• Journal of the Korean Vacuum Society
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• v.13 no.2
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• pp.86-91
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• 2004

Transiton-metal gallides attract wide interest as a candidate for high-temperature structural materials. In a wide composition range, in which it was known that Co-Ga alloy have CsCl (B2) crystallographic structure, a systematic study on the correlation between physical properties and electronic structures of Co-gallides was performed. $Co_{l-x}Ga$ $_{x}$ alloys ($0.35\leq$x$\leq0.55$) were prepared by arc-melting method and were annealed at $1000 ^{\circ}C$ for 48hour to increase the homogeneity. In this composition range all the prepared alloys have the CsCl (B2) structure. The chemical states and the electronic structure were studied by using x-ray photoemission spectroscopy (XPS), and x-ray absorption near-edge structure (XANES), and exhibit different physical properties depending on the composition. During the annealing, a significant oxidation has happened and all the oxygen atoms are incorporated with the Ga atoms to form a $Ga_2O_3$ phase. In a view point of electronic structure, the $Co_{l-x}Ga$ $_{x}$ alloys were formed by the Ga(p) - Co(d) hybridization.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.7 no.12
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• pp.3071-3095
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• 2013

Configuring optimization of wireless sensor networks, which can improve the network performance such as utilization efficiency and network lifetime with minimal energy, has received considerable attention in recent years. In this paper, a cross layer optimal approach is proposed for multi-source linear network and grid network under Rayleigh block-fading channels, which not only achieves an optimal utility but also guarantees the end-to-end reliability. Specifically, in this paper, we first strictly present the optimization method for optimal nodal number $N^*$, nodal placement $d^*$ and nodal transmission structure $p^*$ under constraints of minimum total energy consumption and minimum unit data transmitting energy consumption. Then, based on the facts that nodal energy consumption is higher for those nodes near the sink and those nodes far from the sink may have remaining energy, a cross layer optimal design is proposed to achieve balanced network energy consumption. The design adopts lower reliability requirement and shorter transmission distance for nodes near the sink, and adopts higher reliability requirement and farther transmission distance for nodes far from the sink, the solvability conditions is given as well. In the end, both the theoretical analysis and experimental results for performance evaluation show that the optimal design indeed can improve the network lifetime by 20-50%, network utility by 20% and guarantee desire level of reliability.

• Geomechanics and Engineering
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• v.15 no.5
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• pp.1101-1111
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• 2018

This study aims to present accurate soil modeling and validation of a single roadside guardrail post as well as a single concrete pile installed near cut slopes or compacted sloping embankment. The conventional Winkler's elastic spring model and p-y curve approach for horizontal ground cannot directly be applied to sloping ground where ultimate soil resistance is significantly dependent on ground inclination. In this study, both grid-based 3-D FE model and particle-based SPH (smoothed particle hydrodynamics) model available in LS-DYNA have been adopted to predict the static behavior of a laterally loaded guardrail post. The SPH model has potential to eliminate any artificial soil stiffness due to the deterioration of the node-connected Lagrangian soil mesh. For this purpose, this study comprises two parts. Firstly, only 3-D FE modeling has been tested to show the numerical validity for a single concrete pile in sloping ground using Mohr-Coulomb material. However, this material option cannot be implemented for SPH elements. Nevertheless, Mohr-Coulomb model has been used since this material model requires six input soil data that can be obtained from the comparative papers in literatures. Secondly, this work is extended to compute the lateral resistance of a guardrail post located near the slope using the hybrid approach that combines Lagrange FE elements and SPH elements by the suitable node-merging option provided by LS-DYNA. For this analysis, the FHWA soil material developed for application to road-base soils has been used and also allows the application of SPH element.

• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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• 2001.06a
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• pp.1255-1255
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• 2001

The study used 356 veal calf meat samples received from Finland (n=16), France (n=109), Italy (n=81) and The Netherlands (n=150). Calves were raised under experimental protocols that compared feeding and housing practices normally used in each county to treatments aiming at improving animal welfare. Samples were taken at the $8^{th}$ rib of Longissimus thoracis muscle 24h after slaughter, They were kept refrigerated ( $2-4^{\circ}C$) under vacuum package for 6d and then frozen ($-20^{\circ}C$) until meat quality evaluation. Measurements included pH, color (Hunter Lab system), shear force, chemical composition (DM, Ash, Ether Extract, collagen and haematin content), weight and area cooking losses and a sensory evaluation by a group of panelists. A sample of meat was ground with a blade mill and scanned in duplicate between 1100 and 1498 nm (FOSS NIR Systems 5000). WinISI software was used to develop a discriminating equation using NIR spectra (SNV-detrend, derivative=1, gap=4nm, smooth=4nm). The Proc ANOVA and DISCRIM of SAS were used for all the laboratory determinations. County of production had a significant (P<0.01) effect on all the parameters. However, discriminant analysis using any or few laboratory parameters resulted in great errors of county classification. A more accurate (98.8%) classification was obtained only when using all the laboratory parameters. NIRS classified correctly 354 of the 356 samples (99.4%). Provided with a larger data set, NIRS could be used to identify country of production of veal meat.

• Development and Reproduction
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• v.10 no.2
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• pp.85-92
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• 2006

Progesterone(P4) is an important intermediate in the synthesis of androgens and estrogens. Furthermore, P4 itself plays a crucial role in ovulation, atresia and luteinization, and is essential for the continuation of early pregnancy in all mammalian species. In spite of the hormone's physiological importance, the exact action mechanism(s) of P4 in mammalian ovary has not been fully understood yet. In this context, a decades-long controversy regarding the identity of receptors that mediate non-genomic, transcription-independent cellular responses to P4 is presently attracting huge scientific interests. P4 may exert its action in mammalian ovary by several ways: 1) the well-documented genomic pathway, involving hormone binding to so-called classic cytosolic receptor(PGR) and subsequent modulation of gene expression by the ligand-receptor complex as transcription factor. 2) pathways are operating that do not act on the genome, therefore refered to as non-genomic actions. The prominent characteristics of the non-genomic P4 actions are: (i) rapid, (ii) insensitive to transcription inhibitors, (iii) transduced by membrane associated molecules. In particular, the non-genomic P4 actions could be mediated by: (a) classic genomic P4 receptor(PGR) that localizes at or near the plasma membrane, (b) a family of membrane progestin receptors(MPR $\alpha$, MPR $\beta$ and MPR $\gamma$), (c) progesterone receptor membrane component I(PGRMC1), and (d) a membrane complex composed of serpine I mRNA binding protein(SERBP1). The present review summarized these rapid signaling pathways of P4 in the mammalian ovary.

• Journal of Korean Society of Environmental Engineers
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• v.38 no.5
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• pp.228-235
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• 2016

Nitrite accumulation is essential for constructing an anammox process. As the pH in the reactor exerts a complicated and strong influence on the reaction rate, we investigated its effects upon treatment of an ammonic wastewater (2,000 mgN/L) through modeling and experiment. The modeling results indicated that the reaction stability is strongly affected by pH, which results in a severe reduction of the 'stable region' of operation under alkaline environments. On a coordinate of the total ammonia nitrogen (TAN) concentration vs. pH, the maximal stable reaction rates and the maximal nitrite accumulation potentials could be found on the 'stability ridge' that separates the stable region from the unstable region. We achieved a stable and high ammonia oxidation rate (${\sim}6kgN/m^3-d$) with a nitrite accumulation ratio of ~99% when operated near the 'stability ridge'. The optimum pH that can be observed in experiments varies with the TAN concentrations utilized, although the intrinsic optimum pH is fixed. The direction of change is that the optimum operational pH falls as the TAN concentration increases, which is in excellent accordance with the observations in the literature. The optimum operational pH for 95% nitritation was predicted to be ~8.0, whereas it was ~7.2 for 55% partial nitritation to produce an anammox feed in our experimental conditions.

• The Bulletin of The Korean Astronomical Society
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• v.35 no.2
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• pp.51.1-51.1
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• 2010

We report an example of Pi2 pulsation exhibiting different frequency between dawn and dusk. This Pi2 pulsation occurred around 1932 UT on February 14, 2008, and was observed at low-latitude Bohyun (BOH, L = 1.35, MLT = 3.8) and Hermanus (HER, L = 1.83, MLT = 20.1) stations. The pulsation starts simultaneously at both stations but the frequency is higher at BOH than at HER. At the time of the Pi2, THEMIS-A (THA) and THEMIS-D (THD) were on dawn (L = 2.9, MLT = 5.3) and dusk (L = 2.8, MLT = 18), respectively, in the inner magnetosphere. We find a nearly identical waveform and period between THA ${\delta}Bz$ and BOH ${\delta}H$ and between THD ${\delta}Bz$ and HER ${\delta}H$ with a near $0^{\circ}$ phase delay. This observation implies that Pi2-associated fastmode wave in the inner magnetosphere is not excited globally as a single frequency at all longitudes. We suggest that the different frequency between dawn and dusk is due to dawn-dusk asymmetry of the plasmasphere.

• Korean Journal of Veterinary Pathology
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• v.2 no.2
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• pp.73-84
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• 1998

This study was carried out to investigate on the serum chemistry and the DNA ploidy changes in carcinogenesis of the rat liver and kidney. Sixty male Sprague-Dawley rats were divided into two groups. Group I was non-treated control. Group II was given initiators (2,2'-dihydroxy- di-N-propylnitrosamine, 0.1% in drinking water(d.w.) for 1 week and N-ethyl-N-hydroxy-ethylnitrosamine; 0.15% in d.w. for 1 week) and promoters (3'methyl-cholanthrene; 3'MC, l0mg/kg, intraperitoneally(i.p.) twice a week and DL-serine; 0.05% in d.w. for 5 weeks, from 3 to 8 weeks). All examinations were performed at 12 and 20 weeks RBC, HGBCp＜0.05) and PCVCp＜0.01) significantly decreased in Group II at 20 weeks. Activities of ALT, AST(p＜0.05) and GGT(p＜0.01) were significantly increased in Group II at 20 weeks. Flow cytometric analysis showed hepatocyte nuclei from normal livers were predominantly tetraploid(66~67%) and then diploid(28~30%). Most of hepatocyte nuclei from carcinogen-treated rats were diploid (52~68%) and less were tetraploid(28~42%). Neoplastic liver nodules and hepatocellular carcinoma contained almost exclusively diploid nuclei. Renal cell nuclei from normal kidney were predominantly diploid(88~93%), those from carcinogen-treated rats had an abnormal DNA-content peak(aneuploidy, 6-7%), near the tetraploidy area. These results suggest that diploidy may be an effective screening marker of the liver carcinogenesis. Aneuploidy may be an useful marker in assessment of the experimental renal carcinogenesis.

• Journal of the Korean GEO-environmental Society
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• v.14 no.9
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• pp.13-19
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• 2013

The Chongok karst cave which is located in Donghae-city, has high tourist and educational value due to existence of many doline(sink hole). Whereas this cave is easy to approach for the tourists, because this cave is located near the downtown, a high environmental riskiness such as sewage flowing has been also involved. In study, we observed the variation of water quality with long-term monitoring and investigated the possibility of existence of impact factor to water eco-system and determined the proper long-term monitoring factor among many monitoring criteria. The groundwater quality was maintained in the range of about $14^{\circ}C$ in temperature, over 10mg/l in dissolved oxygen and 7-8 in pH, so the impact factor in water eco-system was not observed. The guide line to make sure of tourist safety was determined to 60mm/d as daily rainfall. The conductivity was suggested to main factor for long-term monitoring main factor and pH/turbidity was suitable for the supplementary factor. For the seasonal variation monitoring, ORP was recommended.

• Korean Journal of Radiology
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• v.1 no.2
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• pp.65-72
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• 2000

Objective: To compare the efficacy of suprapapillary and transpapillary methods of transhepatic biliary metallic stent placement in malignant biliary strictures and to specify the indications of each method applied. Materials and Methods: Stents were placed in 59 patients. Strictures were categorized as type A (within 3 cm of the ampulla, n = 27), type B (over 3 cm from ampulla, n = 7), type C (within 3 cm of the bending portion, n = 9), or type D (over 3 cm above the bending portion, n=16). The stenting method was suprapapillary in 34 cases and transpapillary in 25. The rates of initial and long-term patency and of early recurrence were compared. Results: Initial patency rates for the suprapapillary and transpapillary methods were 1/7 (14.3%) and 20/20 (100%) respectively for type A (p < 0.0001), 4/5 (80.0%) and 2/2 for type B, 3/7 (42.9%) and 2/2 for type C, and 15/16 (93.8%) and 0/0 for type D. Early recurrence rates were 7/30 (23.3%) using the suprapapillary method and 4/29 (13.8%) using the transpapillary method (p = 0.51). The long-term patency rate did not differ significantly according to either type (p = 0.37) or method (p = 0.62). Conclusion: For good initial patency, the transpapillary method is recommended for strictures of the distal extrahepatic duct near the ampulla and just above the bending portion. Long-term patency is not influenced by the stenting method employed.