• 한국해양학회지
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• v.19 no.2
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• pp.163-171
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• 1984

The atmospheric and oceanic influences on the air-sea thermal interaction in the East Sea (Japan Sea) are studied by means of an analytic model which is based on the heat budget of the ocean. By means of the model, the model, the annual variations of heat fluxes and air temperatures in the East Sea are analytically simulated. The model shows that the back radiation, the latent heat and the sensible heat increase with the warn water advection. The latent heat increases with the sea surface temperature (SST) but the back radiation and the sensible heat dcrease as the SST increases. In the East Sea, an increase of mean SST by 1.0$^{\circ}C$ yields an increase of mean air temperature by 1.2$^{\circ}C$. The heat storage in the ocean plays an important role in the annual variations of heat flux across the sea surface.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.9
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• pp.971-978
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• 2010

In this paper, we propose a compact multiple meander RFID tag antenna with broadband characteristic. The proposed tag antenna has been designed using the multiple meander form to effectively minimize the U-shaped half wavelength dipole antenna as the radiator part. The commercial tag chip is attached to the upper center of the rectangular shaped feed for impedance matching. The size of the antenna is $20{\times}19.7\;mm^2$ and VSWR<5.8 bandwidth is 855~964 MHz which covers the world UHF RFID bandwidth.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.08a
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• pp.69-69
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• 2010

현대 건축물에서 건물에너지의 손실은 대부분은 창호를 통하여 유출되어지고 있으며 에너지 절감을 위해서는 창호의 단열성을 향상시켜야한다. 저방사(Low Emissivity) 코팅유리는 건축물의 냉난방비용을 절약할 수 있는 대표적인 건축재료로써 외부에서 유입되는 태양광의 가시광선 영역은 높은 투과율을 가지면서 적외선 영역과 겨울철 실내 난방열을 반사하는 특징을 지니는 박막코팅기술이다. 이 코팅유리는 일반적으로 유전체/금속/유전체 다층박막 구조로 되어있으며, 유전체층은 내구성 증진과 금속층의 반사를 낮추어 투과율이 향상된다. 금속층은 적외선영역의 복사에너지를 반사하는 역할을 하며 전도성이 우수한 Ag 또는 Au, Pt 등을 이용하고 있다. Ag의 경우 산화물기판 위에 증착하였을 경우 island 성장을 하고 이들의 합체는 전기적, 광학적 특성에 큰 영향을 미치게 된다. 본 연구에서는 DC-sputtering법으로 제조된 Ag/glass, Ag/Ta/glass 박막을 제조하고 Ta seeding이 Ag의 전기적, 광학적 성질에 미치는 영향을 관찰하였다. 박막의 표면 미세구조는 FE-SEM(Field Emission Scanning Electron Microscope)과 AFM(Atomic Force Microscope)으로, 표면저항은 4 point probe로 분석하였다. 광투과율은 UV-Vis spectroscopy와 FT-IR로 측정하였으며 측정파장범위는 각각 200~1100nm와 1400~2400nm 이다.

• Journal of the Korean Institute of Telematics and Electronics
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• v.27 no.2
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• pp.39-46
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• 1990

In this paper, Rectangular microstrip patch array antenna. relative current of which is distributed to 1:2:2:1, is designed and fabricated by using Tschebyscheff's polynominal expression and is verified by theoretical analysis and experiment. Seeking for more accurate resonant frequency, an equivlent network, which is consisted including feed line and power distribution line, is analyzed by using the analysis method of transmission line mode. As a result of their comparison and examination, such as resonant frequency by fringing effects, by return loss, by experiment, it is conformed that errors are not barely and agreed with each other. is also agreed with a measured values.

• Transactions of the Korean Society of Mechanical Engineers
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• v.12 no.5
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• pp.1113-1120
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• 1988

This paper presents the results of an experimental investigation on one dimensional excess enthalpy flame formed in a porous block. The investigation is undertaken in order to further the physical understanding of internal heat recirculation from reaction zone to unburned mixture. Two porous blocks are placed at both sides of combustion block to control the temperature distribution in the combustion block by means of radiation heat transfer. Mean temperature measurement reveals the general nature of the reaction zone in the porous material. It is conformed that the temperature of reaction zone exceeds the adiabatic flame temperature and the flame is stabilized at the out range of flammibility limit derived by conventional burner.

• Journal of the Korean Solar Energy Society
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• v.31 no.2
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• pp.37-46
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• 2011

The GWNU (Gangnung-Wonju national university) solar radiation model was developed with radiative transfer theory by Iqbal and it is applied the NREL (National Research Energy Laboratory). Input data were collected and accomplished from the model prediction data from RDAPS (Regional Data Assimilated Prediction Model), satellite data and ground observations. And GWNU solar model calculates not only horizontal surface but also complicated terrain surface. Also, We collected the statistical data related on photovoltaic power generation of the Korean Peninsula and analyzed about photovoltaic power efficiency of the Gangwon region. Finally, the solar energy resource and photovoltaic generation possibility map established up with 4 km, 1 km and 180 m resolution on Gangwon region based on actual equipment from Shinan solar plant,statistical data for photovoltaic and complicated topographical effect.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.16 no.10
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• pp.942-951
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• 2004

This paper presents the results of a theoretical study of the effect of radiation during free convective laminar film boiling for methanol/water binary mixtures on an isothermal vertical wall at atmospheric pressure. With the well-known boundary layer theory as a basis, a theoretical model has been formulated into consideration for mass diffusion at liquid phase. The equations are numerically solved by a similarity method to investigate the effects of radiation emissivity on the surface with various parameters such as wall superheat and composition of more volatile component at liquid phase far from the wall. From the results, the distributions of the physical quantifies are investigated in both phases. New correlations are proposed to predict the heat transfer coefficient of binary mixtures. It is shown that the proposed correlations are in good agreement with numerical results and with Bromley's correlation within maximum $11\%$ errors. It is also found that as the wall superheat is increased, radiation effect becomes more important.

• Korean Journal of Optics and Photonics
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• v.2 no.4
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• pp.203-208
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• 1991

We investigated the nonradiative energy transfer process from Rhodamine 6G to Malachite Green in ethylen glycol solvent using time correlated single photon counting system equipped with a modelocked Ar ' laser. The reduced concentration and critical transfer distance for various acceptor concentration were obtained by using a full-fitting analysis of the fluorescence decay curves. We found that Huber model is more suitable than Forster model and the influence of energy migration through the dipole-dipole interaction becomes more significant for the low acceptor concentrations relative to the donor concentration($5\times 10^4$mol/l).

• Journal of Industrial Convergence
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• v.16 no.4
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• pp.47-52
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• 2018

WebShell is a web script file created by a hacker to remotely commands to a web server. The hacker can bypass the security system using the web shell, access the system, control the system such as file modification, copying and deletion, install malicious code in the web source code, attack the user's PC, And so on. There are many types of WebShell attack, but we study about attacks on PHP and JSP based web server which are used as representative ones. And we propose the method of web page management, method of development, and several other methods. By using these countermeasures, it is possible to effectively prevent damage caused by WebShell attacks.

• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.385-385
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• 2023

우리나라의 경우 여름철에 강우가 집중되는 특성 및 기후변동을 체감하고 있는 현 시점에서 수자원 시스템을 효과적으로 관리하는 것은 점차 중요해지고 있다. 그러나 IPCC의 미래 기후변화 예측 시나리오는 특정 복사강제력에 기반을 하기에 그 자체만으로도 불확실성이 존재하며, 전 지구적 모형을 활용하는 점에서 우리나라 기후변화 예측 정확성이 저하될 가능성이 있다. 장래 수자원 공급의 의사결정 객관성 및 체계를 확보하고 위에 제시된 단점을 보완하기 위하여, 본 연구에서는 Decision-Scaling을 적용하여 댐 이수안전도를 분석하였다. 연구지역은 충주, 용담, 합천, 섬진강댐을 선정하였다. 기후스트레스 시나리오는 총 91개(순위 기반 강우 스트레스 시나리오 13개 및 0℃에서 6℃까지의 7개 온도 스트레스 시나리오)를 1995년부터 2014년까지 관측된 자료를 바탕으로 구축하였다. 수문모형(IHACRES)과 저수지모형(HEC-ResSim)을 결합하여 이수안전도 분석 모형을 개발하였다. 모형의 검정은 과거 댐 유입량과 비교하였으며, 개발된 모형은 매우 높은 정확도(R²≥0.81)를 보여, 과거 사상에 대한 모의가 가능한 것으로 평가 되었다. 본 연구의 결과로 여름철 강우 변동이 온도와 비교하여 용수공급에 더 큰 영향을 주는 것으로 평가 되었다. (i) 강우와 온도가 동시에 변화하는 시나리오와, (ii) 개별적으로 변화하는 시나리오에 대한 이수안전도의 합과 비교하여, (i)의 경우가 이수안전도에 더 큰 영향 주는 것으로 평가되었다. 이러한 결과는 여름철 강수량의 감소와 증가로 인해 각각 물과 에너지가 제한된 실제증발산이 발생한 것으로 사료된다. 본 연구의 결과는 미래를 포함한 기후 스트레스 발생 시 효율적인 댐 관리 및 운영을 위한 의사결정에 활용 될 수 있을 것으로 판단된다.