• Annual Conference of KIPS
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• 2024.05a
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• pp.383-385
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• 2024

이동통신 분야 사실표준화 기구인 3GPP(3rd Generation Partnership Project)에서는 기존의 5G 이동통신 기술을 향상시키기 위한 5G-Advanced 연구를 시작했다. 5G 및 5G-Advanced 시대에 접어들면서 네트워크를 향상시키기 위한 다양한 요소기술들이 등장하였지만, 이러한 기술 변화에 비례하여 네트워크를 위협하는 공격 표면들이 증가할 것으로 예상된다. 점진적인 네트워크 보안 위협에 대응하기 위해 보안 기술은 에드온(Add-on) 형태로 개발되었지만, 이는 이동통신시스템에서 보안 기술의 신뢰성을 낮추고 네트워크에 대한 보안 품질을 보장하지 못한다. 따라서, 본 논문에서는 5G-Advanced에서 사용되는 N2/N3 인터페이스에서 발생가능한 DoS(Denial of Service) 공격에 대해 실험하고 분석한다. 분석 결과는 5G-Advanced 이동통신시스템의 공격 표면을 나타내고 보안 내재화의 필요성을 강조한다.

• Journal of Korean Elementary Science Education
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• v.36 no.3
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• pp.193-207
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• 2017

The purpose of this study was to investigate pre-service elementary teachers' attitudes towards science teaching using 'Dimensions of Attitude Toward the Teaching of Science (DAS)'. After confirming the factors and reliabilities of the translated questionnaire by pilot test (N=68), the survey was administered online at one national university of education in Korea (N=527). The pre-service teachers generally thought elementary science education is important and did not believe gender difference in students and in teachers. Science education majors than other majors, males than females, and those who completed high school science track than humanity track had more positive attitudes toward science teaching in elementary school. The extent of teacher education curriculum completion had a little effect on the pre-service teachers' attitudes toward science teaching. The implications for teacher education were discussed.

• 한국정보통신설비학회:학술대회논문집
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• 2007.08a
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• pp.92-99
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• 2007

현재 통신 시장은 보다 편리하고 다양한 서비스를 찾는 소비자의 욕구와 맞물려 TPS(Triple Play Service) 방향으로 급속히 나아가고 있다. 인터넷 전화의 보급은 이미 보편적 서비스가 된 초고속인터넷 서비스와 연계하여 빠르게 확산되고 있으며, 2007년 들어 방송서비스까지 결합한 TPS에 대한 통신사업자간 경쟁이 본격화되고 있는 추세이다. 트리플 플레이 서비스(Triple Play Service;이하 TPS)는 초고속 인터넷과 인터넷 전화와 방송 서비스를 하나의 회선으로 제공하는 종합 인터넷 서비스로, 광대역 통합망(BcN; Broadband Convergence Network)의 핵심 서비스이다. 액세스 스위치(Access Switch) 단은 TPS로 인해 더욱 많은 역할을 담당할 것으로 전망되는데, 디지털 방송을 인터넷 프로토콜을 통해 전송하기 위한 멀티캐스트 기능과 혼재된 이종간의 디지털 신호를 각 서비스의 품질에 맞게 보장해 주는 QoS(Quality of Service) 기능이 무엇보다 중요하게 고려 되어야 한다. 본 논문에서는 TPS의 핵심일 수 있는 방송 서비스를 위해 액세스 스위치 단에서 제공해야 할 멀티캐스트와 QoS 기능 구현 방안에 대해 제시한다

• Journal of Korean Institute of Industrial Engineers
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• v.27 no.1
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• pp.89-94
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• 2001

There are many queueing systems where customers wait for service up to a certain amount of time and leave the system if they are not served during that time. This paper considers a finite capacity multi-server queueing system with Poisson input and Erlang service time, where a customer becomes a lost customer when his service has not begun within an exponential patient time after his arrival. Performance measures such as average queue length, the average number of customers in service, and the proportion of lost customers can be obtained exactly through the proposed numerical solution procedure.

• International Journal of Human Ecology
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• v.13 no.1
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• pp.1-16
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• 2012

Information about the characteristics of street-living versus shelter-residing youth is vital for tailoring prevention and intervention efforts to the unique needs of runaway and homeless youth. The present study compared two samples of youth [street-living (n=73) versus shelter-residing (n=205)], between the ages of 14 to 17 years, on behavioral and emotional factors and service use. Based on the different characteristics of the two groups, the predictors explaining the living status of the runaways and homeless youth were explored. In general, street-living youth reported more severe substance use, depressive symptoms, and risky sexual behavior, but less lifetime service involvement compared to shelter-residing youth. The factors that predicted shelter-residing status were related to younger age, prior service care experience, more knowledge about HIV, and engaging in less delinquent and risky behavior. Given the little overlap among youth in service involvement and the greater severity faced by street-living youth, the conclusions highlight the need for increased funding and attention towards facilitating the ability of street-living youth to find and enter mental health and reintegration services.

• Convergence Security Journal
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• v.6 no.2
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• pp.61-69
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• 2006

For the efficient business, the telecommunication providers should have an attention for the minimization of the basic setup cost to implement the network infrastructure. Furthermore, the provision of the quality of service (QoS) to the service users is crucial for the service providers and vendors. In this paper, we propose the new algorithm to provide the user's QoS under the various traffic in the broadband convergence network. Using the NS-2 network simulator, we evaluate the QoS for the proposed algorithm, and compare those with the results of the previous differentiated service network.

• Korean Journal of Microbiology
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• v.44 no.3
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• pp.178-185
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• 2008

Avian influenza virus (AIV) is recognized as key to the emergence of pandemic influenza for humans; there are growing concerns that AIV H9N2 may become more efficient to transmit to humans in the near future, since the infection of poultry with AIV H9N2 has been common in recent years. In this study, we aimed to produce antisera recognizing the HA and NA proteins of AIV H9N2. Initially, coding sequences corresponding to the N-terminal regions of the HA and NA proteins of the Korean AIV H9N2 (A/Ck/Kr/MS96/96) isolated from a domestic chicken were amplified from the genomic RNA. Following cloning of the amplified cDNA fragments into pGEX4T-1 vector, two GST-fusion proteins (GST-HAln and GST-NAn) were expressed in E. coli BL21 and purified with glutathione sepharose columns; the recombinant GST-HAln and GST-NAn proteins were both used as immunogens in rabbits. The antigenicity of the rabbit antisera was analyzed by immunoblotting of the cell lysates prepared from AIV H9N2-infected MDCK cells. Overall, the recombinant HAln and NAn proteins fused to the C-terminus of GST and the rabbit antisera raised against the corresponding recombinant proteins would provide a valuable reagent for AIV diagnosis and basic research.

• Korean Journal of Veterinary Research
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• v.41 no.3
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• pp.381-385
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• 2001

Neospora caninum infections have been associated with neonatal paresis as well as abortion around the world. Bovine abortion induced by N caninum was first reported in 1997 in Korea. Diagnosis of N caninum infection is usually based on histopathology and immunohistochemical detection of organism. However, often the tissues having lesion suggestive of N caninum infection were negative on immunohistochemistry. Here, we describe establishment of PCR-based diagnostic strategy for N caninum infection using DNA extracted from paraffin blocks containing the lesion. PCR was able to amplify N caninum-specific bands from the paraffin blocks containing at least moderate degree of inflammation. Compared to paraffin-blocks, DNA extracted from fresh tissues were less sensitive than that of paraffin blocks. This PCR-based method can be practically applicable for rapid diagnosis of bovine N caninum infection with high specificity and sensitivity. Based on this method, 17% of bovine abortion surveyed during a designated period was associated with N caninum infection.

• Korean Journal of Veterinary Service
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• v.42 no.4
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• pp.169-175
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• 2019

Naegleria fowleri, a pathogenic free-living amoeba, leads to a fatal infection known as primary amebic meningoencephalitis (PAM) in human and animals. PAM is an acute, fulminant, necrotizing, and hemorrhagic disease that leads to death in approximately seven days. In this study, we investigate the cytotoxicity of target cells and the secreted molecules of N. fowleri under the non-contact condition. The target cell (U87MG cell) treated with N. fowleri lysates showed no morphological changes and no cytotoxicity. By contrast, the U87MG cells co-cultured with N. fowleri trophozoites under the non-contact condition induced morphological changes and reduction in number. When U87MG cells were co-cultured with N. fowleri trophozoites under the non-contact condition for 30 min, 2 hr, and 4 hr, the levels of cytotoxicity of target cells were 32.3, 35.5, and 37.8%, respectively. Particularly, when the ratio of amoeba to target cells is 10 to 1, the level of cytotoxicity of target cells was 49.7% at 30 min. To show the proteins secreted from N. fowleri under the non-contact condition, we carried out 2D electrophoresis and observed 6 major proteins. Finally, these results suggest that the molecules released from N. fowleri under the non-contact condition induce the cell death and this process is an important step in pathogenesis of N. fowleri.

• Journal of the Korea Society of Computer and Information
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• v.18 no.3
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• pp.11-18
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• 2013

In this paper, we propose a new design scheme of N-Screen emulator based on Cloud and then implement the emulator, in order to solve the critical point of N-Screen emulator based on Cloud. This method, without the emulator in the server, will be able to confirm the features of the emulator with a browser using Web Service. This means that the identical service is possible without regard to personal computer or mobile environment. Also, in order to emulating each different web browser engine of the various devices separately, we revise and manage the WebKit engine to be suitable to the characteristics of each device. In the previous design method, the number of emulators which can be shown in a monitor is restricted to 2 or 3. However, we show that the proposed design method can improve the performance of server to the extent that this method could operate more than 100 emulators per each server.