• Economic and Environmental Geology
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• v.42 no.4
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• pp.315-333
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• 2009

In this study, the hydrochemical and the isotopic characteristics of major streams in the Daejeon area were investigated during rainy and dry seasons. The stream water shows the electrical conductivity of the range of $37{\sim}527{\mu}s$/cm, and pH $6.21{\sim}9.83$. The chemical composition of stream waters can be grouped as three types: the upper streams of Ca(Mg)-$HCO_3$ type, Ca(Mg)-$SO_4(Cl)$ type of middle streams flowing through urban area, and Na(Ca)-$HCO_3$(Cl, $SO_4$) type of the down streams. Based on in-situ investigation, the high pH of stream waters flowing through urban area is likely to be caused by the inflow of a synthetic detergent discharging from the apartment complex. The electrical conductivity of stream waters at a dry season is higher than those of at a rainy season. We suggest that the hydro-chemical composition of stream waters in the Daejeon area was affected by the discharging water from the sewage treatment facilities and anthropogenic contaminants as well as the interaction with soil and rocks. ${\delta}D$ and ${\delta}^{18}O$ values of the stream waters show the relationship of ${\delta}D=6.45{\delta}^{18}O-7.4$, which is plotted at a lower area than global meteoric water line(GMWL) of Craig(1961). It is likely that this isotopic range results from the evaporation effect of stram waters and the change of an air mass. The isotope value shows an increasing trend from upper stream to lower stream, that reflects the isotopic altitude effect. The relationship between ${\delta}^{13}C$ and $EpCO_2$ indicates that the carbon as bicarbonate in stream water is mainly originated from $CO_2$ in the air and organic materials. The increasing trend of ${\delta}^{13}C$ value from upper stream waters to lower stream waters can be attributed to the following reasons: (1) an increasing dissolution of $CO_2$ gas from a contaminated air in downtown area of the Daejeon, and (2) the increment of an inorganic carbon of groundwater inflowed into stream by base flow. Based on the relationship between ${\delta}^{34}S$ and $SO_4$ of stream waters, the stream waters can be divided into four groups. $SO_4$ content increases as a following order: upper and middle Gab stream${\delta}^{34}S$ value decreases as above order. ${\delta}^{34}S$ value indicates that sulfur of stream waters is mainly originated from atmosphere, and is additionally supplied by pyrite source according to the increase of sulfate content. The sulfur isotope analysis of a synthetic detergent and sewage water as a potential source of the sulfur in stream waters is furtherly needed.

• Food Science and Preservation
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• v.22 no.3
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• pp.437-442
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• 2015

In a continuing screening of selected medicinal plants native to South Korea, the antioxidant and pancreatic lipase inhibitory activities of an aqueous methanolic extract from the heartwood of Aquilaria agallocha were investigated. Eighty percent of the methanolic extract of A. agallocha was further divided into $CH_2Cl_2$, EtOAc and n-BuOH in order to yield four solvent-soluble portions, namely $CH_2Cl_2$-soluble, EtOAc-soluble, n-BuOH-soluble and $H_2O$ residue. The antioxidant properties were evaluated by employing radical scavenging assays using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) ($ABTS^+$) radicals, while the anti-obesity efficacy of A. agallocha extracts and solvent-soluble portions were tested by porcine pancreatic lipase assay. All tested samples showed dose-dependent radical scavenging and pancreatic lipase inhibitory activities. Among the tested extracts and solvent-soluble portions, the $CH_2Cl_2$-soluble portion showed much higher radical scavenging activity and pancreatic lipase inhibitory properties when compared with other solvent-soluble portions. This result suggested that there was a significant relationship between the total phenolic content and biological efficacies, and A. agallocha extract might be considered as a new potential source of natural antioxidants and as a pancreatic lipase inhibitory source. A more systematic investigation of this biomass will be performed for further investigation of activity against antioxidative and anti-obesity effects.

• Clean Technology
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• v.18 no.2
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• pp.200-208
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• 2012

This study was performed to prevent the health damage of environmental contaminants in Industrial Complex Area. And, this study aimed to identify the concentration levels and distribution characteristics of environmental contaminants and Polycyclic Aromatic Hydrocarbons (PAHs) at soil in Industrial Complex Area and control area. The concentration of the soil pollution standard such as the heavy metals in the soil, VOCs, PAHs, and PCB were measured and analyzed using the soil specimens in the Industrial Complex Area and control area. Soil specimens from the Industrial Complex Area (the direct exposure area) and the control area were surveyed. Songdo-dong, Haedo-dong and Jechul-dong, which are in the direct exposure area and near the emission source, showed relatively high concentrations of contaminant materials when compared with Jangki-myeon, which is far off and in the control area. The concentration of zinc was 20.8-58.9% of the level of concern (300 mg/kg) in the 1st region, which is a relatively high concentration. The concentration of fluoride was under the standard in every region, but it was about 74% of the level of concern (400 mg/kg) in the 1st region. It is recommended that controlling fluoride emissions is necessary. Levels of organic phosphate, phenol, and VOCs like benzene, toluene, ethylbenzene and xylene were under the detection limit of the analysis instruments. The concentration of TPH was high in Songdo-dong. The concentration of contaminants in Jechul-dong was high. In addition, it was observed that the level of soil contamination changed depending on the distance from the emission source. The concentration of PAH compounds in the soil was 18.71-1744.59 ng/g, and the concentration of six potential cancer-causing PAH materials was 6.54-695.94 ng/g. The highest concentration was in Songdo-dong. The PAH concentration in the direct exposure area near the complex was relatively high compared to the indirect exposure area.

• Journal of Life Science
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• v.23 no.3
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• pp.426-431
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• 2013

With the objective of developing a functional food source, we established optimal processing conditions for the larvae of Allomyrina dichotoma, which have been used in traditional medicine to treat hepatic disorders in Korea. Without suitable processing, the larvae are difficult to consume as a food because of their disgusting taste and smell; moreover, in this form they might be a potential microbial hazard. In this study, we investigated the effect of feeding material, sterilization, and powdering after freeze-drying on the food quality of the larvae of A. dichotoma and on cytotoxicity against Raw 264.7 cells. Three to five days feeding with the sawdust from discarded oak-trees is sufficient for the breeding process. The sawdust was sterilized by vapor for five minutes. Sterilization of the larvae at a high temperature ($115^{\circ}C$ for 5 min, 0.9 $kgf/cm^2$) is necessary to eliminate pathogenic bacteria and fungi. The results of the cytotoxicity assay showed no toxicity in the prepared extract from larvae of A. dichotoma. In addition, to prepare the larvae for human consumption, various feeds were used and the smell, color, and taste were evaluated. Our results suggested that larvae of A. dichotoma could be developed as food source when a suitable processing method is established.

• KDI Journal of Economic Policy
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• v.14 no.2
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• pp.55-75
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• 1992

At the outset of import liberalization, most economists expected a significant drop in the prices of domestic goods that faced foreign competition. However, it is now generally acknowledge that a significant drop in prices of those goods has not occurred. A common claim is that the prices did not drop significantly because the major importers of many imported goods were also the domestic producers of competing goods. The objective of this paper is to analyze the welfare effect of importation by domestic firms that produce competing goods, to identify the factors that facilitate such business practices, and to formulate a policy that could improve the welfare. We proved that importation by competing domestic firms definitely raises the prices of both imported and domestic goods compared to the situation where foreign goods are imported by non-producers, ceteris paribus. The intuition behind this result is that since a producer-importer is essentially a cartel, its overall profit maximization requires reduced competition between the products that it sells. On the other hand, if a producer-importer is more efficient at distrinbution than a simple importer, the comparison between the two cases is a priori indeterminate. We also find that the industries in which domestic producers are actively involved in importing competing goods are the ones in which the distribution channels are tightly controlled by importer-producers. This finding suggests that exclusive dealing contracts, which work as an entry barrier, may be the source of importing by domestic producers. We argue that in a country such as Korea, where financial market is highly incomplete, tight control of the distribution channels by oligopolistic manufacturers is likely to be an effective entry barrier that leads to importing by domestic producers of similar goods. We further argue that seemingly superior distribution costs of importer-producers is likely to be a result of market foreclosure which would disappear once the entry barrier of exclusive dealing contracts is removed. Above findings suggest that market imperfections are the source of importation by domestic competitors, which in turn constitutes a market imperfection in itself and reduces consumer welfare. As potential remedies, we considered three alternatives; direct price control by the government over the imported goods sold by major domestic producers, regulation of trade itself between major producers, and regulation of exclusive dealing contracts. For reasons both theoretical and pratical, we find that the last alternative is the most attrative. Prohibiting exclusive contracts between manufacturers and dealers in industries where exclusive dealing contracts are a significant entry barrier is expected to break up the importer-producer cartel and improve the welfare.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.47 no.5
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• pp.50-60
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• 2010

For the last half a century, the personal computer and software industries have been prosperous due to the incessant evolution of computer systems. In the 21st century, the embedded system market has greatly increased as the market shifted to the mobile gadget field. While a lot of multimedia gadgets such as mobile phone, navigation system, PMP, etc. are pouring into the market, most industrial control systems still rely on 8-bit micro-controllers and simple application software techniques. Unfortunately, the technological barrier which requires additional investment and higher quality manpower to overcome, and the business risks which come from the uncertainty of the market growth and the competitiveness of the resulting products have prevented the companies in the industry from taking advantage of such fancy technologies. However, high performance, low-power and low-cost hardware and software platforms will enable their high-technology products to be developed and recognized by potential clients in the future. This paper presents such a platform for industrial embedded systems. The platform was designed based on Telechips TCC8300 multimedia processor which embedded a variety of parallel hardware for the implementation of multimedia functions. And open-source Embedded Linux, TinyX and GTK+ are used for implementation of GUI to minimize technology costs. In order to estimate the expected performance and power consumption, the performance improvement and the power consumption due to each of enabled hardware sub-systems including YUV2RGB frame converter are measured. An analytic model was devised to check the feasibility of a new application and trade off its performance and power consumption. The validity of the model has been confirmed by implementing a real target system. The cost can be further mitigated by using the hardware parts which are being used for mass production products mostly in the cell-phone market.

• Korean Journal of Breeding Science
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• v.41 no.3
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• pp.288-291
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• 2009

A new commercial rice variety "Donghaejinmi" is a japonica rice (Oryza sativa L.) with lodging resistance and high grain quality. It has been developed by the rice breeding team of Yeongdeog Substation, National Institute of Crop Science (NICS), RDA. This variety was derived from a cross between "Milyang 64" as a resistance source of brown planthopper (Bph) and "Milyang 165" as grain quality source. The donor parent, "Milyang64" has been backcrossed three times with recurrent parent, "Milyang165" and selected by the pedigree breeding method. The pedigree of "Donghaejinmi", designated as "Yeongdeog 41" in 2003, was YR21259-B-B-68-1. It has a short culm length with 69 cm and medium-late growth time. This variety is resistant to stripe virus and moderately resistant to leaf blast disease with durable resistance. It also has tolerance to unfavorable environment such as cold, dried wind and storm. Milled rice kernel of "Donghaejinmi" is translucent, clear in chalkness and good at eating quality in panel test. The merit of this variety is high head rice ratio, which is essential element to produce an article of superior quality rice brand. The yield potential of "Donhaejinmi" in milled rice is about 6.05 MT/ha at ordinary fertilizer level of local adaptability test. This cultivar would be adaptable to Yeongnam inland plains and eastern costal area of Yeongnam province.

• Korea journal of population studies
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• v.11 no.1
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• pp.58-75
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• 1988

1.Objectives of the Study It is a well known fact that a prompt and reliable data on demographic information is essential in a proper planning and evaluation of any program of national or community level. Especially vital statistics are an important demographic component among demographic information. Realizing the importance of vital statistics, the government has made some efforts for years to improve the vital registration system which has a close relationship with the production of vital statistics. However, it is still observed that there are some limitations in utilizing vital registration data due to considerable amount of vital events which are never registered and registered but not in time or inaccurately, even though vital registration system in Korea has sound legal basis. In this connection, the objectives of the study is as follows :(1) To examine some problems of the vital registration system in various aspects, (2) To make improvement programme of continuous Demographic Survey as a supplementary source of vital statistics, and (3) To find out some alternatives for making it possible to produce and utilize the reliable vital statistics by developing analytical methodologies on that. 2. Current Situation of Vital Registration System All the vital events, i.e. births, deaths, marriages and divorces, are to be registered in time under the Civil Registration Law, Statistics Law and Regulation on Vital Statstics as a duty of people. Some recent tendencies in each of recent registration are summarized as below: (1) The completeness of vital registration .Out of all births which are occurred during a year, around 75% of those compared to the estimates are registered in the year of occurrence. .In case of death registration, the percentage of registration in the year of occurrene has been gradually increased from 86.2% in the year of 1980, but it is still below the level of 90% compared to the estimates. .The percentage of registration for marriages and divorces in the year of occurrence out of total registered numbers was revealed to be 69% and 73% respectively in 1985. (2) Continuous Demographic Survey .It is a kind of sample survey for the purpose of producing reliable vital statistics which could not be provided by the vital registration. .It covers about 17, 000 sample households at national level and important information for vital events are collected in every month by 323 expertized enumerators who are regular staff of the government. .Although the result of the survey seems to be more reliable than of vital registration, the reliability of the data is still bellow the acceptable level if compared with relevant information from other sources such as population census or special surveys. 3. Problems of Vital Registration System There are four major obstacles in improving vital registration system in Korea; (1) In general, policy priority is not given on any programme of improving vital registration system. It is, therefore, very difficult to formulate comprehensive programme through having cooperation from related authorities and sufficient financial assistance. (2) In all the laws related and system itself, there is substantial degree of overlap and irrationality. Registration of each vital event is maintained according to several laws and regulation such as Civil Registration Law, Statistics Law, Resident Registration Law and Regulation on Vital Statistics. However they are mutually overlapped and overall supervision can not be done systematically due to lack of co-operation among the authorities concerned. (3) The administration of vital registration system seems to be working inefficiently, because of most of civil servants who are in charge of vital registration are lacking of conception on vital statistics and also there is a certain extent of regidity in handling the works. Therefore, they are doing their jobs in a passive way. (4) A substantial proportion of vital events occurred is not registered within the legal time limit (i.e. within one month after the occurrence in case of birth and death) or not registered forever. Some of social customs and superstitution seem to be the potential causes especially in case of births and deaths. 4. Recommendations for the Improvement of Vital Statistics (1) Reporting systems such as civil registration, vital statistics and resident registration should be integrated under the single law. Also, administrative supervision, personnel and budget with regard to the registration system should be under the control of a single ministry. (2) It is necessary to simplify the procedures and methods of reporting vital events, i.e., reducing number of sheets of the form, making corrections easily, reducing registration items, etc. (3) Continuous Demographic Survey as a supplementary source of vital registration should be improved and special ad-hoc surveys should be conducted wth regular interval. (4) In-depth analysis should be done using various sources of data on vital statistics. 5. Concluding Remarks From this study, we can notice that temporary campaign and motivation programs are not sufficient to improve the quality of vital statistics. Strong intentions and continuous efforts of the government are needed for the improvement of the vital registration system. Furthermore, most of the data collected through the registration are not properly analyzed and utilized, partly due to the lack of appreciation among high-level governmental officials of the need for vital statistics. It is, therefore, requested that long-term improvement programs of vital statistics be implemented with policy priority and continuous efforts be given to this purpose as a long-term goal of development in Korea.

• Journal of Applied Biological Chemistry
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• v.62 no.2
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• pp.187-193
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• 2019

The newly bred Picnic apple was extracted using water and ethanol for extracting solvent. Each water and ethanol extract showed relatively high phenolic compound of 3.69 and 5.55 mg/g. Each water and ethanol extract of Picnic apple showed 1,1-diphenyl-2-picrylhydrazyl of 88.10 and 88.07%, 2,2'-Azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) of 98.79 and 97.25%, antioxidant protection factor of 2.07 and 2.00 PF and thiobarbituric acid reactive substances showed anti-oxidation effect of 9.69 and 19.83% all at $100{\mu}g/mL$ phenolics concentration. Therefore extract of Picnic apple can be considered as anti-oxidant for anti-aging. The anti-inflammatory effect (hyaluronidase inhibition) of extract of Picnic apple were 4.62% with water extract and 4.39% with ethanol extract both at $200{\mu}g/mL$ phenolics concentration. Both water and ethanol extract showed low ${\alpha}$-amylase inhibition effect but each showed 67.37 and 79.16% of ${\alpha}$-glucosidase inhibition effect at $200{\mu}g/mL$ phenolics concentration. In anti-wrinkle effect, water extract showed each 23.70 and 66.29% in elastase inhibition and collagenase inhibition and ethanol extract showed 64.83 and 65.70% each. These result show high potential for functional food and cosmetic source. Picnic apple was identified to have various functions of anti-oxidation, anti-inflammation, anti-wrinkle effect, and anti-diabetic effect. Therefore, Picnic apple is qualified as a source for new functional cosmetics and functional foods.

• Korean Chemical Engineering Research
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• v.60 no.1
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• pp.86-92
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• 2022

Recently, the bio-healthcare market is enlarging worldwide due to various reasons such as the COVID-19 pandemic. Among them, biometric measurement and analysis technology are expected to bring about future technological innovation and socio-economic ripple effect. Existing systems require a large-capacity battery to drive signal processing, wireless transmission part, and an operating system in the process. However, due to the limitation of the battery capacity, it causes a spatio-temporal limitation on the use of the device. This limitation can act as a cause for the disconnection of data required for the user's health care monitoring, so it is one of the major obstacles of the health care device. In this study, we report the concept of a standalone healthcare monitoring module, which is based on both triboelectric effects and electromagnetic effects, by converting biomechanical energy into suitable electric energy. The proposed system can be operated independently without an external power source. In particular, the wireless foot pressure measurement monitoring system, which is rationally designed triboelectric sensor (TES), can recognize the user's walking habits through foot pressure measurement. By applying the triboelectric effects to the contact-separation behavior that occurs during walking, an effective foot pressure sensor was made, the performance of the sensor was verified through an electrical output signal according to the pressure, and its dynamic behavior is measured through a signal processing circuit using a capacitor. In addition, the biomechanical energy dissipated during walking is harvested as electrical energy by using the electromagnetic induction effect to be used as a power source for wireless transmission and signal processing. Therefore, the proposed system has a great potential to reduce the inconvenience of charging caused by limited battery capacity and to overcome the problem of data disconnection.