• Journal of Communications and Networks
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• v.18 no.3
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• pp.273-287
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• 2016

White-box cryptography presented by Chow et al. is an obfuscation technique for protecting secret keys in software implementations even if an adversary has full access to the implementation of the encryption algorithm and full control over its execution platforms. Despite its practical importance, progress has not been substantial. In fact, it is repeated that as a proposal for a white-box implementation is reported, an attack of lower complexity is soon announced. This is mainly because most cryptanalytic methods target specific implementations, and there is no general attack tool for white-box cryptography. In this paper, we present an analytic toolbox on white-box implementations of the Chow et al.'s style using lookup tables. According to our toolbox, for a substitution-linear transformation cipher on n bits with S-boxes on m bits, the complexity for recovering the $$O\((3n/max(m_Q,m))2^{3max(m_Q,m)}+2min\{(n/m)L^{m+3}2^{2m},\;(n/m)L^32^{3m}+n{\log}L{\cdot}2^{L/2}\}\)$$, where $m_Q$ is the input size of nonlinear encodings,$m_A$ is the minimized block size of linear encodings, and $L=lcm(m_A,m_Q)$. As a result, a white-box implementation in the Chow et al.'s framework has complexity at most $O\(min\{(2^{2m}/m)n^{m+4},\;n{\log}n{\cdot}2^{n/2}\}\)$ which is much less than $2^n$. To overcome this, we introduce an idea that obfuscates two advanced encryption standard (AES)-128 ciphers at once with input/output encoding on 256 bits. To reduce storage, we use a sparse unsplit input encoding. As a result, our white-box AES implementation has up to 110-bit security against our toolbox, close to that of the original cipher. More generally, we may consider a white-box implementation of the t parallel encryption of AES to increase security.

• Journal of Microbiology and Biotechnology
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• v.23 no.1
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• pp.15-21
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• 2013

We previously observed that Bacillus subtilis spores from sspE mutants presented a lower germination capacity in media containing high salt concentrations (0.9M NaCl). This deficiency was attributed to the absence of SASP-E (gamma-type small-acid-soluble protein), rich in osmocompatible amino acids released by degradation. Herein we observed that, in addition, this mutant spore presented a reduced capacity to use L-alanine as germinant (L-ala pathway), required longer times to germinate in calcium dipicolinate ($Ca^{2+}$-DPA), but germinated well in asparagine, glucose, fructose, and potassium chloride (AGFK pathway). Moreover, mild sonic treatment of mutant spores partially recovered their germination capacity in L-ala. Spore qualities were also altered, since sporulating colonies from the sspE mutant showed a pale brownish color, a higher adherence to agar plates, and lower autofluorescence, properties related to their spore coat content. Furthermore, biochemical analysis showed a reduced partition in hexadecane and a higher content of $Ca^{2+}$-DPA when compared with its isogenic wild-type control. Coat protein preparations showed a different electrophoretic pattern, in particular when detected with antibodies against CotG and CotE. The complementation with a wild-type sspE gene in a plasmid allowed for recovering the wild-type coat phenotype. This is the first report of a direct involvement of SASP-E in the spore coat assembly during the differentiation program of sporulation.

• The Korean Society of Law and Medicine
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• v.10 no.1
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• pp.213-260
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• 2009

While the medical supplies have positive functions such as extending lifespan, recovering health, and preventing diseases, they also cause unexpected tragic consequences due to their side effects, and the magnitude of such damage inevitably increases due to the mechanism of mass production, mass distribution, and mass consumption of those medical supplies. Therefore, needless to say, the optimal way to prevent or reduce such damage is rather through medical supply manufacturers' producing non-defective products, or through the government's controlling production and sales of medical supplies with more aggressive exercise of regulatory authority on medical supply manufacturers, than through a remedy by a legal relief after using medical supplies. In this case, although the victim died due to the defect of the cold medicine, 'CONTAC 600', the drug company's responsibility to cover damages was not recognized because a defect could not be found in the then-manufacturing process. Thus, while pharmaceutical companies are gaining economic profits by producing and selling a medical supplies, if they do not take any remedy measures for the victims of their products' side effects, the victims have to use medical supplies under their own responsibility of taking a risk, and they have to accept the full damage of the potential consequence. Therefore, to remove such absurdity and contradiction, and to practically remedy the victim of medical supplies' side effects, the pharmaceutical side effects remedy project pending in the the Drugs, Cosmetics and Medical Instruments Lawneeds to be actively implemented.

• Journal of the Korean Society of Marine Environment & Safety
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• v.12 no.2 s.25
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• pp.89-98
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• 2006

The microbial response after treatment of antibiotics was studied for investigating the resistance pattern under simulated aquaculture environment. A marine microcosm was developed for marine fish farm environment using artificial seawater and sediment. Oxolinic acid, which has been commonly used in aquaculture, was employed for the experiment. Resistance patterns and the changes of microbial community were monitored before. during and after use of oxolinic acid. Vibrionaceae was the dominant bacterial species throughout the experiment, consisting 65-75% of total bacterial number in fish farm environment. However, some gram-positive bacteria, Micrococcos sp. and Bacillus sp. strains in marine farm environment were increased in proportion to their number during the treatment. ETS activity of the bacterial communities in aquaculture environment was reduced to 42-67% during the treatment of oxolinic acid. But recovering trends of bacterial number were also detected immediately after cease of oxolinic acid treatment. Frequent treatment of oxolinic acid under the simulated fish farm environment showed bacterial resistance to increase sharply.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.13 no.1
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• pp.139-146
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• 2003

In this paper we demonstrate a cryptanalysis of the stream cipher LILI-128. Our approach to analysis on LILI-128 is to solve an overdefined system of multivariate equations. The LILI-128 keystream generato $r^{[8]}$ is a LFSR-based synchronous stream cipher with 128 bit key. This cipher consists of two parts, “CLOCK CONTROL”, pan and “DATA GENERATION”, part. We focus on the “DATA GENERATION”part. This part uses the function $f_d$. that satisfies the third order of correlation immunity, high nonlinearity and balancedness. But, this function does not have highly nonlinear order(i.e. high degree in its algebraic normal form). We use this property of the function $f_d$. We reduced the problem of recovering the secret key of LILI-128 to the problem of solving a largely overdefined system of multivariate equations of degree K=6. In our best version of the XL-based cryptanalysis we have the parameter D=7. Our fastest cryptanalysis of LILI-128 requires $2^{110.7}$ CPU clocks. This complexity can be achieved using only $2^{26.3}$ keystream bits.

• Physical Therapy Rehabilitation Science
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• v.11 no.1
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• pp.66-77
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• 2022

Objective: This study is a systematic review conducted to analyze the environmental factors that cause falls in the older adult. Design: Systematic review Methods: The study was conducted by searching the Research Information Sharing Service (RISS), Korean studies Information Service System (KISS), and Data Base Periodical Information Academic (DBpia) databases for literature published in South Korea up to July 2020. A total of 12 studies were selected for analysis based on the inclusion and exclusion criteria. Results: The results of the analysis revealed that all the selected literature were surveys and the study subjects were 65 years of age and above. The sample size ranged from a minimum of 95 subjects to a maximum of 3,278. A total of eight tools were used to measure the environmental factors associated with falls. The prevalence and recurrence of falls increase with age and deterioration of health. Older adult individuals who experience falls encounter difficulties in recovering from impaired physical function and disability; moreover, in severe cases, falls may lead to death. Falls are largely associated with a combination of intrinsic and extrinsic (i.e., environmental) factors. The purpose of this study was to assess potential extrinsic risk factors for falls. Falls occur in indoor environments, such as washrooms, bathrooms and living rooms, and outdoor environments, including roads and stairways, depending on the season, time of day, and use of ambulatory aids. In such environments, falls are mainly caused by slipping and stuttering. Conclusions: Therefore, as the rate of fall is influenced by several factors, extrinsic factors should be improved by developing comprehensive accident prevention programs that address the improvement of environmental risk factors around places of residence to reduce risk factors among the older adult, who, especially, are at a high risk for falls.

• Archives of Plastic Surgery
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• v.49 no.3
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• pp.397-404
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• 2022

Background Excessive use of corticosteroids therapy along with gross immunocompromised conditions in the novel coronavirus disease 2019 (COVID-19) pandemic has raised the risks of contracting opportunistic fungal infections. Here, we describe our experience with the implementation of a surgical protocol to treat and reconstruct rhino-orbital-cerebral mucormycosis. Methods A retrospective review of our prospectively maintained database was conducted on consecutive patients diagnosed with mucormycosis undergoing immediate reconstruction utilizing our "Mucormycosis Management Protocol." All patients included in this study underwent reconstruction after recovering from COVID-19. Wide local excision was performed in all cases removing all suspected and edematous tissue. Reconstruction was done primarily after clear margins were achieved on clinical assessment under a cover of injectable liposomal amphotericin B. Results Fourteen patients were included. The average age was 43.6 years and follow-up was 24.3 days. Thirteen patients had been admitted for inpatient care of COVID-19. Steroid therapy was implemented for 2 weeks in 11 patients and for 3 weeks in 3 patients. Eight patients (57.1%) had a maxillectomy and mucosal lining resection with/without skin excision, and six patients (42.8%) underwent maxillectomy and wide tissue excision (maxillectomy and partial zygomatic resection, orbital exenteration, orbital floor resection, nose debridement, or skull base debridement). Anterolateral thigh (ALT) flaps were used to cover defects in all patients. All flaps survived. No major or minor complications occurred. No recurrence of mucormycosis was noted. Conclusion The approach presented in this study indicates that immediate reconstruction is safe and reliable in cases when appropriate tissue resection is accomplished. Further studies are required to verify the external validity of these findings.

• Korean Journal of Legislative Studies
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• v.15 no.1
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• pp.93-118
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• 2009

Why the National Assembly of Korea shows the serious disagreements or arguments in its operation? Regarding the question, this study pays attention to the perceptual differences among the parties for the structure of collective decision-making in the National Assembly of Korea. In addition, this study asserts that deepens the conflicts and the distrust in it. To be more specific, this study discusses about the optimal model for collective decision-making in legislative politics based on Buchanan and Tullock's opinion about it. And then, the trust in legislature forms the basis that makes it possible to respect the will of majority and protect the right of minority. The main reason that can't make the collective decision-making optimally in the National Assembly of Korea is to fight each other without the consensus about it. In this vein, making the collective decision-making optimally and recovering the trust among the parties are necessary to adopt a more consensual system. It will be helpful to prevent the use of noninstitutional means like the outside struggles or physical resistances in the National Assembly of Korea.

• Journal of Microbiology and Biotechnology
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• v.26 no.6
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• pp.1035-1045
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• 2016

To evaluate the effects of lactic acid bacteria (LAB) on Peyer's patch cells, mice were treated with a high dose of kanamycin to disturb the gut microbial environment. The overarching goal was to explore the potential of LAB for use as a dietary probiotic that buffers the negative consequences of antibiotic treatment. In vitro, LAB stimulated the production of immunoglobulin A (IgA) from isolated Peyer's patch cells. Inflammation-related genes (TNF-α, IL-1β, and IL-8) were up-regulated in Caco-2 cells stimulated with lipopolysaccharide (LPS), while tight-junction-related genes (ZO-1 and occludin) were down-regulated; the effects of LPS on inflammatory gene and tight-junction gene expression were reversed by treatment with LAB. Mice treated with a high dose of kanamycin showed increased serum IgE levels and decreases in serum IgA and fecal IgA levels; the number of Peyer's patch cells decreased with kanamycin treatment. However, subsequent LAB treatment was effective in reducing the serum IgE level and recovering the serum IgA and fecal IgA levels, as well as the number of Peyer's patch cells. In addition, ZO-1 and occludin mRNA levels were up-regulated in the ileum tissues of mice receiving LAB treatment. Lactic acid bacteria can enhance the intestinal immune system by improving the integrity of the intestinal barrier and increasing the production of IgA in Peyer's patches. Lactic acid bacteria should be considered a potential probiotic candidate for improving intestinal immunity, particularly in mitigating the negative consequences of antibiotic use.

• Resources Recycling
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• v.31 no.4
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• pp.34-39
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• 2022

In this study, effects of ultrasonic energy on the cementation reaction and copper recovery rate were investigated for different types of iron samples, such as plate, chip, and powder, for recovering copper from waste etchant, which contained ~3.5% copper. The cementation reaction using the ultrasonic energy was more effective than the simple stirring reaction, with the former exhibiting a high copper recovery rate than the latter for the same time interval. When cementation was performed for 25 min with ultrasonic treatment, rather than simple stirring, the copper recovery rate of the plate, chip, and powder improved from 7.0% to 12.0%, 14.0% to 46.1%, and 41.9% to 77.2%, respectively. Therefore, the use of ultrasonic energy could detach the copper recovered by the cementation reaction from the surface of the iron samples, thereby increasing the copper recovery rate. Owing to the use of ultrasonic energy, the copper recovery rate increased by 2-6 times, and the recovered copper exhibited a decreased particle size compared to that obtained via simple stirring.