• Title/Summary/Keyword: Intermittent flow

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Improvement of wireless communications environment of Web-pad on board Yard tractor in container terminal use convergence technology (융복합 기술을 이용하는 컨테이너 항만에서 야드 트랙터에 탑재된 웹-패드의 무선통신 환경 개선 방안)

  • Hong, Dong-Hee;Kim, Chang-Gon
    • Journal of Digital Convergence
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    • v.13 no.8
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    • pp.281-288
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    • 2015
  • The container terminals use convergence technology that exchange information for cargo work, using wireless communication between the TOS(Terminal Operations System) and the handling equipments(CC, TC, YT). But if the container cargoes pile up high in the container yard, delayed cargo work and cargo working list information error happen because of communication dead spots(the worker can not receive the information) which wireless communication is disconnected. At this time the driver of the yard tractor(YT) must be able to recognize the communication state. If then, delayed cargo work and cargo working list information errors that occur in the shaded communication area can be avoided, and can process the delayed work due to wireless communication break. In this project, we have built wireless communication environment to increase the efficiency of the loading and unloading operations which the operator can respond actively, when the work is delayed and work orders result in errors. That is, the flow of the wireless communication module has been changed.

Effects of Water Temperature Changes on the Oxygen Consumption Rhythm in the Japanese eel, Anguilla japonica

  • Kim, Jong-Wook;Lee, Tae-Won;Noh, Il;Kim, Wan-Soo
    • Journal of Environmental Science International
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    • v.20 no.8
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    • pp.943-951
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    • 2011
  • We investigated the effects of temperature changes on the oxygen consumption rhythm in Japanese eels, Anguilla japonica, using an automatic intermittent flow respirometer (AIFR). The endogenous rhythm of the oxygen consumption rate (OCR) in the eels (n = 18; 44-74 cm, 145-690 g), freshly collected by bag net from estuaries, was nearly synchronous with the tidal pattern of the estuarine collection site. The magnitude of mean OCR (mOCR) of eels showed variable range of 82.2 - 116.5 ml $O_2\;kg^{-1}ww \;h^{-1}$ under constant conditions. In case of increasing temperature from 25 to $38^{\circ}C$, the OCR of eels exhibited a gradually increasing trend with a rhythmic pattern until $36^{\circ}C$. Above $36^{\circ}C$ the rhythms of the OCR dampened and the OCR decreased rapidly at around $36-37^{\circ}C$. The OCR of the eels exhibited the maximum value at $38^{\circ}C$, and then it sharply decreased. The results suggested that the critical thermal maximum (CTM) regarding the endogenous rhythms of the eels was at around $36-37^{\circ}C$ when water temperature increased at $0.5^{\circ}C$/14 h following the acclimation at $25^{\circ}C$. In case of decreasing temperature ($0.5^{\circ}C$/14 h) from 25 to $0^{\circ}C$, the OCR of the eels displayed a abrupt decrease up to $23^{\circ}C$, and between at 23 and $20^{\circ}C$, there was an agitation which showed a slight increase in the OCR with a duration of 1-2 days. Below $9^{\circ}C$, the OCR rhythm of the eels showed a constant state regardless of temperature decreasing. These results suggest that the Japanese eel has an upper incipient lethal temperature at $36^{\circ}C$, with a lower thermal limit at $9^{\circ}C$. The biochemical aspects of the eels influenced by water temperature need to be further studied.

Coronary Artery Disease Affected by Moyamoya Disease - A case report - (관상 동맥 질환을 동반한 모야모야 병 1례의 증례 보고)

  • 김학제;조원민;류세민;황재준;손영상;최영호
    • Journal of Chest Surgery
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    • v.35 no.3
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    • pp.231-234
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    • 2002
  • Moyamoya disease is an unusual cerebrovascular disorder characterized by occlusive intimal dysplasia of the distal internal carotid and proximal cerebral arteries as well as other collateral arteries. However, moyamoya diseases are recently being reported as a systemic process. We experienced one case of coronary artery occlusive disease affected by moyamoya disease. The patient was a 35-year-old female, experiencing intermittent NYHA class ll dyspnea and exertional chest pain for 6 months and right paresthesia for 1 month before admission. Cerebral artery angiogram showed abnormal cerebrovascular systems and confirmed moyamoya disease with cerebral infarction of the left frontal lobe. In coronary artery angiogram, left coronary artery was not visualized due to total occlusion of the left main ostium and left coronary blood flow was supplied from normal right coronary artery. CABG was performed with OPCAB. Both internal mammary arteries were used for LAD and LCx. Intraoperative coronary artery findings showed intimal hyperplasia and no definite thrombi, and nondiseased coronary arteries were good and patent. We concluded that this patient's coronary artery disease was affected by moyamoya disease, and moyamoya disease should be evaluated in the extracerebral cardiovascular system.

Holocene Climate Optimum and environmental changes in the Paju and the Cheollipo areas of Korea (한반도 홀로세 온난기후 최적기 (Holocene Climate Optimum)와 지표환경 변화)

  • Nahm, Wook-Hyun;Lim, Jae-Soo
    • The Korean Journal of Quaternary Research
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    • v.25 no.1
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    • pp.15-30
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    • 2011
  • Three sediment cores from two different locations (UJ-03 and UJ-12 cores of valley sediment in Paju area, and CL-4 core of wetland sediment in Cheollipo area) along the western Korean Peninsula yield crucial information on the timing and spatial pattern of century-scale climate changes and subsequent surficial responses during the Holocene. In Paju area, the sediments included abundant coarse-grained sediment (coarse sands and pebbles) from 7100 to 5000 cal. yrBP, total organic carbon (TOC) values showed a marked increase from 5000 to 2200 cal. yrBP, several intermittent depositional layers were observed from 2200 cal. yrBP. In Cheollipo area, lake environment developed from 7360 to 5000 cal. yrBP, the deposition of organic materials increased from 5000 to 2600 cal. yrBP, peatland formed from 2600 cal. yrBP. The two patterns of surficial responses to the climate changes through the Holocene are different to each other. This might be due to the dissimilarity in geomorphic conditions. However, the approximate simultaneity of environmental changes in two areas shows that they both can be correlated to the major climate changes. Two areas which have undergone significant changes indicated that the hydrological factors including precipitation and strength of water flow were most responsible for the landscape and geomorphic evolutions. Although the upwards trend in relative sea-level also played a primary role for environmental changes in coastal area (Cheollipo area), detailed studies have still to be undertaken.

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Late Quaternary Depositional Processes in the Korea Plateau and Ulleung Interplain Gap, East Sea (동해 한국대지 및 울릉 분지간통로의 제4기 후기 해저퇴적작용)

  • 윤석훈;박장준;한상준
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.8 no.2
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    • pp.187-198
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    • 2003
  • High-resolution (Chirp, 3-11 kHz) echo facies and sedimentary facies of piston-core sediments were analyzed to reveal the late Quaternary depositional processes in the Korea Plateau and Ulleung Interplain Gap. The Korea Plateau is an Isolated topographic high with a very restricted input of terrigenous sediments, and its slope is characterized by a thin sediment cover and various-scale submarine canyons and valleys. Echo and sedimentary facies suggest that the plateau has been moulded mainly by persistent (hemi) pelagic sedimentation and intermittent settling of volcanic ashes. Sediments on the plateau slope and steep margins of ridges and seamounts were reworked by earthquake-induced, large-scale slope failures accompanied by slides, slumps and debris flows. As major fraction of the reworked sediments consists of (hemi) pelagic clay particles, large amounts of sediments released from mass flows were easily suspended to form turbid nepheloid layers rather than bottom-hugging turbidity currents, which flowed further downslope through the submarine canyons and spreaded over the Ulleung Basin plain. In the Ulleung Interplain Gap, sediments were introduced mainly by (hemi) pelagic settling and subordinate episodic mass flows (turbidity currents and debris flows) along the submarine channels from the slopes of the Oki Bank and Dok Island. The sediments in the Ulleung Interplain Channel and its margin were actively eroded and reworked by the deep water flow from the Japan Basin.

Changes in metabolic rate and hematological parameters of black rockfish (Sebastes schlegeli) in relation to temperature and hypoxia (수온과 저산소에 따른 조피볼락(Sebastes schlegeli)의 호흡대사와 혈액성상의 변화)

  • Kim, Heung-Yun
    • Journal of fish pathology
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    • v.34 no.2
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    • pp.213-224
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    • 2021
  • Experiments were performed to investigate changes in metabolic rate (MO2), critical oxygen saturation (Scrit) and hematological parameters of black rockfish, Sebastes schlegeli exposed to hypoxia at 15, 20 and 25℃. The MO2 was measured at an interval of 10 min using intermittent-flow respirometry. The normoxic standard metabolic rate (SMR) was 116.5±5.5, 188.6±4.2 and 237.4±6.8 mg O2/kg/hr, and Scrit was 22.1±1.2, 30.6±1.5 and 41.9±1.4% air saturation at 15, 20 and 25℃, respectively. Q10 values were 2.62 between 15 and 20℃, 1.58 between 20 and 25℃, and 2.04 over the full temperature range. In the investigation of blood (hematocrit and hemoglobin) and biochemical parameters (plasma cortisol, glucose, electrolyte and osmolality), the rockfish were subjected to Scrit for each temperature during 4 hr. All of hematological parameters of the rockfish exposed to hypoxic water were significantly higher than those of normoxic control. Moreover, blood and biochemical parameters of the rockfish maintained to normoxic water showed the tendency of increase with temperature, and were significantly higher at 25C. As a result of this experiment, it was found that physiological stress due to hypoxia increased at high temperature.

Characteristics of the Species Composition by Plant Community in the Shincheon Wetland of Mangyeong River, Jeonbuk (만경강 신천습지의 식물군락별 종조성적 특성)

  • Kwang-Jin, Cho;Jung-A, Lee;Jeoncheol, Lim;Yeounsu, Chu
    • Journal of Environmental Impact Assessment
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    • v.31 no.6
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    • pp.409-422
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    • 2022
  • Riverine wetlands are an important element of the river ecosystem and account for approximately 38% of the inland wetlands surveyed so far. The Shincheon Wetland located in Mangyeong River is also a channel wetland as the flow rate is slowed by the constructed weirs, leading to sediment accumulation. To identify the conservation value and ecological characteristics of Shincheon Wetland, its vegetation and plant diversity were identified using a phytosociological method, and a total of 45 vegetation-related datasets were collected. Overall, 24 plant communities, comprising a total of 153 taxa (49 families, 117 genera, 146 species, 2 subspecies, 5 varieties) were identified. The plant with the highest appearance rate in the communities was Humulus japonicus Siebold & Zucc. In addition, annual herb species, including Rumex crispus L., Bromusjaponicus Thunb., Erigeron annuus (L.) Pers., and Artemisia indica Willd. were frequently observed to be growing in the secondary grassland. Naturalized plants were surveyed in the 38 taxa; the urbanization index was 10.3% and the naturalized index was 24.8%. Plant communities were largely classified into submerged vegetation, floating and floating-leaved vegetation, annual and biennial vegetation, perennial herb vegetation, and woody vegetation. The distribution of plant communities reflecting various habitats, including the lentic and lotic zone maintaining a constant water depth, littoral zone experiencing intermittent water level fluctuations, and dry floodplain environment was also confirmed. Overall, plant community development plays an important role in the habitat for wild animals; therefore, it is expected to positively impact biodiversity enhancement.

Analysis of Applicability by Filter Technique for Water Level Correction of Agricultural Canal (농업용 수로부의 수위 보정을 위한 필터기법별 적용성 분석)

  • Joo, Donghyuk;Na, Ra;Kim, Ha-Young;Choi, Gyu-hoon;Yun, Hyung Chang;Park, Sang-Bin;Yoo, Seung-Hwan
    • Journal of The Korean Society of Agricultural Engineers
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    • v.65 no.5
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    • pp.51-68
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    • 2023
  • Due to the recent integrated water management policy, it is important to identify a reliable supply amount for establishing an agricultural water supply plan. In order to identify the amount of agricultural water supply, it is essential to calculate the discharge by measuring the water level and flow velocity of reservoirs and canal agricultural water, and quality control to ensure reliability must be preceded. Unlike agricultural reservoirs, canal agricultural water are more sensitive to the surrounding environment and reservoir irrigation methods (continuous, intermittent irrigation, etc.), making it difficult to estimate general water level patterns and at the same time a lot of erroneous data. The Korea Rural Community Corporation is applying a filter technique as a quality control method capable of processing large quantities and real-time processing of canal agricultural water level data, and applicability evaluation is needed. In this study, the types of errors generated by the automatic water level measurement system were first determined. In addition, by using the manual quality control data, a technique with high applicability is derived by comparing and analyzing data calibrated with Gaussian, Savitzky-Golay, Hampel, and Median filter techniques, RMSE, and NSE, and the optimal parameters of the technique range was derived. As a result, the applicability of the Median filter was evaluated the highest, and the optimal parameters were derived in the range of 120min to 240min. Through the results of this study, it is judged that it can be used for quantitative evaluation to establish an agricultural water supply plan.

Feasibility Study of Wetland-pond Systems for Water Quality Improvement and Agricultural Reuse (습지-연못 연계시스템에 의한 수질개선과 농업적 재이용 타당성 분석)

  • Jang, Jae-Ho;Jung, Kwang-Wook;Ham, Jong-Hwa;Yoon, Chun-Gyeong
    • Korean Journal of Ecology and Environment
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    • v.37 no.3 s.108
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    • pp.344-354
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    • 2004
  • A pilot study was performed from September 2000 to April 2004 to examine the feasibility of the wetland-pond system for the agricultural reuse of reclaimed water. The wetland system was a subsurface flow type, with a hydraulic residence time of 3.5 days, and the subsequent pond was 8 $m^3$ in volume (2 m ${\times}$ 2 m ${\times}$ 2 m) and operated with intermittent-discharge and continuous flow types. The wetland system was effective in treating the sewage; median removal efficiencies of $BOD_5$ and TSS were above 70.0%, with mean effluent concentrations of 27.1 and 16.8 mg $L^{-1}$, respectively, for these constituents. However, they did often exceed the effluent water quality standards of 20 mg $L^{-1}$. Removal of T-N and T-P was relatively less effective and mean effluent concentrations were approximately 103.2 and 7.2 mg $L^{-1}$, respectively. The wetland system demonstrated high removal rate (92 ${\sim}$ 90%) of microorganisms, but effluent concentrations were in the range of 300 ${\sim}$ 16,000 MPN 100 $mL^{-1}$ which is still high for agricultural reuse. The subsequent pond system provided further treatment of the wetland effluent, and especially additional microorganisms removal in addition to wetland-pond system could reduce the mean concentration to 1,000 MPN 100 $mL^{-1}$ from about $10^5$ MPN 100 $mL^{-1}$ of wetland influent. Other parameters in the pond system showed seasonal variation, and the upper layer of the pond water column became remarkably clear immediately after ice melt. Overall, the wetland system was found to be adequate for treating sewage with stable removal efficiency, and the subsequent pond was effective for further polishing. This study concerned agricultural reuse of reclaimed water using natural systems. Considering stable performance and effective removal of bacterial indicators as well as other water quality parameters, low maintenance, and cost-effectiveness, wetland- pond system was thought to be an effective and feasible alternative for agricultural reuse of reclaimed water in rural area.

Weaning Following a 60 Minutes Spontaneous Breathing Trial (1시간 자가호흡관찰에 의한 기계적 호흡치료로부터의 이탈)

  • Park, Keon-Uk;Won, Kyoung-Sook;Koh, Young-Min;Baik, Jae-Jung;Chung, Yeon-Tae
    • Tuberculosis and Respiratory Diseases
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    • v.42 no.3
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    • pp.361-369
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    • 1995
  • Background: A number of different weaning techniques can be employed such as spontaneous breathing trial, Intermittent mandatory ventilation(IMV) or Pressure support ventilation(PSV). However, the conclusive data indicating the superiority of one technique over another have not been published. Usually, a conventional spontaneous breathing trial is undertaken by supplying humidified $O_2$ through T-shaped adaptor connected to endotracheal tube or tracheostomy tube. In Korea, T-tube trial is not popular because the high-flow oxygen system is not always available. Also, the timing of extubation is not conclusive and depends on clinical experiences. It is known that to withdraw the endotracheal tube after weaning is far better than to go through any period. The tube produces varying degrees of resistance depending on its internal diameter and the flow rates encountered. The purpose of present study is to evaluate the effectiveness of weaning and extubation following a 60 minutes spontaneous breathing trial with simple oxygen supply through the endotracheal tube. Methods: We analyzed the result of weaning and extubation following a 60 minutes spontaneous breathing trial with simple oxygen supply through the endotracheal tube in 18 subjects from June, 1993 to June, 1994. They consisted of 9 males and 9 females. The duration of mechanical ventilation was from 38 hours to 341 hours(mean: $105.9{\pm}83.4$ hours). In all cases, the cause of ventilator dependency should be identified and precipitating factors should be corrected. The weaning trial was done when the patient became alert and arterial $O_2$ tension was adequate($PaO_2$ > 55mmHg) with an inspired oxygen fraction of 40%. We conducted a careful physical examination when the patient was breathing spontaneously through the endotracheal tube. Failure of weaning trial was signaled by cyanosis, sweating, paradoxical respiration, intercostal recession. Weaning failure was defined as the need for mechanical ventilation within 48 hours. Results: In 19 weaning trials of 18 patients, successful weaning and extubation was possible in 16/19(84.2 %). During the trial of spontaneous breathing for 60 minutes through the endotracheal tube, the patients who could wean developed slight increase in respiratory rates but significant changes of arterial blood gas values were not noted. But, the patients who failed weaning trial showed the marked increase in respiratory rates without significant changes of arterial blood gas values. Conclusion: The result of present study indicates that weaning from mechanical ventilation following a 60 minutes spontaneous breathing with $O_2$ supply through the endotracheal tube is a simple and effective method. Extubation can be done at the same time of successful weaning except for endobronchial toilet or airway protection.

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