• Journal of Communications and Networks
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• 제18권3호
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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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• 제23권1호
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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.

• 의료법학
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• 제10권1호
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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.

• 해양환경안전학회지
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• 제12권2호
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• pp.89-98
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• 2006

이 연구는 해산어 양식장 환경을 재현한 해양 microcosm을 이용하여, 양식장에서 빈번히 사용하고 있는 옥소린산에 대한 미생물이 나타내는 항생제 내성획득에 관해 알아보고자 하였다. 옥소린산 처리 전과 후의 세균상을 비교한 결과, 비브리오 과 세균은 실험기간 전반에 걸쳐 65-75% 정도로 우점하였으며, 그람양성세균인 Micrococcos sp. 와 Bacillus sp. 는 옥소린산 처리 기간 중에 출현 빈도가 증가하였다. 해산어양식 환경에서 세균의 ETS 활성은옥소린산 처리 기간중 42-67%로 줄어들었지만, 옥소린산의 처리가 종료된 후에 세균은 다시 회복되었다. 해산어 양식장에서 옥소린산의 빈번한 사용은 옥소린산에 대한 세균의 내성을 증가시키는 것으로 관찰되었다.

• 정보보호학회논문지
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• 제13권1호
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• pp.139-146
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• 2003

본 논문은 과포화 다변수 방정식을 이용하여 LILI-128 스트림 암호를 분석한다. LILI-128 암호$^{[8]}$ 는 128비트 키를 가진 선형귀환 쉬프트 레지스터 기반의 스트림 암호로 구조를 살펴보면 크게 “CLOCK CONTROL” 부분과 “DATA GENERATION” 부분으로 나뉘어진다. 분석 방법은 “DATA CENERATION” 부분에 사용되는 함수 \ulcorne $r^{d}$ 의 대수적 차수가 높지 못하다는 성질을 이용한다. 간략히 설명하면 차수(K)가 6차인 다변수 방정식을 많이 얻을 수 있고, 이를 7차 (D)의 다변수 방정식으로 확장하여 주어진 변수보다 많은 연립방정식을 얻어 그 해를 구하는 XL 알고리즘을 통해 전수조사보다 빠르게 키정보를 찾을 수 있다. 결과 중 가장 좋은 것은 출력 키수열 2$^{26.3}$비트를 가지고 2$^{110.7}$ CPU 시간을 통해 128비트 키정보를 얻는 것이다.다.

• Physical Therapy Rehabilitation Science
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• 제11권1호
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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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• 제49권3호
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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.

• 의정연구
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• 제15권1호
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• pp.93-118
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• 2009

왜 한국의 국회는 첨예하게 갈등하고 파행적으로 운영되는 모습을 빈번하게 보여주고 있는가? 이 질문과 관련하여 본 연구는 국회의 집합적 의사결정 구조에 대한 정당들간의 인식 차이가 존재하고, 이것이 국회 내 갈등과 불신을 심화시키는 요인으로 작용하고 있다는 점에 주목하고 있다. 구체적으로 본 연구는 뷰캐넌과 튤락이 제시한 대의민주주의 하의 집합적 의사결정 모델을 활용하여 의회 내 신뢰의 문제는 다수 의사의 존중과 소수 의사의 보호를 최적으로 추구할 수 있는 토대가 된다는 점을 논의하고 있다. 그리고 한국의 국회가 최적의 집합적 의사결정을 이루어내지 못하는 이유는 국회의 집합적 의사결정 구조에 대한 합의가 부족한 상황 속에서 다수결적 방식과 합의적 방식을 선호하는 정당들이 서로 충돌하기 때문이라는 점을 지적하고 있다. 이를 토대로 본 연구는 한국의 국회가 최적의 집합적 의사결정을 이루어내기 위해서는, 그리고 국회 내 정당들간의 신뢰를 회복하기 위해서는 합의적 의사결정 제도의 도입을 확대하고, 장외투쟁과 물리적 저항 등과 같은 비제도적 수단의 동원을 방지하는 것이 최선의 선택이 될 수 있다는 점을 제안하고 있다.

• Journal of Microbiology and Biotechnology
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• 제26권6호
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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.

• 자원리싸이클링
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• 제31권4호
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• pp.34-39
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• 2022

본 연구에서는 약 3.5% 구리 함유 폐에칭액으로부터 구리를 회수하기 위한 철 샘플에 따른 시멘테이션 반응 시 초음파 에너지 인가에 의한 반응 속도와 구리 회수율에 미치는 영향을 조사하였다. 그 결과 단순 교반 공정에 비해 시멘테이션 반응이 효과적으로 일어나 같은 시간 대비 높은 구리 회수율을 나타냈다. 단순 교반과 초음파에너지를 가하였을 때를 비교해보면, 25분 반응에 따라 철 샘플 형태가 plate를 사용하였을 때, 약 9.5%가 56.6%로 향상되었으며, chip은 약 14.0%에서 46.1%, powder는 약 41.9%에서 77.2%로 증가하였다. 이는 시멘테이션 반응으로 생성되어 철 표면을 덮고 있던 구리가 탈착되며 연속반응이 유도되었고, 구리 회수율은 약 2배에서 6배까지 증가하였으며, 회수된 구리의 입자 크기 또한 감소하는 경향을 확인할 수 있었다.