• Title/Summary/Keyword: step-changed

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A Word Line Ramping Technique to Suppress the Program Disturbance of NAND Flash Memory

  • Lee, Jin-Wook;Lee, Yeong-Taek;Taehee Cho;Lee, Seungjae;Kim, Dong-Hwan;Wook-Ghee, Hahn;Lim, Young-Ho;Suh, Kang-Deog
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.1 no.2
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    • pp.125-131
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    • 2001
  • When the program voltage is applied to a word line, a part of the boosted channel charge in inhibited bit lines is lost due to the coupling between the string select line (SSL) and the adjacent word line. This phenomenon causes the program disturbance in the cells connected to the inhibited bit lines. This program disturbance becomes more serious, as the word line pitch is decreased. To reduce the word line coupling, the rising edge of the word-line voltage waveform was changed from a pulse step into a ramp waveform with a controlled slope. The word-line ramping circuit was composed of a timer, a decoder, a 8 b D/A converter, a comparator, and a high voltage switch pump (HVSP). The ramping voltage was generated by using a stepping waveform. The rising time and the stepping number of the word-line voltage for programming were set to $\mutextrm{m}-$ and 8, respectively,. The ramping circuit was used in a 512Mb NAND flash memory fabricated with a $0.15-\mutextrm{m}$ CMOS technology, reducing the SSL coupling voltage from 1.4V into a value below 0.4V.

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(A Process Model to Improve the Requirements Change Management for the Development Methodologies) (개발 방법론의 요구 사항 변경 관리를 개선하기 위한 프로세스 모델)

  • 정규장;신종철;구연설
    • Journal of KIISE:Software and Applications
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    • v.30 no.5_6
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    • pp.503-514
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    • 2003
  • In conventional development methodologies, requirements are considered to be not changing after analysis phase, and requirements specifications are used for the next step system design purpose. But in the real world, requirements can be changed and modified throughout the development life cycle according to end-user's more understanding about the target system, new IT technologies, changes of customer environment and market situation, and so on. So there needs a requirements change management process that can extend requirements management over the entire development life cycle and can support managing changes to the requirements after design phase. In this paper, a requirements change management process that can be integrated into conventional development methodologies is proposed to support the extension of requirements life cycle and managing changes to the requirements after design phase. This process was evaluated through an verification test with a widely used development methodology‘MaRMI’.

External pH Effects on Delayed Rectifier $K^+$ Currents of Small Dorsal Root Ganglion Neuron of Rat

  • Kim, Young-Ho;Hahn, Jung-Hyun;Lim, In-Ja;Chung, Sung-Kwon;Bang, Hyo-Weon
    • The Korean Journal of Physiology and Pharmacology
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    • v.2 no.2
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    • pp.165-172
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    • 1998
  • Under certain pathophysiological conditions, such as inflammation and ischemia, the concentration of H^+$ ion in the tissue surrounding neurons is changed. Variations in H^+$ concentration are known to alter the conduction and/of the gating properties of several types of ion channels. Several types of K^+$ channels are modulated by pH. In this study, the whole cell configuration of the patch clamp technique has been applied to the recording of the responses of change of external pH on the delayed rectifier K^+$ current of cultured DRG neurons of rat. Outward K^+$ currents were examined in DRG cells, and the Charybdotoxin and Mn^{2+}$ could eliminate Ca^{2+}-dependent$ K^+$ currents from outward K^+$ currents. This outward K^+$ current was activated around -60 mV by step depolarizing pulses from holding potential -70 mV. Outward K^+$ currents were decreased by low external pH. Activation and steady-state inactivation curve were shifted to the right by acidification, while there was small change by alkalization. These results suggest that H^+$ could be alter the sensory modality by changing and modifying voltage-dependent K^+$ currents, which participated in repolarization.

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A Design of Generalized Chebyshev LPF Using Defected Ground Structure (결함 기저면 구조를 이용한 일반화된 체비셰프 저역 통과 필터 설계)

  • Kim In-Seon;Kim Jong-Wook;Ahn Dal
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.17 no.7 s.110
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    • pp.673-683
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    • 2006
  • In this paper, we investgate variation of phase and magnitude characteristics which become different as the variables of DGS are changed and propose the new method to easily decide the best optimum DGS pattern taking advantage of this trend. Generalized Chebyshev(GC) low pass filter(LPF) is designed by using DGS obtained from this method GC DGS LPF is more available for filter application than Chevyshev DGS LPF because GC LPF have parallel resonators as series circuits, therefore unlikely Chebyshev LPF, transform step of the series elements can be omitted. By using the proposed method, GC DGS LPF(N=5) and as a subject of comparison, conventional Chbyshev LPF(N=7) are designed and implementation. From the comparison of the measured data, we confirmed that the implemented GC DGS 5th order LPF have much better cutoff characteristics and reduce by 0.58 times size, on the other hand the stop bandwidth become widen about 1.57 times or more in comparison with the conventional Chevyshev 7th order LPF.

A Study on the Dyeing Method of Silk/Polyester Blend Fabrics (견/Polyester 혼방직물의 염색에 관한 연구)

  • Park, Hyun-Tea;Song, Mi-Kyoung;Kim, Gong-Ju
    • Textile Coloration and Finishing
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    • v.3 no.2
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    • pp.16-24
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    • 1991
  • The textile fabric have the functions of sanitation, decoration, wearing style and washing in the practical use. Among various texitle fiber, silk has less utilities than synthetic fiber in practical use although silk has good benefits of the high quality. Thus no textile fiber, neither natural nor synthetic, has all the functions. In this sence, many blend yarns have been improved various functions of fabric. However, this has been disturbed with the problem of dyeing, especially in the case of blend fabric of silk. In this study, we dyed silk/PET blend fabric in one step useing one bath dyeing method by acid dyes/disperse dyes. The results of the experiments can be summarized as follows; 1) Yellow index of silk fabric treated at $130^{\circ}C$ increased about 7.8 (color difference 4.5 NBS) and whiteness decrease about 5%. 2) Both elongation and tensile strength of silk fabric treated at $130^{\circ}C$ of pH 5-6 decreased about 10% and tensile strength of silk spun yarn treated at $60^{\circ}C$ of pH 10 have little changed. 3) While silk/PET blend frbric dyeing, silk soiling of disperse dyes causes from difference of dyeing rate and degree of silk soiling with dyes. 4) Fastness and soiling of silk/PET blend fabric dyed by one bath dyeing method of acid dyes/disperse dyes was same as two bath dyeing method.

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Altered Expression of Pyrophosphate: Fructose-6-Phosphate 1-Phosphotransferase Affects the Growth of Transgenic Arabidopsis Plants

  • Lim, Hyemin;Cho, Man-Ho;Jeon, Jong-Seong;Bhoo, Seong Hee;Kwon, Yong-Kook;Hahn, Tae-Ryong
    • Molecules and Cells
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    • v.27 no.6
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    • pp.641-649
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    • 2009
  • Pyrophosphate:fructose-6-phosphate 1-phosphotransferase (PFP) catalyzes the reversible interconversion of fructose-6-phosphate and fructose-1,6-bisphosphate, a key step in the regulation of the metabolic flux toward glycolysis or gluconeogenesis. To examine the role of PFP in plant growth, we have generated transgenic Arabidopsis plants that either overexpress or repress Arabidopsis PFP subunit genes. The overexpressing lines displayed increased PFP activity and slightly faster growth relative to wild type plants, although their photosynthetic activities and the levels of metabolites appeared not to have significantly changed. In contrast, the RNAi lines showed significantly retarded growth in parallel with the reduced PFP activity. Analysis of photosynthetic activity revealed that the growth retardation phenotype of the RNAi lines was accompanied by the reduced rates of $CO_2$ assimilation. Microarray analysis of our transgenic plants further revealed that the altered expression of $AtPFP{\beta}$ affects the expression of several genes involved in diverse physiological processes. Our current data thus suggest that PFP is important in carbohydrate metabolism and other cellular processes.

A Study on the Spectrum Analysis for the Sound Synthesis of Piri (국악기 피리의 소리합성을 위한 음색분석 연구)

  • Kim, Hye-Jee;Yoon, Hye-Jung;Cho, Hyung-Je;Kim, Jun
    • Journal of Korea Multimedia Society
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    • v.9 no.7
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    • pp.801-807
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    • 2006
  • This study analyzed the timbral characteristics of Pliri by basis step for the sound synthesis for Piri, Korean traditional musical Instrument. By analyzing this material, we can find out three characteristics about the study of the spectrum analysis for the sound synthesis of Piri. First, compared the timbral characteristics of Piri with Oboe through the spectrum analysis, Second, analyzed the timbral characteristics by the sound occurrence process through the time zone analysis of the attack part of the sound started. Finally, analyzed the special characteristics of the vibrato that is important role of musical instrument performance. As a result, the timbral characteristics of Piri is that the volume of the high harmonics was appeared to be high unlike the general classical instrument and the noise quantity rapidly decreased in the sound attack part but the volume value of harmonics increased. And also vibrato that is performance technique is changed pitch and amplitude at the same time by contrast with the general classical instrument. Thus, the timbral characteristic of Piri by the harmonics and the timbre change by the attack part which is sound occurrence process and the change of the pitch and amplitude in the vibrato is characteristic that represented unique quality of Piri. We expect that this achievement can be applied to sound synthesis.

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Dewatering and Settling Characteristics of Digested Sludge from the Anaerobic Sequencing Batch Reactor for Treatment of Nightsoil (혐기성 연속회분식 공정을 이용한 분뇨처리시 소화슬러지의 침강 및 탈수특성)

  • Lee, Jun-Geol;Jang, Duk;Heo, Jun-Mu;Son, Boo-Soon;Jang, Bong-Ki;Park, Jong-An
    • Journal of Environmental Science International
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    • v.7 no.6
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    • pp.867-873
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    • 1998
  • Laboratory study was conducted to provide basic data for operating anaerobic sequencing batch reactor(ASBR) process for treatment of nightsoil. The experiments were concerned with digestion characteristics, settleabiltity and dewaterability of digested sludge in ASBR system. Completely-mixed dally-fed control reactor without solid-liquid separation step was also operated to evaluate the baseline performance since the nature of nightsoil was changed with time. In all case, gas production from the ASBR shows 1.3 to 1.44 times higher than that from control, in spite of almost similar trend in organics removal. During thickening period, remarkable decrease in surface settling velocity was observed at the ASBRs compared with the control. In case of the ASBR run, flotation of mixed digested sludge was not occurred. Also, ultimate thickened volume of ASBRs increased 1.2~1.5 times compared with control. Dewaterability of digested sludge without conditioning decreased when the completely-mixed daily-fed reactor for ASBR run was converted to the ASBR. However, improvement of dewaterability of digested sludge from the ASBRs was observed as a result of addition of FeCl$_3$ to digested sludge for conditioning.

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The Mutation that Makes Escherichia coli Resistant to λ P Gene-mediated Host Lethality Is Located within the DNA Initiator Gene dnaA of the Bacterium

  • Datta, Indrani;Banik-Maiti, Sarbani;Adhikari, Lopa;Sau, Subrata;Das, Niranjan;Mandal, Nitai Chandra
    • BMB Reports
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    • v.38 no.1
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    • pp.89-96
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    • 2005
  • Earlier, we reported that the bacteriophage $\lambda$ P gene product is lethal to Escherichia coli, and the E. coli rpl mutants are resistant to this $\lambda$ P gene-mediated lethality. In this paper, we show that under the $\lambda$ P gene-mediated lethal condition, the host DNA synthesis is inhibited at the initiation step. The rpl8 mutation maps around the 83 min position in the E. coli chromosome and is 94% linked with the dnaA gene. The rpl8 mutant gene has been cloned in a plasmid. This plasmid clone can protect the wild-type E. coli from $\lambda$ P gene-mediated killing and complements E. coli dnaAts46 at $42^{\circ}C$. Also, starting with the wild-type dnaA gene in a plasmid, the rpl-like mutations have been isolated by in vitro mutagenesis. DNA sequencing data show that each of the rpl8, rpl12 and rpl14 mutations has changed a single base in the dnaA gene, which translates into the amino acid changes N313T, Y200N, and S246T respectively within the DnaA protein. These results have led us to conclude that the rpl mutations, which make E. coli resistant to $\lambda$ P gene-mediated host lethality, are located within the DNA initiator gene dnaA of the host.

Effects of Temperature and Humidity on NDIR CO2 Gas Sensor (비분산 적외선 이산화탄소 가스센서 특성의 온·습도 영향)

  • Kim, JinHo;Yi, SeungHwan
    • Journal of Sensor Science and Technology
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    • v.26 no.3
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    • pp.179-185
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    • 2017
  • This article describes the characteristics of nondispersive infrared carbon dioxide gas sensor according to the temperatures and humidifies. In this researches, a thermopile sensor that included application-specific integrated circuit (ASIC) was used and the White-cell structure was implemented as an optical waveguide. The developed sensor modules were installed in gas chamber and then the temperature of gas chamber has been increased from 283 K to 313 K with 10K temperature step. In order to analyze the effects of humidity levels, the relative humidity levels were changed from 30 to 80%R.H. with small humidifier. Then, the characteristics of sensor modules were acquired with the increment of carbon dioxide concentrations from 0 to 2,000 ppm. When the initial voltages of sensors were compared before and after humidifying the chamber at constant temperature, the decrements of the output voltages of sensors are like these: 9mV (reference infrared sensor), 41 mV (carbon dioxide sensor), 2 mV (temperature sensor). With the increment of ambient temperature, the averaged output voltage of carbon dioxide sensor was increased 19 mV, however, when the humidity level was increased, it was decreased 14mV. Based upon the experimental results, the humidity effect could be alleviated by the increment of temperature, so the effects of humidity and temperature could be only compensated by the ambient temperature itself. The estimated carbon dioxide concentrations showed 10% large errors below 200 ppm, however, the errors of the estimations of carbon dioxide concentrations were less than ${\pm}5%$ from 400 to 2,000 ppm.