• Proceedings of the Korea Inteligent Information System Society Conference
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• 2001.01a
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• pp.473-477
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• 2001

Artificial neural network (ANN) is known to identify relationships even when some of the input data are very complex, ill-defined and ill-structured. One of the advantages in ANN is that it can discriminate the linearly inseparable data. This study presents an application of ANN to classify and predict the symptomatic status of HIV/AIDS patients. Even though ANN techniques have been applied to a variety of areas, this study has a substantial contribution to the HIV/AIDS care and prevention planning area. ANN model in classifying both the HIV and AIDS status of HIV/AIDS patients is developed and analyzed. The diagnostic accuracy of the ANN in classifying both the HIV status and AIDS status of HIV/AIDS status is evaluated. Several different ANN topologies are applied to AIDS Cost and Services Utilization Survey (ACSUS) datasets in order to demonstrate the model\`s capability. If ANN design models are different, it would be interesting to see what influence would have on classification of HIV/AIDS-related persons.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.48 no.2
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• pp.89-95
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• 1999

This study investigates the population model of the spread of HIV/AIDS which the infection is generated by an infectious individual in a population of susceptible. A mathematical model is presented for the transmission dynamics of HIV infection within the communities of homosexual males. The pattern on the epidemic character of HIV, the causative agent of AIDS, was analysed by the mathematical model of AIDS system which is derived according to the ecological relationship between five epidemilogic states of individuals. The computer simulation was performed using real data and the following conclusions are drawn on the basis of the simulations. 1. The model structure and the algorithm described n the thesis is good. 2. In proportion to increase Ro, the population of AIDS patient increases and the time of its widespread reaches earlier. 3. The AIDS patients will be maximum between 7 and 21 years after an attack of AIDS and widespread between 10 and 20 years. 4. Considering the properties of the incubation periods, the maximum number of infected person is increased, and the attack rate is decreased.

• Korean Journal of Health Education and Promotion
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• v.14 no.2
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• pp.125-147
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• 1997

This study was conducted in order to identify the extent to which Health Belief Model (HBM) constructs explain the likelihood of taking preventive behaviors for AIDS among the young adolescents in Korea. HBM was applied as the theoretical framework for developing questionnaire items in this study. The survey instrument included all of the constructs of Health Belief Model, namely, perceived susceptibility, perceived severity, perceived benefit, perceived barriers, cue to actions for preventive behaviors concerning AIDS. Additionally, demographic characteristics of the respondents, their sexual experiences, and AIDS Knowledge Test were included in the study. Each of HBM constructs were developed with a 5-point Likert type scale from l(never agree) to 5 (absolutely agree). The survey was conducted with a total of 247 military men in a city on September 18, 1996, using self-reported questionnaire. The results of the study were summarized as follows: 1. Because the subjects for this study were military soldiers, their demographic characteristics were limited to all men, young age, and ummarried. Educational status was evenly distributed between high school graduates and university students. 2. On the average, the respondents started their first sexual relationship at 18 years old and 82.6% of them did not use condom when having their first sexual experience. Thirty-one percent of the subjects had sexual contact with prostitutes and the average number of sexual contact with prostitutes was 5 times during the past 2 years. 3. The results of AIDS Knowledge Test scores demonstrated that the respondents had a high level of knowledge about AIDS. However, some misconceptions about transmission of AIDS through casual contact were still prevailed. Sixty-six percent of the respondents expressed that people infected with HIV should be isolated from the society in order to protect the general public. 4. All the respondents expressed that they had heard about AIDS before. TV was found to be the source which provided information on AIDS most frequently. 5. Among fundamental constructs of Health Belief Model, scores of perceived benefit of taking preventive action against AIDS marked the highest score, while scores of perceived susceptibility were the lowest. As a result of Multiple Stepwise Regression analysis, 13 variable groups were found to predict the preventive action by 25%. Among them, only perceived benefit variables was the most significant factor to explain preventive behaviors by 17%.

• Journal of Preventive Medicine and Public Health
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• v.35 no.1
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• pp.65-71
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• 2002

Objective : To estimate the status of HIV infection and AIDS incidence using a back-calculation model in Korea. Methods : Back-calculation is a method for estimating the past infection rate using AIDS incidence data. The method has been useful for obtaining short-term projections of AIDS incidence and estimating previous HIV prevalence. If the density of the incubation periods is known, together with the AIDS incidence, we can estimate historical HIV infections and forecast AIDS incidence in any time period up to time t. In this paper, we estimated the number of HIV infections and AIDS incidence according to the distribution of various incubation periods Results : The cumulative numbers of HIV infection from 1991 to 1996 were $708{\sim}1,426$ in Weibull distribution and $918{\sim}1,980$ in Gamma distribution. The projected AIDS incidence in 1997 was $16{\sim}25$ in Weibull distribution and $13{\sim}26$ in Gamma distribution. Conclusions : The estimated cumulative HIV infections from 1991 to 1996 were $1.4{\sim}4.0$ times more than notified cumulative HIV infections. Additionally, the projected AIDS incidence in 1997 was less than the notified AIDS cases. The reason for this underestimation derives from the very low level of HIV prevalence in Korea, further research is required for the distribution of the incubation period of HIV infection in Korea, particularly for the effects of combination treatments.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.41 no.2
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• pp.209-216
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• 1992

Deafs train articulation by observing mouth of a tutor, sensing tactually the motions of the vocal organs, or using speech training aids. Present speech training aids for deafs can measure only single speech parameter, or display only frequency spectra in histogram of pseudo-color. In this study, a speech training aids that can display subject's articulation in the form of a cross section of the vocal organs and other speech parameters together in a single system is to be developed and this system makes a subject know where to correct. For our objective, first, speech production mechanism is assumed to be AR model in order to estimate articulatory motions of the vocal organs from speech signal. Next, a vocal tract profile model using LP analysis is made up. And using this model, articulatory motions for Korean vowels are estimated and displayed in the vocal tract profile graphics.

• Proceedings of the KIEE Conference
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• 1998.07b
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• pp.699-702
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• 1998

This study investigates the population model of the spread of HIV/AIDS which the infection is generated by an infectious in dividual in a population of susceptibles. A mathematical model is presented for the transmission dynamics of HIV infection within the communities of homosexual males. The pattern on the epidemic character of HIV, the causative agent of AIDS, was analysed by the mathematical model of AIDS system which is derived according to the ecological relationship between five epidemilogic states of individuals. The computer simulation was performed using real data.

• Korean Journal of Health Education and Promotion
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• v.16 no.2
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• pp.1-17
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• 1999

AIDS (Acquired Immunodeficiency Syndrome) known as 20th century's pest is spreading rapidly internationally, and the number of patients are increasing. Since the prevention vaccine has not been developed yet, the only available effective method for preventing AIDS is the health education. Most of the AIDS-infected persons are males, and especially over twenties of age. Therefore, it is necessary to measure the knowledge and attitudes on AIDS of male workers. The purpose of this study is to examine the knowledge, attitudes and education-needs of male workers on AIDS. The data were collected by a questionnaire survey of 977 workers who work in Seoul and Kyungki areas from September 1 thru October 4, 1997. The results were as follows: 1. We examined the level of knowledge on AIDS transmission, symptoms, diagnoses, and prevention methods. Even though respondents had a moderate level of AIDS-related knowledge, still sizable numbers believed that AIDS could be transmitted through casual contact. White-collar workers, higher education groups, higher income groups or those with age thirties showed respectively higher level of knowledge than the other comparison groups. 2. 85％ of the respondents recognized AIDS as a serious problem. Statistical analysis revealed that white-collar workers, higher education groups or those with age twenties had more positive attitudes towards a AIDS patient than their counterparts. 3. Over 80％ of the respondents replied that AIDS education in schools, work places, social agencies or by mass-media was necessary. 62.8％ of the respondents mentioned that government should play the major role in developing AIDS education program. 4. The prediction model of AIDS-education needs was examined with using the multiple logistic regression method. The education level and AIDS-related knowledge were turned to be statistically significant factors influencing positively the perceived needs of AIDS education.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.50 no.12
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• pp.597-603
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• 2001

In the mathematical model for the transmission dynamics of HIV infection described in previous papers, the population under consideration is assumed to be homogeneous community of homosexual males for which the parameter x represents the constant rate at which individual members of the population acquire new sexual partners. This is a gross oversimplification since it is well known that individuals vary widely in their levels of sexual activity and in this papers the heterogeneous model is modified to allow for this variation. The pattern on the epidemic character of HIV, the causative agent of AIDS, was analysed by heterogeneous-mixing model. The computer simulation was performed using real date.

• The Journal of Fisheries Business Administration
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• v.44 no.1
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• pp.59-70
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• 2013

The purpose of this paper is to integrate various models of price formation and let the data choose the most proper model. After the data choose the proper model, one can analyze the price formation process and demand structures for fishery resources under the restriction of Korean fisheries regulations. This study suggests the integrated model including quasi-linear price formation model, Translog price formation model, AIDS price formation model and Lewbel price formation model as level variables. It also suggests another integrated model including AIDS price formation model, Rotterdam price formation model, Latinen-Theil price formation model and Neves price formation model as difference variables. The empirical results show that the AIDS price formation model is the most preferred in both level and difference variables of fishery resources. The estimated parameters show that all sample species have (-) sign of price flexibilities, thus following the law of demand. The scale flexibilities of all species are estimated as (-) sign, thus being adapted to the theory. The contribution and results are summarized as follows. First, the integrated model of fishery market demand has been developed and the data can choose the proper model without arbitrary choice of the researcher. Second, the fishery market demand structure could be analyzed in a way different from the ordinary demand analysis, which is based upon price flexibility and scale flexibility. Third, the integrated model for fishery resources can be used easily when catching restrictions are imposed by policies.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.1
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• pp.174-182
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• 2007

In this paper, we study the influence of infection ratio on gradual reduction of drug dose for the five state HIV infection model that explicitly includes the population of the virus. We first compute all equilibrium points of the model and investigate the stabilities of them. As a result, a bifurcation diagram is obtained which shows a change in the equilibrium points, or in their stability properties, as the drug effect $\eta$ is varied from 0 to 1(alternatively, drug dose is changed from 1 to 0). Based on the bifurcation diagram, we show that the gradual reduction of drug dose can be applied for the treatment of AIDS patients. Moreover, we analyze the influence of the variation of infection ratio on the gradual reduction treatment. Computer simulation results are also presented to validate the proposed results.