• Publications of The Korean Astronomical Society
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• v.13 no.1 s.14
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• pp.135-147
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• 1998

We have simulated the interaction of supernova remnants with constant ambient medium to explore the dynamics of Type Ia supernova remnant. We assumed the supernova ejecta density distribution of the central constant and the outer power-law density distribution$({\rho}{\propto}{\gamma}^{-n})$. We have calculated four different cases with different n. By scaling the length and time scales from the initial parameters-ejecta mass, ejecta energy, the ambient density, we could compare effects of the different density distribution of the ejecta on the dynamics of the SNRs. The radius of the outer forward shock converges the Sedov-Talyor solution at t' = 2.3 when the swept-up mass is 8 times of the ejecta mass. On the other hand, the motion of the reverse shock are largely affected by n. The ejecta with smaller n takes comparably long time to thermalize the whole ejecta at $t'{\simeq}5.3,\;M_{sw}{\simeq}18M_{ej}$. We have applied our calculated results to obtain the ejecta density distributions of Tycho and SN1006 with $n{\simeq}6$.

• International Journal of Fluid Machinery and Systems
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• v.1 no.1
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• pp.33-37
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• 2008

EquiMar (Equitable Testing and Evaluation of Marine Energy Extraction Devices in terms of Performance, Cost and Environmental Impact) is one of the first round of energy projects under the European Commissions 7th Framework Programme (FP7). The three year EquiMar project aims to deliver a suite of protocols for the evaluation of both wave and tidal converters, harmonizing testing and evaluation procedures across the wide range of available devices, accelerating adoption through technology matching and improving the understanding of both environmental and economic impacts associated with the deployment of devices. The EquiMar protocols will cover site selection, initial design, scaling up of designs, the deployment of arrays and environmental impact assessment as well as economic issues. EquiMar will build on existing protocols, e.g. UK DTI Marine Renewables Development Fund (MRDF) protocols for wave and tidal energy, and engage with international standards setting activities, e.g. IEC TC114.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2002.11b
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• pp.6-7
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• 2002

The goal of this research was to develop the effectiveness of in vitro culture method for A. formosanus and study the environment in vitro conditions affecting on growth. The first series of experiments were examined to investigate the response of three different basal media, MS (Murashige and Skoog, 1962), Knudson (KC; Knudson, 1946) and modified hyponex on growth and multiplication during in vitro culture. Multiple shoot proliferation was induced in shoot tip explants on Hyponex (H3) media supplemented with BA (1 mg1$^{-1}$) or TDZ (1-2 mg1$^{-1}$). Addition of activated charcoal (1%) to the TDZ containing medium promoted rapid shoot tip proliferation (11.1 shoots per explant) but the same medium had an opposite effect resulting in poor proliferation in the nodal explants. However, the regenerated shoots had slow growth rate and failed to elongate. This problem was overcome by transferring the shoot clumps to a hormone free H3 media supplemented with 2% sucrose and 0.5% activated charcoal. Using bioreactor culture for scaling up was also shown the best way for multiple shoot induction and growth of this plant.(중략)

• Journal of the Society of Cosmetic Scientists of Korea
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• v.27 no.1
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• pp.53-72
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• 2001

Dry skin is caused mainly by the perturbation of stratum corneum lipids which affected by ageing, change of season, excess use of surfactant and the effect of disease like atopic dermatitis and psoriasis. Intercellular lipid structures in stratum corneum are responsible for the barrier function of mammalian skin. The major lipd classes that can be extracted from stratum corneum are ceramides, cholesterol and fatty acid, which make up approximately 50, 25, 10 percent of the stratum corneum lipid mass, respectively. Small amount of cholesterol sulfate, phospholipids, glycosylceramide and cholesterol esters are also present. Recent studies have shown that application of one or two these lipids to the perturbed skin delays barrier recovery; only equimolar mixtures allow normal recovery. We observed that barrier recovery rate was improved in hairless mouse by topical application of single neutral lipids (ceramide, free fatty acid, cholesterol) and lipid mixtures. Whereas the application of single lipid didn’t allows a significant enhancement comparing with normal barrier repair, the equimolar mixtures of 3 components(including synthetic pseudoceramide PC104) improved barrier repair, as assessed by the transepidermal water loss. At clinical study to the volunteers aged over sixty, skin dryness recuperated by the increase of moisture(capacitance) and the reduction of scaling. Utilization of physiologic lipid mixture containing natural ceramides or synthetic pseudoceramide could lead to new forms of topical therapy for the dryness and dermatoses(e.g., psoriasis, atopic dermatitis and irritant dermatitis).

• Health Policy and Management
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• v.18 no.1
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• pp.21-42
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• 2008

This study investigates economies of scale, cost complementarity and economies of scope for healthcare organizations using econometric approaches. The economies of scale appear to exist in each service provided by a hospital such as inpatient treatment services, outpatient treatment services, and other patient treatment services, respectively. When we test all services in aggregate level, it also indicates that the healthcare industry on average exhibits the economies of scale of 6 percent, which implies that scaling up hospital sizes will bring substantial cost savings to them Evidence shows that cost complementarity exists between outpatient services and other services for patients and, i.e., these other services for patients experience the reduction in marginal costs as the outputs of the outpatient services increase. For the economies of scope, they are present in most service areas; aggregate level services, outpatient services, and other services for patients, respectively. Inpatient treatment services, however, do not show any evidence of the economies of scope. Results show that the economies of scope are achieved by the general hospital type that provides all service areas such as inpatient treatments, outpatient treatments, and other services for patients. The existence of the economies of scope provides the rationale for extending the existing line of business in a hospital into more diverse areas of services where its benefit comes in the form of cost savings. In sum, it overall provides evidence that the M&As in this industry are encouraged to achieve cost reductions from the economies of scale and scope by changing the size and the output mix.

• Journal of Soil and Groundwater Environment
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• v.21 no.3
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• pp.14-20
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• 2016

Remediation of crude oil contaminated soil is complicate and hard to apply traditional methods because of its persistency, durability, and high viscosity. Therefore, in this study, the efficiency of crude oil contaminated soil remediation was tested by developing a pilot-scale thermal desorption system using the indirect heating method with an exhaust gas treatment. Under optimal condition drawed by temperature and retention time, the remedial efficiency of crude oil contaminated soil and treatability of exhaust gas were analyzed. Total Petroleum Hydrocarbon (TPH) concentration of crude oil contaminated soil was decreased to 69.7 mg/kg on average and the remedial efficiency was measured at 99.60%. Through the exhaust gas, 86.0% of Volatile Organic Compounds (VOC) was degraded and 97.16% of complex malodor was reduced under the suggested optimum operation condition. This study provides important basic data to be useful in scaling up of the indirect thermal desorption system for the remediation of crude oil contaminated soil.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.14 no.1
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• pp.15-21
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• 2014

Due to the development of manufacturing technology scaling, more transistors can be placed on a cache memories of a processor. However, processors become more vulnerable to the soft errors because of highly integrated transistors, the reliability of cache memory must consider seriously at the design level. Various researches are proposed to overcome the vulnerability of soft error, but researches of tag bit are proposed very rarely. In this paper, we revaluate the reliability improvement technique for tag bit, and analyse the protection rate of write-back operation, which is a typical case of not satisfying temporal locality. We also propose the methodology to improve the protection rate of write-back operation. The experiments of the proposed scheme shows up to 76.8% protection rate without performance degradations.

• JSTS:Journal of Semiconductor Technology and Science
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• v.4 no.1
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• pp.41-44
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• 2004

The trend of decreasing the minimal structure sizes in microelectronics is still being continued. Therefore in its roadmap the Semiconductor Industries Association predicts a printed minimum MOS-transistor channel length of 10 nm for the year 2018. Although the resolution of optical lithography still dramatically increases, there are known and proved solutions for structure sizes significantly below 50 nm up to now. In this work a new method for the fabrication of extremely small MOS-transistors with a channel length and width below 50 nm with low demands to the used lithography will be explained. It's a further development of our deposition and etchback technique which was used in earlier research to produce transistors with very small channel lengths down to 30 nm, with a scaling of the transistor's width. The used technique is proved in a first charge of MOS-transistors with a channel area of W=200 nm and L=80 nm. The full CMOS compatible technique is easily transferable to almost any other technology line and results in an excellent homogeneity and reproducibility of the generated structure size. The electrical characteristics of such small transistor will be analyzed and the ultimate limits of the technique will be discussed.

• Journal of Advanced Marine Engineering and Technology
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• v.40 no.2
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• pp.146-151
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• 2016

This study concentrates on the design of floater for 15kW-class wave energy converter that extracts the ocean energy by oscillating vertically along the wave motion. The floater connects to a arm structure that connects to a hydraulic cylinder, which drives a hydraulic generator. The study mainly focuses on the structural analysis of the floater. Previous studies have been conducted using a miniature model; however, this study focuses on the size selection of the floater for a full scale model. Static structural analysis is conducted using fine numerical grids. Due to the complexity of the whole model, it is analyzed as a separate component. There are several load cases for each floater size, and they are analyzed thoroughly for stress (von-mises, shear, and normal) and deformation. The initial design was conducted by scaling up from the miniature model of the previous study, and the final design has been redesigned by changing the thickness and internal support structure shape.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1988.05a
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• pp.33-34
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• 1988

Recent developments in characterization techniques for solar cells are reviewed. First, general rules of material selection for solar cells such as $CuInSe_2$ and amorphous silicon of photovoltaic application are studied. Secondly, a method to obtain correct cell efficiency measurements under AM1 condition is introduced. Thirdly, various characterization techniques for solar cells are discussed. A special emphasis is given to up-scaling and computer control of the characterizations in the following systems; cell I-V characteristics for cell efficiency and other cell parameters, spectral response for quantum efficiency, surface photovoltage for diffusion length of minority carriers, and photothermal deflection for density of states in energy gaps.