The reinforced retaining wall was introduced in the late 1980s and has been actively used since the 1990s in Korea 's expressway construction. At the beginning of the introduction, proper stiffeners and backfill materials were used and compaction management was thoroughly carried out, which was recognized as an economical and excellent workability method. However, the current understanding of reinforced earth retaining walls about 30 years old is a negative image such as inadequate reinforcement materials, backfill materials, insufficient compaction, and insufficient drainage system. In this way, the reinforced earth retaining walls that have been constructed in the midst of the negative perception are about 1,000 at the expressway site, and about 1000 will be completed in a few years and about 2,000 will be used. Most of the problems of reinforced earth retaining wall were found during maintenance, and countermeasures are suggested by tracing back to what problems were observed in the design and construction of the observed phenomena. The retaining walls to be installed in future maintenance should be minimized in designing and constructing to prevent problems. It is estimated that such a problem can be solved by changing the recognition. Therefore, in this study, damage cases of reinforcement retaining wall which is frequently occurred in the expressway of Korea were analyzed to derive the preventive maintenance method of reinforced earth retaining walls. Then, the problems and countermeasures were analyzed for each type of damage.

Reinforced earth retaining walls are easier to construct and more economical than concrete retaining walls, and the applicability to the parts where the retaining wall structures are needed is gradually increasing. Since 1980, reinforced earth retaining walls have been used in various ground and environmental conditions, and various types of damage have been found in the maintenance stage due to various conditions of the applied site. Especially, when the ground is sloped, the damage is more serious than the case where it is not. Therefore, in this study, the long-term behavior of reinforced earth retaining wall constructed on the expressway according to the slope of the ground is analyzed.

In Korea, the structure is mostly located on the upper part of the high embankment considering the geographical conditions at the time of expressway construction. Embankment was managed stepwise compaction according to height, but creep settlement of embankment itself may negatively affect superstructure. Reinforced earth retaining walls, which were recognized as flexible structures, were no exception to such geographical conditions. Especially, in the case of reinforced earth retaining wall located on abutment wing wall, damage due to differential settlement supported by pile, damage due to differential settlement and uneven settlement of reinforced earth retaining wall itself was frequently occurred. Therefore, in this study, the damage of reinforced earth retaining wall structure located on the high toe part was analyzed based on case. These data will be used as basic data for future maintenance.

Reinforced earth retaining walls are applied to various fields such as clay part, cut part, adjacent part of structure (alternation, culvert) and reinforcement soil alternation in Korea. Therefore, they are applied more favorably than concrete retaining wall because of its excellent economy and construction. Analysis of reinforced earth retaining wall construction shows that the height is more than 10m higher than that of foreign countries, and when it is applied in multi - stage, it is more than 20m. The reinforced earth retaining wall was introduced in Korea in the 1980s, and the number of years of damage has been increasing due to the fact that the number of public years has been increased to 30 years since it was first applied to the present. Especially, in the case of multi-stage reinforced earth retaining walls having a height of 10 m or more, And the risk of the risk to reach the situation is found. Therefore, in this study, damage characteristics occurred in reinforced earth retaining wall constructed in multi - stage in expressway were analyzed.

본 연구의 목적은 우리나라에서 수행된 지구과학교육 분야의 개념변화 연구 동향을 분석하여 향후 개념변화 연구의 기초 자료로 제공하는 것이다. 우리나라 지구과학 개념변화 연구의 경향성을 논문의 키워드, 발표 연도, 논문 출처, 연구 목적, 연구 대상, 연구 영역, 연구 방법 측면에서 분석하였다. 연구 대상은 우리나라 지구과학교육의 개념변화 연구 논문이 처음 발표된 1989년부터 2017년 7월까지, 총 126편의 지구과학교육의 개념변화 논문이었다. 본 연구의 분석 결과는 다음과 같다. 첫째, 지구과학 개념변화 논문은 ‘개념변화’라는 용어를 ‘오개념’, ‘선개념’ 보다 더 많이 사용하였다. 둘째, 개념변화 논문은 2000년대에 많은 양적인 성장을 이루었다. 셋째, 개념변화는 석사 학위의 연구주제로 많이 이루어지고 있었다. 넷째, 오개념 조사와 그에 따른 교정을 함께 다룬 연구가 많았고, 오개념 조사로는 자유응답 검사법을, 오개념 교정 방법으로는 인지갈등 수업모형과 CAI 교수전략을 주로 활용하였다. 다섯째, 초등학생 대상 연구가 가장 많이 이루어졌다. 여섯째, 개념변화 연구의 지구과학 영역은 천문과 대기의 비중이 높았다. 마지막으로, 연구 초기에는 양적 분석 방법을 많이 사용하였지만, 2010년대에 들어서는 질적 분석 방법을 많이 사용하였다. 향후 개념변화의 연구 과제로 예비 및 현직 교사 대상의 개념변화 연구, 지질·해양·대기 등 다양한 영역으로의 연구 확대, 오개념 형성원인 파악 및 정의적 요인에 관한 연구 등을 제안하였다.

Feeding effects of the honeybee pollen products from both domestic, China, Spain and mixture of different origin on the colony development of earth bumblebee, Bombus terrestris L., were surveyed to evaluate efficient nutritional resources for commercial bombiculture in Korea. As the results, the domestic pollen was most effective to achieve high rates of oviposition (88%), colony foundation (70%), and queen production. While feeding with domestic pollens during the egg-laying period, and domestic+Chinese mixture (5:2) during the breeding period (Plot-2), it revealed high oviposition rate of 75%, colony foundation of 65%, and large numbers of adult queen production, indicating its suitability for generation subculturing. In the Plot-3, the same high oviposition rate (75%) was obtained except for feeding with the domestic+Chinese mixture (2:5) during the breeding period, which produced large number of workers.

Dianthus caryophyllus (carnation) is a globally important ornamental plant. Tissue culture techniques have been used for the commercial production of carnation; however, the micropropagation of carnation has been impeded due to the occurrence of hyperhydricity during the shoot multiplication process or micropropagation stage 2. In the present study, the effects of different concentrations of rare earth elements on the reduction of hyperhydricity in micropropagated carnation were investigated. Nodal explants of D. caryophyllus ‘13827’ were cultured on Murashige and Skoog medium containing 1.0 mg·L-1 6-benzyladenine and 0.5 mg·L-1 indole-3-acetic acid with 3.0% (w/v) sucrose and 0.8% (w/v) agar (control medium). The medium was supplemented with lanthanum nitrate, La(NO3)3, cerium nitrate, Ce(NO3)3, or neodymium chloride, NdCl3 at a concentration of 0.05, 0.1, or 0.15 mM. Hyperhydricity was observed in 68.9% of the cultures produced on the control medium. The lowest percentage (42.2%) of hyperhydricity was observed in plants propagated on the medium supplemented with 0.05 mM Ce(NO3)3. Furthermore, the soluble protein concentration was higher in both the non-hyperhydric and hyperhydric plants produced on the medium supplemented with 0.05 mM Ce(NO3)3, whereas the activity of catalase, guaiacol peroxidase, and ascorbate peroxidase was lower in comparison with the media lacking Ce3+. The results of this study suggest that supplementation of the culture medium with 0.05 mM Ce(NO3)3 alleviates oxidative stress and reduces hyperhydricity in carnation during the adventitious shoot multiplication stage.

산업과 의학이 발전되면서 많은 인구는 삶의 질에 관심을 가지게 되었다. 건강에 대한 시각이 높아지면서 육류보다 채식 또는 식물성 오일을 선호하게 되었다. 오늘날 주로 니켈 촉매를 사용한 공정이 개발되면서 식물성 오일의 보존기간이 늘어나고 이동성이 편리해졌다. 현재 유지경화용 니켈 촉매는 외국기업이 세계시장을 장악하고 있다. 한편, 국내 니켈 촉매의 대량 생산 기술은 퇴보 되어 전량 외국에서 수입하고 있는 실정이다. 따라서 활발한 기초연구가 필요하고 국내에서 상용화 할 수 있는 촉매개발이 필요하다. 본 연구는 수소화 반응으로부터 유지경화에 기반이 되는 니켈을 주 활성 촉매제로 사용하였고, 희토류가 촉매의 활성에 주는 영향을 알아보았다. 일정량의 희토류는 니켈의 분산을 유도하여 효율을 증가시키고 조촉매로써 사용이 가능하였다.

한국교회에 만연한 숨 떨어지면 천국으로 직행한다는 통속적 천국관의 폐해는 이 땅과 이 땅에서의 삶에 대한 경시이다. 사도신경과 주기도문에서 이미 명확하게 드러난 하늘과 땅의 불가분리성과 새 하늘과 새 땅에 대한 소망을 주요 신학자들을 중심으로 재조명해 그 선교적 함의를 밝히는 것이 이 논문의 목적이다. 2장에서는 통속적 천국관을 극복하기 위해서 조종남을 중심으로 종말론을 다룬다. 자유주의 신학의 영혼 불멸설과 신정통주의 신학의 순간적 부활설과 가톨릭의 연옥설과 재세례주의자들과 안식교인들의 영혼 취침설과 정통주의 신학의 중간 상태, 즉 낙원과 음부를 다룬 후 조종남의 구원의 여정인 몸의 부활과 최후의 심판과 우주의 회복인 새 하늘과 새 땅과 하늘나라와 지옥에서의 영생을 소개한다. 3장에서는 하워드 스나이더(Howard A. Snyder)와 톰 라이트(Nicholas Thomas Wright)를 중심으로 부당하게 이혼된 하늘과 땅의 재결합을 다룬다. 4장에서는 라이트와 칼 바르트(Karl Barth)를 중심으로 하늘과 땅의 재결합을 가장 명확하게 밝히는 주기도를 다룬다. 결론에서는 이신론과 영지주의적 영성과 개인주의적인 현실도피적인 구원관을 넘어서 성경적 방식으로 창조세 계를 대할 것을 제안하며 스나이더의 네 번째 회심을 소개한다.

Theory of Earth’s free oscillation is revisited. Firstly, we summarized the underlying formulations, such as the equation of motion and its conversion into numerically integrable form and then explained computational procedures including the treatment of inner core-outer core boundary and core-mantle boundary, while the latter information has not been explicitly given in most publications. Secondly, we re-calculated the periods of Earth’s free oscillation modes (period >200 s) for PREM model. In doing so we acquired the values of modes missing in Dziewonski and Anderson (1981). As a case observation, one seismogram after 2011 Tohoku earthquake recorded at Daejeon, Korea (KIGAM seismic station) was briefly analyzed to identify free oscillation mode excitations on its spectra. The material in this article will be most clear guide for those on calculating the Earth’s free oscillation mode.

Urban planning and engineering undergraduate students need to understand the earth physical systems and that how human beings interact with the earth systems to planning and engineering urban area. The eco-friendly or geofriendly design and planning of an urban area is a critical issue not only for economic benefits but more importantly for the sustainable future of urban life. However, little study has been done dealing with the urban engineering students’ understanding of the earth as a system and what pedagogical approach is appropriate to improve their understanding of the earth as a system. This study is to investigate the impact of a purposely designed ESS course on urban engineering students’ understanding of the earth as a system and their perceptions about the instructional approaches of the course on their learning competency. This study utilized a mixed-methodology with three main data sources: concept maps, student’s perception survey about their learning competency, and course contents. Both the survey and concept maps were analyzed quantitatively as well as qualitatively. The result of this study showed that the urban engineering students’ experience of team-based research about the topic they chose based on their own interest had a positive impact on their understanding of the earth as a system and their learning competency. The results of this study suggest that structuring and presenting the earth system contents in the context of engineering students’ understanding and their future career be effective not only for the improvement of students’ content knowledge but also for the enhancement of their learning competency such as creativity and problem-solving skills in everyday life situation

In Donghak, an awareness of Hanul in all aspects of life awakens spirituality and vitality in human beings and begins to heal the world. Dong-yup Shin determinedly searched for a literary re-contextualizing of this thought of Donghak to reestablish oppressed people as the subject of history. This article examines such an attempt in “The Talking Ploughman’s Earth,” Shin's debut work. The singularity of this poem lies, especially, in how it embodies the spirituality and vision of Donghak through the narrative of a rite of passage. By passing through Donghak’s initiation rite, Ploughman, the narrator of this poem, acquires spiritual subjectivity and gains the key to world healing. Finally, his adventure encounters the philosophy of the history of Donghak, which tries to transform the ‘here and now’ into a site of hope, and with this, it secures the possibility of restoring the subjective puissance of the people.

Volatile organic compounds (VOCs) are a source of air pollution and are harmful to both human health and the environment. In this study, we fabricated polyurethane/rare earth (PU/RE) composite nanofibrous membranes via electrospinning with the aim of removing VOCs from air. The morphological structure of PU/RE nanofibrous mats were investigated using FE-SEM, EDX, and XRD experimental analyses. A certain amount of RE (up to 50 wt% compared to PU pellets) particles could be loaded on/into PU fibers. The PU nanofiber containing 50 wt% RE powder had the smallest fiber diameter of 356 nm; it also showed the highest VOCs absorption capacity compared with other composite membranes, having an absorption capacity about 3 times greater than pure PU nanofibers. In addition, all of the PU/RE nanofibrous membranes readily absorbed styrene the most, followed by xylene, toluene, benzene and chloroform. Therefore, the PU/RE nanofibrous membrane can play an important role in removing VOCs from the air, and its development prospects are impressive because they are emerging materials.

In general, the design concepts of earth-observation satellites are established depending on the purposes of utilization such as commercial imagery business, public services, scientific research. Nowadays, The lightweight satellite structure is considered as an effective method for developing the earth-observation satellite. This paper introduces a design concept of the lightweight satellite structure for the constellation of earth-observation satellites. The modular design of the satellite structure is applied to save manpower and shorten the AIT process, in addition, a propulsion module is adopted to allow a hydrazine propulsion system to be installed on the satellite. The finite element method is used for the structural analysis of the satellite. The axial and lateral frequency requirements of satellite structure were verified by mode analysis. also, the margin of safety of satellite structure parts were satisfied with design requirements. As a result, the structural integrity of the suggested satellite structure is verified by mode analysis and static analysis.

이 연구의 목적은 사범 대학 과학교육학부에 재학 중인 예비 과학 교사들을 대상으로 고등학교에서의 지구과학 선택 과목의 이수 여부와 대학 전공이 일반지구과학 수업에 대한 태도, 학업 성취도에 미치는 영향을 분석하는 것이다. 이 연구의 대상은 광역시 소재 대학교 과학교육학부 소속의 학생들 중 2012년 2학기부터 2015년 2학기까지 총 4개 학 기 동안 일반지구과학 강의를 수강한 273명의 학생들이다. 현재 전공과 고등학교 지구과학 교과목 이수 여부가 일반지 구과학 수업에 대한 태도 및 시험 체감 난이도, 학업 성취도에 미치는 영향을 SPSS 23.0을 활용하여 이원분산분석 (two-way ANOVA)을 실시하였다. 연구 결과에 따르면, 지구과학교육 전공 학생들과 타 과학교육전공 학생들 사이에는 일반지구과학 수업에 대한 태도와 시험 체감 난이도에 대해서 차이가 없었지만, 고등학교에서 지구과학의 이수 여부는 학생들의 태도와 성취도에 영향을 미쳤다. 즉, 고등학교에서 지구과학 I과 지구과학 II를 모두 이수한 학생은 지구과학 I만 이수한 학생 또는 지구과학을 전혀 선택하지 않은 학생들보다 일반지구과학 수업 태도가 더 좋았으며 높은 성취 수 준을 보이는 것으로 분석되었다. 과학 교사를 양성하는 사범 대학의 교육에서는 학생들의 요구와 수준을 반영한 교수학습적 접근이 필요하며, 과학 교사로서 필요한 교과 지식을 효과적으로 학습할 수 있도록 사범 대학 과학과 교육과정의 지속적인 보완이 있어야 할 것이다.

이 연구의 목적은 지구과학 탐구에서 통합 탐구 기능에 대한 학생들의 학습발달과정을 탐색하는 것이다. 이를 위해 과학 탐구 기능 발달과정 관련 문헌의 조사를 통해 ‘탐구 설계’, ‘자료 수집’, ‘자료 해석’, 그리고 ‘결론 도출’을 발달 변인으로 설정하고, 각각에 대한 가설적 학습발달과정(HLP)을 4개 수준으로 개발하였다. 또한, 통합 탐구 기능에 대한 학생들의 학습발달과정을 조사하기 위한 도구로 3가지 지구과학 탐구 과제를 개발하였는데, 이들은 학생들이 주어 진 문제 인식에서 출발하여 결론 도출에 이르기까지의 통합 탐구 기능을 포함하는 가설-연역적 탐구이다. 중학생, 고등 학생, 대학생 총 126명을 대상으로 각각 개발된 지구과학 탐구 과제를 수행하게 한 후 HLP를 토대로 개별 학생들의 통합 탐구 기능을 요소별로 평가하였다. 또한, 학생들의 평가 자료를 Rasch 모델에 적용하여 HLP에 대한 타당화 과정 을 거쳤다. 마지막으로, 분석 결과를 근거로 HLP를 수정 보완하여 경험적 학습발달과정을 개발하였다. 이 연구는 학생 들의 통합 탐구 기능의 발달에 영향을 주는 요인들을 규명함으로써 지구과학 탐구 수업에서 학생들의 통합 탐구 기능 을 효과적으로 향상시키기 위한 스캐폴딩 방안을 찾는데 도움을 줄 수 있을 뿐만 아니라, 지구과학 탐구 수업에 대한 교사들의 PCK를 향상시키는데 필요한 시사점을 제공한다.