• Journal of Korean Society of Forest Science
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• v.95 no.3
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• pp.342-349
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• 2006

The survey guideline of forest products statistics suggests a certain type of standard to aggregate production amount of each item such as dry bracken, raw dates, cracked nuts, It does not, however, give any information about transition ratios, which would apply to convert weights of fresh bracken into dry one, or cracked nuts into the non-cracked. This has been one of the main factors which would make the statistics unreliable. The purpose of this study is to examine the aggregation realities and to put forward some proposals to improve forest products statistics with transition ratios. Targets of this study are 10 forest products that are strongly related to the mentioned problems. With the calculated transition ratios and some assumptions the changing rate of the official statistics of 2004 production amounts ranged from -41% to 474% for the 10 subjects. The suggested figures for transitions are based only on one-year analysis results. Therefore more periods are required to improve the accuracy and the reliability, and this study would be a good starting point.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.35 no.3
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• pp.533-544
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• 2015

Unlike the concrete structure built on land, that exposed to the marine environment is greatly degraded in durability due to the exposure to not only the physical action caused by sea wind, tide, and wave, but also the harsh conditions, including the chemical erosion and freeze-thaw which result from $SO_4{^{2-}}$, $Cl^-$ and $Mg^{2+}$ ions in seawater. In the process of the large scaled construction of submerged concrete structures, of course environmental hazardous substance, such as alkaline (pH) and heavy metals, may be leached. Thus, this issue needs to be adequately reviewed and studied. Therefore, this study attempted to develop a CSA (Calcium Sulfo Aluminate) activator using electric arc furnace reducing slags, as well as the eco-friendly concrete for artificial reefs using electric arc furnace oxidizing slag as aggregate for concrete. The strength properties of the eco-friendly concrete exposed to the marine environment were lower than those of the normal concrete by curing 28 days. This suggest that additional studies are needed to improve the early strength of the eco-friendly concrete. With respect to seawater resistance of the eco-friendly concrete, the average strength loss against 1 year of curing days reached 8-9%. the eco-friendly concrete using high volume of ground granulated blast furnace slags and high specific gravity of electronic arc furnace oxidizing slag demonstrated the sufficient usability as a freeze-thaw resistant material. With respect to heavy metal leaching properties of the eco-friendly concrete, heavy metal substances were immobilized by chemical bonding in the curing process through the hydration of concrete. Thus, heavy metal substances were neither identified at or below environmental hazard criteria nor detected, suggesting that the eco-friendly concrete is safe in terms of leaching of hazardous substances.

• Journal of the Korea Concrete Institute
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• v.18 no.4 s.94
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• pp.517-526
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• 2006

In this study, in order to utilize waste concrete powder(WCP) which is occurred in manufacturing high quality recycled aggregate as an admixture for self-compacting concrete(SCC), the properties of cement paste, mortar, and concrete that were mixed two types of WCP, 928 and 1,360 $cm^2/g$ of surface area, were analyzed. As a result of experiment, we have found that WCP was a porous material with angle. When WCP was utilized as an admixture for SCC, its flowability and viscosity increased in proportion to the increase of a replacement ratio, and that a replacement ratio of WCP was proper within 15%. The compressive strength at 28 days mixed respectively with WCP2, 15 and 30%, showed about 36 and 28 MPa, and it showed a similar trend with a function suggested in CEB-FIP for the relationship of compressive strength and elastic modulus. According to the results, it is judged that WCP2 can be utilized as an mineral admixture of normal strength SCC.

• Economic and Environmental Geology
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• v.36 no.5
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• pp.365-374
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• 2003

Various deleterious chemicals can be introduced to existing concrete structures from various external sources. The deterioration of concrete by seawater attack is involved in complex processes due to various elements contained in seawater. In the present study, attention was paid to the formation of secondary minerals and characteristics of mineralogical and micro-structural changes involved in concrete deterioration caused by the influence of major seawater composition. The characteristics of deterioration occurred in existing concrete structures was carefully observed and samples were collected at many locations of coastal areas in Busan-Kyungnam. The petrographic, XRD, SEM/EDAX analyses were conducted to determine chemical, mineralogical and micro-structural changes in the aggregate and cement paste of samples. The experimental concrete deteriorations were performed using various chloride solutions (NaCl, CaCl, $MgCl_2$ and $Na_2SO_4$ solution. The experimental results were compared with the observation results in order to determine the effect of major elements in seawater on the deterioration. The alkalies in seawater appear to accelerate alkali-silica reaction (ASR). The gel formed by ASR is alkali-calcium-silica gel which known to cause severe expansion and cracking in concrete. Carbonation causes the formation of abundant less-cementitious calcite and weaken the cement paste. Progressive carbonation significantly affects on the composition and stability of some secondary minerals. Abundant gypsum generally occurs in concretes subjected to significant carbonation, but thaumasite ({$Ca_6/[Si(OH)_6]_2{\cdot}24H_2O$}${\cdot}[(SO_4)_2]{\cdot}[(CO_3))2]$) occurs as ettringite-thaumasite solid solution in concretes subjected to less significant carbonation. Experimentally, ettringite can be transformed to trichloroaluminate or decomposed by chloride ingress under controlled pH conditions. Mg ions in seawater cause cement paste deterioration by forming non-cementitious brucite and magnesium silicate hydrate (MSH).

• Economic and Environmental Geology
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• v.41 no.3
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• pp.335-344
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• 2008

The acid rock drainage (ARD) production potential of rock was assessed for a tunnel construction area, Kimhae and the damage reduction strategy was discussed based on the ARD risk evaluation. The geology of the studied area consisted of Mesozoic quartz porphyry, sandstone, tuff and granite. Sulfides occurred as a disseminated type in quartz porphyry and granite, and a vein type in sandstone. Quartz porphyry and sandstone with a high content of sulfide were classified as a potentially ARD forming rock. The drainage originated from those rocks may acidify and contaminate the surrounding area during the tunnel construction. Therefore, the drainage should be treated before it is discharged. A slope stability problem due to the ARD was also expected and the coating technology was recommended for the reduction of ARD generation before the application of supplementary work for enhancing slope stability such as shotcrete and anchor. From the ARD risk analysis, those rocks should not be used as aggregate and be used as bank fill material with the system for the minimum contact with rain water and ground-water.

• Archives of design research
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• v.13 no.1
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• pp.121-130
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• 2000

This study can be expressed by gathered and formed into the exhibition space's structure practical progress/ application. For the one model of fascinating exhibition's space thru inter-space's pertinent adjustment, production between spactator and exhibition constituent on an exhibition story-line, I adjusted the focus to follow mentioned methods systematically for the example; An exhibition space is completed to be very impressive and attractive space by proper adjustment and production of M-M/C interface in exhibition storyline. Quantity space is transfered into quality space through the transmission of an exhibition which can be define as the point of an exhibition structure. And also could de transferd into a bodily sensation space that inherent full of interactive constituent. Changeable exhibition constituents (exhibition item and text) that sporadically expatiated (not trimed, the original form) in the process of an exhibition structure draw much higer quality of the optimal solution in optimize process which is given when aggregate again to contextual flow of synthetic exhibition scenario. Reconstruction of individual exhibition constituents to the new story, that is, transference of exhibition text to exhibition context is inspirit to an exhibition by maximize the exhibition effect in connection can be systematized through carrying out an outcentripetalpart. However, since pattern of an exhibition structure that consequtively meet variety spacetime of an exhibittion environmental can't be exist, this study presents centralizing the exhibition plan of Korea communication pavilion of the annual Expo Comm Wireress Korea, sustained process from design proposal, research and analysis to synthesis, development, transmission and management to an example of an applying crystallization.

• International Journal of Highway Engineering
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• v.20 no.1
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• pp.87-95
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• 2018

PURPOSES : A geo-grid pavement, e.g., a stress-absorbing membrane interlayer (SAMI), can be applied to an asphalt-overlay method on the existing surface-pavement layer for pavement maintenance related to reflection cracking. Reflection cracking can occur when a crack in the existing surface layer influences the overlay pavement. It can reduce the pavement life cycle and adversely affect traffic safety. Moreover, a failed overlay can reduce the economic value. In this regard, the objective of this study is to evaluate the bonding properties between the rigid pavement and a SAMI by using the direct shear test and the pull-off test. The predicted fractural energy functions with the shear stress were determined from a numerical analysis of the moving average method and the polynomial regression method. METHODS : In this research, the shear and pull-off tests were performed to evaluate the properties of mixtures constructed using no interlayer, a tack-coat, and SAMI with fabric and without fabric. The lower mixture parts (describing the existing pavement) were mixed using the 25-40-8 joint cement-concrete standard. The overlay layer was constructed especially using polymer-modified stone mastic asphalt (SMA) pavement. It was composed of an SMA aggregate gradation and applied as the modified agent. The sixth polynomial regression equation and the general moving average method were utilized to estimate the interlayer shear strength. These numerical analysis methods were also used to determine the predictive models for estimating the fracture energy. RESULTS : From the direct shear test and the pull-off test results, the mixture bonded using the tack-coat (applied as the interlayer between the overlay layer and the jointed cement concrete) had the strongest shear resistance and bonding strength. In contrast, the SAMI pavement without fiber has a strong need for fractural energy at failure. CONCLUSIONS : The effects of site-reflection cracking can be determined using the same tests on cored specimens. Further, an empirical-mechanical finite-element method (FEM) must be done to understand the appropriate SAMI application. In this regard, the FEM application analy pavement-design analysis using thesis and bonding property tests using cored specimens from public roads will be conducted in further research.

• Journal of Life Science
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• v.16 no.5
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• pp.716-722
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• 2006

Superoxide dismutase (SOD) is physiologically important in regulating cellular homeostasis and apoptotic cell death, and its mutations are the cause of familial amyotrophic lateral sclerosis (FALS). Mitochondrial serine protease HtrA2 has a pro-apoptotic function and has known to be associated with neurodegenerative disorders. To investigate the relationship between genes associated with apoptotic cell death, such as HtrA2 and SOD1, we utilized the pGEX expression system to develop a simple and rapid method for purifying wild-type and ALS-associated mutant SOD1 proteins in a suitable form for biochemical studies. We purified SOD1 and SOD1 (G93A) proteins to approximately 90% purity with relatively high yields (3 mg per liter of culture). Consistent with the result in mammalian cells, SOD1 (G93A) was more insoluble than wild-type SOD1 in E. coli, indicating that research on the aggregate formation of SOD1 may be possible using this pGEX expression system in E. coli. We investigated the HtrA2 serine protease activity on SOD1 to assess the relationship between two proteins. Not only wild-type SOD1 but also ALS-associated mutant SOD1 (G93A) were cleaved by HtrA2, resulting in the production of the 19 kDa and 21 kDa fragments that were specific for anti-SOD1 antibody. Using protein gel electrophoresis and immunoblot assay, we compared the relative molecular masses of thrombin-cleaved GST-SOD1 and HtrA2-cleaved SOD1 fragments and can predict that the HtrA2-cleavage sites within SOD1 are the peptide bonds between leucine 9-lysine 10 (L9-K10) and glutamine 23-lysine 24 (Q23-K24). Our study indicates that SOD1 is one of the substrate for HtrA2, suggesting that both HtrA2 and SOD1 may be important for modulating the HtrA2-SOD1-mediated apopotic cell death that is associated with the pathogenesis of neurodegenerative disorder.

• Journal of Preventive Medicine and Public Health
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• v.33 no.2
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• pp.150-156
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• 2000

Objective : To analyze the factors affecting the participation rate in the health screening program of medical insurance. Method : We investigated the factors associated with the participation rate in the health screening program in Korea. Data were collected at the aggregate level from 145 employee health insurance societies and 227 self-employed health insurance societies from 1995 to 1997 Data were also collected at the individual level from four health insurance societies. This study hypothesized that the participation rate of the health screening program was related to 1) the characteristics of its members and the size of the health insurance society; 2) the specifications of the health screening program; 3) the venue of the health screening institution and the interests of individuals in the health screening program; and 4) the activities of the health insurance society. We used bivariate and multiple regression models to examine the factors on the participation rate of the health screening program. Results : First, in the case of dependents of on employee health insurance society, the ratio of dependents 40 years old and over, the average monthly contribution per household, the interest and satisfaction level of individuals in health screening, and the level of refunds for over-payment were all associated with the participation rate in the health screening program, accounting for 54.4% of the participation rate. Second, in case of those insured by the self-employed health insurance society, the interest and satisfaction level of individuals in health screening, the level of refunds for over-payment, and the performance level of on-the-spot health screening were statistically significant, accounting for 40.1% of the participation rate. Conclusion : The factors concerning the participation rate in the health screening program of medical insurance, in both a health insurance society and for individuals, were closely related to the age and gender of individuals and household contributions.

• International Journal of Highway Engineering
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• v.8 no.3 s.29
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• pp.105-114
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• 2006

A popular alternative to extend the life of aged pavement is asphalt overlay. However, it has a very serious and inherent shortcoming in deterring a reflection crack. Although joint-rehabilitation and stress-relief techniques have been applied to deter such reflection cracks in aged pavement, the techniques had a limited success only in slowing down the progress of a reflection crack. Rubblization technique rubblizes the concrete pavement slab in situ and uses the rubblized slab as the base material. Then, pavement overlay is applied to finish off the rehabilitation of aged pavement. This rubblization technique has the advantage of solving the problem of reflection cracking completely. When rubblization technique is applied, the upper layer of aged concrete pavement is rubblized between 40mm-70mm in depth. However, the lower layer is typically rubblized more than 100mm in depth. Nevertheless, it is difficult to turn the entire concrete pavement of more than 30cm in depth into rubblized aggregate of appropriate size. Thus, a simulation experiment was carried out to find the appropriate rubblized depth, which avoids the reflection cracking and still maintains the function of subbase, by varying the depth of rubblized depth in loom increments of 0cm, 10cm, and 20cm. The result indicated the optimum rubblized depth was 10cm (Lee, 2006). Additionally, a small rubblizinge equipment was developed in order to derive the rubblization technique appropriate for thick concrete pavement. This equipment was tested out on an experimental pavement, which was constructed with the same standard and specification for the road in actual use, by varying its rubblizing head shape and energy as well as the effective area of rubblization. This experiment led to a prototype equipment for rubblization of thick concrete pavement. The prototype was put into use on a highway, undergoing a test construction and monitoring afterwards. This entire process was necessary for the validation of the proposed rubblization technique.