• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.9 no.2
• /
• pp.149-158
• /
• 1998

The SAR patterns of biological objects contacted with coaxial waveguide antennal has been investigated, in which the biological object was modeled by a homogeneous and four-layered lossy human body. We derived the finite-difference time-domain(FDTD) algorithm and equation of MUR and generalized perfectly matched layer(GPML) ABCs in cylindrical coordination. The coupling between coaxial waveguide antenna and a biological object was analyzed by use of MUR and GPML ABCs in the FDTD method to obtain the absorbed power patterns in the media. The specific absorption rates (SAR) distribution which was corresponding to the temperature distribution was calculated in each region by use of the steady-state response in the FDTD method. The SAR patterns of the FDTD method using MUR absorbing boundary conditions(ABCs) was compared with those of the FDTD method using GPML ABCs. The comparison exhibits that the penetration depth of the SAR patterns using MUR ABCs is deeper than that of the SAR patterns using GPML ABCs because of loss in free space. However, the spread in the lateral directions of the SAR patterns using GPML ABCs is smaller than of the SAR patterns using MUR ABCs.

• Korean journal of communication and information
• /
• v.40
• /
• pp.287-320
• /
• 2007

This study was to look into the press policy and the related activities performed by North Korea in the South during the Korean War and to evaluate them. In order to understand the concrete contents of the activities and their characteristics, the two representative newspapers published in the South by North Korea at that times - the Chosuninmin Bo and the Haebang Ilbo - were reviewed and analyzed. North Korea operated broadcasting and started newspapers just after the possession of Seoul. and also performed various positive press activities - such as the distribution of the newspapers and periodicals of North Korea and U.S.S.R., putting the movies on the screen, and founding the weekly, etc. But the target of all the media were the same. It aimed to support Kim Il-Sung's scheme which intended to carry out the war successfully and to make the South under occupation Communism System by introducing the Northern law and system. The two newspapers, as agent of power, made only such a role to agitate and exaggerate the false things with unrealistic optimism. They intended to ideologically mobilize the South people and to affect on their perspectives and acts. However the media including the two newspapers being operated in the South during the war had not got the faith or the good response from the South people as an audience. Most of South Koreans were tired with their endless and one-sided propaganda, agitation and ideological enlightenment. It could therefore be evaluated that the press activities by North Korea in the South during the Korean War resulted with many limitations in ideologically organizing and mobilizing the South Koreans.

• The Journal of Natural Sciences
• /
• v.8 no.2
• /
• pp.289-321
• /
• 1996

After the two big wars (Imjin Woeran and Byungia Horan), the Lee Dynasty confronted rapid transitional periods in almost all aspects of the society. Corruption of the governmental system by the wars and disordered social structures also caused confusion in the social position system. In addition, development of the commercial economic system and monetary economy brought up a new rich middle-class, "Joong in Gyegeup". In ideological aspects, Confucianism indulged in and stick to isms and ics, and the Confucian morality slackened, thus a more pragmatic ideology, "Silhak Sasang", developed. And the emergence of the modern literature and art of the 'common people' was followed by the appearance of the common-people class including those having the common-people concept among the noble-class "Yangban Gyegeup". This evoked a new common costume culture and the fashion appeared. The public could no longer find the power and appeal from the preexisting ruling classes due to the changed role and sense of value. Thus, they sought a new symbolic leader group that would to be the new standard of the newly changed society. That was a group of people called as "Kisaeng" liberal and independent. They were performing social activities, enjoying poetry, music and dancing, and classy dressers, having physically attractive bodies. The erotic as well as luxurious mode proposed by them reflected the trend of that time. It concurred well with the concept and taste of the public, so it was accepted with a good response. That is, by following these leaders, the public achieved their identification and tried to share the prestige of the leaders. For this reason, the Kisaeng group attracted the public attention and led the taste of the public, thereby becoming the influential fashion leaders of that age.

• Korean Journal of Optics and Photonics
• /
• v.19 no.1
• /
• pp.68-72
• /
• 2008

Fiber-optic strain sensors based on Bragg reflection gratings produce the change of reflection spectrum when an external stress is applied on the sensor. To measure the Bragg reflection wavelength in high speed, an arrayed waveguide grating device is incorporated in this work. By monitoring the output power from each channel of the AWG, the peak wavelength corresponding to the applied strain could be obtained. To enhance the accuracy of the AWG wavelength interrogation system, a chirped fiber Bragg grating with a 3-dB bandwith of 5.4 nm is utilized. The high-speed response of the proposed system is demonstrated by measuring a fast varying strain produced by the damped oscillation of a cantilever. An oscillation frequency of 17.8 Hz and a damping time constant of 0.96 second are obtained in this measurement.

• Journal of Life Science
• /
• v.27 no.4
• /
• pp.450-455
• /
• 2017

Codonopsis lanceolata (Campanulaceae) has been widely used in traditional medicine and is considered to have medicinal properties to treat diseases and symptoms such as bronchitis, coughs, spasm, edema, hepatitis, colitis, and lung injury. In order to investigate whether native Codonopsis lanceolata extract alleviates ashmatic symptoms in vivo, we first carried out various antioxidant activities by 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, ferric reducing antioxidant power (FRAP), and cupric reducing antioxidant capacity (CUPRAC) assays. The antioxidant activities were increased by adding Codonopsis lanceolata extract in a concentration-dependent manner which compared to ascorbic acid as a positive control. Histological studies using an ovalbumin-induced animal model exhibited potent anti-inflammatory potential by decreasing immuno-responsive cells in the lung by the extract by confirming H&E and PAS staining. It is revelaed that further immunihistochemical analysis showed anti-ashmatic capabilities by assessing histamine, IL-31, and MMP-9 expressions. The level of IL-13 expression in Codonopsis lanceolata extract-treated group was decreased upto 73.7% compared to control, whereas that of total cells and eosinophil counting in Codonopsis lanceolata extract-treated group was diminished to 73.5% and 80.9%, respectively. These results collectively indicate that the C. lanceolata extract ameliorates asthmatic symptoms effectively in an ovalbumin-challenged mice model, in that the extract can be used for the development of an anti-asthmatic food ingredient.

• Radiation Oncology Journal
• /
• v.13 no.2
• /
• pp.113-120
• /
• 1995

Purpose : To investigate the effect of alkaloid fraction from Korean ginseng on radiation-induced DNA double strand breaks (dsb) formation and repair in murine lymphocytes Materials and Methods : We used the neutral filter elution technique to assay $^{60}Co\;{\gamma}$ ray-induced DNA double strand breaks formation and repair in C57BL/6 mouse spleen lymphocytes for evaluating the dose-response relationship in the presence of alkaloid fraction as a radioprotective agent. The lymphocytes were stimulated with Phytohemagglutinin (PHA, 2 u g/ml) to label $^3[H]-thymidine.$ Isotope-labelled lymphocytes in suspension were exposed to 100 Gy at $0^{\cdot}C$ in the alkaloid fraction-treated group and elution procedure was performed at PH 9.6. The extents of formation of radiation-induced DNA double strand breaks and repair were compared respectively via strand scission factor (SSF) and relative strand scission factor (RSSF). Results: Alkaloid fraction reduced the formation of double strand breaks with dose modification factor of 2 15, compared to control group Rejoining of DNA dsb appeared to take place via two components. The first fast component was completed within 20.4 minutes, but the second slow component was not completed until 220.2 minutes after irradiation. About $30\%$ of dsb formed by irradiation was ultimately unrejoined despite the administration of alkaloid fraction. The administration of alkaloid fraction had a great effect on the second slow component of repair; the half-time of fast component repair was not changed, but that of slow component was 621.8 minutes. Conclusion: Neutral filter elution assay Proved to be a very effective method to quantitate the extents of DNA dsb formation and its repair. By using this technique, we were able to evaluate the efficiency of alkaloid fraction from Korean ginseng as a valuable radioprotector. Alkaloid fraction can be used prophylactically to prevent or ameliorate the severe radiation damages in workers and neighbors around the atomic power plants. For more refined study, however, more advanced purification of alkaloid fraction wil be needed in the near future.

• Journal of Korea Society of Industrial Information Systems
• /
• v.21 no.1
• /
• pp.61-70
• /
• 2016

This paper describes a new PMU(parametric measurement unit) design technique for automatic test equipment(ATE). Only one DDA(differential difference amplifier) is used to force the test signals to DUT(device under test), while conventional design uses two or more amplifiers to force test signals. Since the proposed technique does not need extra amplifiers in feedback path, the proposed PMU inherently guarantees stable operation. Moreover, to measure the response signals from DUT, proposed technique also adopted only one DDA amplifier as an IA(instrument amplifier), while conventional IA uses 3 amplifiers and several resistors. The DDA adopted two rail-to-rail differential input stages to handle full-range differential signals. Gain enhancement technique is used in folded-cascode type DDA to get open loop gain of 100 dB. Proposed PMU design enables accurate and stable operation with smaller hardware and lower power consumption. This PMU is implemented with 0.18 um CMOS process and supply voltage is 1.8 V. Input ranges for each force mode are 0.25~1.55 V at voltage force and 0.9~0.935 V at current force mode.

• Land and Housing Review
• /
• v.4 no.1
• /
• pp.43-54
• /
• 2013

This This paper investigates the variation of the factors to determinate housing price in Seoul metropolitan area after sub-prime financial crisis, in Korea, using a VAR model. The model includes housing price and housing rent (Jeonse) in Seoul metropolitan area from 1999 to 2011, and uses interest rate, real GDP, KOSPI, Producer Price Index and practices to impulse response and variance decomposition analysis to grasp the dynamic relation between a variable of macro economy and and a variable of housing price. Data is classified to 2 groups before and after the 3rd quater of 2008, when sub-prime crisis occurred; one is from the 1st quater of 1999 to the 3rd quater of 2008, and the other is from the 2nd quater of 1999 and the 4th quater of 2011. As a result, comparing before and after sub-prime crisis, housing price is more influenced by its own variation or Jeonse price's variation instead of interest rate and KOSPI. Both before and after sub-prime financial crisis, Jeonse price is also influenced by its own variation and housing price. While after sub-prime financial crisis, influences of Producer Price Index, KOSPI and interest rate were weakened, influence of real GDP is expanded. As housing price and housing rent are more influenced by real economy factors such as GDP, its own variation than before sub-prime financial crisis, the recent trend that the house prices is declined is difficult to be converted, considering domestic economic recession and uncertainty, continued by Europe financial crisis. In the future to activate the housing business, it ia necessary to promote purchasing power rather than relaxation of financial and supply regulation.

• Journal of the Microelectronics and Packaging Society
• /
• v.9 no.3
• /
• pp.19-23
• /
• 2002

This paper presents a micro fluxgate magnetic sensor in printed circuit board (PCB). In order to observe the effect of the closed magnetic path, the magnetic cores of rectangular-ring and two bars were each fabricated. Each fluxgate sensor consists of five PCB stack layers including one layer magnetic core and four layers of excitation and pick-up coils. The center layer as a magnetic core is made of a Co-based amorphous magnetic ribbon with extremely high DC permeability of ~100,000. Four outer layers as an excitation and pick-up coils have a planar solenoid and are made of copper foil. In case of the fluxgate sensor having the rectangular-ring shaped core, excellent linear response over the range of -100 $\mu$T to ＋ 100 $\mu$T is obtained with 540 V/Tsensitivity at excitation square wave of 3 $V_{p-p}$ and 360 KHz. The chip size of the fabricated sensing element is $7.3 \times 5.7\textrm{mm}^2$. The very low power consumption of ~8 mW was measured. This magnetic sensor is very useful for various applications such as: portable navigation systems, telematics, VR game and so on.n.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.37 no.8
• /
• pp.28-34
• /
• 2000

Pyroelectric properties of the $Pb(Zr_{0.9}Ti_{0.1})O_3$ ceramics having the rhombohedral structure have been studied by using the dynamic measurement method. The pyroelectric responses of the $Pb(Zr_{0.9}Ti_{0.1})O_3$ ceramics are characterized in both low and high medulation frequency regions and their frequency depences are observed. In the low frequency region (2~200Hz), the change of polarization increases and shows the maximum since the reorientation rate of domains is higher than the modulation frequency. Inthe high frequency region (200~2000Hz), the pyroelectrci response decreases as the frequency increases, because the reorientation of domains is suppressed and so the change of polarization decreases. Pyroelectric coefficient, figure of merit, noise equivalent power and detectivity of the $Pb(Zr_{0.9}Ti_{0.1})O_3$ ceramics are measured as $1.6{\times}10^{-8}C/cm^2{\cdot},\;1.6{\times}10^{-11}C{\cdot}cm/J,\;2.4{\times}10^{-7}W/Hz^{1/2}\;and\;4.17{\times}10^6cm{\cdot}Hz^{1/2}/W$, respectively.