• 한국대기환경학회지
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• 제24권1호
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• pp.55-62
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• 2008

This study is aimed at substantially reducing the particulate matter (dust) emission during the combustion of heavy fuel in boilers by addition of combustion improver. The combustion improver used were the oil-soluble organometallic compounds that were found to be more effective than the dispersing agents that are generally used for reducing the particulate emission. The dust reduction effect was found to depend on the active materials (metals) as well as on the organic ligand part of organometallic compounds. Acetylacetonoate and naphthenate of Fe and Ca were found to be most effective for dust reduction. Addition of Fe and Ca organometallic compounds as combustion improver in concentration of 30 ppm (metal basis) to heavy fuel oil, caused dust reduction by 50 wt% to 80 wt%.

• 동의생리병리학회지
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• 제20권5호
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• pp.1303-1310
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• 2006

In oriental medicine, Samul-tang (SMT) has been used for the treatment of cardiovascular diseases and neuronal disorders. Here, possible effects of SMT on axonal regeneration after the spinal cord injury were examined. SMT treatment induced increases in regeneration-related proteins GAP-43, cell division cycle 2 (Cdc2) and phospho-Erk1/2 in the peripheral sciatic nerves after crush injury. Increased levels of Cdc2 and phospho-Erk1/2 were observe mostly in the gray matter area and some in the dorsomedial white matter. These increases correlated with increased cell numbers in affected areas. Moreover, axons of corticospinal tract (CST) showed increased sprouting in the injured spinal cord when administrated with SMT compared with saline-treated control. Thus, the present data indicate that SMT may be useful for identifying active components and for therapeutic application toward the treatment of spinal cord disorders after injury.

• 한국식품과학회지
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• 제26권6호
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• pp.655-658
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• 1994

가열 산화된 유지들의 품질평가를 위한 방법의 하나로 분광기를 이용한 산화생성물외 측정과 여러가지 이화학적 향수들을 분석하였다. 산값은 가열시간의 경과에 따라 증가하는 경향이었으며, 특히 가열산화의 경우 대두유가 팜유 및 팜을레인유 보다 상승이 뚜렷하였다. 아니시딘값 및 공액중지방산값은 가열시간의 경과에 따라 중가하는 경향이었으며 팜유 및 팜을레인유보다 대두유에서 크게 상승하는 경향이었다. AOM 안정성의 변화는 팜유, 팜을레인유, 대두유외 순으로 좋게 나타났다. 또한, 가열산화유지의 산과정도를 POM과 SOM으로 측정할 수있었고, 일차 및 이차산화생성물은 가열산화시간에 따라 전반적으로 빠르게 중가하는 경향을 나타내었다. 본 연구의 결과로서 간단한 분광기를 이용하여 가열유지중의 POM과 SOM을 신속하게 측정할 수 있었고, 산업적으로 가열유지의 품질을 평가하는 방법의 하나로 사용가능할 것으로 본다.

• Ocean and Polar Research
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• 제40권4호
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• pp.281-288
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• 2018

The transmission of solar light according to the distribution of chromophoric dissolved organic matter (CDOM) was measured in the Pacific Arctic Ocean. The Research Vessel Araon visited the ice-covered East Siberian and Chukchi Seas in August 2016. In the Arctic, solar [ultraviolet-A (UV-A), ultraviolet-B (UV-B), and photosynthetically active radiation (PAR)] radiation reaching the surface of the ocean is primarily protected by the distribution of sea ice. The transmission of solar light in the ocean is controlled by sea ice and dissolved organic matter, such as CDOM. The concentration of CDOM is the major factor controlling the penetration depth of UV radiation into the ocean. The relative CDOM concentration of surface sea water was higher in the East Siberian Sea than in the Chukchi Sea. Due to the distribution of CDOM, the penetration depth of solar light in the East Siberian Sea (UV-B, $9{\pm}2m$; UV-A, $13{\pm}2m$; PAR, $36{\pm}4m$) was lower than in the Chukchi Sea (UV-B, $15{\pm}3m$; UV-A, $22{\pm}3m$; PAR, $49{\pm}3m$). Accelerated global warming and the rapid decrease of sea ice in the Arctic have resulted in marine organisms being exposed to increased harmful UV radiation. With changes in sea ice covered areas and concentrations of dissolved organic matter in the Arctic Ocean, marine ecosystems that consist of a variety of species from primary producers to high-trophic-level organisms will be directly or indirectly affected by solar UV radiation.

• 지역연구
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• 제37권1호
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• pp.29-44
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• 2021

미세먼지는 인간의 수명을 단축시키고 각종 암을 유발하는 대기오염 물질이다. 따라서 도시민은 미세먼지 농도에 따라 도시활동을 조정할 수 있다. 미세먼지가 도시민의 활동에 미치는 영향은 미세먼지의 지속 기간, 미세먼지 경보 여부에 따라 달라질 수 있다. 또한 도시활동의 유형과 장소, 도시민의 미세먼지 취약 정도에 따라 회피행동의 수준이 다르게 나타날 수 있다. 이처럼 다양한 요인들에 따라 도시민의 미세먼지 대응 방식이 다르게 나타날 수 있음에도, 이에 관한 연구적 증거는 매우 미흡한 상황이다. 따라서 본 연구에서는 서울시 도심 중 하나인 종로구를 대상으로 미세먼지가 도시민의 활동에 미치는 영향을 분석하였다. 이를 위해 SKT의 휴대전화신호 자료와 토지이용 자료를 연계하여 도시활동 유형·연령별 일 단위 활동인구 수를 추출하고, 미세먼지 농도, 미세먼지 지속일 수, 미세먼지 경보 여부의 영향을 분석하였다. 분석 결과, 미세먼지에 대한 회피행동이 도시활동의 유형, 활동장소의 물리적 특성(실내·야외), 미세먼지 지속 기간, 미세먼지 경보 여부, 도시민의 연령에 따라 다른 것으로 나타났다. 본 연구의 결과는 미세먼지가 도시민의 활동에 미치는 영향을 다각적으로 제공하여, 공공의 미세먼지 저감 및 적응 정책 수립을 위한 기초자료로 활용될 수 있다.

• Asian Pacific Journal of Cancer Prevention
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• 제14권6호
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• pp.3411-3417
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• 2013

Over the last 10 years, the number of cancer survivors in South Korea has reached nearly one million with a survival rate of 49.4%. However, integrated supportive care for cancer survivors is lagging. One area in which the current cancer control policy needs updating is in the utilization of information and communication technology (ICT). The remarkable progress in the field of ICT over the past 10 years presents exciting new opportunities for health promotion. Recent communication innovations are conducive to the exchange of meta-information, giving rise to a new service area and transforming patients into active medical consumers. Consequently, such innovations encourage active participation in the mutual utilization and sharing of high-quality information. However, these benefits from new ICTs will almost certainly not be equally available to all, leading to so-called communication inequalities where cancer survivors from lower socioeconomic classes will likely have more limited access to the best means of making use of the health information. Therefore, most essentially, emphasis must be placed on helping cancer survivors and their caregivers utilize such advances in ICT to create a more efficient flow of health information, thereby reducing communication inequalities and expanding social support. Once we enhance access to health information and better manage the quality of information, as a matter of fact, we can expect an alleviation of the health inequalities faced by cancer survivors.

• International journal of advanced smart convergence
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• 제9권1호
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• pp.70-81
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• 2020

Plastics that we use and simply throw away have a life span of about 500 years and barely decompose. The practice of producing and using common plastics needs to be challenged. Until now, they have been useful in the industrial structure of mass production, but it can be said that there is a lack of research into new materials to introduce and apply in terms of material recycling. As a result of this, we have come to the uncomfortable realization of the fact that we cannot incinerate or reuse these precious resources indiscriminately. No matter how well-designed a product is, it has a competitive advantage if production and consumption activities, waste, collection, sorting and treatment are considered in terms of a continuous cycle, and in this respect, Extended Producer Responsibility (EPR) can help. We are implementing the EPR system, and active industrialization in the field of recycling is required, which is also a challenge for producers to participate actively in recycling and seek to save and recycle resources in design and manufacturing. Against this backdrop, We would like to examine the possibilities, through various studies and developments on product design of recyclable materials, which is being conducted mainly in Europe. In particular, we would like to examine the methods, and value of solving environmental problems and the active efforts to achieve this in the design world, and in particular the case of product design using recycled plastics.

• Journal of Electrical Engineering and Technology
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• 제6권3호
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• pp.293-301
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• 2011

This paper presents a novel theoretical method based on power analysis to obtain voltage reference values for an inverter-based compensator. This type of compensator, which is installed in parallel with the load, is usually referred to as the active filter. The proposed method is tailored to design the compensator in such a way that it can simultaneously balance the asymmetric load, as well as correct the power factor of the supply side. For clarity, a static compensator is first considered and a recursive algorithm is utilized to calculate the reactance values. The algorithm is then extended to calculate voltage reference values when the compensator is inverter based. It is evident that the compensator would be asymmetric since the load is unbalanced. The salient feature associated with the proposed method is that the circuit representation of system load is not required and that the load is recognized just by its active and reactive consumptions. Hence, the type and connection of load do not matter. The validity and performance of the new approach are analyzed via a numerical example, and the obtained results are thoroughly discussed.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2005년도 국제학술회의
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• pp.100-113
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• 2005

Leaf color and plant vigor are key indicators of crop health. These visual plant attributes are frequently used by greenhouse managers, producers, and consultants to make water, nutrient, and disease management decisions. Remote sensing techniques can quickly quantify soil and plant attributes, but it requires humans to translate such data into meaningful information. Over time, scientists have used reflectance data from individual wavebands to develop a series of indices that attempt to quantify things like soil organic matter content, leaf chlorophyll concentration, leaf area index, vegetative cover, amount of living biomass, and grain yield. The recent introduction of active sensors that function independent of natural light has greatly expanded the capabilities of scientists and managers to obtain useful information. Characteristics and limitations of active sensors need to be understood to optimize their use for making improved management decisions. Pot experiments involving sand culture were conducted in 2003 and 2004 in a green house to evaluate corn and red pepper biomass. The rNDVI, gNDVI and aNDVI by ground-based remote sensors were used for evaluation of corn and red pepper biomass. The result obtained from the case study was shown that ground remote sensing as a non-destructive real-time assessment of plant nitrogen status was thought to be a useful tool for in season crop nitrogen management providing both spatial and temporal information.

• 천문학회지
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• 제14권2호
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• pp.55-71
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• 1981

On the basis of observational constraints, particularly the relationship between metal abundance and cumulative stellar mass, a simple two-zone disk-halo model for the chemical evolution of our Galaxy was investigated, assuming different chemical processes in the disk and halo and the infall rates of the halo gas defined by the halo evolution. The main results of the present model calculations are: (i) The halo formation requires more than 80% of the initial galactic mass and it takes a period of $2{\sim}3{\times}10^9$ yrs. (ii) The halo evolution is divided into two phases, a fast collapse phase ($t=2{\sim}3{\times}10^8$ yrs) during which period most of the halo stars $({\sim}95%)$ are formed and a later slow collapse phase which is characterized by the chemical enrichment due to the inflow of external matter to the halo. (iii) The disk evolution is also divided into two phases, an active disk formation phase with a time-dependent initial mass function (IMF) up to $t{\approx}6{\times}10^9$ yrs and a later steady slow formation phase with a constant IMF. It is found that at the very early time $t{\approx}5{\times}10^8$ yrs, the metal abundance in the disk is rapidly increased to ${\sim}1/3$ of the present value but the total stellar mass only to ${\sim}10%$ of the present value, finally reaching about 80% of the present values toward the end of the active formation phase.