• Title/Summary/Keyword: key exposure

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Use of autonomous maximal smile to evaluate dental and gingival exposure

  • Wang, Shuai;Lin, Hengzhe;Yang, Yan;Zhao, Xin;Mei, Li;Zheng, Wei;Li, Yu;Zhao, Zhihe
    • The korean journal of orthodontics
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    • v.48 no.3
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    • pp.182-188
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    • 2018
  • Objective: This study was performed to validate the autonomous maximal smile (AMS) as a new reference for evaluating dental and gingival exposure. Methods: Digital video clips of 100 volunteers showing posed smiles and AMS at different verbal directives were recorded for evaluation a total of three times at 1-week intervals. Lip-teeth relationship width (LTRW) and buccal corridor width (BCW) were measured. LTRW represented the vertical distance between the inferior border of the upper vermilion and the edge of the maxillary central incisors. Intraclass correlation coefficients (ICCs) for reproducibility, and the m-value (minimum number of repeated measurements required for an ICC level over 0.75), were calculated. Results: LTRW and BCW of the AMS were 1.41 and 2.04 mm, respectively, greater than those of the posed smile (p < 0.05), indicating significantly larger dental and gingival exposure in the AMS. The reproducibility of the AMS (0.74 to 0.77) was excellent, and higher than that of the posed smile (0.62 to 0.65), which had fair-to-good reproducibility. Moreover, the m-value of the AMS (0.88 to 1.05) was lower than that of the posed smile (1.59 to 1.85). Conclusions: Compared to the posed smile, the AMS shows significantly larger LTRW and BCW, with significantly higher reproducibility. The AMS might serve as an adjunctive reference, in addition to the posed smile, in orthodontic and other dentomaxillofacial treatments.

Two-factor Authentication technology based on Key-Stroke (Key-Stroke 기반 Two-Factor 인증 기술)

  • An, Jun-Yeon;Ko, Gwang-Feel;Lee, Tae-jin
    • Convergence Security Journal
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    • v.20 no.3
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    • pp.29-37
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    • 2020
  • Password based authentication technology is yet certain and id to provide a level of security being used in most systems, but already a myriad of personal information exposure to the accident. Above all, and once exposed, it is difficult to recover the password. Thus, the various authentication techniques - factor two was introduced, but they are expensive and discomfort to users, to lead. In this paper, the existing unique to users in such a single accreditation process / password id key - stroke, user authentication and cost effectively and at the same time. And not cause discomfort, suggested technologies that can also ensure high security exposure, password id. This paper's proposals and determine the effectiveness of the system to build model.

Changes in microbial population and chemical composition of corn stover during field exposure and effects on silage fermentation and in vitro digestibility

  • Sun, Lin;Wang, Zhijun;Gentu, Ge;Jia, Yushan;Hou, Meiling;Cai, Yimin
    • Asian-Australasian Journal of Animal Sciences
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    • v.32 no.6
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    • pp.815-825
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    • 2019
  • Objective: To effectively use corn stover resources as animal feed, the changes in microbial population and chemical composition of corn stover during field exposure, and their silage fermentation and in vitro digestibility were studied. Methods: Corn cultivars (Jintian, Jinnuo, and Xianyu) stovers from 4 random sections of the field were harvested at the preliminary dough stage of maturity on September 2, 2015. The corn stover exposed in the field for 0, 7, 15, 30, 60, 90, and 180 d, and their silages at 60 d of ensiling were used for the analysis of microbial population, chemical composition, fermentation quality, and in vitro digestibility. Data were analyzed with a completely randomized $3{\times}6$ [corn stover cultivar $(C){\times}exposure$ d (D)] factorial treatment design. Analysis of variance was performed using SAS ver. 9.0 software (SAS Institute Inc., Cary, NC, USA). Results: Aerobic bacteria were dominant population in fresh corn stover. After ensiling, the lactic acid bacteria (LAB) became the dominant bacteria, while other microbes decreased or dropped below the detection level. The crude protein (CP) and water-soluble carbohydrate (WSC) for fresh stover were 6.74% to 9.51% and 11.75% to 13.21% on a dry matter basis, respectively. After exposure, the CP and WSC contents decreased greatly. Fresh stover had a relatively low dry matter while high WSC content and LAB counts, producing silage of good quality, but the dry stover did not. Silage fermentation inhibited nutrient loss and improved the fermentation quality and in vitro digestibility. Conclusion: The results confirm that fresh corn stover has good ensiling characteristics and that it can produce silage of good quality.

Estimating Exchange Rate Exposure over Various Return Horizons: Focusing on Major Countries in East Asia

  • Lee, Jeong Wook;Ahn, Sunghee;Kang, Sammo
    • East Asian Economic Review
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    • v.20 no.4
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    • pp.469-491
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    • 2016
  • In this paper, we estimate the exchange rate exposure, indicating the effect of exchange rate movements on firm values, for a sample of 1,400 firms in seven East Asian countries. The exposure estimates based on various exchange rate variables, return horizons and a control variable are compared. A key result from our analysis is that the long term effect of exchange rate movements on firm values is greater than the short term effect. And we find very similar results from using other exchange rate variables such as the U.S. dollar exchange rate, etc. Second, we add exchange rate volatility as a control variable and find that the extent of exposure is not much changed. Third, we examine the changes in exposure to exchange rate volatility with an increase in return horizon. Consequently the ratio of firms with significant exposures increases with the return horizons. Interestingly, the increase of exposure with the return horizons is faster for exposure to volatility than for exposure to exchange rate itself. Taken as a whole, our findings suggest that the socalled "exposure puzzle" may be a matter of the methodology used to measure exposure.

A Coordinated Ciphertext Policy Attribute-based PHR Access Control with User Accountability

  • Lin, Guofeng;You, Lirong;Hu, Bing;Hong, Hanshu;Sun, Zhixin
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.12 no.4
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    • pp.1832-1853
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    • 2018
  • The personal health record (PHR) system is a promising application that provides precise information and customized services for health care. To flexibly protect sensitive data, attribute-based encryption has been widely applied for PHR access control. However, escrow, exposure and abuse of private keys still hinder its practical application in the PHR system. In this paper, we propose a coordinated ciphertext policy attribute-based access control with user accountability (CCP-ABAC-UA) for the PHR system. Its coordinated mechanism not only effectively prevents the escrow and exposure of private keys but also accurately detects whether key abuse is taking place and identifies the traitor. We claim that CCP-ABAC-UA is a user-side lightweight scheme. Especially for PHR receivers, no bilinear pairing computation is needed to access health records, so the practical mobile PHR system can be realized. By introducing a novel provably secure construction, we prove that it is secure against selectively chosen plaintext attacks. The analysis indicates that CCP-ABAC-UA achieves better performance in terms of security and user-side computational efficiency for a PHR system.

The effect of melatonin on cardio fibrosis in juvenile rats with pressure overload and deregulation of HDACs

  • Wu, Yao;Si, Feifei;Luo, Li;Jing, Fengchuan;Jiang, Kunfeng;Zhou, Jiwei;Yi, Qijian
    • The Korean Journal of Physiology and Pharmacology
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    • v.22 no.6
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    • pp.607-616
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    • 2018
  • The effect of melatonin on juveniles with cardio fibrosis is poorly understood. We investigated whether HDACs participate in the anti-fibrotic processes regulated by melatonin during hypertrophic remodeling. Abdominal aortic constriction (AAC) was employed in juvenile rats resulting in pressure overload-induced ventricular hypertrophy and melatonin was subsequently decreased via continuous light exposure for 5 weeks after surgery. AAC rats displayed an increased cross-sectional area of myocardial fibers and significantly elevated collagen deposition compared to sham-operated rats, as measured by HE and Masson Trichrome staining. Continuous light exposure following surgery exacerbated the increase in the cross-sectional area of myocardial fibers. The expression of HDAC1, HDAC2, HDAC3, HDAC4 and HDAC6 genes were all significantly enhanced in AAC rats with light exposure relative to the other rats. Moreover, the protein level of $TNF-{\alpha}$ was also upregulated in the AAC light exposure groups when compared with the sham. However, Smad4 protein expression was unchanged in the juveniles' hearts. In contrast, beginning 5 weeks after the operation, the AAC rats were treated with melatonin (10 mg/kg, intraperitoneal injection every evening) or vehicle 4 weeks, and sham rats were given vehicle. The changes in the histological measures of cardio fibrosis and the gene expressions of HDAC1, HDAC2, HDAC3, HDAC4 and HDAC6 were attenuated by melatonin administration. The results reveal that melatonin plays a role in the development of cardio fibrosis and the expression of HDAC1, HDAC2, HDAC3, HDAC4 and HDAC6 in cardiomyocytes.

Parameters Affecting Indoor Air Exposure to Volatile Organic Compounds (휘발성 유기화합물에 대한 실내공기노출에 영향을 미치는 인자)

  • ;C.P. Weisel
    • Journal of Environmental Science International
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    • v.1 no.1
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    • pp.47-51
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    • 1992
  • Volatile organic rompounds(VOCs) present in the VOCs-contaminated water are released to air while showering and their air concentrations depend on the shower parameters, resulting in the variation of the VOCs breath concentration. The present study evaluated the key shower parameters(water temperature and inhalation duration) that affect the inhalation exposure to air chloroform while showering, by determining chloroform breath concentration. The chloroform breath concentrations increased with water temperature and inhalation duration increase. The two inhalation exposure conditions which resulted in the greatest chloroform breath contentration difference were a 5 min-inhalation exposure with warm water and a 15 min-inhalation exposure with hot water. The chloroform breath concentration was almost three times higher after later exposure. The mathematical model analyzing the relationship between two key shower parameters and breath concentration normalized to water concentration fits quite Ivell with the experimental data at a probability of p : 0.0001.

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Parallel Key-Insulated Signature Scheme without Random Oracles

  • Wan, Zhongmei;Li, Jiguo;Hong, Xuan
    • Journal of Communications and Networks
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    • v.15 no.3
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    • pp.252-257
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    • 2013
  • To alleviate the damage caused by key exposures, Dodis et al. introduced the notion of key-insulated security where secret keys are periodically updated by using a physically insulated helper key. To decrease the risk of helper key exposures, Hanaoka et al. advocated parallel key-insulated mechanism where distinct helpers are independently used in key updates. In this paper, we propose the first parallel key-insulated signature scheme which is provably secure without resorting to the random oracle methodology. Our scheme not only allows frequent key updating, but also does not increase the risk of helper key exposures.

Privacy-Preserving Key-Updatable Public Key Encryption with Keyword Search Supporting Ciphertext Sharing Function

  • Wang, Fen;Lu, Yang;Wang, Zhongqi;Tian, Jinmei
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.16 no.1
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    • pp.266-286
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    • 2022
  • Public key encryption with keyword search (PEKS) allows a user to make search on ciphertexts without disclosing the information of encrypted messages and keywords. In practice, cryptographic operations often occur on insecure devices or mobile devices. But, these devices face the risk of being lost or stolen. Therefore, the secret keys stored on these devices are likely to be exposed. To handle the key exposure problem in PEKS, the notion of key-updatable PEKS (KU-PEKS) was proposed recently. In KU-PEKS, the users' keys can be updated as the system runs. Nevertheless, the existing KU-PEKS framework has some weaknesses. Firstly, it can't update the keyword ciphertexts on the storage server without leaking keyword information. Secondly, it needs to send the search tokens to the storage server by secure channels. Thirdly, it does not consider the search token security. In this work, a new PEKS framework named key-updatable and ciphertext-sharable PEKS (KU-CS-PEKS) is devised. This novel framework effectively overcomes the weaknesses in KU-PEKS and has the ciphertext sharing function which is not supported by KU-PEKS. The security notions for KU-CS-PEKS are formally defined and then a concrete KU-CS-PEKS scheme is proposed. The security proofs demonstrate that the KU-CS-PEKS scheme guarantees both the keyword ciphertext privacy and the search token privacy. The experimental results and comparisons bear out that the proposed scheme is practicable.

A Pilot Establishment of the Job-Exposure Matrix of Lead Using the Standard Process Code of Nationwide Exposure Databases in Korea

  • Ju-Hyun Park;Sangjun Choi;Dong-Hee Koh;Dae Sung Lim;Hwan-Cheol Kim;Sang-Gil Lee;Jihye Lee;Ji Seon Lim;Yeji Sung;Kyoung Yoon Ko;Donguk Park
    • Safety and Health at Work
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    • v.13 no.4
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    • pp.493-499
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    • 2022
  • Background: The purpose of this study is to construct a job-exposure matrix for lead that accounts for industry and work processes within industries using a nationwide exposure database. Methods: We used the work environment measurement data (WEMD) of lead monitored nationwide from 2015 to 2016. Industrial hygienists standardized the work process codes in the database to 37 standard process and extracted key index words for each process. A total of 37 standardized process codes were allocated to each measurement based on an automated key word search based on the degree of agreement between the measurement information and the standard process index. Summary statistics, including the arithmetic mean, geometric mean, and 95th percentile level (X95), was calculated according to industry, process, and industry process. Using statistical parameters of contrast and precision, we compared the similarity of exposure groups by industry, process, and industry process. Results: The exposure intensity of lead was estimated for 583 exposure groups combined with 128 industry and 35 process. The X95 value of the "casting" process of the "manufacture of basic precious and non-ferrous metals" industry was 53.29 ㎍/m3, exceeding the occupational exposure limit of 50 ㎍/m3. Regardless of the limitation of the minimum number of samples in the exposure group, higher contrast was observed when the exposure groups were by industry process than by industry or process. Conclusion: We evaluated the exposure intensities of lead by combination of industry and process. The results will be helpful in determining more accurate information regarding exposure in lead-related epidemiological studies.