• Title, Summary, Keyword: GEM

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The Synthesis of 2-Methyl-5,5'-gem-Disubstituted-${\Delta}^2$-Thiazolines (2-Methyl-5,5'-gem-Disubstituted-${\Delta}^2$-Thiazoline系 化合物의 合成)

  • Chi Sun Hahn
    • Journal of the Korean Chemical Society
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    • v.7 no.4
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    • pp.230-237
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    • 1963
  • The synthesis of 2-methyl-5,5'-gem-disubstituted-$\Delta^2$-thiazolines has been undertaken by two methods. The first involves the preparation of gem-disubstituted N-or S-acetylamino mercaptan intermediates by ring opening of the corresponding thiiranes with ammonia. The second consists of the ring opening of gem-disubstituted ethylene imines using thiolacetic acid. The thiirane rings have never been opened under conditions as vigorous as that of using sodium amide in liquid ammonia. This is probably due to retardation by the gem-disubstituents. In contrast to this, the corresponding ethylene imine ring opens easily, in spite of the same stereochemical situation. The stabilization of gem-disubstituted cyclic compounds has been discussed from a stereochemical point of view. It has been concluded from the results of this work that the compression effect of gem-disubstitution is not due to bond angle deformation, which was observed by Thorpe and Ingold, but mostly to an electronic bond interaction of the gem-disubstituents and to the hetero atom(s), if any.

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Constructing a Metadata Database to Enhance Internet Retrieval of Educational Materials

  • Oh Sam-Gyun
    • Journal of the Korean Society for Library and Information Science
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    • v.32 no.3
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    • pp.143-156
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    • 1998
  • This paper reports the GEM (Gateway to Educational Materials) project whose goal is to develop an operational framework to provide the K-12 teachers in the world with 'one-stop/any-stop' access to thousands of lesson plans, curriculum units and other Internet-based educational resources. To the IS-element Dublin Core base package, the GEM project added an 8-element, domain-specific GEM package. The GEM project employed the conceptual data modeling approach to designing the GEM database, used the Sybase relational database management system (RDBMS) to construct the backend database for storing the metadata of educational resources, and also employed the active server page (ASP) technology to provide Web interfaces to that database. The consortium members catalog lesson plans and other Internet-based educational resources using a cataloging module program that produces HTML meta tags. A harvest program collects these meta tags across the Internet and outputs an ASCII file that conforms to the standard agreed by the consortium members. A parser program processes this file to enter meta tags automatically into appropriate relational tables in the Sybase database. The conceptual/logical schemas of Dublin Core and GEM profile are presented. The advantages of conceptual modeling approach to manage metadata are discussed. A prototype system that provides access to the GEM metadata is available at http://lis.skku.ac.kr/gem/.

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The Efficacy of Enhanced Growth by Ectopic Expression of Ghrelin and Its Variants Using Injectable Myogenic Vectors

  • Xie, Q.F.;Wu, C.X.;Meng, Q.Y.;Li, N.
    • Asian-Australasian Journal of Animal Sciences
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    • v.17 no.1
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    • pp.146-152
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    • 2004
  • Ghrelin is an acylated peptide recently identified as the endogenous ligand for the growth hormone (GH) secretagogues receptor 1a (GHS-R1a) and is involved in a novel system for regulating GH release. To understand the long-term effects of ghrelin, here we constructed six myogenic expression vectors containing the cDNA of swine mature ghrelin (pGEM-wt-sGhln, pGEM-wt-hGhln), ghrelin mutant of $Ser^3$ with $Trp^3$ (pGEM-mt-sGhln, pGEM-mt-hGhln) and truncated ghrelin derivative (pGEM-tmtsGhln, pGEM-tmt-hGhln) encompassing the first 7 residues of ghrelin (including $Ser^3$ substituted with $Trp^3$) and adding a basic amino acid, Lys (K) in the C-terminus. The constructs, pGEM-wt-sGhln, pGEM-mt-sGhln and pGEM-tmt-sGhln were linked with the ghrelin leader sequence, while the pGEM-wt-hGhln, pGEM-mt-hGhln and pGEM-tmt-hGhln were linked with a leader sequence from the human growth hormone releasing hormone (hGHRH). Intramuscular injection of 200 ${\mu}g$ pGEM-wt-sGhln or pGEM-tmt-sGhln augmented growth over 3 weeks in normal rats and peaked at day 21 or 14 post-injection respectively, whose body weight gains were on average approximately 6% or 19% heavier over controls. However, other injectable vectors had no such enhanced growth effects. Our results suggested that the efficacy of the ghrelin leader sequence was more effective than that of hGHRH in our system. Moreover, the results indicated that skeletal muscle might have the ability to posttranslationally modify the in vivo expressed ghrelin. And the most strikingly, the short ghrelin analog seems to mimic the biological effects more efficiently when compared with the full-length ghrelin.

Implementation of a High Speed GEM frame Synchronization Circuit in the G-PON TC Sublayer Payload (G-PON TC 계층 유료부하 내에서 고속 GEM 프레임 동기회로 구현)

  • Chung, Hae;Kwon, Young-Jin
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.34 no.5B
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    • pp.469-479
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    • 2009
  • The GEM frame is used a mean to deliver the variable length user data and consists of the header and the payload in the G-PON system. The HEC field of header protects contents of the header and is used to maintain GEM frame synchronization at the same time. When an LCDG (Loss of GEM Channel Delineation) occurs while receiving frames, the receiver have to discard corrupted frames until acquiring the synchronization again. Accordingly, high-speed synchronization method is required to minimize the frame loss. In this paper, we suggest not only a main state machine but a sub-state machine to reduce the frame loss when undetectable errors occurred in the GEM header. Also, we provide a more efficient and fast parallel structure to detect the starting point of the header. Finally, the proposed method is implemented with the FPGA and verified by the logic analyzer.

Performance of Gas Electron Multiplier (GEM) detector

  • Han, S.H.;Moon, B.S.;Kim, Y.K.;Chung, C.E.;Kang, H.D.;Cho, H.S.
    • Journal of Radiation Protection and Research
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    • v.28 no.4
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    • pp.343-348
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    • 2003
  • We have investigated in detail the operating properties of Gas Electron Multiplier (GEM) detectors with a double conical and a cylindrical structure in a wide range of external fields and GEM voltages. With the double conical GEM, the gain gradually increased with time by 10%; whereas this surface charging was eliminated with the cylindrical GEM. Effective gains above 1000 were easily observed over a wide range of collection field strengths in a gas mixture of $Ar/CO_2(70/30)$. The transparency and electron collection efficiency were found to depend on the ratio of external field and the applied GEM voltage; the mutual influence of both drift and collection fields was found to be trivial.

Development of general purpose interface module for mini-MAP (Mini-MAP을 위한 범용 접속장치 개발)

  • 김현기;이전우;하정현;정하재;채영도
    • 제어로봇시스템학회:학술대회논문집
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    • pp.31-36
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    • 1992
  • This paper describes the development of a 'General-purpose ETRI MAP interface module' (GEM) for a Mini-MAP network. GEM operates as a Mini-MAP node in our FA system. To communicate between GEM and programmable devices such as PLC, CNC, and robot, RS232C is used, which is a traditional method. A Mini-MAP host system controls and monitors programmable devices via GEM. The Mini-MAP function of GEM is implemented and tested on the basis of the MAP V3.0.

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A Study on the Implemention of a Mini-MAP Network Interface Module for CIM (CIM을 위한 Mini-MAP 네트워크 접속장치의 구현에 관한 연구)

  • 김현기;이전우;하정현;정하재;채영도
    • Journal of the Korean Institute of Telematics and Electronics B
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    • v.30B no.10
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    • pp.59-68
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    • 1993
  • This paper describes implemation of 'General-purpose ETRI MAP interface module' (GEM) for Mini-MAP network. GEM operates as a Mini-MAP node in our FA system. To communicate between GEM and programmable devices(PD) such as PLC and CNC, serial communication is used. Application programs of a MiNi-MAP host system control and monitor programmable devices via GEM. GEM is implemented and tested on the basis of the MAP 3.0. TBC in the Nini-MAP board performs the function of the MAC sublayer. The LLC sublayer is implemented according to the specification of Class 3 that includes Type 1 and 3. And the MMS services are designed within the scope of implementation class MAP3. All the softwares are implemented under the real-time multitask OS for real-time application of the Mini-MAP and they are loaded into PROMs at the network board of GEM. We tested the LLC functions to make use of a protocol analyzer for the token-passing protocol. Also the MMS conformance test was carried out by exchanging primitives between GEM and a MMS product that had already passed the conformance test. Therefore GEM is proposed as a network tool of Computer Integrated Manufacturing (CIM) to integrate PDs which don't support MAP functions.

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Gemcitabine-based Concurrent Chemoradiotherapy Versus Chemotherapy Alone in Patients with Locally Advanced Pancreatic Cancer

  • Wang, Bu-Hai;Cao, Wen-Miao;Yu, Jie;Wang, Xiao-Lei
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.5
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    • pp.2129-2132
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    • 2012
  • Objective: To explore improved treatment by retrospectively comparing survival time of gemcitabine-based concurrent chemoradiotherapy (GemRT) versus chemotherapy (Gem) alone in patients with locally advanced pancreatic cancer (LAPC). Methods: From January 2005 to June 2010, 56 patients with LAPC from Subei People's Hospital were treated either with Gem (n=21) or GemRT (n=35). Gem consisted of 4-6 cycles gemcitabine alone (1000 mg/m2 on Days 1, 8, 15, 28-day a cycle). GemRT consisted of 50.4Gy/28F radiotherapy with concurrent 2 cycles of gemcitabine (1000 $mg/m^2$ on days of radiation 1, 8, 15, 21-day a cycle). Radiation was delivered to the gross tumor volume plus 1-1.5 cm by use of a three-dimensional conformal technique. The follow-up time was calculated from the time of diagnosis to the date of death or last contact. Kaplan-Meier methodology wes used to evaluate survival. Results: Patient characteristics were not significantly different between treatment groups. The disease control rate and the objective response rate of GemRT versus Gem was 97.1% vs 71.4%, 74.3% vs 38.1%. The overall survival (OS) was significantly better for GemRT compared to Gem (median 13 months versus 8 months; 51.4% versus 14.3% at 1 year, respectively). Conclusion: Radiation therapy at 50.4Gy with 2 concurrent cycles of gemcitabine results in favorable rates of OS. Concurrent chemoradiotherapy should be the first choice for patients with LAPC.

Object-oriented model for Generic Equipment Model

  • Jung, Myong-Soon;Ahn, Gye-Jin;Park, Hong-Seong
    • 제어로봇시스템학회:학술대회논문집
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    • pp.447-447
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    • 2000
  • This paper proposes an Object-oriented model for Generic Equipment Model(GEM) which is applied to semiconductor processing Equipment. A proposed implementation model for GEM consists of three modules : a module to convert SECS-II message and a module to transmit messages between GEM and a physical equipment. The proposed Object-oriented model for GEM has advantages in reuse and user management from the point of view of development program. Especially, this paper proposes a GEM agent COM, which is a base of GEM, transmits messages and events among modules. This Object-oriented model is analysed and developed by using UML.

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Implementation of an Ethernet Adapter for the G-PON TC Layer (G-PON TC 계층을 위한 이더넷 정합기의 구현)

  • Chung, Hae;Ahn, Eu-Kwang
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.36 no.5B
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    • pp.429-436
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    • 2011
  • The G-PON is an efficient solution to implement the FTTH and have GEM frame to accomodate various protocols like Ethernet frames, IP packets, and TDM signals. Above all, the Ethernet is one of the most widely used 2nd layer protocol in the campus, the subscriber access, and the carrier service. So G-PON system has to provide an Ethernet interface with top priority. In this paper, we implement a gigabit Ethernet adapter based on Ethernet over GEM in the ITU-T G.984.3 to accommodate Ethernet protocol in the G-PON TC chip. The adapter maps each Ethernet frame to a single or multiple GEM frames and has several functions including generation of the GEM header, encapsulation of frames and the SAR. In particular, the adapter have converter (LUT) MAC address to port-ID which is a key to identify logical connections though it is not defined in specification but important. We implement the adapter with a FPGA and verify the functions of segmentation and reassembling, MAC address learning, and throughput with the logic analyzer and the Ethernet analyzer.