• Atmosphere
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• v.19 no.2
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• pp.155-168
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• 2009

Characteristics of seasonal mean diurnal temperature range (DTR) and their causes over South Korea are investigated using the 60 stations data of Korea Meteorological Administration from 1976 to 2005. In general, the seasonal mean DTR is greatest during spring (in inland area) and least during summer (urban and coastal area). The spatial and seasonal variations of DTR are closely linked with the land surface conditions (especially vegetation activity and soil moisture) and atmospheric conditions (cloud amount, precipitation, local circulation). The seasonal mean DTR shows a decreasing trend at the major urban areas and at the north-eastern part of South Korea. Whereas, it shows an increasing trend at the central area of the southern part. Decreasing and increasing trends of DTR are more significant during summer and fall, and during spring and winter. The decrease (increase) of DTR is mainly caused by the stronger increase of daily minimum (maximum) temperature than daily maximum (minimum) temperature. The negative effects of precipitation and cloud amount on the DTR are greater during spring and at the inland area than during winter and at the coastal area. And the effect of daytime precipitation on the DTR is greater than that of nighttime precipitation.

• Korean Journal of Plant Tissue Culture
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• v.27 no.6
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• pp.453-459
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• 2000

Three rice (Oryza sativa L. var Dong-Jin) mutants (DTR1, DTR2, DTR3) resistant to S-methyltryptophan (5MT) were selected by mutagenized M3 seeds. The frequency of chlorophyll mutations induced by the EMS (0.2%) treatment performed 2 hours after flowering is clearly higher than that induced by other treatments in M1 generation. Progeny obtained from the self-pollinating of 5MT-resistant lines segregated with 3 : 1 of resistant to sensitive ratio. Furthermore, the ratio of homozygote to heterozygote in 5MT-resistant plants of the M4 generation was 1：2. These results show that 5MT resistance was inherited as a single dominant nuclear gene. The resistance was also expressed in callus derived from seeds. Total free amino acid content in homozygous seeds of DTR1 and DTR2 showed about 1.7 fold-increased compared to the wild-type seeds. In particular, the levels of phenylalanine and Iysine were, respectively, 6.2 and 3.2 times higher than those in the wild-type seeds. However, seeds of DTR3 had lower levels of free amino acid than the wild-type seeds. This result indicate that these mutants as a significant step towards the production of new rice with balanced amino acid content.

• Atmosphere
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• v.17 no.2
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• pp.147-157
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• 2007

A weekend effect has been investigated in diurnal temperature range (DTR) for Seoul in Korea using 50-year (1955 ~ 2005) surface measurements of maximum and minimum temperatures, and particle mass concentrations (PM10). The minimum temperature increases by 0.42K per decade, 2 times faster than the maximum temperature during 1955 to 2005, for rapid urbanization has occurred in Seoul. The weekend effect, which is defined as the DTR for Sunday minus the average DTR for Tuseday through Thursday, can be as large as +0.08 K for the recent 20-year period relative to 0.01K for 1955 to 1975. Especially the wintertime DTR tends to have a remarkable positive weekend effect (+0.17K), that is, larger DTR on Sunday compared to weekdays, which seems to be associated with increased maximum temperature and thus an increase in DTR. This result could be explained by relative differences in PM10 concentration between Sunday and weekdays (Tuesday through Thursday), such that PM10 concentration on Sundays appears to be systematically lower about 12% than on weekdays. The annually average weekend DTR increases by 0.2K with $10{\mu}gm^{-3}$ decrease in PM10 concentration in comparison with weekdays. The results could be possible evidence of an anthropogenic link to DTR, one of climate important indicators, since no meteorological phenomenon is supposed to occur over a 7 day cycle.

• Atmosphere
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• v.16 no.1
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• pp.49-53
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• 2006

The present study has examined interdecadal variations of the diurnal temperature range (DTR, daily maximum temperature minus daily minimum temperature) during the New Year season in Seoul for the period 1954-2005. Here, the average DTR for the New Year holidays (three consecutive days; one day before the New Year, the New Year day, and one day after the New Year) minus the average DTR for 14 days, 7 days before and 7 days after the New Year holidays, is defined for representing the New Year effect. The DTR index does not show notable trend until the late 1970s but shows obvious positive values afterward. For example, the difference of the average DTR between two periods (1980-2005 minus 1954-1979) is $0.65^{\circ}C$, which is meaningful at the 95% confidence level. This result demonstrates that intense human activity even for the limited period may provide climate impact in local regions. Its plausible causes are discussed.

• Journal of Electrical Engineering and Technology
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• v.12 no.2
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• pp.576-585
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• 2017

Dynamic thermal rating (DTR) of overhead transmission lines can provide a significant increase in transmission capacity compared to the static thermal rating. However, the DTR are usually estimated by the traditional thermal model of overhead conductor that is highly dependent on the solar, wind speed and wind direction data. Consequently, the estimated DTR would be unreliable and the safety of transmission lines would be reduced when the solar and wind sensors are out of function. To address this issue, this study proposed a novel thermal model of overhead conductor based on the thermal-electric analogy theory and Markov chain. Using this thermal model, the random variation of conductor temperature can be simulated with any specific current level and ambient temperature, even if the solar and wind sensors are out of function or uninstalled. On this basis, an estimation method was proposed to determine the DTR in the form of probability. The laboratory experiments prove that the proposed method can estimate the DTR reliably without measured solar and wind data.

• Journal of Gastric Cancer
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• v.22 no.2
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• pp.94-106
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• 2022

Purpose: Laparoscopic proximal gastrectomy with double-tract reconstruction (LPG-DTR) is a function-preserving procedure performed for treating upper early gastric cancer (EGC). However, few studies have compared the outcomes of LPG-DTR with those of laparoscopic total gastrectomy (LTG). This study aimed at comparing the short-term outcomes of LPG-DTR between LTG and upper EGC. Materials and Methods: For upper-third EGC, a multicenter, prospective, randomized trial was performed to compare those who underwent LPG-DTR with those who underwent LTG. Short-term outcomes, including clinicopathologic results, morbidity, mortality, and postoperative courses, were evaluated using a full analysis set based on the intention-to-treat principle and the per-protocol set. Results: Of the patients, 138 who fulfilled the criteria were randomized to each group. One patient in the LPG-DTR group withdrew consent. Sixty-eight patients underwent LPG-DTR and 69 underwent LTG. The operative time (LPG-DTR=219.4 minutes; LTG=201.8 minutes; P=0.085), estimated blood loss (LPG-DTR=76.0 mL; LTG=66.1 mL; P=0.413), and the morbidity rate (LPG-DTR=23.5%; LTG=17.4%; P=0.373) between the groups were not significantly different. No mortality occurred in either of the study groups. Two weeks post operation, the Visick scores for postprandial symptoms, including reflux symptoms, were not significantly different between the groups (P=0.749). Laboratory findings on postoperative day 5 were not significantly different between the groups. Conclusions: The short-term outcomes of LPG-DTR for upper EGC were comparable to those of LTG.

• Journal of the Korean association of regional geographers
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• v.17 no.2
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• pp.167-180
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• 2011

This paper investigates the changes of diurnal temperature range (DTR) by season and region in South Korea using daily maximum temperature and daily minimum temperature from 1954 to 2009. It also attempts to find what causes these changes. The daily minimum temperature distinctively increased during the latter half of the research period (1988~2009) than the first half of the year (1954~1987) leading decreases in DTR, while the rise in daily maximum temperature was not distinct during the research period. The DTR shows slightly increasing trend in spring. but decreasing trend in fall. The DTR is decreasing in urban region while it is increasing in rural area. The degree of the DTR decrease is bigger in large urban region than in medium-small urban region. The DTR in urban region is affected by the amount of clouds in spring and tile duration of sunshine in fall. The DTR in rural area is affected by the amount of clouds in spring and the number of days with precipitation in fall.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 2006.07a
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• pp.536-536
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• 2006

• Journal of the Korean Society of Marine Environment & Safety
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• v.20 no.6
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• pp.671-676
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• 2014

Based on the data of PSC information management system of MOF(Ministry of oceans and fisheries) and APCIS(Asia-Pacific Computerized Information System) of Tokyo-MOU information system, the result of the evaluation on the reality of PSC was done, and base on 2009, it showed a trend of decrease in every DFR(Deficiency Rate) and DTR(Detention Rate). But for vessels built for more than 30 years, flags of convenience vessels, RO-RO ferry and general cargo vessel, small size vessels with gross tonnage less than 1,000 ton showed a high DFR and DTR. Each harbours is classified by the total harbours' average DFR which was 82.5 % and the average DTR was 5.1 %, excluding the Jeju harbour, showing a hugh deviation for classification of each harbour. Classification of each harbour has to be inspected by PSC and it showed a great unbalance of the number of vessels for each territory for inspection. the biggest problem with our country's PSC, where it was pointed out by the PSCO was lack of workers and independent inspection by just one worker. To strength the substantiality of the inspection of our country is to have concentrated inspection on the high risk cautious vessels, forming a human network each classified by four different sectors of the area, recalculating the amount of assignment of inspection classified by each harbour and securing workforce the PSCO improvements are necessary.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.5 no.1 s.9
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• pp.45-54
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• 2006

The UWB signal distortion in frequency selective channel has made it difficult to implement the channel estimator and the synchronizer of the UWB receiver. In this paper, we examine the performances of TR(Transmitted Reference) and DTR(Differential TR) UWB which use either reference pulse or differential method to estimate the channels. we also propose a FSK-based PRM(Pulse Repetition Modulation) UWB system as an another form of UWB system which is advantageous in frequency selective channel. Finally, resorting to statistical analysis, we examine the noise effect due to noisy reference at an auto-correlation(AcR) receiver. moreover, SNR dependance of the integration length in the AcR receiver is also investigated.