• Title, Summary, Keyword: Exploration

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Mobile Robot Based Down-Scaled Mineral Resources Exploration Test System (이동로봇을 이용한 자원탐사 축소모형 실험 시스템 구축 응용)

  • Yu, Son-Cheol;Jung, Hyun-Key;Yoon, Joong-Sun;Pyo, Ju-Hyun;Cho, Sung-Ho;Oh, Dong-Moon;Kang, Dong-Joung
    • Geophysics and Geophysical Exploration
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    • v.12 no.4
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    • pp.355-360
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    • 2009
  • This paper presents mobile robot based down-scale mineral resources exploration test system for the USN (Ubiquitous Sensor Network) based exploration. The system emulates the actual exploration environment. Underneath the metal free test plate, a metal object is attached. A magneto-meter mounted mobile robot runs around on the plate to find the metal. The measured magneto-meter values are transferred to the host PC via wireless network. The system enables to improve the reliability of simulation as well as to help efficient exploration system design. Metal-detecting experiments were carried out to illustrate the efficiency of the proposed system.

Discovery of a Faint Quasar at z ~ 6 and Implications for Cosmic Reionization

  • Kim, Yongjung;Im, Myungshin;Jeon, Yiseul;Kim, Minjin;Choi, Changsu;Hong, Jueun;Hyun, Minhee;Jun, Hyunsung David;Karouzos, Marios;Kim, Dohyeong;Kim, Duho;Kim, Jae-Woo;Kim, Ji Hoon;Lee, Seong-Kook;Pak, Soojong;Park, Won-Kee;Taak, Yoon Chan;Yoon, Yongmin
    • The Bulletin of The Korean Astronomical Society
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    • v.41 no.1
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    • pp.37.3-38
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    • 2016
  • Recent studies suggest that faint active galactic nuclei may be responsible for the reionization of the universe. Confirmation of this scenario requires spectroscopic identification of faint quasars ($M_{1450}$ > -24 mag) at z > 6, but only a very small number of such quasars have been spectroscopically identified so far. Here, we report the discovery of a faint quasar IMS J220417.92+011144.8 at z ~ 6 in a $12.5deg^2$ region of the SA22 field of the Infrared Medium-deep Survey (IMS). The spectrum of the quasar shows a sharp break at ${\sim}8443{\AA}$, with emission lines redshifted to $z=5.944{\pm}0.002$ and rest-frame ultraviolet continuum magnitude $M_{1450}=-23.59{\pm}0.10$ AB mag. The discovery of IMS J220417.92+011144.8 is consistent with the expected number of quasars at z ~6 estimated from quasar luminosity functions based on previous observations of spectroscopically identified low-luminosity quasars. This suggest that the number of $M_{1450}$ ~ -23 mag quasars at z ~ 6 may not be high enough to fully account for the reionization of the universe. In addition, our study demonstrates that faint quasars in the early universe can be identified effectively with a moderately wide and deep near-infrared survey such as the IMS.

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The Effects of a group counseling program for career exploration on college students' self-efficacy (대학생을 위한 진로탐색 집단상담 프로그램의 효과연구 - 학부 신입생을 대상으로 -)

  • Cho, Hea-Joung;Kim, Mill-Yang
    • Korean Journal of Human Ecology
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    • v.15 no.2
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    • pp.353-362
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    • 2006
  • The purpose of this study is to develop a group counseling program for career exploration and to explore its effects on college students' self-efficacy. Main program activities consisted of 8-week sessions. Equivalent control group pretest-posttest design was employed for this study. 40 college students voluntarily participated in a group counseling of career exploration. Another 40 students were selected for a control group of this study design. The self-efficacy (23 items) was administered to both the experimental and the control groups before and after the 8-week treatments. The results of this research showed that the differences (program effects) of the experimental group in the scale were higher than those of the control group. In conclusion, a group counseling program for the career exploration had significant effects on the career exploration and self-efficacy of college students.

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Numerical Study of Pressure Waves Generated by H-IIA Launch Vehicle at Lift-off

  • Tsutsumi, Seiji;Shimizu, Taro;Takaki, Ryoji;Shima, Eiji;Fujii, Kozo;Arita, Makoto
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • pp.266-271
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    • 2008
  • Generation mechanisms of pressure waves from the H-IIA launch vehicle are analyzed numerically. The Mach wave radiated downstream from wavy shearlayer of supersonic exhaust plume is revealed to be the dominant noise source. Reflecting from the constructions of the launch-pad, the Mach wave turns to propagate to the vehicles. It was also found that the fluctuating supersonic plume entering into the flame duct is the dominant noise source that appears in the flame duct. Then, the pressure wave propagates through the flame duct and is ejected outside to the vehicle.

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The Effect of Natural Exploration Activity on Environmental Perception of the Science High School Students (자연탐사활동이 과학고 학생들의 환경인식에 미치는 효과)

  • Kim, Soon-Shik;Choi, Sung-Bong
    • Journal of Environmental Science International
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    • v.19 no.3
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    • pp.343-351
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    • 2010
  • Since the effect of environmental education at class using textbooks or materials related to environment is limited, the importance of activities for field experience is getting increased day by day. Thereby, the education tends to change into the type of education providing students with direct environmental experience. Students attending the science high school have excellent aptitude and ability for science and will lead the development of science in the future. Now it is urgent to develop various experiential programs which are helpful for them to establish desirable values on environment. However, the field of environmental education that allows science high school students equipped with ample environmental knowledge to improve environment sensitivity and have proper environment awareness is quite restricted as of now. Natural exploration activities are the programs which provide science high school students having lack of chance for environmental education with good opportunities to contact nature and also play significant roles in arousing their interest in issues related with environment. Therefore, it is thought that they will let science high school students explore the natural features of Korea, understand the importance of preserving environment and ecosystem profoundly, and encourage environmental awareness and will of environmental practice. Thereupon, with the study subjects of 121 first and second graders at U Science High School, this article analyzed their recognition of the necessity for environmental education and environmental pollution problems before and after the natural exploration activities, and conducted a survey on their satisfaction after the natural exploration activities and analyzed it. The result of this research is as follows. First, it was shown that the natural exploration activities were effective to raise the science high school students' awareness of issues related with environmental pollution. Second, the natural exploration activities had effect upon enhancing the students' willingness of environmental practice. Third, there was statistically significant correlation between the science high school students' satisfaction with the natural exploration activities and their achievement in the science subject. Fourth, there also was a statistically non or weakness significant correlation between their satisfaction with the natural exploration activities and preference for the science subject. In particular, it was found that students preferring biology indicated higher satisfaction.

Development Study of A Precooled Turbojet Engine for Flight Demonstration

  • Sato, Tetsuya;Taguchi, Hideyuki;Kobayashi, Hiroaiki;Kojima, Takayuki;Fukiba, Katsuyoshi;Masaki, Daisaku;Okai, Keiichi;Fujita, Kazuhisa;Hongoh, Motoyuki;Sawai, Shujiro
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • pp.109-114
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    • 2008
  • This paper presents the development status of a subscale precooled turbojet engine "S-engine" for the hypersonic cruiser and space place. S-engine employs the precooled-cycle using liquid hydrogen as fuel and coolant. It has $23cm{\times}23cm$ of rectangular cross section, 2.6 m of the overall length and about 100 kg of the target weight employing composite materials for a variable-geometry rectangular air-intake and nozzle. The design thrust and specific impulse at sea-level-static(SLS) are 1.2 kN and 2,000 sec respectively. After the system design and component tests, a prototype engine made of metal was manufactured and provided for the system firing test using gaseous hydrogen in March 2007. The core engine performance could be verified in this test. The second firing test using liquid hydrogen was conducted in October 2007. The engine, fuel supplying system and control system for the next flight test were used in this test. We verified the engine start-up sequence, compressor-turbine matching and performance of system and components. A flight test of S-engine is to be conducted by the Balloon-based Operation Vehicle(BOV) at Taiki town in Hokkaido in October 2008. The vehicle is about 5 m in length, 0.55 m in diameter and 500 kg in weight. The vehicle is dropped from an altitude of 40 km by a high-altitude observation balloon. After 40 second free-fall, the vehicle pulls up and S-engine operates for 60 seconds up to Mach 2. High altitude tests of the engine components corresponding to the BOV flight condition are also conducted.

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Efficient Exploration for Room Finding Using Wall-Following based Path Planning (벽추종 경로계획 기반의 효과적인 방 찾기 탐사)

  • Park, Joong-Tae;Song, Jae-Bok
    • Journal of Institute of Control, Robotics and Systems
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    • v.15 no.12
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    • pp.1232-1239
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    • 2009
  • This paper proposes an exploration strategy to efficiently find a specific place in large unknown environments with wall-following based path planning. Many exploration methods proposed so far showed good performance but they focused only on efficient planning for modeling unknown environments. Therefore, to successfully accomplish the room finding task, two additional requirements should be considered. First, suitable path-planning is needed to recognize the room number. Most conventional exploration schemes used the gradient method to extract the optimal path. In these schemes, the paths are extracted in the middle of the free space which is usually far from the wall. If the robot follows such a path, it is not likely to recognize the room number written on the wall because room numbers are usually too small to be recognized by camera image from a distance. Second, the behavior which re-explores the explored area is needed. Even though the robot completes exploration, it is possible that some rooms are not registered in the constructed map for some reasons such as poor recognition performance, occlusion by a human and so on. With this scheme, the robot does not have to visit and model the whole environment. This proposed method is very simple but it guarantees that the robot can find a specific room in most cases. The proposed exploration strategy was verified by various experiments.

The Effect of a Career Exploration Program Using Career Portfolio on Self-efficacy and Career Identity of Vocational High School Students (커리어포트폴리오를 활용한 진로탐색 프로그램이 전문계 고등학생의 자기효능감 및 진로정체감에 미치는 효과)

  • LEE, Jong-Ho;KIM, Jong-Un
    • Journal of Fisheries and Marine Sciences Education
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    • v.21 no.1
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    • pp.1-15
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    • 2009
  • The purpose of this study was to examine the effect of a career exploration program using career portfolio for vocational high school students and suggest ideas for making a decision their career and occupation. The number of subjects in this study were 50 high school students in Busan metropolitan city among which 25 were assigned for the experimental group and 25 in the control group. The career exploration program utilizing career portfolio in this study was composed of 12 sessions utilizing the career portfolio. This program was based on Jeong et al.'s career development program(2005) for high school students and Choi's career exploration program using internet(2005). The instruments of this study were self-efficacy scale and career identity scale. The average, standard deviation and the differences between the pre and post-test were calculated and processed by SPSS WIN 14.0. The major findings of this study can be summarized as follows: First, the career exploration program using career portfolio was effective to enhance significantly the level of the self-efficacy of vocational high school students. Second, the career exploration program using career portfolio was also effective to enhance career identity.