• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.12
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• pp.1314-1317
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• 2014

In this letter, we designed monopole microstrip antenna for WLAN / WiMAX system. The monopole antenna is designed by FR-4 substrate with size is $30mm{\times}40mm$. The proposed antenna is based on a planar monopole design which cover WLAN and WiMAX frequency bands. To obtainthe optimized parameters, we used the simulator, CST's Microwave Studio Program and found the parameters that greatly effect antenna characteristics. Using the obtained parameters, the antenna is designed. Thus the proposed antenna satisfied the -10 dB impedance bandwidth requirement while simultaneously covering the WLAN and WiMAX bands. And characteristics of gain and radiation patterns are obtained for WLAN/WiMAX frequency bands.

• The Korean Journal of Nuclear Medicine Technology
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• v.23 no.1
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• pp.69-74
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• 2019

Purpose $^{18}F$-FDOPA using amino acid is particularly attractive for imaging of brain tumors because of the high uptake in tumor tissue and the low uptake in normal brain tissue. But, on the other hand, $^{18}F$-FDG is highly uptake in both tumor tissue and normal brain tissue. The purpose of study is to evaluate comparison of contrasts in $^{18}F$-FDOPA Brain PET/CT and $^{18}F$-FDG Brain PET/CT and to find out optimal scan time by analysis of variation in SUV with the passage of uptake time. Materials and Methods A region of interest of approximately $350mm^2$ at the center of the tumor and cerebellum in 12 patients ($51.4{\pm}12.8yrs$) who $^{18}F$-FDG Brain PET/CT and $^{18}F$-FDOPA Brain PET/CT were examined more than once each. The $SUV_{max}$ was measured, and the $SUV_{max}$ ratio (T/C ratio) of the tumor cerebellum was calculated. In the analysis of SUV, T/C ratio was calculated for each frame after dividing into 15 frames of 2 minutes each using List mode data in 25 patients ($49.{\pm}10.3yrs$). SPSS 21 was used to compare T/C ratio of $^{18}F$-FDOPA and T/C ratio of $^{18}F$-FDG. Results The T/C ratio of $^{18}F$-FDOPA Brain PET/CT was higher than the T/C ratio of $^{18}F$-FDG Brain, and show a significant difference according to a paired t-test(t=-5.214, p=0.000). As a result of analyzing changes in $SUV_{max}$ and T/C ratio, the peak point of $SUV_{max}$ was $5.6{\pm}2.9$ and appeared in the fourth frame (6 to 8 minutes), and the peak of T/C ratio also appeared in the fourth frame (6 to 8 minutes). Taking this into consideration and comparing the existing 10 to 30 minutes image and 6 to 26 minutes image, the $SUV_{max}$ and T/C ratio increased by 0.2 and 0.1 each, compared to the 10 to 30 minutes image for 6 to 26 minutes image. Conclusion From this study, $^{18}F$-FDOPA Brain PET/CT is effective when reading the image, because the T/C ratio of $^{18}F$-FDOPA Brain PET/CT was higher than T/C ratio of $^{18}F$-FDG Brain PET/CT. In addition, in the case of $^{18}F$-FDOPA Brain PET/CT, there was no difference between the existing 10 to 30 minutes image and 6 to 26 minutes image. Through continuous research, we can find possibility of shortening examination time in $^{18}F$-FDOPA Brain PET/CT. Also, we can help physician to accurate reading using additional scan data.

• Journal of Welding and Joining
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• v.18 no.6
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• pp.42-47
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• 2000

The object of this study is to estimate Sn-Ag-Bi-Ga solder alloy as a substitute for Sn-37Pb alloy. For Sn-Ag-Bi-Ga alloys, Ag, Bi and Ga contents are varied. (Ag : 1~5%, Ga : 3%, Bi : 3~6%) Comparing to Sn-37Pb alloy Sn-Ag-Bi-Ga alloys have wider melting temperature range up to max. $18.7^{\circ}C$. With increasing Ag, Bi contents, the wettability of the alloys increased up to max. 6.6 mN. The vickers hardness of the alloys was max. 46.4 Hv. The ultimate tensile stress of the alloys was max. 60.3 MPa and the elongation was max. 1.2%. The joint strength between circuit board and solder was max. 55.5 N and the joint strength between connector and solder was max. 176.1 N. There were no cracks in this alloys after thermal shock test.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.6C
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• pp.438-443
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• 2008

The efficient method to implement the Max-Log-MAP algorithm is proposed by modifying the conventional algorithm. It is called a parallel soft output Viterbi algorithm (SOVA) and the rigorous proof is given for the equivalence between the Max-Log-MAP algorithm and the parallel SOVA. The parallel SOVA is compared with the conventional algorithms and we show that it is an efficient algorithm implementing the modified SOVA in parallel.

• Transactions of Materials Processing
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• v.10 no.1
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• pp.30-34
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• 2001

The magnetic and metallurgical characteristics of Mischmetal(MM) -Ferroboron (FeB) Permanent magnets have been investigated by X-ray diffractometer, scanning and transmission electron microscope and vibrating sample magnetometer under hot-pressing and die-upsetting process. The best magnetic properties obtained in these studies were $H_c$=5.8 kOe, $B_r$=5.0 kG with $(BH)_{max}=7.6 MGOe for melt-spun ribbons, $H_c$=3.0 kOe, $B_r$=4.6 kG with $(BH)_{max}$=2.9 MGOe for hot-pressed magnets and $H_c$=1.8 kOe, $B_r$=5.5 kG with $(BH)_{max}$=4.1 MGOe for die-upset magnets. The higher magnetic properties in die-upset magnets were resulted from alignment of the c-axis along the die-upsetting direction.

• Journal of Pharmaceutical Investigation
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• v.34 no.3
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• pp.215-222
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• 2004

The purpose of the present study was designed to evaluate the bioequivalence of two oxiracetam tablets, Neuromed tablet (Korea Drug Co., reference drug) and Neuracetam tablet (Sam Jin Pharmaceutical Co., test drug), according to the guidelines of Korea Food and Drug Administration (KFDA). Release of oxiracetam from the tablet in vitro was tested using KP VIII Apparatus II method with various dissolution media (pH 1.2, 4.0, 6.8 buffer solution and water). Twenty-four healthy volunteers, $23.7\;{\pm}\;2.4$ year in age and $68.9\;{\pm}\;6.2$ kg in body weight, were divided into two groups and a randomized $2{\times}2$ cross-over study was performed. After oral administration of a tablet containing 800 mg of oxiracetam, blood samples were taken at predetermined time intervals and concentrations of oxiracetam in plasma were determined using HPLC-MS-MS. The dissolution profiles of two formulations were very similar at all dissolution media. In addition, pharmacokinetic parameters such as $AUC_t$, $C_{max}$ and $T_{max}$ were calculated and ANOVA test was utilized for the statistical analysis of the parameters using logarithmically transformed $AUC_t$ and $C_{max}$ untransformed $T_{max}$. The results showed that the differences between two formulations based on the reference drug were 0.42%, 0.45% and -12.58% for $AUC_t$, $C_{max}$ and $T_{max}$, respectively. There were no sequence effects between two formulations in these parameters. The 90% confidence intervals for the log transformed data were within the acceptance range of log 0.8 to log 1.25 (e.g., $log0.94{\sim}log1.06$ and $log0.90{\sim}log1.07$ for $AUC_t$, and $C_{max}$, respectively), indicating that Neuracetam tablet is bioequivalent to Neuromed tablet. The major pharmacokinetic parameters, $AUC_t$, and $C_{max}$ met the criteria set by KFDA for bioequivalence indicating that Neuracetam tablet is bioequivalent to Neuromed tablet.

• Journal of Pharmaceutical Investigation
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• v.41 no.5
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• pp.309-315
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• 2011

A sensitive and specific liquid chromatographic method coupled with tandem mass spectrometry (LC-MS/MS) was developed for the analysis of ambroxol (active moiety of acebrophylline). After acetonitrile precipitation of proteins from plasma samples, ambroxol and the domperidone (internal standard, IS) were eluted on a C18 column. The isocratic mobile phase was consisted of 10 mM ammonium acetate and methanol (10 : 90, v/v), with flow rate at 0.2 mL/min. A tandem mass spectrometer, as detector, was used for quantitative analysis in positive mode by a multiple reaction monitoring mode to monitor the m/z 379.2${\rightarrow}$264.0 and the m/z 426.2${\rightarrow}$175.1 transitions for ambroxol and the IS, respectively. Twenty four healthy Korean male subjects received two capsules (100 mg ${\times}$ 2) of either the test or the reference formulation of acebrophylline HCl in a 2 ${\times}$ 2 crossover study, this was followed by a 1week washout period between either formulation. $AUC_{0-t}$ (the area under the plasma concentration-time curve) was calculated by the linear trapezoidal rule. $C_{max}$ (maximum plasma drug concentration) and $T_{max}$ (time to reach $C_{max}$) were compiled from the plasma concentration-time data. The 90% confidence intervals for the log transformed data were acceptable range of log 0.8 to log 1.25 (e.g., log 0.8964 - log 0.9910 for $AUC_{0-t}$ log 0.8690 - log 1.0750 for $C_{max}$). The major parameters, $AUC_{0-t}$ and $C_{max}$ met the criteria of Korea Food and Drug Administration for bioequivalence indicating that Acephyll$^{(R)}$ capsule (test) is bioequivalent to Surfolase$^{(R)}$ capsule (reference).

• YAKHAK HOEJI
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• v.45 no.6
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• pp.650-655
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• 2001

Carvedilol is a nonselective $\beta$-blocking agent with vasodilating properties that are attributed mainly to its blocking activity at $\alpha$$^{1}$-receptors. Carvedilol is used in the treatment of mild to moderate hypertention and angina pectoris and is often used in combination with other drugs. This study was carried out to evaluate the bioequivalence and pharmacokinetics of two carvedilol 25mg tablet formulations according to the guidelines of Korea Food and Drug Administration (KFDA). Twenty healthy volunteers are enrolled and received a single dose (25mg as carvedilol) of each drug in the fasting state, in a randomized 2-way crossover design. After oral administration, blond samples were collected for a period of 30 hours. Plasma concentrations of carvedilol were determined by a rapid and sensitive HPLC method with spectrofluorometric detection. The major pharmacokinetic parameters such as AU $C_{0-}$30hr/, AU $C_{inf}$ , $C_{max}$, $T_{max}$, $t_{1}$2 / Cl/F and V $_{\beta}$//F were calculated. ANOVA test and t-test were utilized for the statistical analysis of each parameter. The results showed that the differences in AU $C_{0-}$30hr/, $C_{max}$ and $T_{max}$ between two were ~5.66, 1.74 and 0.00%, respectively. Minimum detectable differences ($\Delta$) at $\alpha$=0.05 were less than$\pm$ 20% except $T_{max}$ (8.44, 18.36, and 33.86%, respectively). The 90% confidence intervals of all parameters were within $\pm$20% (-10.60~ -0.72, -9.00~12.49 and -19.81~19.81%, respectively). Therefore, it is concluded that the two formulations are bioequivalent for both the extent and the rate of absorption after single dose administration.ation.ion.ion.ation.ion.n.

• YAKHAK HOEJI
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• v.46 no.4
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• pp.290-294
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• 2002

Cephradine is an orally absorbed cephalosporin with a broad spectrum of activity against gram-positive and gram-negative bacteria and is highly resistant to beta-lactamase degradation. The purpose of the present study was to evaluate the bioequivalence of two cephradine capules, Cephradine capsule (Donggu Pharmaceutical Co., reference drug) and Cephradine capsule (Shinpoong Pharmaceutical Co., test drug), according to the guidelines of Korea Food and Drug Administration. Twenty-six normal volunteers, 24.6 $\pm$ 3.70 years in age and 62.4 $\pm$ 8.99 kg in body weight, were divided into two groups and a randomized 2 $\times$ 2 cross-over study was employed. After one capsule containing 250 mg of cephrdine was orally administered, blood was taken at predetermined time intervals and the concentrations of cephrdine in serum were determined using HPLC with UV detector. The pharmacokinetic parameters such as AU $C_{t}$ to $C_{max}$ and $T_{max}$ were calculated and ANOVA test was utilized for the statistical analysis of the parameters. The results showed that the differences in AUCt, $C_{max}$ and $T_{max}$ between two products were 2.89％, 1.05％ and 1.06％, respectively, when calculated against the reference drug. The 90％ confidence intervals were within log0.8 $\leq$ $\delta$ $\leq$ log1.25 (e.g., log0.9803 $\leq$ $\delta$ $\leq$ log1.0734 and log0.9674 $\leq$ $\delta$ $\leq$ log1.220 for AU $C_{t}$, and $C_{max}$, respectively). Two parameters met the criteria of KFDA for bioequivalence, indicating that Cephradine capsules (Shinpoong Pharmaceutical Co.) is bioequivalent to Cephradine capsules (Donggu Pharmaceutical Co.).o.).o.).).o.).

• Biomolecules & Therapeutics
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• v.10 no.4
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• pp.303-308
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• 2002

A bioequivalence study of Shin II Cefadroxil capsule (Shin II Pharm. Co. Ltd.) to Duricef capsule(Bo Ryung Pharm. Co. Ltd.), each containing 500 mg of cefadroxil, was conducted. Twenty three healthy Korean male subjects administered each formulation at the dose of 1 capsule (500 mg as cefadroxil) in 2 $\times$ 2 cross-over study. There was a I-week washout period between the doses. Plasma concentrations of cefadroxil were monitored for a period of 8 hr after each administration by an LC/UV method. Area under the plasma concentration-time curve up to 8 hr ($AUC_t$) was calculated by a linear trapezoidal method. $C_{max}$ was compiled from the plasma drug concentration-time data. ANOVA test was conducted for logarithmically transformed $AUC_t$ and $C_{max}$ The results showed that there are no significant differences in $AUC_t$ and $C_{max}$ between the two formulations: The differences between d1e formulations in these log transformed parameters were all for less than 20% (i.e., －0.57%, 3.84% for $AUC_t$ and $C_{max}$, respectively). The 90% confidence intervals for the log transformed data were within the acceptance range of log 0.8 to log 1.25 (i.e., log 0.94~log 1.04 and log 0.95~log 1.10 for $AUC_t$ and $C_{max}$, respectively). Based on d1e bioequivalence criteria of KFDA guidelines, the two formulations of cefadroxil were concluded to be bioequivalent.