• Korean Journal of Heritage: History & Science
• /
• v.45 no.2
• /
• pp.72-99
• /
• 2012

Cheomseongdae, Korea's so-called "star-gazing tower" located in the former Silla Dynasty capital of Gyeongju, is generally believed to have maintained its original shape since its construction in 647. The stone structure was closely examined and measured by Gyeongju National Museum in 1962 and reexamined by Korean National Research Institute of Cultural Heritage in 2009. This research noted the following structural anomalies of Cheomseongdae. A corner of the top rectangle layer was broken diagonally in a form that can never be attributed to a natural cause. The four metal clamps under the top rectangle layer had been missing. Four grooves, with unknown usage, exist on the sides of the long rectangular stones projected out of the circular body at the second and third circular layers from the top. On the second circular layer from the top, there are three flat stones, less than a half as tall as their surrounding stones. The average height of the third circular layer from the top is only 23.5 cm, while the overall average of the entire 27 circular layers is 29.9cm. This research postulates that all these anomalies are due to prior destructions and improper restorations of the structure. The first destruction and restoration of Cheomsengdae was likely to have occurred before the mid 15th century. The damages might include a pavilion on the top of the structure and a stone with the name of the structure carved in. The Mongolian invasion in the 13th century was a most likely cause. After the restoration, the structure suffered at least another attack. The damages on the top layer and the missing iron clamps were due to the later attack. The grooves and flat stones were to house holding device that affixed certain objects to the outer surface of the circular body. The metal or stone objects might have faced upward at the four corners of Chemseongdae, bridging the gaps between the rectangle layers and circular layers. The current Chemseongdae lost at least the four affixed objects, four holding devices, and one flat stone.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.16 no.4
• /
• pp.335-341
• /
• 1991

We derive the radiation field equation at the naar field region to analyse EMI by the rectangular horn antenna. The EMI loadk current calculated from the load current induced on the transmission line being close to the rectangular horn antenna using the field theory and the transmission line theory. We find the conditions minimizing the EMI from the load current transfer function of distance, frequency and impedances at sending and receiving end. The smaller sending end impedance, the larger EMI load current and the larger sending impedance, the smaller EMI load current.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2021.11a
• /
• pp.251-254
• /
• 2021

국가 4차 산업혁명의 성장 동력으로 데이터 경제가 주목받고 있으며, 현(現)산업계는 초연결, 초지능, 초융합 사회로 진보하고 있다. 이와 같은 환경에서는 산업군 간의 경계가 사라지고 전방위적인 상호 유기적인 복합 생태계를 구성하게 된다. 따라서 사이버 보안사고 발생 시 단순 데이터 탈취 정도에 국한되지 않고 안보, 생명, 국가 경제 등에 돌이킬 수 없는 손실을 끼칠 것으로 예상된다. 그러나 현재 사이버 보안의 각종 제도 및 법령 등은 중복·혼재되어 있거나 특정 산업군에 적용하기에는 일부 미흡한 요소도 존재한다. 본 논문에서는 이와 같은 문제점을 개선하고 전방위적인 보안거버넌스를 달성하기 위한 통합 사이버 보안 프레임워크 구축 방안을 제언한다.

• Design Convergence Study
• /
• v.14 no.4
• /
• pp.193-208
• /
• 2015

This study is to search a meaning of treagedy to show by the 6th generation through charecter's tragedy in the 6'th Generation Chinese film. For this, it examined an inner characteristic behind of the tragedy's moment and externalized ending in directors' films of the 6'th Generation's representation. The 6'th Generation of Chinese film reorganized newly Chinese film's cultural topography in the 1990s. The 6'th Generation films, which rebelled against the primary melody and the 5'th Generation on the system, is expressed commonly a tragedy moment with the time and space by character's tragedy. Characters of the 6'th Generation in the tragedy moment attempts various efforts to escape from the tragedy moment. However, no one can overcome the wall of reality, and their concealed emotion as keeping it out of the public eye lead that play. The moment that the 6th generation film meets a tragedy, the main character's accumulated tragedy situations begin to unfold all together. A tragedy embodied through : a collapsed tragedy due to the past's wound, a tragedy due to loss of jobs, a tragedy due to a family's departure, a tragedy from a time of chaos, a tragedy of a woman who became a head of a household and other tragedies.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.16 no.4
• /
• pp.661-668
• /
• 2012

A coaxial-cable impedance transformer that can be used in high power and wideband frequency range is an arbitrary impedance transformation ratio by an additional coaxial cable. The coaxial-cable impedance transformer to be 50-${\Omega}$ to 25-${\Omega}$ impedance transformation ratio is easily operated an wideband power divider by connecting two 50-${\Omega}$ lines at 25-${\Omega}$ impedance point. This wideband power divider has a poor output matching characteristic and a poor isolation characteristic between two output ports. In this paper, it proposes a coaxial-cable power divider to be a good output matching and isolation characteristics as it uses the singly terminated filter design theory. The odd-mode operation characteristic of the suggested power divider to use singly terminated low pass filter coefficient due to matching order and ripple value is examined by ADS program. And, it fabricates and measures the operation characteristic of 2-way power divider with 2nd-order and 4th-order matching circuit.

• Journal of the Microelectronics and Packaging Society
• /
• v.25 no.4
• /
• pp.59-66
• /
• 2018

In this paper, we analyzed the usefulness of single-structured printed circuit board (PCB) modeling by using numerical analysis to model the PCB structure applied to a package for semiconductor purposes and applying modeling assuming a single structure. PCBs with circuit layer of 3rd and 4th were used for analysis. In addition, measurements were made on actual products to obtain material characteristics of a single structure PCB. The analysis results showed that if the PCB was modeled in a single structure compared to a multi-layered structure, the warpage analysis results resulting from modeling the PCB structure would increase and there would be a significant difference. In addition, as the circuit layer of the PCB increased, the mechanical properties of the PCB, the elastic coefficient and inertia moment of the PCB increased, decreasing the package's warpage.

• Nuclear Engineering and Technology
• /
• v.3 no.2
• /
• pp.77-97
• /
• 1971

The experimental fission cross-section data of U-238, Np-237 and Th-232, published up to the end of 1970, are reviewed and analyzed between their respective thresholds and 20.0 MeV. The results of a statistical analysis of the available data, performed with a weighted Least-squares Orthogonal Polynomial Pitting computer programme are presented in the form of point-wise cross-section values together with their uncertainties, and in the form of graphs of the fitted curves with an indication of a region of 95% statistical confidence level. An estimate of the fission spectrum weighted average cross-sections and their respective uncertainties is also given.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2022.04a
• /
• pp.37-38
• /
• 2022

This study is attempted to propose an appropriate number of measurements by checking and statistically analyzing the change in hardness according to the number of measurements. As a result, there was no significant difference between the 20th and 30th data, and in the 10th case, the effect on errors occurring during measurement was found to be dominant. Therefore, as the number of measurements, proposing 20 times in consideration of the convenience of use. In addition, in order to minimize the effect on the measurement error, it is proposed to remeasure the surface mane of the measurement surface and the test value in which the error occurs on the average of the test values.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.46 no.1
• /
• pp.92-97
• /
• 2009

Low power consumption is crucial for medical implantable devices. A low-power 4th-order band-pass Gm-C filter with distributed gain stage for the sensing stage of the implantable cardiac pacemaker is proposed. For the implementation of large-time constants, a floating-gate operational transconductance amplifier with current division is employed. Experimental results for the filter have shown a SFDR of 50 dB. The power consumption is below $1.8{\mu}W$, the power supply is 1.5 V, and the core area is $2.4\;mm{\times}1.3\;mm$. The filter was fabricated in a 1-poly 4-metal $0.35-{\mu}m$ CMOS process.

• Proceedings of the KIEE Conference
• /
• 2009.07a
• /
• pp.1336_1337
• /
• 2009

본 논문에서는 유기 박막 트랜지스터의 전극을 잉크젯 프린팅과 스크린 프린팅 방법을 이용하여 유기 박막 트랜지스터를 제작하였다. 전극으로 PEDOT:PSS와 Ag 잉크를 사용하였고, 게이트 절연막으로 polymethyl methacrylate (PMMA)와 poly(4-vinylphenol) (PVP)를 사용하였다. 유기물 활성층으로 pentacene을 진공 증착하였다. 잉크젯 프린팅 방법을 이용하여 제작한 유기 박막 트랜지스터는 전계이동도 (${\mu}_{FET}$) $0.068\;cm^2$/Vs, 문턱전압 ($V_{th}$) -15 V, 전류 점멸비 ($I_{on}/I_{off}$ current ratio) >$10^4$의 전기적 특성을 보였고, 스크린 인쇄 방법을 이용하여 제작한 유기 박막 트랜지스터는 전계이동도 (${\mu}_{FET}$) $0.016\;cm^2$/Vs, 문턱전압 ($V_{th}$) 6 V, 전류 점멸비 ($I_{on}/I_{off}$ current ratio) >$10^4$의 전기적 특성을 보였다. 이를 통하여 프린팅 방법을 이용한 유기 박막 트랜지스터 단일 소자 및 유기 전자 회로 제작의 가능성을 확인 하였다.