• Bulletin of the Korean Chemical Society
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• v.25 no.5
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• pp.639-646
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• 2004

Metal treated activated carbons are prepared using various metals. Adsorption behaviors, morphologies, as well as antibacterial effects of metal treated samples are compared before and after solvent washing. Adsorption isotherms are used to characterize the porous structure of metal treated activated carbons before and after the solvent washing with acetone or ethyl alcohol. From these data, it is noticed that the changes in physicochemical properties of metal treated activated carbons depend on the solvents employed. Similar results are observed from BET data obtained from nitrogen adsorption isotherms. From scanning electron microscopy (SEM) studies, the changes in shape and size of metal particles are observed after the samples are washed with solvents. These changes result in different blocking effects, which, in turn, affect the adsorption behavior of metal treated activated carbons. X-ray diffraction (XRD) patterns of the samples treated with different metals are different each other. High intense sharp peaks attributed to metals are observed from silver treated samples, while the peaks are not observed from copper treated samples. To compare thermodynamic behavior of metal treated activated carbons washed with different type of solvents, differential scanning calorimetric (DSC) analysis is carried out. The analysis shows similar endothermic curves for all of the samples. Finally, antibacterial effects of metal treated activated carbon against Escherichia coli are discussed. Comparing the effects among the metals employed, highest effects are obtained from Cd, while lowest effects are obtained from Cu. Antibacterial activity becomes higher with the increase of the amount of metals treated, Optimum concentrations of metals to treat activated carbons, obtained from a shake flask test, are known to be 0.4, 0.1, and 0.6 moles for Ag, Cd, and Cu, respectively.

• Journal of Korean Society of Transportation
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• v.22 no.3 s.74
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• pp.179-201
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• 2004

Online traffic flow modeling is attracting more attention due to intelligent transport systems and technologies. The flow-density relation plays an important role in traffic flow modeling and provides a basic way to illustrate traffic flow behavior under different traffic flow and traffic density conditions. Until now the research effort has focused mainly on the shape of the relation. The time series of the relation has not been identified clearly, even though the time series of the relation reflects the upstream/downstream traffic conditions and should be considered in the traffic flow modeling. In this paper the flow-density relation is analyzed dynamically and interpreted as a states diagram. The dynamic flow-density relation is quantified by applying fuzzy logic. The quantified dynamic flow-density relation builds the basis for online application of a macroscopic traffic flow model. The new approach to online modeling of traffic flow applying the dynamic flow-density relation alleviates parameter calibration problems stemming from the static flow-density relation.

• Journal of the Korean Vacuum Society
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• v.6 no.3
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• pp.249-254
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• 1997

We investigated characteristics of Fe-doped semi-insulating InP by means of photoreflectance(PR) measurement. The band gap energy($E_0$) and broadening parameter($\Gamma$) from PR signals at 300K are 1.336 eV and 11.2 meV, respectively. As the temperature is decreased from 300 to 80 K, PR signals are varied from an overlapped shape of exciton and 2-dimensional band gap transitions(300 K) to that of exciton transition(80 K). We calculated Varshni coefficient($\alpha=0.94\pm$0.07 meV/K, $\beta=587\pm$35.2 K) and Bose-Einstein coefficient ($a_B=33.6{\pm}2.02meV$ , $\theta=165\pm$33K). After annealing of isothermal and isochronism crystallinity of InP is found to be excellent when annealed at $300^{\circ}C$ for 10~20 min, qualitatively.

• The Bulletin of The Korean Astronomical Society
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• v.43 no.1
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• pp.58.2-58.2
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• 2018

Fossil groups of galaxies have characteristic features of a dominant central elliptical galaxy (${\Delta}M_{12}$ > 2 in $0.5R_{vir}$) embedded in highly relaxed X-ray halo, which indicates dynamically stable and evolved systems. These are thought as a final stage of the evolution of galaxy groups in the hierarchical structure formation scenario. However, the formation and evolution of fossil clusters are still unclear due to lack of detailed studies. Therefore, we perform a kinematic research of a known fossil cluster Abell 2261 (A2261 hereafter) using spectroscopic data of 589 galaxies in the A2261 field. Even though A2261 is known as a fossil cluster, previous studies found several unusual features such as quite high X-ray entropy for a stable cluster, and an elongated shape, which are not expected in standard fossil clusters. Using the caustic method, we identify cluster member galaxies and discover a second bright galaxy (${\Delta}M_{12}=1.68$) at ${\sim}1.5R_{vir}$. The presence of such a bright galaxy can break the current fossil state of cluster in the near future. In addition, with two independent substructure finding methods, we confirm that the previously detected elongated galaxy distribution of the cluster is a real feature. These findings indicate that A2261 is not in a fully stable state, unlike the existing fossil definition diagnostic. We require a more stringent criterion for the fossil definition to represent a genuinely final stage of cluster evolution.

• Journal of the Korean housing association
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• v.20 no.4
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• pp.79-88
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• 2009

A planned access method on constantly-changing-community unit plan changes and develops based on the periodical situation and also plan theory. In this research, it is to present the link between the theory of complex city change and the plan factor of it, and to show how Korean residential complex plan has changed as time passed and how new concept of city plan came up and by applying new methods how can this affect our real world and the past plan. In the phase of analysis, it analyzed the flow of 'community unit plan' and its theory and investigated the factor of compositional space and built a analysis frame. The factors of community unit plan are space structure, size and shape of block, population, distribution of facilities and movement system. It chose the place that can represent the flow of community unit plan trand and that indicates the obvious development leading to Jamsil (1975), Gwa Chun (1980), Mok Dong (1983), Sang Ge (1985), Ilsan (1989), Dong tan (2001) and Eun Jung (2003) total of 7 places. And to compare a similar size of the city, it selected a small community unit. Based on the result of theoretical study and prior research, it can be said that the space composition style has change from a whole complete complex area to a linked-cross over community unit and the access of urban level was on set. Also, a pedestrian walking area was secured and the dense of building structure and pleasant environment wanting need was in balance. For facility plans, the usage of facility and functional change brought change of type, size and disposition. The walking area for pedestrian became a huge matter. Therefore, market, education, public facilities and green system collaborated to co-build a whole community unit and activated the walking environment. Also, public transportation, environment friendly city organization was built.

• Progress in Superconductivity and Cryogenics
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• v.18 no.1
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• pp.37-40
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• 2016

We have investigated the addition effect of NiO magnetic nanoparticles on crystal structure, microstructure as well as superconducting properties of $MgB_2$. NiO-added $MgB_2$ samples were prepared by the solid-state reaction method. The superconducting transition temperature ($T_c$) of 37.91 K was obtained for pure $MgB_2$, and $T_c$ was found to decrease systematically on increasing the addition level of NiO. X-ray diffraction (XRD) analysis revealed that no substitution of Ni for Mg in the lattice of $MgB_2$ was occurred. The microstructural analysis shows that the pure $MgB_2$ sample consists of plate shape $MgB_2$ grains, and the grains get refined to smaller size with the addition of NiO nanoparticles. At 5 K, high values of critical current density ($J_c$) were obtained for small amount NiO-added $MgB_2$ samples as compared to pure sample. The enhancement in $J_c$ could be attributed to the refinement of $MgB_2$ grains which leads to high density of grain boundaries in NiO-added $MgB_2$ samples.

• Journal of the Korean Society of Costume
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• v.62 no.1
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• pp.120-136
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• 2012

This thesis takes an aim to investigate the relationship between the costume and enlightenment ideology by studying the change of costume, and reviewing the portraiture of Queen Marie Antoinette. The method of this research is to select the 29 pieces among the portraitures from 1770 to 1793, and to analyze the headdress, shape of robes and ornaments. The results are as follows. The first period(1770-1774): The costume in this period of Dauphin of France is described as vivid, and simple like her characters, and also represents her active lifestyle. The ideology of equality between the two sexes from the enlightenment slightly influence the costumes seen inside the portrait of Dauphin. The second period (1775-1779): This is the early period of the Queen's enthronement and also before her childbirth. The relatively small number of portraits showed her as an authoritative figure because her skirts were expanded with huge panier, the waist were tightened with corset, and her headdress was enlarged. Thus, this period could not be defined as the one of enlightenment philosophies in light of the persistent unsanitary construction of costumes distorting the body. The third period(1780-1789): There are many portraits depicting the Queen and her children. It is noteworthy that the English style picturesque garden was illustrated as a background while the costume was simple and sanitary, both being affected by the enlightenment. The last period(1789-1793): This is the period between the French revolution and the death of the Queen. The form of costumes was transformed into the neoclassic style, headdress was reduced in size, and was simplified as a result of complete change of costume for the enlightenment. This research is to be interpreted as a tool of study about the relationship of costume, society and ideological streams and also be a means of elucidating the contemporary times in view of the past ones.

• 한국전산유체공학회:학술대회논문집
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• 2008.03b
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• pp.193-196
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• 2008

The vortical structures in a turbulent boundary layer (TBL) developed over a flat plate have been investigated experimentally. The flow conditions tested in this study were Re$_{\theta}$ = 3700, Re$_{\delta}$ = 11${\times}$105 and the shape factor H = 1.3. Instantaneous velocity fields in the streamwise-wall-normal planes were measured by using a dynamic PIV system. A trip-wire and sandpapers were placed behind the leading edge to promote the turbulent transition. 1000 velocity fields were obtained consecutively with a time interval of 1 millisecond. Streamwise u-velocity components were temporally averaged in the measuring plane. In addition, 2000 velocity fields were obtained randomly and ensemble-averaged to get the fully-developed turbulent characteristics. Profiles of the normalized u-component, turbulent intensities and Reynolds shear stress were evaluated. The structures of spanwise vortices were extracted from the instantaneous velocity fields by determining the swirling strength, ${\lambda}_{ci}$. The wall-normalized locations of vortices were temporally averaged in the measuring plane with respect to their rotational direction. The correlations between the temporally averaged u and the temporally averaged $y^+$ of vortices were evaluated. For the case of positive vortices, the correlation is not significant. However, the negative vortices show a strong negative correlation. The y-location of negative vortices tends to increase, as the averaged u decreases and vice versa. These findings indicate that the number of negative vortices in the outer layer increases during the outward bursting events.

• Fashion & Textile Research Journal
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• v.19 no.4
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• pp.385-399
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• 2017

This study will broaden the application of doll costume product with historical characteristics and the image of unlined cheollik in the $17^{th}$ century period of transition during the Joseon Dynasty. Historical design sources were extracted from old documents and precedent studies. Unlined cheollik of Shin Gyeong-yu, meritorious retainer, were selected as main reference-relic because of various fabric, preserved conditions and definite shape. 'Baby doll' was selected as main model because of consumer preferences and awareness. Design sources from unlined cheollik in the early $17^{th}$ century were about a 1:2 ratio of upper and under parts, removable separated doori-somae, knife-shaped collar (outside), projected square collar (inside), long pleats line, side slit, traditional flat fell seam sewing. Trapezoidal side line, round waistline, and thin fabric were applied in designs because of toddler-body of doll model. Three designs were produced in step 1: Cheollik A focusing on the historical remake (traditional type), Cheollik B with belt and side slit (crossover type), and Cheollik C with back- opening (modern type). In step 2, interview with fashion major student was conducted to increase the utility of designs. As a result, modern trend sources (frill, velcro, round armhole line, slope of sleeves, and floral pattern) were reflected in Cheollik B, C. Finally, three doll cheollik and cheollik-styled doll apron sample were produced. Various versions must be suggested in the study of doll costume products with traditional sources that balance historical characteristics and practicality to improve customer satisfaction.

• Journal of Korea Foundry Society
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• v.12 no.3
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• pp.220-229
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• 1992

The degree of purification and the macrostructure of high purity aluminium were studied through the alternate stirring method in order to improve the nonuniformity of solute concentration in the unidirectional stirring method. The $2^3$ factorial design was done to examine the effects of experimental factors more qualitatively. In the relatively low stirring speed of 1500 rpm with alternate stirring mode, the uniform solute profile and refined grain structure were obtained due to strong washing effect and turbulent fluid flow. It was induced by the transition of the momentum boundary layer by alternation of the stirrer. It was concluded from this study that the alternate stirring mode was more effective to obtain the uniformity of solute even in the stirring speed of 1500 rpm. But the degree of purification decreased below the critical alternating period. When 2N(99.8wt.%) aluminium was used as the starting material the morphology of solid-liquid showed the cellular shape and the columnar grains were inclined to the direction of rotation. This inclined grain growth resulted from the difference of relative velocities of solid and liquid. The inclined angle was increased as the stirring speed increased and solidification proceeded. In the case of 4N aluminium, there was no inclined grain growth and it was confirmed from the macrostructure and SEM work that the morphology of solid-liquid interface was planar. From the factorial design, it was found that the alternate stirring mode showed poorer purification effect than that of unidirectional stirring mode at low speed(500 rpm). In addition, the factor that had the most significant effect on the degree of purification was the stirring speed.