• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.36 no.6
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• pp.588-593
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• 2023

The advantage of OTFT technology is that large-area circuits can be manufactured on flexible substrates using a low-cost solution process such as inkjet printing. Compared to silicon-based inorganic semiconductor processes, the process temperature is lower and the process time is shorter, so it can be widely applied to fields that do not require high electron mobility. Materials that have utility as electrode materials include carbon that can be solution-processed, transparent carbon thin films, and metallic nanoparticles, etc. are being studied. Recently, a technology has been developed to facilitate charge injection by coating the surface of the Al electrode with solution-processable titanium oxide (TiOx), which can greatly improve the performance of OTFT. In order to commercialize OTFT technology, an appropriate method is to use a complementary circuit with excellent reliability and stability. For this, insulators and channel semiconductors using organic materials must have stability in the air. In this study, carbon-doped Mo (MoC) thin films were fabricated with different graphite target power densities via unbalanced magnetron sputtering (UBM). The influence of graphite target power density on the structural, surface area, physical, and electrical properties of MoC films was investigated. MoC thin films deposited by the unbalanced magnetron sputtering method exhibited a smooth and uniform surface. However, as the graphite target power density increased, the rms surface roughness of the MoC film increased, and the hardness and elastic modulus of the MoC thin film increased. Additionally, as the graphite target power density increased, the resistivity value of the MoC film increased. In the performance of an organic thin film transistor using a MoC gate electrode, the carrier mobility, threshold voltage, and drain current on/off ratio (I_on/I_off) showed 0.15 cm²/V·s, -5.6 V, and 7.5×10⁴, respectively.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.34 no.4
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• pp.192-203
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• 2023

Digital therapeutics based on software, such as artificial intelligence, virtual reality, games, and smartphone applications, are in the spotlight as new therapeutic alternatives in child and adolescent psychiatry. It draws attention to overcoming conventional therapeutics' limitations, such as toxicity, cost, and accessibility, and encourages patients to participate in the treatment attractively. The growth potential of the digital therapeutics market for psychiatric disorders in children and adolescents in Korea and abroad has been highlighted. Clinical studies and Food and Drug Administration approvals for digital therapeutics have increased, and cases approved by the Ministry of Food and Drug Safety have emerged in Korea. As seen above, digital transformation in child and adolescent psychiatry will change treatment paradigms significantly. Therefore, as this new field has just begun to emerge, it is necessary to verify the effectiveness and scope of the application of digital therapeutics and consider preparing a compensation system and institutional arrangements. Accordingly, this study analyzed the development trends and application status of digital therapeutics in children and adolescents and presented limitations and development directions from the perspective of application in healthcare. Further, the study is expected to identify the utility and limitations of digital therapeutics for children and adolescents and establish effective application measures.

• Korean Journal of Remote Sensing
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• v.40 no.3
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• pp.257-268
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• 2024

Drone-mounted hyperspectral sensors (DHSs) have revolutionized remote sensing in agriculture by offering a cost-effective and flexible platform for high-resolution spectral data acquisition. Their ability to capture data at low altitudes minimizes atmospheric interference, enhancing their utility in agricultural monitoring and management. This study focused on addressing the challenges of radiometric and geometric distortions in preprocessing drone-acquired hyperspectral data. Radiometric correction, using the empirical line method (ELM) and spectral reference panels, effectively removed sensor noise and variations in solar irradiance, resulting in accurate surface reflectance values. Notably, the ELM correction improved reflectance for measured reference panels by 5-55%, resulting in a more uniform spectral profile across wavelengths, further validated by high correlations (0.97-0.99), despite minor deviations observed at specific wavelengths for some reflectors. Geometric correction, utilizing a rubber sheet transformation with ground control points, successfully rectified distortions caused by sensor orientation and flight path variations, ensuring accurate spatial representation within the image. The effectiveness of geometric correction was assessed using root mean square error(RMSE) analysis, revealing minimal errors in both east-west(0.00 to 0.081 m) and north-south directions(0.00 to 0.076 m).The overall position RMSE of 0.031 meters across 100 points demonstrates high geometric accuracy, exceeding industry standards. Additionally, image mosaicking was performed to create a comprehensive representation of the study area. These results demonstrate the effectiveness of the applied preprocessing techniques and highlight the potential of DHSs for precise crop health monitoring and management in smart agriculture. However, further research is needed to address challenges related to data dimensionality, sensor calibration, and reference data availability, as well as exploring alternative correction methods and evaluating their performance in diverse environmental conditions to enhance the robustness and applicability of hyperspectral data processing in agriculture.

• Journal of the Korean Society of Safety
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• v.39 no.1
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• pp.41-54
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• 2024

Efforts to reduce on-site safety incidents have expanded, leading to active research in this domain. However, a systematic analysis to improve the utility of technology is lacking. In this study, we conducted a survey on the various institutional and technical improvement measures to promote the application of smart construction safety technology over three years after the implementation of the "Smart Safety Equipment Support Project." The results showed that financial constraint was the primary obstacle in the adoption of this innovation. Fostering a flexible environment in the utilization of management fees and financial support of projects was determined to aid in the extensive application of the technology. Ensuring cost efficiency and user-friendliness were principally necessary for technical enhancements in the smart construction safety technology. Technologies, such as VR/AR safety education, real-time location tracking, wearable devices, and innovation on streamlining safety-related work efficiency, had been anticipated to contribute to on-site safety. Operating a smart safety control center was expected to be beneficial in the systematic securing of data and reduction of safety blind spots. Effective methods had been suggested to overcome the barriers that hindered the development and application of smart construction safety technology. This study facilitates in the technological improvements in this field.

• Korean Journal of Environment and Ecology
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• v.30 no.2
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• pp.253-260
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• 2016

This research aimed to quantitatively measure the environmental values of Taebaeksan, Naksan, and Gyeongpo provincial parks located in Gangwon-do. The research was based on the CVM technique which estimates the economic values for all kinds of ecosystem. Also, the estimated value of environment goods can suggest the magnitude of additional utility other than the cost people pay when they visit the provincial parks. Such result can be used as basic data in addition to information on natural ecology or cultural landscape to decide whether the park should be promoted as a national park. The questionnaires-collected from Taebaeksan(180 copies), Naksan(179 copies), and Gyeongpo(180 copies) provincial parks were used to measure the environmental value of each provincial park. Variables that affect the response of 'yes(Y)' or 'no(N)' to the cost suggestion for the economic valuation of environment are estimated under the catagories of environment conservation status (env.), degree of park management (manage.), environmental conservation effort, education (edu.), and income (inc.) of the respondents (execu.), pertaining to the 3 provincial parks in Gangwon-do. The value of natural environment to 1 visitor to the 3 Gangwon provincial parks was estimated by the Logit method that Hanemann proposed using the average of inserted variables. The results showed that the additional environmental value that 1 visitor can gain is 44,060 won for Taebaeksan Provincial Park, 41,191 won for Naksan, and 41,844 won for the Gyeongpo Provincial Park. Taebaeksan Provincial Park's environmental value is estimated at the highest as the respondents judge that its natural environment is well preserved and the facilities are managed well.

• Korea journal of population studies
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• v.28 no.2
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• pp.1-32
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• 2005

The optimum population of a society or country can be defined as 'the population growth path that maximizes the welfare level of the society over the whole generations of both the present and the future, under the paths allowed by its endowments of production factors such as technology, capital and labor'. Thus, the optimum size or growth rate of population depends on: (i) the social welfare function, (ii) the production function, and (iii)demographic economic interrelationship which defines how the national income is disposed into consumption(birth and education of children included) and savings on the one hand and how the demographic and economic change induced thereby, in turn, affect production capacities on the other. The optimum population growth path can, then, be derived in the process of dynamic optimization of (i) under the constraints of (ii) and (iii), which will give us the optimum population growth rate defined as a function of parameters thereof. This paper estimates the optimum population growth rate of Korea by: specifying (i), (ii), and (iii) based on the recent development of economic theories, solving the dynamic optimization problem and inserting empirical estimates in Korea as the parametric values. The result shows that the optimum path of population growth in Korea is around TFR=1.81, which is affected most sensitively, in terms of the size of the partial elasticity around the optimum path, by the cost of children, share of capital income, consumption rate, time preference, population elasticity of utility function, etc. According to a survey implemented as a follow up study, there are quite a significant variations in the perceived cost of children, time preference rate, population elasticity of utility across different socio-economic classes in Korea, which implied that, compared to their counterparts, older generation and more highly educated classes prefer higher growth path for the population of Korea.

• Journal of Korean Society for Atmospheric Environment
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• v.19 no.6
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• pp.689-699
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• 2003

This study was to examine characteristics of treating toluene vapor, which gets to be problematic due to its harmful carcinogenicity and mass generation from various sources, through a biological treatment facility which is environment-friendly and adopts a high-efficient and low-cost clean technology. In order to identify whether Alnus Firma Fruit (AFF) can be used as a media for a bioreactor, its utility and basic operating factors, a study was conducted on pressure drop, supply of nutrient substances and retention time which are operating factors of a biofilter, and eliminating characteristics were compared between AFF and the conventional biological activatedcarbon (BAC) widely used as filter media. In the case of AFF, the initial microbial deposits was 2.3${\times}$10$^{7}$ CFU/g dry AFF, which represents the initial microbial density higher than the case of BAC showing 5.5${\times}$10$^{6}$ CFU/g dry BAC And it took about 2 weeks to acclimate until its eliminating rate got to be increased over 90%. As a result of comparing pressure loss taking place with the lapse of time between BAC and AFF, after 130 days passed at SV 25h$^{-1}$ , BAC showed that its eliminating efficiency had a tendency to drop greatly due to a great pressure loss (0.53\longrightarrow54.7 mm$H_2O$/m) caused by an excess of biomass as accumulated. On the other hand. AFF showed that the pressure drop was 0.53 mm$H_2O$/m, about 2 times as much as the initial pressure loss of 0.4 mm$H_2O$/m, which represents no great change in the pressure loss, and its eliminating efficiency was also shown to be continuously high. Therefore, when AFF was used as a filler for a biological treatment facility, a biological filter enabling improvement of the purifying efficiency to be promoted could be provided, and moreover, the pressure loss was so small that the filler replacement cycle or the back flushing cycle could be extended. So, even in terms of the operating cost, it was identified to be an economical filler When an inorganic material was used as a filler, the biofilters performance acted sensitively on whether nutrient substances were supplied or not. In the case of AFF with low adsorptivity, addition of ethyl-alcohol increased the solubility of toluene, and consequently, biodegradation got to be actively made by microbes, and thus, its eliminating rate could be increased. As the flow velocity and the inflow concentration got to be more increased, its eliminating rate got to be lower, and particularly, an increase in the flow velocity made its eliminating rate drop more greatly than an increase in the concentration.

• The Journal of the Korea Contents Association
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• v.20 no.7
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• pp.404-416
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• 2020

Flooding is an unavoidable natural disaster for the city. Flood disasters seriously undermine the city's economy, safety, and sustained development. In the course of development and construction of waterfront space in the same city, the construction of basic disaster prevention facilities cannot be avoided completely even if huge amounts of capital are invested to reduce the economic damage of flooding. The cost of rebuilding the city after the disaster is much higher than the cost of building disaster prevention facilities. In recent years, the theory of elasticity in urban reconstruction and so on has been a subject of city problem solving, creating widespread discussion and attention in academia. In other words, how to transform the concept of elasticity into practice based on theoretical and empirical factors is a real problem facing urban disaster. Through theoretical literature on the waterfront (space) buffer zone of a city (flood-weak area) and the case study of the city's practice, this paper tries to clarify the element of 5R, the theory of elastomeric fire prevention, and present detailed measures accordingly. In addition, the following two problems are addressed while emphasizing the feasibility of implementing the urban waterfront (space) plan of the elastomeric element around the urban water buffer zone. First, the means of disaster prevention planning are used to mitigate conflicts between individual utility of urban waterfront and disaster prevention functions in waterfront buffer zones, and second, the waterfront buffer zone can respond to flood-causing problems in terms of disaster prevention as much as possible through the elastic disaster prevention plan.

• Korean Journal of Clinical Pharmacy
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• v.25 no.3
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• pp.151-158
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• 2015

Objective: This study was designed to compare pegfilgrastim and filgrastim in diffuse large B-cell lymphoma (DLBCL) patients treated with a rituximab with cyclophosphamide, hydroxydaunorubicin, oncovin, and prednisone (R-CHOP) regimen in terms of clinical efficacy and cost-effectiveness. Method: Clinical efficacy was measured by trough level of absolute neutrophil count (ANC), days of ANC under 50% of baseline value, days of ANC under 90% of baseline value, duration of ANC recovery to baseline value, days of ANC less than $0.5{\times}10^9cells/L$, and difference of peak and trough level of ANC during 1 cycle of R-CHOP regimen. To evaluate cost-effectiveness, total prices of used filgrastim and pegfilgrastim within 1 cycle of R-CHOP were analyzed. Results: In terms of clinical efficacy, trough level of ANC and days to ANC recovery showed statistical significance. The median trough levels of ANC with administration of filgrastim and pegfilgrastim were 0.18 and 1.94 (p = 0.021), respectively, and the median durations of ANC recovery to baseline value were 5.5 days and 2 days (p = 0.023), respectively. For the median days of ANC under 50% of baseline value, days of ANC under 90% of baseline value, days of ANC less than $0.5{\times}10^9cells/L$, and difference of peak and trough level of ANC during 1 cycle of R-CHOP, the pegfilgrastim group performed better than the filgrastim group. However the difference was not statistically significant. In terms of overall expense during 1 cycle of R-CHOP, pegfilgrastim is about 3.43 times more expensive than filgrastim. Conclusion: Pegfilgrastim is more efficient than filgrastim in terms of clinical efficacy. In terms of prices, pegfilgrastim is more expensive than filgrastim for patients, but it is more convenient in clinical use. Therefore, pegfilgrastim should be the preferred choice of G-CSF for neutropenic patients. Further comparative study of pegfilgrastim and filgrastim is needed.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.3 no.2
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• pp.119-126
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• 1983

The purposes of this study are to analyze/model the mode choice behavior of the regional traveler by express bus/express train and to offer useful source in deciding the public transportation policy. The data analyzed were trips of both modes from March, 1980 to November, 1981, between Seoul and other nineteen cities; the data were grouped as five groups according to the change of service variables. Service variables were travel time(unit: minute), cost(:won), average allocation time(:won), service hour(:hour), and dummy variables by mode. As model Logit Model with linear or log utility function were postulated. As the result of this study, some reseanable models were constructed at Model Type I(eq. 2. of this paper) based on the above data except the dummy. It was judged that the parameters calibrated by Group III and Group IV data in table 4, were optimal. Among the parameters, the parameter of travel cost was most reliable. There was a tendency preferring express bus to train in October and November. With the constructed model and Pivot-Point Method. the demand change of express train caused by the service variables' change could be forecasted over 99%.