• Environmental and Resource Economics Review
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• v.26 no.3
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• pp.417-449
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• 2017

The purpose of this study is to analyze the effect of local area concentration of particulate matter on life satisfaction, by matching subjective satisfaction in the Korea Labor & Income Panel Study data with daily data of $PM_{10}$ and $PM_{2.5}$. We find that the concentration of particulate matter has a significant negative effect on satisfaction. A $1{\mu}g/m^3$ increase in $PM_{10}$($PM_{2.5}$) leads to lower the probability of choosing 'satisfaction' by 0.042%p~0.091%p(0.034%p~0.153%p) and a 1% increase in annual income per household raises the probability of choosing 'satisfaction' by 0.16%p~0.18%p respectively. To estimate the monetary value of reducing $PM_{10}$ and $PM_{2.5}$, we calculate willingness-to-pay for mitigating air pollution, which represents the tradeoff between the reduction in particulate matter and income. We find that people on average are willing to pay \108,787($96)~209,519($186) for a $1{\mu}g/m^3$ reduction in $PM_{10}$ and to pay 89,345($79)~362,930($322) in $PM_{2.5}$. This amount corresponds to 0.26%~0.50%(0.22%~0.88%) of the average annual household income in South Korea.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.39 no.11
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• pp.1169-1174
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• 2015

Risk-Risk-based inspection (RBI) has been developed in order to identify risky equipments that can cause major accidents or damages in large-scale plants. This assessment evaluates the equipment's risk, categorizes their priorities based on risk level, and then determines the urgency of their maintenance or allocates maintenance resources. An earlier version of the risk-based assessment software is already installed within the equipment management system; however, the assessment is based on examination by an inspector, and the results can be influenced by his subjective judgment, rather than assessment being based on failure probability. Moreover, the system is housed within a server, which limits the inspector's work space and time, and such a system can be used only on site. In this paper, the development of independent risk-based assessment software is introduced; this software calculates the failure probability by an analytical method, and analyzes the field inspection results, as well as inspection effectiveness. It can also operate on site, since it can be installed on an independent platform, and has the ability to generate an I/O function for the field inspection results regarding the period for an optimum maintenance cycle. This program will provide useful information not only to the field users who are participating in maintenance, but also to the engineers who need to decide whether to extend the lifecycle of the power machinery or replace only specific components.

• Journal of the Korean Regional Science Association
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• v.34 no.4
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• pp.35-48
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• 2018

The purpose of this study is to empirically investigate the experiences and subjective opinions of urban agriculture in order to explore ways to vitalize urban agriculture. More specifically, we divides environmental value into three categories of ecology, landscape, and participation, and defines a function of urban agriculture to improve environmental values related to the three categories mentioned above. The main results of the empirical analysis using the survey data are summarized as follows. First, the probability of gathering information about urban agriculture is higher in metropolitan cities than small cities, and the larger the residence size, the higher the probability of actual urban agriculture participation. Second, the positive response rate was high for the three categories of urban agriculture, while the negative response rate was high for the surrounding environment. The implications derived from the analysis are as follows. First, the opposite results of experiences of urban agriculture suggests that local governments should further promote urban agriculture-based investment policies. In addition, these policies need to be preceded by analysis of the characteristics of population groups in the region Also, it is necessary to improve the environment through urban agriculture.

• Journal of the Korean Applied Science and Technology
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• v.40 no.5
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• pp.936-944
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• 2023

The purpose of this study is to verify the effect of essence containing Coptis Japonica extract on skin barrier strengthening and moisturizing. The essence containing the Coptis Japonica extract was used by 22 subjects for four weeks, and the amount of percutaneous water loss (g/m²h) and water (A.U.) in the designated upper limit were measured. As a result of measuring percutaneous water loss using a vapometer, it was found to be 11.08±2.55 after 4 weeks of use from 14.82±4.01 before use, and the significance probability decreased significantly by 25.27% to p<0.001. The amount of skin moisture measured by the Corneometer was found to be 46.73±7.45 after use from 31.73±8.09 before use, and the significance probability increased by 47.26% to p<0.001, and the subject's subjective efficacy evaluation through a questionnaire showed that all subjects were 100% satisfied without skin adverse reactions. As a result of this, it has been confirmed that Coptis Japonica essence is effective in strengthening skin barriers and moisturizing, which is expected to be a cornerstone for the development of cosmetics using various activities of Coptis Japonica extract in the future.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.47 no.4
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• pp.105-111
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• 2010

This paper proposes the recursive algorithm for passive proximity detection system based on signal strength. The system is designed to be used in the smart medicine chest in order to provide location-based service for the senior personnel. Due to the system profile, single receiver and uni-direction communication are applied over the signal attenuation model for the determination of user existence within certain proximity. The performance of conventional methods is subjective to the sight between the transmitter and receiver unless the direction of target is known. To appreciate the temporal and spatial locality of human subjects, the authors present exponential moving average (EMA) to compensate the unexpected position error from the direction and/or environment. By using optimal parameter, the experiments with EMA algorithm demonstrates 32.26% (maximum 40.80%) reduction in average of the error probability with 50% of consecutive sight in time.

• Journal of the Ergonomics Society of Korea
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• v.31 no.5
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• pp.657-670
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• 2012

Background: Today, numerous telematics technologies, i.e., technologies developed by integrating telecommunications with information processing, are applied in vehicles. One such developmental application of this technology to vehicles is to increase the safety or convenience of drivers by providing them with necessary information such as warnings and information on emergencies and traffic situations. However, under certain conditions, there is a high probability of traffic accidents if the driving workload is high. Nowadays, the navigation system is frequently used in the vehicles, this system provides various information including route to the driver. But, the existing navigation systems are not only considered a driver's reaction but also provide unilaterally to the information regardless of them. Such one-side information service type may miss important information to the driver. In addition, it sometimes interferes safety driving. Objective: To solve this problem, the intelligent navigation system needs to the providing way that it checks the driver's reactions after providing information. Namely, if the driver passes the information received from the navigation, then the intelligent system provides more loudly and more frequently. Method: Therefore, in this study we introduce the intelligent navigation system that it automatically controls modality type and its strength when the driver misses or overlooks the information for their safety and entertainment and we analyze the driver's cognitive responses about the modality type and its strength. Results: To evaluate the effectiveness of the proposed system, we analyzed the reaction time and driving workload for each type of the information, modality and its strength. Also we evaluated the users' subjective satisfaction and understanding based on a questionnaire.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.11 no.2
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• pp.167-182
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• 2016

The purpose of this study is to investigate the effects of CEO technological capability on management performance and mediating role of firm's technological capability. The empirical data for this study are taken not from subjective studies released by companies but from the Korea Technology Guarantee Fund's(KTGF) technology assessment data. The result are as follows. First, CEO technological capability has a very significant and important influence on firm's technological capabilities and on technological performance(intellectual property rights(-), technology spillover effect(+)) and on management performance. Second, mediating role of firm's technological capability is revealed negatively only between CEO technological capability and intellectual property rights. Because of CEO technological capability has a significant influence on firm's technological capability and management performance, start-up based on expertise show a higher probability of success than the founder.

• Journal of Korea Game Society
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• v.16 no.5
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• pp.7-22
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• 2016

The risk is subjectively perceived by the subject to judge. In the case of the game, game organizations and watchdog groups also recognized differently occurrence probability and intensity of risk to form a physical relationships of the game with each. Thus, we look only at the risk of their own subjective opinion, the fundamental solution is not possible. In this paper, we conducted a study on the form, occurrence point, and generating processes of risk by analyzing the physical components that make up the network of the game based on ATN in order to confirm definitely the substance and the presence of the game risk. In view of ANT, the game and humans constitute a network through their ability to act as each actor. If the gamer does not clearly recognize the nature of the ability to act of the game, the reverse control and the excess flow occur through remediation properties of the game. Therefore, it requires a more in-depth study in the future with respect to complex structure and relationships of the game-gamer network.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.33 no.6
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• pp.507-516
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• 2015

Debris flow is a representative natural disaster in Korea and occurs frequently every year. Recently, it has caused considerable damage to property and considerable loss of life in both mountainous and urban regions. Therefore, It is necessary to estimate the scope of damage for a large area in order to predict the debris flow. A response model such as the random walk model(RWM) can be used as a useful tool instead of a physics-based numerical model. RWM is a probability model that simplifies both debris flows and sedimentation characteristics as a factor of slopes for a subjective site and represents a relatively simple calculation method compared to other debris flow behavior calculation models. Although RWM can be used to analyzing and predicting the scope of damage caused by a debris flow, input variables for terrain conditions are yet to be determined. In this study, optimal input variables were estimated using DEM generated from the Aerial Photograph and LiDAR data of Mt. Umyeon, Seoul, where a large-scale debris flow occurred in 2011. Further, the deposition volume resulting from the debris flow was predicted using the input variables for a specific area in which the deposition volume could not be calculated because of work restoration and the passage of time even though a debris flow occurred there. The accuracy of the model was verified by comparing the result of predicting the deposition volume in the debris flow with the result obtained from a debris flow behavior analysis model, Debris 2D.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.1
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• pp.288-307
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• 2016

Image distortions are typically characterized by degradations of structures. Dictionaries learned from natural images can capture the underlying structures in images, which are important for image quality assessment (IQA). This paper presents a general-purpose no-reference image quality metric using a GRadient-Induced Dictionary (GRID). A dictionary is first constructed based on gradients of natural images using K-means clustering. Then image features are extracted using the dictionary based on Euclidean-norm coding and max-pooling. A distortion classification model and several distortion-specific quality regression models are trained using the support vector machine (SVM) by combining image features with distortion types and subjective scores, respectively. To evaluate the quality of a test image, the distortion classification model is used to determine the probabilities that the image belongs to different kinds of distortions, while the regression models are used to predict the corresponding distortion-specific quality scores. Finally, an overall quality score is computed as the probability-weighted distortion-specific quality scores. The proposed metric can evaluate image quality accurately and efficiently using a small dictionary. The performance of the proposed method is verified on public image quality databases. Experimental results demonstrate that the proposed metric can generate quality scores highly consistent with human perception, and it outperforms the state-of-the-arts.