• Title/Summary/Keyword: Deep space communication

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Link Scenario Design and Performance Analysis for Korean Lunar Explorations (한국형 달 탐사를 위한 링크 시나리오 설계 및 성능분석)

  • Jeong, Jinwoo;Oh, Janghoon;Yoon, Dongweon;Kim, Sang Goo
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.39A no.4
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    • pp.212-214
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    • 2014
  • In this paper, we present the scenario designs of the possibility of space communications for Korean Lunar Explorer and the analysis of its performance, depending upon the explorer's position within the moon's orbit after being launched from earth. As per each scenario, we would like to propose the analysis of the possible communication times and total transmission throughput data per day in two cases: one for using DSN and another for using only Korean's ground station.

Study on Downlink Capacity based on the Visibility Analysis between KPLO and KDSA/DSN (시험용 달 궤도선과 KDSA 및 DSN 간 가시성 분석을 통한 다운링크 용량 연구)

  • Kim, Changkyoon;Jeon, Moon-Jin;Lee, Sang-Rok;Lim, Seong-Bin
    • Journal of Satellite, Information and Communications
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    • v.11 no.3
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    • pp.86-91
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    • 2016
  • KARI(Korea Aerospace Research Institute) has been developing the KPLO(Korea Pathfinder Lunar Orbiter) for Korean first lunar exploration, and analysing various subjects for the mission success. Especially the performance of the communication is one of important factors, because massive scientific and technical data acquired by multiple payloads might be transferred to ground stations on the Earth. In this paper, we explained the study on the 1-day average downlink capacity based on the visibility analysis between ground stations and KPLO, and described its results.

Development of Korean Preliminary Lunar Mission Design Software (한국형 달탐사 임무 예비 설계 소프트웨어의 개발)

  • Song, Young-Joo;Park, Sang-Young;Choi, Kyu-Hong;Shim, Eun-Seop
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.36 no.4
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    • pp.357-367
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    • 2008
  • Preparing for future Korean Lunar missions, preliminary Lunar mission design software is developed using a impulsive thrusting method. Developed software is capable of design and analysis every required mission phases to design Lunar mission, including the Earth departure, Lunar transfer, Lunar arrival and mission operation phases. Also, assuming that KSLV-II is selected as a launch vehicle, future Korean Lunar explorer's mass budget is estimated based on driven optimal trajectory characteristics. Tracking analysis is also performed using Deep Space Network including angle geometry analysis between Earth - Moon - Lunar explorer - Sun which are very important for communication, solar panel pointing strategy and eclipse analysis when Lunar missions are under designing phase.

DECODE: A Novel Method of DEep CNN-based Object DEtection using Chirps Emission and Echo Signals in Indoor Environment (실내 환경에서 Chirp Emission과 Echo Signal을 이용한 심층신경망 기반 객체 감지 기법)

  • Nam, Hyunsoo;Jeong, Jongpil
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.21 no.3
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    • pp.59-66
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    • 2021
  • Humans mainly recognize surrounding objects using visual and auditory information among the five senses (sight, hearing, smell, touch, taste). Major research related to the latest object recognition mainly focuses on analysis using image sensor information. In this paper, after emitting various chirp audio signals into the observation space, collecting echoes through a 2-channel receiving sensor, converting them into spectral images, an object recognition experiment in 3D space was conducted using an image learning algorithm based on deep learning. Through this experiment, the experiment was conducted in a situation where there is noise and echo generated in a general indoor environment, not in the ideal condition of an anechoic room, and the object recognition through echo was able to estimate the position of the object with 83% accuracy. In addition, it was possible to obtain visual information through sound through learning of 3D sound by mapping the inference result to the observation space and the 3D sound spatial signal and outputting it as sound. This means that the use of various echo information along with image information is required for object recognition research, and it is thought that this technology can be used for augmented reality through 3D sound.

Classification of Alzheimer's Disease with Stacked Convolutional Autoencoder

  • Baydargil, Husnu Baris;Park, Jang Sik;Kang, Do Young
    • Journal of Korea Multimedia Society
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    • v.23 no.2
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    • pp.216-226
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    • 2020
  • In this paper, a stacked convolutional autoencoder model is proposed in order to classify Alzheimer's disease with high accuracy in PET/CT images. The proposed model makes use of the latent space representation - which is also called the bottleneck, of the encoder-decoder architecture: The input image is sent through the pipeline and the encoder part, using stacked convolutional filters, extracts the most useful information. This information is in the bottleneck, which then uses Softmax classification operation to classify between Alzheimer's disease, Mild Cognitive Impairment, and Normal Control. Using the data from Dong-A University, the model performs classification in detecting Alzheimer's disease up to 98.54% accuracy.

Europe's Space Exploration and Korea's Space Exploration Strategy from the Perspective of Science and Technology Diplomacy (과학기술외교 관점에서 바라본 유럽의 우주탐사와 우리나라 우주탐사전략)

  • Nammi Choe
    • Journal of Space Technology and Applications
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    • v.2 no.3
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    • pp.195-205
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    • 2022
  • Space exploration is an area where international cooperation takes place more actively than any other space activities such as Earth observation, communication and navigation. This is because a country cannot afford a huge budget to have full infrastructure for deep space exploration, such as a heavy launch vehicle, communication and energy infrastructure, and human habitats, and has learned that it is not sustainable. Korea expressed its willingness to join humanity's epic exploration journey by signing the Artemis Accords in 2021 and launching Danuri lunar orbiter in 2022. The beginning of space exploration means that Korea's space activities have expanded beyond the stage of focusing only on technology development to set norms necessary to accompany other countries and cooperate diplomatically to solve exposed problems. This paper analyzed European space policy and space exploration, which are most actively participating in the Artemis Program and exerting diplomatic power in the space field, from the perspective of science and technology diplomacy. The suggestions for Korea's space exploration strategy from the perspective of science and technology diplomacy were drawn by examining the international cooperation strategies in Europe's space activities ranging from space policy, space strategy, and space exploration program to project units.

An Educational Service Platform using Collective Intelligence and Presence of Web 2.0

  • Kim, Chang-Suk;Son, Dong-Cheul;Cho, Chung-Ho
    • Journal of the Korean Institute of Intelligent Systems
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    • v.19 no.1
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    • pp.115-121
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    • 2009
  • Web 2.0 has become the face next generation Web among the business world and research community. Web 2.0 is instant superficial gratification of people. On the other hand, Semantic Web is deep, meaningful and lasting relationship with data. So, it is difficult to apply the Semantic Web to the real world. In this paper, a platform for educational services using the Semantic Web and Web 2.0 is proposed. The proposed platform is based mix of the Semantic Web and Web 2.0, so it is useful to apply in the real world applications. Two services are presented, one is a semantic email system and the other is a cyber study space. The cyber study space adjusted each student is presented. The study environment is called iStudySpace that has personal scheduler, study status plan table, personalized search engine and several gadgets. Finally characteristics and limitations of the Semantic Web and Web 2.0, the organization and components of the platform, evaluation of iStudySpace are shown.

A Study on Development of Technology System for Deep-Sea Unmanned Underwater Robot of S. Korea analysed by the Application of Scenario Planning (한국형 수중로봇시스템의 기술개발연구 - 시나리오플래닝 적용으로 -)

  • Lee, Sang-Yun;Yoon, Hong-Joo
    • The Journal of the Korea institute of electronic communication sciences
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    • v.8 no.1
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    • pp.27-40
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    • 2013
  • This study is about development of technology system for an advanced deep-sea unmanned underwater robot of S. Korea analysed by the application of scenario planning. It was developed a 6000m class next-generation deep-sea unmanned underwater vehicle(or robot, UUV) system, soonly ROV 'Hemire' and Depressor 'Henuvy' in 2006 at S. Korea and motion control, adaptive control algolithm, a work-space manipulator control algolithm, especially the underwater inertial-acoustic navigation system robust to initial errors and sensor failures. But there are remained matters on position tracking of the USBL, inertial-acoustic navigation system, attitude sensor, designed sonar sensors. So this study suggest the new idea for settle the matters and then this idea help the development of the underwater inertial-acoustic navigation system robust to initial errors and sensor failures, such as acoustic signal drop-out, by modifying the error covariance of the failed sonar signal when drop-out occurs. As a result, the future policy for deep-sea unmanned underwater robot of S. Korea is to further spur the development of new technology and more improvement of the technology level for deep-sea unmanned underwater robot system with indicator and imaginary wall as external device.

A Study on the Characteristics in Image Expression of Interior Space (실내공간의 이미지 표현 특성에 관한 연구 -상업공간의 디자인을 중심으로-)

  • 홍승대
    • Archives of design research
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    • v.12 no.4
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    • pp.243-250
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    • 1999
  • Interior design is depend on combination way of between invisible meaning and visible form, then it has a several meaning by that. The meaning of interior space is a invisible concept which is shown by a form and it is mainly recognized by a image. The purpose of this study is to explore that characters of image in communication process, typical aspect and structural aspect have been shown in interior design. On this study, I try to study space analysis about commercial space to explore character of spatial image through theoretical approach. In a result, the image of interior space is made by deep representation as a designer's basic concept and is delivered by conversion of various codes. Therefore, the image of interior space is not a additional concept which is made by natural factor of space, it is a design concept which must be dealt with space planning.

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Cyclic loading behavior of high-strength steel framed-tube structures with replaceable shear links constructed using Q355 structural steel

  • Guo, Yan;Lian, Ming;Zhang, Hao;Cheng, Qianqian
    • Steel and Composite Structures
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    • v.42 no.6
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    • pp.827-841
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    • 2022
  • The rotation capacities of the plastic hinges located at beam-ends are significantly reduced in traditional steel framed-tube structures (SFTSs) because of the small span-to-depth ratios of the deep beams, leading to the low ductility and energy dissipation capacities of the SFTSs. High-strength steel framed-tube structures with replaceable shear links (HSSFTS-RSLs) are proposed to address this issue. A replaceable shear link is located at the mid-span of a deep spandrel beam to act as a ductile fuse to dissipate the seismic energy in HSSFTS-RSLs. A 2/3-scaled HSSFTS-RSL specimen with a shear link fabricated of high-strength low-alloy Q355 structural steel was created, and a cyclic loading test was performed to study the hysteresis behaviors of this specimen. The test results were compared to the specimens with soft steel shear links in previous studies to investigate the feasibility of using high-strength low-alloy steel for shear links in HSSFTS-RSLs. The effects of link web stiffener spaces on the cyclic performance of the HSSFTS-RSLs with Q355 steel shear links were investigated based on the nonlinear numerical analysis. The test results indicate that the specimen with a Q355 steel shear link exhibited a reliable and stable seismic performance. If the maximum interstory drift of HSSFTS-RSL is designed lower than 2% under earthquakes, the HSSFTS-RSLs with Q355 steel shear links can have similar seismic performance to the structures with soft steel shear links, even though these shear links have similar shear and flexural strength. For the Q355 steel shear links with web height-to-thickness ratios higher than 30.7 in HSSFTS-RSLs, it is suggested that the maximum intermediate web stiffener space is decreased by 15% from the allowable space for the shear link in AISC341-16 due to the analytical results.