• Atmosphere
• /
• v.20 no.3
• /
• pp.355-366
• /
• 2010

The tropopause pressure in the Arctic region is calculated by the conventional thermal and dynamical methods using 30-year reanalysis data. The tropopause pressures determined thermally and dynamically both show semiannual cycles with one peak in April and May, and another in October, contrary to the tropopause temperatures. Although tropopause levels are higher both in January and July, the level of the tropopause in January seems to be associated with the stratospheric temperatures while that of July seems to be associated with the tropospheric temperatures. During the 30-year period the most significant trend appears in April, and it is shown that the altitude of the Arctic tropopause has been rising. Although a potential reason for this trend is stratospheric cooling due to ozone depletion, significant tropospheric warming in April is considered to be another reason.

• Journal of Korean Society of Transportation
• /
• v.13 no.1
• /
• pp.5-33
• /
• 1995

This paper addresses the outlines of the traffic signal timing principles engaged in TRACS and the results of field test. Research team, encompassing research institute, university, and electronic company, conducted the three-year project for developing the new system, named TRACS(Traffic Adaptive Control System). The project was successfully completed in 1994. TRACS aims at accomplishing the objectives of better traffic adaptability and more reliable travel time prediction. TRACS operates in real-time adjusting signal timings throughout the system in response to variations in traffic demand and system capacity. The purpose of TRACS is to control traffic on an area basis rather than on an isolated intersection basis. An other purpose of TRACS is to provide real-time road traffic information such as volume, speed, delay , travel time, and so on. The performance of the first version of TRACS was compared to the conventional TOD control through field test. The test result was promi ing in that TRACS consistantly outperformed the conventional control method. The change of signaltiming reacted timely to the variation of traffic demand. Extensive operational test of TRACS will be conducted this year, and some functions will be enhanced.

• Atmosphere
• /
• v.22 no.4
• /
• pp.401-413
• /
• 2012

In this study, an investigation has been carried out to understand 1) temporal variation of rainfall amount in summer over south Korea during the 30-year period of 1979-2008 and 2) the relationship between the variation of rainfall amount and the change of large-scale monsoon circulation around 1993/1994 over East Asia. The analysis of rainfall amount is carried out separately for whole summer (June-August), climatological Changma period of 23 June-23 July, and August to consider variations within summer. To relate the variation of rainfall amount with the change of large-scale circulation, we have considered two 15-year periods of 1979-1993 and 1994-2008. This study has used observations at 58 stations in South Korea and NCEP-NCAR $2.5^{\circ}{\times}2.5^{\circ}$ reanalysis data. The major change in synoptic environment for the Changma period is characterized by the intensified anticyclone over Mongolia during 1994-2008, which results in a weak meridional oscillation of Changma front. As a result, rainfall amount for the Changma period and the frequency of extreme events have significantly increased after 1993/1994. A major change of synoptic environment for August is the significant westward extension of the western Pacific subtropical high, which allows not only more moisture transports but also stronger cyclonic circulation over the Korean peninsula. Rainfall amount for August and frequency of extreme events have also increased after 1993/1994. However, variability of rainfall amount is larger for August than that for the Changma period, with some years showing very dry August (monthly rainfall amount less than 150 mm).

• Near Infrared Analysis
• /
• v.2 no.1
• /
• pp.55-58
• /
• 2001

The object of this work was to investigate the influence of growing district and harvest year on calibration for sweetness (Brix) determination of Fuji apple fruit using near infrared (NIR) reflectance spectroscopy, and to develop the robust calibration across these variation. The calibration models was based on wavelength range of 1100∼2500 nm using a stepwise multiple linear regression. A calibration model by sample set of one growing district was not transferable to other growing districts. The combined calibration (data of three growing districts) predicted reasonable well against a population set drawn from all growing districts (SEP=0.69, Bias=0.075). A calibration model by sample set of one harvest year was not also transferable to other harvest years. The combined calibration (data of three harvest years) predicted well against a population set drawn from all harvest years (SEP=0.53, Bias=0.004).

• Proceedings of the Zoological Society Korea Conference
• /
• 1995.10a
• /
• pp.68-73
• /
• 1995

Most female Great Tits lay one egg each day until the clutch is complete. However, some exceptions are found. “Pause day/s” most frequently occur after the 1st egg is laid. In general, egg-size increase with laying sequence, but there is year-to-year variation. The relationship between egg size and laying sequence is found more significantly in relatively larger clutches than in smaller ones. Great Tits tend to advance the hatching of their chicks by starting to incubate earlier in relation to clutch completion as the breeding season progresses. hatching asynchrony affects chick´s growth rate, but when the effect of laying date on hatching asynchrony is controlled, the effect of hatching asynchrony on growth rate is not found. These findings support the ´hurry-up´ hypothesis.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.65 no.3
• /
• pp.382-387
• /
• 2016

This paper deals with the assessment of voltage sags regarding the variation of system operating conditions. In general, voltage sag assessment is performed by assuming the constant operating condition throughout the year. However, the assumption can lead to assessment errors in case of considerable changes of system operation condition. This paper presents a method to estimate ESF(expected sag frequency) considering the operating conditions according to the changes of power demand throughout the year.

• Journal of the Korean Society of Costume
• /
• v.51 no.7
• /
• pp.147-165
• /
• 2001

The objective of this study was to develop the Jeogori Pattern for 9 to 10 year-old boys To determine the measurement items for the Jeogori Pattern making, applied factor analysis, correlation analysis and regression analysis to the 37 measurement items of the 9 to 10 year-old boys classified as a standard somatotype. To understand the shape and variation of the body surface, analyzed the replica of the upper body surface that was obtained by the method of using surgical tape. Be based on the results of the above studies, designed the Jeogori Pattern. The designed pattern was evaluated by the sensory test. The drafting methods of Jeogori Pattern obtained are as follows. $\circled1$ The measurement items are Bust Girth, Center Back Waist Length, Neck Width, and Hwajang Length. $\circled2$ Jeogori Length Center Back Waist Length$\times$4/3 $\circled3$ Front Body Girth(1/2) : B/2 + 1.5cm Back Body Girth(1/2) : B/2 + 3.5cm $\circled4$ Jin-Dong : B/4 + 3cm $\circled5$ Back Godae Width(1/2) : Neck Width/2 + 1.7cm Front Godae Width(l/2) : Back Godae Width(1/2) - 2cm $\circled6$Back Godae Point is 1.5cm higher than shoulder line, and Front Godae Point is 1.5cm lower than shoulder line. $\circled7$ Back Godae Depth: 1.2cm + 1.5cm = 2.7cm The Jeogori Pattern designed by the above method Is as (fig. 8) The results of the sensory test of the new pattern are as fellows. Except for 2 items, every mark of 24 test items has over 5.0 point and a total average mark is 5.25 point. Witch is a good mark. Therefore the new pattern is valid. Especially, the parts of Git, sleeves and back face have a high mark, so the appearances of those parts are excellent.

• Journal of Korean Society of Rural Planning
• /
• v.16 no.4
• /
• pp.109-116
• /
• 2010

Climate change is known to affect both natural and managed ecosystems, and will likely impact on the terrestrail carbon balance. This paper reports the effects of climate change on spatial-temporal changes in carbon reductions in South Korea's during 2000-2100. Future carbon (C) stock distributions are simulated for the same period using various spatial data sets including land cover, net primary production(NPP) and leaf area index (LAI) obtained from MODIS(Moderate Resolution Imaging Spectroradiometer), and climate data from Data Assimilation Office(DAO) and Korea Meteorological Administration(KMA). This study attempts to predict future NPP using multiple linear regression and to model dependence of soil respiration on soil temperature. Plants store large amounts of carbon during the growing periods. During 2030-2100, Carbon accumulation in vegetation was increased to $566{\sim}610gC/m^2$/year owing to climate change. On the other hand, soil respiration is a key ecosystem process that releases carbon from the soil in the form of carbon dioxide. The estimated soil respiration spatially ranged from $49gC/m^2$/year to $231gC/m^2$/year in the year of 2010, and correlating well with the reference value. This results include Spatial-Temporal C reduction variation caused by climate change. Therefore this results is more comprehensive than previous results. The uncertainty in this study is still large, but it can be reduced if a detailed map becomes available.

• Journal of Environmental Science International
• /
• v.19 no.1
• /
• pp.81-87
• /
• 2010

Cool island intensity urban green space was investigated based in Dalsung Park, that is one of the largest parks in Daegu. Cool island intensity(CII), which is defined as the temperature difference between the green space and its surrounding built-up areas, shows time variations. A through-year measurement(2008-2009) of ground level air temperature revealed seasonal variation and relationship to the atmospheric condition of CII. The temperature variation in the park and the reference downtown Daegu was as same order as CII. The noontime CII is larger in summer than that in winter due to the leaf fall of the park trees. On the other hand, seasonal variation of nighttime CII is not so clear. The nighttime CII was larger under the stable atmosphere.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.20
• /
• pp.142-147
• /
• 1975

The varietal variations of protein and amylose content of rice grown at field and green house were studied. The protein content was negatively correlated with growth duration, and the amylose content was positively correlated with heading date. The environmental variation of the amylose content by cultural season and year was greater in the low amylose varieties than in the high amylose one.