쇄석의 진동다짐 특성에 관한 실험적 고찰

정길수,박병수,홍영길,유남재 江原大學校 産業技術硏究所 2004 産業技術硏究 Vol.24 No.B

This Study is results of experimental works to investigate the characteristics of vibro-compaction of crushed stones having coarse grain sizes. For testing material, crushed stone, sieved within very narrow ranges of grain size distribution, was used. Cyclic loading apparatus was used to apply cyclic loading to the specimen prepared in the mold. Tests were performed by changing the ratio of the maximum to the minimum stress, frequency and the magnitude of the maximum and the minimum stresses. Settlement of specimen due to cyclic loading was measured to analyze the compaction efficiency and sieve analysis test after cyclic loading test was also carried out to find the crushing rate of the specimen. As results of cyclic loading test, normalized settlement in terms of specimen height tends to be converged around loading cycle number of 1500. The magnitude of normalized settlement is in the range of 3.11 ~ 8.57%. The crushing rate is in the range of 4.46 ~ 8.78%. Normalize settlement and the crushing rate tend to increase with decreasing the ratio of the maximum to the minimum stresses and they tend to increase with increasing the frequency and the magnitude of the maximum and the minimum stresses for the given ratio. In conclusions, compaction rate of crushed stone is controlled by the dynamic stress (difference between the maximum and the minimum stresses) and the crushing rate is dominated by applied energy to the specimen.

야생 등줄쥐 (Apodemus agrarius coreae) 간뇌의 Dopamine성 신경세포

정영길,이남섭,민성기,김무강 대한해부학회 1997 Anatomy & Cell Biology Vol.30 No.6

흰쥐의 감각신경절세포에 대한 Methylmercuric chloride의 독성효과

鄭榮吉,白承和,韓斗錫,柳道坤,朴承澤 한국전통의학연구소 1998 한국전통의학지 Vol.8 No.1

흰쥐의 배양 척수감각신경절세포에 대한 methylmercuric chloride(MMC)의 세포독성을 조사하기 위하여 여러 농도의 MMC가 포함된 배앙액에서 24시간 동안 배양한 후 MTI assay법에 의하여 세포의 생존율을 조사하였다. MMC는 농도에 비례하여 세포의 생존율을 감소시켰다. 또한 여러 농도의 MMC가 포함된 배앙액에서 흰쥐의 척수 감각신경절(dorsal root ganglion, DRG) 세포를 24시간 동안 처리한 결과 MTI_(50) 값이 25μM MMC에서 나타났다. MMC는 Borenfreund등(1988)의 독성판정기준에 의하여 흰쥐의 배앙 DRG 세포에 고독성인 것으로 나타났다. 이상의 결과는 MMC가 흰쥐의 배양 척수감각신경절세포에 강한 신경독성 효과가 있음을 제시하였으며 또한 배양신경세포는 약제의 효과를 검색하는데 효과적이었다. To examine the cytotoxic effect of methyl mercuric chloride(MMC) on the cultured rat spinal dorsal root ganglion(ORG) neurons, cell viability was measured by MTT assay after rat spinal ORG neurons were incubated with media containing various concentrations of MMC for 24 hours The results were as follows ; 1. MMC decresed cell viability of rat spinal ORG neurons in a dose-dependent manner. 2. MIT_(950) value was a 25uM MMC after spinal ORG neurons were cultured for 24 hours at various concentrations of MMC. 3. MMC was heighly toxic on the cultured ORG neurons by the toxic criteria of Borenfreund et al.(1988). From above the results, it is suggested that methylmercury involves in neurotoxicity by the decrease of cell viability in cultured rat spinal DRG neurons, and cultured neurons are effective in screening the putative agents.

등줄쥐 연수의 Tyrosine Hydroxylase, Dopamine-β-Hydroxylase 및 Phenylethanolamine-N-Methyltransferase 면역반응신경세포

정영길,이남섭,민성기 대한해부학회 1998 Anatomy & Cell Biology Vol.31 No.3

저분자량 폴리에틸렌이민을 이용한 유전자 송달 및 발현 유효성 연구

정길재,박귀례,신지영,최한곤,오유경 한국약제학회 2004 Journal of Pharmaceutical Investigation Vol.34 No.4

Branched and linear polyethylenimines (PEIs) have been studied as efficient and versatile agents for gene delivery in vitro and in vivo. PEIs exist in a linear or branched topology and are available in a wide range of molecular weight (Mw). Most studies have been done using PEIs with Mw higher than 10Kd. This study was aimed to test the transfection efficiency and the cell viability following gene delivery using PEI of Mw 2Kd, a relatively lower Mw cationic polymer. We used murine interleukin-2(mIL-2) plasmid DNA complexed with branched PEI 2Kd or 25Kd, and transfected them into a myoblast muscle cell line, C2C12. The cellular uptake of mIL-2 plasmid DNA was determined using quantitative polymerase chain reaction. RNA transcript levels were studied in the myoblast cells. Our results show that PEI 2Kd was as effective as PEI 25Kd in celluar gene delivery and transfection efficiency in C2C12 cells. Moreover, MTT assay indicated that PEI 2Kd/DNA complexes did not significantly reduce the cell viability regardless of N/P ratios. These results suggest that PEI of Mw 2Kd might play a role as effective and low toxic nonviral vector systems for muscular cell lines.

농어촌 인구 정주에 관한 환경 계획적 연구

정성찬,이길영 大田大學校 環境問題硏究所 2002 환경문제연구소 논문집 Vol.6 No.-

The settlement of population in agricultural areas helps to prevent the influx of agricultural population to metropolitan areas and also contributes to improving residential environments of large cities. Constituting a major pillar to support balanced development of a nation, it can be said to be the key task in regional planning. Recently, Korean agricultural society has gone through a tremendous change. The economic policy of urbanization and industrialization enforced in the 1970's resulted in the concentration of industries and economies mostly in cities, which inevitably led to the phenomenon of so-called "leaving countries for cities." This indicates the outflow of agricultural population from countries into cities. As a result, the development of agricultural regions has slowed down, with the population decreasing and the community becoming empty, in contrast to urban areas. Consequently, agricultural areas are facing a crisis, and it is hard even to maintain them as residential areas. Furthermore, the wide regional gap between cities and agricultural areas derived from the process of urbanization and industrialization is recognized as a big barrier to the efficient use and balanced development of the land of the nation. Therefore, plans of rearrangements of residential environments in the agricultural areas are emergingas an urgenttask, both in revitalization of decreasing agricultural areas and in balanced developmentof the national territory. However, academic investment or developmental policies up to now have been mostly concentrated on cities. Matters of agricultural areas, thus, have been neglected as secondary problems to those of cities. It is essential to view the question of the settlement of agricultural population from various perspectives and to have academic involvement. Yet, the settlement of population, the result of movement, is a very complicated phenomenon originated in the relationships between residents, the subjects of settlement, and the surrounding regional circumstances. These phenomena vary according to the behaviors and attitudes of the residents. And the degrees of satisfaction of the residents differ depending on each individual's value system. Therefore, the attempt to establish the settlement of the agricultural population can be seen in this context. It is the biggest mission, then, to simultaneously examine both aspects, the aspect regarding regional environments and the aspect related to residents, the subjects of settlement. Finally, as mentioned before, it is necessary to note that the attributes and conditions are various both in a macroscopic level involving regions and in a microscopic level involving individuals as subjects of settlement. It is also necessary to investigate the perspectives from which the settlement in the agricultural regions is dealt with in the regional, environmental planning. Obviously, this issue needs be handled with external and internal analyses as it involves both the reality and the ideal of the residents' value system. Therefore, this study is not about simply restoring the past in regard to a series of problems with the settlement of agricultural population. This study aims to pursue the natural essence of agricultural areas in which new agricultural regions and cities can be integrated under the conditions of national territory, and at the same time, to deal with the agricultural areas as new space for settlement.

손상받은고양이 줄무늬체에서 축삭반응에 관한 미세구조적 연구

양남길,조영열,안의태,고정식,박경호,김진국 대한해부학회 1994 Anatomy & Cell Biology Vol.27 No.3

SM20C 旋削時 加工條件 變化에 따른 칩 形狀에 관한 硏究

정태상,황광성,김명규,김길진,박영태 진주산업대학교 산업과학기술연구소 2007 산업과학기술연구소보 Vol.- No.14

This study was to look for cutting conditions which are safe, comfortable and contributable to the increase in productivity at the time in turning. The shape of chips while turning have a strong effect on cutting processing. If chips fail to be well controlled, systematic cutting is not possible by revolution of chips entangled with workpiece or damage of tool edges, and this causes problems threatening the safety of the operator. This study is designed to identify conditions which chips effectively controlled and able to treat properly, and the results are as follows: 1. Feed rate, which determined the shape of chips, was found to have a stronger impact on the shape of resulting chips than any other cutting condition. 2. When feed rate was 0.25mm or over, controlled chips(coil spring type) were produced under whatever cutting conditions. 3. When feed rate was 0.25mm or over and depth of cut was 1.0mm, well-controlled shorter coil type chips were produced at every spindle speed, which implied they were the most suitable cutting conditions. 4. Feed rate 0.2mm was found to be an unstable section where coil spring and linear mixed type chips were produced together, and as feed rate decreased, more linear chips beyond control were produced. 5. At the same spindle speed, as the diameter of the material became bigger, controlled chips were produced only when the depth of cut was reduced, and vice versa under feed rate 0.2mm. 6. At the same feed rate, the lower spindle speed was, the more stable chips were produced.

고교 축구선수의 운동스트레스 척도 개발

김정수,윤영길 세명대학교 2000 世明論叢 Vol.8 No.-

In a competitive sport situation, stress arise from multiple factors which were psychological, cultural and health problems, and causes poor performance. The purpose of this study was to develop a stress scale with reliability and validity for soccer player. participants were 464 high school male soccer players registered in the Korea Football Association(KFA). To generate initial stress items, 164 high school soccer players responded to an open-ended questionnaire regarding stress situation as a soccer player. Inductive content analysis of the responses resulted in 946 cases and 794 cases of stress situations for high school soccer players, respectively. The data were grouped into 57themes (high school) regarding specific stress domain. specific domains were categorized into 10 more general domains. Drawing on the results of the content analysis, 66 stress items for high school soccer player were generated. In the pilot study stage, 85 high school soccer players were completed the preliminary version. based on the results of factor analysis and reliability, 41 items for high school soccer player on stress were adopted for further item refinement. In the main study, 215 high school soccer players completed the 41-item versions, respectively. Confirmatory factor analysis, reliability, item correlation, and item analysis were used. The results of the analysis lead to 6-factor 24-item stress scale high school soccer players soccer players. The scale contains six stress-specific sub scale; undue oppression by a senior, restricted private life, dissatisfaction with soccer skills, dissatisfaction with coachability, career concern, and unfairness of a game. Using qualitative and quantitative approaches, this study developed measures to assess device and unique sources of stress which reflect cultural trait on korean school sport. Future studies should (a)focus on further validation of the measures, (b)examine relationship between sources and others stress sources and personal character, and (c)examine relationship between stress psychological factors.

自生 山菜類의 開發에 관한 硏究

申永澈,金在佶,申貞和 충북대학교 농업과학기술연구소 1992 農業科學硏究 Vol.10 No.1

In order to use as vegetable, studies on valuable wild plants-Pimpinella brachycarpa, Cryptotaenia japonica., Synurus deltoids., Solidago virga-aurea var. gigantean., Hemerocallis fulva. Were carried out by field observation and cultivation. The result were obtained as follow : 1. Pimpinella brachycarpa, Cryptotaenia japonica, Solidago virga-aurea var. gigantea were distributed at the higher altitude of 600M, but Synurus deltoids, Hemerocallis fulva were distributed under 500M. 2. Pimpinella brachycarpa, Cryptotaenia japonica, Solidago virga-aurea vat. Gigantean, Hemerocallis fulva except Synurus deltoids grew well on fertile soil in habitat. 3. The germination of Hemerocallis fulva were promoted at 25℃ under dark condition with Ethrel, whereas Synurus deltoides were promoted at 20℃ under dark condition with IBA treatment. 4. Te transplant seedlings of 5 plants, shading was necessary. Low light intensity under 5000Lux is recommended for low rate of bolting and for softening of tissue. 5. All 5 plants grew vigorously toward the end of July. 6. Plants would be harvested after 3 years with seed germination, but it would be desirable to transplant in order to reduce cultivation time. 7. It is desired that 5 plants should be subjected to suppressing or forcing cultivation.