• Toxicological Research
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• v.35 no.4
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• pp.295-301
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• 2019

In this review, we describe the absorption rates (Caco-2 cell permeability) and hepatic/plasma pharmacokinetics of 53 diverse chemicals estimated by modeling virtual oral administration in rats. To ensure that a broad range of chemical structures is present among the selected substances, the properties described by 196 chemical descriptors in a chemoinformatics tool were calculated for 50,000 randomly selected molecules in the original chemical space. To allow visualization, the resulting chemical space was projected onto a two-dimensional plane using generative topographic mapping. The calculated absorbance rates of the chemicals based on cell permeability studies were found to be inversely correlated to the no-observed-effect levels for hepatoxicity after oral administration, as obtained from the Hazard Evaluation Support System Integrated Platform in Japan (r = -0.88, p < 0.01, n = 27). The maximum plasma concentrations and the areas under the concentration-time curves (AUC) of a varied selection of chemicals were estimated using two different methods: simple one-compartment models (i.e., high-throughput toxicokinetic models) and simplified physiologically based pharmacokinetic (PBPK) modeling consisting of chemical receptor (gut), metabolizing (liver), and central (main) compartments. The results obtained from the two methods were consistent. Although the maximum concentrations and AUC values of the 53 chemicals roughly correlated in the liver and plasma, inconsistencies were apparent between empirically measured concentrations and the PBPK-modeled levels. The lowest-observed-effect levels and the virtual hepatic AUC values obtained using PBPK models were inversely correlated (r = -0.78, p < 0.05, n = 7). The present simplified PBPK models could estimate the relationships between hepatic/plasma concentrations and oral doses of general chemicals using both forward and reverse dosimetry. These methods are therefore valuable for estimating hepatotoxicity.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.10
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• pp.3815-3833
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• 2021

MILP-based automatic search is the most common method in analyzing the security of cryptographic algorithms. However, this method brings many issues such as low efficiency due to the large size of the model, and the difficulty in finding the contradiction of the impossible differential distinguisher. To analyze the security of ESF algorithm, this paper introduces a simplified MILP-based search model of the differential distinguisher by reducing constrains of XOR and S-box operations, and variables by combining cyclic shift with its adjacent operations. Also, a new method to find contradictions of the impossible differential distinguisher is proposed by introducing temporary variables, which can avoid wrong and miss selection of contradictions. Based on a 9-round impossible differential distinguisher, 15-round attack of ESF can be achieved by extending forward and backward 3-round in single-key setting. Compared with existing results, the exact lower bound of differential active S-boxes in single-key setting for 10-round ESF are improved. Also, 2108 9-round impossible differential distinguishers in single-key setting and 14 12-round impossible differential distinguishers in related-key setting are obtained. Especially, the round of the discovered impossible differential distinguisher in related-key setting is the highest, and compared with the previous results, this attack achieves the highest round number in single-key setting.

• PNF and Movement
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• v.17 no.1
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• pp.41-46
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• 2019

Purpose: Continuous use of a smartphone increases the angle of forward bending of the user's cervical vertebrae, causing pain in the shoulders and back, including the thorax, lumbar region, and vertebrae. Although there are many studies on changes in the cervical spine due to smartphone usage, the changes in the shoulders, thoracolumbar spine, and pelvic have rarely been compared. The purpose of this study is to investigate the change in the spinal segments, shoulders, and pelvic when using a smartphone with both hands while in the standing position. Methods: This study was conducted on 35 adults in their twenties. The selection criteria for the subjects were limited to those in a similar age group, thus excluding posture differences according to age, and to those who did not have specific diseases or pain in the spinal and musculoskeletal system for 12 months prior to the study. In this study, we used a 3D spinal diagnostic imaging system (Back Mapper, Frickenhausen) to compare the changing conditions in each vertebral segment before and during smartphone usage with both hands while in the standing position. Posture differences according to smartphone usage were compared using the paired t-test for the motion of each spinal segment. Results: This study showed that the thoracic and lumbar angle increased posteriorly during smartphone usage (p<0.05). In addition, the anterior rotation angle of the shoulder bone significantly increased, but no significant difference occurred in the pelvic region. Conclusion: Based on the results of this study, smartphone usage with both hands while in the standing position showed that the spine, as a whole, forms a kyphotic curve. Therefore, we propose to present a postural guideline for correct smartphone usage, considering the change in each vertebral segment.

• Journal of Internet Computing and Services
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• v.20 no.5
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• pp.1-8
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• 2019

This paper carried out a study to reduce damage from jellyfish whose population has increased due to global warming. The emergence of jellyfish on the beach could result in casualties from jellyfish stings and economic losses from closures. This paper confirmed from the preceding studies that the pattern of jellyfish's appearance is predictable through machine learning. This paper is an extension of The prediction model of emergence of Busan coastal jellyfish using SVM. In this paper, we used deep neural network to expand from the existing methods of predicting the existence of jellyfish to the classification by index. Due to the limitations of the small amount of data collected, the 84.57% prediction accuracy limit was sought to be resolved through data expansion using bootstraping. The expanded data showed about 7% higher performance than the original data, and about 6% better performance compared to the transfer learning. Finally, we used the test data to confirm the prediction performance of jellyfish appearance. As a result, although it has been confirmed that jellyfish emergence binary classification can be predicted with high accuracy, predictions through indexation have not produced meaningful results.

• International Journal of Computer Science & Network Security
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• v.21 no.11
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• pp.301-311
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• 2021

The technological advancements of the last two decades directed the era of the Internet of Things (IoT). IoT enables billions of devices to connect through the internet and share their information and resources on a global level. These devices can be anything, from smartphones to embedded sensors. The main purpose of IoT is to make devices capable of achieving the desired goal with minimal to no human intervention. Although it hascome as a social and economic blessing, it still brought forward many security risks. This paper focuses on providing a survey of the most commonly used application layer protocols in the IoT domain, namely, Constrained Application Protocol (CoAP), Message Queuing Telemetry Transport (MQTT), Advanced Message Queuing Protocol (AMQP), and Extensible Messaging and Presence Protocol (XMPP). MQTT, AMQP, and XMPP use TCP for device-to-device communication, while CoAP utilizes UDP to achieve this purpose. MQTT and AMQP are based on a publish/subscribe model, CoAP uses the request/reply model for its structuring. In addition to this, the quality of service provision of MQTT, AMQP, and CoAP is not very high, especially when the deliverance of messages is concerned. The selection of protocols for each application is very a tedious task.This survey discusses the architectures, advantages, disadvantages, and applications of each of these protocols. The main contribution of this work is to describe each of the aforementioned application protocols in detail as well as providing their thorough comparative analysis. This survey will be helpful to the developers in selecting the protocol ideal for their system and/or application.

• The korean journal of orthodontics
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• v.52 no.5
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• pp.313-323
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• 2022

Objective: This study aimed to estimate the clinical effects of different types of bone-anchored maxillary protraction devices by using a network meta-analysis. Methods: We searched seven databases for randomized and controlled clinical trials that compared bone-anchored maxillary protraction with tooth-anchored maxillary protraction interventions or untreated groups up to May 2021. After literature selection, data extraction, and quality assessment, we calculated the mean differences, 95% confidence intervals, and surface under the cumulative ranking scores of eleven indicators. Statistical analysis was performed using R statistical software with the GeMTC package based on the Bayesian framework. Results: Six interventions and 667 patients were involved in 18 studies. In comparison with the tooth-anchored groups, the bone-anchored groups showed significantly more increases in Sella-Nasion-Subspinale (°), Subspinale-Nasion-Supramentale(°) and significantly fewer increases in mandibular plane angle and the labial proclination angle of upper incisors. In comparison with the control group, Sella-Nasion-Supramentale(°) decreased without any statistical significance in all treated groups. IMPA (angle of lower incisors and mandibular plane) decreased in groups with facemasks and increased in other groups. Conclusions: Bone-anchored maxillary protraction can promote greater maxillary forward movement and correct the Class III intermaxillary relationship better, in addition to showing less clockwise rotation of mandible and labial proclination of upper incisors. However, strengthening anchorage could not inhibit mandibular growth better and the lingual inclination of lower incisors caused by the treatment is related to the use of a facemask.

• Journal of Korea Trade
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• v.26 no.5
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• pp.1-22
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• 2022

Purpose - This study aims to analyze the influence of South Korea's outward foreign direct investment (OFDI) under the effect of both multinational enterprises' (MNEs) investment motivation and host country institutions. Some suggestions are put forward with regard to South Korean MNEs participating in and integrating into the fierce and changeable world of international market competition. Design/methodology - The basic hypotheses are that MNEs' investment motivations and the host country's superior institutions both boost South Korea's OFDI in those host countries. South Korea's OFDI is divided into investment choice stage and investment scale stage. A Heckman two-stage selection model is established for empirical analysis, using the panel data of South Korea's OFDI and related variables, from 2002 to 2019. Findings - (1) The influence on the investment scale of South Korea's OFDI is more regular and noteworthy than the influence on investment choice. (2) In the investment scale stage, there are obvious motivations to seek markets, labor force and superior technology, but not natural resources. (3) In the investment scale stage, the South Korea's OFDI is more obviously attracted by the host country's superior political institutions, economic institutions and legal institutions, but not cultural institutions. Originality/value - The choices of variables and uses of model expand the theoretical basis and empirical method of OFDI research. The results of the empirical study also provide some reference for the transnational investment of South Korean MNEs and the investment policy formulation of the South Korean government.

• Journal of the Korean Society of Physical Medicine
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• v.19 no.1
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• pp.61-68
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• 2024

PURPOSE: This study aimed to provide basic clinical data by analyzing the impact of motion observation training and stretching exercises for improving postures on the neck alignment and balance of stroke patients to enable them to accurately recognize the correct exercise method. METHODS: After sampling 20 stroke patients who met the selection criteria, this study randomly assigned 10 people who were administered the stretching exercise with observation training to the experimental group and 10 who received only the stretching exercise intervention to the control group by drawing lots. Next, neck alignment and balance were pre-tested. All interventions were conducted for 30 minutes, 3 times a week for 4 weeks, and when all the interventions were completed after 4 weeks, neck alignment and balance were re-measured in the same way as the pre-test. RESULTS: The comparison of changes in neck alignment and balance within the experimental and control groups showed statistically significant differences in the craniovertebral angle, cranial rotation angle, and balance (p < .05) (p < .01). Between the groups, statistically significant differences were found in the craniovertebral angle, cranial rotation angle, and balance (p < .05) (p < .01). CONCLUSION: A statistically significant difference in neck alignment and balance was observed in the group that underwent stretching exercises combined with observational training and a statistically significant difference was found between the groups. Therefore, it is believed that observation training should be used in clinical practice to improve forward head posture and restore balance in stroke patients.

• Journal of the Korean Institute of Landscape Architecture
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• v.46 no.5
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• pp.69-81
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• 2018

Recently, user participatory workshops have been applied as a way to plan landscape spaces that reflects the needs and demands of the users. It is also required to improve the quality of the FECC (Forest Experience Center for Children), which is growing rapidly. Therefore, the purpose of this study is to deduct the design elements (forest play activities and space), the basic needs, and the demands of users in making the FECC a preschooler participatory workshop. For this, materials for preschooler participation were selected, and a step-by-step workshop was conducted to satisfy the demands of the preschooler's development. First, in the pre-workshops phase, design elements standards were deducted through the preschooler participatory results (41 children aged 6 and 7, Kindergarten). Second, in the main workshop phase, the design elements to be introduced on the site (Songsan-mulbit FECC) were deducted through the participating preschooler's selection and those results were analyzed. The materials used at the preschooler participatory process were 'drawing a picture' in the pre-workshop phase, and the design elements and the standard types charts were the forest play activity pictogram chart, and the forest play space general images chart in the main workshop. As for results, frst, there are 38 standard types of forest play activities that have been deducted. It consists of 27 cognitive activities (functional 16, constructive 4, symbolic 4, game on rule 3), 9 games (sensory 5, other 4), and two social play activities (solo, group). There are 21 standard types of forest play spaces. They consist of 8 play facility spaces (5 facility, 3 natural), 2 water spaces, and 11 spaces of 5 types. Second, as a result of applying the results to the site, the forest play activities to be introduced on the site were selected, and the functional play was most selected. Additionally, climbing and water play were most selected as the unit activities. Also, functional, constructive, symbolic, games based on rules were selected, even in the preschooler's development play. In the case of the forest play spaces to be introduced in the site, the preschooler's selection results by sex and age tended to be similar to the preschooler's comprehensive selection results, but the boys preferred function and adventure spaces more than the girls, while the girls preferred rest spaces more than the boys. This result is similar to the previous study results, which directly observed the preschooler's forest play behavior, and analysis that the preschooler recognized the site and selected the design elements introduced on the site. Therefore, the participatory workshop process and the materials process in this study are analyzed and applied to the purpose of the study. It is valuable as a case to be applied in design of the FECC from this point forward.

• Asia pacific journal of information systems
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• v.18 no.3
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• pp.45-65
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• 2008

The rapid growth of the Internet has increased the amount of transmission of personally identifiable information. At the same time, with new Internet related technologies, organizations are trying to collect and access more personal information than before, which in turn makes individuals concern more about their information privacy. For their successful businesses, organizations have tried to alleviate these concerns in two ways: (1) by offering privacy policies that promise certain level of privacy protection; (2) by offering benefits such as financial gains or convenience. In this paper, we interpret these actions in the context of the information processing theory of motivation. This paper follows Hann et al.(2007)'s methods to analyze Internet users privacy concerns in Korea and tries to compare the findings. Our research objectives are as follows: First, we analyze privacy concern mitigation strategies in the framework of the expectancy theory of motivation. Subsequently, we show how the expectancy theory based framework is linked o the conjoint analysis. We empirically validate the predictions that the means to mitigate privacy concerns are associated with positive valences resulting in an increase in motivational score. In order to accommodate real-life contexts, we investigate these means in trade-off situation, where an organization may only be able to offer partially complete privacy protection and/or promotions and/or convenience, While privacy protection (secondary use, improper access) are associated with positive valences, we also find that financial gains can significantly increase the individuals' motivational score of a website in Korea. One important implication of this empirical analysis is that organizations may possess means to actively manage the privacy concerns of Internet users. Our findings show that privacy policies are valued by users in Korea just as in the US or Singapore. Hence, organizations can capitalize on this, by stating their privacy policy more prominently. Also organizations would better think of strategies or means that may increase online users' willingness to provide personal information. Since financial incentives also significantly increase the individuals' motivational score of website participation, we can quantify the value of website privacy protection in terms of monetary gains. We find that Korean Internet users value the total privacy protection (protection against errors, improper access, and secondary use of personal information) as worthy as KW 25,550, which is about US 28. Having done this conjoint analysis, we next adopt cluster analysis methodology. We identify two distinct segments of Korea's internet users-privacy guardians and information sellers, and convenience seekers. The immediate implication of our study is that firms with online presence must differentiate their services to serve these distinct segments to best meet the needs of segments with differing trade-offs between money and privacy concerns. Information sellers are distinguished from privacy guardians by prior experience of information provision, To the extent that businesses cannot observe an individual's prior experience, they must use indirect methods to induce segmentation by self-selection as suggested in classic economics literature of price discrimination, Businesses could use monetary rewards to attract information sellers to provide personal information. One step forward from the societal trends that emphasize the need of legal protection of information privacy, our study wants to encourage organizations and related authorities to have the viewpoints to consider both importance of privacy protection and the necessity of information trade for the growth of e-commerce.