• Title/Summary/Keyword: Copy Propagation

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Copy Propagation in CTOC (CTOC에서 복사 전파)

  • Kim, Ki-Tae;Kim, Je-Min;Yoo, Won-Hee
    • Journal of the Korea Society of Computer and Information
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    • v.12 no.1 s.45
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    • pp.1-8
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    • 2007
  • Although the Java bytecode has numerous advantages. there ate also shortcomings such as slow execution speed and difficulty in analysis. Therefore. in order for the Java class file to be effectively executed under the execution environment such as the network, it is necessary to convert it into optimized code. We implements CTOC. CTOC generated CFG using the existing bytecode then created the SSA Form for analysis and optimization. However. due to insertion or the ${\phi}$-function in the process of conversion into the SSA Form, the number of nodes increased. As a means of reducing the number of nodes, we performed copy propagation, which is an optimization method applicable to the SSA form. Copy propagation is the process of a value of a variable being topied to another variable. There are cases where conversion due to copy propagation alone does not yield significant effects. However, when variables are not used in the later optimization stages, copy propagation provides a means for eliminating the copy statement for the corresponding variable, making it an important step. This paper shows the copy propagation to obtain a more optimized code in SSA Form.

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Processing of Code Optimization in CTOC (CTOC에서 코드 최적화 수행)

  • Kim, Ki-Tae;Yoo, Weon-Hee
    • Journal of Korea Multimedia Society
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    • v.10 no.5
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    • pp.687-697
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    • 2007
  • Although the Java bytecode has numerous advantages, there are also shortcomings such as slow execution speed and difficulty in analysis. Therefore, in order for the Java class file to be effectively executed under the execution environment such as the network, it is necessary to convert it into optimized code. We implemented CTOC for transforming to optimized code. In Optimization, SSA Form that distinguish variable by assignment is used to determine value and type statically. Copy propagation, dead code elimination optimization is applied to SSA Form. However, existing SSA Form is related to variable than expression. Therefore, in this paper, to performing optimization to SSA Form expression, after performing copy propagation and dead code elimination, in addition to that, partial redundant expression elimination is performed

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Plasmid Propagation and Heterologous Gene Expression in Recombinant Yeast (효모균에서의 Plasmid 번식체계와 혼성유전자 발현)

  • 홍억기
    • KSBB Journal
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    • v.8 no.2
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    • pp.133-142
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    • 1993
  • The effects of genetic and environmental factors on productivity of a cloned protein were studied in recombinant Saccharomyces cerevisiae. Plasmid stability and copy level were very high for a $REP^+$ system(at ca. 10 generations, stability: 65-90%, plasmid copy number per cell: 40-200), whereas these were very low for a yep- system(at ca. 10 generations, stability: 30%, plasmid copy number per cell 20). In plasmids containing the $2{\mu}m$ circle genome, a $[cir^o]$ strain was a preferred host cell since the plasmid stability and the copy number in a $[cir^o]$ strain were higher than in a $[cir^+]$strain. Cloned gene expression was dependent on plasmid copy number and stability. The inducer (galactose) level played a very important role in cloned lacZ gene expression, showing that a galactose concentration of 0.8% was sufficient for induction of gene expression. Induction rate was very fast in the case of plasmids exhibiting high stability and copy number by a factor of 4 to 25. The time to reach the peak value of gene expression was longer when galactose was added at the start of fermentation (ca. 26 hours) than at the mid-exponential phase (ca. 6 hours). Glucose repression was reduced by a factor of 2 to 5 as the relative inducer level increased.

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Database Construction for Design of the Components Software by Using an Incremental Update Propagation

  • Oh, Am-Suk;Kwon, Oh-Hyun
    • Journal of Korea Multimedia Society
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    • v.6 no.4
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    • pp.583-593
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    • 2003
  • Engineering design applications require the support of long transactions in cooperative environments. The problem of the existing copy/update/merge approaches is that the partial effects of a committed transaction may be not part of the merged version. This paper introduces a new cooperative transaction model, which allows updates to be progressively notified or propagated into other transactions accessing the same object. To support incremental update propagation and notification, we use the term dynamic dependency to define the intertransaction dependency relationships among all the objects checked out from the public database. Consistency in multiple copies of the same object is achieved by a two-phase delta-merge protocol. Our model provides a synchronization of cooperative updates performed in several workspaces without using locking mechanisms.

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A Design of Update Propagation Algorithm for Replica Consistency of Transaction (트랜잭션의 복제 일관성을 위한 갱신 전파 알고리즘 설계)

  • Lee Byung-Wook
    • Journal of Internet Computing and Services
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    • v.4 no.6
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    • pp.87-93
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    • 2003
  • Data Replication makes distributed system and database system improved in availability and performance. But it is difficult to keep strict consistency in data update. Existing algorithms keep strict consistency, but have problems of cost a great deal and delay time. It is to introduce hybrid update propagation algorithm which permits eager update for original copy and propagates lazy update for other copies. Hybrid update propagation algorithm also permits group update in ownership. This algorithm menages replica version in order to control group update consistency. Consistency and performance is improved by combining eager update and lazy update with group ownership. Simulation shows improvement of transaction throughput and response time depending on application and execution environment.

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Nano stamp fabrication for photonic crystal waveguides (나노 광소자용 나노스탬프 제조공정 연구)

  • Jeong, Myung-Yung;Jung, Une-Teak;Kim, Chang-Seok
    • Journal of the Korean Society for Precision Engineering
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    • v.22 no.12 s.177
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    • pp.16-21
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    • 2005
  • Photonic crystals, periodic structure with a high refractive index contrast modulation, have recently become very interesting platform for the manipulation of light. The existence of a photonic bandgap, a frequency range in which the propagation of light is prevented in all directions, makes photonic crystal very useful in application where the spatial localization of light is required, for example waveguide, beam splitter, and cavity. However, the fabrication of 3 dimensional photonic crystals is still difficult process. A concept that has recently attracted a lot of attention is a planar photonic crystal based on a dielectric membrane, suspended in the air and perforated with two dimensional lattice of hole. The fabrication of Si master with pillar structure using hot embossing process is investigated for two dimensional, low-index-contrast photonic crystal waveguide. From our research we show that the multiple stamp copy process proved to be feasible and useful.

cDNA Microarray Analysis of the Gene Expression Profile of Swine Muscle

  • Kim, Chul Wook;Chang, Kyu Tae;Hong, Yeon Hee;Jung, Won Yong;Kwon, Eun Jung;Cho, Kwang Keun;Chung, Ki Hwa;Kim, Byeong Woo;Lee, Jung Gyu;Yeo, Jung Sou;Kang, Yang Su;Joo, Young Kuk
    • Asian-Australasian Journal of Animal Sciences
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    • v.18 no.8
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    • pp.1080-1087
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    • 2005
  • By screening specific genes related to the muscle growth of swine using cDNA microarray technology, a total of 5 novel genes (GF (growth factor) I, II, III, IV and V) were identified. Results of southern blotting to investigate the number of copies of these genes in the genome of swine indicated that GF I, GF III, and GF V existed as one copy and GF II, and GF IV existed as more than two copies. It was suggested that there are many isoforms of these genes in the genome of swine. Also, results of northern blotting to investigate whether these genes were expressed in grown muscle, using GF I, III, and V indicated that all the genes were much more expressed in the muscle of swine with body weight of 90 kg. Expression patterns of these genes in other organs, namely muscle and propagation and fat tissues, were investigated by extracting RNA from the tissues. These genes were not expressed in the propagation and fat tissues, but were expressed in the muscle tissue. To determine the mechanism of muscle growth, further studies should be preceded using the 3 specific genes related to muscle growth, that is GF I, III, and V.

Replication of Hepatitis B Virus is repressed by tumor suppressor p53 (간암치료신약개발 및 이의 제제화 연구)

  • 이현숙;허윤실;이영호;김민재;김학대;윤영대;문홍모
    • Proceedings of the Korean Society of Applied Pharmacology
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    • 1994.04a
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    • pp.178-178
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    • 1994
  • Hepatitis B Virus (HBV) is a DNA virus with a 3.2kb partially double-stranded genome. The life cycle of the virus involves a reverse transcription of the greater than genome length 3.5kb mRNA. This pegenomic RNA contains all the genetic information encoded by the virus and functions as an intermediate in viral replication. Tumor suppressor p53 has previously been shown to interact with the X-gene product of the HBV, which led us to hypothesize that p53 may act as a negative regulator of HBV replication and the role of the X-gene product is to overcome the p53-mediated restriction. As a first step to prove the above hypothesis, we tested whether p53 represses the propagation of HBV in in vitro replication system. By transient cotransfection of the plasmid containing a complete copy of the HBV genome and/or the plasmid encoding p53, we found that the replication of HBV is specifically blocked by wild-type p53. The levels of HBV DNA, HBs Ag and HBc/e Ag secreted in cell culture media were dramatically reduced upon coexpresion of wild-type p53 but not by the coexpression of the mutants of p53 (G154V and R273L). Furthermore, levels of RNAs originated from HBV genome were repressed more than 10 fold by the cotransfection of the p53 encoding plasmid. These results clearly states that p53 is a nesative regulator of the HBV replication. Next, to addresss the mechanism by which p53 represses the HBV replication, we performed the transient transfection experiments employing the pregenomic/core promoter-CAT(Chloramphenicol Acetyl Transferase) construct as a reporter. Cotransfection of wild-type p53 but not the mutant p53 expression plasmids repressed the CAT activity more than 8 fold. Integrating the above results, we propose that p53 represses the replication of HBV specifically by the down-regulation of the pregenomic/core promoter, which results in the reduced DNA synthesis of HBV. Currently, the mechanism by which HBV overcomes the observed p53-mediated restriction of replication is tinder investigation.

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An Extension of Data Flow Analysis for Detecting Polymorphic Script Virus (다형성 스크립트 바이러스 탐지를 위한 자료 흐름 분석기법의 확장)

  • Kim, Chol-Min;Lee, Hyoung-Jun;Lee, Seong-Uck;Hong, Man-Pyo
    • The KIPS Transactions:PartC
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    • v.10C no.7
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    • pp.843-850
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    • 2003
  • Script viruses are easy to make a variation because they can be built easily and be spread in text format. Thus signature-based method has a limitation in detecting script viruses. In a consequence, many researches suggest simple heuristic methods, but high false-positive error is always being an obstacle. In order to overcome this problem, our previous study concentrated on analyzing data flow of codes and has low-false positive error, but still could not detect a polymorphic virus because polymorphic virus loads self body and changes it before make a descendent. We suggest a heuristic detection method which expands the detection range of previous method to include polymorphic script viruses. Expanded data flow analysis heuristic has an expanded grammar to detect Polymorphic copy Propagation. Finally, we will show the experimental result for the effectiveness of suggested method.