• Transactions of the Korean Society of Mechanical Engineers
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• v.15 no.1
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• pp.252-261
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• 1991

A particle trajectory model to simulate two-phase particle-laden crossjets into two-dimensional horizontal free stream has been developed to study the variations of the jet trajectories and velocity variations of the gaseous and the particulate phases. The following conclusions may be drawn from the predicted results, which are in agreement with experimental observations. The penetration of the two-phase jet in a crossflow is greater than that of the single-phase jet. The penetration of particles into the free stream increases with increasing particle size, solids-gas loading ratio and carrier gas to free stream velocity ratio at the jet exit. When the particle size is large, the solid particles separate from the carrier gas , while the particles are completely suspended in the carrier gas for the case of small size particles. As the particle to carrier gas velocity ratio at the jet exit is less than unity, the particles in the vicinity of the jet exit are accelerated by the carrier gas. As the injection angle is increased, the difference of the particle trajectory from that of the pure gas becomes larger. Therefore, it can be concluded that the velocities and trajectories of the particle-laden jets in a crossflow change depending on the solids-gas loading ratio, particle size, carrier gas to free stream velocity ratio and particle to gas velocity ratio at the jet exit.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.14 no.4
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• pp.194-200
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• 1981

Boiled-dried anchovy is one of nation-widely consumed dried fish foods in Korea. In this study, the taste compounds including nucleotides and their related compounds, free amino acids, trimethylamine oxide and total creatinine were analyzed, and their roles in tasting activity were investigated. IMP content in large size, middle size, small size and least size boiled-dried anchovy was $22.7{\mu}mole/g,\;18.6{\mu}mole/g,\;20.3{\mu}mole/g\;and\;4.0{\mu}mole/g$, respectively, and the ratio of IMP to the total nucleotides and their related compounds in each sample was $55.0\%,\;51.0\%,\;69.1\%\;and\;47.0\%$, respectively. In the free amino acid composition of the four size groups of boiled-dried anchovy, abundant amino acids were histidine, lysine, alanine and proline, and the sum of these amino acids occupied $69.0\%,\;67.7\%$. $66.8\%\;and\;45.9\%$ of the total free amino acid in each sample, respectively. Among these. histidine was the most dominant in all samples amounting to 589.0 mg/100g in lage size, 373.9 mg/100g in middle size, 437.8 mg/100g in small sire and 101.0 mg/100g in least size, while aspartic acid and methionine were poor in content. Among the organic bases, total creatinine was abundant, and its nitrogen content ranged from $21\%\;to\;39\%$ of the total extractive nitogen. From the results of omission test, the taste-active compounds of the boiled-dried anchovy are assumed to be IMP and free amino acids.

• Archives of Reconstructive Microsurgery
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• v.19 no.1
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• pp.68-79
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• 2010

Lower abdominal tissue is regarded as an ideal donor site for the breast reconstruction because it provides large skin territory and huge amount of soft tissues enough to the breast size. However it is not easy for the surgeon to reconstruct the really natural breast, and needs the learning curve with long time experience. Author represent the various reconstruction procedures for the breast using lower abdominal tissue such as muscle sparing free TRAM, DIEP, and SIEA free flaps to reinsure like breast. Indications, and selection of reconstructive methods, surgical timing, selection of donor sites and recipient vessel of these flaps were reviewed. In addition, detailed procedures, surgical tips and secondary adjuvant procedures are described for more symmetry of reconstructed breast. The muscle sparing free TRAM, DIEP, and SIEA free flaps would be enough to provide supple, huge amount of well vascularized tissue for the breast, if these flaps were selected for the appropriate indication according to patient's general condition, obesity, the opposite breast and abdominal tissue condition. Lower abdominal tissue was able to provide versatile designs with sufficient adipose tissue without compromising the integrity of abdominal wall.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2000.04a
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• pp.391-398
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• 2000

To evaluate the seismic performance of a base isolated building accurate analytical model should be selected. The analytical results such as reduced accelerations member forces and relative displacements of the superstructure of the base isolated building are only meaningful when the analytical model is close enough to the real structure. Real size one bay-two story steel frame and two kinds of seismic isolators(laminated elastomeric bearing and lead-rubber bearing) are designed. manufactured and constructed in the laboratory. Free vibration tests using fuse bars were conducted to evaluate the change of dynamic characteristics(period and damping) before and after base isolation of the steel frame. The experimental results of free vibration tests were also used as a bench mark for adjusting the selected analytical modeling to real base isolated steel frame.

• International Commerce and Information Review
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• v.11 no.1
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• pp.157-176
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• 2009

This study analyzed the information factors which determine cash liquidity in Korean export-oriented companies. In this paper, cash liquidity means the ratio of the value of cash or cash equivalent to the asset value subtracted marketable securities value from total asset value. The empirical test shows that main information factors are the size of company, the growth opportunity of company, the volatility of operating cash flows and free cash flows, the credit yield spread of company, the debt ratio, the turnover ratio of cash flows and free cash flows, and the estimate of bankruptcy that amounts to the inverse number of Z score. In summary, the size of company, debt ratio, turnover ratio of cash flows and free cash flows, and Z-score have negative influence on the cash liquidity of Korean export-oriented companies. but the volatility of operating cash flows affect the cash liquidity positively.

• Journal of the Korean Society for Precision Engineering
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• v.13 no.2
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• pp.176-184
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• 1996

The paper describes the vibration characteristics of the mechanical system consisting of a uniform Timoshenko beam with a guided mass and an elastic spring support. The free end of the beam does not rotate and the spring attatched to the guided mass is elastically restrained against translation. The guided mass is assumed to be a rigid body having a finite size, but not a mass point as it has been assumed so far. The effect of magnitudes, rotary inertia and the size of the guided mass on the vibration characteristics is fully investigated by the numerical simulation using FEM and experiment. In order to verify the eigenvalue sensitivity for considered system, comparison exact solutions with FEM is conducted, and a good agreement between two solutions is also highlighted.

• Journal of Korean Vacuum Science & Technology
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• v.3 no.1
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• pp.10-15
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• 1999

Using micro-wells on the Mo substrate, we could obtain various tubular-volcano-types of free-standing diamond field emitters by depositing a diamond film detaching the film and turning the film upside down. The field emission characteristics of these structures were investigated as a function of size, shape and the number density of the tubular-volcano-type diamond field emitters. The field emission characteristics, especially the current density, were greatly enhanced with increasing the number density of the tubular-volcano-type diamond field emitters on the Mo substrate. Based on these results, we suggest that the reduction of the well size can give better field emission characteristics by the increase in the number density of the tubular-volcano-type diamond field emitters. Finally, we suggest the feasibility of fabricating a large-area field emission display using our patterned tubular-volcano-type free-standing diamond field emitters.

• Journal of the Optical Society of Korea
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• v.19 no.6
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• pp.619-628
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• 2015

In this paper, we consider a method for estimating a stripe-type defect and the reconstruction of a defect-free L/S type mask used in lithography. Comparing diffraction patterns of defected and defect-free masks, we derive equations for the estimation of the location and size of the defect. We construct an analytical model for this problem and derive closed form equations to determine the location and size using phase retrieval problem solving techniques. Consequently, we develop an algorithm that determines a defect-free mask pattern. An example shows the validity of the equations.

• Transactions of Materials Processing
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• v.19 no.2
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• pp.95-100
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• 2010

Drawing and normalizing are efficient means for controlling strength, fatigue and machinability of free machining steel. Normally strength and machinability are conflicting properties which need to be optimized. In this study, the effects of normalizing temperature and reduction of area on strength, fatigue and machinability were investigated. Fine grains were generated at lower normalizing temperature and fatigue life was increased with decreasing grain size. Matrix was work hardened and elongated with increasing reduction of area. Inclusions also were elongated and cross-sectional area of inclusions along drawing axis was decreased. The effects of work hardening and grain size on fatigue life were significant, but only work hardening affected machinability. Shape and distribution of inclusions after drawing had little effect on fatigue life and machinability.

• Biotechnology and Bioprocess Engineering:BBE
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• v.11 no.5
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• pp.377-381
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• 2006

A study was carried out to determine a suitable light intensity and inoculum size for the growth of Rhodopseudomonas palustris strain B1. The pollution reduction of sago effluent using free and immobilised R. palustris cells was also evaluated. The growth rate in glutamatemalate medium was highest at 4 klux compared to 2.5 and 3 klux. The optimal inoculum size was 10% (v/v). Both the COD and BOD of the sago effluent were reduced by 67% after three days of treatment. The difference in biomass production or BOD and COD removal with higher inoculum sizes of 15 and 20% was minimal. This could be attributed to limited nutrient availability in the substrate. The use of immobilised cells of R. palustris reduced the pollution load 10% less compared to pollution reduction by free cells. Hence, there was no significant difference in using free or immobilised cells for the treatment of sago effluent.