• Title/Summary/Keyword: 지구의 운동

Search Result 519, Processing Time 0.032 seconds

Analysis of Test Items of Earth Science and the Applicants' Responses on the Items in the College Scholastic Ability Test (대학수학능력시험의 지구과학영역 문항 및 응시자 반응 분석)

  • Lee, Yang-Rak
    • Journal of the Korean earth science society
    • /
    • v.22 no.6
    • /
    • pp.469-479
    • /
    • 2001
  • This study investigated the trends in the number of applicants and mean score and applicants’ responses on the test items of Earth Science in the College Scholastic Ability Test (CSAT) implemented for 3 years (1999-2001). The percentage of applicants of science track were 43.14% in 1995, but reduced through 29.5% in 2001 to 26.92% in 2002 CSAT For elective subject, about 22% of science track students applied to Earth Science II which ranked third to Biology II and Chemistry II. In 1999, test items were developed to have the expected difficulty 40 ${\sim}$ 59% (6 items) to 60 ${\sim}$ 79% (10 items). But in 2001 every 16 items were developed to have difficulty 60 ${\sim}$ 79%, which was caused by the policy of so called ‘easy CSAT’. Thus the mean score of ‘Earth Science II’ was increased from 50.26 in 1999 through 64.47 in 2000, to 67.58 in 2001. Applicants were generally very good at solving test items focusing on process skills only and familar items but poor at solving test items related to the motion of the earth and planets and sea wave, especially items calling two or more concepts. Thus special measures to cope with the decrease in applicants of science track should be provided. And it is recommended to develop test items with wider range of difficulty and to reduce test items calling process skills only. And special consideration should be given to teaching the content area with poor achievement and high actual difficulty compared to the expected.

  • PDF

Satellite Trajectory Correction Maneuver for Lunar Mission based on Three-Body Dynamics (달탐사 임무를 위한 3체 운동방정식 기반의 인공위성 궤적보정 기동)

  • Cho, Dong-Hyun;Jung, Young-Suk;Lee, Dong-Hun;Jung, Bo-Young;Bang, Hyo-Choong
    • Journal of the Korean Society for Aeronautical & Space Sciences
    • /
    • v.38 no.9
    • /
    • pp.875-881
    • /
    • 2010
  • During the lunar mission, spacecraft are subject to various unexpected disturbance sources such as third body attraction, solar pressure and operating impulsive maneuver error. Therefore, efficient trajectory correction maneuver (TCM) strategy must be required to follow the designed mission trajectory. In the early days of space exploration, the mission trajectory has been designed by using patched conic approach based on two-body dynamics for the lunar mission. Thus the TCM based on two-body dynamics has been usually adopted. However, with the advanced in computing power, the mission trajectory based on three-body dynamics is attempted recently. Thus, these approaches based on two-body dynamics are essentially different from real environment and large amount of energy for the TCM is required. In this work, we study the trajectory correction maneuver based on three-body dynamics.

DYNAMIC MODEL DEVELOPMENT FOR INTERPLANETARY NAVIGATION (행성탐사 항행해 결정을 위한 동역학 모델 개발)

  • Park, Eun-Seo;Song, Young-Joo;Yoo, Sung-Moon;Park, Sang-Young;Choi, Kyu-Hong;Yoon, Jae-Cheol;Yim, Jo-Ryeong;Choi, Joon-Min;Kim, Byung-Kyo
    • Journal of Astronomy and Space Sciences
    • /
    • v.22 no.4
    • /
    • pp.463-472
    • /
    • 2005
  • In this paper, the dynamic model development for interplanetary navigation has been discussed. The Cowell method for special perturbation theories was employed to develop an interplanetary trajectory propagator including the perturbations due to geopotential, the Earth's dynamic polar motion, the gravity of the Sun, the Moon and the other planets in the solar system, the relativistic effect of the Sun, solar radiation pressure, and atmospheric drag. The equations of motion in dynamic model were numerically integrated using Adams-Cowell 11th order predictor-corrector method. To compare the influences of each perturbation, trajectory propagation was performed using initial transfer orbit elements of the Mars Express mission launched in 2003, because it can be the criterion to choose proper perturbation models for navigation upon required accuracy. To investigate the performance of dynamic model developed, it was tested whether the spacecraft can reach the Mars. The interplanetary navigation tool developed in this study demonstrated the spacecraft entering the Mars SOI(Sphere of Influence) and its velocity .elative to the Mars was less than the escape velocity of the Mars, hence, the spacecraft can arrive at the target planet. The obtained results were also verified by using the AGI Satellite Tool Kit. It is concluded that the developed program is suitable for supporting interplanetary spacecraft mission for a future Korean Mars mission.

전북 남원 일대의 야외지질 학습자료 개발

  • Jo, Gyu-Seong;Jeong, Deok-Ho;Park, Gyeong-Jin;Jang, Hyeon-Geun
    • 한국지구과학회:학술대회논문집
    • /
    • 2010.04a
    • /
    • pp.66-66
    • /
    • 2010
  • 야외지질학습은 교실에서 경험할 수 없는 물질과 현상을 관찰하고 직접 경험할 수 있는 기회를 제공받을 수 있어서 매우 중요하다(Orion 1989). 또한 체험활동으로서 교실에서 학습한 내용의 구체적인 예를 제공하여 교육과정을 촉진시키는데 중요한 요소로 인식되고 있다. 일반적으로 야외 활동은 교실 활동보다 학생들의 경험과 훨씬 더 밀접히 관련되어 있기 때문에 보다 의미가 있을 수 있다. 야외실습 중에서 얻은 경험은 학생들이 그가 관찰한 것에 대해 읽도록 동기화시키고, 교과서와 자연조건에서의 실제적 경험 사이의 차이를 연결해 주는 다리를 제공해 줄 수 있다(홍정수, 장남기, 1997). 야외학습을 위한 적절한 장소는 먼저 학습주제나 목표와 부합되는 곳이어야 하며, 지리적으로 가깝고 안전한 곳이어야 한다(김찬종, 2008). 그렇기 때문에 각 지역별로 학습주제와 부합된 지역을 선정하여 야외지질 학습자료를 개발하는 것은 무엇보다 중요하다. 따라서, 본 연구에서는 전북 남원 일대를 중심으로 한 야외지질 학습자료를 개발하는데 그 목적이 있다. 전북 남원지역은 한반도의 중요지괴에 해당하는 영남육괴 지리산지구에 해당하며 편마암 복합체를 기저로 이를 관입하는 수 차례의 화성활동과 지구조운동으로 복잡한 지질양상을 보인다. 또한 지리산 지역은 평안분지와 경상분지의 일부가 보존되어 있고 지질시대를 달리하는 각종 화성암류가 골고루 분포하여 각 지질시대별로 화성활동과 지구조 운동이 활발했음을 시사해준다. 본 연구에서는 남원 지역의 지질학적 특징을 관찰하기 용이한 지역을 대상으로 총 5곳을 선정하였다. 남원 시내에 소재한 춘향대교 아래 지역은 중생대 쥐라기에 관입한 저반상의 남원화강암과 페그마타이트가 다수 분포하는 곳이다. 이 지역에서는 무수히 많은 관입암체를 찾을 수 있는데 다수의 지진과 지각변동이 있었음을 알 수 있다. 두 번째 장소는 다양한 바위들을 관찰할 수 있는 구룡계곡 일대이다. 이 장소는 오랜기간 동안 물의 흐름에 의해 풍화와 침식을 받은 다양한 크기의 바위를 관찰하고 구별함으로써 풍화에 따른 원마도의 관계, 바위들의 배치 형태를 통해 고지형 및 고수류의 방향을 유추해 볼 수 있다. 남원에서 장수 방향에 위치한 만행산 주변에는 흑운모편마암에 우세한데, 이 지역에서는 흑운모편마암에 나타나는 변성구조로 볼 때 높은 열과 압력을 받은 광역변성작용을 받는 것으로 판단된다. 또한 관입암체 내에 다양한 맥들이 관입을 해와 이를 통해 관입암체들의 상대연령을 판단해보는 학습자료로 활용될 수 있다. 네 번째 장소는 남원시 인월면 인풍리 소재의 인월 피바위 지역이다. 이 지역에서는 압쇄상 화강암이 주로 관찰되는데 이는 기원암인 반상화강암이 동력변성작용을 받아 생성된 것이다. 다섯 번째 지역은 지리산 내의 뱀사골로 지리산 인근에 분포하는 대표적인 편마암인 반상변정질 편마암을 관찰할 수 있다. 변정이란 변성작용을 받는 동안 형성되는 것으로 변성작용을 받는 동안 생긴 것도 있으나 경우에 따라 생성당시 원래 모암속에 포함되어 있는 반정들도 있다.

  • PDF

Effects of Exercise Intensity on PGC-1α, PPAR-γ, and Insulin Resistance in Skeletal Muscle of High Fat Diet-fed Sprague-Dawley Rats (운동 강도 차이가 고지방식이 Sprague-Dawley Rat의 골격근 내 PGC-1α, PPAR-γ 및 인슐린 저항에 미치는 영향)

  • Jung, Hyun-Lyung;Kang, Ho-Youl
    • Journal of the Korean Society of Food Science and Nutrition
    • /
    • v.43 no.7
    • /
    • pp.963-971
    • /
    • 2014
  • This study investigated the effects of exercise intensity on PGC-$1{\alpha}$, PPAR-${\gamma}$, and insulin resistance in skeletal muscle of high fat diet-fed Sprague-Dawley rats. Forty rats were randomly divided into five groups: sedentary control group (SED), high fat diet group (HF), high fat diet+low-intensity exercise group (HFLE, 22 m/min, 60 min, 6 days/week), high fat diet+moderate-intensity exercise group (HFME, 26 m/min, 51 min), and high fat diet+high-intensity exercise group (HFHE, 30 m/min, 46 min). After 4 weeks of high fat diet and endurance exercise training, the lipid profiles, insulin, and glucose concentrations were determined in plasma. PGC-$1{\alpha}$, PPAR-${\gamma}$, and GLUT-4 contents were measured in plantaris muscle. The rate of glucose transport in soleus muscle was determined under submaximal insulin concentration ($1,000{\mu}IU/mL$ insulin, 20 min) during muscle incubation. Plasma glucose during oral glucose tolerance test in HF was significantly greater than that in SED, and plasma glucose levels in the three exercise (EX) groups were significantly lower that those in SED and HF at 30 and 60 min, respectively (P<0.05). Plasma insulin levels in the EX groups were significantly reduced by 60 min compared to that in HF (P<0.05). The protein expression level of PGC-$1{\alpha}$ as well as muscle glucose uptake were significantly higher in SED and HF than those in the three EX groups (P<0.05), and HFHE showed significantly higher levels than HFLE and HFME. Expression levels of GLUT-4 and PPAR-${\gamma}$ were significantly higher in the HFLE, HFME, and HFHE groups compared to the SED and HF (P<0.05). Therefore, the results of this study indicate that 4 weeks of high fat diet significantly developed whole body insulin resistance but did not affect PGC-$1{\alpha}$, PPAR-${\gamma}$, or the glucose transport rate in skeletal muscle, and exercise training was able to attenuate deteriorated whole body insulin resistance due to high fat diet. In addition, high intensity training significantly affected PGC-$1{\alpha}$ expression and the glucose transport rate of skeletal muscle in comparison with low and middle training intensities.

Paleoseismological Study and Evaluation of Maximum Earthquake Magnitude along the Yangsan and Ulsan Fault Zones in the Southeastern Part of Korea (남한 남동부 양산단층대와 울산단층대의 고지진 연구와 최대 지진 규모 평가)

  • Kyung, Jai-Bok
    • Geophysics and Geophysical Exploration
    • /
    • v.13 no.3
    • /
    • pp.187-197
    • /
    • 2010
  • The paleoseismological study in Korea has begun along the Yangsan fault zone (YFZ) and Ulsan fault zone (UFZ) since 1994. Some evidences related to late Quaternary movement are found at only some part of the YFZ, such as Pyonghae, Yuge, and Eonyang-Tongdosa areas. However, it is found along the most of the UFZ except the northen and southern ends of the fault. The dominant time span of faulting events along the YFZ and UFZ are quite different, and 500 ka to 200 ka and 300 ka to recent time, respectively. The dominant faulting senses of the YFZ and UFZ are right-lateral strike slip and reverse, respectively. These senses correspond well with the focal mechanism of recent occurring earthquakes along these two fault zones. If we evaluate the intensity of the activity of the YFZ from the average slip rate, which is 0.1~0.04 m/ka, it is comparable with the faults of higher C class in Japan. The slip rate of UFZ, which is 0.2~0.06 m/ka, is comparable with the faults of lower B to higher C class. Based on the relationship between maximum displacement and magnitude, the maximum earthquake magnitude is evaluated to be 6.8 and 7.0 in the YFZ and UFZ, respectively. An intensive studies are needed to clarify the problems such as segmentation of faults, return period, and geological evidences related to historical earthquakes.

Crustal velocities around the Korean Peninsula estimated with GPS (GPS로 잰 한반도 주변의 지각운동 속도)

  • Park, Pil-Ho;Ahn, Yong-Won;Park, Jong-Uk;Joh, Jeong-Ho;Lim, Hyung-Chul
    • Journal of the Korean Geophysical Society
    • /
    • v.3 no.3
    • /
    • pp.153-160
    • /
    • 2000
  • Crustal velocities around the Korea peninsula are estimated and investigated from eight IGS permanent stations in eastern Asia area. GPS data for the period of May 1995 to December 1991 were analyzed to estimate daily coordinates of each site relative to TAEJ site. The velocity vector of each site is estimated from linear regression analysis with time series of coordinates. As the result, horizontal velocity components for four stations(Tsukuba, Usuda,Taiwan and Shanghai) using thirty-two months data were estimated with the standard error less than 1 mm/year. Our GPS velocity of six sites on the interiors of the Eurasia plate are similar within 1 cm/year with small differences respectively. On the other hand, the velocities of Tsukuba and Usuda showed the great differences from the other six sites. This can be explained by the fact that these two sites are enforced by the surrounding four plates, such as the Pacific, Eurasia, North America and Philipine plate. This study showed that the distance between Korea and Japan is shortened with the rate of 3 cm per year.

  • PDF

Seismic Studies on Ground Motion using the Multicomponent Complex Trace Analysis Method (다성분 복소 트레이스 분석법을 이용한 지진파 입자운동 연구)

  • Lee, So-Young;Kim, Ki-Young;Kim, Han-Joon
    • Journal of the Korean Geophysical Society
    • /
    • v.3 no.1
    • /
    • pp.37-48
    • /
    • 2000
  • In order to investigate in-line ground motions caused by earthquakes, we examine the multicomponent complex trace analysis method (MCTAM) for the synthetic data and apply it to real earthquake data. An experimental result for synthetic data gives correct information on the arrival times, duration of individual phases, and approaching angles for body waves. Rayleigh waves are also easily identified with the MCTAM. A deep earthquake with magnitude of 7.3 was chosen to test various polarization attributes of ground motions. For P waves, instantaneous phase difference between the vertical and the in-line horizontal components ${\phi}(t)$, instantaneous reciprocal ellipticity ${\rho}(t)$, and approaching angle ${\tau}(t)$ are computed to be ${\pm}180^{\circ},\;0{\sim}0.25,\;and\;-30^{\circ}{\sim}-45^{\circ}$, respectively. For S waves, ${\phi}(t)$ tends to vary while ${\rho}(t)$ have values of $0{\sim}0.3\;and\;{\tau}(t)$ remains near vertical, respectively. A relatively low frequency signal registered just prior to the S wave event is interpreted as a P-wave phase based on its polarization characteristics. Velocities of P and S waves are computed to be 8.633 km/s and 4.762 km/s, and their raypath parameters 0.074 s/km and 0.197 s/km. Dynamic Poisson's ratio is obtained as 0.281 from the velocities of P and S waves.

  • PDF

Evaluating Physical Characteristics of Raindrop in Anseong, Gyeonggi Province (강우입자의 물리적 특성평가: 경기도 안성시 지역을 사례로)

  • KIM, Jin Kwan;YANG, Dong Yoon;KIM, Min Seok
    • Journal of The Geomorphological Association of Korea
    • /
    • v.17 no.1
    • /
    • pp.49-57
    • /
    • 2010
  • To evaluate physical characteristics of open rainfall in Korea, terminal velocity of raindrop and drop size distributions (DSD) were continuously measured using by laser-optical disdrometer around Gosam reservoir, Anseong-si, Gyeonggi-do during three rainfall events from 2008 to 2009. The relationships between kinetic energies (KE, Jm-2mm-1; KER, Jm-2h-1) and rainfall intensity were obtained, respectively. Moreover, we compared the rainfall intensity from a disdrometer with the rainfall intensity from a tipping bucket raingauge to transform the kinetic energy of rainfall using the data from a tipping bucket raingauge. Therefore, the established relationships between kinetic energies (KE and KER) and rainfall intensity could be a useful model to consider the kinetic energy of raindrop using the rainfall intensity below 40mmh-1 of max 5-min rainfall intensity in the middle of South Korea. However, to better examine the relationship between kinetic energy and rainfall intensity, further measurement will be required.

회원병원 소개 - 온세상을 건강한 미소로... - 창원파티마병원 -

  • 한국가톨릭의료협회
    • Health and Mission
    • /
    • s.17
    • /
    • pp.24-27
    • /
    • 2009
  • 지난 6.29일자 중앙일보에 보도에 의하면 창원파티마병원은 2005년에 이어 2008년에도 보건복지가족부 주관 전국의료기관평가서 최우수병원으로 선정되었다. 의료서비스 및 환자만족도 등 20개 부문 중 19개 부문에서 A등급을 받아 평가 대상 의료기관 중 최고의 성적을 거두었다. 창원파티마병원은 1969년 마산시 대성동에서 4개 진료과, 10개 병상의 마산파티마병원에서 출발하여 2002년 창원으로 이전, 진료를 시작한 이래 응급환자의 진료에 만전을 기하기 위해 응급의료센터를 개설하고, 보건복지가족부 지정 중증외상 및 응급뇌질환 특성화후보센터를 운영하고 있다. 말기 암 환자를 위한 호스피스 병동을 지역최초로 개설하였고, 전신 암 조기진단장비인 PET-CT 등 첨단 장비를 지속적으로 보강하여 보다 질 높은 의료서비스 제공을 위해 노력하고 있다. 또한 온생명 Care 캠페인을 통해 지구의 환경을 보전하기 위한 환경 운동을 전개하는 한편 다문화 가정 지원사업, 환자와 보호자를 위한 사랑의 음악회, 찾아가는 시민강좌 등 다양한 사회공헌 활동을 하고 있다.

  • PDF