• Journal of the Korean Institute of Telematics and Electronics
• /
• v.25 no.5
• /
• pp.559-565
• /
• 1988

A new valley operator is presented for extracting sketch features which contain valleys and edges subject to local intensities. It is a very simple operator using the local probablities in a 3x3 local window. Experimental results show its excellent performance over the existing valley or edge operators.

• Korean Journal of Soil Science and Fertilizer
• /
• v.49 no.4
• /
• pp.310-317
• /
• 2016

This study aimed to evaluate the nutrient load balance from rice paddy fields with different topographies, alluvial plain and local valley. Continuous monitoring from May to September, 2013 was conducted for water quantification and qualification from alluvial plain in Yeoju region (32 ha) and local valley in Jincheon region (24 ha). The discharge rates of T-N from the alluvial plain were 57.2, 5.84, 22.7, and $5.20kg\;ha^{-1}$ for irrigation, precipitation, drainage, and percolation, respectively. In case of local valley, T-N loads were 34.6, 4.73, 21.1, and $4.15kg\;ha^{-1}$ for irrigation, precipitation, drainage, and percolation, respectively. In contrary, the T-P loads from the alluvial plain were 2.23, 2.22, 2.54, and $0.41kg\;ha^{-1}$ for irrigation, precipitation, drainage, and percolation, respectively. In case of local valley, T-P loads were 1.44, 1.57, 1.82, and $0.34kg\;ha^{-1}$ for irrigation, precipitation, drainage, and percolation, respectively. The nutrient contents in drainage water were influenced by the amount of waters, rainfall, and surface drainage water. The Pearson correlation analysis showed that rainfall was significantly correlated with nutrient loads from July to August due to the amount of runoff in local valley paddy field, and irrigation was related with nutrient loads of drainage from July to August. This study showed that paddy rice farming in alluvial plain and local valley might be beneficial to water quality protection.

• Journal of Environmental Science International
• /
• v.19 no.10
• /
• pp.1257-1269
• /
• 2010

In this study the AWS was installed in three areas to analyze creation and characteristics of local wind circulation through observation. According to the result, in night time when mountain wind is well developed showed temperature in A area located in Dalbigol valley and B area adjacent with the valley was lower than C area located in the lowland of the center of city by $1.5\sim4^{\circ}C$. The wind speed was also shown two times stronger than C area. In addition, in terms of wind direction, A and B areas showed east wind consistently according to topographic shapes of Dalbigol valley with high altitude and residential sites of lowland with low altitude. Although the C area didn't show big changes in wind direction due to the effects of city structures, east wind is often seen so mountain wind from Dalbigol valley is found to have an effect at least. Through the analysis of temperature, wind speed, and wind direction, nigh time showed relatively cold mountain wind blew following Dalbigol valley, throughout residential sites and to the center of city with lowland. During the daytime, the temperature in the city with lowland and residential sites is constantly higher than A area located in Dalbigol valley, and strong wind speed following Dalbigol valley, and three areas have $200\sim300^{\circ}$ of main wind direction, so west valley wind throughout the city with lowland and following Dalbigol is clearly formed.

• Journal of the Korean Institute of Telematics and Electronics B
• /
• v.33B no.5
• /
• pp.118-126
• /
• 1996

In object analysis by image processing, finding lines plays a universal role. And these lines can be easily found by detecting ridges and valleys in digital gray scale images. In this paper, a new method of detecting ridges and valleys by using local min/max operations was presented. This method detects ridges and valleys of desired width by using erosion and dilation properties of local min/max operations, and requires no information of ridge or valley direction. Therefore the method is efficient and computationally simple in comparision with the conventional analytical method.

• Asian-Australasian Journal of Animal Sciences
• /
• v.15 no.6
• /
• pp.866-871
• /
• 2002

An experiment was conducted at the experimental duck farm of Cantho University to determine the effects of feeding duckweed (Lemna minor) that replaced commercial protein supplements in diets for local and Cherry Valley breeding ducks. The experiment included a total of 180 ducks, with five treatments and three replicates and six breeding ducks (one male plus five females together) per replicate, for both local and exotic Cherry Valley ducks. The five diets were fed ad libitum and were based on rice byproducts supplemented with roasted soya bean meal plus dried fishmeal at levels of 100% (SF100, control), 75 (SF75), 50 (SF50), 25 (SF25) or zero (SF0) % of the protein in the control diet, corresponding to 18, 15, 13, 10 and 8% CP in the diets for both breeds, respectively. Fresh duckweed was supplied ad libitum for all treatments. These diets were fed to local breeding ducks from 7 to 12 months of age, and to exotic breeding ducks (Cherry Valley) from 8 to 13 months of age. Total mean daily dry matter (DM) intakes were 183, 178, 176, 177 and 174 g (p<0.05) for the local ducks, and 221, 208, 215, 219 and 210 g (p<0.01) for the exotic ducks for the SF100 (control), SF75, SF50, SF25 and SF0 diets, respectively. Laying rates of the local ducks were 66.5, 65.2, 62.9, 63.1 and 62.3%, and of the Cherry Valley ducks 61.9, 58.4, 58.9, 59.1 and 53.5% (p<0.001) for the control (SF100), SF75, SF50, SF25 and SF0 treatments, respectively. Fertile egg rates were 95.6, 95.6, 97.8, 97.8 and 92.2%, and hatchabilities 89.4, 80.6, 87.2, 88.6 and 77.8% (p<0.05) for the local breed, and 97.8, 97.8, 91.1, 92.2 and 90.0% (p<0.05) and 72.8, 74.7, 75.0, 74.3 and 76.7% for the Cherry Valley ducks for diets SF100, SF75, SF50, SF25 and SF0, respectively. Corresponding feed conversion ratios (dry matter basis) were 3.83, 3.82, 3.89, 4.01 and 3.96 kg feed per kg egg mass for the local ducks and 4.52, 4.56, 4.58, 4.73 and 5.02 kg feed per kg egg mass for the Cherry Valley ducks for the SF100, SF75, SF50, SF25 and SF0 treatments, respectively. Replacement of 100% of the protein supplement by fresh duckweed in the diets of the local laying ducks decreased the feed costs by 25% compared to the control diet.

• The Korean Journal of Ecology
• /
• v.21 no.6
• /
• pp.809-814
• /
• 1998

Changes of annual seed production related to climate change were studied for 12 years in Piagol, a riparian valley in Mt. Jiri. Sixty-four seed traps (sized 0.5 ${\times}$ 0.5 $m^{2}$) were set up on the forest floor of surveyed area. Seeds were collected from these traps at an interval of 15 days from September to November since 1984. Vegetation of the study area was mainly consisted of the naturally regenerated Carpinus tschonoskii in the tree layer. Acer mono, Quercus serrata, Carpinus laxiflora and Symplocos chinensis also appeared in the same layer. Maximum production occurred in 1984 and 1994. As a result of comparing seed production with local climate factors for 12 years, seed productivity and the year of maximum production of Carpinus forest were merely related with precipitation, air temperature and duration of sunshine among local climate factors. Duration of sunshine was, however, not contributed to periodically high productivity of seed of riparian valley carpinus forest.

• Journal of Environmental Science International
• /
• v.32 no.5
• /
• pp.375-384
• /
• 2023

Climate data were obtained over an eight-year period (July 2013 to June 2021) using an automatic weather observation system (AWS) installed at the foot of Mt. Geumo in Chilgok, Gyeongbuk. Using climate data, the statistical and meteorological characteristics of the local circulation between the Nakdong River and Mt. Geumo were analyzed. This study is based on automatic weather observation system data for Dongyeong, along with comparative climate data from the Korea Meteorological Administration (Chilgok) and the Gumi meteorological observatory. Over the eight- years, mountain and valley winds have occurred 48 times a year on average, with the highest occurring in May and the weakest winds in June and December. When mountain winds occurred, the temperature in the nearby lowland region more strongly decreased than when valley winds blew. However, the potential to use mountain winds to improve urban thermal environments is limited because mountain winds occur infrequently in summer when a drop in nighttime temperature is required.

• Journal of Environmental Science International
• /
• v.16 no.1
• /
• pp.73-79
• /
• 2007

The purpose of this study is to clarify the effect of mountain-valley wind on heat island formed in urban area which is located around valley mouth. The meteorological observations were carried out over the Dalbi-valley under a clear summer pressure patterns, and some consideration were tried from the results. In order to make clear the climatological characteristics and air-mass modification process of the mountain-valley wind over the valley, the meteorological observations were done simultaneously at two points. The observational points were located at the breast and valley mouth parts, respectively. The results were as follows: First, it was found that the valley wind was observed through the daytime, and it was replaced by a mountain wind after sunset. Second, the heat budget is also investigated with observation data. The sensible heat flux over the breast of Dalbi-valley reached to about $200 W/m^2$ during daytime, which is a little more than one third of net radiation. On the other hand, the sensible heat flux represented negative values during nighttime. But the sensible heat flux over the valley mouth covered by asphalt showed plus value(about $20{\sim}30 W/m^2$) during the nighttime.

• Wind and Structures
• /
• v.13 no.3
• /
• pp.275-292
• /
• 2010

Wind tunnel experiments were conducted to investigate the wind characteristics in the mountainous valley terrain with 4 simplified valley models and a 1:500 scale model of an existing valley terrain in the simulated atmospheric neutral boundary layer model. Measurements were focused on the mean wind flow and longitudinal turbulence intensity. The relationship between hillside slopes and the velocity speed-up effect were studied. By comparing the preliminary results obtained from the simplified valley model tests and the existing terrain model test, some fundamental information was obtained. The measured results indicate that it is inappropriate to describe the mean wind velocity profiles by a power law using the same roughness exponent along the span wise direction in the mountainous valley terrain. The speed-up effect and the significant change in wind direction of the mean flow were observed, which provide the information necessary for determining the design wind speed such as for a long-span bridge across the valley. The longitudinal turbulence intensity near the ground level is reduced due to the speed-up effect of the valley terrain. However, the local topographic features of a more complicated valley terrain may cause significant perturbation to the general wind field characteristics in the valley.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.16 no.3
• /
• pp.246-260
• /
• 2014

A 90-m horizontal-resolution numerical model was configured to study the micrometeorological features of local winds in the valley of Gwangneung KoFlux (Korea Flux network) Sites (GDK: Gwangneung Deciduous forest site in Korea, GCK: Gwangneung Coniferous forest site in Korea) during summer days. The U. S. Geological Survey (USGS) Shuttle Radar Topography Mission (SRTM) data were employed for high-resolution model terrain height. Model performance was evaluated by comparing observed and simulated near-surface temperature and winds. Detailed qualitative analysis of the model-simulated wind field was carried out for two selected cases which are a clear day (Case I) and a cloudy day (Case II). Observed winds exhibited that GDK and GCK, as well as Case I and Case II, had differences in timing, duration and strength of daytime and nighttime wind direction and speeds. The model simulation results strongly supported the existence of the drainage flow in the valley of the KoFlux tower sites. Overall, the simulated model fields realistically presented the diurnal cycle of local winds in and around the valley, including the morning drainage-upslope transition and the evening reversal of upslope wind. Also, they indicated the complexity of local winds interactions by presenting that daytime westerly winds in the valley were not always pure mountain winds and were often coupled with larger-scale wind systems, such as synoptic-scale winds or mesoscale sea breezes blowing from the west coast of the peninsula.