• Journal of Korean Society of Forest Science
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• v.102 no.4
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• pp.543-549
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• 2013

This study was conducted to evaluate age-specific and generalized allometric equations and biomass expansion factors (BEFs) for each tree component across three age-sequence stands (35-year-old, 51-year-old, 62-year-old) of black pine (Pinus thunbergii Parl.) in Jinju, located in the western part of Gyeongnam province, Korea. Biomass in each tree component, i.e. foliage, branch, and stem, was quantified by destructive tree harvesting. Allometric regression equations were significant (P<0.05) with diameter at breast height (DBH) or combination of DBH and height ($DBH^2H$) accounting for 55-98% of the variation (as indicated by coefficients of determination, $R^2$) in aboveground biomass except for foliage biomass of the 62-year-old stand. Generalized allometric equations can be used to estimate the biomass of black pine stands because the slopes of age-specific equations over 35-year-old stands were not significantly different by the age-sequence. The stem density and biomass expansion factor (BEFs) were not significantly different (P>0.05) from different stand ages and ranged from 0.45 to $0.51gcm^{-3}$, and from 1.32 to 1.38, respectively. The results indicate that allometric equations, stem density and aboveground BEFs in the matured black pine over 35-year-old are little influenced by different stand ages.

• The Journal of Engineering Geology
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• v.7 no.2
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• pp.151-159
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• 1997

Since healed microcracks in quartz grain of grantic rocks within the same mass have identical preferred orientations, the oreintations of granitic cores may be determined if the distinctive feature of healed microcracks can be used.In this study, the possibility of determining orientations of granitic cores using healed microcrack orientations were examined using samples from the borehole drilled to 200 m in depth at the Hongcheon. Eight sections whose core recoveries are 100% were selected. Two to six samples were collected in each section and orientations of healed microcracks in each sample were measured. Healed microcracks in samples from each section show almost identical orientations. The error range for sections with only one preferred orientations is within $\pm$5$^{\circ}$, indicating that correct orientations of core can be determined. However, orientations of cores in sections which have 2 or more healed microcrack orientations should be determined using orientations as well as distribution of peaks of orientations. The error range for this case is lager than former one and is within $\pm$15$^{\circ}$. The orientations of joint which is very impontant factor for designing tunnel and slope stability can be determined using healed microcrack orientation in cores.

• Journal of Food Hygiene and Safety
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• v.16 no.2
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• pp.103-110
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• 2001

Predictive food microbiology(PFM) is an emerging area of food microbiology since the later 1980’s. It does apply mathematical models to predict the responses of microorganism to specified environmental variables. Although, at present, PFM models do not completely developed, models can provide very useful information for microbiological responses in HACCP(Hazard Analysis Critical Control Point) system and Risk Assessment. This study illustrates the possible use of PFM models(PMP: Pathogen Modeling Program win5.1) with milk in several elements in the HACCP system, such as conduction of hazard analysis and determination of CCP(Critical Control Points) and CL(Critical Limits). The factors likely to affect the growth of the pathogens in milk involved storage fixed factors were pH 6.7, Aw 0.993 and NaCl 1.3%. PMPwin5.1 calculated generation time, lag phase duration, time to level of infective dose for pathogens across a range of storage (Critical Control Points) and CL(Critical Limits). The factors likely to affect the growth of the pathogens in milk involved storage temperature, pH, Aw and NaCl content. The factors likely to affect the growth of the pathogens in milk involved storage temperature, pH, Aw and NaCl content. The variable factor was storage temperature at the range of 4~15$^{\circ}C$ and the fixed factors were pH 6.7, Aw 0.993 and NaC 1.3%. PMPwin5.1 calculated generation time, lag phase duration, time to level of infective dose for pathogens across a range of storage temperature.

• Journal of Plant Biotechnology
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• v.44 no.4
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• pp.372-378
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• 2017

For comparison of the transcription profiles in apple (Malus domestica L.) cultivars differing in flesh color expression, two cDNA libraries were constructed. Differences in gene expression between red flesh apple cultivar, 'Redfield' and white flesh apple cultivar, 'Granny Smith' were investigated by next-generation sequencing (NGS). Expressed sequence tag (EST) of clones from the red flesh apple cultivar and white flesh apple cultivar were selected for nucleotide sequence determination and homology searches. High resolution melting (HRM) technique measures temperature induced strand separation of short PCR amplicons, and is able to detect variation as small as one base difference between red flesh apple cultivars and white flesh apple cultivars. We applied high resolution melting (HRM) analysis to discover single nucleotide polymorphisms (SNP) based on the predicted SNP information derived from the apple EST database. All 103 pairs of SNPs were discriminated, and the HRM profiles of amplicons were established. Putative SNPs were screened from the apple EST contigs by HRM analysis displayed specific difference between 10 red flesh apple cultivars and 11 white flesh apple cultivars. In this study, we report an efficient method to develop SNP markers from an EST database with HRM analysis in apple. These SNP markers could be useful for apple marker assisted breeding and provide a good reference for relevant research on molecular mechanisms of color variation in apple cultivars.

• International Journal of Highway Engineering
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• v.7 no.2 s.24
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• pp.45-55
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• 2005

It is known that the Q/C(Quality Control) in the early age of portland cement concrete(PCC) pavement gives a huge effect on long term pavement performance. Thus, many studies regarding the construction of PCC pavement have focused on how to assure construction quality at the early age stage. Curing is one of the most important factor in Q/C of PCC pavement. Membrane curing that protects the evaporation of moisture by placing an impermeable layer on the slab surface is the most common practice for curing the PCC pavement. In order to improve the membrane curing practice, the rate of curing compound should be optimized. However, the optimum rate of curing compound considering Korean weather and environmental conditions has not been specified in the pavement construction specifications. In this study, a proper application rate was recommended in terms of minimizing evaporation with several full-scale tests where various rates of curing compound have been applied. Four test sites on the expressway were enlisted during the summer of 2002 and 2003. Application rates tested were in the range of $0. The rate of evaporation, the temperature pattern of the slab and the pulse velocity of concrete surface have been monitored at each test construction. The result from this study showed that the rate of current construction was approximately $160ml/m^2$ and that approximately $400ml/m^2$ of curing application was recommended as the proper rate for minimizing the moisture evaporation.

• Tunnel and Underground Space
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• v.26 no.5
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• pp.396-408
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• 2016

Rock fracture mechanics has been widely applied to various fields of rock and civil engineering. But most researches covered mode I behavior, though mode II behavior is dominant in rock engineering. Until now, there is only one ISRM suggested method for mode II toughness of rock. A new SCC (Short Core in Compression) mode II toughness test method was developed considering 1) application of confining pressure, 2) easiness of notch creation, 3) utilization of existing equipment, 4) simple test procedure. The stress intensity factors were determined by 3D finite element method considering line and distributed loading conditions. The tests with granite specimens were carried out using MTS 815 rock test system with a loading rate of 0.002 mm/s. The mean value of mode II fracture toughness of granite showed $2.33MPa{\sqrt{m}}$. Mode I toughness of the same granite was $1.12MPa{\sqrt{m}}$, determined by Brazilian disk test and $K_{IIC}/K_{IC}=2.08$. The smooth fracture surface with rock powder formation also supported mode II behavior of SCC method. The SCC method can be used for the determination of mode II fracture toughness of rocks based on the current results.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.6 no.1
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• pp.45-54
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• 2008

A new proposed repository has a final capacity of 800,000 drums radioactive waste. Most of foreign repositories have a general practice of segregating control zones which mainly contributes to classification of degree of control, whether it is called buffer zone or not. Domestic regulatory requirements of establishment of buffer zone in a repository are not much different from those of nuclear power plants for operation period, in which satisfactory design objective or performance objective is the most important factor in determination of the buffer zone. The meaning of buffer zone after closure is a minimum requested area which can prevent inadvertant intruders from leading to non-allowable exposure during institutional control period. Safety assessment with drinking well scenario giving rise to the highest probability of exposure among the intruder's actions can verify fulfillment of the buffer zone which is determined by operational safety of the repository. At present. for the repository to be constructed in a few years, the same procedure and concept as described in this paper are applied that can satisfy regulatory requirements and radiological safety as well. However, the capacity of the repository will be stepwise extended upto 800,000 drums, consequently its layout will be varied too. Timely considerations will be necessary for current boundary of the buffer zone which has been established on the basis of 100,000 drums disposal.

• The Journal of Engineering Geology
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• v.30 no.3
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• pp.315-325
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• 2020

This study was performed to develop a model to predict landslides and determine the variable importance of landslides susceptibility factors based on the probabilistic prediction of landslides occurring on slopes along the road. Field survey data of 30,615 slopes from 2007 to 2020 in Korea were analyzed to develop a landslide prediction model. Of the total 131 variable factors, 17 topographic factors and 114 geological factors (including 89 bedrocks) were used to predict landslides. Automated machine learning (AutoML) was used to classify landslides and non-landslides. The verification results revealed that the best model, an extremely randomized tree (XRT) with excellent predictive performance, yielded 83.977% of prediction rates on test data. As a result of the analysis to determine the variable importance of the landslide susceptibility factors, it was composed of 10 topographic factors and 9 geological factors, which was presented as a percentage for each factor. This model was evaluated probabilistically and quantitatively for the likelihood of landslide occurrence by deriving the ranking of variable importance using only on-site survey data. It is considered that this model can provide a reliable basis for slope safety assessment through field surveys to decision-makers in the future.

• The Journal of the Korea Contents Association
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• v.20 no.8
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• pp.128-137
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• 2020

Academic research on entrepreneurship has long been studied in various fields, but research on the relationship between entrepreneurship and subjective well-being is insufficient. This study aims to examine how challenge and hindrance stress affect subjective well-being in the impact of entrepreneurship on subjective well-being in the enterpriser of domestic company, and to determine whether the relationship among the individual characteristics of self-determination factors in this relationship has a mediating effect. According to research results, First, entrepreneurship had a positive effect on challenge stress and subjective well-being, while hindrance stress had an effect of negative. Second, challenge stress had a positive effect on relationships and subjective well-being had a positive influence but was insufficient and hindrance stress had a negative effect on both relational and subjective well-being. Third, Challenge stress and hindrance stress both influenced positive on subjective well-being through relationships. When you summarize the results of the research, It has been confirmed that the entrepreneurship of enterpriser effects subjective well-being, that hindrance stress is a factor that can interfere with subjective well-being, and that relationships play an important role in enhance subjective well-being of enterpriser. Based on these findings, conclusions were discussed and implications and directions for follow-up research were presented.

• Journal of Microbiology and Biotechnology
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• v.28 no.5
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• pp.718-731
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• 2018

The beneficial effects of lactic acid bacteria (LAB) have been intensively investigated in recent decades with special focus on modulation of the host intestinal microbiota. Numerous discoveries of effective probiotics are driven by a significantly increasing demand for dietary supplements. Consequently, technological advances in the large-scale production and lyophilization are needed by probiotic-related industries for producing probiotic LAB for commercial use. Our study had a dual objective, to determine the optimum growth medium composition and to investigate appropriate cryoprotective additives (CPAs) for Lactobacillus salivarius, and compare its responses with other Lactobacillus species. The one-factor-at-a-time method and central composite design were applied to determine the optimal medium composition for L. salivarius cultivation. The following composition of the medium was established (per liter): 21.64 g maltose, 85 g yeast extract, 1.21 ml Tween 80, 6 g sodium acetate, $0.2g\;MgSO_4{\cdot}7H_2O$, $0.02g\;MnSO_4{\cdot}H_2O$, $1g\;K_2HPO_4$, $1.5g\;KH_2PO_4$, $0.01g\;FeSO_4{\cdot}7H_2O$, and 1 g sodium citrate. A cryoprotective additive combination comprising 10% (w/v) skim milk and 10% (w/v) sucrose supplemented with 2.5% (w/v) sodium glutamate was selected for L. salivarius, and its effectiveness was confirmed using culture-independent methods in the freeze-dried cells of the Lactobacillus strains. In conclusion, the optimized medium enhanced the species-specific cultivation of L. salivarius. On the other hand, the cryoprotective effects of the selected CPA mixture may also be dependent on the bacterial strain. This study highlights the necessity for precise and advanced processing techniques for large-scale production of probiotics in the food and feed industries.