• Journal of electromagnetic engineering and science
• /
• v.17 no.1
• /
• pp.20-28
• /
• 2017

A fully integrated dual-band CMOS power amplifier (PA) is developed for 802.11n WLAN applications using wafer-level package (WLP) technology. This paper presents a detailed design for the optimal impedance of dual-band PA (2 GHz/5 GHz PA) output transformers with low loss, which is provided by using 2:2 and 2:1 output transformers for the 2 GHz PA and the 5 GHz PA, respectively. In addition, several design issues in the dual-band PA design using WLP technology are addressed, and a design method is proposed. All considerations for the design of dual-band WLP PA are fully reflected in the design procedure. The 2 GHz WLP CMOS PA produces a saturated power of 26.3 dBm with a peak power-added efficiency (PAE) of 32.9%. The 5 GHz WLP CMOS PA produces a saturated power of 24.7 dBm with a PAE of 22.2%. The PA is tested using an 802.11n signal, which satisfies the stringent error vector magnitude (EVM) and mask requirements. It achieved an EVM of -28 dB at an output power of 19.5 dBm with a PAE of 13.1% at 2.45 GHz and an EVM of -28 dB at an output power of 18.1 dBm with a PAE of 8.9% at 5.8 GHz.

• Journal of the Korean Chemical Society
• /
• v.55 no.5
• /
• pp.819-823
• /
• 2011

The relationship between the microstructure, mechanical properties, and oxidation behavior of pitch-, polyacrylonitrile (PAN)-, and Rayon-based carbon fibers (CFs) has been studied in detail. Three types of carbon fiber were exposed to isothermal oxidation in air and the weight change was measured by thermogravimetric analyzer (TGA) apparatus. After activation energy was gained according to the conversion at reacting temperature, the value of specific surface area and the surface morphology was compared, and the reaction mechanism of oxidation affecting development of pores of carbon fibers was examined. This study will lead to a new insight into the relationship between the microstructure and mechanical properties of carbon fibers.

• The Korean Journal of Rehabilitation Nursing
• /
• v.3 no.2
• /
• pp.141-153
• /
• 2000

The several Chinese herbs such as Soon-Ki-Hwal-Hyul-Tang, Bo-Yang-Hwan-O-Tang, Seong-Hyang-Jeong-Ki-San, So-Hap-Hyang-Won and O-Yak-Soon-Ki-San were extracted with water and then lyophilized. For identification of the effect of extracted herbs, they were medicated to 103 patients of cerebrovascular accident for 4 week. They were hospitalized in D-Oriental Medical Hospital from April to August in 1999. The herbs were extracted with water and lyophilized and then, used as samples. The medical history of each patient was detected and analyzed from their medical records. The results were as follows; 1) Each sample (Soon-Ki-Hwal-Hyul-Tang, Bo-Yang-Hwan-O-Tang, Seong-Hyang-Jeong-Ki-San, and O-Yak-Soon-Ki-San) was statistically significant differences of systolic blood pressure(t=4.22, P=0.0004; t=3.44, P=0.0028; t=2.11, P=0.0463; t=3.23, P=0.0052). The statistically significant difference of diastolic blood pressure showed by medicated with Soon-Ki-Hwal-Hyal-Tang, Seong-Hyang-Jeong-Ki-San, and O-Yak-Soon-ki-San (t=2.13, P=0.0459; t=2.68, P=0.0136; t=3.12, P=0.0066). 2) The statistically significant difference of the arm/leg-ROM showed by medicated with Soon-Ki-Hwal-Hyul-Tang, Bo-Yang-Hwan-O Tang, So-Hap-Hyang-Won(t=4.74/4.95, P=0.0002/0.0001; t=2.25/2.44, P=0.0368/0.0248; t=5.85/6.76, P=0.0001/0.0001). 3) In the verbal disorder, Soon-Ki-Hwal-Hyul-Tang, Bo-Yang-Hwan-O-Tang had statistically significant differences(t=4.50, P=0.0002; t=3.32, P=0.0036). 4) In the conscious disorder, Soon-Ki-Hwal-Hyul-Tang, Bo-Yang-Hwan-O-Tang, Seong-Hyang-Jeong-Ki-San, and So-Hap-Hyang-Won had statistically significant differences(t=6.32, P =0.0001; t=8.32, P=0.0001; t=3.74, P=0.0012; t=5.14, P=0.0001). 5) Bovine aortic endothelial cell (BAEC) were cultured in DMEM treating 0.01mg/ml, and 0.1mg/ml of each lyophilized samples for 24 hours. In BAECs were treated by 5 kinds of samples, the effect of So-Hyap-Hyang-Won induced syncytium of adjacent endothelial cells. It may induce the recovering of the damaged blood vessels in cerebrovascular accidental patient by angiogensis of endothelial cells. Therefore, it suggests that the medication of So-Hap-Hyang-Won will help to nursing care for cerebrovascular accidental patients.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2003.07a
• /
• pp.7-10
• /
• 2003

Samsung SDI has developed a full color 5.0" WVGA AMOLED display with top emission and a super fine pitch of 0.1365mm(l86ppi), the world's highest resolution OLED display ever reported to date. Scan driver circuits and demux circuit were integrated into the display panel, using low temperature poly-Si TFT CMOS technology, and data driver circuit were mounted using COG chips. Peak luminescence was greater than 300cd/ $m^2$ with power consumption of 500mW with 30% of the pixels on illuminated.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.11 no.1
• /
• pp.87-96
• /
• 1987

Dan-Ryong is the traditional clothing that was worn the entire of oriental nations, and it was spreaded from Sun-Bi tribe to China about A.D. 4C. The first, the name of Dan-Ryong was translated with 25-Sa and Ancient-History Book. Among the name of Dan-Ryong, the follows were different between the name and shape. Jang-Bok was the colored Dan-Ryong, So-Bok was the unfigured black Dan-Ryong and removed Hyung-Bae, Ea-Mun-Pho was the Dan-Ryong of embroidered figure poetry, and Ja-Sam was the real short and tight Dan-Ryong. The second, some problems were given by translated Dan-Ryong's name. The results of the problems were as follows; 1. Dan-Ryong was oriented from Won-Wi. 2. At Su-Dynasty, there was going to the persuit of Han-Dynasty Courtesy, but they liked useful custom. Therefore Dan-Ryong was worn in daily life among the population. 3. At Dang-Dynasty, Ho-Bok was devided with three meanings. The first was Go-Sub, the second was Dan-Ryong of Buk-Jo about A.D. 3$\~$5 C and the last meaning was the clothing of Uighur, Turkey, Persia and etc. about A.D. 7 C. 4. The name of neck-line shape was started at Song and the majority arised about A.D. 12 C. and Dan-Ryong was only arised at Myong-Dynasty. 5. Gok-Ryong, except Song-Sa and Sam-Je-He-Bo, was different from Dan-Ryong and it was shape of neck-line inside of Jik-Ryong.

• Journal of Broadcast Engineering
• /
• v.11 no.2 s.31
• /
• pp.222-228
• /
• 2006

In this paper, we propose a receive diversity method for orthogonal frequency division multiplexing (OFDM) systems with cochannel interference. In the method, combining is done in the frequency domain by using the subcarrier based maximum ratio combining (MRC) method. For MRC, we exploit the power of cochannel interference as well as the power of channel noise. The accuracy of the power estimate of interference plus noise is enhanced by averaging the initial estimates over the correlated subchannels where the coherency between the subchannel gains comes from the limited delay spread of the channel. Simulation results show that the proposed method yields 2-3.5dB gain of signal to noise ratio compared to the conventional MRC method and less than 1 dB difference to the ideal case.

• Journal of Magnetics
• /
• v.13 no.4
• /
• pp.170-172
• /
• 2008

Fe-6.5% Si alloys have good magnetic properties due to their high electrical resistivity, very low magneto-striction, and low crystalline anisotropy. Despite their strong potential, these alloys have seldom been used in magnetic applications because of the very poor ductility of Si-steel above 3.0 wt% Si [1-4]. It is difficult to achieve compressed Fe-6.5% Si powder cores with excellent properties because of the low density due to poor ductility. In compressed powder cores, high density is essential in order to obtain high magnetization and permeability. In this study, an attempt was made to produce Fe-3%Si powder cores because the Fe-3.0 wt% Si alloys have relatively good magnetic properties and room temperature ductility. Gas atomized Fe-3.0 wt% Si powder was compressed into toroid shape cores. By reducing the Si content to 3.0 wt%, the hysteresis loss could be greatly reduced and thus the total core loss could be minimized. The total core loss is 600 mW/$cm^3$ at 0.1 T and 50 kHz.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.12 no.4
• /
• pp.487-493
• /
• 2001

In this paper, A new microstrip bandpass filter is proposed. The novelty of the proposed structures is to use a interdigital capacitor and embeded slot that are fanned on a patch resonator such that its insertion loss and size can be significantly reduced simultaneously. As a result, it is found that the resonant frequency of patch filter designed at 5 GHz is decreased to 1.8946 GHz and the insertion loss is reduced from -2.168 dB to -0.379 dB. This proposed filter has small size and low insertion loss in comparison with the conventional parallel edge coupled bandpass filter.

• The Journal of Korean Society for Radiation Therapy
• /
• v.28 no.1
• /
• pp.35-46
• /
• 2016

Purpose : BoS(Base of Skull) Frame, the fixation tool which is used for the proton of brain cancer increases the lateral penumbra by increasing the airgap (the distance between patient and beam jet), due to the collision of the beam of the posterior oblique direction. Thus, we manufactured the fixation tool per se for improving the limits of BoS frame, and we'd like to evaluate the utility of the manufactured fixation tool throughout this study. Materials and Methods : We've selected the 3 patients of brain cancer who have received the proton therapy from our hospital, and also selected the 6 beam angles; for this, we've selected the beam angle of the posterior oblique direction. We' ve measured the planned BoS frame and the distance of Snout for each beam which are planned for the treatment of the patient using the BoS frame. After this, we've proceeded with the set-up that is above the location which was recommended by the manufacturer of the BoS frame, at the same beam angle of the same patient, by using our in-house Bos frame fixation tool. The set-up was above 21 cm toward the superior direction, compared to the situation when the BoS frame was only used with the basic couch. After that, we've stacked the snout to the BoS frame as much as possible, and measured the distance of snout. We've also measured the airgap, based on the gap of that snout distance; and we've proceeded the normalization based on each dose (100% of each dose), after that, we've conducted the comparative analysis of lateral penumbra. Moreover, we've established the treatment plan according to the changed airgap which has been transformed to the Raystation 5.0 proton therapy planning system, and we've conducted the comparative analysis of DVH(Dose Volume Histogram). Results : When comparing the result before using the in-house Bos frame fixation tool which was manufactured for each beam angle with the result after using the fixation tool, we could figure out that airgap than when not used in accordance with the use of the in-house Bos frame fixation tool was reduced by 5.4 cm ~ 15.4 cm, respectively angle. The reduced snout distance means the airgap. Lateral Penumbra could reduce left, right, 0.1 cm ~ 0.4 cm by an angle in accordance with decreasing the airgap while using each beam angle in-house Bos frame fixation tool. Due to the reduced lateral penumbra, Lt.eyeball, Lt.lens, Lt. hippocampus, Lt. cochlea, Rt. eyeball, Rt. lens, Rt. cochlea, Rt. hippocampus, stem that can be seen that the dose is decreased by 0 CGE ~ 4.4 CGE. Conclusion : It was possible to reduced the airgap by using our in-house Bos frame fixation tool for the proton therapy; as a result, it was possible to figure out that the lateral penumbra reduced. Moreover, it was also possible to check through the comparative analysis of the treatment plan that when we reduce the lateral penumbra, the reduction of the unnecessary irradiation for the normal tissues. Therefore, Using the posterior oblique the Brain cancer proton therapy should be preceded by decreasing the airgap, by using our in-house Bos frame fixation tool; also, the continuous efforts for reducing the airgap as much as possible for the proton therapy of other area will be necessary as well.

• Korean Journal of Pharmacognosy
• /
• v.31 no.3
• /
• pp.340-344
• /
• 2000

Lonicerae Flos, the flower of Lonicera japonica Thunb., has been used as a diuretic, stomachic, antipyretic, analgesic and anti-inflammatory agent in Korea. In order to evaluate the quality of Lonicerae Flos, the method of isolation and quantitative determination of luteolin $7-O-{\beta}-D-glucoside$ as a reference standard compound has been developed. Different specimens of Lonicerae Flos were collected from twenty Korean markets and were analyzed with HPLC using the mobile phase of MeOH-4.5% acetic acid solution (16.5:83.5). The average content of luteolin $7-O-{\beta}-D-glucoside$ from Lonicerae Flos in Korean markets was $0.43{\pm}0.34%$.