• Korean Journal of Fisheries and Aquatic Sciences
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• v.29 no.5
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• pp.663-676
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• 1996

Physical properties and textural parameters of thirty-five piston tore samples recovered from the southeastern coast of Korea (Korea Strait), were investigated using the autopycnometer. The physical properties (porosity, water content, wet bulk density, dry bulk density, gram density, and void ratio) were measured at rather uniform intervals along each core. Sediment texture (grain size, sand, silt, and clay contents) was also measured at the same subbottom depth. The measured and calculated results are; mean grain size $0.57\~8.09\phi(average:3.67\phi)$, porosity $26\~81\%\;(average:\;55\%)$, water content $16.7\~61.4\%(average:\;31.6\%)$, wet bulk density $1.37\~2.18g/cm^3\;(average:\;1.85g/cm^3)$, dry bulk density $2.55\~3.11g/cm^3\;(average:\;2.35g/cm^3)$, grain density $2.40\~3.10g/cm^3\;(average:\;2.85g/cm^3)$, and void ratio $0.56\~2.54$ (average: 0.94). The sediment texture generally coincides well with the bathymetry indicating the influence of Pleistocene-Holocene sea level changes. Also the contours of physical properties are closely related to the sediment texture. Fluctuation of physical properties are similar to the textural variation. It seems that sediment texture is a significant factor in determining physical property in this study area.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.39 no.2
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• pp.106-117
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• 2006

We measured the concentrations of organic matter and metallic elements (Al, Fe, Cr, Mn, Ni, Cu, Zn, As, Cd, Pb and Hg) in the surface sediments of Masan Harbor (in the southern sea, Korea) to evaluate the geochemical characters of sediment and the pollutions by organic matter and metallic elements. The mean grain size of the surface sediments in the study area ranged from $5.6{\phi}$ to $7.8{\phi}$, indicating silt sediment. The water content of the surface sediments exceeded 60% except at some stations. The contents of ignition loss (IL), total organic carbon (TOC) and total nitrogen (TN) ranged from 7.2-14.3%, 1.2-3.2%, and 0.10-0.28%, respectively. Based on the C/N ratios, the organic matter in the surface sediments of Masan Harbor may originate from terrigenous sources including fluvial inputs (mainly sewage in urban areas). The chemical oxygen demand (COD) and acid volatile sulfide (AVS) ranged from $11.3-29.9\;mgO_2/g\;dry$ and 0.20-4.47 mgS/g dry, respectively, and low concentrations were observed near a shipping route. In addition, the concentrations of metallic elements showed large spatial variations in Masan Harbor and the distributions of metallic elements were also comparable to those of organic matter. This implies that the distributions of organic matter and metallic elements in the surface sediments of Masan Harbor are mainly controlled by biogenic matter and artificial action (mainly dredging). In addition, we calculated the enrichment facto. (EF) and geoaccumulation index (Igeo) in order to evaluate pollution by metallic elements. The enrichment of metallic elements relative to Al was three to eighteen times higher at the study sites, compared to levels in the Earth's crust except for Fe, Ni and Mn. In addition, the Igeo class indicated that the surface sediments in the study area were moderately to strongly polluted in terms of metallic elements.

• Korean Journal of Environmental Agriculture
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• v.25 no.2
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• pp.118-123
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• 2006

To remove effectively order component ($NH_3\;and\;H_2S$) from pig house, biofilter was made of composted pine tree bark and polite and odor removal efficiency was evaluated in the lab and pilot scales. The columns were designed with ${\Phi}120mm{\times}450mm$ (H) and ${\Phi}850mm{\times}900mm$ (H) in the size in the lab and pilot scale testes, respectively. Single material of composted pine tree bark and polite and the mixture of two materials with 7:3 ratios (vol/vol) were packed in the column, and, herein air flow was controlled upward direction from column bottom. To enhance the efficiency of biofilter, ammonia (Rhodococcus equi A3) and hydrogen sulfide oxidizing bacteria (Alcaligenes sp. S5-5.2) were inoculated in packing materials before the test Removal effect of ammonia and hydrogen sulfide gases were higher in the mixture$[88.7{\sim}98.2%,\;89.5{\sim}97.9%]$ than that in single packing material (composted pine tree haft$[89.4{\sim}98.7%,\;78.7{\sim}85.6%]$ and petite$[65.3{\sim}73.2%,\;88.7{\sim}98.2%]$ by the lab scale biofilter. In the modeled pig house, about 96 and 91% of ammonia and hydrogen sulfide gases were removed by the pilot scale of biofilter, respectively. Conclusively, composted pine tree bark and polite could be a good candidate of biofilter packing materials to remove the odor components.

• Tunnel and Underground Space
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• v.20 no.6
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• pp.475-490
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• 2010

The analysis of slope stability was performed from seven sites among total eleven sites of waste rock which are divided into two objects (mullock-pile and rock mass) according to the location of dumping-dropping point in L limestone Mine. The analysis of circular failure using Bishop's simplified method and the finite element method for mullock-pile slopes were adopted. For rock mass slopes, identification of failure modes on stereonet projection was determined, thereby limit equilibrium analysis was applied to obtain the safety factor of slopes and the finite element method was used to understand overall behavior of slope. Phi-c reduction method was used to calculate the safety factor of slopes through the finite element method. In mullock-pile slope of zone D and rock slopes of zone F and G, the assurance of slope stability was difficult, and the plans to assure the stability of slopes were proposed on the basis of the analysis of slopes at disposal sites of waste rock. Therefore, the method of piling with waste rock by dozer pushing after dumping for mullock-pile slope of zone D is required, and the method of piling after moving to the place which has no fault zone for rock slope of zone F and G is recommended.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.6 no.8
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• pp.15-23
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• 2016

Recently the interest in secondary use of medical information has emerged. But the domestic legislation or guidelines, such as being able to say that already specialize in healthcare information, can be seen a 'national medical privacy guidelines'. However the guidelines have suggested that only a violation of privacy laws in the medical information, it does not defined clearly with respect to protected health information(PHI) for secondary use. In this paper, we learn the HIPAA(Health Insurance Portability and Accountability Act) Privacy Rule of the US legislation which provides a non-identifiable screen instructions for secondary utilization of medical information, domestic guidelines and other country's guidelines. comparing with the HIPAA, national medical privacy guidelines and the domestic studies, we propose a new domestic target non-identifying information suitable for the domestic field and present future research direction.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.14 no.2
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• pp.75-80
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• 2015

The rebar factory production process involves the repetitive bending of rebars. Therefore, the fatigue failure of the rebar bending machine needs to be considered. In this paper, fatigue analysis of the rebar machine was performed using the commercial software DAFUL, which is based on MFBD (Multi Flexible Body Dynamics). The rotating roller, fixing roller and rebar were modeled by the finite element method. The rebar bending process is simulated and the mechanical stresses on the rollers are calculated. Structural analysis of the rebar bending roller was performed using the maximum bending angle of $180^{\circ}$ and maximum processing rebar diameter of ${\Phi}19mm$. Then, for fatigue analysis, the S-N curve of STD-11 was. The fatigue life of rollers is estimated by modified Goodman diagram. The fatigue life range of the rotating roller is $2.99961{\times}10^5{\sim}1{\times}10^8$ while that of the fixed roller is $2.53142{\times}10^5{\sim}1{\times}10^8$. STD-11 has an infinite life cycle after $1{\times}10^8$. Therefore, the rollers of the rebar bending machine may be expected to suffer fatigue failure. Thus, we performed a parameter study of fatigue life according to various axial radii of the fixed roller and rotating roller, and redesign of the rebar bending machine. Consequently, the axial radius of the fixed roller and rotating roller was found to be 35~37.5mm and 30~35mm, respectively, and an infinite life cycle was confirmed at these.

• Journal of Environmental Science International
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• v.22 no.11
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• pp.1403-1413
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• 2013

The effects of cadmium ions ($Cd^{2+}$) on the Chl a fluorescence of Ricciocarpos natans were investigated in order to determine whether Chl fluorescence can be used as a biomarker to estimate the physiological responses of plants to cadmium stress. In all plants treated with $Cd^{2+}$, the image of Fv/Fm, which represents the maximum photochemical efficiency of PSII, changed as the $Cd^{2+}$ concentration increased, when treated for 48 h or more. Changes of ${\Phi}_{PSII}$ and $Q_P$ images were recognized even at 10 ${\mu}M$ $Cd^{2+}$. The Chl a O-J-I-P fluorescence transient was also affected even at 10 ${\mu}M$ $Cd^{2+}$. The fluorescence yield decreased considerably in steps J, I and P in plants treated with $Cd^{2+}$, although a typical polyphasic rise was observed in non-treated plants. The Chl fluorescence parameters, Fm, Fv/Fo, Sm, SFIabs, PIabs and ETo/CS, decreased as the $Cd^{2+}$ concentration increased, while the Mo and Kn parameters increased. Peroxidase activity decreased significantly and catalase activity increased as the $Cd^{2+}$ concentration increased. Because of its sensitivity to $Cd^{2+}$ Ricciocarpos natans is useful in experiments investigating the responses of plants to cadmium exposure. Several parameters (Fm, Fv/Fo, Sm, SFIabs, PIabs, ETo/CS, Mo and Kn) can be applied to determine quantitatively the physiological states of plants under cadmium stress.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.10
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• pp.3647-3653
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• 2010

An experimental investigation of the flame appearance and heat transfer characteristics in both unexcited and excited impinging inverse diffusion flames with a loud speaker has been performed. The flame is found to become broader and shorter (in length) with acoustic excitation. The heat flux at the stagnation point is increased with the acoustic excitation. The acoustic excitation is more effective in lean conditions than in rich conditions. The reasons for these behaviors are that acoustic excitation improves the entrainment of surrounding air into the jet. From this study, it is found that the maximum increase of 57% in the total heat flux is obtained at the stagnation point of $\Phi$=0.8. Therefore, it is ascertained that the excitation combustion can be adopted with effective instruments as a method for improving heat transfer in impinging jet flames.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.22 no.11
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• pp.980-986
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• 2009

In a triple-layered structure of ITO/N,N'-diph enyl-N,N'bis(3-methylphenyl)-1,1' - biphenyl-4,4'-diamine(TPD)/tris(8-hydroxyquinoline)aluminum($Alq_3$)/(2,9-Dimethyl-4,7-diphenyl-1,10-phenanthroline(BCP)/Al device, we have studied the electrical and optical characteristics of organic light-emitting diodes(OLEDs) depending on the deposition condition of BCP layer. Several different sizes of holes on boat and several different deposition rates were employed in evaporating the organic materials. And then, electrical properties of the organic light-emitting diodes were measured and the performance of the devices was analyzed. It was found that the hole-size of crucible boat and the evaporation rate affect on the surface roughness of BCP layer as well as the performance of the device. When the hole-size of crucible boat and the deposition rate of BCP are 1.2 mm and $1.0\;{\AA}/s$, respectively, average surface roughness of BCP layer is lower and the efficiency of the device is higher than the ones made with other conditions. From the analysis of current density-luminance-voltage characteristics of a triple layered device, we divided the conductive mechanism by four region according to applied voltage. So we have obtained a coefficient of ${\beta}_{ST}$ in schottky region is $3.85{\times}10^{-24}$, a coefficient of ${\beta}_{PF}$ in Poole-Frenkel region is $7.35{\times}10^{-24}$, and a potential barrier of ${\phi}_{FN}$ in Fower-Nordheim region is 0.39 eV.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.40 no.9
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• pp.613-620
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• 2016

In order to scrutinize the fluid conductivity effects on the electromagnetic flowmeter(EMF) characteristics, a small scale EMF was designed and fabricated. The measuring tube has a $3mm{\times}4mm$ rectangular cross-section, 9 mm length, and a $2mm{\times}3mm$ plate electrode and a ${\Phi}1.5mm$ point electrode. The design parameters, such as the magnetizing frequency and the number of coil turns, and the diameter were optimized. The EMF was tested with a gravimetric calibrator and showed good linearity in the range of 0 to $1.17{\times}10^{-5}m^3/s$. The fluid conductivity was varied between 3 and $11{\mu}S/cm$, and the magnitude of the flow signal was proportional to the fluid conductivity and the wetted area of the electrode. The design information and the test results provide flow measurement techniques for very low flowrate.