• 한국지반공학회논문집
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• 제36권11호
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• pp.51-60
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• 2020

횡방향의 토압에 저항하는 앵커블록, 흙막이 가설벽체, 레이커 지지블록 등에서 수동토압 산정은 중요한 요소이다. 실무에서는 사용의 편의성으로 인하여 파괴면을 직선으로 가정한 Coulomb과 Rankine의 이론을 사용하여 토압을 산정하는 것이 일반적이다. 하지만 실제 발생하는 수동파괴면은 벽면과 지반의 마찰로 인하여 벽체부근에서는 곡면이고 지표부근에서는 평면이 되는 복합파괴면을 형성한다. 흙막이 구조물의 안정검토에서 저항력으로 산정되는 수동토압이 발생되는 변위는 주동토압이 발생되는 주동변위 보다 커 대부분 구조물의 안정성을 초과하는 변위가 발생하여야 수동토압의 저항력이 발휘되므로 수동토압을 설계에 적용하기 위해서는 허용변위 이내의 임의변위에서 발휘되는 수동측토압의 산정이 매우 중요한 요소이다. 본 연구에서는 복합파괴면을 반영한 한계변위 내의 임의 변위에서 발휘되는 수동측토압을 산정할 수 있는 반경험식을 활용하여 벽체의 세 가지 거동조건에 따라 임의 변위에서 발휘되는 수동토압을 분석하였다.

• 대한지구과학교육학회지
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• 제5권1호
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• pp.88-94
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• 2012

This study was created to resolve the problems embedded in the formal measuring experiments to determine the earth's size in the current curriculum, to develop an updated measuring experiment to determine the earth's size and to establish its effect. For this study, pre-service elementary teachers, who had attempted the experiment of measuring the size of the earth when they were in middle school, performed the experiments in the existing national curriculum, and their responses, collected through in-depth interviews, were examined. To begin with, the pre-service elementary teachers conducted the experiment of measuring the earth size and they recorded the problems while performing it. At the end, an in-depth interview was administered. Based on the problems, an updated measuring experiment to determine the earth's size was suggested to be applied to the same contents and be analyzed through the in-depth interviews. Common themes which were mutually categorized and analyzed by the two researchers were obtained based on the records produced while conducting the experiment and the in-depth interview data. The teachers mentioned that the experiments for measuring the size of the earth in the current curriculum gave rise to difficulties in measuring precisely the angles between the string and the post. Also, there has been a scientific contradiction that solar altitudes were increased in a high latitude region, instead of decreased. For this reason, an alternative method has been developed to measure the earth's size using the distance and the solar altitude difference of two places. The teachers all agreed that by using the updated measuring experiment, they can acquire more precise measurements and it is easier, faster and consequently more effective than the existing methods. Through the results of this study, I suggest that the newly developed experiment by the researchers can overhaul the problems of the current experiments and it can be an effective alternative to the current experiment.

• 한국환경교육학회지:환경교육
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• 제23권3호
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• pp.50-61
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• 2010

As the influence of mankind's actions grows on the earth's climate, the necessity of climate change education is increasing everyday. Therefore, this study will discuss desirable courses about climate changes education that can be used throughout the world. It is meaningful to try to compare the contents and scope of earth global warming education courses of different nations. where education and a research about earth global warming occur simlutaneously. This is key because global warming is not just a national issue, but an international issue. Therefore this study need to understand the status of environmental education is over the world to devise an improvement plan help to solve the problem of climate change on an international level. Therefore, this study compared, the global warming educational contents which appeared in Korean textbooks to Japanese and American textbooks, and analyzed commonalities and differences of each. Also, we will discuss desirable global warming educational instructional strategies. This study analyzed the present situation of nations by looking at common points and differences using an analysis form. Even though the researchers of an each nation analyzed the teaching material through common analysis forms, this study utilized a common analysis method with a colleague researcher regarding environmental education, environment, environmental science to increase the validity of the study in each nation. Also the difference and similarities were aggregated as This study collected the analysis results of each nation. The researchers utilized the results of the analyses to engage in repeated discussion and the sharing of results.

• 한국지구과학회지
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• 제31권5호
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• pp.448-453
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• 2010

The population of House sparrow (Passer domesticus), once a very common bird, has declined markedly in most parts of the world including India. Sparrows were distributed widely in the district Hoogly, West Bengal, India. However over the past few decades, they became not so common in this part of the wo rld. A study has been conductedto establish the database for their current population and to assess the possible causes of their decline at Bandel ($22^{\circ}$52'22''N/$88^{\circ}$22'53''E) placed beside the river Hoogly from September 2008 to May 2009. After prolonged searching, a relatively dense population of sparrow (total subject 270) was found in busy areas of railway station and a nearby market in Bandel. The behavior of these birds was studied extensively from early morning to late night. The noise level of the area varied from 35 to 95 dB with an average of 70.6 dB from 04:30 am-10:30 pm, IST. It was also observed that the sparrows took rest on the site of the tree where the illumination level was low (30-45 lux). Sparrows residing at the Bandel station are habituated with the loud noise, being undisturbed by passing trains. Thus, it can be concluded that in spite of heavy noise of trains, crowdy travelers, and lack of nest sites, they remain at the station because of availability of food in the nearby roadside market. Based on this observation, sound pollution and availability of food are not responsible for their decline.

• 한국지구과학회지
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• 제21권4호
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• pp.479-487
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• 2000

${\ulcorner}$한국지구과학회지${\lrcorner}$가 발간된 지 20년이 지난 이 시점에 우리 나라 지구 과학 연구의 과거와 현재를 살펴보고 이를 근거로 나아갈 방향을 알아보기 위하여 ${\ulcorner}$한국지구과학회지${\lrcorner}$에 게재된 106편의 지구 과학 교육 연구 논문을 분석하였다. 양적 측면의 분석 결과, 지구 과학 교육 관련 연구가 최근 2년 동안 증가 추세에 있는 것으로 나타났다, 연구의 주제 측면에서 보면, 지구 과학 교육 내용에 관한 연구가 가장 많았으나, 우주 과학, 지질 과학, 대기 과학, 해양 과학 등의 ,세부 영역별 연구가 동일한 비중으로 이루어지지는 않았다. 연구의 대상 측면에서 보면, 교사보다는 학생 , 특히 고등 학생을 대상으로 하는 연구가 많았다. 연구의 방법 측면에서 보면, 교과서나 교육 과정을 분석하거나 검사 문항 등을 활용한 조사 연구가 가장 많았고, 문헌 연구는 거의 이루어지지 않았다. 연구의 내용 측면에서 보면, 교수/학습과 관련된 연구가 가장 많이 이루어진 반면 평가나 교사 양성에 관한 연구는 거의 이루어지지 않았다.

• KIEAE Journal
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• 제10권2호
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• pp.3-8
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• 2010

Many countermeasures are presented to make excessive earth circumstance pollution better in the earth. A lot of researches are in progress to lessen $CO_2$ among the industries exhausting it. The industries manufacturing cement are making many countermeasures. Many concernments on ECO-friendly materials, rather than cement, are increased, and researches are in progress to develop them. Lime, material mostly used before Portland cement appeared, attracts the Occident as well as the Orient. In the Occident, lime mortar was used in common, for maintaining and repairing cultural properties, too. This study is aimed at offering basic materials for the modern use of lime, ECO-friendly material. This study measured the change of intensity and weight with lime, sand, and earth, basic materials of Samhoimool. As a result, at the beginning, hydrated lime displayed its density late, but as time was gone, density was promoted continuously. In addition, density was promoted, when it was given heat at the beginning. If heat-generation reaction of quicklime and water was used, density was promoted at the beginning, but liquidity showed a drop.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제51권6호
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• pp.298-306
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• 2002

We performed an safety evaluation on constructing of a common grounding system for electrical railway in view of its efficacy and technical fit. In order to compare the conventional grounding method, which has been individually conducted, with the common grounding with all ground wires connected in common to the counterpoise buried below the surface of the earth in parallel with rail, we set up scenarios with several cases of fault and load conditions in Chungbuk railway sections with the common grounding system. Based on models for railway conductors including the grounded system, line Parameters of railway power system are computed. The circuit model for power system with up and down lines, auto-transformers and railway substations is used to compute impedances of counterpoise and substation ground net. For each scenario with faults and operation conditions of railway, the induced potentials on signal and communication lines are also computed. It is shown that the common grounding for Chungbuk railway is superior experimentally to the conventional method in three respects: (1) the lower rail potentials during operation of railway in line, (2) the lower rail potentials for short-circuit faults between catenary and rail, and (3) the lower stress voltages on signal and communication lines for short-circuit or ground faults. The analysis results confirm that the grounding system for electric railway is required to be built by the common grounding and be evaluated on its safety in design.

• 동남아시아연구
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• 제20권3호
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• pp.223-262
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• 2010

This paper has been written to find facts about the image of earth goddess broadly found in the Southeast Asia. The research findings are as follows: Firstly, the image of earth goddess wringing her hair is phenomenally discovered in both Buddhist temple murals and independent shrines in Thailand. This phenomenon is common in other Indochinese Buddhist countries such as Myanmar, Laos and Cambodia. Secondly, the life of Buddha including the story of the victory over Mara is found in such Buddhist canons as Mahavastu, Buddhacarita, Lalitavistara, Nidanakatha and Patamasambodhi. Among the canons, the story of the victory over Mara is described in differently ways. Earth becomes personified as the goddess in later version. The main cause to expel Mara's army also changes from sound to water. Patamasambodhi is most closely associated with the iconography of the earth goddess of Southeast Asia. Thirdly, Vessantara Jataka and Indian ancient customs tell us that a merit maker performs a rite of pouring water on the earth as an evidence for merit-making. This rite is a key to understanding the meaning of the scene where the earth goddess expels Mara's army into the flood by wringing her hair. The earth goddess is personified from the earth upon which the merit water is poured. Water soaked in her hair is the very holy water poured by the Buddha whenever he made a merit in his former lives. The amount of water flowed from the hair of the earth goddess representing the amount of his merit making was so huge and enough to defeat the Mara's army and for the Buddha to reach the Enlightenment. This legend explains the significance of the notion of merit in the Theravada Buddhist countries such as Thailand and Myanmar where the water pouring rites still take place and the images of the hair wringing earth goddess are commonly discovered. Fourthly, the first image of the earth goddess as the witness of merits for the Buddha appeared in some Gandharan Buddhist sculptures in the form of devotional gesture with her both hands pressed together and the upper half of her body above the ground. The appearance is in accordance with the description of her in the Lalitavistara canon. In later periods, the form changed into various types and finally the image of the earth goddess wringing her hair appeared in Southeast Asia around 11 century C.E. Some researchers argue this image form of the earth goddess shows the influence from China or India. However, the arguments are considered to be hypothetical as they have no strong evidence to prove. Finally, the modern image of earth goddess shows richer and more dynamic expression compared with its predecessors. Especially, outstanding is the standing earth goddess images found in the scene of the victory over Mara in many temple murals of central region of Thailand. The earth goddess in her voluptuous body shape is usually depicted as wringing her hair with her arms wide open in a posture of S curve. This appearance strongly reminds us of the postures of Salabhanjika and Tribhanga originated from Indian art. The adoption presumably has been made to signify her fertile and affluent characteristics.

• 한국지구과학회지
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• 제31권7호
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• pp.813-826
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• 2010

본 연구의 목적은 고등학교 교육과정에서 사용되고 있는 지구과학 불일치 용어를 조사하고 그 대안을 탐색하는 데 있다. 고등학교 지구과학 교과서에서 같은 의미를 지니면서 다른 용어를 사용하는 경우 이를 불일치 용어로 정의하였다. 불일치 용어를 참고문헌과 선행 연구의 용어와 비교한 후, 284명의 교사와 학생을 대상으로 선호도를 조사하였다. 연구 결과 불일치 용어는 고등학교 교과서는 물론 참고문헌에서도 다수 조사되었다. 선호도 조사 결과 의미가 쉽게 전달될 수 있는 용어, 이전에 학습한 용어, 외래어 표기법에 맞는 용어에 대한 선호도가 높았다. 그리고 고유명의 표기가 다르거나 서로 다른 문헌과 배경 지식에 기반하고 있는 불일치 용어는 외래어 표기법과 학회 발간물에 근거하여 대안을 모색할 수 있다. 따라서 공인된 이론에 근거하고 의미 전달이 쉬운 지구과학 용어를 공유하여 사용함으로써 혼란을 해소할 수 있을 것이다.

• 한국지구과학회지
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• 제31권5호
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• pp.430-436
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• 2010

Some materials belonging to the Leptostrobus myeongamensis Kim were found in the Upper Triassic Amisan Formation, Nampo Group, Korea. This species is closely associated with the foliage of Czekanowskia ex gr. rigida Heer. Although none of Leptostrobus myeongamensis Kim has been found in organic connection with Czekanowskia leaves, it is considered that they belong to the same taxa based on their common occurrence. The occurrence of Leptostrobus myeongamensis Kim from the Late Triassic floras of Korea is one of the oldest records in the Mesozoic floras found in the world.