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충주호의 어류상과 유입하천의 생태건강성 평가 (Fish Community and Stream Health Assessment in Lake Chungju and its Tributaries)

  • 최명재;박혜경;윤석환;이장호
    • 한국물환경학회지
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    • 제28권2호
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    • pp.185-196
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    • 2012
  • The fish community within the lake and 5 tributaries of Lake Chungju in spring and autumn, 2009 was surveyed. In this study, the total 128,506 individuals were collected belonging to 11 families 29 genera 34 species. The most dominant species was Squalidus japonicus coreanus that account for 91.6% of population and 49% of biomass of fish community. In the point of population, dominant species were small-sized species, which became the prey of big-sized predatory species. In the point of biomass, dominant species were predatory species which were large-sized. The most dominant species in lacustrine area was S. japonicus coreanus which accounted for 92.2% of total population and 49.1% of total biomass. The most dominant species of tributary streams was Tridentiger brevispinis which accounted for 66.4% of total population and 55.1% of total biomass. The site of C3 in lacustrine area and Dongdal-cheon in tributary streams collected the most number of species. Through ecological health evaluation of five tributary streams using 8 metric index of biological integrity (IBI) model, two streams (Dongdal-cheon, Kwang-cheon were evaluated as, "B", "good" condition, and Jangsung-cheon obtained grade C indicating "Fair" condition, Jecheon-cheon obtained grade D indicating "Poor" condition based on IBI model. Lepomis macrochirus which was designated as a domestic ecosystem-disturbing alien species with wide food niche have shown tendency to increase the number of individuals since 1991 indicating the adverse effect on not only fish community but also aquatic ecosystem food web of Lake Chungju.

Computational design of mould sprue for injection moulding thermoplastics

  • Lakkannan, Muralidhar;Mohan Kumar, G.C.;Kadoli, Ravikiran
    • Journal of Computational Design and Engineering
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    • 제3권1호
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    • pp.37-52
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    • 2016
  • To injection mould polymers, designing mould is a key task involving several critical decisions with direct implications to yield quality, productivity and frugality. One prominent decision among them is specifying sprue-bush conduit expansion as it significantly influences overall injection moulding; abstruseness anguish in its design criteria deceives direct determination. Intuitively designers decide it wisely and then exasperate by optimising or manipulating processing parameters. To overwhelm that anomaly this research aims at proposing an ideal design criteria holistically for all polymeric materials also tend as a functional assessment metric towards perfection i.e., criteria to specify sprue conduit size before mould development. Accordingly, a priori analytical criterion was deduced quantitatively as expansion ratio from ubiquitous empirical relationships specifically a.k.a an exclusive expansion angle imperatively configured for injectant properties. Its computational intelligence advantage was leveraged to augment functionality of perfectly injecting into an impression gap, while synchronising both injector capacity and desired moulding features. For comprehensiveness, it was continuously sensitised over infinite scale as an explicit factor dependent on in-situ spatio-temporal injectant state perplexity with discrete slope and altitude for each polymeric character. In which congregant ranges of apparent viscosity and shear thinning index were conceived to characteristically assort most thermoplastics. Thereon results accorded aggressive conduit expansion widening for viscous incrust, while a very aggressive narrowing for shear thinning encrust; among them apparent viscosity had relative dominance. This important rationale would certainly form a priori design basis as well diagnose filling issues causing several defects. Like this the proposed generic design criteria, being simple would immensely benefit mould designers besides serve as an inexpensive preventive cliché to moulders. Its adaption ease to practice manifests a hope of injection moulding extremely alluring polymers. Therefore, we concluded that appreciating injectant's polymeric character to design exclusive sprue bush offers a definite a priori advantage.

실용적 웨어러블 컴퓨터 품질평가모델 (Quality Assessment Model for Practical Wearable Computers)

  • 오천석;최재현;김종배;박제원
    • 한국통신학회논문지
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    • 제39B권12호
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    • pp.842-855
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    • 2014
  • 스마트폰 시장이 성숙기에 들어서면서 새로운 성장동력으로 웨어러블 컴퓨터가 주목받고 있다. 웨어러블 컴퓨팅 시스템은 무선 네트워크 기술, 임베디드 기술, 센서 기술, 신소재 기술 등 다양한 기술의 복합적인 융합체이다. 이러한 특징들은 기존의 소프트웨어가 가지고 있는 품질특성 이외에 활용성, 이동성 등의 특성을 내포하고 있기 때문에 국제표준인 ISO/IEC 9126의 표준만으로 정확한 품질 평가를 하기에는 어려움이 따른다. 본 논문에서는 이러한 필요성에 따라 기존의 ISO/IEC 9126과 웨어러블 컴퓨팅의 특징에 의해 도출된 품질특성을 추가해 웨어러블 컴퓨터 품질평가모델을 제안하였다. 웨어러블 컴퓨터 품질평가모델의 개발을 위해 웨어러블 컴퓨터의 기능적 요구사항과 품질특성을 도출하여 메트릭과 품질 기준을 제안하였다. 본 연구에서는 시나리오에 제안된 모델을 적용하고 S사, L사, G사의 웨어러블 기기의 품질을 비교하여 품질평가모델의 실용성을 확인하였다. 본 연구에서 제안한 평가모델은 웨어러블 컴퓨터의 품질평가를 위한 가이드라인으로 활용할 수 있을 것으로 기대된다.

반 폐쇄된 무안만 중형동물플랑크톤 군집의 계절 변동 (Seasonal Variation of Mesozooplankton Communities in the Semi-enclosed Muan Bay, Korea)

  • 문성용;서민호;신용식;서호영
    • Ocean and Polar Research
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    • 제34권1호
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    • pp.1-18
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    • 2012
  • We investigated seasonal changes in the mesozooplankton community structure in November 2006 and February, May, and August 2007 at 12 stations in the semi-enclosed Muan Bay, Korea. Forty taxa were sampled, with an average abundance ranging from 1,459 to 20,078 indiv. $m^{-3}$; the highest abundance was detected in August 2007, and the lowest in February 2007. Acartia omorii, A. hudsonica, A. ohtsukai, Bestiolina coreana, Calanopia sp., Paracalanus parvus s. l., Cirripedia larvae, Decapoda larvae, and Gastropoda larvae were the most abundant taxa detected. The species diversity of the mesozooplankton was high around the inner regions in August 2007 but it was relatively low in November 2006. Non-metric multidimensional scaling (nMDS) revealed significant differences in the structure of mesozooplankton community among the seasons. Canonical correspondence analysis (CCA), performed to examine the relationships among dominant taxa, stations, and environmental variables, showed that most species of copepods were positively correlated with temperature, salinity, chlorophyll a, and COD concentration. Our results suggested that the mesozooplankton community structure observed in this study might be affected partly by the seasonal changes in environmental variables, such as the status of the sluice gates (i.e., open or closed) and the in situ production of resting eggs by major copepods.

A Genetic Analysis of Taoyuan Pig and Its Phylogenetic Relationship to Eurasian Pig Breeds

  • Li, Kuan-Yi;Li, Kuang-Ti;Cheng, Chun-Chun;Chen, Chia-Hsuan;Hung, Chien-Yi;Ju, Yu-Ten
    • Asian-Australasian Journal of Animal Sciences
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    • 제28권4호
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    • pp.457-466
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    • 2015
  • Taoyuan pig is a native Taiwan breed. According to the historical record, the breed was first introduced to Taiwan from Guangdong province, Southern China, around 1877. The breed played an important role in Taiwan's early swine industry. It was classified as an indigenous breed in 1986. After 1987, a conserved population of Taoyuan pig was collected and reared in isolation. In this study, mitochondrial DNA sequences and 18 microsatellite markers were used to investigate maternal lineage and genetic diversity within the Taoyuan pig population. Population differentiation among Taoyuan, Asian type, and European type pig breeds was also evaluated using differentiation indices. Only one D-loop haplotype of the Taoyuan pig was found. It clustered with Lower Changjiang River Basin and Central China Type pig breeds. Based on the polymorphism of microsatellite markers, a positive fixation index value ($F_{IS}$) indicates that the conserved Taoyuan population suffers from inbreeding. In addition, high $F_{ST}$ values (>0.2105) were obtained, revealing high differentiation among these breeds. Non-metric multi-dimensional scaling showed a clear geometric structure among 7 breeds. Together these results indicate that maternally Taoyuan pig originated in the Lower Changjiang River Basin and Central China; however, since being introduced to Taiwan differentiation has occurred. In addition, Taoyuan pig has lost genetic diversity in both its mitochondrial and nuclear genomes.

조선 초기 포화 금지령 (The Bans on Po in the Early Years of the Joseon Dynasty)

  • 최규순;고부자
    • 복식문화연구
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    • 제13권5호
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    • pp.729-742
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    • 2005
  • This paper studied the ban on 'Po[포]', including hemp and ramie, on the basis of Joseon Wangcho Silok (the True Record of Joseon Dynasty). Po is the important point which can help to understand the people's life related with clothing. This paper showed that in the early years of the Joseon Dynasty, the state had forced kinds of bans on some fabrics many times. Among the bans of the fabrics-making the main part was the bans on Po, along with rice, used as money in those days. The state had on Po enacted on the policy to intend to promote paper money circulation more widely. However, people didn't want to use paper money. The reason why cloth could be practical and functional as a kind of currency was that people could make clothes with it at any time while they used it as money. People avoided using paper money that could not be used in that way, and so did public officials. At that time, Po that was generally used as money was the hemp of five warp threads. The measurement of the hemp in 7chi[촌; a Korean inch] by 35chok[척] and 32cm by 16m by modern metric. It also showed that it has been thought that the blended fabrics are the fabrics that were made of raw silk-threads and cotton threads as warp and weft respectively. However, the fact that there is a record of 'Jeo Ma Gyo Jik Po[저마교직포의]'(blended fabrics and clothes made of ramie and hemp) and there appear the new proofs of the fieldwork investigation shows that the concept of blended fabrics might be various or changeable as time passed.

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Fast and Accurate Rigid Registration of 3D CT Images by Combining Feature and Intensity

  • June, Naw Chit Too;Cui, Xuenan;Li, Shengzhe;Kim, Hak-Il;Kwack, Kyu-Sung
    • Journal of Computing Science and Engineering
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    • 제6권1호
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    • pp.1-11
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    • 2012
  • Computed tomography (CT) images are widely used for the analysis of the temporal evaluation or monitoring of the progression of a disease. The follow-up examinations of CT scan images of the same patient require a 3D registration technique. In this paper, an automatic and robust registration is proposed for the rigid registration of 3D CT images. The proposed method involves two steps. Firstly, the two CT volumes are aligned based on their principal axes, and then, the alignment from the previous step is refined by the optimization of the similarity score of the image's voxel. Normalized cross correlation (NCC) is used as a similarity metric and a downhill simplex method is employed to find out the optimal score. The performance of the algorithm is evaluated on phantom images and knee synthetic CT images. By the extraction of the initial transformation parameters with principal axis of the binary volumes, the searching space to find out the parameters is reduced in the optimization step. Thus, the overall registration time is algorithmically decreased without the deterioration of the accuracy. The preliminary experimental results of the study demonstrate that the proposed method can be applied to rigid registration problems of real patient images.

한국 초등수학 교과서의 도량형 서술 내용에 대한 분석 (An Analysis about Narrative of Weights and Measures in Korean Elementary Mathematics Textbooks)

  • 이종학;전영주
    • 한국학교수학회논문집
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    • 제22권3호
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    • pp.183-197
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    • 2019
  • 본 연구는 초등 교사들의 도량형 관련 교수·학습과 차기 초등수학 교과서의 도량형 내용 집필 시 참고 자료로서 도움을 주고자 한다. 이를 위해 도량형에 관한 초등수학 교육과정의 내용 체계를 참고하여 정의 및 개념, 측정단위, 연산 등 세 가지 관점으로 교과서의 서술 내용을 분석하였다. 그 결과 첫째, 도량형 정의의 도입은 명시적 표현보다 예시적인 방법을 선택하고 있다. 둘째, 도량형 내용요소와 단위 도입 순서에 몇 가지 문제점이 발견되었다. 셋째, 측정 단위 사이의 연산은 절차적 지식의 접근보다는 연산처리에 집중하고 있다. 넷째, 이수 학년과 이수 학기에 따른 도량형의 학습내용과 학습량에서 차이가 발생하고 있으며, 이 부분에 대한 이유와 근거 제시가 필요하다는 결론을 도출하였다.

Decrease of Global Warming Effect During Dry Etching of Silicon Nitride Layer Using C3F6O/O2 Chemistries

  • Kim, Il-Jin;Moon, Hock-Key;Lee, Jung-Hun;Jung, Jae-Wook;Cho, Sang-Hyun;Lee, Nae-Eung
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2012년도 제42회 동계 정기 학술대회 초록집
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    • pp.459-459
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    • 2012
  • Recently, the discharge of global warming gases in dry etching process of TFT-LCD display industry is a serious issue because perfluorocarbon compound (PFC) gas causes global warming effects. PFCs including CF4, C2F6, C3F8, CHF3, NF3 and SF6 are widely used as etching and cleaning gases. In particular, the SF6 gas is chemically stable compounds. However, these gases have large global warming potential (GWP100 = 24,900) and lifetime (3,200). In this work, we chose C3F6O gas which has a very low GWP (GWP100 = <100) and lifetime (< 1) as a replacement gas. This study investigated the effects of the gas flow ratio of C3F6O/O2 and process pressure in dual-frequency capacitively coupled plasma (CCP) etcher on global warming effects. Also, we compared global warming effects of C3F6O gas with those of SF6 gas during dry etching of a patterned positive type photo-resist/silicon nitride/glass substrate. The etch rate measurements and emission of by-products were analyzed by scanning electron Microscopy (SEM; HITACI, S-3500H) and Fourier transform infrared spectroscopy (FT-IR; MIDAC, I2000), respectively. Calculation of MMTCE (million metric ton carbon equivalents) based on the emitted by-products were performed during etching by controlling various process parameters. The evaluation procedure and results will be discussed in detail.

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A Robust Mobile Video Streaming in Heterogeneous Emerging Wireless Systems

  • Oh, Hayoung
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제6권9호
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    • pp.2118-2135
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    • 2012
  • With the rapid development of heterogeneous emerging wireless technologies and numerous types of mobile devices, the need to support robust mobile video streaming based on the seamless handover in Future Internet is growing. To support the seamless handover, several IP-based mobility management protocols such as Mobile IPv6 (MIPv6), fast handover for the MIPv6 (FMIPv6), Hierarchical MIPv6 (HMIPv6) and Proxy Mobile IPv6 (PMIPv6) were developed. However, MIPv6 depreciates the Quality-of-Service (QoS) and FMIPv6 is not robust for the video services in heterogeneous emerging wireless networks when the Mobile Node (MN) may move to another visited network in contrast with its anticipation. In Future Internet, the possibility of mobile video service failure is more increased because mobile users consisting of multiple wireless network interfaces (WNICs) can frequently change the access networks according to their mobility in heterogeneous wireless access networks such as 3Generation (3G), Wireless Fidelity (Wi-Fi), Worldwide Interoperability for Microwave Access (WiMax) and Bluetooth co-existed. And in this environment, seamless mobility is coupled according to user preferences, enabling mobile users to be "Always Best Connected" (ABC) so that Quality of Experience is optimised and maintained. Even though HMIPv6 and PMIPv6 are proposed for the location management, handover latency enhancement, they still have limit of local mobility region. In this paper, we propose a robust mobile video streaming in Heterogeneous Emerging Wireless Systems. In the proposed scheme, the MN selects the best-according to an appropriate metric-wireless technology for a robust video streaming service among all wireless technologies by reducing the handover latency and initiation time when handover may fail. Through performance evaluation, we show that our scheme provides more robust mechanism than other schemes.