• Journal of applied mathematics & informatics
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• 제18권1_2호
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• pp.95-112
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• 2005

This work concerns the stabilization of uninfected steady state of an ordinary differential equation system modeling the interaction of the HIV virus and the immune system of the human body. The control variable is the drug dose, which, in turn, affects the rate of infection of $CD4^{+}$ T cells by HIV virus. The feedback controller is constructed by a variant of the receding horizon control (RHC) method. Simulation results are discussed.

• 한국식품영양과학회지
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• 제35권10호
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• pp.1329-1335
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• 2006

AIDS로의 진행과정은 단순히 몇몇 기작에 의한 것이 아니라 여러 경로를 거쳐 발생하며 그 진행속도도 개개인에 따라 다양하게 나타나고 있다. 본 연구에서는 쥐 AIDS 모델을 이용하여 항산화호르몬으로 알려진 DHEAS의 면역조절 효과를 확인하고자 하였다. DHEAS의 투여는 LP-BM5 retrovirus 감염으로 인한 T와 B 임파구의 mitogenesis를 증가시켰으며 Th1/Th2 type cytokines의 발현에도 영향을 미쳤는데 주로 전사수준에서 작용한 것으로 생각된다/ 또한 retrovirus 감염으로 인한 간조직의 지질과산화 유발을 억제하여 조직 내의 항산화제인 vitamin E의 함량을 유지시킴으로 NF-kB의 활성화를 통한 retrovirus의 복제를 억제시켜 Th1/Th2 type cytokines의 불균형적인 발현을 저해하였을 것으로 여겨진다. 따라서 쥐 AIDS모델에 있어서 DHEAS의 면역조절 효과를 확인한 본 연구는 향후 HIV감염 이후 AIDS로의 진행 과정 시 항산화제의 역할과 기작 규명에 대한 가능성을 제시할 수 있을 것으로 생각된다.

• 한국항해항만학회지
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• 제37권6호
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• pp.587-595
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• 2013

항만건설 및 운영에서 해양교통시설의 설치와 운영은 해상충돌방지 및 안전에서 매우 중요한 인자이다. 그리고, 해상교통시설의 설치 및 운영은 IMO SOLAS 5장 제13조에 의하여 당국의 의무사항으로 규정되어 있다. 해양교통시설은 과거의 시각적(광학, 형상) 시설에서 AIS, DGPS 및 기타 전파표지 등을 활용한 e-Navigation의 개념으로 발전하고 있다. 그러나 이러한 해양교통시설의 자동화 흐름에도 불구하고 선박의 안전한 항해를 위한 광파표지 및 형상표지의 역할은 여전히 절대적이다. 본 연구에서는 시각표지의 운영관리 효율을 향상시키기 위한 해양교통시설 서비스수준의 결정방법으로 해상교통관련 전체 시설을 하나의 관리시스템으로 조합하고 더욱 효율적인 시스템 관리방안으로서 항로표지 운영율을 제안하였다. 해외의 서비스 수준에 대한 비교와 이론적 배경을 분석하고, 제안된 서비스수준을 인천해역에 실제 적용하여 항로의 안전성을 평가한 사례를 제시하였다.

• 한국의류학회지
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• 제38권1호
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• pp.33-45
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• 2014

This study investigates urban household consumption patterns for clothing items in different income cohorts through the analysis of an Almost Ideal Demand System (AIDS) model. Korea quarterly time-series statistics data for urban household expenditures from 1990 to 2013 analyzed household demand. The price and total consumption expenditure elasticities of 4 clothing items (outer wear, shoes, clothing related services and other miscellaneous clothing) for 7 income cohorts were estimated to investigate the clothing consumption patterns of different income cohorts. The study results show that the different household income cohorts have different consumption patterns for clothing items. The elastic demand of total consumption expenditures in the lowest household income cohort suggests that they consume clothing items as luxuries while other households mostly consume them as necessities. The price elasticity for all household income cohorts and clothing items (except the highest household income cohort and outer wear) was found to be elastic. The highest household income cohort had an inelastic price demand for all clothing items that implied a less sensitive clothing consumption change for the clothing price change than other households.

• 센서학회지
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• 제22권2호
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• pp.150-155
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• 2013

Recently, various hearing aids are developed to overcome hearing loss. There are available hearing aids, such as air conduction hearing aid, implantable middle ear hearing aid and so on. But air conduction hearing aid is inconvenience caused by howling, and ossicle chain driving type implantable middle ear hearing aid has some week point due to problem of possible nercobiosis of coupling spot along incus long process. In recent years, in order to improve these shortcomings round window (RW) driving hearing aid has been paying attention. In this paper, the physical cochlear model is proposed for a performance evaluation of the RW driving hearing aids of a transducer. In order to verify an experiment proposed on a performance of physical cochlear model, the transducer which has ossicles characteristics is used. By measuring and comparing the frequency characteristics of transducer with ossicles and human temporal bone, performance of physical cochlear model was verified. As from the result of experiment, it is expected that an implemented cochlear model is useful for evaluating characteristics of RW transducer.

• 한국통계학회:학술대회논문집
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• 한국통계학회 2004년도 학술발표논문집
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• pp.243-248
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• 2004

The timings of two successive events of interest may not be measurable, instead it may be right censored or interval censored; this data structure is called doubly censored data. In the study of HIV, two such events are the infection with HIV and the onset of AIDS. These data have been analyzed by authors under the assumption that infection time and induction time are independent. This paper investigates the regression problem when two events arc modeled to allow the presence of a possible relation between two events as well as a subject-specific effect. We derive the estimation procedure based on Goetghebeur and Ryan's (2000) piecewise exponential model and Gauss-Hermite integration is applied in the EM algorithm. Simulation studies are performed to investigate the small-sample properties and the method is applied to a set of doubly censored data from an AIDS cohort study.

• International Journal of Computer Science & Network Security
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• 제21권8호
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• pp.238-246
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• 2021

The rapid rise of the Internet and social media has resulted in a large number of text-based reviews being placed on sites such as social media. In the age of social media, utilizing machine learning technologies to analyze the emotional context of comments aids in the understanding of QoS for any product or service. The classification and analysis of user reviews aids in the improvement of QoS. (Quality of Services). Machine Learning algorithms have evolved into a powerful tool for analyzing user sentiment. Unlike traditional categorization models, which are based on a set of rules. In sentiment categorization, Bidirectional Long Short-Term Memory (BiLSTM) has shown significant results, and Convolution Neural Network (CNN) has shown promising results. Using convolutions and pooling layers, CNN can successfully extract local information. BiLSTM uses dual LSTM orientations to increase the amount of background knowledge available to deep learning models. The suggested hybrid model combines the benefits of these two deep learning-based algorithms. The data source for analysis and classification was user reviews of Indian Railway Services on Twitter. The suggested hybrid model uses the Keras Embedding technique as an input source. The suggested model takes in data and generates lower-dimensional characteristics that result in a categorization result. The suggested hybrid model's performance was compared using Keras and Word2Vec, and the proposed model showed a significant improvement in response with an accuracy of 95.19 percent.

• 재활복지공학회논문지
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• 제8권3호
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• pp.213-219
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• 2014

본 연구는 저시력 노인의 시력보조기구 사용에 영향을 미치는 요인을 탐색하기 위해 2차년도 한국노동연구원의 고령화연구패널에서 시력으로 일상생활이 어려운 만 65세 이상의 노인 384명을 최종분석에 활용하였다. 분석은 Andersen-Newman의 서비스 이용모델을 기반으로 선행요인, 가능성요인, 욕구요인으로 구분하여 각각의 요인들이 저시력 노인의 시력보조기 사용에 미치는 영향력을 살펴보기 위해 로지스틱 회귀분석(logistic regression)을 실시하였다. 분석결과 선행요인에서는 교육수준이 높고 미취업상태에서, 가능성 요인에서는 주관적 계층의식이 낮을수록, 욕구요인에서는 인지기능이 높을수록 시력보조기구 사용수준이 유의미하게 높아지는 것으로 나타났다. 이러한 결과를 토대로 연구의 제한점과 함의를 제안하였다.

• Journal of applied mathematics & informatics
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• 제33권5_6호
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• pp.559-578
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• 2015

Human Immune Deficiency Virus (or simply HIV) induces a persistent infection that leads to AIDS causing death in almost every infected individual. As HIV affects the immune system directly by attacking the CD4+ T cells, to exterminate the infection, the natural immune system produces virus-specific cytotoxic T lymphocytes(CTLs) that kills the infected CD4+ T cells. The reduced CD4+ T cell count produce reduced amount of cytokines to stimulate the production of CTLs to fight the invaders that weakens the body immunity succeeding to AIDS. In this paper, we introduce a mathematical model with discrete time-delay to represent this cell dynamics between CD4+ T cells and the CTLs under HIV infection. A modified functional form has been considered to describe the infection mechanism. Characteristics of the system are studied through mathematical analysis. Numerical simulations are carried out to illustrate the analytical findings.

• Journal of Applied Biological Chemistry
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• 제48권4호
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• pp.170-177
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• 2005

Oriental medicinal herb extracts (OHE) showing anticancer activities were investigated for effectiveness as antiviral drugs. Infection of MuLV to cell line resulted in formation of giant syncytia. Number of giant syncytia in culture treated with OHE decreased by 40% compared to that of non-OHE-treated cell culture. To determine OHE effects on progeny release, RT-PCR was performed. In vivo animal studies demonstrated effectiveness of OHE as antiviral drug when administered orally. After OHE administration, viral cytopathic effects decreased. Infected mice showed splenomegaly and over-proliferation of lymphocytes with decreased CD4+ cell counts. These symptoms decreased in OHE-treated mice, indicating OHE maybe useful therapeutics against MuLV/MAIDS as Human Immunodeficiency Virus (HIV)/AIDS animal model. Results show XC plaque assay and in vivo MAIDS model using MuLV are suitable tools for screening anti-retroviral drug candidates.