• The Korean Journal of Malacology
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• v.21 no.1
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• pp.57-64
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• 2005

Samples of Corbicula japonica Prime of Jujin estuary in Gochang were collected from July 2000 to September 2001. Age of C. japonica was determined from the rings on the shell. The relationship between shell length and ring radius in each ring group was expressed as a regression line. Therefore, there is a correspondence in each ring formation. Based on the monthly variation of the marginal index (MI') of the shell, it is assumed that the ring of this species was formed once a year during the period of February and March. The relationship between shell length (SL; mm) and total weight (TW; g) was expressed by the following equation: TW = 1.0942 ${\times}10^{-4}SL^{3.3217}$ ($r^2$ = 0.9905). Shell length (SL) and shell height (SH; mm) was highly correlated with shell height as the following equation: SH = 0.9174 SL - 0.9935 ($r^2$ = 0.9885). The shell length (SL) - shell width (SW) relation was also expressed by the following equation; SW = 0.5925 SL - 1.1706 ($r^2$ = 0.9726). Growth curves for shell length and total weight fitted to the von Bertalanffy's growth curve were expressed as: $$SL_t = 46.4861[1-e^{-0.3383(t+0.0958)}]$$, $$TW_t = 34.54[1-e^{-0.3383(t+0.0958)}]^3.3217$$.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.9 no.4
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• pp.251-255
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• 1976

Three hundred and sixty two specimens of Plecoglossus altivelis were randomly sampled from Chunji Stream in Seogwipo, Cheju-Do, during the period from 25 Aug., 1973 to 14 Feb., 1974 to investigate the relationship between total length and dody weight as well as the condition factor during the spawning period. Results obtained are summarized as follows : The relationships between total length and body weight are calculated as below, respectively : $W=0.008639\;L^{3.1806}$ : Prior to spawning period $W=0.01830\;L^{2.7689}$ : During spawning period The above equations differ each other significantly. Nevertheless, the significant difference is not found between sexes. The mean body length decreased during the spawning season. The fact seems to be caused by the death of large fish after spawning. The condition factor was $13.45\%_{\circ}$ on the average in August. The value decreased continuously from September, giving the minimum mean value of $10.25\%_{\circ}$ on Nobember 29. But the value increased again, showing $11.18\%_{\circ}$ in next February. Majority of the fish survived until next year was small ranging from 11 to 12cm in total length.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.17 no.7
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• pp.1841-1857
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• 2023

CenterNet, a novel object detection algorithm without anchor based on key points, regards the object as a single center point for prediction and directly regresses the object's height and width. However, because the objects have different sizes, directly regressing their height and width will make the model difficult to converge and lose the intrinsic relationship between object's width and height, thereby reducing the stability of the model and the consistency of prediction accuracy. For this problem, we proposed an algorithm based on the regression of the diagonal half-length and the center angle, which significantly compresses the solution space of the regression components and enhances the intrinsic relationship between the decoded components. First, encode the object's width and height into the diagonal half-length and the center angle, where the center angle is the angle between the diagonal and the vertical centreline. Secondly, the predicted diagonal half-length and center angle are decoded into two length components. Finally, the position of the object bounding box can be accurately obtained by combining the corresponding center point coordinates. Experiments show that, when using CenterNet as the improved baseline and resnet50 as the Backbone, the improved model achieved 81.6% and 79.7% mAP on the VOC 2007 and 2012 test sets, respectively. When using Hourglass-104 as the Backbone, the improved model achieved 43.3% mAP on the COCO 2017 test sets. Compared with CenterNet, the improved model has a faster convergence rate and significantly improved the stability and prediction accuracy.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.7 no.2
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• pp.79-86
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• 1974

The results from the experiment of natural collection and growth of arkshell(Anadara broughtoni, SCHRENCK) spat, which was collected at Seok-gok Bay located at Chang-weon-gun, Korea, and grown in the 1ittoral zone of Sa-gok-ri, Geo-je-gun, Korea, beginning from August 1,1973 to April 8,1974 are as follows; The larvae of arkshell came out from the very first day of the study August 1, which continued till the end of September, whose amount was not so much varied, but relatively continuous. The drifting larvae were also rather small amount, from which some 200 to 400 larvae were attached through the respective collecting equipment made from straw with the dimension of length 1.5m and breadth 12cm. It is regarded relatively large amount collected and recognised worth while enough to use as the industrial collecting method. The average shell length of spat attached was 0.54mm on 17th September, 4.11mm on 21st October, 10.47mm on 25th November in 1973 and 11.08mm on 8th April in 1974 whose progress was recognized relatively faster, comparing with the other up-to date report, The relationship between the shell length(L) and the longest radial rib(R) was as follows: Below 2.5mm of the shell length: R=0.7393 L -0.0080 Above 2.5mm of the shell length: R=0.8253 L-0.2595 And the relationship between the shell length (L) and the shell breadth (B) was as follows: Below 2.5mm of the shell length: B=0.3505 L +0.0527 Above 2.5mm of the shell length: B=0.4631 L -0.3602 The exponential curve equation between shell length (L) and the total weight (W)was as follows : Below 16mm of the shell length: W=0.19957 $L^{2.5726}$ Above 16mm of the shell length: W=0.20602 $L^{2.8400}$ In view of the above the relative growth among the shell length, the longest radial rib and the shell breadth was changed in the vicinity of 2.5mm of the shell length. And relationship between the shell length and the total weight was changed in the vicinity of 16mm of the shell length.

• Atmosphere
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• v.26 no.1
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• pp.111-126
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• 2016

In the numerical weather model, surface properties can be defined by various parameters such as terrain height, landuse, surface albedo, soil moisture, surface emissivity, roughness length and so on. And these parameters need to be improved in the Seoul metropolitan area that established high-rise and complex buildings by urbanization at a recent time. The surface roughness length map is developed from digital elevation model (DEM) and it is implemented to the high-resolution numerical weather (WISE-WRF) model. Simulated results from WISE-WRF model are analyzed the relationship between meteorological variables to changes in the surface roughness length. Friction speed and wind speed are improved with various surface roughness in urban, these variables affected to temperature and relative humidity and hence the surface roughness length will affect to the precipitation and Planetary Boundary Layer (PBL) height. When surface variables by the WISE-WRF model are validated with Automatic Weather System (AWS) observations, NEW experiment is able to simulate more accurate than ORG experiment in temperature and wind speed. Especially, wind speed is overestimated over $2.5m\;s^{-1}$ on some AWS stations in Seoul and surrounding area but it improved with positive correlation and Root Mean Square Error (RMSE) below $2.5m\;s^{-1}$ in whole area. There are close relationship between surface roughness length and wind speed, and the change of surface variables lead to the change of location and duration of precipitation. As a result, the accuracy of WISE-WRF model is improved with the new surface roughness length retrieved from DEM, and its surface roughness length is important role in the high-resolution WISE-WRF model. By the way, the result in this study need various validation from retrieved the surface roughness length to numerical weather model simulations with observation data.

• Journal of the Korean GEO-environmental Society
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• v.23 no.6
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• pp.5-17
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• 2022

The performance of the relief wells installed for the purpose of controlling seepage of the dam embankment is affected by various parameters such as diameter, spacing, penetration rate, permeability coefficient of the ground, thickness of the foundation layer. Therefore, when the relief wells are adopted for the purpose of reducing seepage pressure, these parameters should be sufficiently reviewed to determine the installation specifications of the relief wells. This study evaluated the effect of the length of the geosynthetics blanket on the performance of the relief wells installed in the downstream part of the dam embankment with blankets in the upstream and downstream part of the dam embankment as countermeasure methods to control seepage of the dam embankment. In the relationship between the length of the upstream and downstream blanket and the discharge, the discharge of the relief wells decreases as the length of the upstream blanket increases, and on the other hand, the discharge of the relief wells decreases as the length of the downstream blanket increases. In the upper and lower blanket length-spacing relationship, as the length of the upstream blanket increases, the spacing of the relief wells increases and as the length of the downstream blanket increases, the spacing of the relief wells decreases. Therefore, when installing the relief wells in parallel with the blanket, it was found that increasing the length of the upstream blanket is more efficient than increasing the length of the downstream blanket in order to minimize the discharge of seepage discharge and to ensure economic feasibility by wider installation of the relief wells.

• International Journal of Advanced Culture Technology
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• v.4 no.1
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• pp.31-36
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• 2016

Morphology evolution of the active layer in bulk hetero-junction organic photovoltaic is modeled and visualized. The width of the phase domain can be predicted using the relationship of characteristics length and evolution time of the process. The 3D numerical simulation of the PCBM/P3HT blend morphology evolution with respect to time is presented. It is observed that the domain width of composition phase can be predicted by using the relationship between value of characteristic length R(t) and evolution time t.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.14 no.3
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• pp.151-161
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• 2010

A reversed trapezoidal fin is analyzed using a two-dimensional analytical method. Heat loss from the reversed trapezoidal fin is presented as a function of the fin shape factor, fin base thickness and the fin base height. The relationship between the fin tip length and the convection characteristic number as well as that between the fin tip length and the fin base height for equal amounts of heat loss are analyzed. Also the relationship between the fin base thickness and the fin shape factor for equal amount of heat loss is presented. One of the results shows that the heat loss decreases linearly with the increase of the fin shape factor.

• Journal of Industrial Technology
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• v.22 no.B
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• pp.21-26
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• 2002

The non-dimensional heat loss from a thermally asymmetric triangular fin is investigated as a function of a ratio of upper and lower surface Biot numbers (Bi2/Bi1), the non-dimensional fin length and tip surface Biot number using the two-dimensional separation of variables method. The effect of fin tip surface Biot number on the variation of the non-dimensional temperature along the sloped upper and lower surfaces for the thermally asymmetric condition is presented. The relationship between the non-dimensional fin length and the fin tip surface Biot number for equal amount of heat loss is also discussed as well as the relationship between upper surface Biot number and tip surface Biot number for equal amount of heat loss.

• Journal of the Korean Wood Science and Technology
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• v.25 no.2
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• pp.27-32
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• 1997

This study was carried out to find the relationship between anatomical characters and compression strength parallel to grain of Pinus densiflora S. et. Z., the representative conifer species in Korea. The results were as follows ; 1. The compression strength parallel to grain increased with the increase of tracheid length and wall thickness. The strength, however, decreased with the increase of height of uniseriate ray and microfibril angle. 2. The major factors affecting compression strength parallel to grain in heartwood were radial diameter of latewood tracheid and wall thickness of earlywood tracheid but length and tangential diameter of latewood tracheid were the important factors in sapwood.