• Title/Summary/Keyword: Negative conversion

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Fabrication of GaAs Gunn diodes and Characterization of Negative Differential Resistance (GaAs Gunn 다이오드 소자의 제작과 부성미분저항)

  • Kim, Mi-Ra;Lee, Seong-Dae;Chae, Yeon-Sik;Rhee, Jin-Koo
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.44 no.7 s.361
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    • pp.1-8
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    • 2007
  • The DC characteristics of GaAs Gunn diode are investigated as a preliminary study on the planar grade gap injector GaAs Gunn diode which is the transferred electron device with high output power and dc-rf conversion efficiency. The Gunn devices we fabricated were confirmed to have the DC characteristics of negative differential resistance(NDR). We discussed the nature of the NDR effect, including the electron intervalley transfer; the NDR effect was examined for six different cathode radii.

Single-Inductor Multiple-Output DC-DC Converter with Negative Feedback Selection Circuit (부궤환 선택회로를 갖는 단일 인덕터 다중 출력 직류-직류 변환기)

  • Gong, Jung-Chul;Roh, Yong-Seong;Moon, Young-Jin;Choi, Woo-Seok;Yoo, Chang-Sik
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.48 no.12
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    • pp.23-30
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    • 2011
  • This paper presents a Single-Inductor Multiple-Output (SIMO) DC-DC Converter with a negative feedback selection circuit to improve a regulation property at light load and to generate independent multiple outputs. The conventional SIMO DC-DC converter with a fixed negative feedback circuit cannot regulate correctly at light load. The SIMO DC-DC converter with the proposed negative feedback selection circuit has been designed in 0.35um 2-poly 3-metal BCDMOS. This converter is dual output boost converter with the 1.5V input and 2.5V, 3.0V output. The power conversion efficiency varies from 59% at 10mA loads to 85% at 50mA loads.

A Study on the Defaulters of Tuberculosis Patient Registered at Health Center in Kyongnam Area (보건소 등록결핵환자중 중단자에 관한 조사연구)

  • Kim, Yong-Joon
    • Journal of agricultural medicine and community health
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    • v.6 no.1
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    • pp.73-81
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    • 1981
  • This study was designed to analyze the result of Tb worker's activities on the performance of follow up program as part of the government tuberculosis program. The specific objectives of this study was also to improve the method of managing the patient who were registered at health center by the setting the priorities depend upon in their results of sputum examination and X-ray examination. All the medical records of 509 patients who were dropped out from government health center in Kyongnam area during 1978, were analyzed and interpreted. Followings are the result of the study. 1. The number of investigated cases were 509 (356% males and 153 females), by age the most prevalent group was 20~29 year old group as 27.3% and 20~40 year old group was 61.5%, above 61 year old was 14.9%. 2. The microscopic result of their sputum was positive in 52.1%, and by X-ray examination moderate advanced case was 63.9% minimal 18.5% and far advanced 17.6% in order. 3. Average duration of treatment was 9.03 months, 11.4 months in microscopic positive cases and 6.5 months in negative cases. 4. Conversion rate of microscopic positive case was 42.9% on sputum culture, in the negative cases, it was confirmed in negative 20.1% only by the initial sputum culture. 5. The rate who get take X-ray and sputum examination among any family member of the patients was 43.4% in positive cases, 20.9% in negative cases. 6. 80.2% of positive cases took X-ray for following up in every 6 month after registration, 41.0% in negative cases. 7. Defaulting reasons which recorded in individual card were undetermined reason (42.0%), treating elswhere (22. 4%), refused treatment (17.9%) and moved out (17.7%).

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Electrochemical Characteristics of Cu3Si as Negative Electrode for Lithium Secondary Batteries at Elevated Temperatures (리튬 이차전지 음극용 Cu3Si의 고온에서의 전기화학적 특성)

  • Kwon, Ji-Y.;Ryu, Ji-Heon;Kim, Jun-Ho;Chae, Oh-B.;Oh, Seung-M.
    • Journal of the Korean Electrochemical Society
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    • v.13 no.2
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    • pp.116-122
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    • 2010
  • A $Cu_3Si$ film electrode is obtained by Si deposition on a Cu foil using DC magnetron sputtering, which is followed by annealing at $800^{\circ}C$ for 10 h. The Si component in $Cu_3Si$ is inactive for lithiation at ambient temperature. The linear sweep thermammetry (LSTA) and galvano-static charge/discharge cycling, however, consistently illustrate that $Cu_3Si$ becomes active for the conversion-type lithiation reaction at elevated temperatures (> $85^{\circ}C$). The $Cu_3Si$ electrode that is short-circuited with Li metal for one week is converted to a mixture of $Li_{21}Si_5$ and metallic Cu, implying that the Li-Si alloy phase generated at 0.0 V (vs. Li/$Li^+$) at the quasi-equilibrium condition is the most Li-rich $Li_{21}Si_5$. However, the lithiation is not extended to this phase in the constant-current charging (transient or dynamic condition). Upon de-lithiation, the metallic Cu and Si react to be restored back to $Cu_3Si$. The $Cu_3Si$ electrode shows a better cycle performance than an amorphous Si electrode at $120^{\circ}C$, which can be ascribed to the favorable roles provided by the Cu component in $Cu_3Si$. The inactive element (Cu) plays as a buffer against the volume change of Si component, which can minimize the electrode failure by suppressing the detachment of Si from the Cu substrate.

The Effect of Different Stocking Rate on Growth, Cast production and Conversion Efficiency of Organic Matter to Tissues of Earthworm (Eisenia fetida L.) (사육밀도의 차이가 지렁이의 생육, 체조직으로의 유기물 전환효율 및 분립생산에 미치는 영향)

  • Lee, Ji-Young;Lee, Ju-Sam
    • Journal of Animal Environmental Science
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    • v.18 no.2
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    • pp.63-74
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    • 2012
  • This experiment was carried out to investigate the effect of different stocking rate on growth, cast production and conversion efficiency of organic matter to tissues of earthworm. The carbon and nitrogen ratio (C/N) of tested Korean cow manure was 25.1, it was estimated an adequate ratio as feed for earthworms. The different stocking rates were 1:8(S-1), 1:16(S-2), 1:32(S-3) 1:64(S-4) 1:128(S-5) and 1:256 (S-6) as the ratios of earthworm fresh weight to biomass of Korean cow manure, respectively. A stocking rate of 1:32(S-3) was obtained a significantly highest values of increasing rate and conversion efficiency of organic matter to earthworm tissues. The mean values of increasin g rate of fresh weight and conversion efficiency of organic matter to earthworm tissues were 10.63 mg/day and 6.65% at the ratio of 1:32(S-3) with a rearing volume was $56.6cm^3$. A stocking rate of 1:8(S-1) was obtained a highest ratio of vermicasts, but showed a negative values of increasing rate and conversion efficiency of organic matter to earthworm tissues, it may due to severely food competition between individuals during the rearing periods. The pH, total nitrogen, available phosphorus, cation exchange capacity and exchangeable cations of vermicasts tended to increase with stocking rate. Especially, available phosphorus, cation exchange capacity and exchangeable cations of vermicasts tended to increase with rearing progressed. Vermicasts have the potential for improving plant growth when amended to container medium and soil according to increased availability of nutrients and improved physicochemical properties.

Growth Promoters and Their Effects on Beef Production - Review -

  • Song, M.K.;Choi, S.H.
    • Asian-Australasian Journal of Animal Sciences
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    • v.14 no.1
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    • pp.123-135
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    • 2001
  • Application of growth promoters by means of implantation or supplementation to the diets has been routine in the beef cattle industry of many countries for the better performance in growth and improvement of feed efficiency. Anabolic implants (zeranol, trenbolone acetate, and estradiol with testosterone or progesterone) have generated various positive effects. Zeranol implantation, in general, improved average daily gain (ADG), feed conversion (FC), dressing percentage (DP) and yield grade (YG) of cattle, and increased dry matter intake (DMI). Trenbolone acetate with or without estradiol also increased mean values of ADG and loin eye area (LEA) but reduced DMI and improved FC of cattle. Estradiol with testosterone or progesterone increased ADG and DMI. Anabolic implants, however, had minimal or negative effects on marbling or quality grade. The magnitude of the response to these anabolic implants in performance of beef cattle has varied depending on the type of implants, amount and duration of exposure, age of animals and combination of implants. Administration of bovine somatotropin improved ADG and FC, and decreased fat deposition. Ionophores improved FC in cattle from reduced DMI without great response to ADG. Supplementation of monensin and lasalocid reduced molar proportion of propionate. Monensin and lysocellin increased apparent absorption and retention of some minerals in cattle. Despite the improved cattle performance in growth and FC, results in beef quality from the application of the growth promoters appeared to vary or in conflict under a variety of environmental conditions.

Impact of Working Capital Management on Firm's Profitability: Empirical Evidence from Vietnam

  • NGUYEN, Anh Huu;PHAM, Huong Thanh;NGUYEN, Hang Thu
    • The Journal of Asian Finance, Economics and Business
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    • v.7 no.3
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    • pp.115-125
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    • 2020
  • This paper investigates the impact of working capital management on the firm's profitability. The research sample includes 119 non-financial listed companies on Vietnam stock market over a period of 9 years from 2010 to 2018. Two statistical approaches include Ordinary least squares (OLS) and fixed effects model (FEM) are employed to address econometric issues and to improve the accuracy of the regression coefficients. The empirical results show the negative and significant impacts of the working capital management, which measured by cash conversion cycle (CCC) and three components of the CCC including accounts receivable turnover in days (ARD), inventory turnover in days (INVD), and accounts payable turnover in days (APD) on the firm's profitability measured by return on assets (ROA) and Tobin's Q. It implies that firms can increase profitability by keeping the optimization of the working capital management measured by the CCC, which includes shortening the time to collect money from clients, accelerating inventory flow and hold the low payment time to creditors. Besides, the profitability of firms was impacted by the sale growth rate, firm size, leverage, and age. Therefore, this paper provides a new insight to managers on how to improve the firm's profitability with working capital management.

The Effect of Dietary Black Cumin Seeds (Nigella Sativa L.) on the Performance of Broilers

  • Guler, Talat;Dalkilic, B.;Ertas, O.N.;Ciftci, M.
    • Asian-Australasian Journal of Animal Sciences
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    • v.19 no.3
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    • pp.425-430
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    • 2006
  • Three hundred and sixty sexed 3-day-old broiler chicks were divided randomly into six treatment groups (control, antibiotic and black cumin at four levels) of 60 birds each. Black cumin seeds at 0.5%, 1%, 2% or 3% and avilamycin at 10 mg/kgt were added to the basal diet and their effects determined on feed intake, daily live weight gain, feed conversion ratio and carcass characteristics. There were no significant differences in daily feed intake at 21 and 42 days (p>0.05). Average daily gain was significantly different between the treatments. The birds fed the diet containing 1% black cumin seeds and antibiotic were the highest average daily gain, followed by those the other treatment diets and negative control (p<0.05). From 1 to 42 days of age, feed conversion ratios were improved significantly by supplementation with 1% black cumin seeds and with antibiotic (p<0.05) by approximately 5% compared to the control group. Similarly, the highest cold carcass, thigh, breast, wing, neck and liver weights were observed in the 1% black cumin and antibiotic groups (p<0.05). Accordingly, 1% supplementation of black cumin seeds to diets could be considered as an alternative natural growth promoter for poultry instead of antibiotics.

The Relationship between Working Capital Management and Profitability: A Case Study of Tobacco Industry of Pakistan

  • Muhammad, Hussain;Rehman, Ashfaq U.;Waqas, Muhammad
    • The Journal of Asian Finance, Economics and Business
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    • v.3 no.2
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    • pp.13-20
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    • 2016
  • Firms can use working capital management which is one of the essential determinants to influence their profitability. The main theme of present study is to investigate the relationship between working capital management and profitability of Tobacco Industry of Pakistan. This study is based on secondary data collected from financial statements of selected companies of Tobacco Industry of Pakistan for the period of 2005-2014. For data analysis, both descriptive and inferential statistics were used. Correlation analysis is used to check the relationship between the variables, while multiple regression analysis is used to examine the effects of working capital management on profitability of firms. The result reveals that there is a strong negative relationship between variables of working capital management and profitability of Tobacco Industry of Pakistan. This means that as the cash conversion cycle increases, it will lead to declining of firm profitability and managers can create a positive value for shareholders by reducing the cash conversion cycle at optimal level. The study concludes that managers can create value for shareholders by managing the working capital well designed and implemented, and by keeping each components of it at optimal level.

An Exploratory Study of the Character Education Programs using Maumgrarm (마음그램을 활용한 인성교육프로그램의 기초적 탐색)

  • An, Kwan-Su
    • Journal of Digital Convergence
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    • v.15 no.1
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    • pp.393-401
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    • 2017
  • This article aims to suggest a principle frame and direction for the development of the character education program using Maumgram. Maumgram is said to clearly illustrate step-by-step structures of character education, for which the human mind is classified as four types(indulged type, rage-type, competition type, selfishness type) on the basis of the existing analytical psychology and Yogacara Thought. The design of the mind type program is composed of three steps. The first step is the 'discovery' step to awaken the cause of self-consciousness through observation, and the second is the 'conversion' step. Learning process to control the negative desires in a positive desire, and the third is the 'relationship'-oriented step to promote a sense of community with other people.