• Journal of Plant Biotechnology
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• 제35권4호
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• pp.257-263
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• 2008

Improvement of the macro- and micro-elements density of rice (Oryza sativa L.) is gradually becoming a new breeding objective. In this study, the genomic regions associated with potassium, calcium, magnesium and iron content in rice grain were identified and characterized by using a doubled haploid (DH) population. Fifty-six simple sequence repeat (SSR) and one hundred and twelve sequence tagged site (STS) markers were selected to construct the genetic linkage map of the DH population with a full length of 1808.3cM scanning 12 rice chromosomes. Quantitative trait loci (QTLs) were detected, and QTL effects and QTL interactions were calculated for five traits related to macro- and micro-elements in the DH population from a cross between 'Samgang' (Tongil) and 'Nagdong' (Japonica). Twelve QTLs were located on five chromosomes, consisting of two QTLs for potassium, three QTLs for calcium, two QTLs for magnesium, one QTL for iron content and four QTLs for the ratio of magnesium to potassium (Mg/K). Among them, qca1.1 was detected on chromosome 1 with an LOD value of 8.58 for calcium content. It explained 27% of phenotype variations with increasing effects from 'Samgang' allele. Furthermore, fifteen epistatic combinations with significant interactions were observed on ten chromosomes for five traits, which totally accounted for 4.19% to 12.72% of phenotype variations. The screening of relatively accurate QTLs will contribute to increase the efficiency of marker-assisted selection (MAS), and to accelerate the establishment of near-isogenic lines (NILs) and QTL pyramiding.

• 한국지구과학회지
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• 제25권7호
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• pp.565-575
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• 2004

이 연구에서는 과학사를 활용한 교수-학습 자료를 개발하고 교육 현장에 적용하여 과학 학업 성취도와 과학과 관련된 태도에 미치는 효과를 중학생의 성취수준에 따라 조사하였다. 여중생 3학년 4개 학급을 대상으로 실험 집단에서 대하여 과학사 활용 수업, 통제 집단에 대하여 전통적인 수업을 실시하였다. 과학사 활용 수업에서는 필수 학습요소와 관련된 과학사를 다양한 방법으로 학생들에게 소개하여, 학습자의 흥미와 STS인식을 유도하였다. 과학사 활용 수업은 전통적인 수업에 비하여 학생들의 과학 학업 성취도와 태도 향상에 효과적인 것으로 나타났다. 이러한 과학사 활용수업은 과학 학업 성취도에서는 상위권에게 유의미한 효과가 나타났으며, 과학과 관련된 태도에서는 상, 중위권에서 긍정적인 효과를 보였다. 이와 관련하여 학습자의 수준을 고려한 교수-학습 자료와 수업 모형 개발은 과학사 활용 수업에 도움을 줄 수 있다.

• 열처리공학회지
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• 제22권5호
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• pp.290-297
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• 2009

In case of using Asymmetric Bipolar Pulsed DC (ABPD) power generator, thin film is efficiently deposited as ions are getting higher energy by suppressing target poisoning and electric arc. In this article, the mechanical properties of CNx thin films deposited on the STS 316L were compared with DC and ABPD power generators. The CNx thin films deposited with ABPD clearly improved wear resistance by higher ratio of sp3CN as compared with DC. Nb interlayer affected to increase the value of 10N of adhesion between CNx thin films and substrate. But, CNx thin films deposited with ABPD couldn't endure to wear load and decreased wear resistance as the films were too thinner than substrate. Nevertheless the higher substrate bias energy applied to perform the dense films, it wasn't shown benefits about the wear properties from DC sputtering. But, in case of using ABPD sputtering, the wear resistance was largely improved without changing morphology despite of thin films.

• 미생물학회지
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• 제30권3호
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• pp.154-159
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• 1992

섬유소 분해능이 우수한 P. verruculosum 의 분생포자로부터 원형질체의 생성 및 재생에 대하여 조사하였다. 균의 원형질체 생성을 위한여 2-deoxy-D-glucose(2-DG) 가 첨가된 최소배지에서 분생포자를 10-12 시간 전배양 시킨후 시판 세포벽분해효소들을 작용시켜 본 결과 그중 Novozyme 234 (1%, w/v) 에서 50% 이상의 가장 좋은 원형질체 생성 수율을 보였다. 전배양 되지 않은 포자로부터는 원형질체 생성이 이루어지지 않았으며 원형질체 생성율을 향상시키기 위한 첨가테로서 2-DG 의 효과가 무첨가에 비해 2배 이상의 수율을 증가시켰다. 포자 원형질체의 재생율은 49.2% 로 동 균주의 균사체 원형질체의 재생율4.6-27.8%(삼투압 조절체로서 0.6 M magnesium sulfate) 보다 높았다. 원형질체 생성 및 재생을 위한 상투압 안정제로서는 0.6M ammonium sulfate 와0.6 M magnesium sulfate가 가장 적절하였다. 광학 형미경을 통하여 부풀린 포자로부터 원형질체의 생성과정과 두 가지 각기 다른 양상의 재생과정이 관찰되었다.

• 종양간호연구
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• 제1권2호
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• pp.217-228
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• 2001

Cancer survivor's self-help group may promote psychosocial adjustment in cancer patients. Self-transcendence has been shown to be related with crisis and adjustment in women with breast cancer. The purpose of this study is to determine the effectiveness of self-transcendence promoting program to facilitate self-transcendence, physical, and emotional well-being in women with breast cancer. Thirty patients who received mastectomy were recruited, but 9 subjects of experimental group and 14 subjects of control group participated in this study. Subjects of experimental group attended the self-help group for self-transcendence once a week for 6 weeks. Each session of program was proceeded for 2hours and the program contained activities for promoting self-transcendence, stress management, communication skill, exercise and relaxation, symptom management, and family support. Data were collected by self-reporting questionnaires within seven days after mastectomy and after the program was finished in experimental group, within 7 days after mastectomy and after 3 months in control group. Self-transcendence was assessed using the self-transcendence scale (STS) developed by Reed. Physical well being was assessed using Symptom distress scale (SDS) developed by McCorkle and Young and emotional well being was assessed using Profile of mood states (POMS). As a result, no significant differences were found between both groups in changes of self-transcendence, emotional well-being, and physical well-being. Self-transcendence score was significantly decreased in control group (p =0.16). But that of experimental group showed no decrease. In conclusions, when the self-transcendence promoting program is provided to the patients with breast cancer, it can be helpful for promoting self- transcendence. For the further study, repeated research with appropriate sample size and more intensive nursing intervention to promote self-transcendence is suggested. And reassessment after 6 months is recommended for testing long term effects of the program.

• 대한지구과학교육학회지
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• 제6권1호
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• pp.1-12
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• 2013

20 preservice teachers at college level participated in this study and interacted with students at elementary and middle school levels during science camp offered by science center in Taiwan. Preservice teachers displayed moderate (above the average, 4 point out of 5) understandings about scientific literacy and scientific views in all aspects of the nature of science before the camp. Then, the researchers designed science camp programs which were expected to promote students' scientific literacy; scientific knowledge, inquiry skills for experimentation as well as for argumentation, affective domain such as the attitude toward science and the understandings about nature of science and the relationship among STS (Science-Technology-Society), all of which were embedded in the programs. Preservice teachers seemed to perceive scientific literacy pretty well (over 4 point) before the camp, however, preservice teachers' understandings about scientific literacy were not much scored (around 3 point, but still moderate scores of average) as expected after concrete inquiry activities. The reasons why this happened could be that preservice teachers were not trained to employ theory into the context to be more practical or the researchers did not develop camp program which included the aspect of scientific literacy successfully. The discussion and implication were made in teacher education in that preservice teachers must be prepared how to bridge theory into practice, and informal science education in that educators at science centers must be trained to be experts in providing the envisioned educational programs to meet the goal of science education, scientific literacy.

• Tribology and Lubricants
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• 제31권4호
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• pp.157-162
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• 2015

In this study, an ultrasonic nanocrystalline surface modification (UNSM) technique is applied to tungsten carbide-cobalt (WC-Co) to extend the service life of carbide parts used in press mold. The UNSM technique modifies the structure, reduces the surface roughness, increases the surface hardness, induces the compressive residual stress, and increases the wear resistance of materials by introducing severe plastic deformation. The surface roughness, hardness, and compressive residual stress of WC after UNSM treatment improve by about 42, 10, and 71%, respectively. A wear test under dry conditions is used to assess the effectiveness of the UNSM technique on the friction and wear behavior of WC. The UNSM technique is found to reduce the WC friction coefficient by approximately 21% and enhance the wear resistance by approximately 85%. The improved friction and wear behavior of WC may be mainly attributed to the increased hardness and compressive residual stress. Moreover, the WC specimen is treated by UNSM technique using three different WC, silicon nitride (Si₃N₄) and stainless steel (STS304) balls. The surface treated by WC balls shows the highest hardness when compared with treatment by stainless steel and silicon nitride balls. According to the obtained results, the UNSM technique is believed to increase the durability of the carbide component by improving the friction and wear behavior.

• Journal of Welding and Joining
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• 제15권6호
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• pp.96-104
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• 1997

The present study was aimed to correlate the microstructure and the hardness as well as the wear resistance of the metal-ceramic particulated composite layer on the pure Al plate. The composite layers were constructed by the addition of TiC particles on the surface of Al-Cu alloyed layers by PTA overlaying process. Initially, the Al-Cu alloyed layers were achieved by the deposition of Al-(25 ~ 48%) Cu alloys on the pure Al plate by TIG process. It was revealed that TiC particles were uniformly dispersed without any reaction with matrix in the composite layer. The volume fraction of TiC particles (TiC V F) increased from 12% to 55% with increasing the number of pass of composite layer. Hardnesses of (Al-48%Cu + TiC (3&4layers)) composite layer were Hv450 and Hv560, respectively, due to the increase of TiC V/F. Hardnesses of (Al-Cu + TiC) composite layers decreased gradually with insreasing temperature from 100$^{\circ}$C to 400$^{\circ}$C, and hardnesses at 400$^{\circ}$C were then reached to 1/5 - 1/10 of room temperature hardness depending on the construction of composite layers. The Specific wear of (Al + Tic) layer and Al-48%Cu alloyed layer decreased to 1/10 of the of pure Al, while the specific wear of (Al-48%Cu + TiC (4 layers)) composite layer exhibited 1/15 of that of steel such as SS400 and STS304.

• 정보교육학회논문지
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• 제13권2호
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• pp.127-134
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• 2009

무선인터넷과 이동형 컴퓨터의 발달로 다양한 수업 전략과 새로운 교육 방법이 제시되고 있다. 본 연구에서는 u-러닝의 환경에서 수업을 효과적으로 적용하기 위해 학습자 중심의 새로운 통합수업 전략을 제안하였다. 우선 무선네트워크 기술을 효과적으로 교육에 활용하기 위하여 학습자를 중심으로 한 다양한 교육적 요소를 파악하였다. 이동 단말컴퓨터를 지원하는 3개의 핵심적인 교육 요소로 교육내용, 시간요소, 공간요소로 범주를 나누어 분석하였다. 그리고 이러한 핵심 교육 요소를 통합하여 이동형 컴퓨터 기술을 적용한 통합적 수업 전략을 제안하였다. 초등학생들을 대상으로 통합적 수업을 실시하고 그에 따른 효과성을 검증하였다. 검증 결과 통합적 수업 전략은 효과성 지표로 제시된 고차원적 사고 및 학습동기, 자기주도적 학습의 영역에서 효과적임을 알 수 있었다. 본 연구는 향후u-러닝 환경에서 학습자 중심의 수월성 교육을 촉진시키고 총체적인 통합 교육을 효과적으로 지원할 것으로 기대된다.

• 한국초등과학교육학회지:초등과학교육
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• 제22권2호
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• pp.192-199
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• 2003

The Journal of Korean Elementary Science Education has been developed in both quantitative and qualitative aspects during twenty years since first published year 1983. This study was intended to survey the research trend of the journals, which has been published so far. It will give an orientation of science education research and suggestions towards research to improve science education. The 243 articles of the journals, which were published from 1983 to 2002 by Korean Elementary Science Education Society, were classified into 7 categories including science teaching, science learning, assessment in science, science teacher education, science curriculum, educational facilities & materials, and general science education. The results are as follows: 1. The articles published last decade are increased four times compared with the first decade. 2. The half of articles published so far concentrated on science teaching and learning. The articles on educational facilities & materials or general science education are few. 3. During the last decade, the articles on science teacher education, educational facilities & materials, assessment in science, and science learning relatively increased than the first decade. The number of articles on science curriculum was fluctuated every five years. 4. Most of articles were focused on the narrow subject areas. For example, the articles on science teaching, science learning, assessment in science, science teacher education, science curriculum, and educational facilities & materials were largely focused on the teaching strategies, pupils' conception, affective assessment and teaching practice survey, teachers' appreciation about the nature of science or instruction, analysis of science textbooks, development of the experimental materials or the audiovisual aids respectively. 5. The subject areas highlighted so far in science education, for example, inquiry or experimental activities, STS instruction, environmental education, gifted education, instruction with multimedia, problem-solving or reasoning, experimental skill assessment, etc. were not much researched.