신축학교 실내공기질이 초등학생들의 인지기능에 미치는 영향

김태섭,김선주,박시영,전만중,김규태,김창윤,정종학,백성옥,사공준 대한산업의학회 2007 대한직업환경의학회지 Vol.19 No.1

목적: 신축초등학교와 대조학교를 선정하여 교실 내 포름알데히드와 TVOCs를 측정하고 컴퓨터 신경행동검사를 이용하여 실내공기 오염물질이 학생들의 인지기능에 미치는 영향을 평가하였다. 방법: 신축초등학교 5학년 71명을 실내공기 오염물질 노출군으로 하고, 개교한지 12년째인 대구시의 일개 초등학교 5학년 2학급 63명을 대조군으로 하여 실내공기 오염물질농도 측정 및 컴퓨터 신경행동검사를 실시하였다. 결과: 신축학교에서 의도적으로 창문을 개방한 학급에서 1교시 포름알데히드 농도는 34.6 ㎍/㎥, 4교시에는 27.3 ㎍/㎥, 창문을 개방하지 않은 학급에서 1교시 80.2 ㎍/㎥, 4교시 127.1 ㎍/㎥, 대조학교에서는 2학급 각각 1교시에 12.6 ㎍/㎥, 7.5 ㎍/㎥, 4교시에 19.8 ㎍/㎥, 25.2 ㎍/㎥였다. TVOCs의 경우 신축학교의 의도적으로 창문을 개방한 학급에서 1교시에 농도는 487.2 ㎍/㎥, 4교시에 428.2 ㎍/㎥, 창문을 개방하지 않은 학급에서 1 교시에 농도는 1,283.5 ㎍/㎥, 4교시에 1,715.4 ㎍/㎥, 대조학교의 경우 2학급에서 각각 1교시에 농도는 240.9 ㎍/㎥, 150.8 ㎍/㎥, 4교시에 농도는 371.9 ㎍/㎥, 448.0 ㎍/㎥였다. 부호숫자 짝짓기의 평균반응시간은 대조학급이 1교시에 2,585 msec에서 4교시에 2,459 msec으로 감소한 반면 신축학교의 창문을 의도적으로 개방한 학급은 2,343 msec에서 2,510 msec으로, 평소대로 수업한 학급은 2,340 msec에서 2,563 msec으로 반응시간이 각각 167 msec, 223 msec 증가하였다. 1교시의 부호숫자 짝짓기 의 반응시간을 100%로 했을 때 창문을 의도적으로 개방 한 학급은 4교시에 5.9% 증가하였고(p<0.01), 평소대로 수업한 학급은8.3% 증가하였다(p<0.01). 반면에 대조학급은 4교시에 5.0% 감소하였다(p<0.01). 결론: 향후 학교의 실내공기질의 안전성 평가는 샘플링 된 공기의 오염수준의 측정뿐만 아니라 학생들의 건강영향도 함께 고려되는 것이 바람직할 것이다. Objectives: Most studies on the indoor air quality of newly built schools have focused only on the number of schools exceeding a standard or on subjective symptoms, such as sneezing, irritated eyes and an irritated nose. However, there has been no report on how poor indoor air quality affects children's academic performance. This study evaluated the effects of indoor air quality on the neurobehavioral performance of elementary school children. Methods: This study measured the indoor air pollutants and compared children's performance, using a computerized neurobehavioral test, between a newly built and a 12-year-old school. In addition, a questionnaire was administered regarding the indoor air quality related symptoms of children in a newly built and a 12-year-old school. Results: In the newly built school, the formaldehyde levels in the 1^(st) and 4^(th) classes with an open window were 34.6 and 27.3 μg/㎥, respectively. The levels in the 1^(st) and 4^(th) classes with the window closed were 80.2 and 127.1 μg/㎥, respectively. In the 12-year-old school, the formaldehyde levels in 1^(st) and 4^(th) class with open and closed window were 12.6 and 7.5 μg/㎥, and 19.8 and 25.2 μg/㎥, respectively. With respect to total volatile organic compounds, the levels in the 1^(st) and 4^(th) classes with the window open in the newly built school were 87.2 and 428.2 μg/㎥, respectively. In the 1^(st) and 4^(th) classes with the window closed, the total volatile organic compounds were 1,283.5 and 1,715.4 μg/㎥, respectively. In the 12-year-old school, the total volatile organic compounds were 240.9 and 150.8 μg/㎥, and 371.9 and 448.0 μg/㎥ in the 1^(st) and 4^(th) classes, respectively. In the case of a newly built school, the performance of the students in the neurobehavioral test in the 4^(th) class with the window closed was 8.3% lower than for those in the 1^(st) class with the window closed, but was only 5.9% lower when the windows were open. There was a statistical significant difference in the total numbers of symptoms between the two schools. Conclusions: These results suggest a proper evaluation of the indoor air quality within schools is required into both the level of contamination and the health effects of these contaminants toward children.

初期引張力을 받는 보의 分數調波 振動에 關한 硏究

노광춘,이규섭,박영필 연세대학교 산업기술연구소 1984 논문집 Vol.16 No.1

Subharmonic vibration of order 1/2 of a simply supported uniform beam subjected to initial tention is studied for a concentrated lateral harmonic excitation force. Theoretical analysis is carried out by assumming the deflection as a superposition of linear eigenfunctions. Harmonic balance method is used for the steady state solution. The steady state solutions are obtained by using Newton-Raphson method. Experiments are carried out and show good agreement with the theoretical results.

자유단의 운동이 제한된 외팔보의 진동에 관한 연구

박영필,이규섭,김진수 연세대학교 대학원 1987 延世論叢 Vol.23 No.1

In this study, the vibration of a harmonically excited cantilever beam with motion-limiting stops at the free end is studied. The responses of the beam are calculated by numerical analysis with Galerkin's mode summation method. The modal displacement and velocity of the beam are obtained for various forcing amplitudes and clearances of the stops. The resuluts of the numerical analysis are compared with the results of the experiments. The number of the rebounds is increased with (i) the increase of the magnitude of the force and (ii) the decrease of the clearance of the stops. And the effects of the higher modes become significant as the magnitude of the farce is increased and the clearance of the stops is decreased.

鐵道 車輛 緩衝 裝置의 性能 向上에 관한 硏究

朴寧弼,李圭燮,權聖奎 연세대학교 대학원 1988 延世論叢 Vol.24 No.-

In order to improve the performance of the suspension system for mass transport vehicle with prescribed dynamic behavior, a synthesis procedure of eliminating "Hunting" was studied to yield resonant velocities outside the range of most frequent operation. Effect of changing in the spring stiffnesses on the resonant velocities of the system was considered. The effects of damping on the suspension system was analyzed through the Root Locus Analysis. And Root Contours Method was used to obtain the optimal damping values. Hunting is controlled by using a proper damping into the secondary suspension.

敎務分掌 運營 方案에 관한 硏究

최옥이 인간교육자원경영학회 2004 人間敎育硏究 Vol.11 No.1

It has long been pointed out that the existing school system is not organized for maximum efficiency of education but is destined for convenience only of control and management within the huge frame of vertical bureaucracy. Under these circumstances, priority has been given to administrative work, not to educational activities inherent to school system, and teachers themselves have been mainly concerned about administrative procedures, instead of education-related duties. Teachers are now so vastly involved in extra-educational jobs that they even regard themselves responsible for clerical duties, not for teaching. It seems unlikely to expect efficient teaching by teacher alone under the new curriculum which, rather, is believed to require active discussion, deliberation and information exchange of teachers. As the concept of classroom is disregarded, teachers tend to have increasing difficulties in and necessities for life guidance of students. In response to the change of curriculum and requests for improved teaching quality, the change of the teaching system may be said to be an undisputed demand of the time. It is the objective of this study to analyze the current status of academic job division system of schools, investigate the issues related to the administration-oriented job division of middle schools, examine desirable models of curriculum-oriented job division, compare advantages and disadvantages of each model and, finally, suggest improving measures.

배관계의 진동 및 소음특성

류봉조,임경빈,이규섭,송영봉,임경빈 한밭대학교 생산기반기술연구소 2003 생산기반기술연구소 논문집 Vol.3 No.1

This paper deals with the vibration and noise characteristics of three different kinds of pipe structures (PVC pipe, cast-iron pipe and newly developed pp pipe). In order to measure the structure born noise, an impact force generated by dropping a small ball was applied to three different kinds of pipes. It was confirmed that the structure born noise could be reduced by employing a high damping material. Also, transmission loss of a pipe was investigated for various frequency ranges by using a speaker as a sound source.

지지행거를 갖는 배관계의 구조해석

류봉조,임경빈,이규섭,송영봉,공용식,오부진 한밭대학교 생산기반기술연구소 2002 생산기반기술연구소 논문집 Vol.2 No.1

The paper deals with stress and deflection analyses for newly developed PP-pipe structures of LG-Caltex company. In order to calculate the values of stress and deflection, the elements of pipes and its hanger supports are discretized. Through the numerical simulations using commercial FEM code, stresses and deflections of pipes with two or more hanger supports are obtained, and the stability of pipes are checked. Finally, optimal numbers of hanger supports satisfying allowable bending stress is proposed.

Morphology‐ and composition‐controlled silver‐containing rhodium nanoparticles for the oxygen reduction reaction

Gyu Seop Hwang,Hongje Jang,Yang-Rae Kim,Woojun Shin,Gyeonghye Yim,Jae Hyuk Choi,Young-Kwan Kim 대한화학회 2022 Bulletin of the Korean Chemical Society Vol.43 No.11

Rh nanoparticles (RhNPs) have attracted significant attention due to their superiorelectrocatalytic activity in several energy conversion reactions. However,studies relating their morphology and performance are rare. In this study, threetypes of RhNPs, i.e., nanoshells, nanoframes, and porous nanoplates, were synthesizedvia inverse-directional galvanic replacement. The relationship betweenthe performance of the RhNPs at catalyzing the oxygen reduction reaction(ORR) and their morphology was investigated using cyclic voltammetry, linearsweep voltammetry, the Tafel slope, and electrochemical impedance spectroscopy. X-ray photoelectron spectroscopy and X-ray diffraction data revealed thatthe RhNPs contained different Rh/Ag ratios. All the RhNPs exhibited long-termstability under acidic conditions. In particular, nanoshell-structured RhNPsexhibited superior ORR activity as determined from the slope of the Tafel plot,the number of electrons, and the onset potential compared to a commercialRh electrocatalyst and other RhNPs. Evidently, controlling the morphology andcomposition of RhNPs greatly facilitates efficient electrocatalysis.

A Medium-Maturing, Lodging Tolerance, and Good-Quality Rice Variety "Seoan1"

Yeon Gyu Kim,Ha Cheol Hong,Im Soo Choi,Man Kee Baek,Young Chan Cho,Chang In Yang,Yong Hwan Choi,Myung Gyu Oh,Young Seop Shin,Myeong Ki Kim,Hung Goo Hwang,Ki Jong Kim,Seong Sook Han 한국육종학회 2007 한국육종학회지 Vol.39 No.4

"Seoanl" is a new japonica rice variety developed from a cross between Namyang9, a line of lodging tolerance and adaptable to reclaimed saline area, and Gyehwa7, a line of good-quality, adaptable to reclaimed saline area and high yield by the rice breeding team of National Institute of Crop Science, RDA, in 2005. This variety has about 131 days of growth duration from transplanting to harvesting in central plain area, and mid-western coastal area in Korea. It is about 73 cm in culm length and tolerance to lodging. It has also semi-erect pubescent leaf blade and slightly tough culm with good canopy architecture. The number of panicles per hill of Seoanl is slightly more than that of Hwaseongbyeo. Seoanl was susceptible to major diseases, blast, bacterial blight and viruses, and insect, brown plant hopper. This variety has lower amylose content of 18.8% and better palatability of cooked rice than those of Hwaseongbyeo. The milled rice yield performance of this variety is about 5.60MT/ha in local adaptability test for three years. Seoanl would be adaptable to central plain area and mid-western coastal area of Korea.

준경험적 설계기법을 위한 FAB. 구조요소의 데이터베이스 구축

이규섭(Gyu-seop Lee),이현준(Hyun-jun Lee) 한국소음진동공학회 2012 한국소음진동공학회 학술대회논문집 Vol.2012 No.4