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"Dust, Ice, and Gas In Time" (DIGIT) Herschel observations of GSS30-IRS1

  • Je, Hyerin;Lee, Jeong-Eun
    • The Bulletin of The Korean Astronomical Society
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    • v.38 no.1
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    • pp.50.1-50.1
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    • 2013
  • As part of the DIGIT key program, we observed GSS30-IRS1, a Class I object located in Ophiuchus (d=125 pc), with Herschel-PACS. More than 70 lines were detected: CO lines of $J=14{\rightarrow}13$ to $41{\rightarrow}40$, several $H_2O$ lines of Eu=100 to 1500 K, 16 OH lines, and two atomic [OI] lines at 63 and 145 ${\mu}m$. All lines, except for [OI], were detected only at the central spaxel of $9.4^{\prime\prime}{\times}9.4^{\prime\prime}$ while the [OI] emission is extended along the NE-SW direction. One interesting feature in GSS30-IRS1 is that the continuum is extended beyond PSF, unlike the line emission. For detail analysis, we apply the non-LTE LVG model, RADEX as well as simple rotational diagrams to the detected line fluxes. We will discuss about the physical conditions around GSS30-IRS1, learned by the line flux analysis.

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북극해 항로와 빙하해역 선박운항 지침에 대하여

  • Lee, Dong-Seop
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2012.10a
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    • pp.55-57
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    • 2012
  • Suez운하를 이용할 경우 부산항에서 로테르담항까지의 수송거리가 11,340마일이 북극해 항로를 이용할 경우 6,860마일로 36%가 줄고 수송기간도 10일 이상 단축되므로 북극해항로를 통한 유럽과 아시아간의 상업적인 수송이 이뤄진다면 해운회사들의 물류비용이 대폭 절감될 것으로 전망된다. 이런 시점에서 2011년 9월 한-러 국장급 해운회담이 열렸으며, 2011년 11월 23일 부산 누리마루 APEC House에서 "북극해항로 상업운항의 현황과 전망"이라는 주제로 국제세미나가 개최 되었다. 현재 북극해 항로를 통과한 선박이 2007년 2척, 2008년 3척, 2009년 4척, 2010년 10척이었던 것이 2011년에는 34척 총 82만톤의 통과 수송이 이뤄졌고, 러시아 북극내의 물동량은 2백20만톤에 달할 것으로 전망되었으며, 2012년의 통과 물동량은 100만톤을 상회 할 것으로 전망된다. 이에 북극해 항로에 대한 소개와 빙하지역을 항해하는 선박에 대한 운항지침에 대하여 검토해보고저 한다.

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A Study on QoS Performance Based on CBQ Using Real-time Transport Protocol (RTP를 이용한 CBQ기반의 QoS 성능에 관한 연구)

  • 하미숙;박승섭
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2004.04a
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    • pp.43-48
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    • 2004
  • RTP that is proposed supplement of real-time services on internet environment, as Real-time Transport Protocol, is the protocol that for the purpose of sending data of stream type. RTP and RTCP(Real-time Transport Control Protocol) basically work at the same time, RTCP serves with state information of network at present. RTP has important properties of a transport protocol that runs on end-to-end systems and provides demultiplexing. It also offer reliability and protocol-defined flow/congestion control that transport protocol like TCP can not provides. In this paper, we look around concept and construction of Differentiated sen1ice tint run on RTP and by setting parameters of packet transfer method be used CBQ(Class-Based Queuing) for packet transfer on Differentiated service, each service queue controls properly through packet scheduling method, such as WRR(Weighted Round Robin) and PRR(Packet-by-packet Round Robin) all service classes do not experience the starvation and confirm the performance through computer simulation to achieve fairly scheduling.

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Dynamic Performance of Natural Gas Injection Valve for Heavy-Duty CNG Dual Fuel Engine (대형 CNG 혼소 엔진용 천연가스 분사밸브 동특성 연구)

  • Kim, Yong-Rae;Choi, Young
    • Journal of the Korean Institute of Gas
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    • v.21 no.5
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    • pp.9-15
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    • 2017
  • Natural gas fuel has known to be very promising in terms of abundancy and economic value. Therefore it is widely treated as research topics in a variety field of production, storage and utilization. Natural gas has become one of the major sources for the power generation by using internal combustion engines(ICE). Development of natural gas fuel injection device should be preceded to realize a reliable natural gas fuel supply system for a MW class power generation reciprocating ICE. In this research, an injection valve which consists of solenoid and body part with a moving plate was designed and its dynamic performance was experimented in the engine-like environment. Displacement length and diameter of an armature and diameter of a solenoid coil were tested at former study. In this research the effect of materials of solenoid core, size of main housing inlet and supply gas pressure are examined.

"Dust, Ice, and Gas In Time" (DIGIT) Herschel Observations of GSS30-IRS1 in Ophiuchus

  • Je, Hyerin;Lee, Jeong-Eun;Green, Joel D.;Evans, Neal J. II
    • The Bulletin of The Korean Astronomical Society
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    • v.39 no.1
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    • pp.63.2-63.2
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    • 2014
  • As a part of the "Dust, Ice, and Gas In Time" (DIGIT) key program on Herschel, we observed GSS30-IRS1, a Class I protostar located in Ophiuchus (d =125 pc), with Herschel/Photodetector Array Camera and Spectrometer (PACS). More than 70 lines were detected within a wavelength range from 50 ${\mu}m$ to 200 ${\mu}m$: CO lines from J = 14-13 to 41-40, several $H_2O$ lines of Eup = 100 K to 1500 K, 16 transitions of OH rotational lines, and two atomic [O I] lines at 63 and 145 ${\mu}m$. The [C II] line, known as a tracer of externally heated gas by the interstellar radiation field, is also detected at 158 ${\mu}m$. All lines, except [O I] and [C II], are detected only at the central spaxel of $9^{\prime\prime}.4{\times}9^{\prime\prime}.4$. The [O I] emission is extended along a NE-SW orientation, which is consistent with the known outflow direction, while the [C II] line is detected over all spaxels. One possible explanation of the detection of the [C II] line and no correlation of its spatial distribution with any other molecular emission is the existence of the enhanced ISRF nearby GSS30-IRS1. One interesting feature of GSS30-IRS1 is that the continuum emission is extended beyond the point-spread function (PSF), unlike the molecular line emission, indicative of significant external heating. The best-fit continuum model of GSS30-IRS1 with the physical structure including flared disk, envelope, and outflow shows that the internal luminosity is 11 $L_{\odot}$, and the region is also externally heated by a radiation field enhanced by a factor of 25 compared to the local standard interstellar field.

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Dynamic Performance of Natural Gas Injection Valve for Heavy-Duty Power Generation Engine - Part I (발전용 대형엔진용 천연가스 분사밸브 동특성 연구 (I))

  • Choi, Young;Kim, Yong-Rae;Lee, Seok-Whan;Kim, Chang-Gi
    • Journal of the Korean Institute of Gas
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    • v.19 no.6
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    • pp.15-21
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    • 2015
  • Natural gas fuel has known to be very promising in terms of abundancy and economic value. Therefore it is widely treated as research topics in a variety field of production, storage and utilization. Natural gas has become one of the major sources for the power generation by using internal combustion engines(ICE). Development of natural gas fuel injection device should be preceded to realize a reliable natural gas fuel supply system for a MW class power generation reciprocating ICE. In this research, an injection valve which consists of solenoid and body part with a moving plate was designed and its dynamic performance was experimented in the engine-like environment. As a result of the experiments, linearity of flow rate was obtained and overall around 2ms of response time was observed at the pressure difference of 1bar. In addition, more than 100Liter/min(@2Hz) of gas flow rate was witnessed, which is expected to be adequate for the fuel supply system of a MW class natural gas engine.

The Current State of College Taekwondo Athletes' Sport Injury and the Measures to Improve Their Coping Ability (대학 태권도 선수의 스포츠상해 실태와 대처능력 방안)

  • Min, Kyeong-Hoon;Lee, Jong-Min;Jung, Han-Kee
    • Journal of radiological science and technology
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    • v.40 no.1
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    • pp.143-153
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    • 2017
  • As for the current state of college taekwondo athletes' sport injury, times of occurrence and major causes showed differences in weight class and career, while situations of occurrence had differences in grade, weight class, and career. As for the measures to improve their coping ability, first aid showed differences in grade, while prevention of injury had differences in grade and career. Treatment methods turned out to have no differences. For college taekwondo athletes, sport injury occurred during exercise, mostly when they fell. In addition, lack of skill was the greatest major cause of sport injury. As for the sport injury coping ability, ice massage was used as first aid and self-massage was performed. For prevention of injury, sufficient fatigue recovery was considered to be the priority of prevention of injury.

English Predicate Inversion: Towards Data-driven Learning

  • Kim, Jong-Bok;Kim, Jin-Young
    • Journal of English Language & Literature
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    • v.56 no.6
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    • pp.1047-1065
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    • 2010
  • English inversion constructions are not only hard for non-native speakers to learn but also difficult to teach mainly because of their intriguing grammatical and discourse properties. This paper addresses grammatical issues in learning or teaching the so-called 'predicate inversion (PI)' construction (e.g., Equally important in terms of forest depletion is the continuous logging of the forests). In particular, we chart the grammatical (distributional, syntactic, semantic, pragmatic) properties of the PI construction, and argue for adata-driven teaching for English grammar. To depart from the arm-chaired style of grammar teaching (relying on author-made simple sentences), our teaching method introduces a datadriven teaching. With total 25 university students in a grammar-related class, students together have analyzed the British Component of the International Corpus of English (ICE-GB), containing about one million words distributed across a variety of textual categories. We have identified total 290 PI sentences (206 from spoken and 87 from written texts). The preposed syntactic categories of the PI involve five main types: AdvP, PP, VP(ed/ing), NP, AP, and so, all of which function as the complement of the copula. In terms of discourse, we have observed, supporting Birner and Ward's (1998) observation that these preposed phrases represent more familiar information than the postposed subject. The corpus examples gave us the three possible types: The preposed element is discourse-old whereas the postposed one is discourse-new as in Putting wire mesh over a few bricks is a good idea. Both preposed and postposed elements can also be discourse new as in But a fly in the ointment is inflation. These two elements can also be discourse old as in Racing with him on the near-side is Rinus. The dominant occurrence of the PI in the spoken texts also supports the view that the balance (or scene-setting) in information structure is the main trigger for the use of the PI construction. After being exposed to the real data and in-depth syntactic as well as informationstructure analysis of the PI construction, it is proved that the class students have had a farmore clear understanding of the construction in question and have realized that grammar does not mean to live on by itself but tightly interacts with other important grammatical components such as information structure. The study directs us toward both a datadriven and interactive grammar teaching.

A Case Study on the Experience of Science Teacher Participating in Peer Coaching Meetings (동료 장학 모임에 참여한 과학교사의 경험 사례 연구)

  • Chung, Haengnam;Choi, Byungsoon
    • Journal of The Korean Association For Science Education
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    • v.33 no.1
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    • pp.63-78
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    • 2013
  • Purposes of this study were to explore the process of experience that science teachers go through when participating in peer coaching meetings to improve teaching ability and to find out factors that affect each process of experience. The data were collected through recording of peer coaching meetings, videotapes of science class, and interviews. All the data were analyzed after transcription. The results of the study showed that even though Teacher K broke the ice and formed consensus among the peers by developing Content Representation (CoRe) at the beginning of the meetings, he became self-defensive rather than receptive of peers' opinions on the recorded class at the discussion session. But as the peer coaching went on, he realized that peer coaching was not about evaluation but rather on improving his teaching ability. In turn, he was able to look at his teaching in a more objective point of view and accepted suggestions from peer coaching discussion. The self-reflection of Teacher K acted as the key factor in the efforts to improve his teaching ability. He sought the concrete alternatives through the class analysis with fellow teachers and showed major changes in his teaching practice from the language habits, pronunciation, and speed of his speech to the interaction with students and class design. However, there was little change in knowledge of curriculum and assessment due to his strong orientation to improve students' grades as an academic high school teacher. Likewise, it was found that while peer coaching exert a strong influence on instructional methods and strategies of Teacher K, his strong orientation to improve students' grades hinders a balanced development of subcomponents of PCK.

Differences in Health-related Fatty Acids, Intramuscular Fat and the Physico-chemical Quality in Mutton as Affected by Season, Place of Purchase and Meat Portion

  • Rani, Zikhona T.;Nantapo, Carlos W.T.;Hugo, Arnold;Muchenje, Voster
    • Asian-Australasian Journal of Animal Sciences
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    • v.27 no.11
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    • pp.1630-1637
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    • 2014
  • The objective of the study was to determine the quality and fatty acid profiles of mutton cuts purchased from rural and urban localities in South Africa. Five hundred and ten samples were collected in four seasons from both rural and urban shops and butcheries. Samples were immediately transported to the laboratory in cooler boxes with ice where the following physico-chemical characteristics of mutton were determined; meat pH, color ($L^*$, $a^*$, and $b^*$), cooking losses and Warner Braztler shear force and replicates stored at $-20^{\circ}C$ pending fatty acid analysis. Meat $L^*$ values were lowest ($24.7{\pm}0.49$) in winter and highest ($32.2{\pm}0.49$) in spring. The loin and sirloin cuts recorded the highest intramuscular fat whilst rib and leg cuts recorded the lowest intramuscular fat. In conclusion intramuscular fat, fatty acid profiles and physico-chemical quality of mutton were significantly affected by season and meat portion and not necessarily by the locality and class of shop.