• Title/Summary/Keyword: Design Exploration

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Design Optimization of Single-Stage Launch Vehicle Using Hybrid Rocket Engine

  • Kanazaki, Masahiro;Ariyairt, Atthaphon;Yoda, Hideyuki;Ito, Kazuma;Chiba, Kazuhisa;Kitagawa, Koki;Shimada, Toru
    • International Journal of Aerospace System Engineering
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    • v.2 no.2
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    • pp.29-33
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    • 2015
  • The multidisciplinary design optimization (MDO) of a launch vehicle (LV) with a hybrid rocket engine (HRE) was carried out to investigate the ability of an HRE for a single-stage LV. The non-dominated sorting genetic algorithm-II (NSGA-II) was employed to solve two design problems. The design problems were formulated as two-objective cases involving maximization of the downrange distance over the target flight altitude and minimization of the gross weight, for two target altitudes: 50.0 km and 100.0 km. Each objective function was empirically estimated. Several non-dominated solutions were obtained using the NSGA-II for each design problem, and in each case, a trade-off was observed between the two objective functions. The results for the two design problem indicate that economical performance of the LV is limited with the HRE in terms of the maximum downrange distances achievable. The LV geometries determined from the non-dominated solutions were examined.

Development and Application of a Nutrition Education Game for Preschoolers

  • Oh, Yu-Jin;Kim, Dong-Sik
    • Journal of Community Nutrition
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    • v.8 no.4
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    • pp.165-170
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    • 2006
  • This study was conducted to develop and apply a computer-based multimedia nutrition education program for preschoolers based on the Dick and Carey model of instructional design. The Dick and Carey model included 4 phases: analysis, design, development, and evaluation. The program's instructional goals, objectives, assessment instruments, content, examples, and practice questions with feedback were written in the design phase. To be familiar with the 5 food groups, 'Nutrition exploration' were programmed using Hyperstudio. 'Nutrition exploration' was designed as a five-session, interactive multimedia game, with each session taking about 5 minutes to complete. Nineteen preschoolers, aged 6, volunteered to participate formative evaluation. The effectiveness of the program was examined using a pre-post test design. Participants were recruited by personal contact at the individual preschool education center. The application was carried out during 4 weeks. The results showed that intervention participants significantly increased knowledge between pre-test and post-test. The results support using IMM (interactive multimedia) to disseminate nutrition education to the target population. This research provides the basis for continuing development of computer-based nutrition education materials.

Space Planet Exploration Rover Climbing Test Site Design (우주 행성 탐사 로버 등판 시험장 설계)

  • Byung-Hyun Ryu
    • Journal of the Korean Geosynthetics Society
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    • v.22 no.4
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    • pp.1-8
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    • 2023
  • Space exploration is at the forefront of human scientific endeavors, and planetary exploration rovers play a critical role in studying planetary surfaces. Rover performance is especially vital for safely navigating steep terrain and delicate landscapes found on planets like Mars and the Moon. This paper offers a comprehensive overview of a landing testbed designed to simulate challenging extraterrestrial terrain and loose regolith. The paper briefly outlines lunar crater region topographical features and highlights the importance of these simulations in rover testing. It then explores previous landing testbed developments and describes the design process for a landing testbed to be installed in the dirty thermal vacuum chamber at the Korea Institute of Civil Engineering and Building Technology. Once realized, this proposed landing testbed will enable precise evaluations of rover mobility and exploration capabilities under lunar-like conditions, including high vacuum and extreme temperatures.

Remote sensing and GIS technologies for route selection of 'West-East Nature Gas pipeline'

  • Zhu Xiaoge;Zhang Yaoyan;Zhang Yiming;Van Hu;Shihong Wang
    • Proceedings of the KSRS Conference
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    • 2004.10a
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    • pp.28-30
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    • 2004
  • The West-East Nature Gas Pipeline is a great project in China. Advanced remote sensing technology combined with GIS and GPS is used to select the favorable plan from various possible routes through interpreting the information of topographic landform, regional geology, disaster geology, traffic conditions and nature environment from remote sensing images. There are a lot of changes in geographical and environmental factors along such pipelines due to the rapid development in China. Image maps produced from new satellite data can identify these changes and be used successfully not only on route-selection studies but also on in situ investigation, together with GPS. Results from detail analysis provide necessary information and parameters for plan, design and construction of the pipeline and they are also the basic data for the pipeline database. The set of techniques has been applied on planning and designing several pipelines successfully.

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The Effects of Career Education on Career Development for Nursing Students (진로교육이 간호 대학생의 진로발달에 미치는 효과)

  • Park, Soon-Joo
    • The Journal of Korean Academic Society of Nursing Education
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    • v.18 no.2
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    • pp.259-267
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    • 2012
  • Purpose: The purposes of this study were to build the career education course for nursing students' career development and to identify the effects of the education. Method: The study used a one-group pre- and post-test design and the surveys were carried out from April to June, 2011. The participants were 71 undergraduate seniors of department of nursing in E university. The data were obtained via questionnaires survey before and after taking the course. The collected data were analyzed by paired t-test using SPSS 19. Results: 88.7% of the subjects responded being satisfied with their major. The scores of career search efficacy (t=-2.57, p=.012), career exploration (t=-4.62, p<.001), and career adaptability (t=-3.51, p=.001) showed statistically significant improvement after the education. Networking (t=-2.66, p=.010) and personal exploration efficacy (t=-2.89, p=.005) showed statistically significant difference between pre- and post-test. Between two subgroup of career exploration, only the environment exploration (t=-5.92, p<.001) significantly improved. However, there was no significant difference in career identity. Conclusion: From this study, career education showed significant effects on the career search efficacy, career exploration, and career adaptability of nursing students. These findings suggest that career education as a subject would be an efficient way for career development of nursing students.

Design of Systems Architecture for Personalized TV Program and Advertisement Recommendation Services with Multilingualism (다중 언어를 지원하는 개인화된 TV 프로그램 및 광고 추천 서비스를 위한 시스템 구조 설계)

  • Choi, Eunjeong;Kim, Hyo-Min;Park, Seong-Soo;Ahn, Se Yeol;Koo, Myung-Wan
    • Annual Conference on Human and Language Technology
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    • 2009.10a
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    • pp.116-120
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    • 2009
  • 최근 IPTV 상용화와 디지털 방송 본격화는 사용자에게 다양한 방송 프로그램을 제공한다는 장점도 있지만, 동시에 수많은 프로그램을 탐색하여 선별해야 하는 부담을 주고 있다. 이러한 불편함을 해소하고자 최근에는 사용자 선호도와 방송 프로그램 정보를 이용하여 사용자 취향에 맞는 프로그램을 자동으로 추천하는 서비스의 요구가 증대되고 있다. 또한 궁극적으로 방송 서비스가 '개인화'와 '개방화'의 형태로 진행되고 있다는 점을 감안하면, 추천 서비스는 TV 프로그램 뿐만 아니라 광고도 포함해야 하며, 다중 언어를 지원하는 형태로 발전되어야 한다. 본 논문에서는 다중 언어를 지원하는 개인화된 TV 프로그램 및 광고 추천 서비스를 위한 하나의 시스템을 제안한다. 우리는 먼저 사용자 시나리오를 작성하고, 기능 요구사항들을 분석하여 시스템 구조를 설계한다. 그리고 다중 언어를 지원하는 시스템에서의 한글 처리 방법도 간단히 설명한다. 본 연구는 현재 유럽 공동기술 개발 사업 과제의 일환으로 진행되고 있어, 여기에서는 현 시점의 결과물인 시나리오, 시스템 구조 설계, 한글 처리까지 소개하고 있다.

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Experimental investigation of interlaminar mechanical properties on carbon fiber stitched CFRP laminates

  • Iwahori, Yutaka;Ishikawa, Takashi;Watanabe, Naoyuki;Ito, Akira;Hayashi, Yoichi;Sugimoto, Sunao
    • Advanced Composite Materials
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    • v.16 no.2
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    • pp.95-113
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    • 2007
  • Experimental investigations of interlaminar mechanical properties for carbon fiber reinforced plastic (CFRP) laminates were carried out using aramid fiber ($Kevlar^{(R)}$-29 1000d) and carbon fiber (TR40-1K 612d, Mitsubishi Rayon) stitching. Various carbon fiber (CF) stitch densities were used to prepare a number of CF stitched CFRP laminates for double cantilever beam (DCB) tests. An insert tongue-type loading fixture, developed by the Japan Aerospace Exploration Agency (formerly the National Aerospace Laboratory of Japan), was also employed in the DCB test. Interlaminar tension tests were carried out under an out-of-plane directional loading using a single CF stitch thread in the CFRP laminates. The DCB test results clarified that the relationship between the volume fractions of the CF stitch thread ($V_{ft}$) and mode I critical energy release rate ($G_{Ic}$) showed a mostly linear function with a higher gradient than that of the $Kevlar^{(R)}$ stitched CFRP laminates. The CF stitched CFRP tension test results indicated that the consumption energy per unit area ($E_i$) was larger than that of $Kevlar^{(R)}$ stitched CFRP laminates.

Architecture Exploration Using SystemC and Performance Improvement of Network SoC (SystemC를 이용한 아키텍처 탐색과 네트워크 SoC 성능향상에 관한 연구)

  • Lee, Kook-Pyo;Yoon, Yun-Sup
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.45 no.4
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    • pp.78-85
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    • 2008
  • This paper presents a high-level design methodology applied on an SoC using SystemC. The topic will emphasize on high-level design approach for intensive architecture exploration and verifying cycle accurate SystemC models comparative to real Verilog RTL models. Unlike many high-level designs, we started the poject with working Verilog RTL models in hands, which we later compared our SystemC models to real Verilog RTL models. Moreover, we were able to use the on-chip test board performance simulation data to verify our SystemC-based platform. This paper illustrates that in high-level design, we could have the same accuracy as RTL models but achieve over one hundred times faster simulation speed than that of RTL's. The main topic of the paper will be on architecture exploration in search of performance degradation in source.

Experimental Study of the Multi-Row Disk Inlet

  • Maru, Yusuke;Kobayashi, Hiroaki;Kojima, Takoyuki;Sato, Tetsuya;Tanatsugu, Nobuhiro
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2004.03a
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    • pp.634-643
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    • 2004
  • In this paper are presented a concept of a new supersonic air inlet, which is designated a Multi-Row Disk (MRD) inlet, aiming at performance improvement under off-design conditions, and results of wind tunnel tests examined performance characteristics of the MRD inlet. The MRD inlet is frequently called ‘a skeleton inlet’ because of its appearance. The performance of a conventional axisymmetric inlet with a solid center body (spike) deteriorates under off-design Mach number conditions. It is due to the fact that total pressure recovery (TPR) governed by the throat area of inlet and mass capture ratio (MCR) governed by an incidence position of an oblique shock from the spike tip into the cowl can not be controlled independently in such air inlet. The MRD inlet has the spike that is composed of a tip cone and several disks arranged downstream of it, based on the experimental fact that several deep cavities on a conical surface have little negative effect on the boundary layer growth. The overall spike length of the MRD inlet is adjustable to the given flight speed by changing space between disks so that a spillage flow can be controlled independently from controlling the throat area. It could be made clear from the result of wind tunnel tests that the MRD inlet improves TPR by 10% compared with a conventional inlet with a solid spike under off-design conditions.

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A Study on the Attention Concentration Properties in Convergent Exploration Situations in Cafe Space - Focusing on Gaze and Brain wave Data Analysis - (카페공간에 대한 수렴적 탐색상황에서의 주의집중 특성의 분석 방법에 관한 연구 - 선택적 주시데이터에 의한 뇌파 데이터 분석을 중심으로 -)

  • Kim, Jong-Ha;Kim, Ju-Yeon;Kim, Sang-Hee
    • Korean Institute of Interior Design Journal
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    • v.25 no.2
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    • pp.30-40
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    • 2016
  • This study analyzed the attention concentration tendencies of one(1) subject who showed convergent exploratory acts actively through the gaze-brainwave measurement experiment of cafe space images and our research findings are as follows. First, the areas of interest (AOIs) that the subject gazed visually by paying attention to it and concentrating on it at a cafe space include counter&menu area, sign area, partition area, image wall area, stairs area, and movable furniture area, and built-in furniture area: seven areas in total. Second, conscious gaze frequency appeared the highest in counter&menu area, and conscious gaze appeared more later than in initial times. Third, conscious gaze pattern was divided into the zone that explored various areas dispersely (distributed exploratory zone) and the zone that explored between particular areas concentratedly (intensive exploratory zone). Fourth, as a result of analyzing the brainwave attention concentration, it was found that the attention concentration in prefrontal lobe (Fp1, Fp2) and frontal lobe (F3, F4) rose to a higher level in the zone of 15 to 16 seconds and this time zone was considered to be a zone where gazing at counter&menu area was very active. In addition, the attention concentration appeared higher in the initial zone than in the later zone, among the entire experimental time zones. Finally, as a result of analyzing the changes in activation by brain portion of the SMR wave expressed when maintaining the arousal and attention concentration, it was found that the right prefrontal lobe and the frontal lobe became activated in the time zone when the intensive exploration of "counter&menu area" and "movable furniture${\leftrightarrow}$built-in furniture area" had occurred and the time zone when the intensive exploration of "image wall${\leftrightarrow}$partition area" and "counter&menu${\leftrightarrow}$sign area" had occurred.