• Korean Journal of Remote Sensing
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• v.16 no.2
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• pp.117-133
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• 2000

We studied the sea level variations at Kerguelen island in the South Indian Ocean with ARGOS data and meteorological data during about 1 year(May 1993~April 1994) through using filter, spectral analysis, coherency and phase, and found characteristics for the two oceanic signal levels(detided oceanic signal level, h$_{detided}$ and seasonal oceanic level, h$_{corr.ib}$). The forms of atmospheric pressure variations are good agreed to between ARGOS data and meteorological data in the observed periods. This Kerguelen area shows the inflow of an air temperature(gain of a radiant heat) into the sea water and the stagnation of high atmospheric pressure bands in summer, and the outflow of a sea water temperature(loss of sensible and latent heat) toward the atmosphere and the stagnation of low atmospheric pressure bands in winter. The seasonal difference of sea level between summer and winter is about 1.6cm. Both the detided oceanic signal level(h$_{detided}$) variation and the inverted barometer level(h$_{ib}$) variation have a strong correlation for T>1day period bands. The characteristics of h$_{detided}$ variation are not decided by the influence of any meteorological distributions (atmospheric pressure), but the influence of other factors(bottom water temperature) for T>2days periods bands. h$_{corr.ib}$ plays a very important role of sea level variation in the observed periods (especially T>about 180days period bands).

• Korean Journal of Environment and Ecology
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• v.34 no.1
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• pp.55-62
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• 2020

To estimate headwater stream temperature with seasonal variations, we analyzed precipitation, runoff and air temperature in experimental forest of Kangwon National University, Gangwon-do (2017~2018 years). The daily mean value of headwater stream temperature for spring was 6.9~17.7℃ and correlated with air temperature, that for summer and fall were 12.2~26.3℃ and 3.6~19.3℃, correlated with air temperature and runoff. Based on seasonal variations, we applied for stepwise multiple linear regression analyses to estimate headwater stream temperature with seasonal variations. The equations were headwater stream temperature(WT)_spring=(0.553×Air temperature)+(0.086×Runoff)+4.145 (R²=0.505; p<0.01), WT_summer=(0.756×Air temperature)+(-0.072×Runoff)+2.670 (R²=0.510; p<0.01), and WT_fall=(0.738×Air temperature)+(0.028×Precipitation)+2.660 (R²=0.844; p<0.01). The coefficient of determination (R²) was greater than when it was estimated by air temperature in all seasons and progressively increased from spring to winter. Therefore, we indicated difference on estimated magnitude of stepwise multiple linear regression, due to effects on headwater stream temperature of different environmental factors with seasonal variations. Furthermore, temporal factors with spatial characteristics (e.g., river versus headwater stream) could be recommended for estimating headwater stream temperature.

• Korean Journal of Optics and Photonics
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• v.10 no.4
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• pp.273-278
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• 1999

A TDM-multiplexed fiber optic pressure/temperature sensor system utilizing fiber optic Fabry-Perot interferometers as sensing devices was developed and applied to measure water level variations and temperature variations. The maximum measurement speed of the system without saving measurement data is 4500 times per second and the response time of the sensors is thought to be ~ms. The difference between the theoretical value and the measured value for the scale factor of water level sensor and temperature sensor was +13.7%, -18% respectively. The nonlinearity of the sensors after calibration was less than 1%. The sensor system was applied to verify the capability of measuring the temperature variations and water level variations at a high speed.

• 한국해양학회지
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• v.5 no.2
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• pp.41-51
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• 1970

Periodic characters of water temperature in the regions of the Mishima and the Okinoshima were derived through the analysis of the five days interval data during 1914 to 1970 mainly. In terms of ten days mean temperatures, annual variation function of the Mishima region, Korea Strait, is F($\theta_d$)=17.45-5.34 cos $\theta_d$-3.77 sin $\theta_d$+0.62 sin $2\theta_d$ -0.52 sin $3\theta_d$, where $\theta_d$=$\frac{\pi}{18}$(d-2), d is the order of ten days period 1 to 36. And in the region of Okinoshima, Tsushima Strait, we find F($\theta_d$)=18.88-5.39 cos $\theta_d$-3.60 sin $\theta_d$+0.52 sin $2\theta_d$. The annual mean temperature is 17.4$^{\circ}C$ in the Mishima region, 18.9$^{\circ}C$ in the Okinoshima region, and the amplitudes of annual variation functions are 7$^{\circ}C$ in both regions with minimum temperature in the middle ten days of February, maximum in the middle ten days of August. The long term variations of surface water temperature with 12 5 years period were observed in the annual mean temperature, monthly mean temperatures and the fixed day temperatures of every year. In addition to these, relatively short term variations were also found significant periods of 3 years, 4 years and 2 years, respectively.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.32 no.4
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• pp.395-401
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• 1996

In this paper, the propagation characteristics due to the horizontal water temperature variations in the sea such as thermal fronts is analyzed by the ray theory. Two models for the temperature anomaly layer are chosen. One is a plane type and the other is a cylindrical type. In the plane type, the temperature increases linearly from a isothermal region to 5km with the gradient of about $2^{\circ}C.$/km, and decreases with the same gradient in next 5km. In the cylindrical type, water temperature increases only with the same gradient from a half cylindrical thermal boundary surface. The result showed that the gradient of acoustic rays decreases in the temperature increasing region and vice versa in temperature decreasing region. And, the transmission loss due to the temperature variation was less than O.2dB in the plane type model as well as in the cylindrical one.

• Proceedings of the KSRS Conference
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• v.2
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• pp.880-883
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• 2006

Altimeter(Topex/Poseidon) and AVHRR(NOAA) data were used to study the variations and correlations of Sea Level(SL) and Sea Surface Temperature (SST) in the North East Asian Seas from November 1993 to May 1998. This region is influenced simultaneously to continental and oceanic climate as the border of the East Sea(Japan Sea). SL and SST have increased gradually every year because the global warming, and presented usually a strong annual variations in Kuroshio extension region with the influence of bottom topography.

• Proceedings of the KIPE Conference
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• 2007.07a
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• pp.244-246
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• 2007

The LCD backlight technique using light-emitting diode(LED) has been studied in the recent backlight market. The white light is need for LCD backlight and it is generally implemented by combining the RGB-LEDs to obtain the high brightness. However, RGB-LEDs have different color characteristics for the current and temperature variations, which results in the color shift problem. The color shift characteristics of RGB-LEDs for the current and temperature variations are investigated in this paper. This result can be used to control the color of backlight system using RGB-LEDs.

• Korean Journal of Remote Sensing
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• v.23 no.1
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• pp.59-63
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• 2007

Altimeter (Topex/Poseidon) and AVHRR (NOAA) data were used to study the variations and correlations of Sea Level (SL) and Sea Surface Temperature (SST) in the North East Asian Seas from November 1993 to May 1998. This region is influenced simultaneously to continental and oceanic climate as the border of the East Sea (Japan Sea). SL and SST have increased gradually every year because the global warming, and presented usually a strong annual variations in Kuroshio extension region with the influence of bottom topography.

• Journal of Environmental Science International
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• v.6 no.5
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• pp.425-435
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• 1997

One-dimensional thermodynamic mixed layer model to stimulate variations of meteorological variables wish the planetary boundary layer has been developed In this study. This model consists of 2 prognostic equations, which can predict the variations of potential temperature and mixing ratio and several diagnostic equations. Physics within the surface and mixed layers has been considered seperately in the model. For the variations of the model, Its result has been analysed and compared with observated data over Ole Dukyang Bay for one day, July 23, 1992. The simulated height of mixed layer is comparable to the observation and the variations of temperature and mixing ratio in the mixed layer are also reasonably simulated. Those Imply that the model responds appropriately with given boundary conditions In sprite of Its simplilfied assumptions applied to the model and insufficient boundary and Initial conditions.

• Journal of the korean Society of Automotive Engineers
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• v.15 no.1
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• pp.67-72
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• 1993

Wall wetting phenomenon in the intake port of an MPI engine was investigated with different kinds of injectors by an A/F step response test and analysis was done based on the simple wall wetting model to find out a certain correlation between wall wetting and A/F variations. It was found that (1) At fully warmed condition of 90.deg.C water temperature, around 40-60% of injected fuel was wall wetted, (2) At cold condition of 45.deg.C Water temperature, around 68-80% of injected fuel was wall wetted, and (3) A/F variations during acceleration and deceleration were influenced by the wetting area, the fuel droplet size, and the amount of wall wetting fuel.