• Title/Summary/Keyword: Local retention time

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Flexible bistable chiral splay nematic display mode using reactive mesogens

  • Bae, Kwang-Soo;Lee, You-Jin;You, Chang-Jae;Kim, Jae-Hoon
    • Journal of Information Display
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    • v.12 no.4
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    • pp.195-198
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    • 2011
  • Proposed herein is a flexible bistable chiral splay nematic display mode with an enhanced memory retention time under external distortion. By adopting the polymerized reactive-mesogen structure mixed in a liquid crystal layer, local anchoring energy is generated on the boundary between the polymer structures, and the relaxation from the ${\pi}$-twisted state to the initial splay state could be interrupted. As a result, the memory retention time becomes significantly longer, and the stability against the external distortion is enhanced.

Real-time Aircraft Parameter Estimation using LWR

  • Song,Yongkyu;Hong, Sung-Kyung
    • 제어로봇시스템학회:학술대회논문집
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    • 2001.10a
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    • pp.141.4-141
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    • 2001
  • In this paper the Local Weighted Regression LWR technique is applied to the estimation of aircrcraft parameters. The method consists In improving the Local Weighted Regression LWR technique by adding a data Retention-and-Deletion RD strategy. The improvement comes with reduced computational effort since the two techniques can share their main computational procedures. The purpose of the study was to establish if the proposed algorithm could provide fast and reliable real-time estimations, with accuracy comparable to other well-known off-line identification schemes. The algorithm was tested using specific parameter estimation maneuvers and flight data of the NASA F/A-18 HARV. The results were compared with both the estimation obtained from ...

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A Study on Refresh Time Improvement of DRAM using the MEDICI Simulator (MEDICI 시뮬레이터를 이용한 DRAM의 Refresh 시간 개선에 관한 연구)

  • 이용희;이천희
    • Journal of the Korea Society for Simulation
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    • v.9 no.4
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    • pp.51-58
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    • 2000
  • The control of the data retention time is a main issue for realizing future high density dynamic random access memory. The novel junction process scheme in sub-micron DRAM cell with STI(Shallow Trench Isolation) has been investigated to improve the tail component in the retention time distribution which is of great importance in DRAM characteristics. In this' paper, we propose the new implantation scheme by gate-related ion beam shadowing effect and buffer-enhanced ${\Delta}Rp$ (projected standard deviation) increase using buffered N-implantation with tilt and 4X(4 times)-rotation that is designed on the basis of the local-field-enhancement model of the tail component. We report an excellent tail improvement of the retention time distribution attributed to the reduction of electric field across the cell junction due to the redistribution of N-concentration which is Intentionally caused by ion Beam Shadowing and Buffering Effect using tilt implantation with 4X-rotation. And also, we suggest the least requirements for adoption of this new implantation scheme and the method to optimize the key parameters such as tilt angle, rotation number, Rp compensation and Nd/Na ratio. We used MEDICI Simulator to confirm the junction device characteristics. And measured the refresh time using the ADVAN Probe tester.

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Experimental Study on the Foaming Characteristics according to the Plastic Temperature and the Retention Time of Shale (혈암의 소성온도 및 체류시간에 따른 발포특성에 관한 실험적 연구)

  • Mun, Dong Hwan;Lee, Han Seung
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2018.05a
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    • pp.58-59
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    • 2018
  • In this study, firing experiments were carried out to confirm the foamability of the expansive shale collected from the local area. When expansive shales are subjected to high temperature heat, gas is generated inside and voids are formed. Due to this phenomenon, shale is used as a raw material for lightweight aggregate. Experiments were carried out with different plastic temperature and residence time to find the appropriate plastic temperature for this expansive shale. As a result, the higher the plastic temperature, the more the surface viscosity increased and the gas generated inside were retained. Resulting in a number of internal voids. However, even if the plastic temperature or the medium temperature is high, it is confirmed that sufficient gas is not generated when the residence time is shortened.

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The Study on Impurity Concentration Optimizing for the Refresh Time Improvement of DRAM (DRAM의 Refresh 시간 개선을 위한 불순물 농도 최적화에 관한 연구)

  • Lee Yong-Hui;Woo Kyong-Hwan;Yi Cheon Hee
    • Proceedings of the IEEK Conference
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    • 2000.11b
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    • pp.325-328
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    • 2000
  • The control of the data retention time is a main issue for realizing future high density dynamic random access memory. In this paper, we propose the new implantation scheme by gate-related ion beam shadowing effect and buffer-enhanced $\Delta$ Rp increase using buffered N- implantation with tilt and 4X-rotation that is designed on the basis of the local-field-enhancement model of the tail component. We report an excellent tail improvement of the retention time distribution attributed to the reduction of electric field across the cell junction due to the redistribution of N- concentration which is intentionally caused by Ion Beam Shadowing and Buffering Effect using tilt implantation with 4X-rotation.

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An Investigation of Locally Trapped Charge Distribution using the Charge Pumping Method in the Two-bit SONOS Cell

  • An, Ho-Myoung;Lee, Myung-Shik;Seo, Kwang-Yell;Kim, Byung-Cheul;Kim, Joo-Yeon
    • Transactions on Electrical and Electronic Materials
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    • v.5 no.4
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    • pp.148-152
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    • 2004
  • The direct lateral profile and retention characteristics of locally trapped-charges in the nitride layer of the two-bit polysilicon-oxide-nitride-oxide-silicon (SONOS) memory are investigated by using the charge pumping method. After charges injection at the drain junction region, the lateral diffusion of trapped charges as a function of retention time is directly shown by the results of the local threshold voltage and the trapped-charges quantities.

Is It Useful and Safe to Maintain the Sitting Position During Only One Minute before Position Change to the Jack-knife Position?

  • Park, Soo-Young;Park, Jong-Cook;Park, Sang-Hyun
    • The Korean Journal of Pain
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    • v.23 no.3
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    • pp.190-197
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    • 2010
  • Background: Conventional spinal saddle block is performed with the patient in a sitting position, keeping the patient sitting for between 3 to 10 min after injection of a drug. This amount of time, however, is long enough to cause prolonged postoperative urinary retention. The trend in this block is to lower the dose of local anesthetics, providing a selective segmental block; however, an optimal dose and method are needed for adequate anesthesia in variable situations. Therefore, in this study, we evaluated the question of whether only 1 min of sitting after drug injection would be sufficient and safe for minor anorectal surgery. Methods: Two hundred and sixteen patients undergoing minor anorectal surgery under spinal anesthesia remained sitting for 1 min after completion of subarachnoid administration of 1 ml of a 0.5% hyperbaric bupivacaine solution (5 mg). They were then placed in the jack-knife position. After surgery, analgesia levels were assessed using loss of cold sensation in the supine position. The next day, urination and 11-point numeric rating scale (NRS) for postoperative pain were assessed. Results: None of the patients required additional analgesics during surgical manipulation. Postoperative sensory levels were T10 [T8-T12] in patients, and no significant differences were observed between sex (P = 0.857), height (P = 0.065), obesity (P = 0.873), or age (P = 0.138). Urinary retention developed in only 7 patients (3.2%). In this group, NRS was $5.0{\pm}2.4$ (P = 0.014). Conclusions: The one-minute sitting position for spinal saddle block before the jack-knife position is a safe method for use with minor anorectal surgery and can reduce development of postoperative urinary retention.

Chemical Composition and Feeding Value of Chopped Date Fronds (CDF) as Affected by Urea and Date Syrup Extract Treatment

  • El Hag, M.G.;El Shargi, K.M.
    • Asian-Australasian Journal of Animal Sciences
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    • v.11 no.6
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    • pp.685-691
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    • 1998
  • In the first of two experiments, chemical composition (Ash, CP and CF contents), nutritive value (in vitro organic matter disappearance "lVOMD" and energy content "ME") and nitrogen retention of chopped date fronds (CDF) as affected by chemical treatment (CT) and storage duration (SD) were investigated. The experimental design was a completely randomized block, arranged in a $3{\times}4$ factorial, with 3 (CT) and 4 (SD) as the main factors using 2 replications / treatment. Three chemical treatments, were used : Control (With zero or no chemical treatment); treatment with 4% urea solution (w /w) and treatment with 4% urea + Date syrup extract (DS). The 4 (SD) were: Control (immediately after opening - without any storage or zero time storage); one month storage period; two months storage period and three months storage period. Both (CT) and (SD) had significant effects (p < 0.05) on CP and ash contents of the CDF, however there were no significant effects (p > 0.05) due to (CT) and (SD) on CF and nutritive value. High retention value (> 80%) for nitrogen was reported for the treated CDF, immediately after opening the incubated material (zero SD). However, nitrogen retention decreased with increasing (SD) to 67% after one month (SD) but tended to stay at a fairly constant level of 67% until 3 months of storage. In experiment 2, the feeding value of treated CDF was evaluated in comparison to Rhodes grass hay, using growing goats and sheep. A $4{\times}2$ factorial design was used (Four roughage sources were used : Rhodes grass hay, untreated CDF, urea-treated CDF and CDF treated with urea + DS with sheep and goats as two animal species, using three animals / treatment). Untreated CDF had a similar feeding value to Rhodes grass hay. However treatment of CDF with urea alone or with urea + DS depressed animal performance of both goats and sheep, apparently due to depression of feed intake (appetite). Feeding untreated CDF decreased feeding cost by 29% and cost/kg gain by 23%. CDF showed a good potential as a cheap local roughage and emergency feed for ruminants in the Sultanate.

Pharmaceutical Substances of Platycodon grandiflorus (jacquin) A. De Candolle (도라지의 약리성분)

  • Shin, Pyung-Gyun;Ryu, Jin-Chang;Jang, Dae-Sik;Cho, Sung-Hwan;Chung, Jin-Hwan
    • Applied Biological Chemistry
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    • v.40 no.2
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    • pp.152-156
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    • 1997
  • Platycodon root contains abundant pharmaceutical substances and is widely used as a food and a medicinal herb. The three-year-old and the 24-year-old Platycodon roots cultivated in a local farm were analysed and compared with their pharmaceutical substances to identify the major components. Reverse column HPLC analysis of ethanol extracts from the 24-year-old roots showed some distintive peaks after the retention time of 50 min which were absent in the extracts from the three-year-old roots. This indicates that several pharmaceutical substances are present in the older roots. There were no differences in sterol composition and saponin content between the 24-year and three-year-old roots. The 15-year-old and the 23-year-old Platycodon roots, the 6-year-old Ginseng root, and the three-year-old Condonopsis root all did not show significant anticomplement activity.

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Methods for an application of real-time network control on distributed storage facilities (분산형 저류시설의 실시간 네트워크 제어기술 적용시 고려 사항)

  • Beak, Hyunwook;Ryu, Jaena;Oh, Jeill;Kim, Tae-Hyoung
    • Journal of Korean Society of Water and Wastewater
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    • v.27 no.6
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    • pp.711-721
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    • 2013
  • Optimal operation of a combined sewer network with distributed storage facilities aims to use the whole retention capacity of all reservoirs efficiently before overflows take place somewhere in the considered network system. An efficient real-time network control (RTNC) strategy has been emerging as an attractive approach for reducing substantially the overflows from a sewer network compared to the conventional fixed or manually adjusted gate setting method, but the related concrete framework for RTC development has not been throughly introduced so far. The main goal of this study is to give a detailed description of the RTNC systems via reviewing several guidelines published abroad, and finally to suggest methods for the proper application of RTNC on distributed storage facilities. Especially, this study is focused on emphasizing the importance of hierarchical structure of RTNC system that consists of three control layers (management, global control and local control). Further, with regard to the global control layer which is responsible for the central overall network control, the wide-ranging details of two components (adaption and optimization layers) are also presented. This study can provide the valuable basis for the RTNC implementation in the particular sewer network with distributed multiple storage facilities.