http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
이현욱,심규철,목창수,박인근,장남기 韓國生物敎育學會 1997 생물교육 Vol.25 No.2
The purpose of this study is to establish the strategies for participating in International Biology Olympiad(IBO). This study was conducted to investigate the membership and the successive results of IBO, to analyze the contents of competition. The aims of IBO are to encourage gifted students, to expand their talents and to promote their career as a scientist. The competition consists of two part, theoretical and practical examinations. China, Czech and Poland have acquired better fruits than others in successive olympiads. For the participation of our country in IBO, the students who will be participated in IBO must be selected by the Korean Biology Olympiad(KBO). Far this goal, the Commitee of Korean Biology Olympiad must be organized. Educational effects through holding of KBO and participating in IBO are to find the gifted students in biology, to activate biology education much more and to utilize the results of Olympiad as the important informations on biology education policy.
이현욱,임정호,허유,Lee, Hyun-U.,Lim, Jung-H.,Huh, You 한국섬유공학회 2011 한국섬유공학회지 Vol.48 No.4
The tensile properties of basalt fibers were tested with respect to basalt composition. Basalt composition was controlled via the differences in its components' susceptibilities to microwaves, which led to different throughputs according to the employed take-up speed. Elongation at breaking and tensile modulus were strongly dependent on the contents of metals such as Fe, Mg, and Ti. The tensile breaking load or specific strength was dependent on the contents of nonmetals such as Si, Al, Ca, and K. Tensile properties were especially sensitive to Ti and K.
새송이버섯 병재배에서 환기방법이 이산화탄소 농도 및 자실체형성에 미치는 영향
이현욱,안미정,이신우,이철호,Lee, Hyun-Uk,Ahn, Mi-Jeong,Lee, Shin-Woo,Lee, Cheol-Ho 한국생명과학회 2007 생명과학회지 Vol.17 No.1
새송이버섯 재배에서 환기방법이 실내의 이산화탄소 농도 및 자실체형성에 미치는 영향을 알아보기 위하여 평압형, 양압형, 음압형, 복합형의 4종의 환기방법을 사용하여 환기효율, 재배효율 및 생리장해발생정도를 포장에서 조사하였다. 그 결과 복합형의 경우, 실내 이산화탄소 농도가 평압형의 경우 1,400 ppm인 것에 비해 800 ppm으로서 현저하게 낮았고, 기류발생정도도 상대적으로 적어 환기효율이 가장 높은 것으로 나타났다. 대의 길이, 갓의 직경, 품질, 수량 등의 재배효율이 복합형에서 가장 높았으며, 수확소요일수가 단축 되었다. 생리장해의 발생에 있어서는, 세균점액증상, 비늘대증상 및 굴곡대증상의 경우에서는 환기방법에 따라 큰 차이를 보이지 않았으나, 오뚝이증상, 진무름증상 및 갈반증상은 이산화탄소 농도가 다른 환기방법에 비해 낮았던 복합형과 음압형에서 현저하게 줄어드는 경향을 보였다. 전체적으로 볼 때, 평압형 환기방법은 환기효율이 낮아 실내 이산화탄소농도를 유효하게 밖으로 배출해 내지 못함으로서 품질과 수량을 현저하게 떨어뜨리고, 생리장해의 발생을 유도하는 결과를 초래하였으며, 양압형 또한 평압형에 비해 효율성이 다소 높은 경향을 보였으나, 이들 2종은 새송이 버섯의 연중재배에 이용되는 환기방법으로 부적절한 것으로 나타났다. 음압형의 경우 상대적으로 효율성이 높은 환기방법으로서 어느 정도 도입의 가능성을 시사하고 있으나, 복합형이 환기효율, 재배효율 및 생리장해억제효과가 가장 우수한 것으로 조사되어, 새송이버섯 재배에서 복합형 환기방법을 도입할 경우, 품질향상과 생산성향상은 물론 연중 안전재배를 기대할 수 있을 것으로 사료된다. 도움이 되리라 생각된다.리고 실험에 사용된 송신부 및 수신부를 사진으로 보였으며, 이것을 이용하여 통신 수신율을 분석하였다. 주파수에서 측정된 Type 1 안테나의 전기적 성능은 원형 도체 배열을 10개 적층(disk10)하였을 때, 15.65 dBi의 최대 안테나 이득과 11.4 dB 이상의 입력 반사 손실 성능을 보여 주었으며, 다층 원형 도체 배열 구조에 의해 약 5 dB의 이득 향상 효과를 얻을 수 있었다. 또한, 원형 도체를 12개 적층하였을 때, 외곽 유전체 링 효과에 의해 Type 1 안테나는 Type 2 안테나보다 상대적으로 약 1.35 dB 만큼 이득이 더 높았으며, 각 안테나의 3 dB 빔 폭은 각각 약 $28^{\circ}$와 $36^{\circ}$로 측정되었다.. 그러나 기흉 발생 당일은 기흉이 발생하지 않은 날 당일보다 전일 대비 평균 기온이 높고(0.533 vs. $-0.103^{\circ}C$, RR 1.141, Cl $1.038{\sim}l.255$, p=0.006), 기온상승폭도 컸다(9.209 vs. $7.754^{\circ}C$, RR 1.123, Cl $1.061{\sim}1.190$, p=0.000). 결론: 본 연구의 결과를 통해 저자들은 기압이 상승한 뒤 기온이 상승했다. 하강하는 약 4일간의 기상변화가 자발성 기흉 발생에 영향을 미친다고 추론할 수 있었다. 향후 본 연구에서 추론된 기상변화와 기흉 발생과의 인과관계를 확인하고 좀 더 구체화하기 위한 연구가 필요할 것이다.게 이루어질 수 In an attempt to establish the appropriate ventilation device for the bottle culture of king oyster mushroom (Pleurotus eryngii), we investigated carbon dioxide concentration and fruiting body formation according to the various ventilation systems within the mushroom house. In addition to, the efficiency of air circulation and growth rate as well as the appearance of physiologically abnormal phenotypes during their growth stage were also evaluated. four different ventilation devices, parallel-pressure type, positive-pressure type, negative-pressure type, and positive- and negative-pressure type were applied in this study. The positive-and negative-pressure type showed the highest efficiency of air circulation as $CO_2$ concentration was 800 ppm and the level of air current was relatively low compared to the other types (the $CO_2$ concentration of parallel-pressure type was 1,400 ppm). Moreover, the stipe length, the cap diameter, yield, and general quality grown in positive- and negative type ventilation device were also better than in the other three devices though it took slightly longer period for harvesting (18.4 days) than the others (17.6, 17.9 and 18.3 days). The appearance of physiologically abnormal phenotypes such as fruiting body lump, soft rot, and brown rot were significantly decreased in positive-and negative type compared to other types, while the appearance rates were not much different for other symptoms of bacterial ooze, stipe limb and stipe bumpy. In summary, we propose that the optimal ventilation system for the bottle culture of king oyster mushroom is positive- and negative type, and this device is expected to increase the total quality as well as yield all year around.
휠-레일 접촉 미세마모 입자 발생 감소를 통한 살수 방법의 지하철 시스템 공기 질 향상 효과 연구
이현욱 한국냄새환경학회 2022 실내환경 및 냄새 학회지 Vol.21 No.2
Although airborne wear particles (AWPs) generated from wheel-rail contacts are the major source of particulate matter (PM) in subway systems, studies on reducing the generation of such particles in order to enhance air quality are extremely rare. Therefore, this study investigated the effect of applying water-lubricant (applying tap water) on improving air quality by reducing the mass concentration (MC) of AWPs from wheel-rail contacts at a train velocity of 73 km/h using a twin-disk rig. An optical particle sizer was used to measure the MC of particles with the diameter range of 0.3 μm~10 μm. The results showed that the generation trends regarding PM1, PM2.5, and PM10 were different for dry and water-lubricated conditions: all three PMs showed an increasing-decreasing trend with slip rate under dry conditions; however, they were almost constant with slip rate under water-lubricated conditions. The particle size distributions were also different for dry and water-lubricated conditions: the peak occurred in multi-modal with the largest peak at approximately 6 μm in diameter under dry conditions; whereas, the peak occurred in bi-modal with the largest peak at approximately 0.9 μm in diameter under water-lubricated conditions. In addition, MCs were mostly smaller under water-lubricated conditions than dry conditions except at approximately 0.9 μm in diameter. Applying water significantly decreased PM1~2.5 and PM2.5~10 by more than 95%. This caused a decrease in PM2.5 and PM10 by 48.1% and 78.5%, respectively. On the other hand, applying water increased PM0.3~1 (i.e., PM1) by 52.8%, possibly owing to the effect of water vapor and mineral crystals from tap water. Overall, these findings indicate that water-lubrication can improve air quality in subway systems by reducing the MC of APWs generated from wheel-rail contacts. This study may provide a reference for future studies seeking to improve air quality in subway systems by reducing AWPs generated from wheel-rail contacts by applying lubricants. .
압력용기용 A516 강의 미세조직에 미치는 탄소 당량과 냉각 속도의 영향
이현욱,강의구,김민수,신상용,Lee, Hyun Wook,Kang, Ui Gu,Kim, Min Soo,Shin, Sang Yong 한국재료학회 2019 한국재료학회지 Vol.29 No.8
In this study, the effect of carbon equivalent and cooling rate on microstructure and hardness of A516 steels for pressure vessel is investigated. Six kinds of specimens are fabricated by varying carbon equivalent and cooling rate, and their microstructures and hardness levels are analyzed. Specimens with low carbon equivalent consist of ferrite and pearlite. As the cooling rate increases, the size of pearlite decreases slightly. The specimens with high carbon equivalent and rapid cooling rates of 10 and $20^{\circ}C/s$ consist of not only ferrite and pearlite but also bainite structure, such as granular bainite, acicular ferrite, and bainite ferrite. As the cooling rate increases, the volume fractions of bainite structure increase and the effective grain size decreases. The effective grain sizes of granular bainite, acicular ferrite, and bainitic ferrite are ~20, ~5, and ${\sim}10{{\mu}m$, respectively. In the specimens with bainite structure, the volume fractions of acicular ferrite and bainitic ferrite, with small effective grains, increase as cooling rate increases, and so the hardness increases significantly.
이현욱 한국교육과정학회 2003 교육과정연구 Vol.21 No.4
인식론은 인식에 대한 이론이므로 교육에서 어떻게 배우고 가르치느냐에 대한 해답을 얻는 데 도움을 줄 수 있다. 교육과정이 어떤 인식론에 기반하느냐에 따라서 그것이 운영되는 모습이나 교육적 성과는 달라진다. 그러나 전통적인 교육과정 이론인 목표 모형과 내용 모형은 실증주의 인식론에 기반하고 있고, 이에 대한 대안적 성격을 가진 재개념화도 교육과정의 실제 문제에 대해서는 시사를 주지 못하기 때문에 이들 이론들은 지식관, 지식의 형성과 발전에 대한 시각 등에 있어 한계 내지는 많은 허점을 노정하고 있다. 근래에 구조주의, 구성주의 그리고 신과학철학은 지식에 대한 새로운 관점에 있어서 많은 시사점을 주고 있다. 그러나 기존의 교육과정 접근방법으로는 이러한 측면을 탐색하는 데 한계가 있다. 따라서 이 연구에서는 기존의 교육과정 이론을 목표 모형, 내용 모형, 그리고 재개념화로 구분하고 그 한계를 지적하였다. 그리고 나서 그러한 한계를 극복할 수 있는 하나의 대안을 탐색해 보았다. Epistemology is the theory of knowledge and deals with what the truth is and how we get the truth. And so, epistemology can give an insightful answer to the question of how to teach and learn knowledge in the process of education. The discipline of curriculum is closely related to epistemology. However, three current influential curriculum theories or models have some limitations to reflect present or new discussions of knowledge. The objectives-centered model has accepted the main assertions of positivistic epistemology, while the contents-centered model has been influenced heavily by rationalism. The third model of reconceptualism has criticized on-going discussions of curriculum, but not given distinguished viewpoints to them. The present researcher has tried to suggest an alternative approach and find a new model of educational materials. Recently, structuralism, constructivism, phenomenology, hermeneutics, the new philosophy of science, and post-modernism have given many suggestions to the new theory of knowledge. The results drawn from this research are as follows; First, knowledge in the textbook is not the ultimate truth. Knowledge is formed by the interaction between the subject and the environment, and has the possibility of renewal or reconstruction. Second, knowledge is not the simple aggregation of informations. Instead, it has structure or organization. Third, knowledge has tacitness as well as explicitness. And so knowledge is personal rather than objective. This study is in the preliminary step of the new educational research orientation. And this research intends to build a self-regulating discipline of education. So further studies are needed in this field.