• Journal of the Korea institute for structural maintenance and inspection
• /
• v.6 no.3
• /
• pp.177-184
• /
• 2002

The most tunnel damage such as cracks or leakage which exist in tunnel lining commonly, is caused by the cavities where exist behind the tunnel lining, through the tunnel safety inspections. These cavities were analysed to affect a stability of a running-tunnel seriously. This study is on the development of the controlled low-strength and flowable filling material which is able to apply to the cavity behind the tunnel lining. The major materials of backfilling developed are a crushed sand and a stone-dust which exists as a cake-state and is a by-product obtained in the producting process of aggregate. It is conformed with the design standard to the physical characteristics of backfilling. The backfilling material developed is designed to reduce the fair amount of cement. According to the designed compound ratio, it is carried out the laboratory tests such as a compressive strength and a chemical analyses and is applied to dilapidated old tunnel for an application assessment.

• Atmosphere
• /
• v.28 no.3
• /
• pp.273-289
• /
• 2018

This paper evaluates daily precipitation products from Integrated Multisatellite Retrievals for Global Precipitation Measurement (IMERG), Tropical Rainfall Measuring Mission Multisatellite (TRMM) Precipitation Analysis (TMPA), and the Climate Prediction Center Morphing Method (CMORPH), validated against gauge observation over South Korea and gauge-based analysis data East Asia during one year from June 2014 to May 2015. It is found that the three products effectively capture the seasonal variation of mean precipitation with relatively good correlation from spring to fall. Among them, IMERG and TMPA show quite similar precipitation characteristics but overall underestimation is found from all precipitation products during winter compared with observation. IMERG shows reliably high performance in precipitation for all seasons, showing the most unbiased and accurate precipitation estimation. However, it is also noticed that IMERG reveals overestimated precipitation for heavier precipitation thresholds. This assessment work suggests the validity of the IMERG product for not only seasonal precipitation but also daily precipitation, which has the potential to be used as reference precipitation data.

• Wind and Structures
• /
• v.8 no.5
• /
• pp.343-356
• /
• 2005

Overhead sign support structures number in the tens of thousands throughout the trunk-line roadways in the United States. A recent two-phase study sponsored by the National Cooperative Highway Research Program resulted in the most significant changes to the AASHTO design specifications for sign support structures to date. The driving factor for these substantial changes was fatigue related cracks and some recent failures. This paper presents the method and results of a subsequent study sponsored by the Michigan Department of Transportation (MDOT) to develop a relative performance-based procedure to rank overhead sign support structures around the United States based on a linear combination of their expected fatigue life and an approximate measure of cost. This was accomplished by coupling a random vibrations approach with six degree-of-freedom linear dynamic models for fatigue life estimation. Approximate cost was modeled as the product of the steel weight and a constructability factor. An objective function was developed and used to rank selected steel sign support structures from around the country with the goal of maximizing the objective function. Although a purely relative approach, the ranking procedure was found to be efficient and provided the decision support necessary to MDOT.

• Nuclear Engineering and Technology
• /
• v.45 no.5
• /
• pp.581-588
• /
• 2013

This paper deals with the Safety Analysis for $CANDU^{(R)}$ 6 nuclear reactors as affected by main Heat Transport System (HTS) aging. Operational and aging related changes of the HTS throughout its lifetime may lead to restrictions in certain safety system settings and hence some restriction in performance under certain conditions. A step in confirming safe reactor operation is the tracking of relevant data and their corresponding interpretation by the use of appropriate thermal-hydraulic analytic models. Safety analyses ranging from the assessment of safety limits associated with the prevention of intermittent fuel sheath dryout for a slow Loss of Regulation (LOR) analysis and fission gas release after a fuel failure are summarized. Specifically for fission gas release, the thermal-hydraulic analysis for a fresh core and an 11 Effective Full Power Years (EFPY) aged core was summarized, leading to the most severe stagnation break sizes for the inlet feeder break and the channel failure time. Associated coolant conditions provide the input data for fuel analyses. Based on the thermal-hydraulic data, the fission product inventory under normal operating conditions may be calculated for both fresh and aged cores, and the fission gas release may be evaluated during the transient. This analysis plays a major role in determining possible radiation doses to the public after postulated accidents have occurred.

• Journal of the Korea Safety Management & Science
• /
• v.10 no.4
• /
• pp.229-240
• /
• 2008

With the effectuation of Kyoto Protocol, one of the important movement throughout the world is reducing the emission of greenhouse gas which is the main reason of making global warming. The actual factor of greenhouse gas is CO2, and in year of 2002 20% of total CO2 emission was produced only through transportation throughout the South Korea. In the contrary, the recycling of municipal wastes in South Korea was 44.0% in 2002, but it will be targeted upto 53.5% in 2011. All of these show environment-conscious logistics should be implemented together throughout the each stage of distribution with the development of product and service. This study applied survey research for the activities affecting to the emission of CO2 and packaging wastes produced from transportation and packaging stages in logistics area. For this, survey questionary was constructed with five specific areas - strategy, transportation & distribution, custody, packaging, and information. Based on the 148 returned survey questionaries, this study analyzed 52 categories and finally suggests necessary modal shift, collaboration & co-operation in logistics, LCA(life-cycle assessment), and other promoting policies for the environment-conscious logistics in effective way.

• Journal of The Institute of Information and Telecommunication Facilities Engineering
• /
• v.2 no.2
• /
• pp.14-21
• /
• 2003

In 1997, Korean IT enterprises were 9,000 in numbers and Gross Domestic Product (GDP) took 8.6%, and IT industry employed 400,000 persons. In 2002, it has increased : 21,000 companies, 14.9% of GDP, and 500,000 employees. National policy have diverse programs to the IT industry sector. Ministry of (MOC or MIC) have invested the R&D Program since late 1980. National subsidizes have been provided directly or indirectly to the programs. Direct subsidizes policy conflicts to the principle of the free competition market but it's very powerful to the IT organization (such as institutes, colleges, and companies) for the IT industry. This paper analyzes the national R&D subsidy systems and suggests the advanced systems.

• Geomechanics and Engineering
• /
• v.6 no.3
• /
• pp.235-248
• /
• 2014

Population increase and economic developments can lead to construction as well as demolition of infrastructures such as buildings, bridges, roads, etc resulting in used concrete as a primary waste product. Recycling of waste concrete to obtain the recycled concrete aggregates (RCA) for base and/or sub-base materials in road construction is a foremost application to be promoted to gain economical and sustainability benefits. As the mortar, bricks, glass and reclaimed asphalt pavement (RAP) present as constituents in RCA, it exhibits inconsistent properties and performance. In this study, six different types of RCA samples were subjected classification tests such as particle size distribution, plasticity, compaction test, unconfined compressive strength (UCS) and California bearing ratio (CBR) tests. Results were compared with those of the standard road materials used in Queensland, Australia. It was found that material type 'RM1-100/RM3-0' and 'RM1-80/RM3-20' samples are in the margin of the minimum required specifications of base materials used for high volume unbound granular roads while others are lower than that the minimum requirement.

• Bulletin of the Korean Chemical Society
• /
• v.31 no.12
• /
• pp.3663-3667
• /
• 2010

Acetaminophen (N-acetyl-p-aminophenol) is one of the most popular analgesic and antipyretic drugs. An isotope dilution mass spectrometric method based on LC/MS was developed as a candidate reference method for the accurate determination of acetaminophen in pharmaceutical product. After spiking an isotope labeled acetaminophen (acetyl-$^{13}C_2$, $^{15}N$-acetaminophen) as an internal standard, tablet extracts were analyzed by LC/MS in a selected reaction monitoring (SRM) mode to detect ions at m/z $152{\rightarrow}110$ and m/z $155{\rightarrow}111$ for acetaminophen and acetyl-$^{13}C_2$, $^{15}N$-acetaminophen, respectively. The repeatability and reproducibility of the developed ID/LC-MS method were tested for the validation and assessment of metrological quality of the method.

• Journal of Microbiology and Biotechnology
• /
• v.22 no.12
• /
• pp.1692-1697
• /
• 2012

We report a glycoside hydrolase (GH)-118 ${\beta}$-agarase from a strain of Agarivorans, in which we previously reported recombinant expression and characterization of the GH-50 ${\beta}$-agarase. The GH comprised an open reading frame of 1,437 base pairs, which encoded a protein of 52,580 daltons consisting of 478 amino acid residues. Assessment of the entire sequence showed that the enzyme had 97% nucleotide and 99% amino acid sequence similarities to those of GH-118 ${\beta}$-agarase from Pseudoalteromonas sp. CY24, which belongs to a different order within the same class. The gene corresponding to a mature protein of 440 amino acids was inserted, recombinantly expressed in Escherichia coli, and purified to homogeneity with affinity chromatography. It had maximal activity at $35^{\circ}C$ and pH 7.0 and had 208.1 units/mg in the presence of 300 mM NaCl and 1 mM $CaCl_2$. More than 80% activity was maintained after 2 h exposure to $35^{\circ}C$; however, < 40% activity remained at $45^{\circ}C$. The enzyme hydrolyzed agarose to yield neoagarooctaose as the main product. This enzyme could be useful for industrial production of functional neoagarooligosaccharides.

• Journal of Microbiology and Biotechnology
• /
• v.27 no.9
• /
• pp.1617-1627
• /
• 2017

Dietary approaches using structured lipids, including medium-chain fatty acids and diacylglycerols, have been adopted for the prevention of obesity-induced chronic inflammation. In an extension to previous studies, medium-chain fatty acid-diacylglycerol enriched dietary oil (MCDG) was prepared by interesterification of canola oil and medium-chain fatty acid-triacylglycerols. The consequent MCDG product was applied to RAW264.7 macrophages followed by the assessment of multiple inflammatory responses. Compared with conventionally used canola and olive oil controls, MCDG suppressed macrophage phagocytosis, as assessed by the uptake of microsphere beads. Furthermore, the production of IL-6 and $TNF-{\alpha}$, transcription of COX-2 and iNOS, and expression of CD80 on cell surfaces were downregulated by MCDG in LPS-stimulated macrophages. Subsequently, differentiated 3T3-L1 adipocytes were evaluated for proinflammatory cytokine production and lipid accumulation. IL-6 production was marginally affected and lipid accumulation was inhibited by MCDG. Taken together, these results suggest that MCDG has potential as an alternative oil for cooking in order to prevent obesity-induced inflammation.