• The Journal of the Petrological Society of Korea
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• v.5 no.1
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• pp.108-120
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• 1996

This study reports petrography and geochemical characteristics of the Cretaceous volcanic rocks that are distributed in the vicinity of the Cheonsungsan area, Yangsan-Gun, Gyeongsangnam-Do. The Cretaceous volcanic rocks composed of andesitic rocks, Wonhyosan tuff, Cheonsungsan tuff in ascending order. Sedimentary rock is the basement in the study area cofered with volcanic rocks. These volcanic rocks are Wonhyosan tuff and Cheonsungsan tuff that represented the early phase of the Bulgugsa igneous activity. Wonhyosan tuff are classified into dacite tuff and dacite welded tuff based on the rock texture and their mineral composition. They are covered with Cheonsungsan tuff. Dacite tuff composed of lithic lapilli ash-flow tuff and vitric ash-flow tuff. Most dacite welded tuff are lapilli ash-flow tuff. Cheonsungsan tuff overlying the Wonhyosan tuff consists of rhyolite tuff and rhyolite welded tuff. Rhyolite tuff are lithic crystal ash-flow tuff and crystal vitric ash-flow tuff with somewhat accidental fragments of andesitic and sedimentary rocks. Rhyolite welded tuff is distinguishe from rhyolite tuff by is typical eelded fabrics and its rock color. According to petrochemical data, the volcanic rocks in study area belong to high-K orogenic suties. On the discriminant diagrams such as La/Yb versus Th/Yb, these rocks falls into the discriminant fields for the normal continental margin arc.

• Journal of Internet Computing and Services
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• v.14 no.6
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• pp.85-94
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• 2013

With the emergence of world wide web, in particular web 2.0 the rapidly growing amount of news articles has created a problem for users in selection of news articles according to their requirements. To overcome this problem different clustering mechanism has been proposed to broadly categorize news articles. However these techniques are totally machine oriented techniques and lack users' participation in the process of decision making for membership of clustering. In order to overcome the issue of zero-participation in the process of clustering news articles in this paper we have proposed a framework for clustering news articles by combining users' judgments that they post on twitter with the news articles to cluster the objects. We have employed twitter hash-tags for this purpose. Furthermore we have computed the credibility of users' based on frequency of retweets for their tweets in order to enhance the accuracy of the clustering membership function. In order to test performance of proposed methodology, we performed experiments on tweets messages tweeted during general election 2013 in Pakistan. Our results proved over claim that using users' output better outcome can be achieved then ordinary clustering algorithms.

• Korean Journal of Environmental Agriculture
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• v.33 no.2
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• pp.111-120
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• 2014

BACKGROUND: This study was conducted to investigate the levels of pesticide residues in fruits and to assess their risk to human health. METHODS AND RESULTS: Monitoring of 215 samples of fruits collected from local markets in incheon during 2013 was performed. 259 pesticides were analyzed by multi-residue method and Quick, Easy, Cheap, Effective, Rugged, and safe/Mass/Mass(QuEChERS/MS/MS) method using Gas Chromatography-Electron Capture Detector/Nitrogen Phosphorus Detector(GC-ECD/NPD), GC-MS, LC(Liquid Chromatography-Mass/Mass(LC-MS/MS) and High Performance Liquid Chromatography-Photodiode Array/Fluorescence Detector(HPLC-PDA/FLD). In 56.3% of the samples detected pesticide residues and were not found to exceed Maximum Residue Limits(MRL). The highest detected samples were found in citrus fruits(83.9%). Among the detected compounds, carbendazim(13.1%), imazalil (11.7%), thiabendazole(10.7%) and fludioxonil(9.8%) were frequently found in fruits. A risk assessment of pesticide residues in fruits was performed by calculating Estimated Daily Intake(EDI) and Acceptable Daily Intake(ADI). Also, we were evaluated removal efficiency of pesticide residues by washing and peeling. The removal efficiency of pesticide residues in citrus and tropical fruits by peeling processes were 91.6%. After the washing process, the removal rates were 43.1%(Cherry, Grape, Blueberry). CONCLUSION: The level of pesticide residues in fruits was within the MRL. The range of %ADI values was from 0.00011 to 0.98795%. The process of washing or peeling reduces the level of pesticide residues. The results of this research concluded that the detected pesticides are not harmful to human being.

• Korean Journal of Soil Science and Fertilizer
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• v.24 no.4
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• pp.248-253
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• 1991

This study examines the effect of submergence on transformations of inorganic phosphorus and the relation between fractions of inorganic phosphorus and adsorbed phosphorus in Gangseo (paddy soil), Yesan (non-cultivated soil), and Jungdong soil (upland soil). The soils were submerged with glucose sol'n at $28^{\circ}C$ for 17 days. After, the soils were incubated with phosphate solution at $25^{\circ}C$ for 24 hours. The seguential fractionation of inorganic phosphorus and of iron were conducted to investigate transformations of them. Results obtained are as follows; 1. By submergence, Bray I-P were decreased from 53mgP/kg to 48mgP/kg in Gangseo, from 3mgP/kg to 1mgP/kg in Yesan, and from 120mgP/kg to 56mgP/kg in Jungdong soil. 2. $NH_4F$ extractable P was dominant fraction of adsorbed P. It was transformed into NaOH extractable P by submergence in Jungdong soil. 3. Dithionite-citrate-bicarbonate extractable iron (crystalline Fe) was transformed to oxalate extractable iron (amorphous Fe) by submergence in Yesan soil.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.45 no.5
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• pp.13-20
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• 2008

Although digital hearing aid algorithms have been developed to compensate hearing loss and to help hearing impaired people to communicate with others, digital hearing aid user still complain about difficulty of hearing the speech. The reason could be the quality of speech through digital hearing aid is insufficient to understand the speech caused by feedback, residual noise and etc. And another thing is masking effect among formants that makes sound quality low. In this study, we measured the masking characteristics of normal listeners and hearing impaired listeners having presbyacusis to confirm masking effect in speech itself. The experiment is composed of 5 tests; pure tone test, speech reception threshold (SRT) test, word recognition score (WRS) test, puretone masking test and speech masking test. In speech masking test, there are 25 speeches in each speech set. And log likelihood ratio (LLR) is introduced to evaluate the distortion of each speech objectively. As a result, the speech perception became lower by increasing the quantity of formant enhancement. And each enhanced speech in a speech set has statistically similar LLR, however speech perception is not. It means that acoustic masking effect rather than distortion influences speech perception. In actuality, according to the result of frequency analysis of the speech that people can not answer correctly, level difference between first formant and second formant is about 35dB, and it is similar to result of pure tone masking test(normal hearing subject:36.36dB, hearing impaired subject:32.86dB). Characteristics of masking effect is not similar between normal listeners and hearing impaired listeners. So it is required to check the characteristics of masking effect before wearing a hearing aid and to apply this characteristics to fitting.

• Journal of Korean Society of Forest Science
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• v.89 no.1
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• pp.41-48
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• 2000

Mass loss and dynamics of mineral nutrient during decomposition of deciduous leaves and 3 species of needles were investigated for 38 months from October in 1992 to November in 1995 in Kwangneung, Korea. After 38 months, the remaining mass of deciduous leaves, Pinus koraiensis, Pinus rigida and Abies holophylla was 16.2%, 29.8%, 33.5% and 53.9%, respectively. The decay rate (k) of deciduous leaves, Pinus koraiensis, Pinus rigida and Abies holophylla was 0.61, 0.40, 0.37, $0.21yr^{-1}$, respectively. The lowest decay rate in fir needle might be, in part, due to low N concentration. N concentration of the decomposing litter increased during the experimental period except for P. rigida. Deciduous leaves showed a short immobilization period during the early stage of decomposition, and big-cone pine and pitch pine had no immobilization period. However, there was no net N mineralization in fir litter. P increased during the experimental period for all litter. Except for deciduous leaves, there was no net mineralization period. In case of deciduous leaves, however, remaining P after 38 months was 53% of the initial P capital. Remaining cations of the decomposing litter after 38 months were lower than those of initial contents.

• Journal of Korean Society of Forest Science
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• v.88 no.2
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• pp.266-272
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• 1999

Aboveground biomass and nutrient contents of a 31-year-old pitch pine(Pinus rigida) and a 31-year-old Japanese larch(Larix leptolepis) plantations were measured in the Chungbu Forest Experiment Station, Kyunggi Province. Aboveground biomass was 170.2ton/ha in the pitch pine and 87.2ton/ha in the Japanese larch plantations. Aboveground biomass difference between both plantations was due to the difference of stand density. Aboveground biomass in both plantations was allocated as follows : stemwood>branch>stembark>needle. The concentrations of all nutrients(N, P, K, Ca, Mg) were generally higher in the Japanese larch needle than in the pitch pine because of high nutrient uptake characteristics of larch compared with pine tree species. The nutrient concentration in different tree tissues in both tree species decreased in the order of needle>branch>stembark>stemwood. Nutrient contents of aboveground biomass were : N, 335.9 ; P, 40.4 ; K, 121.4 ; Ca, 188.6 ; Mg, 93.8kg/ha in the pitch pine plantation, while nutrient contents in the Japanese larch plantation were : N, 226 ; P, 11.5 ; K, 72.9 ; Ca, 75.7 ; Mg, 37.1kg/ha. The nitrogen use efficiency calculated as the biomass produced by one unit of nitrogen was higher in the pitch pine than in the Japanese larch plantations. This result suggests that pine with high nitrogen use efficiency could be adapted in lower site productivity area compared with larch tree species.

• Korean Journal of Construction Engineering and Management
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• v.11 no.3
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• pp.125-133
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• 2010

Although work-efficiency of construction machinery is a critical factor for estimating its workable-quantity perunit time, the efficiency figure table presented in the Poom-Sam that is used for Construction Cost Estimation of public sectors in Korea is very subjective for practical usage. In order to suggest objective work-efficiency table for a Pump-Dredger, domestic and overseas documentary records were investigated and on-going construction sites were also visited. Moreover, actual work quantities collected from the site visits were compared with the ones calculated based on the Standard Measurement Methods used in Japan. The research found that the table can be revised by means of detailing down by several factors, namely project type, depth of soil, undersea-site shape, and condition on the sea for better estimation of its workable-quantity. The research will be the foundation for applying the rapid development of Construction Equipment and technology to the appropriate cost estimations and the ground work of related studies.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.29 no.1
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• pp.17-25
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• 1996

The results identified for bacterial flora 174, Vibrio spp.132, and coliform group 183 strains isolated from the areas of last China Sea and Yosu coastal sea during from August 6th. to 14th. 1992 were as follow: 40 strains among the 74 strains of bacteria flora isolated from fast China sea area were Pseudomonas spp.$(54\%)$ and 60 strains among the 100 strains isolated from Yosu sea area were Enterobacteriaceae $(60\%)$. Four strains were Vibrio alginoliticus and one strain of V, parahaemolyticus among 5 strains of genus Vibrio isolated from last China Sea. While 54 strains were V. alginolyticus $(43\%)$ and V, parahaemolyticus $(17\%)$ among 127 strains genus Vibrio isolated from Yosu coastal sea area. Seventy nine strains among the 156 strains of coliform group isolated from Vosu sea area were Escherichia coli I $(51\%)$ and each one strain Citrobacter freundii I and II. 3 strains among 27 strains isolated from last China sea area were E. coli$(11\%)$ and 1 strain of C. freundii I. Coliform group was grouped into 16 types by IMViC system, $44^{\circ}C$, gelatin liquefaction test.

• Economic and Environmental Geology
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• v.49 no.2
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• pp.89-95
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• 2016

Mo isotope, one of highly redox-sensitive isotopes, has been shown to be useful tracers of geochemical processes. Many studies for Mo isotope have documented with the help of recently developed analysis tools, but it has not yet been documented in the Korea. In this study, we introduce two-stage column separation method of Mo using column tube (BioRad PolyPrep(R) column, 10 ml) and anion exchange resin (BioRad Resin AG(R) 1-X8, 200-400 mesh). Mo isotope ratios in the solid SRMs (BHVO-2, SDO-1, PACS-2) and liquid SRM (IAPSO) were measured on MC-ICP-MS (Multi-collector Inductively Coupled Plasma Mass Spectrometer) and then compared with reference Mo isotope ratios. Mo isotope ratios in our study overlap with reference Mo isotope ratios within analytical error.