교육적 효과 제고를 위한 웹 사이트 운영 개선 방향

김경원 전남대학교 2016 국내석사

외부에이전트가 존재하지 않은 경우를 고려한 핸드오프 성능개선

김장식 전남대학교 대학원 2003 국내석사

Mobile IP에서 IP층 핸드오프 중에 지연과 패킷 손실이 존재할 수 있으며, 이 중 지연은 실시간 서비스 또는 지연에 민감한 서비스에 크게 영향을 미친다. 이러한 지연을 해결하기 위해서 IETF에서는 링크계층 정보를 이용하여 사전등록과 사후등록을 할 수 있는 Low Latency Handoff를 제안하였다. 여기에서는 이전 외부에이전트와 새로운 외부에이전트가 존재하여야 되며, 만약 새로운 외부 에이전트가 존재하지 않는다면 기본 Mobile IP을 수행하게 된다. 그러나 다양한 네트워크환경에서 외부에이전트가 존재하지 않은 경우도 있을 수 있다. 본 논문에서는 이러한 상황에 적응하도록 링크계층 정보를 사용하여 사전등록과 사후등록을 할 수 있도록 제안한다. Latency and Packet loss may be present in Mobile IP during handoff. The Latency involved in these handoff give bed influence to real-time or delay-sensitive services. So IETF proposed Low Latency Handoff performing Pre-Registration and Post-Registration with Link Layer information. This proposal always require the present of old Foreign Agent (oFA) and new Foreign Agent (nFA). If new Foreign Agent is absent, Mobile IP perform basic Mobile IP Handoff, but the various network environment may do not have new Foreign Agent. To adapt to these situation, This paper propose new Pre-Registration and Post-Registration with using Link Layer information.

무선링크에서 연속된 에러 복구 지연을 줄이는 RLP의 설계 및 구현

김낙현 전남대학교 대학원 2003 국내석사

이동통신 시스템에서 데이터의 효율적인 전송을 위해 데이터링크 계층에서 제공하는 프레임 에러율(FER: Frame Error Rates)을 감소가 필수적이다. 이를 위해 라디오링크 프로토콜(RLP: Radio Link Protocol) 계층에서는 ARQ(Automatic Repeat reQuest) 기법을 사용한다. 본 논문에서는 에러간의 상관 관계를 가지는 페이딩 채널에서 TCP/RLP 성능을 시뮬레이션을 통해 연구하였다. 본 연구의 목적은 RLP에서의 에러 복구 지연을 줄여서 종단간 성능을 높이는데 있다. 이를 위해서 RLP 에러 복구 지연 단축 알고리즘을 제안한다. RLP 에러 복구 지연 단축 알고리즘은 RLP에서의 불필요한 에러 복구를 줄임으로써 RLP에서의 에러 복구에 소요되는 시간 단축을 시도한다. 제안된 알고리즘을 적용하였을 경우에 에러간의 상관관계를 갖는 채널 환경에서 기존의 방법보다 TCP 지연이 향상됨을 보였다. In the mobile communications systems the frame error rate (FER) from the data link layer must be reduced enough low for efficient data transmission. For this, the automatic repeat request (ARQ) scheme is used at the radio link protocol (RLP) layer. In this paper, we studied the performance of TCP/RLP in bursty frame errors by correlated multipath fading channel. The purpose of our study improves the performance of end-to-end by means of decreasing RLP error recovery delay. For this, we propose the scheme in order to reduce RLP error recovery delay. RLP error recovery is improved over correlated multipath fading channel by applying the proposed schemes. We show the improvement of TCP delay.

무선 네트워크에서 비동기적으로 수행되는 RMI의 설계 및 구현

김다정 全南大學校 大學院 2004 국내석사

분산 응용 시스템 구축에 널리 사용되는 자바 RMI가 무선 네트워크에서 실행될 경우 간섭이나 페이딩 같은 외부적인 조건으로 인해 패킷이 손실될 수 있다. 단절 상황에서의 패킷 전송은 손실이 자명하며 데이터 전송 능력이 정상적으로 돌아오기 전까지는 통신이 비효율적으로 이루어진다. 패킷 손실은 RMI를 이용한 응용 프로그램의 성능 저하로 이어지지만 기존의 RMI는 이에 대한 대책이 마련되어 있지 않다. 본 논문에서는 링크 상태 모니터의 정보를 바탕으로 단절을 예측하고 패킷 손실이 예상되는 링크 단절 상황일 때는 메소드를 호스트 상에 캐싱시키고 링크가 복구된 후 지연된 호출을 실행하는 방안을 제시하고자 한다. 이런 방법을 통해 RMI 시스템은 단절을 투명하게 처리하도록 수정하였으며 이전에 작성된 RMI 프로그램과도 호환성을 가지도록 작성되어 프로그램의 재사용이 가능하다. The Java RMI is a popular paradigm for building distribute dappplication. The loss of packet can be caused by frequent disconnection which is due to external conditions such as interference, fading, and handoffs. A packet transmission in the intermittent disconnection may lead to packet loss and inefficiently transfer packets until coming back normal congestion window size. Although packet loss results in poor performance of RMI application, the existing RMI has no appreciate mechanism to deal with it. Framework of RMI is adjusted with queueing the method call and link state monitor. Link state monitor predict disconnection in advance and is disconnection occurs, new RMI caches methods on host. The methods is still delayed invocation until the recovery of the link. This scheme makes it possible to transparently deal with an intermittent disconnection. And RMI's performance can be enhanced without losing backward-compatibility with Java RMI specification.

BPR을 적용한 훈련기관 운영시스템의 설계 및 구축

이형열 전남대학교 대학원 2010 국내석사

훈련기관은 노동부 승인을 받아 실업자 재취업을 위한 실업자 및 계좌제 훈련과 능령향상을 위한 재직자 훈련을 하고 있으며 노동부는 훈련기관을 관리감독 및 평가 하고 있다. 노동부 직업능력개발훈련전산망(HRD-Net)은 지원자관리, 훈련생검색, 상담관리 등의 운영을 위한 시스템이 부족하여 훈련기관 단위프로세스에서 PT(Process Time)이 많이 소요되는 모집, 취업, 훈련신청, 연수과정 등에서 비효율적 업무프로세스 개선이 필요하다. 이와 같은 비효율적 업무프로세스를 개선하기 위해서 BPR(Business Process Reengineering) 방법으로 훈련기관 업무를 분석하고 PT(Process Time)을 단축시킬 수 있는 훈련기관운영시스템 설계 표준안을 마련하고 구축한다. 구축된 시스템을 G훈련기관에 적용하여 업무개선효과를 확인 한다. The purpose of this study is to improve the operating systems of Vocational training Institutions using by BPR(Business Process Reengineering). Now, These institutions are using the administrative support system in vocational training network(HRD-Net). But, This system has problems with certain things, for example, training application, search the trainees, and so forth. In this study, I have done a business process analysis for process time reduction and set up an operating systems of vocational training institutions. Finally, I applied the new systems to a G vocational training institution. The result, the new systems can also have reduced process time and improved business process, compared to more previously systems.

Bacillus methylotrophicus CBMB205에 의해 생산되는 박테리오신의 항균활성 및 물리화학적 특성

백선화 창원대학교 2017 국내석사

Bacterial isolates from various fermented foods were grown in MRS or Luria-Bertari broth at 37℃ or 30℃. Supernatants of their culture broth collected by centrifugation were tested for antibacterial activity by agar well diffusion method. One isolate showed relatively broader antibacterial activity against Gram-positive bacteria and Gram-negative bacteria such as Listeria monocytogenes, Bacillus cereus, Enterococcus faecium, Micrococcus luteus, Staphylococcus aureus subsp aureus and Shigella boydii. This isolate was finally selected for further study. It was identified as Bacillus methylotrophicus CBMB 205 based on the 16S ribosomal RNA sequence analysis. The scanning electron microscopy showed that B. methylotrophicus strain was rod-shaped bacteria. Using the PCR, Bacillus methylotrophicus CBMB205 had no enterotoxin genes such as hbl A, C, B, D, nhe A, B, C and ent FM. The antibacterial activity disappeared by the treatment of supernatant with α-chymotrypsin, proteinase K and subtilisin A, indicating antibacterial substance is a bacteriocin. Heat treatment at 80℃ for 90 min had no effect on antibacterial activity. Antibacterial activity was retained at the pH range from 5.0 to 12.0. At 80% concentration of solvents such as acetone, acetonitrile, methanol, ethanol and 2-propanol did not affect antibacterial activity. Antibacterial activity was resistant to 0.05% detergents like Triton X-100, 114, Tween 20, 80 and N-lauroylsarcosine. It was confirmed that the mode of action of bacteriocin produced by B. methylotrophicus CBMB205 against L. monocytogenes was bacteriostatic. In dose-dependent sensitivity of concentrated supernatant against the test organisms, E. faecium was the most sensitive. The half minimum inhibitory concentration (MIC50) against E. faecium, M. luteus, L. monocytogenes and S. aureus was 0.1, 0.5, 1.0 and 3.0 ㎎/㎖, respectively. The bacteriocin was purified through 2-propanol concentration, Sep-Pak C18 column, gel filtration and RP-HPLC. The molecule weight of the purified bateriocin was determined to be 7.3 kDa by MALDI-TOF mass spectrometry.

토하젓에서 분리한 Bacillus subtilis E9-1가 생산하는 박테리오신의 물리화학적 특성 및 정제

함승희 창원대학교 2016 국내석사

The bacteriocin produced by Bacillus subtilis E9-1 isolated from fermented Korean food, Tohajeot, was purified and characterized. The isolate was identified as Bacillus subtilis E9-1 based on the 16S rRNA gene sequence analysis. It showed antimicrobial activity against Micrococcus luteus IAM 1056, Enterococcus faecium KCCM 12118, Bacillus cereus KCCM 11204, Listeria monocytogens KCCM 40307, and Staphylococcus aureus subsp. aureus KCCM 40050. Among them Micrococcus luteus IAM 1056 was shown to be the most sensitive. The antimicrobial activity was removed or reduced by subtilisin A, α-chymotrypsin, trypsin, proteinase K but not affected by α-amylase, which means its proteinaceous nature, bacteriocin. The bacteriocin was stable in the pH range from 2.0 to 8.0 and stable at up to 100℃ for 60 min. Solvents such as acetone, acetonitrile, ethanol, isopropanol and methanol had no effect on the antimicrobial activity at the concentration of 80%. Four indicator strains were tested for relative sensitivity at increasing concentration of the bacteriocin. Cell growth was dramatically decreased in dose-dependent manner. L. monocytogenes was the most sensitive, but E. faecium was most resistant. B. cereus and S. aureus showed the medium sensitivity. Mode of action of the bacteriocin against B. cereus and L. monocytogenes was bacteriocidal. Food preservation of bacteriocin was tested in the minced beef against L. monocytogenes. The number of viable cells started be much less than negative control after 2-day incubation. The bacteriocin was purified through acetone concentration, gel filtration chromatography and RP-HPLC. The entire purification step led to a 6.82 fold increase in the specific activity and 6% yield of bacteriocin activity. The molecular weight of the purified bacteriocin was determined to be 3.3 kDa by MALDI-TOF/TOF mass spectrometry.

Yeast Two-Hybrid System을 이용한 O-GlcNAcase와 상호작용하는 단백질의 유전자 탐색 및 분석

최정이 창원대학교 2008 국내석사

The enzyme N-Acetyl-β-D glucosaminidase (O-GlcNAcase) encoded by MGEA5 gene catalyzes the cleavage of N-acetylglucosamine from O-GlcNAcylated proteins. It is one of key enzymes in the post-translational modification of intracellular proteins by O - linked N - acetylglucosamine (O-GlcNAc). In order to identify the O-GlcNAcase-related proteins, we screened a human brain cDNA library. The MGEA5 gene was cloned into a bait plasmid, pGBKT7 and was transformed into Saccharomyces cerevisiae AH109. Then, the transformants were mated with S. cerevisiae Y187 pre-transformed with human brain cDNA library. 81 positive clones showing blue colonies were primarily selected on SD(-Trp-Leu-Ade-His)/X-α-Gal agar plates. Finally, we chose 10 clones with high β-galactosidase activity for further analysis. The plasmid DNAs were isolated and nucleotide sequences were analyzed. The partial nucleotide sequencing and blast search suggested screened cDNAs encode presumable S-adenosyl homocysteine hydrolase, growth arrest-specific 7 isoform c and glycine- glutamate- thienylcyclohexylpiperidine-binding protein. Yeast two-hybrid system revealed S-adenosyl homocysteine hydrolase interacted with N-terminal catalytic domain and the others with C-terminal N-acetyl-transferase domain of O-GlcNAcase. For more correct assignment of screened proteins, we performed full nucleotide sequencing by primer walking. Based on Blast search, clone 2 encode human SAHH with 99% identity.

캐쉬 적중률 증가와 오버헤드 감소를 위한 효율적인 RMI 캐싱 시스템 설계

유우람 전남대학교 대학원 2006 국내석사

Java RMI is widely used at a distributed application system setup, that overhead to happen due to TCP of frequently data round trip and Object Serialization. For such reason, applied Large scale Distributed Application, show the non-efficient communication performance. to enhanced RMI performance, proposed Object caching system. but not satisfied because cached object consistency overhead and absence of cache data control protocol. this thesis is propose to cache change technique, consider recent simultaneously with reference. caching system design of be able to maintaining efficiently data, and Architecture design to enhanced performance that cache hit-rate and for maintaining caching object consistency least protocol operated number. 분산 응용 시스템 구축에 널리 사용되는 자바 RMI는 TCP를 이용한 잦은 내부 데이터 왕복과 객체 직렬화를 이용한 통신으로 인한 오버헤드로 대규모 분산 어플리케이션에 적용하였을 때 비효율적인 통신 성능을 보여준다. 이러한 환경에서 RMI의 성능을 향상시키기 위해 객체를 캐싱하는 시스템이 제안 되었으나 캐싱된 객체의 일관성 유지로 인한 오버헤드와 캐쉬 데이터 관리 정책의부재로 인하여 만족할만한 성능을 보여주지 못하였다. 본 논문에서는 최근성과 참조횟수를 동시에 고려하는 교체기법을 객체 리스트에 도입하여 캐쉬 데이터를 유지하도록 하는 방법을 제시하고자 한다. 이 방법을 적용할 수 있도록 효율적인 데이터 유지가 가능한 캐싱 시스템을 설계하도록 하며, 캐쉬 적중률을 높이고 캐싱된 객체의 일관성을 유지하기 위한 프로토콜의 작동횟수를 최소화시켜 성능을 향상 시킬 수 있는 구조를 설계한다.

김치에서 분리한 Bacillus amyloliquefaciens NBRC 15535가 생산하는 박테리오신의 특성 및 식품유래 병원균에 대한 항균활성

정은하 창원대학교 2021 국내석사

Diverse bacterial strains were isolated from kimchi and tested for antibacterial activity by agar well diffusion method. One isolate producing bacteriocin was finally selected and identified Bacillus amyloliquefaciens NBRC 15535 by 16S rRNA gene analysis. SEM photograph showed the morphology of cell was a rod-shape. The treatment of bacteriocin to indicator strains such as M. luteus IAM 1056, B. cereus KCCM 11204, L. monocytogenes KCCM 40307 and S. aureus subsp. aureus KCCM 40050 destructed cell wall or membrane. The antibacterial activity was inactivated by proteinase K, indicating antibacterial identity was a bacteriocin. The bacteriocin mainly showed growth-inhibiting activity against Gram (+) bacteria such as Micrococcus luteus IAM 1056, Bacillus cereus KCCM 11204, Listeria monocytogenes KCCM 40307, Enterococcus faecium KCCM 12118, Staphylococcus aureus subsp. aureus KCCM 40050, Propionibacterium acnes KCTC 3314 and also against Gram (-) bacteria such as Escherichia coli KCCM 11835, Salmonella enteritidis KCCM 12021 and Shigella boydii KCCM 41649. PCR analysis showed Bacillus amyloliquefaciens NBRC 15535 harbored amylocyclicin gene, surfactin genes (srfA, Srf/lch) and iturin genes (ituD, ituA), but no toxin genes were detected. The nucleotide sequencing of PCR product of amylocyclicin ORF revealed one amino acid was different from known amylocyclicin CMW1. Alanine of amylocyclicin CMW1 was replaced by threonine at the 9th position of mature form from N-terminus. In addition, the bacteriocin activity removed by treatment with lipase, α-chymotrypsin, trypsin, subtilisin A and pepsin. Antibacterial activity was not affected up to 100% of organic solvents like methanol, acetone, isopropyl alcohol, ethyl acetate but was decreased more than 40% acetonitrile and 60% ethanol. Moreover, the bacteriocin was stable at 80℃ for 60 min and at pH values from 2.0 to 8.0. It was resistant to 0.1% concentration of triton X-100, triton X-114, SDS, NiSO4, CuSO4 and 1% concentration of tween 20, tween 80, 50 mM EDTA, NaCl, MgCl2, ZnCl2. The approximate half minimal inhibitory concentration (MIC50) of crude concentrate against M. lutueus IAM 1056, L. monocytogenes KCCM 40307, E. faecium KCCM 12118 and B. cereus KCCM 11204, were 0.13 mg/ml, 0.13 mg/ml, 0.06 mg/ml and 0.27 mg/ml, respectively. The bacteriocin exhibited its antibacterial activity through bactericidal action against M. luteus IAM 1056. The number of viable cells of L. monocytogenes KCCM 40307 started to decrease after addition of bacteriocin to the chicken breast and soft soybeane curd. The purification of bacteriocin was performed by ammonium sulfate concentration, Sep-pak C18 cartridges and RP-HPLC. The purification resulted in a final yield of 0.4% and a 12-fold increase in the specific activity. The exact molecular weight was determined to be 6,400 Da by MALDI-TOF MS analysis.