• Journal of the Korea Concrete Institute
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• v.25 no.4
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• pp.371-379
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• 2013

This paper investigates the cracking and tension-stiffening behavior of 100 MPa shrinkage-compensated strain-hardening cement composite (SHCC) and conventional concrete tie elements in monotonic and cyclic tension. Strain and surface crack formation of tension ties were monitored with two strain displacement transducers and a photo microscope with a lens of magnification 50 times. Three different cement composites such as conventional concrete, shrinkage-compensated SHCC, and normal SHCC were used in the tie specimens to investigate the influence of the cement composite type on the tension stiffening and cracking behavior. Test results indicated that initial shrinkage of the ultra high-strength cement composites is greatly reduced as the 10% replacement of cement by the shrinkage-compensating admixture based on calcium sulfo-aluminate (CSA). The test results on the SHCC tension ties showed that the first cracking load decreases proportionally to the initial shrinkage strain. Reinforced ultra high-strength SHCC ties with the initial shrinkage compensation exhibited improved tension stiffening and smaller crack spacings, i.e. the reduction in crack width. Cyclic loading did not have a significant effect on tension stiffening and cracking behavior of tension ties with normal concrete and SHCC materials.

• Journal of the Korean GEO-environmental Society
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• v.16 no.11
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• pp.5-11
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• 2015

The development of Controlled Low Strength Material (CLSM), which is a highly flowable material, has been performed for the application of backfill. The objective of this study is to compare the compressive strength and compressive wave velocity of CLSM according to the curing time. To investigate the characteristics of the CLSM consisting of sand, silt, water, flyash, and CSA cement, uniaxial compression test and flow test were carried out. For the measurement of compressional waves, a cell and a couple of transducers were used. The test results show that the compressive strength increases with the curing time, while the increment of compressive strength decreases with the curing time. In addition, the compressive wave velocity increases with the curing time, and the correlation between the compressive wave velocity and compressive strength is similar to exponential function. This study suggests that the correlation between the compressive wave velocity and compressive strength may be effectively used for the estimation of compressive strength of the CLSM at early curing time.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.17 no.1
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• pp.40-50
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• 2006

Objectives : This study aims to identify sexual behaviors in sexually abused children to assess the Child Sexual Behavior Inventory(CSBI) score of sexual behaviors reported in children by their parents to analyze the relation of these sexual behaviors to demographic variables, familial variables, and characteristics of sexual abuse variables. Method : A large sample of 2-13 year old children(N=121) were rated by their caregiver via parent report consisting of CSBI, the Child Behavior Checklist(CBCL), and a questionnaire assessing characteristics of family history and sexual abuse variables. Results : There were significantly related to the CSBI score; younger children(2-5 year old group) had significantly higher scores than older children. Maternal education also related to the CSBI score, in that mothers with higher levels of education report more CSBI scores than less educated mothers. There were significant differences according to characteristics of victim victim with penile penetration of vegina and genital exposure of offender had higher score in the CSBI than others. Also, when perpeturator was an acquaintance, the CSBI scores increased. Conclusion : Sexual behavior related to childs age, maternal education, penile penetration of vegina, and genital exposure, parental emotional state and personality traits. Findings were primarily similar to previously published studies. The suggestions and the limitations of this study, and directions of future study were discussed.

• Journal of the Korean GEO-environmental Society
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• v.17 no.3
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• pp.13-19
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• 2016

The ultrasonic waves for monitoring concrete materials have been used to investigate the setting and hardening process of concrete. This paper presents the application of bender elements for monitoring the hardening properties of Controlled Low Strength Material (CLSM) and the characterization of shear waves in CLSM according to curing time. To ensure the early age properties and flow, the CLSM consists of CSA cement, sand, silt, water, fly ash, and accelerator. In addition, three different type specimens according to fine contents are mixed. A couple of bender elements are installed at the wall of measurement cell and the CLSM specimen are prepared at the measurement cell for 28 days. Experimental results show that the resonant frequency and shear wave velocities increase with an increase in the curing time, regardless of the fine contents. Up to ten hours, the amplitudes of shear waves also increase, and the resonant frequency and shear wave velocities at the same time increase as the fine contents increase. The shear wave measurement technique using the bender elements may be effectively used to evaluate the hardening properties of CLSM along the curing time.

• Korean Journal of Microbiology
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• v.30 no.4
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• pp.260-264
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• 1992

Pseudotnorju.c sp. EL-071P degrading 2.4.5-trichlorophe~~oxyi~cetaicci d (2.3.5-T) was resistantto antibiotics: rifampicin. ampicillin. kanamycin and metal ions : Zn" and Cu".The plasmitl related to the degradation of 2.4.5-'r and rifa~npicin resistance was isolatecifrom the strain. Its size was about 40 Kb. As result of transforming the plasmid intoEsch~rirhiti coli MClOhl, it was confirmed that the plasmid ura.; related to 2.4.5-T degradation.The strain coulil grow in the various chlorinated aromatic analogs as the solc carbon source.In the case of chlorophcnols. the chlorinated mono-substituteti phenols were easily dcgradetlin the order ol' ortho-. ~ ~ a r um- ,c ~tu-position.T he 2.3.5-T mctaholism was inhibited by 4-chlorophenol of 2.4.5-7' analog. In non-chlorinateci aromatics. ~ C I I L O ~ I ~ Csa.l icylilte i~ndtoluene were uscd ax the carbon source by the strain and typestrain Acudonlotrtr.\ plrtirltrKCTC 1643 having clegrad;~bility of various aromatics. But naphtalene was usecl only bythe A~urlomonri.\ sp. EL-07 1 P.the A~urlomonri.\ sp. EL-07 1 P.

• Journal of the Korean Applied Science and Technology
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• v.20 no.2
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• pp.101-109
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• 2003

Provitamin $B_5$ liquid crystal ($PVB_5$-LC) was the new emulsion system to enhance moisturizing activity on the skin. In this study, it should be mentioned that PVB5-LC could be prepared with the main compound of hydrogenated lecithin (HL) in oil-in water (O/W) emulsion. The key ingredient of humectants was contained 2% of provitamin $B_5$ ($PVB_5$) into the $PVB_5$-LC. The best suitable compositions of $PVB_5$-LC were made from 4.0 wt% of HL, 4.0 wt% of cetostearyl alcohol (CSA) as emulsifier and gelling agent, 3.0 wt% of 1,3-butylene glycol (1,3-BG) and 2.0 wt% of glycerin as moisturizers, 3.0 wt% of cyclomethicone (CMC), 3.0 wt% of isononanoate (ININ), 3.0 wt% of capric/caprylic triglyceride (CCTG), 3.0 wt% of macadamia nut oil (MNO) as emollients. As the analytical result of $PVB_5$-LC, it could know that the distribution range of particle size was 0.14 to 12.37 m level (mean size 3.24 m). It was certified the multi lamellar phase around the droplet of liquid crystal when observed the droplet particles through a polarization microscope. And it clinically was tested the effectiveness of moisturizing activity (in-vivo) compared with control sample (O/W emulsion). The effectiveness of moisturizing activity of $PVB_5$-LC with Skincon-200EX after 6 hours went up 49.0% (p<0.05, n=20) whereas the effectiveness of moisturizing activity of generally O/W emulsion cream was 25.7% (p<005, n=20). Also, in case of Comeometer CM-825, the moisturizing activity of $PVB_5$-LC after 6 hours rose 36.6% (p<0.05, n=20) whereas the effectiveness of moisturizing activity of generally O/W emulsion cream was 10.8%. Therefore, it was known that the effectiveness moisturizing activity of $PVB_5$-LC with HL was remarkably superior compared with O/W emulsion cream.

• Journal of the Korea Concrete Institute
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• v.24 no.3
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• pp.225-232
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• 2012

This paper presents the test results on the shear performance of large-size reinforced concrete beams using recycled fine aggregate to evaluate its applicability to structural concrete. The performance of these beams is compared to that of similar beams casted with natural coarse and fine aggregates. All of the beam specimens without shear reinforcement had $400mm{\times}600mm$ rectangular cross section and a shear span ratio (a/d) of 5.0. Five concrete mixtures with different replacement levels of recycled fine aggregates (0, 30, 60, 70 and 100%) were used to obtain a nominal concrete compressive strength of 28MPa. The test results of load-deflection curve, shear deformation, diagonal cracking load, crack pattern, ultimate shear strength, and failure mode are examined and compared. In addition, code and empirical equations from KCI, JSCE, CSA, Zsutty, and MCFT were considered to evaluate the applicability of these equations for predicting shear strength of reinforced concrete beam with recycled fine aggregate. The results showed that the overall shear behavior of reinforced concrete beams incorporating less than 60% recycled fine aggregate was comparable with that of conventional concrete beam. The MCFT gave good prediction and other code equations were conservative in predicting the shear strength of the tested beams. The beam specimens with replacement of 70 and 100% of natural fine aggregates by recycled fine aggregates showed different failure mode than other tested beams.

• Journal of Environmental Policy
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• v.8 no.3
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• pp.53-79
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• 2009

This study conducted a regulatory impact analysis regarding the introduction of the Korean version of REACH(Registration, Evaluation and Authorization of Chemicals). The direct cost of the Korean REACH is estimated at a total of 101 billion Korean won over the 11 year period. The cost includes pre-registration, testing, registration, Chemical Safety Assessment(CSA) and Chemical Safety Report(CSR), evaluation, and the authorization costs of 15,223 chemical substances produced and imported more than 1 ton per year in Korea in 2006. With regard to the benefit, the only public health benefit is included in the estimation. Based on the available foreign and domestic data, this study estimated that the economic values of public health benefits are in the range of 33.2~138.6 billion Korean won if only the savings of the National Health Expenditures are considered and it reaches 203.9~1,640.3 billion Korean won if the willingness to pay(WTP) for disease prevention is included. This study proved that the Korean REACH passed the cost/benefit criteria. The benefit-cost ratio of the Korean REACH, however, is estimated to be lower than its EU counterpart. Thus it is suggested that a rigorous study to reduce the costs to industry be required before the Korean government introduces the Korean REACH.

• The Korean Journal of Mycology
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• v.31 no.3
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• pp.141-147
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• 2003

The pileus of Pleurotus cystidiosus was attached at the side and was spatular-shape. It grew to the size of $7.6{\sim}9.8\;cm$ with dark brown color. The length of stem was $1.4{\sim}2.9\;cm$. The individual weight of fruiting-body was 25.4 g in average. This study was conducted to Investigate the physiological characteristics and to develop the artificial cultivation technique of P. cystidiosus. To find out the optimum condition of mycelial growth of P. cystidiosus, physiological conditions such as media, temperature, pH carbon sources and nitrogen sources were investigated. Various cultural media were used for the cultivation of P. cystidiosus and compost dextrose agar was favorable for mycelial growth. The optimal growing temperature and pH were in range of 25 to $30^{\circ}C$, pH $7{\sim}9$, respectively. When different carbon sources were compared, glucose was found to be best. However nitrogen sources were different with each strains. When different C/N ratio were compared, 20:1 of C/N ratio was found to be best.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.4
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• pp.637-637
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• 1997

In this paper, format conversion filters are proposed, which have advantages in hardware implementation compared to the ones proposed in MPEG-4 Video Verification Model. since each coefficients of the proposed filters is constrained to have less than two non-zero digits in minimal signed digit representation, multiplication of input and the coefficient can be implemented by a single adder. As a result, the proposed filters have advantages in hardware complexity and speed, compared to the filters which are usually implemented by integer multiplier or carry save adders. Six kinds of filters are proposed in MPEG-4 Video Verification Model for size conversion of 2:1, 4:1, 5:3 and 5:6. We design 5 filters for the same purpose and compare the performance. The remaining one is very simple to implement. For comparing the filtering performance, we first compare the results of sine wave frequency conversion as an indirect but meaningful comparison. Second. We compute the PSNR of the images obtained from the proposed filters and the ones proposed by MPEG, with reference to the images obtained by using double precision arithmetic and high order filter. The results show that the performance of the proposed filters is almost the same as that of the filters proposed by MPEG. In conclusion, the peroformance of the proposed filters is comparable to that of the ones in MPEG-4, while requiring lower hardware complexity and providing high operating speed.