• Journal of Korean Society of Environmental Engineers
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• v.33 no.3
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• pp.174-182
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• 2011

The present study evaluated the major lead sources in a steel metallurgy industrialized city by measuring lead isotopes/lead concentrations of ambient air and potential sources in an industrial area and residential areas according to relative distance. The quality control program obtained during the measurement procedure for lead isotopes and concentrations exhibited $0.5ng/m^3$ for method detection limit, more than 90% for recoveries of standard particulate matters, and lower than 0.2% for reproducibility errors of four lead isotopes ($^{204}Pb$, $^{206}Pb$, $^{207}Pb$, $^{208}Pb$). For all three lead isotope ratios ($^{206}Pb/^{204}Pb$, $^{207}Pb/^{206}Pb$, $^{208}Pb/^{206}Pb$), the ratios were obtained in the industrial area were closer to nearby residential area than those of a residential area far away from the industrial area, thereby suggesting that lead sources were more similar each other in the industrial and nearby residential area. Furthermore, for both summer and winter seasons ambient lead concentrations were more than four times higher in the industrial area than in the residential areas and in turn, they were higher in the nearby residential area compared with the far-away residential area. As a result, it was suggested that lead emitted from the industrial area would influence more the ambient lead in the nearby residential area than the far-away residential area. Both slag and traffic emissions are likely to be major lead sources in the industrial and nearby residential areas, since their three lead isotope ratios ($^{206}Pb/^{204}Pb$, $^{207}Pb/^{206}Pb$, $^{208}Pb/^{206}Pb$) were similar to the ratios obtained from ambient air of these two areas. In addition, the lead isotope ratios revealed different pattern between seasons, and the ambient lead concentrations were higher for winter than for summer.

• Journal of Animal Science and Technology
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• v.52 no.4
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• pp.259-264
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• 2010

This study was carried out to estimate genetic parameters and breeding values of Hanwoo cows for carcass traits. Carcass records were collected from Korean steers raised at the private farms located in rural area of Gangwon-do and slaughtered from December 2004 to June 2008 at the three slaughter houses near fattening farm. The results obtained in this study were summarized as follows; The means and standard deviations of the carcass traits were $5.57{\pm}2.01$ for marbling score (MS), $10.87{\pm}4.06mm$ for backfat thickness (BFT), $87.87{\pm}9.07cm^2$ for eye muscle area (EMA), $426.75{\pm}49.27kg$ for carcass weight (CW), and $65.80{\pm}3.80$ for yield index (YI). Heritability estimates using single trait analyses were 0.36 for MS, 0.35 for BFT, 0.24 for EMA, 0.29 for CW, and 0.40 for YI, respectively. Genetic correlation coefficients of MS with BFT, EMA, CW, and YI were -0.21, 0.30, -0.21 and 0.30, and those of BFT with EMA, CW and YI were -0.12, 0.57 and -0.97, and those of EMA with CW and YI were 0.32 and 0.27, respectively. And genetic correlation of CW with YI was -0.62. Single trait selection for MS might lead to reducing BFT, but might be an obstacle to increase CW due to negative genetic correlations of MS with BFT and CW.

• Archives of design research
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• v.19 no.5 s.67
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• pp.129-138
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• 2006

It is expected that the typical lifestyle of the future will be transformed into an opulent and comfortable existence as the quality of life improves due to the increase in household income and reduction in working hours. In the meantime, as the standard of living becomes increasingly more comfortable and plentiful, the toll on physical health becomes magnified as a result of obesity and insufficient exercise caused by super nutrition and change in labor conditions (from physical labor to mental labor). This has instigated a deep awareness in fitness on the part of many people, forcing them to recognize the significance of daily exercise and physical activity. The high annual growth rate in the fitness and athletic apparatus market, which is more than 20%, is attributed to this phenomenon. The Elliptical Cross Trainer(ECT), which has drawn wide attention recently, is a non-impact athletic apparatus that not only promotes exercise of the upper body parts in such sports as skiing but also the exercise of lower parts of the body on a treadmill. It is a type of cross training athletic gear that has been developed for aerobic exercise throughout the entire body. It has already formed a market as big as that of the treadmill in Europe, America, etc. Recently, its demand is growing sharply in the Korean markets as well as those in Northeast Asian countries, Despite such demand increase and expansion, since most of the expensive ECTs are exclusively supplied by suppliers in only a few advanced countries, localization of the ECT is urgently required in order to enhance competitiveness of Korean manufacturers and to expand the market. This paper introduces the process and results of a design-engineering cooperative study that was peformed for the development of the ECT.

• Korean Journal of Environmental Biology
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• v.36 no.1
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• pp.43-49
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• 2018

The toxic assessment of the PBDEs (BDE-47, BDE-209) has been comprehensively investigated by using the rates of survival and population growth in the marine rotifer, Brachionus plicatilis. Chiefly, the survival rate was determined after a measurement of 24 hours of exposure to the BDE-47 (2,2'4,4'-Tetrabromodiphenyl ether) and the BDE-209 (2,2',4,4'-Decabromodiphenyl ether) was performed. The BDE-47 reduced survival rate in dose-dependent manner and a significant reduction were noted to have occurred at a concentration of greater than $3.9mg\;L^{-1}$, but the BDE-209 had no effect which was subsequently observed in this study. The population growth rate (r) was determined after 72 hours of exposure to toxicants in the study. It was observed that the r value in the controls (absence PBDEs) was greater than 0.5, and that it decreased as the dose-dependent manner as recorded. The survival rate when exposed to BDE-47 and BDE-209, $EC_{50}$ value was $13mg\;L^{-1}$ and $>1,000mg\;L^{-1}$, and population growth rate was $3.67mg\;L^{-1}$ and $862.75mg\;L^{-1}$, respectively. Therefore, the BDE-47 is considered to be 76-235 times more harmful than the BDE-209 as noted. In this study, the ecotoxicological bioassay using a noted survival rate and population growth rate of B. plicatilis can be used as a baseline data for the continued establishment of the environmental quality standard of the incidences of the BDE-47 and BDE-209 in a marine environment.

• Microbiology and Biotechnology Letters
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• v.44 no.1
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• pp.74-83
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• 2016

In order to improve the sour taste and foul odor of fermented soymilk, bacteria were isolated from kimchi and identified. Of the 89 bacterial strains isolated from kimchi, 3 isolates produced fermented soymilk with a sour taste and foul odor. The selected bacterial strains R53, R83, and R84 were identified by morphological, biochemical, and 16S rRNA analyses as Weissella koreensis. The strain R83, which produced fermented soymilk having the mildest sour taste and foul odor, was selected for further investigation and named W. koreensis KO3. The optimum culture condition for the fermentation of soymilk by W. koreensis KO3 was at $30^{\circ}C$ for 12 h. When soymilk was fermented under the optimum culture conditions, the viable cell count reached up to $8.71{\times}10^8CFU/ml$ and pH and acidity reached as low as 6.02 and as high as 0.33%, respectively. Twenty-seven amino acids and their derivatives were detected in fermented soymilk. The amounts of serine, glycine, threonine, alanine, and aspartic acid, which contribute to a sweeter taste, increased during fermentation. Orinithine, which was not detected before fermentation, increased during fermentation. Sensory evaluation showed that W. koreensis KO3-fermented soymilk has improved bean, roasted nut, and sour flavors as well as an enhanced mouthfeel, appearance, preferability, and overall acceptability compared with those of standard fermented soymilk. With further study and development, soymilk fermented by W. koreensis KO3 could serve as a health-promoting food with favorable sensory qualities.

• Analytical Science and Technology
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• v.29 no.3
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• pp.114-125
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• 2016

In this study, 165 wastewater discharge facilities in 10 business types were investigated with regard to 24 specific hazardous substances that included heavy metals, VOCs, CN, and phenol in the Gwangju city. Cu in the range from from 0.008 to 35.420 mg/L was detected in all business types and the detection rate was 46.8 %. Other heavy metals, such as Cd, As, Hg, Pb, and Cr⁺⁶ were detected as well. However, their detection rates ranged between 0.6 and 1.8 %. CN and phenol were detected in one and five facilities, respectively. 12 species of VOCs were detected: chloroform 80.6 % (0.42 to 81.60 μg/L), benzene 16.4 % (1.49 to 3.31 μg/L), trichloroethylene 11.5 % (1.78 to 6.02 μg/L), 1,1-dichloroethylene 10.3 % (1.23 to 5.89 μg/L), and dichloromethane 8.5 % (0.28 to 968.86 μg/L) in the detection rate order. The concentration of VOCs was detected in trace amounts, except for dichloromethane that exceeded the effluent quality standard in three business types, namely, metal manufacturing, food industry, and car washing facility. Chloroform was detected in all business types, where 24.88 μg/L were detected in the laundry business and 53.41 μg/L in the water supply business; the mean concentration of chloroform in these two business types was higher than elsewhere. Therefore, for the disposal of non-degradable specific hazardous substances in industrial wastewater, it is necessary to introduce physical and chemical processes, such as activated carbon adsorption, fenton oxidation, ozone treatment, as well as photocatalyst and the UV radiation.

• Current Research on Agriculture and Life Sciences
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• v.17
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• pp.21-29
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• 1999

This study was carried out to determine the promising method for the production of mother bulbs using garlic bulbs at the experimental field of Ange high school, Eusung in Korea from 1996 to 1998. The bulbs and bulbils were taken from a local cultivar 'Eusung' garlic. The growth of bulbil and yield potential were compared with different harvesting times and cultivation methods of bulbil. The harvesting time of bulbils which were capable of producing the mother bulbs was ranged from 15 days to 30 days after the emergence of flower stalks. The best results based on the yield and number of bulbs were obtained from the bulbils sampled at the just before garlic harvesting, 30 days after flower-stalk emergence. The mulching with transparent polyethylene(PE) film in bulbil cultivation was more effective for the plant growth and bulb formation than that with black PE film. The PE mulching from 30 days after seeding of bulbils to 30 days (late-April) before bulb harvesting was the moot effective for the increase of bulb yield. In the cultivation of garlic bulbils, application of lime (150 kg/10a) and compost (3,000 kg/10a) without any chemical fertilizers produced more bulbs in comparison with the standard level of fertilizer (N - $P_2O_5$ - $K_2O$ - compost - lime = 24.8 - 8.0 - 19.2 - 3,000 - 150 kg/10a). It was determined that the involucre seeding and assemble seeding of bulbils was effective and labour-saving methods for the production of mother bulbs from garlic bulbils. Input of labour force for the involucre seeding was decreased up to 61% as compared with the conventional drill seeding of bulbils. Mean yield from the cultivation of bulbil-derived single cloves was remarkably increased up to 95% in comparison with that of the common cloves. The larger size of single clove produced more yields, and the optimum planting density of single clove was $20{\times}10cm$. The cloves differentiated directly from bulbil showed to have higher yield potential than that from common cloves.

• Journal of Labour Economics
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• v.24 no.3
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• pp.13-38
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• 2001

The question about whether a shorter workweek may increase employment has been a serious issue and been furiously debated among collective bargainers. The advocators recommend publicly that a reduction in standard working hours will provide benefits to the unemployed through the provision of new jobs, and also can improve the quality of life workers. The opponents argue that a shorter workweek will increase labor costs and induce firms to reduce their production levels, and consequently cut back their demand for labor. Although the debate is still continuing, considerable has been made toward achieving the goal workweek reduction. The analytical framework of this paper is a Putty-clay-model, in which the short-and long-term impacts of changes in working time on the employment associated with the interrelations of wages, prices, hourly labour productivity, the firm's labor demand, business cycle and economic growth etc. must be analyzed.

• Journal of the Korea Organic Resources Recycling Association
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• v.28 no.1
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• pp.53-64
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• 2020

A 2㎥/d combined wastewater treatment pilot plant containing the multi-stage vertical stacking type nitrification reactor was installed and operated for more than 1 year under the operating conditions of the short-circuit nitrogen process (pH 8, DO 1mg/L and Internal return rate 4Q from nitrification to denitrification reactor). For economically the combination treatment of food wastewater and the leachate from a landfill, the optimal combination ratio was operated by adjusting the food wastewater with the minimum oil content to 5-25% of the total throughput. The main treatment efficiency of the three-phase centrifugal separator which was introduced to effectively separate solids and oil from the food wastewater was about 52% of SS from 116,000mg/L to 55,700mg/L, and about 48% of normal hexane (NH) from 53,200mg to 27,800 mg/L. During the operational period, the average removal efficiency in the combined wastewater treatment process of BOD was 99.3%, CODcr 94.2%, CODmn 90%, SS 70.1%, T-N 85.8%, and T-P 99.2%. The average concentrations of BOD, CODcr, T-N, and T-P of the treated water were all satisfied with the discharge quality standard for landfill leachate ("Na" region), and SS was satisfied after applying the membrane process. On-site leachate had a relatively high nitrite nitrogen content in the combined wastewater due to intermittent aeration of the equalization tanks and different monthly discharges. Nevertheless nitrite nitrogen was accumulated, denitrification from nitrite nitrogen was observed rather than denitrification after complete nitrification. The average input of anti-forming chemical during the operation period is about 2L/d, which seems to be economical compared to the input of methanol required to treat the same wastewater.

• Journal of Intelligence and Information Systems
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• v.21 no.2
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• pp.131-150
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• 2015

Omission of noun phrases for obligatory cases is a common phenomenon in sentences of Korean and Japanese, which is not observed in English. When an argument of a predicate can be filled with a noun phrase co-referential with the title, the argument is more easily omitted in Encyclopedia texts. The omitted noun phrase is called a zero anaphor or zero pronoun. Encyclopedias like Wikipedia are major source for information extraction by intelligent application systems such as information retrieval and question answering systems. However, omission of noun phrases makes the quality of information extraction poor. This paper deals with the problem of developing a system that can restore omitted noun phrases in encyclopedia documents. The problem that our system deals with is almost similar to zero anaphora resolution which is one of the important problems in natural language processing. A noun phrase existing in the text that can be used for restoration is called an antecedent. An antecedent must be co-referential with the zero anaphor. While the candidates for the antecedent are only noun phrases in the same text in case of zero anaphora resolution, the title is also a candidate in our problem. In our system, the first stage is in charge of detecting the zero anaphor. In the second stage, antecedent search is carried out by considering the candidates. If antecedent search fails, an attempt made, in the third stage, to use the title as the antecedent. The main characteristic of our system is to make use of a structural SVM for finding the antecedent. The noun phrases in the text that appear before the position of zero anaphor comprise the search space. The main technique used in the methods proposed in previous research works is to perform binary classification for all the noun phrases in the search space. The noun phrase classified to be an antecedent with highest confidence is selected as the antecedent. However, we propose in this paper that antecedent search is viewed as the problem of assigning the antecedent indicator labels to a sequence of noun phrases. In other words, sequence labeling is employed in antecedent search in the text. We are the first to suggest this idea. To perform sequence labeling, we suggest to use a structural SVM which receives a sequence of noun phrases as input and returns the sequence of labels as output. An output label takes one of two values: one indicating that the corresponding noun phrase is the antecedent and the other indicating that it is not. The structural SVM we used is based on the modified Pegasos algorithm which exploits a subgradient descent methodology used for optimization problems. To train and test our system we selected a set of Wikipedia texts and constructed the annotated corpus in which gold-standard answers are provided such as zero anaphors and their possible antecedents. Training examples are prepared using the annotated corpus and used to train the SVMs and test the system. For zero anaphor detection, sentences are parsed by a syntactic analyzer and subject or object cases omitted are identified. Thus performance of our system is dependent on that of the syntactic analyzer, which is a limitation of our system. When an antecedent is not found in the text, our system tries to use the title to restore the zero anaphor. This is based on binary classification using the regular SVM. The experiment showed that our system's performance is F1 = 68.58%. This means that state-of-the-art system can be developed with our technique. It is expected that future work that enables the system to utilize semantic information can lead to a significant performance improvement.