http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
- 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
- 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
RISS 인기검색어
- 검색키워드
- 저자 : 김기정(Kim, Ki Jeong) (검색결과 446 건)
- 무료
- 기관 내 무료
- 유료
-
-
-
-
김기정,여정섭,윤지영,김준호,Kim Ki Jeong,Yeo Jeong Sup,Yoon Ji Young,Kim Joon Ho 한국섬유공학회 2005 한국섬유공학회지 Vol.42 No.4
Thermal degradation behavior of the three homologous polyesters, poly(ethylene terephthalate)(PET), poly(trimethylene terephthalate)(PTT) and poly(butylene terephthalate)(PBT) were investigated by using thermogravimetric analysis(TGA) and pyrolysis-gas chromatography-mass spectrometry(PGC-MS). From the results of isothermal thermogravimetry, it was revealed that PTT has higher activation energy of thermal degradation than the other two polyesters. In PGC-MS analysis, the highly volatile products of the polyesters such as acetaldehyde and acetic acid evolved in the early stage of pyrolysis as common degradation products. Benzoic acid, methyl ester of benzoic acid, terephthalic acid and higher oligomers were produced as the main degradation products of poly(alkylene terephthalate)s at longer pyrolysis times. In isothermal pyrolysis, PTT showed the fastest thermal degradation rate among the three polyesters.
-
-
김기정,장창래,Kim, Gi-Jung,Jang, Chang-Lae 응용생태공학회 2016 Ecology and resilient infrastructure Vol.3 No.1
본 연구에서는 2차원 수치모형을 이용하여 복단면 하도에서 낙차공을 고려하여 하도 변화와 사주의 거동 특성을 분석하였다. 교호사주에 의하여 흐름이 분리되며, 사주의 선단부에서 흐름이 집중되고 수충부가 형성되었다. 낙차공에 의하여 흐름은 하도 전체에 균등하게 분산되었으며, 낙차공 하류에서는 흐름이 집중되고 하상고가 낮아졌다. 그러나 사주의 형상은 낙차공 상류의 영향을 받아 교호사주의 형상을 유지되었다. 하폭 대 수심이 증가하면서 교호사주, 중앙사주, 복렬사주가 형성되었으며, 사주의 수가 증가하였다. 낙차공에 의하여 흐름이 집중되어 낙차공 상류에서 사주길이보다 낙차공 하류에서 사주길이가 더 짧게 나타났다.
-
표면치밀화 기술에 의해 제조된 소결 기어의 기계적 특성
김기정,김기범,이두환,박종관,정동국,Kim, Ki-Jung,Kim, Ki-Bum,Lee, Doo-Hwan,Park, Jong-Kwan,Jeong, Dong-Guk 한국분말야금학회 2012 한국분말재료학회지 (KPMI) Vol.19 No.3
A novel PM (powder metallurgy) steel for automotive power-train gear components was developed to reduce manufacturing cost, while meeting application requirements. The high-density PM steel was manufactured by mixing using special Cr-Mo atomized iron powders, high-pressure compaction, and sintering. Tensile strength, charpy impact, bending fatigue, and contact fatigue tests for the PM steel were carried out and compared to conventional forged steel. Pinion gears for auto-transmission were also manufactured by helical pressing, sintering, and surface densification process. In order to evaluate the durability of the PM parts, auto-transmission durability tests were performed using dynamometer tests. Results showed that the PM steel fulfilled the requirements for pinion gears indicating suitable tensile, bending fatigue, contact fatigue strengths and improved gear tooth profile. The PM gears also showed good performance during the transmission durability tests. As a result, the PM gears showed significant potential to replace the conventional forged steel gears manufactured by tooth machining (hobbing, shaving, and grinding) processes.
-
김기정,양세나,박영찬,이한구,김봉수,이한길,Kim, Ki-Jeong,Yang, Se-Na,Park, Young-Chan,Lee, Han-Koo,Kim, Bong-Soo,Lee, Han-Gil 한국진공학회 2011 Applied Science and Convergence Technology Vol.20 No.4
The ring formation and electronic properties of furan adsorbed on graphene layers grown on 6H-SiC (0001) has been investigated using atomic force microscopy (AFM), near edge X-ray absorption fine structure (NEXAFS) spectra for the C K-edge, and core level photoemission spectroscopy (CLPES). Moreover, we observed that furan molecules adsorbed on graphene could be used for chemical functionalization via the lone pair electrons of the oxygen group, allowing chemical doping. We also found that furan spontaneously form rings with one of three different bonding configurations and the electronic properties of the ring formed by furan on graphene can be described using by AFM, NEXAFS and CLPES, respectively.
-
대학생 집단의 학습기술·학습동기·학업적응도와 학업성취와의 관계
김기정 서원대학교 2004 敎育發展 Vol.23 No.1
The study skills, learning motivation. academic adjustments are the significant factors that positively influence the learning process of school learners. In this study, the study skills were measured by 7sub-skills of self-managements, listening and participating in class, task-solving, effectively reading, report writing, information processing, and test-taking Learning motivation were composed of academic self-efficacy and academic failure tolerance And academic adjustments were composed of single scale with 20 items. The purpose of this study were to examine relationships between these process variables and learning outcomes, to explore the relative importance and combined effects of these process variables(10 factors) to academic achievements, and to find the differences in the process variables by sex and academic achievements levels. For this study, 100 male students and 229 female students were purposively sampled in S University. Their GPA were also obtained from their instructors. The major findings in this study were as followings. First, the study skills, learning motivation, and academic adjustments were closely interrelated with the correlation of .53 - .72. The combined effects of study skills and learning motivation to academic-adjustments were 61 percent. Among the variance, the test-taking skill had 57 percent, and self-efficacy skill, task-solving skill, and effectively reading skill had 11 percent, 2 percent, and 1 percent respectively. Second, lower achiever showed more negative behavior and attitudes than normal and higher achiever in 9 factors of the learning process variables. Among these factors. task-solving skill were found to be most important factor through regression analysis. This factor explained 15 percent of variance of academic achievements. Third, the level that college students have utilized study skills in their school learning were 2.8 and the level of learning motivation were 2.5 on 4-point scale. The skill that the students used most frequently were task-solving(3.1 point). Female students showed more positive behavior than male students in the use of study skills. In learning motivation, male showed more positive attitudes. But there were no significant differences by sex in academic adjustment.
-
척수내 종양과 감별을 요하는 비종양성 척수증 : 수술로 확진된 8례의 후향적 분석
김기정,정천기,심기범,김현집,Kim, Ki-Jeong,Chung, Chun-Kee,Sim, Ki-Bum,Kim, Hyun-Jib 대한신경외과학회 2000 Journal of Korean neurosurgical society Vol.29 No.7
Objective : It is difficult to differentiate intramedullary spinal cord tumors preoperatively from non-neoplastic pathologies in patients presenting as non-compressive myelopathies in magnetic resonance imaging(MRI). In this report, the authors reviewed nonneoplastic intramedullary spinal cord lesions preoperatively diagnosed as tumors and discussed their clinical and radiological characteristics and usefulness of surgical intervention. Methods : From January, 1985 to January, 1999, authors experienced eight non-neoplastic pathologies mimicking intramedullary spinal cord tumors and analysed their medical records, radiological findings and histopathological specimens retrospectively. Results : There were five males and three females and the duration of symptoms were from two to 20 months(mean, 9.8 months). The location of lesions were four cervical, one cervicothoracic and three thoracic. All patients manifested sensory abnormality, seven motor weakness, and six bladder symptom. All cases had swollen spinal cords and increased signal intensities in spin-echo sequences. Six cases showed contrast enhancement : four cases were focal and two diffuse. Under the impression of intramedullary tumors, the patients were operated upon. Final diagnoses on the base of clinical and pathologic finding were : three subacute necrotizing myelopathies, two multiple scleroses, two myelopathy of unknown etiology. One case showed no gross abnormality in surgical field in spite of adequate exposure of the lesion, so biopsy was not performed. In that case, postoperative MRI revealed spontaneous resolution of the lesion. Conclusion : MRI is invaluable diagnostic tool in screening myelopathies. However, its high sensitivity and lack of specificity make difficulty in preoperative differential diagnosis of non-compressive myelopathies. Although no surgical morbidity occurred in our series, we sometimes failed to confirm definite diagnosis even with biopsy. In such a circumstance, long-term follow up is needed.
DBpia연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
