• Korean Journal of Fisheries and Aquatic Sciences
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• v.55 no.5
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• pp.514-523
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• 2022

Concentrations of perfluoroalkyl substances (PFASs) were measured in seawater, sediment, and biota collected from Gunsan coast, Korea to investigate their occurrence, distribution, and risk of exposure to humans through seafood consumption. The total concentrations of PFASs in seawater, sediment, and biota ranged from 5.97 to 74.9 ng/L, 0.01 to 13.3 ng/g dry weight, and 0.02 to 5.73 ng/g wet weight, respectively. Predominant PFAS compounds differed across matrices, indicating that the distribution of PFASs in multiple environmental samples is governed by their carbon-chain length. The concentrations of PFASs in seawater were significantly negatively correlated with salinity (P<0.01), suggesting terrestrial input (including land-used PFASs) as the major source of PFAS contamination in coastal environments. The estimated daily intakes (EDIs) of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) through seafood consumption were 0.05 and 0.06 ng/kg body weight/day, respectively. The EDIs of PFOA and PFOS measured in this study were lower those the proposed by the United States Environmental Protection Agency and Canada guidelines, indicating limited health risk for Korean population from PFASs through consumption of seafood from Gunsan coastal environment.

• Korean Chemical Engineering Research
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• v.56 no.4
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• pp.479-495
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• 2018

This study was carried out to research the multimedia fate modeling, concentration distribution and impact assessment of polycyclic aromatic hydrocarbons (PAHs) emitted from automobiles, which are known as carcinogenic and mutation chemicals. The amount of emissions of PAHs was determined based on the census data of automobiles at a target S-city and emission factors of PAHs, where multimedia fugacity modeling was conducted by the restriction of PAHs transfer between air-soil at the impervious area. PAHs' Concentrations and their distributions at several environmental media were predicted by multimedia fugacity model (level III). The residual amounts and the distributions of PAHs through mass transfer of PAHs between environment media were used to assess the health risk of PAHs at unsteady state (level IV), where the sensitivity analyses of the model parameter of each variable were conducted based on Monte Carlo simulation. The experimental result at S-city showed that Fluoranthene among PAHs substances are the highest residual concentrations (60%, 53%, 32% and 34%) at all mediums (atmospheric, water, soil, sediment), respectively, where most of the PAHs were highly accumulated in the sediment media (more than 80%). A result of PAHs concentration changes in S-city over the past 34 years identified that PAHs emissions from all environmental media increased from 1983 to 2005 and decreased until 2016, where the emission of heavy-duty vehicle including truck revealed the largest contribution to the automotive emissions of PAHs at all environment media. The PAHs concentrations in soil and water for the last 34 years showed the less value than the legal standards of PAHs, but the PAHs in air exceeded the air quality standards from 1996 to 2016. The result of this study is expected to contribute the effective management and monitoring of toxic chemicals of PAHs at various environment media of Metropolitan city.

• Journal of Applied Reliability
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• v.9 no.3
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• pp.195-218
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• 2009

Wiper motors are used in every automobile. They are exposed to a very diverse environment and consists of several components and, therefore needs careful approach to the enhancement and assessment of reliability of the item. In this article reliability standards for wiper motors are established in terms of quality certification test and failure rate test.

• Hwankyungkyoyuk
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• v.14 no.2
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• pp.76-94
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• 2001

Promoting positive values, attitudes, participation and personal actions on the basis of the acquisition of one's knowledge and skills is emphasized on teaching environmental education. To complete this purpose of environmental education, it is necessary not only to use various and practical educational resources, but also to develop information system, with multimedia and internet, which are effective for learning. This research attempts to assess the consistency of planning, organization and operation of integrated program for social environmental education which was developed for the necessities mentioned above. We surveyed about the accuracy of contents, usefulness, convenience and easiness of Integrated program for social environmental education. Also, we used a questionnaire to clarify the values and attitudes of respondents after they took environmental education. Then, technically, descriptive statistical method has been used to analyze the results of these surveys. Finally, we conduct an examination of the distribution of chi-square to verify the relationship between the learner's experience of using computer and one's concern about environmental issues. The results of this program, developed by research team, can be assessed by following five basic elements: usefulness, practicality, appropriation, efficiency and effectiveness. More than 90% of respondents said that this program is convenient and easy to loam. Also, more than 85% of whole respondents identified that after teaming this program they recognized more clearly what the main contents of environmental education are. In addition, we got positive response from 93% of respondents that they could understand environmental problems. On the other hand, values and attitudes of respondents have not improved a lot after the environmental education compared with the remarkable change in their recognition and understanding of environmental issues; only 34% of respondents responded that they changed their life style for making better environment after teaming this program. But it is clear that they understand much better about the environmental policy after they are educated. Developed by using information system, this integrated program for social environmental education may get different results according to a respondent's experience of using computer. Therefore, the more a respondent got a chance to use computer for a long period of time, the more he/she gave positive evaluation on the convenience and easiness of this program. However, there was no certain relationship between the frequence of using computer and one's understanding of environmental issues. Futhermore, a person who has constant concerns about environmental problems showed more positive attitudes against the understanding of environmental education. This integrated program for social environmental education, characterized by integrated, specialized and efficient educational system, can also be used as a curriculum or teaching materials for environmental education for adults; especially, it would be appropriate for teaching learners at all levels, who have different personal characteristics, to let them acquire virtual education by using information system.

• Journal of Applied Reliability
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• v.9 no.2
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• pp.131-148
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• 2009

An organic light emitting diode (OLED), also light emitting polymer (LEP) and organic electro luminescence (OEL), is any light emitting diode (LED) whose emissive electroluminescent layer is composed of a film of organic compounds. The layer usually contains a polymer substance that allows suitable organic compounds to be deposited. They are deposited in rows and columns onto a flat carrier by a simple "printing" process. The resulting matrix of pixels can emit light of different colors. Such systems can be used in television screens, computer displays, small, portable system screens such as cell phones and PDAs, advertising, information and indication. OLEDs can also be used in light sources for general space illumination, and large-area light-emitting elements. In this paper, we develop the general guide line of the accelerated life test for assuring B10 life of AMOLED(Active Matrix Organic Light Emitting Diode) and PMOLED(Passive Matrix Organic Light Emitting Diode) which are widely used for display monitor less than 115 mm.

• Journal of the Korean Society for Marine Environment & Energy
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• v.10 no.4
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• pp.201-210
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• 2007

Pollution by chemical substances such as POPs, EDCs and PBTs in the ecosystem has become more complex and varied, increasing the possibility of irreversible damage to human health or the ecosystem. It is necessary to have a exposure assessment in a multi-media environment for various chemical substances is required for efficient management. This study applied MUSEM(Multi-media Simplebox-systems Environmental Model), a multimedia environmental model that can simultaneously evaluate the possibility of exposure of hundreds of chemical substances in order to efficiently manage chemical substances that can have negative impact on human health or ecological environment through environmental contamination. MUSEM executed the modeling for Japan by setting all 47 prefectures of japan as the regional area for 62 chemical substances and the rest of the territory of japan, excluding regional area, as the continental area and made the estimation of concentration among environment media in each administrative area and made the sensitivity analysis on Tokyo area. The results of simulation for chemical distribution showed that most of the target chemicals located in water region. The result of sensitivity analysis for octanol-water partition rate showed that the concentration change of soil in urban/industrial area and sediment in freshwater was high. In the case of sensitivity analysis for degradation rate showed that the concentration change of freshwater, soil in urban/industrial area, and sediment in freshwater was high.

• Journal of IKEEE
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• v.13 no.4
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• pp.116-124
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• 2009

Recently the CPU performance of modem chipsets or multimedia processors of mobile phone is as high as notebook PC. That is why mobile phone has been emerged as a leading ICON on the convergence of consumer electronics. The various applications of mobile phone such as DMB, digital camera, video telephony and internet full browsing are servicing to consumers. To meet all the demands the image quality has been increasingly important. Mobile phone is a portable device which is widely using in both the indoor and outside environments, so it is needed to be overcome to deteriorate image quality depending on environmental light source. Furthermore touch window is popular on the mobile display panel and it makes contrast loss because of low transmittance of ITO film. This paper presents the image enhancement algorithm to be embedded on image enhancement SoC. In contrast enhancement, we propose Clipped histogram stretching method to make it adaptive with the input images, while S-shape curve and gain/offset method for the static application And CIELCh color space is used to sunlight readability enhancement by controlling the lightness and chroma components which is depended on the sensing value of light sensor. Finally the performance of proposed algorithm is evaluated by using histogram, RGB pixel distribution, entropy and dynamic range of resultant images. We expect that the proposed algorithm is suitable for image enhancement of embedded SoC system which is applicable for the small-sized mobile display.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.5 no.5
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• pp.461-470
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• 2015

There has been a significant increase in the amount of research on reducing the lighting power consumption of buildings and also an increasing demand for technological development. Light shelf has been recognized as one of the most efficient solutions to this issue and related researches have been conducted, which have mostly focused on factors related to simple light shelves and are not suitable as an appropriate basis for the design of light shelves. Thus this study aims to establish the proper design basis for light shelves by evaluating the performance of shelves per reflection rate in indoor areas. Power consumption rate and indoor illumination intensity distribution of a testbed built based on actual living conditions were calculated for the performance evaluation, of which the results are as following: 1) Reduction of reflection rate of ceiling and walls caused average illumination intensity in summer, winter and median seasons, and evenness per reflection rate of indoor areas was found to be different in summer, winter and median seasons, making it a necessary consideration for designing light shelves. 2) Calculation of power consumption from lighting control showed that a high reflection rate of indoor areas may be suitable for power consumption reduction, and that reflection rates higher than 80% for ceilings and higher than 75% for walls in terms of the efficiency of researches on the indoor reflection rate and its application would be appropriate. This study is meaningful as the research focuses on light shelves based on considering indoor environmental factors. More studies will be required that consider a variety of factors.

• Korean Journal of Environmental Biology
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• v.39 no.1
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• pp.119-135
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• 2021

Korea has stepped up efforts to investigate and catalog its flora and fauna to conserve the biodiversity of the Korean Peninsula and secure biological resources since the ratification of the Convention on Biological Diversity (CBD) in 1992 and the Nagoya Protocol on Access to Genetic Resources and the Fair and Equitable Sharing of Benefits (ABS) in 2010. Thus, after its establishment in 2007, the National Institute of Biological Resources (NIBR) of the Ministry of Environment of Korea initiated a project called the Korean Indigenous Species Investigation Project to investigate indigenous species on the Korean Peninsula. For 15 years since its beginning in 2006, this project has been carried out in five phases, Phase 1 from 2006-2008, Phase 2 from 2009-2011, Phase 3 from 2012-2014, Phase 4 from 2015-2017, and Phase 5 from 2018-2020. Before this project, in 2006, the number of indigenous species surveyed was 29,916. The figure was cumulatively aggregated at the end of each phase as 33,253 species for Phase 1 (2008), 38,011 species for Phase 2 (2011), 42,756 species for Phase 3 (2014), 49,027 species for Phase 4 (2017), and 54,428 species for Phase 5(2020). The number of indigenous species surveyed grew rapidly, showing an approximately 1.8-fold increase as the project progressed. These statistics showed an annual average of 2,320 newly recorded species during the project period. Among the recorded species, a total of 5,242 new species were reported in scientific publications, a great scientific achievement. During this project period, newly recorded species on the Korean Peninsula were identified using the recent taxonomic classifications as follows: 4,440 insect species (including 988 new species), 4,333 invertebrate species except for insects (including 1,492 new species), 98 vertebrate species (fish) (including nine new species), 309 plant species (including 176 vascular plant species, 133 bryophyte species, and 39 new species), 1,916 algae species (including 178 new species), 1,716 fungi and lichen species(including 309 new species), and 4,812 prokaryotic species (including 2,226 new species). The number of collected biological specimens in each phase was aggregated as follows: 247,226 for Phase 1 (2008), 207,827 for Phase 2 (2011), 287,133 for Phase 3 (2014), 244,920 for Phase 4(2017), and 144,333 for Phase 5(2020). A total of 1,131,439 specimens were obtained with an annual average of 75,429. More specifically, 281,054 insect specimens, 194,667 invertebrate specimens (except for insects), 40,100 fish specimens, 378,251 plant specimens, 140,490 algae specimens, 61,695 fungi specimens, and 35,182 prokaryotic specimens were collected. The cumulative number of researchers, which were nearly all professional taxonomists and graduate students majoring in taxonomy across the country, involved in this project was around 5,000, with an annual average of 395. The number of researchers/assistant researchers or mainly graduate students participating in Phase 1 was 597/268; 522/191 in Phase 2; 939/292 in Phase 3; 575/852 in Phase 4; and 601/1,097 in Phase 5. During this project period, 3,488 papers were published in major scientific journals. Of these, 2,320 papers were published in domestic journals and 1,168 papers were published in Science Citation Index(SCI) journals. During the project period, a total of 83.3 billion won (annual average of 5.5 billion won) or approximately US $75 million (annual average of US $5 million) was invested in investigating indigenous species and collecting specimens. This project was a large-scale research study led by the Korean government. It is considered to be a successful example of Korea's compressed development as it attracted almost all of the taxonomists in Korea and made remarkable achievements with a massive budget in a short time. The results from this project led to the National List of Species of Korea, where all species were organized by taxonomic classification. Information regarding the National List of Species of Korea is available to experts, students, and the general public (https://species.nibr.go.kr/index.do). The information, including descriptions, DNA sequences, habitats, distributions, ecological aspects, images, and multimedia, has been digitized, making contributions to scientific advancement in research fields such as phylogenetics and evolution. The species information also serves as a basis for projects aimed at species distribution and biological monitoring such as climate-sensitive biological indicator species. Moreover, the species information helps bio-industries search for useful biological resources. The most meaningful achievement of this project can be in providing support for nurturing young taxonomists like graduate students. This project has continued for the past 15 years and is still ongoing. Efforts to address issues, including species misidentification and invalid synonyms, still have to be made to enhance taxonomic research. Research needs to be conducted to investigate another 50,000 species out of the estimated 100,000 indigenous species on the Korean Peninsula.