• Korean journal of communication and information
• /
• v.71
• /
• pp.9-32
• /
• 2015

The media, traditionally, serves to reinforce one's limited memory and transform those personal memories of society's members into collective memories. Notably, the mass media collects countless pieces of personalized memories for the creation of collective memories. Through the process of recollecting as well as recreating the past in the present, mass media exerts influence on the means the public appreciates and understands the history. Although numerous new medias like Internet overflows in today's society, television continues to stand firm as the salient means to construct the memories in daily lives. In this context, the research aims to analyze the televised news as the principal agent of memory producer to determine through which memories it recreates the $5{\cdot}18$ in today's media. The analysis of news values clarifies that every government placed distinctive news values on $5{\cdot}18$ within its historical context. Even so, such values were often fixed based on its relations to the existing political issues. Furthermore, through the discourse analysis, this research concludes that today's coverage of $5{\cdot}18$ is softening and becoming conventional.

• The Bulletin of The Korean Astronomical Society
• /
• v.37 no.1
• /
• pp.94.1-94.1
• /
• 2012

천리안위성은 우리나라 최초의 정지궤도복합위성(COMS: Communication, Ocean, and Meteorological Satellite)으로 2010년 6월 27일, 남미 기아나 쿠루기지에서 아리안-5 로켓에 의해 발사된 후 동경 128.2도, 적도 상공 약 35,800 km 고도의 정지궤도에 안착되었다. 이 후 궤도상시험 기간과 안정화 기간을 거쳐 2011년 4월 1일, 기상청은 위성자료 서비스를 시작하였다. 천리안위성의 기상영상기는 한반도 주변의 기상변화와 전 지구적 기후 변화 및 대기 운동을 감시하기 위해 실시간 관측 및 전송 시스템을 갖춘 탑재체이다. 이 기상영상기는 하루 8번의 지구 반면 영역과 각각 80번 내외의 북반구 및 한반도 영역을 관측하며, 이 자료는 지상에서 복사보정과 기하보정을 거친 후 위성을 통해 다시 사용자에게 배포된다. 천리안위성 기상영상기는 쉼 없이 관측하고, 일정 시간 이내에 그 자료를 배포해야 한다. 이러한 자료서비스는 운영시스템의 장애나 자연현상에 의한 자료 미수신 혹은 미처리가 발생할 경우 운영 결과 및 성과에 영향을 미친다. 이와 같은 장애에 대비해 국가기상위성센터는 이중화된 시스템을 구축했으며, 자료 백업 부기관으로서 한국항공우주연구원과의 사이트 이중화도 시행하고 있다. 그러나 정지궤도에 있는 위성과 태양 및 지구의 역학적인 관계에 따라 태양 전파 잡음의 영향인 태양간섭과, 위성 태양전지판 충전 장애를 일으킬 수 있는 위성식, 그리고 위성 자정 주변에 발생할 수 있는 태양광 침입 및 산란광 영향 등은 미리 예측되어야 하며, 이 시기 운영 방안 마련과 사용자 공지 등의 조치가 수반되어야 한다. 국가기상위성센터는 춘 추분 시기에 발생하는 이러한 태양 영향을 예측하고 검증했으며, 이 시기 위성 및 지상국의 효율적인 운영방안을 마련하였다.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.35 no.12
• /
• pp.1599-1606
• /
• 2011

It is possible to study the load characteristics of full-scale hingeless rotor with the changing of physical smallscaled configurations such as rectangular and paddle blades, and metal and composite hubs. In this study, a static test, and a ground and wind-tunnel test were carried out using small-scale rotor models. The static test was carried out to confirm structural stiffness, characteristics of inertia, natural frequency, and damping ratio of rotors, and the ground and wind-tunnel test was carried out to confirm the stability and aerodynamic characteristics under hovering and forward flight conditions. According to the test results, the vertical load in the case of a combination of a small composite hub with paddle blades was higher than that in the case of a metal hub with paddle blades at same condition. Further, it was confirmed that the restraint of the combination of composite hub can be more flexible than the metal hub for the motion of paddle blades.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.31 no.10
• /
• pp.79-88
• /
• 2003

The paper presented here covers the work associated with the flight control law design, ground based and in flight simulation and handling qualities assessment of the Fly-by-Wire type Aircraft (FBWA). The FBWA configurations are of the same generic form of the Korean advanced trainer. The normal acceleration (Nz) and pitch rate (q) feedback control system is employed for longitudinal axis and roll rate (p) and lateral acceleration (Ny) feedback flight control law is developed in lateral/ directional axis. The flight tests for the FBW A dynamics evaluation were executed for the target aircraft (FBWA) on the IFS (In-Flight-Simulator) aircraft . The test results showed that Level 1 handling qualities for the most unstable flight regime and Level 1/2 for the landing approach flight regime were achieved. And the designed FBWA flight control law has revealed acceptable CHR (Cooper-Harper handling qualities Ratings).

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.43 no.2
• /
• pp.156-165
• /
• 2015

A survivability-analysis program has been developed to analyze the ground collision risk of atmospheric reentry objects, such the upper stages of a launch vehicle or satellites, which move at or near the orbital velocity. The aero-thermodynamic load during the free fall, the temperature variation due to thermal load, and the phase shift after reaching the melting point are integrated into the 3 degree-of-freedom trajectory simulation of the reentry objects to analyze the size and weight of its debris impacting the ground. The analysis results of the present method for simple-shaped objects are compared with the data predicted by similar codes developed by NASA and ESA. Also, the analysis for actual reentry orbital objects has been performed, of which results are compared with the measurement data.

• The Bulletin of The Korean Astronomical Society
• /
• v.37 no.2
• /
• pp.211.2-211.2
• /
• 2012

천리안위성은 통신, 해양, 기상 임무를 띤 우리나라 최초의 정지궤도복합위성으로 지난 2010년 6월 27일 성공적으로 발사된 후 동경 128.2도, 적도 상공 약 35,800 km 고도의 정지궤도에 안착되었다. 이 후 약 6개월 여의 궤도상시험 기간과 2개월의 안정화 기간을 거쳐 2011년 4월 1일, 기상청은 위성자료 서비스를 위한 정규운영을 시작하였다. 천리안위성의 기상탑재체인 기상영상기는 다중채널 복사계로 한반도 주변뿐만 아니라 전 지구적 기후 변화 및 대기 운동 그리고 급변하는 기상상황을 감시하기 위해 실시간 관측과 전송 시스템을 갖추고 있다. 이 기상영상기를 운용하는 기상청 국가기상위성센터 지상국에서는 자료수신 및 영상전처리시스템을 갖추고 수신된 위성신호로부터 영상 분리 후 복사보정 및 기하보정을 수행하며, 위성자료배포시스템을 통해 일정 시간 간격 내에 사용자들에게 처리 자료를 배포하고 있다. 영상 복사보정은 기상영상기 내의 각 채널별 디텍터가 감지한 지구복사휘도의 전기적 신호를 지상에서 복사휘도와 휘도온도 값으로 변환하는 작업이다. 절대검정체로서 흑체와 우주보기 값을 이용하는 적외채널과 달리, 가시채널 디텍터는 절대검정체가 탑재되어있지 않기 때문에 우주보기 값 외에 대리검정 방법을 이용한다. 이러한 가시채널 노화도 분석에 달 관측을 통한 비교 분석이 한 방법으로 제시되고 있다. 천리안위성 기상영상기의 정규운영 1년간의 가시채널 디텍터의 노화도는 6 % 이내로 측정되었고, 이는 일반적인 정지궤도위성 센서의 노화도인 6 % 내외 값 변화량에 견주어 잘 운용되고 있음을 시사한다. 본 논문에는 천리안위성 기상영상자료의 품질 및 매개변수의 변화 경향도 함께 제시하였으며, 달을 이용한 기상영상기 노화 분석과 보정에 관한 내용을 싣고 있다.

• Journal of the Korean Society of Earth Science Education
• /
• v.15 no.2
• /
• pp.158-170
• /
• 2022

The purpose of this study is to understand the characteristics of Aristotle's view of nature that is, the static view of the universe, and find implications for education. Plato sought to interpret the natural world using a rational approach rather than an incomplete observation, in terms of from the perspective of geometry and mathematical regularity, as the best way to understand the world. On the other hand, Aristotle believed that we could understand the world by observing what we see. This world is a static worldview full of the purpose of the individual with a sense of purposive legitimacy. In addition, the natural motion of earthly objects and celestial bodies, which are natural movements towards the world of order, are the original actions. Aristotle thought that, given the opportunity, all natural things would carry out some movement, that is, their natural movement. Above all, the world that Plato and Aristotle built is a static universe. It is possible to fully grasp the world by approaching the objective nature that exists independently of human being with human reason and observation. After all, for Aristotle, like Plato, their belief that the natural world was subject to regular and orderly laws of nature, despite the complexity of what seemed to be an embarrassingly continual change, became the basis of Western thought. Since the universe, the metaphysical perspective of ancient Greece and modern philosophy, relies on the development of a dichotomy of understanding (cutting branches) into what has already been completed or planned, ideal and inevitable, so it is the basis of traditional teaching-learning that does not value learner's opinions.

• Journal of Korean Physical Therapy Science
• /
• v.8 no.1
• /
• pp.885-892
• /
• 2001

The purpose at this study was comparied at effect the pulmonary function to breathing exercise(BE) in water with on land. The result was as follow: FVC(Forced Vital Capacity) was decreased 1.5% in control group, increased 1.5% in BE on land group and increased 6.5% in water group after BE, but no significant difference in water group. FEV1(forced expiratory volume at one second) was increased 0.2% in the control group, decreased 0.7% in BE on land group and increased 5.7% in BE in water group after BE, but no significant difference in water group. MVV(maximal voluntary ventilation) was significant difference in BE in water group who was increased 12.2% after BE. It was decreased 1.0% in the control group and increased 0.2% in BE on land group. VC(vital capacity) was decreased 1.5% in the control group, increased 6.2% in BE on land group and increased in BE in water group after BE, but no significant difference in water group. IC(Inspiratory Capacity) was decreased 0.5% in the control group, increased 7.5% in BE on land group and decreased 2.0% in BE in water group after BE, but no significant difference on land group. ERV(Expiratory Reserve Volume) was decreased 0.5% in the control group, increased 3.0% in BE on land group and increased 8.5% in BE in water group after BE, but no significant difference in water group.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.39 no.5
• /
• pp.442-450
• /
• 2011

A measurement system using stereo pattern recognition (SPR) method was configured to measure the rotor blade deformations and motions. An SPR-based measurement system was prepared using six stereo cameras. Through a series of experiments to evaluate the system measurement uncertainty, it was verified that the SPR system had less than 0.2mm standard uncertainty. The combined standard uncertainties for the lead-lag, flapping, and pitching motions were estimated as 0.296mm, 0.209mm, and $0.238^{\circ}$, respectively. The SPR system was installed at a general small-scaled rotor test system at Korea Aerospace Research Institute. The blade motions and elastic deformation were successfully measured under the conditions with rotating speeds of 360rpm or 589rpm, and collective pitch angles of $0^{\circ}$, $4^{\circ}$, or $6^{\circ}$. The advantages of the SPR system was analyzed in comparison with the measurement system used in Higher Harmonic Control Aeroacoustic Rotor Test -II.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.45 no.9
• /
• pp.784-793
• /
• 2017

A two-axis gimbal-type X-band antenna mounted on an observation satellite can efficiently transmit high-capacity image data to a ground station regardless of both the satellite position and the orbital motion. However, this X-band antenna induces unnecessary micro-jitter which can degrade the image quality of the high-resolution observation satellite. Therefore, to achieve the high-resolution image quality from the observation satellite, micro-jitters have been required to be isolated. In this study, to resolve aforementioned drawback, we proposed blade gear using a shape memory alloy (SMA) applied to azimuth stage of X-band antenna. To investigate the rotational basic characteristics of the proposed SMA blade gear, we performed rotational static loading test. Futhermore, to evaluate the cycle to failure of the gear, accelerated life test was conducted. The temperature test was conducted to confirm rotational basic characteristics at various temperature conditions. To verify the isolation performance for micro-jitter, we performed micro-jitter measurement test.