• Title/Summary/Keyword: earth-work

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The Analysis of planning methode and case study for Model 'Climate Change Adaptation City' (기후변화 적응도시 모델개발을 위한 계획기법 및 사례 분석)

  • Kim, Jongkon
    • KIEAE Journal
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    • v.12 no.4
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    • pp.13-19
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    • 2012
  • The Earth's surface temperature still continues to rise, and extreme weather phenomena such as heat waves, drought, and precipitation have been repeated every year. It is reported that international communities attribute the main cause of the Earth's surface temperature rise to the excessive use of the fossil energy. Recently, the damage caused by climate change is getting worse, and the place where we live is suffering the most. Cities have been continuously growing not only meeting the basic functions of human habitation, work and leisure but also being places for various economic and social activities. But Cities, the victims of climate change, have grown only considering human needs and convenience rather than predicting their physical and ecological systems(Albedo effects, urban microclimate, resources and energy of the circulatory system, etc). In other words, the cities offer the cause of the problems of climate change, and even worsen the extreme weather phenomena without coping with them. Therefore, it is urgent priorities to protect the climate, to prevent the causes of the extreme weather phenomena and to enhance the adaptive capacity for the worse weather events. This study is to derive the concept for adapting to these climate changes which can make cities escape from exposure to these climate change impacts and make themselves safer places to live. And it analyzes some European cities and present developing models to implement planning methods. In this study, the concept of the climate adaptive cities will be suggested to prepare the adaptation measures for urban planners, and climate change adaptation models will be presented by analyzing some preliminary cases.

SUNSHINE, EARTHSHINE AND CLIMATE CHANGE I. ORIGIN OF, AND LIMITS ON SOLAR VARIABILITY

  • GOODE PHILIP R.;DZIEMBOWSKI W. A.
    • Journal of The Korean Astronomical Society
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    • v.36 no.spc1
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    • pp.75-81
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    • 2003
  • Changes in the earth's climate depend on changes in the net sunlight reaching us. The net depends on the sun's output and earth's reflectance, or albedo. Here we develop the limits on the changes in the sun's output in historical times based on the physics of the origin of solar cycle changes. Many have suggested that the sun's output could have been $0.5\%$ less during the Maunder minimum, whereas the variation over the solar cycle is only about $0.1\%$. The frequencies of solar oscillations (f- and p-modes) evolve through the solar cycle, and provide the most exact measure of the cycle-dependent changes in the sun. But precisely what are they probing? The changes in the sun's output, structure and oscillation frequencies are driven by some combination of changes in the magnetic field, thermal structure and velocity field. It has been unclear what is the precise combination of the three. One way or another, this thorny issue rests on an understanding of the response of the solar structure to increased magnetic field, but this is complicated. Thus, we do not understand the origin of the sun's irradiance increase with increasing magnetic activity. Until recently, it seemed that an unphysically large magnetic field change was required to account for the frequency evolution during the cycle. However, the problem seems to have been solved (Dziembowski, Goode & Schou 2001) using f-mode data on size variations of the sun. From this and the work of Dziembowski & Goode (2003), we suggest that in historical times the sun couldn't be much dimmer than it is at activity minimum.

Behavior Characteristics of Precast Concrete-Panel Retaining Wall Adhered to In-situ Ground through Large Scaled Load Test (대형재하시험을 통한 원지반 부착식 패널옹벽의 거동특성)

  • Shin, Yuncheol;Min, Kyongnam;Kim, Jinhee;Ahn, Taebong
    • Journal of the Korean GEO-environmental Society
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    • v.17 no.11
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    • pp.45-53
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    • 2016
  • A precast panel wall system resists against the horizontal earth pressure by increasing the shear strength of ground by reinforcement connected to the panel. The application of precast panel wall system is growing to lately minimize the earth work and environmental damage caused by large cut slope and to use the limited land effectively. The ground adhered panel wall system is the construction method that has the panel engraved with natural rock shape to improve the landscape. This system is developed to complete Top-Down method, and it is possible to have vertical cut, and to adhere to in-situ ground, improve construction ability by minimizing the ground relaxation and exclusion the trench and backfill process. In this study the field tests were performed to verify the construction ability about the vertical cut and complete Top-Down process and the construction behavior of ground adhered panel wall system was analyzed by large scale loading test and measurement results during loading test.

Exploring Geosites Considering Geological Characteristics of the Gochang-gun Area, Korea (고창군 일대의 지질학적 특성을 고려한 지질명소 탐색)

  • Cho, Kyu-Seong;Hong, Deok-Pyo;Park, Kyeong-Jin
    • Journal of the Korean earth science society
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    • v.36 no.4
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    • pp.341-350
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    • 2015
  • This study is to explore geosites considering the geological characteristics in Gochang-gun and to investigate a possibility of being designated as the national geopark of Korea. In this study, the geosites within Gochang-gun are explored through literature search and field work. The results indicate that seven of the geosites in the Seonunsan area are relevant as potential national geopark, including Jinheunggul, Dosolam Maebulsang, Youngmungul, Nakjodae and Cheonmabong, Byungbawi, spherulitic rhyolite, and Dolmen site. In addition, there are other areas that have valus in terms of geological and educational aspect, including Hajeon mud flat and Myoungsasipri beach. The results of study imply that if various educational programs for the geotourism are properly developed, the Gochang-gun area has potential to be designated as the national geopark of Korea.

A study on the Kuei of the Jade Tablet, Hole of the Ivory Tablet, Ancient Korea and China, Japan (한.중.일 3국의 圭.笏에 관한 연구)

  • 임명미
    • Journal of the Korean Society of Costume
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    • v.51 no.2
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    • pp.5-25
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    • 2001
  • Jade, which is a kind of stone, with its transparent body, lustrous and bright character, But jade is not the only fair stone. There are three kinds of jade objects 1) tallies used in the court. 2) ceremonial jades. 3) ordinary jade for decoration, for inlaid work and for burial. Among the ceremonial jade, the most important were the "liu jui" and "liu ch′i." The former was supposed to be held by people in the court as symbols of their authority : 1) "then-kuei(鎭圭)" for the emperor. 2) "hang-kuei(恒圭)" for a duke, 3) "hsin-kuei(信圭)" a marquis. 4) "kung-kuei(躬圭)" for an earl, these "kuei" were alike in shape, but differed in size. 4) "ku-pi(穀璧)" for a viscount. 5) "p′u-pi(蒲璧)" for a baron, "pi(璧)" differed in decoration but were alike in shape. "Liu ch′i(六器)" were ceremonial objects used by the emperor in worshipping Heaven, Earth, and the Four Directions : "ts′ang-pi(倉璧)," greenish jade disk, used in worthipping Heaven "huang-tsung(黃琮)," yellow jade cylinder, used in worshipping Earth ; "cuing-kuei,(靑圭)" blue jade tablet. used in worshipping the East : "chih-chang(赤璋)," red jade tablet, used in worshipping the South : "hsuan-huang(玄璜)," black crescent, used in worshipping the North. Five kinds of tallies were "chen-kuei(鎭圭)," "yenkuei(琰圭)," "yuan-kuei(玩圭)," "ku-kuei(穀圭)." They were used to console people during disaster, to subjugate an official who had committed a crime, to reward a prize to an official for his merit or good conduct, to arbitrate disputes between high officials, to marry princess. and to dispatch troops. Since the west wei(西魏), Kuei and Hole were made of Ivory, wood and bamboo, who had ivory for fifth grade and wood and bamboo for under sixth grade. After Eastern Chou, all officials beginning to had kuei hole. symbol of Authority. and his wives. After Dang dynasty, Japan is the same. In korea. After king Bupheung in ancient and South(unification) Silla, North Kingdom Bohai, Koryo, and Chosen dynasty had ceremonial jade, Kuei and Hole.

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Effect of Additives on the Refractive Index of B2O3-SiO2-Al2O3 Glasses for Photolithographic Process in Electronic Micro Devices

  • Won, Ju-Yeon;Hwang, Seong-Jin;Lee, Jung-Ki;Kim, Hyung-Sun
    • Korean Journal of Materials Research
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    • v.20 no.7
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    • pp.370-373
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    • 2010
  • In fabricating plasma display panels, the photolithographic process is used to form patterns of barrier ribs with high accuracy and high aspect ratio. It is important in the photolithographic process to control the refractive index of the photosensitive paste. The composition of this paste for photolithography is based on the $B_2O_3-SiO_2-Al_2O_3$ glass system, including additives of alkali oxides and rare earth oxides. In this work, we investigated the density, structure and refractive index of glasses based on the $B_2O_3-SiO_2-Al_2O_3$ system with the addition of $Li_2O$, $K_2O$, $Na_2O$, CaO, SrO, and MgO. The refractive index of the glasses containing K2O, Na2O and CaO was similar to that of the [BO3] fraction while that of the SrO, MgO and Li2O containing glasses were not correlated with the coordination fraction. The coordination number of the boron atoms was measured by MAS NMR. The refractive index increased with a decrease of molar volume due to the increase in the number of non-bridging oxygen atoms and the polarizability. The lowest refractive index (1.485) in this study was that of the $B_2O_3-SiO_2-Al_2O_3-K_2O$ glass system due to the larger ionic radius of $K^+$. Based on our results, it has been determined that the refractive index of the $B_2O_3-SiO_2-Al_2O_3$ system should be controlled by the addition of alkali oxides and alkali earth oxides for proper formation of the photosensitive paste.

Behavior of Geosynthetic Reinforced Wall with Heat Induce Drainage Method During Rainfall (열유도 토목섬유 배수공법이 적용된 보강토 옹벽의 강우시 거동 특성)

  • Shin, Seung-min;Sin, Chun-won;Yoo, Chung-Sik
    • Journal of the Korean Geosynthetics Society
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    • v.15 no.1
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    • pp.11-19
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    • 2016
  • This paper presents the results of a scale model test to the effect of heat exchanger drainage method in retaining wall of weathered granite soil. Purpose to rise in the temperature of the heat wires inside the weathered granite soil is preventing the collapse of the retaining wall and drainage smoothly moved to the drainage layer. Especially using a spray gun to simulate the rainfall since the rainfall drainage work is important for the rainfall effect on soil, find the difference about displacement of the retaining wall, change of volume water content, drainage, earth pressure and change in the strain of the geosynthetic was effected to heat exchanger within the soil. The result from applying the heat exchanger method decreased the earth pressure and displacement of the wall and increased drainage of water.

Imaging of Seismic Sources Using Time Reversal Wave Propagation (지진파 역행 전파를 이용한 지진원 영상화)

  • Sheen, Dong-Hoon;Baag, Chang-Eob;Hwang, Eui-Hong;Ryoo, Yong Gyu;Youn, Yong-Hoon
    • 한국지구물리탐사학회:학술대회논문집
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    • 2006.06a
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    • pp.181-186
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    • 2006
  • An imaging method of seismic sources using time-reversal wave propagation is presented. The method is based on the time-reversal invariance and the spatial reciprocity of the wave equation. Time-reversal wave propagation has been used to image anomalous features of a midium in medical imaging, non destructive testing and waveform tomography. Seismogram is the record whose energy is propagated from the seismic source. If time-reversed seismogram propagates back into the medium, seismic energy is concentrated at the origin time of the event and at the source location. In this work, a staggered-grid finite-difference method of the elastic wave equation is parallelized for 3-D wave propagation simulation. With numerical experiments, we show that the time-reversal imaging will enable us to explore the spatio-temporal history of complex earthquake.

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CO-SEPARATION OF Am AND RARE EARTH ELEMENTS FROM A HIGHLY ACIDIC RADWASTE SOLUTION BY A SOLVENT EXTRACTION WITH (DIMETHYLDIBUTYL TETRADECYLMALONAMIDE-DIHEXYLOCTANAMIDE)/N-DODECANE

  • Lee, Eil-Hee;Lim, Jae-Gwan;Chung, Dong-Yong;Yoo, Jae-Hyung;Kim, kwang-Wook
    • Nuclear Engineering and Technology
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    • v.41 no.3
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    • pp.319-326
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    • 2009
  • This study was carried out to investigate the high-acidity co-separation of Am and RE from a simulated radwaste solution by a solvent extraction using a mixture of Dimethyldibutyltetradecylmalonamide (DMDBTDMA, as an extractant) and dihexyl octanamide (DHOA, as a phase modifier) diluted with n-dodecane (NDD). All the experiments were conducted as a batch type. First, the environmentally friendly DMDBTDMA and DHOA composed of only CHON atoms were self-synthesized. Then, the conditions for the prevention of a third phase, generated in the organic phase were examined. In addition, the effects of the concentration of nitric acid, DHOA, oxalic acid and $H_2O_2$ on the co-extraction of Am and RE were elucidated. Consequently, the optimum condition of (0.5M DMDBTDMA+0.5M DHOA)/NDD-0.3M $C_2H_2O_4-4.5M$ $HNO_3$ and O/A=2 was obtained through experimental work. Under this condition, the extraction yields were found to be about 80% for Am, more than 70% for RE such as La, Eu, Nd, Ce, etc., 3% for Cs and Sr, 69% for Fe and less than 11% for Mo and Ru. For the co-extraction of Am and RE, Fe should be removed in advance or prevented from a co-extraction with Am by controlling the different extraction rates of Am and Fe. About 95% of the Am and RE in the organic phase were stripped using a 0.5M $HNO_3$.

Analysis of Professional Development in Teaching Practices of Beginning Secondary Science Teachers (중등 초임 과학교사의 수업 전문성 개발 실태 분석)

  • Kwak, Young-Sun
    • Journal of the Korean earth science society
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    • v.30 no.3
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    • pp.354-365
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    • 2009
  • In this research, we investigated the support system and professional development in teaching practices of beginning science teachers through instructional consulting. Using open-ended interviews with the participating teachers and group discussions taking place on a regular basis to analyze and compare classes of six beginning teachers, we analyzed beginning teachers' professional development efforts centering around their teaching practices. The group discussion consisted of 6 beginning teachers and another 6 experienced teachers, they discussed and cross-analyzed beginning teachers' 9th lessons on middle school science unit, 'Work and Energy.' The characteristics of beginning science teachers' professional development drawn from this research are: (1) beginning teachers' teaching practices they were taught, (2) lack of reflection on their teaching practices, (3) no guidance for beginning teachers regarding ways to teach, (4) lack of communication between teachers about teaching science, and (5) lack of time for instructional preparation due to other heavy workload. Suggestions for ways to improve and support beginning teachers' professional development are discussed with experienced teachers. Required conditions for an effective induction program are also discussed.