• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.34 no.5
• /
• pp.435-444
• /
• 2001

Daily time series of longshore wind at 8 stations, sea surface temperature (SST) at 11 stations in the eastern coast of the Korean peninsula during $1983\~1997$ and the NOAA/AVHRR satellite data during $1990\~1998$ were used in order to study the temporal and spatial variations of the upwelling cold water which occurred in the summer season. The cold water occurred frequently in the eastern coastal waters of Korea such as Soimal, Kijang, Ulgi, Kampo, Pohang, Youngduk, Chukbyun, Chumunjin and Sokcho, During the upwelling cold water phenomenon, SST came down more than $-5^{\circ}C$ in a day. The maximum of the averaged RMS amplitude of daily SST was $5.8^{\circ}C$ along the eastern coast of Korea on Julian day 212 from $1983\~1997$. The cross correlation coefficients were higher than 0.5 between Sokcho and Chumunjin in the northern part of the East Sea, and along Soimal, Kijang, Ulgi, Kampo and Pohang in the southern part of the East Sea. In late July, 1995 the cold water occurred at Ulgi coastal area and extended to Ullung island which is located 250 km off the Ulgi coast. Even though the distance between Soimal and the Ulgi coast area is more than 120 km, the cross correlation coefficient related to the anomalies of SST due to upwelling cold water was the highest (0.7) in the southeastern coastal area of the Korean peninsula. This connection may be due to the cyclonic circulation of the Tsushima Current in this area and the topography of the ocean rather than the local south wind which induced the coastal upwelling.

• Journal of the Korean earth science society
• /
• v.22 no.5
• /
• pp.388-404
• /
• 2001

In order to examine the relative accuracy of satellite observations and model reanalyses about lower stratospheric temperature trends, two satellite-observed Microwave Sounding Unit (MSU) channel 4 (Ch 4) brightness temperature data and two GCM (ECMWF and GEOS) reanalyses during 1981${\sim}$1993 have been intercompared with the regression analysis of time series. The satellite data for the period of 1980${\sim}$1999 are MSU4 at nadir direction and SC4 at multiple scans, respectively, derived in this study and Spencer and Christy (1993). The MSU4 temperature over the globe during the above period shows the cooling trend of -0.35 K/decade, and the cooling over the global ocean is 1.2 times as much as that over the land. Lower stratospheric temperatures during the common period (1981${\sim}$1993) globally show the cooling in MSU4 (-0.14 K/decade), SC4 (-0.42 K/decade) and GEOS (-0.15 K/decade) which have strong annual cycles. However, ECMWF shows a little warming and weak annual cycle. The 95% confidence intervals of the lower stratospheric temperature trends are greater than those of midtropospheric (channel 2) trends, indicating less confidence in Ch 4. The lapse rate in the trend between the above two atmospheric layers is largest over the northern hemispheric land. MSU4 has low correlation with ECMWF over the globe, and high value with GEOS near the Korean peninsula. Lower correlations (r < 0.6) between MSU4 and SC4 (or ECMWF) occur over $30^{\circ}$N latitude belt, where subtropical jet stream passes. Temporal correlation among them over the globe is generally high (r > 0.6). Four kinds of lower stratospheric temperature data near the Korean peninsula commonly show cooling trends, of which the SC4 values (-0.82 K/decade) is the largest.

• Journal of the Korean earth science society
• /
• v.40 no.6
• /
• pp.613-623
• /
• 2019

Over the past decades, daily sea surface temperature (SST) composite data have been produced using periodically and extensively observed satellite SST data, and have been used for a variety of purposes, including climate change monitoring and oceanic and atmospheric forecasting. In this study, we evaluated the accuracy and analyzed the error characteristic of the SST composite data in the sea around the Korean Peninsula for optimal utilization in the regional seas. We evaluated the four types of multi-satellite SST composite data including OSTIA (Operational Sea Surface Temperature and Sea Ice Analysis), OISST (Optimum Interpolation Sea Surface Temperature), CMC (Canadian Meteorological Centre) SST, and MURSST (Multi-scale Ultra-high Resolution Sea Surface Temperature) collected from January 2016 to December 2016 by using in-situ temperature data measured from the Ieodo Ocean Research Station (IORS). Each SST composite data showed biases of the minimum of 0.12℃ (OISST) and the maximum of 0.55℃ (MURSST) and root mean square errors (RMSE) of the minimum of 0.77℃ (CMC SST) and the maximum of 0.96℃ (MURSST) for the in-situ temperature measurements from the IORS. Inter-comparison between the SST composite fields exhibited biases of -0.38-0.38℃ and RMSE of 0.55-0.82℃. The OSTIA and CMC SST data showed the smallest error while the OISST and MURSST data showed the most obvious error. The results of comparing time series by extracting the SST data at the closest point to the IORS showed that there was an apparent seasonal variation not only in the in-situ temperature from the IORS but also in all the SST composite data. In spring, however, SST composite data tended to be overestimated compared to the in-situ temperature observed from the IORS.

• Clinical and Experimental Pediatrics
• /
• v.52 no.8
• /
• pp.910-916
• /
• 2009

Purpose : The arterial switch operation (ASO) has become the preferred procedure for the surgical management of transposition of the great arteries (TGA). We conducted a retrospective evaluation of our experience in 30 patients seen from January 2003 to July 2008, in order to determine outcomes and related risk factors after the arterial switch operation. Methods : Patients charts, surgical reports, and echocardiograms were retrospectively reviewed. And they were analyzed in 2 different groups: complex (n=16) versus simple TGAs (n=14). Complex TGAs are TGAs with VSD or the Taussig-Bing anomaly with or without aortic arch anomalies. Simple TGAs are defined as TGAs with intact ventricular septum having no such anomalies. Median follow-up time was 44 months (3-63 months). Results : Hospital mortality was 0%. However, follow-up echocardiographies revealed potential complications, including stenosis of the branch pulmonary arteries, neo-aortic and/or neo-pulmonary valvar regurgitation, and right or left ventricular outflow tract obstructions. Great arterial relationship (side-by-side), association of aortic arch anomalies, and the existence of the Taussig- Bing anomaly were assessed as significant risk factors of neo-aortic and/or neo-pulmonary valvar regurgitation in this series. On the other hand, right or left ventricular outflow tract obstructions were more frequently found in patients demonstrating VSD, side-by-side positioned great arteries, or associated coronary anomalies. Conclusion : The ASO is the procedure of choice in the treatment of TGA. However, special attention and follow-ups are needed to detect residual problems like the stenosis of the branch pulmonary arteries, neo-aortic and/or neo-pulmonary valvar regurgitation, as well as ventricular outflow tract obstructions.

• Korean Journal of Remote Sensing
• /
• v.34 no.2_1
• /
• pp.267-282
• /
• 2018

Despite the continuous development of phenology detection studies using satellite imagery, verification through comparison with the field observed data is insufficient. Especially, in the case of Korean forests patching in various forms, it is difficult to estimate the start of season (SOS) by using only satellite images due to resolution difference. To improve the accuracy of vegetation phenology estimation, this study reconstructed the large scaled forest type map (1:5,000) with MODIS pixel resolution and produced time series vegetation phenology curves from Normalized Difference Vegetation Index (NDVI) and Enhanced Vegetation Index (EVI) derived from MODIS images. Based on the field observed data, extraction methods for the vegetation indices and SOS for Korean forests were compared and evaluated. We also analyzed the correlation between the composition ratio of forest types in each pixel and phenology extraction from the vegetation indices. When we compared NDVI and EVI with the field observed SOS data from the Korea National Arboretum, EVI was more accurate for Korean forests, and the first derivative was most suitable for extracting SOS in the phenology curve from the vegetation index. When the eight pixels neighboring the pixels of 7 broadleaved trees with field SOS data (center pixel) were compared to field SOS, the forest types of the best pixels with the highest correlation with the field data were deciduous forest by 67.9%, coniferous forest by 14.3%, and mixed forest by 7.7%, and the mean coefficient of determination ($R^2$) was 0.64. The average national SOS extracted from MODIS EVI were DOY 112.9 in 2014 at the earliest and DOY 129.1 in 2010 at the latest, which is about 0.16 days faster since 2003. In future research, it is necessary to expand the analysis of deciduous and mixed forests' SOS into the extraction of coniferous forest's SOS in order to understand the various climate and geomorphic factors. As such, comprehensive study should be carried out considering the diversity of forest ecosystems in Korea.

• Korean Journal of Soil Science and Fertilizer
• /
• v.25 no.4
• /
• pp.370-377
• /
• 1992

A series of field and laboratory experimentes were conducted to find out the effects of kinds of crops residues and the different amount of fertilizer to the microbial interaction, chemical properties, plant growth and their interaction under continous cultivation of hot pepper, soybean, sesame and upland rice. The results obtained were summerized follows : 1. Total number of bacteria and actinomycetes were enhanced by cultivation of upland rice and soybean while no appreciable effects were obtained by the cultivation of hot pepper and sesame. 2. The number of bacteria, actinomycetes and fungi were increased by return of crop residues when the cultivation of hot pepper, soybean, sesame and upland rice. Specially, actinomycetes was remarkably increased by upland rice cultivation. 3. Increased amount of fertilizer were remarkably affected to decrease of number of soil microorganisms. Specially, actinomycetes succession was appearently affects while plant growing time. 4. The number of identified soil bacterial species were obtained high in order of Bacillus sp.>Rhizobium sp.>Agrobacterium sp.>Pseudomonas sp. The number of Gram positive bacteria were superior than that of Gram negative bateria. 5. Interaction between microbial succession and crops cultivation, the number of Bacillus sp. was increased in hot pepper, Rhizobium sp. was in soybean, and sesame, and Agrobacterium sp. were increased in soybean, respectively. 6. Survival and habitate of soil microorganisms were differ with kinds of crop, application of residue and fertilizers. Most high number of Bacillus sp. Rhizobium sp. and Pseudomonas sp. were obtained on the rhizoplane and rhizosphere while Agrobacterium sp. and Fusarium sp. were high in rhizosphere. 7. Factors in relation to change of soil microbial population was obtained high in order of climates>crops>organic>matter>fertilizer.

• Journal of Chest Surgery
• /
• v.30 no.3
• /
• pp.287-292
• /
• 1997

.Itrial fibrillation is one of the most common cardiac arrhythmias requiring treatment. About 60% of patients with mitral valvular disease have atrial fibrillation and one third of patients with atrial fibrillation may have the past history of thromboembolic events. Between April 1994 and June 1995, 20 patients with organic heart diseases combined with atrial fibrillation underwent open heart surgery including Cox-maze 111 procedure. There were 6 men and 14 women with an average age of 48 years (range, 31 to 66 years). Nineteen patients had valvular heart diseases and 1 ventricular septal defEct (VSD). Mean duration of atrial fibrillation was 36 months (:42 months) (range, 1 to 132 months). T e past medical history of thromboembolic events was positive in 7 patients (35%) and left atrial thrombus was detected in 9 patients (45%). The concomitant procedures were mitral valve replacement (MVR) and aortic valve replacement (AVR) in 5 patients, MVR in 4, MVd and tricuspid annuloplasty(TAP) in 4, mitral valvuloplasty(Mln) in 3, Mln and Tln in 1, MIW and coronary artery bypass surgery in 1, AVR in 1, and patch closure of VSD in 1. Mean aortic cross-clamping time was 175 minutes (range, 116 to 270 minutes). Atrial fibrillation recurred in 16 patients (80%) during the early postoperative period, but, recurrent atrial fibrillation was converted to regular rhythm at postoperative forty-first day in average. There was no early or late death in this series of 20 patients and postoperative complications were inappropriate tachycardia in 5 patients (25%), low cardiac output syndrome in 3 (15%), aggravated hemiplegic in 1, and acute renal failure in 1. Mean follow-up interval of patient was 16.5 months (range, 10.5 to 24 months) and all patients are currently in regular rhythm. Seventeen patients (85%) are in sinus rhythm and 3 (15%) in junctional rhythm. Right atrial contraction was detected in 95% of patients and left atrial contraction in 63% on postoperative transthoracic echocardiogram. The surgical treatment of atrial fibrillation concomitant with open heart surgery is warranted in the recent clinical setting of improved myocardial protection technique, considering the untoward side-effects of atrial fibrillation.

• Economic and Environmental Geology
• /
• v.34 no.4
• /
• pp.375-383
• /
• 2001

We extracted sea surface heights(SSH) from the TopexJPoseidon(T/P) radar altimeter data to compare with fhe SSH estimated from in-situ lide gauges(T/G) at Ulleungdo, Pohang, and SockcholMucko sites. Selection criteria such as wet/dry troposphere, ionosphere, and ocean tide were used to estimate accurate SSH. For time series analysis, the one-hour interval tide gauge SSHs were resampled al lO-day interval of the satellite SSHs. The ocean tide model applied in the altimeter data processing showed periodic aliasings of 175.5 day, 87.8 day, 62J day, 58.5 day, 49.5 day and 46.0 day, and, hence, the ZOO-day filtering was applied to reduce these spectral noises. Wavenumber correlation analysis was also applied to extract common components between the two SSHs, resulting in enhancing the correlation coefficient(CC) dramatically. The original CCs between the satenite and tide gauge SSHs are 0.46. 0.26, and 0.]5, respectively. Ulleungdo shows the largest cc bec;luase the site is far from the coast resulting in the minimun error in the satellite observations. The CCs were then increased to 0.59, 030, and 0.30, respectively, after 200.day filtering, and to 0.69, 0.63. and 0.59 after removing inversely correlative components using wavenumber correlation analysis. The CCs were greatly increased by 87, 227, and 460% when the wavenumber correlation analysis was followed by 2oo-day filtering, resulting in the final CCs of 0.86, 0.85, 0.84, respectively. It was found that the best SSHs were estimated when the two methods were applied to the original data. The low-pass filtered TIP SSHs were found to be well correlated with the TIG SSHs from tide gauges, and the best correlation results were found when we applied both low-pass filtering and spectral correlation analysis to the original SSHs.

• Korean Journal of Psychosomatic Medicine
• /
• v.9 no.1
• /
• pp.28-36
• /
• 2001

Objectives : This study was undertaken to identify the clinical and psychological characteristics in patients of mental disability assessment following traumatic brain injury who had the finding with or without abnormal brain imaging study. Methods : A consecutive series of 59 patients were assessed in hospital from January 1994 to December 1998. Patients were divided into 2 groups based on normal or abnormal brain imaging and the two groups were compared in demographic characteristics, psychiatric symptoms, type of head injury, clinical psychological findings. There were 27 patients with abnormal findings and 32 with normal findings in brain imaging study. Results : Abnormal finding group in brain imaging study had significantly higher incidence of psychosis, decreased memory, decreased appetite, increased nihilistic idea, and intracranial hemorrhage. Also, abnormal finding group showed significantly lower level of performance on the block design subtest of K-WAIS and had significantly lower scores on F, hypochodriasis, depression, hysteria, psychopathic deviate, psychasthenia and schizophrenia subscale of the MMPI. Conclusion : The findings suggest that the patients undergone brain surgery due to intracranial hemorrage at that time of brain injury may have higher frequency of abnormal findings in brain imaging study, complain more cognitive and affective symptoms, and have lower the abstract concept formation and perceptual organization abilities.

• Journal of Korean Society of Environmental Engineers
• /
• v.34 no.4
• /
• pp.223-231
• /
• 2012

The purpose of this study is to investigate basically the mechanism of heat transfer by the resolution of complex fluid flow inside a sophisticated designed screw dryer for the treatment of sewage sludge by using numerical analysis and experimental study. By doing this, the result was quite helpful to obtain the design criteria for enhancing drying efficiency, thereby achieving the optimal design of a multiple screw type dryer for treating inorganic and organic sludge wastes. One notable design feature of the dryer was to bypass a certain of fraction of the hot combustion gases into the bottom of the screw cylinder, by the fluid flow induction, across the delicately designed holes on the screw surface to agitate internally the sticky sludges. This offers many benefits not only in the enhancement of thermal efficiency even for the high viscosity material but also greater flexibility in the application of system design and operation. However, one careful precaution was made in operation in that when distributing the hot flue gas over the lump of sludge for internal agitation not to make any pore blocking and to avoid too much pressure drop caused by inertial resistance across the lump of sludge. The optimal retention time for rotating the screw at 1 rpm in order to treat 200 kg/hr of sewage sludge was determined empirically about 100 minutes. The corresponding optimal heat source was found to be 150,000 kcal/hr. A series of numerical calculation is performed to resolve flow characteristics in order to assist in the system design as function of important system and operational variables. The numerical calculation is successfully evaluated against experimental temperature profile and flow field characteristics. In general, the calculation results are physically reasonable and consistent in parametric study. In further studies, more quantitative data analyses such as pressure drop across the type and loading of drying sludge will be made for the system evaluation in experiment and calculation.