• 제목/요약/키워드: Grade adjust

검색결과 48건 처리시간 0.024초

가변열원에 대응하기 위한 ORC 사이클의 실험적인 연구 (An Experimental Study on the Organic Rankine Cycle to Utilize Fluctuating Thermal Energy)

  • 조수용;조종현
    • 한국유체기계학회 논문집
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    • 제18권4호
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    • pp.13-21
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    • 2015
  • The system design of the Organic Rankine Cycle(ORC) is greatly influenced by the thermal properties such as the temperature or the thermal capacity of heat source. Typically waste heat, solar energy, geothermal energy, and so on are used as the heat source for the ORC. However, thermal energy supplying from these kinds of heat sources cannot be provided constantly. Hence, an experimental study was conducted to utilize fluctuating thermal energy efficiently. For this experiment, an impulse turbine and supersonic nozzles were applied and the supersonic nozzle was used to increase the velocity at the nozzle exit. In addition, these nozzles were used to adjust the mass flowrate depending on the amount of the supplied thermal energy. The experiment was conducted with maximum three nozzles due to the capacity of thermal energy. The experimented results were compared with the predicted results. The experiment showed that the useful output power could be producted from low-grade thermal energy as well as fluctuating thermal energy.

유기성 폐기물의 자원화 체제구축에 관한 연구 (Construction of Resource Recovery System for Organic Wastes)

  • 양재경;최경민
    • 기술혁신학회지
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    • 제2권2호
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    • pp.290-308
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    • 1999
  • In this study a system for the treatment or recyling of organic wastes from both urban and rural area was recommended. It was developed based on the resource recovery system regarding human being by four tectnologies; forage, methane production, high-grade composting and complete decomposition. High quality compost can be produced by combining several kind of wastes produced from urban and agricultural areas. High quality compost must possess not only general characteristics of ordinary compost, but also a superior ability to improve the soil properties and must contain more nutrients for plant. Cedar chips were recommended as the main bulking agent to adjust moisture contents and air permeability. Charcoal and zeolite can be used not only as the second bulking agent but also as fertilizer for improve the soil amendment. Complete decomposition of organic wastes is defined by organic matter being completely converted to $CO_2$ and water. All the input water was evaporated by the heat produced through the oxidation of organic matter, In the present study, the complete treatments were successfully achieved for Shochu wastewater, swine wastes, thickened excess sewage sludge, wastes produced by Chinese restaurant and anaerobic digested sludge. First of all, recycling center of organic wastes should be established for the protect the environments and effective recovery of organic resources. This may means the way to derive the recovery of human value.

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초등학교 고학년 학생의 학교적응 관련요인에 관한 연구 (Study on the Factors related to School Adjustment of upper Elementary Students)

  • 김나영
    • 한국학교보건학회지
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    • 제29권3호
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    • pp.201-208
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    • 2016
  • Purpose: This study was designed to examine the factors related to school adjustment of upper graders in elementary school. Methods: Data was collected through a questionnaire survey of 304 fifth and sixth grade students from October to November, 2014. The collected data was analyzed statistically through frequency, t-test, ANOVA, $Scheff{\acute{e}}$ test, Pearson's correlation coefficient and multiple regression analysis, using the SPSS/WIN 22.0 program. Results: First, subjective school record and subjective health status showed significant differences in school adjustment. Second, social support and ego-resilience were positively correlated, while bullying was negatively correlated with school adjustment. Third, significant factors related to school adjustment were social support, ego-resilience, subjective school record. These variables explained 56.4% of the students' school adjustment. Bullying was negatively correlated with school adjustment, but the correlation disappeared in the multiple regression analysis, where protective factors such as social support, ego-resilience were controlled for. Conclusion: School nurses should develop plans to enhance social support (teacher support, parents support, friends support) as well as programs to improve the ego-resilience of upper elementary students to help them adjust to school and to prevent and manage bullying. Also family, school and the community should be connected cooperatively with each other.

기구학적 커플링으로 구성된 3자유도 병렬 메커니즘 해석 및 설계 (Analysis and Design of 3-DOF Parallel Mechanism Based on Kinematic Couplings)

  • 왕위준;한창수
    • 한국생산제조학회지
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    • 제21권3호
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    • pp.479-486
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    • 2012
  • This paper presents a high-speed automatic micro-alignment system that is a part of an inspection machine for small-sized molded lenses of mobile phones, palm-top computers, and so on. This work was motivated by the shortcomings of existing highest-grade commercial machine. A simple tip/tilt/Z parallel mechanism is designed based on kinematic couplings, which is a 3-degree-of-freedom (3-DOF) moderate-cost alignment stage. It is used to automatically adjust the posture of each lens on the tray, which is impossible by the conventional instrument. Amplified piezoelectric actuators are used to ensure the accuracy and dynamic response. Forward kinematic analysis and simulation show that the parasitic motion is small enough compared to the actuator stroke. From the workspace analysis of the moving platform, it is clear that the output motion range satisfies the design requirements.

부모의 방임 및 학대가 청소년의 학교생활적응에 미치는 영향 : 사회적 위축의 매개효과 (The Effects of Parents' Neglect and Abuse on the School Adjustment in Adolescents : The Mediating Effects of Social Withdrawal)

  • 박기원
    • 아동학회지
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    • 제35권1호
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    • pp.1-15
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    • 2014
  • In this paper, the effects of parental neglect and abuse on school adjustment mediated by social withdrawal in adolescents were examined using a sample of 2,163 second grade middle school students(1,096 boys and 1,067 girls) from the Korean Child and Youth Panel Survey(KCYPS) data set. All research variables were measured using self-reported questionnaires. They were analyzed by means of Structural Equation Modeling. The results indicated that parents' abuse had no direct effect, but there was an indirect effect on adolescents' school adjustment mediated by adolescents' social withdrawal. Parental neglect had a direct effect on adolescents' school adjustment and also had an indirect effect on adolescents' school adjustment mediated by social withdrawal. The results indicate that parental neglect is a more significant contributor than adolescents' social withdrawal on adolescents' school adjustment. The results of this study show that parenting attitude, more specifically parental neglect, tend to be more important factors on school adjustment compared to adolescents' psychological problems, such as social withdrawal in adolescence. Taken together, these findings suggest that interventions aimed at improving parental neglect and adolescents' social withdrawal need to be emphasized if adolescents are to better adjust to school life.

제7차 지구과학I, II 교육과정 개선 방안 연구 (Research on Ways to Improve the 7th National Earth Science I, II Curriculum)

  • 이양락;김동영;곽영순
    • 한국과학교육학회지
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    • 제27권4호
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    • pp.328-336
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    • 2007
  • In this research we conducted a survey on the actual status of the 7th National Earth Science I & II curriculum to explore ways of revising the next Earth Science curriculum for better education. Of the 180 Earth Science teachers, 60% responded to the survey. The domains of the survey consist of (1) the necessity of Earth Science I & II curriculum revision, (2) educational goals, (3) content coverage, (4) level of difficulty and students' interest for Earth Science content, and (5) ways to overcome the crisis of Earth Science education. Majority of the respondents demanded the revision of Earth Science I, II curriculum because of overlapping and repetition of contents among 10th grade science and Earth Science I and overcrowded Earth Science II contents. Based on the survey results, recommendations on how to improve Earth Science I, II curriculum and how to adjust Earth Science contents are suggested. In addition to curriculum improvement, systematic supports are required for Earth science not to be excluded and turned down by the student and the scholastic aptitude test for university admission.

Back-Projection을 활용한 홍삼 내부 측정 시스템 (A Red Ginseng Internal Measurement System Using Back-Projection)

  • 박재영;이상준
    • 정보처리학회논문지:소프트웨어 및 데이터공학
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    • 제7권10호
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    • pp.377-382
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    • 2018
  • 본 연구는 홍삼 등급 판정을 위한 내부 상태 및 조직의 치밀도 분석 방법에 관한 것이다. 홍삼 내부 측정을 위해 1990년대 이후부터는 자기공명영상법(MRI), X-ray 판별 등의 비파괴 검사 방법에 대한 연구가 다양하게 이루어졌지만, 등급 판정에 가장 중요한 내공(內空), 내백(內白)을 파악하는데 어려움이 있어 정확한 내부 판정이 불가능하였다. 그리하여 본 연구에서는 적외선 조명 환경의 폐쇄형 영상 취득 장치를 제작하고 내공, 내백의 유무와 직경을 파악할 수 있는 내부 측정 시스템을 개발하였다. 제작한 장치는 홍삼 내부 투과율이 높은 950nm 파장대역의 적외선 조명, 적외선 대역 촬영이 가능한 카메라, 카메라에 홍삼의 초점을 자동제어 할 수 있는 Y축 제어 액추에이터 그리고 홍삼을 $1^{\circ}$의 간격으로 $360^{\circ}$ 회전하며 영상을 취득할 수 있는 회전 액추에이터로 구성이 되어있다. 제안하는 알고리즘은 Y축 액추에이터에서 Auto-Focus 알고리즘을 수행하여 홍삼의 크기와 두께 변화에 따라 객체의 선명한 초점을 자동으로 맞춰준다. 그다음 홍삼을 $1^{\circ}$ 간격으로 $360^{\circ}$ 회전하며 총 360장의 홍삼 영상을 취득하면 라돈 변환(Radon transform)을 통해 사이노그램(Sinogram)으로 재구성하고, 역 라돈 변환(Inverse Radon transform)을 통해 단층영상복원(Back-projection) 알고리즘이 수행되어 홍삼 내부 영상을 획득하였다. 알고리즘 수행 결과 홍삼 두께나 모양에 관계없이 내부 단면영상 획득이 가능하였고 영상을 통해 내공, 내백의 유무와 직경을 파악할 수 있었다. 추후 10,000개 이상의 다양한 모양과 크기를 가지는 홍삼에 대하여 내부 영상을 취득하여 등급 판별 기준을 적용한다면 신뢰성 있는 홍삼 등급 자동화 측정 방법으로 사용가능 할 것이다.

TIMSS 2019의 8학년 지구과학 평가틀을 이용한 남한과 북한 지구과학 내용 비교 분석 (A Comparative Analysis of South and North Korean Earth Science Curriculum using the TIMSS 2019 Eighth Grade Earth Science Evaluation Framework)

  • 박기락;박현주
    • 한국지구과학회지
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    • 제41권3호
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    • pp.261-272
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    • 2020
  • 본 연구의 목적은 남한과 북한 지구과학 내용의 학습 시기와 학습량을 비교 분석하여 향후 통일을 대비한 남·북한 통합 교육과정 설계 및 우리나라 교육과정 개정 시에 참고할 수 있는 기초 자료를 제공하는 것이다. 연구 대상으로는 남한은 초등학교 5학년부터 중학교 3학년까지의 과학 교과서와 고등학교의 통합과학과 지구과학 I·II 교과서이며, 북한은 초급중학교의 자연과학 1·2와 조선지리 2, 고급중학교의 지리 1 교과서이다. TIMSS 2019의 8학년 지구과학 평가틀로 분석한 본 연구의 결과는 다음과 같다. 첫째, 남한은 반복 학습을 고려할 필요가 있다. 학습 이해에 효과적인 반복 학습이 적용된 내용은 8학년까지 1개에 그친다. 둘째, 남한은 학습 시기 조정을 고려할 필요가 있다. 북한과의 내용 시기 차이가 발생하고 TIMSS 기준 50%에 해당하는 내용의 학습 시기가 부합하지 않기 때문이다. 셋째, 남한과 북한은 학습하지 않은 TIMSS 내용을 반영할 필요가 있다. 이는 국제 사회에서 교육 경쟁력을 높이는 방안이 될 수 있다. 향후 남·북한의 지구과학 내용에 대한 접근 방법 비교 분석과 통합교육과정 설계를 위한 실질적 연구를 제안하였다.

유효체적 방법과 임상분석을 통한 방사선에 의한 정상 폐조직의 부작용 확률에 관한 연구 (The Study of Normal Tissue Complication Probability(NTCP) for Radiation Pneumonitis by Effective Volume Method)

  • 안승도;최은경;이병용;장혜숙
    • Radiation Oncology Journal
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    • 제15권3호
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    • pp.243-249
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    • 1997
  • 목적 : 방사선에 대한 정상 폐조직의 부작용에 관한 확률은 폐암의 방사선 치료에 있어서 중요한 지표가 됨에도 닥구하호 잘 알려져 있지 안다. 더구나 표적 부위와는 달리 정상 폐조직의 방사선량 분포는 매우 불균일하므로, 대표 선량값을 찾아 내는 것조차 어렵다 본 연구에서는 Dose Volume Histogram(DVH)과 유효체적방법(Effective Volume Method)을 통하여 정상 폐조직의 선량을 정량화하고 정상 폐조직 부작용 확률(Normal Tlssue Complication Probability, NTCP)을 구하여 임상결과와 비교하므로서 이 방법이 치료 결과를 예측할 수 있는 주요 지표로서 가능할 수 있는지에 대하여 살펴 보고자 하였다. 대상 및 방법 : 1993년 8월부터 1994년 12월까지 비세포성 폐암으로 방사선과 복합항암약물요법을 병행하여 치료받은 환자 중에서 36명을 무작위 추출하여, DVH 분석을 통한 정상 폐조직의 NTCP를 구하였다. 36명의 환자는 Mitomycin C, Vlnblastlne, Clsplatln을 사용한 2회의 복합항암 약물요법과 동시에 다분할 방사선추료(120cBy11x, bld)를 6480c0y까지 병행 치료하였다. 각 환자의 치료전 CT scan을 사용하여 우측폐, 좌측폐 그리고 전체폐 각각의 DVH를 구하였다. Kutcher등의 Effective Volume Method로 Nonuniform Histogram을 Uniform Histogram으로 변환시켰고, $TD_{50}$은 Emaml 등의 자료에 의거하여, Lyman 공식을 이용하여 NTCP를 구하였다. 방사선 폐렴의 Grade는 SWOG의 Toxlcity Criteria에 따랐다. 결과 : 대상환자 36명중 6명이 Grade 1, 2명이 Grade II의 방사선 폐렴이 발생하였다. 부작용이 발생한 환자군의 NTCP와 발생하지 않은 환자군의 NTCP는 전체폐를 대상으로 28.4와 23.4, 병소 부위의 폐를 대상으로 66.0과 26.4로 통계적으로 유의할 만한 차이를 보였으나 치료 전후에 시행한 폐기능 검사 소견에서는 두 군 사이에서 통계학적으로 유의한 차이를 찾지 못하였다. 결론 : 부작용이 있는 관과 부작용이 없는 군의 NTCP는 통계적인 유의한 차이가 있었으며 NTCP와 임상적인 부작용 확률은 정량적으로 일치하였다. 그러나 NTCP는 순수하게 방사선의 효과만을 고려하고 있으나 본 연구에서는 항암약물요법을 병용하였다는것과 다분할(Hyperfractionaltion) 방사선 치료에 의한 방사선 생물학적 변화에 대한 고려가 필요할 것으로 생각된다. 본연구결과 유효체적 방법을 이용한 NTCP는 향후 입체조형 치료에서의 선량증가(Dose escalation) 가능성에 대한 부작용 예측 지표로 활용할 수 있을 것으로 생각된다.

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요통환자의 신체상과 생활적응에 관한 연구 (A Study on Adjustment of Daily Living and Body Image of Patients with Low Back Pain)

  • 구희서
    • 보건교육건강증진학회지
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    • 제6권1호
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    • pp.91-105
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    • 1989
  • The purpose of this study is to identify the body images of patints with low back pain and their status on adjustment of daily living. The data were collected from 11 general hospitals during Feburary 2, 1987 through May 30,1987. One hundred and ninety five subjects having physical therapy treatment because of low back pain were analyzed. For measurement of body image, 11 pairs of adjectives were used on semantic differential scale, and for measurement of adjustment of daily living, 10 items were used on a likert type scale. Results of the study are summerised as follows. 1. The average patient age were 34yeats and 62% of the patients were men. High school grade completed were 43.1% and Cause of Low Back Pain were respctively;Unknown etiology 31.8%, lifting heavy objects 27.7%, Traffic accident and injury 17.9%. Types of treatment were;medication plus physical therapy 54.9%, physical therapy only 22.6%. Average treatment duration were 24.5 months. 2. There were significant difference in the body image between before low back pain and after low back pain. The body image before low back pain were 59.89(Mean) but after low back pain were 37,24(Mean) and two groups were statistically significant (t=21.3, p<0.00l). 3. there were no significant difference in the body image between the male and female.(t=1.49, p>0.05) 4. The correlation between body image and adjustment of daily living. in both sexes showed positive correlation coefficient; male(r=0.4648, p<0.00l) female(r=0.4516, p<0.00l) respectively. It means that patients with positive body image can adjust well in daily living. 5. The relation between the body image and general variables revealed sigificant difference with occupation and age.(F=2.12 p<0.05, F=3.48 p<0.05). That is different occupation and different age groups can show different body image. In conculsion with the above results, It is my strong belief that multidisciplinary approach including the concept of body image and patient education about postural care, activities of daily living, lifting mechanics should be applied in treating and dealing with those patients.

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