• Journal of the Institute of Convergence Signal Processing
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• v.14 no.2
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• pp.105-109
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• 2013

There are the free space model, the direct-path and ground reflected model, Egli model, Okumura-Hata model in the representative propagational models. The measured results at the area of PNG area were used as the experimental data in this paper. The new proposed partial interval analysis method is applied on the measured propagation data in the cellular band. The interval for the analysis is divided from the entire 30 Km distance to 5 Km, and next to 1 Km. The best-fit propagation models are chosen on all partial intervals. The means and standard deviations are calculated for the differences between the measured data and all partial interval models. By using the 5 Km- or 1 Km- partial interval analysis, the standard deviation between the measured data and the partial propagation models was improved more than 1.7 dB.

• Korean Journal of Remote Sensing
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• v.35 no.4
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• pp.491-502
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• 2019

Distinguishing debris-covered glaciers from debris-free glaciers is difficult when using only optical remote sensing images to extract glacier boundaries.According to the features that the surface temperature of debris-covered glacier is lower than surrounding objects, and higher than clean glaciers, glacial changes in the Yigong Zangbo basin was analyzed on the basis of visible, near-infrared and thermal-infrared band images of Landsat TM and OLI/TIRS in the support of ancillary digital elevation model (DEM). The results indicated that glacier area gradually declined from $928.76km^2$ in 1990 to $918.46km^2$ in 2000 and $901.51km^2$ in 2015. However, debris-covered glacier area showed a slight increase from $63.39km^2$ in 1990 to $66.24km^2$ in 2000 and $71.16km^2$ in 2015. During 25 years, the glacier length became shorter continuously with terminus elevation rising up. The area of moraine lakes in 1990 was $1.43km^2$, which increased to $1.98km^2$ in 2000 and $3.41km^2$ in 2015. In other words, the total area of the moraine lakes in 2015 is 2.38 times of that in 1990. This increase in moraine lake area could be the result of accelerated glacier melt and retreat, which is consistent with the significant warming trend in recent decades in the basin.

• Journal of the Korean Geophysical Society
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• v.5 no.3
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• pp.211-218
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• 2002

The reversed two station method (RSTM) devised by Chun et al. (1987) is widely used to obtain $Q_{Lg}^{-1}$ for Lg wave data with hypocentral distance greater than 90 km. By applying RSTM to the Lg data of central South Korea with hypocentral distance between 95 and 381 km, we obtained high $Q_{Lg}^{-1}$. The value of $Q_{Lg}^{-1}$ is very similar with that of southeastern S. Korea, which is derived from the same method for similar distances. The studied hypocentral range seems to distort $Q_{Lg}^{-1}$ to high value because decay rate in this range is higher than 0.5, which is typical decay rate of surface wave.

• Korean Journal Plant Pathology
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• v.12 no.4
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• pp.381-388
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• 1996

맥류세균성 줄무늬병균의 선택배양기(KM-1)를 개발하여 이병식물체 및 토양으로부터 Xanthomonas campestris pv. translucens를 선택적으로 분리할 수 있는 효율성을 검토하였다. KM-1배양기의 구성성분은 증류수 1 L당 lactose 10 g, D(+)trehalose 4.0 g, thiobarbituric acid 0.2 g, K\ulcornerHPO\ulcorner 및 KH\ulcornerPO\ulcorner 각각 0.8 g, yeast extract 30 mg, NH\ulcornerCl 1 g, cycloheximide 100 mg, tobramycin 8.0 mg, ampicillin 1.0 mg 및 Bacto agar 15 g이며 1 N NaOH로 pH 6.6으로 조절하였다. X. c. t.의 균주별 KM-1의 배양효율은 비선택성 농후배지인 Wilbrinks agar에 비하여 1.30정도였으며, 기타 토양전염성식물병원세균 Agrobacterium tumefaciens, Agrobacterium rhizogenes, Erwinia carotovora var. atroseptica, Erwinia carotovora var. carotovora, Corynebacterium insidiosum, 및 기타 토양생존 부생세균 Bacillus cereus, Pseudomonas aeruginosa, Pseudomonas fluorescens, and Pseudomonas putida 등의 생장을 완벽하게 억제하였다. KM-1의 저장기간(shelf-life)도 5$^{\circ}C$에서 2개월 동안 선택성을 유지하였다. 따라서 본 병원균의 전염원의 생존 등 발생생태연구에 활용될 수 있는 가치가 충분히 인정되었다.

• Parasites, Hosts and Diseases
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• v.40 no.3
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• pp.139-148
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• 2002

In order to study the range of flight and feeding activity of Anopheles sinensis, the dispersal experiment was conducted in Paju city, located in the northern part of Gyeonggi-do, Republic of Korea, during the period of 7th to 28th September 1998. Unfed females An. sinensis were collected in cowshed and released after being marked with fluorescent dye at 23:00 hours on the same day. Released female mosquitoes were recaptured everyday during 21 days using light traps, which were set at 10 sites in the cowsheds located 1, 3, 6, 9 and 12 km north-northwest and north-northeast and at 3 sites located 1, 6 and 9 km toward south-west from the release point. In addition, to study the longest flight distance in one night, we set the light traps at 16 and 20 km toward north-northeast from the release site. All the collected mosquitoes were placed on filter papers and observed on UV transilluminator after treatment with one drop of 100% ethanol. Out of 12,773 females of An. sinensis released, 194 marked females mosquitoes were recaptured, giving 1.52% recapture rate. Of 194, 72 mosquitoes (37 1%) were recaptured in light traps from three places set at 1 km from the release point, 57 mosquitoes (29.4%) from two places at 1-3 km, 41 mosquitoes (21.1%) from three places at 3-6 km, 20 mosquitoes (10.3%) from three places at 6-9 km, and 4 mosquitoes (2.1%) from two places at 9-12 km. Since 170 female mosquitoes (87.6%) out of 194 marked mosquitoes were captured within 6 km from the release point, this flight radius represents the main activity area. An. sinensis was found to be able to fly at least 12 km during one night.

• Journal of Korean Society of Transportation
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• v.20 no.2
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• pp.47-58
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• 2002

This thesis is based on the speed variations which are observed both in a sing1e tunnel and a continuous tunnel. Kumdae II tunnel and Chiak I tunnel of Jungang Expressway are selected in order to analyze the characteristics of speed variations according to tunnel intervals I place importance on the computation of tunnel intervals according to the speed variations. there's a summary of the results. The results of the study reveal that speed changes occur both on 1km ahead of tunnel and within the tunnel. The speed change amounts to 7.1km/hr(6.7%) on these survey Points 2.7km/hr (2.9%) on access points, and from -3.6km/hr (-3.8%) to, +4.1km/hr(+4.7%) irregularly on egress points. The magnitude of speed chance appears small on the survey points where an interval of tunnel is short whereas the speed chance turn out to be rather significant on the points where the tunnel interval is long. The analysis of tunnel distances using multiple regression models shows that the appropriate tunnel distance turns out to be 732m. The distance of 732m seem to be providing a fecundation for uniform traffic flow in continuous tunnel conditions.

• Korean Journal of Remote Sensing
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• v.34 no.3
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• pp.465-480
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• 2018

On 20 January 2017, the fresh snow cover which is more than 20 cm, accompaning with lightning occurred over Yeongdong coastal region for the first 3-hour of the heavy snowfall event. This study analyzed sounding observations in the heavy snow period which were including the measurements of wind profiler, radiometer and rawinsonde. The features examined from the vertical wind and temperature data at the two adjacent stations, Bukgangneung and Gangneung-Wonju National University, are summarized as follows: 1) The strong (30-40 kts) north-east winds were observed in the level from 2 to 6 km. The Strong atmospheric instability was found from 4 to 6 km, in which the lapse rate of temperature was about $-18^{\circ}C\;km^{-1}$. These features indicate that the deep convective cloud develops up to the height of 6 km in the heavy snowfall period, which is shown in the satellite infrared images. 2) The cooling was observed in the level below 1 km. At this time, the surface air temperature at Bukgangneung station decreased by $4^{\circ}C$. The narrow cooling zone estimated from AWS and buoy data was located in east-west direction. These are the features observed in the cold front of extratropical cyclone. The distributions of radar echo and lightning also show the same shape in east-west direction. Therefore, the results indicate that the Yeongdong thundersnow event was the combined precipitation system of deep convective cloud and cold frontal precipitation.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.20 no.2
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• pp.91-95
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• 1984

This paper describes to analyze regression relation between the ratio mean draft to freeboard and KM/dm, KB/dm and GM/B, respectively with the 43 Korean fishing vessels (7 Danish seiners; 1l Stowers; 14 Poler and liners; 6 Trawlers; 5 Purse seiners) and the 1 Cargo boat in order to obtain the stability factors of the Korean fishing vessels conveniently. The obtained results are as follows; 1. The stability factors by fishing vessels have a tendency to the larger f/dm, the larger KM/dm and KG/dm, and KB/dm and GM/B are constant. 2. It is found out that M and G differ from the kinds of the fishing vessels because KM/dm is the largest in poler and liners and KG/dm in Danish seiner, respectively. 3. It is confirmed that the stability factors of the fishing vessels which the inclining experiment carry out the wholly in the light and the full loaded condition are the same as the inclining experiment uniformly.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.12 no.2
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• pp.163-172
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• 1994

As for the baseline measurement using geodetic GPS receiver, this paper puts forth the effective measurement range of a low-priced GPS system receiving Ll frequency only. Compared with the data of baseline eliminated the ionospheric effects with L1/L2 frequencies, the results with Ll frequency approximate to those with dual frequency within the range of 15 km (the baseline discrepancy of the two methods is less than 2 cm). The results with Ll frequency are better within the range of 18 km. Based upon the analysis of data, we find that the convergence limit of integer ambiguity-applicable to double difference fixed solution- is about 18 km and the ionospheric effects have a great influence on the results when the baseline are longer than 20 km. This study also presents a standard which makes it possible to select the favorable data from the results of the GPS relative distance measurements.

• Journal of the Korean Association of Geographic Information Studies
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• v.16 no.2
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• pp.141-151
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• 2013

This study presents a modeling of aerosol extinction vertical profiles in Korea by using the Moderate Resolution Imaging Spectro-radiometer(MODIS) derived aerosol optical thickness(AOT) and ground based visibility observation data. The method uses a series of physical equations for the derivation of aerosol scale height and vertical profiles from MODIS AOT and surface visibility data. The modelled results under the standard atmospheric condition showed small differences with the standard aerosol vertical profile used in the radiative transfer model. Model derived aerosol scale heights for two cases of clean(${\tau}_{MODIS}=0.12{\pm}0.07$, visibility=$21.13{\pm}3.31km$) and hazy atmosphere(${\tau}_{MODIS}=1.71{\pm}0.85$, visibility=$13.33{\pm}5.66km$) are $0.63{\pm}0.33km$ and $1.71{\pm}0.84km$. Based on these results, aerosol extinction profiles can be estimated and the results are transformed into the KML code for visualization of dataset. This has implications for atmospheric environmental monitoring and environmental policies for the future.