• 제목/요약/키워드: Two-time scale

검색결과 1,710건 처리시간 0.028초

Feasibility Study on the Landfill Monitoring and Leakage Detection System

  • Park, Jun-Boum;Kwon, Ki-Bum;Oh, Myoung-Hak;Mishra, Anil Kumar
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2007년 가을학술발표회
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    • pp.558-569
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    • 2007
  • It is important to obtain real-time data from long-term monitoring of landfills and develop leachate leakage detection system for the integrated management of landfills. A novel real time monitoring system and early leakage detection system was suggested in this study. The suggested monitoring system is composed of two parts; (1) a set of moisture sensors which monitor the areas surrounding the landfill, and (2) a set of moisture and temperature sensors which monitor the landfill inside. For the assessment for landfills stabilization, real-time monitoring system was evaluated in dry and wet cell of pilot-site. In addition, the grid-net electrical conductivity measurement system was also suggested as early leakage detection system. In this study, the field applicability of suggested systems was evaluated through pilot-scale field tests. The results of pilot-scale field model tests indicate that the grid-net electrical conductivity measurement method can be applicable to the detection of landfill leachate at the initial stage of intrusion, and thus has a potential for monitoring leachate leakage at waste landfills.

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Hepatic Angiomyolipoma: Contrast Patterns with SonoVue-enhanced Real-time Gray-scale Ultrasonography

  • Wei, Rui-Xue;Wang, Wen-Ping;Ding, Hong;Huang, Bei-Jian;Li, Chao-Lun;Fan, Pei-Li;Hou, Jun;He, Nian-An
    • Asian Pacific Journal of Cancer Prevention
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    • 제13권2호
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    • pp.493-497
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    • 2012
  • This study was conducted to retrospectively evaluate the pattern of contrast enhancement with SonoVue on gray-scale ultrasonography of hepatic angiomyolipoma (HAML). Imaging features of 33 pathologically proven HAML lesions in 33 patients who underwent baseline ultrasound and contrast-enhanced ultrasonography (CEUS) were assessed retrospectively. All lesions were enhanced in the arterial phase and showed whole-tumor filling in. Thirty-two of 33 (97%) lesions showed early positive enhancement in the arterial phase. Twenty-three of these exhibited isoechoic or hyperechoic features in the portal phase. HAML demonstrate characteristic manifestations with SonoVue-enhanced real-time gray-scale ultrasonography.

변압기실 화재에 대한 미분무수 소화시스템의 적용 -냉각특성을 중심으로(Part 2) (Application of Water Mist System for a Power Transformer Room -Cooling Characteristics (Part 2))

  • 최병일;한용식;김명배
    • 한국화재소방학회논문지
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    • 제19권4호
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    • pp.37-41
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    • 2005
  • 본 연구에서는 미분무수 소화시스템의 변압기에 대한 냉각성능을 기술한다. 재발화를 방지하기 위한 냉각성능은 변압기의 철심으로부터 절연유에 전달되어 축적된 열에너지를 효과적으로 소산시키는 것을 의미한다. 철심이 매우 무겁기 때문에 축소 규모의 변압기를 이용하여 실험을 수행하였고, 이 결과로부터 냉각시간을 결정하기 위하여 상사해석을 수행하였다. 해석 및 실험을 통한 상사법칙으로부터 재발화 방지를 위한 미분무수 소화시스템의 소화시간은 약 12시간으로 나타났다.

일어서서 걷기 검사 시 회전 방향이 뇌졸중 환자의 보행 시간에 미치는 영향 (Effect of Direction to be Used for the Timed Up and Go Test on Walking Time in Stroke Patients)

  • 이건;조철훈;임경진;이주현;윤규리;우영근
    • 한국전문물리치료학회지
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    • 제23권2호
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    • pp.11-19
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    • 2016
  • Background: In the stroke patients with the characteristics of hemiplegic gait, turning direction of the affected and unaffected side influences turning time. Therefore, it is important to investigate the walking response to turning directions in stroke patients. Objects: This study aimed to measure the walking time while turning direction in hemiplegic patients depending on balance ability measured by Berg Balance Scale. Methods: A group of forty-five subjects with stroke (Berg Balance Scale score${\geq}46$ were twenty-eight, Berg Balance Scale score${\leq}45$ were seventeen) were enrolled in this study. Subjects were asked to perform the Timed Up and Go test. Testing indications included two directions for turning in each subject. These indications were for turning toward the affected and unaffected side in stroke patients. The duration of total analysis duration, sit to stand phase, stand to sit phase, mid-turning phase, and end turning phase were recorded. The obtained data were analyzed by using paired t-test and Wilcoxon signed rank test in the group that are below and above 45 points of Berg Balance Scale score. The significance level was set at ${\alpha}=.05$. Results: There were significant increase time in the analysis duration and end turning phase duration while subjects were turned the unaffected side in stroke patients that presented a Berg Balance Scale score${\leq}45$ (p<.05). However, the comparison between the affected side and the unaffected side in the stroke patients with Berg Balance Scale score${\geq}46$, revealed no significant differences of the measured parameters. Conclusion: This finding should be suggested in the specific definition of turning direction for evaluation with Timed Up and Go test in the Berg Balance Scale score${\leq}45$, and other intervention for hemiplegic patients need to be suggested the direction of turning during walking training program.

밀리미터 스케일의 이상 분해 반응기에 대한 실험적 연구 (Experimental Study on Millimeter Scale Two Phase Catalytic Reactor)

  • 조정훈;이대훈;권세진
    • 대한기계학회논문집B
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    • 제28권3호
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    • pp.265-270
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    • 2004
  • Experiment study on a down scaled two-phase catalytic reactor is presented. As a preliminary step for the development of catalytic reactor, nano-particulate catalyst was prepared. Perovskite La$\_$0.8/Sr$\_$0.2/CoO$_3$is chosen and synthesized as a catalyst considering superior catalytic performance in reduction and oxidation process where oxygen is involved among the reagent. Reactor that has a scale of 2${\times}$10${\times}$25mm was made by machining of A1 block as a layered structure considering further extension to micro-machining. Hydrogen peroxide of 70wt% was adopted as reactant and was provided to the reactor loaded with 1.5 g of catalyst. Reactant flow rate was varied by precision pump with a range of 0.15cc/min to 17.2cc/min. Temperature distribution within reactor was recorded by 3 thermocouples and total amount of liquid product was measured. Temperature distribution and factors that affect temperature were observed and relation between temperature distribution and production rate was also analyzed. Relative time scale plays a significant role in the performance of the reactor. To obtain steady state operation, appropriate ratio of flow rate, catalyst mass and reactor geometry is required and furthermore to get more efficient production rate temperature distribution should be evenly distributed. The database obtained by the experiment will be used as a design parameter for micro reactor.

『상한론(傷寒論)』 변병진단체계(辨病診斷體系)에 근거하여 갈근황연황금탕(葛根黃連黃芩湯) 투여 후 호전된 성인, 소아 ADHD 4례 (Case Series Reporting 4 Cases of Attention Deficit Hyperactivity Disorder (ADHD) Treated with Galgeunhwangryeonhwanggeum-tang based on Disease Pattern Identification Diagnostic System by Shanghanlun)

  • 윤효중;김민환;두인선;이성준
    • 대한상한금궤의학회지
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    • 제15권1호
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    • pp.85-115
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    • 2023
  • Objectives : This study reports on the cases of four ADHD patients who treated with herbal medication based on Disease Pattern Identification Diagnostic System (DPIDS). Methods : Two children and two adults were diagnosed with ADHD according to DSM-V, and Galgeunhwangryeonhwanggeum-tang was administered. The parents of the two children completed the Korean ADHD Rating Scale (K-ARS) before and after treatment, while the other patients used the Korean ADHD Self Rating Scale (K-ASRS). The patients' somatic symptoms and other issues were evaluated through interviews. Results : In the first case, the K-ARS scale exhibited a change from 28 to 3. The patient demonstrated improvements in attention, concentration, and social behavior, along with the elimination of self-injurious behavior. In the second case, the K-ARS scale showed a change from 41 to 9. The patient in the third case demonstrated improved chronic fatigue, increased attention, work efficiency, and enhanced social skills, leading to maintaining employment for over six months for the first time in their life after the treatments. Additionally, the patient in the fourth case demonstrated improved work concentration and relief in nocturia. Conclusions : In this study, four patients exhibited improvements in symptoms of attention deficit, hyperactivity, and impulsivity before and after herbal treatment, leading to enhanced academic and social relationships. As the patients progressed in their health restoration, symptoms related to the genitourinary system also showed improvement.

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공급사슬에서 생산 및 물류의 동기화를 위한 발견적 기법 (Heuristics for Synchronization of Production and Transportation Planning in the Supply Chain)

  • 정정우;이영해
    • 한국경영과학회:학술대회논문집
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    • 대한산업공학회/한국경영과학회 2006년도 춘계공동학술대회 논문집
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    • pp.159-166
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    • 2006
  • The aim of synchronization of production and transportation planning in the supply chain is to increase the flexibility and to decrease various costs. The suggested model in this study synchronizes the timing to supply to a downstream manufacturer directly after production and to be consumed in a downstream manufacturer right after receipt. This model deals with the frequent delivery in small amount which is a new trend of the transportation not governed the economy of scale principle. Moreover, various types of transportation governed by the economy of scale principle or not are considered. Then, the two-phase mathematical model is suggested to obtain optimal job sequence and production quantity for each tasks. But, it is difficult to gain optimal solutions if there is a transportation governed by the economy of scale principle in the supply chain, or the size of the problem is increased. Thus, heuristic algorithms based on simulated annealing and genetic algorithm are suggested to find good solutions in the reasonable time.

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웨이브렛 변환을 이용한 전자빔 용접 진단 (Electron Beam Welding Diagnosis Using Wavelet Transform)

  • 윤충섭
    • Journal of Welding and Joining
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    • 제21권6호
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    • pp.33-39
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    • 2003
  • Wavelet transform analysis results show a spectrum energy distribution of CWT along scale factors distinguish the partial, full and over penetration in a electron beam welding by analyzing the curve of spectrum energy at small scale, middle and large scale range, respectively. Two types of signals collected by Ion collector and x-ray sensors and analyzed. The acquired signals from sensors are very complicated since these signals are very closely related the dynamics of keyhole which interact the very high density energy with materials during welding. The results show the wavelet transform is more effective to diagnosis than Fourier Transform, further for the general welding defects which are not a periodic based, but a transient, non-stationary and time-varying phenomena.

Predicting ground-based damage states from windstorms using remote-sensing imagery

  • Brown, Tanya M.;Liang, Daan;Womble, J. Arn
    • Wind and Structures
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    • 제15권5호
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    • pp.369-383
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    • 2012
  • Researchers have recently begun using high spatial resolution remote-sensing data, which are automatically captured and georeferenced, to assess damage following natural and man-made disasters, in addition to, or instead of employing the older methods of walking house-to-house for surveys, or photographing individual buildings from an airplane. This research establishes quantitative relationships between the damage states observed at ground-level, and those observed from space using high spatial resolution remote-sensing data, for windstorms, for individual site-built one- or two-family residences (FR12). "Degrees of Damage" (DOD) from the Enhanced Fujita (EF) Scale were determined for ground-based damage states; damage states were also assigned for remote-sensing imagery, using a modified version of Womble's Remote-Sensing (RS) Damage Scale. The preliminary developed model can be used to predict the ground-level damage state using remote-sensing imagery, which could significantly lessen the time and expense required to assess the damage following a windstorm.

A Study on the Diachronic Evolution of Ancient Chinese Vocabulary Based on a Large-Scale Rough Annotated Corpus

  • Yuan, Yiguo;Li, Bin
    • 아시아태평양코퍼스연구
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    • 제2권2호
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    • pp.31-41
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    • 2021
  • This paper makes a quantitative analysis of the diachronic evolution of ancient Chinese vocabulary by constructing and counting a large-scale rough annotated corpus. The texts from Si Ku Quan Shu (a collection of Chinese ancient books) are automatically segmented to obtain ancient Chinese vocabulary with time information, which is used to the statistics on word frequency, standardized type/token ratio and proportion of monosyllabic words and dissyllabic words. Through data analysis, this study has the following four findings. Firstly, the high-frequency words in ancient Chinese are stable to a certain extent. Secondly, there is no obvious dissyllabic trend in ancient Chinese vocabulary. Moreover, the Northern and Southern Dynasties (420-589 AD) and Yuan Dynasty (1271-1368 AD) are probably the two periods with the most abundant vocabulary in ancient Chinese. Finally, the unique words with high frequency in each dynasty are mainly official titles with real power. These findings break away from qualitative methods used in traditional researches on Chinese language history and instead uses quantitative methods to draw macroscopic conclusions from large-scale corpus.