• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.933-935
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• 2003

Geo-scientifically viable, environmentally suitable, and socially acceptable sanitary landfill sites are very limited in the Kathmandu Valley and is confronted with the burning problem of safe disposal of urban waste. This paper deal with the evaluation and assessment of its interface, following the major criteria defining suitable geological barrier, Cation Exchange Capacity and other necessary physical parameters with the optimum utilization of remotely sense data along with GIS techniques. The study revealed one of the most viable sites at the flat land of natural depression of Taikabu area and has potential to serve all the municipalities of the Kathmandu Valley.

• Steel and Composite Structures
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• v.51 no.5
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• pp.575-586
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• 2024

Steel arch supports are used in mines and underground structures to provide stability. Most of the supports are made up of overlapping arches. They can behave either yieldingly or unyieldingly. If the normal force at any point of overlapping equals the slip resistance, the slide occurs. This paper presents a solution procedure for determining the load-carrying capacity of steel arch supports in the yielding implementation. This solution considers the effects of several significant elements, including differing materials and the number of clamps in yielding friction joints. The direct stiffness method is applied. The solution contains geometric, physical, and structural nonlinearity. The results obtained from numerical modeling using the provided procedure are compared to laboratory tests conducted at GIG Katowice in 2012. They show a good correlation with previously collected data from equivalent laboratory conditions.

• Annual Conference of KIPS
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• 2007.05a
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• pp.31-33
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• 2007

Devising an efficient one-pass frequent pattern mining algorithm has been an issue in data mining research in recent past. Pattern growth algorithms like FP-Growth which are found more efficient than candidate generation and test algorithms still require two database scans. Moreover, FP-growth approach requires rebuilding the base-tree while mining with different support counts. In this paper we propose an item-based tree, called I-Tree that not only efficiently mines frequent patterns with single database scan but also provides multiple mining scopes with multiple support thresholds. The 'build-once-mine-many' property of I-Tree allows it to construct the tree only once and perform mining operation several times with the variation of support count values.

• Journal of the Korean Society of Groundwater Environment
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• v.5 no.1
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• pp.44-55
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• 1998

Imgok creek is the most severly polluted one out of the streams which have been being polluted by acid drainages from the abandoned coal mines in the Gangdong-Myeon area, the central part of the so called Gangreung coal field. Imgok creek is being mainly polluted by the drainage from Youngdong coal mine, which supplies such pollutants as Mg, Fe, Al, Si, Ca, Mn, and SO$_4$as major dissolved components and Cr, Co, Ni, Cu, Zn, Rb, Sr, Cd, Pb, and U as minor dissolved components. After the influx, the pollutants migrate mainly as dissolved solid, rather than as suspended solids along Imgok creek. The suspended solids in Imgok creek are very rich in Fe and Al, indicating that they mainly consist of the precipitates of present and past from the polluted water. Most of the dissolved components in the stream waters of Imgok creek removed from the aqueous phase by precipitation and dilution before reaching the East Sea, so that water quality of the downstreams of Imgok creek is very similar to that of unpolluted tributaries. It suggests that Imgok creek itself is now being severly polluted by the acid drainages from the abandoned coal mines, but the East Sea is relatively safe from the same pollution. The estuary and sea waters around the Goonseon estuary, which accepts Imgok creek water, certainly show no significant difference in chemical compositions from the mean oceanic water. The bottom sediments at the sampling sites of the sea waters also show no significant trend of their component variation, especially the variations of Fe, SO$_4$ and Al concentrations. These facts again supper that the acid mine drainage is not considerablly polluting the East Sea. However, the tributaries supplying the fresh water to the Imgok creek will be certainly polluted by the acid mine drainage as time passes and pollutants will have more chance to migrate in significant amount to the downstream area, which all can be a real threats to the East Sea on the pollution possibility. Therefore, it is suggested that urgently required are not only water quality and environmental improvement of the severely polluted Imgok creek but also preparation of the measures on the possible future pollution of the East Sea by the acid drainage from the abandoned coal mines in the area, while the East Sea is still not much affected by the pollution of the same kind.

• Korean Journal of Ecology and Environment
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• v.45 no.1
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• pp.72-81
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• 2012

We investigated the effects of acid mine drainage (AMD) from abandoned coal mines on benthic macroinvertebrate communities in the upper reaches of the Nakdong River from May to October in 2009. Qualitative and quantitative sampling (Surber sampler: $50{\times}50$ cm; mesh size, 0.2 mm) was conducted at 7 study sites and 3 control sites in the study area. We thus sampled 117 species belonging to 53 families, 15 orders, 6 classes, and 5 phyla; the Ephemeroptera, Plecoptera, and Trichoptera group (EPT-group) represented the majority of the benthic macroinvertebrate community (71 species; 64.5%). In the quantitative sampling, a total of 11,575 individuals belonging to 58 species of benthic maroinvertebrates were sampled from the study sites (Sites 1-7), whereas 2,844 individuals belonging to 79 species were sampled from the control sites (Sites A-C). Tolerant species such as oligochaetes, $Epeorus$ $pellucidus$, $Baetis$ $fuscatus$, Hydropsychidae species, and Chironomidae species were predominant in the study sites. The community indices for the study sites, such as MacNaughton's dominance index (DI) (mean${\pm}$SD, $0.52{\pm}0.21$; range, 0.33-0.85) and the Shannon diversity index ($H^{\prime}$) ($2.06{\pm}0.60$; 1.06-2.57), were different from those for the control sites (DI: $0.29{\pm}0.07$, 0.22-0.35; $H^{\prime}$: $3.13{\pm}0.14$; 3.03-3.30). In the study sites, shredders and scrapers were scarce, whereas gathering-collectors (mainly Chironomidae species) were relatively abundant, as were clingers and burrowers. The detrended correspondence analysis (DCA) and similarity analyses showed that benthic macroinvertebrate communities in the study sites were clearly separated from those of the control sites, with the greatest dissimilarity being noted at the uppermost study site (Site 1), which is located close to an abandoned coal mine. The Korean saprobic index (KSI) and the ecological score using benthic macroinvertebrates (ESB) showed that the uppermost study site (Site 1) was ${\alpha}$-mesosaprobic or heavily polluted, whereas other study sites were in a fair or relatively good condition.

• Journal of Korean Society of Forest Science
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• v.87 no.3
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• pp.466-474
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• 1998

This study was conducted to evaluate heavy metal concentrations(Cd, Cu, Z, and Pb) in the soil of two zinc mines and to correlate heavy metal contents between the soils and trees growing near the mines. Soils and leaves, stems, and roots of five tree species(Corylus heterophylla, Pinus rigida. Populus alba${\times}$glandulosa, Rhododendron mucronulatum, and Robinia pseudoacacia) were collected from Sambo Zinc Mine located in Hwasung and Gahak Zinc Mine in Kwangmyung city in Kyonggido. Soils near two zinc mines were not seriously contaminated by heavy metals, but Zn and Pb concentrations were at toxic level. The heavy metal concentration in soils decreased in the order of Zn, Pb, Cu, and Cd, and decreased with increasing distance from zinc mining sites. Among the five tree species, Populus alba ${\times}$ glandulosa showed the highest heavy metal concentrations in the tissue except for Pb. Particulars, leaves of the species contained the high concentrations of heavy metals to reach the maximum of 91ppm Zn. The roots of Corylus heterophylla contained high concentrations of Cu and Pb. The order of heavy metal concentrations in the tree species was Zn, Cu, Pb and Cd. The concentration of heavy metals in the tree tissues showed a positive correlation with that in soil in which trees are growing. The ratio of heavy metal concentration of trees to that of soils(concentration factor : CF) was highest in Zn and lowest in Pb. Populus alba${\times}$glandulosa had the highest CF value among the five tree species. It was concluded that Populus alba${\times}$glandulosa, based on the high metal uptake ability, could be used for decontaminating of heavy metals from contaminated soils, and Pinus rigida could be used to reflect the level of contamination in soils.

• Korean Journal of Heritage: History & Science
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• v.51 no.1
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• pp.4-31
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• 2018

The Neolithic pottery excavated from the Jungsandong site has been classified into four types of pottery (I: feldspar type, II: mica type, III: talc type and IV: asbestos type) according to their mineral composition. These four types of potteries generally appear to have undergone incomplete firing, while the level of oxidation in the type I pottery objects, which have a relatively higher clay content, was found to be particularly low. The type III objects, which have a high talc content, are judged to have been somewhat slow in removing carbon because they contain saponite belonging to the smectite group. Of the four types of pottery, type IV showed the highest redness and the most uniform characteristics, thus indicating a good level of oxidation. In particular, fixed carbide (C; 33.7 wt.%) with a thickness of about 1mm, and originating from organic substances, was detected inside the walls of the type I pottery, while the deep radial cracks in the outer surfaces of the pottery are thought to have been caused by repeated thermal shocks. Given that all of the pottery except for the type I artifacts are considered to be have been made for storage purposes, those containing talc and tremolite are easy to done liquid storing vessels based on an analysis of their material characteristics. As for the type II relics, which are composed of various minerals and exhibit poor physical properties, they seem to have been used for simple storage purposes. As domestic talc and asbestos mines were concentrated in the areas of Gyeonggi, Gangwon, Chungbuk, and Chungnam, it seems likely that talc and tremolite were produced as contiguous minerals. Considering the distance between the remains in Jungsandong and these mines and their geographical distribution, there is a possibility - albeit somewhat slight - that these mines were developed for the mining of various minerals. Although ultramafic rock masses - such as serpentine capable of generating talc and tremolite - have not been found in the Jungsandong area, limestone and biotite granite containing mica schist have been identified in the northwestern part of Yeongjong Island, indicating that small rock masses might have formed there in the past. Therefore, it is judged necessary to accumulate data on pottery containing talc and tremolite, other than the remains in Jungsandong, and to investigate the rocks and soils in the surrounding area with greater precision. The firing temperatures of the pottery found at the Jungsandong site were interpreted by analyzing the stability ranges of the mineral composition of each type. As a result, they have been estimated to range from 550 to $800^{\circ}C$ for the type I artifacts, and from 550 to $700^{\circ}C$ for the type I, II and IV artifacts. However, these temperatures are not the only factors to have affected their physical properties and firing temperature, and the types, particle sizes, and firing time of the clay should all be taken into consideration.

• Korean Journal of Remote Sensing
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• v.37 no.3
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• pp.531-542
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• 2021

Open-pit mines require constant monitoring as they can cause surface changes and environmental disturbances. In open-pit mines, there is little vegetation at the mining site and can be monitored using InSAR (Interferometric Synthetic Aperture Radar) coherence imageries. In this study, activities occurring in mine were analyzed by applying the recently developed InSAR coherence-based NDAI (Normalized Difference Activity Index). The March 5 Youth Mine is a North Korean mine whose development has been expanded since 2008. NDAI analysis was performed with InSAR coherence imageries obtained using Sentinel-1 SAR images taken at 12-day intervals in the March 5 Youth Mine. First, the area where the elevation decreased by about 75.24 m and increased by about 9.85 m over the 14 years from 2000 was defined as the mining site and the tailings piles. Then, the NDAI images were used for time series analysis at various time intervals. Over the entire period (2017-2019), average mining activity was relatively active at the center of the mining area. In order to find out more detailed changes in the surface activity of the mine, the time interval was reduced and the activity was observed over a 1-year period. In 2017, we analyzed changes in mining operations before and after artificial earthquakes based on seismic data and NDAI images. After the large-scale blasting that occurred on 30 April 2017, activity was detected west of the mining area. It is estimated that the size of the mining area was enlarged by two blasts on 30 September 2017. The time-averaged NDAI images used to perform detailed time-series analysis were generated over a period of 1 year and 4 months, and then composited into RGB images. Annual analysis of activity confirmed an active region in the northeast of the mining area in 2018 and found the characteristic activity of the expansion of tailings piles in 2019. Time series analysis using NDAI was able to detect random surface changes in open-pit mines that are difficult to identify with optical images. Especially in areas where in situ data is not available, remote sensing can effectively perform mining activity analysis.

• Korean Journal of Environmental Biology
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• v.38 no.4
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• pp.733-743
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• 2020

We estimated the carbon storage of coal mines reclaimed using Betula platyphylla (BP), Pinus koraiensis (PK), and Pinus spp. (PS, Pinus densiflora, Pinus rigida, and Pinus thunbergii). The carbon storage of tree biomass (TB), forest floor(FF), mineral soil (MS), and the total forest were quantified. Reclaimed sites were located in Gangwon-do, Gyeongsangbuk-do, and Jeollanam-do; reclamation was conducted at various times in each region. The carbon storage (ton C ha^-1) in FF (BP: 3.31±0.59, PK: 3.60±0.93, PS: 4.65±0.92), MS (BP: 28.62±2.86, PK: 22.26±5.72, PS: 19.95±3.90), and the total forest(BP: 54.81±7.22, PK: 47.29±8.97, PS: 45.50±6.31) were lower than that of natural forests (NF). The carbon storage in TB was lower in BP (22.57±6.18) compared to NF, while those in PK(21.17±8.76) and PS (20.80±6.40) were higher than in NF. While there were no significant differences in the carbon storage of TB, FF, and the total forest among tree species, results from MS showed a significant difference among species. TB and the total forest carbon storages in all sites increased after reclamation. Soil pH and cation exchange capacity values in BP and PS were lower than in NF. Amounts of labile carbon, available phosphate, and microbial biomass carbon in reclaimed sites were less than half of NF. There are a number of methods that could increase the reclamation efficiency. Applications of lime or organic fertilizers, as well as tillage operations, may improve soil properties in reclaimed coal mines. Additionally, pruning and thinning would increase tree growth thereby increasing carbon storage.

• Journal of Life Science
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• v.20 no.4
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• pp.618-622
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• 2010

This study examines the relationship between urinary arsenic concentration and urinary 8-hydroxydeoxyguanosine (8-OHdG) concentrations, an index of oxidative DNA damage, among women who live near abandoned metal mines. The sample consisted of 165 residents living near two abandoned metal mines located in Chungbuk Province. Demographic characteristics as well as environmental factors relevant to arsenic exposure were collected through interviews, and urinary arsenic concentrations and urinary 8-OHdG concentrations of the research subjects were measured. The collected data were subsequently analyzed using the statistics program SPSS 12.0. The geometric average of urinary arsenic concentrations among the research subjects was $5.65\;{\mu}g/g$ creatinine. In a correlation analysis between urinary arsenic and 8-OHdG concentrations, the correlation coefficient was significant (p<0.001) at 0.399. This study suggests that urinary 8-OHdG concentrations may be a DNA damage marker for chronic arsenic exposure in women.