기후온난화에 따른 유역수문응답의 변화

신사철 安東大學校 工業技術硏究所 2000 공업기술연구논문집 Vol.7 No.1

온난화에 의한 하천유역의 수문응답의 변화양상을 수치실험을 통해 정량적으로 평가하였다. 온난화의 진행으로 야기되는 수문학적 평가는 많은 관측자료를 필요로 하며 이를 정량적으로 평가한다는 것은 대단히 어려운 일이다. 따라서 장래의 기후를 예측하는 수단으로서 적정한 시나리오를 상정하여 평가하는 방법을 생각할 수 있다. 본 연구에서는 여러 가지 상정할 수 있는 시나리오 줄 기온은 0℃에서 4.0℃까지 변화하며 강수량은 15%까지 증감할 수 있다는 시나리오를 상정하여 불확실성이 큰 지구온난화의 문제에 대하여 간단하면서 명확한 가정을 도입하였다. 본 연구에서는 2030년을 이산화탄소 농도가 배증되는 시점 (2×CO_(2)), 2010년, 2020년, 2050년을 각각 (1.5×CO_(2)), (1.75×CO_(2)), (2.5×CO_(2))로 설정하였으며, 이 시기에 대한 하천유황의 해석 및 온난화가 발생되지 않았을 때와의 비교 검토를 실시하였다. This study describes results of numerical simulations on river flow response due to global warming. Forecasts of changes in climatic conditions are required to estimate the hydrologic effects of increasing trace gas concentrations in the atmosphere. However, reliable forecasts of regional climate change are unavailable. In there absence, various approaches to the development of scenarios of future climatic conditions are used. The approach in this study is to prescribe climatic changes for a river basin in a simplified manner. The numerical experiments have quantitatively revealed the change of discharge at 2010, 2020, 2030 and 2050 for each warming scenarios and compared it with the results for a non-warming scenario.

위성자료를 이용한 토지피복 분류 기법

신사철 安東大學校 工業技術硏究所 2001 공업기술연구논문집 Vol.8 No.1

Landsat TM자료를 이용하여 안성천 유역에 대한 토지피복분류를 실시함으로서 토지피복의 시간적, 공간적 변화 분석을 실시하였다. 이 유역은 비교적 넓은 지역으로 위도차에 따른 데이터의 변화로 인하여 분류항목 및 training filed의 선정이 어려웠다. 본 연구에서는 수차례의 시행착오를 통하여 이러한 문제에 대한 해결방안을 제시하였으며, 분류 정확도 향상을 위한 Bayesian 최대우도법 및 majority 필터링의 효율성을 입증하였다. This study is provide land cover classification techniques using Landsat TM data. Since spatial effects in large area affect data values, it was difficult to make a selection of classes and traning fields. This paper present a solution about these problems by trial and error method, and found that Bayesian maximum likelihood classification and majority filtering were effective to improve classification accuracy.

식생지표를 이용한 한강유역의 순일차 생산량 추정

신사철,안태용 7개 국립대학교 환경연구 논문집 공동발행 위원회 2002 환경연구논문집 Vol.2 No.1

This study is to evaluate the NPP(Net Primary Prodection) distribution in the Han River basin from the satelite data(NOAA/AVHRR). This has been done using the linear relationship between the natural vegetation condition and the NPP. The NPP of natural vegetation increases proportional to the annual net radition(Rn), where radiative dryness index(RDI) is a proportional constant connecting Rn to NPP. Normalized Difference Vegetation Index(NDVI) is used for monitoring vegetation change, and iNDVI(integrated NDVI) for annual analysis. The iNDVI has a close relation to Rn and NPP, which can be used effectively for estimating NPP distribution of where the meteological data is unavailable. The NPP distribution of the Han river basin was estimated based on the model.

추계학적 기법을 이용한 수문자료의 예측 가능성에 대한 연구

신사철 安東大學校 工業技術硏究所 1999 공업기술연구논문집 Vol.6 No.1

이상기후와 수자원의 사용상황을 고려하여 수자원의 안정적인 공급을 목표로 본 연구에서는 다목적 댐을 운영에 있어서 편익을 최대로 하고 물관리의 효율성을 기하기 위하여 강우량과 유입량 자료의 장기 예측기법을 개발하였다. 또한 본 연구는 수자원의 균형된 수요와 공급을 위하여 중장기 대책수립을 위한 기초자료를 제공하고자 한다. 월예측을 위하여 사용된 추계학적 방법은 ARIMA 모형과 상관계수법을 이용하였으며, 충주댐 유역을 대상유역으로 하였다. ARIMA 모형은 다른 방법에 비하여 오차는 최소화할 수 있으나 월변동을 전혀 반영하지 못하여 월변동을 적절하게 반영해 주기 위해서는 통계적 접근방법에 경험적요소를 결합한 상관계수법이 적절함을 알 수 있었다. For a stable water supply, it is necessary to consider the present unusual changes in the weather and seasonal variation of water use. Therefore, in this study, the monthly forecasting of rainfall and inflow into dam were performed for the long-term planning of dam operation, which will raise the efficiency of water management and give the maximum benefit by dam operation. This study will also provide a fundamental data in establishment of long-term plan for the purpose of balanced water supply and demand. Adopted stochastic methods for monthly forecasting, in this study, are ARIMA(AutoRegressive Integrated Moving Average) model and correlation coefficient method, and study area is Chungju dam basin. The result is that ARIMA model has found to be the best for mean squared errors among correlation coefficient method. But, in practice, correlation coefficient method has better than ARIMA model, which not change to monthly variation as it.

Hamlyn의 인식론에 근거한 학습의 논리적 토대 고찰

장사형 한국교육학회 대구·경북지회 1994 교육학논총 Vol.13 No.-

The purpose of this study is to investigate the presuppositons of learning based on Hamlyn's epistemology. For Hamlyn, learning is the growth of knowledge and understanding through experience, and it implies the initiation into the common and objective community of knowledge and understanding based on form of life. So, learning begins from recognition that the learner must be treated as a person in the community of life sharing the knowledge and understanding. As it were, the learner must be treated as human existence participating in the form of life, with common interest, need and feeling like us. Therefore, if we try to teach something to child, we have to treat the learner as a person. In other words, we must have the consciousness of respect for learner, with recognisig the learner as cenrer of consciousness and respecting his view of world. Especially, we have to take interest in chlid's emotional attitudes and responses which constitute the common form of life and personal relation.

저수지 붕괴의 원인 및 피해분석 : 공실지를 중심으로

신사철,백승철 安東大學校 工業技術硏究所 2000 공업기술연구논문집 Vol.7 No.1

재해가 발생하면 신속한 피해복구 대책을 수립하기 위해서는 무엇보다 먼저 재해지역에 대한 신속하고 정확한 조사가 실시되어야 한다. 본 연구는 저수지 붕괴에 따른 원인분석을 체계적으로 실시하여 특히 수해발생시 수행되어야 분석의 기준을 제시하고 자 한다. 경상북도 안동시에 위치한 공실 지는 2000년 8월 26일 호우로 인하여 8월 27일 01:00 (추정시각)에 우안 여수로에서 좌안 부분 상 약 5m, 하부 약 3m, 정도가 유실되어 농경지와 가옥의 침수피해가 발생하였다. 이 붕괴사상을 대상으로 붕괴에 따른 피해 및 원인 분석을 현장조사와 수문해석 및 토양 및 지질분석을 통하여 실시하였다. 수문해석 및 흔적조사에서도 저수지 제방의 월류의 가능성은 적으며, 지속적인 여수로와 저수지 제체 연결부로 침투가 이루어져 저수지 제체가 불안정한 상황 하에 갑작스러운 호우로 인하여 침투량이 증가하여 과잉공극수압의 증가로 인하여 파괴가 발생한 것으로 판단된다. To prepare measures for dealing with disasters, the exact investigation for disaster area have to take effect. In this study, the factors leading to reservoir break are analyzed, and set a standard analysis in carrying out reservoir break. The Kongsil reservoir located in Andong City was breaked in a localized torrential downpour at Aug. 27, 2000. As the result of the Kongsil reservoir break, submerged farm land and house occurred in the downstream area. The damage analysis caused by Kongsil reservoir break was performed through field investigation, hydrologic and geological analysis. The reservoir bank have been unstable by infiltration into joined area of spillway and reservoir embankment. Consequently, The reason of the Kongsil reservoir break is supposed that a sudden increase of infiltration into unstable embankment led to increase of excess pore pressure.

NDVI와 기온자료를 이용한 광역증발산량의 추정

신사철,안태용 한국지리정보학회 2004 한국지리정보학회지 Vol.7 No.3

원격탐사 기법은 식생 및 토지이용과 같은 지형조건과 관련된 증발산량을 산정하기 위한 하나의 수단으로 효과적으로 이용될 수 있다. 지표면에서 발생되는 증발산량을 지배하는 인자는 기온, 습도, 바람, 일사량 및 토양조건 등 매우 복잡하게 구성된다. 식생은 그 지점의 증발산량에 영향을 주고 있으며, 증발산량을 지배하는 복잡한 인자는 식생의 성장조건에 직접적으로 영향을 미친다. 결국 중발산량과 식생조건 사이에는 강한 상관관계가 성립될 수 있음을 예상할 수 있다. 비교적 넓은 지점에 대한 식생상태를 파악을 위해서는 NOAA/AVHRR 자료가 효과적으로 이용될 수 있으며, 이로부터 얻어지는 식생지수(NBVI)를 이용함으로서 중발산량과 NDVI 사이의 강한 상관관계를 생각할 수 있다. 본 연구에서는 이러한 점을 근거로 하여 NDVI와 기상자료를 조합하는 간편한 방법에 의한 실제중발산량 산정방법을 제안한다. Remote sensing technique is a probable means to estimate distribution of actual evapotranspiration in connection with regional characteristics of vegetation and landuse. The factors controlling evapotranspiration from ground surface are air temperature, humidity, wind, radiation, soil moisture and so on. Not only the vegetation influences directly the evapotranspiration, but also these factors strongly influences the vegetation growth at the area. Therefore, it can be expected that evapotranspiration is highly correlated to vegetation condition. The normalized difference vegetation index (NDVI) showed excellent ability to get the vegetation information. The NDVI is obtained using NOAA/AVHRR have been studied as a tool for vegetation monitoring. In this paper, a simple method to estimate actual avapotranspiration is proposed based on vegetation and meteorological data.

Mathematical analysis of bio-convective micropolar nanofluid

Sohail Nadeem,Muhammad Naveed Khan,Noor Muhammad,Shafiq Ahmad 한국CDE학회 2019 Journal of computational design and engineering Vol.6 No.3

The present investigation concentrates on three dimensional unsteady forced bio-convection flow of a viscous fluid. An incompressible flow of a micropolar nanofluid encloses micro-organisms past an expo-nentially stretching sheet with magnetic field is analyzed. By employing convenient transformation the partial differential equations are converted into the ordinary differential equations which are non-linear. By using shooting method to solved these equations numerically. The influence of the determining parameters on the velocity, temperature, micro-rotation, nanoparticle volume fraction, microorganism are incorporated. The skin friction, heat transfer rate, and the microorganism rate are analyzed. The results depicts that the value of the wall shear stress and Nusselt number are declined while an enhance-ment take place in the microorganism number. The slip parameters increases the velocity, thermal energy, and microorganism number consequentially. The present investigation are important in improv-ing achievement of microbial fuel cells

Atomic hydrogen driven size control of catalytic nanoparticles for single-walled carbon nanotube growth

Hee Jin Jeong,Laurent Eude,Manoharan Gowtham,Bernd Marquardt,Sung Hun Lim,Shaïma Enouz,Costel Sorin Cojocaru,Kyung Ah Park,이영희,디디에르프리밧 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2008 NANO Vol.3 No.3

The effects of an atomic hydrogen (Hat) pretreatment of the catalyst layer on the low temperature growth of single-walled carbon nanotubes (SWCNTs) have been investigated using a modified catalytic chemical vapor deposition system. Well-defined and isolated individual Fe nanoparticles as a catalyst are successfully formed on the defects with high trapping energy which are created on the Al2O3 surface by Hat pretreatment, yielding highly dense SWCNTs. The pretreatment mechanism of Hat, compared to H2, is also discussed. It was also found that the quality of SWCNTs can be enhanced when Hat is flowed with CH4 during nanotubes growth at low temperature. In this case, the undesired carbon products and defects on catalyst seeds and nanotubes walls can be selectively removed by Hat. Therefore, it is essential to use Hat in pretreatment stage for increasing catalytic activity and keep the size of nanoparticles in the nm range. Hat can also be employed in growth stage for enhancing SWCNTs quality and density at low temperature.

How to Develop Future Internet Medical Care? : A Case Study of China

Sha-Sha SHEN(Sha-Sha SHEN),Shu-Feng XIAO(Shu-Feng XIAO) 동아시아경상학회 2022 The East Asian Journal of Business Economics Vol.10 No.4

Purpose – With the increasing medical demands of the public, the development of future Internet medical care has come to represent a major problem. Therefore, the purpose of this study is to discuss future development strategies for Interne medical care while taking China’s Internet hospitals as an example case. Research design, data, and methodology – This study conducted a case study of China’s Internet hospitals to summarize the fundamental problems faced by Internet hospitals and propose future development strategies to overcome these problems for Internet medical care. Result – Although Internet hospitals have been regarded as the ultimate product of Internet medical care, from the perspective of the government, medical institutions, platforms builders and maintainers, and patients, they still face some basic issues. Conclusion – This study concludes that the government and medical institutions play an important role in the future development of Internet medical care and suggests that the government should make overall plans for the policies and standards and should play the main role in enhancing the public trust in Internet medical care, while medical institutions should take steps such as seizing policy opportunities, driving online and offline collaborations, and constructing suitable evaluation systems to promote the development of Internet medical care.