강우 및 지반조건에 따른 토양침식 특성

이명구,송창섭,Lee, Myung-Gu,Song, Chang-Seob 한국농공학회 2011 한국농공학회논문집 Vol.53 No.3

This study is analyzed the characteristics of the soil erosion with the geotechnical conditions and rainfall conditions, such as the ground slope, the compaction ratio, rainfall intensity and duration of rainfall etc. To this ends, a series of model test are conducted on clayey sands. From the results, the variation of soil loss is analyzed with the geotechnical and the rainfall conditions. The amount of soil loss is decreased as the increase of compaction ratio and is increased as the ground slope, rainfall intensity and the duration of rainfall.

유럽국가들의 강구조 피로시험 실태조사를 다녀와서

이명구(Myung Gu Lee) 한국강구조학회 1997 韓國鋼構造學會誌 Vol.9 No.2

대형보시험체 용접구조의 피로시험에 대한 제언

이명구(Myung Gu Lee),송창희 한국강구조학회 1998 韓國鋼構造學會誌 Vol.10 No.2

국외여행인솔자의 자아탄력성이 직무스트레스와 직무만족에 미치는 영향

이명구 ( Myung Gu Lee ) 한국호텔리조트학회(구 한국호텔리조트카지노산학학회) 2015 호텔리조트연구 Vol.14 No.2

This study focuses on researching the relationship between ego-resilience and job stress of tour conductors, and the effects of tour conductor``s ego-resilience on job satisfaction. The survey was conducted from 1st Jan to 20th Feb, 2015 targeting 350 tour conductors who lead foreign tourists on domestic korean tours agencies. Among those distributed, 300 questionnaires were used for a final analysis. The research showed following results; First, as a result of verifying the relation between ego-resilience and job stress, path coefficient between role conflict, role ambiguity which are constructs of ego-resilience. Second, as a result of verifying the relation between ego-resilience and job satisfaction, its indicated that the better role conflict, role ambiguity and anger control which are constructs of ego-resilience are, the higher job factor which is a construct of job satisfaction. Third, as a result of verifying the relation between job stress and job satisfaction, its indicated that the lower role conflict, role ambiguity which are constructs of job stress are, the lower job factor which is a construct of job satisfaction.

국외여행인솔자의 감정노동이 직무스트레스와 직무소진에 미치는 영향

이명구 ( Myung Gu Lee ) 한국호텔리조트학회(구 한국호텔리조트카지노산학학회) 2014 호텔리조트연구 Vol.13 No.2

This study focuses on researching the relationship between emotional labor and job stress of tour conductors, and the effects of tour conductor`s emotional labor on job burnout. The survey was conducted from 1st Jan to 30th Mar, 2014 targeting 350 tour conductors who lead foreign tourists on domestic korean tours agencies. Among those distributed, 322 questionnaires were used for a final analysis. The research showed following results; First, emotional labor in the result of analysis on impact of emotional labor on job stress, it is cleared that a surface acting, deep acting, variety of emotions are required to be expressed, attentiveness to rules is required display and frequency of emotions displayed make a positive impact on job stress. Second, job stress has positive effect on emotional exhaustion. Third, surface acting, deep acting, variety of emotions are required to be expressed, attentiveness to rules is required display and frequency of emotions displayed make a positive impact on job stress.

국외여행상품 선택속성에 따른 여행만족, 여행자 충성도 및 여행자 전환의도에 미치는 영향

이명구 ( Lee Myung Gu ) 한국호텔리조트학회(구 한국호텔리조트카지노산학학회) 2016 호텔리조트연구 Vol.15 No.3

This research aims to identify selection attributes of Overseas Travel Products and test the influence relation that the Travel Satisfaction has the effect on the travel agency’s Switching Intention by grasping the travel agency’s Loyalty. Accordingly, it is expected that these effort present the strategic implication for the efficient operation suitable for the scale of each travel agency in the overseas travel environment that the competition is being deepened. The questionnaire has been collected with the investigation through the e-mail from March 5, to March 31, 2016 and by getting the cooperation from employees of overseas travel enterprises located in Seoul and Metropolitan area. Total 400 copies of questionnaire have been distributed and total 347 copies have been collected, the factor analysis and the reliability verification have been implemented by using SPSS 22.0 and AMOS 22.0 for the 297 copies excluding 50 copies that the non-sampling error occurs owing to the not completed answer or the insincere answer, the covariance structure analysis has been implemented to verify the presented research hypothesis. First, the human service and the reputation of travel agency appeared to have the significant positive (+) effect on the travel agency’s Loyalty. But, the business character, the suitability of Travel Products and the online information appeared not to have the significant effect on the travel agency’s Loyalty. Second, the human service, the business character, the suitability of Travel Products and the online information have been analyzed to have the significant positive (+) effect on the Travel Satisfaction. But the reputation of travel agency appeared not to have the significant effect. Third, the human service appeared to have the significant negative (-) effect on the travel agency’s Switching Intention. But, the business character, the suitability of Travel Products, the online information and the reputation of travel agency appeared not to have the significant effect on the travel agency’s Switching Intention. Fourth, the Travel Satisfaction appeared to have the significant positive (+) effect on the travel agency’s Loyalty. Fifth, the Travel Satisfaction appeared to have the significant negative (-) effect on the travel agency’s Switching Intention. Finally, it appeared to have the significant negative (-) effect on the travel agency’s Loyalty.

프리플렉스형의 피로거동에 관한 실험적 고찰

장동일,이명구(Myung Gu Lee),이승용(Seung Yong Lee) 한국강구조학회 1996 韓國鋼構造學會誌 Vol.8 No.4

치과용 복합레진으로 수리된 CAD-CAM hybrid 수복물의 전단결합강도

문윤희,이종혁,이명구,Moon, Yun-Hee,Lee, Jonghyuk,Lee, Myung-Gu 대한치과보철학회 2016 대한치과보철학회지 Vol.54 No.3

목적: 본 연구에서는 치과용 CAD-CAM (computer aided design-computer aided manufacturing) hybrid 수복재료인 LAVA Ultimate와 VITA ENAMIC을 광중합 복합레진을 사용하여 수리할 때 표면처리방법(grinding, air abrasion with aluminum oxide, HF acid)과 접착재료(Adper Single Bond 2, Single Bond Universal)의 종류가 두 재료 사이의 전단결합강도에 어떠한 영향을 미치는지 알아보고자 하였다. 재료 및 방법: LAVA Ultimate와 VITA ENAMIC 시편을 30일간 $37^{\circ}C$의 인공타액(Xerova solution)에 보관하여 시효처리를 실시한 후 각각 SiC paper grinding한 것, grinding 후 air abrasion처리를 추가한 것, grinding 후 HF 처리한 것으로 분류하고 각각 no bonding, Adper Single Bond 2, 또는, Single Bond Universal 도포로 세분하여 9개의 group, 총 18개의 subgroup으로 나누어 실험을 실시하였다(N=10). HF 처리group에서는 도재시편을 대조군으로 추가하였다(N=10). 표면 처리 후 광중합 복합레진(Filtek Z250)을 각각의 시편에 부착하고 이를 1주일간 실온의 물에 침적시켰고 이후 전단결합강도를 측정하고 파절양상 및 표면처리 효과를 SEM으로 확인하였다. One-way ANOVA를 이용하여 group 간의 유의성을 분석하였고 사후 분석으로 Scheffe test를 실시하였다(${\alpha}=.05$). 결과: 실험 결과 접착재료 처리를 한 group들이 접착재료 처리를 하지 않은 group에 비해 모든 표면처리에서 더 높은 전단결합력을 나타내었으며, 표면처리만 시행한 group에서는 aluminum oxide air abrasion이 전단결합력의 증가에 약간의 영향을 미치는 것으로 나타났으나 통계적 유의성은 보이지 않았다. 결론: LAVA Ultimate와 VITA ENAMIC의 두 재료를 광중합 복합레진을 이용하여 수리를 실시할 경우 각각의 재료에 적합한 표면처리방법과 접착재료의 선택에 대한 연구가 더 필요할 것으로 사료된다. 특히 LAVA Ultimate의 경우 접착재료의 사용은 추천된다고 사료되었다. Purpose: This study was performed in order to assess the effect of the surface treatment methods and the use of bonding agent on the shear bond strength (SBS) between the aged CAD-CAM (computer aided design-computer aided manufacturing) hybrid materials and added composite resin. Materials and methods: LAVA Ultimate (LU) and VITA ENAMIC (VE) specimens were age treated by submerging in a $37^{\circ}C$ water bath filled with artificial saliva (Xerova solution) for 30 days. The surface was ground with #220 SiC paper then the specimens were divided into 9 groups according to the combination of the surface treatment (no treatment, grinding, air abrasion with aluminum oxide, HF acid) and bonding agents (no bonding, Adper Single Bond 2, Single Bond Universal). Each group had 10 specimens. Specimens were repaired (added) using composite resin (Filtek Z250), then all the specimens were stored for 7 days in room temperature distilled water. SBS was measured and the fractured surfaces were observed with a scanning electron microscope (SEM). One-way ANOVA and Scheffe test were used for statistical analysis (${\alpha}=.05$). Results: Mostly groups with bonding agent treatment showed higher SBS than groups without bonding agent. Among the groups without bonding agent the groups with aluminum oxide treatment showed higher SBS. However there was no significant difference between groups except two subgroups within LU group, which revealed a significant increase of SBS when Single Bond Universal was used on the ground LU specimen. Conclusion: The use of bonding agent when repairing an aged LAVA Ultimate restoration is recommended.

병원폐수의 대장균군에 대한 오존소독효과

임봉수(Bong-Su Lim),이명구(Myung-Gu Lee),김병철(Byung-Chul Kim) 대전대학교 환경문제연구소 2009 환경문제연구소 논문집 Vol.13 No.-

In this study, disinfection effect of coliform group treated with ozone was analyzed for the effluent discharging from activated sludge treatment process in hospital wastewater treatment plant. Based on these results, it aims to get basic data to establish the disinfection facility in hospital wastewater treatment, suggesting affecting factors according to hydraulic retention time of the activated sludge process and design basic factors necessary to ozone disinfection. Removal efficiencies of coliform group for the effluent according to HRT such as 4hr, 8hr, 12hr were analyzed using a lab-scale activated sludge process, respectively. To decay the microorganism regulates the CT value multiplied disinfectant concentration by contact time. CT value is highly correlated with a removal efficiency of coliform group and according to increasing an injected ozone concentration, the CT value was increased.. When HRT was 4, 8, 12 hours , CT value takes place at minimum condition 50, 40, 334 mg/L-min, respectively.

구강 바이오필름에 대한 피톤치드의 항균능력

김민정 ( Min-jeong Kim ),이명구 ( Myung-gu Lee ),이준행 ( Joon-haeng Lee ),전열매 ( Yeol-mae Jeon ),유현준 ( Hyun-jun Yoo ) 대한예방치과·구강보건학회 2021 大韓口腔保健學會誌 Vol.45 No.4

Objectives: This study aimed to evaluate the antibacterial activity of phytoncide on oral biofilm. Methods: Antibacterial activity of phytoncide was examined on the bacteria Streptococcus mutans, Aggregatibacter actinomycetemcomitans, Enterococcus faecalis, Porphyromonas gingivalis, and oral biofilm. After mixing the phytoncide, S. mutans, A. actinomycetemcomitans, E. faecalis, and P. gingivalis with a culture alone turbid and mixed, and they were then incubated at 37°C under anaerobic conditions and cultured. Following incubation, a microplate reader was used to measure the absorbance and observe the amount of bacteria. In addition, non-polarized saliva containing bacteria was grown for 72 h under anaerobic conditions for the determination of biofilm biomass and bacterial numbers. Various concentrations of phytoncide were added to the saliva biofilm. Statistical significance tests were conducted using the Mann-Whitney test and SPSS 24.0. Results: S. mutans, A. actinomycetemcomitans, E. faecalis, P. gingivalis, and antibacterial effects were shown as phytoncide concentrations increased in oral biofilm. Observing the growth of bacteria using phase difference microscopes showed that the number of bacteria decreases as the phytoncide concentration increased. Also, the formation of biofilm in the saliva decreased compared to the control group. Conclusions: Based on the experimental results of phytoncide on oral biofilms causing oral cavity formation in the saliva decreased compared to that in the control group. Phytoncide showed antibiosis against oral biofilms when it remained inside the mouth for above certain concentrations. Accordingly, using phytoncide as a clinical method for preventing oral disease is deemed to be effective.