• 한국지구과학회:학술대회논문집
• /
• 2010.04a
• /
• pp.99-100
• /
• 2010

충남 서부에 위치한 보령 지역은 트라이아스기 후기로 알려진 육성 기원의 남포층군이 널리 분포하고 있다. 남포층군은 하부로부터 하조층, 아미산층, 조계리층, 백운사층 및 성주리층으로 구분된다. 남포층군에서 산출되는 화석의 대부분은 식물 화석이며, 기타 이매패 화석, 어류 화석, 곤충의 유충 화석, 패갑류(conchostracans) 등의 화석이 산출되고 있지만, 양적으로 극히 적다. 이들 화석 중에서 체계적으로 연구가 된 것은 식물 화석뿐이고, 나머지 화석들은 전문 연구가의 부재 등에 의해 극히 미미한 연구 수준에 머물러 있다. 이번의 연구를 통해서 아미산층에서 채집된 곤충화석은 모두 107점이고, 그중에서 유충 화석이 94점, 날개 화석이 14점이다. 이들의 분류학적 연구 결과, 아미산층의 곤충화석군은 소시목, 강도래목, 날도래목, 하루살이목, 잠자리목, 바퀴벌레목, 벌목, 매미목을 비롯한 8목 11종에 이르는 유시류의 곤충들로 구성된다. 이들은 현재까지 우리나라에서 발견된 곤충화석 중 시대적으로 가장 오래된 화석이다. 유충 화석은 모두 수서 곤충의 유충화석이다. 이들의 유충은 수중생활에 적응하여 지상생활을 하는 성충과 형태적으로 큰 차이가 있는 불완전변태류 또는 외시류이다. 날개 화석은 수서곤충의 성충의 날개이고 일부는 육상 생활을 하는 곤충의 날개가 포함되어 있다. 아미산층에서 나온 곤충화석에는 육상에서 생활하는 매미목과 바퀴목도 있는데 이들은 불완전변태류에 속한다. 그러나, 똑같은 육상생활자이면서도 벌목은 완전변태류 또는 내시류에 속하는 것도 있다. 따라서 아미산층에서 산출된 곤충화석군에는 불완전변태류와 완전변태류가 섞여 있는 특징을 보인다. 이들은 실제로 같은 시대에 비슷한 장소에서 함께 생활을 했던 생물군집이지만, 서로 살던 장소가 다른 집단들이 섞여 있다는 것은 육상생활자의 일부가 죽은 후 수류에 의해 퇴적분지로 유입되어 매몰된 혼합집단으로 볼 수 있다. 현생의 하루살이목, 강도래목 등은 대표적인 유수성 곤충이고, 잠자리, 노린재 등은 대표적인 정수성 곤충으로 알려져 있다. 이들이 지층에 밀집하여 산출되는 것으로 보아 살던 장소에서 많은 퇴적물의 유입에 따른 급격한 매몰에 의해 화석화된 것으로 판단된다. 동아시아의 중생대 초기에서 보고된 곤충 화석은 양적으로도 수적으로도 그리 많지 않다. 그중에서 일본의 Mine에서 보고된 화석군이 가장 대표적이며 바퀴류(Blattaria)와 딱정벌레(Coleoptera)의 화석이 가장 큰 비율을 차지하지만, 아미산층 곤충화석군과의 공통종은 한 종도 없다. 아미산층의 곤충화석군은 비록 다양성은 쥐라기의 곤충상에 비해 떨어지지만 조성적으로는 쥐라기의 곤충상에 매우 유사하다. 육상에 사는 곤충이 화석으로 보존되기 어렵다는 것을 감안하면 아미산층에서 산출된 곤충화석은 학술적으로 매우 귀중하고 큰 의미가 있다. 보령 지역의 곤충화석은 중생대의 쥐라기와 백악기를 거쳐 현재로 이어지는 곤충 진화사의 잃어버린 고리를 이어줄 수 있는 귀중한 자료로 평가된다.

• Journal of the Korean Recycled Construction Resources Institute
• /
• v.4 no.4
• /
• pp.463-469
• /
• 2016

In this paper, compressive strength and water permeability performance for two types of crack self-healing materials such as SH-PO-0 composed of mineral admixtures(expansive agent, swelling material and crystal growth agent) and SH-PO-(5, 15, 30) blended with SH-PO-0 and phosphate additive(PO) dissolving easily calcium ion, were evaluated. The test results show that the water flow of SH-PO-0 decreased steeply at the early age although compressive strength decreased about 9% at 28 days compared with OPC. The higher PO replacement ratio is, the lower compressive strength and more improved water permeability performance is, and thus, based on such results, adequate PO replacement ratio is 15%. It is also found that the self-healing performance of SH-PO-15 was quite improved at the early ages and however, the performance of SH-PO-15 is similar to one of SH-PO-0 at long-term ages, and 28 days compressive strength of SH-PO-15 decreased about 8% compared with SH-PO-0. In addition, it is confirmed from the analysis of SEM-EDS that calcium ions of SH-PO-15 were crystallized more than those of SH-PO-0.

• The Korean Journal of Financial Studies
• /
• v.10 no.1
• /
• pp.171-189
• /
• 2004

외환시장의 효율성을 증대시키고, 기업이나 금융기관들의 원/달러환율 변동위험관리가 보다 원활하게 이루어질 수 있도록 하며, 원/달러 환율과 연계된 다양한 투자전략 구사가 보다 용이하게 이루어질 수 있도록 하기 위하여 미국달러 선물시장과 미국달러 옵션시장에서의 유동성 확대 및 시장 활성화가 요구된다. 본 논문에서는 미국달러 선물시장과 미국달러 옵션시장의 유동성을 제고시키고 시장을 활성화 시키기 위한 방안들을 제시하였다. 미국달러선물의 만기시 최종결제와 미국달러옵션 만기시 옵션매입자가 옵션을 행사할 때 권리행사에 따른 결제는 실물인수도 방식으로 결제되며, 이러한 실물인수도 방식의 결제는 현물환 포지션을 취하여야 하는 불편함과 현물환 거래와 관련된 거래비용 등으로 인하여 투자자들의 시장 참여를 제약하는 주요 요인으로 작용하고 있다. 미국달러선물과 미국달러옵션의 만기시 결제방식을 현금결제 방식으로 바꾸게 되면 헤지거래자 등 투자자들의 참여가 확대되어 시장 유동성이 증대되고 시장이 활성화될 것이며, 차익거래자들도 적극적으로 참여하게 되어 시장의 효율성이 향상될 것이다. 그리고 미국달러선물과 미국달러옵션을 이용한 투자기법 및 투자전략에 대한 투자자들의 이해 수준을 높이고 환율변동위험 관리의 중요성에 대한 기업들의 인식을 제고시키기 위한 적극적인 노력이 요구되며, 중장기적으로 선물회사들의 지점망 확충과 선물거래소 회원사 확대 방안도 모색되어야 할 것이다. 미국달러 옵션은 거래가 매우 부진한 상태이므로 미국달러 옵션시장에서 유동성이 어느 정도 확보될 때까지는 선물회사들의 시장조성 기능 강화가 요구된다.주었다. 둘째, 주가 수익률을 결정하는 유의성있는 요인들은 당기순이익의 증감, 당해연도의 당기순이익의 분포, 자산증가율, 매매 유동성, 매출액 변동, 거래량 추세, 기업크기(시가총액), 과거 1개월간의 주가수익률, 자기자본증가율등으로 나타났다.이 있을 것으로 여겨진다.다중회귀분석에서 각각 일관되게 관찰할 수 있었다. 또한 이러한 결과는 IMF 이후에도 여전히 유지되는 것으로 나타났다.과와는 별개의 PER효과가 여전히 존재하며, 다만 이 PER 효과는 전통적 의미의 일반적으로 낮은 PER종목이 초과수익률을 내는 것이 아니라, 기업규모가 크더라도 그 기업의 개별특성을 고려했을 때 이와 비교해 상대적으로 PER가 낮은 종목에 투자하면 초과수익을 낼 수 있음을 의미한다. 발견하였다.적 일정하게 하는 소비행동을 목표로 삼고 소비와 투자에 대한 의사결정을 내리고 있음이 실증분석을 통하여 밝혀졌다. 투자자들은 무위험 자산과 위험성 자산을 동시에 고려하여 포트폴리오를 구성하는 투자활동을 행동에 옮기고 있다.서, Loser포트폴리오를 매수보유하는 반전거래전략이 Winner포트폴리오를 매수보유하는 계속거래전략보다 적합한 전략임을 알 수 있었다. 다섯째, Loser포트폴리오와 Winner포트폴리오를 각각 투자대상종목으로써 매수보유한 반전거래전략과 계속거래 전략에 대한 유용성을 비교검증한 Loser포트폴리오와 Winner포트폴리오 각각의 1개월 평균초과수익률에 의하면, 반전거래전략의 Loser포트폴리오가 계속거래전략의 Winner포트폴리오보다 약 5배정도의 높은 1개월 평균초과수익률을 실현하였고, 반전거래전략의 유용성을

• Journal of The Korean Association For Science Education
• /
• v.10 no.1
• /
• pp.1-8
• /
• 1990

Mechanical CAI Program was developed for university science student The program was mainly aimed for individual study. The program was written in BASIC and construct 130s flams. This project was supproted by Ministry of Education research fund. Summary of this study is as follows. 1. The program consisted of main, pretest, tutorial, final, and several other routines for program control. 2. This program written in BASIC. 3. 20 flames for pretest routine, 90 flames for tutorial routine, 20 flames for final test routine were developed. 4. The expected rate of achivement for final test was set 80%. 5. Average mark of final test was 70.2 point through the all course of program. This means that program was constructed of well.

• The Journal of Korean Academy of Sensory Integration
• /
• v.15 no.2
• /
• pp.22-34
• /
• 2017

Objective : The purpose of this study was to draw up sensory integration intervention competency model for occupational therapist and was to confirm a competency model through validation. Methods : We conducted literature review, expert opening survey, and expert focus meeting to draw up draft competency model. And then, we carried out Delphi survey twice and consulted an expert to confirm the sensory integration intervention competency model for occupational therapist. Results : The sensory integration intervention competency model for occupational therapist developed in this study was structured into 4 competency cluster, 15 competency, 60 competency indicators. 4 competency clusters had expertise, professionalism, interpersonal skills, and personal characteristics. Conclusion : The competency model revealed in this study can be used as basic critical data to foster development of competency based curriculum of Korean Academy of Sensory Integration (KASI).

• Korean Journal of Social Welfare
• /
• v.52
• /
• pp.33-61
• /
• 2003

This study aims to identify early retirement and the subsequent career ending patterns and explain the phenomena in terms of social security policies and labor market perspectives. Although many older workers retire early, there are very few studies to examine how the retirees end their careers after quitting the long-time jobs. The paper investigates individual work experiences 55 through 61, identifies the career ending patterns, constitutes the micro and macro analytical models to estimate the impacts of labor market and work-related variables. The findings show that many older workers have diverse career ending patterns after long-time career jobs, that is, still working at age-55 job, exiting and reentering, sporadic work, retired permanently from age-55 job, a repeat of labor force entry. Also the estimation results indicate that pension, social security, labor market condition, work structure variables better explain the career ending behaviors than social psychological factors of health, education, attitudes toward retirement and job, ethnicity. Finally, this paper discusses theoretical importances of labor market perspectives and policy implications at the end of thesis.

• Journal of Korean Society of Forest Science
• /
• v.104 no.1
• /
• pp.117-126
• /
• 2015

Forest statistics of local administrative districts have many social needs, nevertheless we have some difficulties for working out an accurate statistics because of insufficient data in small-area level. Thus, new small-area estimation method has to set aside additional data, decrease errors of statistics and consider the local forest characteristics at the same time. In this study, we researched the spatial divisions that can set aside additional data for statistics production and satisfy the major premise, which is "forest characteristics of spatial divisions have to be equal to that of small-area". And we compared synthetic estimation methods based on three different spatial divisions(provinces, neighbor districts and new expanded districts). New expanded districts were divided based on the criteria of climate, soil type and tree species composition that affects local forest characteristics. Small-area statistics were assessed in terms of the ability to estimate local forest characteristics and consistency within large-area statistics. As a result, new expanded districts synthetic estimation was assessed to calculate statistics that reflects local forest characteristics better than other two estimation methods. Moreover, this synthetic estimation method produced the statistics that was included within 95% confidence interval of large-area statistics and was the closer to large-area statistics than the neighbor districts synthetic estimation.

• Journal of the Korean Geographical Society
• /
• v.51 no.6
• /
• pp.935-955
• /
• 2016

This study aims to analyze the changes of goals and contents of middle school geography education following up the changes in the Korean social studies curriculum over time. The main findings are as follows. First, From the Syllabus period to the Third Curriculum, geography education, history education, general social studies education in the middle school social studies were directed and managed independently. However from the 4th to the 7th Curriculum, the demand for the virtual integration in middle school social studies increased sharply. Since 2009 revision, social studies suffered an identity crisis as integrated subject matter because history education was separated from the social studies and interdisciplinary units were abolished. In spite of much criticism, however, an odd form of social studies integrating geography and general social studies still remains. Second, the stronger the demand for the social studies integration in middle school, students' social studies learning load had become heavier due to severe competition with other areas to ensure more portion in the integrated structure of social studies. Since geography education did not reflect the new tendency of the geography in the integrated structure of middle school social studies, the gap between the geography and geography education has increased and knowledges of geography growing became separated from students' experience. In conclusion, the integrated structure of social studies in the middle school hindered the geography education development as it limited the autonomy of geography education in terms of curriculum development.

• Journal of the Korean Institute of Gas
• /
• v.11 no.4
• /
• pp.41-46
• /
• 2007

The residential fuel cell system was modeled as a box-shaped chamber with vent openings, filled with various components such as reformer, desulfurizer, fuel cell stack and humidifier. When the vent openings are 1% of the total surface and hydrogen leakage 1%, hydrogen concentration is around 0.1% higher than the other regions from leak points in the chamber at 30 seconds and hydrogen concentration is increased from 0.3% to 0.7% in the upper region of the system after 200 seconds. When the vent openings are 1% of the total surface and hydrogen leakage 1%, 3%, 5%, the steady state result of CFD, 5% of hydrogen leakage is reached the lowest ignition limit in the system. When the vent openings are 2% of the total surface and hydrogen leakage 1%, hydrogen concentration is increased in the bottom of the system for 60 seconds. After 250 seconds, hydrogen concentration is reached the steady state in the system. As the vent opening of the total surface increased from 1% to 2%, averaged hydrogen mole fraction is under 1% in the system, however, upper regions of the system from the hydrogen leakage points are shown over 1% of hydrogen mole fraction.

• Journal of the Korean Institute of Gas
• /
• v.16 no.2
• /
• pp.25-30
• /
• 2012

This paper presents a stress safety of a composite pressure cylinder in which is composed of an aluminum liner and composite layers with carbon fiber/epoxy and glass fiber/epoxy resigns. The composite pressure cylinder for a hydrogen gas vehicle contains 9.2 liter hydrogen gas, and hydrogen gases are compressed by a filling pressure of 35MPa. The FEM computed results are analyzed based on the US DOT-CFFC basic requirement for a hydrogen gas cylinder and KS B ISO specification. The FEM results indicate that the stress, 247MPa of an aluminum liner is sufficiently low compared with that of 272MPa, which is 95% level of a yield stress for aluminum. And, the carbon fiber composite layers in which are wound on the surface of an aluminum cylinder are safe because the maximum carbon fiber stresses from 29.43% to 28.87% in hoop and helical directions are below 30% for a given minimum required burst pressure level, respectively. The carbon fiber composite layers are also safe because the stress ratios from 3.40 to 3.46 in hoop and helical directions are above 2.4 for a minimum safety level, respectively.