• Fisheries and Aquatic Sciences
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• v.21 no.11
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• pp.34.1-34.13
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• 2018

Sexual maturity ($L_{50}$), the length at which 50% of fish in a size class are mature, is a key aspect of domestication of new fish species because it guides the procedure for identification of appropriate broodstock size for artificial spawning. In this study, the $L_{50}$ was determined for 1083 Barbus altianalis samples obtained from Lake Edward and the Upper Victoria Nile. Gonads of freshly killed samples were examined macroscopically and verified with standard histological procedures for the maturation stages that were used to determine $L_{50}$. Oocytes and spermatogenic cell sizes were compared for fish obtained from both water bodies. Results indicated that there were no variations in macro gonad features observed for fish from Lake Edward and Upper Victoria Nile. Similarly, there were no significant differences in oocyte sizes (P > 0.05) between the two populations but significant differences in spermatogenic cell sizes were noted (P < 0.05) except for spermatozoa (P > 0.05). This however did not suggest peculiar differences between the two populations for staging the gonads. Consequently, no staging variations were suggested for both populations in determination of $L_{50}$. Sexual maturity was found in the same class size of fork length (FL) 20-24.9 cm and 35-39.9 cm for males and females from both water bodies, respectively. At this FL, however, males were too small, and for good selection of vigor broodstocks for spawning and conservation purposes, they are better picked from class size of 30-34.9 cm FL and above. These findings were crucial for integration of appropriate breeding size in spawning protocol by farmers and fisheries scientists conserving wild B. altianalis populations.

• Journal of the Korea Society of Computer and Information
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• v.27 no.5
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• pp.69-76
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• 2022

In this paper, we presented the contents and methods of AI classes using AI platforms. First, we extracted the content elements of each stage of the AI class using the AI education platform from experts. Classes using the AI education platform were divided into 5 stages and 25 class elements were selected. We also conducted a survey of 82 teachers and analyzed the factors that they acted importantly at each stage of the AI platform class. As a result of the analysis, teachers regarded the following contents as important factors for each stage that are AI model preparation stage (the learning stage of the AI model), problem recognition stage (identification of problems and AI solution potential), data processing stage (understanding the types of data), AI modelingstage (AI value and ethics), and problem solvingstage (AI utilization in real life).

• Journal of Preventive Medicine and Public Health
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• v.33 no.3
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• pp.323-333
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• 2000

Objectives : Chronic HBsAg carriers are the principal source of infection for other susceptible people, and are themselves at high risk of developing serious liver diseases. In Korea, it has been estimated that 65-75% of the HBsAg positives remained as persistent carriers. Additionally, familial clustering of MBV infection has frequently been observed among carriers. Some would become progressive, chronic hepatitis patients, and others would not. The aim of this study was to evaluate the association between various factors, such as the duration of infection, type of virus, mutation of precore/core region in HBV, major histocompatibility class-I, and developing chronic liver diseases among familial HBV carriers. Methods : Chronic carrier status was identified by repeated serological tests for HBsAg at intervals of six months or more. A familial chronic carrier was defined when the disease was observed in a family member over two generations. Two families were recruited, among which a total of 20 chronic HBsAg carriers(11 carriers in No.1, and 9 in No.2 family) were identified. Data on the general characteristics and liver disease status were collected. Identification of the HBV-DNA was successful only for 13 subjects among the 20 carriers. Analysis of viral DNA in terms of subtype, pre-core and core region mutations was carried out. The type of major histocompatibility class-1 for the 13 subjects was also analysed. Results & Conclusions : Seven of 10 chronic HBV carriers of the 1st generation and one of 10 of the 2nd generation were clinical patients with chronic hepatitis, the others, three of the 1 st and nine of the 2nd generation, were asymptomatic carriers. This data indicates that the duration of HBV carriage is one of the major factors for disease severity. The subtype of HBsAg analysed using MBV-DNA identified in 13 carriers were adr, and the pattern of precore nonsense mutation in HBV-DNA was identical among family members, which meads that the same virus strains were transmitted between the family members. The association between the precore or core mutations in HBV-DNA and the disease severity was not observed. While it was suggested that a specific type of MHC class-I may be related to disease progression.

• Survey Research
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• v.10 no.1
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• pp.1-32
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• 2009

This study examines the changes of income, everyday life and living condition of consumer in the aftermath of financial crisis. In this period financial crisis was the crucial factor behind various social problems such as the dissolution of families and individuals. This research explores the range and degree of impact on individuals and social groups after the financial crisis. We explore the social mobility in terns of maintaining middle class and falling into the lower class measured by middle class identification. The 60% of the middle class before the financial crisis maintained the middle class position and the rest of people left out of middle class and fell into lower class. The 60% of those who has been maintained and has just became the members of middle class were college - educated people. The great part of people whose income and assets has increased after financial crisis belongs to college - educated group. Many of those whose income have decreased belong to the high school educated group and blow, the older than 50 years old, self - employed without employee and unpaid family employee. Those whose income and assets decreased and those who experienced downward mobility have undergone changes in everyday life and living conditions as a consumer. Many of them experienced the unemployment, nonpayment or credit - delinquency, dissolution of family, worsening health condition, depression, feeling the impulse to commit suicide simultaneously. The poor consumer disposition, reduction of living expenses, sound consumer culture have expanded to people since economic crisis. The middle class reported that the cost of private education often goes beyond the family ability to pay. The lower class has suffered from the cost of living. In a meanwhile luxury goods preference, consumer consciousness for status symbol have continuously increased among all the classes since 1997. Thus fluctuations of one's income and social mobility during past 10 years were some of the major determinants which brought about the various damaging life events, changes of living conditions and everyday lives as a consumer.

• Proceedings of the Korean Information Science Society Conference
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• 2006.06d
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• pp.91-93
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• 2006

RFID(Radio Frequency IDentification) 기술은 RF 신호를 사용하여 물품에 부착된 전자 태그(tag)를 식별하는 비접촉자동인식 기술이다. 이런 RFID 기술의 확산을 위해서는 리더가 다수의 태그를 빠른 시간 안에 인식하는 다중 태그 식별 문제를 해결 해야만 한다. 지금까지 이 문제를 해결하기 위한 충돌 방지(anti-collision) 알고리즘이 많이 개발되었다. 본 논문에서는 이런 충돌 방지 알고리즘 중에서 18000-6 Type A, Type B와 Type C로 새롭게 채택된 EPCglobal Class1 Generation2, 그리고 Query Tree Protocol에 대한 시뮬레이션 시스템의 구조를 소개하고 실제 시뮬레이션 했을 때의 각 알고리즘에 대한 간단한 성능 평가를 한다.

• Smart Structures and Systems
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• v.8 no.3
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• pp.253-274
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• 2011

In this paper, the harmonic displacement response of a damaged square plate with all-over part-through damage parallel to one edge is utilized as the input signal function in wavelet analysis. The method requires the properties of the damaged plate, i.e., no information about the original undamaged structure is required. The location of damage is identified by sudden changes in the spatial variation of transformed response. The incurred damage causes a change in the stiffness or mass of the plate. This causes a localized singularity which can be identified by a wavelet analysis of the displacement response. In this study via numerical examples shown by using harmonic response is more versatile and effective compared with the static deflection response, specially in the presence of noise. In the light of the obtained results, suggestions for future work are presented and discussed.

• International Journal of Control, Automation, and Systems
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• v.2 no.1
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• pp.118-124
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• 2004

This paper proposes an approach to deriving a fuzzy classifier based on evolutionary supervised clustering, which identifies the optimal clusters necessary to classify classes. The clusters are formed by multi-dimensional weighted Euclidean distance, which allows clusters of varying shapes and sizes. A cluster induces a Gaussian fuzzy antecedent set with unique variance in each dimension, which reflects the tightness of the cluster. The fuzzy classifier is com-posed of as many classification rules as classes. The clusters identified for each class constitute fuzzy sets, which are joined by an "and" connective in the antecedent part of the corresponding rule. The approach is evaluated using six data sets. The comparative results with different classifiers are given.are given.

• Proceedings of the IEEK Conference
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• 2005.11a
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• pp.1113-1116
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• 2005

최근들어 Radio Frequency Identification(RFID) 태그가 다수의 상품에 부착되고 여러 분야에 적용되기 시작했지만, 편리성이나 비용문제로 인해 인증과 암호화 같은 보안기능은 적용되지 않고있다. 보안 기능이 없는 RFID 시스템은 개인정보 노출, 불법 리더의 접근, 위조 태그의 남용과 같은 심각한 부작용을 초래하지만, 태그 자원의 제약으로 인해 보안기능을 적용하기가 쉽지않다. 현재 여러 기술을 따르는 RFID 시스템 중 EPCglobal 의 EPC Class 1 Generation 2(C1G2) 는 산업계의 여러 분야에서 특히, supply-chain 모델에서 사실상 국제표준으로 여겨진다. 본 논문에서는, RFID 보안 프로토콜 중 EPC C1G2 메커니즘의 Inventory 과정에서 태그가 리더를 인증하는 기법을 제안한다. C1G2 시스템에서는 인증되지 않은 리더의 태그 액세스가 가능한데, 이는 태그의 리더 인증으로서 차단될 수 있다. 또한, EPC C1G2 태그-리더 간의 상호인증 기법을 제안한다. 이 과정에서 태그 ID 는 노출되지 않고 전송되며, 태그 인증을 통해 태그 위변조를 방지할 수도 있다. 제안 메커니즘은 태그를 식별하는 절차에서 인증을 위해 프로토콜 패스 수의 증가가 없다. 다만 리더와 태그에서 Inventory 과정의 ACK command 와 태그의 reply 구현에 약간의 수정을 필요로 한다.

• Journal of the Korean Institute of Intelligent Systems
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• v.7 no.4
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• pp.29-39
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• 1997

A discrete model reference control scheme for a vehicle four wheel steering system(4WS) is proposed and evaluated for a class of discrete time nonlinar dynamics. The schmen employs a neural network to identify the plan systems, wher the neural network estimates the nonlinear dynamics of the plant. The algorithm is proven to be globally stable, with tracking errors converging to the neighborhood of zero. The merits of this scheme is that the global system stability is guaranteed. Whith thd resulting identification model which contains the neural networks, the parameters of controller are adjusted. The proposed scheme is applied to the vehicle active four wheel system and shows the validity and effectiveness through simulation. The three-degree-of freedom vehicle handling model is used to investigate vehicle handing performances. In simulation of the J-turn maneuver, the yaw rate overshoot reduction of a typical mid-size car is improved by 30% compared to a two wheel steering system(2WS) case, resulting that the proposed scheme gives faster yaw rate response andl smaller side slip angle than the 2WS case.

• Journal of the Korean Data and Information Science Society
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• v.17 no.2
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• pp.475-486
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• 2006

Space time series data can be viewed either as a set of time series collected simultaneously at a number of spatial locations or as sets of spatial data collected at a number of time points. The major purpose of this article is to formulate a class of space time autoregressive moving average (STARMA) model, to discuss some of the their statistical properties such as model identification approaches, some procedure for estimation and the predictions. For illustration, we apply this STARMA model to the mumps data. The data set of mumps cases consists of the number of cases of mumps reported from twelve states monthly over the years 1969-1988.