• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.40 no.2
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• pp.109-118
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• 2022

GPR (Ground Penetrating Radar), developed as a technology for geotechnical investigations such as sinkhole exploration, was used limitedly as a method to resolve undetectable lines in underground facility exploration. To improve the accuracy of underground facility data, the government made it possible to explore underground facilities using a non-metallic pipeline probe from July 2022. However, GPR has a problem in that the exploration rate is lowered in the soil with high moisture content, such as soft soil, such as clay layer, and there is a lot of variation in long-term accuracy. In this study, as a way to improve the accuracy of exploration considering the characteristics of GPR and the environment of underground facilities, we propose a GPR exploration method for underground facilities using permittivity constant correction and pattern analysis of GPR image data. Through this study, the accuracy of underground facility exploration and high reproducibility were derived as a result of field verification applying GPR frequency band and heterogeneous GPR.

• Korean Journal of Food Science and Technology
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• v.10 no.4
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• pp.398-403
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• 1978

Squid was dried on the fluidized-bed in the drying chamber filled with solid particles which were also fluidized with hot-air, and effects of the fluidized particles, the squid's height from the grid and the drying temperature on the drying rate and quality of the squid were observed The mechanism of moisture transfer during the falling rate period was also derived. 1. Sodium chloride was found to be the most suitable fluidized particles and at an air velocity of 3.8 m/sec, optimal fluidization state of this particle was obtained. 2. Uniform profiles of temperature were obtained at a point 4 cm above the grid and the location of squid on the fluidized-bed observed to be suitable when it was 4 cm above the grid. 3. At an air velocity of 3.8 m/sec and when the location height of the squid on the fluidized-bed was 4 cm, the optimal temperature for the drying time which is required to reduce the moisture from 80.8% to 18-22% was 8.5 hours. 4. Drying data followed the empirical equation of unsteady state diffusion $log\;(\frac{W-We}{Wc-We})=-m{\theta}$ in the region of the moisture contents measured and the drying constant (m) was calculated as $0.32hr^{-1}$. These results suggested that the migration of moisture during the falling rate period is due to a diffusion type mechanism. 5. The short constant rate period was observed in the early stage and thereafter, drying was controlled by the falling rate period, and the time ratio of the fluidized bed drying to the through circulation drying for reducing the squid's moisture contents to the same level at the same drying temperature was 1 : 1.4 6. Comparisons of fluidized-bed dried squid and sun dried squid in sale showed that there was no significant change in qualities such as external appearance and hydrogen ion concentration of dry product.

• Food Science and Preservation
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• v.16 no.6
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• pp.797-803
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• 2009

The effects of drying methods on the browning and moisture sorption characteristics of Rubus coreanus were studied. Fruits were steamed for 5 min at $100^{\circ}C$, dried by sun drying, infrared drying, or freeze drying, and powdered to a size of 20 mesh. Color values were measured and equilibrium moisture contents (EMC) were determined at $20^{\circ}C$, over a range of water activity ($a_w$) from 0.11 to 0.90. The browning indices $L^*$ and $a^*$ values were higher and lower, respectively, in freeze-dried Rubus coreanus compared with other samples. The $b^*$ value was greatest in freeze-dried Rubus coreanus. EMC tended to increase with increasing $a_w$ values, and a particularly sharp increment was observed above 0.75 $a_w$. The EMC of freeze-dried Rubus coreanus was significantly higher compared with the EMC of sun-dried and infrared-dried fruit at constant aw. The moisture sorption isotherms showed a typical sigmoid shape, and the Halsey, Kuhn, and Oswin models were the best fits for the sun-dried, infrared-dried, and freeze-dried powder isotherms, respectively. With respect to monolayer moisture content, the Guggenheim-Anderson-Boer (GAB) equation showed that the various drying methods yielded very different results, with monolayer moisture contents of 0.005 g $H_2O/g$ dry solid in infrared-dried and 0.019 g $H_2O/g$ dry solid in sun- and freeze-dried powders, respectively. These results indicate that the drying method affects the browning and moisture sorption characteristics of Rubus coreanus.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.3
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• pp.253-259
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• 2010

This experiment was conducted to evaluate water use efficiency of barley, wheat, and millet as a substitution crop for rice of fallow paddy field. Dry weight (DW), evapotranspiration, and transpiration of crop grown on the lysimeters controlled with 5 levels of groundwater table (GWT), 0, 25, 50, 75, and 100 cm were evaluated for optimum GWT and water use efficiency. All the lysimeters randomized with four replication arrangements were filled up sandy loam and were adjusted to the constant bulk density treated with twice water infiltration from bottom side to upper side of lysimeter. DW of barley, wheat, and millet in the plot of 0cm GWT that is saturated soil showed 34.9%, 44.7%, and 37.1% of that in the plot of 100 cm GWT, respectively showing a serious obstacle in crop growth. Evapotranspiration ratios calculated by evapotranspiration volume (mL) per DW were 166~605 mL for barley, 136~481 mL for wheat, and 81~418 mL for millet showing the order of barley > wheat > millet. Evapotranspiration ratio was increased with decrease of groundwater table that is the condition of moisture saturation. Estimation of GWT for maximum DW of wheat was 76 cm, and those of barley and millet were 100 cm below. The volumetric moisture content of lysimeter soil with cropping was markedly decreased as increase of crop growth because moisture supplying capability by capillary rise of water was less than amount of moisture required by crop.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.17 no.1
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• pp.40-46
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• 1984

The extraction ratio of oil using solvent from the muscle of sardine, Sardinops melanosticta, was studied. The results were critically evaluated in the light of the theory of oil diffusion in a porous solid model. In addition the effect of temperature and moisture on the extraction rate was examined. Sardine muscle was prepared in a manner to meet the conditions required by the diffusion theory from Fick's law. The results of the model were well coincidenced to the theory derived from Fick's law. Diffusion constants at the direction to muscle fiber($D_1$) and at direction perpendicular to fiber($D_2=D_3$) when extracted at $45^{\circ}C$ were $8.16{\times}10^{-8}cm^2/sec\;and\;4.12{\times}10^{-8}cm^2/sec$, respectivly. The extraction rate was linearly propotional to absolute temperature(T) by eleventh power under the constant condition of moisture contents and muscle size. A comparison of the experiments with the highest($74.22\%$) and the lowest ($32.48\%$) moisture indicated that difference of $1\%$ in moisture contents caused to change the slope(K) of the extraction curve $0.53{\times}10^{-6}sec^{-1}$ approximately.

• Journal of Korean Society for Geospatial Information Science
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• v.12 no.4 s.31
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• pp.3-12
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• 2004

It is necessary to manage water resources in rural areas in order to achieve proper development of new water resources, sustainable usage and reasonable distribution. This paper aims to analyze multi-temporal Landsat-7 ETM+data for soil moisture that is essential for crops in Ahnsung area. The ETM data was also fused with KOMPSAT-1 images in order to be used as backdrop watershed maps at first. Multi-temporal Images showed also the characteristics of soil moisture distribution. Images taken in April showed that rice paddy had as low reflectance as artificial features. Compared with April scenes, those taken in Hay and June showed wetness index increased in the rice paddies. The mountainous areas have almost constant moisture index, so the difference between the dates was very low while reservoirs and livers had dramatic changes. We can calculate total potential areas of distribution of moisture content within the basin and estimate the areas being sensitive to drought. Finally we can point out the sites of small rice paddies lack of water and visualize their distribution within the same basin. It can be said that multi-temporal Landsat-7 ETM+ and KOMPSAT data can be used to show broad drought with quick and simple analysis. Drought sensitiveness maps may enable the decision makers on rural water to evaluate the risk of drought and to measure mitigation, accompanied with proper data on the hydrological and climatic drought.

• Journal of Mushroom
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• v.13 no.3
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• pp.233-236
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• 2015

This report is the result of devising a method for utilizing the device of the load cell to maintain a constant water content of the medium every day to prepare a cultural substrates with the mixer for growing mushrooms bottle cultivation. A load cell was device under the medium mixer. It is developed when the device reaches the weight calculated as amount of substrate bottled and number of the bottle, it is automatically terminated by water injection. In addition, measuring the water content of each medium and the total weight of the medium reaches the target moisture content were calculated by using the program Cheong et al. (2015). Enter the total weight of the medium on the display unit of the load cell, when starting the water supply to reach the weight-based mixing media, the water supply is stopped. This method can improve the convenience by reducing the user's trouble in repeated work medium prepared by automating water supply. The suitable moisture content of the mixed medium for some kind of mushroom can be improved by the composition accuracy. And mycelial culture period, primordial period, mushroom growing period is maintained even of the medium can be produced stably. Therefore, it is possible to achieve a stable management of the mushroom farm according to mushroom quality and quantity stable throughout the year.

• Journal of Biosystems Engineering
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• v.3 no.2
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• pp.100-113
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• 1978

Drying grain with conventional artificial drying methods requires great quantities of petroleum fuels. Depletion of fossil fuel increases the need of the utilization of solar energy as an alternative to petroluem fuels for drying grain , an energy intensive agricultural operation. Many techniques for the utilization of solar energy in grain drying have been developed, however, there are many problems in adopting solar energy as an energy sources for drying grain. Futhermore, very little research has been done on solar grain drying in Korea. This study was conducted to evaluate the availability of solar energy for drying of rough rice in Chuncheon, Suweon, and Jinju areas based on 50year meteorological data, and to analyze experimentally the performance of a solar air collector for dying grain, and to find the effects of solar heated air compared to unheated air on the rate of drying and energy consumption required for drying of rough rice. The results of this study was may be summarized as follows ; 1. Monthly average daily total radiation on a horizontal surface in October was 260.6 ly/day for Chuncheon, 240.3 ly/day for Suweon , and 253.4 ly/day for Jinju area, respectively. 2. the ratio of monthly average daily diffuse radiation to daily total radiation on a horizontal surface was approximately 0.41 for Chuncheon, 0.45 for Suweon, and 0.44 for Jinju area, respectively. 3. Although the statistical distribution curves of daily total radiation for the three locations were not identical , the differences among them were not large and may be neglected for many practical purposes. 4. I was estimated that the optimum tilting angle of the collector in October was approximately 46 degrees for Chuncheon and Suweon and 45 degrees for Jinju. 5. The ratio of the total radiation on a optimum tilting plane to that on a horizontal plane was estimated to be 1.36 for Chuncheon, 1.31 for Suweon, and 1.27 for Jinju , respectively. 6. The collection efficiency of the solar air collector ranged from 47. 8 to 51. 5 percent at the air flow rates of 251. 1-372.96 $m^3$/hr. High efficiency remained nearly , constant during the best sunshine hours, 10 a.m. to 2 p.m. and decreased during other hours. More energy was collected as the air flow rate incresed. 7. The average temperature rise in the drying air from the solar collector for the test period varied from $6.5^\circC$ to $21.8^\circC$ above the ambient air temperature. 8. Solar-dried rough rice averaged 13.7 percent moisture (w.b.) after 130 hours of drying with the air flow rate of 1. 64 ccm/$m^3$, and rough rice dried with natural air averaged 15.1 percent moisture (w.b.) after 325 hours of drying with the same air flow rate. 9. Energy saving of 2.4 kwh per $m^3$ percentage point of moisture removed was obtained from solar heated air drYing. The solar bin used 53.3 percent less energy per percentage point of moisture removed than the natural air bin.

• Applied Biological Chemistry
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• v.21 no.3
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• pp.144-149
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• 1978

Fermented soy sauce was dehydrated by spray drying to form powder, and moisture sorption properties of powdered soy sauce with or without cover of the flexible films were examined on different relative humidity by using saturated salt solutions at $30^{\circ}$. The results obtained were summarized as follows: The equilibrium moisture content of spray-dried soy sauce containing 18.3% moisture was determined to 52% by graphical interpolation method, and E.M.C. of powdered soy sauce covered with plastic films decreased at low relative humidity whereas sharply increased curves were seen at high relative humidity. The rate constant of moisture adsortion K for the power covered with films were $66.2{\times}10^{-5}\;to\;225{\times}10^{-5}/hr$., and K' became greater when film having higher water vapor transmission rate was used. The shelf-life of powdered soy sauce covered with Al. foil/P.E. film by Brown formula at the accelerated condition of $38^{\circ}$, 92% R. H. was the longest period, 164 days compared with any other films used, and the shortest period, 18 days in P.V.C. film.

• Korean Journal of Agricultural Science
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• v.27 no.2
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• pp.81-85
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• 2000

In order to find a proper storage temperature and times for vegetable waxy corn, several waxy hybrids used in the study. Among waxy hybrids, stem height and ear length of Daehakchal and Eulrukchal hybrides were higher than Chalok#1 and #2 used as a check, but flowering daus were later about 7 days than check. Sugar content of Daehakchal was not almost changed at $-4^{\circ}C$ and below, whereas it was rapidly decreased at $4^{\circ}C$. Most hybrids with high sugar content were fast converted into starch than lower content hybrid. While moisture contents of waxy hybrids used were almost constant regardless of storage temperature in vegetable com packaged with poly ethylene vinyl. From these results, storage temperature of vegetable waxy corn was recommended at least $-4^{\circ}C$ below. Under the $-10^{\circ}C$ and below, storage period of vegetable waxy corn could prolong 60 days and above because sugar and moisture content of vegetable corn measure at $-10^{\circ}C$ and $-20^{\circ}C$ were almost no changed compared with those of fresh corn measured at harvest.