• Economic and Environmental Geology
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• v.36 no.2
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• pp.59-74
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• 2003

Prospecting for energy and mineral resources is essential kind of public fundamentals that manage the nation's economy. Most explorations in the past were concentrated in the simple structural traps in relatively shallow depth. Due to their vast exploitation, recent history has shown that the emphasis in explorations has steadily shifted toward the subtle stratigraphic traps in deeper level. Increasing exploration for the subtle stratigraphic traps in deeper level requires precise correlation and assessment of deeply buried strata in the basin. However, the descriptive strati-graphic principles used for evaluation of the simple structural traps are limited to delineate the subtle stratigraphic traps in deeper depth. As this occurs. it is imperative to establish a new stratigraphic paradigm that allows a more sophisticated understanding on the basin stratigraphy. This study provides an exemplary application of integrated stratigraphic approach to defining basin history of the Middle Ordovician Taebacksan Basin, Korea. The integrated stratigraphic approach gives much better insight to unravel the stratigraphic response to tectonic evolution of the basins, which can be utilized fer enhancing the efficiency of resources exploration and development in the basins. Thus, the integrated stratigraphic approach should be emphasized as a new stratigraphic norm that can improve the probability of success in any type of resources exploration and development project.

• Journal of Bio-Environment Control
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• v.7 no.1
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• pp.25-33
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• 1998

Root zone temperature have influenced on protected cultivation in winter season. Especially root zone temperature is acted on limiting factor in crop cultivation. This study was conducted to obtain optimum temperature of root zone in Protected cultivation Root zone was warmed by heated water($28^{\circ}C$) flowing through the PPC pipe(${\phi}15$) buried depth 40 cm. And the flowing water was heated by solar system. Minimum air temperature during night time was set at $14^{\circ}C$ and maximum air temperature during day time was set at $28~30^{\circ}C$ the growing period of cucumber was from Nov. 6, 1996 to Jan. 30, 1997. The results are summarized as follows. 1. Average soil temperature at 15~20 cm depth was $22^{\circ}C$ at warming plots, $17~18^{\circ}C$ at non-warming plots 2. Early growth in leaf length, stem diameter, number of leaves and leaf area for 30 days after planting were accelerated by root zone warming. Especially, the grawing rate of soil warming plots was higher 27% in leaf length, 51% in leaf number, 150% in leaf area than non-warming Plots. Above-ground and underground part of warming plots was higher 117%, 56% than non-warming plots. 3. In total yield analysis, number of fruits were 614 in soil warming and 313 in non-warming plots. In the result, total yield of soil warming plots was increased with 196% than non-warming plots. 3. In total yield analysis. number of fruits were 614 in soil warming and 313 in non-warming plots. In the result. total yield of soil warming plots was increased with 196% than non-warming plots.

• Journal of Advanced Marine Engineering and Technology
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• v.41 no.3
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• pp.269-275
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• 2017

Shipwreck remains below the seabed not only effect the ocean currents and tides, but influence the physical properties of sediments and sedimentary environments that comprise the seabed. In particular, the influence of local shipwrecks discovered buried in the seabed on the sediment is visible. In this study, sediments were collected from the surrounding area of Taean Mado No.3 shipwreck using grab samplers and vibro-corers. The physical properties of these sediments were analyzed to evaluate the impact of the Taean Mado shipwreck No.3 remains. Sediment core analysis by means of density and ultrasonic velocity showed that shear strength tended to increase with depth, whereas moisture content and porosity tended to decrease with depth. Grain size analysis results are shown in terms of Folk's classification, where the grain size of the core samples in the study area indicate mud or sandy mud, and that of the grab sample indicates a muddy sand. Results of the sedimentation rate analysis indicate a rate of 2.84 cm/year and carbon dating of the 150 cm deep seashell indicates the Neolithic age. These sediments were analyzed for the study of the relationship between the Taean Mado shipwreck No.3 remains and the physical properties of the sediment.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.1
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• pp.777-785
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• 2021

Many utility lines are buried underground to provide various functions of the city. Because historical records are not managed systematically, damage has occurred during excavation. In addition, the demand for an underground facility management system is increasing as the aerial underground project is progressing. By attaching an electronic recognition sensor to an underground facility, such as pipelines, the management history and site conditions can be carefully managed. Therefore, in this study, electronic recognition sensors, such as BLE Beacon, UHF RFID, geomagnetic sensor, and commercial marker, were tested to analyze the strengths, weaknesses, and field applicability through a pilot project. According to the limited research results collected through two pilot projects, the installation depth is most important to demonstrate the performance of the electronic reader. In addition, because it should be used in urban areas, the influence of environmental interference should be minimized, and there should be no performance degradation over time. In the case of the geomagnetic recognizer, the effect of environmental interference was large, and performance degradation occurred over time using the BLE Beacon. In the field situation, where the installation depth can be controlled to less than 40cm, the utility of the battery-free UHF RFID was the best.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.2
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• pp.296-301
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• 2021

GPR is used for non-destructive investigations, ground investigations, and underground facilities exploration at construction sites. In this study, the applicability to GPR exploration of water pipes linked to Network RTK was presented. Data on the water supply pipes in the study site were acquired using GPR, and the location and depth of buried water pipes could be measured. The accuracy was evaluated from the GNSS observation performance and showed a deviation of -0.16m ~ 0.15m. This satisfied the equipment performance of the public survey work regulation, suggesting that the exploration of water pipes using GPR is possible. Because GPR does not require grounding installation, as in conventional metal pipe detectors, it will increase the efficiency of work for underground facility exploration. Exploration using GPR can acquire the location and depth of metallic and non-metallic underground facilities, so it can be utilized in the construction of a GIS system. If a comparison of the exploration characteristics is carried out, it will be possible to present various uses of underground facility exploration using GPR.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.19 no.3
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• pp.1-13
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• 2023

Hydronic heated road pavement (HHP) systems have been well established and documented to provide road safety in winter season over the past two decades. However, most of the systems run on asphalt, only a few are tested with concrete, and there rarely is a comparison between those two common road materials in their performance. The aim of this study is to investigate the thermal performance of the concrete HHP systems, including surface temperature variations of experimental pavements in winter season. For preliminary study a small-scale experimental system was installed to evaluate the heat transfer characteristics of the concrete HHP in the test field. The system consists of 3 concrete slabs made of 1 m in width, 1 m in length, and 0.25 m in height. In these slabs, circulating water piping was embedded with different pipe depths of 0.08 m (Case A), 0.12 m (Case B), and 0.20 m (Case C) and same horizontal space of 0.16 m. Heating performance in winter season was tested with different inlet temperatures of 25℃, 30℃, 35℃ and 40℃ during the entire measurement period. Overall, the surface temperature of the concrete HHPs remained above 3℃ in all experimental conditions applied in this study. The results of the surface temperature measurement with respect to the pipe depth showed that Case B was the highest among the three cases. However, the closer the circulating water pipe was to the pavement surface, the greater the heat exchange rate. This results is considered that the heat is continuously accumulated inside the pavements and then the temperature inside the pavements increases, while the amount of heat dissipation decreases as the temperature difference between the inlet and outlet of circulating water decreases. In this preliminary test the applicability of the concrete HHP on road deicing was confirmed. Finally, the results can be used as a basis for studying the effects of various variables on road pavements through numerical analysis and for conducting large-scale empirical experiments.

• Korean Journal of Environmental Agriculture
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• v.17 no.3
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• pp.268-273
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• 1998

Changes of chemical component and losses of chemical fertilizer by infiltration water from 0.5ha of paddy field in Chinan area of Chonbuk province during the rice cultivation were investigated. The infiltration water samples were collected in a ceramic porous cup which was a buried at the 30, 50, 70, 90㎝ of soil depth. pH of infiltration water ranged $6.64{\sim}7.90$ and EC showed $324{\sim}647{\mu}$S/cm. The content of total-N, $NH_4-N$ and $NO_3-N$ were $0.58{\sim}14.59$, $0.05{\sim}4.25$, and $0.15{\sim}7.71mg/L$ respectively. The content of total-P and ortho-P were $0.009{\sim}0.077mg/L$ and $0{\sim}0.029mg/L$ The content of $Ca^{++}$, $Mg^{++}$, $Na^{+}$ and $K^{+}$ showed $0.88{\sim}4.78$, $0.22{\sim}1.04$, $0.17{\sim}0.98$, and $0.84{\sim}3.19㎎/L$. These all at the first transplanting are higher than that of other periods. The content of $SO_4^{2-}$ showed $3.92{\sim}18.72mg/L$ and decreased with a soil depth. However $Cl^-$ of infiltration water ranged $9.03{\sim}19.97mg/L$ and no difference with a soil depth. When infiltrated $2,416.5m^{3}$ of an infiltration water from 0.5ha of paddy field during the rice cultivation, losses of chemical components were 20.34㎏/㏊ of total-N, 3.54㎏/㏊ of $NH_4-N$, 10.44㎏/㏊ of $NO_3-N$, 0.16㎏/㏊ of total-P and 0.028㎏/㏊ of ortho-P. Also $Ca^{++}$, $Mg^{++}$, $Na^+$, $K^+$, $SO_4^{2-}$ and $Cl^-$ were lost 10.24, 2.84, 2.84, 7.22, 50.04 and 62.20㎏/㏊ respectively. There were lost by infiltration water 9.35% of nitrogen, 0.59% of phosphorous and 22.79% of potassium in applied chemical fertilizer.

• Korean journal of applied entomology
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• v.43 no.3 s.136
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• pp.195-200
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• 2004

The occurrence pattern and bionomics of Selatosomus puncticollis (Motschulsky) were surveyed in three net house (6$\times$70m) in the field and in a laboratory ($20^{\circ}C$, RH$75\%$, L16/DB). Emergence of hibernated adults of S. puncricollis started from early May, reached peak at early June and diminished in late June. Occurrence rate to total number was $42.1\%$ in early June and $31.7\%$ in late May, when most of hibernated adults emerged at these periods. Adults started to oviposit from mid June, and eggs hatched from early July Larvae turned into pupae from mid July and emerged to adults from mid August. Egg-period was 23 days and pupal period was 21 days. It is estimated that preovipositional period and larval period were approximately 10 months and 30 months, respectively. Wireworms were distributed at the soil depth of 10-5 cm, $56.8\%$ in 1997 and $45.8\%$ in 1998. To establish bait techniques to attract wireworms in the soil, six baits: pieces of potato, carrot, and sweet potato, wheat grains, corns, and flour dough wrapped with gauze, were buried at 15 cm of soil depth, and collected after 5 and 10 days. The numbers of wireworms attracted by potato pieces, wheat grains and sweet potato pieces after 10 days were 1.8, 1.6, and 1.4/bait, respectively. Therefore, burying potato pieces at 15 cm of soil depth and collected after 10 days could be recommended as a wireworm baiting technique.

• Economic and Environmental Geology
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• v.45 no.3
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• pp.277-294
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• 2012

The characteristics of temporal spacial radon variation in soil according to parent rock type and affecting factors were studied in Busan, Korea. The concentration of $^{222}Rn$ in soils and their parent elements ($^{226}Ra$,$^{228}Ra$, U and Th) in rocks and soils were measured at 24 sites in Busan area. The distribution and transportation behavior of these parent elements were analyzed and their correlations to radon concentration in soil were determined. Topographic effects were also evaluated. Two in-situ radon measurement (soil probe and buried tube) methods were applied to measure radon concentration in soil and their accuracies were evaluated. The spatial variation of radon in soil generally reflected U concentration in the parent rock. Average radon concentrations were higher in plutonic rocks than in volcanic rocks and were decreased in the order of felsic>intermediate>mafic rock. However, the radon concentrations were significantly varied in soils developed from same parent rocks due to the disequilibrium of U and $^{226}Ra$ between rock and soil. As results, the correlation of these element concentrations between rocks and soils was very low and radon concentrations in soils had highly co-related to the concentrations of these elements in soils. Th and $^{228}Ra$ show complex enrichment characteristics, differing significantly with U, in soils developed from same parent rock because the geochemical behavior of these elements during weathering and soil developing process was different with U. The radon concentrations in the same depth of soil in slope area were also different according to positions. The radon concentrations in soils developed from same parent rocks (19 sites at Pusan National University) varied 6.8~29.8Bq/L range because of small scale topographic variation. The opposite seasonal variation pattern of radon were observed according to soil properties. It was determined that buried tube method is more accurate method than soil probe method and was very advantageous application for the analysis for the characteristics of temporal spacial radon variation in soil.

• Geophysics and Geophysical Exploration
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• v.11 no.1
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• pp.34-40
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• 2008

Underwater seismic refraction with advanced interpretation approaches makes important contributions to shallow marine exploration and geotechnical investigations in Australia's coastal areas. A series of case studies are presented to demonstrate the recent applications of continuous and static USR methods to river crossing and port infrastructure projects at various sites around Australia. In Sydney, static underwater seismic refraction (USR) with bottom-placed receivers and borehole seismic imaging assisted the development of improved geotechnical models that reduced construction risk for a tunnel crossing of the Lane Cove River. In Melbourne, combining conventional boomer reflection and continuous USR with near-bottom sources and receivers improved the definition of a buried, variably weathered basalt flow and assisted dredging assessment for navigation channel upgrades at Geelong Ports. Sand quality assessment with continuous USR and widely spaced borehole information assisted commercial decisions on available sand resources for the reclamation phase of development at the Port of Brisbane. Buried reefs and indurated layers occur in Australian coastal sediments with the characteristics of laterally limited, high velocity, cap layers within lower velocity materials. If these features are not recognised then significant error in depth determination to deeper refractors can occur. Application of advanced refraction inversion using wavefront eikonal tomography to continuous USR data obtained along the route of a proposed offshore pipeline near Fremantle allowed these layers and the underlying bedrock refractor to be accurately imaged. Static USR and the same interpretation approach was used to image the drowned granitic regolith beneath sediments and indurated layers in the northern area of Western Australia at a proposed new berthing site where deep piling was required. This allowed preferred piling sites to be identified, reducing overall pile lengths. USR can be expected to find increased application to shallow marine exploration and geotechnical investigations in Australia's coastal areas as economic growth continues and improved interpretation methods are developed.