• Korean Journal of Materials Research
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• v.5 no.1
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• pp.42-54
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• 1995

$Ta_2O_5$ thin film IS a promising material for the high dielectrics of ULSI DRAM. In this study, $Ta_2O_5$ thin film was grown on p-type( 100) Si wafer by thermal metal organic chemical vapo deposition ( MCCVD) method and the effect of operating varialbles including substrate temperature( $T_s$), bubbler temperature( $T_ \sigma$), reactor pressure( P ) was investigated in detail. $Ta_2O_5$ thin film were analyzed by SEM, XRD, XPS, FT-IR, AES, TEM and AFM. In addition, the effect of various anneal methods was examined and compared. Anneal methods were furnace annealing( FA) and rapid thermal annealing( RTA) in $N_{2}$ or $O_{2}$ ambients. Growth rate was evidently classified into two different regimes. : (1) surface reaction rate-limited reglme in the range of $T_s$=300 ~ $400 ^{\circ}C$ and (2: mass transport-limited regime in the range of $T_s$=400 ~ $450^{\circ}C$.It was found that the effective activation energies were 18.46kcal/mol and 1.9kcal/mol, respectively. As the bubbler temperature increases, the growth rate became maximum at $T_ \sigma$=$140^{\circ}C$. With increasing pressure, the growth rate became maximum at P=3torr but the refractive index which is close to the bulk value of 2.1 was obtained in the range of 0.1 ~ 1 torr. Good step coverage of 85. 71% was obtained at $T_s$=$400 ^{\circ}C$ and sticking coefficient was 0.06 by comparison with Monte Carlo simulation result. From the results of AES, FT-IR and E M , the degree of SiO, formation at the interface between Si and TazO, was larger in the order of FA-$O_{2}$ > RTA-$O_{2}$, FA-$N_{2}$ > RTA-$N_{2}$. However, the $N_{2}$ ambient annealing resulted in more severe Weficiency in the $Ta_2O_5$ thin film than the TEX>$O_{2}$ ambient.

• Journal of the Korean Geosynthetics Society
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• v.17 no.2
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• pp.41-49
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• 2018

The purpose of this study is to fabricate a full scale road embankment using lightweight air foamed soil as a soil material on soft ground and to investigate its material characteristics and behavior in order to promote dredged soil utilization and minimize ground improvement. As a result of the laboratory test of the onsite mixed samples, the total unit weight of the specimens decreased almost linearly until curing 28 days. In particular, the total unit weight after 28 days of curing was reduced to about 81% of the slurry state before curing, which will be useful in the formulation of similar native soil materials in the future. The unconfined compressive strength began to decrease with the 14th day of curing as shown in the previous study. When the cement content is increased, the strength decreases sharply at a small strain change after the occurrence of the maximum compressive strength, and the maximum strength is exhibited in a range of a smaller axial strain than normal range. The settlement at the surface layer of the ground due to the lightweight embankment was about 1 / 2.75 of the soil embankment and was in agreement with the unit weight ratio (1 / 2.7) of the embankment materials. This indicates the cause and effect of the settlement due to the difference in self weight of the embankments. Also, the difference in settlement between soil and lightweight embankment increased with increasing depth. This shows that the difference in the point at which the settlement is terminated is clear. The ground horizontal displacement under the lightweight embankment was about 15~20% smaller than that of the soil embankment and the depth of occurrence was also 4.5~5.0m shallower in the lightweight embankment.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.7 no.2
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• pp.195-205
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• 2012

This study examines runaway youths at risk in a youths' shelter who are preparing for an independent life and both the facilitating and adverse factors to personal characteristics and independence of runaway youths at risk with the aim to grasp their recognition of independence and level of desire for it and find out necessary factors for a successful independence in multidimensional perspectives including the economic independence, educational independence, psychological independence, and social independence for their sound growth. This will provide the basis for desirable interventions for youths runaway youths at risk to prepare for an independent life. The findings of this study on the factors that affect the preparation for an independent life are as follows: First, as a result of analyzing the effect of micro-systematic factors on the preparation for an independent life, it turned out that problem-solving abilities and self-efficacy had influence on the preparation for a career Second, as a result of analyzing the effect of mesoscopic-systematic variables on the preparation for an independent life, it turned out that the preparation for a career were affected by whether to participate in independence preparation programs and institutional supports, and that career maturity of runaway youths at risk were affected only by the relationship with teachers and participation in independence preparation programs. Third, as a result of analyzing the effect of macro systematic variables on the preparation for an independent life, it turned out that the preparation for a career were affected by participation of the local community and service network, and that participation of the local community was an predictor variable that would affect a career maturity of runaway youths at risk. Fourth, as a result of analyzing ecological systematic variables that might affect the preparation for a career, it turned out that intervening variables and macro systematic variables had the most powerful influence on the preparation for a career among runaway youths at risk. It is necessary, therefore, to provide education programs organized by policies in order to develop problem-solving abilities and vocational capabilities so that runaway youths at risk, and to train and appoint more professional teachers at shelters. Programs for independence preparation need to be developed actively and practically in consideration of the characteristics of shelters, and the network with the local community for support also need to be established in utilization of the human resources and service programs of the community. With the understanding of leaving home of runaway youths at risk as the previous stage of an independence, there should be a housing support for their stable settlement in the perspective of housing welfare until become adults. In addition, there should be education specialized programs for occupation and careers to train runaway youths at risk as professionals including such areas as health, mentality, learning, and voluntary work for their sound growth.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.10 no.1
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• pp.115-123
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• 1990

The purpose of this study was to examine the uses of coal ash as a type of construction material. The methods of examination were chemical anlysis, soil laboratory test and the soil vibration test. Materials used were coal ash obtained as a by-product from 5 thermal power plants in Yongdong, Yongwol, Sochon(anthracite coal) and in Samchonpo and Honam (bituminous coal). Over 70% of the coal ash consisted of silica and alumina. The fly ash grain size showed a uniform distribution from fine-sand to silt, and that of the bottom ash showed from sand to gravel. The specific gravity and density of the coal ash were low. The long term strength increased gradually due to the self-setting property resulting from pozzolanic activity. The shear strength was higher than that of general soil. Cohesion and optimum moisture content of anthracite coal ash were higher than bituminous coal ash, whereas the maximum dry density was higher in bituminous coal ash. The coal ash dynamic Young's modulous curve range was similar to that of general soil. Of the results from the soil vibration test by car-running, the size relative acceleration level in the ash pond was higher than that of natural ground, but the damping ratio was lower than that of natural ground near the ash pond. The coal ash has more advantageous engineering properties than general soil with particles of the same size. For example, the California Bearing Ratio of the bottom ash at both Yongdong and Yongwol was 77~137%. Therefore we expect that if further study is done, coal ash can be used as a construction material when reclaiming seashore, construction embankments, road construction, making right-weight aggregate, or as a general construction material.

• Food Science of Animal Resources
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• v.25 no.4
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• pp.430-435
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• 2005

Current study was conducted to investigate the effect of organic selenium supplementation originated from mushroom culture medium on meat quality of Hanwoo sleets. The result showed that organic selenium supplementation of 0.9 ppm (DM based ratio) for 2 (T1), 4 (T2) and 6 (T3) months had no effect on moisture content in longissimus muscle, with 63 to $66\%$ compared to non-supplemented control group Similarly, intramuscular fat content ranged from 11.7 to $16.4\%$ did not differ between the treatment groups (p>0.05). T3 group showed the highest protein content with $20.8\%$ while T2 group had the lowest content with $19.2\%$ The data indicated that organic selenium supplementation to the experimental concentration had indictable effect on proximate composition The treatments similarly had no influence on physical and biological characteristics of longissimus muscle, where cooking loss and shear force ranged from 20 to $21\%$ and from 3.6 to 4.4kg, respectively. On the other hand, muscle pH at 24 h postmortem showed 5.52, 5.57, 5.50, 5.50 for control, T1, T2 and T3, respectively, indicating that the longer feeding period resulted in the lower ultimate un A similar trend was observed from water-holding capacity (63.8, 64.4 and $64.2\%$ for T1, T2 and T3, respectively) which was significantly higher than con01 group of $59.5\%$ For sensory evaluation, juiciness did not differ between the treatment groups, but n and n (5.30 and 5.28, respectively) showed significantly tender mat Particularly, T2 group received significantly higher flavor score among the treatment groups including controls. The data indicated that organic selenium supplementation to the experimental concentration had no effect on beef quality, but the treatment effect on anti-oxidation function is remained for further studies.

• Food Science of Animal Resources
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• v.26 no.4
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• pp.411-417
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• 2006

This study was conducted to evaluate the physicochemical properties of pork loin marinated with a solution of Nan and sodium tripolyphosphate, and the sensory attributes of tomato sauce-stewed products using marinated loin. Pork loin samples were cut $(3{\times}3{\times}2cm)$ and assigned to 3 treatment groups [C; unmarinated control (100% distilled water), T1; 10% sodium chloride, T2; 10% sodium chloride + 3% sodium tripolyphosphate]. Samples were marinated for 24hr at $5^{\circ}C$. The uptake of marinade in the treatment groups was significantly greater (p<0.05) than that of C, however no significant difference between the two treatments was observed. Cooking losses were highest (p<0.05) for T1, while lowest (p<0.05) for T2. All marinated loins had a significantly higher (p<0.05) yield than the control. The pH of the marinade solution ranged from 7.00 for T1 to 8.47 for T2. The two marinated loins had a significantly higher (p<0.05) $pH_{24}$ than the control. The water holding capacity (WHC) was highest for T2, and lowest for T1. CIE $L^*,\;a^*,\;b^*$ tended to be slightly higher in the control than either treatment group. The shear force value $(kg/cm^2)$ of yaw meat did not differ between the control and marinated muscle samples. However, cooked meat had a significantly lower (p<0.05) shear force value in T2 than C and T1. Hardness values were significantly lower (p<0.05) for both treatments compared with the control. There were no differences in texture profile, except hardness, between the control and the two treatments. Regarding the sensory evaluation of tomato sauce-stewed products manufactured with marinated pork loin, the treatment groups scored marginally well in tenderness, juiciness and overall acceptability, while the flavor score of the control was significantly higher than those of T1 and T2.

• Food Science of Animal Resources
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• v.27 no.3
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• pp.284-289
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• 2007

This study was conducted to investigate the effects of copper and zinc supplementation on growth performance, nutrient digestibility, and meat and carcass characteristics in finishing pigs. A total of 72 $(Landrace{\times}Yorkshire{\times}Duroc)$ pigs (58.47 kg initial BW) were assigned to 6 treatments in a $2{\times}3$ factorial design $(Zn\;levels{\times}Cu\;levels)$. The sources of zinc and copper were Zn-methionine chelate and Cu-methionine chelate, respectively. Zinc levels used were 80 and 120 ppm and copper levels used were 10, 30 and 60 ppm. Throughout the entire experimental period, the average daily gain (ADG) and average daily feed intake (ADFI) were not significantly affected by Cu or Zn levels, or their relative levels. The G:F ratio was significantly affected by the relative levels of Cu and Zn (p<0.05), specifically at 30 ppm Cu and 120 ppm Zn. Dry matter digestibility was significantly affected by the levels of Cu (p<0.02), Zn (p<0.01) and the relative levels of each (p<0.04), in particular at 30 ppm Cu and 120 ppm Zn. Nitrogen digestibility was significantly affected by Zn levels (p<0.01) and the combination of 30 ppm Cu and 120 ppm Zn (p<0.03). The $L^*-value$, shear force, cooking loss and pH were not significantly affected by Cu levels, Zn levels or their combination. The $a^*- (p<0.04)\;and\;b^*- values (p<0.01)$ were significantly affected by Zn levels at 80 ppm. The Water hoding capacity was significantly affected by Cu and Zn in combination (p<0.01) at 10 ppm Cu and 120ppm Zn. The carcass weight, backfat thickness and carcass grade were not significantly affected by Cu levels, Zn levels or their relative levels. The carcass percentage was significantly affected by the combination (p<0.04) of 30ppm Cu and 120ppm Zn. In conclusion, dietary supplementation of Cu and Zn at 30 and 120 ppm, respectively, is effective for feed efficiency, nutrient digestibility and carcass percentage, while at the levels of Cu at 10 ppm and Zn at 120 ppm have effects on WHC.

• Food Science of Animal Resources
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• v.29 no.1
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• pp.91-98
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• 2009

The objective of this research was to evaluate the chemico-physical and sensory traits of Hanwoo beef quality grade $1^{++}$ ($HW1^{++}$), grade $1^+$ ($HW1^+$), grade 1 (HW1), and Australian Wagyu (AUW) beef. The Longissimus Lumborum (LL) of $HW1^{++}$ beef had the lowest (p<0.05) moisture contents (54.07%) while it had the highest (p<0.05) CIE L, a, b value and water holding capacity (WHC). Fat contents of LL were significantly different (p<0.05) among the beef groups: $HW1^{++}$ (25.58%), $HW1^+$ (16.39%), HW1 (11.29%), and AUW (11.87%) beef. Warner-Bratzler shear force (WBSF) values were the lowest in the beef from AUW (2.81 kg) beef. Cooking loss of AUW beef had the highest value (23.77%) among the beef groups. Quality grade affected sensory traits, with $HW1^{++}$ receiving highest (p<0.05) tenderness, juiciness and flavor. In Hanwoo beef, from grade 1 to $grade1^{++}$, there were significant increases in fat content (from 11.29% to 25.58%), CIE L value (37.56 to 43.15), WHC (55.97% to 60.05%), tenderness (4.63 to 5.28), and decreases in moisture contents (66.84% to 54.07%), protein contents (20.35 to 19.76%), and WBSF value (5.43 kg to 2.93 kg) value. In sensory evaluation, overall acceptability score for Hanwoo $1^{++}$ grade beef was significantly higher than for Australian Wagyu beef. However, there were no significant differences in sensory properties between Hanwoo 1, $1^+$ grade and Australian Wagyu beef.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.4 no.3
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• pp.43-52
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• 1984

This paper is concerned with the strain characteristics of the time effect on the remoulded saturated day sampled from the downstream of the Yeongsan river, and the constitutive equation that can generally explain time-dependent behaviors of norma1ly consolidated clay. This paper examines whether or not the afore-said constitutive equation can be applied to the remoulded Mooan-clay. Throughout this study, the conclusions obtained are as follows. 1. Throughout the isotropic consolidation test for 7 days and the isotropic relaxation test, the existence of the static and dynamic yielding surfaces is confirmed respectively. 2. The characteristics of time effect of the deformation, namely, the existence of a unique stress-strain-time relation, is conformed from the experimental result on the Mooan-clay. 3. The prodictions of the stress path and the strain on the Cam-clay theory is not consistent with those observed during the experiments. 4. Constitutive equation(2-3-12) obtained by applying Cam-clay theory to Perzyna's elastic-viscoplasticity theory can explain the behavior of pore water pressure during isotropic stress relaxation, concerned with time dependency under undrained condition. The equation can also explain the results of the undrained triaxial compression test for the clay with different strain rate under the same or different consolidation history. 5. This constitutive equation has eight material parameters which can be determined from triaxial compression tests.

• Economic and Environmental Geology
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• v.39 no.2 s.177
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• pp.111-128
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• 2006

Three dimensional crustal structure and source features of earthquake hypocenters on the Korean peninsula were investigated using P and S-wave travel time tomography. The main goal of this research was to find Vp/Vs anomalies at earthquake hypocenters as well as those of crustal structure of basins and deep tectonic settings. This allowed fer the extrapolation of more detailed seismotectonic force from the Korean peninsula. The earthquake hypocenters were found to have high Vp/Vs ratio discrepancies (VRD) at the vertical sections. High V/p/Vs ratios were also found in the sedimentary basins and beneath the Chugaryong Rift Zone (CRZ), which was due to mantle plume that subsequently solidified with many fractures and faults which were saturated with connate water. The hypocenters of most earthquakes were found in the upper crust for Youngwol (YE), Kyongju (KE), Hongsung (HE), Kaesong (KSE), Daekwan (DKE), and Daehung (DHE) earthquakes, but near the subcrust or the Moho Discontinuity for Mt. Songni (SE), Sariwon (SRE) and Mt. Jiri (JE) earthquakes. Especially, we found hot springs of the Daekwan, Daehung and Unsan regions coincide with high VRD. Also, this cannot rule out the possibility that there are some partial meltings in the subcrust of this region. High VRD might indicate that many faults and fractures with connate water were dehydrated when earthquakes took place, reducing shear modulus in the hypocenter areas. This is can be explained by due to the fact that a point source which is represented by the moment tensor that may involve changes in volume, shear fracture, and rigidity. High Vp/Vs ratio discrepancies (VRD) were also found beneath Mt. Backdu beneath 40 km, indicating that magma chamber existed beneath Mt. Backdu is reducing shear modulus of S-wave velocity.