• Journal of Environmental Health Sciences
• /
• v.30 no.3
• /
• pp.221-229
• /
• 2004

We estimated decreasing rate of indoor air pollutants which are PM10 and $NO_2$ by the air cleaner in indoor environment. This study respectively examined concentration of PM10 and $NO_2$ two times in 34 sites located in Seoul and Kyung-gi Do from April to September in 2003. Sectional period was respectively divided for operating the air cleaner and non-operating the air cleaner. Moreover, questionnaire was executed to grasp physical characteristic of objective building and residential characteristic of residents by using method of self-entry. There was a trend that concentration of PM10 and $NO_2$ separated number of residents during operating period respectively decreased among indoor air. According to the existence of smoker in indoor, both concentration of PM10 and $NO_2$ during operating period decreased in each case, and according to existence of pets, both cases decreased concentration of pollutants by operating the air cleaner. We used Monte-Calro simulation to remove uncertainty and identify efficiency of eliminated pollutants such as PM10 and $NO_2$ by the air cleaner. Average efficiency of removal for PM10 and $NO_2$ were 61.84${\pm}$23.04% and 48.67${\pm}$18.03% respectively.

• Journal of Digital Contents Society
• /
• v.19 no.1
• /
• pp.165-171
• /
• 2018

Shadow is a physical phenomenon observed in natural scenes and has a negative effect on various image processing systems such as intelligent video surveillance, traffic surveillance and aerial imagery analysis. Therefore, shadow detection should be considered as a preprocessing process in all areas of computer vision. In this paper, we define and analyze various feature elements for shadow detection in a single natural image that does not require a reference image. The shadow elements describe the intensity, chromaticity, illuminant-invariant, color invariance, and entropy image, which indicate the uncertainty of the information. The results show that the chromaticity and illuminant-invariant images are effective for shadow detection. In the future, we will define a fusion map of various shadow feature elements, and continue to study shadow detection that can adapt to various lighting levels, and shadow removal using chromaticity and illuminance invariant images.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.8 no.9
• /
• pp.3231-3249
• /
• 2014

Deniable encryption, introduced in 1997 by Canetti, Dwork, Naor, and Ostrovsky, guarantees that the sender or the receiver of a secret message is able to "fake" the message encrypted in a specific ciphertext in the presence of a coercing adversary, without the adversary detecting that he was not given the real message. Sender - side deniable encryption scheme is considered to be one of the classification of deniable encryption technique which defined as resilient against coercing the sender. M. H. Ibrahim presented a sender - side deniable encryption scheme which based on public key and uncertainty of Jacobi Symbol [6]. This scheme has several problems; (1) it can't be able to derive the fake message $M_f$ that belongs to a valid message set, (2) it is not secure against Quadratic Residue Problem (QRP), and (3) the decryption process is very slow because it is based dramatically on square root computation until reach the message as a Quadratic Non Residue (QNR). The first problem is solved by J. Howlader and S. Basu's scheme [7]; they presented a sender side encryption scheme that allows the sender to present a fake message $M_f$ from a valid message set, but it still suffers from the last two mentioned problems. In this paper we present a new sender-side deniable public-key encryption scheme with fast decryption by which the sender is able to lie about the encrypted message to a coercer and hence escape coercion. While the receiver is able to decrypt for the true message, the sender has the ability to open a fake message of his choice to the coercer which, when verified, gives the same ciphertext as the true message. Compared with both Ibrahim's scheme and J. Howlader and S. Basu's scheme, our scheme enjoys nice two features which solved the mentioned problems: (1) It is semantically secure against Quadratic Residue Problem; (2) It is as fast, in the decryption process, as other schemes. Finally, applying the proposed deniable encryption, we originally give a coercion resistant internet voting model without physical assumptions.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.21 no.3
• /
• pp.372-377
• /
• 2011

This paper propose the robust stability algorithm for controlling a hybrid magnetic bearing system. The control object in the magnetic bearing system enables the rotor to rotate without any physical contact by using magnetic force. Generally, the system dynamics of the magnetic bearing system has severe nonlinearity and uncertainty so that it is not easy to obtain the control objective. For solving these problems, we propose the fuzzy modelling and robust control algorithm for hybrind magnetic bearing system. The sufficient conditions for robust controller are obtained in terms of solutions to linear matrix inequalities (LMIs). Simulation results for HMB are demonstrated to visualize the feasibility of the proposed method.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2019.05a
• /
• pp.147-147
• /
• 2019

The Numerical Weather Prediction (NWP) models determine the future state of the weather by forcing current weather conditions into the atmospheric models. The NWP models approximate mathematically the physical dynamics by nonlinear differential equations; however these approximations include uncertainties. The errors of the NWP estimations can be related to the initial and boundary conditions and model parameterization. Development in the meteorological forecast models did not solve the issues related to the inevitable biases. In spite of the efforts to incorporate all sources of uncertainty into the forecast, and regardless of the methodologies applied to generate the forecast ensembles, they are still subject to errors and systematic biases. The statistical post-processing increases the accuracy of the forecast data by decreasing the errors. Error prediction of the NWP models which is updating the NWP model outputs or model output statistics is one of the ways to improve the model forecast. The regression methods (including linear, polynomial and scaling regression) are applied to the present study to improve the real time forecast skill. Such post-processing consists of two main steps. Firstly, regression is built between forecast and measurement, available during a certain training period, and secondly, the regression is applied to new forecasts. In this study, the WRF real-time forecast data, in comparison with the observed data, had systematic biases; the errors related to the NWP model forecasts were reflected in the underestimation of the meteorological data forecast by the WRF model. The promising results will indicate that the post-processing techniques applied in this study improved the meteorological forecast data provided by WRF model. A comparison between various bias correction methods will show the strength and weakness of the each methods.

• The Journal of the Korea Contents Association
• /
• v.21 no.9
• /
• pp.666-683
• /
• 2021

Organizational humor is generally perceived as a phenomenon that helps to develop happy feelings and positive workspace. While humor may affect organizational members in diverse ways, the ambiguous nature of humor may create uncertainty and unexpected outcomes. In particular, humor used by and between organizational members in diverse organizational situations (including physical office context and work hours) may influence individual's perception of space. Findings suggest that humor interaction acts as a form of deviant behavior that diverts from work. This momentary non-work event (humor) may serve as a ritual to influence individual's perception of space, from work to personal domain, and vice versa. The quality of interpersonal relationships between the communicators may also be influenced by humor. This shift in the nature of interaction (from work to non-work) may lead to blurring boundaries of work and work experiences. Therefore, organizational humor may provide insights into how workers interact, perceive, and manage work and personal space within organizational contexts.

• Journal of the Korea Convergence Society
• /
• v.11 no.12
• /
• pp.137-145
• /
• 2020

The purpose of this study is to analyze the relationship between the two factors and the influence of Chinese cultural orientation on the change of physical dry environment in the domestic Chinese residential area. To this end, Hofsted's cultural dimension theory, which can quantitatively define and compare the national culture, is used to investigate the cultural orientation of China. The association was analyzed. Through this study, it was confirmed that the collectivist and uncertainty-avoidance tendency of the Chinese influenced the formation and change of the dry environment of the Chinese residential area in Daelim 2-dong. This study is meaningful in confirming that the cultural orientation of the migrant community affects the formation and change of collective residences, and through this, it can be used as basic data in preparing policies suitable for various migrant communities including Chinatown.

• Progress in Medical Physics
• /
• v.31 no.4
• /
• pp.145-152
• /
• 2020

Purpose: In ionization-chamber dosimetry for high-dose-rate electron beams-above 20 mGy/pulse-the ion-recombination correction methods recommended by the International Atomic Energy Agency (IAEA) and the American Association of Physicists in Medicine (AAPM) are not appropriate, because they overestimate the correction factor. In this study, we suggest a practical ion-recombination correction method, based on Boag's improved model, and apply it to reference dosimetry for electron beams of about 100 mGy/pulse generated from an electron linear accelerator (LINAC). Methods: This study employed a theoretical model of the ion-collection efficiency developed by Boag and physical parameters used by Laitano et al. We recalculated the ion-recombination correction factors using two-voltage analysis and obtained an empirical fitting formula to represent the results. Next, we compared the calculated correction factors with published results for the same calculation conditions. Additionally, we performed dosimetry for electron beams from a 6 MeV electron LINAC using an Advanced Markus^® ionization chamber to determine the reference dose in water at the source-to-surface distance (SSD)=100 cm, using the correction factors obtained in this study. Results: The values of the correction factors obtained in this work are in good agreement with the published data. The measured dose-per-pulse for electron beams at the depth of maximum dose for SSD=100 cm was 115 mGy/pulse, with a standard uncertainty of 2.4%. In contrast, the k_s values determined using the IAEA and AAPM methods are, respectively, 8.9% and 8.2% higher than our results. Conclusions: The new method based on Boag's improved model provides a practical method of determining the ion-recombination correction factors for high dose-per-pulse radiation beams up to about 120 mGy/pulse. This method can be applied to electron beams with even higher dose-per-pulse, subject to independent verification.

• Journal of English Language & Literature
• /
• v.57 no.2
• /
• pp.191-215
• /
• 2011

This paper aims at investigating Dorothy Wordsworth's later conversation poetry, which has not been the focus of critical discussions on her literary works. While many critics have been emphasizing Dorothy Wordsworth's journals and the tendency of self-effacement in her prose, this paper argues that her later poetry often reveals acute self-consciousness about the circumstances that condition this self-annihilation and searches for a creative way to endorse her own identity. In "Lines Intended for My Niece's Album," she expresses anxiety and uncertainty about the inclusion of her poetic piece in Dora Wordsworth's album, which contains poems by prominent male writers of the contemporary period. "Irregular Verses" presents Dorothy Wordsworth's self-conscious narrative of her girlhood and shows how her own ambition to become a "Poet" has been stifled by external circumstances, including the ideology that instills the idea of proper womanhood into aspiring girls. While these poems examine contemporary gender discourse and the frustrated poethood resulting from it, other poems activate conversations with William Wordsworth's poems and thereby provide a revisionary re-writing of her brother's texts. For example, in "Lines Addressed to Joanna H." Dorothy Wordsworth becomes "a woman addressed who herself addresses others." Her scrupulous approach to her own addressee refuses to subordinate the other to the self's will, and through this revision of "Tintern Abbey," Dorothy Wordsworth vicariously liberates her own self confined in her brother's poems. "Thoughts on My Sick-Bed," which echoes "Tintern Abbey" through borrowed phrases and direct address to William Wordsworth, foregrounds her own poetic identity in the form of the first-person pronoun "I." Dorothy Wordsworth's continual illness during this period of her life paradoxically allows her the time for personal reflection formerly denied to her in her busy life constantly occupied by physical and spiritual labor for others. Instead of earning satisfaction from the subsumption of her creative energy under William Wordsworth's poetical endeavor, Dorothy Wordsworth finally starts to affirm her own poetic identity that can properly express her inner vision and artistic talent. Although this final affirmation remains largely incomplete due to her later mental collapse bordering on madness, it powerfully conveys the hidden literary aspiration of the formerly frustrated female poet.

• The Journal of the Korea Contents Association
• /
• v.21 no.6
• /
• pp.552-560
• /
• 2021

With the recent development of the art distribution system, interest in art investment is increasing rather than seeing art as an object of aesthetic utility. Unlike stocks and bonds, the price of artworks has a heterogeneous characteristic that is determined by reflecting both objective and subjective factors, so the uncertainty in price prediction is high. In this study, we used LSTM Recurrent Neural Network deep learning model to predict the auction winning price by inputting the artist, physical and sales charateristics of the Korean artist. According to the result, the RMSE value, which explains the difference between the predicted and actual price by model, was 0.064. Painter Lee Dae Won had the highest predictive power, and Lee Joong Seop had the lowest. The results suggest the art market becomes more active as investment goods and demand for auction winning price increases.