• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.24 no.9
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• pp.908-914
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• 2013

A shaped Cassegrain antenna is designed from the condition of the same path length at the equi-phase surface by using the conservation of energy and Snell's law. In order to improve the phase error efficiency of aperture surface, the surface profile of the main and sub-reflectors is found to satisfy the power distribution and the equi-phase condition at the aperture surface. The sidelobe levels of 36.4 dB and 33.9 dB are achieved at the AZ and EL planes, respectively from numerical calculation by physical optics method at Ku band and the directivity of designed antenna is 10 percent greater than that of conventional antenna.

• Earthquakes and Structures
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• v.8 no.3
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• pp.779-799
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• 2015

The slosh height and the possibility of water spill from rectangular Spent Fuel Storage Bays (SFSB) and Tray Loading Bays (TLB) of Nuclear power plant (NPP) are studied during 0.2 g, Safe Shutdown Earthquake (SSE) level of earthquake. The slosh height obtained through Computational Fluid dynamics (CFD) is compared the values given by TID-7024 (Housner 1963) and American concrete institute (ACI) seismic codes. An equivalent amplitude method is used to compute the slosh height through CFD. Numerically computed slosh height for first mode of vibration is found to be in agreement the codal values. The combined effect in longitudinal and lateral directions are studied separately, and found that the slosh height is increased by 24.3% and 38.9% along length and width directions respectively. There is no liquid spillage under SSE level of earthquake data in SFSB and TLB at convective level and at free surface acceleration data. Since seismic design codes do not have guidelines for combined excitations and effect of higher modes for irregular geometries, this CFD procedure can be opted for any geometries to study effect of higher modes and combined three directional excitations.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.22 no.3
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• pp.327-335
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• 2011

A study on the RCS of a self-manufactured active transponder, which has a manually adjustable RCS, for SAR(Synthetic Aperture Radar) external calibration and image analysis at X-band is presented in this paper. The RCS of the active transponder was comparably analyzed using the lab-test and the COSMO-SkyMed SAR system, and also precisely analyzed the difference between the adjusted and estimated RCSs. A maximum RCS of the designed and manufactured active transponder is 60 dBsm. The active transponders with 60 dBsm and the adjusted RCS of 40 dBsm were measured using the single target calibration technique(STCT) and 2D target scanning technique(2DTST). And the extracted RCS using power-spill integration technique in a SAR image was compared with the measured RCS of active transponder. The comparison results show that the measured and extracted RCSs are 59.7 dBsm, 40.2 dBsm and 57.3 dBsm, 39.2 dBsm, respectively.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.05a
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• pp.442-447
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• 2007

A very abnormal vibration was occurred at the LP(low pressure) turbine continuously during the pre-operation for a 550MW class USC(ultra super critical) steam turbine. This vibration was initiated at the rotating speed of about 3,450rpm and then the vibration amplitude was highly increased the number by $2{\sim}3$ times with the increase of the rotating speed to the rated speed(3,600rpm). In this paper, this abnormal vibration named spike vibration. This spike vibration was caused by the rubbing between the rotating bucket tip seal and the Lower Half of spill strip. Also, this paper presents the mechanism of the spike vibration and the proper method to eliminate this abnormal vibration problem. This result would be good practice to find the solution of similar high vibration in the USC steam turbines for power plant as well as industrial rotating machineries.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.17 no.12
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• pp.1238-1245
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• 2007

A very abnormal vibration was occurred at the LP(low pressure) turbine continuously during the pre-operation for a 550MW class USC(ultra super critical) steam turbine. This vibration was initiated at the rotating speed of about 3,450 rpm and then the vibration amplitude was highly increased the number by $2{\sim}3$ times with the increase of the rotating speed to the rated speed (3,600 rpm). In this paper, this abnormal vibration named spike vibration. This spike vibration was caused by the rubbing between the rotating bucket tip seal and the lower half of spill strip. Also, this paper presents the mechanism of the spike vibration and the proper method to eliminate this abnormal vibration problem. This result would be good practice to find the solution of similar high vibration in the USC steam turbines for power plant as well as industrial rotating machineries.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.05a
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• pp.301-304
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• 2016

Cyber world constitute the infrastructure of the country and its people and control. Cyber attacks and leakage of personal information are being threatened damage to the national economy and national security. December 2014 had been cyber hacking attacks on Korea Hydro & Nuclear Power Nuclear cooling system design drawings of a spill, and Cheong Wa Dae website hacked, KBS stations occurred in cyber hacking accidents. As a result, ICT-based Protection Act, Promotion of Information and Communications Network Utilization and Information Act on Protection, etc., privacy laws are being enforced, personal information in the form of requirements from leading high-tech eoryeowoona is to prevent the attacks of armed hackers Internet information society It proposes positive measures to keep your personal information officer and laws.

• Proceedings of the KSRS Conference
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• 2009.03a
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• pp.155-158
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• 2009

본 논문에서는 DLR(German Aerospace Center)에서 운영하는 TerraSAR-X를 이용하여 2009년 1월 19일 18:28 (Local time) 에 서해 대부도/제부도 및 대부도 남쪽 해안을 촬영한 stripmap mode (Dual-Pol: HH, VV) 화상을 취득하여 향후 고해상도 X-밴드 화상의 활용 방안 및 효용성에 대해 검토해 보았다. 함께 취득된 현장자료와의 비교를 통하여 2010 년에 발사될 예정인 아리랑 5 호의 활용방안을 찾고자 한다. 여기서는, 연안에 설치된 양식시설, 소형 선박 그리고 코너리플렉터에 대해서 해석을 수행하였다. 김 양식시설의 경우, 구조와 설치 각도에 따라 다른 후방산란특성을 보였으며, 같은 시설에 대해서도 HH 편파의 후방산란계수가 VV 보다 2.6 dB 높게 나타났다. 그 이유는 김 양식시설이 TeraSAR-X의 전파전파 방향과 수직하게 되어 후방 산란이 많이 일어나는 반면에, B 지역에 설치된 김 양식시설은 TeraSAR-X의 전파전파방향과 약 45 도 비스듬하게 설치되어 있어, 상대적으로 낮은 후방산란계수를 나타내기 때문이다. 또한 한 변의 길이가 각각 1 m, 0.6 m 인 사각면 삼각 수동 전파반사기 두 개를 제부도 북쪽의 갯벌에 설치하여 TerraSAR-X 의 화상에 나타난 후방산란특성을 분석하였다. TerraSAR-X 의 화상이 X-밴드를 사용하고, 높은 해상도로 인해 power spill이 넓게 분포하는 것을 볼 수 있다.

• Journal of Korean Port Research
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• v.11 no.2
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• pp.241-255
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• 1997

Three dimensional numerical model is used to simulate the circulation patterns in the Gamcheon Bay located in Pusan, Korea and compared with the observed data. The model is forced by winds, tidal elevation at open boundaries, and warm water discharged from the outfall of power plant, Turbulence mixing coefficients are calculated according to a ${\kippa}-{\varepsilon}$ turbulence closure submodel. Temperature, salinty and current are measuted extensively and these measuted data are compared with the simulation results. Eddy-like features exist both in observed data dna simulation results. These eddies are the results of interaction with the weak tidal current, wind driven current and warm water discharges. Compensational deeects are also found to exit such that while surface current is strong, bottom current tends to weaken and vice versa.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.2
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• pp.472-477
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• 2017

Oil spills cause a lot of damage to the environment. Oil destroys the water environment and ecosystem in a very short period of time once they are contaminated by it, it takes a lot of time to recover from the contamination and the cleaning process is very difficult. Therefore, oil detectors are greatly needed as they can monitor any oil spills over the sea, rivers, and lakes. There are two kinds of technology available for detecting oil, viz. the contact and non-contact types. The former is based on the use of the conductivity, capacitance and microwaves, while the latter employs infrared, UV, laser, optic and radar technologies. As there are also various hurdles in the measuring of oil on water, such as the presence of waves, refraction of light, temperature and saltiness, it is imperative to select the right oil detector which is appropriate for the specific environment. In this study, a contact type oil detector is developed, which can be used in oil related industries, such as refineries, petrochemical companies, and power generation stations. The detector is made up of the sensor module, which floats on the water, and the controller which processes the signal coming from the sensor module and displays it. It is designed in such a way that the existence of oil is detected through the sensor and the change in the permittivity is observed to determine the volume and type of spilled oil.

• The Journal of the Korea Contents Association
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• v.21 no.7
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• pp.363-373
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• 2021

The purpose of this research is to analyze the Spill-over economic effect of the cultural and creative industries(CCI) in Henan Province, China. The research object is the CCI of Henan Province, which is mainly based on five sectors out of 42 industries in the industrial association table of the Statistical Bureau of Henan Province, China in 2017 (culture, sports; recreation and research sector; experimental development and integrated technical services sector; information transmission, computer services and software sector; education sector, etc), and is analyzed through secondary integration and redefinition of the CCI of Henan Province. Through the analysis of Henan Province Industry Association Table, this paper provides some enlightenment to the future direction of the cultural and creative industries. The main analysis results are as follows. The total production inducement of the CCI in Henan province is 48,848 billion yuan, and in particular, the production inducement coefficient of the industry in Henan province is 2.72809, 2.23909 (total of columns and rows), Index of the power of dispersion is 0.26325, and the index of the sensitivity of dispersion is 0.87535. Income induction coefficient is 0.55211, production tax induction coefficient is 0.09291. Because CCI of Henan Province has full development potential, the government needs to provide active support and policy support, in addition to the need for legal provisions and supervision of market management. In order to improve the innovative development of the CCI, it is necessary to develop a new model of "CCI+X".