Effect of bioactive glass addition on the physical properties of mineral trioxide aggregate

김재이,김현정,Seok Woo Chang,Soram Oh,Sun Young Kim,Kyoung-Kyu Choi,Duck-Su Kim,Ji-Hyun Jang 한국생체재료학회 2021 생체재료학회지 Vol.25 No.4

Background: The addition of bioactive glass (BG), a highly bioactive material with remineralization potential, might improve the drawback of weakening property of mineral trioxide aggregates (MTA) when it encounters with body fluid. This study aims to evaluate the effect of BG addition on physical properties of MTA. Methods: ProRoot (MTA), and MTA with various concentrations of BG (1, 2, 5 and 10% BG/MTA) were prepared. Simulated body fluid (SBF) was used to investigate the effect of the storage solution on dentin remineralization. Prepared specimens were examined as following; the push-out bond strength to dentin, compressive strength, setting time solubility and X-ray diffraction (XRD) analysis. Results: The 2% BG/MTA showed higher push-out bond strengths than control group after 7 days of SBF storage. The 2% BG/MTA exhibited the highest compressive strength. Setting times were reduced in the 1 and 2% BG/MTA groups, and solubility of all experimental groups were clinically acceptable. In all groups, precipitates were observed in dentinal tubules via SEM. XRD showed the increased hydroxyapatite peaks in the 2, 5 and 10% BG/MTA groups. Conclusion: It was verified that the BG-added MTA increased dentin push-out bond strength and compressive strength under SBF storage. The addition of BG did not negatively affect the MTA maturation reaction; it increased the amount of hydroxyapatite during SBF maturation.

통신기지국 접지시스템의 과도현상 해석에 관한 연구

김재이,윤태양 東新大學校 工業技術硏究所 2003 工業技術硏究 Vol.9 No.-

The grounding system design of the communication base station can be on the unfavorable conditions to induce the safe designing because of the limited area of the communication base station and the week point of surge caused by the given geographical condition such as the top point of mountain. In this thesis, it is examined throughly about the way of safe designing that can reduce GPR(Ground Potential Rise) within the normal frequency band. And it is also considered the effective counter plan to cope with a transient phenomena that happen when surge of scores MHz-band inserted.

접지계의 경년변화 특성에 관한 연구

김재이 대한전기학회 2005 전기학회논문지C Vol.54 No.5(C)

In this paper, the secular changes of buried grounding electrodes was investigated; the electrodes are such facilities as grounding grid, grounding connector, grounding terminal and grounding rod etc.. The corrosiveness of removed substation grounding electrodes after commercial operation more than 50 years was measured and its conductivity deterioration trend was analyzed. The measuring results using three experimental methods were compared, finally the consideration for safe and economic grounding design were shown. As the result, it shows the maintenance necessity of grounding systems.

PC모니터의 장해전자파 방출 특성

金在珥,高永赫 東新大學校 工業技術硏究所 1997 工業技術硏究 Vol.3 No.-

In this paper, various emission patterns of personal computer monitors were investigated. The typical models of each maker were selected in the study. The frequency and induced voltage of EMI(electromagnetic interference) from each personal computer monitor were measured by using electromagnetic receptor. As the result, we were found that the vertical deflection frequency and induced voltage is about 30∼50[KHz] and 10∼60[db μV] respectively.

부산의 인공도 계획

김재이,KIM Jae Kyoung 대한화약발파공학회 1993 화약발파 Vol.11 No.3

접지계통의 보호계전시스템에 대한 영향

김재이 東新大學校 2002 論文集 Vol.12 No.-

In operating power substation the roll of grounding is closely related with power system protection system. The grounding system is very important in order to raise the power system reliability. This paper presents a effect investigation for asymmetry properties, equivalent modeling of substations grounding system, overvoltage analysis by EMTP and operating examples of protection relay.

FIR 필터 기반 다중 자율주행 인지 센서 결함 감지 알고리즘 개발

김재이,박만복 한국ITS학회 2023 한국ITS학회논문지 Vol.22 No.3

자율주행 차량의 무결성과 내결함성을 보장하기 위한 환경 인식 센서의 결함 감지 및 격리(FDI) 알고리즘이 중요한 연구 주제로 다루어지고 있다. 본 논문에서는 자율주행 차량의 안전성 보장을 위한 레이다, 카메라, 라이다로 구성된 다중 인지 시스템 결함 검출 알고리즘을 제시하였다. 제안된 결함 감지 알고리즘은 FIR(Finite Impulse Response) 필터 추정치에 기반한 레지듀얼의 생성 및 분석으로 고장의 감지 및 격리를 수행한다. 알고리즘의 성능 검증을 위해 가상환경에서의 수치 시뮬레이션을 수행하여 알고리즘을 기존의 칼만 필터 기반 알고리즘과 비교및 고찰하였다. 결과적으로 제안된 알고리즘은 인지 시스템의 강건성을 확보할 수 있음을 검증하였다. 본 연구는 자율주행 차량의 안전성과 신뢰성을 확보하기 위한 필수적인 연구로, 자율주행 차량의 환경 인지 센서의 무결성을 향상 시킬 것으로 판단된다.

접지전극의 경년변화 조사연구

김재이,고태석 동신대학교 환경연구소 2004 환경연구 Vol.9 No.1

In this paper, the secular changes of buried grounding electrodes was investigated; the electrodes are such facilities as grounding grid, grounding connector, grounding terminal and grounding rod etc.. The corrosiveness of removed substation grounding electrodes after commercial operation more than 50 years was measured and its conductivity deterioration trend was analyzed. The measuring results using three experimental methods were compared, finally the consideration for safe and economic grounding design were shown.

통신설비 접지설계기술의 개선

김재이 東新大學校 1996 論文集 Vol.8 No.-

The transient characteristics of grounding systems are very important in the grounding design of communication installations and depend on the shape and size of electrodes, soil resistivity and the magnitude and wave of the injection current. Generally former grounding design was not considered grounding resistance by transient analysis. This paper presents an algorithm to compute the transient grounding resistance of grounding systems and simulation results are compared with the measured datas to prove the validity of the algorithm.

大豆의 遺傳的 變異와 選拔에 關한 硏究

金在利 건국대학교 1976 論文集 Vol.3 No.1

In order to establish gene source bank of soybean, collection of 825 lines currently grown by farmers was made from the southern part of Korean peninsula. From this population, the range of phenotypic variation of several important agronomic characters and the amount of genetic variation within the population with the aid of suitable genetic parameters, such as genetic coefficient of variation, heritability, and genetic advance for improvement of the traits were investigated. An attempt was also made to get available information on the relative importance of yield components fur developing high yielding variety. The results were summarized as follows : 1.Yield was ranged from 190.0 kg to 2,349 kg per hectare with the standard deviation of 494.04. Majority of lines of the collection were ranged between 795 kg and 1,245 kg and 30 lines yielding over 1,620 kg were found. 2.The collection was consisted of two different groups in seed size, 13.5 gr and 29.0 gr in average of 100 seed weight, respectively. Of the collection, five lines were over 40 gr in 100 seed weight. Plant height was ranged from 45.5 cm to 129.0 cm with the average of 74.79 cm and number of pods per plant from 26.0 to 140.5 with the average of 52.83 was observed. 3.Protein content was ranged from 37.0% to 49.5% and the average was 42.03%. The major part of the collection was distributed from 40.7% to 44.2% in protein content. The average of oil content was 11.46%, and 70 percent of the collection was distributed between 16.5% and 19.0%. These results suggest that high protein lines among the collection flay play an significant role for improvement of protein content, whereas high oil content line was not found from this collection. 4.Seed weight, plant height, and number of pods per plant were shown relatively high heritability value and genetic advance. However, maturity showed high heritability estimate but less genetic advance due to the narrow range of phenotypic variation. 5.The genotypic and phenotypic correlation coefficients showed that the yield of soybean was positively associated with seed weight, number of pods per plant, plant height, and maturity. The high possitive correlations between seed yield and yield components may be due to the high positive direct effect of the yield components upon yield . In general, the genotypic correlation coefficients were found to be higher than the phenotypic correlation coefficients. Consequently, it could be concluded that seed weight, number of pods per plant, plant height, and maturity were useful as an indicator for selection of high yielding variety.