• International Journal of Computer Science & Network Security
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• v.23 no.6
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• pp.193-201
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• 2023

In this paper, we consider the maximum scatter traveling salesman problem (MSTSP), a travelling salesman problem (TSP) variant. The problem aims to maximize the minimum length edge in a salesman's tour that travels each city only once in a network. It is a very complicated NP-hard problem, and hence, exact solutions can be found for small sized problems only. For large-sized problems, heuristic algorithms must be applied, and genetic algorithms (GAs) are found to be very successfully to deal with such problems. So, this paper develops a hybrid GA (HGA) for solving the problem. Our proposed HGA uses sequential sampling algorithm along with 2-opt search for initial population generation, sequential constructive crossover, adaptive mutation, randomly selected one of three local search approaches, and the partially mapped crossover along with swap mutation for perturbation procedure to find better quality solution to the MSTSP. Finally, the suggested HGA is compared with a state-of-art algorithm by solving some TSPLIB symmetric instances of many sizes. Our computational experience reveals that the suggested HGA is better. Further, we provide solutions to some asymmetric TSPLIB instances of many sizes.

• Journal of the Korean Ceramic Society
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• v.45 no.9
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• pp.524-530
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• 2008

Anti-Reflective (AR) thin film coatings of $SiO_2$ (n= 1.48) and $TiO_2$ (n=2.17) were deposited by ion-beam assisted deposition (IBAD) with End-Hall ion source and conventional electron beam (e-beam) evaporation to investigate the effect of deposition method on the refractive indicies (n) of the fIlms. Green-light generation using a GaAs laser diode was achieved via excitation of the second harmonic. The latter resulted from the transmission of the fundamental guided-mode wave of 1064 nm through periodically poled $LiNbO_3$. Large differences in the refractive indicies of each of the layers in the multilayer coating may improve AR performance. IBAD of $SiO_2$ reduced its refractive index from 1.45 to 1.34 at 1064 nm. Conversely, e-beam evaporation of $TiO_2$ increased its refractive index from 1.80 to 2.11. In addition, no fluctuations in absorption at the wavelength of 1064 nm were found. The results suggest that films prepared by different deposition methods can increase the effectiveness of multilayer AR coatings.

• Korean Journal of Materials Research
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• v.22 no.9
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• pp.494-498
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• 2012

Geopolymer cements and geopolymer resins are newly advanced mineral binders that are used in order to reduce the carbon dioxide generation that accompanies cement production. The effect of additives on the compressive strength of geopolymerized class-F fly ash was investigated. Blast furnace slag, calcium hydroxide($Ca(OH)_2$), and silica fume powders were added to fly ash. A geopolymeric reaction was initiated by adding a solution of water glass and sodium hydroxide(NaOH) to the powder mixtures. The compressive strength of pure fly ash cured at room temperature for 28 days was found to be as low as 291 $kgf/cm^{-2}$, which was not a suitable value for use in engineering materials. On the contrary, addition of 20 wt% and 40 wt% of blast furnace slag powders to fly ash increased the compressive strength to 458 $kgf/cm^{-2}$ and 750 $kgf/cm^{-2}$, respectively. 5 wt% addition of $Ca(OH)_2$ increased the compressive strength up to 640 $kgf/cm^{-2}$; further addition of $Ca(OH)_2$ further increased the compressive strength. When 2 wt% of silica fume was added, the compressive strength increased to 577 $kgf/cm^{-2}$; the maximum strength was obtained at 6 wt% addition of silica fume. It was confirmed that the addition of CaO and $SiO_2$ to the fly ash powders was effective at increasing the compressive strength of geopolymerized fly ash.

• Proceedings of the KSRS Conference
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• v.1
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• pp.7-10
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• 2006

Four programs, i.e. TRMM, ADEOS2, ASTER, and ALOS are going on in Japanese Earth Observation programs. TRMM and ASTER are operating well, and TRMM operation will be continued to 2009. ADEOS2 was failed, but AMSR-E on Aqua is operating. ALOS (Advanced Land Observing Satellite) was successfully launched on $24^{th}$ Jan. 2006. ALOS carries three instruments, i.e., PRISM (Panchromatic Remote Sensing Instrument for Stereo Mapping), AVNIR-2 (Advanced Visible and Near Infrared Radiometer), and PALSAR (Phased Array L band Synthetic Aperture Radar). PRISM is a 3 line panchromatic push broom scanner with 2.5m IFOV. AVNIR-2 is a 4 channel multi spectral scanner with 10m IFOV. PALSAR is a full polarimetric active phased array SAR. PALSAR has many observation modes including full polarimetric mode and scan SAR mode. After the unfortunate accident of ADEOS2, JAXA still have plans of Earth observation programs. Next generation satellites will be launched in 2008-2012 timeframe. They are GOSAT (Greenhouse Gas Observation Satellite), GCOM-W and GCOM-C (ADEOS-2 follow on), and GPM (Global Precipitation Mission) core satellite. GOSAT will carry 2 instruments, i.e. a green house gas sensor and a cloud/aerosol imager. The main sensor is a Fourier transform spectrometer (FTS) and covers 0.76 to 15 ${\mu}m$ region with 0.2 to 0.5 $cm^{-1}$ resolution. GPM is a joint project with NASA and will carry two instruments. JAXA will develop DPR (Dual frequency Precipitation Radar) which is a follow on of PR on TRMM. Another project is EarthCare. It is a joint project with ESA and JAXA is going to provide CPR (Cloud Profiling Radar). Discussions on future Earth Observation programs have been started including discussions on ALOS F/O.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.23 no.4
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• pp.313-325
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• 2011

Finite element grid system using h-refinement on the Yellow Sea was constructed based on previous study (Suh, 1999b) from 14 K to 210 K and special attention was concentrated on refining the coastal zone. In grid generation, depth change between adjacent points and non-dimensional tidal wave length ratio were considered. As a result approximately a quarter of the total nodes are located nearby 5 m of shallow area. Accurate bathymetry data using 30's and ETOPO1 with open boundary conditions of 8 major tidal constituents extracted automatically from FES2004 have been applied. In tidal simulation a 3-dimensional nonlinear harmonic model was setup and tidal amplification due to changes in vertical turbulent and bottom friction were simulated. In this study not only 8 major tidal constituents but also nonlinear shallow tides $M_4,$, $MS_4$ and long period $M_f,$, $M_{sf}$ were reproduced. It is found that implication of spatial variation of friction coefficient plays a very important role in reproduction of astronomical and shallow tides which are computed by iterative computation of nonlinear terms. Also it should be considered differently with respect to tidal periods. To understand the distribution of tidal asymmetry, amplitude ratio of $M_4/M_2$ and phase differences $2g(M_2)-g(M_4)$ were calculated. Tidal distortion ratio marks up to 0.2 on the west coast showing shallow coastal characteristics and somewhat wide range of ebb-dominances in front of Mokpo area are reproduced.

• The Korean Journal of Petroleum Geology
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• v.5 no.1_2 s.6
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• pp.48-58
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• 1997

Core samples from the B, E, F, H wells in the Tertiary Pohang Basin were analysed for total organic carbon (TOC) content and subject to Rock-Eval pyrolysis in order to assess petroleum geochemical characteristics of organic matter. Following geochemical screening, we selected samples from each well for the study of bitumen and kerogens such as optical observation, infra-red spectroscopy and biomarker analyses. Sediments of the Tertiary Yonil Group contain total organic carbon ranging from $0.55{\%} to 3.74{\%}$ with S1+S2 values higher than 2mgHC/g Rock in B, E and F wells, which indicates fair hydrocarbon generation potential. Most organic matter in the B, E, F wells is compared to type II based on the Rock-Eval pyrolysis, infra-red spectroscopy and optical observation. However, organic matter in the H well is compared to type III because the well is located at the margin of the basin where the preservation of terrestrial material is dominant. Geochemical analyses show that organic matter in the Yonil Group is thermally immature although thermal maturity slightly increases with depth. Maturity levels of the extracted kerogens are similar to those of bulk samples ($Tmax<435^{\circ}C$. Petroleum geochemical charateristics of the sediments in the Tertairy Yonil Group is fair in terms of the organic richness and hydrocarbon genetic potential, but organic matter is thermally immature due to the shallow burial depth. Optical observation of the kerogens and biomarker analysis show that organic matter in the Yonil Group is both marine and terrestrial origin, although it was deposited in marine environment. Pristane/phytane ratio suggests rather anoxic depositional environment. Transitional characteristics of organic matter indicate that the marine Yonil Group was deposited near the terrestrial environments. Input of terrestrial organic matter is more prevalent in the samples recovered from the lowermost horizon in the wells due to the terrestrial environment at the time of basin formation.

• Journal of Life Science
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• v.27 no.5
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• pp.509-516
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• 2017

Perilla frutescens (L.) Britton var. sprouts (PFS) is a plant of the labiatae family. The purpose of this work was to assess the preventive effects of PFS ethanolic extracts (PFSEs) on cytokine-induced ${\beta}$-cell damage. Cytokines, which are released by the infiltration of inflammatory cells around the pancreatic islets, are involved in the pathogenesis of type 1 diabetes mellitus. The combination of interleukin-$1{\beta}$ (IL-1), interferon-${\gamma}$ (IFN-${\gamma}$), and tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$) induced formation of reactive oxygen species (ROS). Accumulation of intracellular ROS led to ${\beta}$-cell dysfunction and apoptosis. PFSEs possess antioxidant activity and thus lead to downregulation of ROS generation. Cytokines decrease cell viability, stimulate the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), and induce the production of nitric oxide (NO). PFSEs prevented cytokine-induced cell viability in a dose-dependent manner. Incubation with PFSE resulted in significant reduction in cytokine-induced NO production that correlated with reduced levels of the iNOS and COX-2 protein expression. Furthermore, PFSE significantly decreased the activation of nuclear factor ${\kappa}B$ (NF-${\kappa}B$) by inhibition of $I{\kappa}B{\alpha}$ phosphorylation in RINm5F cells. In summary, our results suggest that the protective effects of PFSE might serve to counteract cytokine-induced ${\beta}$-cell destruction. Findings indicate that consumption of Perilla frutescens (L.) Britton var. sprouts alleviates hyperglycemia-mediated oxidative stress and pro-inflammatory cytokine-induced ${\beta}$-cell damage and thus has beneficial anti-diabetic effects.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.73-75
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• 2013

Atomic force microscopy (AFM) [1] can now not only image individual atoms but also construct atom letters using atom manipulation method [2]. Therefore, the AFM is the second generation atomic tool following the well-known scanning tunneling microscopy (STM). The AFM, however, has the advantages that it can image even insulating surfaces with atomic resolution and also measure the atomic force itself between the tip-apex outermost atom and the sample surface atom. Noting these advantages, we have been developing a novel bottom-up nanostructuring system, as shown in Fig. 1, based on the AFM. It can identify chemical species of individual atoms [3] and then manipulate selected atom species to the designed site one-by-one [2] to assemble complex nanostructures consisted of many atom species at room temperature (RT). In this invited talk, we will introduce our results toward atom-by-atom assembly of composite nanomaterials based on the AFM at RT. To identify chemical species, we developed the site-specific force spectroscopy at RT by compensating the thermal drift using the atom tracking. By converting the precise site-specific frequency shift curves, we obtained short-range force curves of selected Sn and Si atoms as shown in Fig. 2(a) and 2(b) [4]. Then using the atom-by-atom force spectroscopy at RT, we succeeded in chemical identification of intermixed three atom species in Pb/Sn/Si(111)-(${\surd}3$'${\surd}3$) surface as shown in Fig. 2(c) [3]. To create composite nanostructures, we found the lateral atom interchange phenomenon at RT, which enables us to exchange embedded heterogeneous atoms [2]. By combining this phenomenon with the modified vector scan, we constructed the atom letters "Sn" consisted of substitutional Sn adatoms embedded in Ge adatoms at RT as shown in Fig. 3(a)~(f) [2]. Besides, we found another kind of atom interchange phenomenon at RT that is the vertical atom interchange phenomenon, which directly interchanges the surface selected Sn atoms with the tip apex Si atoms [5]. This method is an advanced interchangeable single atom pen at RT. Then using this method, we created the atom letters "Si" consisted of substituted Si adatoms embedded in Sn adatoms at RT as shown in Fig. 4(a)~(f) [5]. In addition to the above results, we will introduce the simultaneous evaluation of the force and current at the atomic scale using the combined AFM/STM at RT.

• Journal of Families and Better Life
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• v.2 no.1
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• pp.111-129
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• 1984

The purpose of this study is to make a model of Family Life Cycle in Korea now. Answers to a questionnaire were collected from 724 housewives in Seoul area, 232 housewives in big cities, 203 housewives in small cities. The questionnaire contained 10 items about family situations,. Analyzing method employed for modeling to family life cycle are frequency, percentage, X2 -test . Results and findings are as follows; 1) The mean of first marriage age is 22.4yrs old. 23.5yrs old is the result of statistical materials published by E.P.B. 1975. The age of first marriage is higher according to the age, education & residential area. 2) The mean of first baby bearing age is 24.2 yrs old (generally 1 year after marriage). This age is the same as the result of statistical materials published by E.P.B. 3) the mean of last baby berating age is 32.6 yrs old compared to the E.P.B. statistical materials 3 yrs. low. This age is very different according to the age, education & residential area. 4) The mean of first child marriage age is 46.4 yrs old compared to the E.P.B. statistical materials 2.5 yrs old low. 5) the mean of last marriage age is 52.7 yrs old. this age is also 2.3 yrs low compared to the result of E.P.B. materials. 6) The number of child & interval is quite different according to the result of family planning generation of not. 7)According to the wife's employment, it does not show and difference. 8)The result of analyzing by F.L.C.,, we don't have launching stage & middle age stage apparently. So, we can make model of F.L.C. in Korea as follows (it will be change). 1) Establishment stage; from marriage to first baby born (23yrs old -24yrs old). 2) Child bearing & rearing stage; form first baby born to first child enter primary school(24 yrs old-30 yrs old). 3) Families with children's education stage; from first child primary school to high school graduation (30 yrs old-42yrs old) 4)Families with adult children stage; form first child got army college or stay at home(42 yrs- 48 yrs old). 5)Families with children's marriage stage; from first child marriage to last child marriage (48yrs old-57yrs old). 6) Aging stage; from last child marriage to self dying.

• Journal of the Korea Safety Management & Science
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• v.14 no.1
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• pp.43-51
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• 2012

This study was carried out to observe the impacts of a mouse's inhalation of toxic gas SO2 generated from combustion on its organs by different concentrations. As for research methods: First, after concentrations of SO2 generation from combustion had been set to three: low (10.4 ppm), middle (24.9 ppm) and high (122 ppm) through Gas Toxicity Testing Method (KS F 2271) and SO2 combustion gas was exposed to eight mice in each concentration. Five mice that were able to move based on LD50, a criterion, which sets the down time of a mouse's average behaviors to over 9 minutes, were randomly selected in each concentration, and they were set up as the subjects of the study on toxicity bio-markers. Second, tissues were taken from heart, liver, lungs, spleen and the thymus gland of the mice selected in each concentration and a pathological examination of them was carried out. As a result, microvascular congestion appeared in the heart, and cell necrosis, cortex congestion and tubule medulla congestion, etc. in each concentration were observed in addition to vascular congestion in liver, lungs, spleen and the thymus gland. Also, it was found that the higher the concentrations of SO2 exposure is, the greater, the changes in the organs get. Through this study, SO2 of various toxic gases generated from fire turned out to affect the tissues of each organ of a mouse, it is expected that the toxic gases may greatly affect human body in case of actual fire, and this study is evaluated as having a significance as a basic data on inhalation toxicity assessment of toxic substances generated in combustion.