• Title/Summary/Keyword: Sst I

Search Result 70, Processing Time 0.03 seconds

Improved version of LeMoS hybrid model for ambiguous grid densities

  • Shevchuk, I.;Kornev, N.
    • International Journal of Naval Architecture and Ocean Engineering
    • /
    • v.10 no.3
    • /
    • pp.270-281
    • /
    • 2018
  • Application of the LeMoS hybrid (LH) URANS/LES method for the wake parameters prediction is considered. The wake fraction coefficient is calculated for inland ship model M1926 under shallow water conditions and compared to results of PIV measurements. It was shown that due to lack of the resolved turbulence at the interface between LES and RANS zones the artificial grid induced separations can occur. In order to overcome this drawback, a shielding function is introduced into LH model. The new version of the model is compared to the original one, RANS $k-{\omega}$ SST and SST-IDDES models. It is demonstrated that the proposed modification is robust and capable of wake prediction with satisfactory accuracy.

ESTIMATES OF NET AIR-SEA FLUXES FOR THE TROPICAL AND SUBTROPICAL ATLANTIC BASED ON SATELLITE DATA

  • Katsaros, Kristina B.;Pinker, Rachel T.;Bentamy, Abderrahim;Carton, James A.;Drennan, William M.;Mestas-Nunez, Alberto M.
    • Proceedings of the KSRS Conference
    • /
    • v.2
    • /
    • pp.997-1000
    • /
    • 2006
  • We estimate the net heat flux in the tropical and subtropical Atlantic Ocean using satellite data. These fluxes are related to changes in sea surface temperature (SST). This variable influences atmospheric circulations and is indicative of surface and subsurface oceanic circulations. We employ data from the geostationary METEOSAT-7 and 8 satellites and from the Special Sensor Microwave/Imager (SSM/I) for the shortwave and long-wave radiative fluxes, and for estimates of SST. For turbulent flux calculations, we use the bulk aerodynamic method with satellite estimates for wind speed and atmospheric humidity and temperature.

  • PDF

Impacts of OSTIA Sea Surface Temperature in Regional Ocean Data Assimilation System (지역 해양순환예측시스템에 대한 OSTIA 해수면온도 자료동화 효과에 관한 연구)

  • Kim, Ji Hye;Eom, Hyun-Min;Choi, Jong-Kuk;Lee, Sang-Min;Kim, Young-Ho;Chang, Pil-Hun
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
    • /
    • v.20 no.1
    • /
    • pp.1-15
    • /
    • 2015
  • Impacts of Sea Surface Temperature (SST) assimilation to the prediction of upper ocean temperature is investigated by using a regional ocean forecasting system, in which 3-dimensional optimal interpolation is applied. In the present study, Sea Surface Temperature and Sea Ice Analysis (OSTIA) dataset is adopted for the daily SST assimilation. This study mainly compares two experimental results with (Exp. DA) and without data assimilation (Exp. NoDA). When comparing both results with OSTIA SST data during Sept. 2011, Exp. NoDA shows Root Mean Square Error (RMSE) of about $1.5^{\circ}C$ at 24, 48, 72 forecast hour. On the other hand, Exp. DA yields the relatively lower RMSE of below $0.8^{\circ}C$ at all forecast hour. In particular, RMSE from Exp. DA reaches $0.57^{\circ}C$ at 24 forecast hour, indicating that the assimilation of daily SST (i.e., OSTIA) improves the performance in the early SST prediction. Furthermore, reduction ratio of RMSE in the Exp. DA reaches over 60% in the Yellow and East seas. In order to examine impacts in the shallow costal region, the SST measured by eight moored buoys around Korean peninsula is compared with both experiments. Exp. DA reveals reduction ratio of RMSE over 70% in all season except for summer, showing the contribution of OSTIA assimilation to the short-range prediction in the coastal region. In addition, the effect of SST assimilation in the upper ocean temperature is examined by the comparison with Argo data in the East Sea. The comparison shows that RMSE from Exp. DA is reduced by $1.5^{\circ}C$ up to 100 m depth in winter where vertical mixing is strong. Thus, SST assimilation is found to be efficient also in the upper ocean prediction. However, the temperature below the mixed layer in winter reveals larger difference in Exp. DA, implying that SST assimilation has still a limitation to the prediction of ocean interior.

Effect of Strychni Semen Aqua - acupuncture in Rats with Arthritis induced by Freund's Complete Adjuvant (마전자약침(馬錢子藥鍼)이 Adjuvant 관절염(關節炎)에 미치는 영향(影響)에 관한 실험적(實驗的) 연구(硏究))

  • Bae, Chul-Woo;Kim, Kee-Hyun;Hwang, Hyeun-Seo;Kim, Youn-Sub
    • Journal of Acupuncture Research
    • /
    • v.18 no.1
    • /
    • pp.217-225
    • /
    • 2001
  • Objectives and Mtthods : In order to study on the Effect of Strychni Semen aqua-acupuncture on the arthritis induced by injecting Freund's complete adjuvant to the right posterior planta of rat's foot, rats were divided 5 groups equally, one group was not treated(Normal) and the other groups were induced arthritis by injecting Freund's complete adjuvant(Control, ST, SS, SST). Control was not treated after injecting of Freund's complete adjuvant. ST was 0.2cc Saline-injected Group at Chok-Samni(ST36) either days during 2 weeks after injecting of Freund's complete adjuvant. SS was 0.2cc Strychni Semen-subcutaneous injected group either days during 2 weeks after injecting of Freund's complete adjuvant. SST was 0.2cc Strychni Semen-injected group at Chok-Samni(ST36) either days during 2 week after injecting of Freund's complete adjuvant. And then effect of Strychni Semen aqua-acupuncture on the edema, numbers of blood WBC, platelet, hematocrit, contented quantities of total protein, albumin in rats with F.C.A were measured. Results : The following results have been obtained. 1. In effect of Strychni Semen aqua-acupuncture on plantar edema, SS showed significant decrease compared with control. 2. In effect of Strychni Semen aqua-acupuncture on WBC, SS and SST showed significant decrease compated with control. 3. In effect of Strychni Semen aqua-acupuncture on platelet, SS and SST did not show significant decrease. 4. In effect of Strychni Semen aqua-acupuncture on hematocrit, SST showed significant increase compared with control. 5. In effect of Strychni Semen aqus-acupuncture on the contents quantity of total protein and albumin, SS showed significant increase compared with control: Conclusions : Accoring to this result, Strychni Semen aqua-acupunture inserted into Chok-Samn i(ST36) appeared to have effect on Adjuvant arthritis of rats. Therefore it is oxpected that Strychni Semen aqua-acupunture may be available clinically.

  • PDF

TEMPORAL AND SPA TIAL VARIATION OF NIGHTTIME FISHING GROUND DERIVED FROM SATELLITE IMAGERY

  • Kim Sang-Woo;Jeong Hee-Dong;Suh Young-Sang;Go Woo Jin;Jang Lee-Hyun
    • Proceedings of the KSRS Conference
    • /
    • 2005.10a
    • /
    • pp.437-440
    • /
    • 2005
  • We examined the relationship between the 50m temperature estimated by remote sensing sea surface temperature (SST) and fishing ground (squid fishing ground) detected by nighttime visible channel defense meteorological satellite program (DMSP) I operational linescan system (OLS) images in the East/Japan Sea during 1993-2000. The results are as follows: The numbers of nighttime fishing boat were distributed the highest in October, and the lowest in April during this study. A nighttime fishing grounds have concentrated in the East Korea Warm Current region, coastal regions of Honshu Island, and Polar front region. Fishing grounds have distributed $11-18^{\circ}C$ of estimated 50m temperature from the satellite data. Relationship between estimated 50m temperature and the distributed fisheries boats showed that the north boundaries of fishing grounds have distributed the temperature of below $12^{\circ}C$ from 1996 to 2000 and that of $13-15^{\circ}C$ during 1993-1995 and 1997-1999. Stable fishing grounds appeared near the Korea/Tsushima Strait from January to March. The center of fishing grounds in spring (April-Jun) have moved to the northward than that in winter, and variations appeared largely in winter. In summer (July-September), center of fishing grounds have formed near the Uleung Island in the south east coast of Korea, and in autumn maximum fishing ground appeared in October, the fishing ground southward from November.

  • PDF

EFFECT OF LENGTH-SCALE IN DDES FOR BACKWARD-FACING STEP FLOW (후향계단 DDES 해석의 길이척도 영향 분석)

  • Lee, C.Y.;Sa, J.H.;Park, S.H.;Lee, E.S.;Lee, J.I.;Lee, K.S.
    • Journal of computational fluids engineering
    • /
    • v.17 no.4
    • /
    • pp.24-31
    • /
    • 2012
  • Effects of the subgrid length-scale in the Delayed-Detached Eddy Simulation(DDES) are investigated based on the Spalart-Allmaras(S-A) and the k-$\omega$ Shear Stress Transport(SST) turbulence models. Driver & Seegmiller's experimental results are used to validate numerical results. Grid convergence with grid resolution and subgrid length-scale is investigated. The simulation results show that the volume method for the subgrid length-scale is more resistant to unfavorable effects of the grid size in the periodic direction than the maximum method. Using a sufficient grid resolution and an appropriate subgrid length-scale, both S-A based DDES and SST based DDES methods can provide a good correlation with the experimental data.

Numerical Analysis of the Vortex Shedding past a Square Cylinder with Moving Ground (지면 운동에 따른 정사각주 후류의 와류 유동장 수치 해석 Part I. 고정 지면과 이동 지면 비교)

  • Kim, Tae-Yoon;Lee, Bo-Sung;Lee, Dong-Ho;Kohama, Y.
    • Journal of the Korean Society for Aeronautical & Space Sciences
    • /
    • v.33 no.6
    • /
    • pp.1-7
    • /
    • 2005
  • Incompressible Reynolds-averaged Navier-Stokes equations with $\varepsilon{-SST}$ turbulence model are adopted for the investigation of the flow fields between the square cylinder and the ground. When the grounds moves, the diminish of the shear layer intensity on the ground promotes the interaction between the lower and the upper separated shear layer of the cylinder. Hence vortex shedding occurs at the lower gap height than stationary ground. In the moving ground, the secondary shedding frequency disappears due to the absence of the separation bubble on the ground which exists in the stationary ground. In addition, the shedding frequency and aerodynamic coefficients in the moving ground become higher than those of the stationary ground.

Feature Based Techniques for a Driver's Distraction Detection using Supervised Learning Algorithms based on Fixed Monocular Video Camera

  • Ali, Syed Farooq;Hassan, Malik Tahir
    • KSII Transactions on Internet and Information Systems (TIIS)
    • /
    • v.12 no.8
    • /
    • pp.3820-3841
    • /
    • 2018
  • Most of the accidents occur due to drowsiness while driving, avoiding road signs and due to driver's distraction. Driver's distraction depends on various factors which include talking with passengers while driving, mood disorder, nervousness, anger, over-excitement, anxiety, loud music, illness, fatigue and different driver's head rotations due to change in yaw, pitch and roll angle. The contribution of this paper is two-fold. Firstly, a data set is generated for conducting different experiments on driver's distraction. Secondly, novel approaches are presented that use features based on facial points; especially the features computed using motion vectors and interpolation to detect a special type of driver's distraction, i.e., driver's head rotation due to change in yaw angle. These facial points are detected by Active Shape Model (ASM) and Boosted Regression with Markov Networks (BoRMaN). Various types of classifiers are trained and tested on different frames to decide about a driver's distraction. These approaches are also scale invariant. The results show that the approach that uses the novel ideas of motion vectors and interpolation outperforms other approaches in detection of driver's head rotation. We are able to achieve a percentage accuracy of 98.45 using Neural Network.

Seasonal Cycle of Sea Surface Temperature in the East Sea and its Dependence on Wind and Sea Ice

  • Park, Kyung-Ae;Chung, Jong-Yul;Kim, Kuh
    • Proceedings of the KSRS Conference
    • /
    • 2003.11a
    • /
    • pp.618-620
    • /
    • 2003
  • Harmonics of sea surface temperature (SST) in the East Sea and their possible causes are examined by analyzing NOAA/AVHRR data, SSM/I wind speeds, NSCAT wind vectors, and NCEP heat flux data. Detailed spatial structures of amplitudes and phases of the seasonal cycles and their contributions to the total variance of SST have quantitatively. The Subpolar front serves as a boundary between regions of high annual amplitudes (${\geq}$10$^{\circ}$C) in the cold continental region and low amplitudes (${\leq}$10$^{\circ}$C) in the Tsushima Warm Current region. The low phase center of annual cycle is located over a seamount at 132.2$^{\circ}$E, 41.7$^{\circ}$N south of Vladivostok. Semi-annual amplitudes are significantly large leaching over 20% of the annual amplitudes in the Tatarskiy Strait and along the continental shelf off Russian coast in fall and spring, but its forcings are substantially annual. We have shown that fall cooling is attributed by direct and local wind forcing, while spring cooling is remotely forced by cold waters from sea ices in the Tatarskiy Strait.

  • PDF

Effect of Ferrous Ion on the Formation of Exotoxin A from Pseudomonas sp. PY002 and Cloning of it's Gene (Pseudomonas sp. PY002에서 Exotoxin A의 생성에 미치는 철 이온의 영향과 Exotoxin A 유전자의 클로닝)

  • Choi, Sun-Ah;Kim, Ho-Sang;Choi, Ji-Young;Kang, Jeong-Suk;Kim, Chun-Sung;Kim, Duck-Lae;Kim, Young-Ju;Yeo, Myeong-Gu;Park, Yeol
    • Korean Journal of Microbiology
    • /
    • v.35 no.1
    • /
    • pp.7-12
    • /
    • 1999
  • By SDS-polyacrylamide gel elcctrophoresis (SDS-PAGE) and immunoblot analysis that a protein with 66,000 daltons in size was recognized by P. aeruginosa anti-exotoxin A from P. sp. PY002. The yields of exotoxin A in P. sp. PY002 culture were influenced by the concentration of iron in the culture media. Increasing of the exotoxin A production and siderophore production was made slight increasing in the MKB medium. On the other hand, to clone the gene encoding the exoloxin A genomic library of P. sp. PY002 was constructed in pBluescript SK(+). From this library a exotoxin A homologous gene was isolated by immunological hybridization method using P. aemginosa anti-exoloxin A as a probe. Two putative clones were isolated and designated pETA23 and pETA42. Thc restriction analysis ol pETA42 demonstrated that thc 1760 bp insert contained one NcoI, PvuII, SstI, Kpnl and EcoRI site and three SmaI and HaeD sites.

  • PDF