly better results than semi-solid media in the three evaluations. The flocked swabs had better ability to absorption and discharge bacteria than the standard swabs. The liquid medium (S4) had the best survival efficiency. Pneumococcal strains with poor growth had a higher survival efficiency and recovery rate in liquid media (S4, S5). The results of microbial recovery showed that S. pyogenes met all the CLSI standards in all media. S. pneumoniae was inadequate in the semi- solid media (S2, S3) and all the remaining media met the criteria. H. influenzae was unsuitable in semi-solid media (S1, S3) and met the criteria in semi-solid medium (S2) and liquid medium (S4, S5). The viability of the H. influenzae, pneumococcal strain causing respiratory disease, was poor in most media. Overgrowth of P. aeruginosa was observed at room temperature. The combination of liquid medium and flocked swab confirmed the best results in the three evaluation methods.

• Journal of architectural history
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• v.16 no.3
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• pp.7-20
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• 2007

A bridge is a space used as a passage. This space should be functional, solid, and beautiful. Since the beginning of human life, bridge architecture has given importance to function as a connection from one place to another. Stepping stones in the stream were the connections between divided spaces in the agricultural life, the bridge on the entrances of a town was the place for separation, expectation, and communication for people gathering around the community. Southern Chinese provinces such as Zhejiang, Hunan, Yunnan, and Guizhon is famous for it's spectacular scenary, and tribes like the 'Miao' and 'Dong' live in a cooperate community. The 'Dong' tribe is one of the 'Yue' genealogy where the people have settled down in this place in the days of 'Qin Shi Huang(Qin dynasty)'. As the population of the 'Dong' tribe growed, they used a bridge to connect town to town. The scale became larger with additional design, giving splendid achievement to bridge architecture. The 'Fungyu bridge' in Tongdao and 'Chungyang bridge' in Sanjiang are some fine examples. The Fungyu bridge could be defined as a bridge which blocks wind and rain, this has the same function as the lounge bridge in Taishun located in southern Zhejiang province. In Taishun, 5 minority races such as the 'Dong' and 'Miao' people have been living together as a clan society for centuries on mountains as high as 1000m following their own tradition. The 'Xiliu river' flowing thorough has a variety of bridges remaining in it's original form, and it is recently known as a museum of ancient bridges. The formation of the bridges in Tongdao and Taishun shows that it is different with the arch and straight bridges remaining in Korea. In this study, it is readjusting the base data, showing plan characteristics and describing the construction of the wooden structure above the bridge post.

• Communications of the Korean Institute of Information Scientists and Engineers
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• v.1 no.1
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• pp.23-35
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• 1983

In its global meaning language translation refers to the process whereby a program which is executable in one computer can be executed in another computer directly to obtain the same result. There are four different ways of approaching translation. The first way is translation by a Translator or a Compier, the second way is Interpretation, the third way is Simulation, the last way is Emulation. This paper introduces the M-C Translator which was designed as the first way of translation. The MUSS 80 language (the subsystem of the UNIVAC Solid State 80 S-4 assembly language system) was chosen as the source language which includes forty-three instructions, using the CYBER COMPASS as the object language. The M-C translator is a two pass translator and is a two pas translator and es written in Fortran Extended language. For this M-C Translation, seven COMPASS subroutines and a set of thirty-five macros were prepared. Each executable source instruction corresponds to a macro, so it will be a macro instruction within the object profram. Subroutines are used to retain and handle the source data representation the same way in the object program as in the source system, and are used to convert the decimal source data into the equivalent binary result into the equivalent USS-80digits before and after arithmetic operations. The source instructions can be classified into three categories. First, therd are some instructions which are meaningless in the object system and are therefore unnecessary to translate, and the remaining instructions should be translated. Second, There are some instructions are required to indicate dual address portions. Third, there are Three instructions which have overflow conditions, which are lacking in the remaining instructions. The construction and functions of the M-C Translator, are explained including some of the subroutines, and macros. The problems, difficulties and the method of solving them, and easier features on this translation are analysed. The study of how to save memory and time will be continued.

• Journal of the Korean Ceramic Society
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• v.51 no.5
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• pp.505-510
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• 2014

The properties of black ceramic pigments including thermal and glaze stability were systematically investigated so that these pigments could be used to decorate porcelain products. Various compositions of $(Ni,Mn)(Fe,Cr,Mn)_2O_4$ and $Co(Fe,Cr)_2O_4$ powders were synthesised using a solid state reaction method. The obtained $Co(Fe,Cr)_2O_4$ and $(Ni,Mn)(Fe,Cr,Mn)_2O_4$ powders showed single phases of spinel structure after calcination processes at $1000^{\circ}C$ and $1200^{\circ}C$, respectively. CIE $L^*a^*b^*$ colourimetric parameters of glazed $Co(Fe,Cr)_2O_4$ and $(Ni,Mn)(Fe,Cr,Mn)_2O_4$ pigments were analyzed according to the different amounts of Cr substitution. In addition, the amount of $Cr^{+6}$ remaining in the $Co(Fe,Cr)_2O_4$ and $(Ni,Mn)(Fe,Cr,Mn)_2O_4$ pigments was also measured.

• Journal of Korean Society for Atmospheric Environment
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• v.16 no.5
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• pp.499-509
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• 2000

Next to carbon dioxide, methane is the second largest contributor to global warming among anthropogenic greenhouse gases. Methane is emitted into the atmosphere from both natural and anthropogenic sources. Natural sources include wetlands, termites, wildries, ocean and freshwater. Anthropogenic sources include landfill, natural gas and oil production, and agriculture. These manmade sources account for about 70% of total global methane emissions; and among these, landfill accounts for approximately 10% of total manmade emissions. Solid waste landfills produce methane as bacteria decompose organic wastes under anaerobic conditions. Methane accounts for approximately 45 to 50 percent of landfill gas, while carbon dioxide and small quantities of other gases comprise the remaining to 50 to 55 percent. Using the closed enclosure technique, surface emission fluxes of methane from the selected landfill sites were measured. These data were used to estimate national methane emission rate from domestic landfills. During the three different periods, flux experiments were conducted at the sites from June 30 through December 26, 1999. The chamber technique employed for these experiments was validated in situ. Samples were collected directly by on-site flux chamber and analyzed for the variation of methane concentration by gas chromatography equipped with FID. Surface emission rates of methane were found out to vary with space and time. Significant seasonal variation was observed during the experimental period. Methane emission rates were estimated to be 64.5$\pm$54.5mgCH$_4$/$m^2$/hr from Kimpo landifll site. 357.4$\pm$68.9mgCH$_4$/$m^2$/hr and 8.1$\pm$12.4mgCH$_4$/$m^2$/hr at KwanJu(managed and unmanaged), 472.7$\pm$1056mgCH$_4$/$m^2$/hr at JonJu, and 482.4$\pm$1140 mgCH$_4$/$m^2$/hr at KunSan. These measurement data were used for the extrapolation of national methane emission rate based on 1997 national solid waste data. The results were compared to those derived by theoretical first decay model suggested by IPCC guidelines.

• Journal of Korean Society of Environmental Engineers
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• v.37 no.11
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• pp.597-606
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• 2015

This work investigates the carbonation of KOH-dissolved methanol and ethanol solution systems carried out for $CO_2$ fixation. Potassium methyl carbonate (PMC) and potassium ethyl carbonate (PEC) were synthesized during the reaction in each solution as the solid powder, and they were characterized in detail. The amount of $CO_2$ chemically absorbed to produce the PMC and PEC precipitates were calculated to be 97.90% and 99.58% of their theoretical values, respectively. In addition, a substantial amount of $CO_2$ was physically absorbed in the solution during the carbonation. PMC precipitates were consisted of the pure PMC and $KHCO_3$ with the weight ratio of 5:5, respectively. PEC precipitates were also mixture of the pure PEC and $KHCO_3$ with the weight ratio of 8:2, respectively. When these two precipitates were dissolved in excess water, methanol and ethanol were regenerated remaining solid $KHCO_3$ in the solutions. Therefore, the process has the potential to be one of the efficient options of CCS and CCU technologies.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2017.10a
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• pp.74-74
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• 2017

Electrorefining is a key step in pyroprocessing. The electrorefining process is generally composed of two recovery steps - the deposit of uranium onto a solid cathode and the recovery of the remaining uranium and TRU elements simultaneously by a liquid cadmium cathode. Uranium deposit recovered from the solid cathode is a dendritic powder. It is necessary to separate the adhered salt from the deposits prior to the consolidation of uranium deposit. The adhered salt is composed of lithium, potassium, uranium, and rare earth chlorides. Distillation process was employed for the cathode processing. One of the operation methods is distillation of the salt at low temperature ($900^{\circ}C$), and then melting of the deposit at high temperature to avoid a backward reaction. For the development of the salt distiller, the distillation behavior of the low vapor pressure chlorides should be studied. Rare earth chlorides in the adhered salt of uranium deposits have relatively low vapor pressures compared to the process salt (LiCl-KCl). In this study, the evaporation rates of the lanthanum and neodymium chlorides were measured for the salt separation from electrorefiner uranium deposits in the temperature range of $825{\sim}910^{\circ}C$. The evaporation rate of both chlorides increased with an increasing templerature. The evaporation rate of lanthanum chloride varied from 0.12 to $1.68g/cm^2/h$. Neodymium chloride was more volatile than lanthanum chloride. The evaporation rate of neodymium chloride varied from 0.20 to $4.55g/cm^2/h$. The evaporation rate of both chlorides are more than $1g/cm^2/h$ at $900^{\circ}C$. Even though the evaporation rates of both chlorides were less than that of the process salt, the contents of the lanthanide chlorides were small in the adhered salt. Therefore it can be concluded that $900^{\circ}C$ is suitable for the operation temperature of the salt distiller.

• Journal of Internet of Things and Convergence
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• v.7 no.4
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• pp.9-14
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• 2021

In computing systems that require high reliability, the method of predicting the lifetime of a storage device is one of the important factors for system management because it can maximize usability as well as data protection. The life of a solid state drive (SSD) that has recently been used as a storage device in several storage systems is linked to the life of the NAND flash memory that constitutes it. Therefore, in a storage system configured using an SSD, a method of accurately and efficiently predicting the lifespan of a NAND flash memory is required. In this paper, a method for optimizing the lifetime prediction of a flash memory-based storage device using the frequency of NAND flash memory failure is proposed. For this, we design a cost matrix to collect the frequency of defects that occur when processing data in units of Drive Writes Per Day (DWPD). In addition, a method of predicting the remaining cost to the slope where the life-long finish occurs using the Gradient Descent method is proposed. Finally, we proved the excellence of the proposed idea when any defect occurs with simulation.

• Journal of Radiation Protection and Research
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• v.48 no.2
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• pp.77-83
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• 2023

Background: The purpose of this study is to purify uranium (U[VI])-contaminated soil-flushing effluent using the precipitation-distillation process for clearance. Precipitation and distillation are commonly used techniques for water treatment. We propose using a combination of these methods for the simple and effective removal of U(VI) ions from soil-flushing effluents. In addition, the U concentration (Bq/g) of solid waste generated in the proposed treatment process was analyzed to confirm whether it satisfies the clearance level. Materials and Methods: Uranium-contaminated soil was decontaminated by soil-flushing using 0.5 M sulfuric acid. The soil-flushing effluent was treated with sodium hydroxide powder to precipitate U(VI) ions, and the remaining U(VI) ions were removed by phosphate addition. The effluent from which U(VI) ions were removed was distilled for reuse as a soil-flushing eluent. Results and Discussion: The purification method using the precipitation-distillation process proposed in this study effectively removes U(VI) ions from U-contaminated soil-flushing effluent. In addition, most of the solid waste generated in the purification process satisfied the clearance level. Conclusion: The proposed purification process is considered to have potential as a soil-flushing effluent treatment method to reduce the amount of radioactive waste generated.

• Journal of the Korean Society of Combustion
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• v.8 no.1
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• pp.1-8
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• 2003

The behavior and characteristics of heavy metals at different streams in a MSWI(Municipal Solid Waste Incinerator) with a capacity of 100tonnes/day were investigated by measuring the concentration of heavy metals and gases and analyzing their leaching data from ashes. Metal components of Cr, Cu, Cd and Pb were in higher concentrations in the fly ashes collected after the water spray tower than in the bottom ashes. It was due to condensation by a lower temperature with water spray cooling. Metal contents in the bottom ash became higher for finer particles as expected. The mass balance of heavy metals in different stream was estimated from the analyzed data in bottom ash and collected dusts at different locations. For the lower volatility of metals such as Pb, Cu, Cr, 88-97% of them remained in the bottom ash, while Cd and Hg escaped from the combustor with remaining in bottom ash of 18.4 and 0.8%, respectively. In most cases the leaching rate of fly ash showed higher values than that of bottom ash, with the their average acidities of 9.8 and 11.9 respectively.