• Korean Journal of Fisheries and Aquatic Sciences
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• v.22 no.4
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• pp.201-213
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• 1989

This study is just to be carried out to grasp the efficiency of jet stream excavating for the ground. Changing the dynamic pressure, nozzle diameter, distance off the ground, we measured the impulse, the excavated depth, the excavated width. According as each dynamic pressure increases from 100 to $500gf/cm^2$, the impulse of the jet stream increases from 43 to 114gf, from 52 to 227gf, from 114 to 506gf, from 137 to 768gf, in 4, 6, 8, 10mm nozzles respectively, but it makes no difference in the value of distance within 50cm off ground. The excavated depth increases at the invariable rate in accordance with nozzle diameter, dynamic pressure, nozzle distance. We obtain the equations relevant to the ground I, II as follows: $$L_I=[0.01(H/r-100) -0.43\cdot\iota+11.78]{\cdot}D/4$$ $$L_{II}=[0.03(H/r-100) -0.34\cdot\iota+6.39]{\cdot}D/4$$ where, $L_I,\;L_{II}$ are respectively the excavated depths of the ground I, II, cm; H is the dynamic pressure, $gf/cm^2\;:\;\iota$ is the distance off the ground, cm; D is Nozzle diameter, mm; r is the specific weight, $1gf/cm^2$.

• Journal of the Korean Association of Geographic Information Studies
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• v.19 no.1
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• pp.154-166
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• 2016

This study aims to contribute to better understanding the effects of the changes in the parameter values of GroundFilter algorithm(GF), which performs filtering process, and of GridsurfaceCreate algorithm(GC), which creates regular grid, provided in Fusion software on the accuracy of elevation of the final LiDAR-DEM products through comparative analysis. In order to test whether there are significant effects on the accuracy of the final LiDAR-DEM products due to the changes of GF(1, 3, 5, 7, 9) parameter levels and GC(1, 3, 5, 7, 9) parameter levels, two-way ANOVA is conducted based on residuals. The residuals are calculated using the differences between each sample plot's paired field-measured and DEM-derived elevation values given each individual GF and GC level. After that, Tukey HSD test is conducted as a post hoc test for grouping the levels. As a result of two-way ANOVA test, it is found that the change in the GF levels significantly affects the accuracy of LiDAR-DEM elevations(F-value : 27.340, p < 0.01), while the change in the GC levels does not significantly affect the accuracy of LiDAR-DEM elevations(F-value : 0.457). It is also found that the interaction effect between GF and GC levels is not likely to exist(F-value : 0.247). From the results of the Tukey HSD test in the GF levels, GF levels can be divided into two groups('7', '5', '9', '3' vs '1') by the differences of means of residuals. Given the current conditions, LiDAR-DEM can achieve the best accuracy when the level '7' and '3' are given as GF and GC level, respectively.

• Design & Manufacturing
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• v.6 no.1
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• pp.67-72
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• 2012

Most of the plastics products have been manufactured by injection molding. Molding trouble in injection-molded parts is caused by changing a molding product and molding process condition, etc. In this study, warpage in the injection molded part have been studied. Specimens are rectangular flat shape with and without ribs. Non-crystalline resins (ABS+GF30%, PC+GF30%) and crystalline resins (PP+GF30%, PA66+GF30%) were used for material. Flat shape ribs showed higher warpage than flat shape without rib by 10 to 41%. the specimens with ribs that are located parallel to flow direction has higher warpage than the specimens with rib that are located perpendicular to flow direction by 11 to 50%. crystalline resins have higher warpage than non-crystalline resins by 22 to 78%. Warpage decreases as packing time increases as injection temperature increases.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.1
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• pp.143-152
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• 2012

In this paper hardware implementation of GF($2^{191}$) elliptic curve cryptographic coprocessor which supports 7 operations such as scalar multiplication(kP), Menezes-Vanstone(MV) elliptic curve cipher/decipher algorithms, point addition(P+Q), point doubling(2P), finite-field multiplication/division is described. To meet structure resistant against simple power analysis, the ECC processor adopts the Montgomery scalar multiplication scheme which main loop operation consists of the key-independent operations. It has operational characteristics that arithmetic units, such GF_ALU, GF_MUL, and GF_DIV, which have 1, (m/8), and (m-1) fixed operation cycles in GF($2^m$), respectively, can be executed in parallel. The processor has about 68,000 gates and its simulated worst case delay time is about 7.8 ns under 0.35um CMOS technology. Because it has about 320 kbps cipher and 640 kbps rate and supports 7 finite-field operations, it can be efficiently applied to the various cryptographic and communication applications.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.31 no.2 s.51
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• pp.161-167
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• 2005

We investigated the effect on inhibition of matrix metalloproteinase (MMP) in human dermal fibroblast (HDF) by production of exopolysaccharide (GF-glucan) from mycelial culture of Grifola frondosa HB0071. The photoprotective potential of GF-glucan was tested in HDF exposed to ultraviolet-A (UVA) light. It was revealed that GF-glucan had an inhibitory effect on MMP-1 expression in UVA-irradiated HDF without any significant cytotoxicity. The treatment of UVA-irradiated HDF with GF-glucan resulted in a dose-dependent degrease in the expression level of MMP-1 protein and mRNA (by maximum $54.4\%$ at an $0.5\%$ GF-glucan). These results suggest that GF-glucan obtained from mycelial culture of G. frondosa HB0071 may contribute to inhibitory action in photoaging by reducing the MMP-1 related matrix degradation system.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.18 no.3
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• pp.33-44
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• 2008

The efficiency of pairing based cryptosystems depends on the computation of pairings. pairings is defined over finite fileds GF$(3^m)$ by trinomials due to efficiency. The hardware architectures for pairings have been widely studied. This paper proposes new adder and multiplier for GF(3) which are more efficient than previous results. Furthermore, this paper proposes a new unified adder-subtractor for GF$(3^m)$ based on the proposed adder and multiplier. Finally, this paper proposes new multiplier for GF$(3^m)$. The proposed MSB-first bit-serial multiplier for GF$(p^m)$ reduces the time delay by approximately 30 % and the size of register by half than previous LSB-first multipliers. The proposed multiplier can be applied to all finite fields defined by trinomials.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.18 no.3
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• pp.9-21
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• 2008

In this paper, we revisit a generally accepted opinion: implementing Elliptic Curve Cryptosystem (ECC) over GF$(2^m)$ on sensor motes using small word size is not appropriate because partial XOR multiplication over GF$(2^m)$ is not efficiently supported by current low-powered microprocessors. Although there are some implementations over GF$(2^m)$ on sensor motes, their performances are not satisfactory enough due to the redundant memory accesses that result in inefficient field multiplication and reduction. Therefore, we propose some techniques for reducing unnecessary memory access instructions. With the proposed strategies, the running time of field multiplication and reduction over GF$(2^{163})$ can be decreased by 21.1% and 24.7%, respectively. These savings noticeably decrease execution times spent in Elliptic Curve Digital Signature Algorithm (ECDSA) operations (Signing and verification) by around $15{\sim}19%$.

• The Korea Journal of Herbology
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• v.38 no.1
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• pp.21-30
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• 2023

Objective : Gardeniae Fructus (GF) has bitter and cold nature. Thus, it has been traditionally prescribed in processed form roasted with ginger juice for patients with a weak stomach. This study investigated the effects of processed GF in tert-butyl hydroperoxide (tBHP)-treated gastric epithelial cells. Methods : Processed GF was made by applying 40% ginger juice or 10% ethanol for 24 h and then roasting at 150℃ for 5 minutes. Apoptosis was determined by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay. Mitochondrial membrane potential (MMP) was monitored by flow cytometry using the membrane permeable fluorescent dye Rh123. Protein expression was measured by Western blot analysis. Results : Cell viability was reduced by tBHP and restored by ethanol extract of GF (GFE). In the TUNEL assay, it was found that cell death by tBHP was due to apoptosis, and GFE had an anti-apoptotic effect. Processed GF roasted with ginger juice showed the best anti-apoptotic effect. Processed GF also inhibited MMP loss and restored tBHP-induced changes in expression levels of apoptosis-related proteins. Increased ROS production and GSH depletion after tBHP treatment were significantly reduced by processed GF. In addition, tBHP-induced activation of mitogen-activated protein kinase (MAPK) was inhibited by processed GF. Conclusion : These results demonstrate that the processed GF is able to protect gastric epithelial cells from oxidative stress-induced cell death with antiapoptotic and antioxidant activity. In addition, it shows that the processing of GF, which have been traditionally used for gastrointestinal protection, partially have scientific validity.

• Journal of the Korea Concrete Institute
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• v.28 no.3
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• pp.289-298
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• 2016

An experimental research was performed using fibers for the purpose of retrofitting existing reinforced concrete circular columns. Glass fiber (GF) and polyethylene terephthalate (PET) were used as well as combined GF+PET (HF). PET has high tensile strength (over 600 MPa) and high ductility (about 15%), but has very low elastic modulus (about 1/6 of GF). A total of four columns was tested against laterally applied reverse cyclic load: control column, GF-, PET-, and HF-strengthened columns. All columns retrofitted using fibers demonstrated improved moment capacity and ductility. Moment capacity of GF-, PET-, and HF-strengthened columns was 120%, 107%, and 120% of the control column, respectively. Drift ratio of all retrofitted columns also increased by 63 ~ 83% over the control column. The final failure mode of the control column was main bar buckling. The final failure mode of the GF- and HF-strengthened columns was GF rupture while that of the PET-strengthened column was main bar rupture in tension. No damage was observed for PET at the ultimate stage due to excellent strain capacity intrinsic to PET. Current test results indicate that PET can be effectively used for seismic retrofit of RC columns. It is noted that the durability characteristics of PET needs to be investigated in the future.

• Journal of Periodontal and Implant Science
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• v.26 no.1
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• pp.89-102
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• 1996

The goal of periodontal therapy is to regenerate the loss of periodontal attachment appratus. Current theories suggest the cells of the periodontium have the capacity, when appropriately triggered, to actively participate in restoring connective tissues, including mineralized tissues. This study was performed to define the hard tissue regeneration effect of periodontal ligament(PDL) cells in vitro and the effect of rate of the composition in gingival fibroblasts(GF) on the hard tissue regeneration capacity of PDL cells. For this study, Cell growth rate, alkaline phosphatase(Al.Pase) levels and the ability to produce mineralized nodules in co-culture of PDL cells and GF were examined. The results were as follows : 1. At 7 and 15 days, Cell growth of co-culture of PDL and GF(50 : 50) was greater than that of PDL cells or GF alone(P>0.05). 2. Measurements of ALPase levels indicated that PDL cells had significantly higher activity when compared with that of co-culture groups and GF only(p<0.05). And, ALPase activity in 10 days was higher than that of 7 days(P>0.05) 3. The tendency of formation of the mineralized nodule were observed dose-depend pattern of PDL cells. There was statistically significant difference among group 1(PDL 100%), 2(PDL 70% : GF 30%), and 3(PDL 50% : GF 50%)(P<0.01). But, there was no difference among group 3, 4(PDL 30% GF 70%), and 5(GF 100%). 4. Also, the number of nodule was greater in co-culture of PDL 70% and GF 30% than in culture of PDL 70%(P<0.05) From the above results, it is assumed that the co-culture of PDL cells and GF stimulates the cell growth, which is not that of PDL cells but GF. And, the activity of ALPase depends on the ratio of PDL cells, and ALPase may relate to the initial phase of nodule formation. Also, it is thought that the calcified nodule formation principally depends on PDL cells, is inhibited by GF, and affected by cell density.