• Journal of the Korean Wood Science and Technology
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• v.32 no.4
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• pp.27-35
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• 2004

Recalcitrant 4-t-Octylphenol used as a surfactant was subjected to the biodegradation with wood rot fungi, Basidioradulum molare and Schizopora paradoxa. Two fungi were grown in the culture medium containing various concentrations of 4-t-Octylphenol in order to investigate their resistance against 4-t-octylphenol Schizopora paradoxa was reached to the full growth within 14 incubation days in the concentration of more than 200 ppm of 4-t-Octylphenol, while Basidioradulum molare showed the inhibitory mycelium growth as the concentration was increased Schizopora paradoxa and Basidioradulum molare biodegraded 95% and 36% of initial concentration of 4-t-Octylphenol at first incubation day, respectively. However, the biodegradation capability reached to more than 95% after 3 incubation days. During the biodegradation of 4-t-Octylphenol, the activity of manganese dependent peroxidase was induced by the addition of 4-t-Octylphenol in the culture medium of Schizopora paradoxa, but that of laccase was maximal before the addition. The reduction of estrogenecity was assayed by MCF-7 cell proliferation test and measurement of pS2 mRNA expression. The level of pS2 mRNA was decreased down to the level of baseline at first incubation day. Also, estrogenecity of 4-t-Ocrylphenol completely disappeared after treatment with supernatant by Schizopora paradoxa and Basidioradulum molare from first incubation day of culture down to the levels of vehicle.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.40 no.5
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• pp.403-412
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• 2022

As the 4th industrial revolution is in full swing and next-generation ICT(Information & Communications Technology) convergence technology is being developed, various smart construction technologies are being rapidly introduced in the construction field to respond to technological changes. In particular, since the earth-volume calculation process for site design accounts for a large part of the design cost at the construction site, related researches are being actively conducted to improve the efficiency of the process and accurately calculate the earth-volume. The purpose of this study is to present a method for quickly constructing the topography of a construction site in 3D and efficiently calculating earth-volume using the results. For this purpose, the construction site was constructed as a 3D realistic model using large-scale aerial photos obtained from UAV(Unmanned Aerial Vehicle). At this time, since the constructed 3D realistic model has a surface model structure in which volume calculation is impossible, the structure was converted into a 3D solid model to enable volume calculation. And we devised a methodology to calculate earth-volume based on CAD(Computer-Aided Design and Drafting) using the converted solid model. Automatically calculating earth-volume from the solid model by applying the method. As a result, It was possible to confirm a relative deviation of 1.52% from the calculated earth-volume from the existing survey results. In addition, as a result of comparative analysis of the process time required for each method, it was confirmed that the time required is reduced of 60%. The technique presented in this study is expected to be utilized as a technology for smart construction management, such as periodic site monitoring throughout the entire construction process, as well as cost reduction for earth-volume calculation.

• Journal of the Korean Electrochemical Society
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• v.25 no.4
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• pp.184-190
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• 2022

Spinel LiMn₂O₄ (LMO) and layered LiNi_0.5Co_0.2Mn_0.3O₂ (NCM) are widely used as positive electrode materials for lithium-ion batteries. LMO and NCM positive electrode materials have a complementary properties. LMO has low cost and high safety and NCM materials show a relatively high specific capacity and better cycle life even at elevated temperature. Therefore, the LMO and NCM active materials are blended and used as a positive electrode in large-size batteries for electric vehicles (xEV). In this study, the cycle performance of a blended electrode prepared by simply mixing LMO and NCM and a bi-layer electrode in which two electrode layers aree sequentially coated are compared. The bi-layer electrode prepared by composing the same ratio of both active materials has similar capacity and cycle performance to the blend electrode. However, the LN electrode coated with LMO first and then NCM is the best in the full cell cycle performance at elevated temperature, and the NL electrode, in which NCM is first coated with LMO has a faster capacity degradation than the blended electrode because LMO is mainly located on the top of the electrode adjacent to electrolyte and graphite negative electrode. Also, the LSTA (linear sweep thermmametry) analysis results show that the LN bi-layer electrode in which the LMO is located inside the electrode has good thermal stability.

• Journal of the Korean Electrochemical Society
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• v.25 no.3
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• pp.95-104
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• 2022

The development of non-flammable all-solid-state batteries (ASSLBs) has become a hot topic due to the known drawbacks of commercial lithium-ion batteries. As the possibility of applying sulfide solid electrolytes (SSEs) for electric vehicle batteries increases, efforts for the low-cost mass-production are actively underway. Until now, most studies have used high-energy mechanical milling, which is easy to control composition and impurities and can reduce the process time. Through this, various SSEs that exceed the Li⁺ conductivity of liquid electrolytes have been reported, and expectations for the realization of ASSLBs are growing. However, the high-energy mechanical milling method has disadvantages in obtaining the same physical properties when mass-produced, and in controlling the particle size or shape, so that physical properties deteriorate during the full process. On the other hand, wet chemical synthesis technology, which has advantages in mass production and low price, is still in the initial exploration stage. In this technology, SSEs are mainly manufactured through producing a particle-type, solution-type, or mixed-type precursor, but a clear understanding of the reaction mechanism hasn't been made yet. In this review, wet chemical synthesis technologies for SSEs are summarized regarding the reaction mechanism between the raw materials in the solvent.

• Journal of Space Technology and Applications
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• v.2 no.3
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• pp.195-205
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• 2022

Space exploration is an area where international cooperation takes place more actively than any other space activities such as Earth observation, communication and navigation. This is because a country cannot afford a huge budget to have full infrastructure for deep space exploration, such as a heavy launch vehicle, communication and energy infrastructure, and human habitats, and has learned that it is not sustainable. Korea expressed its willingness to join humanity's epic exploration journey by signing the Artemis Accords in 2021 and launching Danuri lunar orbiter in 2022. The beginning of space exploration means that Korea's space activities have expanded beyond the stage of focusing only on technology development to set norms necessary to accompany other countries and cooperate diplomatically to solve exposed problems. This paper analyzed European space policy and space exploration, which are most actively participating in the Artemis Program and exerting diplomatic power in the space field, from the perspective of science and technology diplomacy. The suggestions for Korea's space exploration strategy from the perspective of science and technology diplomacy were drawn by examining the international cooperation strategies in Europe's space activities ranging from space policy, space strategy, and space exploration program to project units.

• Journal of Powder Materials
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• v.30 no.4
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• pp.324-331
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• 2023

Lithium (Li) is a key resource driving the rapid growth of the electric vehicle industry globally, with demand and prices continually on the rise. To address the limited reserves of major lithium sources such as rock and brine, research is underway on seawater Li extraction using electrodialysis and Li-ion selective membranes. Lithium lanthanum titanate (LLTO), an oxide solid electrolyte for all-solid-state batteries, is a promising Li-ion selective membrane. An important factor in enhancing its performance is employing the powder synthesis process. In this study, the LLTO powder is prepared using two synthesis methods: sol-gel reaction (SGR) and solid-state reaction (SSR). Additionally, the powder size and uniformity are compared, which are indices related to membrane performance. X-ray diffraction and scanning electron microscopy are employed for determining characterization, with crystallite size analysis through the full width at half maximum parameter for the powders prepared using the two synthetic methods. The findings reveal that the powder SGR-synthesized powder exhibits smaller and more uniform characteristics (0.68 times smaller crystal size) than its SSR counterpart. This discovery lays the groundwork for optimizing the powder manufacturing process of LLTO membranes, making them more suitable for various applications, including manufacturing high-performance membranes or mass production of membranes.

• Journal of Advanced Information Technology and Convergence
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• v.9 no.1
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• pp.115-125
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• 2019

In this paper, the image is received from the camera and the lane is sensed. There are various ways to detect lanes. Generally, the method of detecting edges uses a lot of the Sobel edge detection and the Canny edge detection. The minimum use of multiplication and division is used when designing for the hardware configuration. The images are tested using a black box image mounted on the vehicle. Because the top of the image of the used the black box is mostly background, the calculation process is excluded. Also, to speed up, YCbCr is calculated from the image and only the data for the desired color, white and yellow lane, is obtained to detect the lane. The median filter is used to remove noise from images. Intermediate filters excel at noise rejection, but they generally take a long time to compare all values. In this paper, by using addition, the time can be shortened by obtaining and using the result value of the median filter. In case of the Sobel edge detection, the speed is faster and noise sensitive compared to the Canny edge detection. These shortcomings are constructed using complementary algorithms. It also organizes and processes data into parallel processing pipelines. To reduce the size of memory, the system does not use memory to store all data at each step, but stores it using four line buffers. Three line buffers perform mask operations, and one line buffer stores new data at the same time as the operation. Through this work, memory can use six times faster the processing speed and about 33% greater quantity than other methods presented in this paper. The target operating frequency is designed so that the system operates at 50MHz. It is possible to use 2157fps for the images of 640by360 size based on the target operating frequency, 540fps for the HD images and 240fps for the Full HD images, which can be used for most images with 30fps as well as 60fps for the images with 60fps. The maximum operating frequency can be used for larger amounts of the frame processing.

• Development and Reproduction
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• v.10 no.2
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• pp.97-103
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• 2006

Vitellogenin(Vg) is a sex specific serum protein present in sexually maturing female blood of oviparous vertebrates. Estrogen($E_2$) is a main inducer of hepatic Vg synthesis. We investigated the effects of androgen and growth hormone(GH) on regulation of Vg and estrogen receptor(ER) genes in Japanese eel. Immature eels($200{\sim}250\;g$) were given a single injection of $E_2(5{\sim}5,000\;{\mu}g/kg\;bw)$ alone, or in combination with eel recombinant GH(eGH, $1{\sim}10\;{\mu}g/kg$) or methyltestosterone(MT, $1{\sim}5\;mg/kg$) and sacrificed 10 days after the hormone treatments. Expression levels of ER and Vg genes from the liver were determined by means of reverse transcription and polymerase chain reaction(RT-PCR). Administration of $E_2$ stimulated Vg gene expression in a dose dependent manner. Levels of Vg mRNA after the injection of $E_2(500\;{\mu}g/kg)$ with MT(5mg/kg) or eGH($10\;{\mu}g/kg$) were much higher than in that of $E_2$ alone($500\;{\mu}g/kg$). Whereas, injection of either vehicle, eGH ($10\;{\mu}g/kg$) or MT(5mg/kg) alone did not induce the expression of Vg gene in the liver. ER mRNA was detected from the fish treated with vehicle alone. $E_2$ injection($5{\sim}500\;{\mu}g/kg\;bw$) increased this ER expression but dose dependent response was not clear. Addition of MT(5mg/kg) or eGH($10\;{\mu}g/kg$) did not affect $E_2-stimulated$ ER mRNA expression. This study confirms the necessity of $E_2$ as the primary factor for Vg gene expression and requirement of additional hormones such as MT or GH for the full expression of Vg mRNA, and suggests that the additive effect of MT or GH on Vg gene expression would be mediated by some unknown factors other than ER.

• KDI Journal of Economic Policy
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• v.13 no.1
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• pp.115-134
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• 1991

The role of pension plans in the macroeconomy has been a subject of much interest for some years. It has come to be recognized that pension plans may alter basic macroeconomic behavior patterns. The net effects on both savings and labor supply are thus matters for speculation. The aim of the present paper is to provide quantitative results which may be helpful in attaching orders of magnitude to some of the possible effects. We are not concerned with the providing empirical evidence relating to actual behavior, but rather with deriving the macroeconomic implications for a alternative possibilities. The pension plan interacts with the economy and the population in a number of ways. Demographic variables may thus affect both the economic burden of a national pension plan and the ability of the economy to sustain the burden. The tax transfer process associated with the pension plan may have implications for national patterns of saving and consumption. The existence of a pension plan may have implications also for the size of the labor force, inasmuch as labor force participation rates may be affected. Changes in technology and the associated changes in average productivity levels bear directly on the size of the national income, and hence on the pension contribution base. The vehicle for the analysis is a hypothetical but broadly realistic simulation model of an economic- demographic system into which is inserted a national pension plan. All income, expenditure, and related aggregates are in real terms. The economy is basically neoclassical; full employment is assumed, output is generated by a Cobb-Douglas production process, and factors receive their marginal products. The model was designed for use in computer simulation experiments. The simulation results suggest a number of general conclusions. These may be summarized as follows; - The introduction of a national pension plan (funded system) tends to increase the rate of economic growth until cost exceeds revenue. - A scheme with full wage indexing is more expensive than one in which pensions are merely price indexed. - The rate of technical progress is not a critical element in determining the economic burden of the pension scheme. - Raising the rate of benefits affects its economic burden, and raising the age of eligibility may decrease the burden substantially. - The level of fertility is an element in determining the long-run burden. A sustained low fertility rate increases the proportion of the aged in total population and increases the burden of the pension plan. High fertility has inverse effects.

• Journal of the Korean Institute of Landscape Architecture
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• v.40 no.5
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• pp.73-87
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• 2012

Nowadays, the Korean society is full of multiculturalism as there are many foreign ethnic enclaves. Many Chinese quarters are built in various parts of Korea along with the increasing population of Chinese immigrant. Especially, the Chinese quarter has shown the sign of time and the cultural characteristic of the local residents. This research is to study the market space of Chinese ethnic enclaves in Dairimdong. This research method is the field study to use a participant observation. Below are the research results: Chinese merchants put a private object such as "tanzi" on a sidewalk and install large awning covered full of sidewalk. Sidewalk transform from an outdoor space into an internal space because of Chinese merchants. Passers-by move to use vehicle roads and transform not only the car's space but also the passers-by space. Urban planners originally classify space into three categories, which are building - sidewalk - vehicles road. However, after Chinese came to the market, Chinese classified space into new three categories which is building - space for both sidewalk and "tanzi" - space for both sidewalk and vehicles road. New classification of space is quite different from the previous. In addition, Chinese thinks that the Dairimdong's Market is a very comfortable place. Because Dairimdong Market have many Chinese physical facilities. Next, Chinese thinks that the Dairimdong Market is a very friendly place to buy Chinese products easily. This market has become a place of consumption for the Chinese. Eventually, Dairimdong's Market has changed because of Chinese immigrants. It is possible to make satisfactory planning and design proposal to build Chinese quarters in the future through the explanation of space and status by way of culture. There are many careless mistakes in previous subjective planning and design proposal of the designers. Thus, it should consider the problems created by their way of use in later planning and design.