• Ocean and Polar Research
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• 제31권4호
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• pp.327-338
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• 2009

Zooplankton community structure was investigated in the Saemangeum region in March, May, July and October of 2007 and 2008 in order to understand the potential effect of post construction of Saemangeum dyke on their temporal and spatial distribution. Mean abundance of zooplankton in the inner and outer area of the dyke, except for dinoflagellate Noctiluca scintillans, ranged from 173 to 15,830 ind.m$^{-3}$, showing higher variability in the inner area compared to the outer area. Zooplankton abundance was higher in the outer area than the inner area in 2007, and vice versa in 2008. In the inner area of the dyke, zooplankton abundance was the highest in May 2007 and March 2008. In the outer area of the dyke, abundance was the highest in October 2007 and July 2008. Brackish species such as Tortanus derjugini and Pseudodiaptomus inopinus were dominant prior to construction of the dyke, and appeared less frequently in the inner area. Marine zooplankton taxa such as juvenile hydromedusa, and calanoid copepods Acartiahongi and Paracalanus parvus s.l. dominated both areas of the dyke. In CCA analysis, zooplankton community structure in the inner and outer area was similar in March and May, but different in July and October. Temperature, salinity and COD were important environmental factors affecting zooplankton community structure. These results suggest that zooplankton community structure in the inner and outer area of Saemangeum dyke are significantly affected by whether the sluice gates are closed or open.

• 대기
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• 제20권3호
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• pp.229-238
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• 2010

The 1,000~500 hPa thickness and the $0^{\circ}C$ isotherm at 850 hPa have been used as the traditional predictors for wintertime precipitation-type forecasts. New approaches are taking on added significance as preexistence method of determination for wintertime precipitation-type exhibits more or less prevalent false alarms. Moreover thicknesses and thermodynamic profiles from ordinary upper-air observation were not adequate to monitor the atmospheric structure. In this regard, Microwave radiometric profiler microwave radiometer is useful in wintertime precipitation-type forecasts because radiometric measurements provide soundings at high temporal resolution. In this study, the determination and the predictability of wintertime precipitation-type were examined by using the calculated thicknesses, temperature of 850 hPa (T850) from a microwave radiometer, and surface observation at National Center for Intensive Observation of severe weather (NCIO) located at Haenam, Korea. The critical values for traditional predictors (thickness of 1000~500 hPa and T850) were evaluated and adjusted to Haenam region because snow rarely occurred with a 1000-500 hPa thickness > 5,300 m and T850 > $-10^{\circ}C$. Three thicknesses (e.g., 1,000~850, 1000~700, and 850~700 hPa thickness), T850, surface air temperature, and wet-bulb temperature were also evaluated as the additional predictors. A simple nomogram and a flow chart were finally designed to determine the wintertime precipitation-type using the microwave radiometer. The skill scores for the predictability of precipitation-type determination are considerably improved and the predictors showed the temporal variations in 12 hours before precipitation. We can monitor the hit and run snowfall in winter successful by realtime watch of the predictors, especially in commutes of big cities.

• 대기
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• 제30권1호
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• pp.47-57
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• 2020

In this study, the climatological spatio-temporal variation of strong wind and gust wind in Korea during the period from 1993 to 2018 was analyzed using daily maximum wind speed and daily maximum instantaneous wind speed data recorded at 61 observations. Strong wind and gust wind were defined as 14 m s^-1 and 20 m s^-1, which are the same as the KMA's criteria of special weather report. The frequency of strong wind and gust wind occurrence was divided into regions with the higher 25 percent (Group A) and the lower 75 percent (Group B). The annual frequency of strong wind and gust wind occurrence tended to be decreased in most parts of the Korean peninsula. In Group A with stations located at coastal region, strong wind and gust wind occurred most frequently in winter with higher frequency at 1200~1600 LST and 2300~2400 LST due to influence of East Asian winter monsoon. In addition, a marked decreasing trend throughout the four seasons was shown at Daegwallyeong, Gunsan and Wando observations. In contrast, it can be found in Group B that the monthly frequency of strong wind and wind gust occurrence was higher in August and September by effect of typhoon and hourly frequency was higher from 1200 LST to 1800 LST.

• 한국컴퓨터산업학회논문지
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• 제10권5호
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• pp.227-234
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• 2009

본 논문은 블록 정합 움직임 추정을 위한 새로운 방식을 제안한다. 비디오 시퀀스의 현재 블록의 움직임 벡터와 이전 블록의 움직임 벡터는 시간적 상관성을 갖고 있다. 따라서 이전 움직임 정보를 이용할 수 있다면 현재 블록의 움직임 추정에 대한 성능을 높일 수 있고 또한 탐색 횟수를 줄임으로써 계산 복잡도를 크게 줄일 수 있다. 본 논문에서는 현재 프레임 블록의 인접 블록으로부터 예측된 움직임 정보를 구하여, 이를 탐색 원점으로 하여 수정된 다이아몬드 지역 레이더 패턴으로 블록 정합을 수행하는 블록 정합 움직임 추정 방식을 제안한다. 실험 결과 제안된 방식은 기존의 방식들에 비해 PSNR 값에 있어서 평균적으로 0.06~0.21[dB] 개선되고 속도면에서 우수한 결과를 나타내었다. 또한 기존의 다이아몬드 지역 탐색 알고리즘보다 탐색 속도면에서 9~32%의 성능 향상을 보이면서 화질면에서는 거의 근접하게 나타났다. 제안된 방식은 정량적인 결과뿐만 아니라 부호화후 복호화한 영상의 화질에 있어서도 다른 고속 탐색 알고리즘보다 월등히 우수한 화질을 제공한다.

• Ocean Science Journal
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• 제42권2호
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• pp.103-116
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• 2007

Seasonal changes of tide signal(s), temperature, salinity and current were studied during the years 2004-2005 in the northernmost Gulf of Aqaba, which is under developmental activities, to obtain scientific bases for best management and sustainability. Spectrum analysis revealed permanent signals of tide measurements during all seasons, which represented semidiurnal and diurnal barotropic tides. The other signal periods of 8.13, 6.10-6.32, 4.16 and 1.02-1.05 h were not detected in all seasons, which were related to shallow water compound and overtides of principle solar and lunar constituent and to seiches generated in the Red Sea and the Gulf of Aqaba. Spatial and temporal distribution of temperature, salinity and density showed significant differences between months in the coastal and offshore region and no significant differences among the coastal sites, between the surface and bottom waters and between coastal and offshore waters. Therefore, the temporal and spatial variation of water properties in the northernmost Gulf of Aqaba behave similarly compared to other parts. The coastal current below 12 m depth was weak $(3-6\;cms^{-1})$ and fluctuated from east-northeastward to west-southwestward (parallel to the shoreline), which may be related to the effect of bottom topography and/or current density due to differential cooling between eastern and western parts in the study area, and wind-induced upwelling and downwelling in the eastern and western side, respectively. The prevailing northerly winds and stratification conditions during summer were the main causes of the southward current at 6 and 12 m depths with average speed of 28 and $12cms^{-1}$ respectively.

• 한국농공학회논문집
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• 제59권5호
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• pp.1-15
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• 2017

In this study, we visualized the regional migration in Korea from 2001 to 2015 using the Chord diagram which can represents amount of migration and flows at the same time. In addition, we constructed a migration network and analyzed the degree centrality of each region for identifying the main regions linking to various regions. In 2001~2005, most of population moved into Geonggi from various regions. However, the capital function was transferred to Sejong in 2011~2015, and population moving into Sejong and Chungnam was increased significantly. The main outflow of population in migration network were shown at the regions in Jeonbuk and Gyeongbuk province in 2001~2004, and recently the regions in Gyeongnam, Gyeonggi, and Seoul were identified as the main nodes in terms of outflow of population. We also focused on migration in rural area through degree centrality, and cord diagram in Chungnam, Jeonbuk, and Jeonnam where include the representative crop area. In 2015. there was the significant increase of migration from Gyeonggi to Chungnam, and internal migration within Jeonbuk increased rather than cross-border migration. In addition, migration from Jeonam to capital area decreased in 2015 but migration among cities within Jeonman increased. In particular, Yesan-gun showed the significant migration to other cities in Jeonnam. Population is necessary to develop community and sustain economic growth in rural regions. Therefore, migration is important for the transfer of manpower. The strength of this study is to approach the temporal change of migration from the viewpoint on quantitative and structural characteristics.

• Archives of Plastic Surgery
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• 제39권1호
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• pp.55-58
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• 2012

We experienced satisfactory outcomes by synchronously transplanting an artery and vein using an anterolateral thigh flap pedicle between the vascular pedicle and recipient vessel of a flap for scalp reconstruction. A 45-year-old man developed a subdural hemorrhage due to a fall injury. In this patient, the right temporal cranium was missing and the patient had $4{\times}3cm$ and $6{\times}5cm$ scalp defects. We planned a scalp reconstruction using a latissimus dorsi free flap. Intraoperatively, there was a severe injury to the right superficial temporal vessel because of previous neurosurgical operations. A 15 cm long pedicle defect was needed to reach the recipient facial vessels. For the vascular graft, the descending branch of the lateral circumflex femoral artery and two venae comitantes were harvested. The flap survived well and the skin graft was successful with no notable complications. When an interposition graft is needed in the reconstruction of the head and neck region for which mobility is mandatory to a greater extent, a sufficient length of graft from an anterolateral flap pedicle could easily be harvested. Thus, this could contribute to not only resolving the disadvantages of a venous graft but also to successfully performing a vascular anastomosis.

• Archives of Plastic Surgery
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• 제36권2호
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• pp.229-232
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• 2009

Purpose: Kimura's disease is a relatively rare head and neck tumor that frequently occurs in young orientals accompanied with eosinophila. We shared our experience of two cases of Kimura's disease, treated by radical resection and post operative steroid therapy, so we report the correlation of eosinophil counts and disease progression. Methods: A 25 years old male came to the clinic with a mass localized to the right cheek inferior to the right auricle. We could not resect the mass totally. During the follow up period, we checked the eosinophil counts, and steroid therapy was started 7 months after the surgery. A 34 year old female came to the clinic with a mass localized inferior to the left auricle reaching from the posterior portion of the auricle to the left temporal portion. We tried to remove as much tumor as possible, save the temporal region, in regard to the impairment of blood supply to the auricle. After operation, steroid therapy was started. Results: In the first case, the tumor was easily approachable, and radical resection of the tumor with post operative steroid therapy was an effective treatment. In tumors located at difficult regions to remove, as in the second case, optimal debulking and post operative steroid therapy was also effective in treating Kimura's. There were no recurrences in both cases. Eosinophil counts were always reduced after surgery and steroid therapy, and during the period with low eosinophil counts, there was no recurrence of Kimura's disease. Conclusion: Surgery and post operative steroid therapy were effective in treatment of Kimura's disease, and we could assume eosinophil counts as a good indicator for evaluation of the prognosis of Kimura's disease during the follow up period.

• 대한수의학회지
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• 제53권1호
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• pp.49-54
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• 2013

To investigate the transmission pattern of geographical area and temporal trends of the 2010~2011 foot-and-mouth disease (FMD) outbreaks in Korea, and to explore temporal intervals at which spatial clustering of FMD cases space-time analysis based on georeferenced database of 3,575 burial sites, from 30 November 2010 to 23 February 2011, was performed. The cases represent approximately 98.1% of all infected farms (n = 3,644) during the same period. Descriptive maps of spatial patterns of the outbreaks were generated by ArcGIS. Spatial Scan Statistics, using SaTScan software, was applied to investigate geographical clusters of FMD cases across the country. Overall, spatial heterogeneity was identified, and the transmission pattern was different by province. Cattle have more clusters in number but smaller in size, as compared to the swine population. In addition, spatiotemporal analysis and the comparison of clustering patterns between the first 7 days and days 8 to 14 of the outbreak revealed that the strongest spatial clustering was identified at the 7-day interval, although clustering over longer intervals (8~14 days) was also observed. We further discussed the importance of time period elapsed between FMD-suspected notice and the date of confirmation, and emphasized the necessity of region-specific and species-specific control measures.

• Journal of Communications and Networks
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• 제11권5호
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• pp.433-444
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• 2009

The bi-directional relay channel is the natural extension of a three-terminal relay channel where node a transmits to node b with the help of a relay r to allow for two-way communication between nodes a and b. That is, in a bi-directional relay channel, a and b wish to exchange independent messages over a shared channel with the help of a relay r. The rates at which this communication may reliably take place depend on the assumptions made on the relay processing abilities. We overview information theoretic limits of the bi-directional relay channel under a variety of conditions, before focusing on half-duplex nodes in which communication takes place in a number of temporal phases (resulting in protocols), and nodes may forward messages in four manners. The relay-forwarding considered are: Amplify and forward (AF), decode and forward (DF), compress and forward (CF), and mixed forward. The last scheme is a combination of CF in one direction and DF in the other. We derive inner and outer bounds to the capacity region of the bi-directional relay channel for three temporal protocols under these four relaying schemes. The first protocol is a two phase protocol where a and b simultaneously transmit during the first phase and the relay r alone transmits during the second. The second protocol considers sequential transmissions from a and b followed by a transmission from the relay while the third protocol is a hybrid of the first two protocols and has four phases. We provide a comprehensive treatment of protocols in Gaussian noise, obtaining their respective achievable rate regions, outer bounds, and their relative performance under different SNR and relay geometries.