• Title/Summary/Keyword: Conversion Rate

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A Study on Engine Performance of the Ignition Spark Timing Conversion for LPG/Gasoline Bi-fuel Vehicle (LPG / 가솔린 겸용차량의 점화시기 변환에 의한 엔진성능고찰)

  • Chun, Bongjun;Park, Myungho
    • Journal of the Korean Society of Mechanical Technology
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    • v.13 no.3
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    • pp.39-47
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    • 2011
  • In a bi-fuel engine using gasoline and LPG fuel, with the current ignition timing for gasoline being used, the optimum performance could not be taken in LPG fuel supply mode. The ignition timing in LPG fuel mode must be advanced much more than that of gasoline mode for the compensation of its higher ignition temperature. The purpose of this study is to investigate how the ignition spark timing conversion influences the engine performance of LPG/Gasoline Bi-Fuel engine. In order to investigate the engine performance during combustion, engine performance are sampled by data acquisition system, for example cylinder pressure, pressure rise rate and heat release rate, while change of the rpm(1500, 2000, 2500) and the ignition timing advance($5^{\circ}$, $10^{\circ}$, $15^{\circ}$, $20^{\circ}$). As the result, between 1500rpm, 2000rpm and 2500rpm, the cylinder pressure and pressure rise rate was increased when the spark ignition was advanced but pressure rise rate at $20^{\circ}$ was smaller value.

A Study on the Rent Characteristics of Small Shopping Malls

  • KIM, Sun-Ju
    • Journal of Distribution Science
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    • v.20 no.12
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    • pp.109-116
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    • 2022
  • Purpose: The purpose of this study is to analyze the rental determinants of a small shopping mall located in Seoul, Korea, and the characteristics of four commercial districts (CBD, GBD, YSD, etc.). Research design, data, and methodology: For the characteristics of the data, descriptive statistics and frequency analysis were used. Artificial Neural Networks (ANNs) have been used as rental determinants for small shopping malls. The characteristics of 4 commercial districts were analyzed using Analysis of variance (ANOVA) and post-hoc analysis. Results: 1) CBD 14.8%, GBD 16.7%, YSD 13.0%, others 55.6%. 2) The order of important variables affecting rent: CBD=1> GBD=1> vacancy rate> rental index> number of buildings> YBD=1> average gross floor area> conversion rate> average floor. 3) Characteristics of commercial district: Rents in CBD and GBD are high. The conversion rate is high in the GBD commercial area. The number of buildings is high in the CBD. The average area of GBD is larger than that of other commercial districts. Conclusions: 1) Several factors should be considered when investing in or renting a small shopping mall. 2) Depending on the investment and business purpose, factors such as rent, conversion rate, building, and area average should be considered.

Statistical Relation between Worst Month and Annual Distribution for Rainfall Rate (강우강도 최악월 분포와 년 분포간의 상관관계 분석)

  • 이주환;최용석김재명
    • Proceedings of the IEEK Conference
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    • 1998.10a
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    • pp.203-206
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    • 1998
  • Since it has been very difficult to collect Korean rain data for winter season, e.g. from November to March, it would be very useful to design satellite communication links if there is a method to extract annual distribution from rain data collected for a specific month. This paper presents a conversion method to annual rainfall rate distribution from rain data for worst month of a year, and illustrates some analysis of the conversion results.

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Interpolation Error Concealment Method of Motion Compensated Interpolated Frame for Motion Compensated Frame Rate Conversion (움직임 보상 프레임 율 변환 기법을 위한 움직임 보상 보간 프레임의 보간 오류 은닉 기법)

  • Lee, Jeong-Hun;Han, Dong-Il
    • Proceedings of the IEEK Conference
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    • 2008.06a
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    • pp.927-928
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    • 2008
  • In this paper, a interpolation error concealment algorithm of motion compensated interpolated frame for motion compensated frame rate conversion to reduce the block artifacts caused by failure of conventional motion estimation based on block matching algorithm is proposed. Experimental results show good performance of the proposed scheme with significant reduction of the block artifacts.

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A 6bit 800MSample/s A/D Converter Design for Hard Disk Drive Read Channel (하드디스크 드라이브 읽기 채널용 6bit 800MSample/s 아날로그/디지털 변환기의 설계)

  • 정대영;장흥석;신경민;정강민
    • Proceedings of the IEEK Conference
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    • 2000.11b
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    • pp.164-167
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    • 2000
  • This paper introduces the design of high-speed analog-to-digital converter for hard disk drive (HDD) read channel. This is based on autozero technique for low-error rate, and Double Speed Dual ADC(DSDA) technique lot efficiently increasing the conversion speed of A/D converter. This An is designed by 6bit resolution, 800M sample/s maximum conversion rate, 390㎽ power dissipation, one clock cycle latency in 0.65 $\mu\textrm{m}$ CMOS technology.

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Frame rate up conversion using deblocking filter (디블로킹 필터를 이용한 프레임율 변환)

  • Kim, Nam-Uk;Lee, Yung-Lyul
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2015.07a
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    • pp.557-559
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    • 2015
  • 움직임 보상 기반 프레임율 변환(Frame rate up-conversion based on motion compensation )에서 발생하는 블로킹 현상(Blocking artifact)을 줄여 영상의 화질을 높이기 위한 디블로킹 필터(De-blocking filter) 방법을 제안한다. 이 방법은 블록 단위로 동작하는 움직임 보상 과정에서 주변 블록과의 움직임이 급격히 달라지는 폐색영역에서 발생하는 블로킹 현상을 크게 줄일 수 있다. 제안하는 방법은 기존의 필터링을 하지 않는 방법보다 화질이 약 0.01db 향상하였다.

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ON THE LIMITING DIFFUSION OF SPECIAL DIPLOID MODEL IN POPULATION GENETICS

  • CHOI, WON
    • Bulletin of the Korean Mathematical Society
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    • v.42 no.2
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    • pp.397-404
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    • 2005
  • In this note, we characterize the limiting diffusion of a diploid model by defining the discrete generator for the resealed Markov chain. We conclude that this limiting diffusion model is with uncountable state space and mutation selection and special 'mutation or gene conversion rate'.

Frame Rate Up-Conversion Using the Motion Vector Correction based on Motion Vector Frequency of Neighboring blocks (주변 블록의 움직임 벡터 빈도수에 기반한 움직임 벡터 교정을 적용한 프레임 율 변환 기법)

  • Lee, Jeong-Hun;Han, Dong-Il
    • Proceedings of the IEEK Conference
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    • 2007.07a
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    • pp.259-260
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    • 2007
  • In this paper, a frame rate up-conversion algorithm using the motion vector frequency of neighboring blocks to reduce the block artifacts caused by failure of conventional motion estimation based on block matching algorithm is proposed. Experimental results show good performance of the proposed scheme with significant reduction of the erroneous motion vectors and block artifacts.

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A Study on the Synthesis of p-phenylenediamine (PPD) Using Copper Catalyst (Copper 촉매를 이용한 p-phenylenediamine (PPD) 합성에 관한 연구)

  • Kim, Jungsuk;Lee, Sang-yong;Lee, Jungho;Choi, Won Choon;Kang, Na Young;Park, Sunyoung;Kim, Kiwoong;Lim, Jong Sung;Park, Yong-Ki;Seo, Hwimin
    • Korean Chemical Engineering Research
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    • v.54 no.3
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    • pp.425-430
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    • 2016
  • p-Phenylenediamine (PPD) was synthesized by aromatic amination of p-diiodobenzene (PDIB) using liquid ammonia and Cu-catalysts. The effects of the catalyst, reductant, ammonia quantity and reaction temperature on PPD production were investigated. Cu(I) compounds and Cu powder were selected as catalyst due to a higher selectivity than Cu(II) compounds. As the catalyst quantity increased, rate of PPD production as well as side reaction of aniline decreased with increasing the quantity of ammonia. Reductants such as ascorbic acid, hydrazine and dihydroxyfumaric acid were tested to lower the catalyst loading. The use of reductants resulted in increasing the reaction rate but also increased the amount of aniline The rate of reaction using ascorbic acid or dihydroxyfumaric acid was faster than that using hydrazine. The lowest side reaction of aniline was found in dihydroxyfumaric acid of reductants investigated.

Assessment of the influence of coal combustion model and turbulent mixing rate in CFD of a 500 MWe tangential-firing boiler (500 MWe급 접선 연소 보일러 해석시 난류 혼합 속도 및 석탄 연소 모델의 영향 평가)

  • Yang, Joo-Hyang;Kang, Kie-Seop;Ryu, Changkook
    • 한국연소학회:학술대회논문집
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    • 2015.12a
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    • pp.69-72
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    • 2015
  • Computational fluid dynamics (CFD) modeling of large-scale coal-fired boilers requires a complicated set of flow, heat transfer and combustion process models based on different degrees of simplification. This study investigates the influence of coal devolatilization, char conversion and turbulent gas reaction models in CFD for a tangential-firing boiler at 500MWe capacity. Devolatilization model is found out not significant on the overall results, when the kinetic rates and the composition of volatiles were varied. In contrast, the turbulence mixing rate influenced significantly on the gas reaction rates, temperature, and heat transfer rate on the wall. The influence of char conversion by the unreacted core shrinking model (UCSM) and the 1st-order global rate model was not significant, but the unburned carbon concentration was predicted in details by the UCSM. Overall, the effects of the selected models were found similar with previous study for a wall-firing boiler.

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