• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.13 no.12
• /
• pp.6159-6174
• /
• 2019

Recently, Kim et al. introduced the Hamming + k with m overlapped pixels data hiding (Hk_mDH) based on matrix encoding. The embedding rate (ER) of this method is 0.54, which is better than Hamming code HC (n, n - k) and HC (n, n - k) +1 DH (H1DH), but not enough. Hamming code data hiding (HDH) is using a covering function COV(1, n = 2^k -1, k) and H1DH has a better embedding efficiency, when compared with HDH. The demerit of this method is that they do not exploit their space of pixels enough to increase ER. In this paper, we increase ER using sequential Hk_mDH (SHk_mDH ) through fully exploiting every pixel in a cover image. In SHk_mDH, a collision maybe happens when the position of two pixels within overlapped two blocks is the same. To solve the collision problem, in this paper, we have devised that the number of modification does not exceed 2 bits even if a collision occurs by using OPAP and LSB. Theoretical estimations of the average mean square error (AMSE) for these schemes demonstrate the advantage of our SHk_mDH scheme. Experimental results show that the proposed method is superior to previous schemes.

• Journal of Surface Science and Engineering
• /
• v.39 no.5
• /
• pp.235-239
• /
• 2006

The aluminum nitride(AlN) layer on Al7075 substrate has been formed through nitrogen ion implantation process. The implantation process was performed under the conditions : 100 keV energy, total ion dose up to $2{\times}10^{18}\;ions/cm^2$. XRD analysis showed that aluminum nitride layers were formed by nitrogen implantation. The formation of Aluminum nitride enhanced surface hardness up to 265HK(0.02 N) from 150HK(0.02 N) for the unimplanted specimen. Micro-Knoop hardness test showed that wear resistance was improved about 2 times for nitrogen implanted specimens above $5\;{\times}\;10^{17}\;ions/cm^2$. The friction coefficient was measured by Ball-on-disc type wear tester and was decreased to 1/3 with increasing total nitrogen ion dose up to $1\;{\times}\;10^{18}ions/cm^2$. The enhancement of mechanical properties was observed to be closely associated with AlN formation. AES analysis showed that the maximum concentration of nitrogen increased as ion dose increased until $5\;{\times}\;10^{17}\;ions/cm^2$.

• Journal of Life Science
• /
• v.28 no.10
• /
• pp.1147-1155
• /
• 2018

Agaricus blazei mycelial liquid culture extract (ABMLCE) promoted the production of testosterone (TS) in TM-3 mouse Leydig testis cells. Now, we report that ABMLCE containing eritadenine (EA) as a minor constituent (15.3 mg/100 g) reduced $5{\alpha}-reductase$ 2 ($5{\alpha}-R2$) enzyme activity and dihydrotestosterone (DHT) content which are key constituents for the benign prostatic hyperplasia (BPH) inductions. RWPE-1 prostate cells were grown in a Keratinocyte serum-free medium (K-SFM) containing ABMLCE (0~50 ppm), EA (0~10 ppm,), and finasteride (FS $10{\mu}M$: a positive control) in a 24-well plate for 24 hr. Supernatants collected from cell-cultured media were used for the assay of $5{\alpha}-R2$, superoxide dismutase (SOD), catalase (CAT) and cyclooxygenase-2 (COX-2) enzyme activities, and for TS, DHT, tumor necrosis $factor-{\alpha}$ ($TNF-{\alpha}$) and $interleukin-1{\beta}$ ($IL-1{\beta}$) contents by their assay kits. The $5{\alpha}-R2$ activity and DHT content were proportionally reduced (p<0.05) to concentrations of ABMLCE. The SOD and CAT enzyme activities were significantly (p<0.05) elevated concomitant with ABMLCE concentrations, while COX-2, $TNF-{\alpha}$ and $IL-1{\beta}$ showed reverse results (p<0.05). Similarly, the effects of EA were similar to those of ABMLCE. Efficacies of ABMLCE 50 ppm and EA 10 ppm in $5{\alpha}-R2$ and DHT reduction were similar to those of $10{\mu}M$ FS. These results suggest that ABMLCE and EA reduced $5{\alpha}-R2$ and DHT through their anti-inflammatory and anti-oxidative actions. This implies that ABMLCE containing EA could be a beneficial material in the cure of BPH in humans.

• Journal of Life Science
• /
• v.28 no.6
• /
• pp.648-655
• /
• 2018

Enhancement mechanistic actions of testosterone (TS) productions in mouse Leydig TM3 cells by the eritadenine (EA) and/or the Agaricus blazei mycelial liquid culture extract (ABMLCE). Productions of TS in TM3 cells were investigated in normal and oxidative-stressed culture conditions. In the normal culture condition, TM3 cells grown in a Dulbecco's Modified Eagle's Medium (DMEM) were treated with EA (0~100 ppm) and ABMLCE (10 ppm) + EA (0~50 ppm) for 24 hr, and in the oxidative-stressed culture condition, the cells grown in DMEM containing $50{\mu}M$ $H_2O_2$ to induce oxidative stress for 4 h were treated with the same as those in the normal culture condition. TS content, $3{\beta}$-hydroxysteroid dehydrogenase 2 (HSD3B2) enzyme activity, $5{\alpha}$-reductase 2 ($5{\alpha}-R2$) enzyme activity, and free-radical nitric oxide (NO) content in the culture media were measured using their corresponding assay kits. EA, ABMLCE, and ABMLCE + EA significantly, p<0.05, enhanced TS productions in both cultural conditions, relative to control treatment. The activity of the HSD3B2 enzyme, which is involved in the production of precursors for TS production, was elevated by EA, ABMLCE, and ABMLCE + EA treatments in both culture conditions. The activity of the $5{\alpha}-R2$ enzyme, which converts TS to dihydroxytestosterone (DHT), was not significantly affected in either culture condition by EA, ABMLCE, or ABMLCE + EA treatments. The treatments included reduced NO content. These results indicate that EA, ABMLCE, and EA + ABMLCE treatments elevated TS in TM3 cells via the enhancements of HSD3B2 activity and the reduction of NO production, and also imply that EA and ABMLCE or EA + ABMLCE could be useful materials for the production of TS in humans.

• Proceedings of the Korean Vacuum Society Conference
• /
• 1995.06a
• /
• pp.151-151
• /
• 1995

Nitrogen implantation process has been applied for improvement of wear resistance of Z Zircaloy-4 fuel cladding materials. Nitrogen was implanted at 120 ke V to a total do range of 1xHP ions/cm2 to 8xlO17 ions/cm2 at various temperatures of 298"C to 676"C. The m microstructure changes by nitrogen implantation were analyzed by using TEM, XRD 뻐d A AES, cmd then wear behavior was evaluated by ball-on-disc wear testings at various loads a and sliding velocity under unlubricated condition. Nitrogen implantation produced ZrNx nitride above 4.37x1017 ions!cm2 as well as heavy d dislocations, which enhanced microhardness of the implanted surface of up to 900 Hk from 2 200 Hk of unimplanted substrate. Hardness was also found to be increased with increasing i implantation temperature and enhanced up to OOOHk at 620 "C. the wear resistance was g greatly improved with increasing total ion do않 as well as implantation temperature. The effective enhancement of wear resistance at high dose and tem야ratures is believed d due to significant hardening associated with high degree of precipitation of Zr nitrides and g generation of prismatic dislocation I$\infty$ps.infty$ps.

• 대한공업교육학회지
• /
• v.33 no.2
• /
• pp.312-324
• /
• 2008

To improve the newly designed HKS(hinge kit system) in common refrigerators, it was investigated the new robust methodologies. There were the study of failure modes, mechanisms in the marketplace, and the design parameters of HKS with various improvements using accelerated life testing. Based on the claimed marketplace product returns and 1st ALT reproduction, the fracturing and cracking occur in the housing of the HKS. The missing design parameters of the failed HKS in the design phase of the refrigerator was the housing hinge kit structure. The corrective action plans are the modifications of the housing hinge kit structure from the open supporting to all supporting structure. Based on 2nd ALTs, the fracturing and cracking occur in the torsion shaft. The missing design parameter was the roundness of torsion shaft. After a sequence of ALT testing, the levels of the missing design parameters were setup. The yearly failure rate and B1 life of the redesigned HKS, based on the results of ALT, were over 0.01 percent and 10 years, respectively. The parameter design through the inspection of the failed product, load analysis, and three rounds of ALT, was very effective in the new robust design methodologies of the mechanical system and this method can be applied to other design system.

• Korean Journal of Food Science and Technology
• /
• v.24 no.5
• /
• pp.414-422
• /
• 1992

To keep up with urgent need of continuous, effective and rapid drying unit, a fluidized bed drying system with computer controlling air temperature, velocity and relative humidity was designed. This study was attempted to determine physical properties and some basic experiments of fluidized bed d교ing of barley. Also experimental data of the designed fluidized bed drying system using the barely were compared with those of published equations to confirm the reliability of the system and the following results were obtained. The physical dimension husked barley were shown larger than that of naked barley from the experiment. When air temperature. relative humidity and charged amount were $35^{\circ}C$, 30% and 300g respectively, the minimum fluidization velocity of naked and husked barley were found 1.5 m/s and 1.7 m/s. And the optimum fluidization velocity was shown as 3.0 m/s from the experiment. The empirical equation of $U_{mf}$ in this fluidized system was obtained as follow; $U_{mf}^2= \frac{{\phi_s}\;d_p}{Hk}\;{\cdot}\;\frac{(\rho_s-\rho_g)g\;{{\varepsilon}_{mf}^3}} {\rho_g}(Re_p>1,000)$ Where HK=0.4881 for naked barley, 0.6649 for husked barley.

• Journal of Magnetics
• /
• v.19 no.4
• /
• pp.333-339
• /
• 2014

Single crystal growth of $BaFe_{12}O_{19}$ by the solid state crystal growth method was attempted. Seed crystals of ${\alpha}-Fe_2O_3$ were pressed into pellets of $BaFe_{12}O_{19}$ + 2 wt% $BaCO_3$ and heat-treated at temperatures between $1150^{\circ}C$ and $1250^{\circ}C$ for up to 100 hours. Instead of single crystal growth taking place on the seed crystal, BaO diffused into the seed crystal and reacted with it to form a polycrystalline reaction layer of $BaFe_{12}O_{19}$. The microstructure, chemical composition and structure of the reaction layer were studied using scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS), x-ray Diffraction (XRD) and micro-Raman scattering and confirmed to be that of $BaFe_{12}O_{19}$. XRD showed that the reaction layer shows a strong degree of orientation in the (h00)/(hk0) planes in the sample sintered at $1200^{\circ}C$. $BaFe_{12}O_{19}$ layers with a degree of orientation in the (hk0) planes could also be grown by heat-treating an ${\alpha}-Fe_2O_3$ seed crystal buried in $BaCO_3$ powder.

• Journal of Surface Science and Engineering
• /
• v.19 no.2
• /
• pp.31-43
• /
• 1986

The properties of the electroless nickel deposit mainly depends on the pH of the bath, the plating temperature, and the molar ratio of nickel to hypophosphite but they are also affected by its formulation and concentration of complexing and buffering agents. According to changeing the concentration of triethanolamine and boric acid, phosphorous contents, microsturcture, crystalline, hardness and wear resistance of deposits obtained from ammoniacal alkaline bath were investigated by EPMA, differential thermal analyser, X-ray diffractometer and wear tester. The results are as follows; (1) Increasing concentration of triethanolamine in the bath, the deposits is slightly inclined to increase its phosphorous content(3.7% P). (2) In the as-plated state, the deposits are not crystallized state but they are thermally unstable phase, and they are crystallized with precipitating $Ni_3P$ at 400$^{\circ}C$. (3) The deposit containing 2.3% P has higher hardness value in the as plated and heat treated state at below 300$^{\circ}C$ than those of 3.7% phosphorous deposit (1090Hk). But in the case of heat treating at 400$^{\circ}C$, the former has lower hardness value (1000Hk) than the latter and has remarkably Ni(III) orientation by heat treatment. (4) The 3.7% phosphorous deposit heat treated at 400$^{\circ}C$ has better wear resistance than hard chromium plating.

• Journal of the Korean Vacuum Society
• /
• v.15 no.6
• /
• pp.563-575
• /
• 2006

Ti(C,N) films are synthesized by pulsed DC plasma enhanced chemical vapor deposition (PEMOCVD) using metal-organic compounds of tetrakis diethylamide titanium at $200-300^{\circ}C$. To compare plasma parameter, in this study, $H_2$ and $He/H_2$ gases are used as carrier gas. The effect of $N_2\;and\;NH_3$ gases as reactive gas is also evaluated in reduction of C content of the films. Radical formation and ionization behaviors in plasma are analyzed in-situ by optical emission spectroscopy (OES) at various pulsed bias voltages and gas species. He and $H_2$ mixture is very effective in enhancing ionization of radicals, especially for the $N_2$. Ammonia $(NH_3)$ gas also highly reduces the formation of CN radical, thereby decreasing C content of Ti(C, N) films in a great deal. The microhardness of film is obtained to be $1,250\;Hk_{0.01}\;to\;1,760\;Hk_{0.01}$ depending on gas species and bias voltage. Higher hardness can be obtained under the conditions of $H_2\;and\;N_2$ gases as well as bias voltage of 600 V. Hf(C, N) films were also obtained by pulsed DC PEMOCYB from tetrakis diethyl-amide hafnium and $N_2/He-H_2$ mixture. The depositions were carried out at temperature of below $300^{\circ}C$, total chamber pressure of 1 Torr and varying the deposition parameters. Influences of the nitrogen contents in the plasma decreased the growth rate and attributed to amorphous components, to the high carbon content of the film. In XRD analysis the domain lattice plain was (111) direction and the maximum microhardness was observed to be $2,460\;Hk_{0.025}$ for a Hf(C,N) film grown under -600 V and 0.1 flow rate of nitrogen. The optical emission spectra measured during PEMOCVD processes of Hf(C, N) film growth were also discussed. $N_2,\;N_2^+$, H, He, CH, CN radicals and metal species(Hf) were detected and CH, CN radicals that make an important role of total PEMOCVD process increased carbon content.