• 제목/요약/키워드: Complex channel

검색결과 588건 처리시간 0.033초

진해 및 마산항로 주변해역의 조석·조류특성 (Tide and tidal current around the sea route of Jinhae and Masan passages)

  • 추효상
    • 수산해양기술연구
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    • 제57권1호
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    • pp.45-56
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    • 2021
  • In order to understand the tide and current around the sea route of Jinhae and Masan passages, tide measurement and 2D numerical model experiments of tidal current and residual flow were carried out. Tide is composed of 84% of semi-diurnal tide, 11% of diurnal tide and 4% of shallow water tide, respectively. Phase lags of the major components for the tide around the study area have little differences. The flows are reversing on the whole, but have rotational form around Jamdo Island, south of Masan passage in spring tide and Ungdo Island, north of Masan passage in middle and neap tide. Current flows the speed of 50 cm/s in the sea areas near small islands, 5 cm/s in Jinhae harbor, Hangam bay and near Jinhae industrial complex and 20-30 cm/s in Jinhae passage, Budo channel and Masan passage. Tide-induced topographical eddies are formed near small islands, but few eddies exist and the flow rate of less than 5 cm/s tidal residual current formed in Jinhae and Masan passages. The flows in Jinhae and Masan passage give a good condition for a passage into Jinhae and Masan harbor.

엑스선 그레이 스케일 리소그래피를 활용한 반원형 단면의 서브 마이크로 선 패턴의 바이오멤스 플랫폼 응용 (X-ray grayscale lithography for sub-micron lines with cross sectional hemisphere for Bio-MEMS application)

  • 김강현;김종현;남효영;김수현;임근배
    • 센서학회지
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    • 제30권3호
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    • pp.170-174
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    • 2021
  • As the rising attention to the medical and healthcare issue, Bio-MEMS (Micro electro mechanical systems) platform such as bio sensor, cell culture system, and microfluidics device has been studied extensively. Bio-MEMS platform mostly has high resolution structure made by biocompatible material such as polydimethylsiloxane (PDMS). In addition, three dimension structure has been applied to the bio-MEMS. Lithography can be used to fabricate complex structure by multiple process, however, non-rectangular cross section can be implemented by introducing optical apparatus to lithography technic. X-ray lithography can be used even for sub-micron scale. Here in, we demonstrated lines with round shape cross section using the tilted gold absorber which was deposited on the oblique structure as the X-ray mask. This structure was used as a mold for PDMS. Molded PDMS was applied to the cell culture platform. Moreover, molded PDMS was bonded to flat PDMS to utilize to the sub-micro channel. This work has potential to the large area bio-MEMS.

Climate change impact assessment of agricultural reservoir using system dynamics model: focus on Seongju reservoir

  • Choi, Eunhyuk
    • 농업과학연구
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    • 제48권2호
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    • pp.311-331
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    • 2021
  • Climate change with extreme hydrological events has become a significant concern for agricultural water systems. Climate change affects not only irrigation availability but also agricultural water requirement. In response, adaptation strategies with soft and hard options have been considered to mitigate the impacts from climate change. However, their implementation has become progressively challenging and complex due to the interconnected impacts of climate change with socio-economic change in agricultural circumstances, and this can generate more uncertainty and complexity in the adaptive management of the agricultural water systems. This study was carried out for the agricultural water supply system in Seongju dam watershed in Seonju-gun, Gyeongbuk in South Korea. The first step is to identify system disturbances. Climate variation and socio-economic components with historical and forecast data were investigated Then, as the second step, problematic trends of the critical performance were identified for the historical and future climate scenarios. As the third step, a system structure was built with a dynamic hypothesis (causal loop diagram) to understand Seongju water system features and interactions with multiple feedbacks across system components in water, agriculture, and socio-economic sectors related to the case study water system. Then, as the fourth step, a mathematical SD (system dynamics) model was developed based on the dynamic hypothesis, including sub-models related to dam reservoir, irrigation channel, irrigation demand, farming income, and labor force, and the fidelity of the SD model to the Seongju water system was checked.

NEW ASPECTS OF MEASURING NOISE AND VIBRATION

  • Genuit, K.
    • 한국음향학회:학술대회논문집
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    • 한국음향학회 1994년도 FIFTH WESTERN PACIFIC REGIONAL ACOUSTICS CONFERENCE SEOUL KOREA
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    • pp.796-801
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    • 1994
  • Measuring noise, sound quality or acoustical comfort presents a difficult task for the acoustic engineer. Sound and noise are ultimately jugded by human beings acting as analysers. Regulations for determining noise levels are based on A-weighted SPL measurement performed with only one microphone. This method of measurement is usually specified when determining whether the ear can be physically damaged. Such a simple measurement procedure is not able to determine annoyance of sound events or sound quality in general. For some years investigations with binaural measurement analysis technique have shown new possibilities for the objective determination of sound quality. By using Artificial Head technology /1/, /2/ in conjunction with psychoacoustic evaluation algorithms - and taking into account binaural signal processing of human hearing, considerable progress regarding the analysis of sounds has been made. Because sound events often arise in a complex way, direct conclusions about components subjectively judged to be annoying with regard to their causes and transmission paths, can be drawn in a limited way only. A new procedure, complementing binaural measurement technology combined with mulit-channel measuements of acceleration sensor signals has been developed. This involves correlating signals influencing sound quality, analyzed by means of human hearing, with signals form different acceleration sensors fixed at different positions of the sound source. Now it is possible to recognize the source and the transmission way of those signals which have an influence on the annoyance of sound.

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How to Boost Workers' Motivation in the Supply Chain based on the Difference between Wholesale and Retail Market

  • Jae-Hyung LEE
    • 유통과학연구
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    • 제21권5호
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    • pp.83-91
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    • 2023
  • Purpose: Increasing their motivation and job satisfaction, employees in the distribution channel may be better able to interact with consumers and provide a more satisfying experience. Thus, increasing employee engagement in the supply chain necessitates a complex strategy considering the distinctive features of wholesale and retail markets. This study investigates how to boost employees' motivation in the supply chain based on the difference between wholesale and retail market. Research design, data, and methodology: The prior study analysis is a useful tool to take a look at relevant previous works via a significant screening and selecting strategy. The Key words based on the topic of the research have used, such as 'Employee Motivation', 'Supply Chain', 'Wholesale' and 'Retail' worker. Results: The findings of this research strongly indicates that motivating employees is essential for the efficient operation of supply chain activities as they continue to expand and become more complicated. The supply chain's two main segments are the wholesale and retail markets, each with distinct characteristics. Conclusions: This research focused exclusively on the factors that motivate supply chain workers, ignoring job satisfaction, corporate culture, and managerial style, which may affect employee motivation. These factors also have the potential to impact employee motivation and should be considered in subsequent research.

단일오류 정정 및 Erasure 발생을 위한 R-S 복호기 설계 (R-S Decoder Design for Single Error Correction and Erasure Generation)

  • 김용석;송동일;김영웅;이근영
    • 대한전자공학회논문지
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    • 제23권5호
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    • pp.719-725
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    • 1986
  • Reed-solomon(R-S) code is very effective to coerrect both random and burst errors over a noise communication channel. However, the required hardware is very complex if the B/M algorithm was employed. Moreover, when the error correction system consists of two R-S decoder and de-interleave, the I/O data bns lines becomes 9bits because of an erasure flag bit. Thus, it increases the complexity of hardware. This paper describes the R-S decoder which consisits of a error correction section that uses a direct decoding algorithm and erasure generation section and a erasure generation section which does not use the erasure flag bit. It can be shown that the proposed R-S dicoder is very effective in reducing the size of required hardware for error correction.

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Pekeris 도파관에서 음선 접근법을 이용한 지면파 해석 (Interpretation of Ground Wave Using Ray Method in Pekeris Waveguide)

  • 최지웅
    • 한국음향학회지
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    • 제28권3호
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    • pp.208-212
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    • 2009
  • 지면파는 해저면 음속이 깊이에 따라 일정할 경우 해저면 음속으로 진행하는 음파로 일반적으로 모드분산으로부터 설명된다. 모드분산은 도파관의 기하학적 구조에 의한 음파의 반사 및 굴절에 의해 발생되므로 본 논문에서는 지면파를 음선이론에 기초하여 모의하였다. 지면파는 일련의 선두파들의 조합으로써 해석될 수 있으므로 [Choi와 Dahl, J. Acoust. Soc. Am. 119, 3660-3668 (2006)], 음선 접근법을 이용하여 시간영역에서 여러 경로로 전파되는 선두파들의 채널 임펄스 응답과 선두파 신호의 컨볼루션을 취하여 지면파를 모의한다. 모의된 지면파는 광대역 시간영역 포물선 방정식 기법을 이용하여 모의된 지면파와 비교, 검증된다.

A Generalized Multicarrier Communication System - Part III: Dual Symbol Superposition Block Carrier Transmission with Frequency Domain Equalization

  • Imran Ali
    • International Journal of Computer Science & Network Security
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    • 제24권9호
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    • pp.41-49
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    • 2024
  • This paper proposes dual symbol superposition block carrier transmission with frequency domain equalization (DSS-FDE) system. This system is based upon χ-transform matrix, which is obtained by concatenation of discrete Hartley transform (DHT) matrix and discrete Fourier transform (DFT) matrices into single matrix that is remarkably sparse, so that, as it will be shown in this paper, it only has non-zero entries on its principal diagonal and one below the principle anti-diagonal, giving it shape of Latin alphabet χ. When multiplied with constellation mapped complex transmit vector, each entry of resultant vector is weighted superposition of only two entries of original vector, as opposed to all entries in conventional DFT based OFDM. Such a transmitter is close to single carrier block transmission with frequency domain equalization (SC-FDE), which is known to have no superposition. The DSS-FDE offers remarkable simplicity in transmitter design and yields great benefits in reduced complexity and low PAPR. At receiver-end, it offers the ability to harvest full diversity from multipath fading channel, full coding gain, with significant bit error rate (BER) improvement. These results will be demonstrated using both analytical expressions, as well as simulation results. As will be seen, this paper is Part III of three-paper series on alternative transforms for multicarrier communication (MC) systems.

난자와 난구세포간 Cell-to-Cell Communication이 난자에 미치는 영향 (Effects of the Cell-to-Cell Communication between Oocyte and Cumulus Cells on the Quality of Oocytes)

  • 신창숙;윤세진;박창은;이경아
    • 한국발생생물학회지:발생과생식
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    • 제5권2호
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    • pp.115-122
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    • 2001
  • 난자와 난포세포는 gap junction channel을 통해 긴밀한 연락을 주고받음으로써 난자의 발달이나 난포의 성장에 영향을 미친다. 본 연구는 같은 크기의 난포에서 나온 난자라고 하여도 cumulus cell(난구세포)들이 붙어있는 상태가 다르다는 것을 관찰, 이렇게 난구세포와의 서로 다른 연결상태를 갖는 난자의 재질에 차이가 있을 것으로 가정하고, 난자의 competence와 이때 난자와 난구세포 사이의 cell-to-cell communication에 관여하는 gap junction protein인 connexin(CX) 37과 CX 43의 발현 정도가 어떤 상관관계가 있는지를 알아보고자 수행하였다. 생후 3주일 된 생쥐에 PMSG를 주입하고 48시간 후에 난소를 적출하여 난포를 450 $\mu\textrm{m}$ 이상(large)의 난포와 200~400 $\mu\textrm{m}$(small) 난포로 분리하여 그 난자를 얻었다. 난자에 난구세포가 compact하게 붙어있는 것은 intact로(L1, Sl), 난구세포가 어느 정도 붙어 있거나, 하나도 붙어있지 않은 것은 partial/denuded로 그룹을 나누었다(LPD. SPD). 각 그룹의 난자를 체외에서 성숙시키고, 수정시켜서 발달율을 비교하였다. 각각의 CX의 mRNA 발현을 RT-PCR과 in situ hybridization으로 비교하였다. intact와 denuded 난자의 비율은 큰 난포의 경우는 55%와45%의 비율로, 작은 난포의 경우는 30%와 70%의 비율로 난포가 작을수록 denude상태의 난자가 많이 나왔다. 어떤 경우의 난자는 체외 성숙율은 차이가 없이 모두 97%이상 성숙하였다. 그러나, 수정률에서는 차이를 보여서 intact한 난자에서 높은 수정율을 보였으며, SPD의 경우, 가장 낮은 수정ㆍ발달율을 보였다. 난자의 경우, 주로 발현되는 것은 CX 37이었으며, CX 43은 발현되지 않았다. 난구세포의 경우, CX 43이 가장 높게 발현하였고, 그 다음으로 CX 37이 관찰되었다. 본 실험 결과, 같은 발달크기의 난포라고 하더라도 그 안에 존재하는 난자의 상태는 난구세포와 얼마나 밀접한 cell-to-cell communication을 이루고 있느냐에 따라 영향을 받는다는 것을 확인하였다. 본 연구결과 다음과 같이 결론 내릴 수 있었다. 1)아직 발달이 끝나지 않은 난포에서 나온 미성숙난자라고 하여도 난구세포와 밀접한 연결을 갖는 경우 성숙난자와 거의 같은 능력을 갖고 있으며, 2) 난자와 난구세포간의 gap junctional communication은 heterotypic channel로 이루어지고, 3) 본 연구에서 관찰한 CX 43과 CX 37 두 종류만으로는 intact와 denuded의 차이점을 설명할 수 없었다.

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정상적(正常的)인 한우(韓牛)의 심전도(心電圖)에 관(關)한 연구(硏究) I. 표준지유도(標準肢誘導) (Studies on electrocardiogram of the normal Korean native cattle I. Standard limb leads)

  • 최인혁;정인성;김남수;서두석
    • 대한수의학회지
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    • 제33권4호
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    • pp.719-734
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    • 1993
  • The electrocardiographic(ECG) parameters on the standard limb leads in the normal Korean native cattle have been measured with a 3 channel Electrocardiograph built in a computed analysis. The study was conducted on the animals 98 heads of mean age of 17.7 months. Conduction parameters, waves, intervals and segments have been recorded. The recordings were analyzed as to shape and amplitude of the P and T waves and the components of the QRS complex. Heart rate was recorded by the Electrocardiogram which were a mean of $80.4{\pm}11.6beats/min$. And the younger had a higher heart rate than the older one. Average conduction times in the RP, the QRS complex and the QTc interval recorded $166.7{\pm}23.1msec.$, $79.7{\pm}8.8msec.$ and $395.5{\pm}30.4msec.$, in the P and T wave duration recorded $70.1{\pm}13.5msec.$ and $97.6{\pm}16.9msec.$, and in the PR and ST segment duration recorded $97.9{\pm}23.5msec.$ and $173.9{\pm}40.3msec.$, respectively. The wave forms in each lead observed various types. The amplitudes of wave type showed the highest frequency in each lead that were analyzed as follow : 1. In P wave, amplitudes of the positive type showed the frequency of 65.3%, 82.7% and 52.0% in leads I, II and III that were $103.1{\pm}47.8{\mu}V$, $115.2{\pm}37.3{\mu}V$ and $67.4{\pm}26.9{\mu}V$, and it showed the frequency of 54.1% and 85.7% in the leads aVL and aVF that were $63.7{\pm}23.0{\mu}V$, $88.0{\pm}83.6{\mu}V$, respectively. Average amplitude of the negative type showed the frequency of 78.6% in lead aVR which was $99.3{\pm}38.0{\mu}V$. 2. Average amplitude of the QRS complex were from $362.8{\pm}177.7{\mu}V$ to $532.8{\pm}253.9{\mu}V$(mean of $449.1{\pm}57.2{\mu}V$) that in all leads except lead I were manifested the Low-Voltage QRS complex(below 0.5mV). Average amplitudes of each wave type in the QRS complex aere $-50.2.4{\pm}258.2{\mu}V$ and $-428.6{\pm}195.1{\mu}V$ in the QS groups type that showed a frequency of 66.3%, 70.4% in the leads I and aVL, were $451.1{\pm}20.4.0{\mu}V$, $387.6{\pm}175.8{\mu}V$ and $299.3{\pm}146.5{\mu}V$ in the R groups type that showed a frequency of 48.0%, 53.1% and 34.7% in the leads III, aVR and aVF, and were $-307.5{\pm}180.3{\mu}V$, $201.4{\pm}77.2{\mu}V$ in the QR wave type which showed a frequency of 39.8% in lead II, respectively. 3. In T wave, amplitude of the positive type showed the frequency of 50.0%, 82.7%, 51.0% and 57.1% in leads II, III aVR and aVF which were $214.9{\pm}115.6{\mu}V$, $188.5{\pm}119.3{\mu}V$, $191.0{\pm}93.7{\mu}V$ and $165.7{\pm}91.9{\mu}V$, and the negative type showed a frequecny of 66.3% and 72.5% in leads I and aVL. that were $221.3{\pm}112.5{\mu}V$, $-173.6{\pm}86.7{\mu}V$, respectively. 4. Amplitude of ST segment in leads I, II and III were a mean of $-12.2{\pm}37.2{\mu}V$, $17.5{\pm}42.6{\mu}V$ and $28.3{\pm}40.4{\mu}V$, in leads aVR, aVL and aVF were $-3.9{\pm}32.5{\mu}V$, $-15.9{\pm}35.6{\mu}V$ and $26.2{\pm}37.5{\mu}V$, respectively.

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